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alistair23-linux/include/uapi/linux/bpf.h

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net: filter: split filter.h and expose eBPF to user space allow user space to generate eBPF programs uapi/linux/bpf.h: eBPF instruction set definition linux/filter.h: the rest This patch only moves macro definitions, but practically it freezes existing eBPF instruction set, though new instructions can still be added in the future. These eBPF definitions cannot go into uapi/linux/filter.h, since the names may conflict with existing applications. Full eBPF ISA description is in Documentation/networking/filter.txt Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-04 23:17:18 -06:00
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#ifndef _UAPI__LINUX_BPF_H__
#define _UAPI__LINUX_BPF_H__
#include <linux/types.h>
net: filter: move common defines into bpf_common.h userspace programs that use eBPF instruction macros need to include two files: uapi/linux/filter.h and uapi/linux/bpf.h Move common macro definitions that are shared between classic BPF and eBPF into uapi/linux/bpf_common.h, so that user app can include only one bpf.h file Cc: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-14 03:08:54 -06:00
#include <linux/bpf_common.h>
net: filter: split filter.h and expose eBPF to user space allow user space to generate eBPF programs uapi/linux/bpf.h: eBPF instruction set definition linux/filter.h: the rest This patch only moves macro definitions, but practically it freezes existing eBPF instruction set, though new instructions can still be added in the future. These eBPF definitions cannot go into uapi/linux/filter.h, since the names may conflict with existing applications. Full eBPF ISA description is in Documentation/networking/filter.txt Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-04 23:17:18 -06:00
/* Extended instruction set based on top of classic BPF */
/* instruction classes */
#define BPF_ALU64 0x07 /* alu mode in double word width */
/* ld/ldx fields */
#define BPF_DW 0x18 /* double word */
#define BPF_XADD 0xc0 /* exclusive add */
/* alu/jmp fields */
#define BPF_MOV 0xb0 /* mov reg to reg */
#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
/* change endianness of a register */
#define BPF_END 0xd0 /* flags for endianness conversion: */
#define BPF_TO_LE 0x00 /* convert to little-endian */
#define BPF_TO_BE 0x08 /* convert to big-endian */
#define BPF_FROM_LE BPF_TO_LE
#define BPF_FROM_BE BPF_TO_BE
#define BPF_JNE 0x50 /* jump != */
#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
#define BPF_CALL 0x80 /* function call */
#define BPF_EXIT 0x90 /* function return */
/* Register numbers */
enum {
BPF_REG_0 = 0,
BPF_REG_1,
BPF_REG_2,
BPF_REG_3,
BPF_REG_4,
BPF_REG_5,
BPF_REG_6,
BPF_REG_7,
BPF_REG_8,
BPF_REG_9,
BPF_REG_10,
__MAX_BPF_REG,
};
/* BPF has 10 general purpose 64-bit registers and stack frame. */
#define MAX_BPF_REG __MAX_BPF_REG
struct bpf_insn {
__u8 code; /* opcode */
__u8 dst_reg:4; /* dest register */
__u8 src_reg:4; /* source register */
__s16 off; /* signed offset */
__s32 imm; /* signed immediate constant */
};
bpf: add a longest prefix match trie map implementation This trie implements a longest prefix match algorithm that can be used to match IP addresses to a stored set of ranges. Internally, data is stored in an unbalanced trie of nodes that has a maximum height of n, where n is the prefixlen the trie was created with. Tries may be created with prefix lengths that are multiples of 8, in the range from 8 to 2048. The key used for lookup and update operations is a struct bpf_lpm_trie_key, and the value is a uint64_t. The code carries more information about the internal implementation. Signed-off-by: Daniel Mack <daniel@zonque.org> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-21 09:26:11 -07:00
/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
struct bpf_lpm_trie_key {
__u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
__u8 data[0]; /* Arbitrary size */
};
bpf: add support for persistent maps/progs This work adds support for "persistent" eBPF maps/programs. The term "persistent" is to be understood that maps/programs have a facility that lets them survive process termination. This is desired by various eBPF subsystem users. Just to name one example: tc classifier/action. Whenever tc parses the ELF object, extracts and loads maps/progs into the kernel, these file descriptors will be out of reach after the tc instance exits. So a subsequent tc invocation won't be able to access/relocate on this resource, and therefore maps cannot easily be shared, f.e. between the ingress and egress networking data path. The current workaround is that Unix domain sockets (UDS) need to be instrumented in order to pass the created eBPF map/program file descriptors to a third party management daemon through UDS' socket passing facility. This makes it a bit complicated to deploy shared eBPF maps or programs (programs f.e. for tail calls) among various processes. We've been brainstorming on how we could tackle this issue and various approches have been tried out so far, which can be read up further in the below reference. The architecture we eventually ended up with is a minimal file system that can hold map/prog objects. The file system is a per mount namespace singleton, and the default mount point is /sys/fs/bpf/. Any subsequent mounts within a given namespace will point to the same instance. The file system allows for creating a user-defined directory structure. The objects for maps/progs are created/fetched through bpf(2) with two new commands (BPF_OBJ_PIN/BPF_OBJ_GET). I.e. a bpf file descriptor along with a pathname is being passed to bpf(2) that in turn creates (we call it eBPF object pinning) the file system nodes. Only the pathname is being passed to bpf(2) for getting a new BPF file descriptor to an existing node. The user can use that to access maps and progs later on, through bpf(2). Removal of file system nodes is being managed through normal VFS functions such as unlink(2), etc. The file system code is kept to a very minimum and can be further extended later on. The next step I'm working on is to add dump eBPF map/prog commands to bpf(2), so that a specification from a given file descriptor can be retrieved. This can be used by things like CRIU but also applications can inspect the meta data after calling BPF_OBJ_GET. Big thanks also to Alexei and Hannes who significantly contributed in the design discussion that eventually let us end up with this architecture here. Reference: https://lkml.org/lkml/2015/10/15/925 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-29 07:58:09 -06:00
/* BPF syscall commands, see bpf(2) man-page for details. */
bpf: introduce BPF syscall and maps BPF syscall is a multiplexor for a range of different operations on eBPF. This patch introduces syscall with single command to create a map. Next patch adds commands to access maps. 'maps' is a generic storage of different types for sharing data between kernel and userspace. Userspace example: /* this syscall wrapper creates a map with given type and attributes * and returns map_fd on success. * use close(map_fd) to delete the map */ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, int max_entries) { union bpf_attr attr = { .map_type = map_type, .key_size = key_size, .value_size = value_size, .max_entries = max_entries }; return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); } 'union bpf_attr' is backwards compatible with future extensions. More details in Documentation/networking/filter.txt and in manpage Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:57 -06:00
enum bpf_cmd {
BPF_MAP_CREATE,
bpf: add lookup/update/delete/iterate methods to BPF maps 'maps' is a generic storage of different types for sharing data between kernel and userspace. The maps are accessed from user space via BPF syscall, which has commands: - create a map with given type and attributes fd = bpf(BPF_MAP_CREATE, union bpf_attr *attr, u32 size) returns fd or negative error - lookup key in a given map referenced by fd err = bpf(BPF_MAP_LOOKUP_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->value returns zero and stores found elem into value or negative error - create or update key/value pair in a given map err = bpf(BPF_MAP_UPDATE_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->value returns zero or negative error - find and delete element by key in a given map err = bpf(BPF_MAP_DELETE_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key - iterate map elements (based on input key return next_key) err = bpf(BPF_MAP_GET_NEXT_KEY, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->next_key - close(fd) deletes the map Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:59 -06:00
BPF_MAP_LOOKUP_ELEM,
BPF_MAP_UPDATE_ELEM,
BPF_MAP_DELETE_ELEM,
BPF_MAP_GET_NEXT_KEY,
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
BPF_PROG_LOAD,
bpf: add support for persistent maps/progs This work adds support for "persistent" eBPF maps/programs. The term "persistent" is to be understood that maps/programs have a facility that lets them survive process termination. This is desired by various eBPF subsystem users. Just to name one example: tc classifier/action. Whenever tc parses the ELF object, extracts and loads maps/progs into the kernel, these file descriptors will be out of reach after the tc instance exits. So a subsequent tc invocation won't be able to access/relocate on this resource, and therefore maps cannot easily be shared, f.e. between the ingress and egress networking data path. The current workaround is that Unix domain sockets (UDS) need to be instrumented in order to pass the created eBPF map/program file descriptors to a third party management daemon through UDS' socket passing facility. This makes it a bit complicated to deploy shared eBPF maps or programs (programs f.e. for tail calls) among various processes. We've been brainstorming on how we could tackle this issue and various approches have been tried out so far, which can be read up further in the below reference. The architecture we eventually ended up with is a minimal file system that can hold map/prog objects. The file system is a per mount namespace singleton, and the default mount point is /sys/fs/bpf/. Any subsequent mounts within a given namespace will point to the same instance. The file system allows for creating a user-defined directory structure. The objects for maps/progs are created/fetched through bpf(2) with two new commands (BPF_OBJ_PIN/BPF_OBJ_GET). I.e. a bpf file descriptor along with a pathname is being passed to bpf(2) that in turn creates (we call it eBPF object pinning) the file system nodes. Only the pathname is being passed to bpf(2) for getting a new BPF file descriptor to an existing node. The user can use that to access maps and progs later on, through bpf(2). Removal of file system nodes is being managed through normal VFS functions such as unlink(2), etc. The file system code is kept to a very minimum and can be further extended later on. The next step I'm working on is to add dump eBPF map/prog commands to bpf(2), so that a specification from a given file descriptor can be retrieved. This can be used by things like CRIU but also applications can inspect the meta data after calling BPF_OBJ_GET. Big thanks also to Alexei and Hannes who significantly contributed in the design discussion that eventually let us end up with this architecture here. Reference: https://lkml.org/lkml/2015/10/15/925 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-29 07:58:09 -06:00
BPF_OBJ_PIN,
BPF_OBJ_GET,
bpf: add BPF_PROG_ATTACH and BPF_PROG_DETACH commands Extend the bpf(2) syscall by two new commands, BPF_PROG_ATTACH and BPF_PROG_DETACH which allow attaching and detaching eBPF programs to a target. On the API level, the target could be anything that has an fd in userspace, hence the name of the field in union bpf_attr is called 'target_fd'. When called with BPF_ATTACH_TYPE_CGROUP_INET_{E,IN}GRESS, the target is expected to be a valid file descriptor of a cgroup v2 directory which has the bpf controller enabled. These are the only use-cases implemented by this patch at this point, but more can be added. If a program of the given type already exists in the given cgroup, the program is swapped automically, so userspace does not have to drop an existing program first before installing a new one, which would otherwise leave a gap in which no program is attached. For more information on the propagation logic to subcgroups, please refer to the bpf cgroup controller implementation. The API is guarded by CAP_NET_ADMIN. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-23 08:52:27 -07:00
BPF_PROG_ATTACH,
BPF_PROG_DETACH,
bpf: introduce BPF_PROG_TEST_RUN command development and testing of networking bpf programs is quite cumbersome. Despite availability of user space bpf interpreters the kernel is the ultimate authority and execution environment. Current test frameworks for TC include creation of netns, veth, qdiscs and use of various packet generators just to test functionality of a bpf program. XDP testing is even more complicated, since qemu needs to be started with gro/gso disabled and precise queue configuration, transferring of xdp program from host into guest, attaching to virtio/eth0 and generating traffic from the host while capturing the results from the guest. Moreover analyzing performance bottlenecks in XDP program is impossible in virtio environment, since cost of running the program is tiny comparing to the overhead of virtio packet processing, so performance testing can only be done on physical nic with another server generating traffic. Furthermore ongoing changes to user space control plane of production applications cannot be run on the test servers leaving bpf programs stubbed out for testing. Last but not least, the upstream llvm changes are validated by the bpf backend testsuite which has no ability to test the code generated. To improve this situation introduce BPF_PROG_TEST_RUN command to test and performance benchmark bpf programs. Joint work with Daniel Borkmann. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-30 22:45:38 -06:00
BPF_PROG_TEST_RUN,
bpf: Add BPF_(PROG|MAP)_GET_NEXT_ID command This patch adds BPF_PROG_GET_NEXT_ID and BPF_MAP_GET_NEXT_ID to allow userspace to iterate all bpf_prog IDs and bpf_map IDs. The API is trying to be consistent with the existing BPF_MAP_GET_NEXT_KEY. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:48 -06:00
BPF_PROG_GET_NEXT_ID,
BPF_MAP_GET_NEXT_ID,
bpf: Add BPF_PROG_GET_FD_BY_ID Add BPF_PROG_GET_FD_BY_ID command to allow user to get a fd from a bpf_prog's ID. bpf_prog_inc_not_zero() is added and is called with prog_idr_lock held. __bpf_prog_put() is also added which has the 'bool do_idr_lock' param to decide if the prog_idr_lock should be acquired when freeing the prog->id. In the error path of bpf_prog_inc_not_zero(), it may have to call __bpf_prog_put(map, false) which does not need to take the prog_idr_lock when freeing the prog->id. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:49 -06:00
BPF_PROG_GET_FD_BY_ID,
bpf: Add BPF_MAP_GET_FD_BY_ID Add BPF_MAP_GET_FD_BY_ID command to allow user to get a fd from a bpf_map's ID. bpf_map_inc_not_zero() is added and is called with map_idr_lock held. __bpf_map_put() is also added which has the 'bool do_idr_lock' param to decide if the map_idr_lock should be acquired when freeing the map->id. In the error path of bpf_map_inc_not_zero(), it may have to call __bpf_map_put(map, false) which does not need to take the map_idr_lock when freeing the map->id. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:50 -06:00
BPF_MAP_GET_FD_BY_ID,
bpf: Add BPF_OBJ_GET_INFO_BY_FD A single BPF_OBJ_GET_INFO_BY_FD cmd is used to obtain the info for both bpf_prog and bpf_map. The kernel can figure out the fd is associated with a bpf_prog or bpf_map. The suggested struct bpf_prog_info and struct bpf_map_info are not meant to be a complete list and it is not the goal of this patch. New fields can be added in the future patch. The focus of this patch is to create the interface, BPF_OBJ_GET_INFO_BY_FD cmd for exposing the bpf_prog's and bpf_map's info. The obj's info, which will be extended (and get bigger) over time, is separated from the bpf_attr to avoid bloating the bpf_attr. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:52 -06:00
BPF_OBJ_GET_INFO_BY_FD,
bpf: introduce BPF syscall and maps BPF syscall is a multiplexor for a range of different operations on eBPF. This patch introduces syscall with single command to create a map. Next patch adds commands to access maps. 'maps' is a generic storage of different types for sharing data between kernel and userspace. Userspace example: /* this syscall wrapper creates a map with given type and attributes * and returns map_fd on success. * use close(map_fd) to delete the map */ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, int max_entries) { union bpf_attr attr = { .map_type = map_type, .key_size = key_size, .value_size = value_size, .max_entries = max_entries }; return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); } 'union bpf_attr' is backwards compatible with future extensions. More details in Documentation/networking/filter.txt and in manpage Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:57 -06:00
};
enum bpf_map_type {
BPF_MAP_TYPE_UNSPEC,
bpf: add hashtable type of eBPF maps add new map type BPF_MAP_TYPE_HASH and its implementation - maps are created/destroyed by userspace. Both userspace and eBPF programs can lookup/update/delete elements from the map - eBPF programs can be called in_irq(), so use spin_lock_irqsave() mechanism for concurrent updates - key/value are opaque range of bytes (aligned to 8 bytes) - user space provides 3 configuration attributes via BPF syscall: key_size, value_size, max_entries - map takes care of allocating/freeing key/value pairs - map_update_elem() must fail to insert new element when max_entries limit is reached to make sure that eBPF programs cannot exhaust memory - map_update_elem() replaces elements in an atomic way - optimized for speed of lookup() which can be called multiple times from eBPF program which itself is triggered by high volume of events . in the future JIT compiler may recognize lookup() call and optimize it further, since key_size is constant for life of eBPF program Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13 18:36:45 -07:00
BPF_MAP_TYPE_HASH,
bpf: add array type of eBPF maps add new map type BPF_MAP_TYPE_ARRAY and its implementation - optimized for fastest possible lookup() . in the future verifier/JIT may recognize lookup() with constant key and optimize it into constant pointer. Can optimize non-constant key into direct pointer arithmetic as well, since pointers and value_size are constant for the life of the eBPF program. In other words array_map_lookup_elem() may be 'inlined' by verifier/JIT while preserving concurrent access to this map from user space - two main use cases for array type: . 'global' eBPF variables: array of 1 element with key=0 and value is a collection of 'global' variables which programs can use to keep the state between events . aggregation of tracing events into fixed set of buckets - all array elements pre-allocated and zero initialized at init time - key as an index in array and can only be 4 byte - map_delete_elem() returns EINVAL, since elements cannot be deleted - map_update_elem() replaces elements in an non-atomic way (for atomic updates hashtable type should be used instead) Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13 18:36:46 -07:00
BPF_MAP_TYPE_ARRAY,
