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 1.35.4.97 2001/02/25 19:09:41 guus Exp $
28 #include <netinet/in.h>
32 #include <sys/signal.h>
34 #include <sys/types.h>
37 #include <sys/ioctl.h>
38 /* SunOS really wants sys/socket.h BEFORE net/if.h,
39 and FreeBSD wants these lines below the rest. */
40 #include <arpa/inet.h>
41 #include <sys/socket.h>
44 #ifdef HAVE_OPENSSL_RAND_H
45 # include <openssl/rand.h>
50 #ifdef HAVE_OPENSSL_EVP_H
51 # include <openssl/evp.h>
56 #ifdef HAVE_OPENSSL_ERR_H
57 # include <openssl/err.h>
62 #ifdef HAVE_OPENSSL_PEM_H
63 # include <openssl/pem.h>
69 #include LINUX_IF_TUN_H
78 #include "connection.h"
89 int taptype = TAP_TYPE_ETHERTAP;
91 int total_tap_out = 0;
92 int total_socket_in = 0;
93 int total_socket_out = 0;
95 config_t *upstreamcfg;
96 static int seconds_till_retry;
101 char *unknown = NULL;
105 int xsend(connection_t *cl, vpn_packet_t *inpkt)
110 struct sockaddr_in to;
111 socklen_t tolen = sizeof(to);
113 outpkt.len = inpkt->len;
115 /* Encrypt the packet. */
117 EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
118 EVP_EncryptUpdate(&ctx, outpkt.data, &outlen, inpkt->data, inpkt->len);
119 EVP_EncryptFinal(&ctx, outpkt.data + outlen, &outpad);
120 outlen += outpad + 2;
123 outlen = outpkt.len + 2;
124 memcpy(&outpkt, inpkt, outlen);
127 if(debug_lvl >= DEBUG_TRAFFIC)
128 syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
129 outlen, cl->name, cl->hostname);
131 total_socket_out += outlen;
133 to.sin_family = AF_INET;
134 to.sin_addr.s_addr = htonl(cl->address);
135 to.sin_port = htons(cl->port);
137 if((sendto(myself->socket, (char *) &(outpkt.len), outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
139 syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
140 cl->name, cl->hostname);
147 int xrecv(connection_t *cl, vpn_packet_t *inpkt)
153 outpkt.len = inpkt->len;
155 /* Decrypt the packet */
157 EVP_DecryptInit(&ctx, myself->cipher_pkttype, myself->cipher_pktkey, myself->cipher_pktkey + myself->cipher_pkttype->key_len);
158 EVP_DecryptUpdate(&ctx, outpkt.data, &outlen, inpkt->data, inpkt->len + 8);
159 EVP_DecryptFinal(&ctx, outpkt.data + outlen, &outpad);
163 outlen = outpkt.len+2;
164 memcpy(&outpkt, inpkt, outlen);
167 return receive_packet(cl, &outpkt);
170 int receive_packet(connection_t *cl, vpn_packet_t *packet)
172 if(debug_lvl >= DEBUG_TRAFFIC)
173 syslog(LOG_ERR, _("Writing packet of %d bytes to tap device"),
176 /* Fix mac address */
178 memcpy(packet->data, mymac.net.mac.address.x, 6);
180 if(taptype == TAP_TYPE_TUNTAP)
182 if(write(tap_fd, packet->data, packet->len) < 0)
183 syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
185 total_tap_out += packet->len;
189 if(write(tap_fd, packet->data - 2, packet->len + 2) < 0)
190 syslog(LOG_ERR, _("Can't write to ethertap device: %m"));
192 total_tap_out += packet->len + 2;
199 send a packet to the given vpn ip.
