3 #if defined(__APPLE__) || defined(__unix) && !defined(__linux)
8 #include <linux/if_link.h>
9 #include <linux/netlink.h>
10 #include <linux/rtnetlink.h>
14 #include "meshlink_internal.h"
16 #include "discovery.h"
21 #include "connection.h"
25 #define MESHLINK_MDNS_SERVICE_TYPE "_%s._tcp"
26 #define MESHLINK_MDNS_NAME_KEY "name"
27 #define MESHLINK_MDNS_FINGERPRINT_KEY "fingerprint"
29 static const sockaddr_t mdns_address_ipv4 = {
30 .in.sin_family = AF_INET,
31 .in.sin_addr.s_addr = 0xfb0000e0,
32 .in.sin_port = 0xe914,
35 static const sockaddr_t mdns_address_ipv6 = {
36 .in6.sin6_family = AF_INET6,
37 .in6.sin6_addr.s6_addr[0x0] = 0xfd,
38 .in6.sin6_addr.s6_addr[0x1] = 0x02,
39 .in6.sin6_addr.s6_addr[0xf] = 0xfb,
40 .in6.sin6_port = 0xe914,
43 typedef struct discovery_address {
47 } discovery_address_t;
49 static int iface_compare(const void *va, const void *vb) {
55 static int address_compare(const void *va, const void *vb) {
56 const discovery_address_t *a = va;
57 const discovery_address_t *b = vb;
59 if(a->index != b->index) {
60 return a->index - b->index;
63 return sockaddrcmp_noport(&a->address, &b->address);
66 static void send_mdns_packet_ipv4(meshlink_handle_t *mesh, int fd, int index, const sockaddr_t *src, const sockaddr_t *dest, void *data, size_t len) {
73 struct in_pktinfo pkti = {
75 .ipi_addr = src->in.sin_addr,
79 char buf[CMSG_SPACE(sizeof(pkti))];
84 .msg_name = (struct sockaddr *) &dest->sa,
85 .msg_namelen = SALEN(dest->sa),
89 .msg_controllen = sizeof(u.buf),
93 struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
94 cmsg->cmsg_level = IPPROTO_IP;
95 cmsg->cmsg_type = IP_PKTINFO;
96 cmsg->cmsg_len = CMSG_LEN(sizeof(pkti));
97 memcpy(CMSG_DATA(cmsg), &pkti, sizeof(pkti));
100 ssize_t result = sendmsg(fd, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
103 ssize_t result = sendto(fd, data, len, MSG_DONTWAIT | MSG_NOSIGNAL, &dest->sa, SALEN(dest->sa));
107 logger(mesh, MESHLINK_ERROR, "Error sending multicast packet: %s", strerror(errno));
111 static void send_mdns_packet_ipv6(meshlink_handle_t *mesh, int fd, int index, const sockaddr_t *src, const sockaddr_t *dest, void *data, size_t len) {
118 struct in6_pktinfo pkti = {
119 .ipi6_ifindex = index,
120 .ipi6_addr = src->in6.sin6_addr,
124 char buf[CMSG_SPACE(sizeof(pkti))];
125 struct cmsghdr align;
128 memset(&u, 0, sizeof u);
130 struct msghdr msg = {
131 .msg_name = (struct sockaddr *) &dest->sa,
132 .msg_namelen = SALEN(dest->sa),
135 .msg_control = u.buf,
136 .msg_controllen = CMSG_LEN(sizeof(pkti)),
139 struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
140 cmsg->cmsg_level = IPPROTO_IPV6;
141 cmsg->cmsg_type = IPV6_PKTINFO;
142 cmsg->cmsg_len = CMSG_LEN(sizeof(pkti));
143 memcpy(CMSG_DATA(cmsg), &pkti, sizeof(pkti));
146 ssize_t result = sendmsg(fd, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
149 ssize_t result = sendto(fd, data, len, MSG_DONTWAIT | MSG_NOSIGNAL, &dest->sa, SALEN(dest->sa));
153 logger(mesh, MESHLINK_ERROR, "Error sending multicast packet: %s", strerror(errno));
157 static void send_mdns_packet(meshlink_handle_t *mesh, const discovery_address_t *addr) {
158 char *host = NULL, *port = NULL;
159 sockaddr2str(&addr->address, &host, &port);
160 fprintf(stderr, "Sending on iface %d %s port %s\n", addr->index, host, port);
164 // Configure the socket to send the packet to the right interface
