Document and clean up MAC address expiry.
[tinc] / src / net.c
index 3a58749..722e8cc 100644 (file)
--- a/src/net.c
+++ b/src/net.c
@@ -1,7 +1,7 @@
 /*
     net.c -- most of the network code
-    Copyright (C) 1998-2001 Ivo Timmermans <itimmermans@bigfoot.com>,
-                  2000,2001 Guus Sliepen <guus@sliepen.warande.net>
+    Copyright (C) 1998-2002 Ivo Timmermans <itimmermans@bigfoot.com>,
+                  2000-2002 Guus Sliepen <guus@sliepen.warande.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: net.c,v 1.35.4.103 2001/03/13 21:32:24 guus Exp $
+    $Id: net.c,v 1.35.4.161 2002/03/01 14:25:10 guus Exp $
 */
 
 #include "config.h"
 #include <fcntl.h>
 #include <netdb.h>
 #include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/tcp.h>
+#ifdef HAVE_LINUX
+ #include <netinet/ip.h>
+ #include <netinet/tcp.h>
+#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/signal.h>
+#include <signal.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <syslog.h>
 #include <sys/socket.h>
 #include <net/if.h>
 
-#ifdef HAVE_OPENSSL_RAND_H
-# include <openssl/rand.h>
-#else
-# include <rand.h>
-#endif
-
-#ifdef HAVE_OPENSSL_EVP_H
-# include <openssl/evp.h>
-#else
-# include <evp.h>
-#endif
-
-#ifdef HAVE_OPENSSL_ERR_H
-# include <openssl/err.h>
-#else
-# include <err.h>
-#endif
-
-#ifdef HAVE_OPENSSL_PEM_H
-# include <openssl/pem.h>
-#else
-# include <pem.h>
-#endif
-
-#ifdef HAVE_TUNTAP
-#include LINUX_IF_TUN_H
-#endif
+#include <openssl/rand.h>
 
 #include <utils.h>
 #include <xalloc.h>
 #include "process.h"
 #include "protocol.h"
 #include "subnet.h"
+#include "graph.h"
 #include "process.h"
 #include "route.h"
+#include "device.h"
+#include "event.h"
 
 #include "system.h"
 
-int tap_fd = -1;
-int taptype = TAP_TYPE_ETHERTAP;
-int total_tap_in = 0;
-int total_tap_out = 0;
-int total_socket_in = 0;
-int total_socket_out = 0;
-
-config_t *upstreamcfg;
-static int seconds_till_retry;
-
-int keylifetime = 0;
-int keyexpires = 0;
-
-char *unknown = NULL;
-
-void send_udppacket(connection_t *cl, vpn_packet_t *inpkt)
-{
-  vpn_packet_t outpkt;
-  int outlen, outpad;
-  EVP_CIPHER_CTX ctx;
-  struct sockaddr_in to;
-  socklen_t tolen = sizeof(to);
-  vpn_packet_t *copy;
-cp
-  if(!cl->status.validkey)
-    {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-       syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
-              cl->name, cl->hostname);
-
-      /* Since packet is on the stack of handle_tap_input(),
-         we have to make a copy of it first. */
-
-      copy = xmalloc(sizeof(vpn_packet_t));
-      memcpy(copy, inpkt, sizeof(vpn_packet_t));
-
-      list_insert_tail(cl->queue, copy);
-
-      if(!cl->status.waitingforkey)
-       send_req_key(myself, cl);
-      return;
-    }
-
-  /* Encrypt the packet. */
-
-  outpkt.len = inpkt->len;
-
-  EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
-  EVP_EncryptUpdate(&ctx, outpkt.data, &outlen, inpkt->data, inpkt->len);
-  EVP_EncryptFinal(&ctx, outpkt.data + outlen, &outpad);
-  outlen += outpad + 2;
-
-  total_socket_out += outlen;
-
-  to.sin_family = AF_INET;
-  to.sin_addr.s_addr = htonl(cl->address);
-  to.sin_port = htons(cl->port);
-
-  if((sendto(myself->socket, (char *) &(outpkt.len), outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
-    {
-      syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
-             cl->name, cl->hostname);
-      return;
-    }
-cp
-}
-
-void receive_packet(connection_t *cl, vpn_packet_t *packet)
-{
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, cl->name, cl->hostname);
-
-  route_incoming(cl, packet);
-cp
-}
-
-void receive_udppacket(connection_t *cl, vpn_packet_t *inpkt)
-{
-  vpn_packet_t outpkt;
-  int outlen, outpad;
-  EVP_CIPHER_CTX ctx;
-cp
-  outpkt.len = inpkt->len;
-
-  /* Decrypt the packet */
-
-  EVP_DecryptInit(&ctx, myself->cipher_pkttype, myself->cipher_pktkey, myself->cipher_pktkey + myself->cipher_pkttype->key_len);
-  EVP_DecryptUpdate(&ctx, outpkt.data, &outlen, inpkt->data, inpkt->len + 8);
-  EVP_DecryptFinal(&ctx, outpkt.data + outlen, &outpad);
-  outlen += outpad;
-
-  receive_packet(cl, &outpkt);
-cp
-}
-
-void accept_packet(vpn_packet_t *packet)
-{
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_DEBUG, _("Writing packet of %d bytes to tap device"),
-           packet->len);
+int do_prune = 0;
+int do_purge = 0;
+int sighup = 0;
+int sigalrm = 0;
 
