Initial work for local multicast registering (work in progress)

edge.c

@@ -324,10 +324,8 @@ static int setOption(int optkey, char *optargument, edge_conf_t *ec, n2n_edge_t
     }
 
   case 'v': /* verbose */
-    {
+    traceLevel = 4; /* DEBUG */
-      ++traceLevel; /* do 2 -v flags to increase verbosity to DEBUG level*/
     break;
-    }
     
   default:
     {
@@ -679,17 +677,42 @@ int main(int argc, char* argv[]) {
   }  
   /* else run in NULL mode */
 
+  /* Populate the multicast group for local edge */
+  eee.multicast_peer.family     = AF_INET;
+  eee.multicast_peer.port       = N2N_MULTICAST_PORT;
+  eee.multicast_peer.addr.v4[0] = 224; /* N2N_MULTICAST_GROUP */
+  eee.multicast_peer.addr.v4[1] = 0;
+  eee.multicast_peer.addr.v4[2] = 0;
+  eee.multicast_peer.addr.v4[3] = 68;
+      
   eee.udp_sock = open_socket(ec.local_port, 1 /* bind ANY */);
   if(eee.udp_sock < 0) {
     traceEvent(TRACE_ERROR, "Failed to bind main UDP port %u", (signed int)ec.local_port);
     return(-1);
   }
   
-  eee.udp_mgmt_sock = open_socket(ec.mgmt_port, 0 /* bind LOOPBACK */);
+  eee.udp_mgmt_sock = open_socket(eee.multicast_peer.port, 0 /* bind LOOPBACK */);  
-  
   if(eee.udp_mgmt_sock < 0) {
     traceEvent(TRACE_ERROR, "Failed to bind management UDP port %u", ec.mgmt_port);
     return(-1);
+  } else {
+
+  }
+
+   eee.udp_multicast_sock = open_socket(N2N_MULTICAST_PORT, 1 /* bind ANY */);
+  if(eee.udp_multicast_sock < 0)
+    return(-5);
+  else {
+    /* Bind eee.udp_multicast_sock to multicast group */
+    struct ip_mreq mreq;
+    
+    mreq.imr_multiaddr.s_addr = inet_addr(N2N_MULTICAST_GROUP);
+    mreq.imr_interface.s_addr = htonl(INADDR_ANY);
+    if (setsockopt(eee.udp_multicast_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+      traceEvent(TRACE_ERROR, "Failed to bind to local multicast group %s:%u",
+		 N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT);
+      return(-6);
+    }    
   }
 
   traceEvent(TRACE_NORMAL, "edge started");

edge_utils.c

@@ -77,6 +77,7 @@ int edge_init(n2n_edge_t * eee) {
   eee->null_transop   = 0;
   eee->udp_sock       = -1;
   eee->udp_mgmt_sock  = -1;
+  eee->udp_multicast_sock = -1;
   eee->dyn_ip_mode    = 0;
   eee->allow_routing  = 0;
   eee->drop_multicast = 1;
@@ -177,15 +178,13 @@ void supernode2addr(n2n_sock_t * sn, const n2n_sn_name_t addrIn) {
 static void try_send_register(n2n_edge_t * eee,
 			      uint8_t from_supernode,
 			      const n2n_mac_t mac,
-			      const n2n_sock_t * peer)
+			      const n2n_sock_t * peer) {
-{
   /* REVISIT: purge of pending_peers not yet done. */
   struct peer_info * scan = find_peer_by_mac(eee->pending_peers, mac);
   macstr_t mac_buf;
   n2n_sock_str_t sockbuf;
 
-  if(NULL == scan)
+  if(scan == NULL) {
-    {
     scan = calloc(1, sizeof(struct peer_info));
 
     memcpy(scan->mac_addr, mac, N2N_MAC_SIZE);
@@ -205,8 +204,12 @@ static void try_send_register(n2n_edge_t * eee,
 
     send_register(eee, &(scan->sock));
 
+    /* no send registration to the local multicast group */
+    traceEvent(TRACE_INFO, "Registering with multicast group %s:%u",
+	       N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT);    
+    send_register(eee, &(eee->multicast_peer));  
+    
     /* pending_peers now owns scan. */
-    } else {
   }
 }
 
