X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=aab226600a8b01ce48830f22bdc18ca538c0aea7;hp=8c6ce920ac6d16c093b7df06596e7ee7765de4ef;hb=6bd93e4c064578b545cb6dcaa28fffb229c929ff;hpb=675ed08a71ec28d8ae99e10e993d5c7cb717f017

diff --git a/src/protocol.c b/src/protocol.c
index 8c6ce920..aab22660 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -1,7 +1,7 @@
 /*
     protocol.c -- handle the meta-protocol
-    Copyright (C) 1999,2000 Ivo Timmermans <itimmermans@bigfoot.com>,
-                       2000 Guus Sliepen <guus@sliepen.warande.net>
+    Copyright (C) 1999-2001 Ivo Timmermans <itimmermans@bigfoot.com>,
+                  2000,2001 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: protocol.c,v 1.28.4.27 2000/09/10 22:49:46 guus Exp $
+    $Id: protocol.c,v 1.28.4.97 2001/07/01 21:42:13 guus Exp $
 */
 
 #include "config.h"
@@ -30,509 +30,953 @@
 #include <sys/socket.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <stdarg.h>
+#include <errno.h>
 
 #include <utils.h>
 #include <xalloc.h>
+#include <avl_tree.h>
+#include <list.h>
 
 #include <netinet/in.h>
 
+#ifdef HAVE_OPENSSL_SHA_H
+# include <openssl/sha.h>
+#else
+# include <sha.h>
+#endif
+
+#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
+
+
 #include "conf.h"
-#include "encr.h"
 #include "net.h"
 #include "netutl.h"
 #include "protocol.h"
+#include "meta.h"
+#include "connection.h"
 
 #include "system.h"
 
-/* Generic outgoing request routine - takes care of logging and error detection as well */
+int mykeyused = 0;
+
+int check_id(char *id)
+{
+  int i;
+
+  for (i = 0; i < strlen(id); i++)
+    if(!isalnum(id[i]) && id[i] != '_')
+      return -1;
+  
+  return 0;
+}
+
+/* Generic request routines - takes care of logging and error
+   detection as well */
 
-int send_request(conn_list_t *cl, const char *format, int request, /*args*/ ...)
+int send_request(connection_t *cl, const char *format, ...)
 {
   va_list args;
-  char *buffer = NULL;
+  char buffer[MAXBUFSIZE];
+  int len, request;
+
 cp
-  if(debug_lvl >= DEBUG_PROTOCOL)
-    syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), requestname[request], cl->id, cl->hostname);
+  /* Use vsnprintf instead of vasprintf: faster, no memory
+     fragmentation, cleanup is automatic, and there is a limit on the
+     input buffer anyway */
 
   va_start(args, format);
-  len = vasprintf(&buffer, format, args);
+  len = vsnprintf(buffer, MAXBUFSIZE, format, args);
+  request = va_arg(args, int);
   va_end(args);
 
-  if(len < 0 || !buffer)
+  if(len < 0 || len > MAXBUFSIZE-1)
     {
-      syslog(LOG_ERR, _("Error during vasprintf(): %m"));
+      syslog(LOG_ERR, _("Output buffer overflow while sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
       return -1;
     }
 
-  if(debug_lvl >= DEBUG_META)
-    syslog(LOG_DEBUG, _("Sending meta data to %s (%s): %s"), cl->id, cl->hostname, buffer);
-
-  if(cl->status.encryptout)
+  if(debug_lvl >= DEBUG_PROTOCOL)
     {
-      /* FIXME: Do encryption */
+      if(debug_lvl >= DEBUG_META)
+        syslog(LOG_DEBUG, _("Sending %s to %s (%s): %s"), request_name[request], cl->name, cl->hostname, buffer);
+      else
+        syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
     }
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  buffer[len++] = '\n';
+cp
+  return send_meta(cl, buffer, len);
+}
+
+int receive_request(connection_t *cl)
+{
+  int request;
+cp
+  if(sscanf(cl->buffer, "%d", &request) == 1)
     {
-      syslog(LOG_ERR, _("Sending meta data failed:  %m"));
+      if((request < 0) || (request >= LAST) || (request_handlers[request] == NULL))
+        {
+          if(debug_lvl >= DEBUG_META)
+            syslog(LOG_DEBUG, _("Unknown request from %s (%s): %s"),
+	           cl->name, cl->hostname, cl->buffer);
+          else
+            syslog(LOG_ERR, _("Unknown request from %s (%s)"),
+                   cl->name, cl->hostname);
+                   
+          return -1;
+        }
+      else
+        {
+          if(debug_lvl >= DEBUG_PROTOCOL)
+            {
+              if(debug_lvl >= DEBUG_META)
+                syslog(LOG_DEBUG, _("Got %s from %s (%s): %s"),
+	               request_name[request], cl->name, cl->hostname, cl->buffer);
+              else
+                syslog(LOG_DEBUG, _("Got %s from %s (%s)"),
+		       request_name[request], cl->name, cl->hostname);
+            }
+	}
+
+      if((cl->allow_request != ALL) && (cl->allow_request != request))
+        {
+          syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), cl->name, cl->hostname);
+          return -1;
+        }
+
+      if(request_handlers[request](cl))
+	/* Something went wrong. Probably scriptkiddies. Terminate. */
+        {
+          syslog(LOG_ERR, _("Error while processing %s from %s (%s)"),
+		 request_name[request], cl->name, cl->hostname);
+          return -1;
+        }
+    }
+  else
+    {
+      syslog(LOG_ERR, _("Bogus data received from %s (%s)"),
+	     cl->name, cl->hostname);
       return -1;
     }
-cp  
+cp
+  return 0;
 }
 
-/* Connection protocol:
-
-   Client               Server
-   send_id(*)
-                        send_challenge
-   send_chal_reply(*)                   
-                        send_id
-   send_challenge
-                        send_chal_reply
-   send_ack
-			send_ack
+/* The authentication protocol is described in detail in doc/SECURITY2,
+   the rest will be described in doc/PROTOCOL. */
 
-   (*) Unencrypted.
-*/      
-
-int send_id(conn_list_t *cl)
+int send_id(connection_t *cl)
 {
 cp
-  return send_request(cl, "%d %s %d %s", ID, myself->id, myself->version, opt2str(myself->options));
+  return send_request(cl, "%d %s %d %lx %hd", ID, myself->name, myself->protocol_version, myself->options, myself->port);
 }
 
