1 files changed, 124 insertions, 0 deletions
diff --git a/resources/traffic_scripts/ipv4_ping_ttl_check.py b/resources/traffic_scripts/ipv4_ping_ttl_check.py
new file mode 100755
index 0000000000..050a1d7b29
--- /dev/null
+++ b/resources/traffic_scripts/ipv4_ping_ttl_check.py
@@ -0,0 +1,124 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2016 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from scapy.all import *
+from resources.libraries.python.PacketVerifier \
+    import Interface, create_gratuitous_arp_request, auto_pad
+from optparse import OptionParser
+
+
+def check_ttl(ttl_begin, ttl_end, ttl_diff):
+    if ttl_begin != ttl_end + ttl_diff:
+        src_if.close()
+        if dst_if_defined:
+            dst_if.close()
+        raise Exception(
+            "TTL changed from {} to {} but decrease by {} expected")\
+            .format(ttl_begin, ttl_end, hops)
+
+
+def ckeck_packets_equal(pkt_send, pkt_recv):
+    pkt_send_raw = str(pkt_send)
+    pkt_recv_raw = str(pkt_recv)
+    if pkt_send_raw != pkt_recv_raw:
+        print "Sent:     {}".format(pkt_send_raw.encode('hex'))
+        print "Received: {}".format(pkt_recv_raw.encode('hex'))
+        print "Sent:"
+        Ether(pkt_send_raw).show2()
+        print "Received:"
+        Ether(pkt_recv_raw).show2()
+        src_if.close()
+        if dst_if_defined:
+            dst_if.close()
+        raise Exception("Sent packet doesn't match received packet")
+
+
+parser = OptionParser()
+parser.add_option("--src_if", dest="src_if")
+parser.add_option("--dst_if", dest="dst_if")  # optional
+parser.add_option("--src_mac", dest="src_mac")
+parser.add_option("--first_hop_mac", dest="first_hop_mac")
+parser.add_option("--dst_mac", dest="dst_mac")  # optional
+parser.add_option("--src_ip", dest="src_ip")
+parser.add_option("--dst_ip", dest="dst_ip")
+parser.add_option("--hops", dest="hops")  # optional
+# If one of 'dst_if', 'dst_mac' and 'hops' is specified all must be specified.
+(opts, args) = parser.parse_args()
+src_if_name = opts.src_if
+dst_if_name = opts.dst_if
+dst_if_defined = True
+if dst_if_name is None:
+    dst_if_defined = False
+src_mac = opts.src_mac
+first_hop_mac = opts.first_hop_mac
+dst_mac = opts.dst_mac
+src_ip = opts.src_ip
+dst_ip = opts.dst_ip
+hops = int(opts.hops)
+
+if dst_if_defined and (src_if_name == dst_if_name):
+    raise Exception("Source interface name equals destination interface name")
+
+src_if = Interface(src_if_name)
+src_if.send_pkt(create_gratuitous_arp_request(src_mac, src_ip))
+if dst_if_defined:
+    dst_if = Interface(dst_if_name)
+    dst_if.send_pkt(create_gratuitous_arp_request(dst_mac, dst_ip))
+
+pkt_req_send = auto_pad(Ether(src=src_mac, dst=first_hop_mac) /
+                        IP(src=src_ip, dst=dst_ip) /
+                        ICMP())
+pkt_req_send = Ether(pkt_req_send)
+src_if.send_pkt(pkt_req_send)
+
+if dst_if_defined:
+    try:
+        pkt_req_recv = dst_if.recv_pkt()
+    except:
+        src_if.close()
+        if dst_if_defined:
+            dst_if.close()
+        raise
+
+    check_ttl(pkt_req_send[IP].ttl, pkt_req_recv[IP].ttl, hops)
+    pkt_req_send_mod = pkt_req_send.copy()
+    pkt_req_send_mod[IP].ttl = pkt_req_recv[IP].ttl
+    del pkt_req_send_mod[IP].chksum  # update checksum
+    ckeck_packets_equal(pkt_req_send_mod[IP], pkt_req_recv[IP])
+
+    pkt_resp_send = auto_pad(Ether(src=dst_mac, dst=pkt_req_recv.src) /
+                             IP(src=dst_ip, dst=src_ip) /
+                             ICMP(type=0))  # echo-reply
+    pkt_resp_send = Ether(pkt_resp_send)
+    dst_if.send_pkt(pkt_resp_send)
+
+try:
+    pkt_resp_recv = src_if.recv_pkt()
+except:
+    src_if.close()
+    if dst_if_defined:
+        dst_if.close()
+    raise
+
+if dst_if_defined:
+    check_ttl(pkt_resp_send[IP].ttl, pkt_resp_recv[IP].ttl, hops)
+    pkt_resp_send_mod = pkt_resp_send.copy()
+    pkt_resp_send_mod[IP].ttl = pkt_resp_recv[IP].ttl
+    del pkt_resp_send_mod[IP].chksum  # update checksum
+    ckeck_packets_equal(pkt_resp_send_mod[IP], pkt_resp_recv[IP])
+
+src_if.close()
+if dst_if_defined:
+    dst_if.close()