-  if(taptype == TAP_TYPE_TUNTAP)
-    {
-      if(write(tap_fd, packet->data, packet->len) < 0)
-        syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
-      else
-        total_tap_out += packet->len;
-    }
-  else /* ethertap */
-    {
-      if(write(tap_fd, packet->data - 2, packet->len + 2) < 0)
-        syslog(LOG_ERR, _("Can't write to ethertap device: %m"));
-      else
-        total_tap_out += packet->len + 2;
-    }
-cp
-}
+time_t now = 0;
 
 /*
-  send a packet to the given vpn ip.
+  put all file descriptors in an fd_set array
 */
-void send_packet(connection_t *cl, vpn_packet_t *packet)
+void build_fdset(fd_set *fs)
 {
+  avl_node_t *node;
+  connection_t *c;
+  int i;
 cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
-           packet->len, cl->name, cl->hostname);
+  FD_ZERO(fs);
 
-  if(cl == myself)
+  for(node = connection_tree->head; node; node = node->next)
     {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-        {
-          syslog(LOG_NOTICE, _("Packet is looping back to us!"));
-        }
-
-      return;
+      c = (connection_t *)node->data;
+      FD_SET(c->socket, fs);
     }
 
-  if(!cl->status.active)
+  for(i = 0; i < listen_sockets; i++)
     {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-       syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
-              cl->name, cl->hostname);
-
-      return;
+      FD_SET(tcp_socket[i], fs);
+      FD_SET(udp_socket[i], fs);
     }
 
-  /* Check if it has to go via TCP or UDP... */
+  FD_SET(device_fd, fs);
 cp
-  if((cl->options | myself->options) & OPTION_TCPONLY)
-    {
-      if(send_tcppacket(cl, packet))
-        terminate_connection(cl);
-    }
-  else
-    send_udppacket(cl, packet);
 }
 
-void flush_queue(connection_t *cl)
-{
-  list_node_t *node, *next;
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
-
-  for(node = cl->queue->head; node; node = next)
-    {
-      next = node->next;
-      send_udppacket(cl, (vpn_packet_t *)node->data);
-      list_delete_node(cl->queue, node);
-    }
-cp
-}
+/* Purge edges and subnets of unreachable nodes. Use carefully. */
 
-/*
-  open the local ethertap device
-*/
-int setup_tap_fd(void)
+void purge(void)
 {
-  int nfd;
-  const char *tapfname;
-  config_t const *cfg;
-#ifdef HAVE_LINUX
-# ifdef HAVE_TUNTAP
-  struct ifreq ifr;
-# endif
-#endif
-
+  avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext, *cnode;
+  node_t *n;
+  edge_t *e;
+  subnet_t *s;
+  connection_t *c;
 cp
-  if((cfg = get_config_val(config, config_tapdevice)))
-    tapfname = cfg->data.ptr;
-  else
-   {
-#ifdef HAVE_LINUX
-# ifdef HAVE_TUNTAP
-      tapfname = "/dev/misc/net/tun";
-# else
-      tapfname = "/dev/tap0";
-# endif
-#endif
-#ifdef HAVE_FREEBSD
-      tapfname = "/dev/tap0";
-#endif
-#ifdef HAVE_SOLARIS
-      tapfname = "/dev/tun";
-#endif
-   }
-cp
-  if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
-    {
-      syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
-      return -1;
-    }
-cp
-  tap_fd = nfd;
+  if(debug_lvl >= DEBUG_PROTOCOL)
+    syslog(LOG_DEBUG, _("Purging unreachable nodes"));
 
-  taptype = TAP_TYPE_ETHERTAP;
-
-  /* Set default MAC address for ethertap devices */
-
-  mymac.type = SUBNET_MAC;
-  mymac.net.mac.address.x[0] = 0xfe;
-  mymac.net.mac.address.x[1] = 0xfd;
-  mymac.net.mac.address.x[2] = 0x00;
-  mymac.net.mac.address.x[3] = 0x00;
-  mymac.net.mac.address.x[4] = 0x00;
-  mymac.net.mac.address.x[5] = 0x00;
-
-#ifdef HAVE_LINUX
- #ifdef HAVE_TUNTAP
-  /* Ok now check if this is an old ethertap or a new tun/tap thingie */
-  memset(&ifr, 0, sizeof(ifr));
-cp
-  ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
-  if (netname)
-    strncpy(ifr.ifr_name, netname, IFNAMSIZ);
-cp
-  if (!ioctl(tap_fd, TUNSETIFF, (void *) &ifr))
+  for(nnode = node_tree->head; nnode; nnode = nnext)
   {
-    syslog(LOG_INFO, _("%s is a new style tun/tap device"), tapfname);
-    taptype = TAP_TYPE_TUNTAP;
-  }
- #endif
-#endif
-#ifdef HAVE_FREEBSD
- taptype = TAP_TYPE_TUNTAP;
-#endif
-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;
-  int option;
-  config_t const *cfg;
-cp
-  if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
-    {
-      syslog(LOG_ERR, _("Creating metasocket failed: %m"));
-      return -1;
-    }
+    nnext = nnode->next;
+    n = (node_t *)nnode->data;
 