-int id_h(conn_list_t *cl)
+int id_h(connection_t *cl)
 {
-  conn_list_t *old;
-  char *options;
+  connection_t *old;
+  unsigned short int port;
+  char name[MAX_STRING_SIZE];
+  avl_node_t *node;
 cp
-  if(sscanf(cl->buffer, "%*d %as %d %as", &cl->id, &cl->version, &options) != 3)
+  if(sscanf(cl->buffer, "%*d "MAX_STRING" %d %lx %hd", name, &cl->protocol_version, &cl->options, &port) != 4)
     {
        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;
-    }
 
-  /* Check if option string is valid */
-  
-  if((cl->options = str2opt(options)) == -1)
+  if(cl->protocol_version != myself->protocol_version)
     {
-      syslog(LOG_ERR, _("Peer %s uses invalid option string"), cl->hostname);
+      syslog(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"),
+             cl->name, cl->hostname, cl->protocol_version);
       return -1;
     }
-    
+
   /* Check if identity is a valid name */
-  
-  if(!check_id(cl->id))
+
+  if(check_id(name))
     {
       syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname);
       return -1;
     }
+  
+  /* Copy string to cl */
+  
+  if(cl->name)
+    free(cl->name);
     
+  cl->name = xstrdup(name);
+
   /* Load information about peer */
-  
-  if(!read_id(cl))
+
+  if(read_host_config(cl))
     {
-      syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->id);
+      syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->name);
       return -1;
     }
 
-
-  /* First check if the host we connected to is already in our
+  /* First check if the host is already in our
      connection list. If so, we are probably making a loop, which
      is not desirable.
    */
 
-  if(cl->status.outgoing)
+  if((old = lookup_id(cl->name)))
     {
-      if((old=lookup_id(cl->id)))
+      if(debug_lvl >= DEBUG_CONNECTIONS)
+        syslog(LOG_NOTICE, _("%s (%s) is already in our connection list"), cl->name, cl->hostname);
+      if(cl->status.outgoing)
         {
-          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;
         }
+      terminate_connection(cl);
+      return 0;
     }
+    
+  /* Now we can add the name to the id tree */
+  
+  id_add(cl);
 
-  /* Since we know the identity now, we can encrypt the meta channel */
+  /* And uhr... cl->port just changed so we have to unlink it from the connection tree and re-insert... */
   
-  cl->status.encryptout = 1;
+  node = avl_unlink(connection_tree, cl);
+  cl->port = port;
+  if(!avl_insert_node(connection_tree, node))
+    {
+      old = avl_search_node(connection_tree, node)->data;
+      syslog(LOG_ERR, _("%s is listening on %s:%hd, which is already in use by %s!"),
+             cl->name, cl->hostname, cl->port, old->name);
+      return -1;
+    }
+    
+  /* Read in the public key, so that we can send a metakey */
 
-  /* Send a challenge to verify the identity */
+  if(read_rsa_public_key(cl))
+    return -1;
 
-  cl->allow_request = CHAL_REPLY;
+  cl->allow_request = METAKEY;
 cp
-  return send_challenge(cl);
+  return send_metakey(cl);
 }
 
-int send_challenge(conn_list_t *cl)
+int ack_h(connection_t *cl)
 {
-  char *buffer;
-  int keylength;
-  int x;
+  config_t const *cfg;
+  connection_t *old, *p;
+  subnet_t *subnet;
+  avl_node_t *node, *node2;
+cp
+  /* Okay, before we active the connection, we check if there is another entry
+     in the connection list with the same name. If so, it presumably is an
+     old connection that has timed out but we don't know it yet.
+   */
+
+  while((old = lookup_id(cl->name)))
+    {
+      if(debug_lvl >= DEBUG_CONNECTIONS)
+        syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"),
+        cl->name, old->hostname, cl->hostname);
+
+      terminate_connection(old);
+    }
+
+  /* Activate this connection */
+
+  cl->allow_request = ALL;
+  cl->status.active = 1;
+  cl->nexthop = cl;
+  cl->cipher_pkttype = EVP_bf_cbc();
+  cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
+
+  if(debug_lvl >= DEBUG_CONNECTIONS)
+    syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname);
+
+  if(cl->status.outgoing)
+    seconds_till_retry = 5;	/* Reset retry timeout */
 cp
-  if(cl->chal_hash)
-    free(cl->chal_hash);
+  /* Check some options */
   
-  /* Allocate buffers for the challenge and the hash */
+  if((cfg = get_config_val(cl->config, config_indirectdata)))
+    {
+      if(cfg->data.val == stupid_true)
+        cl->options |= OPTION_INDIRECT;
+    }
+
+  if((cfg = get_config_val(cl->config, config_tcponly)))
+    {
+      if(cfg->data.val == stupid_true)
+        cl->options |= OPTION_TCPONLY;
+    }
+
+  /* Send him our subnets */
   
-  cl->chal_hash = xmalloc(SHA_DIGEST_LEN);
-  keylength = BN_num_bytes(cl->metakey.n);
-  buffer = xmalloc(keylength*2);
+  for(node = myself->subnet_tree->head; node; node = node->next)
+    {
+      subnet = (subnet_t *)node->data;
+      send_add_subnet(cl, subnet);
+    }
 
-  /* Copy random data and the public key to the buffer */
+  /* And send him all the hosts and their subnets we know... */
   
-  RAND_bytes(buffer, keylength);
-  BN_bn2bin(cl->metakey.n, buffer+keylength);
+  for(node = connection_tree->head; node; node = node->next)
+    {
+      p = (connection_t *)node->data;
+      
+      if(p != cl && p->status.active)
+        {
+          /* Notify others of this connection */
+
+          if(p->status.meta)
+            send_add_host(p, cl);
+
+          /* Notify new connection of everything we know */
+
+          send_add_host(cl, p);
+
+          for(node2 = p->subnet_tree->head; node2; node2 = node2->next)
+            {
+              subnet = (subnet_t *)node2->data;
+              send_add_subnet(cl, subnet);
+            }
+        }
+    }  
+cp
+  return 0;
+}
 
-  /* Calculate the hash from that */
+int send_challenge(connection_t *cl)
+{
+  char *buffer;
+  int len, x;
+cp
+  /* CHECKME: what is most reasonable value for len? */
 
-  SHA1(buffer, keylength*2, cl->chal_hash);
+  len = RSA_size(cl->rsa_key);
 
-  /* Convert the random data to a hexadecimal formatted string */
+  /* Allocate buffers for the challenge */
 
