2 net.c -- most of the network code
3 Copyright (C) 1998-2001 Ivo Timmermans <itimmermans@bigfoot.com>,
4 2000,2001 Guus Sliepen <guus@sliepen.warande.net>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 $Id: net.c,v 1.35.4.116 2001/06/21 16:37:47 guus Exp $
28 #include <netinet/in.h>
30 #include <netinet/ip.h>
31 #include <netinet/tcp.h>
36 #include <sys/signal.h>
38 #include <sys/types.h>
41 #include <sys/ioctl.h>
42 /* SunOS really wants sys/socket.h BEFORE net/if.h,
43 and FreeBSD wants these lines below the rest. */
44 #include <arpa/inet.h>
45 #include <sys/socket.h>
48 #ifdef HAVE_OPENSSL_RAND_H
49 # include <openssl/rand.h>
54 #ifdef HAVE_OPENSSL_EVP_H
55 # include <openssl/evp.h>
60 #ifdef HAVE_OPENSSL_ERR_H
61 # include <openssl/err.h>
66 #ifdef HAVE_OPENSSL_PEM_H
67 # include <openssl/pem.h>
73 #include LINUX_IF_TUN_H
82 #include "connection.h"
95 int taptype = TAP_TYPE_ETHERTAP;
97 int total_tap_out = 0;
98 int total_socket_in = 0;
99 int total_socket_out = 0;
101 config_t *upstreamcfg;
102 int seconds_till_retry = 5;
107 void send_udppacket(connection_t *cl, vpn_packet_t *inpkt)
112 struct sockaddr_in to;
113 socklen_t tolen = sizeof(to);
116 if(!cl->status.validkey)
118 if(debug_lvl >= DEBUG_TRAFFIC)
119 syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
120 cl->name, cl->hostname);
122 /* Since packet is on the stack of handle_tap_input(),
123 we have to make a copy of it first. */
125 copy = xmalloc(sizeof(vpn_packet_t));
126 memcpy(copy, inpkt, sizeof(vpn_packet_t));
128 list_insert_tail(cl->queue, copy);
130 if(!cl->status.waitingforkey)
131 send_req_key(myself, cl);
135 /* Encrypt the packet. */
137 RAND_bytes(inpkt->salt, sizeof(inpkt->salt));
139 EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
140 EVP_EncryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len + sizeof(inpkt->salt));
141 EVP_EncryptFinal(&ctx, outpkt.salt + outlen, &outpad);
144 total_socket_out += outlen;
146 to.sin_family = AF_INET;
147 to.sin_addr.s_addr = htonl(cl->address);
148 to.sin_port = htons(cl->port);
150 if((sendto(myself->socket, (char *) outpkt.salt, outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
152 syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
153 cl->name, cl->hostname);
159 void receive_packet(connection_t *cl, vpn_packet_t *packet)
162 if(debug_lvl >= DEBUG_TRAFFIC)
163 syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, cl->name, cl->hostname);
165 route_incoming(cl, packet);
169 void receive_udppacket(connection_t *cl, vpn_packet_t *inpkt)
175 /* Decrypt the packet */
177 EVP_DecryptInit(&ctx, myself->cipher_pkttype, myself->cipher_pktkey, myself->cipher_pktkey + myself->cipher_pkttype->key_len);
178 EVP_DecryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len);
179 EVP_DecryptFinal(&ctx, outpkt.salt + outlen, &outpad);
181 outpkt.len = outlen - sizeof(outpkt.salt);
183 total_socket_in += outlen;
185 receive_packet(cl, &outpkt);
189 void receive_tcppacket(connection_t *cl, char *buffer, int len)
194 memcpy(outpkt.data, buffer, len);
196 receive_packet(cl, &outpkt);
200 void accept_packet(vpn_packet_t *packet)
203 if(debug_lvl >= DEBUG_TRAFFIC)
204 syslog(LOG_DEBUG, _("Writing packet of %d bytes to tap device"),
207 if(taptype == TAP_TYPE_TUNTAP)
209 if(write(tap_fd, packet->data, packet->len) < 0)
210 syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
212 total_tap_out += packet->len;
216 if(write(tap_fd, packet->data - 2, packet->len + 2) < 0)
217 syslog(LOG_ERR, _("Can't write to ethertap device: %m"));
219 total_tap_out += packet->len;
225 send a packet to the given vpn ip.
