Attribution for Martin Schürrer.
[tinc] / src / net_socket.c
index 21fc017..2d1ecc5 100644 (file)
@@ -1,7 +1,8 @@
 /*
     net_socket.c -- Handle various kinds of sockets.
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2012 Guus Sliepen <guus@tinc-vpn.org>
+                  2006      Scott Lamb <slamb@slamb.org>
                   2009      Florian Forster <octo@verplant.org>
 
     This program is free software; you can redistribute it and/or modify
 #include "utils.h"
 #include "xalloc.h"
 
-#include <assert.h>
-
-#ifdef WSAEINPROGRESS
-#define EINPROGRESS WSAEINPROGRESS
-#endif
-
 /* Needed on Mac OS/X */
 #ifndef SOL_TCP
 #define SOL_TCP IPPROTO_TCP
@@ -47,6 +42,8 @@
 int addressfamily = AF_UNSPEC;
 int maxtimeout = 900;
 int seconds_till_retry = 5;
+int udp_rcvbuf = 0;
+int udp_sndbuf = 0;
 
 listen_socket_t listen_socket[MAXSOCKETS];
 int listen_sockets;
@@ -67,18 +64,18 @@ static void configure_tcp(connection_t *c) {
        unsigned long arg = 1;
 
        if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
-               logger(LOG_ERR, "ioctlsocket for %s: WSA error %d", c->hostname, WSAGetLastError());
+               logger(LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
        }
 #endif
 
 #if defined(SOL_TCP) && defined(TCP_NODELAY)
        option = 1;
-       setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
+       setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof(option));
 #endif
 
 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
        option = IPTOS_LOWDELAY;
-       setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
+       setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof(option));
 #endif
 }
 
@@ -98,7 +95,7 @@ static bool bind_to_interface(int sd) {
        strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
        ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
 
-       status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
+       status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
        if(status) {
                logger(LOG_ERR, "Can't bind to interface %s: %s", iface,
                                strerror(errno));
@@ -111,64 +108,6 @@ static bool bind_to_interface(int sd) {
        return true;
 }
 
-static bool bind_to_address(connection_t *c) {
-       char *node;
-       struct addrinfo *ai_list;
-       struct addrinfo *ai_ptr;
-       struct addrinfo ai_hints;
-       int status;
-
-       assert(c != NULL);
-       assert(c->socket >= 0);
-
-       node = NULL;
-       if(!get_config_string(lookup_config(config_tree, "BindToAddress"),
-                               &node))
-               return true;
-
-       assert(node != NULL);
-
-       memset(&ai_hints, 0, sizeof(ai_hints));
-       ai_hints.ai_family = c->address.sa.sa_family;
-       /* We're called from `do_outgoing_connection' only. */
-       ai_hints.ai_socktype = SOCK_STREAM;
-       ai_hints.ai_protocol = IPPROTO_TCP;
-
-       ai_list = NULL;
-
-       status = getaddrinfo(node, /* service = */ NULL,
-                       &ai_hints, &ai_list);
-       if(status) {
-               free(node);
-               logger(LOG_WARNING, "Error looking up %s port %s: %s",
-                               node, "any", gai_strerror(status));
-               return false;
-       }
-       assert(ai_list != NULL);
-
-       status = -1;
-       for(ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next) {
-               status = bind(c->socket,
-                               ai_list->ai_addr, ai_list->ai_addrlen);
-               if(!status)
-                       break;
-       }
-
-
-       if(status) {
-               logger(LOG_ERR, "Can't bind to %s/tcp: %s", node,
-                               strerror(errno));
-       } else ifdebug(CONNECTIONS) {
-               logger(LOG_DEBUG, "Successfully bound outgoing "
-                               "TCP socket to %s", node);
-       }
-
-       free(node);
-       freeaddrinfo(ai_list);
-
-       return status ? false : true;
-}
-
 int setup_listen_socket(const sockaddr_t *sa) {
        int nfd;
        char *addrstr;
@@ -178,18 +117,22 @@ int setup_listen_socket(const sockaddr_t *sa) {
        nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 
        if(nfd < 0) {
-               ifdebug(STATUS) logger(LOG_ERR, "Creating metasocket failed: %s", strerror(errno));
+               ifdebug(STATUS) logger(LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
                return -1;
        }
 
