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alistair23-linux/net/ipv6/seg6_local.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 00:55:01 -06:00
// SPDX-License-Identifier: GPL-2.0-or-later
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
/*
* SR-IPv6 implementation
*
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
* Authors:
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
* David Lebrun <david.lebrun@uclouvain.be>
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
* eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com>
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
*/
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/net.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/lwtunnel.h>
#include <net/netevent.h>
#include <net/netns/generic.h>
#include <net/ip6_fib.h>
#include <net/route.h>
#include <net/seg6.h>
#include <linux/seg6.h>
#include <linux/seg6_local.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/dst_cache.h>
#ifdef CONFIG_IPV6_SEG6_HMAC
#include <net/seg6_hmac.h>
#endif
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
#include <net/seg6_local.h>
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:58:17 -06:00
#include <linux/etherdevice.h>
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
#include <linux/bpf.h>
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
struct seg6_local_lwt;
struct seg6_action_desc {
int action;
unsigned long attrs;
int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int static_headroom;
};
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
struct bpf_lwt_prog {
struct bpf_prog *prog;
char *name;
};
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
struct seg6_local_lwt {
int action;
struct ipv6_sr_hdr *srh;
int table;
struct in_addr nh4;
struct in6_addr nh6;
int iif;
int oif;
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
struct bpf_lwt_prog bpf;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
int headroom;
struct seg6_action_desc *desc;
};
static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
{
return (struct seg6_local_lwt *)lwt->data;
}
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb)
{
struct ipv6_sr_hdr *srh;
ipv6: sr: fix get_srh() to comply with IPv6 standard "RFC 8200" IPv6 packet may carry more than one extension header, and IPv6 nodes must accept and attempt to process extension headers in any order and occurring any number of times in the same packet. Hence, there should be no assumption that Segment Routing extension header is to appear immediately after the IPv6 header. Moreover, section 4.1 of RFC 8200 gives a recommendation on the order of appearance of those extension headers within an IPv6 packet. According to this recommendation, Segment Routing extension header should appear after Hop-by-Hop and Destination Options headers (if they present). This patch fixes the get_srh(), so it gets the segment routing header regardless of its position in the chain of the extension headers in IPv6 packet, and makes sure that the IPv6 routing extension header is of Type 4. Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com> Acked-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30 02:50:37 -06:00
int len, srhoff = 0;
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
ipv6: sr: fix get_srh() to comply with IPv6 standard "RFC 8200" IPv6 packet may carry more than one extension header, and IPv6 nodes must accept and attempt to process extension headers in any order and occurring any number of times in the same packet. Hence, there should be no assumption that Segment Routing extension header is to appear immediately after the IPv6 header. Moreover, section 4.1 of RFC 8200 gives a recommendation on the order of appearance of those extension headers within an IPv6 packet. According to this recommendation, Segment Routing extension header should appear after Hop-by-Hop and Destination Options headers (if they present). This patch fixes the get_srh(), so it gets the segment routing header regardless of its position in the chain of the extension headers in IPv6 packet, and makes sure that the IPv6 routing extension header is of Type 4. Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com> Acked-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30 02:50:37 -06:00
if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
return NULL;
if (!pskb_may_pull(skb, srhoff + sizeof(*srh)))
return NULL;
srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
len = (srh->hdrlen + 1) << 3;
ipv6: sr: fix get_srh() to comply with IPv6 standard "RFC 8200" IPv6 packet may carry more than one extension header, and IPv6 nodes must accept and attempt to process extension headers in any order and occurring any number of times in the same packet. Hence, there should be no assumption that Segment Routing extension header is to appear immediately after the IPv6 header. Moreover, section 4.1 of RFC 8200 gives a recommendation on the order of appearance of those extension headers within an IPv6 packet. According to this recommendation, Segment Routing extension header should appear after Hop-by-Hop and Destination Options headers (if they present). This patch fixes the get_srh(), so it gets the segment routing header regardless of its position in the chain of the extension headers in IPv6 packet, and makes sure that the IPv6 routing extension header is of Type 4. Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com> Acked-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30 02:50:37 -06:00