227 void send_packet(connection_t *cl, vpn_packet_t *packet)
230 if(debug_lvl >= DEBUG_TRAFFIC)
231 syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
232 packet->len, cl->name, cl->hostname);
236 if(debug_lvl >= DEBUG_TRAFFIC)
238 syslog(LOG_NOTICE, _("Packet is looping back to us!"));
244 if(!cl->status.active)
246 if(debug_lvl >= DEBUG_TRAFFIC)
247 syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
248 cl->name, cl->hostname);
253 /* Check if it has to go via TCP or UDP... */
255 if((cl->options | myself->options) & OPTION_TCPONLY)
257 if(send_tcppacket(cl, packet))
258 terminate_connection(cl);
261 send_udppacket(cl, packet);
264 /* Broadcast a packet to all active connections */
266 void broadcast_packet(connection_t *from, vpn_packet_t *packet)
271 if(debug_lvl >= DEBUG_TRAFFIC)
272 syslog(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
273 packet->len, from->name, from->hostname);
275 for(node = connection_tree->head; node; node = node->next)
277 cl = (connection_t *)node->data;
278 if(cl->status.meta && cl != from)
279 send_packet(cl, packet);
284 void flush_queue(connection_t *cl)
286 list_node_t *node, *next;
288 if(debug_lvl >= DEBUG_TRAFFIC)
289 syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
291 for(node = cl->queue->head; node; node = next)
294 send_udppacket(cl, (vpn_packet_t *)node->data);
295 list_delete_node(cl->queue, node);
301 open the local ethertap device
303 int setup_tap_fd(void)
306 const char *tapfname;
315 if((cfg = get_config_val(config, config_tapdevice)))
316 tapfname = cfg->data.ptr;
321 tapfname = "/dev/net/tun";
323 tapfname = "/dev/tap0";
327 tapfname = "/dev/tap0";
330 tapfname = "/dev/tun";
334 if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
336 syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
342 taptype = TAP_TYPE_ETHERTAP;
344 /* Set default MAC address for ethertap devices */
346 mymac.type = SUBNET_MAC;
347 mymac.net.mac.address.x[0] = 0xff;
348 mymac.net.mac.address.x[1] = 0xff;
349 mymac.net.mac.address.x[2] = 0xff;
350 mymac.net.mac.address.x[3] = 0xff;
351 mymac.net.mac.address.x[4] = 0xff;
352 mymac.net.mac.address.x[5] = 0xff;
356 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
357 memset(&ifr, 0, sizeof(ifr));
359 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
361 strncpy(ifr.ifr_name, netname, IFNAMSIZ);
363 if (!ioctl(tap_fd, TUNSETIFF, (void *) &ifr))
365 syslog(LOG_INFO, _("%s is a new style tun/tap device"), tapfname);
366 taptype = TAP_TYPE_TUNTAP;
371 taptype = TAP_TYPE_TUNTAP;
378 set up the socket that we listen on for incoming
381 int setup_listen_meta_socket(int port)
384 struct sockaddr_in a;
388 if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
390 syslog(LOG_ERR, _("Creating metasocket failed: %m"));
394 flags = fcntl(nfd, F_GETFL);
395 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
398 syslog(LOG_ERR, _("System call `%s' failed: %m"),
403 /* Optimize TCP settings */
406 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
407 setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
409 setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
411 option = IPTOS_LOWDELAY;
412 setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
414 if((cfg = get_config_val(config, config_interface)))
416 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, cfg->data.ptr, strlen(cfg->data.ptr)))
419 syslog(LOG_ERR, _("Unable to bind listen socket to interface %s: %m"), cfg->data.ptr);
425 memset(&a, 0, sizeof(a));
426 a.sin_family = AF_INET;
427 a.sin_port = htons(port);
429 if((cfg = get_config_val(config, config_interfaceip)))
430 a.sin_addr.s_addr = htonl(cfg->data.ip->address);
432 a.sin_addr.s_addr = htonl(INADDR_ANY);
434 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
437 syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
444 syslog(LOG_ERR, _("System call `%s' failed: %m"),
453 setup the socket for incoming encrypted
456 int setup_vpn_in_socket(int port)
459 struct sockaddr_in a;
462 if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
465 syslog(LOG_ERR, _("Creating socket failed: %m"));
469 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
471 flags = fcntl(nfd, F_GETFL);
472 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
475 syslog(LOG_ERR, _("System call `%s' failed: %m"),
480 memset(&a, 0, sizeof(a));
481 a.sin_family = AF_INET;
482 a.sin_port = htons(port);
