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 1.35.4.127 2001/07/24 20:14:30 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 #include <openssl/rand.h>
49 #include <openssl/evp.h>
50 #include <openssl/pem.h>
52 #ifndef HAVE_RAND_PSEUDO_BYTES
53 #define RAND_pseudo_bytes RAND_bytes
59 #include LINUX_IF_TUN_H
61 #include <linux/if_tun.h>
64 #include <net/if_tun.h>
69 #include <sys/sockio.h>
70 #include <sys/stropts.h>
71 #include <net/if_tun.h>
80 #include "connection.h"
93 int taptype = TAP_TYPE_ETHERTAP;
95 int total_tap_out = 0;
96 int total_socket_in = 0;
97 int total_socket_out = 0;
99 config_t *upstreamcfg;
100 int seconds_till_retry = 5;
105 void send_udppacket(connection_t *cl, vpn_packet_t *inpkt)
110 struct sockaddr_in to;
111 socklen_t tolen = sizeof(to);
114 if(!cl->status.validkey)
116 if(debug_lvl >= DEBUG_TRAFFIC)
117 syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
118 cl->name, cl->hostname);
120 /* Since packet is on the stack of handle_tap_input(),
121 we have to make a copy of it first. */
123 copy = xmalloc(sizeof(vpn_packet_t));
124 memcpy(copy, inpkt, sizeof(vpn_packet_t));
126 list_insert_tail(cl->queue, copy);
128 if(!cl->status.waitingforkey)
129 send_req_key(myself, cl);
133 /* Encrypt the packet. */
135 RAND_pseudo_bytes(inpkt->salt, sizeof(inpkt->salt));
137 EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
138 EVP_EncryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len + sizeof(inpkt->salt));
139 EVP_EncryptFinal(&ctx, outpkt.salt + outlen, &outpad);
142 total_socket_out += outlen;
144 to.sin_family = AF_INET;
145 to.sin_addr.s_addr = htonl(cl->address);
146 to.sin_port = htons(cl->port);
148 if((sendto(myself->socket, (char *) outpkt.salt, outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
150 syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
151 cl->name, cl->hostname);
157 void receive_packet(connection_t *cl, vpn_packet_t *packet)
160 if(debug_lvl >= DEBUG_TRAFFIC)
161 syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, cl->name, cl->hostname);
163 route_incoming(cl, packet);
167 void receive_udppacket(connection_t *cl, vpn_packet_t *inpkt)
173 /* Decrypt the packet */
175 EVP_DecryptInit(&ctx, myself->cipher_pkttype, myself->cipher_pktkey, myself->cipher_pktkey + myself->cipher_pkttype->key_len);
176 EVP_DecryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len);
177 EVP_DecryptFinal(&ctx, outpkt.salt + outlen, &outpad);
179 outpkt.len = outlen - sizeof(outpkt.salt);
181 total_socket_in += outlen;
183 receive_packet(cl, &outpkt);
187 void receive_tcppacket(connection_t *cl, char *buffer, int len)
192 memcpy(outpkt.data, buffer, len);
194 receive_packet(cl, &outpkt);
198 void accept_packet(vpn_packet_t *packet)
201 if(debug_lvl >= DEBUG_TRAFFIC)
202 syslog(LOG_DEBUG, _("Writing packet of %d bytes to tap device"),
206 if(write(tap_fd, packet->data + 14, packet->len - 14) < 0)
207 syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
209 total_tap_out += packet->len;
211 if(taptype == TAP_TYPE_TUNTAP)
213 if(write(tap_fd, packet->data, packet->len) < 0)
214 syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
216 total_tap_out += packet->len;
220 if(write(tap_fd, packet->data - 2, packet->len + 2) < 0)
221 syslog(LOG_ERR, _("Can't write to ethertap device: %m"));
223 total_tap_out += packet->len;
230 send a packet to the given vpn ip.
