DHCPAM: Make_reply to use raw to inject IP.

Author: mzen17

scapy/layers/dhcp.py

@@ -39,6 +39,7 @@
     StrField,
     StrFixedLenField,
     XIntField,
+    RawVal
 )
 from scapy.layers.inet import UDP, IP
 from scapy.layers.l2 import Ether, HARDWARE_TYPES
@@ -669,6 +670,24 @@ def make_reply(self, req):
 class DHCP_am(BOOTP_am):
     function_name = "dhcpd"
 
+    def ip_to_bytes(self, ip_string):
+        """Concat a IP str of form IP,IP,IP and returns it as bytes
+        Backcompatible if IP is a single IP.
+        :param ip_string: String of the IP to be packed"""
+        ip_string = ip_string.replace(" ", "")
+        
+        # Split IPs by commas and filter out empty strings
+        ip_list = [ip.strip() for ip in ip_string.split(',') if ip.strip()]
+        
+        # Convert each IP to packed format
+        packed_ips = []
+        for ip in ip_list:
+            packed_ips.append(socket.inet_aton(ip))
+        
+        # Concatenate packed IPs into a single byte string
+        return b''.join(packed_ips)
+        
+
     def make_reply(self, req):
         resp = BOOTP_am.make_reply(self, req)
         if DHCP in req:
@@ -677,12 +696,15 @@ def make_reply(self, req):
                 for op in req[DHCP].options
                 if isinstance(op, tuple) and op[0] == "message-type"
             ]
+            
+            nameserver_list = self.ip_to_bytes(self.nameserver)
+
             dhcp_options += [
                 x for x in [
                     ("server_id", self.gw),
                     ("domain", self.domain),
                     ("router", self.gw),
-                    ("name_server", self.nameserver),
+                    ("name_server", IP(len = RawVal(nameserver_list))),
                     ("broadcast_address", self.broadcast),
                     ("subnet_mask", self.netmask),
                     ("renewal_time", self.renewal_time),