X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fdiscovery.c;h=95e5ed65d86da5e75297fd0fa94a9dd8eb9e762f;hb=HEAD;hp=e0e4fb4ed3e346b46da63287db2141f2f4f6ec78;hpb=4cca574d76767bfb9d193d6360abd5ee8946df6b;p=meshlink

diff --git a/src/discovery.c b/src/discovery.c
index e0e4fb4e..032b5599 100644
--- a/src/discovery.c
+++ b/src/discovery.c
@@ -1,7 +1,36 @@
+/*
+  discovery.c -- local network discovery
+  Copyright (C) 2014-2021 Guus Sliepen <guus@meshlink.io>
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License along
+  with this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#define __APPLE_USE_RFC_3542
 #include "system.h"
 
-#if defined(__APPLE__) || defined(__unix) && !defined(__linux)
+#if defined(__APPLE__)
+#include <CoreFoundation/CoreFoundation.h>
+#include <CoreFoundation/CFArray.h>
+#include <CoreFoundation/CFString.h>
+#include <SystemConfiguration/SystemConfiguration.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#elif defined(__unix) && !defined(__linux)
+#include <net/if.h>
 #include <net/route.h>
+#include <netinet/in.h>
 #elif defined(__linux)
 #include <asm/types.h>
 #include <net/if.h>
@@ -26,6 +55,18 @@
 #define MESHLINK_MDNS_NAME_KEY "name"
 #define MESHLINK_MDNS_FINGERPRINT_KEY "fingerprint"
 
+#ifndef MSG_NOSIGNAL
+#define MSG_NOSIGNAL 0
+#endif
+
+#ifndef IPV6_ADD_MEMBERSHIP
+#define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
+#endif
+
+#ifndef IPV6_DROP_MEMBERSHIP
+#define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
+#endif
+
 static const sockaddr_t mdns_address_ipv4 = {
 	.in.sin_family = AF_INET,
 	.in.sin_addr.s_addr = 0xfb0000e0,
@@ -34,7 +75,7 @@ static const sockaddr_t mdns_address_ipv4 = {
 
 static const sockaddr_t mdns_address_ipv6 = {
 	.in6.sin6_family = AF_INET6,
-	.in6.sin6_addr.s6_addr[0x0] = 0xfd,
+	.in6.sin6_addr.s6_addr[0x0] = 0xff,
 	.in6.sin6_addr.s6_addr[0x1] = 0x02,
 	.in6.sin6_addr.s6_addr[0xf] = 0xfb,
 	.in6.sin6_port = 0xe914,
@@ -44,6 +85,7 @@ typedef struct discovery_address {
 	int index;
 	bool up;
 	sockaddr_t address;
+	time_t last_response_sent;
 } discovery_address_t;
 
 static int iface_compare(const void *va, const void *vb) {
@@ -64,6 +106,19 @@ static int address_compare(const void *va, const void *vb) {
 }
 
 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) {
+#ifdef IP_MULTICAST_IF
+	struct ip_mreqn mreq = {
+		.imr_address = src->in.sin_addr,
+		.imr_ifindex = index,
+	};
+
+	if(setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq)) != 0) {
+		logger(mesh, MESHLINK_ERROR, "Could not set outgoing multicast interface on IPv4 socket");
+		return;
+	}
+
+#endif
+
 #ifdef IP_PKTINFO
 	struct iovec iov  = {
 		.iov_base = data,
@@ -80,6 +135,8 @@ static void send_mdns_packet_ipv4(meshlink_handle_t *mesh, int fd, int index, co
 		struct cmsghdr align;
 	} u;
 
+	memset(&u, 0, sizeof(u));
+
 	struct msghdr msg = {
 		.msg_name = (struct sockaddr *) &dest->sa,
 		.msg_namelen = SALEN(dest->sa),
@@ -89,7 +146,6 @@ static void send_mdns_packet_ipv4(meshlink_handle_t *mesh, int fd, int index, co
 		.msg_controllen = sizeof(u.buf),
 	};
 
-
 	struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
 	cmsg->cmsg_level = IPPROTO_IP;
 	cmsg->cmsg_type = IP_PKTINFO;
@@ -99,6 +155,9 @@ static void send_mdns_packet_ipv4(meshlink_handle_t *mesh, int fd, int index, co
 	// Send the packet
 	ssize_t result = sendmsg(fd, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
 #else
+	(void)index;
+	(void)src;
+
 	// Send the packet
 	ssize_t result = sendto(fd, data, len, MSG_DONTWAIT | MSG_NOSIGNAL, &dest->sa, SALEN(dest->sa));
 #endif
@@ -109,6 +168,15 @@ static void send_mdns_packet_ipv4(meshlink_handle_t *mesh, int fd, int index, co
 }
 