167 char *fingerprint = meshlink_get_fingerprint(mesh, (meshlink_node_t *)mesh->self);
168 const char *keys[] = {MESHLINK_MDNS_NAME_KEY, MESHLINK_MDNS_FINGERPRINT_KEY};
169 const char *values[] = {mesh->name, fingerprint};
170 size_t size = prepare_packet(data, sizeof data, fingerprint, mesh->appname, "tcp", atoi(mesh->myport), 2, keys, values, false);
173 switch(addr->address.sa.sa_family) {
175 fd = mesh->discovery.sockets[0].fd;
176 #ifdef IP_MULTICAST_IF
178 struct ip_mreqn mreq = {
179 .imr_address = addr->address.in.sin_addr,
180 .imr_ifindex = addr->index,
183 if(setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq)) != 0) {
184 logger(mesh, MESHLINK_ERROR, "Could not set outgoing multicast interface on IPv4 socket");
191 send_mdns_packet_ipv4(mesh, fd, addr->index, &addr->address, &mdns_address_ipv4, data, size);
195 fd = mesh->discovery.sockets[1].fd;
196 #ifdef IPV6_MULTICAST_IF
198 if(setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &addr->index, sizeof(addr->index)) != 0) {
199 logger(mesh, MESHLINK_ERROR, "Could not set outgoing multicast interface on IPv6 socket");
205 send_mdns_packet_ipv6(mesh, fd, addr->index, &addr->address, &mdns_address_ipv6, data, size);
213 static void mdns_io_handler(event_loop_t *loop, void *data, int flags) {
215 meshlink_handle_t *mesh = loop->data;
219 socklen_t sl = sizeof(sa);
221 ssize_t len = recvfrom(io->fd, buf, sizeof(buf), MSG_DONTWAIT, &sa.sa, &sl);
224 if(!sockwouldblock(errno)) {
225 fprintf(stderr, "Error reading from discovery socket: %s\n", strerror(errno));
226 logger(mesh, MESHLINK_ERROR, "Error reading from mDNS discovery socket: %s", strerror(errno));
235 const char *keys[2] = {MESHLINK_MDNS_NAME_KEY, MESHLINK_MDNS_FINGERPRINT_KEY};
236 char *values[2] = {NULL, NULL};
239 if(parse_packet(buf, len, &name, mesh->appname, "tcp", &port, 2, keys, values, &response)) {
240 node_t *n = (node_t *)meshlink_get_node(mesh, values[0]);
243 logger(mesh, MESHLINK_INFO, "Node %s is part of the mesh network.\n", n->name);
245 if(!response && n != mesh->self) {
246 // Send a unicast response back
247 char *fingerprint = meshlink_get_fingerprint(mesh, (meshlink_node_t *)mesh->self);
248 const char *response_values[] = {mesh->name, fingerprint};
249 size_t size = prepare_packet(buf, sizeof(buf), fingerprint, mesh->appname, "tcp", atoi(mesh->myport), 2, keys, response_values, true);
250 sendto(io->fd, buf, size, MSG_DONTWAIT | MSG_NOSIGNAL, &sa.sa, sl);
254 switch(sa.sa.sa_family) {
256 sa.in.sin_port = port;
260 sa.in6.sin6_port = port;
264 logger(mesh, MESHLINK_WARNING, "Could not resolve node %s to a known address family type.\n", n->name);
265 sa.sa.sa_family = AF_UNKNOWN;
269 if(sa.sa.sa_family != AF_UNKNOWN) {
270 n->catta_address = sa;
271 node_add_recent_address(mesh, n, &sa);
273 connection_t *c = n->connection;
275 if(c && c->outgoing && !c->status.active) {
276 c->outgoing->timeout = 0;
278 if(c->outgoing->ev.cb) {
279 timeout_set(&mesh->loop, &c->outgoing->ev, &(struct timespec) {
284 c->last_ping_time = -3600;
288 logger(mesh, MESHLINK_WARNING, "Node %s is not part of the mesh network.\n", values[0]);
291 fprintf(stderr, "Got packet from %s port %u\n%s=%s\n%s=%s\n", name, port, keys[0], values[0], keys[1], values[1]);
296 for(int i = 0; i < 2; i++) {
301 static void iface_up(meshlink_handle_t *mesh, int index) {
302 int *p = bsearch(&index, mesh->discovery.ifaces, mesh->discovery.iface_count, sizeof(*p), iface_compare);
