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 1.35.4.121 2001/07/19 12:29:40 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>
74 #include "connection.h"
87 int taptype = TAP_TYPE_ETHERTAP;
89 int total_tap_out = 0;
90 int total_socket_in = 0;
91 int total_socket_out = 0;
93 config_t *upstreamcfg;
94 int seconds_till_retry = 5;
99 void send_udppacket(connection_t *cl, vpn_packet_t *inpkt)
104 struct sockaddr_in to;
105 socklen_t tolen = sizeof(to);
108 if(!cl->status.validkey)
110 if(debug_lvl >= DEBUG_TRAFFIC)
111 syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
112 cl->name, cl->hostname);
114 /* Since packet is on the stack of handle_tap_input(),
115 we have to make a copy of it first. */
117 copy = xmalloc(sizeof(vpn_packet_t));
118 memcpy(copy, inpkt, sizeof(vpn_packet_t));
120 list_insert_tail(cl->queue, copy);
122 if(!cl->status.waitingforkey)
123 send_req_key(myself, cl);
127 /* Encrypt the packet. */
129 RAND_pseudo_bytes(inpkt->salt, sizeof(inpkt->salt));
131 EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
132 EVP_EncryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len + sizeof(inpkt->salt));
133 EVP_EncryptFinal(&ctx, outpkt.salt + outlen, &outpad);
136 total_socket_out += outlen;
138 to.sin_family = AF_INET;
139 to.sin_addr.s_addr = htonl(cl->address);
140 to.sin_port = htons(cl->port);
142 if((sendto(myself->socket, (char *) outpkt.salt, outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
144 syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
145 cl->name, cl->hostname);
151 void receive_packet(connection_t *cl, vpn_packet_t *packet)
154 if(debug_lvl >= DEBUG_TRAFFIC)
155 syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, cl->name, cl->hostname);
157 route_incoming(cl, packet);
161 void receive_udppacket(connection_t *cl, vpn_packet_t *inpkt)
167 /* Decrypt the packet */
169 EVP_DecryptInit(&ctx, myself->cipher_pkttype, myself->cipher_pktkey, myself->cipher_pktkey + myself->cipher_pkttype->key_len);
170 EVP_DecryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len);
171 EVP_DecryptFinal(&ctx, outpkt.salt + outlen, &outpad);
173 outpkt.len = outlen - sizeof(outpkt.salt);
175 total_socket_in += outlen;
177 receive_packet(cl, &outpkt);
181 void receive_tcppacket(connection_t *cl, char *buffer, int len)
186 memcpy(outpkt.data, buffer, len);
188 receive_packet(cl, &outpkt);
192 void accept_packet(vpn_packet_t *packet)
195 if(debug_lvl >= DEBUG_TRAFFIC)
196 syslog(LOG_DEBUG, _("Writing packet of %d bytes to tap device"),
199 if(taptype == TAP_TYPE_TUNTAP)
201 if(write(tap_fd, packet->data, packet->len) < 0)
202 syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
204 total_tap_out += packet->len;
208 if(write(tap_fd, packet->data - 2, packet->len + 2) < 0)
209 syslog(LOG_ERR, _("Can't write to ethertap device: %m"));
211 total_tap_out += packet->len;
217 send a packet to the given vpn ip.
