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 = 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));
176 if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes)) < 0) {
177 avahi_log_warn("SO_REUSEPORT failed: %s", strerror(errno));
182 if (bind(fd, sa, l) < 0) {
183 avahi_log_warn("bind() failed: %s", strerror(errno));
188 /* We enable SO_REUSEADDR afterwards, to make sure that the
189 * user may run other mDNS implementations if he really
193 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
194 avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
202 static int ip_pktinfo (int fd, int yes) {
205 if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) {
206 avahi_log_warn("IP_PKTINFO failed: %s", strerror(errno));
211 #ifdef IP_RECVINTERFACE
212 if (setsockopt (fd, IPPROTO_IP, IP_RECVINTERFACE, &yes, sizeof(yes)) < 0) {
213 avahi_log_warn("IP_RECVINTERFACE failed: %s", strerror(errno));
216 #elif defined(IP_RECVIF)
217 if (setsockopt (fd, IPPROTO_IP, IP_RECVIF, &yes, sizeof(yes)) < 0) {
218 avahi_log_warn("IP_RECVIF failed: %s", strerror(errno));
223 #ifdef IP_RECVDSTADDR
224 if (setsockopt (fd, IPPROTO_IP, IP_RECVDSTADDR, &yes, sizeof(yes)) < 0) {
225 avahi_log_warn("IP_RECVDSTADDR failed: %s", strerror(errno));
230 #endif /* IP_PKTINFO */
235 int avahi_open_socket_ipv4(int no_reuse) {
236 struct sockaddr_in local;
240 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
241 avahi_log_warn("socket() failed: %s", strerror(errno));
246 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
247 avahi_log_warn("IP_MULTICAST_TTL failed: %s", strerror(errno));
252 if (setsockopt(fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) {
253 avahi_log_warn("IP_TTL failed: %s", strerror(errno));
258 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
259 avahi_log_warn("IP_MULTICAST_LOOP failed: %s", strerror(errno));
263 memset(&local, 0, sizeof(local));
264 local.sin_family = AF_INET;
265 local.sin_port = htons(AVAHI_MDNS_PORT);
268 r = bind(fd, (struct sockaddr*) &local, sizeof(local));
270 r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
277 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
278 avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
284 if (ip_pktinfo (fd, yes) < 0) {
288 if (avahi_set_cloexec(fd) < 0) {
289 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
293 if (avahi_set_nonblock(fd) < 0) {
294 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
307 int avahi_open_socket_ipv6(int no_reuse) {
308 struct sockaddr_in6 sa, local;
312 mdns_mcast_group_ipv6(&sa);
314 if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
315 avahi_log_warn("socket() failed: %s", strerror(errno));
320 if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
321 avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s", strerror(errno));
326 if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
327 avahi_log_warn("IPV6_UNICAST_HOPS failed: %s", strerror(errno));
332 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
333 avahi_log_warn("IPV6_V6ONLY failed: %s", strerror(errno));
338 if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
339 avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s", strerror(errno));
343 memset(&local, 0, sizeof(local));
344 local.sin6_family = AF_INET6;
345 local.sin6_port = htons(AVAHI_MDNS_PORT);
348 r = bind(fd, (struct sockaddr*) &local, sizeof(local));
350 r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
357 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPS, &yes, sizeof(yes)) < 0) {
358 avahi_log_warn("IPV6_RECVHOPS failed: %s", strerror(errno));
361 #elif defined(IPV6_RECVHOPLIMIT)
363 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0) {
364 avahi_log_warn("IPV6_RECVHOPLIMIT failed: %s", strerror(errno));
367 #elif defined(IPV6_HOPLIMIT)
369 if (setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
370 avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
375 #ifdef IPV6_RECVPKTINFO
377 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0) {
378 avahi_log_warn("IPV6_RECVPKTINFO failed: %s", strerror(errno));
381 #elif defined(IPV6_PKTINFO)
383 if (setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
384 avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
389 if (avahi_set_cloexec(fd) < 0) {
390 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
394 if (avahi_set_nonblock(fd) < 0) {
395 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
408 static int sendmsg_loop(int fd, struct msghdr *msg, int flags) {
414 if (sendmsg(fd, msg, flags) >= 0)
417 if (errno != EAGAIN) {
418 avahi_log_debug("sendmsg() failed: %s", strerror(errno));
422 if (avahi_wait_for_write(fd) < 0)
429 int avahi_send_dns_packet_ipv4(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv4Address *a, uint16_t port) {
430 struct sockaddr_in sa;
434 struct cmsghdr *cmsg;
435 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)];
440 assert(avahi_dns_packet_check_valid(p) >= 0);
441 assert(!a || port > 0);
444 mdns_mcast_group_ipv4(&sa);
446 ipv4_address_to_sockaddr(&sa, a, port);
448 memset(&io, 0, sizeof(io));
449 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
450 io.iov_len = p->size;
452 memset(&msg, 0, sizeof(msg));
454 msg.msg_namelen = sizeof(sa);
458 msg.msg_control = NULL;
459 msg.msg_controllen = 0;
462 if (interface >= 0) {