308 fprintf(stderr, "iface %d up\n", index);
309 mesh->discovery.ifaces = xrealloc(mesh->discovery.ifaces, ++mesh->discovery.iface_count * sizeof(*p));
310 mesh->discovery.ifaces[mesh->discovery.iface_count - 1] = index;
311 qsort(mesh->discovery.ifaces, mesh->discovery.iface_count, sizeof(*p), iface_compare);
313 // Add multicast membership
314 struct ip_mreqn mreq4 = {
315 .imr_multiaddr = mdns_address_ipv4.in.sin_addr,
316 .imr_ifindex = index,
318 setsockopt(mesh->discovery.sockets[0].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq4, sizeof(mreq4));
319 setsockopt(mesh->discovery.sockets[0].fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq4, sizeof(mreq4));
321 struct ipv6_mreq mreq6 = {
322 .ipv6mr_multiaddr = mdns_address_ipv6.in6.sin6_addr,
323 .ipv6mr_interface = index,
325 setsockopt(mesh->discovery.sockets[1].fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
326 setsockopt(mesh->discovery.sockets[1].fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6));
328 // Send an announcement for all addresses associated with this interface
329 for(int i = 0; i < mesh->discovery.address_count; i++) {
330 if(mesh->discovery.addresses[i].index == index) {
331 send_mdns_packet(mesh, &mesh->discovery.addresses[i]);
335 handle_network_change(mesh, true);
338 static void iface_down(meshlink_handle_t *const mesh, int index) {
339 int *p = bsearch(&index, mesh->discovery.ifaces, mesh->discovery.iface_count, sizeof(*p), iface_compare);
345 // Drop multicast membership
346 struct ip_mreqn mreq4 = {
347 .imr_multiaddr = mdns_address_ipv4.in.sin_addr,
348 .imr_ifindex = index,
350 setsockopt(mesh->discovery.sockets[0].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq4, sizeof(mreq4));
352 struct ipv6_mreq mreq6 = {
353 .ipv6mr_multiaddr = mdns_address_ipv6.in6.sin6_addr,
354 .ipv6mr_interface = index,
356 setsockopt(mesh->discovery.sockets[1].fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
358 fprintf(stderr, "iface %d down\n", index);
359 memmove(p, p + 1, (mesh->discovery.ifaces + --mesh->discovery.iface_count - p) * sizeof(*p));
361 handle_network_change(mesh, mesh->discovery.iface_count);
364 static void addr_add(meshlink_handle_t *mesh, const discovery_address_t *addr) {
365 discovery_address_t *p = bsearch(addr, mesh->discovery.addresses, mesh->discovery.address_count, sizeof(*p), address_compare);
371 bool up = bsearch(&addr->index, mesh->discovery.ifaces, mesh->discovery.iface_count, sizeof(int), iface_compare);
372 char *host = NULL, *port = NULL;
373 sockaddr2str(&addr->address, &host, &port);
374 fprintf(stderr, "address %d %s port %s up %d\n", addr->index, host, port, up);
378 mesh->discovery.addresses = xrealloc(mesh->discovery.addresses, ++mesh->discovery.address_count * sizeof(*p));
379 mesh->discovery.addresses[mesh->discovery.address_count - 1] = *addr;
380 mesh->discovery.addresses[mesh->discovery.address_count - 1].up = up;
383 send_mdns_packet(mesh, &mesh->discovery.addresses[mesh->discovery.address_count - 1]);
386 qsort(mesh->discovery.addresses, mesh->discovery.address_count, sizeof(*p), address_compare);
389 static void addr_del(meshlink_handle_t *mesh, const discovery_address_t *addr) {
390 discovery_address_t *p = bsearch(addr, mesh->discovery.addresses, mesh->discovery.address_count, sizeof(*p), address_compare);
396 char *host = NULL, *port = NULL;
397 sockaddr2str(&addr->address, &host, &port);