-  bin2hex(buffer,buffer,keylength);
-  buffer[keylength*2] = '\0';
+  buffer = xmalloc(len*2+1);
 
+  if(cl->hischallenge)
+    free(cl->hischallenge);
+    
+  cl->hischallenge = xmalloc(len);
+cp
+  /* Copy random data to the buffer */
+
+  RAND_bytes(cl->hischallenge, len);
+
+cp
+  /* Convert to hex */
+
+  bin2hex(cl->hischallenge, buffer, len);
+  buffer[len*2] = '\0';
+
+cp
   /* Send the challenge */
-  
-  cl->allow_request = CHAL_REPLY;
+
   x = send_request(cl, "%d %s", CHALLENGE, buffer);
   free(buffer);
 cp
   return x;
 }
 
-int challenge_h(conn_list_t *cl)
+int challenge_h(connection_t *cl)
 {
-  char *challenge;
+  char buffer[MAX_STRING_SIZE];
+  int len;
 cp
-  if(sscanf(cl->buffer, "%*d %as", &cl->id, &challenge) != 1)
+  if(sscanf(cl->buffer, "%*d "MAX_STRING, buffer) != 1)
     {
-       syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->id, cl->hostname);
+       syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->name, cl->hostname);
        return -1;
     }
 
-  /* Rest is done by send_chal_reply() */
-  
-  x = send_chal_reply(cl, challenge);
-  free(challenge);
-cp
-  return x;
-}
-
-int send_chal_reply(conn_list_t *cl, char *challenge)
-{
-  char *buffer;
-  int keylength;
-  char *hash;
-  int x;
-cp
-  keylength = BN_num_bytes(myself->meyakey.n);
+  len = RSA_size(myself->rsa_key);
 
   /* Check if the length of the challenge is all right */
 
-  if(strlen(challenge) != keylength*2)
+  if(strlen(buffer) != len*2)
     {
-      syslog(LOG_ERROR, _("Intruder: wrong challenge length from %s (%s)"), cl->id, cl->hostname);
+      syslog(LOG_ERR, _("Intruder: wrong challenge length from %s (%s)"), cl->name, cl->hostname);
       return -1;
     }
 
-  /* Allocate buffers for the challenge and the hash */
-  
-  buffer = xmalloc(keylength*2);
-  hash = xmalloc(SHA_DIGEST_LEN*2+1);
+  /* Allocate buffers for the challenge */
 
-  /* Copy the incoming random data and our public key to the buffer */
+  if(!cl->mychallenge)
+    cl->mychallenge = xmalloc(len);
 
-  hex2bin(challenge, buffer, keylength); 
-  BN_bn2bin(myself->metakey.n, buffer+keylength);
+  /* Convert the challenge from hexadecimal back to binary */
 
-  /* Calculate the hash from that */
-  
-  SHA1(buffer, keylength*2, hash);
-  free(buffer);
+  hex2bin(buffer,cl->mychallenge,len);
+
+  cl->allow_request = CHAL_REPLY;
+
+  /* Rest is done by send_chal_reply() */
+cp
+  return send_chal_reply(cl);
+}
+
+int send_chal_reply(connection_t *cl)
+{
+  char hash[SHA_DIGEST_LENGTH*2+1];
+cp
+  if(!cl->mychallenge)
+    {
+      syslog(LOG_ERR, _("Trying to send CHAL_REPLY to %s (%s) without a valid CHALLENGE"), cl->name, cl->hostname);
+      return -1;
+    }
+     
+  /* Calculate the hash from the challenge we received */
+
+  SHA1(cl->mychallenge, RSA_size(myself->rsa_key), hash);
 
   /* Convert the hash to a hexadecimal formatted string */
 
-  bin2hex(hash,hash,SHA_DIGEST_LEN);
-  hash[SHA_DIGEST_LEN*2] = '\0';
+  bin2hex(hash,hash,SHA_DIGEST_LENGTH);
+  hash[SHA_DIGEST_LENGTH*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 x;
-} 
+  return send_request(cl, "%d %s", CHAL_REPLY, hash);
+}
 
-int chal_reply_h(conn_list_t *cl)
+int chal_reply_h(connection_t *cl)
 {
-  char *hash;
+  char hishash[MAX_STRING_SIZE];
+  char myhash[SHA_DIGEST_LENGTH];
 cp
-  if(sscanf(cl->buffer, "%*d %as", &cl->id, &hash) != 2)
+  if(sscanf(cl->buffer, "%*d "MAX_STRING, hishash) != 1)
     {
-       syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->id, cl->hostname);
+       syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->name, cl->hostname);
        return -1;
     }
 
   /* Check if the length of the hash is all right */
-  
-  if(strlen(hash) != SHA_DIGEST_LEN*2)
+
+  if(strlen(hishash) != SHA_DIGEST_LENGTH*2)
     {
-      syslog(LOG_ERROR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->id, cl->hostname);
+      syslog(LOG_ERR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->name, cl->hostname);
       return -1;
     }
-    
+
   /* Convert the hash to binary format */
-  
-  hex2bin(hash, hash, SHA_DIGEST_LEN);
-  
+
+  hex2bin(hishash, hishash, SHA_DIGEST_LENGTH);
+
+  /* Calculate the hash from the challenge we sent */
+
+  SHA1(cl->hischallenge, RSA_size(cl->rsa_key), myhash);
+
   /* Verify the incoming hash with the calculated hash */
-  
-  if{!memcmp(hash, cl->chal_hash, SHA_DIGEST_LEN)}
+
+  if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH))
     {
-      syslog(LOG_ERROR, _("Intruder: wrong challenge reply from %s (%s)"), cl->id, cl->hostname);
+      syslog(LOG_ERR, _("Intruder: wrong challenge reply from %s (%s)"), cl->name, cl->hostname);
+      if(debug_lvl >= DEBUG_SCARY_THINGS)
+        {
+          bin2hex(myhash, hishash, SHA_DIGEST_LENGTH);
+          hishash[SHA_DIGEST_LENGTH*2] = '\0';
+          syslog(LOG_DEBUG, _("Expected challenge reply: %s"), hishash);
+        }
       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.
+     ack_h() handles the rest from now on.
    */
-   
-  free(hash);
-  free(cl->chal_hash);
+cp
+  return ack_h(cl);
+}
 