bpf: allow bpf programs to tail-call other bpf programs introduce bpf_tail_call(ctx, &jmp_table, index) helper function which can be used from BPF programs like: int bpf_prog(struct pt_regs *ctx) { ... bpf_tail_call(ctx, &jmp_table, index); ... } that is roughly equivalent to: int bpf_prog(struct pt_regs *ctx) { ... if (jmp_table[index]) return (*jmp_table[index])(ctx); ... } The important detail that it's not a normal call, but a tail call. The kernel stack is precious, so this helper reuses the current stack frame and jumps into another BPF program without adding extra call frame. It's trivially done in interpreter and a bit trickier in JITs. In case of x64 JIT the bigger part of generated assembler prologue is common for all programs, so it is simply skipped while jumping. Other JITs can do similar prologue-skipping optimization or do stack unwind before jumping into the next program. bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table Since all BPF programs are idenitified by file descriptor, user space need to populate the jmp_table with FDs of other BPF programs. If jmp_table[index] is empty the bpf_tail_call() doesn't jump anywhere and program execution continues as normal. New BPF_MAP_TYPE_PROG_ARRAY map type is introduced so that user space can populate this jmp_table array with FDs of other bpf programs. Programs can share the same jmp_table array or use multiple jmp_tables. The chain of tail calls can form unpredictable dynamic loops therefore tail_call_cnt is used to limit the number of calls and currently is set to 32. Use cases: Acked-by: Daniel Borkmann <daniel@iogearbox.net> ========== - simplify complex programs by splitting them into a sequence of small programs - dispatch routine For tracing and future seccomp the program may be triggered on all system calls, but processing of syscall arguments will be different. It's more efficient to implement them as: int syscall_entry(struct seccomp_data *ctx) { bpf_tail_call(ctx, &syscall_jmp_table, ctx->nr /* syscall number */); ... default: process unknown syscall ... } int sys_write_event(struct seccomp_data *ctx) {...} int sys_read_event(struct seccomp_data *ctx) {...} syscall_jmp_table[__NR_write] = sys_write_event; syscall_jmp_table[__NR_read] = sys_read_event; For networking the program may call into different parsers depending on packet format, like: int packet_parser(struct __sk_buff *skb) { ... parse L2, L3 here ... __u8 ipproto = load_byte(skb, ... offsetof(struct iphdr, protocol)); bpf_tail_call(skb, &ipproto_jmp_table, ipproto); ... default: process unknown protocol ... } int parse_tcp(struct __sk_buff *skb) {...} int parse_udp(struct __sk_buff *skb) {...} ipproto_jmp_table[IPPROTO_TCP] = parse_tcp; ipproto_jmp_table[IPPROTO_UDP] = parse_udp; - for TC use case, bpf_tail_call() allows to implement reclassify-like logic - bpf_map_update_elem/delete calls into BPF_MAP_TYPE_PROG_ARRAY jump table are atomic, so user space can build chains of BPF programs on the fly Implementation details: ======================= - high performance of bpf_tail_call() is the goal. It could have been implemented without JIT changes as a wrapper on top of BPF_PROG_RUN() macro, but with two downsides: . all programs would have to pay performance penalty for this feature and tail call itself would be slower, since mandatory stack unwind, return, stack allocate would be done for every tailcall. . tailcall would be limited to programs running preempt_disabled, since generic 'void *ctx' doesn't have room for 'tail_call_cnt' and it would need to be either global per_cpu variable accessed by helper and by wrapper or global variable protected by locks. In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue. - bpf_prog_array_compatible() ensures that prog_type of callee and caller are the same and JITed/non-JITed flag is the same, since calling JITed program from non-JITed is invalid, since stack frames are different. Similarly calling kprobe type program from socket type program is invalid. - jump table is implemented as BPF_MAP_TYPE_PROG_ARRAY to reuse 'map' abstraction, its user space API and all of verifier logic. It's in the existing arraymap.c file, since several functions are shared with regular array map. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:03 -06:00
BPF_MAP_TYPE_PROG_ARRAY,
bpf: Add new bpf map type to store the pointer to struct perf_event Introduce a new bpf map type 'BPF_MAP_TYPE_PERF_EVENT_ARRAY'. This map only stores the pointer to struct perf_event. The user space event FDs from perf_event_open() syscall are converted to the pointer to struct perf_event and stored in map. Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-06 01:02:34 -06:00
BPF_MAP_TYPE_PERF_EVENT_ARRAY,
bpf: introduce BPF_MAP_TYPE_PERCPU_HASH map Introduce BPF_MAP_TYPE_PERCPU_HASH map type which is used to do accurate counters without need to use BPF_XADD instruction which turned out to be too costly for high-performance network monitoring. In the typical use case the 'key' is the flow tuple or other long living object that sees a lot of events per second. bpf_map_lookup_elem() returns per-cpu area. Example: struct { u32 packets; u32 bytes; } * ptr = bpf_map_lookup_elem(&map, &key); /* ptr points to this_cpu area of the value, so the following * increments will not collide with other cpus */ ptr->packets ++; ptr->bytes += skb->len; bpf_update_elem() atomically creates a new element where all per-cpu values are zero initialized and this_cpu value is populated with given 'value'. Note that non-per-cpu hash map always allocates new element and then deletes old after rcu grace period to maintain atomicity of update. Per-cpu hash map updates element values in-place. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-01 23:39:53 -07:00
BPF_MAP_TYPE_PERCPU_HASH,
bpf: introduce BPF_MAP_TYPE_PERCPU_ARRAY map Primary use case is a histogram array of latency where bpf program computes the latency of block requests or other events and stores histogram of latency into array of 64 elements. All cpus are constantly running, so normal increment is not accurate, bpf_xadd causes cache ping-pong and this per-cpu approach allows fastest collision-free counters. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-01 23:39:54 -07:00
BPF_MAP_TYPE_PERCPU_ARRAY,
bpf: introduce BPF_MAP_TYPE_STACK_TRACE add new map type to store stack traces and corresponding helper bpf_get_stackid(ctx, map, flags) - walk user or kernel stack and return id @ctx: struct pt_regs* @map: pointer to stack_trace map @flags: bits 0-7 - numer of stack frames to skip bit 8 - collect user stack instead of kernel bit 9 - compare stacks by hash only bit 10 - if two different stacks hash into the same stackid discard old other bits - reserved Return: >= 0 stackid on success or negative error stackid is a 32-bit integer handle that can be further combined with other data (including other stackid) and used as a key into maps. Userspace will access stackmap using standard lookup/delete syscall commands to retrieve full stack trace for given stackid. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17 20:58:58 -07:00
BPF_MAP_TYPE_STACK_TRACE,
cgroup: bpf: Add BPF_MAP_TYPE_CGROUP_ARRAY Add a BPF_MAP_TYPE_CGROUP_ARRAY and its bpf_map_ops's implementations. To update an element, the caller is expected to obtain a cgroup2 backed fd by open(cgroup2_dir) and then update the array with that fd. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Tejun Heo <tj@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-30 11:28:43 -06:00
BPF_MAP_TYPE_CGROUP_ARRAY,
bpf: Add BPF_MAP_TYPE_LRU_HASH Provide a LRU version of the existing BPF_MAP_TYPE_HASH. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-11 11:55:09 -07:00
BPF_MAP_TYPE_LRU_HASH,
bpf: Add BPF_MAP_TYPE_LRU_PERCPU_HASH Provide a LRU version of the existing BPF_MAP_TYPE_PERCPU_HASH Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-11 11:55:10 -07:00
BPF_MAP_TYPE_LRU_PERCPU_HASH,
bpf: add a longest prefix match trie map implementation This trie implements a longest prefix match algorithm that can be used to match IP addresses to a stored set of ranges. Internally, data is stored in an unbalanced trie of nodes that has a maximum height of n, where n is the prefixlen the trie was created with. Tries may be created with prefix lengths that are multiples of 8, in the range from 8 to 2048. The key used for lookup and update operations is a struct bpf_lpm_trie_key, and the value is a uint64_t. The code carries more information about the internal implementation. Signed-off-by: Daniel Mack <daniel@zonque.org> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-21 09:26:11 -07:00
BPF_MAP_TYPE_LPM_TRIE,
bpf: Add array of maps support This patch adds a few helper funcs to enable map-in-map support (i.e. outer_map->inner_map). The first outer_map type BPF_MAP_TYPE_ARRAY_OF_MAPS is also added in this patch. The next patch will introduce a hash of maps type. Any bpf map type can be acted as an inner_map. The exception is BPF_MAP_TYPE_PROG_ARRAY because the extra level of indirection makes it harder to verify the owner_prog_type and owner_jited. Multi-level map-in-map is not supported (i.e. map->map is ok but not map->map->map). When adding an inner_map to an outer_map, it currently checks the map_type, key_size, value_size, map_flags, max_entries and ops. The verifier also uses those map's properties to do static analysis. map_flags is needed because we need to ensure BPF_PROG_TYPE_PERF_EVENT is using a preallocated hashtab for the inner_hash also. ops and max_entries are needed to generate inlined map-lookup instructions. For simplicity reason, a simple '==' test is used for both map_flags and max_entries. The equality of ops is implied by the equality of map_type. During outer_map creation time, an inner_map_fd is needed to create an outer_map. However, the inner_map_fd's life time does not depend on the outer_map. The inner_map_fd is merely used to initialize the inner_map_meta of the outer_map. Also, for the outer_map: * It allows element update and delete from syscall * It allows element lookup from bpf_prog The above is similar to the current fd_array pattern. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 11:00:33 -06:00
BPF_MAP_TYPE_ARRAY_OF_MAPS,
bpf: Add hash of maps support This patch adds hash of maps support (hashmap->bpf_map). BPF_MAP_TYPE_HASH_OF_MAPS is added. A map-in-map contains a pointer to another map and lets call this pointer 'inner_map_ptr'. Notes on deleting inner_map_ptr from a hash map: 1. For BPF_F_NO_PREALLOC map-in-map, when deleting an inner_map_ptr, the htab_elem itself will go through a rcu grace period and the inner_map_ptr resides in the htab_elem. 2. For pre-allocated htab_elem (!BPF_F_NO_PREALLOC), when deleting an inner_map_ptr, the htab_elem may get reused immediately. This situation is similar to the existing prealloc-ated use cases. However, the bpf_map_fd_put_ptr() calls bpf_map_put() which calls inner_map->ops->map_free(inner_map) which will go through a rcu grace period (i.e. all bpf_map's map_free currently goes through a rcu grace period). Hence, the inner_map_ptr is still safe for the rcu reader side. This patch also includes BPF_MAP_TYPE_HASH_OF_MAPS to the check_map_prealloc() in the verifier. preallocation is a must for BPF_PROG_TYPE_PERF_EVENT. Hence, even we don't expect heavy updates to map-in-map, enforcing BPF_F_NO_PREALLOC for map-in-map is impossible without disallowing BPF_PROG_TYPE_PERF_EVENT from using map-in-map first. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 11:00:34 -06:00
BPF_MAP_TYPE_HASH_OF_MAPS,
bpf: introduce BPF syscall and maps BPF syscall is a multiplexor for a range of different operations on eBPF. This patch introduces syscall with single command to create a map. Next patch adds commands to access maps. 'maps' is a generic storage of different types for sharing data between kernel and userspace. Userspace example: /* this syscall wrapper creates a map with given type and attributes * and returns map_fd on success. * use close(map_fd) to delete the map */ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, int max_entries) { union bpf_attr attr = { .map_type = map_type, .key_size = key_size, .value_size = value_size, .max_entries = max_entries }; return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); } 'union bpf_attr' is backwards compatible with future extensions. More details in Documentation/networking/filter.txt and in manpage Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:57 -06:00
};
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
enum bpf_prog_type {
BPF_PROG_TYPE_UNSPEC,
bpf: verifier: add checks for BPF_ABS | BPF_IND instructions introduce program type BPF_PROG_TYPE_SOCKET_FILTER that is used for attaching programs to sockets where ctx == skb. add verifier checks for ABS/IND instructions which can only be seen in socket filters, therefore the check: if (env->prog->aux->prog_type != BPF_PROG_TYPE_SOCKET_FILTER) verbose("BPF_LD_ABS|IND instructions are only allowed in socket filters\n"); Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-01 16:06:34 -07:00
BPF_PROG_TYPE_SOCKET_FILTER,
tracing, perf: Implement BPF programs attached to kprobes BPF programs, attached to kprobes, provide a safe way to execute user-defined BPF byte-code programs without being able to crash or hang the kernel in any way. The BPF engine makes sure that such programs have a finite execution time and that they cannot break out of their sandbox. The user interface is to attach to a kprobe via the perf syscall: struct perf_event_attr attr = { .type = PERF_TYPE_TRACEPOINT, .config = event_id, ... }; event_fd = perf_event_open(&attr,...); ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); 'prog_fd' is a file descriptor associated with BPF program previously loaded. 'event_id' is an ID of the kprobe created. Closing 'event_fd': close(event_fd); ... automatically detaches BPF program from it. BPF programs can call in-kernel helper functions to: - lookup/update/delete elements in maps - probe_read - wraper of probe_kernel_read() used to access any kernel data structures BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is architecture dependent) and return 0 to ignore the event and 1 to store kprobe event into the ring buffer. Note, kprobes are a fundamentally _not_ a stable kernel ABI, so BPF programs attached to kprobes must be recompiled for every kernel version and user must supply correct LINUX_VERSION_CODE in attr.kern_version during bpf_prog_load() call. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-25 13:49:20 -06:00
BPF_PROG_TYPE_KPROBE,
ebpf: add sched_cls_type and map it to sk_filter's verifier ops As discussed recently and at netconf/netdev01, we want to prevent making bpf_verifier_ops registration available for modules, but have them at a controlled place inside the kernel instead. The reason for this is, that out-of-tree modules can go crazy and define and register any verfifier ops they want, doing all sorts of crap, even bypassing available GPLed eBPF helper functions. We don't want to offer such a shiny playground, of course, but keep strict control to ourselves inside the core kernel. This also encourages us to design eBPF user helpers carefully and generically, so they can be shared among various subsystems using eBPF. For the eBPF traffic classifier (cls_bpf), it's a good start to share the same helper facilities as we currently do in eBPF for socket filters. That way, we have BPF_PROG_TYPE_SCHED_CLS look like it's own type, thus one day if there's a good reason to diverge the set of helper functions from the set available to socket filters, we keep ABI compatibility. In future, we could place all bpf_prog_type_list at a central place, perhaps. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-01 04:31:46 -07:00
BPF_PROG_TYPE_SCHED_CLS,
ebpf: add sched_act_type and map it to sk_filter's verifier ops In order to prepare eBPF support for tc action, we need to add sched_act_type, so that the eBPF verifier is aware of what helper function act_bpf may use, that it can load skb data and read out currently available skb fields. This is bascially analogous to 96be4325f443 ("ebpf: add sched_cls_type and map it to sk_filter's verifier ops"). BPF_PROG_TYPE_SCHED_CLS and BPF_PROG_TYPE_SCHED_ACT need to be separate since both will have a different set of functionality in future (classifier vs action), thus we won't run into ABI troubles when the point in time comes to diverge functionality from the classifier. The future plan for act_bpf would be that it will be able to write into skb->data and alter selected fields mirrored in struct __sk_buff. For an initial support, it's sufficient to map it to sk_filter_ops. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Jiri Pirko <jiri@resnulli.us> Reviewed-by: Jiri Pirko <jiri@resnulli.us> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20 08:11:11 -06:00
BPF_PROG_TYPE_SCHED_ACT,
perf, bpf: allow bpf programs attach to tracepoints introduce BPF_PROG_TYPE_TRACEPOINT program type and allow it to be attached to the perf tracepoint handler, which will copy the arguments into the per-cpu buffer and pass it to the bpf program as its first argument. The layout of the fields can be discovered by doing 'cat /sys/kernel/debug/tracing/events/sched/sched_switch/format' prior to the compilation of the program with exception that first 8 bytes are reserved and not accessible to the program. This area is used to store the pointer to 'struct pt_regs' which some of the bpf helpers will use: +---------+ | 8 bytes | hidden 'struct pt_regs *' (inaccessible to bpf program) +---------+ | N bytes | static tracepoint fields defined in tracepoint/format (bpf readonly) +---------+ | dynamic | __dynamic_array bytes of tracepoint (inaccessible to bpf yet) +---------+ Not that all of the fields are already dumped to user space via perf ring buffer and broken application access it directly without consulting tracepoint/format. Same rule applies here: static tracepoint fields should only be accessed in a format defined in tracepoint/format. The order of fields and field sizes are not an ABI. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-06 19:43:25 -06:00
BPF_PROG_TYPE_TRACEPOINT,
bpf: add XDP prog type for early driver filter Add a new bpf prog type that is intended to run in early stages of the packet rx path. Only minimal packet metadata will be available, hence a new context type, struct xdp_md, is exposed to userspace. So far only expose the packet start and end pointers, and only in read mode. An XDP program must return one of the well known enum values, all other return codes are reserved for future use. Unfortunately, this restriction is hard to enforce at verification time, so take the approach of warning at runtime when such programs are encountered. Out of bounds return codes should alias to XDP_ABORTED. Signed-off-by: Brenden Blanco <bblanco@plumgrid.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-19 13:16:47 -06:00
BPF_PROG_TYPE_XDP,
bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type Introduce BPF_PROG_TYPE_PERF_EVENT programs that can be attached to HW and SW perf events (PERF_TYPE_HARDWARE and PERF_TYPE_SOFTWARE correspondingly in uapi/linux/perf_event.h) The program visible context meta structure is struct bpf_perf_event_data { struct pt_regs regs; __u64 sample_period; }; which is accessible directly from the program: int bpf_prog(struct bpf_perf_event_data *ctx) { ... ctx->sample_period ... ... ctx->regs.ip ... } The bpf verifier rewrites the accesses into kernel internal struct bpf_perf_event_data_kern which allows changing struct perf_sample_data without affecting bpf programs. New fields can be added to the end of struct bpf_perf_event_data in the future. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-01 19:37:22 -06:00
BPF_PROG_TYPE_PERF_EVENT,
bpf: add new prog type for cgroup socket filtering This program type is similar to BPF_PROG_TYPE_SOCKET_FILTER, except that it does not allow BPF_LD_[ABS|IND] instructions and hooks up the bpf_skb_load_bytes() helper. Programs of this type will be attached to cgroups for network filtering and accounting. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-23 08:52:25 -07:00
BPF_PROG_TYPE_CGROUP_SKB,