398 fprintf(stderr, "address %d %s port %s down\n", addr->index, host, port);
402 memmove(p, p + 1, (mesh->discovery.addresses + --mesh->discovery.address_count - p) * sizeof(*p));
406 static void netlink_getlink(int fd) {
407 static const struct {
409 struct ifinfomsg ifi;
411 .nlm.nlmsg_len = NLMSG_LENGTH(sizeof(msg.ifi)),
412 .nlm.nlmsg_type = RTM_GETLINK,
413 .nlm.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
415 .ifi.ifi_family = AF_UNSPEC,
417 send(fd, &msg, msg.nlm.nlmsg_len, 0);
420 static void netlink_getaddr(int fd) {
421 static const struct {
423 struct ifaddrmsg ifa;
425 .nlm.nlmsg_len = NLMSG_LENGTH(sizeof(msg.ifa)),
426 .nlm.nlmsg_type = RTM_GETADDR,
427 .nlm.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
429 .ifa.ifa_family = AF_UNSPEC,
431 send(fd, &msg, msg.nlm.nlmsg_len, 0);
435 static void netlink_parse_link(meshlink_handle_t *mesh, const struct nlmsghdr *nlm) {
436 const struct ifinfomsg *ifi = (const struct ifinfomsg *)(nlm + 1);
438 if(ifi->ifi_flags & IFF_UP && ifi->ifi_flags & IFF_MULTICAST) {
439 iface_up(mesh, ifi->ifi_index);
441 iface_down(mesh, ifi->ifi_index);
445 static void netlink_parse_addr(meshlink_handle_t *mesh, const struct nlmsghdr *nlm) {
446 const struct ifaddrmsg *ifa = (const struct ifaddrmsg *)(nlm + 1);
447 const uint8_t *ptr = (const uint8_t *)(ifa + 1);
448 size_t len = nlm->nlmsg_len - (ptr - (const uint8_t *)nlm);
450 while(len >= sizeof(struct rtattr)) {
451 const struct rtattr *rta = (const struct rtattr *)ptr;
453 if(rta->rta_len <= 0 || rta->rta_len > len) {
457 if(rta->rta_type == IFA_ADDRESS) {
458 discovery_address_t addr = {
459 .index = ifa->ifa_index,
462 if(rta->rta_len == 8) {
463 addr.address.sa.sa_family = AF_INET;
464 memcpy(&addr.address.in.sin_addr, ptr + 4, 4);
465 addr.address.in.sin_port = 5353;
466 } else if(rta->rta_len == 20) {
467 addr.address.sa.sa_family = AF_INET6;
468 memcpy(&addr.address.in6.sin6_addr, ptr + 4, 16);
469 addr.address.in6.sin6_port = 5353;
470 addr.address.in6.sin6_scope_id = ifa->ifa_index;
472 addr.address.sa.sa_family = AF_UNKNOWN;
475 if(addr.address.sa.sa_family != AF_UNKNOWN) {
476 if(nlm->nlmsg_type == RTM_NEWADDR) {
477 addr_add(mesh, &addr);
479 addr_del(mesh, &addr);
484 unsigned short rta_len = (rta->rta_len + 3) & ~3;
490 static void netlink_parse(meshlink_handle_t *mesh, const void *data, size_t len) {
491 const uint8_t *ptr = data;
493 while(len >= sizeof(struct nlmsghdr)) {
494 const struct nlmsghdr *nlm = (const struct nlmsghdr *)ptr;
496 if(nlm->nlmsg_len > len) {
500 switch(nlm->nlmsg_type) {
503 netlink_parse_link(mesh, nlm);
508 netlink_parse_addr(mesh, nlm);
511 ptr += nlm->nlmsg_len;
512 len -= nlm->nlmsg_len;
516 static void netlink_io_handler(event_loop_t *loop, void *data, int flags) {
519 static time_t prev_update;
520 meshlink_handle_t *mesh = loop->data;
528 ssize_t result = recv(mesh->discovery.pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
531 if(result == 0 || errno == EAGAIN || errno == EINTR) {
535 logger(mesh, MESHLINK_ERROR, "Reading from Netlink socket failed: %s\n", strerror(errno));
536 io_set(loop, &mesh->discovery.pfroute_io, 0);
539 if((size_t)result < sizeof(msg.nlm)) {
540 logger(mesh, MESHLINK_ERROR, "Invalid Netlink message\n");
544 if(msg.nlm.nlmsg_type == NLMSG_DONE) {
545 if(msg.nlm.nlmsg_seq == 1) {
546 // We just got the result of GETLINK, now send GETADDR.