201 int send_packet(ip_t to, vpn_packet_t *packet)
207 if((subnet = lookup_subnet_ipv4(&to)) == NULL)
209 if(debug_lvl >= DEBUG_TRAFFIC)
211 syslog(LOG_NOTICE, _("Trying to look up %d.%d.%d.%d in connection list failed!"),
222 if(debug_lvl >= DEBUG_TRAFFIC)
224 syslog(LOG_NOTICE, _("Packet with destination %d.%d.%d.%d is looping back to us!"),
231 if(!cl->status.active)
233 if(debug_lvl >= DEBUG_TRAFFIC)
234 syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
235 cl->name, cl->hostname);
240 if(!cl->status.validkey)
242 if(debug_lvl >= DEBUG_TRAFFIC)
243 syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
244 cl->name, cl->hostname);
246 /* Since packet is on the stack of handle_tap_input(),
247 we have to make a copy of it first. */
249 copy = xmalloc(sizeof(vpn_packet_t));
250 memcpy(copy, packet, sizeof(vpn_packet_t));
252 list_insert_tail(cl->queue, copy);
254 if(!cl->status.waitingforkey)
255 send_req_key(myself, cl); /* Keys should be sent to the host running the tincd */
259 /* Check if it has to go via UDP or TCP... */
261 if(cl->options & OPTION_TCPONLY)
262 return send_tcppacket(cl, packet);
264 return xsend(cl, packet);
267 void flush_queue(connection_t *cl)
269 list_node_t *node, *next;
271 if(debug_lvl >= DEBUG_TRAFFIC)
272 syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
274 for(node = cl->queue->head; node; node = next)
277 xsend(cl, (vpn_packet_t *)node->data);
278 list_delete_node(cl->queue, node);
284 open the local ethertap device
286 int setup_tap_fd(void)
289 const char *tapfname;
298 if((cfg = get_config_val(config, config_tapdevice)))
299 tapfname = cfg->data.ptr;
304 tapfname = "/dev/misc/net/tun";
306 tapfname = "/dev/tap0";
310 tapfname = "/dev/tap0";
313 tapfname = "/dev/tun";
317 if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
319 syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
325 taptype = TAP_TYPE_ETHERTAP;
327 /* Set default MAC address for ethertap devices */
329 mymac.type = SUBNET_MAC;
330 mymac.net.mac.address.x[0] = 0xfe;
331 mymac.net.mac.address.x[1] = 0xfd;
332 mymac.net.mac.address.x[2] = 0x00;
333 mymac.net.mac.address.x[3] = 0x00;
334 mymac.net.mac.address.x[4] = 0x00;
335 mymac.net.mac.address.x[5] = 0x00;
339 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
340 memset(&ifr, 0, sizeof(ifr));
342 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
344 strncpy(ifr.ifr_name, netname, IFNAMSIZ);
346 if (!ioctl(tap_fd, TUNSETIFF, (void *) &ifr))
348 syslog(LOG_INFO, _("%s is a new style tun/tap device"), tapfname);
349 taptype = TAP_TYPE_TUNTAP;
354 taptype = TAP_TYPE_TUNTAP;
361 set up the socket that we listen on for incoming
364 int setup_listen_meta_socket(int port)
367 struct sockaddr_in a;
371 if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
373 syslog(LOG_ERR, _("Creating metasocket failed: %m"));
377 if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
380 syslog(LOG_ERR, _("System call `%s' failed: %m"),
385 if(setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one)))
388 syslog(LOG_ERR, _("System call `%s' failed: %m"),
393 flags = fcntl(nfd, F_GETFL);
394 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
397 syslog(LOG_ERR, _("System call `%s' failed: %m"),
402 if((cfg = get_config_val(config, config_interface)))
404 if(setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, cfg->data.ptr, strlen(cfg->data.ptr)))
407 syslog(LOG_ERR, _("Unable to bind listen socket to interface %s: %m"), cfg->data.ptr);
412 memset(&a, 0, sizeof(a));
413 a.sin_family = AF_INET;
414 a.sin_port = htons(port);
416 if((cfg = get_config_val(config, config_interfaceip)))
417 a.sin_addr.s_addr = htonl(cfg->data.ip->address);
419 a.sin_addr.s_addr = htonl(INADDR_ANY);
421 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
424 syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
431 syslog(LOG_ERR, _("System call `%s' failed: %m"),
440 setup the socket for incoming encrypted
443 int setup_vpn_in_socket(int port)
446 struct sockaddr_in a;
449 if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
452 syslog(LOG_ERR, _("Creating socket failed: %m"));
456 if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
459 syslog(LOG_ERR, _("System call `%s' failed: %m"),
464 flags = fcntl(nfd, F_GETFL);
465 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
468 syslog(LOG_ERR, _("System call `%s' failed: %m"),
473 memset(&a, 0, sizeof(a));
474 a.sin_family = AF_INET;
475 a.sin_port = htons(port);
476 a.sin_addr.s_addr = htonl(INADDR_ANY);