bpf: Add new cgroup attach type to enable sock modifications Add new cgroup based program type, BPF_PROG_TYPE_CGROUP_SOCK. Similar to BPF_PROG_TYPE_CGROUP_SKB programs can be attached to a cgroup and run any time a process in the cgroup opens an AF_INET or AF_INET6 socket. Currently only sk_bound_dev_if is exported to userspace for modification by a bpf program. This allows a cgroup to be configured such that AF_INET{6} sockets opened by processes are automatically bound to a specific device. In turn, this enables the running of programs that do not support SO_BINDTODEVICE in a specific VRF context / L3 domain. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-01 09:48:04 -07:00
BPF_PROG_TYPE_CGROUP_SOCK,
bpf: BPF for lightweight tunnel infrastructure Registers new BPF program types which correspond to the LWT hooks: - BPF_PROG_TYPE_LWT_IN => dst_input() - BPF_PROG_TYPE_LWT_OUT => dst_output() - BPF_PROG_TYPE_LWT_XMIT => lwtunnel_xmit() The separate program types are required to differentiate between the capabilities each LWT hook allows: * Programs attached to dst_input() or dst_output() are restricted and may only read the data of an skb. This prevent modification and possible invalidation of already validated packet headers on receive and the construction of illegal headers while the IP headers are still being assembled. * Programs attached to lwtunnel_xmit() are allowed to modify packet content as well as prepending an L2 header via a newly introduced helper bpf_skb_change_head(). This is safe as lwtunnel_xmit() is invoked after the IP header has been assembled completely. All BPF programs receive an skb with L3 headers attached and may return one of the following error codes: BPF_OK - Continue routing as per nexthop BPF_DROP - Drop skb and return EPERM BPF_REDIRECT - Redirect skb to device as per redirect() helper. (Only valid in lwtunnel_xmit() context) The return codes are binary compatible with their TC_ACT_ relatives to ease compatibility. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30 09:10:10 -07:00
BPF_PROG_TYPE_LWT_IN,
BPF_PROG_TYPE_LWT_OUT,
BPF_PROG_TYPE_LWT_XMIT,
bpf: BPF support for sock_ops Created a new BPF program type, BPF_PROG_TYPE_SOCK_OPS, and a corresponding struct that allows BPF programs of this type to access some of the socket's fields (such as IP addresses, ports, etc.). It uses the existing bpf cgroups infrastructure so the programs can be attached per cgroup with full inheritance support. The program will be called at appropriate times to set relevant connections parameters such as buffer sizes, SYN and SYN-ACK RTOs, etc., based on connection information such as IP addresses, port numbers, etc. Alghough there are already 3 mechanisms to set parameters (sysctls, route metrics and setsockopts), this new mechanism provides some distinct advantages. Unlike sysctls, it can set parameters per connection. In contrast to route metrics, it can also use port numbers and information provided by a user level program. In addition, it could set parameters probabilistically for evaluation purposes (i.e. do something different on 10% of the flows and compare results with the other 90% of the flows). Also, in cases where IPv6 addresses contain geographic information, the rules to make changes based on the distance (or RTT) between the hosts are much easier than route metric rules and can be global. Finally, unlike setsockopt, it oes not require application changes and it can be updated easily at any time. Although the bpf cgroup framework already contains a sock related program type (BPF_PROG_TYPE_CGROUP_SOCK), I created the new type (BPF_PROG_TYPE_SOCK_OPS) beccause the existing type expects to be called only once during the connections's lifetime. In contrast, the new program type will be called multiple times from different places in the network stack code. For example, before sending SYN and SYN-ACKs to set an appropriate timeout, when the connection is established to set congestion control, etc. As a result it has "op" field to specify the type of operation requested. The purpose of this new program type is to simplify setting connection parameters, such as buffer sizes, TCP's SYN RTO, etc. For example, it is easy to use facebook's internal IPv6 addresses to determine if both hosts of a connection are in the same datacenter. Therefore, it is easy to write a BPF program to choose a small SYN RTO value when both hosts are in the same datacenter. This patch only contains the framework to support the new BPF program type, following patches add the functionality to set various connection parameters. This patch defines a new BPF program type: BPF_PROG_TYPE_SOCKET_OPS and a new bpf syscall command to load a new program of this type: BPF_PROG_LOAD_SOCKET_OPS. Two new corresponding structs (one for the kernel one for the user/BPF program): /* kernel version */ struct bpf_sock_ops_kern { struct sock *sk; __u32 op; union { __u32 reply; __u32 replylong[4]; }; }; /* user version * Some fields are in network byte order reflecting the sock struct * Use the bpf_ntohl helper macro in samples/bpf/bpf_endian.h to * convert them to host byte order. */ struct bpf_sock_ops { __u32 op; union { __u32 reply; __u32 replylong[4]; }; __u32 family; __u32 remote_ip4; /* In network byte order */ __u32 local_ip4; /* In network byte order */ __u32 remote_ip6[4]; /* In network byte order */ __u32 local_ip6[4]; /* In network byte order */ __u32 remote_port; /* In network byte order */ __u32 local_port; /* In host byte horder */ }; Currently there are two types of ops. The first type expects the BPF program to return a value which is then used by the caller (or a negative value to indicate the operation is not supported). The second type expects state changes to be done by the BPF program, for example through a setsockopt BPF helper function, and they ignore the return value. The reply fields of the bpf_sockt_ops struct are there in case a bpf program needs to return a value larger than an integer. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30 21:02:40 -06:00
BPF_PROG_TYPE_SOCK_OPS,
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
};
bpf: add new prog type for cgroup socket filtering This program type is similar to BPF_PROG_TYPE_SOCKET_FILTER, except that it does not allow BPF_LD_[ABS|IND] instructions and hooks up the bpf_skb_load_bytes() helper. Programs of this type will be attached to cgroups for network filtering and accounting. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-23 08:52:25 -07:00
enum bpf_attach_type {
BPF_CGROUP_INET_INGRESS,
BPF_CGROUP_INET_EGRESS,
bpf: Add new cgroup attach type to enable sock modifications Add new cgroup based program type, BPF_PROG_TYPE_CGROUP_SOCK. Similar to BPF_PROG_TYPE_CGROUP_SKB programs can be attached to a cgroup and run any time a process in the cgroup opens an AF_INET or AF_INET6 socket. Currently only sk_bound_dev_if is exported to userspace for modification by a bpf program. This allows a cgroup to be configured such that AF_INET{6} sockets opened by processes are automatically bound to a specific device. In turn, this enables the running of programs that do not support SO_BINDTODEVICE in a specific VRF context / L3 domain. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-01 09:48:04 -07:00
BPF_CGROUP_INET_SOCK_CREATE,
bpf: BPF support for sock_ops Created a new BPF program type, BPF_PROG_TYPE_SOCK_OPS, and a corresponding struct that allows BPF programs of this type to access some of the socket's fields (such as IP addresses, ports, etc.). It uses the existing bpf cgroups infrastructure so the programs can be attached per cgroup with full inheritance support. The program will be called at appropriate times to set relevant connections parameters such as buffer sizes, SYN and SYN-ACK RTOs, etc., based on connection information such as IP addresses, port numbers, etc. Alghough there are already 3 mechanisms to set parameters (sysctls, route metrics and setsockopts), this new mechanism provides some distinct advantages. Unlike sysctls, it can set parameters per connection. In contrast to route metrics, it can also use port numbers and information provided by a user level program. In addition, it could set parameters probabilistically for evaluation purposes (i.e. do something different on 10% of the flows and compare results with the other 90% of the flows). Also, in cases where IPv6 addresses contain geographic information, the rules to make changes based on the distance (or RTT) between the hosts are much easier than route metric rules and can be global. Finally, unlike setsockopt, it oes not require application changes and it can be updated easily at any time. Although the bpf cgroup framework already contains a sock related program type (BPF_PROG_TYPE_CGROUP_SOCK), I created the new type (BPF_PROG_TYPE_SOCK_OPS) beccause the existing type expects to be called only once during the connections's lifetime. In contrast, the new program type will be called multiple times from different places in the network stack code. For example, before sending SYN and SYN-ACKs to set an appropriate timeout, when the connection is established to set congestion control, etc. As a result it has "op" field to specify the type of operation requested. The purpose of this new program type is to simplify setting connection parameters, such as buffer sizes, TCP's SYN RTO, etc. For example, it is easy to use facebook's internal IPv6 addresses to determine if both hosts of a connection are in the same datacenter. Therefore, it is easy to write a BPF program to choose a small SYN RTO value when both hosts are in the same datacenter. This patch only contains the framework to support the new BPF program type, following patches add the functionality to set various connection parameters. This patch defines a new BPF program type: BPF_PROG_TYPE_SOCKET_OPS and a new bpf syscall command to load a new program of this type: BPF_PROG_LOAD_SOCKET_OPS. Two new corresponding structs (one for the kernel one for the user/BPF program): /* kernel version */ struct bpf_sock_ops_kern { struct sock *sk; __u32 op; union { __u32 reply; __u32 replylong[4]; }; }; /* user version * Some fields are in network byte order reflecting the sock struct * Use the bpf_ntohl helper macro in samples/bpf/bpf_endian.h to * convert them to host byte order. */ struct bpf_sock_ops { __u32 op; union { __u32 reply; __u32 replylong[4]; }; __u32 family; __u32 remote_ip4; /* In network byte order */ __u32 local_ip4; /* In network byte order */ __u32 remote_ip6[4]; /* In network byte order */ __u32 local_ip6[4]; /* In network byte order */ __u32 remote_port; /* In network byte order */ __u32 local_port; /* In host byte horder */ }; Currently there are two types of ops. The first type expects the BPF program to return a value which is then used by the caller (or a negative value to indicate the operation is not supported). The second type expects state changes to be done by the BPF program, for example through a setsockopt BPF helper function, and they ignore the return value. The reply fields of the bpf_sockt_ops struct are there in case a bpf program needs to return a value larger than an integer. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30 21:02:40 -06:00
BPF_CGROUP_SOCK_OPS,
bpf: add new prog type for cgroup socket filtering This program type is similar to BPF_PROG_TYPE_SOCKET_FILTER, except that it does not allow BPF_LD_[ABS|IND] instructions and hooks up the bpf_skb_load_bytes() helper. Programs of this type will be attached to cgroups for network filtering and accounting. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-23 08:52:25 -07:00
__MAX_BPF_ATTACH_TYPE
};
#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
bpf: introduce BPF_F_ALLOW_OVERRIDE flag If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command to the given cgroup the descendent cgroup will be able to override effective bpf program that was inherited from this cgroup. By default it's not passed, therefore override is disallowed. Examples: 1. prog X attached to /A with default prog Y fails to attach to /A/B and /A/B/C Everything under /A runs prog X 2. prog X attached to /A with allow_override. prog Y fails to attach to /A/B with default (non-override) prog M attached to /A/B with allow_override. Everything under /A/B runs prog M only. 3. prog X attached to /A with allow_override. prog Y fails to attach to /A with default. The user has to detach first to switch the mode. In the future this behavior may be extended with a chain of non-overridable programs. Also fix the bug where detach from cgroup where nothing is attached was not throwing error. Return ENOENT in such case. Add several testcases and adjust libbpf. Fixes: 3007098494be ("cgroup: add support for eBPF programs") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Daniel Mack <daniel@zonque.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-10 21:28:24 -07:00
/* If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
* to the given target_fd cgroup the descendent cgroup will be able to
* override effective bpf program that was inherited from this cgroup
*/
#define BPF_F_ALLOW_OVERRIDE (1U << 0)
bpf: Add strict alignment flag for BPF_PROG_LOAD. Add a new field, "prog_flags", and an initial flag value BPF_F_STRICT_ALIGNMENT. When set, the verifier will enforce strict pointer alignment regardless of the setting of CONFIG_EFFICIENT_UNALIGNED_ACCESS. The verifier, in this mode, will also use a fixed value of "2" in place of NET_IP_ALIGN. This facilitates test cases that will exercise and validate this part of the verifier even when run on architectures where alignment doesn't matter. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
2017-05-10 12:38:07 -06:00
/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
* verifier will perform strict alignment checking as if the kernel
* has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
* and NET_IP_ALIGN defined to 2.
*/
#define BPF_F_STRICT_ALIGNMENT (1U << 0)
ebpf: export BPF_PSEUDO_MAP_FD to uapi We need to export BPF_PSEUDO_MAP_FD to user space, as it's used in the ELF BPF loader where instructions are being loaded that need map fixups. An initial stage loads all maps into the kernel, and later on replaces related instructions in the eBPF blob with BPF_PSEUDO_MAP_FD as source register and the actual fd as immediate value. The kernel verifier recognizes this keyword and replaces the map fd with a real pointer internally. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-01 04:31:43 -07:00
#define BPF_PSEUDO_MAP_FD 1
bpf: add 'flags' attribute to BPF_MAP_UPDATE_ELEM command the current meaning of BPF_MAP_UPDATE_ELEM syscall command is: either update existing map element or create a new one. Initially the plan was to add a new command to handle the case of 'create new element if it didn't exist', but 'flags' style looks cleaner and overall diff is much smaller (more code reused), so add 'flags' attribute to BPF_MAP_UPDATE_ELEM command with the following meaning: #define BPF_ANY 0 /* create new element or update existing */ #define BPF_NOEXIST 1 /* create new element if it didn't exist */ #define BPF_EXIST 2 /* update existing element */ bpf_update_elem(fd, key, value, BPF_NOEXIST) call can fail with EEXIST if element already exists. bpf_update_elem(fd, key, value, BPF_EXIST) can fail with ENOENT if element doesn't exist. Userspace will call it as: int bpf_update_elem(int fd, void *key, void *value, __u64 flags) { union bpf_attr attr = { .map_fd = fd, .key = ptr_to_u64(key), .value = ptr_to_u64(value), .flags = flags; }; return bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); } First two bits of 'flags' are used to encode style of bpf_update_elem() command. Bits 2-63 are reserved for future use. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13 18:36:44 -07:00
/* flags for BPF_MAP_UPDATE_ELEM command */
#define BPF_ANY 0 /* create new element or update existing */
#define BPF_NOEXIST 1 /* create new element if it didn't exist */
#define BPF_EXIST 2 /* update existing element */
bpf: pre-allocate hash map elements If kprobe is placed on spin_unlock then calling kmalloc/kfree from bpf programs is not safe, since the following dead lock is possible: kfree->spin_lock(kmem_cache_node->lock)...spin_unlock->kprobe-> bpf_prog->map_update->kmalloc->spin_lock(of the same kmem_cache_node->lock) and deadlocks. The following solutions were considered and some implemented, but eventually discarded - kmem_cache_create for every map - add recursion check to slow-path of slub - use reserved memory in bpf_map_update for in_irq or in preempt_disabled - kmalloc via irq_work At the end pre-allocation of all map elements turned out to be the simplest solution and since the user is charged upfront for all the memory, such pre-allocation doesn't affect the user space visible behavior. Since it's impossible to tell whether kprobe is triggered in a safe location from kmalloc point of view, use pre-allocation by default and introduce new BPF_F_NO_PREALLOC flag. While testing of per-cpu hash maps it was discovered that alloc_percpu(GFP_ATOMIC) has odd corner cases and often fails to allocate memory even when 90% of it is free. The pre-allocation of per-cpu hash elements solves this problem as well. Turned out that bpf_map_update() quickly followed by bpf_map_lookup()+bpf_map_delete() is very common pattern used in many of iovisor/bcc/tools, so there is additional benefit of pre-allocation, since such use cases are must faster. Since all hash map elements are now pre-allocated we can remove atomic increment of htab->count and save few more cycles. Also add bpf_map_precharge_memlock() to check rlimit_memlock early to avoid large malloc/free done by users who don't have sufficient limits. Pre-allocation is done with vmalloc and alloc/free is done via percpu_freelist. Here are performance numbers for different pre-allocation algorithms that were implemented, but discarded in favor of percpu_freelist: 1 cpu: pcpu_ida 2.1M pcpu_ida nolock 2.3M bt 2.4M kmalloc 1.8M hlist+spinlock 2.3M pcpu_freelist 2.6M 4 cpu: pcpu_ida 1.5M pcpu_ida nolock 1.8M bt w/smp_align 1.7M bt no/smp_align 1.1M kmalloc 0.7M hlist+spinlock 0.2M pcpu_freelist 2.0M 8 cpu: pcpu_ida 0.7M bt w/smp_align 0.8M kmalloc 0.4M pcpu_freelist 1.5M 32 cpu: kmalloc 0.13M pcpu_freelist 0.49M pcpu_ida nolock is a modified percpu_ida algorithm without percpu_ida_cpu locks and without cross-cpu tag stealing. It's faster than existing percpu_ida, but not as fast as pcpu_freelist. bt is a variant of block/blk-mq-tag.c simlified and customized for bpf use case. bt w/smp_align is using cache line for every 'long' (similar to blk-mq-tag). bt no/smp_align allocates 'long' bitmasks continuously to save memory. It's comparable to percpu_ida and in some cases faster, but slower than percpu_freelist hlist+spinlock is the simplest free list with single spinlock. As expeceted it has very bad scaling in SMP. kmalloc is existing implementation which is still available via BPF_F_NO_PREALLOC flag. It's significantly slower in single cpu and in 8 cpu setup it's 3 times slower than pre-allocation with pcpu_freelist, but saves memory, so in cases where map->max_entries can be large and number of map update/delete per second is low, it may make sense to use it. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-07 22:57:15 -07:00
#define BPF_F_NO_PREALLOC (1U << 0)
bpf: Add BPF_MAP_TYPE_LRU_HASH Provide a LRU version of the existing BPF_MAP_TYPE_HASH. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-11 11:55:09 -07:00
/* Instead of having one common LRU list in the
bpf: Add BPF_MAP_TYPE_LRU_PERCPU_HASH Provide a LRU version of the existing BPF_MAP_TYPE_PERCPU_HASH Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-11 11:55:10 -07:00
* BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
bpf: Add BPF_MAP_TYPE_LRU_HASH Provide a LRU version of the existing BPF_MAP_TYPE_HASH. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-11 11:55:09 -07:00
* which can scale and perform better.
