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 #include <bpf/bpf_tracing.h>
7
8 char _license[] SEC("license") = "GPL";
9
SOCK_INODE(struct socket * socket)10 static __attribute__((noinline)) struct inode *SOCK_INODE(struct socket *socket)
11 {
12 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
13 }
14
15 SEC("iter/netlink")
dump_netlink(struct bpf_iter__netlink * ctx)16 int dump_netlink(struct bpf_iter__netlink *ctx)
17 {
18 struct seq_file *seq = ctx->meta->seq;
19 struct netlink_sock *nlk = ctx->sk;
20 unsigned long group, ino;
21 struct inode *inode;
22 struct socket *sk;
23 struct sock *s;
24
25 if (nlk == (void *)0)
26 return 0;
27
28 if (ctx->meta->seq_num == 0)
29 BPF_SEQ_PRINTF(seq, "sk Eth Pid Groups "
30 "Rmem Wmem Dump Locks Drops "
31 "Inode\n");
32
33 s = &nlk->sk;
34 BPF_SEQ_PRINTF(seq, "%pK %-3d ", s, s->sk_protocol);
35
36 if (!nlk->groups) {
37 group = 0;
38 } else {
39 /* FIXME: temporary use bpf_probe_read_kernel here, needs
40 * verifier support to do direct access.
41 */
42 bpf_probe_read_kernel(&group, sizeof(group), &nlk->groups[0]);
43 }
44 BPF_SEQ_PRINTF(seq, "%-10u %08x %-8d %-8d %-5d %-8d ",
45 nlk->portid, (u32)group,
46 s->sk_rmem_alloc.counter,
47 s->sk_wmem_alloc.refs.counter - 1,
48 nlk->cb_running, s->sk_refcnt.refs.counter);
49
50 sk = s->sk_socket;
51 if (!sk) {
52 ino = 0;
53 } else {
54 /* FIXME: container_of inside SOCK_INODE has a forced
55 * type conversion, and direct access cannot be used
56 * with current verifier.
57 */
58 inode = SOCK_INODE(sk);
59 bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
60 }
61 BPF_SEQ_PRINTF(seq, "%-8u %-8lu\n", s->sk_drops.counter, ino);
62
63 return 0;
64 }
65