-bool discovery_start(meshlink_handle_t *mesh)
-{
- logger(mesh, MESHLINK_DEBUG, "discovery_start called\n");
-
- // asserts
- assert(mesh != NULL);
- assert(mesh->avahi_poll == NULL);
- assert(mesh->avahi_server == NULL);
- assert(mesh->avahi_browser == NULL);
- assert(mesh->discovery_threadstarted == false);
- assert(mesh->avahi_servicetype == NULL);
-
- // create service type string
- size_t servicetype_strlen = sizeof(MESHLINK_MDNS_SERVICE_TYPE) + strlen(mesh->appname) + 1;
- mesh->avahi_servicetype = malloc(servicetype_strlen);
-
- if(mesh->avahi_servicetype == NULL)
- {
- logger(mesh, MESHLINK_ERROR, "Failed to allocate memory for service type string.\n");
- goto fail;
- }
-
- snprintf(mesh->avahi_servicetype, servicetype_strlen, MESHLINK_MDNS_SERVICE_TYPE, mesh->appname);
-
- // Allocate discovery loop object
- if(!(mesh->avahi_poll = avahi_simple_poll_new()))
- {
- logger(mesh, MESHLINK_ERROR, "Failed to create discovery poll object.\n");
- goto fail;
- }
-
- // generate some unique host name (we actually do not care about it)
- uuid_t hostname;
- uuid_generate(hostname);
-
- char hostnamestr[36+1];
- uuid_unparse_lower(hostname, hostnamestr);
-
- // Let's set the host name for this server.
- AvahiServerConfig config;
- avahi_server_config_init(&config);
- config.host_name = avahi_strdup(hostnamestr);
- config.publish_workstation = 0;
- config.disallow_other_stacks = 0;
- config.publish_hinfo = 0;
- config.publish_addresses = 1;
- config.publish_no_reverse = 1;
-
- /* Allocate a new server */
- int error;
- mesh->avahi_server = avahi_server_new(avahi_simple_poll_get(mesh->avahi_poll), &config, discovery_server_callback, mesh, &error);
-
- /* Free the configuration data */
- avahi_server_config_free(&config);
-
- /* Check wether creating the server object succeeded */
- if(!mesh->avahi_server)
- {
- logger(mesh, MESHLINK_ERROR, "Failed to create discovery server: %s\n", avahi_strerror(error));
- goto fail;
- }
-
- // Create the service browser
- if(!(mesh->avahi_browser = avahi_s_service_browser_new(mesh->avahi_server, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, mesh->avahi_servicetype, NULL, 0, discovery_browse_callback, mesh)))
- {
- logger(mesh, MESHLINK_ERROR, "Failed to create discovery service browser: %s\n", avahi_strerror(avahi_server_errno(mesh->avahi_server)));
- goto fail;
- }
-
- // Start the discovery thread
- if(pthread_create(&mesh->discovery_thread, NULL, discovery_loop, mesh) != 0)
- {
- logger(mesh, MESHLINK_ERROR, "Could not start discovery thread: %s\n", strerror(errno));
- memset(&mesh->discovery_thread, 0, sizeof mesh->discovery_thread);
- goto fail;
- }
-
- mesh->discovery_threadstarted = true;
+static void netlink_parse(meshlink_handle_t *mesh, const void *data, size_t len) {
+ const uint8_t *ptr = data;
+
+ while(len >= sizeof(struct nlmsghdr)) {
+ const struct nlmsghdr *nlm = (const struct nlmsghdr *)ptr;
+
+ if(nlm->nlmsg_len > len) {
+ break;
+ }
+
+ switch(nlm->nlmsg_type) {
+ case RTM_NEWLINK:
+ case RTM_DELLINK:
+ netlink_parse_link(mesh, nlm);
+ break;
+
+ case RTM_NEWADDR:
+ case RTM_DELADDR:
+ netlink_parse_addr(mesh, nlm);
+ }
+
+ ptr += nlm->nlmsg_len;
+ len -= nlm->nlmsg_len;
+ }
+}
+
+static void netlink_io_handler(event_loop_t *loop, void *data, int flags) {
+ (void)flags;
+ (void)data;
+ meshlink_handle_t *mesh = loop->data;
+
+ struct {
+ struct nlmsghdr nlm;
+ char data[16384];
+ } msg;
+
+ while(true) {
+ ssize_t result = recv(mesh->discovery.pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
+
+ if(result <= 0) {
+ if(result == 0 || errno == EAGAIN || errno == EINTR) {
+ break;
+ }
+
+ logger(mesh, MESHLINK_ERROR, "Reading from Netlink socket failed: %s\n", strerror(errno));
+ io_set(loop, &mesh->discovery.pfroute_io, 0);
+ }
+
+ if((size_t)result < sizeof(msg.nlm)) {
+ logger(mesh, MESHLINK_ERROR, "Invalid Netlink message\n");
+ break;
+ }
+
+ if(msg.nlm.nlmsg_type == NLMSG_DONE) {
+ if(msg.nlm.nlmsg_seq == 1) {
+ // We just got the result of GETLINK, now send GETADDR.
