3 * Copyright (c) 2015 Steven Barth <cyrus@openwrt.org>
4 * Copyright (c) 2017 Hans Dedecker <dedeckeh@gmail.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 #include <netinet/icmp6.h>
17 #include <netinet/in.h>
18 #include <sys/socket.h>
19 #include <arpa/inet.h>
27 static void sighandler(__attribute__((unused)) int signal)
31 int main(int argc, const char *argv[])
33 char buf[INET6_ADDRSTRLEN], prefix[INET6_ADDRSTRLEN + 4];
37 fprintf(stderr, "Usage: %s <name> [ifname] [ipv6prefix] [ipv4addr] [ipv6addr]\n", argv[0]);
41 snprintf(buf, sizeof(buf), "/var/run/%s.pid", argv[1]);
42 FILE *fp = fopen(buf, "r");
44 if (fscanf(fp, "%d", &pid) == 1)
54 if (!argv[3] || !argv[4] || !(fp = fopen(buf, "wx")))
57 signal(SIGTERM, SIG_DFL);
58 setvbuf(fp, NULL, _IOLBF, 0);
59 fprintf(fp, "%d\n", getpid());
61 prefix[sizeof(prefix) - 1] = 0;
62 strncpy(prefix, argv[3], sizeof(prefix) - 1);
65 struct addrinfo hints = { .ai_family = AF_INET6 }, *res;
66 if (getaddrinfo("ipv4only.arpa", NULL, &hints, &res) || !res) {
68 if (getaddrinfo("ipv4only.arpa", NULL, &hints, &res) || !res)
72 struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)res->ai_addr;
73 inet_ntop(AF_INET6, &sin6->sin6_addr, prefix, sizeof(prefix) - 4);
74 strcat(prefix, "/96");
80 struct sockaddr_in6 saddr;
83 socklen_t saddrlen = sizeof(saddr);
84 struct icmp6_filter filt;
86 sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
87 ICMP6_FILTER_SETBLOCKALL(&filt);
88 setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, sizeof(filt));
89 setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, argv[2], strlen(argv[2]));
90 memset(&saddr, 0, sizeof(saddr));
91 saddr.sin6_family = AF_INET6;
92 saddr.sin6_addr.s6_addr32[0] = htonl(0x2001);
93 saddr.sin6_addr.s6_addr32[1] = htonl(0xdb8);
94 if (connect(sock, (struct sockaddr*)&saddr, sizeof(saddr)) ||
95 getsockname(sock, (struct sockaddr*)&saddr, &saddrlen))
98 if (!IN6_IS_ADDR_LINKLOCAL(&saddr.sin6_addr) || argv[5])
106 struct ipv6_mreq mreq = {saddr.sin6_addr, if_nametoindex(argv[2])};
108 if (IN6_IS_ADDR_LINKLOCAL(&mreq.ipv6mr_multiaddr))
111 srandom(mreq.ipv6mr_multiaddr.s6_addr32[0] ^ mreq.ipv6mr_multiaddr.s6_addr32[1] ^
112 mreq.ipv6mr_multiaddr.s6_addr32[2] ^ mreq.ipv6mr_multiaddr.s6_addr32[3]);
113 mreq.ipv6mr_multiaddr.s6_addr32[2] = random();
114 mreq.ipv6mr_multiaddr.s6_addr32[3] = random();
115 } else if (inet_pton(AF_INET6, argv[5], &mreq.ipv6mr_multiaddr) != 1) {
119 if (setsockopt(sock, SOL_IPV6, IPV6_JOIN_ANYCAST, &mreq, sizeof(mreq)))
122 inet_ntop(AF_INET6, &mreq.ipv6mr_multiaddr, buf, sizeof(buf));
127 FILE *nat46 = fopen("/proc/net/nat46/control", "w");
128 if (!nat46 || fprintf(nat46, "add %s\nconfig %s local.style NONE local.v4 %s/32 local.v6 %s/128 "
129 "remote.style RFC6052 remote.v6 %s\n", argv[1], argv[1], argv[4], buf, prefix) < 0 ||
133 if (!(pid = fork())) {
140 signal(SIGTERM, sighandler);
143 nat46 = fopen("/proc/net/nat46/control", "w");
145 fprintf(nat46, "del %s\n", argv[1]);
150 fprintf(fp, "%d\n", pid);