1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Facebook */
3#include "bpf_iter.h"
4#include "bpf_tracing_net.h"
5#include <bpf/bpf_helpers.h>
6
7char _license[] SEC("license") = "GPL";
8
9static __attribute__((noinline)) struct inode *SOCK_INODE(struct socket *socket)
10{
11	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
12}
13
14SEC("iter/netlink")
15int dump_netlink(struct bpf_iter__netlink *ctx)
16{
17	struct seq_file *seq = ctx->meta->seq;
18	struct netlink_sock *nlk = ctx->sk;
19	unsigned long group, ino;
20	struct inode *inode;
21	struct socket *sk;
22	struct sock *s;
23
24	if (nlk == (void *)0)
25		return 0;
26
27	if (ctx->meta->seq_num == 0)
28		BPF_SEQ_PRINTF(seq, "sk               Eth Pid        Groups   "
29				    "Rmem     Wmem     Dump  Locks    Drops    "
30				    "Inode\n");
31
32	s = &nlk->sk;
33	BPF_SEQ_PRINTF(seq, "%pK %-3d ", s, s->sk_protocol);
34
35	if (!nlk->groups)  {
36		group = 0;
37	} else {
38		/* FIXME: temporary use bpf_probe_read_kernel here, needs
39		 * verifier support to do direct access.
40		 */
41		bpf_probe_read_kernel(&group, sizeof(group), &nlk->groups[0]);
42	}
43	BPF_SEQ_PRINTF(seq, "%-10u %08x %-8d %-8d %-5d %-8d ",
44		       nlk->portid, (u32)group,
45		       s->sk_rmem_alloc.counter,
46		       s->sk_wmem_alloc.refs.counter - 1,
47		       nlk->cb_running, s->sk_refcnt.refs.counter);
48
49	sk = s->sk_socket;
50	if (!sk) {
51		ino = 0;
52	} else {
53		/* FIXME: container_of inside SOCK_INODE has a forced
54		 * type conversion, and direct access cannot be used
55		 * with current verifier.
56		 */
57		inode = SOCK_INODE(sk);
58		bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
59	}
60	BPF_SEQ_PRINTF(seq, "%-8u %-8lu\n", s->sk_drops.counter, ino);
61
62	return 0;
63}
64