1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include "vmlinux.h" |
3 | #include <bpf/bpf_helpers.h> |
4 | #include <bpf/bpf_tracing.h> |
5 | #include <bpf/bpf_core_read.h> |
6 | #include "bpf_misc.h" |
7 | |
8 | static struct sockaddr_in old; |
9 | |
10 | static int handle_sys_connect_common(struct sockaddr_in *uservaddr) |
11 | { |
12 | struct sockaddr_in new; |
13 | |
14 | bpf_probe_read_user(&old, sizeof(old), uservaddr); |
15 | __builtin_memset(&new, 0xab, sizeof(new)); |
16 | bpf_probe_write_user(uservaddr, &new, sizeof(new)); |
17 | |
18 | return 0; |
19 | } |
20 | |
21 | SEC("ksyscall/connect" ) |
22 | int BPF_KSYSCALL(handle_sys_connect, int fd, struct sockaddr_in *uservaddr, |
23 | int addrlen) |
24 | { |
25 | return handle_sys_connect_common(uservaddr: uservaddr); |
26 | } |
27 | |
28 | #if defined(bpf_target_s390) |
29 | #ifndef SYS_CONNECT |
30 | #define SYS_CONNECT 3 |
31 | #endif |
32 | |
33 | SEC("ksyscall/socketcall" ) |
34 | int BPF_KSYSCALL(handle_sys_socketcall, int call, unsigned long *args) |
35 | { |
36 | if (call == SYS_CONNECT) { |
37 | struct sockaddr_in *uservaddr; |
38 | |
39 | bpf_probe_read_user(&uservaddr, sizeof(uservaddr), &args[1]); |
40 | return handle_sys_connect_common(uservaddr); |
41 | } |
42 | |
43 | return 0; |
44 | } |
45 | #endif |
46 | |
47 | char _license[] SEC("license" ) = "GPL" ; |
48 | |