-
-#include "system.h"
-
-int tap_fd = -1;
-
-int total_tap_in = 0;
-int total_tap_out = 0;
-int total_socket_in = 0;
-int total_socket_out = 0;
-
-int upstreamindex = 0;
-static int seconds_till_retry;
-
-/* The global list of existing connections */
-conn_list_t *conn_list = NULL;
-conn_list_t *myself = NULL;
-
-/*
- strip off the MAC adresses of an ethernet frame
-*/
-void strip_mac_addresses(vpn_packet_t *p)
-{
- unsigned char tmp[MAXSIZE];
-cp
- memcpy(tmp, p->data, p->len);
- p->len -= 12;
- memcpy(p->data, &tmp[12], p->len);
-cp
-}
-
-/*
- reassemble MAC addresses
-*/
-void add_mac_addresses(vpn_packet_t *p)
-{
- unsigned char tmp[MAXSIZE];
-cp
- memcpy(&tmp[12], p->data, p->len);
- p->len += 12;
- tmp[0] = tmp[6] = 0xfe;
- tmp[1] = tmp[7] = 0xfd;
- *((ip_t*)(&tmp[2])) = (ip_t)(htonl(myself->vpn_ip));
- *((ip_t*)(&tmp[8])) = *((ip_t*)(&tmp[26]));
- memcpy(p->data, &tmp[0], p->len);
-cp
-}
-
-int xsend(conn_list_t *cl, void *packet)
-{
- real_packet_t rp;
-cp
- do_encrypt((vpn_packet_t*)packet, &rp, cl->key);
- rp.from = htonl(myself->vpn_ip);
- rp.data.len = htons(rp.data.len);
- rp.len = htons(rp.len);
-
- if(debug_lvl > 3)
- syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
- ntohs(rp.len), cl->vpn_hostname, cl->real_hostname);
-
- total_socket_out += ntohs(rp.len);
-
- cl->want_ping = 1;
-
- if((cl->flags | myself->flags) & TCPONLY)
- return send_tcppacket(cl, (void*)&rp, ntohs(rp.len));
-
- if((send(cl->socket, (char*)&rp, ntohs(rp.len), 0)) < 0)
- {
- syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
- cl->vpn_hostname, cl->real_hostname);
- return -1;
- }
-cp
- return 0;
-}
-
-int xrecv(conn_list_t *cl, void *packet)
-{
- vpn_packet_t vp;
- int lenin;
-cp
- do_decrypt((real_packet_t*)packet, &vp, cl->key);
-cp
- add_mac_addresses(&vp);
-cp
- if(debug_lvl > 3)
- syslog(LOG_ERR, _("Receiving packet of %d bytes from %s (%s)"),
- ((real_packet_t*)packet)->len, cl->vpn_hostname, cl->real_hostname);
-cp
- if((lenin = write(tap_fd, &vp, vp.len + sizeof(vp.len))) < 0)
- syslog(LOG_ERR, _("Can't write to tap device: %m"));
- else
- total_tap_out += lenin;
-cp
- cl->want_ping = 0;
- cl->last_ping_time = time(NULL);
-cp
- return 0;
-}
-
-/*
- add the given packet of size s to the
- queue q, be it the send or receive queue
-*/
-void add_queue(packet_queue_t **q, void *packet, size_t s)
-{
- queue_element_t *e;
-cp
- e = xmalloc(sizeof(*e));
- e->packet = xmalloc(s);
- memcpy(e->packet, packet, s);
-
- if(!*q)
- {
- *q = xmalloc(sizeof(**q));
- (*q)->head = (*q)->tail = NULL;
- }
-
- e->next = NULL; /* We insert at the tail */
-
- if((*q)->tail) /* Do we have a tail? */
- {
- (*q)->tail->next = e;
- e->prev = (*q)->tail;
- }
- else /* No tail -> no head too */
- {
- (*q)->head = e;
- e->prev = NULL;
- }
-
- (*q)->tail = e;
-cp
-}
-
-/* Remove a queue element */
-void del_queue(packet_queue_t **q, queue_element_t *e)
-{
-cp
- free(e->packet);
-
- if(e->next) /* There is a successor, so we are not tail */
- {
- if(e->prev) /* There is a predecessor, so we are not head */
- {
- e->next->prev = e->prev;
- e->prev->next = e->next;
- }
- else /* We are head */
- {
- e->next->prev = NULL;
- (*q)->head = e->next;
- }
- }
- else /* We are tail (or all alone!) */
- {
- if(e->prev) /* We are not alone :) */
- {
- e->prev->next = NULL;
- (*q)->tail = e->prev;
- }
- else /* Adieu */
- {
- free(*q);
- *q = NULL;
- }
- }
-
- free(e);
-cp
-}
-
-/*
- flush a queue by calling function for
- each packet, and removing it when that
- returned a zero exit code
-*/
-void flush_queue(conn_list_t *cl, packet_queue_t **pq,