if (!pskb_may_pull(skb, srhoff + len))
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
return NULL;
if (!seg6_validate_srh(srh, len))
return NULL;
return srh;
}
static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
{
struct ipv6_sr_hdr *srh;
srh = get_srh(skb);
if (!srh)
return NULL;
if (srh->segments_left == 0)
return NULL;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (!seg6_hmac_validate_skb(skb))
return NULL;
#endif
return srh;
}
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
static bool decap_and_validate(struct sk_buff *skb, int proto)
{
struct ipv6_sr_hdr *srh;
unsigned int off = 0;
srh = get_srh(skb);
if (srh && srh->segments_left > 0)
return false;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (srh && !seg6_hmac_validate_skb(skb))
return false;
#endif
if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0)
return false;
if (!pskb_pull(skb, off))
return false;
skb_postpull_rcsum(skb, skb_network_header(skb), off);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
skb->encapsulation = 0;
return true;
}
static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
{
struct in6_addr *addr;
srh->segments_left--;
addr = srh->segments + srh->segments_left;
*daddr = *addr;
}
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
u32 tbl_id)
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
{
struct net *net = dev_net(skb->dev);
struct ipv6hdr *hdr = ipv6_hdr(skb);
int flags = RT6_LOOKUP_F_HAS_SADDR;
struct dst_entry *dst = NULL;
struct rt6_info *rt;
struct flowi6 fl6;
fl6.flowi6_iif = skb->dev->ifindex;
fl6.daddr = nhaddr ? *nhaddr : hdr->daddr;
fl6.saddr = hdr->saddr;
fl6.flowlabel = ip6_flowinfo(hdr);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = hdr->nexthdr;
if (nhaddr)
fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
if (!tbl_id) {
net/ipv6: Pass skb to route lookup IPv6 does path selection for multipath routes deep in the lookup functions. The next patch adds L4 hash option and needs the skb for the forward path. To get the skb to the relevant FIB lookup functions it needs to go through the fib rules layer, so add a lookup_data argument to the fib_lookup_arg struct. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-02 09:32:17 -07:00
dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags);
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
} else {
struct fib6_table *table;
table = fib6_get_table(net, tbl_id);
if (!table)
goto out;
net/ipv6: Pass skb to route lookup IPv6 does path selection for multipath routes deep in the lookup functions. The next patch adds L4 hash option and needs the skb for the forward path. To get the skb to the relevant FIB lookup functions it needs to go through the fib rules layer, so add a lookup_data argument to the fib_lookup_arg struct. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-02 09:32:17 -07:00
rt = ip6_pol_route(net, table, 0, &fl6, skb, flags);
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
dst = &rt->dst;
}
if (dst && dst->dev->flags & IFF_LOOPBACK && !dst->error) {
dst_release(dst);
dst = NULL;
}
out:
if (!dst) {
rt = net->ipv6.ip6_blk_hole_entry;
dst = &rt->dst;
dst_hold(dst);
}
skb_dst_drop(skb);
skb_dst_set(skb, dst);
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
return dst->error;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
}
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
/* regular endpoint function */
static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
seg6_lookup_nexthop(skb, NULL, 0);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* regular endpoint, and forward to specified nexthop */
static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
seg6_lookup_nexthop(skb, &slwt->nh6, 0);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:58:17 -06:00
static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
seg6_lookup_nexthop(skb, NULL, slwt->table);
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:58:17 -06:00
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* decapsulate and forward inner L2 frame on specified interface */
static int input_action_end_dx2(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct net *net = dev_net(skb->dev);
struct net_device *odev;
struct ethhdr *eth;
if (!decap_and_validate(skb, NEXTHDR_NONE))
goto drop;
if (!pskb_may_pull(skb, ETH_HLEN))
goto drop;
skb_reset_mac_header(skb);
eth = (struct ethhdr *)skb->data;
/* To determine the frame's protocol, we assume it is 802.3. This avoids
* a call to eth_type_trans(), which is not really relevant for our
* use case.
*/
if (!eth_proto_is_802_3(eth->h_proto))
goto drop;
odev = dev_get_by_index_rcu(net, slwt->oif);
if (!odev)
goto drop;
/* As we accept Ethernet frames, make sure the egress device is of
* the correct type.
*/
if (odev->type != ARPHRD_ETHER)
goto drop;
if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev))
goto drop;
skb_orphan(skb);
if (skb_warn_if_lro(skb))
goto drop;
skb_forward_csum(skb);
if (skb->len - ETH_HLEN > odev->mtu)
goto drop;
skb->dev = odev;
skb->protocol = eth->h_proto;
return dev_queue_xmit(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
/* decapsulate and forward to specified nexthop */
static int input_action_end_dx6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
struct in6_addr *nhaddr = NULL;
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
/* this function accepts IPv6 encapsulated packets, with either
* an SRH with SL=0, or no SRH.
