1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2018 Facebook
6 #include <linux/stddef.h>
10 #include <sys/socket.h>
12 #include "bpf_helpers.h"
13 #include "bpf_endian.h"
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
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
25 #define DST_REWRITE_PORT6 6666
27 int _version SEC("version") = 1;
29 SEC("cgroup/connect6")
30 int connect_v6_prog(struct bpf_sock_addr *ctx)
32 struct bpf_sock_tuple tuple = {};
33 struct sockaddr_in6 sa;
36 /* Verify that new destination is available. */
37 memset(&tuple.ipv6.saddr, 0, sizeof(tuple.ipv6.saddr));
38 memset(&tuple.ipv6.sport, 0, sizeof(tuple.ipv6.sport));
40 tuple.ipv6.daddr[0] = bpf_htonl(DST_REWRITE_IP6_0);
41 tuple.ipv6.daddr[1] = bpf_htonl(DST_REWRITE_IP6_1);
42 tuple.ipv6.daddr[2] = bpf_htonl(DST_REWRITE_IP6_2);
43 tuple.ipv6.daddr[3] = bpf_htonl(DST_REWRITE_IP6_3);
45 tuple.ipv6.dport = bpf_htons(DST_REWRITE_PORT6);
47 if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
49 else if (ctx->type == SOCK_STREAM)
50 sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof(tuple.ipv6), 0, 0);
52 sk = bpf_sk_lookup_udp(ctx, &tuple, sizeof(tuple.ipv6), 0, 0);
57 if (sk->src_ip6[0] != tuple.ipv6.daddr[0] ||
58 sk->src_ip6[1] != tuple.ipv6.daddr[1] ||
59 sk->src_ip6[2] != tuple.ipv6.daddr[2] ||
60 sk->src_ip6[3] != tuple.ipv6.daddr[3] ||
61 sk->src_port != DST_REWRITE_PORT6) {
68 /* Rewrite destination. */
69 ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_0);
70 ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_1);
71 ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2);
72 ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_3);
74 ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
77 memset(&sa, 0, sizeof(sa));
79 sa.sin6_family = AF_INET6;
80 sa.sin6_port = bpf_htons(0);
82 sa.sin6_addr.s6_addr32[0] = bpf_htonl(SRC_REWRITE_IP6_0);
83 sa.sin6_addr.s6_addr32[1] = bpf_htonl(SRC_REWRITE_IP6_1);
84 sa.sin6_addr.s6_addr32[2] = bpf_htonl(SRC_REWRITE_IP6_2);
85 sa.sin6_addr.s6_addr32[3] = bpf_htonl(SRC_REWRITE_IP6_3);
87 if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
93 char _license[] SEC("license") = "GPL";