From 04e928180c14332fb15a1b8c64418b602978a51e Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Sat, 14 Aug 2021 10:57:17 +0900 Subject: [PATCH] selftest/bpf: Implement sample UNIX domain socket iterator program. The iterator can output almost the same result compared to /proc/net/unix. The header line is aligned, and the Inode column uses "%8lu" because "%5lu" can be easily overflown. # cat /sys/fs/bpf/unix Num RefCount Protocol Flags Type St Inode Path ffff963c06689800: 00000002 00000000 00010000 0001 01 18697 private/defer ffff963c7c979c00: 00000002 00000000 00000000 0001 01 598245 @Hello@World@ # cat /proc/net/unix Num RefCount Protocol Flags Type St Inode Path ffff963c06689800: 00000002 00000000 00010000 0001 01 18697 private/defer ffff963c7c979c00: 00000002 00000000 00000000 0001 01 598245 @Hello@World@ Signed-off-by: Kuniyuki Iwashima Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210814015718.42704-4-kuniyu@amazon.co.jp --- tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 16 +++++ tools/testing/selftests/bpf/progs/bpf_iter.h | 8 +++ tools/testing/selftests/bpf/progs/bpf_iter_unix.c | 80 ++++++++++++++++++++++ .../testing/selftests/bpf/progs/bpf_tracing_net.h | 4 ++ 4 files changed, 108 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_unix.c diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index 1f1aade..77ac24b 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -13,6 +13,7 @@ #include "bpf_iter_tcp6.skel.h" #include "bpf_iter_udp4.skel.h" #include "bpf_iter_udp6.skel.h" +#include "bpf_iter_unix.skel.h" #include "bpf_iter_test_kern1.skel.h" #include "bpf_iter_test_kern2.skel.h" #include "bpf_iter_test_kern3.skel.h" @@ -313,6 +314,19 @@ static void test_udp6(void) bpf_iter_udp6__destroy(skel); } +static void test_unix(void) +{ + struct bpf_iter_unix *skel; + + skel = bpf_iter_unix__open_and_load(); + if (!ASSERT_OK_PTR(skel, "bpf_iter_unix__open_and_load")) + return; + + do_dummy_read(skel->progs.dump_unix); + + bpf_iter_unix__destroy(skel); +} + /* The expected string is less than 16 bytes */ static int do_read_with_fd(int iter_fd, const char *expected, bool read_one_char) @@ -1255,6 +1269,8 @@ void test_bpf_iter(void) test_udp4(); if (test__start_subtest("udp6")) test_udp6(); + if (test__start_subtest("unix")) + test_unix(); if (test__start_subtest("anon")) test_anon_iter(false); if (test__start_subtest("anon-read-one-char")) diff --git a/tools/testing/selftests/bpf/progs/bpf_iter.h b/tools/testing/selftests/bpf/progs/bpf_iter.h index 3d83b18..8cfaeba 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__((preserve_access_index)); + struct bpf_iter__bpf_map_elem { struct bpf_iter_meta *meta; struct bpf_map *map; diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_unix.c b/tools/testing/selftests/bpf/progs/bpf_iter_unix.c new file mode 100644 index 0000000..9442390 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_unix.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright Amazon.com Inc. or its affiliates. */ +#include "bpf_iter.h" +#include "bpf_tracing_net.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +static long sock_i_ino(const struct sock *sk) +{ + const struct socket *sk_socket = sk->sk_socket; + const struct inode *inode; + unsigned long ino; + + if (!sk_socket) + return 0; + + inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode; + bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino); + return ino; +} + +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"); + + BPF_SEQ_PRINTF(seq, "%pK: %08X %08X %08X %04X %02X %8lu", + 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)); + + if (unix_sk->addr) { + if (!UNIX_ABSTRACT(unix_sk)) { + BPF_SEQ_PRINTF(seq, " %s", unix_sk->addr->name->sun_path); + } else { + /* The name of the abstract UNIX domain socket starts + * with '\0' and can contain '\0'. The null bytes + * should be escaped as done in unix_seq_show(). + */ + __u64 i, len; + + len = unix_sk->addr->len - sizeof(short); + + BPF_SEQ_PRINTF(seq, " @"); + + for (i = 1; i < len; i++) { + /* unix_mkname() tests this upper bound. */ + if (i >= sizeof(struct sockaddr_un)) + break; + + BPF_SEQ_PRINTF(seq, "%c", + unix_sk->addr->name->sun_path[i] ?: + '@'); + } + } + } + + BPF_SEQ_PRINTF(seq, "\n"); + + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index 3af0998..eef5646 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -5,6 +5,10 @@ #define AF_INET 2 #define AF_INET6 10 +#define __SO_ACCEPTCON (1 << 16) +#define UNIX_HASH_SIZE 256 +#define UNIX_ABSTRACT(unix_sk) (unix_sk->addr->hash < UNIX_HASH_SIZE) + #define SOL_TCP 6 #define TCP_CONGESTION 13 #define TCP_CA_NAME_MAX 16 -- 2.7.4