+int send_metakey(connection_t *cl)
+{
+  char *buffer;
+  int len, x;
 cp
-  if(cl->status.outgoing)
+  len = RSA_size(cl->rsa_key);
+
+  /* Allocate buffers for the meta key */
+
+  buffer = xmalloc(len*2+1);
+
+  if(!cl->cipher_outkey)
+    cl->cipher_outkey = xmalloc(len);
+    
+  if(!cl->cipher_outctx)
+    cl->cipher_outctx = xmalloc(sizeof(*cl->cipher_outctx));
+cp
+  /* Copy random data to the buffer */
+
+  RAND_bytes(cl->cipher_outkey, len);
+
+  /* The message we send must be smaller than the modulus of the RSA key.
+     By definition, for a key of k bits, the following formula holds:
+     
+       2^(k-1) <= modulus < 2^(k)
+     
+     Where ^ means "to the power of", not "xor".
+     This means that to be sure, we must choose our message < 2^(k-1).
+     This can be done by setting the most significant bit to zero.
+  */
+  
+  cl->cipher_outkey[0] &= 0x7F;
+  
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
     {
-      cl->allow_request = ACK;
-      return send_ack(cl);
+      bin2hex(cl->cipher_outkey, buffer, len);
+      buffer[len*2] = '\0';
+      syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer);
     }
-  else
+
+  /* Encrypt the random data
+  
+     We do not use one of the PKCS padding schemes here.
+     This is allowed, because we encrypt a totally random string
+     with a length equal to that of the modulus of the RSA key.
+  */
+  
+  if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len)
     {
-      cl->allow_request = CHALLENGE;
-      return send_id(cl);
+      syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
+      free(buffer);
+      return -1;
     }
-}
+cp
+  /* Convert the encrypted random data to a hexadecimal formatted string */
 
-int send_ack(conn_list_t *cl)
-{
+  bin2hex(buffer, buffer, len);
+  buffer[len*2] = '\0';
+
+  /* Send the meta key */
+
+  x = send_request(cl, "%d %s", METAKEY, buffer);
+  free(buffer);
+
+  /* Further outgoing requests are encrypted with the key we just generated */
+
+  EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(),
+                  cl->cipher_outkey + len - EVP_bf_cfb()->key_len,
+                  cl->cipher_outkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len);
+
+  cl->status.encryptout = 1;
 cp
-  return send_request(cl, "%d", ACK);
+  return x;
 }
 
-int ack_h(conn_list_t *cl)
+int metakey_h(connection_t *cl)
 {
-  conn_list_t old;
+  char buffer[MAX_STRING_SIZE];
+  int len;
 cp
-  /* 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(sscanf(cl->buffer, "%*d "MAX_STRING, buffer) != 1)
+    {
+       syslog(LOG_ERR, _("Got bad METAKEY from %s (%s)"), cl->name, cl->hostname);
+       return -1;
+    }
 
-  while((old = lookup_id(cl->id))) 
+  len = RSA_size(myself->rsa_key);
+
+  /* Check if the length of the meta key is all right */
+
+  if(strlen(buffer) != len*2)
     {
-      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);
+      syslog(LOG_ERR, _("Intruder: wrong meta key length from %s (%s)"), cl->name, cl->hostname);
+      return -1;
     }
 
-  /* Activate this connection */
+  /* Allocate buffers for the meta key */
 
-  cl->allow_request = ALL;
-  cl->status.active = 1;
+  if(!cl->cipher_inkey)
+    cl->cipher_inkey = xmalloc(len);
+
+  if(!cl->cipher_inctx)
+    cl->cipher_inctx = xmalloc(sizeof(*cl->cipher_inctx));
 
-  if(debug_lvl > DEBUG_CONNECTIONS)
-    syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->id, cl->hostname);
+  /* Convert the challenge from hexadecimal back to binary */
 
-  /* Exchange information about other tinc daemons */
+  hex2bin(buffer,buffer,len);
 
-  notify_others(cl, NULL, send_add_host);
-  notify_one(cl);
+  /* Decrypt the meta key */
+  
+  if(RSA_private_decrypt(len, buffer, cl->cipher_inkey, myself->rsa_key, RSA_NO_PADDING) != len)	/* See challenge() */
+    {
+      syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
+      return -1;
+    }
 
-  upstreamindex = 0;
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
+    {
+      bin2hex(cl->cipher_inkey, buffer, len);
+      buffer[len*2] = '\0';
+      syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer);
+    }
 
+  /* All incoming requests will now be encrypted. */
+
+  EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(),
+                  cl->cipher_inkey + len - EVP_bf_cfb()->key_len,
+                  cl->cipher_inkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len);
+  
+  cl->status.decryptin = 1;
+
+  cl->allow_request = CHALLENGE;
 cp
-  if(cl->status.outgoing)
-    return 0;
-  else
-    return send_ack(cl);
+  return send_challenge(cl);
 }
 
 /* Address and subnet information exchange */
 
-int send_add_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
+int send_add_subnet(connection_t *cl, subnet_t *subnet)
 {
+  int x;
+  char *netstr;
+  char *owner;
+cp
+  if((cl->options | myself->options | subnet->owner->options) & OPTION_INDIRECT)
+    owner = myself->name;
+  else
+    owner = subnet->owner->name;
+
+  x = send_request(cl, "%d %s %s", ADD_SUBNET,
+                      owner, netstr = net2str(subnet));
+  free(netstr);
 cp
-  return send_request(cl, "%d %s %d %s", ADD_SUBNET, other->id, subnet->type, net2str(subnet));
+  return x;
 }
 
-int add_subnet_h(conn_list_t *cl)
+int add_subnet_h(connection_t *cl)
 {
+  char subnetstr[MAX_STRING_SIZE];
+  char name[MAX_STRING_SIZE];
+  connection_t *owner, *p;
+  subnet_t *subnet;
+  avl_node_t *node;
+cp
+  if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 2)
+    {
+      syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if owner name is a valid */
+
+  if(check_id(name))
+    {
+      syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if subnet string is valid */
+
+  if(!(subnet = str2net(subnetstr)))
+    {
+      syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if somebody tries to add a subnet of ourself */
+
+  if(!strcmp(name, myself->name))
+    {
+      syslog(LOG_ERR, _("Warning: got ADD_SUBNET from %s (%s) for ourself, restarting"),
+             cl->name, cl->hostname);
+      sighup = 1;
+      return 0;
+    }
+
+  /* Check if the owner of the new subnet is in the connection list */
+
+  if(!(owner = lookup_id(name)))
+    {
+      syslog(LOG_ERR, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"),
+             name, cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* If everything is correct, add the subnet to the list of the owner */
+
+  subnet_add(owner, subnet);
+
+  /* Tell the rest */
+  
+  for(node = connection_tree->head; node; node = node->next)
+    {
+      p = (connection_t *)node->data;
+      if(p->status.meta && p->status.active && p!= cl)
+        send_add_subnet(p, subnet);
+    }
+cp
+  return 0;
 }
 