*/
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
if (!decap_and_validate(skb, IPPROTO_IPV6))
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
goto drop;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
goto drop;
/* The inner packet is not associated to any local interface,
* so we do not call netif_rx().
*
* If slwt->nh6 is set to ::, then lookup the nexthop for the
* inner packet's DA. Otherwise, use the specified nexthop.
*/
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
if (!ipv6_addr_any(&slwt->nh6))
nhaddr = &slwt->nh6;
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
seg6_lookup_nexthop(skb, nhaddr, 0);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:58:17 -06:00
static int input_action_end_dx4(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct iphdr *iph;
__be32 nhaddr;
int err;
if (!decap_and_validate(skb, IPPROTO_IPIP))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
skb->protocol = htons(ETH_P_IP);
iph = ip_hdr(skb);
nhaddr = slwt->nh4.s_addr ?: iph->daddr;
skb_dst_drop(skb);
err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
if (err)
goto drop;
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int input_action_end_dt6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
if (!decap_and_validate(skb, IPPROTO_IPV6))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto drop;
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
seg6_lookup_nexthop(skb, NULL, slwt->table);
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:58:17 -06:00
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
/* push an SRH on top of the current one */
static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
err = seg6_do_srh_inline(skb, slwt->srh);
if (err)
goto drop;
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
seg6_lookup_nexthop(skb, NULL, 0);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
/* encapsulate within an outer IPv6 header and a specified SRH */
static int input_action_end_b6_encap(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
ipv6: sr: add helper functions for seg6local This patch adds three helper functions to be used with the seg6local packet processing actions. The decap_and_validate() function will be used by the End.D* actions, that decapsulate an SR-enabled packet. The advance_nextseg() function applies the fundamental operations to update an SRH for the next segment. The lookup_nexthop() function helps select the next-hop for the processed SR packets. It supports an optional next-hop address to route the packet specifically through it, and an optional routing table to use. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:47 -06:00
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
skb_reset_inner_headers(skb);
skb->encapsulation = 1;
ipv6: sr: add support for ip4ip6 encapsulation This patch enables the SRv6 encapsulation mode to carry an IPv4 payload. All the infrastructure was already present, I just had to add a parameter to seg6_do_srh_encap() to specify the inner packet protocol, and perform some additional checks. Usage example: ip route add 1.2.3.4 encap seg6 mode encap segs fc00::1,fc00::2 dev eth0 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:44 -06:00
err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
if (err)
goto drop;
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:13 -06:00
seg6_lookup_nexthop(skb, NULL, 0);
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
bpf: Add IPv6 Segment Routing helpers The BPF seg6local hook should be powerful enough to enable users to implement most of the use-cases one could think of. After some thinking, we figured out that the following actions should be possible on a SRv6 packet, requiring 3 specific helpers : - bpf_lwt_seg6_store_bytes: Modify non-sensitive fields of the SRH - bpf_lwt_seg6_adjust_srh: Allow to grow or shrink a SRH (to add/delete TLVs) - bpf_lwt_seg6_action: Apply some SRv6 network programming actions (specifically End.X, End.T, End.B6 and End.B6.Encap) The specifications of these helpers are provided in the patch (see include/uapi/linux/bpf.h). The non-sensitive fields of the SRH are the following : flags, tag and TLVs. The other fields can not be modified, to maintain the SRH integrity. Flags, tag and TLVs can easily be modified as their validity can be checked afterwards via seg6_validate_srh. It is not allowed to modify the segments directly. If one wants to add segments on the path, he should stack a new SRH using the End.B6 action via bpf_lwt_seg6_action. Growing, shrinking or editing TLVs via the helpers will flag the SRH as invalid, and it will have to be re-validated before re-entering the IPv6 layer. This flag is stored in a per-CPU buffer, along with the current header length in bytes. Storing the SRH len in bytes in the control block is mandatory when using bpf_lwt_seg6_adjust_srh. The Header Ext. Length field contains the SRH len rounded to 8 bytes (a padding TLV can be inserted