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 1.35.4.101 2001/03/01 21:32:01 guus Exp $
28 #include <netinet/in.h>
29 #include <netinet/ip.h>
30 #include <netinet/tcp.h>
34 #include <sys/signal.h>
36 #include <sys/types.h>
39 #include <sys/ioctl.h>
40 /* SunOS really wants sys/socket.h BEFORE net/if.h,
41 and FreeBSD wants these lines below the rest. */
42 #include <arpa/inet.h>
43 #include <sys/socket.h>
46 #ifdef HAVE_OPENSSL_RAND_H
47 # include <openssl/rand.h>
52 #ifdef HAVE_OPENSSL_EVP_H
53 # include <openssl/evp.h>
58 #ifdef HAVE_OPENSSL_ERR_H
59 # include <openssl/err.h>
64 #ifdef HAVE_OPENSSL_PEM_H
65 # include <openssl/pem.h>
71 #include LINUX_IF_TUN_H
80 #include "connection.h"
92 int taptype = TAP_TYPE_ETHERTAP;
94 int total_tap_out = 0;
95 int total_socket_in = 0;
96 int total_socket_out = 0;
98 config_t *upstreamcfg;
99 static int seconds_till_retry;
104 char *unknown = NULL;
108 int xsend(connection_t *cl, vpn_packet_t *inpkt)
113 struct sockaddr_in to;
114 socklen_t tolen = sizeof(to);
116 outpkt.len = inpkt->len;
118 /* Encrypt the packet. */
120 EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
121 EVP_EncryptUpdate(&ctx, outpkt.data, &outlen, inpkt->data, inpkt->len);
122 EVP_EncryptFinal(&ctx, outpkt.data + outlen, &outpad);
123 outlen += outpad + 2;
126 outlen = outpkt.len + 2;
127 memcpy(&outpkt, inpkt, outlen);
130 if(debug_lvl >= DEBUG_TRAFFIC)
131 syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
132 outlen, cl->name, cl->hostname);
134 total_socket_out += outlen;
136 to.sin_family = AF_INET;
137 to.sin_addr.s_addr = htonl(cl->address);
138 to.sin_port = htons(cl->port);
140 if((sendto(myself->socket, (char *) &(outpkt.len), outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
142 syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
143 cl->name, cl->hostname);
150 int xrecv(connection_t *cl, vpn_packet_t *inpkt)
156 outpkt.len = inpkt->len;
158 /* Decrypt the packet */
160 EVP_DecryptInit(&ctx, myself->cipher_pkttype, myself->cipher_pktkey, myself->cipher_pktkey + myself->cipher_pkttype->key_len);
161 EVP_DecryptUpdate(&ctx, outpkt.data, &outlen, inpkt->data, inpkt->len + 8);
162 EVP_DecryptFinal(&ctx, outpkt.data + outlen, &outpad);
166 outlen = outpkt.len+2;
167 memcpy(&outpkt, inpkt, outlen);
170 return receive_packet(cl, &outpkt);
173 int receive_packet(connection_t *cl, vpn_packet_t *packet)
175 if(debug_lvl >= DEBUG_TRAFFIC)
176 syslog(LOG_ERR, _("Writing packet of %d bytes to tap device"),
179 /* Fix mac address */
181 memcpy(packet->data, mymac.net.mac.address.x, 6);
183 if(taptype == TAP_TYPE_TUNTAP)
185 if(write(tap_fd, packet->data, packet->len) < 0)
186 syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
188 total_tap_out += packet->len;
192 if(write(tap_fd, packet->data - 2, packet->len + 2) < 0)
193 syslog(LOG_ERR, _("Can't write to ethertap device: %m"));
195 total_tap_out += packet->len + 2;
202 send a packet to the given vpn ip.
