interface.c

   1 /*
   2  * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
   3  * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
   4  *
   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
   8  *
   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.
  13  */
  14
  15 #define _GNU_SOURCE
  16 #include <sys/socket.h>
  17 #include <sys/ioctl.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <sys/utsname.h>
  21 #include <net/if.h>
  22 #include <netinet/in.h>
  23 #include <arpa/inet.h>
  24 #include <sys/types.h>
  25
  26 #include <ifaddrs.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <stdio.h>
  31 #include <errno.h>
  32
  33 #include <libubox/usock.h>
  34 #include <libubox/uloop.h>
  35 #include <libubox/avl-cmp.h>
  36 #include <libubox/utils.h>
  37 #include "interface.h"
  38 #include "util.h"
  39 #include "dns.h"
  40 #include "announce.h"
  41 #include "service.h"
  42
  43 static int
  44 interface_send_packet4(struct interface *iface, struct sockaddr_in *to, struct iovec *iov, int iov_len)
  45 {
  46         static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
  47         static struct sockaddr_in a;
  48         static struct msghdr m = {
  49                 .msg_name = (struct sockaddr *) &a,
  50                 .msg_namelen = sizeof(a),
  51                 .msg_control = cmsg_data,
  52                 .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
  53         };
  54         struct in_pktinfo *pkti;
  55         struct cmsghdr *cmsg;
  56         int fd = iface->fd.fd;
  57
  58         a.sin_family = AF_INET;
  59         a.sin_port = htons(MCAST_PORT);
  60         m.msg_iov = iov;
  61         m.msg_iovlen = iov_len;
  62
  63         memset(cmsg_data, 0, sizeof(cmsg_data));
  64         cmsg = CMSG_FIRSTHDR(&m);
  65         cmsg->cmsg_len = m.msg_controllen;
  66         cmsg->cmsg_level = IPPROTO_IP;
  67         cmsg->cmsg_type = IP_PKTINFO;
  68
  69         pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
  70         pkti->ipi_ifindex = iface->ifindex;
  71
  72         if (iface->multicast) {
  73                 a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
  74                 if (to)
  75                         fprintf(stderr, "Ignoring IPv4 address for multicast interface\n");
  76         } else {
  77                 a.sin_addr.s_addr = to->sin_addr.s_addr;
  78         }
  79
  80         return sendmsg(fd, &m, 0);
  81 }
  82
  83 static int
  84 interface_send_packet6(struct interface *iface, struct sockaddr_in6 *to, struct iovec *iov, int iov_len)
  85 {
  86         static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in6_pktinfo)) / sizeof(size_t)) + 1];
  87         static struct sockaddr_in6 a;
  88         static struct msghdr m = {
  89                 .msg_name = (struct sockaddr *) &a,
  90                 .msg_namelen = sizeof(a),
  91                 .msg_control = cmsg_data,
  92                 .msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo)),
  93         };
  94         struct in6_pktinfo *pkti;
  95         struct cmsghdr *cmsg;
  96         int fd = iface->fd.fd;
  97
  98         a.sin6_family = AF_INET6;
  99         a.sin6_port = htons(MCAST_PORT);
 100         m.msg_iov = iov;
 101         m.msg_iovlen = iov_len;
 102
 103         memset(cmsg_data, 0, sizeof(cmsg_data));
 104         cmsg = CMSG_FIRSTHDR(&m);
 105         cmsg->cmsg_len = m.msg_controllen;
 106         cmsg->cmsg_level = IPPROTO_IPV6;
 107         cmsg->cmsg_type = IPV6_PKTINFO;
 108
 109         pkti = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 110         pkti->ipi6_ifindex = iface->ifindex;
 111
 112         if (iface->multicast) {
 113                 inet_pton(AF_INET6, MCAST_ADDR6, &a.sin6_addr);
 114                 if (to)
 115                         fprintf(stderr, "Ignoring IPv6 address for multicast interface\n");
 116         } else {
 117                 a.sin6_addr = to->sin6_addr;
 118         }
 119
 120         return sendmsg(fd, &m, 0);
 121 }
 122
 123 int
 124 interface_send_packet(struct interface *iface, struct sockaddr *to, struct iovec *iov, int iov_len)
