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