Add stun lookup messages

constants.h

@@ -125,6 +125,8 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #define MAX_SIGNATURES 16
 
 #define MDP_PORT_KEYMAPREQUEST 1
+#define MDP_PORT_STUNREQ 4
+#define MDP_PORT_STUN 5
 #define MDP_PORT_PROBE 6
 #define MDP_PORT_ECHO 7
 #define MDP_PORT_DNALOOKUP 10

overlay_address.c

@@ -413,7 +413,8 @@ static int find_subscr_buffer(struct decode_context *context, struct overlay_buf
     ob_append_bytes(context->please_explain->payload, id, len);
     
   }else{
-    context->previous=*subscriber;
+    if (context)
+      context->previous=*subscriber;
   }
   return 0;
 }

overlay_interface.c

@@ -131,7 +131,16 @@ error:
   return -1;
 }
 
-overlay_interface * overlay_interface_find(struct in_addr addr){
+overlay_interface * overlay_interface_get_default(){
+  int i;
+  for (i=0;i<OVERLAY_MAX_INTERFACES;i++){
+    if (overlay_interfaces[i].state==INTERFACE_STATE_UP && overlay_interfaces[i].default_route)
+      return &overlay_interfaces[i];
+  }
+  return NULL;
+}
+
+overlay_interface * overlay_interface_find(struct in_addr addr, int return_default){
   int i;
   overlay_interface *ret = NULL;
   for (i=0;i<OVERLAY_MAX_INTERFACES;i++){
@@ -143,7 +152,7 @@ overlay_interface * overlay_interface_find(struct in_addr addr){
     }
     
     // check if this is a default interface
-    if (overlay_interfaces[i].default_route)
+    if (return_default && overlay_interfaces[i].default_route)
       ret=&overlay_interfaces[i];
   }
   
@@ -186,7 +195,7 @@ overlay_interface_read_any(struct sched_ent *alarm){
     struct in_addr src = ((struct sockaddr_in *)&src_addr)->sin_addr;
     
     /* Try to identify the real interface that the packet arrived on */
-    interface = overlay_interface_find(src);
+    interface = overlay_interface_find(src, 0);
     
     /* Drop the packet if we don't find a match */
     if (!interface){

overlay_mdp.c

@@ -527,6 +527,8 @@ int overlay_mdp_check_binding(struct subscriber *subscriber, int port, int userG
     case MDP_PORT_RHIZOME_RESPONSE:
     case MDP_PORT_RHIZOME_REQUEST:
     case MDP_PORT_PROBE:
+    case MDP_PORT_STUNREQ:
+    case MDP_PORT_STUN:
       return 0;
     }
   }
@@ -1017,7 +1019,7 @@ void overlay_mdp_poll(struct sched_ent *alarm)
 	      schedule(&scans[i].alarm);
 	    }
 	  }else{
-	    struct overlay_interface *interface = overlay_interface_find(scan->addr);
+	    struct overlay_interface *interface = overlay_interface_find(scan->addr, 1);
 	    if (!interface){
 	      overlay_mdp_reply_error(alarm->poll.fd,recvaddr_un,recvaddrlen, 1, "Unable to find matching interface");
 	      return;

overlay_mdp_services.c

@@ -314,7 +314,7 @@ overlay_mdp_service_probe(overlay_mdp_frame *mdp)
 
 int overlay_send_probe(struct subscriber *peer, struct sockaddr_in addr, overlay_interface *interface){
   if (interface==NULL)
-    interface = overlay_interface_find(addr.sin_addr);
+    interface = overlay_interface_find(addr.sin_addr, 1);
   
   if (!interface)
     return WHY("I don't know which interface to use");
@@ -338,6 +338,8 @@ int overlay_send_probe(struct subscriber *peer, struct sockaddr_in addr, overlay
   frame->payload = ob_new();
   frame->send_copies=3;
   
