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| author | Daniel T. Lee <danieltimlee@gmail.com> | 2023-01-15 16:16:07 +0900 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-01-15 13:32:45 -0800 |
| commit | 31b12a4159fae818ac1043539ec9656da57b2e2c (patch) | |
| tree | c507ad91ce0075bbc59670056c42c539179bbd60 /samples | |
| parent | dac808c90749c7dddd91f01f1f4252d2518d5ea0 (diff) | |
| download | linux-31b12a4159fae818ac1043539ec9656da57b2e2c.tar.gz | |
samples/bpf: fix broken cgroup socket testing
Currently, executing test_cgrp2_sock2 fails due to wrong section
header. This 'cgroup/sock1' style section is previously used at
'samples/bpf_load' (deprecated) BPF loader. Because this style isn't
supported in libbpf, this commit fixes this problem by correcting the
section header.
$ sudo ./test_cgrp2_sock2.sh
libbpf: prog 'bpf_prog1': missing BPF prog type, check ELF section name 'cgroup/sock1'
libbpf: prog 'bpf_prog1': failed to load: -22
libbpf: failed to load object './sock_flags_kern.o'
ERROR: loading BPF object file failed
In addition, this BPF program filters ping packets by comparing whether
the socket type uses SOCK_RAW. However, after the ICMP socket[1] was
developed, ping sends ICMP packets using SOCK_DGRAM. Therefore, in this
commit, the packet filtering is changed to use SOCK_DGRAM instead of
SOCK_RAW.
$ strace --trace socket ping -6 -c1 -w1 ::1
socket(AF_INET6, SOCK_DGRAM, IPPROTO_ICMPV6) = 3
[1]: https://lwn.net/Articles/422330/
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-5-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/bpf/sock_flags_kern.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/samples/bpf/sock_flags_kern.c b/samples/bpf/sock_flags_kern.c index 6d0ac7569d6f48..1d58cb9b6fa452 100644 --- a/samples/bpf/sock_flags_kern.c +++ b/samples/bpf/sock_flags_kern.c @@ -5,7 +5,7 @@ #include <uapi/linux/in6.h> #include <bpf/bpf_helpers.h> -SEC("cgroup/sock1") +SEC("cgroup/sock") int bpf_prog1(struct bpf_sock *sk) { char fmt[] = "socket: family %d type %d protocol %d\n"; @@ -17,29 +17,29 @@ int bpf_prog1(struct bpf_sock *sk) bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol); bpf_trace_printk(fmt2, sizeof(fmt2), uid, gid); - /* block PF_INET6, SOCK_RAW, IPPROTO_ICMPV6 sockets + /* block PF_INET6, SOCK_DGRAM, IPPROTO_ICMPV6 sockets * ie., make ping6 fail */ if (sk->family == PF_INET6 && - sk->type == SOCK_RAW && + sk->type == SOCK_DGRAM && sk->protocol == IPPROTO_ICMPV6) return 0; return 1; } -SEC("cgroup/sock2") +SEC("cgroup/sock") int bpf_prog2(struct bpf_sock *sk) { char fmt[] = "socket: family %d type %d protocol %d\n"; bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol); - /* block PF_INET, SOCK_RAW, IPPROTO_ICMP sockets + /* block PF_INET, SOCK_DGRAM, IPPROTO_ICMP sockets * ie., make ping fail */ if (sk->family == PF_INET && - sk->type == SOCK_RAW && + sk->type == SOCK_DGRAM && sk->protocol == IPPROTO_ICMP) return 0; |