-/*
- 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__)
-#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>
-#include <linux/if_link.h>
-#include <linux/netlink.h>
-#include <linux/rtnetlink.h>
-#endif
-
-#include "mdns.h"
-#include "meshlink_internal.h"
-#include "event.h"
-#include "discovery.h"
-#include "sockaddr.h"
-#include "logger.h"
-#include "netutl.h"
-#include "node.h"
-#include "connection.h"
-#include "utils.h"
-#include "xalloc.h"
-
-#define MESHLINK_MDNS_SERVICE_TYPE "_%s._tcp"
-#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,
- .in.sin_port = 0xe914,
-};
-
-static const sockaddr_t mdns_address_ipv6 = {
- .in6.sin6_family = AF_INET6,
- .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,
-};
-
-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) {
- const int *a = va;
- const int *b = vb;
- return *a - *b;
-}
-
-static int address_compare(const void *va, const void *vb) {
- const discovery_address_t *a = va;
- const discovery_address_t *b = vb;
-
- if(a->index != b->index) {
- return a->index - b->index;
- }
-
- return sockaddrcmp_noport(&a->address, &b->address);
-}
-
-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,
- .iov_len = len,
- };
-
- struct in_pktinfo pkti = {
- .ipi_ifindex = index,
- .ipi_addr = src->in.sin_addr,
- };
-
- union {
- char buf[CMSG_SPACE(sizeof(pkti))];
- struct cmsghdr align;
- } u;
-
- memset(&u, 0, sizeof(u));
-
- struct msghdr msg = {
- .msg_name = (struct sockaddr *) &dest->sa,
- .msg_namelen = SALEN(dest->sa),
- .msg_iov = &iov,
- .msg_iovlen = 1,
- .msg_control = u.buf,
- .msg_controllen = sizeof(u.buf),
- };
-
- struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
- cmsg->cmsg_level = IPPROTO_IP;
- cmsg->cmsg_type = IP_PKTINFO;
- cmsg->cmsg_len = CMSG_LEN(sizeof(pkti));
- memcpy(CMSG_DATA(cmsg), &pkti, sizeof(pkti));
-
- // 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
-
- if(result <= 0) {
- logger(mesh, MESHLINK_ERROR, "Error sending multicast packet: %s", strerror(errno));
- }
-}
-
-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,
- .iov_len = len,
- };
-
- struct in6_pktinfo pkti = {
- .ipi6_ifindex = index,
- .ipi6_addr = src->in6.sin6_addr,
- };
-
- union {
- char buf[CMSG_SPACE(sizeof(pkti))];
- struct cmsghdr align;
- } u;
-
- memset(&u, 0, sizeof u);
-
- struct msghdr msg = {
- .msg_name = (struct sockaddr *) &dest->sa,
- .msg_namelen = SALEN(dest->sa),
- .msg_iov = &iov,
- .msg_iovlen = 1,
- .msg_control = u.buf,
- .msg_controllen = CMSG_LEN(sizeof(pkti)),
- };
-
- struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
- cmsg->cmsg_level = IPPROTO_IPV6;
- cmsg->cmsg_type = IPV6_PKTINFO;
- cmsg->cmsg_len = CMSG_LEN(sizeof(pkti));
- memcpy(CMSG_DATA(cmsg), &pkti, sizeof(pkti));
-
- // 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
-
- if(result <= 0) {
- logger(mesh, MESHLINK_ERROR, "Error sending multicast packet: %s", strerror(errno));
- }
-}
-
-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
- 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:
- send_mdns_packet_ipv4(mesh, mesh->discovery.sockets[0].fd, addr->index, &addr->address, &mdns_address_ipv4, msg, msg_size);
- break;
-
- case AF_INET6:
- send_mdns_packet_ipv6(mesh, mesh->discovery.sockets[1].fd, addr->index, &addr->address, &mdns_address_ipv6, msg, msg_size);
- break;
-
- default:
- break;
- }
-}
-
-static void mdns_io_handler(event_loop_t *loop, void *data, int flags) {
- (void)flags;
- meshlink_handle_t *mesh = loop->data;
- io_t *io = data;
- uint8_t buf[1024];
- 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)) {
- logger(mesh, MESHLINK_ERROR, "Error reading from mDNS discovery socket: %s", strerror(errno));
- io_set(loop, io, 0);
- }
-
- return;
- }
-
- char *name = NULL;
- uint16_t port = 0;
- const char *keys[2] = {MESHLINK_MDNS_NAME_KEY, MESHLINK_MDNS_FINGERPRINT_KEY};
- char *values[2] = {NULL, NULL};
-
- 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) {
- 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 = htons(port);
- break;
-
- case AF_INET6:
- sa.in6.sin6_port = htons(port);
- break;
-
- default:
- logger(mesh, MESHLINK_WARNING, "Could not resolve node %s to a known address family type.\n", n->name);
- sa.sa.sa_family = AF_UNKNOWN;
- break;
- }
-
- if(sa.sa.sa_family != AF_UNKNOWN) {
- n->catta_address = sa;