 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) {
+#ifdef IPV6_MULTICAST_IF
+
+	if(setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &index, sizeof(index)) != 0) {
+		logger(mesh, MESHLINK_ERROR, "Could not set outgoing multicast interface on IPv6 socket");
+		return;
+	}
+
+#endif
+
 #ifdef IPV6_PKTINFO
 	struct iovec iov  = {
 		.iov_base = data,
@@ -145,6 +213,9 @@ static void send_mdns_packet_ipv6(meshlink_handle_t *mesh, int fd, int index, co
 	// Send the packet
 	ssize_t result = sendmsg(fd, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
 #else
+	(void)index;
+	(void)src;
+
 	// Send the packet
 	ssize_t result = sendto(fd, data, len, MSG_DONTWAIT | MSG_NOSIGNAL, &dest->sa, SALEN(dest->sa));
 #endif
@@ -154,54 +225,29 @@ static void send_mdns_packet_ipv6(meshlink_handle_t *mesh, int fd, int index, co
 	}
 }
 
-static void send_mdns_packet(meshlink_handle_t *mesh, const discovery_address_t *addr) {
-	char *host = NULL, *port = NULL;
-	sockaddr2str(&addr->address, &host, &port);
-	fprintf(stderr, "Sending on iface %d %s port %s\n", addr->index, host, port);
-	free(host);
-	free(port);
-
+static void send_mdns_packet(meshlink_handle_t *mesh, discovery_address_t *addr, bool response) {
 	// Configure the socket to send the packet to the right interface
-	int fd;
-	uint8_t data[1024];
-	char *fingerprint = meshlink_get_fingerprint(mesh, (meshlink_node_t *)mesh->self);
-	const char *keys[] = {MESHLINK_MDNS_NAME_KEY, MESHLINK_MDNS_FINGERPRINT_KEY};
-	const char *values[] = {mesh->name, fingerprint};
-	size_t size = prepare_packet(data, sizeof data, fingerprint, mesh->appname, "tcp", atoi(mesh->myport), 2, keys, values);
+	uint8_t msg[1024];
+	size_t msg_size;
+
+	if(response) {
+		char *fingerprint = meshlink_get_fingerprint(mesh, (meshlink_node_t *)mesh->self);
+		static const char *keys[] = {MESHLINK_MDNS_NAME_KEY, MESHLINK_MDNS_FINGERPRINT_KEY};
+		const char *values[] = {mesh->name, fingerprint};
+		msg_size = prepare_response(msg, sizeof msg, fingerprint, mesh->appname, "tcp", atoi(mesh->myport), 2, keys, values);
+		free(fingerprint);
+		addr->last_response_sent = mesh->loop.now.tv_sec;
+	} else {
+		msg_size = prepare_request(msg, sizeof msg, mesh->appname, "tcp");
+	}
 
 	switch(addr->address.sa.sa_family) {
 	case AF_INET:
-		fd = mesh->discovery_sockets[0].fd;
-#ifdef IP_MULTICAST_IF
-		{
-			struct ip_mreqn mreq = {
-				.imr_address = addr->address.in.sin_addr,
-				.imr_ifindex = addr->index,
-			};
-
-			if(setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq)) != 0) {
-				logger(mesh, MESHLINK_ERROR, "Could not set outgoing multicast interface on IPv4 socket");
-				return;
-			}
-		}
-
-#endif
-
-		send_mdns_packet_ipv4(mesh, fd, addr->index, &addr->address, &mdns_address_ipv4, data, size);
+		send_mdns_packet_ipv4(mesh, mesh->discovery.sockets[0].fd, addr->index, &addr->address, &mdns_address_ipv4, msg, msg_size);
 		break;
 
 	case AF_INET6:
-		fd = mesh->discovery_sockets[1].fd;
-#ifdef IPV6_MULTICAST_IF
-
-		if(setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &addr->index, sizeof(addr->index)) != 0) {
-			logger(mesh, MESHLINK_ERROR, "Could not set outgoing multicast interface on IPv6 socket");
-			return;
-		}
-
-#endif
-
-		send_mdns_packet_ipv6(mesh, fd, addr->index, &addr->address, &mdns_address_ipv6, data, size);
+		send_mdns_packet_ipv6(mesh, mesh->discovery.sockets[1].fd, addr->index, &addr->address, &mdns_address_ipv6, msg, msg_size);
 		break;
 
 	default:
@@ -217,11 +263,35 @@ static void mdns_io_handler(event_loop_t *loop, void *data, int flags) {
 	sockaddr_t sa;
 	socklen_t sl = sizeof(sa);
 