+#ifdef FD_CLOEXEC
+       fcntl(nfd, F_SETFD, FD_CLOEXEC);
+#endif
+
        /* Optimize TCP settings */
 
        option = 1;
-       setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
+       setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
 
 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
        if(sa->sa.sa_family == AF_INET6)
-               setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
+               setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
 #endif
 
        if(get_config_string
@@ -200,10 +143,10 @@ int setup_listen_socket(const sockaddr_t *sa) {
                memset(&ifr, 0, sizeof(ifr));
                strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
 
-               if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
+               if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr))) {
                        closesocket(nfd);
                        logger(LOG_ERR, "Can't bind to interface %s: %s", iface,
-                                  strerror(errno));
+                                  strerror(sockerrno));
                        return -1;
                }
 #else
@@ -214,16 +157,14 @@ int setup_listen_socket(const sockaddr_t *sa) {
        if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
                closesocket(nfd);
                addrstr = sockaddr2hostname(sa);
-               logger(LOG_ERR, "Can't bind to %s/tcp: %s", addrstr,
-                          strerror(errno));
+               logger(LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
                free(addrstr);
                return -1;
        }
 
        if(listen(nfd, 3)) {
                closesocket(nfd);
-               logger(LOG_ERR, "System call `%s' failed: %s", "listen",
-                          strerror(errno));
+               logger(LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
                return -1;
        }
 
@@ -238,10 +179,14 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
        nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
 
        if(nfd < 0) {
-               logger(LOG_ERR, "Creating UDP socket failed: %s", strerror(errno));
+               logger(LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
                return -1;
        }
 
+#ifdef FD_CLOEXEC
+       fcntl(nfd, F_SETFD, FD_CLOEXEC);
+#endif
+
 #ifdef O_NONBLOCK
        {
                int flags = fcntl(nfd, F_GETFL);
@@ -258,33 +203,57 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
                unsigned long arg = 1;
                if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
                        closesocket(nfd);
-                       logger(LOG_ERR, "Call to `%s' failed: WSA error %d", "ioctlsocket",
-                               WSAGetLastError());
+                       logger(LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
                        return -1;
                }
        }
 #endif
 
        option = 1;
-       setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
+       setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
+       setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof(option));
 
-#if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
+       if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
+               logger(LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
+
+       if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
+               logger(LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
+
+#if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
        if(sa->sa.sa_family == AF_INET6)
-               setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
+               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(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
        if(myself->options & OPTION_PMTU_DISCOVERY) {
                option = IP_PMTUDISC_DO;
-               setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, &option, sizeof(option));
+               setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
        }
+#elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
+       if(myself->options & OPTION_PMTU_DISCOVERY) {
+               option = 1;
+               setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
+       }
+#else
+#warning No way to disable IPv4 fragmentation
 #endif
 
 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
        if(myself->options & OPTION_PMTU_DISCOVERY) {
                option = IPV6_PMTUDISC_DO;
-               setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, &option, sizeof(option));
+               setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
+       }
+#elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
+       if(myself->options & OPTION_PMTU_DISCOVERY) {
+               option = 1;
+               setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
        }
+#else
+#warning No way to disable IPv6 fragmentation
 #endif
 
        if (!bind_to_interface(nfd)) {
@@ -295,8 +264,7 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
        if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
                closesocket(nfd);
                addrstr = sockaddr2hostname(sa);
-               logger(LOG_ERR, "Can't bind to %s/udp: %s", addrstr,
-                          strerror(errno));
+               logger(LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
                free(addrstr);
                return -1;
        }
@@ -305,18 +273,18 @@ int setup_vpn_in_socket(const sockaddr_t *sa) {
 } /* int setup_vpn_in_socket */
 
 void retry_outgoing(outgoing_t *outgoing) {
-       event_t *event;
-
        outgoing->timeout += 5;
 
        if(outgoing->timeout > maxtimeout)
                outgoing->timeout = maxtimeout;
 