- int (*function)(conn_list_t*,void*))
-{
- queue_element_t *p, *next = NULL;
-cp
- for(p = (*pq)->head; p != NULL; )
- {
- next = p->next;
-
- if(!function(cl, p->packet))
- del_queue(pq, p);
-
- p = next;
- }
-
- if(debug_lvl > 3)
- syslog(LOG_DEBUG, _("Queue flushed"));
-cp
-}
-
-/*
- flush the send&recv queues
- void because nothing goes wrong here, packets
- remain in the queue if something goes wrong
-*/
-void flush_queues(conn_list_t *cl)
-{
-cp
- if(cl->sq)
- {
- if(debug_lvl > 3)
- syslog(LOG_DEBUG, _("Flushing send queue for %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
- flush_queue(cl, &(cl->sq), xsend);
- }
-
- if(cl->rq)
- {
- if(debug_lvl > 3)
- syslog(LOG_DEBUG, _("Flushing receive queue for %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
- flush_queue(cl, &(cl->rq), xrecv);
- }
-cp
-}
-
-/*
- send a packet to the given vpn ip.
-*/
-int send_packet(ip_t to, vpn_packet_t *packet)
-{
- conn_list_t *cl;
-cp
- if((cl = lookup_conn(to)) == NULL)
- {
- if(debug_lvl > 3)
- {
- syslog(LOG_NOTICE, _("Trying to look up %d.%d.%d.%d in connection list failed!"),
- IP_ADDR_V(to));
- }
-
- /* Is this really necessary? If we can't find "to", then neither should any uplink. (GS) */
-
- return -1;
-
- for(cl = conn_list; cl != NULL && !cl->status.outgoing; cl = cl->next);
- if(!cl)
- { /* No open outgoing connection has been found. */
- if(debug_lvl > 3)
- syslog(LOG_NOTICE, _("There is no remote host I can send this packet to!"));
- return -1;
- }
- }
-
- /* If we ourselves have indirectdata flag set, we should send only to our uplink! */
-
- if(myself->flags & EXPORTINDIRECTDATA)
- {
- for(cl = conn_list; cl != NULL && !cl->status.outgoing; cl = cl->next);
- if(!cl)
- { /* No open outgoing connection has been found. */
- if(debug_lvl > 3)
- syslog(LOG_NOTICE, _("There is no remote host I can send this packet to!"));
- return -1;
- }
- }
- else
-
- /* If indirectdata flag is set for the destination we just looked up,
- * then real_ip is actually the vpn_ip of the gateway tincd
- * it is behind.
- */
-
- if(cl->flags & INDIRECTDATA)
- {
- if(debug_lvl > 3)
- syslog(LOG_NOTICE, _("Indirect packet to %s via %s"),
- cl->vpn_hostname, cl->real_hostname);
- if((cl = lookup_conn(cl->real_ip)) == NULL)
- {
- if(debug_lvl > 3)
- syslog(LOG_NOTICE, _("Indirect look up %d.%d.%d.%d in connection list failed!"),
- IP_ADDR_V(to));
-
- /* Gateway tincd dead? Should we kill it? (GS) */
-
- return -1;
- }
- if(cl->flags & INDIRECTDATA) /* This should not happen */
- {
- if(debug_lvl > 3)
- syslog(LOG_NOTICE, _("Double indirection for %d.%d.%d.%d"),
- IP_ADDR_V(to));
- return -1;
- }
- }
-
- if(my_key_expiry <= time(NULL))
- regenerate_keys();
-
- if(!cl->status.dataopen)
- if(setup_vpn_connection(cl) < 0)
- {
- syslog(LOG_ERR, _("Could not open UDP connection to %s (%s)"), cl->vpn_hostname, cl->real_hostname);
- return -1;
- }
-
- if(!cl->status.validkey)
- {
- if(debug_lvl > 3)
- syslog(LOG_INFO, _("%s (%s) has no valid key, queueing packet"), cl->vpn_hostname, cl->real_hostname);
- add_queue(&(cl->sq), packet, packet->len + 2);
- if(!cl->status.waitingforkey)
- send_key_request(cl->vpn_ip); /* Keys should be sent to the host running the tincd */
- return 0;
- }
-
- if(!cl->status.active)
- {
- if(debug_lvl > 3)
- syslog(LOG_INFO, _("%s (%s) is not ready, queueing packet"), cl->vpn_hostname, cl->real_hostname);
- add_queue(&(cl->sq), packet, packet->len + 2);
- return 0; /* We don't want to mess up, do we? */
- }
-
- /* can we send it? can we? can we? huh? */
-cp
- return xsend(cl, packet);
-}
-
-/*
