/* net_socket.c -- Handle various kinds of sockets. Copyright (C) 1998-2005 Ivo Timmermans, 2000-2010 Guus Sliepen 2006 Scott Lamb 2009 Florian Forster 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. */ #include "system.h" #include "splay_tree.h" #include "conf.h" #include "connection.h" #include "logger.h" #include "meta.h" #include "net.h" #include "netutl.h" #include "protocol.h" #include "utils.h" #include "xalloc.h" #include /* Needed on Mac OS/X */ #ifndef SOL_TCP #define SOL_TCP IPPROTO_TCP #endif int addressfamily = AF_UNSPEC; int maxtimeout = 900; int seconds_till_retry = 5; listen_socket_t listen_socket[MAXSOCKETS]; int listen_sockets; list_t *outgoing_list = NULL; /* Setup sockets */ static void configure_tcp(connection_t *c) { int option; #ifdef O_NONBLOCK int flags = fcntl(c->socket, F_GETFL); if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) { logger(LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno)); } #elif defined(WIN32) unsigned long arg = 1; if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) { 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); #endif #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY) option = IPTOS_LOWDELAY; setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof option); #endif } static bool bind_to_interface(int sd) { char *iface; #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) struct ifreq ifr; int status; #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */ if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface)) return true; #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) memset(&ifr, 0, sizeof(ifr)); 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)); if(status) { logger(LOG_ERR, "Can't bind to interface %s: %s", iface, strerror(errno)); return false; } #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */ logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface"); #endif 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, sockstrerror(sockerrno)); } 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; int option; char *iface; nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP); if(nfd < 0) { ifdebug(STATUS) logger(LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno)); return -1; } /* Optimize TCP settings */ option = 1; setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &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); #endif if(get_config_string (lookup_config(config_tree, "BindToInterface"), &iface)) { #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) struct ifreq ifr; memset(&ifr, 0, sizeof ifr); strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ); if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof ifr)) { closesocket(nfd); logger(LOG_ERR, "Can't bind to interface %s: %s", iface, strerror(sockerrno)); return -1; } #else logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface"); #endif } if(bind(nfd, &sa->sa, SALEN(sa->sa))) { closesocket(nfd); addrstr = sockaddr2hostname(sa); 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", sockstrerror(sockerrno)); return -1; } return nfd; } int setup_vpn_in_socket(const sockaddr_t *sa) { int nfd; char *addrstr; int option; nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP); if(nfd < 0) { logger(LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno)); return -1; } #ifdef O_NONBLOCK { int flags = fcntl(nfd, F_GETFL); if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) { closesocket(nfd); logger(LOG_ERR, "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(LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno)); return -1; } } #endif option = 1; setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof option); #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY) if(sa->sa.sa_family == AF_INET6) setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, &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)); } #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT) if(myself->options & OPTION_PMTU_DISCOVERY) { option = 1; setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, &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)); } #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG) if(myself->options & OPTION_PMTU_DISCOVERY) { option = 1; setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, &option, sizeof(option)); } #else #warning No way to disable IPv6 fragmentation #endif if (!bind_to_interface(nfd)) { closesocket(nfd); return -1; } if(bind(nfd, &sa->sa, SALEN(sa->sa))) { closesocket(nfd); addrstr = sockaddr2hostname(sa); logger(LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno)); free(addrstr); return -1; } return nfd; } /* int setup_vpn_in_socket */ static void retry_outgoing_handler(int fd, short events, void *data) { setup_outgoing_connection(data); } void retry_outgoing(outgoing_t *outgoing) { outgoing->timeout += 5; if(outgoing->timeout > maxtimeout) outgoing->timeout = maxtimeout; timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing); event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0}); ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout); } void finish_connecting(connection_t *c) { ifdebug(CONNECTIONS) logger(LOG_INFO, "Connected to %s (%s)", c->name, c->hostname); configure_tcp(c); c->last_ping_time = time(NULL); c->status.connecting = false; send_id(c); } void do_outgoing_connection(connection_t *c) { char *address, *port, *space; 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) { ifdebug(CONNECTIONS) logger(LOG_ERR, "Could not set up a meta connection to %s", c->name); retry_outgoing(c->outgoing); c->outgoing = NULL; connection_del(c); return; } get_config_string(c->outgoing->cfg, &address); 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); free(port); c->outgoing->aip = c->outgoing->ai; c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg); } if(!c->outgoing->aip) { if(c->outgoing->ai) freeaddrinfo(c->outgoing->ai); c->outgoing->ai = NULL; goto begin; } memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen); c->outgoing->aip = c->outgoing->aip->ai_next; if(c->hostname) free(c->hostname); c->hostname = sockaddr2hostname(&c->address); 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(c->socket == -1) { 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); #endif bind_to_interface(c->socket); bind_to_address(c); /* Optimize TCP settings */ configure_tcp(c); /* Connect */ result = connect(c->socket, &c->address.sa, SALEN(c->address.sa)); if(result == -1) { if(sockinprogress(sockerrno)) { c->status.connecting = true; return; } closesocket(c->socket); ifdebug(CONNECTIONS) logger(LOG_ERR, "%s: %s", c->hostname, sockstrerror(sockerrno)); goto begin; } finish_connecting(c); return; } void handle_meta_read(struct bufferevent *event, void *data) { logger(LOG_EMERG, "handle_meta_read() called"); abort(); } void handle_meta_write(struct bufferevent *event, void *data) { ifdebug(META) logger(LOG_DEBUG, "handle_meta_write() called"); } void handle_meta_connection_error(struct bufferevent *event, short what, void *data) { connection_t *c = data; logger(LOG_EMERG, "handle_meta_connection_error() called: %d: %s", what, strerror(errno)); terminate_connection(c, c->status.active); } void setup_outgoing_connection(outgoing_t *outgoing) { connection_t *c; node_t *n; event_del(&outgoing->ev); n = lookup_node(outgoing->name); if(n) if(n->connection) { ifdebug(CONNECTIONS) logger(LOG_INFO, "Already connected to %s", outgoing->name); n->connection->outgoing = outgoing; return; } c = new_connection(); c->name = xstrdup(outgoing->name); c->outcipher = myself->connection->outcipher; c->outdigest = myself->connection->outdigest; c->outmaclength = myself->connection->outmaclength; c->outcompression = myself->connection->outcompression; init_configuration(&c->config_tree); read_connection_config(c); outgoing->cfg = lookup_config(c->config_tree, "Address"); if(!outgoing->cfg) { logger(LOG_ERR, "No address specified for %s", c->name); free_connection(c); return; } c->outgoing = outgoing; c->last_ping_time = time(NULL); connection_add(c); do_outgoing_connection(c); event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c); event_add(&c->inevent, NULL); c->buffer = bufferevent_new(c->socket, handle_meta_read, handle_meta_write, handle_meta_connection_error, c); if(!c->buffer) { logger(LOG_EMERG, "bufferevent_new() failed: %s", strerror(errno)); abort(); } bufferevent_disable(c->buffer, EV_READ); } /* accept a new tcp connect and create a new connection */ void handle_new_meta_connection(int sock, short events, void *data) { connection_t *c; sockaddr_t sa; int fd; socklen_t len = sizeof sa; fd = accept(sock, &sa.sa, &len); if(fd < 0) { logger(LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno)); return; } sockaddrunmap(&sa); c = new_connection(); c->name = xstrdup(""); c->outcipher = myself->connection->outcipher; c->outdigest = myself->connection->outdigest; c->outmaclength = myself->connection->outmaclength; c->outcompression = myself->connection->outcompression; c->address = sa; c->hostname = sockaddr2hostname(&sa); c->socket = fd; c->last_ping_time = time(NULL); ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection from %s", c->hostname); event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c); event_add(&c->inevent, NULL); c->buffer = bufferevent_new(c->socket, NULL, handle_meta_write, handle_meta_connection_error, c); if(!c->buffer) { logger(LOG_EMERG, "bufferevent_new() failed: %s", strerror(errno)); abort(); } bufferevent_disable(c->buffer, EV_READ); configure_tcp(c); connection_add(c); c->allow_request = ID; send_id(c); } void free_outgoing(outgoing_t *outgoing) { if(outgoing->ai) freeaddrinfo(outgoing->ai); if(outgoing->name) free(outgoing->name); free(outgoing); } void try_outgoing_connections(void) { static config_t *cfg = NULL; char *name; outgoing_t *outgoing; outgoing_list = list_alloc((list_action_t)free_outgoing); for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) { get_config_string(cfg, &name); if(!check_id(name)) { logger(LOG_ERR, "Invalid name for outgoing connection in %s line %d", cfg->file, cfg->line); free(name); continue; } outgoing = xmalloc_and_zero(sizeof *outgoing); outgoing->name = name; list_insert_tail(outgoing_list, outgoing); setup_outgoing_connection(outgoing); } }