547 netlink_getaddr(mesh->discovery.pfroute_io.fd);
550 netlink_parse(mesh, &msg, result);
552 if(loop->now.tv_sec > prev_update + 5) {
553 prev_update = loop->now.tv_sec;
554 handle_network_change(mesh, 1);
559 #elif defined(RTM_NEWADDR)
560 static void pfroute_io_handler(event_loop_t *loop, void *data, int flags) {
563 static time_t prev_update;
564 meshlink_handle_t *mesh = loop->data;
567 struct rt_msghdr rtm;
572 msg.rtm.rtm_version = 0;
573 ssize_t result = recv(mesh->discovery.pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
576 if(result == 0 || errno == EAGAIN || errno == EINTR) {
580 logger(mesh, MESHLINK_ERROR, "Reading from PFROUTE socket failed: %s\n", strerror(errno));
581 io_set(loop, &mesh->discovery.pfroute_io, 0);
584 if(msg.rtm.rtm_version != RTM_VERSION) {
585 logger(mesh, MESHLINK_ERROR, "Invalid PFROUTE message version\n");
589 switch(msg.rtm.rtm_type) {
593 if(loop->now.tv_sec > prev_update + 5) {
594 prev_update = loop->now.tv_sec;
595 handle_network_change(mesh, 1);
607 bool discovery_start(meshlink_handle_t *mesh) {
608 logger(mesh, MESHLINK_DEBUG, "discovery_start called\n");
612 // Set up multicast sockets for mDNS
613 static const int one = 1;
614 static const int ttl = 255;
616 int fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
618 .in.sin_family = AF_INET,
619 .in.sin_port = ntohs(5353),
621 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
622 bind(fd, &sa4.sa, SALEN(sa4.sa));
623 setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one));
624 setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
625 io_add(&mesh->loop, &mesh->discovery.sockets[0], mdns_io_handler, &mesh->discovery.sockets[0], fd, IO_READ);
628 .in6.sin6_family = AF_INET6,
629 .in6.sin6_port = ntohs(5353),
631 fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
632 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
633 setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
634 bind(fd, &sa6.sa, SALEN(sa6.sa));
635 setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one));
636 setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl));
637 io_add(&mesh->loop, &mesh->discovery.sockets[1], mdns_io_handler, &mesh->discovery.sockets[1], fd, IO_READ);
640 int sock = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
643 struct sockaddr_nl sa;
644 memset(&sa, 0, sizeof(sa));
645 sa.nl_family = AF_NETLINK;
646 sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR | RTMGRP_IPV6_IFADDR;
648 if(bind(sock, (struct sockaddr *)&sa, sizeof(sa)) != -1) {
649 io_add(&mesh->loop, &mesh->discovery.pfroute_io, netlink_io_handler, NULL, sock, IO_READ);
650 netlink_getlink(sock);
652 logger(mesh, MESHLINK_WARNING, "Could not bind AF_NETLINK socket: %s", strerror(errno));
655 logger(mesh, MESHLINK_WARNING, "Could not open AF_NETLINK socket: %s", strerror(errno));
658 #elif defined(RTM_NEWADDR)
659 int sock = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
662 io_add(&mesh->loop, &mesh->discovery.pfroute_io, pfroute_io_handler, NULL, sock, IO_READ);
664 logger(mesh, MESHLINK_WARNING, "Could not open PF_ROUTE socket: %s", strerror(errno));
672 void discovery_stop(meshlink_handle_t *mesh) {
673 logger(mesh, MESHLINK_DEBUG, "discovery_stop called\n");
677 free(mesh->discovery.ifaces);
678 free(mesh->discovery.addresses);
679 mesh->discovery.ifaces = NULL;
680 mesh->discovery.addresses = NULL;
681 mesh->discovery.iface_count = 0;
682 mesh->discovery.address_count = 0;
684 if(mesh->discovery.pfroute_io.cb) {
685 close(mesh->discovery.pfroute_io.fd);
686 io_del(&mesh->loop, &mesh->discovery.pfroute_io);
689 for(int i = 0; i < 2; i++) {
690 if(mesh->discovery.sockets[i].cb) {
691 close(mesh->discovery.sockets[i].fd);
692 io_del(&mesh->loop, &mesh->discovery.sockets[i]);
697 void discovery_refresh(meshlink_handle_t *mesh) {
698 for(int i = 0; i < mesh->discovery.address_count; i++) {
699 if(mesh->discovery.addresses[i].up) {
700 send_mdns_packet(mesh, &mesh->discovery.addresses[i]);