X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=a8860fb2929c473d90c69f2e547478db68021189;hp=12d279a4ceb591e1100a28d09a246e0df19817ce;hb=6365d0627b9b1e9a31371ec891db0d2cfb4d6ed4;hpb=07a08f5539f441e66946d1db1711dc584f8621c4

diff --git a/src/protocol.c b/src/protocol.c
index 12d279a4..a8860fb2 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 1.28.4.73 2001/01/07 15:25:45 guus Exp $
+    $Id: protocol.c,v 1.28.4.96 2001/07/01 09:21:01 guus Exp $
 */
 
 #include "config.h"
@@ -31,6 +31,7 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <stdarg.h>
+#include <errno.h>
 
 #include <utils.h>
 #include <xalloc.h>
@@ -67,6 +68,8 @@
 
 #include "system.h"
 
+int mykeyused = 0;
+
 int check_id(char *id)
 {
   int i;
@@ -103,11 +106,15 @@ cp
       return -1;
     }
 
-  len++;
-
   if(debug_lvl >= DEBUG_PROTOCOL)
-    syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+    {
+      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);
+    }
 
+  buffer[len++] = '\n';
 cp
   return send_meta(cl, buffer, len);
 }
@@ -115,20 +122,31 @@ cp
 int receive_request(connection_t *cl)
 {
   int request;
-cp  
+cp
   if(sscanf(cl->buffer, "%d", &request) == 1)
     {
-      if((request < 0) || (request > 255) || (request_handlers[request] == NULL))
+      if((request < 0) || (request >= LAST) || (request_handlers[request] == NULL))
         {
-          syslog(LOG_ERR, _("Unknown request from %s (%s)"),
-		 cl->name, cl->hostname);
+          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)
-            syslog(LOG_DEBUG, _("Got %s from %s (%s)"),
-		   request_name[request], cl->name, cl->hostname);
+            {
+              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))
@@ -155,39 +173,11 @@ cp
   return 0;
 }
 
-/* Connection protocol:
-
-   Client               Server
-   send_id(u)
-                        send_challenge(R)
-   send_chal_reply(H)
-                        send_id(u)
-   send_challenge(R)
-                        send_chal_reply(H)
-   ---------------------------------------
-   send_metakey(R)
-                        send_metakey(R)
-   ---------------------------------------
-   send_ack(u)
-                        send_ack(u)
-   ---------------------------------------
-   Other requests(E)...
-
-   (u) Unencrypted,
-   (R) RSA,
-   (H) SHA1,
-   (E) Encrypted with symmetric cipher.
-
-   Part of the challenge is directly used to set the symmetric cipher
-   key and the initial vector.  Since a man-in-the-middle cannot
-   decrypt the RSA challenges, this means that he cannot get or forge
-   the key for the symmetric cipher.
-*/
+/* The authentication protocol is described in detail in doc/SECURITY2,
+   the rest will be described in doc/PROTOCOL. */
 
 int send_id(connection_t *cl)
 {
-cp
-  cl->allow_request = CHALLENGE;
 cp
   return send_request(cl, "%d %s %d %lx %hd", ID, myself->name, myself->protocol_version, myself->options, myself->port);
 }
@@ -224,6 +214,9 @@ cp
   
   /* Copy string to cl */
   
+  if(cl->name)
+    free(cl->name);
+    
   cl->name = xstrdup(name);
 
   /* Load information about peer */
@@ -260,15 +253,107 @@ cp
   
   node = avl_unlink(connection_tree, cl);
   cl->port = port;
-  avl_insert_node(connection_tree, node);
-
-  /* Read in the public key, so that we can send a challenge */
+  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 */
 
   if(read_rsa_public_key(cl))
     return -1;
 
+  cl->allow_request = METAKEY;
 cp
-  return send_challenge(cl);
+  return send_metakey(cl);
+}
+
+int ack_h(connection_t *cl)
+{
+  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
+  /* Check some options */
+  
+  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 */
+  
+  for(node = myself->subnet_tree->head; node; node = node->next)
+    {
+      subnet = (subnet_t *)node->data;
+      send_add_subnet(cl, subnet);
+    }
+
+  /* And send him all the hosts and their subnets we know... */
+  
+  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;
 }
 
 int send_challenge(connection_t *cl)
@@ -276,6 +361,8 @@ int send_challenge(connection_t *cl)
   char *buffer;
   int len, x;
 cp
+  /* CHECKME: what is most reasonable value for len? */
+
   len = RSA_size(cl->rsa_key);
 
   /* Allocate buffers for the challenge */
@@ -291,32 +378,15 @@ cp
 
   RAND_bytes(cl->hischallenge, len);
 
-  cl->hischallenge[0] &= 0x7F;	/* Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
-cp
-  if(debug_lvl >= DEBUG_SCARY_THINGS)
-    {
-      bin2hex(cl->hischallenge, buffer, len);
-      buffer[len*2] = '\0';
-      syslog(LOG_DEBUG, _("Generated random challenge (unencrypted): %s"), buffer);
-    }
-
-  /* Encrypt the random data */
-
-  if(RSA_public_encrypt(len, cl->hischallenge, buffer, cl->rsa_key, RSA_NO_PADDING) != len)	/* NO_PADDING because the message size equals the RSA key size and it is totally random */
-    {
-      syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname);
-      free(buffer);
-      return -1;
-    }
 cp
-  /* Convert the encrypted random data to a hexadecimal formatted string */
+  /* Convert to hex */
 
