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"
37 struct interface *cur_iface = NULL;
40 interface_send_packet(struct interface *iface, struct iovec *iov, int iov_len)
42 static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
43 static struct sockaddr_in a = {
44 .sin_family = AF_INET,
45 .sin_port = htons(MCAST_PORT),
47 static struct msghdr m = {
48 .msg_name = (struct sockaddr *) &a,
49 .msg_namelen = sizeof(a),
50 .msg_control = cmsg_data,
51 .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
53 struct in_pktinfo *pkti;
55 int fd = iface->fd.fd;
58 m.msg_iovlen = iov_len;
60 memset(cmsg_data, 0, sizeof(cmsg_data));
61 cmsg = CMSG_FIRSTHDR(&m);
62 cmsg->cmsg_len = m.msg_controllen;
63 cmsg->cmsg_level = IPPROTO_IP;
64 cmsg->cmsg_type = IP_PKTINFO;
66 pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
67 pkti->ipi_ifindex = iface->ifindex;
69 a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
71 return sendmsg(fd, &m, 0);
74 static void interface_free(struct interface *iface)
76 if (cur_iface == iface)
80 if (iface->fd.fd >= 0) {
81 uloop_fd_delete(&iface->fd);
87 static void interface_start(struct interface *iface)
93 iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
94 struct vlist_node *node_old)
96 struct interface *iface;
99 iface = container_of(node_old, struct interface, node);
100 interface_free(iface);
104 iface = container_of(node_new, struct interface, node);
105 interface_start(iface);
109 int interface_socket_setup(struct interface *iface)
111 struct ip_mreqn mreq;
115 struct sockaddr_in sa = { 0 };
117 int fd = iface->fd.fd;
119 inet_aton(iface->ip, &in);
121 sa.sin_family = AF_INET;
122 sa.sin_port = htons(MCAST_PORT);
123 inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
125 memset(&mreq, 0, sizeof(mreq));
126 mreq.imr_address.s_addr = in.s_addr;
127 mreq.imr_multiaddr = sa.sin_addr;
128 mreq.imr_ifindex = iface->ifindex;
130 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
131 fprintf(stderr, "ioctl failed: IP_MULTICAST_TTL\n");
133 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
134 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
136 /* Some network drivers have issues with dropping membership of
137 * mcast groups when the iface is down, but don't allow rejoining
138 * when it comes back up. This is an ugly workaround
139 * -- this was copied from avahi --
141 setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
143 if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
144 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
150 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0)
151 fprintf(stderr, "ioctl failed: IP_RECVTTL\n");
153 if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
154 fprintf(stderr, "ioctl failed: IP_PKTINFO\n");
156 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0)
157 fprintf(stderr, "ioctl failed: IP_MULTICAST_LOOP\n");
163 get_iface_ipv4(const char *ifname)
165 static char buffer[INET_ADDRSTRLEN];
170 sock = socket(AF_INET, SOCK_DGRAM, 0);
174 memset(&ir, 0, sizeof(struct ifreq));
175 strncpy(ir.ifr_name, ifname, sizeof(ir.ifr_name));
177 if (ioctl(sock, SIOCGIFADDR, &ir) < 0)
180 ret = inet_ntop(AF_INET, &((struct sockaddr_in *) &ir.ifr_addr)->sin_addr, buffer, sizeof(buffer));
186 int interface_add(const char *name)
188 struct interface *iface;
190 char *name_buf, *ip_buf;
192 ip_str = get_iface_ipv4(name);
196 iface = calloc_a(sizeof(*iface),
197 &name_buf, strlen(name) + 1,
198 &ip_buf, strlen(ip_str) + 1);
200 iface->name = strcpy(name_buf, name);
201 iface->ip = strcpy(ip_buf, ip_str);
202 iface->ifindex = if_nametoindex(name);
205 if (iface->ifindex <= 0)
208 vlist_add(&interfaces, &iface->node, name);
216 VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);