232 void send_packet(connection_t *cl, vpn_packet_t *packet)
235 if(debug_lvl >= DEBUG_TRAFFIC)
236 syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
237 packet->len, cl->name, cl->hostname);
241 if(debug_lvl >= DEBUG_TRAFFIC)
243 syslog(LOG_NOTICE, _("Packet is looping back to us!"));
249 if(!cl->status.active)
251 if(debug_lvl >= DEBUG_TRAFFIC)
252 syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
253 cl->name, cl->hostname);
258 /* Check if it has to go via TCP or UDP... */
260 if((cl->options | myself->options) & OPTION_TCPONLY)
262 if(send_tcppacket(cl, packet))
263 terminate_connection(cl, 1);
266 send_udppacket(cl, packet);
269 /* Broadcast a packet to all active direct connections */
271 void broadcast_packet(connection_t *from, vpn_packet_t *packet)
276 if(debug_lvl >= DEBUG_TRAFFIC)
277 syslog(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
278 packet->len, from->name, from->hostname);
280 for(node = connection_tree->head; node; node = node->next)
282 cl = (connection_t *)node->data;
283 if(cl->status.active && cl != from)
284 send_packet(cl, packet);
289 void flush_queue(connection_t *cl)
291 list_node_t *node, *next;
293 if(debug_lvl >= DEBUG_TRAFFIC)
294 syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
296 for(node = cl->queue->head; node; node = next)
299 send_udppacket(cl, (vpn_packet_t *)node->data);
300 list_delete_node(cl->queue, node);
306 open the local ethertap device
308 int setup_tap_fd(void)
311 const char *tapfname;
319 int ip_fd = -1, if_fd = -1;
325 if((cfg = get_config_val(config, config_tapdevice)))
326 tapfname = cfg->data.ptr;
331 tapfname = "/dev/net/tun";
333 tapfname = "/dev/tap0";
337 tapfname = "/dev/tap0";
340 tapfname = "/dev/tun";
344 if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
346 syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
352 /* Set default MAC address for ethertap devices */
354 mymac.type = SUBNET_MAC;
355 mymac.net.mac.address.x[0] = 0xfe;
356 mymac.net.mac.address.x[1] = 0xfd;
357 mymac.net.mac.address.x[2] = 0x00;
358 mymac.net.mac.address.x[3] = 0x00;
359 mymac.net.mac.address.x[4] = 0x00;
360 mymac.net.mac.address.x[5] = 0x00;
364 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
365 memset(&ifr, 0, sizeof(ifr));
367 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
369 strncpy(ifr.ifr_name, netname, IFNAMSIZ);
371 if (!ioctl(tap_fd, TUNSETIFF, (void *) &ifr))
373 syslog(LOG_INFO, _("%s is a tun/tap device"), tapfname);
374 taptype = TAP_TYPE_TUNTAP;
379 syslog(LOG_INFO, _("%s is an ethertap device"), tapfname);
380 taptype = TAP_TYPE_ETHERTAP;
384 syslog(LOG_INFO, _("%s is a tun/tap device"), tapfname);
385 taptype = TAP_TYPE_TUNTAP;
391 while(*ptr && !isdigit((int)*ptr)) ptr++;
394 if( (ip_fd = open("/dev/ip", O_RDWR, 0)) < 0){
395 syslog(LOG_ERR, _("Could not open /dev/ip: %m"));
399 /* Assign a new PPA and get its unit number. */
400 if( (ppa = ioctl(nfd, TUNNEWPPA, ppa)) < 0){
401 syslog(LOG_ERR, _("Can't assign new interface: %m"));
405 if( (if_fd = open(tapfname, O_RDWR, 0)) < 0){
406 syslog(LOG_ERR, _("Could not open %s twice: %m"), tapfname);
410 if(ioctl(if_fd, I_PUSH, "ip") < 0){
411 syslog(LOG_ERR, _("Can't push IP module: %m"));
415 /* Assign ppa according to the unit number returned by tun device */
416 if(ioctl(if_fd, IF_UNITSEL, (char *)&ppa) < 0){
417 syslog(LOG_ERR, _("Can't set PPA %d: %m"), ppa);
421 if(ioctl(ip_fd, I_LINK, if_fd) < 0){
422 syslog(LOG_ERR, _("Can't link TUN device to IP: %m"));
426 syslog(LOG_INFO, _("%s is a tun/tap device"), tapfname);
434 set up the socket that we listen on for incoming
437 int setup_listen_meta_socket(int port)