 125 {
 126         if (!iface->multicast && !to) {
 127                 fprintf(stderr, "No IP address specified for unicast interface\n");
 128                 return -1;
 129         }
 130
 131         if (debug > 1) {
 132                 fprintf(stderr, "TX ipv%d: %s\n", iface->v6 * 2 + 4, iface->name);
 133                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 134         }
 135
 136         if (iface->v6)
 137                 return interface_send_packet6(iface, (struct sockaddr_in6 *)to, iov, iov_len);
 138
 139         return interface_send_packet4(iface, (struct sockaddr_in *)to, iov, iov_len);
 140 }
 141
 142 static void interface_close(struct interface *iface)
 143 {
 144         if (iface->fd.fd < 0)
 145                 return;
 146
 147         announce_free(iface);
 148         uloop_fd_delete(&iface->fd);
 149         close(iface->fd.fd);
 150         iface->fd.fd = -1;
 151 }
 152
 153 static void interface_free(struct interface *iface)
 154 {
 155         interface_close(iface);
 156         free(iface);
 157 }
 158
 159 static int
 160 interface_valid_src(void *ip1, void *mask, void *ip2, int len)
 161 {
 162         uint8_t *i1 = ip1;
 163         uint8_t *i2 = ip2;
 164         uint8_t *m = mask;
 165         int i;
 166
 167         if (cfg_no_subnet)
 168                 return 0;
 169
 170         for (i = 0; i < len; i++, i1++, i2++, m++) {
 171                 if ((*i1 & *m) != (*i2 & *m))
 172                         return -1;
 173         }
 174
 175         return 0;
 176 }
 177
 178 static void
 179 read_socket4(struct uloop_fd *u, unsigned int events)
 180 {
 181         struct interface *iface = container_of(u, struct interface, fd);
 182         static uint8_t buffer[8 * 1024];
 183         struct iovec iov[1];
 184         char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo)) + CMSG_SPACE(sizeof(int)) + 1];
 185         struct cmsghdr *cmsgptr;
 186         struct msghdr msg;
 187         socklen_t len;
 188         struct sockaddr_in from;
 189         int flags = 0, ifindex = -1;
 190         uint8_t ttl = 0;
 191         struct in_pktinfo *inp = NULL;
 192
 193         if (u->eof) {
 194                 interface_close(iface);
 195                 uloop_timeout_set(&iface->reconnect, 1000);
 196                 return;
 197         }
 198
 199         iov[0].iov_base = buffer;
 200         iov[0].iov_len = sizeof(buffer);
 201
 202         memset(&msg, 0, sizeof(msg));
 203         msg.msg_name = (struct sockaddr *) &from;
 204         msg.msg_namelen = sizeof(struct sockaddr_in);
 205         msg.msg_iov = iov;
 206         msg.msg_iovlen = 1;
 207         msg.msg_control = &cmsg;
 208         msg.msg_controllen = sizeof(cmsg);
 209
 210         len = recvmsg(u->fd, &msg, flags);
 211         if (len == -1) {
 212                 perror("read failed");
 213                 return;
 214         }
 215         for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
 216                 void *c = CMSG_DATA(cmsgptr);
 217
 218                 switch (cmsgptr->cmsg_type) {
 219                 case IP_PKTINFO:
 220                         inp = ((struct in_pktinfo *) c);
 221                         break;
 222
 223                 case IP_TTL:
 224                         ttl = (uint8_t) *((int *) c);
 225                         break;
 226
 227                 default:
 228                         fprintf(stderr, "unknown cmsg %x\n", cmsgptr->cmsg_type);
 229                         return;
 230                 }
 231         }
 232
 233         if (ttl != 255)
 234                 return;
 235
 236         if (debug > 1) {
 237                 char buf[256];
 238
 239                 fprintf(stderr, "RX ipv4: %s\n", iface->name);
 240                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 241                 inet_ntop(AF_INET, &from.sin_addr, buf, 256);
 242                 fprintf(stderr, "  src %s:%d\n", buf, from.sin_port);
 243                 inet_ntop(AF_INET, &inp->ipi_spec_dst, buf, 256);
 244                 fprintf(stderr, "  dst %s\n", buf);
