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 1.35.4.129 2001/09/01 12:36:06 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 int seconds_till_retry = 5;
104 void send_udppacket(connection_t *cl, vpn_packet_t *inpkt)
109 struct sockaddr_in to;
110 socklen_t tolen = sizeof(to);
113 if(!cl->status.validkey)
115 if(debug_lvl >= DEBUG_TRAFFIC)
116 syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
117 cl->name, cl->hostname);
119 /* Since packet is on the stack of handle_tap_input(),
120 we have to make a copy of it first. */
122 copy = xmalloc(sizeof(vpn_packet_t));
123 memcpy(copy, inpkt, sizeof(vpn_packet_t));
125 list_insert_tail(cl->queue, copy);
127 if(!cl->status.waitingforkey)
128 send_req_key(myself, cl);
132 /* Encrypt the packet. */
134 RAND_pseudo_bytes(inpkt->salt, sizeof(inpkt->salt));
136 EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
137 EVP_EncryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len + sizeof(inpkt->salt));
138 EVP_EncryptFinal(&ctx, outpkt.salt + outlen, &outpad);
141 total_socket_out += outlen;
143 to.sin_family = AF_INET;
144 to.sin_addr.s_addr = htonl(cl->address);
145 to.sin_port = htons(cl->port);
147 if((sendto(myself->socket, (char *) outpkt.salt, outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
149 syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
150 cl->name, cl->hostname);
156 void receive_packet(connection_t *cl, vpn_packet_t *packet)
159 if(debug_lvl >= DEBUG_TRAFFIC)
160 syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, cl->name, cl->hostname);
162 route_incoming(cl, packet);
166 void receive_udppacket(connection_t *cl, vpn_packet_t *inpkt)
172 /* Decrypt the packet */
174 EVP_DecryptInit(&ctx, myself->cipher_pkttype, myself->cipher_pktkey, myself->cipher_pktkey + myself->cipher_pkttype->key_len);
175 EVP_DecryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len);
176 EVP_DecryptFinal(&ctx, outpkt.salt + outlen, &outpad);
178 outpkt.len = outlen - sizeof(outpkt.salt);
180 total_socket_in += outlen;
182 receive_packet(cl, &outpkt);
186 void receive_tcppacket(connection_t *cl, char *buffer, int len)
191 memcpy(outpkt.data, buffer, len);
193 receive_packet(cl, &outpkt);
197 void accept_packet(vpn_packet_t *packet)
200 if(debug_lvl >= DEBUG_TRAFFIC)
201 syslog(LOG_DEBUG, _("Writing packet of %d bytes to tap device"),
205 if(write(tap_fd, packet->data + 14, packet->len - 14) < 0)
206 syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
208 total_tap_out += packet->len;
210 if(taptype == TAP_TYPE_TUNTAP)
212 if(write(tap_fd, packet->data, packet->len) < 0)
213 syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
215 total_tap_out += packet->len;
219 if(write(tap_fd, packet->data - 2, packet->len + 2) < 0)
220 syslog(LOG_ERR, _("Can't write to ethertap device: %m"));
222 total_tap_out += packet->len;
229 send a packet to the given vpn ip.