440 struct sockaddr_in a;
444 if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
446 syslog(LOG_ERR, _("Creating metasocket failed: %m"));
450 flags = fcntl(nfd, F_GETFL);
451 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
454 syslog(LOG_ERR, _("System call `%s' failed: %m"),
459 /* Optimize TCP settings */
462 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
463 setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
465 setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
467 option = IPTOS_LOWDELAY;
468 setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
470 if((cfg = get_config_val(config, config_interface)))
472 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, cfg->data.ptr, strlen(cfg->data.ptr)))
475 syslog(LOG_ERR, _("Unable to bind listen socket to interface %s: %m"), cfg->data.ptr);
481 memset(&a, 0, sizeof(a));
482 a.sin_family = AF_INET;
483 a.sin_port = htons(port);
485 if((cfg = get_config_val(config, config_interfaceip)))
486 a.sin_addr.s_addr = htonl(cfg->data.ip->address);
488 a.sin_addr.s_addr = htonl(INADDR_ANY);
490 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
493 syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
500 syslog(LOG_ERR, _("System call `%s' failed: %m"),
509 setup the socket for incoming encrypted
512 int setup_vpn_in_socket(int port)
515 struct sockaddr_in a;
518 if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
521 syslog(LOG_ERR, _("Creating socket failed: %m"));
525 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
527 flags = fcntl(nfd, F_GETFL);
528 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
531 syslog(LOG_ERR, _("System call `%s' failed: %m"),
536 memset(&a, 0, sizeof(a));
537 a.sin_family = AF_INET;
538 a.sin_port = htons(port);
539 a.sin_addr.s_addr = htonl(INADDR_ANY);
541 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
544 syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
552 setup an outgoing meta (tcp) socket
554 int setup_outgoing_meta_socket(connection_t *cl)
557 struct sockaddr_in a;
561 if(debug_lvl >= DEBUG_CONNECTIONS)
562 syslog(LOG_INFO, _("Trying to connect to %s"), cl->hostname);
564 if((cfg = get_config_val(cl->config, config_port)) == NULL)
567 cl->port = cfg->data.val;
569 cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
570 if(cl->meta_socket == -1)
572 syslog(LOG_ERR, _("Creating socket for %s port %d failed: %m"),
573 cl->hostname, cl->port);
577 /* Bind first to get a fix on our source port */
579 a.sin_family = AF_INET;
580 a.sin_port = htons(0);
581 a.sin_addr.s_addr = htonl(INADDR_ANY);
583 if(bind(cl->meta_socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
585 close(cl->meta_socket);
586 syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
590 /* Optimize TCP settings */
593 setsockopt(cl->meta_socket, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
595 setsockopt(cl->meta_socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
597 option = IPTOS_LOWDELAY;
598 setsockopt(cl->meta_socket, SOL_IP, IP_TOS, &option, sizeof(option));
602 a.sin_family = AF_INET;
603 a.sin_port = htons(cl->port);
604 a.sin_addr.s_addr = htonl(cl->address);
606 if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
608 close(cl->meta_socket);
609 syslog(LOG_ERR, _("%s port %hd: %m"), cl->hostname, cl->port);
613 flags = fcntl(cl->meta_socket, F_GETFL);
614 if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
616 close(cl->meta_socket);
617 syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
618 cl->hostname, cl->port);
622 if(debug_lvl >= DEBUG_CONNECTIONS)
623 syslog(LOG_INFO, _("Connected to %s port %hd"),
624 cl->hostname, cl->port);
