add support for sending port along as icmp payload. needs tested on NAT boxes to...

diff --git a/src/transport/gnunet-nat-client.c b/src/transport/gnunet-nat-client.c
index b9c61a143a8e0483512f6578d0cc87a16fb00d7b..cbfc0a28c088164085a72615e7ca3ad159284a22 100644 (file)
--- a/src/transport/gnunet-nat-client.c
+++ b/src/transport/gnunet-nat-client.c
@@ -58,6 +58,7 @@
  * Must match IP given in the server.
  */
 #define DUMMY_IP "1.2.3.4"
+#define HAVE_PORT 1
 
 struct ip_packet 
 {
@@ -79,7 +80,18 @@ struct icmp_packet
   uint8_t code;
   uint16_t checksum;
   uint32_t reserved;
+
 };
+
+struct icmp_echo_packet
+{
+  uint8_t type;
+  uint8_t code;
+  uint16_t checksum;
+  uint32_t reserved;
+  uint32_t data;
+};
+
  
 static int rawsock;
 
@@ -87,6 +99,9 @@ static struct in_addr dummy;
  
 static struct in_addr target;
 
+#if HAVE_PORT
+  static uint32_t port;
+#endif
 
 static uint16_t 
 calc_checksum(const uint16_t *data, 
@@ -104,18 +119,36 @@ calc_checksum(const uint16_t *data,
 }
 
 
+
+#if HAVE_PORT
+
 static void
 make_echo (const struct in_addr *src_ip,
-          struct icmp_packet *echo)
+          struct icmp_echo_packet *echo, uint32_t num)
 {
-  memset(echo, 0, sizeof(struct icmp_packet));
+  memset(echo, 0, sizeof(struct icmp_echo_packet));
   echo->type = ICMP_ECHO;
   echo->code = 0;
   echo->reserved = 0;
   echo->checksum = 0;
+  echo->data = htons(num);
   echo->checksum = htons(calc_checksum((uint16_t*)echo, 
-                                      sizeof (struct icmp_packet)));
+                                      sizeof (struct icmp_echo_packet)));
 }
+#else
+static void
+make_echo (const struct in_addr *src_ip,
+           struct icmp_packet *echo)
+{
+  memset(echo, 0, sizeof(struct icmp_packet));
+  echo->type = ICMP_ECHO;
+  echo->code = 0;
+  echo->reserved = 0;
+  echo->checksum = 0;
+  echo->checksum = htons(calc_checksum((uint16_t*)echo,
+                                       sizeof (struct icmp_packet)));
+}
+#endif
 
 
 /**
@@ -130,9 +163,17 @@ send_icmp (const struct in_addr *my_ip,
 {
   struct ip_packet ip_pkt;
   struct icmp_packet *icmp_pkt;
+#if HAVE_PORT
+  struct icmp_echo_packet icmp_echo;
+#else
   struct icmp_packet icmp_echo;
+#endif
   struct sockaddr_in dst;
+#if HAVE_PORT
+  char packet[sizeof (struct ip_packet)*2 + sizeof (struct icmp_packet) + sizeof(struct icmp_echo_packet)];
+#else
   char packet[sizeof (struct ip_packet)*2 + sizeof (struct icmp_packet)*2];
+#endif
   size_t off;
   int err;
 
@@ -159,12 +200,18 @@ send_icmp (const struct in_addr *my_ip,
   icmp_pkt->code = 0; 
   icmp_pkt->reserved = 0;
   icmp_pkt->checksum = 0;
+
   off += sizeof (struct icmp_packet);
 