-  flags = fcntl(nfd, F_GETFL);
-  if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
+    if(!n->status.reachable)
     {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "fcntl");
-      return -1;
-    }
-
-  /* Optimize TCP settings */
+      if(debug_lvl >= DEBUG_SCARY_THINGS)
+        syslog(LOG_DEBUG, _("Purging node %s (%s)"), n->name, n->hostname);
 
-  option = 1;
-  setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
-  setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
-  setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
-
-  option = IPTOS_LOWDELAY;
-  setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
-
-  if((cfg = get_config_val(config, config_interface)))
-    {
-      if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, cfg->data.ptr, strlen(cfg->data.ptr)))
-        {
-          close(nfd);
-          syslog(LOG_ERR, _("Unable to bind listen socket to interface %s: %m"), cfg->data.ptr);
-          return -1;
-        }
-    }
-
-  memset(&a, 0, sizeof(a));
-  a.sin_family = AF_INET;
-  a.sin_port = htons(port);
-
-  if((cfg = get_config_val(config, config_interfaceip)))
-    a.sin_addr.s_addr = htonl(cfg->data.ip->address);
-  else
-    a.sin_addr.s_addr = htonl(INADDR_ANY);
-
-  if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
-      return -1;
-    }
-
-  if(listen(nfd, 3))
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "listen");
-      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)
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("Creating socket failed: %m"));
-      return -1;
-    }
-
-  setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
-
-  flags = fcntl(nfd, F_GETFL);
-  if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "fcntl");
-      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)))
-    {
-      close(nfd);
-      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(connection_t *cl)
-{
-  int flags;
-  struct sockaddr_in a;
-  config_t const *cfg;
-  int option;
-cp
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_INFO, _("Trying to connect to %s"), cl->hostname);
-
-  if((cfg = get_config_val(cl->config, config_port)) == 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->hostname, cl->port);
-      return -1;
-    }
-
-  /* Bind first to get a fix on our source port */
-
-  a.sin_family = AF_INET;
-  a.sin_port = htons(0);
-  a.sin_addr.s_addr = htonl(INADDR_ANY);
-
-  if(bind(cl->meta_socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
-    {
-      close(cl->meta_socket);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
-      return -1;
-    }
-
-  /* Optimize TCP settings */
-
-  option = 1;
-  setsockopt(cl->meta_socket, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
-  setsockopt(cl->meta_socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
-
-  option = IPTOS_LOWDELAY;
-  setsockopt(cl->meta_socket, SOL_IP, IP_TOS, &option, sizeof(option));
-
-  /* Connect */
-
-  a.sin_family = AF_INET;
-  a.sin_port = htons(cl->port);
-  a.sin_addr.s_addr = htonl(cl->address);
-
-  if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
-    {
-      close(cl->meta_socket);
-      syslog(LOG_ERR, _("%s port %hd: %m"), cl->hostname, cl->port);
-      return -1;
-    }
-
-  flags = fcntl(cl->meta_socket, F_GETFL);
-  if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
-    {
-      close(cl->meta_socket);
-      syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
-             cl->hostname, cl->port);
-      return -1;
-    }
-
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_INFO, _("Connected to %s port %hd"),
-         cl->hostname, cl->port);
-
-  cl->status.meta = 1;
-cp
-  return 0;
-}
-
-/*
-  Setup an outgoing meta connection.
-*/
-int setup_outgoing_connection(char *name)
-{
-  connection_t *ncn;
-  struct hostent *h;
-  config_t const *cfg;
-cp
-  if(check_id(name))
-    {
-      syslog(LOG_ERR, _("Invalid name for outgoing connection"));
-      return -1;
-    }
-
-  ncn = new_connection();
-  asprintf(&ncn->name, "%s", name);
-
-  if(read_host_config(ncn))
-    {
-      syslog(LOG_ERR, _("Error reading host configuration file for %s"), ncn->name);
-      free_connection(ncn);
-      return -1;
-    }
-
-  if(!(cfg = get_config_val(ncn->config, config_address)))
-    {
-      syslog(LOG_ERR, _("No address specified for %s"), ncn->name);
-      free_connection(ncn);
-      return -1;
-    }
-
-  if(!(h = gethostbyname(cfg->data.ptr)))
-    {
-      syslog(LOG_ERR, _("Error looking up `%s': %m"), cfg->data.ptr);
-      free_connection(ncn);
-      return -1;
-    }
-
-  ncn->address = ntohl(*((ip_t*)(h->h_addr_list[0])));
-  ncn->hostname = hostlookup(htonl(ncn->address));
-
-  if(setup_outgoing_meta_socket(ncn) < 0)
-    {
-      syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
-             ncn->hostname);
-      free_connection(ncn);
-      return -1;
-    }
-
-  ncn->status.outgoing = 1;
-  ncn->buffer = xmalloc(MAXBUFSIZE);
-  ncn->buflen = 0;
-  ncn->last_ping_time = time(NULL);
-
-  connection_add(ncn);
-
-  send_id(ncn);
-cp
-  return 0;
-}
-
-int read_rsa_public_key(connection_t *cl)
-{
-  config_t const *cfg;
-  FILE *fp;
-  char *fname;
-  void *result;
-cp
-  if(!cl->rsa_key)
-    cl->rsa_key = RSA_new();
-
-  /* First, check for simple PublicKey statement */
-
-  if((cfg = get_config_val(cl->config, config_publickey)))
-    {
-      BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
-      BN_hex2bn(&cl->rsa_key->e, "FFFF");
-      return 0;
-    }
-
-  /* Else, check for PublicKeyFile statement and read it */
-
-  if((cfg = get_config_val(cl->config, config_publickeyfile)))