+#ifdef IP_PKTINFO
+	struct iovec iov  = {
+		.iov_base = buf,
+		.iov_len = sizeof(buf),
+	};
+
+	union {
+		char buf[1024];
+		struct cmsghdr align;
+	} u;
+
+	struct msghdr msg = {
+		.msg_name = &sa,
+		.msg_namelen = sl,
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+		.msg_control = u.buf,
+		.msg_controllen = sizeof(u.buf),
+	};
+
+	ssize_t len = recvmsg(io->fd, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
+
+	sl = msg.msg_namelen;
+#else
 	ssize_t len = recvfrom(io->fd, buf, sizeof(buf), MSG_DONTWAIT, &sa.sa, &sl);
+#endif
 
 	if(len == -1) {
 		if(!sockwouldblock(errno)) {
-			fprintf(stderr, "Error reading from discovery socket: %s\n", strerror(errno));
 			logger(mesh, MESHLINK_ERROR, "Error reading from mDNS discovery socket: %s", strerror(errno));
 			io_set(loop, io, 0);
 		}
@@ -234,19 +304,21 @@ static void mdns_io_handler(event_loop_t *loop, void *data, int flags) {
 	const char *keys[2] = {MESHLINK_MDNS_NAME_KEY, MESHLINK_MDNS_FINGERPRINT_KEY};
 	char *values[2] = {NULL, NULL};
 
-	if(parse_packet(buf, len, &name, mesh->appname, "tcp", &port, 2, keys, values)) {
+	if(parse_response(buf, len, &name, mesh->appname, "tcp", &port, 2, keys, values)) {
 		node_t *n = (node_t *)meshlink_get_node(mesh, values[0]);
 
 		if(n) {
-			logger(mesh, MESHLINK_INFO, "Node %s is part of the mesh network.\n", n->name);
+			if(n != mesh->self) {
+				logger(mesh, MESHLINK_INFO, "Node %s discovered on the local network.\n", n->name);
+			}
 
 			switch(sa.sa.sa_family) {
 			case AF_INET:
-				sa.in.sin_port = port;
+				sa.in.sin_port = htons(port);
 				break;
 
 			case AF_INET6:
-				sa.in6.sin6_port = port;
+				sa.in6.sin6_port = htons(port);
 				break;
 
 			default:
@@ -257,27 +329,72 @@ static void mdns_io_handler(event_loop_t *loop, void *data, int flags) {
 
 			if(sa.sa.sa_family != AF_UNKNOWN) {
 				n->catta_address = sa;
+				n->last_connect_try = 0;
 				node_add_recent_address(mesh, n, &sa);
 
-				connection_t *c = n->connection;
+				if(n->connection) {
+					n->connection->last_ping_time = -3600;
+				}
 
-				if(c && c->outgoing && !c->status.active) {
-					c->outgoing->timeout = 0;
+				for list_each(outgoing_t, outgoing, mesh->outgoings) {
+					if(outgoing->node != n) {
+						continue;
+					}
 
-					if(c->outgoing->ev.cb) {
-						timeout_set(&mesh->loop, &c->outgoing->ev, &(struct timespec) {
+					outgoing->timeout = 0;
+
+					if(outgoing->ev.cb) {
+						timeout_set(&mesh->loop, &outgoing->ev, &(struct timespec) {
 							0, 0
 						});
 					}
+				}
+			}
+		}
+	} else if(parse_request(buf, len, mesh->appname, "tcp")) {
+		char *fingerprint = meshlink_get_fingerprint(mesh, (meshlink_node_t *)mesh->self);
+		const char *response_values[] = {mesh->name, fingerprint};
+		size_t size = prepare_response(buf, sizeof(buf), fingerprint, mesh->appname, "tcp", atoi(mesh->myport), 2, keys, response_values);
+
+		int index = -1;
+		int family = AF_UNSPEC;
+
+		for(struct cmsghdr *cmptr = CMSG_FIRSTHDR(&msg); cmptr != NULL; cmptr = CMSG_NXTHDR(&msg, cmptr)) {
+#ifdef IP_PKTINFO
+
+			if(cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO) {
+				struct in_pktinfo *pktinfo = (struct in_pktinfo *) CMSG_DATA(cmptr);
+				index = pktinfo->ipi_ifindex;
+				family = AF_INET;
+				break;
+			} else
+#endif
+#ifdef IPV6_PKTINFO
+				if(cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == IPV6_PKTINFO) {
+					struct in6_pktinfo *pktinfo = (struct in6_pktinfo *) CMSG_DATA(cmptr);
+					index = pktinfo->ipi6_ifindex;
+					family = AF_INET6;
+					break;
+				}
+
+#endif
+		}
+
+		if(index) {
+			// Send a multicast response back using all addresses matching the interface
+			for(int i = 0; i < mesh->discovery.address_count; i++) {
+				discovery_address_t *p = &mesh->discovery.addresses[i];
 
