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 #include <bpf/bpf_endian.h>
8 
9 char _license[] SEC("license") = "GPL";
10 
11 static long sock_i_ino(const struct sock *sk)
12 {
13 	const struct socket *sk_socket = sk->sk_socket;
14 	const struct inode *inode;
15 	unsigned long ino;
16 
17 	if (!sk_socket)
18 		return 0;
19 
20 	inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode;
21 	bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
22 	return ino;
23 }
24 
25 SEC("iter/udp")
26 int dump_udp4(struct bpf_iter__udp *ctx)
27 {
28 	struct seq_file *seq = ctx->meta->seq;
29 	struct udp_sock *udp_sk = ctx->udp_sk;
30 	struct inet_sock *inet;
31 	__u16 srcp, destp;
32 	__be32 dest, src;
33 	__u32 seq_num;
34 	int rqueue;
35 
36 	if (udp_sk == (void *)0)
37 		return 0;
38 
39 	seq_num = ctx->meta->seq_num;
40 	if (seq_num == 0)
41 		BPF_SEQ_PRINTF(seq,
42 			       "  sl  local_address rem_address   st tx_queue "
43 			       "rx_queue tr tm->when retrnsmt   uid  timeout "
44 			       "inode ref pointer drops\n");
45 
46 	/* filter out udp6 sockets */
47 	inet = &udp_sk->inet;
48 	if (inet->sk.sk_family == AF_INET6)
49 		return 0;
50 
51 	inet = &udp_sk->inet;
52 	dest = inet->inet_daddr;
53 	src = inet->inet_rcv_saddr;
54 	srcp = bpf_ntohs(inet->inet_sport);
55 	destp = bpf_ntohs(inet->inet_dport);
56 	rqueue = inet->sk.sk_rmem_alloc.counter - udp_sk->forward_deficit;
57 
58 	BPF_SEQ_PRINTF(seq, "%5d: %08X:%04X %08X:%04X ",
59 		       ctx->bucket, src, srcp, dest, destp);
60 
61 	BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
62 		       inet->sk.sk_state,
63 		       inet->sk.sk_wmem_alloc.refs.counter - 1,
64 		       rqueue,
65 		       0, 0L, 0, ctx->uid, 0,
66 		       sock_i_ino(&inet->sk),
67 		       inet->sk.sk_refcnt.refs.counter, udp_sk,
68 		       inet->sk.sk_drops.counter);
69 
70 	return 0;
71 }
72