231 void send_packet(connection_t *cl, vpn_packet_t *packet)
234 if(debug_lvl >= DEBUG_TRAFFIC)
235 syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
236 packet->len, cl->name, cl->hostname);
240 if(debug_lvl >= DEBUG_TRAFFIC)
242 syslog(LOG_NOTICE, _("Packet is looping back to us!"));
248 if(!cl->status.active)
250 if(debug_lvl >= DEBUG_TRAFFIC)
251 syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
252 cl->name, cl->hostname);
257 /* Check if it has to go via TCP or UDP... */
259 if((cl->options | myself->options) & OPTION_TCPONLY)
261 if(send_tcppacket(cl, packet))
262 terminate_connection(cl, 1);
265 send_udppacket(cl, packet);
268 /* Broadcast a packet to all active direct connections */
270 void broadcast_packet(connection_t *from, vpn_packet_t *packet)
275 if(debug_lvl >= DEBUG_TRAFFIC)
276 syslog(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
277 packet->len, from->name, from->hostname);
279 for(node = connection_tree->head; node; node = node->next)
281 cl = (connection_t *)node->data;
282 if(cl->status.active && cl != from)
283 send_packet(cl, packet);
288 void flush_queue(connection_t *cl)
290 list_node_t *node, *next;
292 if(debug_lvl >= DEBUG_TRAFFIC)
293 syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
295 for(node = cl->queue->head; node; node = next)
298 send_udppacket(cl, (vpn_packet_t *)node->data);
299 list_delete_node(cl->queue, node);
305 open the local ethertap device
307 int setup_tap_fd(void)
310 const char *tapfname;
318 int ip_fd = -1, if_fd = -1;
324 if((cfg = get_config_val(config, config_tapdevice)))
325 tapfname = cfg->data.ptr;
330 tapfname = "/dev/net/tun";
332 tapfname = "/dev/tap0";
336 tapfname = "/dev/tap0";
339 tapfname = "/dev/tun";
343 if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
345 syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
351 /* Set default MAC address for ethertap devices */
353 mymac.type = SUBNET_MAC;
354 mymac.net.mac.address.x[0] = 0xfe;
355 mymac.net.mac.address.x[1] = 0xfd;
356 mymac.net.mac.address.x[2] = 0x00;
357 mymac.net.mac.address.x[3] = 0x00;
358 mymac.net.mac.address.x[4] = 0x00;
359 mymac.net.mac.address.x[5] = 0x00;
363 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
364 memset(&ifr, 0, sizeof(ifr));
366 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
368 strncpy(ifr.ifr_name, netname, IFNAMSIZ);
370 if (!ioctl(tap_fd, TUNSETIFF, (void *) &ifr))
372 syslog(LOG_INFO, _("%s is a tun/tap device"), tapfname);
373 taptype = TAP_TYPE_TUNTAP;
378 syslog(LOG_INFO, _("%s is an ethertap device"), tapfname);
379 taptype = TAP_TYPE_ETHERTAP;
383 syslog(LOG_INFO, _("%s is a tun/tap device"), tapfname);
384 taptype = TAP_TYPE_TUNTAP;
390 while(*ptr && !isdigit((int)*ptr)) ptr++;
393 if( (ip_fd = open("/dev/ip", O_RDWR, 0)) < 0){
394 syslog(LOG_ERR, _("Could not open /dev/ip: %m"));
398 /* Assign a new PPA and get its unit number. */
399 if( (ppa = ioctl(nfd, TUNNEWPPA, ppa)) < 0){
400 syslog(LOG_ERR, _("Can't assign new interface: %m"));
404 if( (if_fd = open(tapfname, O_RDWR, 0)) < 0){
405 syslog(LOG_ERR, _("Could not open %s twice: %m"), tapfname);
409 if(ioctl(if_fd, I_PUSH, "ip") < 0){
410 syslog(LOG_ERR, _("Can't push IP module: %m"));
414 /* Assign ppa according to the unit number returned by tun device */
415 if(ioctl(if_fd, IF_UNITSEL, (char *)&ppa) < 0){
416 syslog(LOG_ERR, _("Can't set PPA %d: %m"), ppa);
420 if(ioctl(ip_fd, I_LINK, if_fd) < 0){
421 syslog(LOG_ERR, _("Can't link TUN device to IP: %m"));
425 syslog(LOG_INFO, _("%s is a tun/tap device"), tapfname);
433 set up the socket that we listen on for incoming
436 int setup_listen_meta_socket(int port)
439 struct sockaddr_in a;
443 if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
445 syslog(LOG_ERR, _("Creating metasocket failed: %m"));
449 flags = fcntl(nfd, F_GETFL);
450 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
453 syslog(LOG_ERR, _("System call `%s' failed: %m"),
458 /* Optimize TCP settings */
461 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
462 setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
464 setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
466 option = IPTOS_LOWDELAY;
467 setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
469 if((cfg = get_config_val(config, config_interface)))
471 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, cfg->data.ptr, strlen(cfg->data.ptr)))
474 syslog(LOG_ERR, _("Unable to bind listen socket to interface %s: %m"), cfg->data.ptr);
480 memset(&a, 0, sizeof(a));
481 a.sin_family = AF_INET;
482 a.sin_port = htons(port);