-    {
-      if(is_safe_path(cfg->data.ptr))
-        {
-          if((fp = fopen(cfg->data.ptr, "r")) == NULL)
-            {
-              syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
-                    cfg->data.ptr);
-              return -1;
-            }
-          result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
-          fclose(fp);
-          if(!result)
-            {
-              syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
-                    cfg->data.ptr);
-              return -1;
-            }
-          return 0;
-        }
-      else
-        return -1;
-    }
-
-  /* Else, check if a harnessed public key is in the config file */
-
-  asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
-  if((fp = fopen(fname, "r")))
-    {
-      result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
-      fclose(fp);
-      free(fname);
-      if(result)
-        return 0;
-    }
-
-  free(fname);
-
-  /* Nothing worked. */
-
-  syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
-cp
-  return -1;
-}
-
-int read_rsa_private_key(void)
-{
-  config_t const *cfg;
-  FILE *fp;
-  void *result;
-cp
-  if(!myself->rsa_key)
-    myself->rsa_key = RSA_new();
-
-  if((cfg = get_config_val(config, config_privatekey)))
-    {
-      BN_hex2bn(&myself->rsa_key->d, cfg->data.ptr);
-      BN_hex2bn(&myself->rsa_key->e, "FFFF");
-    }
-  else if((cfg = get_config_val(config, config_privatekeyfile)))
-    {
-      if((fp = fopen(cfg->data.ptr, "r")) == NULL)
-        {
-          syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
-                cfg->data.ptr);
-          return -1;
-        }
-      result = PEM_read_RSAPrivateKey(fp, &myself->rsa_key, NULL, NULL);
-      fclose(fp);
-      if(!result)
-        {
-          syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
-                cfg->data.ptr);
-          return -1;
-        }
-    }
-  else
-    {
-      syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
-      return -1;
-    }
-cp
-  return 0;
-}
-
-/*
-  Configure connection_t myself and set up the local sockets (listen only)
-*/
-int setup_myself(void)
-{
-  config_t const *cfg;
-  config_t *next;
-  subnet_t *net;
-cp
-  myself = new_connection();
-
-  asprintf(&myself->hostname, "MYSELF");
-  myself->options = 0;
-  myself->protocol_version = PROT_CURRENT;
-
-  if(!(cfg = get_config_val(config, config_name))) /* Not acceptable */
-    {
-      syslog(LOG_ERR, _("Name for tinc daemon required!"));
-      return -1;
-    }
-  else
-    asprintf(&myself->name, "%s", (char*)cfg->data.val);
-
-  if(check_id(myself->name))
-    {
-      syslog(LOG_ERR, _("Invalid name for myself!"));
-      return -1;
-    }
-cp
-  if(read_rsa_private_key())
-    return -1;
-
-  if(read_host_config(myself))
-    {
-      syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
-      return -1;
-    }
-
-  if(read_rsa_public_key(myself))
-    return -1;
-cp
-
-/*
-  if(RSA_check_key(myself->rsa_key) != 1)
-    {
-      syslog(LOG_ERR, _("Invalid public/private keypair!"));
-      return -1;
-    }
-*/
-  if(!(cfg = get_config_val(myself->config, config_port)))
-    myself->port = 655;
-  else
-    myself->port = cfg->data.val;
-
-  if((cfg = get_config_val(myself->config, config_indirectdata)))
-    if(cfg->data.val == stupid_true)
-      myself->options |= OPTION_INDIRECT;
-
-  if((cfg = get_config_val(myself->config, config_tcponly)))
-    if(cfg->data.val == stupid_true)
-      myself->options |= OPTION_TCPONLY;
-
-/* Read in all the subnets specified in the host configuration file */
-
-  for(next = myself->config; (cfg = get_config_val(next, config_subnet)); next = cfg->next)
-    {
-      net = new_subnet();
-      net->type = SUBNET_IPV4;
-      net->net.ipv4.address = cfg->data.ip->address;
-      net->net.ipv4.mask = cfg->data.ip->mask;
-
-      /* Teach newbies what subnets are... */
-
-      if((net->net.ipv4.address & net->net.ipv4.mask) != net->net.ipv4.address)
-        {
-          syslog(LOG_ERR, _("Network address and subnet mask do not match!"));
-          return -1;
-        }
-
-      subnet_add(myself, net);
-    }
-
-  if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
-    {
-      syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
-      return -1;
-    }
-
-  if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
-    {
-      syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
-      return -1;
-    }
-cp
-  /* Generate packet encryption key */
-
-  myself->cipher_pkttype = EVP_bf_cbc();
-
-  myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
-
-  myself->cipher_pktkey = (char *)xmalloc(myself->cipher_pktkeylength);
-  RAND_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
-
-  if(!(cfg = get_config_val(config, config_keyexpire)))
-    keylifetime = 3600;
-  else
-    keylifetime = cfg->data.val;
-
-  keyexpires = time(NULL) + keylifetime;
-cp
-  /* Check some options */
-
-  if((cfg = get_config_val(config, config_indirectdata)))
-    {
-      if(cfg->data.val == stupid_true)
-        myself->options |= OPTION_INDIRECT;
-    }
-
-  if((cfg = get_config_val(config, config_tcponly)))
-    {
-      if(cfg->data.val == stupid_true)
-        myself->options |= OPTION_TCPONLY;
-    }
-
-  if(myself->options & OPTION_TCPONLY)
-    myself->options |= OPTION_INDIRECT;
-
-  /* Activate ourselves */
-
-  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_config_val(upstreamcfg, config_connectto);
+      for(snode = n->subnet_tree->head; snode; snode = snext)
+      {
+        snext = snode->next;
+        s = (subnet_t *)snode->data;
 
