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);
172 switch(addr->address.sa.sa_family) {
174 fd = mesh->discovery_sockets[0].fd;
175 #ifdef IP_MULTICAST_IF
177 struct ip_mreqn mreq = {
178 .imr_address = addr->address.in.sin_addr,
179 .imr_ifindex = addr->index,
182 if(setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq)) != 0) {
183 logger(mesh, MESHLINK_ERROR, "Could not set outgoing multicast interface on IPv4 socket");
190 send_mdns_packet_ipv4(mesh, fd, addr->index, &addr->address, &mdns_address_ipv4, data, size);
194 fd = mesh->discovery_sockets[1].fd;
195 #ifdef IPV6_MULTICAST_IF
197 if(setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &addr->index, sizeof(addr->index)) != 0) {
198 logger(mesh, MESHLINK_ERROR, "Could not set outgoing multicast interface on IPv6 socket");
204 send_mdns_packet_ipv6(mesh, fd, addr->index, &addr->address, &mdns_address_ipv6, data, size);
212 static void mdns_io_handler(event_loop_t *loop, void *data, int flags) {
214 meshlink_handle_t *mesh = loop->data;
218 socklen_t sl = sizeof(sa);
220 ssize_t len = recvfrom(io->fd, buf, sizeof(buf), MSG_DONTWAIT, &sa.sa, &sl);
223 if(!sockwouldblock(errno)) {
224 fprintf(stderr, "Error reading from discovery socket: %s\n", strerror(errno));
225 logger(mesh, MESHLINK_ERROR, "Error reading from mDNS discovery socket: %s", strerror(errno));
234 const char *keys[2] = {MESHLINK_MDNS_NAME_KEY, MESHLINK_MDNS_FINGERPRINT_KEY};
235 char *values[2] = {NULL, NULL};
237 if(parse_packet(buf, len, &name, mesh->appname, "tcp", &port, 2, keys, values)) {
238 node_t *n = (node_t *)meshlink_get_node(mesh, values[0]);
241 logger(mesh, MESHLINK_INFO, "Node %s is part of the mesh network.\n", n->name);
243 switch(sa.sa.sa_family) {
245 sa.in.sin_port = port;
249 sa.in6.sin6_port = port;
253 logger(mesh, MESHLINK_WARNING, "Could not resolve node %s to a known address family type.\n", n->name);
254 sa.sa.sa_family = AF_UNKNOWN;
258 if(sa.sa.sa_family != AF_UNKNOWN) {
259 n->catta_address = sa;
260 node_add_recent_address(mesh, n, &sa);
262 connection_t *c = n->connection;
264 if(c && c->outgoing && !c->status.active) {
265 c->outgoing->timeout = 0;
267 if(c->outgoing->ev.cb) {
268 timeout_set(&mesh->loop, &c->outgoing->ev, &(struct timespec) {
273 c->last_ping_time = -3600;
277 logger(mesh, MESHLINK_WARNING, "Node %s is not part of the mesh network.\n", values[0]);
280 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]);
285 for(int i = 0; i < 2; i++) {
290 static void iface_up(meshlink_handle_t *mesh, int index) {
291 int *p = bsearch(&index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare);
297 fprintf(stderr, "iface %d up\n", index);
298 mesh->discovery_ifaces = xrealloc(mesh->discovery_ifaces, ++mesh->discovery_iface_count * sizeof(*p));
299 mesh->discovery_ifaces[mesh->discovery_iface_count - 1] = index;
300 qsort(mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare);
302 // Add multicast membership
303 struct ip_mreqn mreq4 = {
304 .imr_multiaddr = mdns_address_ipv4.in.sin_addr,
305 .imr_ifindex = index,
307 setsockopt(mesh->discovery_sockets[0].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq4, sizeof(mreq4));
308 setsockopt(mesh->discovery_sockets[0].fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq4, sizeof(mreq4));
310 struct ipv6_mreq mreq6 = {
311 .ipv6mr_multiaddr = mdns_address_ipv6.in6.sin6_addr,
312 .ipv6mr_interface = index,
314 setsockopt(mesh->discovery_sockets[1].fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
315 setsockopt(mesh->discovery_sockets[1].fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6));
317 // Send an announcement for all addresses associated with this interface
318 for(int i = 0; i < mesh->discovery_address_count; i++) {
319 if(mesh->discovery_addresses[i].index == index) {
320 send_mdns_packet(mesh, &mesh->discovery_addresses[i]);
324 handle_network_change(mesh, true);
327 static void iface_down(meshlink_handle_t *const mesh, int index) {
328 int *p = bsearch(&index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare);
334 // Drop multicast membership
335 struct ip_mreqn mreq4 = {
336 .imr_multiaddr = mdns_address_ipv4.in.sin_addr,
337 .imr_ifindex = index,
339 setsockopt(mesh->discovery_sockets[0].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq4, sizeof(mreq4));
341 struct ipv6_mreq mreq6 = {
342 .ipv6mr_multiaddr = mdns_address_ipv6.in6.sin6_addr,
343 .ipv6mr_interface = index,
345 setsockopt(mesh->discovery_sockets[1].fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
347 fprintf(stderr, "iface %d down\n", index);
348 memmove(p, p + 1, (mesh->discovery_ifaces + --mesh->discovery_iface_count - p) * sizeof(*p));