219 void send_packet(connection_t *cl, vpn_packet_t *packet)
222 if(debug_lvl >= DEBUG_TRAFFIC)
223 syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
224 packet->len, cl->name, cl->hostname);
228 if(debug_lvl >= DEBUG_TRAFFIC)
230 syslog(LOG_NOTICE, _("Packet is looping back to us!"));
236 if(!cl->status.active)
238 if(debug_lvl >= DEBUG_TRAFFIC)
239 syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
240 cl->name, cl->hostname);
245 /* Check if it has to go via TCP or UDP... */
247 if((cl->options | myself->options) & OPTION_TCPONLY)
249 if(send_tcppacket(cl, packet))
250 terminate_connection(cl);
253 send_udppacket(cl, packet);
256 /* Broadcast a packet to all active connections */
258 void broadcast_packet(connection_t *from, vpn_packet_t *packet)
263 if(debug_lvl >= DEBUG_TRAFFIC)
264 syslog(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
265 packet->len, from->name, from->hostname);
267 for(node = connection_tree->head; node; node = node->next)
269 cl = (connection_t *)node->data;
270 if(cl->status.meta && cl != from)
271 send_packet(cl, packet);
276 void flush_queue(connection_t *cl)
278 list_node_t *node, *next;
280 if(debug_lvl >= DEBUG_TRAFFIC)
281 syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
283 for(node = cl->queue->head; node; node = next)
286 send_udppacket(cl, (vpn_packet_t *)node->data);
287 list_delete_node(cl->queue, node);
293 open the local ethertap device
295 int setup_tap_fd(void)
298 const char *tapfname;
307 if((cfg = get_config_val(config, config_tapdevice)))
308 tapfname = cfg->data.ptr;
313 tapfname = "/dev/net/tun";
315 tapfname = "/dev/tap0";
319 tapfname = "/dev/tap0";
322 tapfname = "/dev/tun";
326 if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
328 syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
334 taptype = TAP_TYPE_ETHERTAP;
336 /* Set default MAC address for ethertap devices */
338 mymac.type = SUBNET_MAC;
339 mymac.net.mac.address.x[0] = 0xfe;
340 mymac.net.mac.address.x[1] = 0xfd;
341 mymac.net.mac.address.x[2] = 0x00;
342 mymac.net.mac.address.x[3] = 0x00;
343 mymac.net.mac.address.x[4] = 0x00;
344 mymac.net.mac.address.x[5] = 0x00;
348 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
349 memset(&ifr, 0, sizeof(ifr));
351 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
353 strncpy(ifr.ifr_name, netname, IFNAMSIZ);
355 if (!ioctl(tap_fd, TUNSETIFF, (void *) &ifr))
357 syslog(LOG_INFO, _("%s is a new style tun/tap device"), tapfname);
358 taptype = TAP_TYPE_TUNTAP;
362 taptype = TAP_TYPE_TUNTAP;
369 set up the socket that we listen on for incoming
372 int setup_listen_meta_socket(int port)
375 struct sockaddr_in a;
379 if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
381 syslog(LOG_ERR, _("Creating metasocket failed: %m"));
385 flags = fcntl(nfd, F_GETFL);
386 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
389 syslog(LOG_ERR, _("System call `%s' failed: %m"),
394 /* Optimize TCP settings */
397 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
398 setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
400 setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
402 option = IPTOS_LOWDELAY;
403 setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
405 if((cfg = get_config_val(config, config_interface)))
407 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, cfg->data.ptr, strlen(cfg->data.ptr)))
410 syslog(LOG_ERR, _("Unable to bind listen socket to interface %s: %m"), cfg->data.ptr);
416 memset(&a, 0, sizeof(a));
417 a.sin_family = AF_INET;
418 a.sin_port = htons(port);
420 if((cfg = get_config_val(config, config_interfaceip)))
421 a.sin_addr.s_addr = htonl(cfg->data.ip->address);
423 a.sin_addr.s_addr = htonl(INADDR_ANY);
425 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
428 syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
435 syslog(LOG_ERR, _("System call `%s' failed: %m"),
444 setup the socket for incoming encrypted
447 int setup_vpn_in_socket(int port)
450 struct sockaddr_in a;
453 if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
456 syslog(LOG_ERR, _("Creating socket failed: %m"));
460 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
462 flags = fcntl(nfd, F_GETFL);
463 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
466 syslog(LOG_ERR, _("System call `%s' failed: %m"),
471 memset(&a, 0, sizeof(a));
472 a.sin_family = AF_INET;
473 a.sin_port = htons(port);
474 a.sin_addr.s_addr = htonl(INADDR_ANY);
476 if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
479 syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
487 setup an outgoing meta (tcp) socket
489 int setup_outgoing_meta_socket(connection_t *cl)
492 struct sockaddr_in a;
496 if(debug_lvl >= DEBUG_CONNECTIONS)
497 syslog(LOG_INFO, _("Trying to connect to %s"), cl->hostname);
499 if((cfg = get_config_val(cl->config, config_port)) == NULL)
502 cl->port = cfg->data.val;
504 cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
505 if(cl->meta_socket == -1)
507 syslog(LOG_ERR, _("Creating socket for %s port %d failed: %m"),
508 cl->hostname, cl->port);
512 /* Bind first to get a fix on our source port */
514 a.sin_family = AF_INET;
515 a.sin_port = htons(0);
516 a.sin_addr.s_addr = htonl(INADDR_ANY);
518 if(bind(cl->meta_socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
520 close(cl->meta_socket);
521 syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
525 /* Optimize TCP settings */
528 setsockopt(cl->meta_socket, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
530 setsockopt(cl->meta_socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
532 option = IPTOS_LOWDELAY;
533 setsockopt(cl->meta_socket, SOL_IP, IP_TOS, &option, sizeof(option));
537 a.sin_family = AF_INET;
538 a.sin_port = htons(cl->port);
539 a.sin_addr.s_addr = htonl(cl->address);
541 if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
543 close(cl->meta_socket);
544 syslog(LOG_ERR, _("%s port %hd: %m"), cl->hostname, cl->port);
548 flags = fcntl(cl->meta_socket, F_GETFL);
549 if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
551 close(cl->meta_socket);
552 syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
553 cl->hostname, cl->port);
557 if(debug_lvl >= DEBUG_CONNECTIONS)
558 syslog(LOG_INFO, _("Connected to %s port %hd"),
559 cl->hostname, cl->port);
