X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=57e071ae03b8c2e76dce54489a210cf333bbdd13;hp=3b23c9e28e1c92e612dd2da1668dee863518fd2c;hb=76b5f255c6cb0c5dfb5a870c371ec6f7c7879bb2;hpb=e4ff969a9868ecc25a85daab620f97227de8d493

diff --git a/src/protocol.c b/src/protocol.c
index 3b23c9e2..57e071ae 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -1,6 +1,7 @@
 /*
     protocol.c -- handle the meta-protocol
-    Copyright (C) 1999,2000 Ivo Timmermans <zarq@iname.com>
+    Copyright (C) 1999,2000 Ivo Timmermans <itimmermans@bigfoot.com>,
+                       2000 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
@@ -15,6 +16,8 @@
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+    $Id: protocol.c,v 1.28.4.28 2000/09/10 23:11:37 guus Exp $
 */
 
 #include "config.h"
@@ -31,766 +34,817 @@
 #include <utils.h>
 #include <xalloc.h>
 
+#include <netinet/in.h>
+
 #include "conf.h"
 #include "encr.h"
 #include "net.h"
 #include "netutl.h"
 #include "protocol.h"
 
-char buffer[MAXBUFSIZE+1];
-int buflen;
+#include "system.h"
 
-/* Outgoing request routines */
+/* Generic outgoing request routine - takes care of logging and error detection as well */
 
-int send_ack(conn_list_t *cl)
+int send_request(conn_list_t *cl, const char *format, int request, /*args*/ ...)
 {
+  va_list args;
+  char *buffer = NULL;
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Send ACK to %s", cl->hostname);
+  if(debug_lvl >= DEBUG_PROTOCOL)
+    syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), requestname[request], cl->id, cl->hostname);
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d\n", ACK);
+  va_start(args, format);
+  len = vasprintf(&buffer, format, args);
+  va_end(args);
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(len < 0 || !buffer)
     {
-      syslog(LOG_ERR, "send failed: %d:%d: %m", __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Error during vasprintf(): %m"));
       return -1;
     }
 
-  syslog(LOG_NOTICE, "Connection with %s activated.", cl->hostname);
-cp
-  return 0;
-}
+  if(debug_lvl >= DEBUG_META)
+    syslog(LOG_DEBUG, _("Sending meta data to %s (%s): %s"), cl->id, cl->hostname, buffer);
 
-int send_termreq(conn_list_t *cl)
-{
-cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Send TERMREQ to " IP_ADDR_S,
-	   IP_ADDR_V(cl->vpn_ip));
-
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx\n", TERMREQ, myself->vpn_ip);
+  if(cl->status.encryptout)
+    {
+      /* FIXME: Do encryption */
+    }
 
-  if(write(cl->meta_socket, buffer, buflen) < 0)
+  if((write(cl->meta_socket, buffer, buflen)) < 0)
     {
-      if(debug_lvl > 1)
-	syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Sending meta data failed:  %m"));
       return -1;
     }
-cp
-  return 0;
+cp  
 }
 
-int send_timeout(conn_list_t *cl)
+/* Connection protocol:
+
+   Client               Server
+   send_id(*)
+                        send_challenge
+   send_chal_reply(*)                   
+                        send_id
+   send_challenge
+                        send_chal_reply
+   send_ack
+			send_ack
+
+   (*) Unencrypted.
+*/      
+
+int send_id(conn_list_t *cl)
 {
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Send TIMEOUT to " IP_ADDR_S,
-	   IP_ADDR_V(cl->vpn_ip));
+  return send_request(cl, "%d %s %d %s", ID, myself->id, myself->version, opt2str(myself->options));
+}
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx\n", PINGTIMEOUT, myself->vpn_ip);
+int id_h(conn_list_t *cl)
+{
+  conn_list_t *old;
+  char *options;
+cp
+  if(sscanf(cl->buffer, "%*d %as %d %as", &cl->id, &cl->version, &options) != 3)
+    {
+       syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname);
+       return -1;
+    }
+    
+  /* Check if version matches */
+  
+  if(cl->version != myself->version)
+    {
+      syslog(LOG_ERR, _("Peer %s uses incompatible version %d"), cl->hostname, cl->min_version, cl->max_version);
+      return -1;
+    }
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  /* Check if option string is valid */
+  
+  if((cl->options = str2opt(options)) == -1)
     {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Peer %s uses invalid option string"), cl->hostname);
+      return -1;
+    }
+    
+  /* Check if identity is a valid name */
+  
+  if(!check_id(cl->id))
+    {
+      syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname);
+      return -1;
+    }
+    
+  /* Load information about peer */
+  
+  if(!read_id(cl))
+    {
+      syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->id);
       return -1;
     }
-cp
-  return 0;
-}
 