-  if(!cfg && upstreamcfg == config)
-    {
-      /* No upstream IP given, we're listen only. */
-      signal(SIGALRM, SIG_IGN);
-      return;
-    }
-    
-  while(cfg)
-    {
-      upstreamcfg = cfg->next;
-      if(!setup_outgoing_connection(cfg->data.ptr))   /* function returns 0 when there are no problems */
+        for(cnode = connection_tree->head; cnode; cnode = cnode->next)
         {
-          signal(SIGALRM, SIG_IGN);
-          return;
+          c = (connection_t *)cnode->data;
+          if(c->status.active)
+            send_del_subnet(c, s);
         }
-      cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
-    }
 
-  signal(SIGALRM, sigalrm_handler);
-  upstreamcfg = config;
-  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
-}
+        subnet_del(n, s);
+      }
 
-/*
-  setup all initial network connections
-*/
-int setup_network_connections(void)
-{
-  config_t const *cfg;
-cp
-  init_connections();
-  init_subnets();
+      for(enode = n->edge_tree->head; enode; enode = enext)
+      {
+        enext = enode->next;
+        e = (edge_t *)enode->data;
 
-  if((cfg = get_config_val(config, config_pingtimeout)) == NULL)
-    timeout = 60;
-  else
-    {
-      timeout = cfg->data.val;
-      if(timeout < 1)
+        for(cnode = connection_tree->head; cnode; cnode = cnode->next)
         {
-          timeout = 86400;
+          c = (connection_t *)cnode->data;
+          if(c->status.active)
+            send_del_edge(c, e);
         }
-     }
 
-  if(setup_tap_fd() < 0)
-    return -1;
-
-  /* Run tinc-up script to further initialize the tap interface */
-  execute_script("tinc-up");
-
-  if(setup_myself() < 0)
-    return -1;
-
-  if(!(cfg = get_config_val(config, config_connectto)))
-    /* No upstream IP given, we're listen only. */
-    return 0;
-
-  while(cfg)
-    {
-      upstreamcfg = cfg->next;
-      if(!setup_outgoing_connection(cfg->data.ptr))   /* function returns 0 when there are no problems */
-        return 0;
-      cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
-    }
-
-  if(do_detach)
-    {
-      signal(SIGALRM, sigalrm_handler);
-      upstreamcfg = config;
-      seconds_till_retry = MAXTIMEOUT;
-      syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
-      alarm(seconds_till_retry);
-    }
-  else
-    return -1;
-
-cp
-  return 0;
-}
-
-/*
-  close all open network connections
-*/
-void close_network_connections(void)
-{
-  avl_node_t *node;
-  connection_t *p;
-cp
-  for(node = connection_tree->head; node; node = node->next)
-    {
-      p = (connection_t *)node->data;
-      p->status.outgoing = 0;
-      p->status.active = 0;
-      terminate_connection(p);
-    }
-
-  if(myself)
-    if(myself->status.active)
-      {
-       close(myself->meta_socket);
-        free_connection(myself);
-        myself = NULL;
+        edge_del(e);
       }
 