204 int send_packet(ip_t to, vpn_packet_t *packet)
210 if((subnet = lookup_subnet_ipv4(&to)) == NULL)
212 if(debug_lvl >= DEBUG_TRAFFIC)
214 syslog(LOG_NOTICE, _("Trying to look up %d.%d.%d.%d in connection list failed!"),
225 if(debug_lvl >= DEBUG_TRAFFIC)
227 syslog(LOG_NOTICE, _("Packet with destination %d.%d.%d.%d is looping back to us!"),
234 if(!cl->status.active)
236 if(debug_lvl >= DEBUG_TRAFFIC)
237 syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
238 cl->name, cl->hostname);
243 if(!cl->status.validkey)
245 if(debug_lvl >= DEBUG_TRAFFIC)
246 syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
247 cl->name, cl->hostname);
249 /* Since packet is on the stack of handle_tap_input(),
250 we have to make a copy of it first. */
252 copy = xmalloc(sizeof(vpn_packet_t));
253 memcpy(copy, packet, sizeof(vpn_packet_t));
255 list_insert_tail(cl->queue, copy);
257 if(!cl->status.waitingforkey)
258 send_req_key(myself, cl); /* Keys should be sent to the host running the tincd */
262 /* Check if it has to go via UDP or TCP... */
264 if(cl->options & OPTION_TCPONLY)
265 return send_tcppacket(cl, packet);
267 return xsend(cl, packet);
270 void flush_queue(connection_t *cl)
272 list_node_t *node, *next;
274 if(debug_lvl >= DEBUG_TRAFFIC)
275 syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
277 for(node = cl->queue->head; node; node = next)
280 xsend(cl, (vpn_packet_t *)node->data);
281 list_delete_node(cl->queue, node);
287 open the local ethertap device
289 int setup_tap_fd(void)
292 const char *tapfname;
301 if((cfg = get_config_val(config, config_tapdevice)))
302 tapfname = cfg->data.ptr;
307 tapfname = "/dev/misc/net/tun";
309 tapfname = "/dev/tap0";
313 tapfname = "/dev/tap0";
316 tapfname = "/dev/tun";
320 if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
322 syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
328 taptype = TAP_TYPE_ETHERTAP;
330 /* Set default MAC address for ethertap devices */
332 mymac.type = SUBNET_MAC;
333 mymac.net.mac.address.x[0] = 0xfe;
334 mymac.net.mac.address.x[1] = 0xfd;
335 mymac.net.mac.address.x[2] = 0x00;
336 mymac.net.mac.address.x[3] = 0x00;
337 mymac.net.mac.address.x[4] = 0x00;
338 mymac.net.mac.address.x[5] = 0x00;
342 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
343 memset(&ifr, 0, sizeof(ifr));
345 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
347 strncpy(ifr.ifr_name, netname, IFNAMSIZ);
349 if (!ioctl(tap_fd, TUNSETIFF, (void *) &ifr))
351 syslog(LOG_INFO, _("%s is a new style tun/tap device"), tapfname);
352 taptype = TAP_TYPE_TUNTAP;
357 taptype = TAP_TYPE_TUNTAP;
364 set up the socket that we listen on for incoming
367 int setup_listen_meta_socket(int port)
370 struct sockaddr_in a;
374 if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
376 syslog(LOG_ERR, _("Creating metasocket failed: %m"));
380 flags = fcntl(nfd, F_GETFL);
381 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
384 syslog(LOG_ERR, _("System call `%s' failed: %m"),
389 /* Optimize TCP settings */
392 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
393 setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
394 setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
396 option = IPTOS_LOWDELAY;
397 setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
399 if((cfg = get_config_val(config, config_interface)))
401 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, cfg->data.ptr, strlen(cfg->data.ptr)))
404 syslog(LOG_ERR, _("Unable to bind listen socket to interface %s: %m"), cfg->data.ptr);
409 memset(&a, 0, sizeof(a));
410 a.sin_family = AF_INET;
411 a.sin_port = htons(port);
413 if((cfg = get_config_val(config, config_interfaceip)))
414 a.sin_addr.s_addr = htonl(cfg->data.ip->address);
416 a.sin_addr.s_addr = htonl(INADDR_ANY);
418 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
421 syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
428 syslog(LOG_ERR, _("System call `%s' failed: %m"),
437 setup the socket for incoming encrypted
440 int setup_vpn_in_socket(int port)
443 struct sockaddr_in a;
446 if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
449 syslog(LOG_ERR, _("Creating socket failed: %m"));
453 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
455 flags = fcntl(nfd, F_GETFL);
456 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