-int send_del_host(conn_list_t *cl, conn_list_t *new_host)
-{
-cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Sending delete host " IP_ADDR_S " to " IP_ADDR_S,
-	   IP_ADDR_V(new_host->vpn_ip), IP_ADDR_V(cl->vpn_ip));
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx\n", DEL_HOST, new_host->vpn_ip);
+  /* First check if the host we connected to is already in our
+     connection list. If so, we are probably making a loop, which
+     is not desirable.
+   */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(cl->status.outgoing)
     {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
+      if((old=lookup_id(cl->id)))
+        {
+          if(debug_lvl > DEBUG_CONNECTIONS)
+            syslog(LOG_NOTICE, _("Uplink %s (%s) is already in our connection list"), cl->id, cl->hostname);
+          cl->status.outgoing = 0;
+          old->status.outgoing = 1;
+          terminate_connection(cl);
+          return 0;
+        }
     }
+
+  /* Since we know the identity now, we can encrypt the meta channel */
+  
+  cl->status.encryptout = 1;
+
+  /* Send a challenge to verify the identity */
+
+  cl->allow_request = CHAL_REPLY;
 cp
-  return 0;
+  return send_challenge(cl);
 }
 
-int send_ping(conn_list_t *cl)
+int send_challenge(conn_list_t *cl)
 {
+  char *buffer;
+  int keylength;
+  int x;
 cp
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, "pinging " IP_ADDR_S, IP_ADDR_V(cl->vpn_ip));
+  if(cl->chal_hash)
+    free(cl->chal_hash);
+  
+  /* Allocate buffers for the challenge and the hash */
+  
+  cl->chal_hash = xmalloc(SHA_DIGEST_LEN);
+  keylength = BN_num_bytes(cl->metakey.n);
+  buffer = xmalloc(keylength*2);
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d\n", PING);
+  /* Copy random data and the public key to the buffer */
+  
+  RAND_bytes(buffer, keylength);
+  BN_bn2bin(cl->metakey.n, buffer+keylength);
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
-    {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
-    }
+  /* Calculate the hash from that */
+
+  SHA1(buffer, keylength*2, cl->chal_hash);
+
+  /* Convert the random data to a hexadecimal formatted string */
+
+  bin2hex(buffer,buffer,keylength);
+  buffer[keylength*2] = '\0';
+
+  /* Send the challenge */
+  
+  cl->allow_request = CHAL_REPLY;
+  x = send_request(cl, "%d %s", CHALLENGE, buffer);
+  free(buffer);
 cp
-  return 0;
+  return x;
 }
 
-int send_pong(conn_list_t *cl)
+int challenge_h(conn_list_t *cl)
 {
+  char *challenge;
 cp
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d\n", PONG);
-
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(sscanf(cl->buffer, "%*d %as", &cl->id, &challenge) != 1)
     {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
+       syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->id, cl->hostname);
+       return -1;
     }
+
+  /* Rest is done by send_chal_reply() */
+  
+  x = send_chal_reply(cl, challenge);
+  free(challenge);
 cp
-  return 0;
+  return x;
 }
 
-int send_add_host(conn_list_t *cl, conn_list_t *new_host)
+int send_chal_reply(conn_list_t *cl, char *challenge)
 {
+  char *buffer;
+  int keylength;
+  char *hash;
+  int x;
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Sending add host to " IP_ADDR_S,
-	   IP_ADDR_V(cl->vpn_ip));
+  keylength = BN_num_bytes(myself->meyakey.n);
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx %lx/%lx:%x\n", ADD_HOST, new_host->real_ip, new_host->vpn_ip, new_host->vpn_mask, new_host->port);
+  /* Check if the length of the challenge is all right */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(strlen(challenge) != keylength*2)
     {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
+      syslog(LOG_ERROR, _("Intruder: wrong challenge length from %s (%s)"), cl->id, cl->hostname);
       return -1;
     }
+
+  /* Allocate buffers for the challenge and the hash */
+  
+  buffer = xmalloc(keylength*2);
+  hash = xmalloc(SHA_DIGEST_LEN*2+1);
+
+  /* Copy the incoming random data and our public key to the buffer */
+
+  hex2bin(challenge, buffer, keylength); 
+  BN_bn2bin(myself->metakey.n, buffer+keylength);
+
+  /* Calculate the hash from that */
+  
+  SHA1(buffer, keylength*2, hash);
+  free(buffer);
+
+  /* Convert the hash to a hexadecimal formatted string */
+
+  bin2hex(hash,hash,SHA_DIGEST_LEN);
+  hash[SHA_DIGEST_LEN*2] = '\0';
+
+  /* Send the reply */
+
+  if(cl->status.outgoing)
+    cl->allow_resuest = ID;
+  else
+    cl->allow_request = ACK;
+
+  x = send_request(cl, "%d %s", CHAL_REPLY, hash);
+  free(hash);
 cp
-  return 0;
-}
+  return x;
+} 
 