484 if((cfg = get_config_val(config, config_interfaceip)))
485 a.sin_addr.s_addr = htonl(cfg->data.ip->address);
487 a.sin_addr.s_addr = htonl(INADDR_ANY);
489 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
492 syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
499 syslog(LOG_ERR, _("System call `%s' failed: %m"),
508 setup the socket for incoming encrypted
511 int setup_vpn_in_socket(int port)
514 struct sockaddr_in a;
517 if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
520 syslog(LOG_ERR, _("Creating socket failed: %m"));
524 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
526 flags = fcntl(nfd, F_GETFL);
527 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
530 syslog(LOG_ERR, _("System call `%s' failed: %m"),
535 memset(&a, 0, sizeof(a));
536 a.sin_family = AF_INET;
537 a.sin_port = htons(port);
538 a.sin_addr.s_addr = htonl(INADDR_ANY);
540 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
543 syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
551 setup an outgoing meta (tcp) socket
553 int setup_outgoing_meta_socket(connection_t *cl)
556 struct sockaddr_in a;
560 if(debug_lvl >= DEBUG_CONNECTIONS)
561 syslog(LOG_INFO, _("Trying to connect to %s"), cl->hostname);
563 if((cfg = get_config_val(cl->config, config_port)) == NULL)
566 cl->port = cfg->data.val;
568 cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
569 if(cl->meta_socket == -1)
571 syslog(LOG_ERR, _("Creating socket for %s port %d failed: %m"),
572 cl->hostname, cl->port);
576 /* Bind first to get a fix on our source port */
578 a.sin_family = AF_INET;
579 a.sin_port = htons(0);
580 a.sin_addr.s_addr = htonl(INADDR_ANY);
582 if(bind(cl->meta_socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
584 close(cl->meta_socket);
585 syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
589 /* Optimize TCP settings */
592 setsockopt(cl->meta_socket, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
594 setsockopt(cl->meta_socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
596 option = IPTOS_LOWDELAY;
597 setsockopt(cl->meta_socket, SOL_IP, IP_TOS, &option, sizeof(option));
601 a.sin_family = AF_INET;
602 a.sin_port = htons(cl->port);
603 a.sin_addr.s_addr = htonl(cl->address);
605 if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
607 close(cl->meta_socket);
608 syslog(LOG_ERR, _("%s port %hd: %m"), cl->hostname, cl->port);
612 flags = fcntl(cl->meta_socket, F_GETFL);
613 if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
615 close(cl->meta_socket);
616 syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
617 cl->hostname, cl->port);
621 if(debug_lvl >= DEBUG_CONNECTIONS)
622 syslog(LOG_INFO, _("Connected to %s port %hd"),
623 cl->hostname, cl->port);
631 Setup an outgoing meta connection.
633 int setup_outgoing_connection(char *name)
635 connection_t *ncn, *old;
641 syslog(LOG_ERR, _("Invalid name for outgoing connection"));
645 /* Make sure we don't make an outgoing connection to a host that is already in our connection list */
647 if((old = lookup_id(name)))
649 if(!old->status.outgoing)
651 if(debug_lvl >= DEBUG_CONNECTIONS)
652 syslog(LOG_NOTICE, _("We are already connected to %s."), name);
654 old->status.outgoing = 1;
659 ncn = new_connection();
660 asprintf(&ncn->name, "%s", name);
662 if(read_host_config(ncn))
664 syslog(LOG_ERR, _("Error reading host configuration file for %s"), ncn->name);
665 free_connection(ncn);
669 if(!(cfg = get_config_val(ncn->config, config_address)))
671 syslog(LOG_ERR, _("No address specified for %s"), ncn->name);
672 free_connection(ncn);
676 if(!(h = gethostbyname(cfg->data.ptr)))
678 syslog(LOG_ERR, _("Error looking up `%s': %m"), cfg->data.ptr);
679 free_connection(ncn);
683 ncn->address = ntohl(*((ipv4_t*)(h->h_addr_list[0])));
684 ncn->hostname = hostlookup(htonl(ncn->address));
686 if(setup_outgoing_meta_socket(ncn) < 0)
688 syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
690 free_connection(ncn);
694 ncn->status.outgoing = 1;
695 ncn->buffer = xmalloc(MAXBUFSIZE);
697 ncn->last_ping_time = time(NULL);
706 int read_rsa_public_key(connection_t *cl)
714 cl->rsa_key = RSA_new();
716 /* First, check for simple PublicKey statement */
718 if((cfg = get_config_val(cl->config, config_publickey)))
720 BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
721 BN_hex2bn(&cl->rsa_key->e, "FFFF");
725 /* Else, check for PublicKeyFile statement and read it */
727 if((cfg = get_config_val(cl->config, config_publickeyfile)))
729 if(is_safe_path(cfg->data.ptr))
731 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
733 syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