459 syslog(LOG_ERR, _("System call `%s' failed: %m"),
464 memset(&a, 0, sizeof(a));
465 a.sin_family = AF_INET;
466 a.sin_port = htons(port);
467 a.sin_addr.s_addr = htonl(INADDR_ANY);
469 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
472 syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
480 setup an outgoing meta (tcp) socket
482 int setup_outgoing_meta_socket(connection_t *cl)
485 struct sockaddr_in a;
489 if(debug_lvl >= DEBUG_CONNECTIONS)
490 syslog(LOG_INFO, _("Trying to connect to %s"), cl->hostname);
492 if((cfg = get_config_val(cl->config, config_port)) == NULL)
495 cl->port = cfg->data.val;
497 cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
498 if(cl->meta_socket == -1)
500 syslog(LOG_ERR, _("Creating socket for %s port %d failed: %m"),
501 cl->hostname, cl->port);
505 /* Bind first to get a fix on our source port */
507 a.sin_family = AF_INET;
508 a.sin_port = htons(0);
509 a.sin_addr.s_addr = htonl(INADDR_ANY);
511 if(bind(cl->meta_socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
513 close(cl->meta_socket);
514 syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
518 /* Optimize TCP settings */
521 setsockopt(cl->meta_socket, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
522 setsockopt(cl->meta_socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
524 option = IPTOS_LOWDELAY;
525 setsockopt(cl->meta_socket, SOL_IP, IP_TOS, &option, sizeof(option));
529 a.sin_family = AF_INET;
530 a.sin_port = htons(cl->port);
531 a.sin_addr.s_addr = htonl(cl->address);
533 if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
535 close(cl->meta_socket);
536 syslog(LOG_ERR, _("%s port %hd: %m"), cl->hostname, cl->port);
540 flags = fcntl(cl->meta_socket, F_GETFL);
541 if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
543 close(cl->meta_socket);
544 syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
545 cl->hostname, cl->port);
549 if(debug_lvl >= DEBUG_CONNECTIONS)
550 syslog(LOG_INFO, _("Connected to %s port %hd"),
551 cl->hostname, cl->port);
559 Setup an outgoing meta connection.
561 int setup_outgoing_connection(char *name)
569 syslog(LOG_ERR, _("Invalid name for outgoing connection"));
573 ncn = new_connection();
574 asprintf(&ncn->name, "%s", name);
576 if(read_host_config(ncn))
578 syslog(LOG_ERR, _("Error reading host configuration file for %s"), ncn->name);
579 free_connection(ncn);
583 if(!(cfg = get_config_val(ncn->config, config_address)))
585 syslog(LOG_ERR, _("No address specified for %s"), ncn->name);
586 free_connection(ncn);
590 if(!(h = gethostbyname(cfg->data.ptr)))
592 syslog(LOG_ERR, _("Error looking up `%s': %m"), cfg->data.ptr);
593 free_connection(ncn);
597 ncn->address = ntohl(*((ip_t*)(h->h_addr_list[0])));
598 ncn->hostname = hostlookup(htonl(ncn->address));
600 if(setup_outgoing_meta_socket(ncn) < 0)
602 syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
604 free_connection(ncn);
608 ncn->status.outgoing = 1;
609 ncn->buffer = xmalloc(MAXBUFSIZE);
611 ncn->last_ping_time = time(NULL);
620 int read_rsa_public_key(connection_t *cl)
628 cl->rsa_key = RSA_new();
630 /* First, check for simple PublicKey statement */
632 if((cfg = get_config_val(cl->config, config_publickey)))
634 BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
635 BN_hex2bn(&cl->rsa_key->e, "FFFF");
639 /* Else, check for PublicKeyFile statement and read it */
641 if((cfg = get_config_val(cl->config, config_publickeyfile)))
643 if(is_safe_path(cfg->data.ptr))
645 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
647 syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
651 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
655 syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
665 /* Else, check if a harnessed public key is in the config file */
667 asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
668 if((fp = fopen(fname, "r")))
670 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
679 /* Nothing worked. */
681 syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
686 int read_rsa_private_key(void)
693 myself->rsa_key = RSA_new();
695 if((cfg = get_config_val(config, config_privatekey)))
697 BN_hex2bn(&myself->rsa_key->d, cfg->data.ptr);
698 BN_hex2bn(&myself->rsa_key->e, "FFFF");
700 else if((cfg = get_config_val(config, config_privatekeyfile)))
702 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