-int send_key_changed(conn_list_t *cl, conn_list_t *src)
+int chal_reply_h(conn_list_t *cl)
 {
+  char *hash;
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Sending KEY_CHANGED to " IP_ADDR_S,
-	   IP_ADDR_V(cl->vpn_ip));
-
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx\n", KEY_CHANGED, src->vpn_ip);
+  if(sscanf(cl->buffer, "%*d %as", &cl->id, &hash) != 2)
+    {
+       syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->id, cl->hostname);
+       return -1;
+    }
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  /* Check if the length of the hash is all right */
+  
+  if(strlen(hash) != SHA_DIGEST_LEN*2)
     {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
+      syslog(LOG_ERROR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->id, cl->hostname);
       return -1;
     }
+    
+  /* Convert the hash to binary format */
+  
+  hex2bin(hash, hash, SHA_DIGEST_LEN);
+  
+  /* Verify the incoming hash with the calculated hash */
+  
+  if{!memcmp(hash, cl->chal_hash, SHA_DIGEST_LEN)}
+    {
+      syslog(LOG_ERROR, _("Intruder: wrong challenge reply from %s (%s)"), cl->id, cl->hostname);
+      return -1;
+    }
+
+  /* Identity has now been positively verified.
+     If we are accepting this new connection, then send our identity,
+     if we are making this connecting, acknowledge.
+   */
+   
+  free(hash);
+  free(cl->chal_hash);
+
 cp
-  return 0;
+  if(cl->status.outgoing)
+    {
+      cl->allow_request = ACK;
+      return send_ack(cl);
+    }
+  else
+    {
+      cl->allow_request = CHALLENGE;
+      return send_id(cl);
+    }
 }
 
-void send_key_changed_all(void)
+int send_ack(conn_list_t *cl)
 {
-  conn_list_t *p;
-cp
-  for(p = conn_list; p != NULL; p = p->next)
-    if(p->status.meta && p->active)
-      send_key_changed(p, myself);
 cp
+  return send_request(cl, "%d", ACK);
 }
 
-int send_basic_info(conn_list_t *cl)
+int ack_h(conn_list_t *cl)
 {
+  conn_list_t old;
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Send BASIC_INFO to " IP_ADDR_S,
-	   IP_ADDR_V(cl->real_ip));
-
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %d %lx/%lx:%x\n", BASIC_INFO, PROT_CURRENT, myself->vpn_ip, myself->vpn_mask, myself->port);
+  /* Okay, before we active the connection, we check if there is another entry
+     in the connection list with the same vpn_ip. If so, it presumably is an
+     old connection that has timed out but we don't know it yet.
+   */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  while((old = lookup_id(cl->id))) 
     {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
+      if(debug_lvl > DEBUG_CONNECTIONS)
+        syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"),
+        cl->id, old->hostname, cl->hostname);
+      old->status.active = 0;
+      terminate_connection(old);
     }
-cp
-  return 0;
-}
 
-int send_passphrase(conn_list_t *cl)
-{
-  passphrase_t tmp;
-cp
-  encrypt_passphrase(&tmp);
+  /* Activate this connection */
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Send PASSPHRASE %s to " IP_ADDR_S,
-	   tmp.phrase, IP_ADDR_V(cl->vpn_ip));
+  cl->allow_request = ALL;
+  cl->status.active = 1;
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", PASSPHRASE, tmp.phrase);
+  if(debug_lvl > DEBUG_CONNECTIONS)
+    syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->id, cl->hostname);
+
+  /* Exchange information about other tinc daemons */
+
+  notify_others(cl, NULL, send_add_host);
+  notify_one(cl);
+
+  upstreamindex = 0;
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
-    {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
-    }
 cp
-  return 0;
+  if(cl->status.outgoing)
+    return 0;
+  else
+    return send_ack(cl);
 }
 
-int send_public_key(conn_list_t *cl)
+/* Address and subnet information exchange */
+
+int send_add_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
 {
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Send PUBLIC_KEY %s to " IP_ADDR_S,
-	   my_public_key_base36, IP_ADDR_V(cl->vpn_ip));
+  return send_request(cl, "%d %s %d %s", ADD_SUBNET, other->id, subnet->type, net2str(subnet));
+}
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", PUBLIC_KEY, my_public_key_base36);
+int add_subnet_h(conn_list_t *cl)
+{
+}
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
-    {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
-    }
+int send_del_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
+{
 cp
-  return 0;
+  return send_request(cl, "%d %s %d %s", DEL_SUBNET, other->id, subnet->type, net2str(subnet));
 }
 
-int send_calculate(conn_list_t *cl, char *k)
+int del_subnet_h(conn_list_t *cl)
 {
-cp
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", CALCULATE, k);
+}
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
-    {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
-    }
+/* New and closed connections notification */
+
+int send_add_host(conn_list_t *cl, conn_list_t *other)
+{
 cp
-  return 0;
+  return send_request(cl, "%d %s %lx:%d %s", ADD_HOST, other->id, other->address, other->port, opt2str(other->options));
 }
 
-int send_key_request(ip_t to)
+int add_host_h(conn_list_t *cl)
 {
-  conn_list_t *fw;
+  char *options;
+  conn_list_t *old, *new;
 cp
-  fw = lookup_conn(to);
-  if(!fw)
-    {
-      syslog(LOG_ERR, "Attempting to send key request to " IP_ADDR_S ", which does not exist?",
-	     IP_ADDR_V(to));
-      return -1;
-    }
+  new = new_conn_list();
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Sending out request for public key to " IP_ADDR_S,
-	   IP_ADDR_V(fw->nexthop->vpn_ip));
-
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx %lx\n", REQ_KEY, to, myself->vpn_ip);
+  if(sscanf(cl->buffer, "%*d %as %lx:%d %as", &new->id, &new->address, &new->port, &options) != 4)
+    {
+       syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->id, cl->hostname);
+       return -1;
+    }  
 