478 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
481 syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
489 setup an outgoing meta (tcp) socket
491 int setup_outgoing_meta_socket(connection_t *cl)
494 struct sockaddr_in a;
497 if(debug_lvl >= DEBUG_CONNECTIONS)
498 syslog(LOG_INFO, _("Trying to connect to %s"), cl->hostname);
500 if((cfg = get_config_val(cl->config, config_port)) == NULL)
503 cl->port = cfg->data.val;
505 cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
506 if(cl->meta_socket == -1)
508 syslog(LOG_ERR, _("Creating socket for %s port %d failed: %m"),
509 cl->hostname, cl->port);
513 /* Bind first to get a fix on our source port */
515 a.sin_family = AF_INET;
516 a.sin_port = htons(0);
517 a.sin_addr.s_addr = htonl(INADDR_ANY);
519 if(bind(cl->meta_socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
521 close(cl->meta_socket);
522 syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
526 a.sin_family = AF_INET;
527 a.sin_port = htons(cl->port);
528 a.sin_addr.s_addr = htonl(cl->address);
530 if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
532 close(cl->meta_socket);
533 syslog(LOG_ERR, _("%s port %hd: %m"), cl->hostname, cl->port);
537 flags = fcntl(cl->meta_socket, F_GETFL);
538 if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
540 close(cl->meta_socket);
541 syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
542 cl->hostname, cl->port);
546 if(debug_lvl >= DEBUG_CONNECTIONS)
547 syslog(LOG_INFO, _("Connected to %s port %hd"),
548 cl->hostname, cl->port);
556 Setup an outgoing meta connection.
558 int setup_outgoing_connection(char *name)
566 syslog(LOG_ERR, _("Invalid name for outgoing connection"));
570 ncn = new_connection();
571 asprintf(&ncn->name, "%s", name);
573 if(read_host_config(ncn))
575 syslog(LOG_ERR, _("Error reading host configuration file for %s"), ncn->name);
576 free_connection(ncn);
580 if(!(cfg = get_config_val(ncn->config, config_address)))
582 syslog(LOG_ERR, _("No address specified for %s"), ncn->name);
583 free_connection(ncn);
587 if(!(h = gethostbyname(cfg->data.ptr)))
589 syslog(LOG_ERR, _("Error looking up `%s': %m"), cfg->data.ptr);
590 free_connection(ncn);
594 ncn->address = ntohl(*((ip_t*)(h->h_addr_list[0])));
595 ncn->hostname = hostlookup(htonl(ncn->address));
597 if(setup_outgoing_meta_socket(ncn) < 0)
599 syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
601 free_connection(ncn);
605 ncn->status.outgoing = 1;
606 ncn->buffer = xmalloc(MAXBUFSIZE);
608 ncn->last_ping_time = time(NULL);
617 int read_rsa_public_key(connection_t *cl)
625 cl->rsa_key = RSA_new();
627 /* First, check for simple PublicKey statement */
629 if((cfg = get_config_val(cl->config, config_publickey)))
631 BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
632 BN_hex2bn(&cl->rsa_key->e, "FFFF");
636 /* Else, check for PublicKeyFile statement and read it */
638 if((cfg = get_config_val(cl->config, config_publickeyfile)))
640 if(is_safe_path(cfg->data.ptr))
642 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
644 syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
648 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
652 syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
662 /* Else, check if a harnessed public key is in the config file */
664 asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
665 if((fp = fopen(fname, "r")))
667 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
676 /* Nothing worked. */
678 syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
683 int read_rsa_private_key(void)
690 myself->rsa_key = RSA_new();
692 if((cfg = get_config_val(config, config_privatekey)))
694 BN_hex2bn(&myself->rsa_key->d, cfg->data.ptr);
695 BN_hex2bn(&myself->rsa_key->e, "FFFF");
697 else if((cfg = get_config_val(config, config_privatekeyfile)))
699 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
701 syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
705 result = PEM_read_RSAPrivateKey(fp, &myself->rsa_key, NULL, NULL);
709 syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
716 syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
724 Configure connection_t myself and set up the local sockets (listen only)
726 int setup_myself(void)
732 myself = new_connection();
734 asprintf(&myself->hostname, "MYSELF");
736 myself->protocol_version = PROT_CURRENT;
738 if(!(cfg = get_config_val(config, config_name))) /* Not acceptable */
740 syslog(LOG_ERR, _("Name for tinc daemon required!"));
744 asprintf(&myself->name, "%s", (char*)cfg->data.val);
746 if(check_id(myself->name))