483 a.sin_addr.s_addr = htonl(INADDR_ANY);
485 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
488 syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
496 setup an outgoing meta (tcp) socket
498 int setup_outgoing_meta_socket(connection_t *cl)
501 struct sockaddr_in a;
505 if(debug_lvl >= DEBUG_CONNECTIONS)
506 syslog(LOG_INFO, _("Trying to connect to %s"), cl->hostname);
508 if((cfg = get_config_val(cl->config, config_port)) == NULL)
511 cl->port = cfg->data.val;
513 cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
514 if(cl->meta_socket == -1)
516 syslog(LOG_ERR, _("Creating socket for %s port %d failed: %m"),
517 cl->hostname, cl->port);
521 /* Bind first to get a fix on our source port */
523 a.sin_family = AF_INET;
524 a.sin_port = htons(0);
525 a.sin_addr.s_addr = htonl(INADDR_ANY);
527 if(bind(cl->meta_socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
529 close(cl->meta_socket);
530 syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
534 /* Optimize TCP settings */
537 setsockopt(cl->meta_socket, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
539 setsockopt(cl->meta_socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
541 option = IPTOS_LOWDELAY;
542 setsockopt(cl->meta_socket, SOL_IP, IP_TOS, &option, sizeof(option));
546 a.sin_family = AF_INET;
547 a.sin_port = htons(cl->port);
548 a.sin_addr.s_addr = htonl(cl->address);
550 if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
552 close(cl->meta_socket);
553 syslog(LOG_ERR, _("%s port %hd: %m"), cl->hostname, cl->port);
557 flags = fcntl(cl->meta_socket, F_GETFL);
558 if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
560 close(cl->meta_socket);
561 syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
562 cl->hostname, cl->port);
566 if(debug_lvl >= DEBUG_CONNECTIONS)
567 syslog(LOG_INFO, _("Connected to %s port %hd"),
568 cl->hostname, cl->port);
576 Setup an outgoing meta connection.
578 int setup_outgoing_connection(char *name)
586 syslog(LOG_ERR, _("Invalid name for outgoing connection"));
590 ncn = new_connection();
591 asprintf(&ncn->name, "%s", name);
593 if(read_host_config(ncn))
595 syslog(LOG_ERR, _("Error reading host configuration file for %s"), ncn->name);
596 free_connection(ncn);
600 if(!(cfg = get_config_val(ncn->config, config_address)))
602 syslog(LOG_ERR, _("No address specified for %s"), ncn->name);
603 free_connection(ncn);
607 if(!(h = gethostbyname(cfg->data.ptr)))
609 syslog(LOG_ERR, _("Error looking up `%s': %m"), cfg->data.ptr);
610 free_connection(ncn);
614 ncn->address = ntohl(*((ipv4_t*)(h->h_addr_list[0])));
615 ncn->hostname = hostlookup(htonl(ncn->address));
617 if(setup_outgoing_meta_socket(ncn) < 0)
619 syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
621 free_connection(ncn);
625 ncn->status.outgoing = 1;
626 ncn->buffer = xmalloc(MAXBUFSIZE);
628 ncn->last_ping_time = time(NULL);
637 int read_rsa_public_key(connection_t *cl)
645 cl->rsa_key = RSA_new();
647 /* First, check for simple PublicKey statement */
649 if((cfg = get_config_val(cl->config, config_publickey)))
651 BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
652 BN_hex2bn(&cl->rsa_key->e, "FFFF");
656 /* Else, check for PublicKeyFile statement and read it */
658 if((cfg = get_config_val(cl->config, config_publickeyfile)))
660 if(is_safe_path(cfg->data.ptr))
662 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
664 syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
668 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
672 syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
682 /* Else, check if a harnessed public key is in the config file */
684 asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
685 if((fp = fopen(fname, "r")))
687 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
696 /* Nothing worked. */
698 syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
703 int read_rsa_private_key(void)
710 myself->rsa_key = RSA_new();
712 if((cfg = get_config_val(config, config_privatekey)))
714 BN_hex2bn(&myself->rsa_key->d, cfg->data.ptr);
715 BN_hex2bn(&myself->rsa_key->e, "FFFF");
717 else if((cfg = get_config_val(config, config_privatekeyfile)))
719 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
721 syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
725 result = PEM_read_RSAPrivateKey(fp, &myself->rsa_key, NULL, NULL);
729 syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