-int send_del_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
+int send_del_subnet(connection_t *cl, subnet_t *subnet)
 {
+  int x;
+  char *netstr;
+  char *owner;
 cp
-  return send_request(cl, "%d %s %d %s", DEL_SUBNET, other->id, subnet->type, net2str(subnet));
+  if(cl->options & OPTION_INDIRECT)
+    owner = myself->name;
+  else
+    owner = subnet->owner->name;
+
+  x = send_request(cl, "%d %s %s", DEL_SUBNET, owner, netstr = net2str(subnet));
+  free(netstr);
+cp
+  return x;
 }
 
-int del_subnet_h(conn_list_t *cl)
+int del_subnet_h(connection_t *cl)
 {
+  char subnetstr[MAX_STRING_SIZE];
+  char name[MAX_STRING_SIZE];
+  connection_t *owner, *p;
+  subnet_t *subnet;
+  avl_node_t *node;
+cp
+  if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 3)
+    {
+      syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s)"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if owner name is a valid */
+
+  if(check_id(name))
+    {
+      syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if subnet string is valid */
+
+  if(!(subnet = str2net(subnetstr)))
+    {
+      syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  free(subnetstr);
+  
+  /* Check if somebody tries to add a subnet of ourself */
+
+  if(!strcmp(name, myself->name))
+    {
+      syslog(LOG_ERR, _("Warning: got DEL_SUBNET from %s (%s) for ourself, restarting"),
+             cl->name, cl->hostname);
+      sighup = 1;
+      return 0;
+    }
+
+  /* Check if the owner of the new subnet is in the connection list */
+
+  if(!(owner = lookup_id(name)))
+    {
+      syslog(LOG_ERR, _("Got DEL_SUBNET for %s from %s (%s) which is not in our connection list"),
+             name, cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* If everything is correct, delete the subnet from the list of the owner */
+
+  subnet_del(subnet);
+
+  /* Tell the rest */
+  
+  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_subnet(p, subnet);
+    }
+cp
+  return 0;
 }
 
 /* New and closed connections notification */
 
-int send_add_host(conn_list_t *cl, conn_list_t *other)
+int send_add_host(connection_t *cl, connection_t *other)
 {
 cp
-  return send_request(cl, "%d %s %lx:%d %s", ADD_HOST, other->id, other->address, other->port, opt2str(other->options));
+  if(!((cl->options | myself->options | other->options) & OPTION_INDIRECT))
+    return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST,
+                      other->name, other->address, other->port, other->options);
+  else
+    return 0;
 }
 
-int add_host_h(conn_list_t *cl)
+int add_host_h(connection_t *cl)
 {
-  char *options;
-  conn_list_t *old, *new;
+  connection_t *old, *new, *p;
+  char name[MAX_STRING_SIZE];
+  avl_node_t *node;
 cp
-  new = new_conn_list();
+  new = new_connection();
 
-  if(sscanf(cl->buffer, "%*d %as %lx:%d %as", &new->id, &new->address, &new->port, &options) != 4)
+  if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx", name, &new->address, &new->port, &new->options) != 4)
     {
-       syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->id, cl->hostname);
+       syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname);
        return -1;
-    }  
-
-  /* Check if option string is valid */
-  
-  if((new->options = str2opt(options) == -1)
-    {
-      syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid option string"), cl->hostname);
-      return -1;
     }
 
   /* Check if identity is a valid name */
-  
-  if(!check_id(new->id))
+
+  if(check_id(name))
     {
-      syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->id, cl->hostname);
+      syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      free_connection(new);
       return -1;
     }
-    
+
   /* Check if somebody tries to add ourself */
-  
-  if(!strcmp(new->id, myself->id))
+
+  if(!strcmp(name, myself->name))
     {
-      syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->id, cl->hostname);
+      syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname);
       sighup = 1;
+      free_connection(new);
       return 0;
     }
-
-  /* Fill in more of the new conn_list structure */
+    
+  /* Fill in more of the new connection structure */
 
   new->hostname = hostlookup(htonl(new->address));
-  
+
   /* Check if the new host already exists in the connnection list */
 
-  if((old = lookup_id(id))
+  if((old = lookup_id(name)))
     {
       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;
+          if(debug_lvl >= DEBUG_CONNECTIONS)
+            syslog(LOG_NOTICE, _("Got duplicate ADD_HOST for %s (%s) from %s (%s)"),
+                   old->name, old->hostname, name, new->hostname);
+          free_connection(new);
+          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;
+          if(debug_lvl >= DEBUG_CONNECTIONS)
+            syslog(LOG_NOTICE, _("Removing old entry for %s (%s) in favour of new connection"),
+                   old->name, old->hostname);
+
           terminate_connection(old);
         }
     }
 
-  /* Fill in rest of conn_list structure */
-
-  new->nexthop = cl;
-  new->status.active = 1;
-  
-  /* Hook it up into the conn_list */
+  /* Hook it up into the connection */
 
-  conn_list_add(conn_list, new);
+  new->name = xstrdup(name);
+  connection_add(new);
+  id_add(new);
 
   /* Tell the rest about the new host */
-  
-  notify_others(new, cl, send_add_host);
-  
+
+  for(node = connection_tree->head; node; node = node->next)
+    {
+      p = (connection_t *)node->data;
+      if(p->status.meta && p->status.active && p!=cl)
+        send_add_host(p, new);
+    }
+
+  /* Fill in rest of connection structure */
+
+  new->nexthop = cl;
+  new->status.active = 1;
+  new->cipher_pkttype = EVP_bf_cbc();
+  new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
 cp
   return 0;
 }
 
-int send_del_host(conn_list_t *cl, conn_list_t *other)
+int send_del_host(connection_t *cl, connection_t *other)
 {
 cp
-  return send_request(cl, "%d %s %lx:%d", DEL_HOST, other->id, other->address, other->port);
+  if(!((cl->options | myself->options) & OPTION_INDIRECT))
+    return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST,
+                      other->name, other->address, other->port, other->options);
+  else
+    return 0;
 }
 