748 syslog(LOG_ERR, _("Invalid name for myself!"));
752 if(read_rsa_private_key())
755 if(read_host_config(myself))
757 syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
761 if(read_rsa_public_key(myself))
766 if(RSA_check_key(myself->rsa_key) != 1)
768 syslog(LOG_ERR, _("Invalid public/private keypair!"));
772 if(!(cfg = get_config_val(myself->config, config_port)))
775 myself->port = cfg->data.val;
777 if((cfg = get_config_val(myself->config, config_indirectdata)))
778 if(cfg->data.val == stupid_true)
779 myself->flags |= EXPORTINDIRECTDATA;
781 if((cfg = get_config_val(myself->config, config_tcponly)))
782 if(cfg->data.val == stupid_true)
783 myself->flags |= TCPONLY;
785 /* Read in all the subnets specified in the host configuration file */
787 for(next = myself->config; (cfg = get_config_val(next, config_subnet)); next = cfg->next)
790 net->type = SUBNET_IPV4;
791 net->net.ipv4.address = cfg->data.ip->address;
792 net->net.ipv4.mask = cfg->data.ip->mask;
794 /* Teach newbies what subnets are... */
796 if((net->net.ipv4.address & net->net.ipv4.mask) != net->net.ipv4.address)
798 syslog(LOG_ERR, _("Network address and subnet mask do not match!"));
802 subnet_add(myself, net);
805 if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
807 syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
811 if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
813 syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
817 /* Generate packet encryption key */
819 myself->cipher_pkttype = EVP_bf_cbc();
821 myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
823 myself->cipher_pktkey = (char *)xmalloc(myself->cipher_pktkeylength);
824 RAND_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
826 if(!(cfg = get_config_val(config, config_keyexpire)))
829 keylifetime = cfg->data.val;
831 keyexpires = time(NULL) + keylifetime;
833 /* Check some options */
835 if((cfg = get_config_val(config, config_indirectdata)))
837 if(cfg->data.val == stupid_true)
838 myself->options |= OPTION_INDIRECT;
841 if((cfg = get_config_val(config, config_tcponly)))
843 if(cfg->data.val == stupid_true)
844 myself->options |= OPTION_TCPONLY;
846 /* Activate ourselves */
848 myself->status.active = 1;
850 syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
856 sigalrm_handler(int a)
860 cfg = get_config_val(upstreamcfg, config_connectto);
862 if(!cfg && upstreamcfg == config)
863 /* No upstream IP given, we're listen only. */
868 upstreamcfg = cfg->next;
869 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
871 signal(SIGALRM, SIG_IGN);
874 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
877 signal(SIGALRM, sigalrm_handler);
878 upstreamcfg = config;
879 seconds_till_retry += 5;
880 if(seconds_till_retry > MAXTIMEOUT) /* Don't wait more than MAXTIMEOUT seconds. */
881 seconds_till_retry = MAXTIMEOUT;
882 syslog(LOG_ERR, _("Still failed to connect to other, will retry in %d seconds"),
884 alarm(seconds_till_retry);
889 setup all initial network connections
891 int setup_network_connections(void)
898 if((cfg = get_config_val(config, config_pingtimeout)) == NULL)
902 timeout = cfg->data.val;
909 if(setup_tap_fd() < 0)
912 /* Run tinc-up script to further initialize the tap interface */
913 execute_script("tinc-up");
915 if(setup_myself() < 0)
918 if(!(cfg = get_config_val(config, config_connectto)))
919 /* No upstream IP given, we're listen only. */
924 upstreamcfg = cfg->next;
925 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
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 = MAXTIMEOUT;
933 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
934 alarm(seconds_till_retry);
940 close all open network connections
942 void close_network_connections(void)
947 for(node = connection_tree->head; node; node = node->next)
949 p = (connection_t *)node->data;
950 p->status.active = 0;
951 terminate_connection(p);
955 if(myself->status.active)
957 close(myself->meta_socket);
958 free_connection(myself);
964 /* Execute tinc-down script right after shutting down the interface */
965 execute_script("tinc-down");
967 destroy_connection_tree();
973 create a data (udp) socket
974 OBSOLETED: use only one listening socket for compatibility with non-Linux operating systems
976 int setup_vpn_connection(connection_t *cl)
979 struct sockaddr_in a;
982 if(debug_lvl >= DEBUG_TRAFFIC)
983 syslog(LOG_DEBUG, _("Opening UDP socket to %s"), cl->hostname);
985 nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
988 syslog(LOG_ERR, _("Creating UDP socket failed: %m"));