 245                 inet_ntop(AF_INET, &inp->ipi_addr, buf, 256);
 246                 fprintf(stderr, "  real %s\n", buf);
 247         }
 248
 249         if (inp->ipi_ifindex != iface->ifindex)
 250                 fprintf(stderr, "invalid iface index %d != %d\n", ifindex, iface->ifindex);
 251         else if (!interface_valid_src((void *) &iface->v4_addr, (void *) &iface->v4_netmask, (void *) &from.sin_addr, 4))
 252                 dns_handle_packet(iface, (struct sockaddr *) &from, from.sin_port, buffer, len);
 253 }
 254
 255 static void
 256 read_socket6(struct uloop_fd *u, unsigned int events)
 257 {
 258         struct interface *iface = container_of(u, struct interface, fd);
 259         static uint8_t buffer[8 * 1024];
 260         struct iovec iov[1];
 261         char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(sizeof(int)) + 1];
 262         struct cmsghdr *cmsgptr;
 263         struct msghdr msg;
 264         socklen_t len;
 265         struct sockaddr_in6 from;
 266         int flags = 0, ifindex = -1;
 267         int ttl = 0;
 268         struct in6_pktinfo *inp = NULL;
 269
 270         if (u->eof) {
 271                 interface_close(iface);
 272                 uloop_timeout_set(&iface->reconnect, 1000);
 273                 return;
 274         }
 275
 276         iov[0].iov_base = buffer;
 277         iov[0].iov_len = sizeof(buffer);
 278
 279         memset(&msg, 0, sizeof(msg));
 280         msg.msg_name = (struct sockaddr *) &from;
 281         msg.msg_namelen = sizeof(struct sockaddr_in6);
 282         msg.msg_iov = iov;
 283         msg.msg_iovlen = 1;
 284         msg.msg_control = &cmsg6;
 285         msg.msg_controllen = sizeof(cmsg6);
 286
 287         len = recvmsg(u->fd, &msg, flags);
 288         if (len == -1) {
 289                 perror("read failed");
 290                 return;
 291         }
 292         for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
 293                 void *c = CMSG_DATA(cmsgptr);
 294
 295                 switch (cmsgptr->cmsg_type) {
 296                 case IPV6_PKTINFO:
 297                         inp = ((struct in6_pktinfo *) c);
 298                         break;
 299
 300                 case IPV6_HOPLIMIT:
 301                         ttl = (uint8_t) *((int *) c);
 302                         break;
 303
 304                 default:
 305                         fprintf(stderr, "unknown cmsg %x\n", cmsgptr->cmsg_type);
 306                         return;
 307                 }
 308         }
 309
 310         if (ttl != 255)
 311                 return;
 312
 313         if (debug > 1) {
 314                 char buf[256];
 315
 316                 fprintf(stderr, "RX ipv6: %s\n", iface->name);
 317                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 318                 inet_ntop(AF_INET6, &from.sin6_addr, buf, 256);
 319                 fprintf(stderr, "  src %s:%d\n", buf, from.sin6_port);
 320                 inet_ntop(AF_INET6, &inp->ipi6_addr, buf, 256);
 321                 fprintf(stderr, "  dst %s\n", buf);
 322         }
 323
 324         if (inp->ipi6_ifindex != iface->ifindex)
 325                 fprintf(stderr, "invalid iface index %d != %d\n", ifindex, iface->ifindex);
 326         else if (!interface_valid_src((void *) &iface->v6_addr, (void *) &iface->v6_netmask, (void *) &from.sin6_addr, 16))
 327                 dns_handle_packet(iface, (struct sockaddr *) &from, from.sin6_port, buffer, len);
 328 }
 329
 330 static int
 331 interface_mcast_setup4(struct interface *iface)
 332 {
 333         struct ip_mreqn mreq;
 334         uint8_t ttl = 255;
 335         int no = 0;
 336         struct sockaddr_in sa = { 0 };
 337         int fd = iface->fd.fd;
 338
 339         sa.sin_family = AF_INET;
 340         sa.sin_port = htons(MCAST_PORT);
 341         inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
 342
 343         memset(&mreq, 0, sizeof(mreq));
 344         mreq.imr_address.s_addr = iface->v4_addr.s_addr;
 345         mreq.imr_multiaddr = sa.sin_addr;
 346         mreq.imr_ifindex = iface->ifindex;
 347