736 syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
744 Configure connection_t myself and set up the local sockets (listen only)
746 int setup_myself(void)
752 myself = new_connection();
754 asprintf(&myself->hostname, _("MYSELF"));
756 myself->protocol_version = PROT_CURRENT;
758 if(!(cfg = get_config_val(config, config_name))) /* Not acceptable */
760 syslog(LOG_ERR, _("Name for tinc daemon required!"));
764 asprintf(&myself->name, "%s", (char*)cfg->data.val);
766 if(check_id(myself->name))
768 syslog(LOG_ERR, _("Invalid name for myself!"));
772 if(read_rsa_private_key())
775 if(read_host_config(myself))
777 syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
781 if(read_rsa_public_key(myself))
786 if(RSA_check_key(myself->rsa_key) != 1)
788 syslog(LOG_ERR, _("Invalid public/private keypair!"));
792 if(!(cfg = get_config_val(myself->config, config_port)))
795 myself->port = cfg->data.val;
797 /* Read in all the subnets specified in the host configuration file */
799 for(next = myself->config; (cfg = get_config_val(next, config_subnet)); next = cfg->next)
802 net->type = SUBNET_IPV4;
803 net->net.ipv4.address = cfg->data.ip->address;
804 net->net.ipv4.mask = cfg->data.ip->mask;
806 /* Teach newbies what subnets are... */
808 if((net->net.ipv4.address & net->net.ipv4.mask) != net->net.ipv4.address)
810 syslog(LOG_ERR, _("Network address and subnet mask do not match!"));
814 subnet_add(myself, net);
818 /* Check some options */
820 if((cfg = get_config_val(config, config_indirectdata)))
821 if(cfg->data.val == stupid_true)
822 myself->options |= OPTION_INDIRECT;
824 if((cfg = get_config_val(config, config_tcponly)))
825 if(cfg->data.val == stupid_true)
826 myself->options |= OPTION_TCPONLY;
828 if((cfg = get_config_val(myself->config, config_indirectdata)))
829 if(cfg->data.val == stupid_true)
830 myself->options |= OPTION_INDIRECT;
832 if((cfg = get_config_val(myself->config, config_tcponly)))
833 if(cfg->data.val == stupid_true)
834 myself->options |= OPTION_TCPONLY;
836 if(myself->options & OPTION_TCPONLY)
837 myself->options |= OPTION_INDIRECT;
839 if((cfg = get_config_val(config, config_mode)))
841 if(!strcasecmp(cfg->data.ptr, "router"))
842 routing_mode = RMODE_ROUTER;
843 else if (!strcasecmp(cfg->data.ptr, "switch"))
844 routing_mode = RMODE_SWITCH;
845 else if (!strcasecmp(cfg->data.ptr, "hub"))
846 routing_mode = RMODE_HUB;
849 syslog(LOG_ERR, _("Invalid routing mode!"));
854 routing_mode = RMODE_ROUTER;
859 if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
861 syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
865 if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
867 syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
871 /* Generate packet encryption key */
873 myself->cipher_pkttype = EVP_bf_cbc();
875 myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
877 myself->cipher_pktkey = (char *)xmalloc(myself->cipher_pktkeylength);
878 RAND_pseudo_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
880 if(!(cfg = get_config_val(config, config_keyexpire)))
883 keylifetime = cfg->data.val;
885 keyexpires = time(NULL) + keylifetime;
888 /* Activate ourselves */
890 myself->status.active = 1;
892 syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
898 sigalrm_handler(int a)
902 cfg = get_config_val(upstreamcfg, config_connectto);
906 if(upstreamcfg == config)
908 /* No upstream IP given, we're listen only. */
909 signal(SIGALRM, SIG_IGN);
915 /* We previously tried all the ConnectTo lines. Now wrap back to the first. */
916 cfg = get_config_val(config, config_connectto);
921 upstreamcfg = cfg->next;
922 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
924 signal(SIGALRM, SIG_IGN);
927 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
930 signal(SIGALRM, sigalrm_handler);
931 upstreamcfg = config;
932 seconds_till_retry += 5;
933 if(seconds_till_retry > MAXTIMEOUT) /* Don't wait more than MAXTIMEOUT seconds. */
934 seconds_till_retry = MAXTIMEOUT;
935 syslog(LOG_ERR, _("Still failed to connect to other, will retry in %d seconds"),
937 alarm(seconds_till_retry);
942 setup all initial network connections
944 int setup_network_connections(void)
951 if((cfg = get_config_val(config, config_pingtimeout)) == NULL)
955 timeout = cfg->data.val;
962 if(setup_tap_fd() < 0)
965 /* Run tinc-up script to further initialize the tap interface */
966 execute_script("tinc-up");
968 if(setup_myself() < 0)