992 if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
995 syslog(LOG_ERR, _("System call `%s' failed: %m"),
1000 flags = fcntl(nfd, F_GETFL);
1001 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
1004 syslog(LOG_ERR, _("System call `%s' failed: %m"),
1009 memset(&a, 0, sizeof(a));
1010 a.sin_family = AF_INET;
1011 a.sin_port = htons(myself->port);
1012 a.sin_addr.s_addr = htonl(INADDR_ANY);
1014 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
1017 syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), myself->port);
1021 a.sin_family = AF_INET;
1022 a.sin_port = htons(cl->port);
1023 a.sin_addr.s_addr = htonl(cl->address);
1025 if(connect(nfd, (struct sockaddr *)&a, sizeof(a)) == -1)
1028 syslog(LOG_ERR, _("Connecting to %s port %d failed: %m"),
1029 cl->hostname, cl->port);
1033 flags = fcntl(nfd, F_GETFL);
1034 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
1037 syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m %s (%s)"), __FILE__, __LINE__, nfd,
1038 cl->name, cl->hostname);
1043 cl->status.dataopen = 1;
1049 handle an incoming tcp connect call and open
1052 connection_t *create_new_connection(int sfd)
1055 struct sockaddr_in ci;
1056 int len = sizeof(ci);
1058 p = new_connection();
1060 if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
1062 syslog(LOG_ERR, _("System call `%s' failed: %m"),
1069 p->address = ntohl(ci.sin_addr.s_addr);
1070 p->hostname = hostlookup(ci.sin_addr.s_addr);
1071 p->port = htons(ci.sin_port); /* This one will be overwritten later */
1072 p->meta_socket = sfd;
1074 p->buffer = xmalloc(MAXBUFSIZE);
1076 p->last_ping_time = time(NULL);
1078 if(debug_lvl >= DEBUG_CONNECTIONS)
1079 syslog(LOG_NOTICE, _("Connection from %s port %d"),
1080 p->hostname, htons(ci.sin_port));
1082 p->allow_request = ID;
1088 put all file descriptors in an fd_set array
1090 void build_fdset(fd_set *fs)
1097 FD_SET(myself->socket, fs);
1099 for(node = connection_tree->head; node; node = node->next)
1101 p = (connection_t *)node->data;
1103 FD_SET(p->meta_socket, fs);
1106 FD_SET(myself->meta_socket, fs);
1112 receive incoming data from the listening
1113 udp socket and write it to the ethertap
1114 device after being decrypted
1116 int handle_incoming_vpn_data(void)
1119 int x, l = sizeof(x);
1121 struct sockaddr_in from;
1122 socklen_t fromlen = sizeof(from);
1125 if(getsockopt(myself->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
1127 syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
1128 __FILE__, __LINE__, myself->socket);
1133 syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
1137 if((lenin = recvfrom(myself->socket, (char *) &(pkt.len), MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
1139 syslog(LOG_ERR, _("Receiving packet failed: %m"));
1143 cl = lookup_connection(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
1147 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));
1151 if(debug_lvl >= DEBUG_TRAFFIC)
1153 syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), lenin,
1154 cl->name, cl->hostname);
1158 return xrecv(cl, &pkt);
1162 terminate a connection and notify the other
1163 end before closing the sockets
1165 void terminate_connection(connection_t *cl)
1169 avl_node_t *node, *next;
1171 if(cl->status.remove)
1174 if(debug_lvl >= DEBUG_CONNECTIONS)
1175 syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
1176 cl->name, cl->hostname);
1178 cl->status.remove = 1;
1183 close(cl->meta_socket);
1188 /* Find all connections that were lost because they were behind cl
1189 (the connection that was dropped). */
1191 for(node = connection_tree->head; node; node = node->next)
1193 p = (connection_t *)node->data;
1194 if(p->nexthop == cl && p != cl)
1195 terminate_connection(p);
1198 /* Inform others of termination if it was still active */
1200 if(cl->status.active)
1201 for(node = connection_tree->head; node; node = node->next)
1203 p = (connection_t *)node->data;
1204 if(p->status.meta && p->status.active && p != cl)
1205 send_del_host(p, cl); /* Sounds like recursion, but p does not have a meta connection :) */
1209 /* Remove the associated subnets */
1211 for(node = cl->subnet_tree->head; node; node = next)
1214 subnet = (subnet_t *)node->data;
1218 /* Check if this was our outgoing connection */
1220 if(cl->status.outgoing && cl->status.active)
1222 signal(SIGALRM, sigalrm_handler);
1223 seconds_till_retry = 5;
1224 alarm(seconds_till_retry);
1225 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in 5 seconds"));
1230 cl->status.active = 0;