@@ -219,13 +222,10 @@ void check_peer(n2n_edge_t * eee,
 		const n2n_sock_t * peer) {
   struct peer_info * scan = find_peer_by_mac(eee->known_peers, mac);
   
-  if(NULL == scan)
+  if(NULL == scan) {
-    {
     /* Not in known_peers - start the REGISTER process. */
     try_send_register(eee, from_supernode, mac, peer);
-    }
+  } else {
-  else
-    {
     /* Already in known_peers. */
     update_peer_address(eee, from_supernode, mac, peer, time(NULL));
   }
@@ -470,9 +470,7 @@ static void send_register_super(n2n_edge_t * eee,
   memcpy(cmn.community, eee->community_name, N2N_COMMUNITY_SIZE);
 
   for(idx=0; idx < N2N_COOKIE_SIZE; ++idx)
-    {
     eee->last_cookie[idx] = rand() % 0xff;
-    }
 
   memcpy(reg.cookie, eee->last_cookie, N2N_COOKIE_SIZE);
   reg.auth.scheme=0; /* No auth yet */
@@ -564,23 +562,17 @@ static void send_register_ack(n2n_edge_t * eee,
  *  This is frequently called by the main loop.
  */
 void update_supernode_reg(n2n_edge_t * eee, time_t nowTime) {
-  if(eee->sn_wait && (nowTime > (eee->last_register_req + (eee->register_lifetime/10))))
+  if(eee->sn_wait && (nowTime > (eee->last_register_req + (eee->register_lifetime/10)))) {
-    {
     /* fall through */
     traceEvent(TRACE_DEBUG, "update_supernode_reg: doing fast retry.");
-    }
+  } else if(nowTime < (eee->last_register_req + eee->register_lifetime))
-  else if(nowTime < (eee->last_register_req + eee->register_lifetime))
-    {
     return; /* Too early */
-    }
 
-  if(0 == eee->sup_attempts)
+  if(0 == eee->sup_attempts) {
-    {
     /* Give up on that supernode and try the next one. */
     ++(eee->sn_idx);
 
-      if (eee->sn_idx >= eee->sn_num)
+    if (eee->sn_idx >= eee->sn_num) {
-        {
       /* Got to end of list, go back to the start. Also works for list of one entry. */
       eee->sn_idx=0;
     }
@@ -591,14 +583,10 @@ void update_supernode_reg(n2n_edge_t * eee, time_t nowTime) {
     eee->sup_attempts = N2N_EDGE_SUP_ATTEMPTS;
   }
   else
-    {
     --(eee->sup_attempts);
-    }
 
   if(eee->re_resolve_supernode_ip || (eee->sn_num > 1))
-    {
     supernode2addr(&(eee->supernode), eee->sn_ip_array[eee->sn_idx]);
-    }
 
   traceEvent(TRACE_DEBUG, "Registering with supernode (%s) (attempts left %u)",
 	     supernode_ip(eee), (unsigned int)eee->sup_attempts);
@@ -786,7 +774,7 @@ static void readFromMgmtSocket(n2n_edge_t * eee, int * keep_running) {
 
   now = time(NULL);
   i = sizeof(sender_sock);
-  recvlen=recvfrom(eee->udp_mgmt_sock, udp_buf, N2N_PKT_BUF_SIZE, 0/*flags*/,
+  recvlen = recvfrom(eee->udp_mgmt_sock, udp_buf, N2N_PKT_BUF_SIZE, 0/*flags*/,
 		     (struct sockaddr *)&sender_sock, (socklen_t*)&i);
 
   if(recvlen < 0)
@@ -1230,7 +1218,7 @@ static void startTunReadThread(n2n_edge_t *eee) {
 /* ************************************** */
 