* Note, the LRU nodes (including free nodes) cannot be moved
* across different LRU lists.
*/
#define BPF_F_NO_COMMON_LRU (1U << 1)
bpf: pre-allocate hash map elements If kprobe is placed on spin_unlock then calling kmalloc/kfree from bpf programs is not safe, since the following dead lock is possible: kfree->spin_lock(kmem_cache_node->lock)...spin_unlock->kprobe-> bpf_prog->map_update->kmalloc->spin_lock(of the same kmem_cache_node->lock) and deadlocks. The following solutions were considered and some implemented, but eventually discarded - kmem_cache_create for every map - add recursion check to slow-path of slub - use reserved memory in bpf_map_update for in_irq or in preempt_disabled - kmalloc via irq_work At the end pre-allocation of all map elements turned out to be the simplest solution and since the user is charged upfront for all the memory, such pre-allocation doesn't affect the user space visible behavior. Since it's impossible to tell whether kprobe is triggered in a safe location from kmalloc point of view, use pre-allocation by default and introduce new BPF_F_NO_PREALLOC flag. While testing of per-cpu hash maps it was discovered that alloc_percpu(GFP_ATOMIC) has odd corner cases and often fails to allocate memory even when 90% of it is free. The pre-allocation of per-cpu hash elements solves this problem as well. Turned out that bpf_map_update() quickly followed by bpf_map_lookup()+bpf_map_delete() is very common pattern used in many of iovisor/bcc/tools, so there is additional benefit of pre-allocation, since such use cases are must faster. Since all hash map elements are now pre-allocated we can remove atomic increment of htab->count and save few more cycles. Also add bpf_map_precharge_memlock() to check rlimit_memlock early to avoid large malloc/free done by users who don't have sufficient limits. Pre-allocation is done with vmalloc and alloc/free is done via percpu_freelist. Here are performance numbers for different pre-allocation algorithms that were implemented, but discarded in favor of percpu_freelist: 1 cpu: pcpu_ida 2.1M pcpu_ida nolock 2.3M bt 2.4M kmalloc 1.8M hlist+spinlock 2.3M pcpu_freelist 2.6M 4 cpu: pcpu_ida 1.5M pcpu_ida nolock 1.8M bt w/smp_align 1.7M bt no/smp_align 1.1M kmalloc 0.7M hlist+spinlock 0.2M pcpu_freelist 2.0M 8 cpu: pcpu_ida 0.7M bt w/smp_align 0.8M kmalloc 0.4M pcpu_freelist 1.5M 32 cpu: kmalloc 0.13M pcpu_freelist 0.49M pcpu_ida nolock is a modified percpu_ida algorithm without percpu_ida_cpu locks and without cross-cpu tag stealing. It's faster than existing percpu_ida, but not as fast as pcpu_freelist. bt is a variant of block/blk-mq-tag.c simlified and customized for bpf use case. bt w/smp_align is using cache line for every 'long' (similar to blk-mq-tag). bt no/smp_align allocates 'long' bitmasks continuously to save memory. It's comparable to percpu_ida and in some cases faster, but slower than percpu_freelist hlist+spinlock is the simplest free list with single spinlock. As expeceted it has very bad scaling in SMP. kmalloc is existing implementation which is still available via BPF_F_NO_PREALLOC flag. It's significantly slower in single cpu and in 8 cpu setup it's 3 times slower than pre-allocation with pcpu_freelist, but saves memory, so in cases where map->max_entries can be large and number of map update/delete per second is low, it may make sense to use it. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-07 22:57:15 -07:00
bpf: introduce BPF syscall and maps BPF syscall is a multiplexor for a range of different operations on eBPF. This patch introduces syscall with single command to create a map. Next patch adds commands to access maps. 'maps' is a generic storage of different types for sharing data between kernel and userspace. Userspace example: /* this syscall wrapper creates a map with given type and attributes * and returns map_fd on success. * use close(map_fd) to delete the map */ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, int max_entries) { union bpf_attr attr = { .map_type = map_type, .key_size = key_size, .value_size = value_size, .max_entries = max_entries }; return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); } 'union bpf_attr' is backwards compatible with future extensions. More details in Documentation/networking/filter.txt and in manpage Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:57 -06:00
union bpf_attr {
struct { /* anonymous struct used by BPF_MAP_CREATE command */
__u32 map_type; /* one of enum bpf_map_type */
__u32 key_size; /* size of key in bytes */
__u32 value_size; /* size of value in bytes */
__u32 max_entries; /* max number of entries in a map */
bpf: pre-allocate hash map elements If kprobe is placed on spin_unlock then calling kmalloc/kfree from bpf programs is not safe, since the following dead lock is possible: kfree->spin_lock(kmem_cache_node->lock)...spin_unlock->kprobe-> bpf_prog->map_update->kmalloc->spin_lock(of the same kmem_cache_node->lock) and deadlocks. The following solutions were considered and some implemented, but eventually discarded - kmem_cache_create for every map - add recursion check to slow-path of slub - use reserved memory in bpf_map_update for in_irq or in preempt_disabled - kmalloc via irq_work At the end pre-allocation of all map elements turned out to be the simplest solution and since the user is charged upfront for all the memory, such pre-allocation doesn't affect the user space visible behavior. Since it's impossible to tell whether kprobe is triggered in a safe location from kmalloc point of view, use pre-allocation by default and introduce new BPF_F_NO_PREALLOC flag. While testing of per-cpu hash maps it was discovered that alloc_percpu(GFP_ATOMIC) has odd corner cases and often fails to allocate memory even when 90% of it is free. The pre-allocation of per-cpu hash elements solves this problem as well. Turned out that bpf_map_update() quickly followed by bpf_map_lookup()+bpf_map_delete() is very common pattern used in many of iovisor/bcc/tools, so there is additional benefit of pre-allocation, since such use cases are must faster. Since all hash map elements are now pre-allocated we can remove atomic increment of htab->count and save few more cycles. Also add bpf_map_precharge_memlock() to check rlimit_memlock early to avoid large malloc/free done by users who don't have sufficient limits. Pre-allocation is done with vmalloc and alloc/free is done via percpu_freelist. Here are performance numbers for different pre-allocation algorithms that were implemented, but discarded in favor of percpu_freelist: 1 cpu: pcpu_ida 2.1M pcpu_ida nolock 2.3M bt 2.4M kmalloc 1.8M hlist+spinlock 2.3M pcpu_freelist 2.6M 4 cpu: pcpu_ida 1.5M pcpu_ida nolock 1.8M bt w/smp_align 1.7M bt no/smp_align 1.1M kmalloc 0.7M hlist+spinlock 0.2M pcpu_freelist 2.0M 8 cpu: pcpu_ida 0.7M bt w/smp_align 0.8M kmalloc 0.4M pcpu_freelist 1.5M 32 cpu: kmalloc 0.13M pcpu_freelist 0.49M pcpu_ida nolock is a modified percpu_ida algorithm without percpu_ida_cpu locks and without cross-cpu tag stealing. It's faster than existing percpu_ida, but not as fast as pcpu_freelist. bt is a variant of block/blk-mq-tag.c simlified and customized for bpf use case. bt w/smp_align is using cache line for every 'long' (similar to blk-mq-tag). bt no/smp_align allocates 'long' bitmasks continuously to save memory. It's comparable to percpu_ida and in some cases faster, but slower than percpu_freelist hlist+spinlock is the simplest free list with single spinlock. As expeceted it has very bad scaling in SMP. kmalloc is existing implementation which is still available via BPF_F_NO_PREALLOC flag. It's significantly slower in single cpu and in 8 cpu setup it's 3 times slower than pre-allocation with pcpu_freelist, but saves memory, so in cases where map->max_entries can be large and number of map update/delete per second is low, it may make sense to use it. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-07 22:57:15 -07:00
__u32 map_flags; /* prealloc or not */
bpf: Add array of maps support This patch adds a few helper funcs to enable map-in-map support (i.e. outer_map->inner_map). The first outer_map type BPF_MAP_TYPE_ARRAY_OF_MAPS is also added in this patch. The next patch will introduce a hash of maps type. Any bpf map type can be acted as an inner_map. The exception is BPF_MAP_TYPE_PROG_ARRAY because the extra level of indirection makes it harder to verify the owner_prog_type and owner_jited. Multi-level map-in-map is not supported (i.e. map->map is ok but not map->map->map). When adding an inner_map to an outer_map, it currently checks the map_type, key_size, value_size, map_flags, max_entries and ops. The verifier also uses those map's properties to do static analysis. map_flags is needed because we need to ensure BPF_PROG_TYPE_PERF_EVENT is using a preallocated hashtab for the inner_hash also. ops and max_entries are needed to generate inlined map-lookup instructions. For simplicity reason, a simple '==' test is used for both map_flags and max_entries. The equality of ops is implied by the equality of map_type. During outer_map creation time, an inner_map_fd is needed to create an outer_map. However, the inner_map_fd's life time does not depend on the outer_map. The inner_map_fd is merely used to initialize the inner_map_meta of the outer_map. Also, for the outer_map: * It allows element update and delete from syscall * It allows element lookup from bpf_prog The above is similar to the current fd_array pattern. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 11:00:33 -06:00
__u32 inner_map_fd; /* fd pointing to the inner map */
bpf: introduce BPF syscall and maps BPF syscall is a multiplexor for a range of different operations on eBPF. This patch introduces syscall with single command to create a map. Next patch adds commands to access maps. 'maps' is a generic storage of different types for sharing data between kernel and userspace. Userspace example: /* this syscall wrapper creates a map with given type and attributes * and returns map_fd on success. * use close(map_fd) to delete the map */ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, int max_entries) { union bpf_attr attr = { .map_type = map_type, .key_size = key_size, .value_size = value_size, .max_entries = max_entries }; return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); } 'union bpf_attr' is backwards compatible with future extensions. More details in Documentation/networking/filter.txt and in manpage Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:57 -06:00
};
bpf: add lookup/update/delete/iterate methods to BPF maps 'maps' is a generic storage of different types for sharing data between kernel and userspace. The maps are accessed from user space via BPF syscall, which has commands: - create a map with given type and attributes fd = bpf(BPF_MAP_CREATE, union bpf_attr *attr, u32 size) returns fd or negative error - lookup key in a given map referenced by fd err = bpf(BPF_MAP_LOOKUP_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->value returns zero and stores found elem into value or negative error - create or update key/value pair in a given map err = bpf(BPF_MAP_UPDATE_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->value returns zero or negative error - find and delete element by key in a given map err = bpf(BPF_MAP_DELETE_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key - iterate map elements (based on input key return next_key) err = bpf(BPF_MAP_GET_NEXT_KEY, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->next_key - close(fd) deletes the map Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:59 -06:00
struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
__u32 map_fd;
__aligned_u64 key;
union {
__aligned_u64 value;
__aligned_u64 next_key;
};
bpf: add 'flags' attribute to BPF_MAP_UPDATE_ELEM command the current meaning of BPF_MAP_UPDATE_ELEM syscall command is: either update existing map element or create a new one. Initially the plan was to add a new command to handle the case of 'create new element if it didn't exist', but 'flags' style looks cleaner and overall diff is much smaller (more code reused), so add 'flags' attribute to BPF_MAP_UPDATE_ELEM command with the following meaning: #define BPF_ANY 0 /* create new element or update existing */ #define BPF_NOEXIST 1 /* create new element if it didn't exist */ #define BPF_EXIST 2 /* update existing element */ bpf_update_elem(fd, key, value, BPF_NOEXIST) call can fail with EEXIST if element already exists. bpf_update_elem(fd, key, value, BPF_EXIST) can fail with ENOENT if element doesn't exist. Userspace will call it as: int bpf_update_elem(int fd, void *key, void *value, __u64 flags) { union bpf_attr attr = { .map_fd = fd, .key = ptr_to_u64(key), .value = ptr_to_u64(value), .flags = flags; }; return bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); } First two bits of 'flags' are used to encode style of bpf_update_elem() command. Bits 2-63 are reserved for future use. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13 18:36:44 -07:00
__u64 flags;
bpf: add lookup/update/delete/iterate methods to BPF maps 'maps' is a generic storage of different types for sharing data between kernel and userspace. The maps are accessed from user space via BPF syscall, which has commands: - create a map with given type and attributes fd = bpf(BPF_MAP_CREATE, union bpf_attr *attr, u32 size) returns fd or negative error - lookup key in a given map referenced by fd err = bpf(BPF_MAP_LOOKUP_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->value returns zero and stores found elem into value or negative error - create or update key/value pair in a given map err = bpf(BPF_MAP_UPDATE_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->value returns zero or negative error - find and delete element by key in a given map err = bpf(BPF_MAP_DELETE_ELEM, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key - iterate map elements (based on input key return next_key) err = bpf(BPF_MAP_GET_NEXT_KEY, union bpf_attr *attr, u32 size) using attr->map_fd, attr->key, attr->next_key - close(fd) deletes the map Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:59 -06:00
};
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
struct { /* anonymous struct used by BPF_PROG_LOAD command */
__u32 prog_type; /* one of enum bpf_prog_type */
__u32 insn_cnt;
__aligned_u64 insns;
__aligned_u64 license;
bpf: verifier (add ability to receive verification log) add optional attributes for BPF_PROG_LOAD syscall: union bpf_attr { struct { ... __u32 log_level; /* verbosity level of eBPF verifier */ __u32 log_size; /* size of user buffer */ __aligned_u64 log_buf; /* user supplied 'char *buffer' */ }; }; when log_level > 0 the verifier will return its verification log in the user supplied buffer 'log_buf' which can be used by program author to analyze why verifier rejected given program. 'Understanding eBPF verifier messages' section of Documentation/networking/filter.txt provides several examples of these messages, like the program: BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), BPF_LD_MAP_FD(BPF_REG_1, 0), BPF_CALL_FUNC(BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), BPF_ST_MEM(BPF_DW, BPF_REG_0, 4, 0), BPF_EXIT_INSN(), will be rejected with the following multi-line message in log_buf: 0: (7a) *(u64 *)(r10 -8) = 0 1: (bf) r2 = r10 2: (07) r2 += -8 3: (b7) r1 = 0 4: (85) call 1 5: (15) if r0 == 0x0 goto pc+1 R0=map_ptr R10=fp 6: (7a) *(u64 *)(r0 +4) = 0 misaligned access off 4 size 8 The format of the output can change at any time as verifier evolves. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:03 -06:00
__u32 log_level; /* verbosity level of verifier */
__u32 log_size; /* size of user buffer */
__aligned_u64 log_buf; /* user supplied buffer */
tracing, perf: Implement BPF programs attached to kprobes BPF programs, attached to kprobes, provide a safe way to execute user-defined BPF byte-code programs without being able to crash or hang the kernel in any way. The BPF engine makes sure that such programs have a finite execution time and that they cannot break out of their sandbox. The user interface is to attach to a kprobe via the perf syscall: struct perf_event_attr attr = { .type = PERF_TYPE_TRACEPOINT, .config = event_id, ... }; event_fd = perf_event_open(&attr,...); ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); 'prog_fd' is a file descriptor associated with BPF program previously loaded. 'event_id' is an ID of the kprobe created. Closing 'event_fd': close(event_fd); ... automatically detaches BPF program from it. BPF programs can call in-kernel helper functions to: - lookup/update/delete elements in maps - probe_read - wraper of probe_kernel_read() used to access any kernel data structures BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is architecture dependent) and return 0 to ignore the event and 1 to store kprobe event into the ring buffer. Note, kprobes are a fundamentally _not_ a stable kernel ABI, so BPF programs attached to kprobes must be recompiled for every kernel version and user must supply correct LINUX_VERSION_CODE in attr.kern_version during bpf_prog_load() call. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-25 13:49:20 -06:00
__u32 kern_version; /* checked when prog_type=kprobe */
bpf: Add strict alignment flag for BPF_PROG_LOAD. Add a new field, "prog_flags", and an initial flag value BPF_F_STRICT_ALIGNMENT. When set, the verifier will enforce strict pointer alignment regardless of the setting of CONFIG_EFFICIENT_UNALIGNED_ACCESS. The verifier, in this mode, will also use a fixed value of "2" in place of NET_IP_ALIGN. This facilitates test cases that will exercise and validate this part of the verifier even when run on architectures where alignment doesn't matter. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
2017-05-10 12:38:07 -06:00
__u32 prog_flags;
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
};
