2 * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
3 * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License version 2.1
7 * as published by the Free Software Foundation
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <sys/socket.h>
16 #include <sys/ioctl.h>
17 #include <sys/types.h>
19 #include <sys/utsname.h>
21 #include <linux/sockios.h>
22 #include <arpa/inet.h>
30 #include <libubox/avl-cmp.h>
31 #include <libubox/utils.h>
32 #include "interface.h"
36 struct interface *cur_iface = NULL;
39 interface_send_packet(struct interface *iface, struct iovec *iov, int iov_len)
41 static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
42 static struct sockaddr_in a = {
43 .sin_family = AF_INET,
44 .sin_port = htons(MCAST_PORT),
46 static struct msghdr m = {
47 .msg_name = (struct sockaddr *) &a,
48 .msg_namelen = sizeof(a),
49 .msg_control = cmsg_data,
50 .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
52 struct in_pktinfo *pkti;
54 int fd = iface->fd.fd;
57 m.msg_iovlen = iov_len;
59 memset(cmsg_data, 0, sizeof(cmsg_data));
60 cmsg = CMSG_FIRSTHDR(&m);
61 cmsg->cmsg_len = m.msg_controllen;
62 cmsg->cmsg_level = IPPROTO_IP;
63 cmsg->cmsg_type = IP_PKTINFO;
65 pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
66 pkti->ipi_ifindex = iface->ifindex;
68 a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
70 return sendmsg(fd, &m, 0);
73 static void interface_free(struct interface *iface)
75 if (cur_iface == iface)
78 if (iface->fd.fd >= 0) {
79 uloop_fd_delete(&iface->fd);
85 static void interface_start(struct interface *iface)
91 iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
92 struct vlist_node *node_old)
94 struct interface *iface;
97 iface = container_of(node_old, struct interface, node);
98 interface_free(iface);
102 iface = container_of(node_new, struct interface, node);
103 interface_start(iface);
107 int interface_socket_setup(struct interface *iface)
109 struct ip_mreqn mreq;
113 struct sockaddr_in sa = { 0 };
115 int fd = iface->fd.fd;
117 inet_aton(iface->ip, &in);
119 sa.sin_family = AF_INET;
120 sa.sin_port = htons(MCAST_PORT);
121 inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
123 memset(&mreq, 0, sizeof(mreq));
124 mreq.imr_address.s_addr = in.s_addr;
125 mreq.imr_multiaddr = sa.sin_addr;
126 mreq.imr_ifindex = iface->ifindex;
128 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
129 fprintf(stderr, "ioctl failed: IP_MULTICAST_TTL\n");
131 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
132 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
134 /* Some network drivers have issues with dropping membership of
135 * mcast groups when the iface is down, but don't allow rejoining
136 * when it comes back up. This is an ugly workaround
137 * -- this was copied from avahi --
139 setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
141 if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
142 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
148 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0)
149 fprintf(stderr, "ioctl failed: IP_RECVTTL\n");
151 if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
152 fprintf(stderr, "ioctl failed: IP_PKTINFO\n");
154 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0)
155 fprintf(stderr, "ioctl failed: IP_MULTICAST_LOOP\n");
161 get_iface_ipv4(const char *ifname)
163 static char buffer[INET_ADDRSTRLEN];
168 sock = socket(AF_INET, SOCK_DGRAM, 0);
172 memset(&ir, 0, sizeof(struct ifreq));
173 strncpy(ir.ifr_name, ifname, sizeof(ir.ifr_name));
175 if (ioctl(sock, SIOCGIFADDR, &ir) < 0)
178 ret = inet_ntop(AF_INET, &((struct sockaddr_in *) &ir.ifr_addr)->sin_addr, buffer, sizeof(buffer));
184 int interface_add(const char *name)
186 struct interface *iface;
188 char *name_buf, *ip_buf;
190 ip_str = get_iface_ipv4(name);
194 iface = calloc_a(sizeof(*iface),
195 &name_buf, strlen(name) + 1,
196 &ip_buf, strlen(ip_str) + 1);
198 iface->name = strcpy(name_buf, name);
199 iface->ip = strcpy(ip_buf, ip_str);
200 iface->ifindex = if_nametoindex(name);
203 if (iface->ifindex <= 0)
206 vlist_add(&interfaces, &iface->node, name);
214 VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);