-  close(tap_fd);
-
-  /* Execute tinc-down script right after shutting down the interface */
-  execute_script("tinc-down");
-
-  destroy_connection_tree();
-cp
-  return;
-}
-
-/*
-  handle an incoming tcp connect call and open
-  a connection to it.
-*/
-connection_t *create_new_connection(int sfd)
-{
-  connection_t *p;
-  struct sockaddr_in ci;
-  int len = sizeof(ci);
-cp
-  p = new_connection();
-
-  if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
-    {
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "getpeername");
-      close(sfd);
-      return NULL;
+      node_del(n);
     }
-
-  p->name = unknown;
-  p->address = ntohl(ci.sin_addr.s_addr);
-  p->hostname = hostlookup(ci.sin_addr.s_addr);
-  p->port = htons(ci.sin_port);                                /* This one will be overwritten later */
-  p->meta_socket = sfd;
-  p->status.meta = 1;
-  p->buffer = xmalloc(MAXBUFSIZE);
-  p->buflen = 0;
-  p->last_ping_time = time(NULL);
-
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_NOTICE, _("Connection from %s port %d"),
-         p->hostname, htons(ci.sin_port));
-
-  p->allow_request = ID;
+  }
 cp
-  return p;
 }
 
 /*
-  put all file descriptors in an fd_set array
+  Terminate a connection:
+  - Close the socket
+  - Remove associated edge and tell other connections about it if report = 1
+  - Check if we need to retry making an outgoing connection
+  - Deactivate the host
 */
-void build_fdset(fd_set *fs)
+void terminate_connection(connection_t *c, int report)
 {
   avl_node_t *node;
-  connection_t *p;
-cp
-  FD_ZERO(fs);
-
-  FD_SET(myself->socket, fs);
-
-  for(node = connection_tree->head; node; node = node->next)
-    {
-      p = (connection_t *)node->data;
-      if(p->status.meta)
-        FD_SET(p->meta_socket, fs);
-    }
-
-  FD_SET(myself->meta_socket, fs);
-  FD_SET(tap_fd, fs);
-cp
-}
-
-/*
-  receive incoming data from the listening
-  udp socket and write it to the ethertap
-  device after being decrypted
-*/
-void handle_incoming_vpn_data(void)
-{
-  vpn_packet_t pkt;
-  int x, l = sizeof(x);
-  int lenin;
-  struct sockaddr_in from;
-  socklen_t fromlen = sizeof(from);
-  connection_t *cl;
-cp
-  if(getsockopt(myself->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
-    {
-      syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
-            __FILE__, __LINE__, myself->socket);
-      return;
-    }
-  if(x)
-    {
-      syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
-      return;
-    }
-
-  if((lenin = recvfrom(myself->socket, (char *) &(pkt.len), MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
-    {
-      syslog(LOG_ERR, _("Receiving packet failed: %m"));
-      return;
-    }
-
-  cl = lookup_connection(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
-
-  if(!cl)
-    {
-      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));
-      return;
-    }
-
-  receive_udppacket(cl, &pkt);
-cp
-}
-
-/*
-  terminate a connection and notify the other
-  end before closing the sockets
-*/
-void terminate_connection(connection_t *cl)
-{
-  connection_t *p;
-  subnet_t *subnet;
-  avl_node_t *node, *next;
+  connection_t *other;
 cp
-  if(cl->status.remove)
+  if(c->status.remove)
     return;
 
   if(debug_lvl >= DEBUG_CONNECTIONS)
     syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
-           cl->name, cl->hostname);
+           c->name, c->hostname);
 
-  cl->status.remove = 1;
+  c->status.remove = 1;
 
-  if(cl->socket)
-    close(cl->socket);
-  if(cl->status.meta)
-    close(cl->meta_socket);
+  if(c->socket)
+    close(c->socket);
 
-  if(cl->status.meta)
+  if(c->edge)
     {
+      if(report)
+        {
+          for(node = connection_tree->head; node; node = node->next)
+            {
+              other = (connection_t *)node->data;
+              if(other->status.active && other != c)
+                send_del_edge(other, c->edge);
+            }
+        }
 
-      /* Find all connections that were lost because they were behind cl
-         (the connection that was dropped). */
-
-        for(node = connection_tree->head; node; node = node->next)
-          {
-            p = (connection_t *)node->data;
-            if(p->nexthop == cl && p != cl)
-              terminate_connection(p);
-          }
-
-      /* Inform others of termination if it was still active */
-
-      if(cl->status.active)
-        for(node = connection_tree->head; node; node = node->next)
-          {
-            p = (connection_t *)node->data;
-            if(p->status.meta && p->status.active && p != cl)
-              send_del_host(p, cl);    /* Sounds like recursion, but p does not have a meta connection :) */
-          }
+      edge_del(c->edge);
     }
 