463 struct in_pktinfo *pkti;
465 memset(cmsg_data, 0, sizeof(cmsg_data));
466 cmsg = (struct cmsghdr*) cmsg_data;
467 cmsg->cmsg_len = sizeof(cmsg_data);
468 cmsg->cmsg_level = IPPROTO_IP;
469 cmsg->cmsg_type = IP_PKTINFO;
471 pkti = (struct in_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
472 pkti->ipi_ifindex = interface;
474 msg.msg_control = cmsg_data;
475 msg.msg_controllen = sizeof(cmsg_data);
479 return sendmsg_loop(fd, &msg, 0);
482 int avahi_send_dns_packet_ipv6(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv6Address *a, uint16_t port) {
483 struct sockaddr_in6 sa;
486 struct cmsghdr *cmsg;
487 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in6_pktinfo)];
491 assert(avahi_dns_packet_check_valid(p) >= 0);
494 mdns_mcast_group_ipv6(&sa);
496 ipv6_address_to_sockaddr(&sa, a, port);
498 memset(&io, 0, sizeof(io));
499 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
500 io.iov_len = p->size;
503 memset(&msg, 0, sizeof(msg));
505 msg.msg_namelen = sizeof(sa);
510 if (interface >= 0) {
511 struct in6_pktinfo *pkti;
513 memset(cmsg_data, 0, sizeof(cmsg_data));
514 cmsg = (struct cmsghdr*) cmsg_data;
515 cmsg->cmsg_len = sizeof(cmsg_data);
516 cmsg->cmsg_level = IPPROTO_IPV6;
517 cmsg->cmsg_type = IPV6_PKTINFO;
519 pkti = (struct in6_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
520 pkti->ipi6_ifindex = interface;
522 msg.msg_control = cmsg_data;
523 msg.msg_controllen = sizeof(cmsg_data);
525 msg.msg_control = NULL;
526 msg.msg_controllen = 0;
529 return sendmsg_loop(fd, &msg, 0);
532 AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, AvahiIPv4Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
533 AvahiDnsPacket *p= NULL;
538 struct cmsghdr *cmsg;
539 int found_iface = 0, found_addr = 0;
544 if (ioctl(fd, FIONREAD, &ms) < 0) {
545 avahi_log_warn("ioctl(): %s", strerror(errno));
549 p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
551 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
552 io.iov_len = p->max_size;
554 memset(&msg, 0, sizeof(msg));
556 msg.msg_name = ret_sa;
557 msg.msg_namelen = sizeof(struct sockaddr_in);
564 msg.msg_control = aux;
565 msg.msg_controllen = sizeof(aux);
568 if ((l = recvmsg(fd, &msg, 0)) < 0) {
569 avahi_log_warn("recvmsg(): %s", strerror(errno));
573 if (ret_sa && ret_sa->sin_addr.s_addr == INADDR_ANY) {
574 /* Linux 2.4 behaves very strangely sometimes! */
576 /*avahi_hexdump(AVAHI_DNS_PACKET_DATA(p), l); */
580 assert(!(msg.msg_flags & MSG_CTRUNC));
581 assert(!(msg.msg_flags & MSG_TRUNC));
582 p->size = (size_t) l;
587 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
589 if (cmsg->cmsg_level == IPPROTO_IP) {
590 switch (cmsg->cmsg_type) {
596 *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
602 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
605 *ret_iface = (int) i->ipi_ifindex;
607 if (ret_dest_address)
608 ret_dest_address->address = i->ipi_addr.s_addr;
610 found_addr = found_iface = 1;
616 struct sockaddr_dl *sdl = (struct sockaddr_dl *) CMSG_DATA (cmsg);
619 *ret_iface = (int) sdl->sdl_index;
626 #ifdef IP_RECVDSTADDR
628 if (ret_dest_address)
629 memcpy(&ret_dest_address->address, CMSG_DATA (cmsg), 4);
636 avahi_log_warn("Unhandled cmsg_type : %d", cmsg->cmsg_type);
649 avahi_dns_packet_free(p);
654 AvahiDnsPacket* avahi_recv_dns_packet_ipv6(int fd, struct sockaddr_in6 *ret_sa, AvahiIPv6Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
655 AvahiDnsPacket *p = NULL;
662 struct cmsghdr *cmsg;
663 int found_ttl = 0, found_iface = 0;
667 if (ioctl(fd, FIONREAD, &ms) < 0) {
668 avahi_log_warn("ioctl(): %s", strerror(errno));
672 p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
674 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
675 io.iov_len = p->max_size;
677 memset(&msg, 0, sizeof(msg));
679 msg.msg_name = ret_sa;
680 msg.msg_namelen = sizeof(struct sockaddr_in6);
688 msg.msg_control = aux;
689 msg.msg_controllen = sizeof(aux);
692 if ((l = recvmsg(fd, &msg, 0)) < 0) {
693 avahi_log_warn("recvmsg(): %s", strerror(errno));
697 p->size = (size_t) l;
702 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
703 if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_HOPLIMIT) {
706 *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
711 if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
712 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
715 *ret_iface = i->ipi6_ifindex;
717 if (ret_dest_address)
718 memcpy(ret_dest_address->address, i->ipi6_addr.s6_addr, 16);
731 avahi_dns_packet_free(p);
736 int avahi_open_unicast_socket_ipv4(void) {
737 struct sockaddr_in local;
740 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
741 avahi_log_warn("socket() failed: %s", strerror(errno));
745 memset(&local, 0, sizeof(local));
746 local.sin_family = AF_INET;
748 if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
749 avahi_log_warn("bind() failed: %s", strerror(errno));
755 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
756 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 defined(IPV6_RECVHOPLIMIT)
810 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0) {
811 avahi_log_warn("IPV6_RECVHOPLIMIT failed: %s", strerror(errno));
814 #elif defined(IPV6_HOPLIMIT)
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));
828 #elif defined(IPV6_PKTINFO)
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));