4 This file is part of avahi.
6 avahi is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as
8 published by the Free Software Foundation; either version 2.1 of the
9 License, or (at your option) any later version.
11 avahi is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
14 Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with avahi; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
30 #include <sys/socket.h>
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
37 #include <sys/ioctl.h>
41 #include <net/if_dl.h>
49 /* this is a portability hack */
50 #ifndef IPV6_ADD_MEMBERSHIP
51 #ifdef IPV6_JOIN_GROUP
52 #define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
56 #ifndef IPV6_DROP_MEMBERSHIP
57 #ifdef IPV6_LEAVE_GROUP
58 #define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
62 static void mdns_mcast_group_ipv4(struct sockaddr_in *ret_sa) {
65 memset(ret_sa, 0, sizeof(struct sockaddr_in));
66 ret_sa->sin_family = AF_INET;
67 ret_sa->sin_port = htons(AVAHI_MDNS_PORT);
68 inet_pton(AF_INET, AVAHI_IPV4_MCAST_GROUP, &ret_sa->sin_addr);
71 static void mdns_mcast_group_ipv6(struct sockaddr_in6 *ret_sa) {
74 memset(ret_sa, 0, sizeof(struct sockaddr_in6));
75 ret_sa->sin6_family = AF_INET6;
76 ret_sa->sin6_port = htons(AVAHI_MDNS_PORT);
77 inet_pton(AF_INET6, AVAHI_IPV6_MCAST_GROUP, &ret_sa->sin6_addr);
80 static void ipv4_address_to_sockaddr(struct sockaddr_in *ret_sa, const AvahiIPv4Address *a, uint16_t port) {
85 memset(ret_sa, 0, sizeof(struct sockaddr_in));
86 ret_sa->sin_family = AF_INET;
87 ret_sa->sin_port = htons(port);
88 memcpy(&ret_sa->sin_addr, a, sizeof(AvahiIPv4Address));
91 static void ipv6_address_to_sockaddr(struct sockaddr_in6 *ret_sa, const AvahiIPv6Address *a, uint16_t port) {
96 memset(ret_sa, 0, sizeof(struct sockaddr_in6));
97 ret_sa->sin6_family = AF_INET6;
98 ret_sa->sin6_port = htons(port);
99 memcpy(&ret_sa->sin6_addr, a, sizeof(AvahiIPv6Address));
102 #ifdef HAVE_STRUCT_IP_MREQN
103 int avahi_mdns_mcast_join_ipv4(int fd, int idx, int join) {
104 struct ip_mreqn mreq;
106 int avahi_mdns_mcast_join_ipv4(int fd, const AvahiAddress *a, int join) {
110 struct sockaddr_in sa;
111 memset(&mreq, 0, sizeof(mreq));
113 #ifdef HAVE_STRUCT_IP_MREQN
114 mreq.imr_ifindex = idx;
117 assert(a->proto == AVAHI_PROTO_INET);
118 mreq.imr_interface.s_addr = htonl(a->data.ipv4.address);
121 mdns_mcast_group_ipv4(&sa);
122 mreq.imr_multiaddr = sa.sin_addr;
124 if (setsockopt(fd, IPPROTO_IP, join ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
125 avahi_log_warn("%s failed: %s", join ? "IP_ADD_MEMBERSHIP" : "IP_DROP_MEMBERSHIP", strerror(errno));
132 int avahi_mdns_mcast_join_ipv6(int fd, int idx, int join) {
133 struct ipv6_mreq mreq6;
134 struct sockaddr_in6 sa6;
136 mdns_mcast_group_ipv6 (&sa6);
138 memset(&mreq6, 0, sizeof(mreq6));
139 mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
140 mreq6.ipv6mr_interface = idx;
142 if (setsockopt(fd, IPPROTO_IPV6, join ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
143 avahi_log_warn("%s failed: %s", join ? "IPV6_ADD_MEMBERSHIP" : "IPV6_DROP_MEMBERSHIP", strerror(errno));
150 static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
157 if (bind(fd, sa, l) < 0) {
159 if (errno != EADDRINUSE) {
160 avahi_log_warn("bind() failed: %s", strerror(errno));
164 avahi_log_warn("*** WARNING: Detected another %s mDNS stack running on this host. This makes mDNS unreliable and is thus not recommended. ***",
165 sa->sa_family == AF_INET ? "IPv4" : "IPv6");
167 /* Try again, this time with SO_REUSEADDR set */
169 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
170 avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
174 if (bind(fd, sa, l) < 0) {
175 avahi_log_warn("bind() failed: %s", strerror(errno));
180 /* We enable SO_REUSEADDR afterwards, to make sure that the
181 * user may run other mDNS implementations if he really
185 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
186 avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