 348         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 349                 fprintf(stderr, "ioctl failed: IP_MULTICAST_TTL\n");
 350
 351         /* Some network drivers have issues with dropping membership of
 352          * mcast groups when the iface is down, but don't allow rejoining
 353          * when it comes back up. This is an ugly workaround
 354          * -- this was copied from avahi --
 355          */
 356         setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
 357
 358         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
 359                 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
 360                 close(fd);
 361                 fd = -1;
 362                 return -1;
 363         }
 364
 365         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0)
 366                 fprintf(stderr, "ioctl failed: IP_MULTICAST_LOOP\n");
 367
 368         return 0;
 369 }
 370
 371 static int
 372 interface_socket_setup6(struct interface *iface)
 373 {
 374         struct ipv6_mreq mreq;
 375         int ttl = 255;
 376         int no = 0;
 377         struct sockaddr_in6 sa = { 0 };
 378         int fd = iface->fd.fd;
 379
 380         sa.sin6_family = AF_INET6;
 381         sa.sin6_port = htons(MCAST_PORT);
 382         inet_pton(AF_INET6, MCAST_ADDR6, &sa.sin6_addr);
 383
 384         memset(&mreq, 0, sizeof(mreq));
 385         mreq.ipv6mr_multiaddr = sa.sin6_addr;
 386         mreq.ipv6mr_interface = iface->ifindex;
 387
 388         if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 389                 fprintf(stderr, "ioctl failed: IPV6_MULTICAST_HOPS\n");
 390
 391         setsockopt(fd, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &mreq, sizeof(mreq));
 392         if (setsockopt(fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
 393                 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
 394                 close(fd);
 395                 fd = -1;
 396                 return -1;
 397         }
 398
 399         if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &no, sizeof(no)) < 0)
 400                 fprintf(stderr, "ioctl failed: IPV6_MULTICAST_LOOP\n");
 401
 402         return 0;
 403 }
 404
 405 static void
 406 reconnect_socket4(struct uloop_timeout *timeout)
 407 {
 408         struct interface *iface = container_of(timeout, struct interface, reconnect);
 409         int ttl = 255;
 410         int yes = 1;
 411
 412         iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK | USOCK_IPV4ONLY,
 413                 (iface->multicast) ? (iface->mcast_addr) : (iface->v4_addrs), "5353");
 414         if (iface->fd.fd < 0) {
 415                 fprintf(stderr, "failed to add listener %s: %s\n", iface->mcast_addr, strerror(errno));
 416                 goto retry;
 417         }
 418
 419         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name, strlen(iface->name) < 0))
 420                 fprintf(stderr, "ioctl failed: SO_BINDTODEVICE\n");
 421
 422         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
 423                 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
 424
 425         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0)
 426                 fprintf(stderr, "ioctl failed: IP_TTL\n");
 427
 428         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0)
 429                 fprintf(stderr, "ioctl failed: IP_RECVTTL\n");
 430
 431         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
 432                 fprintf(stderr, "ioctl failed: IP_PKTINFO\n");
 433
 434         if (iface->multicast && interface_mcast_setup4(iface)) {
 435                 iface->fd.fd = -1;
 436                 goto retry;
 437         }
 438
 439         uloop_fd_add(&iface->fd, ULOOP_READ);
 440         if (iface->multicast) {
 441                 dns_send_question(iface, "_services._dns-sd._udp.local", TYPE_PTR, 0);
 442                 announce_init(iface);
 443         }
 444
 445         return;
 446
 447 retry:
 448         uloop_timeout_set(timeout, 1000);
 449 }
 450
 451 static void
 452 reconnect_socket6(struct uloop_timeout *timeout)
 453 {