+ netlink_getaddr(mesh->discovery.pfroute_io.fd);
+ }
+ } else {
+ netlink_parse(mesh, &msg, result);
+
+ if(loop->now.tv_sec > mesh->discovery.last_update + 5) {
+ mesh->discovery.last_update = loop->now.tv_sec;
+ handle_network_change(mesh, 1);
+ }
+ }
+ }
+}
+#elif defined(__APPLE__)
+static void network_change_callback(SCDynamicStoreRef store, CFArrayRef keys, void *info) {
+ (void)store;
+ (void)keys;
+
+ meshlink_handle_t *mesh = info;
+
+ pthread_mutex_lock(&mesh->mutex);
+
+ logger(mesh, MESHLINK_ERROR, "Network change detected!");
+ scan_ifaddrs(mesh);
+
+ if(mesh->loop.now.tv_sec > mesh->discovery.last_update + 5) {
+ mesh->discovery.last_update = mesh->loop.now.tv_sec;
+ handle_network_change(mesh, 1);
+ }
+
+ pthread_mutex_unlock(&mesh->mutex);
+}
+
+static void *network_change_handler(void *arg) {
+ meshlink_handle_t *mesh = arg;
+
+ mesh->discovery.runloop = CFRunLoopGetCurrent();
+
+ SCDynamicStoreContext context = {0, mesh, NULL, NULL, NULL};
+ SCDynamicStoreRef store = SCDynamicStoreCreate(NULL, CFSTR("network_change_handler"), network_change_callback, &context);
+ CFStringRef interfaces = SCDynamicStoreKeyCreate(NULL, CFSTR("State:/Network/Interface"), kCFStringEncodingUTF8);
+ CFStringRef ipv4 = SCDynamicStoreKeyCreateNetworkInterfaceEntity(NULL, kSCDynamicStoreDomainState, kSCCompAnyRegex, kSCEntNetIPv4);
+ CFStringRef ipv6 = SCDynamicStoreKeyCreateNetworkInterfaceEntity(NULL, kSCDynamicStoreDomainState, kSCCompAnyRegex, kSCEntNetIPv6);
+ CFMutableArrayRef keys = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);
+ CFMutableArrayRef patterns = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);
+ CFRunLoopSourceRef runloop_source = NULL;
+
+ if(!store) {
+ logger(mesh, MESHLINK_ERROR, "Error setting up network change handler: %s\n", SCErrorString(SCError()));
+ goto exit;
+ }
+
+ if(!interfaces || !ipv4 || !ipv6 || !keys || !patterns) {
+ logger(mesh, MESHLINK_ERROR, "Error setting up network change handler: %s\n", SCErrorString(SCError()));
+ goto exit;
+ }
+
+ CFArrayAppendValue(keys, interfaces);
+ CFArrayAppendValue(patterns, ipv4);
+ CFArrayAppendValue(patterns, ipv6);
+
+ if(!SCDynamicStoreSetNotificationKeys(store, keys, patterns)) {
+ logger(mesh, MESHLINK_ERROR, "Error setting up network change handler: %s\n", SCErrorString(SCError()));
+ goto exit;
+ }
+
+ runloop_source = SCDynamicStoreCreateRunLoopSource(NULL, store, 0);
+
+ if(!runloop_source) {
+ logger(mesh, MESHLINK_ERROR, "Error setting up network change handler: %s\n", SCErrorString(SCError()));
+ goto exit;
+ }
+
+ CFRunLoopAddSource(CFRunLoopGetCurrent(), runloop_source, kCFRunLoopDefaultMode);
+ CFRunLoopRun();
+
+exit:
+
+ if(runloop_source) {
+ CFRelease(runloop_source);
+ }
+
+ if(interfaces) {
+ CFRelease(interfaces);
+ }
+
+ if(ipv4) {
+ CFRelease(ipv4);
+ }
+
+ if(ipv6) {
+ CFRelease(ipv6);
+ }