-  if((write(fw->nexthop->meta_socket, buffer, buflen)) < 0)
+  /* Check if option string is valid */
+  
+  if((new->options = str2opt(options) == -1)
     {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid option string"), cl->hostname);
       return -1;
     }
-  fw->status.waitingforkey = 1;
-cp
-  return 0;
-}
-
-int send_key_answer(conn_list_t *cl, ip_t to)
-{
-  conn_list_t *fw;
-cp
 
-  fw = lookup_conn(to);
+  /* Check if identity is a valid name */
   
-  if(!fw)
+  if(!check_id(new->id))
     {
-      syslog(LOG_ERR, "Attempting to send key answer to " IP_ADDR_S ", which does not exist?",
-	     IP_ADDR_V(to));
+      syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->id, cl->hostname);
       return -1;
     }
+    
+  /* Check if somebody tries to add ourself */
+  
+  if(!strcmp(new->id, myself->id))
+    {
+      syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->id, cl->hostname);
+      sighup = 1;
+      return 0;
+    }
 
- if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Sending public key to " IP_ADDR_S,
-	   IP_ADDR_V(fw->nexthop->vpn_ip));
+  /* Fill in more of the new conn_list structure */
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx %lx %d %s\n", ANS_KEY, to, myself->vpn_ip, my_key_expiry, my_public_key_base36);
+  new->hostname = hostlookup(htonl(new->address));
+  
+  /* Check if the new host already exists in the connnection list */
 
-  if((write(fw->nexthop->meta_socket, buffer, buflen)) < 0)
+  if((old = lookup_id(id))
     {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
+      if((new->address == old->address) && (new->port == old->port))
+        {
+          if(debug_lvl > DEBUG_CONNECTIONS)
+            syslog(LOG_NOTICE, _("Got duplicate ADD_HOST for %s (%s) from %s (%s)"), old->id, old->hostname, new->id, new->hostname);
+	  return 0;
+        }
+      else
+        {
+          if(debug_lvl > DEBUG_CONNECTIONS)
+            syslog(LOG_NOTICE, _("Removing old entry for %s (%s)"), old->id, old->hostname);
+          old->status.active = 0;
+          terminate_connection(old);
+        }
     }
-cp
-  return 0;
-}
 
-/*
-  notify all my direct connections of a new host
-  that was added to the vpn, with the exception
-  of the source of the announcement.
-*/
-int notify_others(conn_list_t *new, conn_list_t *source,
-		  int (*function)(conn_list_t*, conn_list_t*))
-{
-  conn_list_t *p;
-cp
-  for(p = conn_list; p != NULL; p = p->next)
-    if(p != new && p != source && p->status.meta && p->active)
-      function(p, new);
+  /* Fill in rest of conn_list structure */
+
+  new->nexthop = cl;
+  new->status.active = 1;
+  
+  /* Hook it up into the conn_list */
+
+  conn_list_add(conn_list, new);
+
+  /* Tell the rest about the new host */
+  
+  notify_others(new, cl, send_add_host);
+  
 cp
   return 0;
 }
 
-/*
-  notify one connection of everything
-  i have connected
-*/
-int notify_one(conn_list_t *new)
+int send_del_host(conn_list_t *cl, conn_list_t *other)
 {
-  conn_list_t *p;
-cp
-  for(p = conn_list; p != NULL; p = p->next)
-    if(p != new && p->active)
-      send_add_host(new, p);
 cp
-  return 0;
+  return send_request(cl, "%d %s %lx:%d", DEL_HOST, other->id, other->address, other->port);
 }
 
-/*
-  The incoming request handlers
-*/
-
-int basic_info_h(conn_list_t *cl)
+int del_host_h(conn_list_t *cl)
 {
+  char *id;
+  ip_t address;
+  port_t port;
+  conn_list_t *old;
 cp
-  if(sscanf(cl->buffer, "%*d %d %lx/%lx:%hx", &cl->protocol_version, &cl->vpn_ip, &cl->vpn_mask, &cl->port) != 4)
+  if(sscanf(cl->buffer, "%*d %as %lx:%d", &id, &address, &port) != 3)
     {
-       syslog(LOG_ERR, "got bad BASIC_INFO request: %s", cl->buffer);
+       syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"), cl->id, cl->hostname);
        return -1;
     }  
 