350 handle_network_change(mesh, mesh->discovery_iface_count);
353 static void addr_add(meshlink_handle_t *mesh, const discovery_address_t *addr) {
354 discovery_address_t *p = bsearch(addr, mesh->discovery_addresses, mesh->discovery_address_count, sizeof(*p), address_compare);
360 bool up = bsearch(&addr->index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(int), iface_compare);
361 char *host = NULL, *port = NULL;
362 sockaddr2str(&addr->address, &host, &port);
363 fprintf(stderr, "address %d %s port %s up %d\n", addr->index, host, port, up);
367 mesh->discovery_addresses = xrealloc(mesh->discovery_addresses, ++mesh->discovery_address_count * sizeof(*p));
368 mesh->discovery_addresses[mesh->discovery_address_count - 1] = *addr;
369 mesh->discovery_addresses[mesh->discovery_address_count - 1].up = up;
372 send_mdns_packet(mesh, &mesh->discovery_addresses[mesh->discovery_address_count - 1]);
375 qsort(mesh->discovery_addresses, mesh->discovery_address_count, sizeof(*p), address_compare);
378 static void addr_del(meshlink_handle_t *mesh, const discovery_address_t *addr) {
379 discovery_address_t *p = bsearch(addr, mesh->discovery_addresses, mesh->discovery_address_count, sizeof(*p), address_compare);
385 char *host = NULL, *port = NULL;
386 sockaddr2str(&addr->address, &host, &port);
387 fprintf(stderr, "address %d %s port %s down\n", addr->index, host, port);
391 memmove(p, p + 1, (mesh->discovery_addresses + --mesh->discovery_address_count - p) * sizeof(*p));
395 static void netlink_getlink(int fd) {
396 static const struct {
398 struct ifinfomsg ifi;
400 .nlm.nlmsg_len = NLMSG_LENGTH(sizeof(msg.ifi)),
401 .nlm.nlmsg_type = RTM_GETLINK,
402 .nlm.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
404 .ifi.ifi_family = AF_UNSPEC,
406 send(fd, &msg, msg.nlm.nlmsg_len, 0);
409 static void netlink_getaddr(int fd) {
410 static const struct {
412 struct ifaddrmsg ifa;
414 .nlm.nlmsg_len = NLMSG_LENGTH(sizeof(msg.ifa)),
415 .nlm.nlmsg_type = RTM_GETADDR,
416 .nlm.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
418 .ifa.ifa_family = AF_UNSPEC,
420 send(fd, &msg, msg.nlm.nlmsg_len, 0);
424 static void netlink_parse_link(meshlink_handle_t *mesh, const struct nlmsghdr *nlm) {
425 const struct ifinfomsg *ifi = (const struct ifinfomsg *)(nlm + 1);
427 if(ifi->ifi_flags & IFF_UP && ifi->ifi_flags & IFF_MULTICAST) {
428 iface_up(mesh, ifi->ifi_index);
430 iface_down(mesh, ifi->ifi_index);
434 static void netlink_parse_addr(meshlink_handle_t *mesh, const struct nlmsghdr *nlm) {
435 const struct ifaddrmsg *ifa = (const struct ifaddrmsg *)(nlm + 1);
436 const uint8_t *ptr = (const uint8_t *)(ifa + 1);
437 size_t len = nlm->nlmsg_len - (ptr - (const uint8_t *)nlm);
439 while(len >= sizeof(struct rtattr)) {
440 const struct rtattr *rta = (const struct rtattr *)ptr;
442 if(rta->rta_len <= 0 || rta->rta_len > len) {
446 if(rta->rta_type == IFA_ADDRESS) {
447 discovery_address_t addr = {
448 .index = ifa->ifa_index,
451 if(rta->rta_len == 8) {
452 addr.address.sa.sa_family = AF_INET;
453 memcpy(&addr.address.in.sin_addr, ptr + 4, 4);
454 addr.address.in.sin_port = 5353;
455 } else if(rta->rta_len == 20) {
456 addr.address.sa.sa_family = AF_INET6;
457 memcpy(&addr.address.in6.sin6_addr, ptr + 4, 16);
458 addr.address.in6.sin6_port = 5353;
459 addr.address.in6.sin6_scope_id = ifa->ifa_index;
461 addr.address.sa.sa_family = AF_UNKNOWN;
464 if(addr.address.sa.sa_family != AF_UNKNOWN) {
465 if(nlm->nlmsg_type == RTM_NEWADDR) {
466 addr_add(mesh, &addr);
468 addr_del(mesh, &addr);
473 unsigned short rta_len = (rta->rta_len + 3) & ~3;
479 static void netlink_parse(meshlink_handle_t *mesh, const void *data, size_t len) {
480 const uint8_t *ptr = data;
482 while(len >= sizeof(struct nlmsghdr)) {
483 const struct nlmsghdr *nlm = (const struct nlmsghdr *)ptr;
485 if(nlm->nlmsg_len > len) {
489 switch(nlm->nlmsg_type) {
492 netlink_parse_link(mesh, nlm);
497 netlink_parse_addr(mesh, nlm);
500 ptr += nlm->nlmsg_len;
501 len -= nlm->nlmsg_len;
505 static void netlink_io_handler(event_loop_t *loop, void *data, int flags) {
507 static time_t prev_update;
508 meshlink_handle_t *mesh = data;
516 ssize_t result = recv(mesh->pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
519 if(result == 0 || errno == EAGAIN || errno == EINTR) {
523 logger(mesh, MESHLINK_ERROR, "Reading from Netlink socket failed: %s\n", strerror(errno));
524 io_set(loop, &mesh->pfroute_io, 0);
527 if((size_t)result < sizeof(msg.nlm)) {
528 logger(mesh, MESHLINK_ERROR, "Invalid Netlink message\n");
532 if(msg.nlm.nlmsg_type == NLMSG_DONE) {
533 if(msg.nlm.nlmsg_seq == 1) {
534 // We just got the result of GETLINK, now send GETADDR.