632 Setup an outgoing meta connection.
634 int setup_outgoing_connection(char *name)
636 connection_t *ncn, *old;
642 syslog(LOG_ERR, _("Invalid name for outgoing connection"));
646 /* Make sure we don't make an outgoing connection to a host that is already in our connection list */
648 if((old = lookup_id(name)))
650 if(debug_lvl >= DEBUG_CONNECTIONS)
651 syslog(LOG_NOTICE, _("We are already connected to %s."), name);
652 old->status.outgoing = 1;
656 ncn = new_connection();
657 asprintf(&ncn->name, "%s", name);
659 if(read_host_config(ncn))
661 syslog(LOG_ERR, _("Error reading host configuration file for %s"), ncn->name);
662 free_connection(ncn);
666 if(!(cfg = get_config_val(ncn->config, config_address)))
668 syslog(LOG_ERR, _("No address specified for %s"), ncn->name);
669 free_connection(ncn);
673 if(!(h = gethostbyname(cfg->data.ptr)))
675 syslog(LOG_ERR, _("Error looking up `%s': %m"), cfg->data.ptr);
676 free_connection(ncn);
680 ncn->address = ntohl(*((ipv4_t*)(h->h_addr_list[0])));
681 ncn->hostname = hostlookup(htonl(ncn->address));
683 if(setup_outgoing_meta_socket(ncn) < 0)
685 syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
687 free_connection(ncn);
691 ncn->status.outgoing = 1;
692 ncn->buffer = xmalloc(MAXBUFSIZE);
694 ncn->last_ping_time = time(NULL);
703 int read_rsa_public_key(connection_t *cl)
711 cl->rsa_key = RSA_new();
713 /* First, check for simple PublicKey statement */
715 if((cfg = get_config_val(cl->config, config_publickey)))
717 BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
718 BN_hex2bn(&cl->rsa_key->e, "FFFF");
722 /* Else, check for PublicKeyFile statement and read it */
724 if((cfg = get_config_val(cl->config, config_publickeyfile)))
726 if(is_safe_path(cfg->data.ptr))
728 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
730 syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
734 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
738 syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
748 /* Else, check if a harnessed public key is in the config file */
750 asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
751 if((fp = fopen(fname, "r")))
753 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
762 /* Nothing worked. */
764 syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
769 int read_rsa_private_key(void)
776 myself->rsa_key = RSA_new();
778 if((cfg = get_config_val(config, config_privatekey)))
780 BN_hex2bn(&myself->rsa_key->d, cfg->data.ptr);
781 BN_hex2bn(&myself->rsa_key->e, "FFFF");
783 else if((cfg = get_config_val(config, config_privatekeyfile)))
785 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
787 syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
791 result = PEM_read_RSAPrivateKey(fp, &myself->rsa_key, NULL, NULL);
795 syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
802 syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
810 Configure connection_t myself and set up the local sockets (listen only)
812 int setup_myself(void)
818 myself = new_connection();
820 asprintf(&myself->hostname, _("MYSELF"));
822 myself->protocol_version = PROT_CURRENT;
824 if(!(cfg = get_config_val(config, config_name))) /* Not acceptable */
826 syslog(LOG_ERR, _("Name for tinc daemon required!"));
830 asprintf(&myself->name, "%s", (char*)cfg->data.val);
832 if(check_id(myself->name))
834 syslog(LOG_ERR, _("Invalid name for myself!"));
838 if(read_rsa_private_key())
841 if(read_host_config(myself))
843 syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
847 if(read_rsa_public_key(myself))
852 if(RSA_check_key(myself->rsa_key) != 1)
854 syslog(LOG_ERR, _("Invalid public/private keypair!"));
858 if(!(cfg = get_config_val(myself->config, config_port)))
861 myself->port = cfg->data.val;
863 /* Read in all the subnets specified in the host configuration file */
865 for(next = myself->config; (cfg = get_config_val(next, config_subnet)); next = cfg->next)
868 net->type = SUBNET_IPV4;