 454         struct interface *iface = container_of(timeout, struct interface, reconnect);
 455         char mcast_addr[128];
 456         int ttl = 255;
 457         int yes = 1;
 458
 459         snprintf(mcast_addr, sizeof(mcast_addr), "%s%%%s", (iface->multicast) ? (iface->mcast_addr) : (iface->v6_addrs), iface->name);
 460         iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK | USOCK_IPV6ONLY, mcast_addr, "5353");
 461         if (iface->fd.fd < 0) {
 462                 fprintf(stderr, "failed to add listener %s: %s\n", mcast_addr, strerror(errno));
 463                 goto retry;
 464         }
 465
 466         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name, strlen(iface->name) < 0))
 467                 fprintf(stderr, "ioctl failed: SO_BINDTODEVICE\n");
 468
 469         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 470                 fprintf(stderr, "ioctl failed: IPV6_UNICAST_HOPS\n");
 471
 472         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0)
 473                 fprintf(stderr, "ioctl failed: IPV6_RECVPKTINFO\n");
 474
 475         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0)
 476                 fprintf(stderr, "ioctl failed: IPV6_RECVHOPLIMIT\n");
 477
 478         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
 479                 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
 480
 481         if (iface->multicast && interface_socket_setup6(iface)) {
 482                 iface->fd.fd = -1;
 483                 goto retry;
 484         }
 485
 486         uloop_fd_add(&iface->fd, ULOOP_READ);
 487
 488         if (iface->multicast) {
 489                 dns_send_question(iface, "_services._dns-sd._udp.local", TYPE_PTR, 0);
 490                 announce_init(iface);
 491         }
 492
 493         return;
 494
 495 retry:
 496         uloop_timeout_set(timeout, 1000);
 497 }
 498
 499
 500 static void interface_start(struct interface *iface)
 501 {
 502         if (iface->v6) {
 503                 iface->fd.cb = read_socket6;
 504                 iface->reconnect.cb = reconnect_socket6;
 505         } else {
 506                 iface->fd.cb = read_socket4;
 507                 iface->reconnect.cb = reconnect_socket4;
 508         }
 509         uloop_timeout_set(&iface->reconnect, 100);
 510 }
 511
 512 static void
 513 iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
 514                 struct vlist_node *node_old)
 515 {
 516         struct interface *iface;
 517
 518         if (node_old) {
 519                 iface = container_of(node_old, struct interface, node);
 520                 interface_free(iface);
 521         }
 522
 523         if (node_new) {
 524                 iface = container_of(node_new, struct interface, node);
 525                 interface_start(iface);
 526         }
 527 }
 528
 529 static struct interface* _interface_add(const char *name, int multicast, int v6)
 530 {
 531         struct interface *iface;
 532         char *name_buf;
 533         char *id_buf;
 534
 535         iface = calloc_a(sizeof(*iface),
 536                 &name_buf, strlen(name) + 1,
 537                 &id_buf, strlen(name) + 5);
 538
 539         sprintf(id_buf, "%d_%d_%s", multicast, v6, name);
 540         iface->name = strcpy(name_buf, name);
 541         iface->id = id_buf;
 542         iface->ifindex = if_nametoindex(name);
 543         iface->fd.fd = -1;
 544         iface->multicast = multicast;
 545         iface->v6 = v6;
 546         if (v6)
 547                 iface->mcast_addr = MCAST_ADDR6;
 548         else
 549                 iface->mcast_addr = MCAST_ADDR;
 550
 551         if (iface->ifindex <= 0)
 552                 goto error;
 553
 554         vlist_add(&interfaces, &iface->node, iface->id);
 555         return iface;
 556
 557 error:
 558         free(iface);
 559         return NULL;
 560 }
 561
 562 int interface_add(const char *name)
 563 {
 564         struct interface *v4 = NULL, *v6 = NULL, *unicast;
 565         struct ifaddrs *ifap, *ifa;
 566
 567         getifaddrs(&ifap);
 568
