On Wed, Aug 4, 2021 at 12:09 AM Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx> wrote: > > If there are no abstract sockets, this prog can output the same result > compared to /proc/net/unix. > > # cat /sys/fs/bpf/unix | head -n 2 > Num RefCount Protocol Flags Type St Inode Path > ffff9ab7122db000: 00000002 00000000 00010000 0001 01 10623 private/defer > > # cat /proc/net/unix | head -n 2 > Num RefCount Protocol Flags Type St Inode Path > ffff9ab7122db000: 00000002 00000000 00010000 0001 01 10623 private/defer > > According to the analysis by Yonghong Song (See the link), the BPF verifier > cannot load the code in the comment to print the name of the abstract UNIX > domain socket due to LLVM optimisation. It can be uncommented once the > LLVM code gen is improved. > > Link: https://lore.kernel.org/netdev/1994df05-8f01-371f-3c3b-d33d7836878c@xxxxxx/ Our patchworks tooling, used to apply patches, is using Link: tag to record original discussion, so this will be quite confusing if you use the same "Link: " for referencing relevant discussions. Please use standard link reference syntax: According to the analysis by Yonghong Song ([0]), ... ... [0] https://lore.kernel.org/netdev/1994df05-8f01-371f-3c3b-d33d7836878c@xxxxxx/ > Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx> > --- > .../selftests/bpf/prog_tests/bpf_iter.c | 16 ++++ > tools/testing/selftests/bpf/progs/bpf_iter.h | 8 ++ > .../selftests/bpf/progs/bpf_iter_unix.c | 86 +++++++++++++++++++ > .../selftests/bpf/progs/bpf_tracing_net.h | 4 + > 4 files changed, 114 insertions(+) > create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_unix.c > [...] > diff --git a/tools/testing/selftests/bpf/progs/bpf_iter.h b/tools/testing/selftests/bpf/progs/bpf_iter.h > index 3d83b185c4bc..d92648621bcb 100644 > --- a/tools/testing/selftests/bpf/progs/bpf_iter.h > +++ b/tools/testing/selftests/bpf/progs/bpf_iter.h > @@ -12,6 +12,7 @@ > #define tcp6_sock tcp6_sock___not_used > #define bpf_iter__udp bpf_iter__udp___not_used > #define udp6_sock udp6_sock___not_used > +#define bpf_iter__unix bpf_iter__unix___not_used > #define bpf_iter__bpf_map_elem bpf_iter__bpf_map_elem___not_used > #define bpf_iter__bpf_sk_storage_map bpf_iter__bpf_sk_storage_map___not_used > #define bpf_iter__sockmap bpf_iter__sockmap___not_used > @@ -32,6 +33,7 @@ > #undef tcp6_sock > #undef bpf_iter__udp > #undef udp6_sock > +#undef bpf_iter__unix > #undef bpf_iter__bpf_map_elem > #undef bpf_iter__bpf_sk_storage_map > #undef bpf_iter__sockmap > @@ -103,6 +105,12 @@ struct udp6_sock { > struct ipv6_pinfo inet6; > } __attribute__((preserve_access_index)); > > +struct bpf_iter__unix { > + struct bpf_iter_meta *meta; > + struct unix_sock *unix_sk; > + uid_t uid __attribute__((aligned(8))); just fyi, aligned doesn't matter here, CO-RE will relocate offsets appropriately anyways > +} __attribute__((preserve_access_index)); > + > struct bpf_iter__bpf_map_elem { > struct bpf_iter_meta *meta; > struct bpf_map *map; [...] > +SEC("iter/unix") > +int dump_unix(struct bpf_iter__unix *ctx) > +{ > + struct unix_sock *unix_sk = ctx->unix_sk; > + struct sock *sk = (struct sock *)unix_sk; > + struct seq_file *seq; > + __u32 seq_num; > + > + if (!unix_sk) > + return 0; > + > + seq = ctx->meta->seq; > + seq_num = ctx->meta->seq_num; > + if (seq_num == 0) > + BPF_SEQ_PRINTF(seq, "Num RefCount Protocol Flags " > + "Type St Inode Path\n"); nit: please keep format strings on a single line > + > + BPF_SEQ_PRINTF(seq, "%pK: %08X %08X %08X %04X %02X %5lu", > + unix_sk, > + sk->sk_refcnt.refs.counter, > + 0, > + sk->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, > + sk->sk_type, > + sk->sk_socket ? > + (sk->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : > + (sk->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), > + sock_i_ino(sk)); > + [...]