869 net->net.ipv4.address = cfg->data.ip->address;
870 net->net.ipv4.mask = cfg->data.ip->mask;
872 /* Teach newbies what subnets are... */
874 if((net->net.ipv4.address & net->net.ipv4.mask) != net->net.ipv4.address)
876 syslog(LOG_ERR, _("Network address and subnet mask do not match!"));
880 subnet_add(myself, net);
884 /* Check some options */
886 if((cfg = get_config_val(config, config_indirectdata)))
887 if(cfg->data.val == stupid_true)
888 myself->options |= OPTION_INDIRECT;
890 if((cfg = get_config_val(config, config_tcponly)))
891 if(cfg->data.val == stupid_true)
892 myself->options |= OPTION_TCPONLY;
894 if((cfg = get_config_val(myself->config, config_indirectdata)))
895 if(cfg->data.val == stupid_true)
896 myself->options |= OPTION_INDIRECT;
898 if((cfg = get_config_val(myself->config, config_tcponly)))
899 if(cfg->data.val == stupid_true)
900 myself->options |= OPTION_TCPONLY;
902 if(myself->options & OPTION_TCPONLY)
903 myself->options |= OPTION_INDIRECT;
905 if((cfg = get_config_val(config, config_mode)))
907 if(!strcasecmp(cfg->data.ptr, "router"))
908 routing_mode = RMODE_ROUTER;
909 else if (!strcasecmp(cfg->data.ptr, "switch"))
910 routing_mode = RMODE_SWITCH;
911 else if (!strcasecmp(cfg->data.ptr, "hub"))
912 routing_mode = RMODE_HUB;
915 syslog(LOG_ERR, _("Invalid routing mode!"));
920 routing_mode = RMODE_ROUTER;
925 if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
927 syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
931 if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
933 syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
937 /* Generate packet encryption key */
939 myself->cipher_pkttype = EVP_bf_cbc();
941 myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
943 myself->cipher_pktkey = (char *)xmalloc(myself->cipher_pktkeylength);
944 RAND_pseudo_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
946 if(!(cfg = get_config_val(config, config_keyexpire)))
949 keylifetime = cfg->data.val;
951 keyexpires = time(NULL) + keylifetime;
955 myself->status.active = 1;
958 syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
964 sigalrm_handler(int a)
968 cfg = get_config_val(upstreamcfg, config_connectto);
972 if(upstreamcfg == config)
974 /* No upstream IP given, we're listen only. */
975 signal(SIGALRM, SIG_IGN);
981 /* We previously tried all the ConnectTo lines. Now wrap back to the first. */
982 cfg = get_config_val(config, config_connectto);
987 upstreamcfg = cfg->next;
988 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
990 signal(SIGALRM, SIG_IGN);
993 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
996 signal(SIGALRM, sigalrm_handler);
997 upstreamcfg = config;
998 seconds_till_retry += 5;
999 if(seconds_till_retry > MAXTIMEOUT) /* Don't wait more than MAXTIMEOUT seconds. */
1000 seconds_till_retry = MAXTIMEOUT;
1001 syslog(LOG_ERR, _("Still failed to connect to other, will retry in %d seconds"),
1002 seconds_till_retry);
1003 alarm(seconds_till_retry);
1008 setup all initial network connections
1010 int setup_network_connections(void)
1012 config_t const *cfg;
1017 if((cfg = get_config_val(config, config_pingtimeout)) == NULL)
1021 timeout = cfg->data.val;
1028 if(setup_tap_fd() < 0)
1031 /* Run tinc-up script to further initialize the tap interface */
1032 execute_script("tinc-up");
1034 if(setup_myself() < 0)
1037 if(!(cfg = get_config_val(config, config_connectto)))
1038 /* No upstream IP given, we're listen only. */
1043 upstreamcfg = cfg->next;
1044 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
1046 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
1051 signal(SIGALRM, sigalrm_handler);
1052 upstreamcfg = config;
1053 seconds_till_retry = MAXTIMEOUT;
1054 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
1055 alarm(seconds_till_retry);
1065 close all open network connections
1067 void close_network_connections(void)
1069 avl_node_t *node, *next;
1072 for(node = connection_tree->head; node; node = next)