-  if(cl->protocol_version != PROT_CURRENT)
+  /* Check if somebody tries to delete ourself */
+  
+  if(!strcmp(id, myself->id))
     {
-      syslog(LOG_ERR, "Peer uses incompatible protocol version %d.",
-	     cl->protocol_version);
-      return -1;
+      syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"), cl->id, cl->hostname);
+      sighup = 1;
+      return 0;
     }
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "got BASIC_INFO(%hd," IP_ADDR_S "," IP_ADDR_S ")", cl->port,
-	   IP_ADDR_V(cl->vpn_ip), IP_ADDR_V(cl->vpn_mask));
-  if(debug_lvl > 1)
-    syslog(LOG_DEBUG, "Peer uses protocol version %d",
-	   cl->protocol_version);
+  /* Check if the new host already exists in the connnection list */
 
-  if(cl->status.outgoing)
+  if((old = lookup_id(id))
     {
-      if(setup_vpn_connection(cl) < 0)
-	return -1;
-      send_basic_info(cl);
+      if((address == old->address) && (port == old->port))
+        {
+          notify_others(old, cl, send_del_host);
+
+          fw->status.termreq = 1;
+          fw->status.active = 0;
+
+          terminate_connection(fw);
+cp
+          return 0;
+        }
     }
-  else
+
+  if(debug_lvl > DEBUG_CONNECTIONS)
     {
-      if(setup_vpn_connection(cl) < 0)
-	return -1;
-      send_passphrase(cl);
+      syslog(LOG_NOTICE, _("Got DEL_HOST for %s from %s (%s) which is not in our connection list"), id, cl->id, cl->hostname);
     }
 cp
   return 0;
 }
 
-int passphrase_h(conn_list_t *cl)
+/* Status and error notification routines */
+
+int send_status(conn_list_t *cl, int statusno, char *statusstring)
 {
 cp
-  cl->pp = xmalloc(sizeof(*(cl->pp)));
+  if(!statusstring)
+    statusstring = status_text[statusno];
+cp
+  return send_request(cl, "%d %d %s", STATUS, statusno, statusstring);
+}
 
-  if(sscanf(cl->buffer, "%*d %as", &(cl->pp->phrase)) != 1)
+int status_h(conn_list_t *cl)
+{
+  int statusno;
+  char *statusstring;
+cp
+  if(sscanf(cl->buffer, "%*d %d %as", &statusno, &statusstring) != 2)
     {
-      syslog(LOG_ERR, "got bad PASSPHRASE request: %s", cl->buffer);
-      return -1;
+       syslog(LOG_ERR, _("Got bad STATUS from %s (%s)"), cl->id, cl->hostname);
+       return -1;
+    }
+
+  if(debug_lvl > DEBUG_STATUS)
+    {
+      syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"), cl->id, cl->hostname, status_text[statusno], statusstring);
     }
-  cl->pp->len = strlen(cl->pp->phrase);
-    
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "got PASSPHRASE");
 
-  if(cl->status.outgoing)
-    send_passphrase(cl);
-  else
-    send_public_key(cl);
 cp
+  free(statusstring);
   return 0;
 }
 
-int public_key_h(conn_list_t *cl)
+int send_error(conn_list_t *cl, int errno, char *errstring)
 {
-  char *g_n;
-  conn_list_t *old;
 cp
-  if(sscanf(cl->buffer, "%*d %as", &g_n) != 1)
+  if(!errorstring)
+    errorstring = error_text[errno];
+  return send_request(cl, "%d %d %s", ERROR, errno, errstring);
+}
+
+int error_h(conn_list_t *cl)
+{
+  int errno;
+  char *errorstring;
+cp
+  if(sscanf(cl->buffer, "%*d %d %as", &errno, &errorstring) != 2)
     {
-       syslog(LOG_ERR, "got bad PUBLIC_KEY request: %s", cl->buffer);
+       syslog(LOG_ERR, _("Got bad error from %s (%s)"), cl->id, cl->hostname);
        return -1;
-    }  
-
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "got PUBLIC_KEY %s",  g_n);
+    }
 
-  if(verify_passphrase(cl, g_n))
+  if(debug_lvl > DEBUG_error)
     {
-      /* intruder! */
-      syslog(LOG_ERR, "Intruder: passphrase does not match.");
-      return -1;
+      syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"), cl->id, cl->hostname, error_text[errno], errorstring);
     }
 
-  if(debug_lvl > 2)
-    syslog(LOG_INFO, "Passphrase OK");
-
-  if(cl->status.outgoing)
-    send_public_key(cl);
-  else
-    send_ack(cl);
-
-  /* Okay, before we active the connection, we check if there is another entry
-     in the connection list with the same vpn_ip. If so, it presumably is an
-     old connection that has timed out but we don't know it yet. Because our
-     conn_list entry is not active, lookup_conn will skip ourself. */
-
-  if(old=lookup_conn(cl->vpn_ip)) 
-    terminate_connection(old);
-
-  cl->status.active = 1;
-  notify_others(cl, NULL, send_add_host);
-  notify_one(cl);
+  free(errorstring);
+  cl->status.termreq = 1;
+  terminate_connection(cl);
 cp
   return 0;
 }
 
