![Alexei Starovoitov](/assets/img/avatar_default.png)
Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
24 lines
768 B
Plaintext
24 lines
768 B
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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menuconfig BPFILTER
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bool "BPF based packet filtering framework (BPFILTER)"
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depends on NET && BPF && INET
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select USERMODE_DRIVER
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help
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This builds experimental bpfilter framework that is aiming to
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provide netfilter compatible functionality via BPF
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if BPFILTER
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config BPFILTER_UMH
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tristate "bpfilter kernel module with user mode helper"
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depends on CC_CAN_LINK
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depends on m || CC_CAN_LINK_STATIC
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default m
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help
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This builds bpfilter kernel module with embedded user mode helper
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Note: To compile this as built-in, your toolchain must support
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building static binaries, since rootfs isn't mounted at the time
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when __init functions are called and do_execv won't be able to find
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the elf interpreter.
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endif
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