704 syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
708 result = PEM_read_RSAPrivateKey(fp, &myself->rsa_key, NULL, NULL);
712 syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
719 syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
727 Configure connection_t myself and set up the local sockets (listen only)
729 int setup_myself(void)
735 myself = new_connection();
737 asprintf(&myself->hostname, "MYSELF");
739 myself->protocol_version = PROT_CURRENT;
741 if(!(cfg = get_config_val(config, config_name))) /* Not acceptable */
743 syslog(LOG_ERR, _("Name for tinc daemon required!"));
747 asprintf(&myself->name, "%s", (char*)cfg->data.val);
749 if(check_id(myself->name))
751 syslog(LOG_ERR, _("Invalid name for myself!"));
755 if(read_rsa_private_key())
758 if(read_host_config(myself))
760 syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
764 if(read_rsa_public_key(myself))
769 if(RSA_check_key(myself->rsa_key) != 1)
771 syslog(LOG_ERR, _("Invalid public/private keypair!"));
775 if(!(cfg = get_config_val(myself->config, config_port)))
778 myself->port = cfg->data.val;
780 if((cfg = get_config_val(myself->config, config_indirectdata)))
781 if(cfg->data.val == stupid_true)
782 myself->flags |= EXPORTINDIRECTDATA;
784 if((cfg = get_config_val(myself->config, config_tcponly)))
785 if(cfg->data.val == stupid_true)
786 myself->flags |= TCPONLY;
788 /* Read in all the subnets specified in the host configuration file */
790 for(next = myself->config; (cfg = get_config_val(next, config_subnet)); next = cfg->next)
793 net->type = SUBNET_IPV4;
794 net->net.ipv4.address = cfg->data.ip->address;
795 net->net.ipv4.mask = cfg->data.ip->mask;
797 /* Teach newbies what subnets are... */
799 if((net->net.ipv4.address & net->net.ipv4.mask) != net->net.ipv4.address)
801 syslog(LOG_ERR, _("Network address and subnet mask do not match!"));
805 subnet_add(myself, net);
808 if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
810 syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
814 if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
816 syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
820 /* Generate packet encryption key */
822 myself->cipher_pkttype = EVP_bf_cbc();
824 myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
826 myself->cipher_pktkey = (char *)xmalloc(myself->cipher_pktkeylength);
827 RAND_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
829 if(!(cfg = get_config_val(config, config_keyexpire)))
832 keylifetime = cfg->data.val;
834 keyexpires = time(NULL) + keylifetime;
836 /* Check some options */
838 if((cfg = get_config_val(config, config_indirectdata)))
840 if(cfg->data.val == stupid_true)
841 myself->options |= OPTION_INDIRECT;
844 if((cfg = get_config_val(config, config_tcponly)))
846 if(cfg->data.val == stupid_true)
847 myself->options |= OPTION_TCPONLY;
849 /* Activate ourselves */
851 myself->status.active = 1;
853 syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
859 sigalrm_handler(int a)
863 cfg = get_config_val(upstreamcfg, config_connectto);
865 if(!cfg && upstreamcfg == config)
866 /* No upstream IP given, we're listen only. */
871 upstreamcfg = cfg->next;
872 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
874 signal(SIGALRM, SIG_IGN);
877 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
880 signal(SIGALRM, sigalrm_handler);
881 upstreamcfg = config;
882 seconds_till_retry += 5;
883 if(seconds_till_retry > MAXTIMEOUT) /* Don't wait more than MAXTIMEOUT seconds. */
884 seconds_till_retry = MAXTIMEOUT;
885 syslog(LOG_ERR, _("Still failed to connect to other, will retry in %d seconds"),
887 alarm(seconds_till_retry);
892 setup all initial network connections
894 int setup_network_connections(void)
901 if((cfg = get_config_val(config, config_pingtimeout)) == NULL)
905 timeout = cfg->data.val;
912 if(setup_tap_fd() < 0)
915 /* Run tinc-up script to further initialize the tap interface */
916 execute_script("tinc-up");
918 if(setup_myself() < 0)
921 if(!(cfg = get_config_val(config, config_connectto)))
922 /* No upstream IP given, we're listen only. */
927 upstreamcfg = cfg->next;
928 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
930 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
935 signal(SIGALRM, sigalrm_handler);
936 upstreamcfg = config;
937 seconds_till_retry = MAXTIMEOUT;