737 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
741 syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
751 /* Else, check if a harnessed public key is in the config file */
753 asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
754 if((fp = fopen(fname, "r")))
756 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
765 /* Nothing worked. */
767 syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
772 int read_rsa_private_key(void)
779 myself->rsa_key = RSA_new();
781 if((cfg = get_config_val(config, config_privatekey)))
783 BN_hex2bn(&myself->rsa_key->d, cfg->data.ptr);
784 BN_hex2bn(&myself->rsa_key->e, "FFFF");
786 else if((cfg = get_config_val(config, config_privatekeyfile)))
788 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
790 syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
794 result = PEM_read_RSAPrivateKey(fp, &myself->rsa_key, NULL, NULL);
798 syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
805 syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
813 Configure connection_t myself and set up the local sockets (listen only)
815 int setup_myself(void)
821 myself = new_connection();
823 asprintf(&myself->hostname, _("MYSELF"));
825 myself->protocol_version = PROT_CURRENT;
827 if(!(cfg = get_config_val(config, config_name))) /* Not acceptable */
829 syslog(LOG_ERR, _("Name for tinc daemon required!"));
833 asprintf(&myself->name, "%s", (char*)cfg->data.val);
835 if(check_id(myself->name))
837 syslog(LOG_ERR, _("Invalid name for myself!"));
841 if(read_rsa_private_key())
844 if(read_host_config(myself))
846 syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
850 if(read_rsa_public_key(myself))
855 if(RSA_check_key(myself->rsa_key) != 1)
857 syslog(LOG_ERR, _("Invalid public/private keypair!"));
861 if(!(cfg = get_config_val(myself->config, config_port)))
864 myself->port = cfg->data.val;
866 /* Read in all the subnets specified in the host configuration file */
868 for(next = myself->config; (cfg = get_config_val(next, config_subnet)); next = cfg->next)
871 net->type = SUBNET_IPV4;
872 net->net.ipv4.address = cfg->data.ip->address;
873 net->net.ipv4.mask = cfg->data.ip->mask;
875 /* Teach newbies what subnets are... */
877 if((net->net.ipv4.address & net->net.ipv4.mask) != net->net.ipv4.address)
879 syslog(LOG_ERR, _("Network address and subnet mask do not match!"));
883 subnet_add(myself, net);
887 /* Check some options */
889 if((cfg = get_config_val(config, config_indirectdata)))
890 if(cfg->data.val == stupid_true)
891 myself->options |= OPTION_INDIRECT;
893 if((cfg = get_config_val(config, config_tcponly)))
894 if(cfg->data.val == stupid_true)
895 myself->options |= OPTION_TCPONLY;
897 if((cfg = get_config_val(myself->config, config_indirectdata)))
898 if(cfg->data.val == stupid_true)
899 myself->options |= OPTION_INDIRECT;
901 if((cfg = get_config_val(myself->config, config_tcponly)))
902 if(cfg->data.val == stupid_true)
903 myself->options |= OPTION_TCPONLY;
905 if(myself->options & OPTION_TCPONLY)
906 myself->options |= OPTION_INDIRECT;
908 if((cfg = get_config_val(config, config_mode)))
910 if(!strcasecmp(cfg->data.ptr, "router"))
911 routing_mode = RMODE_ROUTER;
912 else if (!strcasecmp(cfg->data.ptr, "switch"))
913 routing_mode = RMODE_SWITCH;
914 else if (!strcasecmp(cfg->data.ptr, "hub"))
915 routing_mode = RMODE_HUB;
918 syslog(LOG_ERR, _("Invalid routing mode!"));
923 routing_mode = RMODE_ROUTER;
928 if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
930 syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
934 if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
936 syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
940 /* Generate packet encryption key */
942 myself->cipher_pkttype = EVP_bf_cbc();
944 myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
946 myself->cipher_pktkey = (char *)xmalloc(myself->cipher_pktkeylength);
947 RAND_pseudo_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
949 if(!(cfg = get_config_val(config, config_keyexpire)))
952 keylifetime = cfg->data.val;
954 keyexpires = time(NULL) + keylifetime;
958 myself->status.active = 1;
961 syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
966 void randomized_alarm(int seconds)
969 RAND_pseudo_bytes(&r, 1);
970 alarm((seconds * (int)r) / 128 + 1);
974 try_outgoing_connections(int a)
979 cfg = get_config_val(config, config_connectto);
983 if(setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
985 cfg = get_config_val(cfg, config_connectto); /* Or else we try the next ConnectTo line */
990 seconds_till_retry += 5;
