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authorDmitry Valter <d-valter@yandex-team.ru>2022-12-09 19:34:22 +0000
committerOle Tr�an <otroan@employees.org>2023-02-03 14:31:54 +0000
commit6b97c43005f6458ce2e253f87af6f609eaebef60 (patch)
treef7a7a8f67a4e1e0dd0f158e423dd0c8e6f7559cf /test
parentfc2d95d115ea5e82bc3efb18cf40632449112fdf (diff)
nat: fix accidental o2i deletion/reuse
Nat session is allocated before the port allocation. During port allocation candidate address+port are set to o2i 6-tuple and tested against the flow hash. If insertion fails, the port is busy and rejected. When all N attempts are unsuccessful, "out-of-ports" error is recorded and the session is to be deleted. During session deletion o2i and i2o tuples are deleted from the flow hash. In case of "out-of-ports" i2o tuple is not valid, however o2i is and it refers to **some other** session that's known to be allocated. By backing match tuple up session should be invalidated well enough not to collide with any valid one. Type: fix Signed-off-by: Dmitry Valter <d-valter@yandex-team.ru> Change-Id: Id30be6f26ecce7a5a63135fb971bb65ce318af82
Diffstat (limited to 'test')
-rw-r--r--test/test_nat44_ed.py75
1 files changed, 73 insertions, 2 deletions
diff --git a/test/test_nat44_ed.py b/test/test_nat44_ed.py
index 8a8c96870f4..7279b6a7d56 100644
--- a/test/test_nat44_ed.py
+++ b/test/test_nat44_ed.py
@@ -4,6 +4,7 @@ import unittest
from io import BytesIO
from random import randint, choice
+import re
import scapy.compat
from framework import tag_fixme_ubuntu2204, is_distro_ubuntu2204
from framework import VppTestCase, VppTestRunner, VppLoInterface
@@ -48,8 +49,9 @@ class TestNAT44ED(VppTestCase):
if not self.vpp_dead:
self.plugin_disable()
- def plugin_enable(self):
- self.vapi.nat44_ed_plugin_enable_disable(sessions=self.max_sessions, enable=1)
+ def plugin_enable(self, max_sessions=None):
+ max_sessions = max_sessions or self.max_sessions
+ self.vapi.nat44_ed_plugin_enable_disable(sessions=max_sessions, enable=1)
def plugin_disable(self):
self.vapi.nat44_ed_plugin_enable_disable(enable=0)
@@ -616,6 +618,16 @@ class TestNAT44ED(VppTestCase):
return pkts
+ def create_udp_stream(self, in_if, out_if, count, base_port=6303):
+ return [
+ (
+ Ether(dst=in_if.local_mac, src=in_if.remote_mac)
+ / IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=64)
+ / UDP(sport=base_port + i, dport=20)
+ )
+ for i in range(count)
+ ]
+
def create_stream_frag(
self, src_if, dst, sport, dport, data, proto=IP_PROTOS.tcp, echo_reply=False
):
@@ -4821,6 +4833,65 @@ class TestNAT44EDMW(TestNAT44ED):
)
self.send_and_expect(self.pg0, p, self.pg1)
+ def test_dynamic_ports_exhausted(self):
+ """NAT44ED dynamic translation test: address ports exhaused"""
+
+ sessions_per_batch = 128
+ n_available_ports = 65536 - 1024
+ n_sessions = n_available_ports + 2 * sessions_per_batch
+
+ # set high enough session limit for ports to be exhausted
+ self.plugin_disable()
+ self.plugin_enable(max_sessions=n_sessions)
+
+ self.nat_add_inside_interface(self.pg0)
+ self.nat_add_outside_interface(self.pg1)
+
+ # set timeouts to high for sessions to reallistically expire
+ config = self.vapi.nat44_show_running_config()
+ old_timeouts = config.timeouts
+ self.vapi.nat_set_timeouts(
+ udp=21600,
+ tcp_established=old_timeouts.tcp_established,
+ tcp_transitory=old_timeouts.tcp_transitory,
+ icmp=old_timeouts.icmp,
+ )
+
+ # in2out after NAT addresses added
+ self.nat_add_address(self.nat_addr)
+
+ for i in range(n_sessions // sessions_per_batch):
+ pkts = self.create_udp_stream(
+ self.pg0,
+ self.pg1,
+ sessions_per_batch,
+ base_port=i * sessions_per_batch + 100,
+ )
+
+ self.pg0.add_stream(pkts)
+ self.pg_start()
+
+ err = self.statistics.get_err_counter(
+ "/err/nat44-ed-in2out-slowpath/out of ports"
+ )
+ if err > sessions_per_batch:
+ break
+
+ # Check for ports to be used no more than once
+ ports = set()
+ sessions = self.vapi.cli("show nat44 sessions")
+ rx = re.compile(
+ f" *o2i flow: match: saddr {self.pg1.remote_ip4} sport [0-9]+ daddr {self.nat_addr} dport ([0-9]+) proto UDP.*"
+ )
+ for line in sessions.splitlines():
+ m = rx.match(line)
+ if m:
+ port = int(m.groups()[0])
+ self.assertNotIn(port, ports)
+ ports.add(port)
+
+ self.assertGreaterEqual(err, sessions_per_batch)
+
if __name__ == "__main__":
unittest.main(testRunner=VppTestRunner)