567 Setup an outgoing meta connection.
569 int setup_outgoing_connection(char *name)
571 connection_t *ncn, *old;
577 syslog(LOG_ERR, _("Invalid name for outgoing connection"));
581 /* Make sure we don't make an outgoing connection to a host that is already in our connection list */
583 if((old = lookup_id(name)))
585 if(debug_lvl >= DEBUG_CONNECTIONS)
586 syslog(LOG_NOTICE, _("We are already connected to %s."), name);
587 old->status.outgoing = 1;
591 ncn = new_connection();
592 asprintf(&ncn->name, "%s", name);
594 if(read_host_config(ncn))
596 syslog(LOG_ERR, _("Error reading host configuration file for %s"), ncn->name);
597 free_connection(ncn);
601 if(!(cfg = get_config_val(ncn->config, config_address)))
603 syslog(LOG_ERR, _("No address specified for %s"), ncn->name);
604 free_connection(ncn);
608 if(!(h = gethostbyname(cfg->data.ptr)))
610 syslog(LOG_ERR, _("Error looking up `%s': %m"), cfg->data.ptr);
611 free_connection(ncn);
615 ncn->address = ntohl(*((ipv4_t*)(h->h_addr_list[0])));
616 ncn->hostname = hostlookup(htonl(ncn->address));
618 if(setup_outgoing_meta_socket(ncn) < 0)
620 syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
622 free_connection(ncn);
626 ncn->status.outgoing = 1;
627 ncn->buffer = xmalloc(MAXBUFSIZE);
629 ncn->last_ping_time = time(NULL);
638 int read_rsa_public_key(connection_t *cl)
646 cl->rsa_key = RSA_new();
648 /* First, check for simple PublicKey statement */
650 if((cfg = get_config_val(cl->config, config_publickey)))
652 BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
653 BN_hex2bn(&cl->rsa_key->e, "FFFF");
657 /* Else, check for PublicKeyFile statement and read it */
659 if((cfg = get_config_val(cl->config, config_publickeyfile)))
661 if(is_safe_path(cfg->data.ptr))
663 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
665 syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
669 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
673 syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
683 /* Else, check if a harnessed public key is in the config file */
685 asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
686 if((fp = fopen(fname, "r")))
688 result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
697 /* Nothing worked. */
699 syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
704 int read_rsa_private_key(void)
711 myself->rsa_key = RSA_new();
713 if((cfg = get_config_val(config, config_privatekey)))
715 BN_hex2bn(&myself->rsa_key->d, cfg->data.ptr);
716 BN_hex2bn(&myself->rsa_key->e, "FFFF");
718 else if((cfg = get_config_val(config, config_privatekeyfile)))
720 if((fp = fopen(cfg->data.ptr, "r")) == NULL)
722 syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
726 result = PEM_read_RSAPrivateKey(fp, &myself->rsa_key, NULL, NULL);
730 syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
737 syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
745 Configure connection_t myself and set up the local sockets (listen only)
747 int setup_myself(void)
753 myself = new_connection();
755 asprintf(&myself->hostname, _("MYSELF"));
757 myself->protocol_version = PROT_CURRENT;
759 if(!(cfg = get_config_val(config, config_name))) /* Not acceptable */
761 syslog(LOG_ERR, _("Name for tinc daemon required!"));
765 asprintf(&myself->name, "%s", (char*)cfg->data.val);
767 if(check_id(myself->name))
769 syslog(LOG_ERR, _("Invalid name for myself!"));
773 if(read_rsa_private_key())
776 if(read_host_config(myself))
778 syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
782 if(read_rsa_public_key(myself))
787 if(RSA_check_key(myself->rsa_key) != 1)
789 syslog(LOG_ERR, _("Invalid public/private keypair!"));
793 if(!(cfg = get_config_val(myself->config, config_port)))
796 myself->port = cfg->data.val;
798 /* Read in all the subnets specified in the host configuration file */