-  /* Remove the associated subnets */
+  /* Run MST and SSSP algorithms */
 
-  for(node = cl->subnet_tree->head; node; node = next)
-    {
-      next = node->next;
-      subnet = (subnet_t *)node->data;
-      subnet_del(subnet);
-    }
+  graph();
 
   /* Check if this was our outgoing connection */
 
-  if(cl->status.outgoing)
+  if(c->outgoing)
     {
-      cl->status.outgoing = 0;
-      signal(SIGALRM, sigalrm_handler);
-      seconds_till_retry = 5;
-      alarm(seconds_till_retry);
-      syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in 5 seconds"));
+      retry_outgoing(c->outgoing);
+      c->outgoing = NULL;
     }
 
-  /* Inactivate */
+  /* Deactivate */
 
-  cl->status.active = 0;
+  c->status.active = 0;
+  if(c->node)
+    c->node->connection = NULL;
+  do_prune = 1;
 cp
 }
 
 */
 void check_dead_connections(void)
 {
-  time_t now;
-  avl_node_t *node;
-  connection_t *cl;
+  avl_node_t *node, *next;
+  connection_t *c;
 cp
-  now = time(NULL);
-
-  for(node = connection_tree->head; node; node = node->next)
+  for(node = connection_tree->head; node; node = next)
     {
-      cl = (connection_t *)node->data;
-      if(cl->status.active && cl->status.meta)
+      next = node->next;
+      c = (connection_t *)node->data;
+      if(c->last_ping_time + pingtimeout < now)
         {
-          if(cl->last_ping_time + timeout < now)
+          if(c->status.active)
             {
-              if(cl->status.pinged)
+              if(c->status.pinged)
                 {
                   if(debug_lvl >= DEBUG_PROTOCOL)
-                   syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
-                          cl->name, cl->hostname);
-                 cl->status.timeout = 1;
-                 terminate_connection(cl);
+                    syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
+                           c->name, c->hostname);
+                  c->status.timeout = 1;
+                  terminate_connection(c, 1);
                 }
               else
                 {
-                  send_ping(cl);
+                  send_ping(c);
                 }
             }
+          else
+            {
+              if(debug_lvl >= DEBUG_CONNECTIONS)
+                syslog(LOG_WARNING, _("Timeout from %s (%s) during authentication"),
+                       c->name, c->hostname);
+              terminate_connection(c, 0);
+            }
         }
     }
 cp
 }
 
-/*
-  accept a new tcp connect and create a
-  new connection
-*/
-int handle_new_meta_connection()
-{
-  connection_t *ncn;
-  struct sockaddr client;
-  int nfd, len = sizeof(client);
-cp
-  if((nfd = accept(myself->meta_socket, &client, &len)) < 0)
-    {
-      syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
-      return -1;
-    }
-
-  if(!(ncn = create_new_connection(nfd)))
-    {
-      shutdown(nfd, 2);
-      close(nfd);
-      syslog(LOG_NOTICE, _("Closed attempted connection"));
-      return 0;
-    }
-
-  connection_add(ncn);
-
-  send_id(ncn);
-cp
-  return 0;
-}
-
 /*
   check all connections to see if anything
   happened on their sockets
 */
 void check_network_activity(fd_set *f)
 {
-  connection_t *p;
+  connection_t *c;
   avl_node_t *node;
+  int result, i;
+  int len = sizeof(result);
+  vpn_packet_t packet;
 cp
-  if(FD_ISSET(myself->socket, f))
-    handle_incoming_vpn_data();
-
-  for(node = connection_tree->head; node; node = node->next)
+  if(FD_ISSET(device_fd, f))
     {
-      p = (connection_t *)node->data;
-
-      if(p->status.remove)
-       return;
-
-      if(p->status.meta)
-       if(FD_ISSET(p->meta_socket, f))
-         if(receive_meta(p) < 0)
-           {
-             terminate_connection(p);
-             return;
-           }
+      if(!read_packet(&packet))
+        route_outgoing(&packet);
     }
 
-  if(FD_ISSET(myself->meta_socket, f))
-    handle_new_meta_connection();
-cp
-}
-
-/*
-  read, encrypt and send data that is
-  available through the ethertap device
-*/
-void handle_tap_input(void)
-{
-  vpn_packet_t vp;
-  int lenin;
-cp
-  if(taptype == TAP_TYPE_TUNTAP)
+  for(i = 0; i < listen_sockets; i++)
     {
-      if((lenin = read(tap_fd, vp.data, MTU)) <= 0)
-        {
-          syslog(LOG_ERR, _("Error while reading from tun/tap device: %m"));
-          return;
-        }
-      vp.len = lenin;
+      if(FD_ISSET(udp_socket[i], f))
+       handle_incoming_vpn_data(udp_socket[i]);
+      if(FD_ISSET(tcp_socket[i], f))
+       handle_new_meta_connection(tcp_socket[i]);
     }
-  else                 /* ethertap */
+
+  for(node = connection_tree->head; node; node = node->next)
     {
-      if((lenin = read(tap_fd, vp.data - 2, MTU)) <= 0)
+      c = (connection_t *)node->data;
+
+      if(c->status.remove)
+        return;
+
+      if(FD_ISSET(c->socket, f))
         {
-          syslog(LOG_ERR, _("Error while reading from ethertap device: %m"));
-          return;
+          if(c->status.connecting)
+            {
+              c->status.connecting = 0;
+              getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
+              if(!result)
+                finish_connecting(c);
+              else
+                {
+                  if(debug_lvl >= DEBUG_CONNECTIONS)
+                    syslog(LOG_DEBUG, _("Error while connecting to %s (%s): %s"), c->name, c->hostname, strerror(result));
+                  close(c->socket);
+                  do_outgoing_connection(c);
+                  continue;
+                }
+            }
+          if(receive_meta(c) < 0)
+            {
+              terminate_connection(c, c->status.active);
+              return;
+            }
         }
-      vp.len = lenin - 2;
     }
+cp
+}
 