- open the local ethertap device
-*/
-int setup_tap_fd(void)
-{
- int nfd;
- const char *tapfname;
- config_t const *cfg;
-cp
- if((cfg = get_config_val(tapdevice)) == NULL)
- tapfname = "/dev/tap0";
- else
- tapfname = cfg->data.ptr;
-
- if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
- {
- syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
- return -1;
- }
-
- tap_fd = nfd;
-cp
- return 0;
-}
-
-/*
- set up the socket that we listen on for incoming
- (tcp) connections
-*/
-int setup_listen_meta_socket(int port)
-{
- int nfd, flags;
- struct sockaddr_in a;
- const int one = 1;
-cp
- if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
- {
- syslog(LOG_ERR, _("Creating metasocket failed: %m"));
- return -1;
- }
-
- if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
- {
- syslog(LOG_ERR, _("setsockopt: %m"));
- return -1;
- }
-
- flags = fcntl(nfd, F_GETFL);
- if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
- {
- syslog(LOG_ERR, _("fcntl: %m"));
- return -1;
- }
-
- memset(&a, 0, sizeof(a));
- a.sin_family = AF_INET;
- a.sin_port = htons(port);
- a.sin_addr.s_addr = htonl(INADDR_ANY);
-
- if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
- {
- syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
- return -1;
- }
-
- if(listen(nfd, 3))
- {
- syslog(LOG_ERR, _("listen: %m"));
- return -1;
- }
-cp
- return nfd;
-}
-
-/*
- setup the socket for incoming encrypted
- data (the udp part)
-*/
-int setup_vpn_in_socket(int port)
-{
- int nfd, flags;
- struct sockaddr_in a;
- const int one = 1;
-cp
- if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
- {
- syslog(LOG_ERR, _("Creating socket failed: %m"));
- return -1;
- }
-
- if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
- {
- syslog(LOG_ERR, _("setsockopt: %m"));
- return -1;
- }
-
- flags = fcntl(nfd, F_GETFL);
- if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
- {
- syslog(LOG_ERR, _("fcntl: %m"));
- return -1;
- }
-
- memset(&a, 0, sizeof(a));
- a.sin_family = AF_INET;
- a.sin_port = htons(port);
- a.sin_addr.s_addr = htonl(INADDR_ANY);
-
- if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
- {
- syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
- return -1;
- }
-cp
- return nfd;
-}
-
-/*
- setup an outgoing meta (tcp) socket
-*/
-int setup_outgoing_meta_socket(conn_list_t *cl)
-{
- int flags;
- struct sockaddr_in a;
- config_t const *cfg;
-cp
- if(debug_lvl > 0)
- syslog(LOG_INFO, _("Trying to connect to %s"), cl->real_hostname);
-
- if((cfg = get_config_val(upstreamport)) == NULL)
- cl->port = 655;
- else
- cl->port = cfg->data.val;
-
- cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
- if(cl->meta_socket == -1)
- {
- syslog(LOG_ERR, _("Creating socket for %s port %d failed: %m"),
- cl->real_hostname, cl->port);
- return -1;
- }
-
- a.sin_family = AF_INET;
- a.sin_port = htons(cl->port);
- a.sin_addr.s_addr = htonl(cl->real_ip);
-
- if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
- {
- syslog(LOG_ERR, _("%s port %hd: %m"), cl->real_hostname, cl->port);
- return -1;
- }
-
- flags = fcntl(cl->meta_socket, F_GETFL);
-/* if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
- {
- syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
- cl->real_hostname, cl->port);
- return -1;
- }
-*/
- if(debug_lvl > 0)
- syslog(LOG_INFO, _("Connected to %s port %hd"),
- cl->real_hostname, cl->port);
-cp
- return 0;
-}
-
-/*
- setup an outgoing connection. It's not
- necessary to also open an udp socket as
- well, because the other host will initiate
- an authentication sequence during which
- we will do just that.
