CDP: add CDPMsgPowerRequest and CDPMsgPowerAvailable (#3805)

* CDP: add CDPMsgPowerRequest and CDPMsgPowerAvailable

* add test for CDPMsgPowerRequest and CDPMsgPowerAvailable

Author: cq674350529

scapy/contrib/cdp.py

@@ -19,7 +19,9 @@
     ByteEnumField,
     ByteField,
     FieldLenField,
+    FieldListField,
     FlagsField,
+    IntField,
     IP6Field,
     IPField,
     OUIField,
@@ -63,8 +65,8 @@
                 #                 0x0015: "CDPMsgSystemOID",
                 0x0016: "CDPMsgMgmtAddr",
                 #                 0x0017: "CDPMsgLocation",
-                0x0019: "CDPMsgUnknown19",
-                #                 0x001a: "CDPPowerAvailable"
+                0x0019: "CDPMsgPowerRequest",
+                0x001a: "CDPMsgPowerAvailable"
                 }
 
 _cdp_tlv_types = {0x0001: "Device ID",
@@ -91,7 +93,7 @@
                   0x0016: "Management Address",
                   0x0017: "Location",
                   0x0018: "CDP Unknown command (send us a pcap file)",
-                  0x0019: "CDP Unknown command (send us a pcap file)",
+                  0x0019: "Power Request",
                   0x001a: "Power Available"}
 
 
@@ -351,9 +353,28 @@ class CDPMsgMgmtAddr(CDPMsgAddr):
     type = 0x0016
 
 
-class CDPMsgUnknown19(CDPMsgGeneric):
-    name = "Unknown CDP Message"
-    type = 0x0019
+class CDPMsgPowerRequest(CDPMsgGeneric):
+    name = "Power Request"
+    fields_desc = [XShortEnumField("type", 0x0019, _cdp_tlv_types),
+                   FieldLenField("len", None, "power_requested_list", fmt="!H",
+                                 adjust=lambda pkt, x: x + 8),
+                   ShortField("req_id", 0),
+                   ShortField("mgmt_id", 0),
+                   FieldListField("power_requested_list", [],
+                                  IntField("power_requested", 0),
+                                  count_from=lambda pkt: (pkt.len - 8) // 4)]
+
+
+class CDPMsgPowerAvailable(CDPMsgGeneric):
+    name = "Power Available"
+    fields_desc = [XShortEnumField("type", 0x001a, _cdp_tlv_types),
+                   FieldLenField("len", None, "power_available_list", fmt="!H",
+                                 adjust=lambda pkt, x: x + 8),
+                   ShortField("req_id", 0),
+                   ShortField("mgmt_id", 0),
+                   FieldListField("power_available_list", [],
+                                  IntField("power_available", 0),
+                                  count_from=lambda pkt: (pkt.len - 8) // 4)]
 
 
 class CDPMsg(CDPMsgGeneric):

test/contrib/cdp.uts

@@ -89,3 +89,27 @@ assert cdp_msg_addr.haslayer(CDPAddrRecordIPv6)
 assert len(cdp_msg_addr.addr) == 2
 
 assert raw(cdp_msg_addr)[4:8] == b'\x00\x00\x00\x02'
+
+= CDPv2 - CDPMsgPowerRequest and CDPMsgPowerAvailable Packet
+s = b'\x02\xb4\x39\xfa\x00\x01\x00\x09\x53\x63\x61\x70\x79\x00\x02\x00\x11\x00\x00\x00\x01\x01\x01\xcc\x00\x04\x7f\x00\x00\x01\x00\x10\x00\x06\x00\x10\x00\x19\x00\x18\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00\x04\x00\x1a\x00\x14\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00\x06\x00\x00\x00\x07'
+cdpv2 = CDPv2_HDR(s)
+assert cdpv2.vers == 2
+assert cdpv2.ttl == 180
+assert cdpv2.cksum == 0x39fa
+assert cdpv2.haslayer(CDPMsgDeviceID)
+assert cdpv2.haslayer(CDPMsgAddr)
+assert cdpv2.haslayer(CDPMsgPower)
+assert cdpv2.haslayer(CDPMsgPowerRequest)
+assert cdpv2.haslayer(CDPMsgPowerAvailable)
+assert cdpv2[CDPMsgPowerRequest].type == 0x0019
+assert cdpv2[CDPMsgPowerRequest].len == 24
+assert cdpv2[CDPMsgPowerRequest].req_id == 0
+assert cdpv2[CDPMsgPowerRequest].mgmt_id == 0
+assert len(cdpv2[CDPMsgPowerRequest].power_requested_list) == 4
+assert cdpv2[CDPMsgPowerRequest].power_requested_list == [1, 2, 3, 4]
+assert cdpv2[CDPMsgPowerAvailable].type == 0x001a
+assert cdpv2[CDPMsgPowerAvailable].len == 20
+assert cdpv2[CDPMsgPowerAvailable].req_id == 0
+assert cdpv2[CDPMsgPowerAvailable].mgmt_id == 0
+assert len(cdpv2[CDPMsgPowerAvailable].power_available_list) == 3
+assert cdpv2[CDPMsgPowerAvailable].power_available_list == [5, 6, 7]