535 netlink_getaddr(mesh->pfroute_io.fd);
538 netlink_parse(mesh, &msg, result);
540 if(loop->now.tv_sec > prev_update + 5) {
541 prev_update = loop->now.tv_sec;
542 handle_network_change(mesh, 1);
547 #elif defined(RTM_NEWADDR)
548 static void pfroute_io_handler(event_loop_t *loop, void *data, int flags) {
550 static time_t prev_update;
551 meshlink_handle_t *mesh = data;
554 struct rt_msghdr rtm;
559 msg.rtm.rtm_version = 0;
560 ssize_t result = recv(mesh->pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
563 if(result == 0 || errno == EAGAIN || errno == EINTR) {
567 logger(mesh, MESHLINK_ERROR, "Reading from PFROUTE socket failed: %s\n", strerror(errno));
568 io_set(loop, &mesh->pfroute_io, 0);
571 if(msg.rtm.rtm_version != RTM_VERSION) {
572 logger(mesh, MESHLINK_ERROR, "Invalid PFROUTE message version\n");
576 switch(msg.rtm.rtm_type) {
580 if(loop->now.tv_sec > prev_update + 5) {
581 prev_update = loop->now.tv_sec;
582 handle_network_change(mesh, 1);
594 bool discovery_start(meshlink_handle_t *mesh) {
595 logger(mesh, MESHLINK_DEBUG, "discovery_start called\n");
599 // Set up multicast sockets for mDNS
600 static const int one = 1;
601 static const int ttl = 255;
603 int fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
605 .in.sin_family = AF_INET,
606 .in.sin_port = ntohs(5353),
608 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
609 bind(fd, &sa4.sa, SALEN(sa4.sa));
610 setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one));
611 setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
612 io_add(&mesh->loop, &mesh->discovery_sockets[0], mdns_io_handler, &mesh->discovery_sockets[0], fd, IO_READ);
615 .in6.sin6_family = AF_INET6,
616 .in6.sin6_port = ntohs(5353),
618 fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
619 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
620 setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
621 bind(fd, &sa6.sa, SALEN(sa6.sa));
622 setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one));
623 setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl));
624 io_add(&mesh->loop, &mesh->discovery_sockets[1], mdns_io_handler, &mesh->discovery_sockets[1], fd, IO_READ);
627 int sock = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
630 struct sockaddr_nl sa;
631 memset(&sa, 0, sizeof(sa));
632 sa.nl_family = AF_NETLINK;
633 sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR | RTMGRP_IPV6_IFADDR;
635 if(bind(sock, (struct sockaddr *)&sa, sizeof(sa)) != -1) {
636 io_add(&mesh->loop, &mesh->pfroute_io, netlink_io_handler, mesh, sock, IO_READ);
637 netlink_getlink(sock);
639 logger(mesh, MESHLINK_WARNING, "Could not bind AF_NETLINK socket: %s", strerror(errno));
642 logger(mesh, MESHLINK_WARNING, "Could not open AF_NETLINK socket: %s", strerror(errno));
645 #elif defined(RTM_NEWADDR)
646 int sock = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
649 io_add(&mesh->loop, &mesh->pfroute_io, pfroute_io_handler, mesh, sock, IO_READ);
651 logger(mesh, MESHLINK_WARNING, "Could not open PF_ROUTE socket: %s", strerror(errno));
659 void discovery_stop(meshlink_handle_t *mesh) {
660 logger(mesh, MESHLINK_DEBUG, "discovery_stop called\n");
664 free(mesh->discovery_ifaces);
665 free(mesh->discovery_addresses);
666 mesh->discovery_iface_count = 0;
667 mesh->discovery_address_count = 0;
669 if(mesh->pfroute_io.cb) {
670 close(mesh->pfroute_io.fd);
671 io_del(&mesh->loop, &mesh->pfroute_io);
674 for(int i = 0; i < 2; i++) {
675 if(mesh->discovery_sockets[i].cb) {
676 close(mesh->discovery_sockets[i].fd);
677 io_del(&mesh->loop, &mesh->discovery_sockets[i]);