to ensure the 8-bytes boundary). When adding/deleting TLVs within the BPF program, the SRH may temporary be in an invalid state where its length cannot be rounded to 8 bytes without remainder, hence the need to store the length in bytes separately. The caller of the BPF program can then ensure that the SRH's final length is valid using this value. Again, a final SRH modified by a BPF program which doesn’t respect the 8-bytes boundary will be discarded as it will be considered as invalid. Finally, a fourth helper is provided, bpf_lwt_push_encap, which is available from the LWT BPF IN hook, but not from the seg6local BPF one. This helper allows to encapsulate a Segment Routing Header (either with a new outer IPv6 header, or by inlining it directly in the existing IPv6 header) into a non-SRv6 packet. This helper is required if we want to offer the possibility to dynamically encapsulate a SRH for non-SRv6 packet, as the BPF seg6local hook only works on traffic already containing a SRH. This is the BPF equivalent of the seg6 LWT infrastructure, which achieves the same purpose but with a static SRH per route. These helpers require CONFIG_IPV6=y (and not =m). Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:14 -06:00
DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states);
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 20:10:40 -06:00
bool seg6_bpf_has_valid_srh(struct sk_buff *skb)
{
struct seg6_bpf_srh_state *srh_state =
this_cpu_ptr(&seg6_bpf_srh_states);
struct ipv6_sr_hdr *srh = srh_state->srh;
if (unlikely(srh == NULL))
return false;
if (unlikely(!srh_state->valid)) {
if ((srh_state->hdrlen & 7) != 0)
return false;
srh->hdrlen = (u8)(srh_state->hdrlen >> 3);
if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3))
return false;
srh_state->valid = true;
}
return true;
}
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
static int input_action_end_bpf(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct seg6_bpf_srh_state *srh_state =
this_cpu_ptr(&seg6_bpf_srh_states);
struct ipv6_sr_hdr *srh;
int ret;
srh = get_and_validate_srh(skb);
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 20:10:40 -06:00
if (!srh) {
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
/* preempt_disable is needed to protect the per-CPU buffer srh_state,
* which is also accessed by the bpf_lwt_seg6_* helpers
*/
preempt_disable();
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 20:10:40 -06:00
srh_state->srh = srh;
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
srh_state->hdrlen = srh->hdrlen << 3;
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 20:10:40 -06:00
srh_state->valid = true;
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
rcu_read_lock();
bpf_compute_data_pointers(skb);
ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb);
rcu_read_unlock();
switch (ret) {
case BPF_OK:
case BPF_REDIRECT:
break;
case BPF_DROP:
goto drop;
default:
pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret);
goto drop;
}
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 20:10:40 -06:00
if (srh_state->srh && !seg6_bpf_has_valid_srh(skb))
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
goto drop;
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 20:10:40 -06:00
preempt_enable();
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
if (ret != BPF_REDIRECT)
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
bpf: add End.DT6 action to bpf_lwt_seg6_action helper The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 20:10:40 -06:00
preempt_enable();
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
static struct seg6_action_desc seg6_action_table[] = {
{
.action = SEG6_LOCAL_ACTION_END,
.attrs = 0,
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
.input = input_action_end,
},
{
.action = SEG6_LOCAL_ACTION_END_X,
.attrs = (1 << SEG6_LOCAL_NH6),
.input = input_action_end_x,
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
},
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:58:17 -06:00
{
.action = SEG6_LOCAL_ACTION_END_T,
.attrs = (1 << SEG6_LOCAL_TABLE),
.input = input_action_end_t,
},
{
.action = SEG6_LOCAL_ACTION_END_DX2,
.attrs = (1 << SEG6_LOCAL_OIF),
.input = input_action_end_dx2,
},
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
{
.action = SEG6_LOCAL_ACTION_END_DX6,
.attrs = (1 << SEG6_LOCAL_NH6),
.input = input_action_end_dx6,
},
ipv6: sr: implement additional seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the next-hop looked up in the specified routing table. - SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to the specified network interface. - SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it, possibly to the specified next-hop. - SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it to the next-hop looked up in the specified routing table. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:58:17 -06:00
{
.action = SEG6_LOCAL_ACTION_END_DX4,
.attrs = (1 << SEG6_LOCAL_NH4),