-					c->last_ping_time = -3600;
+				if(p->index == index && p->address.sa.sa_family == family) {
+					send_mdns_packet(mesh, p, true);
 				}
 			}
 		} else {
-			logger(mesh, MESHLINK_WARNING, "Node %s is not part of the mesh network.\n", values[0]);
+			// Send a unicast response back
+			sendto(io->fd, buf, size, MSG_DONTWAIT | MSG_NOSIGNAL, &sa.sa, sl);
 		}
 
-		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]);
+		free(fingerprint);
 	}
 
 	free(name);
@@ -288,44 +405,45 @@ static void mdns_io_handler(event_loop_t *loop, void *data, int flags) {
 }
 
 static void iface_up(meshlink_handle_t *mesh, int index) {
-	int *p = bsearch(&index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare);
+	int *p = bsearch(&index, mesh->discovery.ifaces, mesh->discovery.iface_count, sizeof(*p), iface_compare);
 
 	if(p) {
 		return;
 	}
 
-	fprintf(stderr, "iface %d up\n", index);
-	mesh->discovery_ifaces = xrealloc(mesh->discovery_ifaces, ++mesh->discovery_iface_count * sizeof(*p));
-	mesh->discovery_ifaces[mesh->discovery_iface_count - 1] = index;
-	qsort(mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare);
+	mesh->discovery.ifaces = xrealloc(mesh->discovery.ifaces, ++mesh->discovery.iface_count * sizeof(*p));
+	mesh->discovery.ifaces[mesh->discovery.iface_count - 1] = index;
+	qsort(mesh->discovery.ifaces, mesh->discovery.iface_count, sizeof(*p), iface_compare);
 
 	// Add multicast membership
 	struct ip_mreqn mreq4 = {
 		.imr_multiaddr = mdns_address_ipv4.in.sin_addr,
 		.imr_ifindex = index,
 	};
-	setsockopt(mesh->discovery_sockets[0].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq4, sizeof(mreq4));
-	setsockopt(mesh->discovery_sockets[0].fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq4, sizeof(mreq4));
+
+	setsockopt(mesh->discovery.sockets[0].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq4, sizeof(mreq4));
+	setsockopt(mesh->discovery.sockets[0].fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq4, sizeof(mreq4));
 
 	struct ipv6_mreq mreq6 = {
 		.ipv6mr_multiaddr = mdns_address_ipv6.in6.sin6_addr,
 		.ipv6mr_interface = index,
 	};
-	setsockopt(mesh->discovery_sockets[1].fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
-	setsockopt(mesh->discovery_sockets[1].fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6));
+
+	setsockopt(mesh->discovery.sockets[1].fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
+	setsockopt(mesh->discovery.sockets[1].fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6));
 
 	// Send an announcement for all addresses associated with this interface
-	for(int i = 0; i < mesh->discovery_address_count; i++) {
-		if(mesh->discovery_addresses[i].index == index) {
-			send_mdns_packet(mesh, &mesh->discovery_addresses[i]);
+	for(int i = 0; i < mesh->discovery.address_count; i++) {
+		if(mesh->discovery.addresses[i].index == index) {
+			send_mdns_packet(mesh, &mesh->discovery.addresses[i], false);
 		}
 	}
 
 	handle_network_change(mesh, true);
 }
 
-static void iface_down(meshlink_handle_t *const mesh, int index) {
-	int *p = bsearch(&index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare);
+static void iface_down(meshlink_handle_t *mesh, int index) {
+	int *p = bsearch(&index, mesh->discovery.ifaces, mesh->discovery.iface_count, sizeof(*p), iface_compare);
 
 	if(!p) {
 		return;
@@ -336,59 +454,151 @@ static void iface_down(meshlink_handle_t *const mesh, int index) {
 		.imr_multiaddr = mdns_address_ipv4.in.sin_addr,
 		.imr_ifindex = index,
 	};
-	setsockopt(mesh->discovery_sockets[0].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq4, sizeof(mreq4));
+	setsockopt(mesh->discovery.sockets[0].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq4, sizeof(mreq4));
 
 	struct ipv6_mreq mreq6 = {
 		.ipv6mr_multiaddr = mdns_address_ipv6.in6.sin6_addr,
 		.ipv6mr_interface = index,
 	};
-	setsockopt(mesh->discovery_sockets[1].fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
+	setsockopt(mesh->discovery.sockets[1].fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
 