-int del_host_h(conn_list_t *cl)
+int del_host_h(connection_t *cl)
 {
-  char *id;
-  ip_t address;
+  char name[MAX_STRING_SIZE];
+  ipv4_t address;
   port_t port;
-  conn_list_t *old;
+  long int options;
+  connection_t *old, *p;
+  avl_node_t *node;
 cp
-  if(sscanf(cl->buffer, "%*d %as %lx:%d", &id, &address, &port) != 3)
+  if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx", name, &address, &port, &options) != 4)
     {
-       syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"), cl->id, cl->hostname);
-       return -1;
-    }  
+      syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"),
+             cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if identity is a valid name */
+
+  if(check_id(name))
+    {
+      syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      return -1;
+    }
 
   /* Check if somebody tries to delete ourself */
-  
-  if(!strcmp(id, myself->id))
+
+  if(!strcmp(name, myself->name))
     {
-      syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"), cl->id, cl->hostname);
+      syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"),
+             cl->name, cl->hostname);
       sighup = 1;
       return 0;
     }
 
   /* Check if the new host already exists in the connnection list */
 
-  if((old = lookup_id(id))
+  if(!(old = lookup_id(name)))
     {
-      if((address == old->address) && (port == old->port))
-        {
-          notify_others(old, cl, send_del_host);
+      syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) for %s which is not in our connection list"),
+             name, cl->name, cl->hostname);
+      return -1;
+    }
+  
+  /* Check if the rest matches */
+  
+  if(address!=old->address || port!=old->port || options!=old->options || cl!=old->nexthop)
+    {
+      syslog(LOG_WARNING, _("Got DEL_HOST from %s (%s) for %s which doesn't match"), cl->name, cl->hostname, old->name);
+      return 0;
+    }
 
-          fw->status.termreq = 1;
-          fw->status.active = 0;
+  /* Ok, since EVERYTHING seems to check out all right, delete it */
 
-          terminate_connection(fw);
-cp
-          return 0;
-        }
-    }
+  old->status.active = 0;
+  terminate_connection(old);
+
+  /* Tell the rest about the new host */
 
-  if(debug_lvl > DEBUG_CONNECTIONS)
+  for(node = connection_tree->head; node; node = node->next)
     {
-      syslog(LOG_NOTICE, _("Got DEL_HOST for %s from %s (%s) which is not in our connection list"), id, cl->id, cl->hostname);
+      p = (connection_t *)node->data;
+      if(p->status.meta && p->status.active && p!=cl)
+        send_del_host(p, old);
     }
 cp
   return 0;
@@ -540,7 +984,7 @@ cp
 
 /* Status and error notification routines */
 
-int send_status(conn_list_t *cl, int statusno, char *statusstring)
+int send_status(connection_t *cl, int statusno, char *statusstring)
 {
 cp
   if(!statusstring)
@@ -549,431 +993,358 @@ cp
   return send_request(cl, "%d %d %s", STATUS, statusno, statusstring);
 }
 
-int status_h(conn_list_t *cl)
+int status_h(connection_t *cl)
 {
   int statusno;
-  char *statusstring;
+  char statusstring[MAX_STRING_SIZE];
 cp
-  if(sscanf(cl->buffer, "%*d %d %as", &statusno, &statusstring) != 2)
+  if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &statusno, statusstring) != 2)
     {
-       syslog(LOG_ERR, _("Got bad STATUS from %s (%s)"), cl->id, cl->hostname);
+       syslog(LOG_ERR, _("Got bad STATUS from %s (%s)"),
+              cl->name, cl->hostname);
        return -1;
     }
 
-  if(debug_lvl > DEBUG_STATUS)
+  if(debug_lvl >= DEBUG_STATUS)
     {
-      syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"), cl->id, cl->hostname, status_text[statusno], statusstring);
+      syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"),
+             cl->name, cl->hostname, status_text[statusno], statusstring);
     }
 
 cp
-  free(statusstring);
   return 0;
 }
 
-int send_error(conn_list_t *cl, int errno, char *errstring)
+int send_error(connection_t *cl, int err, char *errstring)
 {
 cp
-  if(!errorstring)
-    errorstring = error_text[errno];
-  return send_request(cl, "%d %d %s", ERROR, errno, errstring);
+  if(!errstring)
+    errstring = strerror(err);
+  return send_request(cl, "%d %d %s", ERROR, err, errstring);
 }
 
-int error_h(conn_list_t *cl)
+int error_h(connection_t *cl)
 {
-  int errno;
-  char *errorstring;
+  int err;
+  char errorstring[MAX_STRING_SIZE];
 cp
-  if(sscanf(cl->buffer, "%*d %d %as", &errno, &errorstring) != 2)
+  if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &err, errorstring) != 2)
     {
-       syslog(LOG_ERR, _("Got bad error from %s (%s)"), cl->id, cl->hostname);
+       syslog(LOG_ERR, _("Got bad ERROR from %s (%s)"),
+              cl->name, cl->hostname);
        return -1;
     }
 
-  if(debug_lvl > DEBUG_error)
+  if(debug_lvl >= DEBUG_ERROR)
     {
-      syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"), cl->id, cl->hostname, error_text[errno], errorstring);
+      syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"),
+             cl->name, cl->hostname, strerror(err), errorstring);
     }
 
-  free(errorstring);
-  cl->status.termreq = 1;
   terminate_connection(cl);
 cp
   return 0;
 }
 
-int send_termreq(conn_list_t *cl)
+int send_termreq(connection_t *cl)
 {
 cp
   return send_request(cl, "%d", TERMREQ);
 }
 
-int termreq_h(conn_list_t *cl)
+int termreq_h(connection_t *cl)
 {
 cp
-  cl->status.termreq = 1;
   terminate_connection(cl);
 cp
   return 0;
 }
 
-/* Keepalive routines - FIXME: needs a closer look */
-
-int send_ping(conn_list_t *cl)
+int send_ping(connection_t *cl)
 {
+  char salt[SALTLEN*2+1];
+cp
   cl->status.pinged = 1;
+  cl->last_ping_time = time(NULL);
+  RAND_bytes(salt, SALTLEN);
+  bin2hex(salt, salt, SALTLEN);
+  salt[SALTLEN*2] = '\0';
 cp
-  return send_request(cl, "%d", PING);
+  return send_request(cl, "%d %s", PING, salt);
 }
 
-int ping_h(conn_list_t *cl)
+int ping_h(connection_t *cl)
 {
 cp
   return send_pong(cl);
 }
 