991 if(seconds_till_retry > MAXTIMEOUT) /* Don't wait more than MAXTIMEOUT seconds. */
992 seconds_till_retry = MAXTIMEOUT;
994 syslog(LOG_ERR, _("Failed to setup all outgoing connections, will retry in %d seconds"),
997 /* Randomize timeout to avoid global synchronisation effects */
998 randomized_alarm(seconds_till_retry);
1002 seconds_till_retry = 5;
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 signal(SIGALRM, try_outgoing_connections);
1044 close all open network connections
1046 void close_network_connections(void)
1048 avl_node_t *node, *next;
1051 for(node = connection_tree->head; node; node = next)
1054 p = (connection_t *)node->data;
1055 p->status.outgoing = 0;
1056 terminate_connection(p, 0);
1059 terminate_connection(myself, 0);
1063 execute_script("tinc-down");
1071 handle an incoming tcp connect call and open
1074 connection_t *create_new_connection(int sfd)
1077 struct sockaddr_in ci;
1078 int len = sizeof(ci);
1080 p = new_connection();
1082 if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
1084 syslog(LOG_ERR, _("System call `%s' failed: %m"),
1090 asprintf(&p->name, _("UNKNOWN"));
1091 p->address = ntohl(ci.sin_addr.s_addr);
1092 p->hostname = hostlookup(ci.sin_addr.s_addr);
1093 p->port = htons(ci.sin_port); /* This one will be overwritten later */
1094 p->meta_socket = sfd;
1096 p->buffer = xmalloc(MAXBUFSIZE);
1098 p->last_ping_time = time(NULL);
1100 if(debug_lvl >= DEBUG_CONNECTIONS)
1101 syslog(LOG_NOTICE, _("Connection from %s port %d"),
1102 p->hostname, htons(ci.sin_port));
1104 p->allow_request = ID;
1110 put all file descriptors in an fd_set array
1112 void build_fdset(fd_set *fs)
1119 FD_SET(myself->socket, fs);
1121 for(node = connection_tree->head; node; node = node->next)
1123 p = (connection_t *)node->data;
1124 FD_SET(p->meta_socket, fs);
1127 FD_SET(myself->meta_socket, fs);
1133 receive incoming data from the listening
1134 udp socket and write it to the ethertap
1135 device after being decrypted
1137 void handle_incoming_vpn_data(void)
1140 int x, l = sizeof(x);
1141 struct sockaddr_in from;
1142 socklen_t fromlen = sizeof(from);
1145 if(getsockopt(myself->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
1147 syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
1148 __FILE__, __LINE__, myself->socket);
1153 syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
1157 if((pkt.len = recvfrom(myself->socket, (char *) pkt.salt, MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
1159 syslog(LOG_ERR, _("Receiving packet failed: %m"));
1163 cl = lookup_active(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
1167 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));
1171 cl->last_ping_time = time(NULL);
1173 receive_udppacket(cl, &pkt);
1178 Terminate a connection:
1180 - Remove associated hosts and subnets
1181 - Deactivate the host
1182 - Since it might still be referenced, put it on the prune list.
1183 - If report == 1, then send DEL_HOST messages to the other tinc daemons.
1185 void terminate_connection(connection_t *cl, int report)
1189 avl_node_t *node, *next;
1191 if(cl->status.remove)
1194 cl->status.remove = 1;
1199 close(cl->meta_socket);
1205 if(debug_lvl >= DEBUG_CONNECTIONS)
1206 syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
1207 cl->name, cl->hostname);
1209 if(cl->status.active)
1211 /* Find all connections that were lost because they were behind cl
1212 (the connection that was dropped). */
1214 for(node = active_tree->head; node; node = next)
1217 p = (connection_t *)node->data;
1218 if(p->nexthop == cl)
1219 terminate_connection(p, report);
1224 /* Inform others of termination if needed */
1227 for(node = connection_tree->head; node; node = node->next)
1229 p = (connection_t *)node->data;
1230 if(p->status.active)
1231 send_del_host(p, cl); /* Sounds like recursion, but p does not have a meta connection :) */
1234 /* Remove the associated subnets */
1236 for(node = cl->subnet_tree->head; node; node = next)
1239 subnet = (subnet_t *)node->data;
1243 /* Check if this was our outgoing connection */
1245 if(cl->status.outgoing)
1247 cl->status.outgoing = 0;
1248 signal(SIGALRM, try_outgoing_connections);
1249 alarm(seconds_till_retry);
1250 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
1253 /* Schedule it for pruning */
1259 Check if the other end is active.
1260 If we have sent packets, but didn't receive any,
1261 then possibly the other end is dead. We send a
1262 PING request over the meta connection. If the other
1263 end does not reply in time, we consider them dead
1264 and close the connection.