-	fprintf(stderr, "iface %d down\n", index);
-	memmove(p, p + 1, (mesh->discovery_ifaces + --mesh->discovery_iface_count - p) * sizeof(*p));
+	memmove(p, p + 1, (mesh->discovery.ifaces + --mesh->discovery.iface_count - p) * sizeof(*p));
 
-	handle_network_change(mesh, mesh->discovery_iface_count);
+	handle_network_change(mesh, mesh->discovery.iface_count);
 }
 
 static void addr_add(meshlink_handle_t *mesh, const discovery_address_t *addr) {
-	discovery_address_t *p = bsearch(addr, mesh->discovery_addresses, mesh->discovery_address_count, sizeof(*p), address_compare);
+	discovery_address_t *p = bsearch(addr, mesh->discovery.addresses, mesh->discovery.address_count, sizeof(*p), address_compare);
 
 	if(p) {
 		return;
 	}
 
-	bool up = bsearch(&addr->index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(int), iface_compare);
-	char *host = NULL, *port = NULL;
-	sockaddr2str(&addr->address, &host, &port);
-	fprintf(stderr, "address %d %s port %s up %d\n", addr->index, host, port, up);
-	free(host);
-	free(port);
+	bool up = bsearch(&addr->index, mesh->discovery.ifaces, mesh->discovery.iface_count, sizeof(int), iface_compare);
 
-	mesh->discovery_addresses = xrealloc(mesh->discovery_addresses, ++mesh->discovery_address_count * sizeof(*p));
-	mesh->discovery_addresses[mesh->discovery_address_count - 1] = *addr;
-	mesh->discovery_addresses[mesh->discovery_address_count - 1].up = up;
+	mesh->discovery.addresses = xrealloc(mesh->discovery.addresses, ++mesh->discovery.address_count * sizeof(*p));
+	mesh->discovery.addresses[mesh->discovery.address_count - 1] = *addr;
+	mesh->discovery.addresses[mesh->discovery.address_count - 1].up = up;
 
 	if(up) {
-		send_mdns_packet(mesh, &mesh->discovery_addresses[mesh->discovery_address_count - 1]);
+		send_mdns_packet(mesh, &mesh->discovery.addresses[mesh->discovery.address_count - 1], false);
 	}
 
-	qsort(mesh->discovery_addresses, mesh->discovery_address_count, sizeof(*p), address_compare);
+	qsort(mesh->discovery.addresses, mesh->discovery.address_count, sizeof(*p), address_compare);
 }
 
 static void addr_del(meshlink_handle_t *mesh, const discovery_address_t *addr) {
-	discovery_address_t *p = bsearch(addr, mesh->discovery_addresses, mesh->discovery_address_count, sizeof(*p), address_compare);
+	discovery_address_t *p = bsearch(addr, mesh->discovery.addresses, mesh->discovery.address_count, sizeof(*p), address_compare);
 
 	if(!p) {
 		return;
 	}
 
-	char *host = NULL, *port = NULL;
-	sockaddr2str(&addr->address, &host, &port);
-	fprintf(stderr, "address %d %s port %s down\n", addr->index, host, port);
-	free(host);
-	free(port);
+	memmove(p, p + 1, (mesh->discovery.addresses + --mesh->discovery.address_count - p) * sizeof(*p));
+}
+
+void scan_ifaddrs(meshlink_handle_t *mesh) {
+#ifdef HAVE_GETIFADDRS
+	struct ifaddrs *ifa = NULL;
+
+	if(getifaddrs(&ifa) == -1) {
+		logger(mesh, MESHLINK_ERROR, "Could not get list of interface addresses: %s", strerror(errno));
+		return;
+	}
+
+	// Check for interfaces being removed
+	for(int i = 0; i < mesh->discovery.iface_count;) {
+		bool found = false;
+
+		for(struct ifaddrs *ifap = ifa; ifap; ifap = ifap->ifa_next) {
+			if(!ifap->ifa_name) {
+				continue;
+			}
+
+			int index = if_nametoindex(ifap->ifa_name);
+
+			if(mesh->discovery.ifaces[i] == index) {
+				found = true;
+				break;
+			}
+		}
+
+		if(!found) {
+			iface_down(mesh, mesh->discovery.ifaces[i]);
+		} else {
+			i++;
+		}
+	}
+
+	// Check for addresses being removed
+	for(int i = 0; i < mesh->discovery.address_count;) {
+		discovery_address_t *p = &mesh->discovery.addresses[i];
+		bool found = false;
+
+		for(struct ifaddrs *ifap = ifa; ifap; ifap = ifap->ifa_next) {
+			if(!ifap->ifa_name || !ifap->ifa_addr) {
+				continue;
+			}
+
+			int index = if_nametoindex(ifap->ifa_name);
+
+			if(p->index == index && sockaddrcmp_noport(&p->address, (sockaddr_t *)ifap->ifa_addr) == 0) {
+				found = true;
+				break;
+			}
+		}
+
+		if(!found) {
+			(void)addr_del;
+			memmove(p, p + 1, (mesh->discovery.addresses + --mesh->discovery.address_count - p) * sizeof(*p));
+		} else {
+			i++;
+		}
+	}
+
+	// Check for interfaces state changes and addresses going up
+	for(struct ifaddrs *ifap = ifa; ifap; ifap = ifap->ifa_next) {
+		if(!ifap->ifa_name) {
+			continue;
+		}
+
+		int index = if_nametoindex(ifap->ifa_name);
+
+		if(ifap->ifa_flags & IFF_UP && ifap->ifa_flags & IFF_MULTICAST && !(ifap->ifa_flags & IFF_LOOPBACK)) {
+			iface_up(mesh, index);
+		} else {
+			iface_down(mesh, index);
+		}
+
+		if(!ifap->ifa_addr) {
+			continue;
+		}
+
+		discovery_address_t addr  = {
+			.index = index,
+		};
+
+		sockaddr_t *sa = (sockaddr_t *)ifap->ifa_addr;
 