-int ack_h(conn_list_t *cl)
+int send_termreq(conn_list_t *cl)
 {
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "got ACK");
-  
-  cl->status.active = 1;
-  syslog(LOG_NOTICE, "Connection with %s activated.", cl->hostname);
-cp
-  return 0;
+  return send_request(cl, "%d", TERMREQ);
 }
 
 int termreq_h(conn_list_t *cl)
 {
 cp
-  syslog(LOG_NOTICE, IP_ADDR_S " wants to quit", IP_ADDR_V(cl->vpn_ip));
   cl->status.termreq = 1;
   terminate_connection(cl);
-
-  notify_others(cl, NULL, send_del_host);
 cp
   return 0;
 }
 
-int timeout_h(conn_list_t *cl)
+/* Keepalive routines - FIXME: needs a closer look */
+
+int send_ping(conn_list_t *cl)
 {
+  cl->status.pinged = 1;
 cp
-  syslog(LOG_NOTICE, IP_ADDR_S " says it's gotten a timeout from us", IP_ADDR_V(cl->vpn_ip));
-  cl->status.termreq = 1;
-  terminate_connection(cl);
-cp
-  return 0;
+  return send_request(cl, "%d", PING);
 }
 
-int del_host_h(conn_list_t *cl)
+int ping_h(conn_list_t *cl)
 {
-  ip_t vpn_ip;
-  conn_list_t *fw;
 cp
-  if(sscanf(cl->buffer, "%*d %lx", &vpn_ip) != 1)
-    {
-       syslog(LOG_ERR, "got bad DEL_HOST request: %s", cl->buffer);
-       return -1;
-    }  
-
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "got DEL_HOST for " IP_ADDR_S,
-	   IP_ADDR_V(vpn_ip));
-
-  if(!(fw = lookup_conn(vpn_ip)))
-    {
-      syslog(LOG_ERR, "Somebody wanted to delete " IP_ADDR_S " which does not exist?",
-	     IP_ADDR_V(vpn_ip));
-      return 0;
-    }
-
-  notify_others(cl, fw, send_del_host);
+  return send_pong(cl);
+}
 
-  fw->status.termreq = 1;
-  terminate_connection(fw);
+int send_pong(conn_list_t *cl)
+{
 cp
-  return 0;
+  return send_request(cl, "%d", PONG);
 }
 
-int ping_h(conn_list_t *cl)
+int pong_h(conn_list_t *cl)
 {
 cp
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, "responding to ping from " IP_ADDR_S, IP_ADDR_V(cl->vpn_ip));
-  cl->status.pinged = 0;
   cl->status.got_pong = 1;
-
-  send_pong(cl);
 cp
   return 0;
 }
 
-int pong_h(conn_list_t *cl)
+/* Key exchange */
+
+int send_key_changed(conn_list_t *from, conn_list_t *cl)
 {
+  conn_list_t *p;
 cp
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, "ok, got pong from " IP_ADDR_S, IP_ADDR_V(cl->vpn_ip));
-  cl->status.got_pong = 1;
+  for(p = conn_list; p != NULL; p = p->next)
+    {
+      if(p!=cl && p->status.meta && p->status.active)
+        send_request(p, "%d %s", KEY_CHANGED, from->id);
+    }
 cp
   return 0;
 }
 
-int add_host_h(conn_list_t *cl)
+int key_changed_h(conn_list_t *cl)
 {
-  ip_t real_ip;
-  ip_t vpn_ip;
-  ip_t vpn_mask;
-  unsigned short port;
-  conn_list_t *ncn, *fw;
+  char *from_id;
+  conn_list_t *from;
 cp
-  if(sscanf(cl->buffer, "%*d %lx %lx/%lx:%hx", &real_ip, &vpn_ip, &vpn_mask, &port) != 4)
+  if(sscanf(cl->buffer, "%*d %as", &from_id) != 1)
     {
-       syslog(LOG_ERR, "got bad ADD_HOST request: %s", cl->buffer);
+       syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"), cl->id, cl->hostname);
        return -1;
     }  
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Add host request from " IP_ADDR_S, IP_ADDR_V(cl->vpn_ip));
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, "got ADD_HOST(" IP_ADDR_S "," IP_ADDR_S ",%hd)",
-	   IP_ADDR_V(vpn_ip), IP_ADDR_V(vpn_mask), port);
-
-  /*
-    Suggestion of Hans Bayle
-  */
-  if((fw = lookup_conn(vpn_ip)))
+  if(!(from = lookup_id(from_id)))
     {
-      notify_others(fw, cl, send_add_host);
-      return 0;
+      syslog(LOG_ERR, _("Got KEY_CHANGED from %s (%s) origin %s which does not exist in our connection list"), cl->id, cl->hostname, from_id);
+      free(from_id);
+      return -1;
     }
 