194 static int ip_pktinfo (int fd, int yes)
199 if ((ret = setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes))) < 0) {
200 avahi_log_warn("IP_PKTINFO failed: %s", strerror(errno));
203 #ifdef IP_RECVINTERFACE
204 if ((ret = setsockopt (fd, IPPROTO_IP, IP_RECVINTERFACE, &yes, sizeof (yes))) < 0) {
205 avahi_log_warn("IP_RECVINTERFACE failed: %s", strerror(errno));
209 if ((ret = setsockopt (fd, IPPROTO_IP, IP_RECVIF, &yes, sizeof (yes))) < 0) {
210 avahi_log_warn("IP_RECVIF failed: %s", strerror(errno));
212 #endif /* IP_RECVIF */
213 #endif /* IP_RECVINTERFACE */
214 #if defined (IP_RECVDSTADDR) /* && !defined(solaris) */
215 if ((ret = setsockopt (fd, IPPROTO_IP, IP_RECVDSTADDR, &yes, sizeof (yes))) < 0) {
216 avahi_log_warn("IP_RECVDSTADDR failed: %s", strerror(errno));
218 #endif /* IP_RECVDSTADDR */
219 #endif /* IP_PKTINFO */
224 int avahi_open_socket_ipv4(int no_reuse) {
225 struct sockaddr_in local;
226 int fd = -1, ttl, yes, r;
228 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
229 avahi_log_warn("socket() failed: %s", strerror(errno));
234 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
235 avahi_log_warn("IP_MULTICAST_TTL failed: %s", strerror(errno));
240 if (setsockopt(fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) {
241 avahi_log_warn("IP_TTL failed: %s", strerror(errno));
246 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
247 avahi_log_warn("IP_MULTICAST_LOOP failed: %s", strerror(errno));
251 memset(&local, 0, sizeof(local));
252 local.sin_family = AF_INET;
253 local.sin_port = htons(AVAHI_MDNS_PORT);
256 r = bind(fd, (struct sockaddr*) &local, sizeof(local));
258 r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
264 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
265 avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
270 if (ip_pktinfo (fd, yes) < 0) {
274 if (avahi_set_cloexec(fd) < 0) {
275 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
279 if (avahi_set_nonblock(fd) < 0) {
280 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
293 int avahi_open_socket_ipv6(int no_reuse) {
294 struct sockaddr_in6 sa, local;
295 int fd = -1, ttl, yes, r;
297 mdns_mcast_group_ipv6(&sa);
299 if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
300 avahi_log_warn("socket() failed: %s", strerror(errno));
305 if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
306 avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s", strerror(errno));
311 if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
312 avahi_log_warn("IPV6_UNICAST_HOPS failed: %s", strerror(errno));
317 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
318 avahi_log_warn("IPV6_V6ONLY failed: %s", strerror(errno));
323 if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
324 avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s", strerror(errno));
328 memset(&local, 0, sizeof(local));
329 local.sin6_family = AF_INET6;
330 local.sin6_port = htons(AVAHI_MDNS_PORT);
333 r = bind(fd, (struct sockaddr*) &local, sizeof(local));
335 r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
342 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPS, &yes, sizeof(yes)) < 0) {
343 avahi_log_warn("IPV6_RECVHOPS failed: %s", strerror(errno));
346 #elif IPV6_RECVHOPLIMIT
348 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0) {
349 avahi_log_warn("IPV6_RECVHOPLIMIT failed: %s", strerror(errno));
354 if (setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
355 avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
360 #ifdef IPV6_RECVPKTINFO
362 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0) {
363 avahi_log_warn("IPV6_RECVPKTINFO failed: %s", strerror(errno));
368 if (setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
369 avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
374 if (avahi_set_cloexec(fd) < 0) {
375 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
379 if (avahi_set_nonblock(fd) < 0) {
380 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