-	memmove(p, p + 1, (mesh->discovery_addresses + --mesh->discovery_address_count - p) * sizeof(*p));
+		if(sa->sa.sa_family == AF_INET) {
+			memcpy(&addr.address.in, &sa->in, sizeof(sa->in));
+			addr.address.in.sin_port = ntohs(5353);
+		} else if(sa->sa.sa_family == AF_INET6) {
+			memcpy(&addr.address.in6, &sa->in6, sizeof(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) {
+			addr_add(mesh, &addr);
+		}
+	}
+
+	freeifaddrs(ifa);
+#else
+	(void)mesh;
+#endif
 }
 
 #if defined(__linux)
@@ -420,7 +630,6 @@ static void netlink_getaddr(int fd) {
 	send(fd, &msg, msg.nlm.nlmsg_len, 0);
 }
 
-
 static void netlink_parse_link(meshlink_handle_t *mesh, const struct nlmsghdr *nlm) {
 	const struct ifinfomsg *ifi = (const struct ifinfomsg *)(nlm + 1);
 
@@ -451,11 +660,11 @@ static void netlink_parse_addr(meshlink_handle_t *mesh, const struct nlmsghdr *n
 			if(rta->rta_len == 8) {
 				addr.address.sa.sa_family = AF_INET;
 				memcpy(&addr.address.in.sin_addr, ptr + 4, 4);
-				addr.address.in.sin_port = 5353;
+				addr.address.in.sin_port = ntohs(5353);
 			} else if(rta->rta_len == 20) {
 				addr.address.sa.sa_family = AF_INET6;
 				memcpy(&addr.address.in6.sin6_addr, ptr + 4, 16);
-				addr.address.in6.sin6_port = 5353;
+				addr.address.in6.sin6_port = ntohs(5353);
 				addr.address.in6.sin6_scope_id = ifa->ifa_index;
 			} else {
 				addr.address.sa.sa_family = AF_UNKNOWN;
@@ -504,8 +713,8 @@ static void netlink_parse(meshlink_handle_t *mesh, const void *data, size_t len)
 
 static void netlink_io_handler(event_loop_t *loop, void *data, int flags) {
 	(void)flags;
-	static time_t prev_update;
-	meshlink_handle_t *mesh = data;
+	(void)data;
+	meshlink_handle_t *mesh = loop->data;
 
 	struct {
 		struct nlmsghdr nlm;
@@ -513,7 +722,7 @@ static void netlink_io_handler(event_loop_t *loop, void *data, int flags) {
 	} msg;
 
 	while(true) {
-		ssize_t result = recv(mesh->pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
+		ssize_t result = recv(mesh->discovery.pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
 
 		if(result <= 0) {
 			if(result == 0 || errno == EAGAIN || errno == EINTR) {
@@ -521,7 +730,7 @@ static void netlink_io_handler(event_loop_t *loop, void *data, int flags) {
 			}
 
 			logger(mesh, MESHLINK_ERROR, "Reading from Netlink socket failed: %s\n", strerror(errno));
-			io_set(loop, &mesh->pfroute_io, 0);
+			io_set(loop, &mesh->discovery.pfroute_io, 0);
 		}
 
 		if((size_t)result < sizeof(msg.nlm)) {
@@ -532,23 +741,137 @@ static void netlink_io_handler(event_loop_t *loop, void *data, int flags) {
 		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->pfroute_io.fd);
+				netlink_getaddr(mesh->discovery.pfroute_io.fd);
 			}
 		} else {
 			netlink_parse(mesh, &msg, result);
 