+
+ if(keys) {
+ CFRelease(keys);
+ }
+
+ if(patterns) {
+ CFRelease(patterns);
+ }
+
+ if(store) {
+ CFRelease(store);
+ }
+
+ mesh->discovery.runloop = NULL;
+
+ return NULL;
+
+}
+#elif defined(RTM_NEWADDR)
+static void pfroute_parse_iface(meshlink_handle_t *mesh, const struct rt_msghdr *rtm) {
+ const struct if_msghdr *ifm = (const struct if_msghdr *)rtm;
+
+ if(ifm->ifm_flags & IFF_UP && ifm->ifm_flags & IFF_MULTICAST && !(ifm->ifm_flags & IFF_LOOPBACK)) {
+ iface_up(mesh, ifm->ifm_index);
+ } else {
+ iface_down(mesh, ifm->ifm_index);
+ }
+}
+
+static void pfroute_parse_addr(meshlink_handle_t *mesh, const struct rt_msghdr *rtm) {
+ const struct ifa_msghdr *ifam = (const struct ifa_msghdr *)rtm;
+ const char *p = (const char *)(ifam + 1);
+
+ for(unsigned int i = 1; i; i <<= 1) {
+ if(!(ifam->ifam_addrs & i)) {
+ continue;
+ }
+
+ const sockaddr_t *sa = (const sockaddr_t *)p;
+
+ if(i == RTA_IFA) {
+ discovery_address_t addr = {
+ .index = ifam->ifam_index,
+ };
+
+ if(sa->sa.sa_family == AF_INET) {
+ addr.address.in = sa->in;
+ addr.address.in.sin_port = ntohs(5353);
+ } else if(sa->sa.sa_family == AF_INET6) {
+ addr.address.in6 = sa->in6;
+ addr.address.in6.sin6_port = ntohs(5353);
+ } else {
+ addr.address.sa.sa_family = AF_UNKNOWN;
+ }
+
+ if(addr.address.sa.sa_family != AF_UNKNOWN) {
+ if(ifam->ifam_type == RTM_NEWADDR) {
+ addr_add(mesh, &addr);
+ } else {
+ addr_del(mesh, &addr);
+ }
+ }
+
+ break;
+ }
+
+ size_t len = (sa->sa.sa_len + 3) & ~3;
+ p += len;
+ }
+}
+
+static void pfroute_io_handler(event_loop_t *loop, void *data, int flags) {
+ (void)flags;
+ (void)data;
+ meshlink_handle_t *mesh = loop->data;
+
+ struct {
+ struct rt_msghdr rtm;
+ char data[2048];
+ } msg;
+
+ while(true) {
+ msg.rtm.rtm_version = 0;
+ ssize_t result = recv(mesh->discovery.pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
+
+ if(result <= 0) {
+ if(result == 0 || errno == EAGAIN || errno == EINTR) {
+ break;
+ }
+
+ logger(mesh, MESHLINK_ERROR, "Reading from PFROUTE socket failed: %s\n", strerror(errno));
+ io_set(loop, &mesh->discovery.pfroute_io, 0);
+ }
+
+ if(msg.rtm.rtm_version != RTM_VERSION) {
+ logger(mesh, MESHLINK_ERROR, "Invalid PFROUTE message version\n");
+ break;
+ }
+
+ switch(msg.rtm.rtm_type) {
+ case RTM_IFINFO:
+ pfroute_parse_iface(mesh, &msg.rtm);
+ break;
+
+ case RTM_NEWADDR:
+ case RTM_DELADDR:
+ pfroute_parse_addr(mesh, &msg.rtm);
+ break;
+
+ default:
+ break;
+ }
+ }
+}
+#endif
+
+bool discovery_start(meshlink_handle_t *mesh) {
+ logger(mesh, MESHLINK_DEBUG, "discovery_start called\n");
+
+ assert(mesh);
+
+ // Set up multicast sockets for mDNS
+ static const int one = 1;
+ static const int ttl = 255;
+ static const uint8_t one8 = 1;
+ static const uint8_t ttl8 = 255;
+
+ int fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+
+ if(fd == -1) {