bpf: add support for persistent maps/progs This work adds support for "persistent" eBPF maps/programs. The term "persistent" is to be understood that maps/programs have a facility that lets them survive process termination. This is desired by various eBPF subsystem users. Just to name one example: tc classifier/action. Whenever tc parses the ELF object, extracts and loads maps/progs into the kernel, these file descriptors will be out of reach after the tc instance exits. So a subsequent tc invocation won't be able to access/relocate on this resource, and therefore maps cannot easily be shared, f.e. between the ingress and egress networking data path. The current workaround is that Unix domain sockets (UDS) need to be instrumented in order to pass the created eBPF map/program file descriptors to a third party management daemon through UDS' socket passing facility. This makes it a bit complicated to deploy shared eBPF maps or programs (programs f.e. for tail calls) among various processes. We've been brainstorming on how we could tackle this issue and various approches have been tried out so far, which can be read up further in the below reference. The architecture we eventually ended up with is a minimal file system that can hold map/prog objects. The file system is a per mount namespace singleton, and the default mount point is /sys/fs/bpf/. Any subsequent mounts within a given namespace will point to the same instance. The file system allows for creating a user-defined directory structure. The objects for maps/progs are created/fetched through bpf(2) with two new commands (BPF_OBJ_PIN/BPF_OBJ_GET). I.e. a bpf file descriptor along with a pathname is being passed to bpf(2) that in turn creates (we call it eBPF object pinning) the file system nodes. Only the pathname is being passed to bpf(2) for getting a new BPF file descriptor to an existing node. The user can use that to access maps and progs later on, through bpf(2). Removal of file system nodes is being managed through normal VFS functions such as unlink(2), etc. The file system code is kept to a very minimum and can be further extended later on. The next step I'm working on is to add dump eBPF map/prog commands to bpf(2), so that a specification from a given file descriptor can be retrieved. This can be used by things like CRIU but also applications can inspect the meta data after calling BPF_OBJ_GET. Big thanks also to Alexei and Hannes who significantly contributed in the design discussion that eventually let us end up with this architecture here. Reference: https://lkml.org/lkml/2015/10/15/925 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-29 07:58:09 -06:00
struct { /* anonymous struct used by BPF_OBJ_* commands */
__aligned_u64 pathname;
__u32 bpf_fd;
};
bpf: add BPF_PROG_ATTACH and BPF_PROG_DETACH commands Extend the bpf(2) syscall by two new commands, BPF_PROG_ATTACH and BPF_PROG_DETACH which allow attaching and detaching eBPF programs to a target. On the API level, the target could be anything that has an fd in userspace, hence the name of the field in union bpf_attr is called 'target_fd'. When called with BPF_ATTACH_TYPE_CGROUP_INET_{E,IN}GRESS, the target is expected to be a valid file descriptor of a cgroup v2 directory which has the bpf controller enabled. These are the only use-cases implemented by this patch at this point, but more can be added. If a program of the given type already exists in the given cgroup, the program is swapped automically, so userspace does not have to drop an existing program first before installing a new one, which would otherwise leave a gap in which no program is attached. For more information on the propagation logic to subcgroups, please refer to the bpf cgroup controller implementation. The API is guarded by CAP_NET_ADMIN. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-23 08:52:27 -07:00
struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
__u32 target_fd; /* container object to attach to */
__u32 attach_bpf_fd; /* eBPF program to attach */
__u32 attach_type;
bpf: introduce BPF_F_ALLOW_OVERRIDE flag If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command to the given cgroup the descendent cgroup will be able to override effective bpf program that was inherited from this cgroup. By default it's not passed, therefore override is disallowed. Examples: 1. prog X attached to /A with default prog Y fails to attach to /A/B and /A/B/C Everything under /A runs prog X 2. prog X attached to /A with allow_override. prog Y fails to attach to /A/B with default (non-override) prog M attached to /A/B with allow_override. Everything under /A/B runs prog M only. 3. prog X attached to /A with allow_override. prog Y fails to attach to /A with default. The user has to detach first to switch the mode. In the future this behavior may be extended with a chain of non-overridable programs. Also fix the bug where detach from cgroup where nothing is attached was not throwing error. Return ENOENT in such case. Add several testcases and adjust libbpf. Fixes: 3007098494be ("cgroup: add support for eBPF programs") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Daniel Mack <daniel@zonque.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-10 21:28:24 -07:00
__u32 attach_flags;
bpf: add BPF_PROG_ATTACH and BPF_PROG_DETACH commands Extend the bpf(2) syscall by two new commands, BPF_PROG_ATTACH and BPF_PROG_DETACH which allow attaching and detaching eBPF programs to a target. On the API level, the target could be anything that has an fd in userspace, hence the name of the field in union bpf_attr is called 'target_fd'. When called with BPF_ATTACH_TYPE_CGROUP_INET_{E,IN}GRESS, the target is expected to be a valid file descriptor of a cgroup v2 directory which has the bpf controller enabled. These are the only use-cases implemented by this patch at this point, but more can be added. If a program of the given type already exists in the given cgroup, the program is swapped automically, so userspace does not have to drop an existing program first before installing a new one, which would otherwise leave a gap in which no program is attached. For more information on the propagation logic to subcgroups, please refer to the bpf cgroup controller implementation. The API is guarded by CAP_NET_ADMIN. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-23 08:52:27 -07:00
};
bpf: introduce BPF_PROG_TEST_RUN command development and testing of networking bpf programs is quite cumbersome. Despite availability of user space bpf interpreters the kernel is the ultimate authority and execution environment. Current test frameworks for TC include creation of netns, veth, qdiscs and use of various packet generators just to test functionality of a bpf program. XDP testing is even more complicated, since qemu needs to be started with gro/gso disabled and precise queue configuration, transferring of xdp program from host into guest, attaching to virtio/eth0 and generating traffic from the host while capturing the results from the guest. Moreover analyzing performance bottlenecks in XDP program is impossible in virtio environment, since cost of running the program is tiny comparing to the overhead of virtio packet processing, so performance testing can only be done on physical nic with another server generating traffic. Furthermore ongoing changes to user space control plane of production applications cannot be run on the test servers leaving bpf programs stubbed out for testing. Last but not least, the upstream llvm changes are validated by the bpf backend testsuite which has no ability to test the code generated. To improve this situation introduce BPF_PROG_TEST_RUN command to test and performance benchmark bpf programs. Joint work with Daniel Borkmann. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-30 22:45:38 -06:00
struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
__u32 prog_fd;
__u32 retval;
__u32 data_size_in;
__u32 data_size_out;
__aligned_u64 data_in;
__aligned_u64 data_out;
__u32 repeat;
__u32 duration;
} test;
bpf: Add BPF_(PROG|MAP)_GET_NEXT_ID command This patch adds BPF_PROG_GET_NEXT_ID and BPF_MAP_GET_NEXT_ID to allow userspace to iterate all bpf_prog IDs and bpf_map IDs. The API is trying to be consistent with the existing BPF_MAP_GET_NEXT_KEY. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:48 -06:00
bpf: Add BPF_PROG_GET_FD_BY_ID Add BPF_PROG_GET_FD_BY_ID command to allow user to get a fd from a bpf_prog's ID. bpf_prog_inc_not_zero() is added and is called with prog_idr_lock held. __bpf_prog_put() is also added which has the 'bool do_idr_lock' param to decide if the prog_idr_lock should be acquired when freeing the prog->id. In the error path of bpf_prog_inc_not_zero(), it may have to call __bpf_prog_put(map, false) which does not need to take the prog_idr_lock when freeing the prog->id. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:49 -06:00
struct { /* anonymous struct used by BPF_*_GET_*_ID */
union {
__u32 start_id;
__u32 prog_id;
bpf: Add BPF_MAP_GET_FD_BY_ID Add BPF_MAP_GET_FD_BY_ID command to allow user to get a fd from a bpf_map's ID. bpf_map_inc_not_zero() is added and is called with map_idr_lock held. __bpf_map_put() is also added which has the 'bool do_idr_lock' param to decide if the map_idr_lock should be acquired when freeing the map->id. In the error path of bpf_map_inc_not_zero(), it may have to call __bpf_map_put(map, false) which does not need to take the map_idr_lock when freeing the map->id. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:50 -06:00
__u32 map_id;
bpf: Add BPF_PROG_GET_FD_BY_ID Add BPF_PROG_GET_FD_BY_ID command to allow user to get a fd from a bpf_prog's ID. bpf_prog_inc_not_zero() is added and is called with prog_idr_lock held. __bpf_prog_put() is also added which has the 'bool do_idr_lock' param to decide if the prog_idr_lock should be acquired when freeing the prog->id. In the error path of bpf_prog_inc_not_zero(), it may have to call __bpf_prog_put(map, false) which does not need to take the prog_idr_lock when freeing the prog->id. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:49 -06:00
};
bpf: Add BPF_(PROG|MAP)_GET_NEXT_ID command This patch adds BPF_PROG_GET_NEXT_ID and BPF_MAP_GET_NEXT_ID to allow userspace to iterate all bpf_prog IDs and bpf_map IDs. The API is trying to be consistent with the existing BPF_MAP_GET_NEXT_KEY. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:48 -06:00
__u32 next_id;
};
bpf: Add BPF_OBJ_GET_INFO_BY_FD A single BPF_OBJ_GET_INFO_BY_FD cmd is used to obtain the info for both bpf_prog and bpf_map. The kernel can figure out the fd is associated with a bpf_prog or bpf_map. The suggested struct bpf_prog_info and struct bpf_map_info are not meant to be a complete list and it is not the goal of this patch. New fields can be added in the future patch. The focus of this patch is to create the interface, BPF_OBJ_GET_INFO_BY_FD cmd for exposing the bpf_prog's and bpf_map's info. The obj's info, which will be extended (and get bigger) over time, is separated from the bpf_attr to avoid bloating the bpf_attr. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:52 -06:00
struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */
__u32 bpf_fd;
__u32 info_len;
__aligned_u64 info;
} info;
bpf: introduce BPF syscall and maps BPF syscall is a multiplexor for a range of different operations on eBPF. This patch introduces syscall with single command to create a map. Next patch adds commands to access maps. 'maps' is a generic storage of different types for sharing data between kernel and userspace. Userspace example: /* this syscall wrapper creates a map with given type and attributes * and returns map_fd on success. * use close(map_fd) to delete the map */ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, int max_entries) { union bpf_attr attr = { .map_type = map_type, .key_size = key_size, .value_size = value_size, .max_entries = max_entries }; return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); } 'union bpf_attr' is backwards compatible with future extensions. More details in Documentation/networking/filter.txt and in manpage Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:16:57 -06:00
} __attribute__((aligned(8)));
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
/* BPF helper function descriptions:
*
* void *bpf_map_lookup_elem(&map, &key)
* Return: Map value or NULL
*
* int bpf_map_update_elem(&map, &key, &value, flags)
* Return: 0 on success or negative error
*
* int bpf_map_delete_elem(&map, &key)
* Return: 0 on success or negative error
*
* int bpf_probe_read(void *dst, int size, void *src)
* Return: 0 on success or negative error
*
* u64 bpf_ktime_get_ns(void)
* Return: current ktime
*
* int bpf_trace_printk(const char *fmt, int fmt_size, ...)
* Return: length of buffer written or negative error
*
* u32 bpf_prandom_u32(void)
* Return: random value
*
* u32 bpf_raw_smp_processor_id(void)
* Return: SMP processor ID
*
* int bpf_skb_store_bytes(skb, offset, from, len, flags)
* store bytes into packet
* @skb: pointer to skb
* @offset: offset within packet from skb->mac_header
* @from: pointer where to copy bytes from
* @len: number of bytes to store into packet
* @flags: bit 0 - if true, recompute skb->csum
* other bits - reserved
* Return: 0 on success or negative error
*
* int bpf_l3_csum_replace(skb, offset, from, to, flags)
* recompute IP checksum
* @skb: pointer to skb
* @offset: offset within packet where IP checksum is located
* @from: old value of header field
* @to: new value of header field
* @flags: bits 0-3 - size of header field
* other bits - reserved
* Return: 0 on success or negative error
*
* int bpf_l4_csum_replace(skb, offset, from, to, flags)
* recompute TCP/UDP checksum
* @skb: pointer to skb
* @offset: offset within packet where TCP/UDP checksum is located
* @from: old value of header field
* @to: new value of header field
* @flags: bits 0-3 - size of header field
* bit 4 - is pseudo header
* other bits - reserved
* Return: 0 on success or negative error
*
* int bpf_tail_call(ctx, prog_array_map, index)
* jump into another BPF program
* @ctx: context pointer passed to next program
* @prog_array_map: pointer to map which type is BPF_MAP_TYPE_PROG_ARRAY
* @index: index inside array that selects specific program to run
* Return: 0 on success or negative error
*
* int bpf_clone_redirect(skb, ifindex, flags)
* redirect to another netdev
* @skb: pointer to skb
* @ifindex: ifindex of the net device
* @flags: bit 0 - if set, redirect to ingress instead of egress
* other bits - reserved
* Return: 0 on success or negative error
*
* u64 bpf_get_current_pid_tgid(void)
* Return: current->tgid << 32 | current->pid
*
* u64 bpf_get_current_uid_gid(void)
* Return: current_gid << 32 | current_uid
*
* int bpf_get_current_comm(char *buf, int size_of_buf)
* stores current->comm into buf
* Return: 0 on success or negative error
*
* u32 bpf_get_cgroup_classid(skb)
* retrieve a proc's classid
* @skb: pointer to skb
* Return: classid if != 0
*
* int bpf_skb_vlan_push(skb, vlan_proto, vlan_tci)
* Return: 0 on success or negative error
*
* int bpf_skb_vlan_pop(skb)
* Return: 0 on success or negative error
*
* int bpf_skb_get_tunnel_key(skb, key, size, flags)
* int bpf_skb_set_tunnel_key(skb, key, size, flags)
* retrieve or populate tunnel metadata
* @skb: pointer to skb
* @key: pointer to 'struct bpf_tunnel_key'
* @size: size of 'struct bpf_tunnel_key'
* @flags: room for future extensions
* Return: 0 on success or negative error
*
bpf: update perf event helper functions documentation This commit updates documentation of the bpf_perf_event_output and bpf_perf_event_read helpers to match their implementation. Signed-off-by: Teng Qin <qinteng@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-02 22:03:54 -06:00
* u64 bpf_perf_event_read(map, flags)
* read perf event counter value
* @map: pointer to perf_event_array map
* @flags: index of event in the map or bitmask flags
* Return: value of perf event counter read or error code
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
*
* int bpf_redirect(ifindex, flags)
* redirect to another netdev
* @ifindex: ifindex of the net device
* @flags: bit 0 - if set, redirect to ingress instead of egress
* other bits - reserved
* Return: TC_ACT_REDIRECT
*
* u32 bpf_get_route_realm(skb)
* retrieve a dst's tclassid
* @skb: pointer to skb
* Return: realm if != 0
*
bpf: update perf event helper functions documentation This commit updates documentation of the bpf_perf_event_output and bpf_perf_event_read helpers to match their implementation. Signed-off-by: Teng Qin <qinteng@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-02 22:03:54 -06:00
* int bpf_perf_event_output(ctx, map, flags, data, size)
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
* output perf raw sample
* @ctx: struct pt_regs*
* @map: pointer to perf_event_array map
bpf: update perf event helper functions documentation This commit updates documentation of the bpf_perf_event_output and bpf_perf_event_read helpers to match their implementation. Signed-off-by: Teng Qin <qinteng@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-02 22:03:54 -06:00
* @flags: index of event in the map or bitmask flags
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
* @data: data on stack to be output as raw data
* @size: size of data
* Return: 0 on success or negative error
*
* int bpf_get_stackid(ctx, map, flags)
* walk user or kernel stack and return id
* @ctx: struct pt_regs*
* @map: pointer to stack_trace map
* @flags: bits 0-7 - numer of stack frames to skip
* bit 8 - collect user stack instead of kernel
* bit 9 - compare stacks by hash only
* bit 10 - if two different stacks hash into the same stackid
* discard old
* other bits - reserved
* Return: >= 0 stackid on success or negative error
*
* s64 bpf_csum_diff(from, from_size, to, to_size, seed)
* calculate csum diff
* @from: raw from buffer
* @from_size: length of from buffer
* @to: raw to buffer
* @to_size: length of to buffer
* @seed: optional seed
* Return: csum result or negative error code
*
* int bpf_skb_get_tunnel_opt(skb, opt, size)
* retrieve tunnel options metadata
* @skb: pointer to skb
* @opt: pointer to raw tunnel option data
* @size: size of @opt
* Return: option size
*
* int bpf_skb_set_tunnel_opt(skb, opt, size)
* populate tunnel options metadata
* @skb: pointer to skb
* @opt: pointer to raw tunnel option data
* @size: size of @opt
* Return: 0 on success or negative error
*
* int bpf_skb_change_proto(skb, proto, flags)
* Change protocol of the skb. Currently supported is v4 -> v6,
* v6 -> v4 transitions. The helper will also resize the skb. eBPF
* program is expected to fill the new headers via skb_store_bytes
* and lX_csum_replace.
* @skb: pointer to skb
* @proto: new skb->protocol type
* @flags: reserved
* Return: 0 on success or negative error
*
* int bpf_skb_change_type(skb, type)
* Change packet type of skb.
* @skb: pointer to skb
* @type: new skb->pkt_type type
* Return: 0 on success or negative error
*
* int bpf_skb_under_cgroup(skb, map, index)
* Check cgroup2 membership of skb
* @skb: pointer to skb
* @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
* @index: index of the cgroup in the bpf_map
* Return:
* == 0 skb failed the cgroup2 descendant test
* == 1 skb succeeded the cgroup2 descendant test
* < 0 error
*
* u32 bpf_get_hash_recalc(skb)
* Retrieve and possibly recalculate skb->hash.
* @skb: pointer to skb
* Return: hash
*
* u64 bpf_get_current_task(void)
* Returns current task_struct
* Return: current
*
* int bpf_probe_write_user(void *dst, void *src, int len)
* safely attempt to write to a location
* @dst: destination address in userspace
* @src: source address on stack
* @len: number of bytes to copy
* Return: 0 on success or negative error
*
* int bpf_current_task_under_cgroup(map, index)
* Check cgroup2 membership of current task
* @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
* @index: index of the cgroup in the bpf_map
* Return:
* == 0 current failed the cgroup2 descendant test
* == 1 current succeeded the cgroup2 descendant test
* < 0 error
*
* int bpf_skb_change_tail(skb, len, flags)
* The helper will resize the skb to the given new size, to be used f.e.
* with control messages.