-			if(loop->now.tv_sec > prev_update + 5) {
-				prev_update = loop->now.tv_sec;
-				handle_network_change(mesh, 1);
+			if(loop->now.tv_sec > mesh->discovery.last_update + 5) {
+				mesh->discovery.last_update = loop->now.tv_sec;
+				handle_network_change(mesh, true);
 			}
 		}
 	}
 }
+#elif defined(__APPLE__)
+static void reachability_change_callback(SCNetworkReachabilityRef reachability, SCNetworkReachabilityFlags flags, void *info) {
+	(void)reachability;
+	(void)flags;
+
+	meshlink_handle_t *mesh = info;
+
+	pthread_mutex_lock(&mesh->mutex);
+
+	scan_ifaddrs(mesh);
+
+	if(mesh->loop.now.tv_sec > mesh->discovery.last_update + 5) {
+		logger(mesh, MESHLINK_INFO, "Network change detected");
+		mesh->discovery.last_update = mesh->loop.now.tv_sec;
+		handle_network_change(mesh, true);
+	}
+
+	pthread_mutex_unlock(&mesh->mutex);
+}
+
+static void *network_change_handler(void *arg) {
+	meshlink_handle_t *mesh = arg;
+
+	mesh->discovery.runloop = CFRunLoopGetCurrent();
+
+	SCNetworkReachabilityRef reach_v4 = SCNetworkReachabilityCreateWithName(NULL, "93.184.216.34");
+	SCNetworkReachabilityRef reach_v6 = SCNetworkReachabilityCreateWithName(NULL, "2606:2800:220:1:248:1893:25c8:1946");
+
+	SCNetworkReachabilityContext context;
+	memset(&context, 0, sizeof(context));
+	context.info = mesh;
+
+	if(reach_v4) {
+		SCNetworkReachabilitySetCallback(reach_v4, reachability_change_callback, &context);
+		SCNetworkReachabilityScheduleWithRunLoop(reach_v4, mesh->discovery.runloop, kCFRunLoopDefaultMode);
+	} else {
+		logger(mesh, MESHLINK_ERROR, "Could not create IPv4 network reachability watcher");
+	}
+
+	if(reach_v6) {
+		SCNetworkReachabilitySetCallback(reach_v6, reachability_change_callback, &context);
+		SCNetworkReachabilityScheduleWithRunLoop(reach_v6, mesh->discovery.runloop, kCFRunLoopDefaultMode);
+	} else {
+		logger(mesh, MESHLINK_ERROR, "Could not create IPv6 network reachability watcher");
+	}
+
+	CFRunLoopRun();
+
+	mesh->discovery.runloop = NULL;
+
+	if(reach_v4) {
+		SCNetworkReachabilityUnscheduleFromRunLoop(reach_v4, mesh->discovery.runloop, kCFRunLoopDefaultMode);
+		CFRelease(reach_v4);
+	}
+
+	if(reach_v6) {
+		SCNetworkReachabilityUnscheduleFromRunLoop(reach_v6, mesh->discovery.runloop, kCFRunLoopDefaultMode);
+		CFRelease(reach_v6);
+	}
+
+	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;
-	static time_t prev_update;
-	meshlink_handle_t *mesh = data;
+	(void)data;
+	meshlink_handle_t *mesh = loop->data;
 
 	struct {
 		struct rt_msghdr rtm;
@@ -557,7 +880,7 @@ static void pfroute_io_handler(event_loop_t *loop, void *data, int flags) {
 
 	while(true) {
 		msg.rtm.rtm_version = 0;
-		ssize_t result = recv(mesh->pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
+		ssize_t result = recv(mesh->discovery.pfroute_io.fd, &msg, sizeof(msg), MSG_DONTWAIT);
 
 		if(result <= 0) {
 			if(result == 0 || errno == EAGAIN || errno == EINTR) {
@@ -565,7 +888,7 @@ static void pfroute_io_handler(event_loop_t *loop, void *data, int flags) {
 			}
 
 			logger(mesh, MESHLINK_ERROR, "Reading from PFROUTE socket failed: %s\n", strerror(errno));
-			io_set(loop, &mesh->pfroute_io, 0);
+			io_set(loop, &mesh->discovery.pfroute_io, 0);
 		}
 
 		if(msg.rtm.rtm_version != RTM_VERSION) {
@@ -575,13 +898,12 @@ static void pfroute_io_handler(event_loop_t *loop, void *data, int flags) {
 