-  ncn = new_conn_list();
-  ncn->real_ip = real_ip;
-  ncn->vpn_ip = vpn_ip;
-  ncn->vpn_mask = vpn_mask;
-  ncn->port = port;
-  ncn->hostname = hostlookup(real_ip);
-  ncn->nexthop = cl;
-  ncn->next = conn_list;
-  conn_list = ncn;
-  ncn->status.active = 1;
-  notify_others(ncn, cl, send_add_host);
+  free(from_id);
+    
+  from->status.validkey = 0;
+  from->status.waitingforkey = 0;
+  
+  send_key_changed(from, cl);
 cp
   return 0;
 }
+  
+int send_req_key(conn_list_t *from, conn_list_t *to)
+{
+cp
+  return send_request(to->nexthop, "%d %s %s", REQ_KEY, from->id, to->id);
+}
 
 int req_key_h(conn_list_t *cl)
 {
-  ip_t to;
-  ip_t from;
-  conn_list_t *fw;
+  char *from_id, *to_id;
+  conn_list_t *from, *to;
 cp
-  if(sscanf(cl->buffer, "%*d %lx %lx", &to, &from) != 2)
+  if(sscanf(cl->buffer, "%*d %as %as", &from_id, &to_id) != 2)
     {
-       syslog(LOG_ERR, "got bad request: %s", cl->buffer);
+       syslog(LOG_ERR, _("Got bad REQ_KEY from %s (%s)"), cl->id, cl->hostname);
        return -1;
     }  
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "got REQ_KEY from " IP_ADDR_S " for " IP_ADDR_S,
-	   IP_ADDR_V(from), IP_ADDR_V(to));
-
-  if((to & myself->vpn_mask) == (myself->vpn_ip & myself->vpn_mask))
-    {  /* hey! they want something from ME! :) */
-      send_key_answer(cl, from);
-      return 0;
-    }
-
-  fw = lookup_conn(to);
-  
-  if(!fw)
+  if(!(from = lookup_id(from_id)))
     {
-      syslog(LOG_ERR, "Attempting to forward key request to " IP_ADDR_S ", which does not exist?",
-	     IP_ADDR_V(to));
+      syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) origin %s which does not exist in our connection list"), cl->id, cl->hostname, from_id);
+      free(from_id); free(to_id);
       return -1;
     }
 
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, "Forwarding request for public key to " IP_ADDR_S,
-	   IP_ADDR_V(fw->nexthop->vpn_ip));
-  
-  cl->buffer[cl->reqlen-1] = '\n';
-  
-  if(write(fw->nexthop->meta_socket, cl->buffer, cl->reqlen) < 0)
-    {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
-    }
-cp
-  return 0;
-}
+  /* Check if this key request is for us */
 
-void set_keys(conn_list_t *cl, int expiry, char *key)
-{
-  char *ek;
-cp
-  if(!cl->public_key)
+  if(!strcmp(id, myself->strcmp))
     {
-      cl->public_key = xmalloc(sizeof(*cl->key));
-      cl->public_key->key = NULL;
+      send_ans_key(myself, from, myself->datakey);
     }
-    
-  if(cl->public_key->key)
-    free(cl->public_key->key);
-  cl->public_key->length = strlen(key);
-  cl->public_key->expiry = expiry;
-  cl->public_key->key = xmalloc(cl->public_key->length + 1);
-  strcpy(cl->public_key->key, key);
-
-  ek = make_shared_key(key);
-  
-  if(!cl->key)
+  else
     {
-      cl->key = xmalloc(sizeof(*cl->key));
-      cl->key->key = NULL;
+      if(!(to = lookup_id(to_id)))
+        {
+          syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) destination %s which does not exist in our connection list"), cl->id, cl->hostname, to_id);
+          free(from_id); free(to_id);
+          return -1;
+        }
+      send_req_key(from, to);
     }
 
-  if(cl->key->key)
-    free(cl->key->key);
+  free(from_id); free(to_id);
+cp
+  return 0;
+}
 
-  cl->key->length = strlen(ek);
-  cl->key->expiry = expiry;
-  cl->key->key = xmalloc(cl->key->length + 1);
-  strcpy(cl->key->key, ek);
+int send_ans_key(conn_list_t *from, conn_list_t *to, char *datakey)
+{
 cp
+  return send_request(to->nexthop, "%d %s %s %s", ANS_KEY, from->id, to->id, datakey);
 }
 
 int ans_key_h(conn_list_t *cl)
 {
-  ip_t to;
-  ip_t from;
-  int expiry;
-  char *key;
-  conn_list_t *fw, *gk;
+  char *from_id, *to_id, *datakey;
+  int keylength;
+  conn_list_t *from, *to;
 cp
-  if(sscanf(cl->buffer, "%*d %lx %lx %d %as", &to, &from, &expiry, &key) != 4)
+  if(sscanf(cl->buffer, "%*d %as %as %as", &from_id, &to_id, &datakey) != 3)
     {
-       syslog(LOG_ERR, "got bad ANS_KEY request: %s", cl->buffer);
+       syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s)"), cl->id, cl->hostname);
        return -1;
     }  
 
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, "got ANS_KEY from " IP_ADDR_S " for " IP_ADDR_S,
-	   IP_ADDR_V(from), IP_ADDR_V(to));
+  if(!(from = lookup_id(from_id)))
+    {
+      syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) origin %s which does not exist in our connection list"), cl->id, cl->hostname, from_id);
+      free(from_id); free(to_id); free(datakey);
+      return -1;
+    }
 
