1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2026 Isovalent */
3
4 #include "vmlinux.h"
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_tracing.h>
7 #include <bpf/bpf_endian.h>
8 #include "bpf_tracing_net.h"
9 #include "ksock_common.h"
10
11 char send_data[32] = "hello from bpf ksock";
12
13 __be32 ipv4_remote;
14 __u16 remote_port;
15 int target_pid;
16 int send_ret = -1;
17
18 SEC("syscall")
ksock_setup(void * ctx)19 int ksock_setup(void *ctx)
20 {
21 struct bpf_ksock_create_opts create_opts = {};
22 union bpf_ksock_addr addr = {};
23 struct bpf_ksock *ks;
24 int err = 0;
25
26 create_opts.family = AF_INET;
27 create_opts.type = SOCK_DGRAM;
28 create_opts.protocol = IPPROTO_UDP;
29
30 ks = bpf_ksock_create(&create_opts, sizeof(create_opts), &err);
31 if (!ks)
32 return err;
33
34 addr.sin.sin_family = AF_INET;
35 addr.sin.sin_port = bpf_htons(remote_port);
36 addr.sin.sin_addr.s_addr = ipv4_remote;
37
38 err = bpf_ksock_connect(ks, &addr, sizeof(addr));
39 if (err) {
40 bpf_ksock_release(ks);
41 return err;
42 }
43
44 err = ksock_ctx_insert(ks);
45 if (err && err != -EEXIST)
46 return err;
47 return 0;
48 }
49
50 SEC("lsm.s/socket_bind")
BPF_PROG(ksock_socket_bind,struct socket * sock,struct sockaddr * address,int addrlen,int ret)51 int BPF_PROG(ksock_socket_bind, struct socket *sock, struct sockaddr *address,
52 int addrlen, int ret)
53 {
54 struct bpf_ksock *ks;
55 u32 pid = bpf_get_current_pid_tgid() >> 32;
56
57 if (ret || pid != target_pid)
58 return ret;
59
60 ks = ksock_ctx_get();
61 if (!ks) {
62 send_ret = -ENOENT;
63 return ret;
64 }
65
66 send_ret = bpf_ksock_send(ks, send_data, sizeof(send_data));
67 bpf_ksock_release(ks);
68
69 return ret;
70 }
71
72 char __license[] SEC("license") = "GPL";
73