393 static int sendmsg_loop(int fd, struct msghdr *msg, int flags) {
399 if (sendmsg(fd, msg, flags) >= 0)
402 if (errno != EAGAIN) {
403 avahi_log_debug("sendmsg() failed: %s", strerror(errno));
407 if (avahi_wait_for_write(fd) < 0)
414 int avahi_send_dns_packet_ipv4(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv4Address *a, uint16_t port) {
415 struct sockaddr_in sa;
418 struct cmsghdr *cmsg;
420 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)];
422 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct sockaddr_dl)];
423 #elif IP_RECVINTERFACE
424 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(u_short)];
429 assert(avahi_dns_packet_check_valid(p) >= 0);
430 assert(!a || port > 0);
433 mdns_mcast_group_ipv4(&sa);
435 ipv4_address_to_sockaddr(&sa, a, port);
437 memset(&io, 0, sizeof(io));
438 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
439 io.iov_len = p->size;
441 memset(&msg, 0, sizeof(msg));
443 msg.msg_namelen = sizeof(sa);
448 if (interface >= 0) {
450 memset(cmsg_data, 0, sizeof(cmsg_data));
451 cmsg = (struct cmsghdr*) cmsg_data;
452 cmsg->cmsg_len = sizeof(cmsg_data);
453 cmsg->cmsg_level = IPPROTO_IP;
456 struct in_pktinfo *pkti;
458 cmsg->cmsg_type = IP_PKTINFO;
459 pkti = (struct in_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
460 pkti->ipi_ifindex = interface;
464 struct sockaddr_dl *sdl;
466 cmsg->cmsg_type = IP_RECVIF;
467 sdl = (struct sockaddr_dl*) (cmsg_data + sizeof(struct cmsghdr));
468 sdl->sdl_index = interface;
470 #elif IP_RECVINTERFACE
474 cmsg->cmsg_type = IP_RECVINTERFACE;
475 i = (u_short *) (cmsg_data + sizeof(struct cmsghdr));
476 memcpy(&i, CMSG_DATA (cmsg), sizeof(u_short));
479 msg.msg_control = cmsg_data;
480 msg.msg_controllen = sizeof(cmsg_data);
482 msg.msg_control = NULL;
483 msg.msg_controllen = 0;
486 return sendmsg_loop(fd, &msg, 0);
489 int avahi_send_dns_packet_ipv6(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv6Address *a, uint16_t port) {
490 struct sockaddr_in6 sa;
493 struct cmsghdr *cmsg;
494 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in6_pktinfo)];
498 assert(avahi_dns_packet_check_valid(p) >= 0);
501 mdns_mcast_group_ipv6(&sa);
503 ipv6_address_to_sockaddr(&sa, a, port);
505 memset(&io, 0, sizeof(io));
506 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
507 io.iov_len = p->size;
510 memset(&msg, 0, sizeof(msg));
512 msg.msg_namelen = sizeof(sa);
517 if (interface >= 0) {
518 struct in6_pktinfo *pkti;
520 memset(cmsg_data, 0, sizeof(cmsg_data));
521 cmsg = (struct cmsghdr*) cmsg_data;
522 cmsg->cmsg_len = sizeof(cmsg_data);
523 cmsg->cmsg_level = IPPROTO_IPV6;
524 cmsg->cmsg_type = IPV6_PKTINFO;
526 pkti = (struct in6_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
527 pkti->ipi6_ifindex = interface;
529 msg.msg_control = cmsg_data;
530 msg.msg_controllen = sizeof(cmsg_data);
532 msg.msg_control = NULL;
533 msg.msg_controllen = 0;
536 return sendmsg_loop(fd, &msg, 0);
539 AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, AvahiIPv4Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
540 AvahiDnsPacket *p= NULL;
545 struct cmsghdr *cmsg;
546 int found_ttl = 0, found_iface = 0, found_addr = 0;
551 if (ioctl(fd, FIONREAD, &ms) < 0) {
552 avahi_log_warn("ioctl(): %s", strerror(errno));
556 p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
558 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
559 io.iov_len = p->max_size;
561 memset(&msg, 0, sizeof(msg));
563 msg.msg_name = ret_sa;
564 msg.msg_namelen = sizeof(struct sockaddr_in);
571 msg.msg_control = aux;
572 msg.msg_controllen = sizeof(aux);
575 if ((l = recvmsg(fd, &msg, 0)) < 0) {
576 avahi_log_warn("recvmsg(): %s", strerror(errno));
580 if (ret_sa && ret_sa->sin_addr.s_addr == INADDR_ANY) {
581 /* Linux 2.4 behaves very strangely sometimes! */
583 /*avahi_hexdump(AVAHI_DNS_PACKET_DATA(p), l); */
587 assert(!(msg.msg_flags & MSG_CTRUNC));
588 assert(!(msg.msg_flags & MSG_TRUNC));
589 p->size = (size_t) l;