+ logger(mesh, MESHLINK_ERROR, "Error creating IPv4 socket: %s", strerror(errno));
+ }
+
+ sockaddr_t sa4 = {
+ .in.sin_family = AF_INET,
+ .in.sin_port = ntohs(5353),
+ };
+ setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
+ setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
+ setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one8, sizeof(one8));
+ setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl8, sizeof(ttl8));
+
+ if(bind(fd, &sa4.sa, SALEN(sa4.sa)) == -1) {
+ logger(mesh, MESHLINK_ERROR, "Error binding to IPv4 multicast socket: %s", strerror(errno));
+ } else {
+ io_add(&mesh->loop, &mesh->discovery.sockets[0], mdns_io_handler, &mesh->discovery.sockets[0], fd, IO_READ);
+ }
+
+ sockaddr_t sa6 = {
+ .in6.sin6_family = AF_INET6,
+ .in6.sin6_port = ntohs(5353),
+ };
+ fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
+
+ if(fd == -1) {
+ logger(mesh, MESHLINK_ERROR, "Error creating IPv6 socket: %s", strerror(errno));
+ }
+
+ setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
+ setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
+ setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
+ setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one));
+ setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl));
+ setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
+
+ if(bind(fd, &sa6.sa, SALEN(sa6.sa)) == -1) {
+ logger(mesh, MESHLINK_ERROR, "Error binding to IPv4 multicast socket: %s", strerror(errno));
+ } else {
+ io_add(&mesh->loop, &mesh->discovery.sockets[1], mdns_io_handler, &mesh->discovery.sockets[1], fd, IO_READ);
+ }
+
+#if defined(__linux)
+ int sock = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+
+ if(sock != -1) {
+ struct sockaddr_nl sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.nl_family = AF_NETLINK;
+ sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR | RTMGRP_IPV6_IFADDR;
+
+ if(bind(sock, (struct sockaddr *)&sa, sizeof(sa)) != -1) {
+ io_add(&mesh->loop, &mesh->discovery.pfroute_io, netlink_io_handler, NULL, sock, IO_READ);
+ netlink_getlink(sock);
+ } else {
+ logger(mesh, MESHLINK_WARNING, "Could not bind AF_NETLINK socket: %s", strerror(errno));
+ scan_ifaddrs(mesh);
+ }
+ } else {
+ logger(mesh, MESHLINK_WARNING, "Could not open AF_NETLINK socket: %s", strerror(errno));
+ scan_ifaddrs(mesh);
+ }
+
+#elif defined(__APPLE__)
+ pthread_create(&mesh->discovery.thread, NULL, network_change_handler, mesh);
+ // TODO: Do we need to wait for the thread to start succesfully?
+ scan_ifaddrs(mesh);
+#elif defined(RTM_NEWADDR)
+ int sock = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
+
+ if(sock != -1) {
+ io_add(&mesh->loop, &mesh->discovery.pfroute_io, pfroute_io_handler, NULL, sock, IO_READ);
+ } else {
+ logger(mesh, MESHLINK_WARNING, "Could not open PF_ROUTE socket: %s", strerror(errno));
+ }
+
+ scan_ifaddrs(mesh);
+#endif