938 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
939 alarm(seconds_till_retry);
949 close all open network connections
951 void close_network_connections(void)
956 for(node = connection_tree->head; node; node = node->next)
958 p = (connection_t *)node->data;
959 p->status.outgoing = 0;
960 p->status.active = 0;
961 terminate_connection(p);
965 if(myself->status.active)
967 close(myself->meta_socket);
968 free_connection(myself);
974 /* Execute tinc-down script right after shutting down the interface */
975 execute_script("tinc-down");
977 destroy_connection_tree();
983 handle an incoming tcp connect call and open
986 connection_t *create_new_connection(int sfd)
989 struct sockaddr_in ci;
990 int len = sizeof(ci);
992 p = new_connection();
994 if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
996 syslog(LOG_ERR, _("System call `%s' failed: %m"),
1003 p->address = ntohl(ci.sin_addr.s_addr);
1004 p->hostname = hostlookup(ci.sin_addr.s_addr);
1005 p->port = htons(ci.sin_port); /* This one will be overwritten later */
1006 p->meta_socket = sfd;
1008 p->buffer = xmalloc(MAXBUFSIZE);
1010 p->last_ping_time = time(NULL);
1012 if(debug_lvl >= DEBUG_CONNECTIONS)
1013 syslog(LOG_NOTICE, _("Connection from %s port %d"),
1014 p->hostname, htons(ci.sin_port));
1016 p->allow_request = ID;
1022 put all file descriptors in an fd_set array
1024 void build_fdset(fd_set *fs)
1031 FD_SET(myself->socket, fs);
1033 for(node = connection_tree->head; node; node = node->next)
1035 p = (connection_t *)node->data;
1037 FD_SET(p->meta_socket, fs);
1040 FD_SET(myself->meta_socket, fs);
1046 receive incoming data from the listening
1047 udp socket and write it to the ethertap
1048 device after being decrypted
1050 int handle_incoming_vpn_data(void)
1053 int x, l = sizeof(x);
1055 struct sockaddr_in from;
1056 socklen_t fromlen = sizeof(from);
1059 if(getsockopt(myself->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
1061 syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
1062 __FILE__, __LINE__, myself->socket);
1067 syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
1071 if((lenin = recvfrom(myself->socket, (char *) &(pkt.len), MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
1073 syslog(LOG_ERR, _("Receiving packet failed: %m"));
1077 cl = lookup_connection(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
1081 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));
1085 if(debug_lvl >= DEBUG_TRAFFIC)
1087 syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), lenin,
1088 cl->name, cl->hostname);
1092 return xrecv(cl, &pkt);
1096 terminate a connection and notify the other
1097 end before closing the sockets
1099 void terminate_connection(connection_t *cl)
1103 avl_node_t *node, *next;
1105 if(cl->status.remove)
1108 if(debug_lvl >= DEBUG_CONNECTIONS)
1109 syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
1110 cl->name, cl->hostname);
1112 cl->status.remove = 1;
1117 close(cl->meta_socket);
1122 /* Find all connections that were lost because they were behind cl
1123 (the connection that was dropped). */
1125 for(node = connection_tree->head; node; node = node->next)
1127 p = (connection_t *)node->data;
1128 if(p->nexthop == cl && p != cl)
1129 terminate_connection(p);
1132 /* Inform others of termination if it was still active */
1134 if(cl->status.active)
1135 for(node = connection_tree->head; node; node = node->next)
1137 p = (connection_t *)node->data;
1138 if(p->status.meta && p->status.active && p != cl)
1139 send_del_host(p, cl); /* Sounds like recursion, but p does not have a meta connection :) */
1143 /* Remove the associated subnets */
1145 for(node = cl->subnet_tree->head; node; node = next)
1148 subnet = (subnet_t *)node->data;
1152 /* Check if this was our outgoing connection */
1154 if(cl->status.outgoing)
1156 cl->status.outgoing = 0;
1157 signal(SIGALRM, sigalrm_handler);
1158 seconds_till_retry = 5;
1159 alarm(seconds_till_retry);
1160 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in 5 seconds"));
1165 cl->status.active = 0;
1170 Check if the other end is active.
1171 If we have sent packets, but didn't receive any,
1172 then possibly the other end is dead. We send a
1173 PING request over the meta connection. If the other
1174 end does not reply in time, we consider them dead
1175 and close the connection.