   /* ip header of the presumably 'lost' udp packet */
   ip_pkt.vers_ihl = 0x45;
   ip_pkt.tos = 0;
+#if HAVE_PORT
+  ip_pkt.pkt_len = (sizeof (struct ip_packet) + sizeof (struct icmp_echo_packet));
+#else
   ip_pkt.pkt_len = (sizeof (struct ip_packet) + sizeof (struct icmp_packet));
+#endif
+
   ip_pkt.id = 1; 
   ip_pkt.flags_frag_offset = 0;
   ip_pkt.ttl = 1; /* real TTL would be 1 on a time exceeded packet */
@@ -175,11 +222,28 @@ send_icmp (const struct in_addr *my_ip,
   ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (struct ip_packet)));  
   memcpy (&packet[off], &ip_pkt, sizeof (struct ip_packet));
   off += sizeof (struct ip_packet);
+
+#if HAVE_PORT
+  make_echo (other, &icmp_echo, port);
+  memcpy (&packet[off], &icmp_echo, sizeof(struct icmp_echo_packet));
+  off += sizeof (struct icmp_echo_packet);
+#else
   make_echo (other, &icmp_echo);
   memcpy (&packet[off], &icmp_echo, sizeof(struct icmp_packet));
   off += sizeof (struct icmp_packet);
+#endif
+
+#if HAVE_PORT
+  icmp_pkt->checksum = htons(calc_checksum((uint16_t*)icmp_pkt,
+                                             sizeof (struct icmp_packet) + sizeof(struct ip_packet) + sizeof(struct icmp_echo_packet)));
+
+#else
   icmp_pkt->checksum = htons(calc_checksum((uint16_t*)icmp_pkt, 
-                                          sizeof (struct icmp_packet)*2 + sizeof(struct ip_packet)));
+                                             sizeof (struct icmp_packet)*2 + sizeof(struct ip_packet)));
+
+#endif
+
+
 
   memset (&dst, 0, sizeof (dst));
   dst.sin_family = AF_INET;
@@ -243,12 +307,22 @@ main (int argc, char *const *argv)
     fprintf (stderr,
             "Failed to setresuid: %s\n",
             strerror (errno));
+#if HAVE_PORT
+  if (argc != 4)
+    {
+      fprintf (stderr,
+              "This program must be started with our IP, the targets external IP, and our port as arguments.\n");
+      return 1;
+    }
+  port = atoi(argv[3]);
+#else
   if (argc != 3)
     {
       fprintf (stderr,
-              "This program must be started with our IP and the targets external IP as arguments.\n");
+               "This program must be started with our IP and the targets external IP as arguments.\n");
       return 1;
     }
+#endif
   if ( (1 != inet_pton (AF_INET, argv[1], &external)) ||
        (1 != inet_pton (AF_INET, argv[2], &target)) )
     {

diff --git a/src/transport/gnunet-nat-server.c b/src/transport/gnunet-nat-server.c
index df6b69c65ed317a03f3f754ebb3b0a5b1a3dd7b9..6bead4c3132173bd5f50e90e5c234e68fa52ba51 100644 (file)
--- a/src/transport/gnunet-nat-server.c
+++ b/src/transport/gnunet-nat-server.c
@@ -62,7 +62,7 @@
  */
 #define DUMMY_IP "1.2.3.4"
 
-#define VERBOSE GNUNET_NO
+#define VERBOSE 1
 
 /**
  * How often do we send our ICMP messages to receive replies?
@@ -193,6 +193,8 @@ process_icmp_response ()
   struct ip_packet ip_pkt;
   struct icmp_packet icmp_pkt;
   size_t off;
+  int have_port;
+  uint32_t port;
   
   have = read (icmpsock, buf, sizeof (buf));
   if (have == -1)
@@ -202,7 +204,12 @@ process_icmp_response ()
               strerror (errno));
       return; 
     }
-  if (have != sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) * 2)
+  have_port = 0;
+  if (have == sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) * 2 + sizeof(uint32_t))
+    {
+      have_port = 1;
+    }
+  else if (have != sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) * 2)
     {
 #if VERBOSE
       fprintf (stderr,
@@ -226,12 +233,26 @@ process_icmp_response ()
   memcpy(&sip, 
         &ip_pkt.src_ip, 
         sizeof (sip));
-  fprintf (stdout,
-          "%s\n",
-          inet_ntop (AF_INET,
-                     &sip,
-                     buf,
-                     sizeof (buf)));
+  if (have_port)
+    {
+      memcpy(&port, &buf[sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) * 2], sizeof(uint32_t));
+      port = ntohs(port);
+      fprintf (stdout,
+              "%s:%d\n",
+              inet_ntop (AF_INET,
+                         &sip,
+                         buf,
+                         sizeof (buf)), port);
+    }
+  else
+    {
+      fprintf (stdout,
+              "%s\n",
+              inet_ntop (AF_INET,
+                         &sip,
+                         buf,
+                         sizeof (buf)));
+    }
   fflush (stdout);
 }