800 for(next = myself->config; (cfg = get_config_val(next, config_subnet)); next = cfg->next)
803 net->type = SUBNET_IPV4;
804 net->net.ipv4.address = cfg->data.ip->address;
805 net->net.ipv4.mask = cfg->data.ip->mask;
807 /* Teach newbies what subnets are... */
809 if((net->net.ipv4.address & net->net.ipv4.mask) != net->net.ipv4.address)
811 syslog(LOG_ERR, _("Network address and subnet mask do not match!"));
815 subnet_add(myself, net);
819 /* Check some options */
821 if((cfg = get_config_val(config, config_indirectdata)))
822 if(cfg->data.val == stupid_true)
823 myself->options |= OPTION_INDIRECT;
825 if((cfg = get_config_val(config, config_tcponly)))
826 if(cfg->data.val == stupid_true)
827 myself->options |= OPTION_TCPONLY;
829 if((cfg = get_config_val(myself->config, config_indirectdata)))
830 if(cfg->data.val == stupid_true)
831 myself->options |= OPTION_INDIRECT;
833 if((cfg = get_config_val(myself->config, config_tcponly)))
834 if(cfg->data.val == stupid_true)
835 myself->options |= OPTION_TCPONLY;
837 if(myself->options & OPTION_TCPONLY)
838 myself->options |= OPTION_INDIRECT;
840 if((cfg = get_config_val(config, config_mode)))
842 if(!strcasecmp(cfg->data.ptr, "router"))
843 routing_mode = RMODE_ROUTER;
844 else if (!strcasecmp(cfg->data.ptr, "switch"))
845 routing_mode = RMODE_SWITCH;
846 else if (!strcasecmp(cfg->data.ptr, "hub"))
847 routing_mode = RMODE_HUB;
850 syslog(LOG_ERR, _("Invalid routing mode!"));
855 routing_mode = RMODE_ROUTER;
860 if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
862 syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
866 if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
868 syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
872 /* Generate packet encryption key */
874 myself->cipher_pkttype = EVP_bf_cbc();
876 myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
878 myself->cipher_pktkey = (char *)xmalloc(myself->cipher_pktkeylength);
879 RAND_pseudo_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
881 if(!(cfg = get_config_val(config, config_keyexpire)))
884 keylifetime = cfg->data.val;
886 keyexpires = time(NULL) + keylifetime;
889 /* Activate ourselves */
891 myself->status.active = 1;
893 syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
899 sigalrm_handler(int a)
903 cfg = get_config_val(upstreamcfg, config_connectto);
907 if(upstreamcfg == config)
909 /* No upstream IP given, we're listen only. */
910 signal(SIGALRM, SIG_IGN);
916 /* We previously tried all the ConnectTo lines. Now wrap back to the first. */
917 cfg = get_config_val(config, config_connectto);
922 upstreamcfg = cfg->next;
923 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
925 signal(SIGALRM, SIG_IGN);
928 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
931 signal(SIGALRM, sigalrm_handler);
932 upstreamcfg = config;
933 seconds_till_retry += 5;
934 if(seconds_till_retry > MAXTIMEOUT) /* Don't wait more than MAXTIMEOUT seconds. */
935 seconds_till_retry = MAXTIMEOUT;
936 syslog(LOG_ERR, _("Still failed to connect to other, will retry in %d seconds"),
938 alarm(seconds_till_retry);
943 setup all initial network connections
945 int setup_network_connections(void)
952 if((cfg = get_config_val(config, config_pingtimeout)) == NULL)
956 timeout = cfg->data.val;
963 if(setup_tap_fd() < 0)
966 /* Run tinc-up script to further initialize the tap interface */
967 execute_script("tinc-up");
969 if(setup_myself() < 0)
972 if(!(cfg = get_config_val(config, config_connectto)))
973 /* No upstream IP given, we're listen only. */
978 upstreamcfg = cfg->next;
979 if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
981 cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
986 signal(SIGALRM, sigalrm_handler);
987 upstreamcfg = config;
988 seconds_till_retry = MAXTIMEOUT;
989 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
990 alarm(seconds_till_retry);
1000 close all open network connections