.input = input_action_end_dx4,
},
{
.action = SEG6_LOCAL_ACTION_END_DT6,
.attrs = (1 << SEG6_LOCAL_TABLE),
.input = input_action_end_dt6,
},
ipv6: sr: implement several seg6local actions This patch implements the following seg6local actions. - SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet is updated to the next segment and forwarded accordingly. - SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is forwarded to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to inner IPv6 packet to the specified IPv6 next-hop. - SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after the IPv6 header of the packet. - SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within an outer IPv6 header, containing the specified SRH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:39:48 -06:00
{
.action = SEG6_LOCAL_ACTION_END_B6,
.attrs = (1 << SEG6_LOCAL_SRH),
.input = input_action_end_b6,
},
{
.action = SEG6_LOCAL_ACTION_END_B6_ENCAP,
.attrs = (1 << SEG6_LOCAL_SRH),
.input = input_action_end_b6_encap,
.static_headroom = sizeof(struct ipv6hdr),
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
},
{
.action = SEG6_LOCAL_ACTION_END_BPF,
.attrs = (1 << SEG6_LOCAL_BPF),
.input = input_action_end_bpf,
},
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
};
static struct seg6_action_desc *__get_action_desc(int action)
{
struct seg6_action_desc *desc;
int i, count;
ipv6: use ARRAY_SIZE for array sizing calculation on array seg6_action_table Use the ARRAY_SIZE macro on array seg6_action_table to determine size of the array. Improvement suggested by coccinelle. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-07 16:50:26 -07:00
count = ARRAY_SIZE(seg6_action_table);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
for (i = 0; i < count; i++) {
desc = &seg6_action_table[i];
if (desc->action == action)
return desc;
}
return NULL;
}
static int seg6_local_input(struct sk_buff *skb)
{
struct dst_entry *orig_dst = skb_dst(skb);
struct seg6_action_desc *desc;
struct seg6_local_lwt *slwt;
ipv6: sr: enforce IPv6 packets for seg6local lwt This patch ensures that the seg6local lightweight tunnel is used solely with IPv6 routes and processes only IPv6 packets. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:46 -06:00
if (skb->protocol != htons(ETH_P_IPV6)) {
kfree_skb(skb);
return -EINVAL;
}
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
desc = slwt->desc;
return desc->input(skb, slwt);
}
static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
[SEG6_LOCAL_ACTION] = { .type = NLA_U32 },
[SEG6_LOCAL_SRH] = { .type = NLA_BINARY },
[SEG6_LOCAL_TABLE] = { .type = NLA_U32 },
[SEG6_LOCAL_NH4] = { .type = NLA_BINARY,
.len = sizeof(struct in_addr) },
[SEG6_LOCAL_NH6] = { .type = NLA_BINARY,
.len = sizeof(struct in6_addr) },
[SEG6_LOCAL_IIF] = { .type = NLA_U32 },
[SEG6_LOCAL_OIF] = { .type = NLA_U32 },
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
[SEG6_LOCAL_BPF] = { .type = NLA_NESTED },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
};
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:27 -06:00
static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int len;
srh = nla_data(attrs[SEG6_LOCAL_SRH]);
len = nla_len(attrs[SEG6_LOCAL_SRH]);
/* SRH must contain at least one segment */
if (len < sizeof(*srh) + sizeof(struct in6_addr))
return -EINVAL;
if (!seg6_validate_srh(srh, len))
return -EINVAL;
ipv6: sr: Use kmemdup instead of duplicating it in parse_nla_srh Replace calls to kmalloc followed by a memcpy with a direct call to kmemdup. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23 02:33:19 -06:00
slwt->srh = kmemdup(srh, len, GFP_KERNEL);
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:27 -06:00
if (!slwt->srh)
return -ENOMEM;
slwt->headroom += len;
return 0;
}
static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
struct nlattr *nla;
int len;
srh = slwt->srh;
len = (srh->hdrlen + 1) << 3;
nla = nla_reserve(skb, SEG6_LOCAL_SRH, len);
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), srh, len);
return 0;
}
static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
int len = (a->srh->hdrlen + 1) << 3;
if (len != ((b->srh->hdrlen + 1) << 3))
return 1;
return memcmp(a->srh, b->srh, len);
}
static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]);
return 0;
}
static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->table != b->table)
return 1;
return 0;
}
static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]),
sizeof(struct in_addr));
return 0;
}
static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nla;
nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr));
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr));
return 0;
}
static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr));
}
static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]),
sizeof(struct in6_addr));
return 0;
}
static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nla;
nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr));