-int send_pong(conn_list_t *cl)
+int send_pong(connection_t *cl)
 {
+  char salt[SALTLEN*2+1];
 cp
-  return send_request(cl, "%d", PONG);
+  RAND_bytes(salt, SALTLEN);
+  bin2hex(salt, salt, SALTLEN);
+  salt[SALTLEN*2] = '\0';
+cp
+  return send_request(cl, "%d %s", PONG, salt);
 }
 
-int pong_h(conn_list_t *cl)
+int pong_h(connection_t *cl)
 {
 cp
-  cl->status.got_pong = 1;
+  cl->status.pinged = 0;
 cp
   return 0;
 }
 
 /* Key exchange */
 
-int send_key_changed(conn_list_t *from, conn_list_t *cl)
+int send_key_changed(connection_t *from, connection_t *cl)
 {
-  conn_list_t *p;
+  connection_t *p;
+  avl_node_t *node;
 cp
-  for(p = conn_list; p != NULL; p = p->next)
+  /* Only send this message if some other daemon requested our key previously.
+     This reduces unnecessary key_changed broadcasts.
+  */
+
+  if(from==myself && !mykeyused)
+    return 0;
+
+  for(node = connection_tree->head; node; node = node->next)
     {
-      if(p!=cl && p->status.meta && p->status.active)
-        send_request(p, "%d %s", KEY_CHANGED, from->id);
+      p = (connection_t *)node->data;
+      if(p != cl && p->status.meta && p->status.active)
+        if(!(p->options & OPTION_INDIRECT) || from == myself)
+          send_request(p, "%d %s", KEY_CHANGED, from->name);
     }
 cp
   return 0;
 }
 
-int key_changed_h(conn_list_t *cl)
+int key_changed_h(connection_t *cl)
 {
-  char *from_id;
-  conn_list_t *from;
+  char from_id[MAX_STRING_SIZE];
+  connection_t *from;
 cp
-  if(sscanf(cl->buffer, "%*d %as", &from_id) != 1)
+  if(sscanf(cl->buffer, "%*d "MAX_STRING, from_id) != 1)
     {
-       syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"), cl->id, cl->hostname);
-       return -1;
-    }  
+      syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"),
+             cl->name, cl->hostname);
+      return -1;
+    }
 
   if(!(from = lookup_id(from_id)))
     {
-      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);
+      syslog(LOG_ERR, _("Got KEY_CHANGED from %s (%s) origin %s which does not exist in our connection list"),
+             cl->name, cl->hostname, from_id);
       return -1;
     }
-    
+
   from->status.validkey = 0;
   from->status.waitingforkey = 0;
-  
-  send_key_changed(from, cl);
+
+  if(!(from->options | cl->options | myself->options) & OPTION_INDIRECT)
+    send_key_changed(from, cl);
 cp
   return 0;
 }
-  
-int send_req_key(conn_list_t *from, conn_list_t *to)
+
+int send_req_key(connection_t *from, connection_t *to)
 {
 cp
-  return send_request(to->nexthop, "%d %s %s", REQ_KEY, from->id, to->id);
+  return send_request(to->nexthop, "%d %s %s", REQ_KEY,
+                      from->name, to->name);
 }
 
-int req_key_h(conn_list_t *cl)
+int req_key_h(connection_t *cl)
 {
-  char *from_id, *to_id;
-  conn_list_t *from, *to;
+  char from_id[MAX_STRING_SIZE];
+  char to_id[MAX_STRING_SIZE];
+  connection_t *from, *to;
+  char pktkey[129];
 cp
-  if(sscanf(cl->buffer, "%*d %as %as", &from_id, &to_id) != 2)
+  if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, from_id, to_id) != 2)
     {
-       syslog(LOG_ERR, _("Got bad REQ_KEY from %s (%s)"), cl->id, cl->hostname);
+       syslog(LOG_ERR, _("Got bad REQ_KEY from %s (%s)"),
+              cl->name, cl->hostname);
        return -1;
-    }  
+    }
 
   if(!(from = lookup_id(from_id)))
     {
-      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); free(to);
+      syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) origin %s which does not exist in our connection list"),
+             cl->name, cl->hostname, from_id);
       return -1;
     }
 
   /* Check if this key request is for us */
 
-  if(!strcmp(id, myself->strcmp))
+  if(!strcmp(to_id, myself->name))	/* Yes, send our own key back */
     {
-      send_ans_key(myself, from, myself->datakey);
+      bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength);
+      pktkey[myself->cipher_pktkeylength*2] = '\0';
+      send_ans_key(myself, from, pktkey);
+      mykeyused = 1;
     }
   else
     {
       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); free(to);
+          syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) destination %s which does not exist in our connection list"),
+                 cl->name, cl->hostname, to_id);
           return -1;
         }
-      send_req_key(from, to);
+        
+      if(to->status.validkey)	/* Proxy keys */
+        {
+          bin2hex(to->cipher_pktkey, pktkey, to->cipher_pktkeylength);
+          pktkey[to->cipher_pktkeylength*2] = '\0';
+          send_ans_key(to, from, pktkey);
+        }
+      else
+        send_req_key(from, to);
     }
 
-  free(from); free(to);
 cp
   return 0;
 }
 
-int send_ans_key(conn_list_t *from, conn_list_t *to, char *datakey)
+int send_ans_key(connection_t *from, connection_t *to, char *pktkey)
 {
 cp
-  return send_request(to->nexthop, "%d %s %s %s", ANS_KEY, from->id, to->id, datakey);
+  return send_request(to->nexthop, "%d %s %s %s", ANS_KEY,
+                      from->name, to->name, pktkey);
 }
 
-int ans_key_h(conn_list_t *cl)
+int ans_key_h(connection_t *cl)
 {
-  char *from_id, *to_id, *datakey;
-  conn_list_t *from, *to;
+  char from_id[MAX_STRING_SIZE];
+  char to_id[MAX_STRING_SIZE];
+  char pktkey[MAX_STRING_SIZE];
+  int keylength;
+  connection_t *from, *to;
 cp
-  if(sscanf(cl->buffer, "%*d %as %as %as", &from_id, &to_id, &datakey) != 3)
+  if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING, from_id, to_id, pktkey) != 3)
     {
-       syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s)"), cl->id, cl->hostname);
+       syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s)"),
+              cl->name, cl->hostname);
        return -1;
-    }  
+    }
 
   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); free(to); free(datakey);
+      syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) origin %s which does not exist in our connection list"),
+             cl->name, cl->hostname, from_id);
       return -1;
     }
 
-  /* Check if this key request is for us */
+  /* Check correctness of packet key */
 
