From 254c803612c0c9ec5dfc1b90de6efb23ec5bedd5 Mon Sep 17 00:00:00 2001 From: Klement Sekera Date: Tue, 27 Jul 2021 13:33:51 +0200 Subject: nat: fix ICMP checksum validation Handle case where extra data is present in buffer which is not part of IP/ICMP headers. Type: fix Fixes: 05b5a5b3b4b04823776feed6403b5a99b2e06d76 Change-Id: Icfef811470056d38c60fc45cc302139ed7594385 Signed-off-by: Klement Sekera --- test/test_nat44_ed.py | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'test') diff --git a/test/test_nat44_ed.py b/test/test_nat44_ed.py index ee76ce845c6..b11e3c03cde 100644 --- a/test/test_nat44_ed.py +++ b/test/test_nat44_ed.py @@ -949,6 +949,50 @@ class TestNAT44ED(NAT44EDTestCase): self.logger.info(ppp("p2 packet:", p2)) self.logger.info(ppp("capture packet:", capture)) + def test_icmp_echo_reply_trailer(self): + """ ICMP echo reply with ethernet trailer""" + + self.nat_add_address(self.nat_addr) + self.nat_add_inside_interface(self.pg0) + self.nat_add_outside_interface(self.pg1) + + # in2out + p1 = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) / + IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) / + ICMP(type=8, id=0xabcd, seq=0)) + + self.pg0.add_stream(p1) + self.pg_enable_capture(self.pg_interfaces) + self.pg_start() + c = self.pg1.get_capture(1)[0] + + self.logger.debug(self.vapi.cli("show trace")) + + # out2in + p2 = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) / + IP(src=self.pg1.remote_ip4, dst=self.nat_addr, id=0xee59) / + ICMP(type=0, id=c[ICMP].id, seq=0)) + + # force checksum calculation + p2 = p2.__class__(bytes(p2)) + + self.logger.debug(ppp("Packet before modification:", p2)) + + # hex representation of vss monitoring ethernet trailer + # this seems to be just added to end of packet without modifying + # IP or ICMP lengths / checksums + p2 = p2 / Raw("\x00\x00\x52\x54\x00\x46\xab\x04\x84\x18") + # change it so that IP/ICMP is unaffected + p2[IP].len = 28 + + self.logger.debug(ppp("Packet with added trailer:", p2)) + + self.pg1.add_stream(p2) + self.pg_enable_capture(self.pg_interfaces) + self.pg_start() + + self.pg0.get_capture(1) + def test_users_dump(self): """ NAT44ED API test - nat44_user_dump """ -- cgit 1.2.3-korg