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr));
return 0;
}
static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr));
}
static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]);
return 0;
}
static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->iif != b->iif)
return 1;
return 0;
}
static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]);
return 0;
}
static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->oif != b->oif)
return 1;
return 0;
}
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
#define MAX_PROG_NAME 256
static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = {
[SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, },
[SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING,
.len = MAX_PROG_NAME },
};
static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1];
struct bpf_prog *p;
int ret;
u32 fd;
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 06:07:28 -06:00
ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_BPF_PROG_MAX,
attrs[SEG6_LOCAL_BPF],
bpf_prog_policy, NULL);
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
if (ret < 0)
return ret;
if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME])
return -EINVAL;
slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL);
if (!slwt->bpf.name)
return -ENOMEM;
fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]);
p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL);
if (IS_ERR(p)) {
kfree(slwt->bpf.name);
return PTR_ERR(p);
}
slwt->bpf.prog = p;
return 0;
}
static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nest;
if (!slwt->bpf.prog)
return 0;
netlink: make nla_nest_start() add NLA_F_NESTED flag Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 03:13:06 -06:00
nest = nla_nest_start_noflag(skb, SEG6_LOCAL_BPF);
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
if (!nest)
return -EMSGSIZE;
if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id))
return -EMSGSIZE;
if (slwt->bpf.name &&
nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name))
return -EMSGSIZE;
return nla_nest_end(skb, nest);
}
static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (!a->bpf.name && !b->bpf.name)
return 0;
if (!a->bpf.name || !b->bpf.name)
return 1;
return strcmp(a->bpf.name, b->bpf.name);
}
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
struct seg6_action_param {
int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
};
static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:27 -06:00
[SEG6_LOCAL_SRH] = { .parse = parse_nla_srh,
.put = put_nla_srh,
.cmp = cmp_nla_srh },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:27 -06:00
[SEG6_LOCAL_TABLE] = { .parse = parse_nla_table,
.put = put_nla_table,
.cmp = cmp_nla_table },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:27 -06:00
[SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4,
.put = put_nla_nh4,
.cmp = cmp_nla_nh4 },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:27 -06:00
[SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6,
.put = put_nla_nh6,
.cmp = cmp_nla_nh6 },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:27 -06:00
[SEG6_LOCAL_IIF] = { .parse = parse_nla_iif,
.put = put_nla_iif,
.cmp = cmp_nla_iif },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
ipv6: sr: add rtnetlink functions for seg6local action parameters This patch adds the necessary functions to parse, fill, and compare seg6local rtnetlink attributes, for all defined action parameters. - The SRH parameter defines an SRH to be inserted or encapsulated. - The TABLE parameter defines the table to use for the route lookup of the next segment or the inner decapsulated packet. - The NH4 parameter defines the IPv4 next-hop for an inner decapsulated IPv4 packet. - The NH6 parameter defines the IPv6 next-hop for the next segment or for an inner decapsulated IPv6 packet - The IIF parameter defines an ingress interface index. - The OIF parameter defines an egress interface index. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:27 -06:00
[SEG6_LOCAL_OIF] = { .parse = parse_nla_oif,
.put = put_nla_oif,
.cmp = cmp_nla_oif },
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
[SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf,
.put = put_nla_bpf,
.cmp = cmp_nla_bpf },
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
};
static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
struct seg6_action_param *param;
struct seg6_action_desc *desc;
int i, err;
desc = __get_action_desc(slwt->action);
if (!desc)
return -EINVAL;
if (!desc->input)
return -EOPNOTSUPP;
slwt->desc = desc;
slwt->headroom += desc->static_headroom;
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
if (desc->attrs & (1 << i)) {
if (!attrs[i])
return -EINVAL;
param = &seg6_action_params[i];
err = param->parse(attrs, slwt);
if (err < 0)
return err;
}
}
return 0;
}
static int seg6_local_build_state(struct nlattr *nla, unsigned int family,