-  if(to == myself->vpn_ip)
-    {  /* hey! that key's for ME! :) */
-      if(debug_lvl > 2)
-	syslog(LOG_DEBUG, "Yeah! key arrived. Now do something with it.");
-      gk = lookup_conn(from);
+  /* Check if this key request is for us */
 
-      if(!gk)
+  if(!strcmp(id, myself->strcmp))
+    {
+      /* It is for us, convert it to binary and set the key with it. */
+      
+      keylength = strlen(datakey);
+      
+      if((keylength%1) || (keylength <= 0))
         {
-          syslog(LOG_ERR, "Receiving key from " IP_ADDR_S ", which does not exist?",
-	         IP_ADDR_V(from));
+          syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key"), cl->id, cl->hostname, from->id);
+          free(from_id); free(to_id); free(datakey);
           return -1;
         }
-
-      set_keys(gk, expiry, key);
-      gk->status.validkey = 1;
-      gk->status.waitingforkey = 0;
-      flush_queues(gk);
-      return 0;
+      keylength /= 2;
+      hex2bin(datakey, datakey, keylength);
+      BF_set_key(cl->datakey, keylength, datakey);
     }
-
-  fw = lookup_conn(to);
-  
-  if(!fw)
+  else
     {
-      syslog(LOG_ERR, "Attempting to forward key to " IP_ADDR_S ", which does not exist?",
-	     IP_ADDR_V(to));
-      return -1;
+      if(!(to = lookup_id(to_id)))
+        {
+          syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) destination %s which does not exist in our connection list"), cl->id, cl->hostname, to_id);
+          free(from_id); free(to_id); free(datakey);
+          return -1;
+        }
+      send_ans_key(from, to, datakey);
     }
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "Forwarding public key to " IP_ADDR_S,
-	   IP_ADDR_V(fw->nexthop->vpn_ip));
-
-  cl->buffer[cl->reqlen-1] = '\n';
-
-  if((write(fw->nexthop->meta_socket, cl->buffer, cl->reqlen)) < 0)
-    {
-      syslog(LOG_ERR, "send failed: %s:%d: %m", __FILE__, __LINE__);
-      return -1;
-    }
+  free(from_id); free(to_id); free(datakey);
 cp
   return 0;
 }
 
-int key_changed_h(conn_list_t *cl)
-{
-  ip_t from;
-  conn_list_t *ik;
-cp
-  if(sscanf(cl->buffer, "%*d %lx", &from) != 1)
-    {
-       syslog(LOG_ERR, "got bad ANS_KEY request: %s", cl->buffer);
-       return -1;
-    }  
+/* Old routines */
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, "got KEY_CHANGED from " IP_ADDR_S,
-	   IP_ADDR_V(from));
-
-  ik = lookup_conn(from);
-
-  if(!ik)
-    {
-      syslog(LOG_ERR, "Got changed key from " IP_ADDR_S ", which does not exist?",
-	     IP_ADDR_V(from));
-      return -1;
-    }
+/*
+  Notify all my direct connections of a new host
+  that was added to the vpn, with the exception
+  of the source of the announcement.
+*/
 
-  ik->status.validkey = 0;
-  ik->status.waitingforkey = 0;
+int notify_others(conn_list_t *new, conn_list_t *source,
+		  int (*function)(conn_list_t*, conn_list_t*))
+{
+  conn_list_t *p;
+cp
+  for(p = conn_list; p != NULL; p = p->next)
+    if(p != new && p != source && p->status.meta && p->status.active)
+      function(p, new);
+cp
+  return 0;
+}
 
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, "Forwarding key invalidation request");
+/*
+  Notify one connection of everything
+  I have connected
+*/
 
-  notify_others(cl, ik, send_key_changed);
+int notify_one(conn_list_t *new)
+{
+  conn_list_t *p;
+cp
+  for(p = conn_list; p != NULL; p = p->next)
+    if(p != new && p->status.active)
+      send_add_host(new, p);
 cp
   return 0;
 }
 
-int (*request_handlers[256])(conn_list_t*) = {
-  0, ack_h, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  termreq_h, timeout_h, del_host_h, 0, 0, 0, 0, 0, 0, 0,
-  ping_h, pong_h, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  add_host_h, basic_info_h, passphrase_h, public_key_h, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  req_key_h, ans_key_h, key_changed_h, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0
+/* "Complete overhaul". */
+
+int (*request_handlers[])(conn_list_t*) = {
+  id_h, challenge_h, chal_reply_h, ack_h,
+  status_h, error_h, termreq_h,
+  ping_h, pong_h,
+  add_host_h, del_host_h,
+  add_subnet_h, del_subnet_h,
+  key_changed_h, req_key_h, ans_key_h,
+};
+
+char (*request_name[]) = {
+  "ID", "CHALLENGE", "CHAL_REPLY", "ACK",
+  "STATUS", "ERROR", "TERMREQ",
+  "PING", "PONG",
+  "ADD_HOST", "DEL_HOST",
+  "ADD_SUBNET", "DEL_SUBNET",
+  "KEY_CHANGED", "REQ_KEY", "ANS_KEY",
 };