1235 Check if the other end is active.
1236 If we have sent packets, but didn't receive any,
1237 then possibly the other end is dead. We send a
1238 PING request over the meta connection. If the other
1239 end does not reply in time, we consider them dead
1240 and close the connection.
1242 void check_dead_connections(void)
1250 for(node = connection_tree->head; node; node = node->next)
1252 cl = (connection_t *)node->data;
1253 if(cl->status.active && cl->status.meta)
1255 if(cl->last_ping_time + timeout < now)
1257 if(cl->status.pinged)
1259 if(debug_lvl >= DEBUG_PROTOCOL)
1260 syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
1261 cl->name, cl->hostname);
1262 cl->status.timeout = 1;
1263 terminate_connection(cl);
1276 accept a new tcp connect and create a
1279 int handle_new_meta_connection()
1282 struct sockaddr client;
1283 int nfd, len = sizeof(client);
1285 if((nfd = accept(myself->meta_socket, &client, &len)) < 0)
1287 syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
1291 if(!(ncn = create_new_connection(nfd)))
1295 syslog(LOG_NOTICE, _("Closed attempted connection"));
1299 connection_add(ncn);
1307 check all connections to see if anything
1308 happened on their sockets
1310 void check_network_activity(fd_set *f)
1315 if(FD_ISSET(myself->socket, f))
1316 handle_incoming_vpn_data();
1318 for(node = connection_tree->head; node; node = node->next)
1320 p = (connection_t *)node->data;
1322 if(p->status.remove)
1326 if(FD_ISSET(p->meta_socket, f))
1327 if(receive_meta(p) < 0)
1329 terminate_connection(p);
1334 if(FD_ISSET(myself->meta_socket, f))
1335 handle_new_meta_connection();
1340 read, encrypt and send data that is
1341 available through the ethertap device
1343 void handle_tap_input(void)
1348 if(taptype == TAP_TYPE_TUNTAP)
1350 if((lenin = read(tap_fd, vp.data, MTU)) <= 0)
1352 syslog(LOG_ERR, _("Error while reading from tun/tap device: %m"));
1359 if((lenin = read(tap_fd, vp.data - 2, MTU)) <= 0)
1361 syslog(LOG_ERR, _("Error while reading from ethertap device: %m"));
1367 total_tap_in += lenin;
1371 if(debug_lvl >= DEBUG_TRAFFIC)
1372 syslog(LOG_WARNING, _("Received short packet from tap device"));
1376 if(debug_lvl >= DEBUG_TRAFFIC)
1378 syslog(LOG_DEBUG, _("Read packet of length %d from tap device"), vp.len);
1381 send_packet(ntohl(*((unsigned long*)(&vp.data[30]))), &vp);
1386 this is where it all happens...
1388 void main_loop(void)
1393 time_t last_ping_check;
1396 last_ping_check = time(NULL);
1400 tv.tv_sec = timeout;
1403 prune_connection_tree();
1406 if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
1408 if(errno != EINTR) /* because of alarm */
1410 syslog(LOG_ERR, _("Error while waiting for input: %m"));
1417 syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
1419 close_network_connections();
1420 clear_config(&config);
1422 if(read_server_config())
1424 syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
1430 if(setup_network_connections())
1438 /* Let's check if everybody is still alive */
1440 if(last_ping_check + timeout < t)
1442 check_dead_connections();
1443 last_ping_check = time(NULL);
1445 /* Should we regenerate our key? */
1449 if(debug_lvl >= DEBUG_STATUS)
1450 syslog(LOG_INFO, _("Regenerating symmetric key"));
1452 RAND_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
1453 send_key_changed(myself, NULL);
1454 keyexpires = time(NULL) + keylifetime;
1460 check_network_activity(&fset);
1462 /* local tap data */
1463 if(FD_ISSET(tap_fd, &fset))