+  // TODO call mdp payload encryption / signing without calling overlay_mdp_dispatch...
+  
   if ((!peer) || !(peer->reachable&REACHABLE))
     my_subscriber->send_full=1;
   
@@ -367,6 +369,128 @@ int overlay_send_probe(struct subscriber *peer, struct sockaddr_in addr, overlay
   return 0;
 }
 
+// append the address of a unicast link into a packet buffer
+static int overlay_append_unicast_address(struct subscriber *subscriber, struct overlay_buffer *buff)
+{
+  if (!(subscriber->reachable & REACHABLE_UNICAST))
+    return 0;
+  if (subscriber->reachable & REACHABLE_ASSUMED)
+    return 0;
+  if (overlay_address_append(NULL, buff, subscriber))
+    return -1;
+  if (ob_append_ui32(buff, subscriber->address.sin_addr.s_addr))
+    return -1;
+  if (ob_append_ui16(buff, subscriber->address.sin_port))
+    return -1;
+  ob_checkpoint(buff);
+  DEBUGF("Added STUN info for %s", alloca_tohex_sid(subscriber->sid));
+  return 0;
+}
+
+static int overlay_mdp_service_stun_req(overlay_mdp_frame *mdp)
+{
+  DEBUGF("Processing STUN request from %s", alloca_tohex_sid(mdp->out.src.sid));
+  
+  struct overlay_buffer *payload = ob_static(mdp->out.payload, mdp->out.payload_length);
+  ob_limitsize(payload, mdp->out.payload_length);
+  
+  overlay_mdp_frame reply;
+  bzero(&reply, sizeof(reply));
+  reply.packetTypeAndFlags=MDP_TX;
+  
+  bcopy(mdp->out.src.sid, reply.out.dst.sid, SID_SIZE);
+  bcopy(mdp->out.dst.sid, reply.out.src.sid, SID_SIZE);
+  reply.out.src.port=MDP_PORT_STUNREQ;
+  reply.out.dst.port=MDP_PORT_STUN;
+  
+  struct overlay_buffer *replypayload = ob_static(reply.out.payload, sizeof(reply.out.payload));
+  
+  ob_checkpoint(replypayload);
+  while(ob_remaining(payload)>0){
+    struct subscriber *subscriber=NULL;
+    
+    if (overlay_address_parse(NULL, payload, &subscriber))
+      break;
+    
+    if (!subscriber)
+      continue;
+    
+    if (overlay_append_unicast_address(subscriber, replypayload))
+      break;
+  }
+  
+  ob_rewind(replypayload);
+  reply.out.payload_length=ob_position(replypayload);
+  
+  if (reply.out.payload_length)
+    overlay_mdp_dispatch(&reply,0 /* system generated */,
+			 NULL,0);
+  
+  ob_free(replypayload);
+  ob_free(payload);
+  return 0;
+}
+
+static int overlay_mdp_service_stun(overlay_mdp_frame *mdp)
+{
+  struct overlay_buffer *buff = ob_static(mdp->out.payload, mdp->out.payload_length);
+  ob_limitsize(buff, mdp->out.payload_length);
+  
+  DEBUGF("Processing STUN info from %s", alloca_tohex_sid(mdp->out.src.sid));
+  
+  while(ob_remaining(buff)>0){
+    struct subscriber *subscriber=NULL;
+    struct sockaddr_in addr;
+    
+    // TODO explain addresses, link expiry time, resolve differences between addresses...
+    
+    if (overlay_address_parse(NULL, buff, &subscriber)){
+      break;
+    }
+    
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = ob_get_ui32(buff);
+    addr.sin_port = ob_get_ui16(buff);
+    
+    if (!subscriber || (subscriber->reachable!=REACHABLE_NONE))
+      continue;
+    
+    overlay_send_probe(subscriber, addr, NULL);
+  }
+  
+  ob_free(buff);
+  return 0;
+}
+
+int overlay_send_stun_request(struct subscriber *server, struct subscriber *request){
+  if ((!server) || (!request))
+    return -1;
+  if (!(subscriber_is_reachable(server)&REACHABLE))
+    return -1;
+  // don't bother with a stun request if the peer is already reachable directly
+  // TODO link timeouts
+  if (subscriber_is_reachable(request)&REACHABLE_DIRECT)
+    return -1;
+  
+  overlay_mdp_frame mdp;
+  bzero(&mdp, sizeof(mdp));
+  mdp.packetTypeAndFlags=MDP_TX;
+  
+  bcopy(my_subscriber->sid, mdp.out.src.sid, SID_SIZE);
+  bcopy(server->sid, mdp.out.dst.sid, SID_SIZE);
+  mdp.out.src.port=MDP_PORT_STUN;
+  mdp.out.dst.port=MDP_PORT_STUNREQ;
+  
+  struct overlay_buffer *payload = ob_static(mdp.out.payload, sizeof(mdp.out.payload));
+  overlay_address_append(NULL, payload, request);
+  mdp.out.payload_length=ob_position(payload);
+  DEBUGF("Sending STUN request to %s", alloca_tohex_sid(server->sid));
+  overlay_mdp_dispatch(&mdp,0 /* system generated */,
+		       NULL,0);
+  ob_free(payload);
+  return 0;
+}
+
 int overlay_mdp_try_interal_services(overlay_mdp_frame *mdp)
 {
   IN();
@@ -376,6 +500,8 @@ int overlay_mdp_try_interal_services(overlay_mdp_frame *mdp)
   case MDP_PORT_DNALOOKUP:        RETURN(overlay_mdp_service_dnalookup(mdp));
   case MDP_PORT_ECHO:             RETURN(overlay_mdp_service_echo(mdp));
   case MDP_PORT_PROBE:            RETURN(overlay_mdp_service_probe(mdp));
+  case MDP_PORT_STUNREQ:          RETURN(overlay_mdp_service_stun_req(mdp));
+  case MDP_PORT_STUN:             RETURN(overlay_mdp_service_stun(mdp));
   case MDP_PORT_RHIZOME_REQUEST: 
     if (is_rhizome_mdp_server_running()) {
       RETURN(overlay_mdp_service_rhizomerequest(mdp));

