Fix the order of socket operations when setting up listening sockets.

[meshlink] / src / net_setup.c

diff --git a/src/net_setup.c b/src/net_setup.c
index 4cff1a5ee83d679ff952fe181cf0c84fbe738d07..d0e450039913c995298f304f3b4003730ad606f8 100644 (file)
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -301,6 +301,117 @@ static bool load_node(meshlink_handle_t *mesh, const char *name, void *priv) {
        return true;
 }
 
+static int setup_tcp_listen_socket(meshlink_handle_t *mesh, const struct addrinfo *aip) {
+       int nfd = socket(aip->ai_family, SOCK_STREAM, IPPROTO_TCP);
+
+       if(nfd == -1) {
+               return -1;
+       }
+
+#ifdef FD_CLOEXEC
+       fcntl(nfd, F_SETFD, FD_CLOEXEC);
+#endif
+
+       int option = 1;
+       setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
+
+#if defined(IPV6_V6ONLY)
+
+       if(aip->ai_family == AF_INET6) {
+               setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
+       }
+
+#else
+#warning IPV6_V6ONLY not defined
+#endif
+
+       if(bind(nfd, aip->ai_addr, aip->ai_addrlen)) {
+               closesocket(nfd);
+               return -1;
+       }
+
+       if(listen(nfd, 3)) {
+               logger(mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
+               closesocket(nfd);
+               return -1;
+       }
+
+       return nfd;
+}
+
+static int setup_udp_socket(meshlink_handle_t *mesh, const struct addrinfo *aip) {
+       int nfd = socket(aip->ai_family, SOCK_DGRAM, IPPROTO_UDP);
+
+       if(nfd == -1) {
+               return -1;
+       }
+
+#ifdef FD_CLOEXEC
+       fcntl(nfd, F_SETFD, FD_CLOEXEC);
+#endif
+
+#ifdef O_NONBLOCK
+       int flags = fcntl(nfd, F_GETFL);
+
+       if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
+               closesocket(nfd);
+               logger(mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl", strerror(errno));
+               return -1;
+       }
+
+#elif defined(WIN32)
+       unsigned long arg = 1;
+
+       if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
+               closesocket(nfd);
+               logger(mesh, MESHLINK_ERROR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
+               return -1;
+       }
+
+#endif
+
+       int option = 1;
+       setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
+       setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
+
+#if defined(IPV6_V6ONLY)
+
+       if(aip->ai_family == AF_INET6) {
+               setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
+       }
+
+#endif
+
+#if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
+#define IP_DONTFRAGMENT IP_DONTFRAG
+#endif
+
+#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
+       option = IP_PMTUDISC_DO;
+       setsockopt(nfd, IPPROTO_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
+#elif defined(IP_DONTFRAGMENT)
+       option = 1;
+       setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
+#endif
+
+       if(aip->ai_family == AF_INET6) {
+#if defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
+               option = IPV6_PMTUDISC_DO;
+               setsockopt(nfd, IPPROTO_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
+#elif defined(IPV6_DONTFRAG)
+               option = 1;
+               setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
+#endif
+       }
+
+       if(bind(nfd, aip->ai_addr, aip->ai_addrlen)) {
+               closesocket(nfd);
+               return -1;
+       }
+
+       return nfd;
+}
+
 /*
   Add listening sockets.
 */
@@ -345,15 +456,9 @@ static bool add_listen_sockets(meshlink_handle_t *mesh) {
 
                /* Try to bind to TCP */
 
-               int tcp_fd = socket(aip->ai_family, SOCK_STREAM, IPPROTO_TCP);
+               int tcp_fd = setup_tcp_listen_socket(mesh, aip);
 
                if(tcp_fd == -1) {
-                       continue;
-               }
-
-               if(bind(tcp_fd, aip->ai_addr, aip->ai_addrlen)) {
-                       closesocket(tcp_fd);
-
                        if(errno == EADDRINUSE) {
                                /* If this port is in use for any address family, avoid it. */
                                success = false;
@@ -363,15 +468,9 @@ static bool add_listen_sockets(meshlink_handle_t *mesh) {
                        }
                }
 
-               if(!setup_listen_socket(mesh, tcp_fd, aip->ai_family)) {
-                       closesocket(tcp_fd);
-                       success = false;
-                       break;
-               }
-
                /* If TCP worked, then we require that UDP works as well. */
 
-               int udp_fd = socket(aip->ai_family, SOCK_DGRAM, IPPROTO_UDP);
+               int udp_fd = setup_udp_socket(mesh, aip);
 
                if(udp_fd == -1) {
                        closesocket(tcp_fd);
@@ -379,13 +478,6 @@ static bool add_listen_sockets(meshlink_handle_t *mesh) {
                        break;
                }
 
-               if(bind(udp_fd, aip->ai_addr, aip->ai_addrlen) || !setup_vpn_in_socket(mesh, udp_fd, aip->ai_family)) {
-                       closesocket(tcp_fd);
-                       closesocket(udp_fd);
-                       success = false;
-                       break;
-               }
-
                io_add(&mesh->loop, &mesh->listen_socket[mesh->listen_sockets].tcp, handle_new_meta_connection, &mesh->listen_socket[mesh->listen_sockets], tcp_fd, IO_READ);
                io_add(&mesh->loop, &mesh->listen_socket[mesh->listen_sockets].udp, handle_incoming_vpn_data, &mesh->listen_socket[mesh->listen_sockets], udp_fd, IO_READ);