 /** Read a datagram from the main UDP socket to the internet. */
-static void readFromIPSocket(n2n_edge_t * eee) {
+static void readFromIPSocket(n2n_edge_t * eee, int in_sock) {
   n2n_common_t        cmn; /* common fields in the packet header */
 
   n2n_sock_str_t      sockbuf1;
@@ -1252,11 +1240,10 @@ static void readFromIPSocket(n2n_edge_t * eee) {
   size_t              i;
 
   i = sizeof(sender_sock);
-  recvlen=recvfrom(eee->udp_sock, udp_buf, N2N_PKT_BUF_SIZE, 0/*flags*/,
+  recvlen = recvfrom(in_sock, udp_buf, N2N_PKT_BUF_SIZE, 0/*flags*/,
 		     (struct sockaddr *)&sender_sock, (socklen_t*)&i);
 
-  if(recvlen < 0)
+  if(recvlen < 0) {
-    {
     traceEvent(TRACE_ERROR, "recvfrom failed with %s", strerror(errno));
     
     return; /* failed to receive data from UDP */
@@ -1264,7 +1251,7 @@ static void readFromIPSocket(n2n_edge_t * eee) {
 
   /* REVISIT: when UDP/IPv6 is supported we will need a flag to indicate which
    * IP transport version the packet arrived on. May need to UDP sockets. */
-  sender.family = AF_INET; /* udp_sock was opened PF_INET v4 */
+  sender.family = AF_INET; /* UDP socket was opened PF_INET v4 */
   sender.port = ntohs(sender_sock.sin_port);
   memcpy(&(sender.addr.v4), &(sender_sock.sin_addr.s_addr), IPV4_SIZE);
 
@@ -1343,9 +1330,7 @@ static void readFromIPSocket(n2n_edge_t * eee) {
 	  decode_REGISTER_ACK(&ra, &cmn, udp_buf, &rem, &idx);
 
 	  if(ra.sock.family)
-            {
 	    orig_sender = &(ra.sock);
-            }
 
 	  traceEvent(TRACE_INFO, "Rx REGISTER_ACK src=%s dst=%s from peer %s (%s)",
 		     macaddr_str(mac_buf1, ra.srcMac),
@@ -1448,6 +1433,9 @@ int run_edge_loop(n2n_edge_t * eee, int *keep_running) {
     FD_SET(eee->udp_sock, &socket_mask);
     FD_SET(eee->udp_mgmt_sock, &socket_mask);
     max_sock = max(eee->udp_sock, eee->udp_mgmt_sock);
+    FD_SET(eee->udp_multicast_sock, &socket_mask);
+    max_sock = max(eee->udp_sock, eee->udp_multicast_sock);
+    
 #ifndef WIN32
     FD_SET(eee->device.fd, &socket_mask);
     max_sock = max(max_sock, eee->device.fd);
@@ -1459,22 +1447,26 @@ int run_edge_loop(n2n_edge_t * eee, int *keep_running) {
     nowTime=time(NULL);
 
     /* Make sure ciphers are updated before the packet is treated. */
-    if((nowTime - lastTransop) > TRANSOP_TICK_INTERVAL)
+    if((nowTime - lastTransop) > TRANSOP_TICK_INTERVAL) {
-      {
       lastTransop = nowTime;
       
       n2n_tick_transop(eee, nowTime);
     }
     
-    if(rc > 0)
+    if(rc > 0) {
-      {
       /* Any or all of the FDs could have input; check them all. */
 
-	if(FD_ISSET(eee->udp_sock, &socket_mask))
+      if(FD_ISSET(eee->udp_sock, &socket_mask)) {
-	  {
+	/* Read a cooked socket from the internet socket (unicast). Writes on the TAP
-	    /* Read a cooked socket from the internet socket. Writes on the TAP
 	 * socket. */
-	    readFromIPSocket(eee);
+	readFromIPSocket(eee, eee->udp_sock);
+      }
+
+      if(FD_ISSET(eee->udp_multicast_sock, &socket_mask)) {
+	/* Read a cooked socket from the internet socket (multicast). Writes on the TAP
+	 * socket. */
+	traceEvent(TRACE_WARNING, "**** Received packet from multicast socket ****");
+	readFromIPSocket(eee, eee->udp_multicast_sock);
       }
 
 #ifdef __ANDROID_NDK__
@@ -1500,8 +1492,6 @@ int run_edge_loop(n2n_edge_t * eee, int *keep_running) {
     }
 