-  total_tap_in += lenin;
-
-  if(lenin < 32)
+void prune_connections(void)
+{
+  connection_t *c;
+  avl_node_t *node, *next;
+cp
+  for(node = connection_tree->head; node; node = next)
     {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-       syslog(LOG_WARNING, _("Received short packet from tap device"));
-      return;
-    }
+      next = node->next;
+      c = (connection_t *)node->data;
 
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    {
-      syslog(LOG_DEBUG, _("Read packet of length %d from tap device"), vp.len);
+      if(c->status.remove)
+        connection_del(c);
     }
 
-  route_outgoing(&vp);
+  if(!connection_tree->head)
+    purge();
 cp
 }
 
@@ -1310,76 +356,109 @@ void main_loop(void)
   int r;
   time_t last_ping_check;
   int t;
+  event_t *event;
 cp
-  last_ping_check = time(NULL);
+  last_ping_check = now;
+
+  srand(now);
 
   for(;;)
     {
-      tv.tv_sec = timeout;
+      now = time(NULL);
+
+      tv.tv_sec = 1 + (rand() & 7); /* Approx. 5 seconds, randomized to prevent global synchronisation effects */
       tv.tv_usec = 0;
 
-      prune_connection_tree();
       build_fdset(&fset);
 
       if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
         {
-         if(errno != EINTR) /* because of alarm */
+          if(errno != EINTR) /* because of a signal */
             {
-              syslog(LOG_ERR, _("Error while waiting for input: %m"));
+              syslog(LOG_ERR, _("Error while waiting for input: %s"), strerror(errno));
               return;
             }
         }
 
-      if(sighup)
-        {
-          syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
-          sighup = 0;
-          close_network_connections();
-          clear_config(&config);
-
-          if(read_server_config())
-            {
-              syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
-              exit(1);
-            }
-
-          sleep(5);
-
-          if(setup_network_connections())
-            return;
+      if(r > 0)
+        check_network_activity(&fset);
 
-          continue;
+      if(do_prune)
+        {
+          prune_connections();
+          do_prune = 0;
         }
 
-      t = time(NULL);
+     if(do_purge)
+        {
+          purge();
+          do_purge = 0;
+        }
 
       /* Let's check if everybody is still alive */
 
-      if(last_ping_check + timeout < t)
-       {
-         check_dead_connections();
-          last_ping_check = time(NULL);
+      if(last_ping_check + pingtimeout < now)
+        {
+          check_dead_connections();
+          last_ping_check = now;
+
+          if(routing_mode== RMODE_SWITCH)
+           age_mac();
 
           /* Should we regenerate our key? */
 
-          if(keyexpires < t)
+          if(keyexpires < now)
             {
               if(debug_lvl >= DEBUG_STATUS)
                 syslog(LOG_INFO, _("Regenerating symmetric key"));
 
-              RAND_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
-              send_key_changed(myself, NULL);
-              keyexpires = time(NULL) + keylifetime;
+              RAND_pseudo_bytes(myself->key, myself->keylength);
+              send_key_changed(myself->connection, myself);
+              keyexpires = now + keylifetime;
             }
-       }
+        }
 
-      if(r > 0)
+
+      while((event = get_expired_event()))
+        {
+          event->handler(event->data);
+          free(event);
+        }
+
+      if(sigalrm)
         {
-          check_network_activity(&fset);
+          syslog(LOG_INFO, _("Flushing event queue"));
 
-          /* local tap data */
-          if(FD_ISSET(tap_fd, &fset))
-           handle_tap_input();
+          while(event_tree->head)
+            {
+              event = (event_t *)event_tree->head->data;
+              event->handler(event->data);
+              event_del(event);
+            }
+          sigalrm = 0;
+        }
+
+      if(sighup)
+        {
+          sighup = 0;
+          close_network_connections();
+          exit_configuration(&config_tree);
+
+          syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
+          sleep(5);
+
+          init_configuration(&config_tree);
+
+          if(read_server_config())
+            {
+              syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
+              exit(1);
+            }
+
+          if(setup_network_connections())
+            return;
+
+          continue;
         }
     }
 cp