* @skb: pointer to skb
* @len: new skb length
* @flags: reserved
* Return: 0 on success or negative error
*
* int bpf_skb_pull_data(skb, len)
* The helper will pull in non-linear data in case the skb is non-linear
* and not all of len are part of the linear section. Only needed for
* read/write with direct packet access.
* @skb: pointer to skb
* @len: len to make read/writeable
* Return: 0 on success or negative error
*
* s64 bpf_csum_update(skb, csum)
* Adds csum into skb->csum in case of CHECKSUM_COMPLETE.
* @skb: pointer to skb
* @csum: csum to add
* Return: csum on success or negative error
*
* void bpf_set_hash_invalid(skb)
* Invalidate current skb->hash.
* @skb: pointer to skb
*
* int bpf_get_numa_node_id()
* Return: Id of current NUMA node.
bpf: BPF for lightweight tunnel infrastructure Registers new BPF program types which correspond to the LWT hooks: - BPF_PROG_TYPE_LWT_IN => dst_input() - BPF_PROG_TYPE_LWT_OUT => dst_output() - BPF_PROG_TYPE_LWT_XMIT => lwtunnel_xmit() The separate program types are required to differentiate between the capabilities each LWT hook allows: * Programs attached to dst_input() or dst_output() are restricted and may only read the data of an skb. This prevent modification and possible invalidation of already validated packet headers on receive and the construction of illegal headers while the IP headers are still being assembled. * Programs attached to lwtunnel_xmit() are allowed to modify packet content as well as prepending an L2 header via a newly introduced helper bpf_skb_change_head(). This is safe as lwtunnel_xmit() is invoked after the IP header has been assembled completely. All BPF programs receive an skb with L3 headers attached and may return one of the following error codes: BPF_OK - Continue routing as per nexthop BPF_DROP - Drop skb and return EPERM BPF_REDIRECT - Redirect skb to device as per redirect() helper. (Only valid in lwtunnel_xmit() context) The return codes are binary compatible with their TC_ACT_ relatives to ease compatibility. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30 09:10:10 -07:00
*
* int bpf_skb_change_head()
* Grows headroom of skb and adjusts MAC header offset accordingly.
* Will extends/reallocae as required automatically.
* May change skb data pointer and will thus invalidate any check
* performed for direct packet access.
* @skb: pointer to skb
* @len: length of header to be pushed in front
* @flags: Flags (unused for now)
* Return: 0 on success or negative error
bpf: xdp: Allow head adjustment in XDP prog This patch allows XDP prog to extend/remove the packet data at the head (like adding or removing header). It is done by adding a new XDP helper bpf_xdp_adjust_head(). It also renames bpf_helper_changes_skb_data() to bpf_helper_changes_pkt_data() to better reflect that XDP prog does not work on skb. This patch adds one "xdp_adjust_head" bit to bpf_prog for the XDP-capable driver to check if the XDP prog requires bpf_xdp_adjust_head() support. The driver can then decide to error out during XDP_SETUP_PROG. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-07 16:53:11 -07:00
*
* int bpf_xdp_adjust_head(xdp_md, delta)
* Adjust the xdp_md.data by delta
* @xdp_md: pointer to xdp_md
* @delta: An positive/negative integer to be added to xdp_md.data
* Return: 0 on success or negative on error
bpf: add bpf_probe_read_str helper Provide a simple helper with the same semantics of strncpy_from_unsafe(): int bpf_probe_read_str(void *dst, int size, const void *unsafe_addr) This gives more flexibility to a bpf program. A typical use case is intercepting a file name during sys_open(). The current approach is: SEC("kprobe/sys_open") void bpf_sys_open(struct pt_regs *ctx) { char buf[PATHLEN]; // PATHLEN is defined to 256 bpf_probe_read(buf, sizeof(buf), ctx->di); /* consume buf */ } This is suboptimal because the size of the string needs to be estimated at compile time, causing more memory to be copied than often necessary, and can become more problematic if further processing on buf is done, for example by pushing it to userspace via bpf_perf_event_output(), since the real length of the string is unknown and the entire buffer must be copied (and defining an unrolled strnlen() inside the bpf program is a very inefficient and unfeasible approach). With the new helper, the code can easily operate on the actual string length rather than the buffer size: SEC("kprobe/sys_open") void bpf_sys_open(struct pt_regs *ctx) { char buf[PATHLEN]; // PATHLEN is defined to 256 int res = bpf_probe_read_str(buf, sizeof(buf), ctx->di); /* consume buf, for example push it to userspace via * bpf_perf_event_output(), but this time we can use * res (the string length) as event size, after checking * its boundaries. */ } Another useful use case is when parsing individual process arguments or individual environment variables navigating current->mm->arg_start and current->mm->env_start: using this helper and the return value, one can quickly iterate at the right offset of the memory area. The code changes simply leverage the already existent strncpy_from_unsafe() kernel function, which is safe to be called from a bpf program as it is used in bpf_trace_printk(). Signed-off-by: Gianluca Borello <g.borello@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18 10:55:49 -07:00
*
* int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr)
* Copy a NUL terminated string from unsafe address. In case the string
* length is smaller than size, the target is not padded with further NUL
* bytes. In case the string length is larger than size, just count-1
* bytes are copied and the last byte is set to NUL.
* @dst: destination address
* @size: maximum number of bytes to copy, including the trailing NUL
* @unsafe_ptr: unsafe address
* Return:
* > 0 length of the string including the trailing NUL on success
* < 0 error
Add a helper function to get socket cookie in eBPF Retrieve the socket cookie generated by sock_gen_cookie() from a sk_buff with a known socket. Generates a new cookie if one was not yet set.If the socket pointer inside sk_buff is NULL, 0 is returned. The helper function coud be useful in monitoring per socket networking traffic statistics and provide a unique socket identifier per namespace. Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 18:27:34 -06:00
*
bpf: fix comment typo o s/bpf_bpf_get_socket_cookie/bpf_get_socket_cookie Signed-off-by: Alexander Alemayhu <alexander@alemayhu.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-08 14:08:10 -06:00
* u64 bpf_get_socket_cookie(skb)
Add a helper function to get socket cookie in eBPF Retrieve the socket cookie generated by sock_gen_cookie() from a sk_buff with a known socket. Generates a new cookie if one was not yet set.If the socket pointer inside sk_buff is NULL, 0 is returned. The helper function coud be useful in monitoring per socket networking traffic statistics and provide a unique socket identifier per namespace. Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 18:27:34 -06:00
* Get the cookie for the socket stored inside sk_buff.
* @skb: pointer to skb
* Return: 8 Bytes non-decreasing number on success or 0 if the socket
* field is missing inside sk_buff
Add a eBPF helper function to retrieve socket uid Returns the owner uid of the socket inside a sk_buff. This is useful to perform per-UID accounting of network traffic or per-UID packet filtering. The socket need to be a fullsock otherwise overflowuid is returned. Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 18:27:35 -06:00
*
* u32 bpf_get_socket_uid(skb)
* Get the owner uid of the socket stored inside sk_buff.
* @skb: pointer to skb
bpf: Fix inaccurate helper function description The description inside uapi/linux/bpf.h about bpf_get_socket_uid helper function is no longer valid. It returns overflowuid rather than 0 when failed. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-26 17:41:23 -06:00
* Return: uid of the socket owner on success or overflowuid if failed.
bpf: add bpf_set_hash helper for tc progs Allow for tc BPF programs to set a skb->hash, apart from clearing and triggering a recalc that we have right now. It allows for BPF to implement a custom hashing routine for skb_get_hash(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10 16:50:47 -06:00
*
* u32 bpf_set_hash(skb, hash)
* Set full skb->hash.
* @skb: pointer to skb
* @hash: hash to set
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
FN(map_lookup_elem), \
FN(map_update_elem), \
FN(map_delete_elem), \
FN(probe_read), \
FN(ktime_get_ns), \
FN(trace_printk), \
FN(get_prandom_u32), \
FN(get_smp_processor_id), \
FN(skb_store_bytes), \
FN(l3_csum_replace), \
FN(l4_csum_replace), \
FN(tail_call), \
FN(clone_redirect), \
FN(get_current_pid_tgid), \
FN(get_current_uid_gid), \
FN(get_current_comm), \
FN(get_cgroup_classid), \
FN(skb_vlan_push), \
FN(skb_vlan_pop), \
FN(skb_get_tunnel_key), \
FN(skb_set_tunnel_key), \
FN(perf_event_read), \
FN(redirect), \
FN(get_route_realm), \
FN(perf_event_output), \
FN(skb_load_bytes), \
FN(get_stackid), \
FN(csum_diff), \
FN(skb_get_tunnel_opt), \
FN(skb_set_tunnel_opt), \
FN(skb_change_proto), \
FN(skb_change_type), \
FN(skb_under_cgroup), \
FN(get_hash_recalc), \
FN(get_current_task), \
FN(probe_write_user), \
FN(current_task_under_cgroup), \
FN(skb_change_tail), \
FN(skb_pull_data), \
FN(csum_update), \
FN(set_hash_invalid), \
bpf: BPF for lightweight tunnel infrastructure Registers new BPF program types which correspond to the LWT hooks: - BPF_PROG_TYPE_LWT_IN => dst_input() - BPF_PROG_TYPE_LWT_OUT => dst_output() - BPF_PROG_TYPE_LWT_XMIT => lwtunnel_xmit() The separate program types are required to differentiate between the capabilities each LWT hook allows: * Programs attached to dst_input() or dst_output() are restricted and may only read the data of an skb. This prevent modification and possible invalidation of already validated packet headers on receive and the construction of illegal headers while the IP headers are still being assembled. * Programs attached to lwtunnel_xmit() are allowed to modify packet content as well as prepending an L2 header via a newly introduced helper bpf_skb_change_head(). This is safe as lwtunnel_xmit() is invoked after the IP header has been assembled completely. All BPF programs receive an skb with L3 headers attached and may return one of the following error codes: BPF_OK - Continue routing as per nexthop BPF_DROP - Drop skb and return EPERM BPF_REDIRECT - Redirect skb to device as per redirect() helper. (Only valid in lwtunnel_xmit() context) The return codes are binary compatible with their TC_ACT_ relatives to ease compatibility. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30 09:10:10 -07:00
FN(get_numa_node_id), \
bpf: xdp: Allow head adjustment in XDP prog This patch allows XDP prog to extend/remove the packet data at the head (like adding or removing header). It is done by adding a new XDP helper bpf_xdp_adjust_head(). It also renames bpf_helper_changes_skb_data() to bpf_helper_changes_pkt_data() to better reflect that XDP prog does not work on skb. This patch adds one "xdp_adjust_head" bit to bpf_prog for the XDP-capable driver to check if the XDP prog requires bpf_xdp_adjust_head() support. The driver can then decide to error out during XDP_SETUP_PROG. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-07 16:53:11 -07:00
FN(skb_change_head), \
bpf: add bpf_probe_read_str helper Provide a simple helper with the same semantics of strncpy_from_unsafe(): int bpf_probe_read_str(void *dst, int size, const void *unsafe_addr) This gives more flexibility to a bpf program. A typical use case is intercepting a file name during sys_open(). The current approach is: SEC("kprobe/sys_open") void bpf_sys_open(struct pt_regs *ctx) { char buf[PATHLEN]; // PATHLEN is defined to 256 bpf_probe_read(buf, sizeof(buf), ctx->di); /* consume buf */ } This is suboptimal because the size of the string needs to be estimated at compile time, causing more memory to be copied than often necessary, and can become more problematic if further processing on buf is done, for example by pushing it to userspace via bpf_perf_event_output(), since the real length of the string is unknown and the entire buffer must be copied (and defining an unrolled strnlen() inside the bpf program is a very inefficient and unfeasible approach). With the new helper, the code can easily operate on the actual string length rather than the buffer size: SEC("kprobe/sys_open") void bpf_sys_open(struct pt_regs *ctx) { char buf[PATHLEN]; // PATHLEN is defined to 256 int res = bpf_probe_read_str(buf, sizeof(buf), ctx->di); /* consume buf, for example push it to userspace via * bpf_perf_event_output(), but this time we can use * res (the string length) as event size, after checking * its boundaries. */ } Another useful use case is when parsing individual process arguments or individual environment variables navigating current->mm->arg_start and current->mm->env_start: using this helper and the return value, one can quickly iterate at the right offset of the memory area. The code changes simply leverage the already existent strncpy_from_unsafe() kernel function, which is safe to be called from a bpf program as it is used in bpf_trace_printk(). Signed-off-by: Gianluca Borello <g.borello@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18 10:55:49 -07:00
FN(xdp_adjust_head), \
Add a helper function to get socket cookie in eBPF Retrieve the socket cookie generated by sock_gen_cookie() from a sk_buff with a known socket. Generates a new cookie if one was not yet set.If the socket pointer inside sk_buff is NULL, 0 is returned. The helper function coud be useful in monitoring per socket networking traffic statistics and provide a unique socket identifier per namespace. Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 18:27:34 -06:00
FN(probe_read_str), \
Add a eBPF helper function to retrieve socket uid Returns the owner uid of the socket inside a sk_buff. This is useful to perform per-UID accounting of network traffic or per-UID packet filtering. The socket need to be a fullsock otherwise overflowuid is returned. Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 18:27:35 -06:00
FN(get_socket_cookie), \
bpf: add bpf_set_hash helper for tc progs Allow for tc BPF programs to set a skb->hash, apart from clearing and triggering a recalc that we have right now. It allows for BPF to implement a custom hashing routine for skb_get_hash(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10 16:50:47 -06:00
FN(get_socket_uid), \
FN(set_hash),
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
*/
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
#define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
enum bpf_func_id {
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
__BPF_FUNC_MAPPER(__BPF_ENUM_FN)
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
__BPF_FUNC_MAX_ID,
};
bpf: Print function name in addition to function id The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 03:23:51 -06:00
#undef __BPF_ENUM_FN
bpf: expand BPF syscall with program load/unload eBPF programs are similar to kernel modules. They are loaded by the user process and automatically unloaded when process exits. Each eBPF program is a safe run-to-completion set of instructions. eBPF verifier statically determines that the program terminates and is safe to execute. The following syscall wrapper can be used to load the program: int bpf_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, int insn_cnt, const char *license) { union bpf_attr attr = { .prog_type = prog_type, .insns = ptr_to_u64(insns), .insn_cnt = insn_cnt, .license = ptr_to_u64(license), }; return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } where 'insns' is an array of eBPF instructions and 'license' is a string that must be GPL compatible to call helper functions marked gpl_only Upon succesful load the syscall returns prog_fd. Use close(prog_fd) to unload the program. User space tests and examples follow in the later patches Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 01:17:00 -06:00
bpf: export helper function flags and reject invalid ones Export flags used by eBPF helper functions through UAPI, so they can be used by programs (instead of them redefining all flags each time or just using the hard-coded values). It also gives a better overview what flags are used where and we can further get rid of the extra macros defined in filter.c. Moreover, reject invalid flags. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:16:38 -07:00
/* All flags used by eBPF helper functions, placed here. */
/* BPF_FUNC_skb_store_bytes flags. */
#define BPF_F_RECOMPUTE_CSUM (1ULL << 0)
bpf: add flags to bpf_skb_store_bytes for clearing hash When overwriting parts of the packet with bpf_skb_store_bytes() that were fed previously into skb->hash calculation, we should clear the current hash with skb_clear_hash(), so that a next skb_get_hash() call can determine the correct hash related to this skb. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-04 07:15:03 -07:00
#define BPF_F_INVALIDATE_HASH (1ULL << 1)
bpf: export helper function flags and reject invalid ones Export flags used by eBPF helper functions through UAPI, so they can be used by programs (instead of them redefining all flags each time or just using the hard-coded values). It also gives a better overview what flags are used where and we can further get rid of the extra macros defined in filter.c. Moreover, reject invalid flags. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:16:38 -07:00
/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
* First 4 bits are for passing the header field size.
