tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2018 Facebook
3
4#include <string.h>
5
6#include <linux/stddef.h>
7#include <linux/bpf.h>
8#include <linux/in.h>
9#include <linux/in6.h>
10#include <sys/socket.h>
11
12#include "bpf_helpers.h"
13#include "bpf_endian.h"
14
15#define SRC_REWRITE_IP6_0 0
16#define SRC_REWRITE_IP6_1 0
17#define SRC_REWRITE_IP6_2 0
18#define SRC_REWRITE_IP6_3 6
19
20#define DST_REWRITE_IP6_0 0
21#define DST_REWRITE_IP6_1 0
22#define DST_REWRITE_IP6_2 0
23#define DST_REWRITE_IP6_3 1
24
25#define DST_REWRITE_PORT6 6666
26
27int _version SEC("version") = 1;
28
29SEC("cgroup/connect6")
30int connect_v6_prog(struct bpf_sock_addr *ctx)
31{
32 struct sockaddr_in6 sa;
33
34 /* Rewrite destination. */
35 ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_0);
36 ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_1);
37 ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2);
38 ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_3);
39
40 ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
41
42 if (ctx->type == SOCK_DGRAM || ctx->type == SOCK_STREAM) {
43 /* Rewrite source. */
44 memset(&sa, 0, sizeof(sa));
45
46 sa.sin6_family = AF_INET6;
47 sa.sin6_port = bpf_htons(0);
48
49 sa.sin6_addr.s6_addr32[0] = bpf_htonl(SRC_REWRITE_IP6_0);
50 sa.sin6_addr.s6_addr32[1] = bpf_htonl(SRC_REWRITE_IP6_1);
51 sa.sin6_addr.s6_addr32[2] = bpf_htonl(SRC_REWRITE_IP6_2);
52 sa.sin6_addr.s6_addr32[3] = bpf_htonl(SRC_REWRITE_IP6_3);
53
54 if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
55 return 0;
56 }
57
58 return 1;
59}
60
61char _license[] SEC("license") = "GPL";