971 if(!(cfg = get_config_val(config, config_connectto)))
972 /* No upstream IP given, we're listen only. */
977 upstreamcfg = cfg->next;
978 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
980 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
985 signal(SIGALRM, sigalrm_handler);
986 upstreamcfg = config;
987 seconds_till_retry = MAXTIMEOUT;
988 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
989 alarm(seconds_till_retry);
999 close all open network connections
1001 void close_network_connections(void)
1006 for(node = connection_tree->head; node; node = node->next)
1008 p = (connection_t *)node->data;
1009 p->status.outgoing = 0;
1010 p->status.active = 0;
1011 terminate_connection(p);
1015 if(myself->status.active)
1017 close(myself->meta_socket);
1018 free_connection(myself);
1024 /* Execute tinc-down script right after shutting down the interface */
1025 execute_script("tinc-down");
1027 destroy_connection_tree();
1033 handle an incoming tcp connect call and open
1036 connection_t *create_new_connection(int sfd)
1039 struct sockaddr_in ci;
1040 int len = sizeof(ci);
1042 p = new_connection();
1044 if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
1046 syslog(LOG_ERR, _("System call `%s' failed: %m"),
1052 asprintf(&p->name, _("UNKNOWN"));
1053 p->address = ntohl(ci.sin_addr.s_addr);
1054 p->hostname = hostlookup(ci.sin_addr.s_addr);
1055 p->port = htons(ci.sin_port); /* This one will be overwritten later */
1056 p->meta_socket = sfd;
1058 p->buffer = xmalloc(MAXBUFSIZE);
1060 p->last_ping_time = time(NULL);
1062 if(debug_lvl >= DEBUG_CONNECTIONS)
1063 syslog(LOG_NOTICE, _("Connection from %s port %d"),
1064 p->hostname, htons(ci.sin_port));
1066 p->allow_request = ID;
1072 put all file descriptors in an fd_set array
1074 void build_fdset(fd_set *fs)
1081 FD_SET(myself->socket, fs);
1083 for(node = connection_tree->head; node; node = node->next)
1085 p = (connection_t *)node->data;
1087 FD_SET(p->meta_socket, fs);
1090 FD_SET(myself->meta_socket, fs);
1096 receive incoming data from the listening
1097 udp socket and write it to the ethertap
1098 device after being decrypted
1100 void handle_incoming_vpn_data(void)
1103 int x, l = sizeof(x);
1104 struct sockaddr_in from;
1105 socklen_t fromlen = sizeof(from);
1108 if(getsockopt(myself->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
1110 syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
1111 __FILE__, __LINE__, myself->socket);
1116 syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
1120 if((pkt.len = recvfrom(myself->socket, (char *) pkt.salt, MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
1122 syslog(LOG_ERR, _("Receiving packet failed: %m"));
1126 cl = lookup_connection(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
1130 syslog(LOG_WARNING, _("Received UDP packets on port %hd from unknown source %x:%hd"), myself->port, ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
1134 cl->last_ping_time = time(NULL);
1136 receive_udppacket(cl, &pkt);
1141 terminate a connection and notify the other
1142 end before closing the sockets
1144 void terminate_connection(connection_t *cl)
1148 avl_node_t *node, *next;
1150 if(cl->status.remove)
1153 if(debug_lvl >= DEBUG_CONNECTIONS)
1154 syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
1155 cl->name, cl->hostname);
1157 cl->status.remove = 1;
1162 close(cl->meta_socket);
1167 /* Find all connections that were lost because they were behind cl
1168 (the connection that was dropped). */
1170 for(node = connection_tree->head; node; node = node->next)
1172 p = (connection_t *)node->data;
1173 if(p->nexthop == cl && p != cl)
1174 terminate_connection(p);
1177 /* Inform others of termination if it was still active */
1179 if(cl->status.active)
1180 for(node = connection_tree->head; node; node = node->next)
1182 p = (connection_t *)node->data;
1183 if(p->status.meta && p->status.active && p != cl)
1184 send_del_host(p, cl); /* Sounds like recursion, but p does not have a meta connection :) */
1188 /* Remove the associated subnets */
1190 for(node = cl->subnet_tree->head; node; node = next)
1193 subnet = (subnet_t *)node->data;
1197 /* Check if this was our outgoing connection */
1199 if(cl->status.outgoing)
1201 cl->status.outgoing = 0;
1202 signal(SIGALRM, sigalrm_handler);
1203 alarm(seconds_till_retry);
1204 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
1209 cl->status.active = 0;