*/
#define BPF_F_HDR_FIELD_MASK 0xfULL
/* BPF_FUNC_l4_csum_replace flags. */
#define BPF_F_PSEUDO_HDR (1ULL << 4)
bpf: fix csum update in bpf_l4_csum_replace helper for udp When using this helper for updating UDP checksums, we need to extend this in order to write CSUM_MANGLED_0 for csum computations that result into 0 as sum. Reason we need this is because packets with a checksum could otherwise become incorrectly marked as a packet without a checksum. Likewise, if the user indicates BPF_F_MARK_MANGLED_0, then we should not turn packets without a checksum into ones with a checksum. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-19 15:05:26 -07:00
#define BPF_F_MARK_MANGLED_0 (1ULL << 5)
bpf: allow option for setting bpf_l4_csum_replace from scratch When programs need to calculate the csum from scratch for small UDP packets and use bpf_l4_csum_replace() to feed the result from helpers like bpf_csum_diff(), then we need a flag besides BPF_F_MARK_MANGLED_0 that would ignore the case of current csum being 0, and which would still allow for the helper to set the csum and transform when needed to CSUM_MANGLED_0. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-23 17:06:28 -07:00
#define BPF_F_MARK_ENFORCE (1ULL << 6)
bpf: export helper function flags and reject invalid ones Export flags used by eBPF helper functions through UAPI, so they can be used by programs (instead of them redefining all flags each time or just using the hard-coded values). It also gives a better overview what flags are used where and we can further get rid of the extra macros defined in filter.c. Moreover, reject invalid flags. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:16:38 -07:00
/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
#define BPF_F_INGRESS (1ULL << 0)
bpf: support ipv6 for bpf_skb_{set,get}_tunnel_key After IPv6 support has recently been added to metadata dst and related encaps, add support for populating/reading it from an eBPF program. Commit d3aa45ce6b ("bpf: add helpers to access tunnel metadata") started with initial IPv4-only support back then (due to IPv6 metadata support not being available yet). To stay compatible with older programs, we need to test for the passed structure size. Also TOS and TTL support from the ip_tunnel_info key has been added. Tested with vxlan devs in collect meta data mode with IPv4, IPv6 and in compat mode over different network namespaces. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:16:39 -07:00
/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
#define BPF_F_TUNINFO_IPV6 (1ULL << 0)
bpf: introduce BPF_MAP_TYPE_STACK_TRACE add new map type to store stack traces and corresponding helper bpf_get_stackid(ctx, map, flags) - walk user or kernel stack and return id @ctx: struct pt_regs* @map: pointer to stack_trace map @flags: bits 0-7 - numer of stack frames to skip bit 8 - collect user stack instead of kernel bit 9 - compare stacks by hash only bit 10 - if two different stacks hash into the same stackid discard old other bits - reserved Return: >= 0 stackid on success or negative error stackid is a 32-bit integer handle that can be further combined with other data (including other stackid) and used as a key into maps. Userspace will access stackmap using standard lookup/delete syscall commands to retrieve full stack trace for given stackid. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17 20:58:58 -07:00
/* BPF_FUNC_get_stackid flags. */
#define BPF_F_SKIP_FIELD_MASK 0xffULL
#define BPF_F_USER_STACK (1ULL << 8)
#define BPF_F_FAST_STACK_CMP (1ULL << 9)
#define BPF_F_REUSE_STACKID (1ULL << 10)
bpf: fix csum setting for bpf_set_tunnel_key The fix in 35e2d1152b22 ("tunnels: Allow IPv6 UDP checksums to be correctly controlled.") changed behavior for bpf_set_tunnel_key() when in use with IPv6 and thus uncovered a bug that TUNNEL_CSUM needed to be set but wasn't. As a result, the stack dropped ingress vxlan IPv6 packets, that have been sent via eBPF through collect meta data mode due to checksum now being zero. Since after LCO, we enable IPv4 checksum by default, so make that analogous and only provide a flag BPF_F_ZERO_CSUM_TX for the user to turn it off in IPv4 case. Fixes: 35e2d1152b22 ("tunnels: Allow IPv6 UDP checksums to be correctly controlled.") Fixes: c6c33454072f ("bpf: support ipv6 for bpf_skb_{set,get}_tunnel_key") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-22 18:05:26 -07:00
/* BPF_FUNC_skb_set_tunnel_key flags. */
#define BPF_F_ZERO_CSUM_TX (1ULL << 1)
bpf: allow to propagate df in bpf_skb_set_tunnel_key Added by 9a628224a61b ("ip_tunnel: Add dont fragment flag."), allow to feed df flag into tunneling facilities (currently supported on TX by vxlan, geneve and gre) as a hint from eBPF's bpf_skb_set_tunnel_key() helper. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-04 07:15:05 -07:00
#define BPF_F_DONT_FRAGMENT (1ULL << 2)
bpf: fix csum setting for bpf_set_tunnel_key The fix in 35e2d1152b22 ("tunnels: Allow IPv6 UDP checksums to be correctly controlled.") changed behavior for bpf_set_tunnel_key() when in use with IPv6 and thus uncovered a bug that TUNNEL_CSUM needed to be set but wasn't. As a result, the stack dropped ingress vxlan IPv6 packets, that have been sent via eBPF through collect meta data mode due to checksum now being zero. Since after LCO, we enable IPv4 checksum by default, so make that analogous and only provide a flag BPF_F_ZERO_CSUM_TX for the user to turn it off in IPv4 case. Fixes: 35e2d1152b22 ("tunnels: Allow IPv6 UDP checksums to be correctly controlled.") Fixes: c6c33454072f ("bpf: support ipv6 for bpf_skb_{set,get}_tunnel_key") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-22 18:05:26 -07:00
bpf, trace: add BPF_F_CURRENT_CPU flag for bpf_perf_event_read Follow-up commit to 1e33759c788c ("bpf, trace: add BPF_F_CURRENT_CPU flag for bpf_perf_event_output") to add the same functionality into bpf_perf_event_read() helper. The split of index into flags and index component is also safe here, since such large maps are rejected during map allocation time. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-28 04:18:25 -06:00
/* BPF_FUNC_perf_event_output and BPF_FUNC_perf_event_read flags. */
bpf, trace: add BPF_F_CURRENT_CPU flag for bpf_perf_event_output Add a BPF_F_CURRENT_CPU flag to optimize the use-case where user space has per-CPU ring buffers and the eBPF program pushes the data into the current CPU's ring buffer which saves us an extra helper function call in eBPF. Also, make sure to properly reserve the remaining flags which are not used. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-18 13:01:23 -06:00
#define BPF_F_INDEX_MASK 0xffffffffULL
#define BPF_F_CURRENT_CPU BPF_F_INDEX_MASK
bpf: avoid stack copy and use skb ctx for event output This work addresses a couple of issues bpf_skb_event_output() helper currently has: i) We need two copies instead of just a single one for the skb data when it should be part of a sample. The data can be non-linear and thus needs to be extracted via bpf_skb_load_bytes() helper first, and then copied once again into the ring buffer slot. ii) Since bpf_skb_load_bytes() currently needs to be used first, the helper needs to see a constant size on the passed stack buffer to make sure BPF verifier can do sanity checks on it during verification time. Thus, just passing skb->len (or any other non-constant value) wouldn't work, but changing bpf_skb_load_bytes() is also not the proper solution, since the two copies are generally still needed. iii) bpf_skb_load_bytes() is just for rather small buffers like headers, since they need to sit on the limited BPF stack anyway. Instead of working around in bpf_skb_load_bytes(), this work improves the bpf_skb_event_output() helper to address all 3 at once. We can make use of the passed in skb context that we have in the helper anyway, and use some of the reserved flag bits as a length argument. The helper will use the new __output_custom() facility from perf side with bpf_skb_copy() as callback helper to walk and extract the data. It will pass the data for setup to bpf_event_output(), which generates and pushes the raw record with an additional frag part. The linear data used in the first frag of the record serves as programmatically defined meta data passed along with the appended sample. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-14 10:08:05 -06:00
/* BPF_FUNC_perf_event_output for sk_buff input context. */
#define BPF_F_CTXLEN_MASK (0xfffffULL << 32)
bpf, trace: add BPF_F_CURRENT_CPU flag for bpf_perf_event_output Add a BPF_F_CURRENT_CPU flag to optimize the use-case where user space has per-CPU ring buffers and the eBPF program pushes the data into the current CPU's ring buffer which saves us an extra helper function call in eBPF. Also, make sure to properly reserve the remaining flags which are not used. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-18 13:01:23 -06:00
bpf: allow extended BPF programs access skb fields introduce user accessible mirror of in-kernel 'struct sk_buff': struct __sk_buff { __u32 len; __u32 pkt_type; __u32 mark; __u32 queue_mapping; }; bpf programs can do: int bpf_prog(struct __sk_buff *skb) { __u32 var = skb->pkt_type; which will be compiled to bpf assembler as: dst_reg = *(u32 *)(src_reg + 4) // 4 == offsetof(struct __sk_buff, pkt_type) bpf verifier will check validity of access and will convert it to: dst_reg = *(u8 *)(src_reg + offsetof(struct sk_buff, __pkt_type_offset)) dst_reg &= 7 since skb->pkt_type is a bitfield. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-13 12:57:42 -06:00
/* user accessible mirror of in-kernel sk_buff.
* new fields can only be added to the end of this structure
*/
struct __sk_buff {
__u32 len;
__u32 pkt_type;
__u32 mark;
__u32 queue_mapping;
bpf: allow BPF programs access 'protocol' and 'vlan_tci' fields as a follow on to patch 70006af95515 ("bpf: allow eBPF access skb fields") this patch allows 'protocol' and 'vlan_tci' fields to be accessible from extended BPF programs. The usage of 'protocol', 'vlan_present' and 'vlan_tci' fields is the same as corresponding SKF_AD_PROTOCOL, SKF_AD_VLAN_TAG_PRESENT and SKF_AD_VLAN_TAG accesses in classic BPF. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-16 19:06:02 -06:00
__u32 protocol;
__u32 vlan_present;
__u32 vlan_tci;
filter: introduce SKF_AD_VLAN_TPID BPF extension If vlan offloading takes place then vlan header is removed from frame and its contents, both vlan_tci and vlan_proto, is available to user space via TPACKET interface. However, only vlan_tci can be used in BPF filters. This commit introduces a new BPF extension. It makes possible to load the value of vlan_proto (vlan TPID) to register A. Support for classic BPF and eBPF is being added, analogous to skb->protocol. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Jiri Pirko <jpirko@redhat.com> Signed-off-by: Michal Sekletar <msekleta@redhat.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Reviewed-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-24 07:48:41 -06:00
__u32 vlan_proto;
ebpf: add skb->priority to offset map for usage in {cls, act}_bpf This adds the ability to read out the skb->priority from an eBPF program, so that it can be taken into account from a tc filter or action for the use-case where the priority is not being used to directly override the filter classification in a qdisc, but to tag traffic otherwise for the classifier; the priority can be assigned from various places incl. user space, in future we may also mangle it from an eBPF program. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-03 12:52:24 -06:00
__u32 priority;
bpf: allow BPF programs access skb->skb_iif and skb->dev->ifindex fields classic BPF already exposes skb->dev->ifindex via SKF_AD_IFINDEX extension. Allow eBPF program to access it as well. Note that classic aborts execution of the program if 'skb->dev == NULL' (which is inconvenient for program writers), whereas eBPF returns zero in such case. Also expose the 'skb_iif' field, since programs triggered by redirected packet need to known the original interface index. Summary: __skb->ifindex -> skb->dev->ifindex __skb->ingress_ifindex -> skb->skb_iif Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-27 16:30:39 -06:00
__u32 ingress_ifindex;
__u32 ifindex;
bpf: allow programs to write to certain skb fields allow programs read/write skb->mark, tc_index fields and ((struct qdisc_skb_cb *)cb)->data. mark and tc_index are generically useful in TC. cb[0]-cb[4] are primarily used to pass arguments from one program to another called via bpf_tail_call() which can be seen in sockex3_kern.c example. All fields of 'struct __sk_buff' are readable to socket and tc_cls_act progs. mark, tc_index are writeable from tc_cls_act only. cb[0]-cb[4] are writeable by both sockets and tc_cls_act. Add verifier tests and improve sample code. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-04 11:11:54 -06:00
__u32 tc_index;
__u32 cb[5];
ebpf: add skb->hash to offset map for usage in {cls, act}_bpf or filters Add skb->hash to the __sk_buff offset map, so it can be accessed from an eBPF program. We currently already do this for classic BPF filters, but not yet on eBPF, it might be useful as a demuxer in combination with helpers like bpf_clone_redirect(), toy example: __section("cls-lb") int ingress_main(struct __sk_buff *skb) { unsigned int which = 3 + (skb->hash & 7); /* bpf_skb_store_bytes(skb, ...); */ /* bpf_l{3,4}_csum_replace(skb, ...); */ bpf_clone_redirect(skb, which, 0); return -1; } I was thinking whether to add skb_get_hash(), but then concluded the raw skb->hash seems fine in this case: we can directly access the hash w/o extra eBPF helper function call, it's filled out by many NICs on ingress, and in case the entropy level would not be sufficient, people can still implement their own specific sw fallback hash mix anyway. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 16:46:29 -06:00
__u32 hash;
cls_bpf: introduce integrated actions Often cls_bpf classifier is used with single action drop attached. Optimize this use case and let cls_bpf return both classid and action. For backwards compatibility reasons enable this feature under TCA_BPF_FLAG_ACT_DIRECT flag. Then more interesting programs like the following are easier to write: int cls_bpf_prog(struct __sk_buff *skb) { /* classify arp, ip, ipv6 into different traffic classes * and drop all other packets */ switch (skb->protocol) { case htons(ETH_P_ARP): skb->tc_classid = 1; break; case htons(ETH_P_IP): skb->tc_classid = 2; break; case htons(ETH_P_IPV6): skb->tc_classid = 3; break; default: return TC_ACT_SHOT; } return TC_ACT_OK; } Joint work with Daniel Borkmann. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-16 00:05:42 -06:00
__u32 tc_classid;
bpf: direct packet access Extended BPF carried over two instructions from classic to access packet data: LD_ABS and LD_IND. They're highly optimized in JITs, but due to their design they have to do length check for every access. When BPF is processing 20M packets per second single LD_ABS after JIT is consuming 3% cpu. Hence the need to optimize it further by amortizing the cost of 'off < skb_headlen' over multiple packet accesses. One option is to introduce two new eBPF instructions LD_ABS_DW and LD_IND_DW with similar usage as skb_header_pointer(). The kernel part for interpreter and x64 JIT was implemented in [1], but such new insns behave like old ld_abs and abort the program with 'return 0' if access is beyond linear data. Such hidden control flow is hard to workaround plus changing JITs and rolling out new llvm is incovenient. Therefore allow cls_bpf/act_bpf program access skb->data directly: int bpf_prog(struct __sk_buff *skb) { struct iphdr *ip; if (skb->data + sizeof(struct iphdr) + ETH_HLEN > skb->data_end) /* packet too small */ return 0; ip = skb->data + ETH_HLEN; /* access IP header fields with direct loads */ if (ip->version != 4 || ip->saddr == 0x7f000001) return 1; [...] } This solution avoids introduction of new instructions. llvm stays the same and all JITs stay the same, but verifier has to work extra hard to prove safety of the above program. For XDP the direct store instructions can be allowed as well. The skb->data is NET_IP_ALIGNED, so for common cases the verifier can check the alignment. The complex packet parsers where packet pointer is adjusted incrementally cannot be tracked for alignment, so allow byte access in such cases and misaligned access on architectures that define efficient_unaligned_access [1] https://git.kernel.org/cgit/linux/kernel/git/ast/bpf.git/?h=ld_abs_dw Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-05 20:49:10 -06:00
__u32 data;
__u32 data_end;
bpf: add napi_id read access to __sk_buff Add napi_id access to __sk_buff for socket filter program types, tc program types and other bpf_convert_ctx_access() users. Having access to skb->napi_id is useful for per RX queue listener siloing, f.e. in combination with SO_ATTACH_REUSEPORT_EBPF and when busy polling is used, meaning SO_REUSEPORT enabled listeners can then select the corresponding socket at SYN time already [1]. The skb is marked via skb_mark_napi_id() early in the receive path (e.g., napi_gro_receive()). Currently, sockets can only use SO_INCOMING_NAPI_ID from 6d4339028b35 ("net: Introduce SO_INCOMING_NAPI_ID") as a socket option to look up the NAPI ID associated with the queue for steering, which requires a prior sk_mark_napi_id() after the socket was looked up. Semantics for the __sk_buff napi_id access are similar, meaning if skb->napi_id is < MIN_NAPI_ID (e.g. outgoing packets using sender_cpu), then an invalid napi_id of 0 is returned to the program, otherwise a valid non-zero napi_id. [1] http://netdevconf.org/2.1/slides/apr6/dumazet-BUSY-POLLING-Netdev-2.1.pdf Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-19 15:01:17 -06:00
__u32 napi_id;
bpf: allow extended BPF programs access skb fields introduce user accessible mirror of in-kernel 'struct sk_buff': struct __sk_buff { __u32 len; __u32 pkt_type; __u32 mark; __u32 queue_mapping; }; bpf programs can do: int bpf_prog(struct __sk_buff *skb) { __u32 var = skb->pkt_type; which will be compiled to bpf assembler as: dst_reg = *(u32 *)(src_reg + 4) // 4 == offsetof(struct __sk_buff, pkt_type) bpf verifier will check validity of access and will convert it to: dst_reg = *(u8 *)(src_reg + offsetof(struct sk_buff, __pkt_type_offset)) dst_reg &= 7 since skb->pkt_type is a bitfield. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-13 12:57:42 -06:00
};
bpf: add helpers to access tunnel metadata Introduce helpers to let eBPF programs attached to TC manipulate tunnel metadata: bpf_skb_[gs]et_tunnel_key(skb, key, size, flags) skb: pointer to skb key: pointer to 'struct bpf_tunnel_key' size: size of 'struct bpf_tunnel_key' flags: room for future extensions First eBPF program that uses these helpers will allocate per_cpu metadata_dst structures that will be used on TX. On RX metadata_dst is allocated by tunnel driver. Typical usage for TX: struct bpf_tunnel_key tkey; ... populate tkey ... bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), 0); bpf_clone_redirect(skb, vxlan_dev_ifindex, 0); RX: struct bpf_tunnel_key tkey = {}; bpf_skb_get_tunnel_key(skb, &tkey, sizeof(tkey), 0); ... lookup or redirect based on tkey ... 'struct bpf_tunnel_key' will be extended in the future by adding elements to the end and the 'size' argument will indicate which fields are populated, thereby keeping backwards compatibility. The 'flags' argument may be used as well when the 'size' is not enough or to indicate completely different layout of bpf_tunnel_key. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 16:36:57 -06:00
struct bpf_tunnel_key {
__u32 tunnel_id;
bpf: support ipv6 for bpf_skb_{set,get}_tunnel_key After IPv6 support has recently been added to metadata dst and related encaps, add support for populating/reading it from an eBPF program. Commit d3aa45ce6b ("bpf: add helpers to access tunnel metadata") started with initial IPv4-only support back then (due to IPv6 metadata support not being available yet). To stay compatible with older programs, we need to test for the passed structure size. Also TOS and TTL support from the ip_tunnel_info key has been added. Tested with vxlan devs in collect meta data mode with IPv4, IPv6 and in compat mode over different network namespaces. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:16:39 -07:00
union {
__u32 remote_ipv4;
__u32 remote_ipv6[4];
};
__u8 tunnel_tos;
__u8 tunnel_ttl;
bpf: make padding in bpf_tunnel_key explicit Make the 2 byte padding in struct bpf_tunnel_key between tunnel_ttl and tunnel_label members explicit. No issue has been observed, and gcc/llvm does padding for the old struct already, where tunnel_label was not yet present, so the current code works, but since it's part of uapi, make sure we don't introduce holes in structs. Therefore, add tunnel_ext that we can use generically in future (f.e. to flag OAM messages for backends, etc). Also add the offset to the compat tests to be sure should some compilers not padd the tail of the old version of bpf_tunnel_key. Fixes: 4018ab1875e0 ("bpf: support flow label for bpf_skb_{set, get}_tunnel_key") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-29 16:02:00 -06:00
__u16 tunnel_ext;
bpf: support flow label for bpf_skb_{set, get}_tunnel_key This patch extends bpf_tunnel_key with a tunnel_label member, that maps to ip_tunnel_key's label so underlying backends like vxlan and geneve can propagate the label to udp_tunnel6_xmit_skb(), where it's being set in the IPv6 header. It allows for having 20 more bits to encode/decode flow related meta information programmatically. Tested with vxlan and geneve. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 19:00:05 -07:00
__u32 tunnel_label;
bpf: add helpers to access tunnel metadata Introduce helpers to let eBPF programs attached to TC manipulate tunnel metadata: bpf_skb_[gs]et_tunnel_key(skb, key, size, flags) skb: pointer to skb key: pointer to 'struct bpf_tunnel_key' size: size of 'struct bpf_tunnel_key' flags: room for future extensions First eBPF program that uses these helpers will allocate per_cpu metadata_dst structures that will be used on TX. On RX metadata_dst is allocated by tunnel driver. Typical usage for TX: struct bpf_tunnel_key tkey; ... populate tkey ... bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), 0); bpf_clone_redirect(skb, vxlan_dev_ifindex, 0); RX: struct bpf_tunnel_key tkey = {}; bpf_skb_get_tunnel_key(skb, &tkey, sizeof(tkey), 0); ... lookup or redirect based on tkey ... 'struct bpf_tunnel_key' will be extended in the future by adding elements to the end and the 'size' argument will indicate which fields are populated, thereby keeping backwards compatibility. The 'flags' argument may be used as well when the 'size' is not enough or to indicate completely different layout of bpf_tunnel_key. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 16:36:57 -06:00
};
bpf: BPF for lightweight tunnel infrastructure Registers new BPF program types which correspond to the LWT hooks: - BPF_PROG_TYPE_LWT_IN => dst_input() - BPF_PROG_TYPE_LWT_OUT => dst_output() - BPF_PROG_TYPE_LWT_XMIT => lwtunnel_xmit() The separate program types are required to differentiate between the capabilities each LWT hook allows: * Programs attached to dst_input() or dst_output() are restricted and may only read the data of an skb. This prevent modification and possible invalidation of already validated packet headers on receive and the construction of illegal headers while the IP headers are still being assembled. * Programs attached to lwtunnel_xmit() are allowed to modify packet content as well as prepending an L2 header via a newly introduced helper bpf_skb_change_head(). This is safe as lwtunnel_xmit() is invoked after the IP header has been assembled completely. All BPF programs receive an skb with L3 headers attached and may return one of the following error codes: BPF_OK - Continue routing as per nexthop BPF_DROP - Drop skb and return EPERM BPF_REDIRECT - Redirect skb to device as per redirect() helper. (Only valid in lwtunnel_xmit() context) The return codes are binary compatible with their TC_ACT_ relatives to ease compatibility. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30 09:10:10 -07:00
/* Generic BPF return codes which all BPF program types may support.