-  if(!strcmp(id, myself->strcmp))
-    {
-      send_ans_key(myself, from);
-    }
-  else
-    {
-      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); free(to); free(datakey);
-          return -1;
-        }
-      send_ans_key(from, to, datakey);
-    }
-
-  free(from); free(to); free(datakey);
-cp
-  return 0;
-}
-
-
-
-
-/* Old routines */
-
-
-
-
-int send_tcppacket(conn_list_t *cl, void *data, int len)
-{
-cp
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, _("Sending PACKET to %s (%s)"),
-	   cl->vpn_hostname, cl->real_hostname);
+  keylength = strlen(pktkey);
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %d\n", PACKET, len);
-
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
-    {
-      syslog(LOG_ERR, _("Send failed: %s:%d: %m"), __FILE__, __LINE__);
-      return -1;
-    }
-    
-  if((write(cl->meta_socket, data, len)) < 0)
+  if(keylength != from->cipher_pktkeylength*2)
     {
-      syslog(LOG_ERR, _("Send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key length"),
+             cl->name, cl->hostname, from->name);
       return -1;
     }
-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.
-*/
+  /* Forward it if necessary */
 
-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;
-}
-
-/*
-  Notify one connection of everything
-  I have connected
-*/
-
-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;
-}
-
-/*
-  The incoming request handlers
-*/
-
-int tcppacket_h(conn_list_t *cl)
-{
-  int len;
-cp
-  if(!cl->status.active)
+  if(strcmp(to_id, myself->name))
     {
-      syslog(LOG_ERR, _("Got unauthorized PACKET from %s (%s)"),
-              cl->vpn_hostname, cl->real_hostname);
-      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->name, cl->hostname, to_id);
+          return -1;
+        }
+      send_ans_key(from, to, pktkey);
     }
 
-  if(sscanf(cl->buffer, "%*d %d", &len) != 1)
-    {
-       syslog(LOG_ERR, _("Got bad PACKET from %s (%s)"),
-              cl->vpn_hostname, cl->real_hostname);
-       return -1;
-    }  
+  /* Update our copy of the origin's packet key */
 
-  if(len > MTU)
-    {
-       syslog(LOG_ERR, _("Got too big PACKET from %s (%s)"),
-              cl->vpn_hostname, cl->real_hostname);
-       return -1;
-    }  
+  if(from->cipher_pktkey)
+    free(from->cipher_pktkey);
 
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, _("Got PACKET length %d from %s (%s)"), len,
-              cl->vpn_hostname, cl->real_hostname);
+  from->cipher_pktkey = xstrdup(pktkey);
+  keylength /= 2;
+  hex2bin(from->cipher_pktkey, from->cipher_pktkey, keylength);
+  from->cipher_pktkey[keylength] = '\0';
 
-  cl->tcppacket=len;
+  from->status.validkey = 1;
+  from->status.waitingforkey = 0;
+  
+  flush_queue(from);
 cp
   return 0;
 }
 
-void set_keys(conn_list_t *cl, int expiry, char *key)
+int send_tcppacket(connection_t *cl, vpn_packet_t *packet)
 {
-  char *ek;
-cp
-  if(!cl->public_key)
-    {
-      cl->public_key = xmalloc(sizeof(*cl->key));
-      cl->public_key->key = NULL;
-    }
-    
-  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)
-    {
-      cl->key = xmalloc(sizeof(*cl->key));
-      cl->key->key = NULL;
-    }
+  int x;
+cp  
+  /* Evil hack. */
 
-  if(cl->key->key)
-    free(cl->key->key);
+  x = send_request(cl->nexthop, "%d %hd", PACKET, packet->len);
 
-  cl->key->length = strlen(ek);
-  cl->key->expiry = expiry;
-  cl->key->key = xmalloc(cl->key->length + 1);
-  strcpy(cl->key->key, ek);
+  if(x)
+    return x;
 cp
+  return send_meta(cl, packet->data, packet->len);
 }
 
-
-int key_changed_h(conn_list_t *cl)
+int tcppacket_h(connection_t *cl)
 {
-  ip_t from;
-  conn_list_t *ik;
-cp
-  if(!cl->status.active)
-    {
-      syslog(LOG_ERR, _("Got unauthorized KEY_CHANGED from %s (%s)"),
-              cl->vpn_hostname, cl->real_hostname);
-      return -1;
-    }
-
-  if(sscanf(cl->buffer, "%*d %lx", &from) != 1)
-    {
-       syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"),
-              cl->vpn_hostname, cl->real_hostname);
-       return -1;
-    }  
-
-  ik = lookup_conn(from);
-
-  if(!ik)
+  short int len;
+cp  
+  if(sscanf(cl->buffer, "%*d %hd", &len) != 1)
     {
-      syslog(LOG_ERR, _("Got KEY_CHANGED origin %d.%d.%d.%d from %s (%s), which does not exist?"),
-	     IP_ADDR_V(from), cl->vpn_hostname, cl->real_hostname);
+      syslog(LOG_ERR, _("Got bad PACKET from %s (%s)"), cl->name, cl->hostname);
       return -1;
     }
 
-  if(debug_lvl > 1)
-    syslog(LOG_DEBUG, _("Got KEY_CHANGED origin %s from %s (%s)"),
-            ik->vpn_hostname, cl->vpn_hostname, cl->real_hostname);
-
-  ik->status.validkey = 0;
-  ik->status.waitingforkey = 0;
+  /* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */
 
-  notify_others(ik, cl, send_key_changed);
+  cl->tcplen = len;
 cp
   return 0;
 }
 
-/* "Complete overhaul". */
+/* Jumptable for the request handlers */
 
-int (*request_handlers[])(conn_list_t*) = {
-  id_h, challenge_h, chal_reply_h, ack_h,
+int (*request_handlers[])(connection_t*) = {
+  id_h, metakey_h, challenge_h, chal_reply_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,
+  tcppacket_h,
 };
 
+/* Request names */
+
 char (*request_name[]) = {
-  "ID", "CHALLENGE", "CHAL_REPLY", "ACK",
+  "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY",
   "STATUS", "ERROR", "TERMREQ",
   "PING", "PONG",
   "ADD_HOST", "DEL_HOST",
   "ADD_SUBNET", "DEL_SUBNET",
   "KEY_CHANGED", "REQ_KEY", "ANS_KEY",
+  "PACKET",
+};
+
+/* Status strings */
+
+char (*status_text[]) = {
+  "Warning",
+};
+
+/* Error strings */
+
+char (*error_text[]) = {
+  "Error",
 };