594 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
596 if (cmsg->cmsg_level == IPPROTO_IP) {
597 switch (cmsg->cmsg_type) {
603 *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
609 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
612 *ret_iface = (int) i->ipi_ifindex;
614 if (ret_dest_address)
615 ret_dest_address->address = i->ipi_addr.s_addr;
616 found_addr = found_iface = 1;
622 struct sockaddr_dl *sdl = (struct sockaddr_dl *) CMSG_DATA (cmsg);
625 *ret_iface = (int) sdl->sdl_index;
630 #ifdef IP_RECVDSTADDR
632 if (ret_dest_address)
633 memcpy (&ret_dest_address->address, CMSG_DATA (cmsg), 4);
638 avahi_log_warn("Unhandled cmsg_type : %d",cmsg->cmsg_type);
652 avahi_dns_packet_free(p);
657 AvahiDnsPacket* avahi_recv_dns_packet_ipv6(int fd, struct sockaddr_in6 *ret_sa, AvahiIPv6Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
658 AvahiDnsPacket *p = NULL;
665 struct cmsghdr *cmsg;
666 int found_ttl = 0, found_iface = 0;
670 if (ioctl(fd, FIONREAD, &ms) < 0) {
671 avahi_log_warn("ioctl(): %s", strerror(errno));
675 p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
677 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
678 io.iov_len = p->max_size;
680 memset(&msg, 0, sizeof(msg));
682 msg.msg_name = ret_sa;
683 msg.msg_namelen = sizeof(struct sockaddr_in6);
691 msg.msg_control = aux;
692 msg.msg_controllen = sizeof(aux);
695 if ((l = recvmsg(fd, &msg, 0)) < 0) {
696 avahi_log_warn("recvmsg(): %s", strerror(errno));
700 p->size = (size_t) l;
705 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
706 if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_HOPLIMIT) {
709 *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
714 if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
715 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
718 *ret_iface = i->ipi6_ifindex;
720 if (ret_dest_address)
721 memcpy(ret_dest_address->address, i->ipi6_addr.s6_addr, 16);
733 avahi_dns_packet_free(p);
738 int avahi_open_unicast_socket_ipv4(void) {
739 struct sockaddr_in local;
742 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
743 avahi_log_warn("socket() failed: %s", strerror(errno));
747 memset(&local, 0, sizeof(local));
748 local.sin_family = AF_INET;
750 if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
751 avahi_log_warn("bind() failed: %s", strerror(errno));
756 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
757 avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
762 if (ip_pktinfo (fd, yes) < 0) {
766 if (avahi_set_cloexec(fd) < 0) {
767 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
771 if (avahi_set_nonblock(fd) < 0) {
772 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
785 int avahi_open_unicast_socket_ipv6(void) {
786 struct sockaddr_in6 local;
789 if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
790 avahi_log_warn("socket() failed: %s", strerror(errno));
794 memset(&local, 0, sizeof(local));
795 local.sin6_family = AF_INET6;
797 if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
798 avahi_log_warn("bind() failed: %s", strerror(errno));
804 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPS, &yes, sizeof(yes)) < 0) {
805 avahi_log_warn("IPV6_RECVHOPS failed: %s", strerror(errno));
808 #elif IPV6_RECVHOPLIMIT
810 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0) {
811 avahi_log_warn("IPV6_RECVHOPLIMIT failed: %s", strerror(errno));
816 if (setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
817 avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
822 #ifdef IPV6_RECVPKTINFO
824 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0) {
825 avahi_log_warn("IPV6_RECVPKTINFO failed: %s", strerror(errno));
830 if (setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
831 avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
836 if (avahi_set_cloexec(fd) < 0) {
837 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
841 if (avahi_set_nonblock(fd) < 0) {
842 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));