-       event = new_event();
-       event->handler = (event_handler_t) setup_outgoing_connection;
-       event->time = now + outgoing->timeout;
-       event->data = outgoing;
-       event_add(event);
+       if(outgoing->event)
+               event_del(outgoing->event);
+       outgoing->event = new_event();
+       outgoing->event->handler = (event_handler_t) setup_outgoing_connection;
+       outgoing->event->time = now + outgoing->timeout;
+       outgoing->event->data = outgoing;
+       event_add(outgoing->event);
 
        ifdebug(CONNECTIONS) logger(LOG_NOTICE,
                           "Trying to re-establish outgoing connection in %d seconds",
@@ -326,17 +294,72 @@ void retry_outgoing(outgoing_t *outgoing) {
 void finish_connecting(connection_t *c) {
        ifdebug(CONNECTIONS) logger(LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 
-       configure_tcp(c);
+       if(proxytype != PROXY_EXEC)
+               configure_tcp(c);
 
        c->last_ping_time = now;
 
        send_id(c);
 }
 
+static void do_outgoing_pipe(connection_t *c, char *command) {
+#ifndef HAVE_MINGW
+       int fd[2];
+
+       if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
+               logger(LOG_ERR, "Could not create socketpair: %s\n", strerror(errno));
+               return;
+       }
+
+       if(fork()) {
+               c->socket = fd[0];
+               close(fd[1]);
+               logger(LOG_DEBUG, "Using proxy %s", command);
+               return;
+       }
+
+       close(0);
+       close(1);
+       close(fd[0]);
+       dup2(fd[1], 0);
+       dup2(fd[1], 1);
+       close(fd[1]);
+
+       // Other filedescriptors should be closed automatically by CLOEXEC
+
+       char *host = NULL;
+       char *port = NULL;
+
+       sockaddr2str(&c->address, &host, &port);
+       setenv("REMOTEADDRESS", host, true);
+       setenv("REMOTEPORT", port, true);
+       setenv("NODE", c->name, true);
+       setenv("NAME", myself->name, true);
+       if(netname)
+               setenv("NETNAME", netname, true);
+
+       int result = system(command);
+       if(result < 0)
+               logger(LOG_ERR, "Could not execute %s: %s\n", command, strerror(errno));
+       else if(result)
+               logger(LOG_ERR, "%s exited with non-zero status %d", command, result);
+       exit(result);
+#else
+       logger(LOG_ERR, "Proxy type exec not supported on this platform!");
+       return;
+#endif
+}
+
 void do_outgoing_connection(connection_t *c) {
-       char *address, *port;
+       char *address, *port, *space;
+       struct addrinfo *proxyai = NULL;
        int result;
 
+       if(!c->outgoing) {
+               logger(LOG_ERR, "do_outgoing_connection() for %s called without c->outgoing", c->name);
+               abort();
+       }
+
 begin:
        if(!c->outgoing->ai) {
                if(!c->outgoing->cfg) {
@@ -344,13 +367,20 @@ begin:
                                           c->name);
                        c->status.remove = true;
                        retry_outgoing(c->outgoing);
+                       c->outgoing = NULL;
                        return;
                }
 
                get_config_string(c->outgoing->cfg, &address);
 
-               if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
-                       xasprintf(&port, "655");
+               space = strchr(address, ' ');
+               if(space) {
+                       port = xstrdup(space + 1);
+                       *space = 0;
+               } else {
+                       if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
+                               port = xstrdup("655");
+               }
 
                c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
                free(address);
@@ -378,45 +408,58 @@ begin:
        ifdebug(CONNECTIONS) logger(LOG_INFO, "Trying to connect to %s (%s)", c->name,
                           c->hostname);
 