* The values are binary compatible with their TC_ACT_* counter-part to
* provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
* programs.
*
* XDP is handled seprately, see XDP_*.
*/
enum bpf_ret_code {
BPF_OK = 0,
/* 1 reserved */
BPF_DROP = 2,
/* 3-6 reserved */
BPF_REDIRECT = 7,
/* >127 are reserved for prog type specific return codes */
};
bpf: Add new cgroup attach type to enable sock modifications Add new cgroup based program type, BPF_PROG_TYPE_CGROUP_SOCK. Similar to BPF_PROG_TYPE_CGROUP_SKB programs can be attached to a cgroup and run any time a process in the cgroup opens an AF_INET or AF_INET6 socket. Currently only sk_bound_dev_if is exported to userspace for modification by a bpf program. This allows a cgroup to be configured such that AF_INET{6} sockets opened by processes are automatically bound to a specific device. In turn, this enables the running of programs that do not support SO_BINDTODEVICE in a specific VRF context / L3 domain. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-01 09:48:04 -07:00
struct bpf_sock {
__u32 bound_dev_if;
bpf: Add support for reading socket family, type, protocol Add socket family, type and protocol to bpf_sock allowing bpf programs read-only access. Add __sk_flags_offset[0] to struct sock before the bitfield to programmtically determine the offset of the unsigned int containing protocol and type. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-01 09:48:06 -07:00
__u32 family;
__u32 type;
__u32 protocol;
bpf: Add new cgroup attach type to enable sock modifications Add new cgroup based program type, BPF_PROG_TYPE_CGROUP_SOCK. Similar to BPF_PROG_TYPE_CGROUP_SKB programs can be attached to a cgroup and run any time a process in the cgroup opens an AF_INET or AF_INET6 socket. Currently only sk_bound_dev_if is exported to userspace for modification by a bpf program. This allows a cgroup to be configured such that AF_INET{6} sockets opened by processes are automatically bound to a specific device. In turn, this enables the running of programs that do not support SO_BINDTODEVICE in a specific VRF context / L3 domain. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-01 09:48:04 -07:00
};
bpf: xdp: Allow head adjustment in XDP prog This patch allows XDP prog to extend/remove the packet data at the head (like adding or removing header). It is done by adding a new XDP helper bpf_xdp_adjust_head(). It also renames bpf_helper_changes_skb_data() to bpf_helper_changes_pkt_data() to better reflect that XDP prog does not work on skb. This patch adds one "xdp_adjust_head" bit to bpf_prog for the XDP-capable driver to check if the XDP prog requires bpf_xdp_adjust_head() support. The driver can then decide to error out during XDP_SETUP_PROG. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-07 16:53:11 -07:00
#define XDP_PACKET_HEADROOM 256
bpf: add XDP prog type for early driver filter Add a new bpf prog type that is intended to run in early stages of the packet rx path. Only minimal packet metadata will be available, hence a new context type, struct xdp_md, is exposed to userspace. So far only expose the packet start and end pointers, and only in read mode. An XDP program must return one of the well known enum values, all other return codes are reserved for future use. Unfortunately, this restriction is hard to enforce at verification time, so take the approach of warning at runtime when such programs are encountered. Out of bounds return codes should alias to XDP_ABORTED. Signed-off-by: Brenden Blanco <bblanco@plumgrid.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-19 13:16:47 -06:00
/* User return codes for XDP prog type.
* A valid XDP program must return one of these defined values. All other
* return codes are reserved for future use. Unknown return codes will result
* in packet drop.
*/
enum xdp_action {
XDP_ABORTED = 0,
XDP_DROP,
XDP_PASS,
bpf: add XDP_TX xdp_action for direct forwarding XDP enabled drivers must transmit received packets back out on the same port they were received on when a program returns this action. Signed-off-by: Brenden Blanco <bblanco@plumgrid.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-19 13:16:53 -06:00
XDP_TX,
bpf: add XDP prog type for early driver filter Add a new bpf prog type that is intended to run in early stages of the packet rx path. Only minimal packet metadata will be available, hence a new context type, struct xdp_md, is exposed to userspace. So far only expose the packet start and end pointers, and only in read mode. An XDP program must return one of the well known enum values, all other return codes are reserved for future use. Unfortunately, this restriction is hard to enforce at verification time, so take the approach of warning at runtime when such programs are encountered. Out of bounds return codes should alias to XDP_ABORTED. Signed-off-by: Brenden Blanco <bblanco@plumgrid.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-19 13:16:47 -06:00
};
/* user accessible metadata for XDP packet hook
* new fields must be added to the end of this structure
*/
struct xdp_md {
__u32 data;
__u32 data_end;
};
bpf: Add BPF_OBJ_GET_INFO_BY_FD A single BPF_OBJ_GET_INFO_BY_FD cmd is used to obtain the info for both bpf_prog and bpf_map. The kernel can figure out the fd is associated with a bpf_prog or bpf_map. The suggested struct bpf_prog_info and struct bpf_map_info are not meant to be a complete list and it is not the goal of this patch. New fields can be added in the future patch. The focus of this patch is to create the interface, BPF_OBJ_GET_INFO_BY_FD cmd for exposing the bpf_prog's and bpf_map's info. The obj's info, which will be extended (and get bigger) over time, is separated from the bpf_attr to avoid bloating the bpf_attr. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 13:15:52 -06:00
#define BPF_TAG_SIZE 8
struct bpf_prog_info {
__u32 type;
__u32 id;
__u8 tag[BPF_TAG_SIZE];
__u32 jited_prog_len;
__u32 xlated_prog_len;
__aligned_u64 jited_prog_insns;
__aligned_u64 xlated_prog_insns;
} __attribute__((aligned(8)));
struct bpf_map_info {
__u32 type;
__u32 id;
__u32 key_size;
__u32 value_size;
__u32 max_entries;
__u32 map_flags;
} __attribute__((aligned(8)));
bpf: BPF support for sock_ops Created a new BPF program type, BPF_PROG_TYPE_SOCK_OPS, and a corresponding struct that allows BPF programs of this type to access some of the socket's fields (such as IP addresses, ports, etc.). It uses the existing bpf cgroups infrastructure so the programs can be attached per cgroup with full inheritance support. The program will be called at appropriate times to set relevant connections parameters such as buffer sizes, SYN and SYN-ACK RTOs, etc., based on connection information such as IP addresses, port numbers, etc. Alghough there are already 3 mechanisms to set parameters (sysctls, route metrics and setsockopts), this new mechanism provides some distinct advantages. Unlike sysctls, it can set parameters per connection. In contrast to route metrics, it can also use port numbers and information provided by a user level program. In addition, it could set parameters probabilistically for evaluation purposes (i.e. do something different on 10% of the flows and compare results with the other 90% of the flows). Also, in cases where IPv6 addresses contain geographic information, the rules to make changes based on the distance (or RTT) between the hosts are much easier than route metric rules and can be global. Finally, unlike setsockopt, it oes not require application changes and it can be updated easily at any time. Although the bpf cgroup framework already contains a sock related program type (BPF_PROG_TYPE_CGROUP_SOCK), I created the new type (BPF_PROG_TYPE_SOCK_OPS) beccause the existing type expects to be called only once during the connections's lifetime. In contrast, the new program type will be called multiple times from different places in the network stack code. For example, before sending SYN and SYN-ACKs to set an appropriate timeout, when the connection is established to set congestion control, etc. As a result it has "op" field to specify the type of operation requested. The purpose of this new program type is to simplify setting connection parameters, such as buffer sizes, TCP's SYN RTO, etc. For example, it is easy to use facebook's internal IPv6 addresses to determine if both hosts of a connection are in the same datacenter. Therefore, it is easy to write a BPF program to choose a small SYN RTO value when both hosts are in the same datacenter. This patch only contains the framework to support the new BPF program type, following patches add the functionality to set various connection parameters. This patch defines a new BPF program type: BPF_PROG_TYPE_SOCKET_OPS and a new bpf syscall command to load a new program of this type: BPF_PROG_LOAD_SOCKET_OPS. Two new corresponding structs (one for the kernel one for the user/BPF program): /* kernel version */ struct bpf_sock_ops_kern { struct sock *sk; __u32 op; union { __u32 reply; __u32 replylong[4]; }; }; /* user version * Some fields are in network byte order reflecting the sock struct * Use the bpf_ntohl helper macro in samples/bpf/bpf_endian.h to * convert them to host byte order. */ struct bpf_sock_ops { __u32 op; union { __u32 reply; __u32 replylong[4]; }; __u32 family; __u32 remote_ip4; /* In network byte order */ __u32 local_ip4; /* In network byte order */ __u32 remote_ip6[4]; /* In network byte order */ __u32 local_ip6[4]; /* In network byte order */ __u32 remote_port; /* In network byte order */ __u32 local_port; /* In host byte horder */ }; Currently there are two types of ops. The first type expects the BPF program to return a value which is then used by the caller (or a negative value to indicate the operation is not supported). The second type expects state changes to be done by the BPF program, for example through a setsockopt BPF helper function, and they ignore the return value. The reply fields of the bpf_sockt_ops struct are there in case a bpf program needs to return a value larger than an integer. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30 21:02:40 -06:00
/* User bpf_sock_ops struct to access socket values and specify request ops
* and their replies.
* Some of this fields are in network (bigendian) byte order and may need
* to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h).
* New fields can only be added at the end of this structure
*/
struct bpf_sock_ops {
__u32 op;
union {
__u32 reply;
__u32 replylong[4];
};
__u32 family;
__u32 remote_ip4; /* Stored in network byte order */
__u32 local_ip4; /* Stored in network byte order */
__u32 remote_ip6[4]; /* Stored in network byte order */
__u32 local_ip6[4]; /* Stored in network byte order */
__u32 remote_port; /* Stored in network byte order */
__u32 local_port; /* stored in host byte order */
};
/* List of known BPF sock_ops operators.
* New entries can only be added at the end
*/
enum {
BPF_SOCK_OPS_VOID,
bpf: Support for per connection SYN/SYN-ACK RTOs This patch adds support for setting a per connection SYN and SYN_ACK RTOs from within a BPF_SOCK_OPS program. For example, to set small RTOs when it is known both hosts are within a datacenter. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30 21:02:42 -06:00
BPF_SOCK_OPS_TIMEOUT_INIT, /* Should return SYN-RTO value to use or
* -1 if default value should be used
*/
bpf: BPF support for sock_ops Created a new BPF program type, BPF_PROG_TYPE_SOCK_OPS, and a corresponding struct that allows BPF programs of this type to access some of the socket's fields (such as IP addresses, ports, etc.). It uses the existing bpf cgroups infrastructure so the programs can be attached per cgroup with full inheritance support. The program will be called at appropriate times to set relevant connections parameters such as buffer sizes, SYN and SYN-ACK RTOs, etc., based on connection information such as IP addresses, port numbers, etc. Alghough there are already 3 mechanisms to set parameters (sysctls, route metrics and setsockopts), this new mechanism provides some distinct advantages. Unlike sysctls, it can set parameters per connection. In contrast to route metrics, it can also use port numbers and information provided by a user level program. In addition, it could set parameters probabilistically for evaluation purposes (i.e. do something different on 10% of the flows and compare results with the other 90% of the flows). Also, in cases where IPv6 addresses contain geographic information, the rules to make changes based on the distance (or RTT) between the hosts are much easier than route metric rules and can be global. Finally, unlike setsockopt, it oes not require application changes and it can be updated easily at any time. Although the bpf cgroup framework already contains a sock related program type (BPF_PROG_TYPE_CGROUP_SOCK), I created the new type (BPF_PROG_TYPE_SOCK_OPS) beccause the existing type expects to be called only once during the connections's lifetime. In contrast, the new program type will be called multiple times from different places in the network stack code. For example, before sending SYN and SYN-ACKs to set an appropriate timeout, when the connection is established to set congestion control, etc. As a result it has "op" field to specify the type of operation requested. The purpose of this new program type is to simplify setting connection parameters, such as buffer sizes, TCP's SYN RTO, etc. For example, it is easy to use facebook's internal IPv6 addresses to determine if both hosts of a connection are in the same datacenter. Therefore, it is easy to write a BPF program to choose a small SYN RTO value when both hosts are in the same datacenter. This patch only contains the framework to support the new BPF program type, following patches add the functionality to set various connection parameters. This patch defines a new BPF program type: BPF_PROG_TYPE_SOCKET_OPS and a new bpf syscall command to load a new program of this type: BPF_PROG_LOAD_SOCKET_OPS. Two new corresponding structs (one for the kernel one for the user/BPF program): /* kernel version */ struct bpf_sock_ops_kern { struct sock *sk; __u32 op; union { __u32 reply; __u32 replylong[4]; }; }; /* user version * Some fields are in network byte order reflecting the sock struct * Use the bpf_ntohl helper macro in samples/bpf/bpf_endian.h to * convert them to host byte order. */ struct bpf_sock_ops { __u32 op; union { __u32 reply; __u32 replylong[4]; }; __u32 family; __u32 remote_ip4; /* In network byte order */ __u32 local_ip4; /* In network byte order */ __u32 remote_ip6[4]; /* In network byte order */ __u32 local_ip6[4]; /* In network byte order */ __u32 remote_port; /* In network byte order */ __u32 local_port; /* In host byte horder */ }; Currently there are two types of ops. The first type expects the BPF program to return a value which is then used by the caller (or a negative value to indicate the operation is not supported). The second type expects state changes to be done by the BPF program, for example through a setsockopt BPF helper function, and they ignore the return value. The reply fields of the bpf_sockt_ops struct are there in case a bpf program needs to return a value larger than an integer. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30 21:02:40 -06:00
};
net: filter: split filter.h and expose eBPF to user space allow user space to generate eBPF programs uapi/linux/bpf.h: eBPF instruction set definition linux/filter.h: the rest This patch only moves macro definitions, but practically it freezes existing eBPF instruction set, though new instructions can still be added in the future. These eBPF definitions cannot go into uapi/linux/filter.h, since the names may conflict with existing applications. Full eBPF ISA description is in Documentation/networking/filter.txt Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-04 23:17:18 -06:00
#endif /* _UAPI__LINUX_BPF_H__ */