-  bin2hex(buffer, buffer, len);
+  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
@@ -351,22 +421,9 @@ cp
 
   /* Convert the challenge from hexadecimal back to binary */
 
-  hex2bin(buffer,buffer,len);
-
-  /* Decrypt the challenge */
-  
-  if(RSA_private_decrypt(len, buffer, cl->mychallenge, myself->rsa_key, RSA_NO_PADDING) != len)	/* See challenge() */
-    {
-      syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname);
-      return -1;
-    }
+  hex2bin(buffer,cl->mychallenge,len);
 
-  if(debug_lvl >= DEBUG_SCARY_THINGS)
-    {
-      bin2hex(cl->mychallenge, buffer, len);
-      buffer[len*2] = '\0';
-      syslog(LOG_DEBUG, _("Received random challenge (unencrypted): %s"), buffer);
-    }
+  cl->allow_request = CHAL_REPLY;
 
   /* Rest is done by send_chal_reply() */
 cp
@@ -394,11 +451,6 @@ cp
 
   /* Send the reply */
 
-  if(cl->status.outgoing)
-    cl->allow_request = ID;
-  else
-    cl->allow_request = METAKEY;
-
 cp
   return send_request(cl, "%d %s", CHAL_REPLY, hash);
 }
@@ -444,16 +496,11 @@ cp
       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.
    */
 cp
-  if(cl->status.outgoing)
-      return send_metakey(cl);
-  else
-      return send_id(cl);
+  return ack_h(cl);
 }
 
 int send_metakey(connection_t *cl)
@@ -477,8 +524,18 @@ cp
 
   RAND_bytes(cl->cipher_outkey, len);
 
-  cl->cipher_outkey[0] &= 0x7F;	/* FIXME: Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
-
+  /* 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)
     {
       bin2hex(cl->cipher_outkey, buffer, len);
@@ -486,9 +543,14 @@ cp
       syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer);
     }
 
-  /* Encrypt the random data */
+  /* 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)	/* NO_PADDING because the message size equals the RSA key size and it is totally random */
+  if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len)
     {
       syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
       free(buffer);
@@ -502,15 +564,16 @@ cp
 
   /* Send the meta key */
 
-  if(cl->status.outgoing)
-    cl->allow_request = METAKEY;
-  else
-    cl->allow_request = ACK;
-    
   x = send_request(cl, "%d %s", METAKEY, buffer);
   free(buffer);
 
-  EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(), cl->cipher_outkey, cl->cipher_outkey + EVP_bf_cfb()->key_len);
+  /* 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 x;
 }
@@ -563,97 +626,17 @@ cp
       syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer);
     }
 
-  EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), cl->cipher_inkey, cl->cipher_inkey + EVP_bf_cfb()->key_len);
-  
-cp
-  if(cl->status.outgoing)
-    return send_ack(cl);
-  else
-    return send_metakey(cl);
-}
-
-int send_ack(connection_t *cl)
-{
-  int x;
-cp
-  if(cl->status.outgoing)
-    cl->allow_request = ACK;
-
-  x = send_request(cl, "%d", ACK);
-  cl->status.encryptout = 1;
-cp
-  return x;
-}
-
-int ack_h(connection_t *cl)
-{
-  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->status.decryptin = 1;
-  cl->nexthop = cl;
-  cl->cipher_pkttype = EVP_bf_cfb();
-  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);
-
-cp
-  if(!cl->status.outgoing)
-    send_ack(cl);
+  /* All incoming requests will now be encrypted. */
 
-  /* Send him our subnets */
-  
-  for(node = myself->subnet_tree->head; node; node = node->next)
-    {
-      subnet = (subnet_t *)node->data;
-      send_add_subnet(cl, subnet);
-    }
-  /* And send him all the hosts and their subnets we know... */
+  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);
   
-  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);
+  cl->status.decryptin = 1;
 
-          for(node2 = p->subnet_tree->head; node2; node2 = node2->next)
-            {
-              subnet = (subnet_t *)node2->data;
-              send_add_subnet(cl, subnet);
-            }
-        }
-    }  
+  cl->allow_request = CHALLENGE;
 cp
-  return 0;
+  return send_challenge(cl);
 }
 
 /* Address and subnet information exchange */
@@ -662,9 +645,15 @@ 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,
-                      subnet->owner->name, netstr = net2str(subnet));
+                      owner, netstr = net2str(subnet));
   free(netstr);
 cp
   return x;
@@ -739,9 +728,14 @@ int send_del_subnet(connection_t *cl, subnet_t *subnet)
 {
   int x;
   char *netstr;
+  char *owner;
 cp
-  netstr = net2str(subnet);
-  x = send_request(cl, "%d %s %s", DEL_SUBNET, subnet->owner->name, netstr);
+  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;
@@ -819,8 +813,11 @@ cp
 int send_add_host(connection_t *cl, connection_t *other)
 {
 cp
-  return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST,
+  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(connection_t *cl)
@@ -831,7 +828,7 @@ int add_host_h(connection_t *cl)
 cp
   new = new_connection();
 
-  if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%d %lx", name, &new->address, &new->port, &new->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->name, cl->hostname);
        return -1;
@@ -901,7 +898,7 @@ cp
 
   new->nexthop = cl;
   new->status.active = 1;
-  new->cipher_pkttype = EVP_bf_cfb();
+  new->cipher_pkttype = EVP_bf_cbc();
   new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
 cp
   return 0;
@@ -910,20 +907,23 @@ cp
 int send_del_host(connection_t *cl, connection_t *other)
 {
 cp
-  return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST,
+  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(connection_t *cl)
 {
   char name[MAX_STRING_SIZE];
-  ip_t address;
+  ipv4_t address;
   port_t port;
   long int options;
   connection_t *old, *p;
   avl_node_t *node;
 cp
-  if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%d %lx", name, &address, &port, &options) != 4)
+  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->name, cl->hostname);
@@ -1015,20 +1015,20 @@ cp
   return 0;
 }
 
-int send_error(connection_t *cl, int errno, char *errstring)
+int send_error(connection_t *cl, int err, char *errstring)
 {
 cp
   if(!errstring)
-    errstring = strerror(errno);
-  return send_request(cl, "%d %d %s", ERROR, errno, errstring);
+    errstring = strerror(err);
+  return send_request(cl, "%d %d %s", ERROR, err, errstring);
 }
 
 int error_h(connection_t *cl)
 {
-  int errno;
+  int err;
   char errorstring[MAX_STRING_SIZE];
 cp
-  if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &errno, errorstring) != 2)
+  if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &err, errorstring) != 2)
     {
        syslog(LOG_ERR, _("Got bad ERROR from %s (%s)"),
               cl->name, cl->hostname);
@@ -1038,7 +1038,7 @@ cp
   if(debug_lvl >= DEBUG_ERROR)
     {
       syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"),
-             cl->name, cl->hostname, strerror(errno), errorstring);
+             cl->name, cl->hostname, strerror(err), errorstring);
     }
 
   terminate_connection(cl);
@@ -1060,15 +1060,17 @@ cp
   return 0;
 }
 
-/* Keepalive routines - FIXME: needs a closer look */
-
 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(connection_t *cl)
@@ -1079,8 +1081,13 @@ cp
 
 int send_pong(connection_t *cl)
 {
+  char salt[SALTLEN*2+1];
+cp
+  RAND_bytes(salt, SALTLEN);
+  bin2hex(salt, salt, SALTLEN);
+  salt[SALTLEN*2] = '\0';
 cp
-  return send_request(cl, "%d", PONG);
+  return send_request(cl, "%d %s", PONG, salt);
 }
 
 int pong_h(connection_t *cl)
@@ -1098,11 +1105,19 @@ int send_key_changed(connection_t *from, connection_t *cl)
   connection_t *p;
   avl_node_t *node;
 cp
+  /* 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)
     {
       p = (connection_t *)node->data;
       if(p != cl && p->status.meta && p->status.active)
-        send_request(p, "%d %s", KEY_CHANGED, from->name);
+        if(!(p->options & OPTION_INDIRECT) || from == myself)
+          send_request(p, "%d %s", KEY_CHANGED, from->name);
     }
 cp
   return 0;
@@ -1130,7 +1145,8 @@ cp
   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;
 }
@@ -1165,11 +1181,12 @@ cp
 
   /* Check if this key request is for us */
 
-  if(!strcmp(to_id, myself->name))
+  if(!strcmp(to_id, myself->name))	/* Yes, send our own key back */
     {
       bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength);
       pktkey[myself->cipher_pktkeylength*2] = '\0';
       send_ans_key(myself, from, pktkey);
+      mykeyused = 1;
     }
   else
     {
@@ -1265,26 +1282,59 @@ cp
   return 0;
 }
 
+int send_tcppacket(connection_t *cl, vpn_packet_t *packet)
+{
+  int x;
+cp  
+  /* Evil hack. */
+
+  x = send_request(cl->nexthop, "%d %hd", PACKET, packet->len);
+
+  if(x)
+    return x;
+cp
+  return send_meta(cl, packet->data, packet->len);
+}
+
+int tcppacket_h(connection_t *cl)
+{
+  short int len;
+cp  
+  if(sscanf(cl->buffer, "%*d %hd", &len) != 1)
+    {
+      syslog(LOG_ERR, _("Got bad PACKET from %s (%s)"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */
+
+  cl->tcplen = len;
+cp
+  return 0;
+}
+
 /* Jumptable for the request handlers */
 
 int (*request_handlers[])(connection_t*) = {
-  id_h, challenge_h, chal_reply_h, metakey_h, ack_h,
+  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", "METAKEY", "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 */