Socket will find best-case interface to connect/listen to.

IPv6 almost always is priority on newer linux systems. This will get
the socket-type the system says it should be.

pyrasite/ipc.py

@@ -74,11 +74,23 @@ class PyrasiteIPC(object):
 
     def listen(self):
         """Listen on a random port"""
-        self.server_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        self.server_sock.settimeout(5)
-        self.server_sock.bind(('localhost', 0))
-        self.server_sock.listen(1)
-        self.port = self.server_sock.getsockname()[1]
+        for res in socket.getaddrinfo('localhost', None, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, 0):
+            af, socktype, proto, canonname, sa = res
+            try:
+                self.server_sock = socket.socket(af, socktype, proto)
+            except socket.error, msg:
+                self.server_sock = None
+                continue
+            try:
+                self.server_sock.bind(sa)
+                self.server_sock.listen(1)
+            except socket.error, msg:
+                self.server_sock.close()
+                self.server_sock = None
+                continue
+            break
+
+        self.hostname, self.port = self.server_sock.getsockname()[0:2]
         self.running = True
 
     def create_payload(self):

pyrasite/reverse.py

@@ -50,8 +50,21 @@ class ReverseConnection(threading.Thread, PyrasiteIPC):
         running = True
         while running:
             try:
-                self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-                self.sock.connect((self.host, self.port))
+                for res in socket.getaddrinfo(self.host, self.port, socket.AF_UNSPEC, socket.SOCK_STREAM):
+                    af, socktype, proto, canonname, sa = res
+                    try:
+                        self.sock = socket.socket(af, socktype, proto)
+                    except socket.error, msg:
+                        self.sock = None
+                        continue
+                    try:
+                        self.sock.connect(sa)
+                    except socket.error, msg:
+                        self.sock.close()
+                        self.sock = None
+                        continue
+                    break
+
                 self.on_connect()
                 while running:
                     cmd = self.recv()