1266 void check_dead_connections(void)
1274 for(node = connection_tree->head; node; node = node->next)
1276 cl = (connection_t *)node->data;
1277 if(cl->status.active)
1279 if(cl->last_ping_time + timeout < now)
1281 if(cl->status.pinged)
1283 if(debug_lvl >= DEBUG_PROTOCOL)
1284 syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
1285 cl->name, cl->hostname);
1286 cl->status.timeout = 1;
1287 terminate_connection(cl, 1);
1300 accept a new tcp connect and create a
1303 int handle_new_meta_connection()
1306 struct sockaddr client;
1307 int nfd, len = sizeof(client);
1309 if((nfd = accept(myself->meta_socket, &client, &len)) < 0)
1311 syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
1315 if(!(ncn = create_new_connection(nfd)))
1319 syslog(LOG_NOTICE, _("Closed attempted connection"));
1323 connection_add(ncn);
1331 check all connections to see if anything
1332 happened on their sockets
1334 void check_network_activity(fd_set *f)
1339 if(FD_ISSET(myself->socket, f))
1340 handle_incoming_vpn_data();
1342 for(node = connection_tree->head; node; node = node->next)
1344 p = (connection_t *)node->data;
1346 if(p->status.remove)
1349 if(FD_ISSET(p->meta_socket, f))
1350 if(receive_meta(p) < 0)
1352 terminate_connection(p, p->status.meta);
1357 if(FD_ISSET(myself->meta_socket, f))
1358 handle_new_meta_connection();
1363 read, encrypt and send data that is
1364 available through the ethertap device
1366 void handle_tap_input(void)
1372 if((lenin = read(tap_fd, vp.data + 14, MTU)) <= 0)
1374 syslog(LOG_ERR, _("Error while reading from tun device: %m"));
1377 memcpy(vp.data, mymac.net.mac.address.x, 6);
1378 memcpy(vp.data + 6, mymac.net.mac.address.x, 6);
1381 vp.len = lenin + 14;
1383 if(taptype == TAP_TYPE_TUNTAP)
1385 if((lenin = read(tap_fd, vp.data, MTU)) <= 0)
1387 syslog(LOG_ERR, _("Error while reading from tun/tap device: %m"));
1394 if((lenin = read(tap_fd, vp.data - 2, MTU)) <= 0)
1396 syslog(LOG_ERR, _("Error while reading from ethertap device: %m"));
1403 total_tap_in += vp.len;
1407 if(debug_lvl >= DEBUG_TRAFFIC)
1408 syslog(LOG_WARNING, _("Received short packet from tap device"));
1412 if(debug_lvl >= DEBUG_TRAFFIC)
1414 syslog(LOG_DEBUG, _("Read packet of length %d from tap device"), vp.len);
1417 route_outgoing(&vp);
1422 this is where it all happens...
1424 void main_loop(void)
1429 time_t last_ping_check;
1432 last_ping_check = time(NULL);
1436 tv.tv_sec = timeout;
1442 if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
1444 if(errno != EINTR) /* because of alarm */
1446 syslog(LOG_ERR, _("Error while waiting for input: %m"));
1453 syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
1455 close_network_connections();
1456 clear_config(&config);
1458 if(read_server_config())
1460 syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
1466 if(setup_network_connections())
1474 /* Let's check if everybody is still alive */
1476 if(last_ping_check + timeout < t)
1478 check_dead_connections();
1479 last_ping_check = time(NULL);
1481 /* Should we regenerate our key? */
1485 if(debug_lvl >= DEBUG_STATUS)
1486 syslog(LOG_INFO, _("Regenerating symmetric key"));
1488 RAND_pseudo_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
1489 send_key_changed(myself, NULL);
1490 keyexpires = time(NULL) + keylifetime;
1496 check_network_activity(&fset);
1498 /* local tap data */
1499 if(FD_ISSET(tap_fd, &fset))