- n->last_connect_try = 0;
- node_add_recent_address(mesh, n, &sa);
-
- if(n->connection) {
- n->connection->last_ping_time = -3600;
- }
-
- for list_each(outgoing_t, outgoing, mesh->outgoings) {
- if(outgoing->node != n) {
- continue;
- }
-
- 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];
-
- if(p->index == index && p->address.sa.sa_family == family) {
- send_mdns_packet(mesh, p, true);
- }
- }
- } else {
- // Send a unicast response back
- sendto(io->fd, buf, size, MSG_DONTWAIT | MSG_NOSIGNAL, &sa.sa, sl);
- }
-
- free(fingerprint);
- }
-
- free(name);
-
- for(int i = 0; i < 2; i++) {
- free(values[i]);
- }
-}
-
-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);
-
- if(p) {
- return;
- }
-
- 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));
-
- 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));
-
- // 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], false);
- }
- }
-
- handle_network_change(mesh, true);
-}
-
-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;
- }
-
- // Drop 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));
-
- 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));
-
- memmove(p, p + 1, (mesh->discovery.ifaces + --mesh->discovery.iface_count - p) * sizeof(*p));
-
- 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);
-
- if(p) {
- return;
- }
-
- 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;
-
- if(up) {
- 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);
-}
-
-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);
-
- if(!p) {
- return;
- }
-
- 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;
-
- 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)
-static void netlink_getlink(int fd) {
- static const struct {
- struct nlmsghdr nlm;
- struct ifinfomsg ifi;
- } msg = {
- .nlm.nlmsg_len = NLMSG_LENGTH(sizeof(msg.ifi)),
- .nlm.nlmsg_type = RTM_GETLINK,
- .nlm.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
- .nlm.nlmsg_seq = 1,
- .ifi.ifi_family = AF_UNSPEC,
- };
- send(fd, &msg, msg.nlm.nlmsg_len, 0);
-}
-
-static void netlink_getaddr(int fd) {
- static const struct {
- struct nlmsghdr nlm;
- struct ifaddrmsg ifa;
- } msg = {
- .nlm.nlmsg_len = NLMSG_LENGTH(sizeof(msg.ifa)),
- .nlm.nlmsg_type = RTM_GETADDR,
- .nlm.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
- .nlm.nlmsg_seq = 2,
- .ifa.ifa_family = AF_UNSPEC,
- };
- 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);
-
- if(ifi->ifi_flags & IFF_UP && ifi->ifi_flags & IFF_MULTICAST) {
- iface_up(mesh, ifi->ifi_index);
- } else {
- iface_down(mesh, ifi->ifi_index);
- }
-}
-
-static void netlink_parse_addr(meshlink_handle_t *mesh, const struct nlmsghdr *nlm) {
- const struct ifaddrmsg *ifa = (const struct ifaddrmsg *)(nlm + 1);
- const uint8_t *ptr = (const uint8_t *)(ifa + 1);
- size_t len = nlm->nlmsg_len - (ptr - (const uint8_t *)nlm);
-
- while(len >= sizeof(struct rtattr)) {
- const struct rtattr *rta = (const struct rtattr *)ptr;
-
- if(rta->rta_len <= 0 || rta->rta_len > len) {
- break;
- }
-
- if(rta->rta_type == IFA_ADDRESS) {
- discovery_address_t addr = {
- .index = ifa->ifa_index,
- };
-
- 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 = 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 = ntohs(5353);
- addr.address.in6.sin6_scope_id = ifa->ifa_index;
- } else {
- addr.address.sa.sa_family = AF_UNKNOWN;
- }
-
- if(addr.address.sa.sa_family != AF_UNKNOWN) {
- if(nlm->nlmsg_type == RTM_NEWADDR) {
- addr_add(mesh, &addr);
- } else {
- addr_del(mesh, &addr);
- }
- }
- }
-
- unsigned short rta_len = (rta->rta_len + 3) & ~3;
- ptr += rta_len;
- len -= rta_len;
- }
-}
-
-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, 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;
- (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));
- } 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);
-
- 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);
-
- 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
-
- return true;
-}
-
-void discovery_stop(meshlink_handle_t *mesh) {
- logger(mesh, MESHLINK_DEBUG, "discovery_stop called\n");
-
- assert(mesh);
-
- 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->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]);
- }
- }
-}
-
-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], false);
- }
- }
-}