1075 p = (connection_t *)node->data;
1076 p->status.outgoing = 0;
1077 terminate_connection(p, 0);
1080 terminate_connection(myself, 0);
1084 execute_script("tinc-down");
1092 handle an incoming tcp connect call and open
1095 connection_t *create_new_connection(int sfd)
1098 struct sockaddr_in ci;
1099 int len = sizeof(ci);
1101 p = new_connection();
1103 if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
1105 syslog(LOG_ERR, _("System call `%s' failed: %m"),
1111 asprintf(&p->name, _("UNKNOWN"));
1112 p->address = ntohl(ci.sin_addr.s_addr);
1113 p->hostname = hostlookup(ci.sin_addr.s_addr);
1114 p->port = htons(ci.sin_port); /* This one will be overwritten later */
1115 p->meta_socket = sfd;
1117 p->buffer = xmalloc(MAXBUFSIZE);
1119 p->last_ping_time = time(NULL);
1121 if(debug_lvl >= DEBUG_CONNECTIONS)
1122 syslog(LOG_NOTICE, _("Connection from %s port %d"),
1123 p->hostname, htons(ci.sin_port));
1125 p->allow_request = ID;
1131 put all file descriptors in an fd_set array
1133 void build_fdset(fd_set *fs)
1140 FD_SET(myself->socket, fs);
1142 for(node = connection_tree->head; node; node = node->next)
1144 p = (connection_t *)node->data;
1145 FD_SET(p->meta_socket, fs);
1148 FD_SET(myself->meta_socket, fs);
1154 receive incoming data from the listening
1155 udp socket and write it to the ethertap
1156 device after being decrypted
1158 void handle_incoming_vpn_data(void)
1161 int x, l = sizeof(x);
1162 struct sockaddr_in from;
1163 socklen_t fromlen = sizeof(from);
1166 if(getsockopt(myself->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
1168 syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
1169 __FILE__, __LINE__, myself->socket);
1174 syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
1178 if((pkt.len = recvfrom(myself->socket, (char *) pkt.salt, MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
1180 syslog(LOG_ERR, _("Receiving packet failed: %m"));
1184 cl = lookup_active(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
1188 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));
1192 cl->last_ping_time = time(NULL);
1194 receive_udppacket(cl, &pkt);
1199 Terminate a connection:
1201 - Remove associated hosts and subnets
1202 - Deactivate the host
1203 - Since it might still be referenced, put it on the prune list.
1204 - If report == 1, then send DEL_HOST messages to the other tinc daemons.
1206 void terminate_connection(connection_t *cl, int report)
1210 avl_node_t *node, *next;
1212 if(cl->status.remove)
1215 cl->status.remove = 1;
1220 close(cl->meta_socket);
1226 if(debug_lvl >= DEBUG_CONNECTIONS)
1227 syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
1228 cl->name, cl->hostname);
1230 if(cl->status.active)
1232 /* Find all connections that were lost because they were behind cl
1233 (the connection that was dropped). */
1235 for(node = active_tree->head; node; node = next)
1238 p = (connection_t *)node->data;
1239 if(p->nexthop == cl)
1240 terminate_connection(p, report);
1245 /* Inform others of termination if needed */
1248 for(node = connection_tree->head; node; node = node->next)
1250 p = (connection_t *)node->data;
1251 if(p->status.active)
1252 send_del_host(p, cl); /* Sounds like recursion, but p does not have a meta connection :) */
1255 /* Remove the associated subnets */
1257 for(node = cl->subnet_tree->head; node; node = next)
1260 subnet = (subnet_t *)node->data;
1264 /* Check if this was our outgoing connection */
1266 if(cl->status.outgoing)
1268 cl->status.outgoing = 0;
1269 signal(SIGALRM, sigalrm_handler);
1270 alarm(seconds_till_retry);
1271 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
1274 /* Schedule it for pruning */
1280 Check if the other end is active.
1281 If we have sent packets, but didn't receive any,
1282 then possibly the other end is dead. We send a
1283 PING request over the meta connection. If the other
1284 end does not reply in time, we consider them dead
1285 and close the connection.
