Allowing set of destination port

udpCallback.c

@@ -48,6 +48,7 @@ static int udpSocket;
 struct sockaddr_in sockaddr;
 static int start_loop = 1;
 char  *dvalue = NULL;
+char  *pvalue = NULL;
 int    flood = 0;
 int    oneByOne = 0;
 long int countToFlood = 0;
@@ -238,11 +239,13 @@ static void callback_handler(u_char *user __attribute__((unused)),
   /* Set destination */
   if (!dvalue)
     sockaddr.sin_addr.s_addr = ip_hdr.ip_dst.s_addr;
+  if (!pvalue) {
 #ifdef HAVE_STRUCT_UDPHDR_UH_DPORT
-  sockaddr.sin_port = udp_hdr.uh_dport;
+    sockaddr.sin_port = udp_hdr.uh_dport;
 #else
-  sockaddr.sin_port = udp_hdr.dest;
+    sockaddr.sin_port = udp_hdr.dest;
 #endif
+  }
 
   if (asterixTime)
   {

udpCallback.h

@@ -18,6 +18,7 @@
 extern struct sockaddr_in sockaddr;
 extern int rewriteDestination;
 extern char *dvalue;
+extern char *pvalue;
 extern int flood;
 extern int oneByOne;
 extern int asterixTime;

udpReplay.1

@@ -26,6 +26,9 @@ Adjust the Asterix Time Of Day to reflect the time the message is sent
 .BR -d\ host | --dest\ host
 Send the datagram to the specified host. It this option is not present, data are sent to the original host as recorded in the pcap file
 .TP
+.BR -p\ port | --port\ port
+Send the datagram to the specified port. It this option is not present, data are sent to the original port as recorded in the pcap file
+.TP
 .BR --mttl\ ttlValue
 Set the time to live for multicast packets to the value specified as argument. Otherwise is set to 1
 .TP

udpReplay.c

@@ -41,13 +41,14 @@ int main(int argc, char* argv[])
     {"step",  no_argument,       0, '1'},
     {"flood", no_argument,       0, 'f'},
     {"dest",  required_argument, 0, 'd'},
+    {"port",  required_argument, 0, 'p'},
     {"astx",  no_argument,       0, 4},
     {"mttl",  required_argument, 0, 1},
     {0,       0,                 0, 0}
   };
   int option_index;
 
-  while ((c = getopt_long(argc, argv, "1fd:", long_options, &option_index)) != -1)
+  while ((c = getopt_long(argc, argv, "1fd:p:", long_options, &option_index)) != -1)
     switch (c) {
       case 1:
         setMulticastTTL = 1;
@@ -65,6 +66,9 @@ int main(int argc, char* argv[])
       case 'd':
         dvalue = optarg;
         break;
+      case 'p':
+        pvalue = optarg;
+        break;
       default:
         break;
     };
@@ -94,6 +98,18 @@ int main(int argc, char* argv[])
       return -1;
     }
   }
+  if (pvalue) {
+    int port = atoi(pvalue);
+    if (port <= 0) {
+      printf("-p %s option is an invalid number or zero\n", pvalue);
+      return -1;
+    }
+    if (port > 65535) {
+      printf("-p %s option is greater then 65535\n", pvalue);
+      return -1;
+    }
+    sockaddr.sin_port = htons(port);
+  }
 
   pcap = pcap_open_offline(pcapName, errbuf);