2 * Copyright (C) 2012 Steven Barth <steven@midlink.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
21 #include <arpa/inet.h>
22 #include <sys/socket.h>
23 #include <linux/rtnetlink.h>
29 static unsigned seq = 0;
32 // Init rtnetlink socket
33 int init_rtnetlink(void)
35 sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
36 struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK };
37 if (connect(sock, (struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel)))
44 // CRUD addresses to interface
45 int set_rtnetlink_addr(int ifindex, const struct in6_addr *addr,
46 time_t pref, time_t valid)
48 int flags = NLM_F_REQUEST | NLM_F_ACK;
49 int cmd = RTM_DELADDR;
52 flags |= NLM_F_CREATE | NLM_F_REPLACE;
59 struct rtattr rta_addr;
61 struct rtattr rta_local;
62 struct in6_addr local;
63 struct rtattr rta_info;
64 struct ifa_cacheinfo info;
66 {sizeof(req), cmd, flags, ++seq, 0},
67 {AF_INET6, 128, 0, RT_SCOPE_UNIVERSE, ifindex},
68 {sizeof(req.rta_addr) + sizeof(req.addr), IFA_ADDRESS},
70 {sizeof(req.rta_local) + sizeof(req.local), IFA_LOCAL},
72 {sizeof(req.rta_info) + sizeof(req.info), IFA_CACHEINFO},
75 send(sock, &req, sizeof(req), 0);
81 recv(sock, &reply, sizeof(reply), 0);
83 char buf[INET6_ADDRSTRLEN];
84 inet_ntop(AF_INET6, addr, buf, sizeof(buf));
85 syslog(LOG_WARNING, "%s address %s/128 for iface %i: %s",
86 (valid) ? "assigning" : "removing", buf,
87 ifindex, strerror(-reply.err.error));
89 if (reply.err.error < 0 || valid == 0)
90 return reply.err.error;
92 // Check for duplicate addresses
93 struct timespec ts = {1, 0};
96 req.nhm.nlmsg_type = RTM_GETADDR;
97 req.nhm.nlmsg_seq = ++seq;
98 req.nhm.nlmsg_flags = NLM_F_REQUEST;
99 send(sock, &req, sizeof(req), 0);
103 struct ifaddrmsg ifa;
106 recv(sock, &dad_reply, sizeof(dad_reply), 0);
108 if (dad_reply.nhm.nlmsg_type != RTM_NEWADDR ||
109 (dad_reply.ifa.ifa_flags & IFA_F_DADFAILED)) {
110 syslog(LOG_WARNING, "Removing duplicate address %s", buf);
111 set_rtnetlink_addr(ifindex, addr, 0, 0);
112 return -EADDRNOTAVAIL;