1287 void check_dead_connections(void)
1295 for(node = connection_tree->head; node; node = node->next)
1297 cl = (connection_t *)node->data;
1298 if(cl->status.active)
1300 if(cl->last_ping_time + timeout < now)
1302 if(cl->status.pinged)
1304 if(debug_lvl >= DEBUG_PROTOCOL)
1305 syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
1306 cl->name, cl->hostname);
1307 cl->status.timeout = 1;
1308 terminate_connection(cl, 1);
1321 accept a new tcp connect and create a
1324 int handle_new_meta_connection()
1327 struct sockaddr client;
1328 int nfd, len = sizeof(client);
1330 if((nfd = accept(myself->meta_socket, &client, &len)) < 0)
1332 syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
1336 if(!(ncn = create_new_connection(nfd)))
1340 syslog(LOG_NOTICE, _("Closed attempted connection"));
1344 connection_add(ncn);
1352 check all connections to see if anything
1353 happened on their sockets
1355 void check_network_activity(fd_set *f)
1360 if(FD_ISSET(myself->socket, f))
1361 handle_incoming_vpn_data();
1363 for(node = connection_tree->head; node; node = node->next)
1365 p = (connection_t *)node->data;
1367 if(p->status.remove)
1370 if(FD_ISSET(p->meta_socket, f))
1371 if(receive_meta(p) < 0)
1373 terminate_connection(p, 1);
1378 if(FD_ISSET(myself->meta_socket, f))
1379 handle_new_meta_connection();
1384 read, encrypt and send data that is
1385 available through the ethertap device
1387 void handle_tap_input(void)
1393 if((lenin = read(tap_fd, vp.data + 14, MTU)) <= 0)
1395 syslog(LOG_ERR, _("Error while reading from tun device: %m"));
1398 memcpy(vp.data, mymac.net.mac.address.x, 6);
1399 memcpy(vp.data + 6, mymac.net.mac.address.x, 6);
1402 vp.len = lenin + 14;
1404 if(taptype == TAP_TYPE_TUNTAP)
1406 if((lenin = read(tap_fd, vp.data, MTU)) <= 0)
1408 syslog(LOG_ERR, _("Error while reading from tun/tap device: %m"));
1415 if((lenin = read(tap_fd, vp.data - 2, MTU)) <= 0)
1417 syslog(LOG_ERR, _("Error while reading from ethertap device: %m"));
1424 total_tap_in += vp.len;
1428 if(debug_lvl >= DEBUG_TRAFFIC)
1429 syslog(LOG_WARNING, _("Received short packet from tap device"));
1433 if(debug_lvl >= DEBUG_TRAFFIC)
1435 syslog(LOG_DEBUG, _("Read packet of length %d from tap device"), vp.len);
1438 route_outgoing(&vp);
1443 this is where it all happens...
1445 void main_loop(void)
1450 time_t last_ping_check;
1453 last_ping_check = time(NULL);
1457 tv.tv_sec = timeout;
1463 if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
1465 if(errno != EINTR) /* because of alarm */
1467 syslog(LOG_ERR, _("Error while waiting for input: %m"));
1474 syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
1476 close_network_connections();
1477 clear_config(&config);
1479 if(read_server_config())
1481 syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
1487 if(setup_network_connections())
1495 /* Let's check if everybody is still alive */
1497 if(last_ping_check + timeout < t)
1499 check_dead_connections();
1500 last_ping_check = time(NULL);
1502 /* Should we regenerate our key? */
1506 if(debug_lvl >= DEBUG_STATUS)
1507 syslog(LOG_INFO, _("Regenerating symmetric key"));
1509 RAND_pseudo_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
1510 send_key_changed(myself, NULL);
1511 keyexpires = time(NULL) + keylifetime;
1517 check_network_activity(&fset);
1519 /* local tap data */
1520 if(FD_ISSET(tap_fd, &fset))