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 27 int _version SEC("version") = 1; 28 29 SEC("cgroup/connect6") connect_v6_prog(struct bpf_sock_addr * ctx)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 61 char _license[] SEC("license") = "GPL"; 62