 569         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 570                 if (strcmp(ifa->ifa_name, name))
 571                         continue;
 572                 if (ifa->ifa_addr->sa_family == AF_INET && !v4) {
 573                         struct sockaddr_in *sa;
 574
 575                         if (cfg_proto && (cfg_proto != 4))
 576                                 continue;
 577
 578                         unicast = _interface_add(name, 0, 0);
 579                         if (!unicast)
 580                                 continue;
 581                         v4 = _interface_add(name, 1, 0);
 582                         if (!v4)
 583                                 continue;
 584
 585                         sa = (struct sockaddr_in *) ifa->ifa_addr;
 586                         memcpy(&v4->v4_addr, &sa->sin_addr, sizeof(v4->v4_addr));
 587                         memcpy(&unicast->v4_addr, &sa->sin_addr, sizeof(unicast->v4_addr));
 588
 589                         inet_ntop(AF_INET, &sa->sin_addr, v4->v4_addrs, sizeof(v4->v4_addrs));
 590                         inet_ntop(AF_INET, &sa->sin_addr, unicast->v4_addrs, sizeof(unicast->v4_addrs));
 591
 592                         sa = (struct sockaddr_in *) ifa->ifa_netmask;
 593                         memcpy(&unicast->v4_netmask, &sa->sin_addr, sizeof(unicast->v4_netmask));
 594                         memcpy(&v4->v4_netmask, &sa->sin_addr, sizeof(v4->v4_netmask));
 595
 596                         v4->peer = unicast;
 597                         unicast->peer = v4;
 598                 }
 599
 600                 if (ifa->ifa_addr->sa_family == AF_INET6 && !v6) {
 601                         uint8_t ll_prefix[] = {0xfe, 0x80 };
 602                         struct sockaddr_in6 *sa6;
 603
 604                         if (cfg_proto && (cfg_proto != 6))
 605                                 continue;
 606
 607                         sa6 = (struct sockaddr_in6 *) ifa->ifa_addr;
 608                         if (memcmp(&sa6->sin6_addr, &ll_prefix, 2))
 609                                 continue;
 610
 611                         unicast = _interface_add(name, 0, 1);
 612                         if (!unicast)
 613                                 continue;
 614                         v6 = _interface_add(name, 1, 1);
 615                         if (!v6)
 616                                 continue;
 617
 618                         memcpy(&v6->v6_addr, &sa6->sin6_addr, sizeof(v6->v6_addr));
 619                         memcpy(&unicast->v6_addr, &sa6->sin6_addr, sizeof(unicast->v6_addr));
 620
 621                         inet_ntop(AF_INET6, &sa6->sin6_addr, v6->v6_addrs, sizeof(v6->v6_addrs));
 622                         inet_ntop(AF_INET6, &sa6->sin6_addr, unicast->v6_addrs, sizeof(unicast->v6_addrs));
 623
 624                         sa6 = (struct sockaddr_in6 *) ifa->ifa_netmask;
 625                         memcpy(&v6->v6_netmask, &sa6->sin6_addr, sizeof(v6->v6_netmask));
 626                         memcpy(&unicast->v6_netmask, &sa6->sin6_addr, sizeof(unicast->v6_netmask));
 627
 628                         v6->peer = unicast;
 629                         unicast->peer = v6;
 630                 }
 631         }
 632
 633         freeifaddrs(ifap);
 634
 635         return !v4 && !v6;
 636 }
 637
 638 void interface_shutdown(void)
 639 {
 640         struct interface *iface;
 641
 642         vlist_for_each_element(&interfaces, iface, node)
 643                 if (iface->fd.fd > 0 && iface->multicast) {
 644                         dns_reply_a(iface, NULL, 0);
 645                         service_announce_services(iface, NULL, 0);
 646                 }
 647         vlist_for_each_element(&interfaces, iface, node)
 648                 interface_close(iface);
 649 }
 650
 651 struct interface*
 652 interface_get(const char *name, int v6, int multicast)
 653 {
 654         char id_buf[32];
 655         snprintf(id_buf, sizeof(id_buf), "%d_%d_%s", multicast, v6, name);
 656         struct interface *iface = vlist_find(&interfaces, id_buf, iface, node);
 657         return iface;
 658 }
 659
 660 VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);