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/usock.h>
31 #include <libubox/uloop.h>
32 #include <libubox/avl-cmp.h>
33 #include <libubox/utils.h>
34 #include "interface.h"
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_close(struct interface *iface)
80 uloop_fd_delete(&iface->fd);
85 static void interface_free(struct interface *iface)
87 interface_close(iface);
92 read_socket(struct uloop_fd *u, unsigned int events)
94 struct interface *iface = container_of(u, struct interface, fd);
95 static uint8_t buffer[8 * 1024];
99 interface_close(iface);
100 uloop_timeout_set(&iface->reconnect, 1000);
104 len = read(u->fd, buffer, sizeof(buffer));
106 fprintf(stderr, "read failed: %s\n", strerror(errno));
110 dns_handle_packet(iface, buffer, len);
114 interface_socket_setup(struct interface *iface)
116 struct ip_mreqn mreq;
120 struct sockaddr_in sa = { 0 };
121 int fd = iface->fd.fd;
123 sa.sin_family = AF_INET;
124 sa.sin_port = htons(MCAST_PORT);
125 inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
127 memset(&mreq, 0, sizeof(mreq));
128 mreq.imr_address.s_addr = iface->v4_addr.s_addr;
129 mreq.imr_multiaddr = sa.sin_addr;
130 mreq.imr_ifindex = iface->ifindex;
132 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
133 fprintf(stderr, "ioctl failed: IP_MULTICAST_TTL\n");
135 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
136 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
138 /* Some network drivers have issues with dropping membership of
139 * mcast groups when the iface is down, but don't allow rejoining
140 * when it comes back up. This is an ugly workaround
141 * -- this was copied from avahi --
143 setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
145 if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
146 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
152 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0)
153 fprintf(stderr, "ioctl failed: IP_RECVTTL\n");
155 if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
156 fprintf(stderr, "ioctl failed: IP_PKTINFO\n");
158 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0)
159 fprintf(stderr, "ioctl failed: IP_MULTICAST_LOOP\n");
165 reconnect_socket(struct uloop_timeout *timeout)
167 struct interface *iface = container_of(timeout, struct interface, reconnect);
169 iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK, MCAST_ADDR, "5353");
170 if (iface->fd.fd < 0) {
171 fprintf(stderr, "failed to add listener: %s\n", strerror(errno));
175 if (interface_socket_setup(iface)) {
180 uloop_fd_add(&iface->fd, ULOOP_READ);
181 dns_send_question(iface, "_services._dns-sd._udp.local", TYPE_PTR);
182 announce_init(iface);
186 uloop_timeout_set(timeout, 1000);
190 static void interface_start(struct interface *iface)
192 iface->fd.cb = read_socket;
193 iface->reconnect.cb = reconnect_socket;
194 uloop_timeout_set(&iface->reconnect, 100);
198 iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
199 struct vlist_node *node_old)
201 struct interface *iface;
204 iface = container_of(node_old, struct interface, node);
205 interface_free(iface);
209 iface = container_of(node_new, struct interface, node);
210 interface_start(iface);
215 get_iface_ipv4(struct interface *iface)
217 struct sockaddr_in *sin;
221 sock = socket(AF_INET, SOCK_DGRAM, 0);
225 memset(&ir, 0, sizeof(struct ifreq));
226 strncpy(ir.ifr_name, iface->name, sizeof(ir.ifr_name));
228 ret = ioctl(sock, SIOCGIFADDR, &ir);
232 sin = (struct sockaddr_in *) &ir.ifr_addr;
233 memcpy(&iface->v4_addr, &sin->sin_addr, sizeof(iface->v4_addr));
240 int interface_add(const char *name)
242 struct interface *iface;
245 iface = calloc_a(sizeof(*iface),
246 &name_buf, strlen(name) + 1);
248 iface->name = strcpy(name_buf, name);
249 iface->ifindex = if_nametoindex(name);
252 if (iface->ifindex <= 0)
255 if (get_iface_ipv4(iface))
258 vlist_add(&interfaces, &iface->node, name);
266 VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);