1214 Check if the other end is active.
1215 If we have sent packets, but didn't receive any,
1216 then possibly the other end is dead. We send a
1217 PING request over the meta connection. If the other
1218 end does not reply in time, we consider them dead
1219 and close the connection.
1221 void check_dead_connections(void)
1229 for(node = connection_tree->head; node; node = node->next)
1231 cl = (connection_t *)node->data;
1232 if(cl->status.active && cl->status.meta)
1234 if(cl->last_ping_time + timeout < now)
1236 if(cl->status.pinged)
1238 if(debug_lvl >= DEBUG_PROTOCOL)
1239 syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
1240 cl->name, cl->hostname);
1241 cl->status.timeout = 1;
1242 terminate_connection(cl);
1255 accept a new tcp connect and create a
1258 int handle_new_meta_connection()
1261 struct sockaddr client;
1262 int nfd, len = sizeof(client);
1264 if((nfd = accept(myself->meta_socket, &client, &len)) < 0)
1266 syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
1270 if(!(ncn = create_new_connection(nfd)))
1274 syslog(LOG_NOTICE, _("Closed attempted connection"));
1278 connection_add(ncn);
1286 check all connections to see if anything
1287 happened on their sockets
1289 void check_network_activity(fd_set *f)
1294 if(FD_ISSET(myself->socket, f))
1295 handle_incoming_vpn_data();
1297 for(node = connection_tree->head; node; node = node->next)
1299 p = (connection_t *)node->data;
1301 if(p->status.remove)
1305 if(FD_ISSET(p->meta_socket, f))
1306 if(receive_meta(p) < 0)
1308 terminate_connection(p);
1313 if(FD_ISSET(myself->meta_socket, f))
1314 handle_new_meta_connection();
1319 read, encrypt and send data that is
1320 available through the ethertap device
1322 void handle_tap_input(void)
1327 if(taptype == TAP_TYPE_TUNTAP)
1329 if((lenin = read(tap_fd, vp.data, MTU)) <= 0)
1331 syslog(LOG_ERR, _("Error while reading from tun/tap device: %m"));
1338 if((lenin = read(tap_fd, vp.data - 2, MTU)) <= 0)
1340 syslog(LOG_ERR, _("Error while reading from ethertap device: %m"));
1346 total_tap_in += vp.len;
1350 if(debug_lvl >= DEBUG_TRAFFIC)
1351 syslog(LOG_WARNING, _("Received short packet from tap device"));
1355 if(debug_lvl >= DEBUG_TRAFFIC)
1357 syslog(LOG_DEBUG, _("Read packet of length %d from tap device"), vp.len);
1360 route_outgoing(&vp);
1365 this is where it all happens...
1367 void main_loop(void)
1372 time_t last_ping_check;
1375 last_ping_check = time(NULL);
1379 tv.tv_sec = timeout;
1382 prune_connection_tree();
1385 if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
1387 if(errno != EINTR) /* because of alarm */
1389 syslog(LOG_ERR, _("Error while waiting for input: %m"));
1396 syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
1398 close_network_connections();
1399 clear_config(&config);
1401 if(read_server_config())
1403 syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
1409 if(setup_network_connections())
1417 /* Let's check if everybody is still alive */
1419 if(last_ping_check + timeout < t)
1421 check_dead_connections();
1422 last_ping_check = time(NULL);
1424 /* Should we regenerate our key? */
1428 if(debug_lvl >= DEBUG_STATUS)
1429 syslog(LOG_INFO, _("Regenerating symmetric key"));
1431 RAND_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
1432 send_key_changed(myself, NULL);
1433 keyexpires = time(NULL) + keylifetime;
1439 check_network_activity(&fset);
1441 /* local tap data */
1442 if(FD_ISSET(tap_fd, &fset))