const void *cfg, struct lwtunnel_state **ts,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[SEG6_LOCAL_MAX + 1];
struct lwtunnel_state *newts;
struct seg6_local_lwt *slwt;
int err;
ipv6: sr: enforce IPv6 packets for seg6local lwt This patch ensures that the seg6local lightweight tunnel is used solely with IPv6 routes and processes only IPv6 packets. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 01:56:46 -06:00
if (family != AF_INET6)
return -EINVAL;
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 06:07:28 -06:00
err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla,
seg6_local_policy, extack);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
if (err < 0)
return err;
if (!tb[SEG6_LOCAL_ACTION])
return -EINVAL;
newts = lwtunnel_state_alloc(sizeof(*slwt));
if (!newts)
return -ENOMEM;
slwt = seg6_local_lwtunnel(newts);
slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
err = parse_nla_action(tb, slwt);
if (err < 0)
goto out_free;
newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
newts->headroom = slwt->headroom;
*ts = newts;
return 0;
out_free:
kfree(slwt->srh);
kfree(newts);
return err;
}
static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
kfree(slwt->srh);
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
if (slwt->desc->attrs & (1 << SEG6_LOCAL_BPF)) {
kfree(slwt->bpf.name);
bpf_prog_put(slwt->bpf.prog);
}
return;
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
}
static int seg6_local_fill_encap(struct sk_buff *skb,
struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
struct seg6_action_param *param;
int i, err;
if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
return -EMSGSIZE;
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
if (slwt->desc->attrs & (1 << i)) {
param = &seg6_action_params[i];
err = param->put(skb, slwt);
if (err < 0)
return err;
}
}
return 0;
}
static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
unsigned long attrs;
int nlsize;
nlsize = nla_total_size(4); /* action */
attrs = slwt->desc->attrs;
if (attrs & (1 << SEG6_LOCAL_SRH))
nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
if (attrs & (1 << SEG6_LOCAL_TABLE))
nlsize += nla_total_size(4);
if (attrs & (1 << SEG6_LOCAL_NH4))
nlsize += nla_total_size(4);
if (attrs & (1 << SEG6_LOCAL_NH6))
nlsize += nla_total_size(16);
if (attrs & (1 << SEG6_LOCAL_IIF))
nlsize += nla_total_size(4);
if (attrs & (1 << SEG6_LOCAL_OIF))
nlsize += nla_total_size(4);
ipv6: sr: Add seg6local action End.BPF This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-20 07:58:16 -06:00
if (attrs & (1 << SEG6_LOCAL_BPF))
nlsize += nla_total_size(sizeof(struct nlattr)) +
nla_total_size(MAX_PROG_NAME) +
nla_total_size(4);
ipv6: sr: define core operations for seg6local lightweight tunnel This patch implements a new type of lightweight tunnel named seg6local. A seg6local lwt is defined by a type of action and a set of parameters. The action represents the operation to perform on the packets matching the lwt's route, and is not necessarily an encapsulation. The set of parameters are arguments for the processing function. Each action is defined in a struct seg6_action_desc within seg6_action_table[]. This structure contains the action, mandatory attributes, the processing function, and a static headroom size required by the action. The mandatory attributes are encoded as a bitmask field. The static headroom is set to a non-zero value when the processing function always add a constant number of bytes to the skb (e.g. the header size for encapsulations). To facilitate rtnetlink-related operations such as parsing, fill_encap, and cmp_encap, each type of action parameter is associated to three function pointers, in seg6_action_params[]. All actions defined in seg6_local.h are detailed in [1]. [1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01 Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-05 04:38:26 -06:00
return nlsize;
}
static int seg6_local_cmp_encap(struct lwtunnel_state *a,
struct lwtunnel_state *b)
{
struct seg6_local_lwt *slwt_a, *slwt_b;
struct seg6_action_param *param;
int i;
slwt_a = seg6_local_lwtunnel(a);
slwt_b = seg6_local_lwtunnel(b);
if (slwt_a->action != slwt_b->action)
return 1;
if (slwt_a->desc->attrs != slwt_b->desc->attrs)
return 1;
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
if (slwt_a->desc->attrs & (1 << i)) {
param = &seg6_action_params[i];
if (param->cmp(slwt_a, slwt_b))
return 1;
}
}
return 0;
}
static const struct lwtunnel_encap_ops seg6_local_ops = {
.build_state = seg6_local_build_state,
.destroy_state = seg6_local_destroy_state,
.input = seg6_local_input,
.fill_encap = seg6_local_fill_encap,
.get_encap_size = seg6_local_get_encap_size,
.cmp_encap = seg6_local_cmp_encap,
.owner = THIS_MODULE,
};
int __init seg6_local_init(void)
{
return lwtunnel_encap_add_ops(&seg6_local_ops,
LWTUNNEL_ENCAP_SEG6_LOCAL);
}
void seg6_local_exit(void)
{
lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
}
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