overlay_olsr.c

@@ -144,7 +144,7 @@ static void parse_frame(struct overlay_buffer *buff){
     goto end;
   
   // locate the interface we should send outgoing unicast packets to
-  overlay_interface *interface = overlay_interface_find(*addr);
+  overlay_interface *interface = overlay_interface_find(*addr, 1);
   if (interface){
     // always update the IP address we heard them from, even if we don't need to use it right now
     context.sender->address.sin_family = AF_INET;

serval.h

@@ -615,7 +615,8 @@ int overlay_route_node_info(overlay_mdp_nodeinfo *node_info);
 int overlay_interface_register(char *name,
 			       struct in_addr addr,
 			       struct in_addr mask);
-overlay_interface * overlay_interface_find(struct in_addr addr);
+overlay_interface * overlay_interface_get_default();
+overlay_interface * overlay_interface_find(struct in_addr addr, int return_default);
 overlay_interface * overlay_interface_find_name(const char *name);
 int overlay_broadcast_ensemble(int interface_number,
 			   struct sockaddr_in *recipientaddr,
@@ -712,6 +713,7 @@ void server_shutdown_check(struct sched_ent *alarm);
 void overlay_mdp_poll(struct sched_ent *alarm);
 int overlay_mdp_try_interal_services(overlay_mdp_frame *mdp);
 int overlay_send_probe(struct subscriber *peer, struct sockaddr_in addr, overlay_interface *interface);
+int overlay_send_stun_request(struct subscriber *server, struct subscriber *request);
 void fd_periodicstats(struct sched_ent *alarm);
 void rhizome_check_connections(struct sched_ent *alarm);