1002 void close_network_connections(void)
1007 for(node = connection_tree->head; node; node = node->next)
1009 p = (connection_t *)node->data;
1010 p->status.outgoing = 0;
1011 p->status.active = 0;
1012 terminate_connection(p);
1016 if(myself->status.active)
1018 close(myself->meta_socket);
1019 free_connection(myself);
1023 execute_script("tinc-down");
1027 destroy_connection_tree();
1033 handle an incoming tcp connect call and open
1036 connection_t *create_new_connection(int sfd)
1039 struct sockaddr_in ci;
1040 int len = sizeof(ci);
1042 p = new_connection();
1044 if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
1046 syslog(LOG_ERR, _("System call `%s' failed: %m"),
1052 asprintf(&p->name, _("UNKNOWN"));
1053 p->address = ntohl(ci.sin_addr.s_addr);
1054 p->hostname = hostlookup(ci.sin_addr.s_addr);
1055 p->port = htons(ci.sin_port); /* This one will be overwritten later */
1056 p->meta_socket = sfd;
1058 p->buffer = xmalloc(MAXBUFSIZE);
1060 p->last_ping_time = time(NULL);
1062 if(debug_lvl >= DEBUG_CONNECTIONS)
1063 syslog(LOG_NOTICE, _("Connection from %s port %d"),
1064 p->hostname, htons(ci.sin_port));
1066 p->allow_request = ID;
1072 put all file descriptors in an fd_set array
1074 void build_fdset(fd_set *fs)
1081 FD_SET(myself->socket, fs);
1083 for(node = connection_tree->head; node; node = node->next)
1085 p = (connection_t *)node->data;
1087 FD_SET(p->meta_socket, fs);
1090 FD_SET(myself->meta_socket, fs);
1096 receive incoming data from the listening
1097 udp socket and write it to the ethertap
1098 device after being decrypted
1100 void handle_incoming_vpn_data(void)
1103 int x, l = sizeof(x);
1104 struct sockaddr_in from;
1105 socklen_t fromlen = sizeof(from);
1108 if(getsockopt(myself->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
1110 syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
1111 __FILE__, __LINE__, myself->socket);
1116 syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
1120 if((pkt.len = recvfrom(myself->socket, (char *) pkt.salt, MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
1122 syslog(LOG_ERR, _("Receiving packet failed: %m"));
1126 cl = lookup_active(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
1130 syslog(LOG_WARNING, _("Received UDP packets on port %hd from unknown source %x:%hd"), myself->port, ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
1134 cl->last_ping_time = time(NULL);
1136 receive_udppacket(cl, &pkt);
1141 terminate a connection and notify the other
1142 end before closing the sockets
1144 void terminate_connection(connection_t *cl)
1148 avl_node_t *node, *next;
1150 if(cl->status.remove)
1153 if(debug_lvl >= DEBUG_CONNECTIONS)
1154 syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
1155 cl->name, cl->hostname);
1157 cl->status.remove = 1;
1162 close(cl->meta_socket);
1167 /* Find all connections that were lost because they were behind cl
1168 (the connection that was dropped). */
1170 for(node = connection_tree->head; node; node = node->next)
1172 p = (connection_t *)node->data;
1173 if(p->nexthop == cl && p != cl)
1174 terminate_connection(p);
1177 /* Inform others of termination if it was still active */
1179 if(cl->status.active)
1180 for(node = connection_tree->head; node; node = node->next)
1182 p = (connection_t *)node->data;
1183 if(p->status.meta && p->status.active && p != cl)
1184 send_del_host(p, cl); /* Sounds like recursion, but p does not have a meta connection :) */
1188 /* Remove the associated subnets */
1190 for(node = cl->subnet_tree->head; node; node = next)
1193 subnet = (subnet_t *)node->data;
1197 /* Check if this was our outgoing connection */
1199 if(cl->status.outgoing)
1201 cl->status.outgoing = 0;
1202 signal(SIGALRM, sigalrm_handler);
1203 alarm(seconds_till_retry);
1204 syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
1209 cl->status.active = 0;