-       c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+       if(!proxytype) {
+               c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+               configure_tcp(c);
+       } else if(proxytype == PROXY_EXEC) {
+               do_outgoing_pipe(c, proxyhost);
+       } else {
+               proxyai = str2addrinfo(proxyhost, proxyport, SOCK_STREAM);
+               if(!proxyai)
+                       goto begin;
+               ifdebug(CONNECTIONS) logger(LOG_INFO, "Using proxy at %s port %s", proxyhost, proxyport);
+               c->socket = socket(proxyai->ai_family, SOCK_STREAM, IPPROTO_TCP);
+       }
 
        if(c->socket == -1) {
-               ifdebug(CONNECTIONS) logger(LOG_ERR, "Creating socket for %s failed: %s", c->hostname,
-                                  strerror(errno));
-
+               ifdebug(CONNECTIONS) logger(LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
                goto begin;
        }
 
-#if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
-       int option = 1;
-       if(c->address.sa.sa_family == AF_INET6)
-               setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, &option, sizeof option);
+#ifdef FD_CLOEXEC
+       fcntl(c->socket, F_SETFD, FD_CLOEXEC);
 #endif
 
-       bind_to_interface(c->socket);
-       bind_to_address(c);
-
-       /* Optimize TCP settings */
+       if(proxytype != PROXY_EXEC) {
+#if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
+               int option = 1;
+               if(c->address.sa.sa_family == AF_INET6)
+                       setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
+#endif
 
-       configure_tcp(c);
+               bind_to_interface(c->socket);
+       }
 
        /* Connect */
 
-       result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
+       if(!proxytype) {
+               result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
+       } else if(proxytype == PROXY_EXEC) {
+               result = 0;
+       } else {
+               result = connect(c->socket, proxyai->ai_addr, proxyai->ai_addrlen);
+               freeaddrinfo(proxyai);
+       }
 
        if(result == -1) {
-               if(errno == EINPROGRESS
-#if defined(WIN32) && !defined(O_NONBLOCK)
-                  || WSAGetLastError() == WSAEWOULDBLOCK
-#endif
-               ) {
+               if(sockinprogress(sockerrno)) {
                        c->status.connecting = true;
                        return;
                }
 
                closesocket(c->socket);
 
-               ifdebug(CONNECTIONS) logger(LOG_ERR, "%s: %s", c->hostname, strerror(errno));
+               ifdebug(CONNECTIONS) logger(LOG_ERR, "%s: %s", c->hostname, sockstrerror(sockerrno));
 
                goto begin;
        }
@@ -430,6 +473,8 @@ void setup_outgoing_connection(outgoing_t *outgoing) {
        connection_t *c;
        node_t *n;
 
+       outgoing->event = NULL;
+
        n = lookup_node(outgoing->name);
 
        if(n)
@@ -479,8 +524,7 @@ bool handle_new_meta_connection(int sock) {
        fd = accept(sock, &sa.sa, &len);
 
        if(fd < 0) {
-               logger(LOG_ERR, "Accepting a new connection failed: %s",
-                          strerror(errno));
+               logger(LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
                return false;
        }
 
@@ -510,7 +554,7 @@ bool handle_new_meta_connection(int sock) {
        return true;
 }
 
-void free_outgoing(outgoing_t *outgoing) {
+static void free_outgoing(outgoing_t *outgoing) {
        if(outgoing->ai)
                freeaddrinfo(outgoing->ai);
 
@@ -524,18 +568,7 @@ void try_outgoing_connections(void) {
        static config_t *cfg = NULL;
        char *name;
        outgoing_t *outgoing;
-       connection_t *c;
-       avl_node_t *node;
        
-       if(outgoing_list) {
-               for(node = connection_tree->head; node; node = node->next) {
-                       c = node->data;
-                       c->outgoing = NULL;
-               }
-
-               list_delete_list(outgoing_list);
-       }
-
        outgoing_list = list_alloc((list_action_t)free_outgoing);
                        
        for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {