X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=fbb0abf31f435cb60cfb12141345f6882e1fd536;hp=f0b7cb9f9a90a7022e8b88f66645f504830a52af;hb=bb2495e569fb161b42efd633eb1c471b8222b1fb;hpb=9fd02ffcb0cacf3de26e876de5f30510bff137a3

diff --git a/src/protocol.c b/src/protocol.c
index f0b7cb9f..fbb0abf3 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -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 1.26 2000/05/29 21:01:25 zarq Exp $
+    $Id: protocol.c,v 1.28.4.60 2000/11/15 01:06:11 zarq Exp $
 */
 
 #include "config.h"
@@ -34,777 +34,1267 @@
 #include <utils.h>
 #include <xalloc.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 "connlist.h"
 
 #include "system.h"
 
-char buffer[MAXBUFSIZE+1];
-int buflen;
+int check_id(char *id)
+{
+  int i;
 
-/* Outgoing request routines */
+  for (i = 0; i < strlen(id); i++)
+    if(!isalnum(id[i]) && id[i] != '_')
+      return -1;
+          
+  return 0;
+}
 
-int send_ack(conn_list_t *cl)
+/* Generic request routines - takes care of logging and error detection as well */
+
+int send_request(conn_list_t *cl, const char *format, ...)
 {
+  va_list args;
+  char buffer[MAXBUFSIZE];
+  int len, request;
+
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Send ACK to %s"), cl->hostname);
+  /* Use vsnprintf instead of vasprintf: faster, no memory fragmentation, cleanup is automatic,
+     and there is a limit on the input buffer anyway */
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d\n", ACK);
+  va_start(args, format);
+  len = vsnprintf(buffer, MAXBUFSIZE, format, args);
+  request = va_arg(args, int);
+  va_end(args);
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(len < 0 || len > MAXBUFSIZE-1)
     {
-      syslog(LOG_ERR, _("send failed: %d:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Output buffer overflow while sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
       return -1;
     }
 
-  syslog(LOG_NOTICE, _("Connection with %s activated."), cl->hostname);
+  len++;
+
+  if(debug_lvl >= DEBUG_PROTOCOL)
+    syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+
 cp
-  return 0;
+  return send_meta(cl, buffer, len);
 }
 
-int send_termreq(conn_list_t *cl)
+int receive_request(conn_list_t *cl)
 {
-cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Send TERMREQ to " IP_ADDR_S),
-	   IP_ADDR_V(cl->vpn_ip));
+  int request;
+cp  
+  if(sscanf(cl->buffer, "%d", &request) == 1)
+    {
+      if((request < 0) || (request > 255) || (request_handlers[request] == NULL))
+        {
+          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);
+	}
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx\n", TERMREQ, myself->vpn_ip);
+      if((cl->allow_request != ALL) && (cl->allow_request != request))
+        {
+          syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), cl->name, cl->hostname);
+          return -1;
+        }
 
-  if(write(cl->meta_socket, buffer, buflen) < 0)
+      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
     {
-      if(debug_lvl > 1)
-	syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Bogus data received from %s (%s)"),
+	     cl->name, cl->hostname);
       return -1;
     }
 cp
   return 0;
 }
 
-int send_timeout(conn_list_t *cl)
+/* 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.
+*/
+
+int send_id(conn_list_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);
+}
+
+int id_h(conn_list_t *cl)
 {
+  conn_list_t *old;
+  config_t const *cfg;
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Send TIMEOUT to " IP_ADDR_S),
-	   IP_ADDR_V(cl->vpn_ip));
+  if(sscanf(cl->buffer, "%*d %as %d %lx %hd", &cl->name, &cl->protocol_version, &cl->options, &cl->port) != 4)
+    {
+       syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname);
+       return -1;
+    }
+
+  /* Check if version matches */
+
+  if(cl->protocol_version != myself->protocol_version)
+    {
+      syslog(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"),
+             cl->name, cl->hostname, cl->protocol_version);
+      return -1;
+    }
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx\n", PINGTIMEOUT, myself->vpn_ip);
+  /* Check if identity is a valid name */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(check_id(cl->name))
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname);
       return -1;
     }
+
+  /* Load information about peer */
 cp
-  return 0;
+  if(read_host_config(cl))
+    {
+      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
+     connection list. If so, we are probably making a loop, which
+     is not desirable.
+   */
+cp
+  if(cl->status.outgoing)
+    {
+      if((old = lookup_id(cl->name)))
+        {
+          if(debug_lvl >= DEBUG_CONNECTIONS)
+            syslog(LOG_NOTICE, _("Uplink %s (%s) is already in our connection list"), cl->name, cl->hostname);
+          cl->status.outgoing = 0;
+          old->status.outgoing = 1;
+          terminate_connection(cl);
+          return 0;
+        }
+    }
+cp    
+  if((cfg = get_config_val(cl->config, config_publickey)))
+    {
+      cl->rsa_key = RSA_new();
+      BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
+      BN_hex2bn(&cl->rsa_key->e, "FFFF");
+    }
+  else
+    {
+      syslog(LOG_ERR, _("No public key known for %s (%s)"), cl->name, cl->hostname);
+      return -1;
+    }
+cp
+  return send_challenge(cl);
 }
 
-int send_del_host(conn_list_t *cl, conn_list_t *new_host)
+int send_challenge(conn_list_t *cl)
 {
+  char *buffer;
+  int len, x;
 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));
+  len = RSA_size(cl->rsa_key);
+
+  /* Allocate buffers for the challenge */
+
+  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);
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx\n", DEL_HOST, new_host->vpn_ip);
+  cl->hischallenge[0] &= 0x7F;	/* Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      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
-  return 0;
+  /* Convert the encrypted random data to a hexadecimal formatted string */
+
+  bin2hex(buffer, buffer, len);
+  buffer[len*2] = '\0';
+
+  /* Send the challenge */
+
+  cl->allow_request = CHAL_REPLY;
+  x = send_request(cl, "%d %s", CHALLENGE, buffer);
+  free(buffer);
+cp
+  return x;
 }
 
-int send_ping(conn_list_t *cl)
+int challenge_h(conn_list_t *cl)
 {
+  char *buffer;
+  int len;
 cp
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, _("pinging " IP_ADDR_S), IP_ADDR_V(cl->vpn_ip));
+  if(sscanf(cl->buffer, "%*d %as", &buffer) != 1)
+    {
+       syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->name, cl->hostname);
+       return -1;
+    }
+
+  len = RSA_size(myself->rsa_key);
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d\n", PING);
+  /* Check if the length of the challenge is all right */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(strlen(buffer) != len*2)
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Intruder: wrong challenge length from %s (%s)"), cl->name, cl->hostname);
+      free(buffer);
       return -1;
     }
+
+  /* Allocate buffers for the challenge */
+
+  if(!cl->mychallenge)
+    cl->mychallenge = xmalloc(len);
+
+  /* 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);
+      free(buffer);
+      return -1;
+    }
+
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
+    {
+      bin2hex(cl->mychallenge, buffer, len);
+      buffer[len*2] = '\0';
+      syslog(LOG_DEBUG, _("Received random challenge (unencrypted): %s"), buffer);
+    }
+
+  free(buffer);
+    
+  /* Rest is done by send_chal_reply() */
 cp
-  return 0;
+  return send_chal_reply(cl);
 }
 
-int send_pong(conn_list_t *cl)
+int send_chal_reply(conn_list_t *cl)
 {
+  char hash[SHA_DIGEST_LENGTH*2+1];
 cp
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d\n", PONG);
-
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(!cl->mychallenge)
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      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_LENGTH);
+  hash[SHA_DIGEST_LENGTH*2] = '\0';
+
+  /* Send the reply */
+
+  if(cl->status.outgoing)
+    cl->allow_request = ID;
+  else
+    cl->allow_request = METAKEY;
+
 cp
-  return 0;
+  return send_request(cl, "%d %s", CHAL_REPLY, hash);
 }
 
-int send_add_host(conn_list_t *cl, conn_list_t *new_host)
+int chal_reply_h(conn_list_t *cl)
 {
+  char *hishash;
+  char myhash[SHA_DIGEST_LENGTH];
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Sending add host to " IP_ADDR_S),
-	   IP_ADDR_V(cl->vpn_ip));
+  if(sscanf(cl->buffer, "%*d %as", &hishash) != 1)
+    {
+       syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->name, cl->hostname);
+       free(hishash);
+       return -1;
+    }
 
-  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 hash is all right */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(strlen(hishash) != SHA_DIGEST_LENGTH*2)
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->name, cl->hostname);
+      free(hishash);
       return -1;
     }
-cp
-  return 0;
-}
 
-int send_key_changed(conn_list_t *cl, conn_list_t *src)
-{
-cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Sending KEY_CHANGED to " IP_ADDR_S),
-	   IP_ADDR_V(cl->vpn_ip));
+  /* Convert the hash to binary format */
+
+  hex2bin(hishash, hishash, SHA_DIGEST_LENGTH);
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx\n", KEY_CHANGED, src->vpn_ip);
+  /* Calculate the hash from the challenge we sent */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  SHA1(cl->hischallenge, RSA_size(cl->rsa_key), myhash);
+
+  /* Verify the incoming hash with the calculated hash */
+
+  if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH))
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      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);
+        }
+      free(hishash);
       return -1;
     }
+
+
+  free(hishash);
+
+  /* Identity has now been positively verified.
+     If we are accepting this new connection, then send our identity,
+     if we are making this connecting, acknowledge.
+   */
 cp
-  return 0;
+  if(cl->status.outgoing)
+      return send_metakey(cl);
+  else
+      return send_id(cl);
 }
 
-void send_key_changed_all(void)
+int send_metakey(conn_list_t *cl)
 {
-  conn_list_t *p;
+  char *buffer;
+  int len, x;
 cp
-  for(p = conn_list; p != NULL; p = p->next)
-    if(p->status.meta && p->status.active)
-      send_key_changed(p, myself);
-cp
-}
+  len = RSA_size(cl->rsa_key);
 
-int send_basic_info(conn_list_t *cl)
-{
+  /* 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
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Send BASIC_INFO to " IP_ADDR_S),
-	   IP_ADDR_V(cl->real_ip));
+  /* Copy random data to the buffer */
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %d %lx/%lx:%x\n", BASIC_INFO, PROT_CURRENT, myself->vpn_ip, myself->vpn_mask, myself->port);
+  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... */
+
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
+    {
+      bin2hex(cl->cipher_outkey, buffer, len);
+      buffer[len*2] = '\0';
+      syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer);
+    }
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  /* Encrypt the random data */
+  
+  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 */
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
+      free(buffer);
       return -1;
     }
 cp
-  return 0;
+  /* Convert the encrypted random data to a hexadecimal formatted string */
+
+  bin2hex(buffer, buffer, len);
+  buffer[len*2] = '\0';
+
+  /* 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);
+cp
+  return x;
 }
 
-int send_passphrase(conn_list_t *cl)
+int metakey_h(conn_list_t *cl)
 {
-  passphrase_t tmp;
+  char *buffer;
+  int len;
 cp
-  encrypt_passphrase(&tmp);
+  if(sscanf(cl->buffer, "%*d %as", &buffer) != 1)
+    {
+       syslog(LOG_ERR, _("Got bad METAKEY from %s (%s)"), cl->name, cl->hostname);
+       return -1;
+    }
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Send PASSPHRASE %s to " IP_ADDR_S),
-	   tmp.phrase, IP_ADDR_V(cl->vpn_ip));
+  len = RSA_size(myself->rsa_key);
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", PASSPHRASE, tmp.phrase);
+  /* Check if the length of the meta key is all right */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  if(strlen(buffer) != len*2)
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Intruder: wrong meta key length from %s (%s)"), cl->name, cl->hostname);
+      free(buffer);
       return -1;
     }
+
+  /* Allocate buffers for the meta key */
+
+  if(!cl->cipher_inkey)
+    cl->cipher_inkey = xmalloc(len);
+
+  if(!cl->cipher_inctx)
+    cl->cipher_inctx = xmalloc(sizeof(*cl->cipher_inctx));
+
+  /* Convert the challenge from hexadecimal back to binary */
+
+  hex2bin(buffer,buffer,len);
+
+  /* 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);
+      free(buffer);
+      return -1;
+    }
+
+  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);
+    }
+
+  free(buffer);
+
+  EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), cl->cipher_inkey, cl->cipher_inkey + EVP_bf_cfb()->key_len);
+  
 cp
-  return 0;
+  if(cl->status.outgoing)
+    return send_ack(cl);
+  else
+    return send_metakey(cl);
 }
 
-int send_public_key(conn_list_t *cl)
+int send_ack(conn_list_t *cl)
 {
+  int x;
 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));
+  if(cl->status.outgoing)
+    cl->allow_request = ACK;
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", PUBLIC_KEY, my_public_key_base36);
+  setup_vpn_connection(cl);
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
-    {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
-      return -1;
-    }
+  x = send_request(cl, "%d", ACK);
+  cl->status.encryptout = 1;
 cp
-  return 0;
+  return x;
 }
 
-int send_calculate(conn_list_t *cl, char *k)
+int ack_h(conn_list_t *cl)
 {
+  conn_list_t *old, *p;
+  subnet_t *s;
 cp
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", CALCULATE, k);
+  /* 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.
+   */
 
-  if((write(cl->meta_socket, buffer, buflen)) < 0)
+  while((old = lookup_id(cl->name)))
     {
-      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->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);
+
+  /* Send him our subnets */
+  
+  for(s = myself->subnets; s; s = s->next)
+    send_add_subnet(cl, s);
+
+  /* And send him all the hosts and their subnets we know... */
+  
+  for(p = conn_list; p; p = p->next)
+    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(s = p->subnets; s; s = s->next)
+          send_add_subnet(cl, s);
+      }
 cp
   return 0;
 }
 
-int send_key_request(ip_t to)
+/* Address and subnet information exchange */
+
+int send_add_subnet(conn_list_t *cl, subnet_t *subnet)
+{
+  int x;
+  char *netstr;
+cp
+  x = send_request(cl, "%d %s %s", ADD_SUBNET,
+                      subnet->owner->name, netstr = net2str(subnet));
+  free(netstr);
+cp
+  return x;
+}
+
+int add_subnet_h(conn_list_t *cl)
 {
-  conn_list_t *fw;
+  char *subnetstr;
+  char *name;
+  conn_list_t *owner, *p;
+  subnet_t *subnet;
 cp
-  fw = lookup_conn(to);
-  if(!fw)
+  if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 2)
     {
-      syslog(LOG_ERR, _("Attempting to send key request to " IP_ADDR_S ", which does not exist?"),
-	     IP_ADDR_V(to));
+      syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname);
+      free(name); free(subnetstr);
       return -1;
     }
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Sending out request for public key to " IP_ADDR_S),
-	   IP_ADDR_V(fw->nexthop->vpn_ip));
+  /* Check if owner name is a valid */
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx %lx\n", REQ_KEY, to, myself->vpn_ip);
-
-  if((write(fw->nexthop->meta_socket, buffer, buflen)) < 0)
+  if(check_id(name))
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      free(name); free(subnetstr);
       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
+  /* Check if subnet string is valid */
 
-  fw = lookup_conn(to);
-  
-  if(!fw)
+  if(!(subnet = str2net(subnetstr)))
     {
-      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_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
+      free(name); free(subnetstr);
       return -1;
     }
 
- if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Sending public key to " IP_ADDR_S),
-	   IP_ADDR_V(fw->nexthop->vpn_ip));
+  free(subnetstr);
+  
+  /* Check if somebody tries to add a subnet of ourself */
 
-  buflen = snprintf(buffer, MAXBUFSIZE, "%d %lx %lx %d %s\n", ANS_KEY, to, myself->vpn_ip, my_key_expiry, my_public_key_base36);
+  if(!strcmp(name, myself->name))
+    {
+      syslog(LOG_ERR, _("Warning: got ADD_SUBNET from %s (%s) for ourself, restarting"),
+             cl->name, cl->hostname);
+      free(name);
+      sighup = 1;
+      return 0;
+    }
 
-  if((write(fw->nexthop->meta_socket, buffer, buflen)) < 0)
+  /* Check if the owner of the new subnet is in the connection list */
+
+  if(!(owner = lookup_id(name)))
     {
-      syslog(LOG_ERR, _("send failed: %s:%d: %m"), __FILE__, __LINE__);
+      syslog(LOG_ERR, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"),
+             name, cl->name, cl->hostname);
+      free(name);
       return -1;
     }
+
+  /* If everything is correct, add the subnet to the list of the owner */
+
+  subnet_add(owner, subnet);
+
+  /* Tell the rest */
+  
+  for(p = conn_list; p; p = p->next)
+    if(p->status.meta && p->status.active && p!= cl)
+      send_add_subnet(p, subnet);
 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*))
+int send_del_subnet(conn_list_t *cl, subnet_t *subnet)
 {
-  conn_list_t *p;
+  int x;
+  char *netstr;
 cp
-  for(p = conn_list; p != NULL; p = p->next)
-    if(p != new && p != source && p->status.meta && p->status.active)
-      function(p, new);
+  netstr = net2str(subnet);
+  x = send_request(cl, "%d %s %s", DEL_SUBNET, subnet->owner->name, netstr);
+  free(netstr);
 cp
-  return 0;
+  return x;
 }
 
-/*
-  notify one connection of everything
-  i have connected
-*/
-int notify_one(conn_list_t *new)
+int del_subnet_h(conn_list_t *cl)
 {
-  conn_list_t *p;
+  char *subnetstr;
+  char *name;
+  conn_list_t *owner, *p;
+  subnet_t *subnet;
 cp
-  for(p = conn_list; p != NULL; p = p->next)
-    if(p != new && p->status.active)
-      send_add_host(new, p);
-cp
-  return 0;
-}
+  if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
+    {
+      syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s)"), cl->name, cl->hostname);
+      free(name); free(subnetstr);
+      return -1;
+    }
 
-/*
-  The incoming request handlers
-*/
+  /* Check if owner name is a valid */
 
-int basic_info_h(conn_list_t *cl)
-{
-cp
-  if(sscanf(cl->buffer, "%*d %d %lx/%lx:%hx", &cl->protocol_version, &cl->vpn_ip, &cl->vpn_mask, &cl->port) != 4)
+  if(check_id(name))
     {
-       syslog(LOG_ERR, _("got bad BASIC_INFO request: %s"), cl->buffer);
-       return -1;
-    }  
+      syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      free(name); free(subnetstr);
+      return -1;
+    }
+
+  /* Check if subnet string is valid */
 
-  if(cl->protocol_version != PROT_CURRENT)
+  if(!(subnet = str2net(subnetstr)))
     {
-      syslog(LOG_ERR, _("Peer uses incompatible protocol version %d."),
-	     cl->protocol_version);
+      syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
+      free(name); free(subnetstr);
       return -1;
     }
 
-  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);
+  free(subnetstr);
+  
+  /* Check if somebody tries to add a subnet of ourself */
 
-  if(cl->status.outgoing)
+  if(!strcmp(name, myself->name))
     {
-      if(setup_vpn_connection(cl) < 0)
-	return -1;
-      send_basic_info(cl);
+      syslog(LOG_ERR, _("Warning: got DEL_SUBNET from %s (%s) for ourself, restarting"),
+             cl->name, cl->hostname);
+      free(name);
+      sighup = 1;
+      return 0;
     }
-  else
+
+  /* Check if the owner of the new subnet is in the connection list */
+
+  if(!(owner = lookup_id(name)))
     {
-      if(setup_vpn_connection(cl) < 0)
-	return -1;
-      send_passphrase(cl);
+      syslog(LOG_ERR, _("Got DEL_SUBNET for %s from %s (%s) which is not in our connection list"),
+             name, cl->name, cl->hostname);
+      free(name);
+      return -1;
     }
+
+  /* If everything is correct, delete the subnet from the list of the owner */
+
+  subnet_del(subnet);
+
+  /* Tell the rest */
+  
+  for(p = conn_list; p; p = p->next)
+    if(p->status.meta && p->status.active && p!= cl)
+      send_del_subnet(p, subnet);
 cp
   return 0;
 }
 
-int passphrase_h(conn_list_t *cl)
+/* New and closed connections notification */
+
+int send_add_host(conn_list_t *cl, conn_list_t *other)
+{
+cp
+  return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST,
+                      other->name, other->address, other->port, other->options);
+}
+
+int add_host_h(conn_list_t *cl)
 {
+  conn_list_t *old, *new;
+  conn_list_t *p;
+
 cp
-  cl->pp = xmalloc(sizeof(*(cl->pp)));
+  new = new_conn_list();
+
+  if(sscanf(cl->buffer, "%*d %as %lx:%d %lx", &new->name, &new->address, &new->port, &new->options) != 4)
+    {
+       syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname);
+       return -1;
+    }
+
+  /* Check if identity is a valid name */
 
-  if(sscanf(cl->buffer, "%*d %as", &(cl->pp->phrase)) != 1)
+  if(check_id(new->name))
     {
-      syslog(LOG_ERR, _("got bad PASSPHRASE request: %s"), cl->buffer);
+      syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      free_conn_list(new);
       return -1;
     }
-  cl->pp->len = strlen(cl->pp->phrase);
+
+  /* Check if somebody tries to add ourself */
+
+  if(!strcmp(new->name, myself->name))
+    {
+      syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname);
+      sighup = 1;
+      free_conn_list(new);
+      return 0;
+    }
     
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("got PASSPHRASE"));
+  /* Fill in more of the new conn_list structure */
 
-  if(cl->status.outgoing)
-    send_passphrase(cl);
-  else
-    send_public_key(cl);
+  new->hostname = hostlookup(htonl(new->address));
+
+  /* Check if the new host already exists in the connnection list */
+
+  if((old = lookup_id(new->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->name, old->hostname, new->name, new->hostname);
+          free_conn_list(new);
+          return 0;
+        }
+      else
+        {
+          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);
+        }
+    }
+
+  /* Hook it up into the conn_list */
+
+  conn_list_add(new);
+
+  /* Tell the rest about the new host */
+
+  for(p = conn_list; p; p = p->next)
+    if(p->status.meta && p->status.active && p!=cl)
+      send_add_host(p, new);
+
+  /* Fill in rest of conn_list structure */
+
+  new->nexthop = cl;
+  new->status.active = 1;
+  new->cipher_pkttype = EVP_bf_cfb();
+  new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
+
+  /* Okay this is a bit ugly... it would be better to setup UDP sockets dynamically, or
+   * perhaps just one UDP socket... but then again, this has benefits too...
+   */
+   
+  setup_vpn_connection(new);
 cp
   return 0;
 }
 
-int public_key_h(conn_list_t *cl)
+int send_del_host(conn_list_t *cl, conn_list_t *other)
 {
-  char *g_n;
-  conn_list_t *old;
 cp
-  if(sscanf(cl->buffer, "%*d %as", &g_n) != 1)
+  return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST,
+                      other->name, other->address, other->port, other->options);
+}
+
+int del_host_h(conn_list_t *cl)
+{
+  char *name;
+  ip_t address;
+  port_t port;
+  long int options;
+  conn_list_t *old, *p;
+cp
+  if(sscanf(cl->buffer, "%*d %as %lx:%d %lx", &name, &address, &port, &options) != 4)
     {
-       syslog(LOG_ERR, _("got bad PUBLIC_KEY request: %s"), cl->buffer);
-       return -1;
-    }  
+      syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"),
+             cl->name, cl->hostname);
+      return -1;
+    }
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("got PUBLIC_KEY %s"), g_n);
+  /* Check if identity is a valid name */
 
-  if(verify_passphrase(cl, g_n))
+  if(check_id(name))
     {
-      /* intruder! */
-      syslog(LOG_ERR, _("Intruder: passphrase does not match."));
+      syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      free(name);
       return -1;
     }
 
-  if(debug_lvl > 2)
-    syslog(LOG_INFO, _("Passphrase OK"));
+  /* Check if somebody tries to delete ourself */
 
-  if(cl->status.outgoing)
-    send_public_key(cl);
-  else
-    send_ack(cl);
+  if(!strcmp(name, myself->name))
+    {
+      syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"),
+             cl->name, cl->hostname);
+      free(name);
+      sighup = 1;
+      return 0;
+    }
 
-  /* 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. */
+  /* Check if the new host already exists in the connnection list */
+
+  if(!(old = lookup_id(name)))
+    {
+      syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) for %s which is not in our connection list"),
+             name, cl->name, cl->hostname);
+      free(name);
+      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;
+    }
 
-  while(old=lookup_conn(cl->vpn_ip)) 
-    terminate_connection(old);
+  /* Ok, since EVERYTHING seems to check out all right, delete it */
 
-  cl->status.active = 1;
-  notify_others(cl, NULL, send_add_host);
-  notify_one(cl);
+  old->status.active = 0;
+  terminate_connection(old);
+
+  /* Tell the rest about the new host */
+
+  for(p = conn_list; p; p = p->next)
+    if(p->status.meta && p->status.active && p!=cl)
+      send_del_host(p, old);
 cp
   return 0;
 }
 
-int ack_h(conn_list_t *cl)
+/* Status and error notification routines */
+
+int send_status(conn_list_t *cl, int statusno, char *statusstring)
 {
 cp
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("got ACK"));
-  
-  cl->status.active = 1;
-  syslog(LOG_NOTICE, _("Connection with %s activated."), cl->hostname);
+  if(!statusstring)
+    statusstring = status_text[statusno];
 cp
-  return 0;
+  return send_request(cl, "%d %d %s", STATUS, statusno, statusstring);
 }
 
-int termreq_h(conn_list_t *cl)
+int status_h(conn_list_t *cl)
 {
+  int statusno;
+  char *statusstring;
 cp
-  syslog(LOG_NOTICE, _(IP_ADDR_S " wants to quit"), IP_ADDR_V(cl->vpn_ip));
-  cl->status.termreq = 1;
-  terminate_connection(cl);
+  if(sscanf(cl->buffer, "%*d %d %as", &statusno, &statusstring) != 2)
+    {
+       syslog(LOG_ERR, _("Got bad STATUS from %s (%s)"),
+              cl->name, cl->hostname);
+       return -1;
+    }
+
+  if(debug_lvl >= DEBUG_STATUS)
+    {
+      syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"),
+             cl->name, cl->hostname, status_text[statusno], statusstring);
+    }
 
-  notify_others(cl, NULL, send_del_host);
 cp
+  free(statusstring);
   return 0;
 }
 
-int timeout_h(conn_list_t *cl)
+int send_error(conn_list_t *cl, int errno, char *errstring)
 {
 cp
-  if(!cl->status.active) return -1;
-  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;
+  if(!errstring)
+    errstring = strerror(errno);
+  return send_request(cl, "%d %d %s", ERROR, errno, errstring);
 }
 
-int del_host_h(conn_list_t *cl)
+int error_h(conn_list_t *cl)
 {
-  ip_t vpn_ip;
-  conn_list_t *fw;
+  int errno;
+  char *errorstring;
 cp
-  if(!cl->status.active) return -1;
-
-  if(sscanf(cl->buffer, "%*d %lx", &vpn_ip) != 1)
+  if(sscanf(cl->buffer, "%*d %d %as", &errno, &errorstring) != 2)
     {
-       syslog(LOG_ERR, _("got bad DEL_HOST request: %s"), cl->buffer);
+       syslog(LOG_ERR, _("Got bad ERROR from %s (%s)"),
+              cl->name, cl->hostname);
        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)))
+  if(debug_lvl >= DEBUG_ERROR)
     {
-      syslog(LOG_ERR, _("Somebody wanted to delete " IP_ADDR_S " which does not exist?"),
-	     IP_ADDR_V(vpn_ip));
-      return 0;
+      syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"),
+             cl->name, cl->hostname, strerror(errno), errorstring);
     }
 
-  notify_others(cl, fw, send_del_host);
+  free(errorstring);
+  terminate_connection(cl);
+cp
+  return 0;
+}
+
+int send_termreq(conn_list_t *cl)
+{
+cp
+  return send_request(cl, "%d", TERMREQ);
+}
 
-  fw->status.termreq = 1;
-  terminate_connection(fw);
+int termreq_h(conn_list_t *cl)
+{
+cp
+  terminate_connection(cl);
 cp
   return 0;
 }
 
+/* Keepalive routines - FIXME: needs a closer look */
+
+int send_ping(conn_list_t *cl)
+{
+cp
+  cl->status.pinged = 1;
+  cl->last_ping_time = time(NULL);
+cp
+  return send_request(cl, "%d", PING);
+}
+
 int ping_h(conn_list_t *cl)
 {
 cp
-  if(!cl->status.active) return -1;
-  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;
+  return send_pong(cl);
+}
 
-  send_pong(cl);
+int send_pong(conn_list_t *cl)
+{
 cp
-  return 0;
+  return send_request(cl, "%d", PONG);
 }
 
 int pong_h(conn_list_t *cl)
 {
 cp
-  if(!cl->status.active) return -1;
-  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;
+  cl->status.pinged = 0;
 cp
   return 0;
 }
 
-int add_host_h(conn_list_t *cl)
+/* Key exchange */
+
+int send_key_changed(conn_list_t *from, conn_list_t *cl)
 {
-  ip_t real_ip;
-  ip_t vpn_ip;
-  ip_t vpn_mask;
-  unsigned short port;
-  conn_list_t *ncn, *fw;
+  conn_list_t *p;
 cp
-  if(!cl->status.active) return -1;
-  if(sscanf(cl->buffer, "%*d %lx %lx/%lx:%hx", &real_ip, &vpn_ip, &vpn_mask, &port) != 4)
+  for(p = conn_list; p != NULL; p = p->next)
     {
-       syslog(LOG_ERR, _("got bad ADD_HOST request: %s"), cl->buffer);
-       return -1;
-    }  
+      if(p!=cl && p->status.meta && p->status.active)
+        send_request(p, "%d %s", KEY_CHANGED,
+                     from->name);
+    }
+cp
+  return 0;
+}
 
-  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);
+int key_changed_h(conn_list_t *cl)
+{
+  char *from_id;
+  conn_list_t *from;
+cp
+  if(sscanf(cl->buffer, "%*d %as", &from_id) != 1)
+    {
+      syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"),
+             cl->name, cl->hostname);
+      return -1;
+    }
 
-  /*
-    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->name, 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->name, to->name);
+}
+
 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;
+  char pktkey[129];
 cp
-  if(!cl->status.active) return -1;
-  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->name, 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->name, 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(to_id, myself->name))
     {
-      cl->public_key = xmalloc(sizeof(*cl->key));
-      cl->public_key->key = NULL;
+      bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength);
+      pktkey[myself->cipher_pktkeylength*2] = '\0';
+      send_ans_key(myself, from, pktkey);
     }
-    
-  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->name, cl->hostname, to_id);
+          free(from_id); free(to_id);
+          return -1;
+        }
+        
+      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);
     }
 
-  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 *pktkey)
+{
 cp
+  return send_request(to->nexthop, "%d %s %s %s", ANS_KEY,
+                      from->name, to->name, pktkey);
 }
 
 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, *pktkey;
+  int keylength;
+  conn_list_t *from, *to;
 cp
-  if(!cl->status.active) return -1;
-  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, &pktkey) != 3)
     {
-       syslog(LOG_ERR, _("got bad ANS_KEY request: %s"), cl->buffer);
+       syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s)"),
+              cl->name, 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(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);
-
-      if(!gk)
-        {
-          syslog(LOG_ERR, _("Receiving key from " IP_ADDR_S ", which does not exist?"),
-	         IP_ADDR_V(from));
-          return -1;
-        }
-
-      set_keys(gk, expiry, key);
-      gk->status.validkey = 1;
-      gk->status.waitingforkey = 0;
-      flush_queues(gk);
-      return 0;
     }
 
-  fw = lookup_conn(to);
-  
-  if(!fw)
+  if(!(from = lookup_id(from_id)))
     {
-      syslog(LOG_ERR, _("Attempting to forward key to " IP_ADDR_S ", which does not exist?"),
-	     IP_ADDR_V(to));
+      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);
+      free(from_id); free(to_id); free(pktkey);
       return -1;
     }
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("Forwarding public key to " IP_ADDR_S),
-	   IP_ADDR_V(fw->nexthop->vpn_ip));
+  /* Check correctness of packet key */
 
-  cl->buffer[cl->reqlen-1] = '\n';
+  keylength = strlen(pktkey);
 
-  if((write(fw->nexthop->meta_socket, cl->buffer, cl->reqlen)) < 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);
+      free(from_id); free(to_id); free(pktkey);
       return -1;
     }
-cp
-  return 0;
-}
-
-int key_changed_h(conn_list_t *cl)
-{
-  ip_t from;
-  conn_list_t *ik;
-cp
-  if(!cl->status.active) return -1;
-  if(sscanf(cl->buffer, "%*d %lx", &from) != 1)
-    {
-       syslog(LOG_ERR, _("got bad ANS_KEY request: %s"), cl->buffer);
-       return -1;
-    }  
 
-  if(debug_lvl > 2)
-    syslog(LOG_DEBUG, _("got KEY_CHANGED from " IP_ADDR_S),
-	   IP_ADDR_V(from));
+  /* Forward it if necessary */
 
-  ik = lookup_conn(from);
-
-  if(!ik)
+  if(strcmp(to_id, myself->name))
     {
-      syslog(LOG_ERR, _("Got changed key from " IP_ADDR_S ", which does not exist?"),
-	     IP_ADDR_V(from));
-      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);
+          free(from_id); free(to_id);
+          return -1;
+        }
+      send_ans_key(from, to, pktkey);
     }
 
-  ik->status.validkey = 0;
-  ik->status.waitingforkey = 0;
+  /* Update our copy of the origin's packet key */
 
-  if(debug_lvl > 3)
-    syslog(LOG_DEBUG, _("Forwarding key invalidation request"));
+  if(from->cipher_pktkey)
+    free(from->cipher_pktkey);
 
-  notify_others(cl, ik, send_key_changed);
+  keylength /= 2;
+  hex2bin(pktkey, pktkey, keylength);
+  pktkey[keylength] = '\0';
+  from->cipher_pktkey = pktkey;
+
+  from->status.validkey = 1;
+  from->status.waitingforkey = 0;
+    
+  free(from_id); free(to_id);
 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
+/* Jumptable for the request handlers */
+
+int (*request_handlers[])(conn_list_t*) = {
+  id_h, challenge_h, chal_reply_h, metakey_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,
+};
+
+/* Request names */
+
+char (*request_name[]) = {
+  "ID", "CHALLENGE", "CHAL_REPLY", "METAKEY", "ACK",
+  "STATUS", "ERROR", "TERMREQ",
+  "PING", "PONG",
+  "ADD_HOST", "DEL_HOST",
+  "ADD_SUBNET", "DEL_SUBNET",
+  "KEY_CHANGED", "REQ_KEY", "ANS_KEY",
+};
+
+/* Status strings */
+
+char (*status_text[]) = {
+  "Warning",
+};
+
+/* Error strings */
+
+char (*error_text[]) = {
+  "Error",
 };