Commit 04e92818 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Andrii Nakryiko
Browse files

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: default avatarKuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210814015718.42704-4-kuniyu@amazon.co.jp
parent 3478cfcf

tools/testing/selftests/bpf/prog_tests/bpf_iter.c

+16 −0
Original line number Diff line number Diff line
@@ -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"))

tools/testing/selftests/bpf/progs/bpf_iter.h

+8 −0
Original line number Diff line number Diff line
@@ -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;

tools/testing/selftests/bpf/progs/bpf_iter_unix.c

0 → 100644
+80 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright Amazon.com Inc. or its affiliates. */

#include "bpf_iter.h"

#include "bpf_tracing_net.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_endian.h>



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;

}

tools/testing/selftests/bpf/progs/bpf_tracing_net.h

+4 −0
Original line number Diff line number Diff line
@@ -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