1214 Check if the other end is active.
1215 If we have sent packets, but didn't receive any,
1216 then possibly the other end is dead. We send a
1217 PING request over the meta connection. If the other
1218 end does not reply in time, we consider them dead
1219 and close the connection.
1221 void check_dead_connections(void)
1229 for(node = connection_tree->head; node; node = node->next)
1231 cl = (connection_t *)node->data;
1232 if(cl->status.active && cl->status.meta)
1234 if(cl->last_ping_time + timeout < now)
1236 if(cl->status.pinged)
1238 if(debug_lvl >= DEBUG_PROTOCOL)
1239 syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
1240 cl->name, cl->hostname);
1241 cl->status.timeout = 1;
1242 terminate_connection(cl);
1255 accept a new tcp connect and create a
1258 int handle_new_meta_connection()
1261 struct sockaddr client;
1262 int nfd, len = sizeof(client);
1264 if((nfd = accept(myself->meta_socket, &client, &len)) < 0)
1266 syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
1270 if(!(ncn = create_new_connection(nfd)))
1274 syslog(LOG_NOTICE, _("Closed attempted connection"));
1278 connection_add(ncn);
1286 check all connections to see if anything
1287 happened on their sockets
1289 void check_network_activity(fd_set *f)
1294 if(FD_ISSET(myself->socket, f))
1295 handle_incoming_vpn_data();
1297 for(node = connection_tree->head; node; node = node->next)
1299 p = (connection_t *)node->data;
1301 if(p->status.remove)
1305 if(FD_ISSET(p->meta_socket, f))
1306 if(receive_meta(p) < 0)
1308 terminate_connection(p);
1313 if(FD_ISSET(myself->meta_socket, f))
1314 handle_new_meta_connection();
1319 read, encrypt and send data that is
1320 available through the ethertap device
1322 void handle_tap_input(void)
1327 if(taptype == TAP_TYPE_TUNTAP)
1329 if((lenin = read(tap_fd, vp.data, MTU)) <= 0)
1331 syslog(LOG_ERR, _("Error while reading from tun/tap device: %m"));
1338 if((lenin = read(tap_fd, vp.data - 2, MTU)) <= 0)
1340 syslog(LOG_ERR, _("Error while reading from ethertap device: %m"));
1346 total_tap_in += vp.len;
1350 if(debug_lvl >= DEBUG_TRAFFIC)
1351 syslog(LOG_WARNING, _("Received short packet from tap device"));
1355 if(debug_lvl >= DEBUG_TRAFFIC)
1357 syslog(LOG_DEBUG, _("Read packet of length %d from tap device"), vp.len);
1360 route_outgoing(&vp);
1365 this is where it all happens...
1367 void main_loop(void)
1372 time_t last_ping_check;
1375 last_ping_check = time(NULL);
1379 tv.tv_sec = timeout;
1382 prune_connection_tree();
1385 if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
1387 if(errno != EINTR) /* because of alarm */
1389 syslog(LOG_ERR, _("Error while waiting for input: %m"));
1396 syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
1398 close_network_connections();
1399 clear_config(&config);
1401 if(read_server_config())
1403 syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
1409 if(setup_network_connections())
1417 /* Let's check if everybody is still alive */
1419 if(last_ping_check + timeout < t)
1421 check_dead_connections();
1422 last_ping_check = time(NULL);
1424 /* Should we regenerate our key? */
1428 if(debug_lvl >= DEBUG_STATUS)
1429 syslog(LOG_INFO, _("Regenerating symmetric key"));
1431 RAND_pseudo_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
1432 send_key_changed(myself, NULL);
1433 keyexpires = time(NULL) + keylifetime;
1439 check_network_activity(&fset);
1441 /* local tap data */
1442 if(FD_ISSET(tap_fd, &fset))