1177 void check_dead_connections(void)
1185 for(node = connection_tree->head; node; node = node->next)
1187 cl = (connection_t *)node->data;
1188 if(cl->status.active && cl->status.meta)
1190 if(cl->last_ping_time + timeout < now)
1192 if(cl->status.pinged)
1194 if(debug_lvl >= DEBUG_PROTOCOL)
1195 syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
1196 cl->name, cl->hostname);
1197 cl->status.timeout = 1;
1198 terminate_connection(cl);
1211 accept a new tcp connect and create a
1214 int handle_new_meta_connection()
1217 struct sockaddr client;
1218 int nfd, len = sizeof(client);
1220 if((nfd = accept(myself->meta_socket, &client, &len)) < 0)
1222 syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
1226 if(!(ncn = create_new_connection(nfd)))
1230 syslog(LOG_NOTICE, _("Closed attempted connection"));
1234 connection_add(ncn);
1242 check all connections to see if anything
1243 happened on their sockets
1245 void check_network_activity(fd_set *f)
1250 if(FD_ISSET(myself->socket, f))
1251 handle_incoming_vpn_data();
1253 for(node = connection_tree->head; node; node = node->next)
1255 p = (connection_t *)node->data;
1257 if(p->status.remove)
1261 if(FD_ISSET(p->meta_socket, f))
1262 if(receive_meta(p) < 0)
1264 terminate_connection(p);
1269 if(FD_ISSET(myself->meta_socket, f))
1270 handle_new_meta_connection();
1275 read, encrypt and send data that is
1276 available through the ethertap device
1278 void handle_tap_input(void)
1283 if(taptype == TAP_TYPE_TUNTAP)
1285 if((lenin = read(tap_fd, vp.data, MTU)) <= 0)
1287 syslog(LOG_ERR, _("Error while reading from tun/tap device: %m"));
1294 if((lenin = read(tap_fd, vp.data - 2, MTU)) <= 0)
1296 syslog(LOG_ERR, _("Error while reading from ethertap device: %m"));
1302 total_tap_in += lenin;
1306 if(debug_lvl >= DEBUG_TRAFFIC)
1307 syslog(LOG_WARNING, _("Received short packet from tap device"));
1311 if(debug_lvl >= DEBUG_TRAFFIC)
1313 syslog(LOG_DEBUG, _("Read packet of length %d from tap device"), vp.len);
1316 send_packet(ntohl(*((unsigned long*)(&vp.data[30]))), &vp);
1321 this is where it all happens...
1323 void main_loop(void)
1328 time_t last_ping_check;
1331 last_ping_check = time(NULL);
1335 tv.tv_sec = timeout;
1338 prune_connection_tree();
1341 if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
1343 if(errno != EINTR) /* because of alarm */
1345 syslog(LOG_ERR, _("Error while waiting for input: %m"));
1352 syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
1354 close_network_connections();
1355 clear_config(&config);
1357 if(read_server_config())
1359 syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
1365 if(setup_network_connections())
1373 /* Let's check if everybody is still alive */
1375 if(last_ping_check + timeout < t)
1377 check_dead_connections();
1378 last_ping_check = time(NULL);
1380 /* Should we regenerate our key? */
1384 if(debug_lvl >= DEBUG_STATUS)
1385 syslog(LOG_INFO, _("Regenerating symmetric key"));
1387 RAND_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
1388 send_key_changed(myself, NULL);
1389 keyexpires = time(NULL) + keylifetime;
1395 check_network_activity(&fset);
1397 /* local tap data */
1398 if(FD_ISSET(tap_fd, &fset))