 		switch(msg.rtm.rtm_type) {
 		case RTM_IFINFO:
+			pfroute_parse_iface(mesh, &msg.rtm);
+			break;
+
 		case RTM_NEWADDR:
 		case RTM_DELADDR:
-			if(loop->now.tv_sec > prev_update + 5) {
-				prev_update = loop->now.tv_sec;
-				handle_network_change(mesh, 1);
-			}
-
+			pfroute_parse_addr(mesh, &msg.rtm);
 			break;
 
 		default:
@@ -599,29 +921,64 @@ bool discovery_start(meshlink_handle_t *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);
-	sockaddr_t sa4 = {
-		.in.sin_family = AF_INET,
-		.in.sin_port = ntohs(5353),
-	};
-	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
-	bind(fd, &sa4.sa, SALEN(sa4.sa));
-	setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one));
-	setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
-	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),
-	};
+
+	if(fd == -1) {
+		logger(mesh, MESHLINK_ERROR, "Error creating IPv4 socket: %s", strerror(errno));
+	} else {
+
+		sockaddr_t sa4 = {
+			.in.sin_family = AF_INET,
+			.in.sin_port = ntohs(5353),
+		};
+		setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
+#ifdef SO_REUSEPORT
+		setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
+#endif
+#ifdef IP_PKTINFO
+		setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
+#endif
+		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);
+		}
+	}
+
 	fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
-	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
-	setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
-	bind(fd, &sa6.sa, SALEN(sa6.sa));
-	setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one));
-	setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl));
-	io_add(&mesh->loop, &mesh->discovery_sockets[1], mdns_io_handler, &mesh->discovery_sockets[1], fd, IO_READ);
+
+	if(fd == -1) {
+		logger(mesh, MESHLINK_ERROR, "Error creating IPv6 socket: %s", strerror(errno));
+	} else {
+		sockaddr_t sa6 = {
+			.in6.sin6_family = AF_INET6,
+			.in6.sin6_port = ntohs(5353),
+		};
+
+		setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
+#ifdef SO_REUSEPORT
+		setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
+#endif
+#ifdef IPV6_RECVPKTINFO
+		setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
+#endif
+		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 IPv6 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);
@@ -633,24 +990,31 @@ bool discovery_start(meshlink_handle_t *mesh) {
 		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->pfroute_io, netlink_io_handler, mesh, sock, IO_READ);
+			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->pfroute_io, pfroute_io_handler, mesh, sock, IO_READ);
+		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
 
 	return true;
@@ -661,28 +1025,39 @@ void discovery_stop(meshlink_handle_t *mesh) {
 
 	assert(mesh);
 
-	free(mesh->discovery_ifaces);
-	free(mesh->discovery_addresses);
-	mesh->discovery_iface_count = 0;
-	mesh->discovery_address_count = 0;
+	free(mesh->discovery.ifaces);
+	free(mesh->discovery.addresses);
+	mesh->discovery.ifaces = NULL;
+	mesh->discovery.addresses = NULL;
+	mesh->discovery.iface_count = 0;
+	mesh->discovery.address_count = 0;
+
+#if defined(__APPLE__)
+
+	if(mesh->discovery.runloop) {
+		CFRunLoopStop(mesh->discovery.runloop);
+		pthread_join(mesh->discovery.thread, NULL);
+	}
+
+#endif
 
-	if(mesh->pfroute_io.cb) {
-		close(mesh->pfroute_io.fd);
-		io_del(&mesh->loop, &mesh->pfroute_io);
+	if(mesh->discovery.pfroute_io.cb) {
+		close(mesh->discovery.pfroute_io.fd);
+		io_del(&mesh->loop, &mesh->discovery.pfroute_io);
 	}
 
 	for(int i = 0; i < 2; i++) {
-		if(mesh->discovery_sockets[i].cb) {
-			close(mesh->discovery_sockets[i].fd);
-			io_del(&mesh->loop, &mesh->discovery_sockets[i]);
+		if(mesh->discovery.sockets[i].cb) {
+			close(mesh->discovery.sockets[i].fd);
+			io_del(&mesh->loop, &mesh->discovery.sockets[i]);
 		}
 	}
 }
 
 void discovery_refresh(meshlink_handle_t *mesh) {
-	for(int i = 0; i < mesh->discovery_address_count; i++) {
-		if(mesh->discovery_addresses[i].up) {
-			send_mdns_packet(mesh, &mesh->discovery_addresses[i]);
+	for(int i = 0; i < mesh->discovery.address_count; i++) {
+		if(mesh->discovery.addresses[i].up) {
+			send_mdns_packet(mesh, &mesh->discovery.addresses[i], false);
 		}
 	}
 }