Namespace subprocess pipes by PID.

Patch by Andrey Olkhin.
http://seclists.org/nmap-dev/2013/q1/210

CHANGELOG

@@ -1,5 +1,9 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o Namespace the pipes used to communicate with subprocesses by PID, to
+  avoid multiple instances of Ncat from interfering with each other.
+  Patch by Andrey Olkhin.
+
 o Nmap may now partially rearrange its target list for more efficient
   host groups. Previously, a single target with a different interface,
   or with an IP address the same as a that of a target already in the

ncat/ncat_exec_win.c

@@ -220,7 +220,8 @@ static int run_command_redirected(char *cmdexec, struct subprocess_info *info)
     }
 
     /* Pipe names must have this special form. */
-    Snprintf(pipe_name, sizeof(pipe_name), "\\\\.\\pipe\\ncat-%d", pipe_serial_no);
+    Snprintf(pipe_name, sizeof(pipe_name), "\\\\.\\pipe\\ncat-%d-%d",
+        GetCurrentProcessId(), pipe_serial_no);
     if (o.debug > 1)
         logdebug("Creating named pipe \"%s\"\n", pipe_name);