-*/
-int setup_outgoing_connection(char *hostname)
-{
- conn_list_t *ncn;
- struct hostent *h;
-cp
- if(!(h = gethostbyname(hostname)))
- {
- syslog(LOG_ERR, _("Error looking up `%s': %m"), hostname);
- return -1;
- }
-
- ncn = new_conn_list();
- ncn->real_ip = ntohl(*((ip_t*)(h->h_addr_list[0])));
- ncn->real_hostname = hostlookup(htonl(ncn->real_ip));
-
- if(setup_outgoing_meta_socket(ncn) < 0)
- {
- syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
- ncn->real_hostname);
- free_conn_element(ncn);
- return -1;
- }
-
- ncn->status.meta = 1;
- ncn->status.outgoing = 1;
- ncn->next = conn_list;
- conn_list = ncn;
-cp
- return 0;
-}
-
-/*
- set up the local sockets (listen only)
-*/
-int setup_myself(void)
-{
- config_t const *cfg;
-cp
- myself = new_conn_list();
-
- if(!(cfg = get_config_val(myvpnip)))
- {
- syslog(LOG_ERR, _("No value for my VPN IP given"));
- return -1;
- }
-
- myself->vpn_ip = cfg->data.ip->ip;
- myself->vpn_hostname = hostlookup(htonl(myself->vpn_ip));
- myself->real_hostname = hostlookup(htonl(myself->vpn_ip));
- myself->vpn_mask = cfg->data.ip->mask;
- myself->flags = 0;
-
- if(!(cfg = get_config_val(listenport)))
- myself->port = 655;
- else
- myself->port = cfg->data.val;
-
- if((cfg = get_config_val(indirectdata)))
- if(cfg->data.val == stupid_true)
- myself->flags |= EXPORTINDIRECTDATA;
-
- if((cfg = get_config_val(tcponly)))
- if(cfg->data.val == stupid_true)
- myself->flags |= TCPONLY;
-
- if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
- {
- syslog(LOG_ERR, _("Unable to set up a listening socket"));
- return -1;
- }
-
- if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
- {
- syslog(LOG_ERR, _("Unable to set up an incoming vpn data socket"));
- close(myself->meta_socket);
- return -1;
- }
-
- myself->status.active = 1;
-
- syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
-cp
- return 0;
-}
-
-RETSIGTYPE
-sigalrm_handler(int a)
-{
- config_t const *cfg;
-cp
- cfg = get_next_config_val(upstreamip, upstreamindex++);
-
- while(cfg)
- {
- if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
- {
- signal(SIGALRM, SIG_IGN);
- return;
- }
- cfg = get_next_config_val(upstreamip, upstreamindex++); /* Or else we try the next ConnectTo line */
- }
-
- signal(SIGALRM, sigalrm_handler);
- upstreamindex = 0;
- seconds_till_retry += 5;
- if(seconds_till_retry > MAXTIMEOUT) /* Don't wait more than MAXTIMEOUT seconds. */
- seconds_till_retry = MAXTIMEOUT;
- syslog(LOG_ERR, _("Still failed to connect to other, will retry in %d seconds"),
- seconds_till_retry);
- alarm(seconds_till_retry);
-cp
-}
-
-/*
- setup all initial network connections
-*/
-int setup_network_connections(void)
-{
- config_t const *cfg;
-cp
- if((cfg = get_config_val(pingtimeout)) == NULL)
- timeout = 5;
- else
- timeout = cfg->data.val;
-
- if(setup_tap_fd() < 0)
- return -1;
-
- if(setup_myself() < 0)
- return -1;
-
- if((cfg = get_next_config_val(upstreamip, upstreamindex++)) == NULL)
- /* No upstream IP given, we're listen only. */
- return 0;
-
- while(cfg)
- {
- if(!setup_outgoing_connection(cfg->data.ptr)) /* function returns 0 when there are no problems */
- return 0;
- cfg = get_next_config_val(upstreamip, upstreamindex++); /* Or else we try the next ConnectTo line */
- }
-
- signal(SIGALRM, sigalrm_handler);
- upstreamindex = 0;
- seconds_till_retry = MAXTIMEOUT;
- syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
- alarm(seconds_till_retry);
-cp
- return 0;
-}
-
-/*
- close all open network connections
-*/
-void close_network_connections(void)
-{
- conn_list_t *p;
-cp
- for(p = conn_list; p != NULL; p = p->next)
- {
- if(p->status.dataopen)
- {
- shutdown(p->socket, 0); /* No more receptions */
- close(p->socket);