     /* Finished processing select data. */
-
-
     update_supernode_reg(eee, nowTime);
 
     numPurged =  purge_expired_registrations(&(eee->known_peers));
@@ -1593,9 +1583,7 @@ int edge_init_keyschedule(n2n_edge_t * eee) {
       n2n_tick_transop(eee, now);
     }
   else    
-    {
     traceEvent(TRACE_ERROR, "Failed to process '%s'", eee->keyschedule);
-    }
     
   return retval;
 }
@@ -1610,6 +1598,9 @@ void edge_term(n2n_edge_t * eee) {
   if(eee->udp_mgmt_sock >= 0)
     closesocket(eee->udp_mgmt_sock);    
 
+  if(eee->udp_multicast_sock >= 0)
+    closesocket(eee->udp_multicast_sock);    
+
   clear_peer_list(&(eee->pending_peers));
   clear_peer_list(&(eee->known_peers));
 
@@ -1670,10 +1661,25 @@ int quick_edge_init(char *device_name, char *community_name,
     return(-3);  
   
   eee.udp_mgmt_sock      = open_socket(0 /* any port */, 0 /* bind LOOPBACK */);
-  
   if(eee.udp_mgmt_sock < 0)
     return(-4);
 
+  eee.udp_multicast_sock = open_socket(N2N_MULTICAST_PORT, 1 /* bind ANY */);
+  if(eee.udp_multicast_sock < 0)
+    return(-5);
+  else {
+    /* Bind eee.udp_multicast_sock to multicast group */
+    struct ip_mreq mreq;
+    
+    mreq.imr_multiaddr.s_addr = inet_addr(N2N_MULTICAST_GROUP);
+    mreq.imr_interface.s_addr = htonl(INADDR_ANY);
+    if (setsockopt(eee.udp_multicast_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+      traceEvent(TRACE_ERROR, "Failed to bind to local multicast group %s:%u",
+		 N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT);
+      return(-6);
+    }    
+  }
+  
   update_supernode_reg(&eee, time(NULL));
   
   return(run_edge_loop(&eee, keep_on_running));

n2n.c

@@ -58,6 +58,7 @@ SOCKET open_socket(int local_port, int bind_any) {
   local_address.sin_family = AF_INET;
   local_address.sin_port = htons(local_port);
   local_address.sin_addr.s_addr = htonl(bind_any ? INADDR_ANY : INADDR_LOOPBACK);
+
   if(bind(sock_fd,(struct sockaddr*) &local_address, sizeof(local_address)) == -1) {
     traceEvent(TRACE_ERROR, "Bind error on local port %u [%s]\n", local_port, strerror(errno));
     return(-1);

n2n.h

@@ -199,6 +199,7 @@ struct n2n_edge {
 
   int                 udp_sock;
   int                 udp_mgmt_sock;          /**< socket for status info. */
+  int                 udp_multicast_sock;     /**< socket for local multicast registrations. */
 
   tuntap_dev          device;                 /**< All about the TUNTAP device */
   int                 dyn_ip_mode;            /**< Interface IP address is dynamically allocated, eg. DHCP. */
@@ -207,7 +208,7 @@ struct n2n_edge {
 
   n2n_trans_op_t      transop[N2N_MAX_TRANSFORMS]; /* one for each transform at fixed positions */
   size_t              tx_transop_idx;         /**< The transop to use when encoding. */
-
+  n2n_sock_t          multicast_peer;         /**< Multicast peer group (for local edges) */
   struct peer_info *  known_peers;            /**< Edges we are connected to. */
   struct peer_info *  pending_peers;          /**< Edges we have tried to register with. */
   time_t              last_register_req;      /**< Check if time to re-register with super*/

n2n_wire.h

@@ -42,6 +42,9 @@
 #define N2N_PKT_BUF_SIZE                2048
 #define N2N_SOCKBUF_SIZE                64      /* string representation of INET or INET6 sockets */
 
+#define N2N_MULTICAST_PORT              1968
+#define N2N_MULTICAST_GROUP             "224.0.0.68"
+
 typedef uint8_t n2n_community_t[N2N_COMMUNITY_SIZE];
 typedef uint8_t n2n_mac_t[N2N_MAC_SIZE];
 typedef uint8_t n2n_cookie_t[N2N_COOKIE_SIZE];