nat: fix incorrect session removal case
Add a condition where a TCP session in transitory timeout is kept
instead of being erroneously deleted.
Type: fix
Signed-off-by: Klement Sekera <ksekera@cisco.com>
Change-Id: Ic625c8c88cc8864293ebd57b0321505652af9380
diff --git a/src/plugins/nat/in2out_ed.c b/src/plugins/nat/in2out_ed.c
index 5973d36..d9a45dc 100644
--- a/src/plugins/nat/in2out_ed.c
+++ b/src/plugins/nat/in2out_ed.c
@@ -586,7 +586,7 @@
nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
u16 src_port, u16 dst_port,
u32 thread_index, u32 rx_sw_if_index,
- u32 tx_sw_if_index)
+ u32 tx_sw_if_index, f64 now)
{
clib_bihash_kv_16_8_t kv, value;
snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
@@ -604,13 +604,12 @@
s =
pool_elt_at_index (tsm->sessions,
ed_value_get_session_index (&value));
- if (nat44_is_ses_closed (s))
+ if (nat44_is_ses_closed (s)
+ && (!s->tcp_closed_timestamp || now >= s->tcp_closed_timestamp))
{
nat_free_session_data (sm, s, thread_index, 0);
nat_ed_session_delete (sm, s, thread_index, 1);
}
- else
- s->flags |= SNAT_SESSION_FLAG_OUTPUT_FEATURE;
return 1;
}
@@ -658,6 +657,7 @@
vlib_main_t *vm = vlib_get_main ();
snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
*dont_translate = 0;
+ f64 now = vlib_time_now (vm);
sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
@@ -679,7 +679,7 @@
if (PREDICT_FALSE
(nat44_ed_not_translate_output_feature
(sm, ip, l_port, r_port, thread_index,
- sw_if_index, vnet_buffer (b)->sw_if_index[VLIB_TX])))
+ sw_if_index, vnet_buffer (b)->sw_if_index[VLIB_TX], now)))
{
*dont_translate = 1;
goto out;
@@ -1311,7 +1311,8 @@
(nat44_ed_not_translate_output_feature
(sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
vnet_buffer (b0)->ip.reass.l4_dst_port, thread_index,
- sw_if_index0, vnet_buffer (b0)->sw_if_index[VLIB_TX])))
+ sw_if_index0, vnet_buffer (b0)->sw_if_index[VLIB_TX],
+ now)))
goto trace0;
/*
diff --git a/src/plugins/nat/nat.h b/src/plugins/nat/nat.h
index 710c86f..a713f7b 100644
--- a/src/plugins/nat/nat.h
+++ b/src/plugins/nat/nat.h
@@ -199,8 +199,7 @@
#define SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT 16
#define SNAT_SESSION_FLAG_FWD_BYPASS 32
#define SNAT_SESSION_FLAG_AFFINITY 64
-#define SNAT_SESSION_FLAG_OUTPUT_FEATURE 128
-#define SNAT_SESSION_FLAG_EXACT_ADDRESS 256
+#define SNAT_SESSION_FLAG_EXACT_ADDRESS 128
/* NAT interface flags */
#define NAT_INTERFACE_FLAG_IS_INSIDE 1
diff --git a/src/plugins/nat/test/test_nat44.py b/src/plugins/nat/test/test_nat44.py
index de4210f..c71b706 100644
--- a/src/plugins/nat/test/test_nat44.py
+++ b/src/plugins/nat/test/test_nat44.py
@@ -5726,6 +5726,14 @@
def test_tcp_close(self):
""" Close TCP session from inside network - output feature """
+ old_timeouts = self.vapi.nat_get_timeouts()
+ new_transitory = 2
+ self.vapi.nat_set_timeouts(
+ udp=old_timeouts.udp,
+ tcp_established=old_timeouts.tcp_established,
+ icmp=old_timeouts.icmp,
+ tcp_transitory=new_transitory)
+
self.vapi.nat44_forwarding_enable_disable(enable=1)
self.nat44_add_address(self.pg1.local_ip4)
twice_nat_addr = '10.0.1.3'
@@ -5808,9 +5816,34 @@
self.pg_start()
self.pg1.get_capture(1)
- sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4,
- 0)
+ # session now in transitory timeout
+ # try SYN packet out->in - should be dropped
+ p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
+ IP(src=self.pg1.remote_ip4, dst=service_ip) /
+ TCP(sport=33898, dport=80, flags="S"))
+ self.pg1.add_stream(p)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ self.sleep(new_transitory, "wait for transitory timeout")
+ self.pg0.assert_nothing_captured(0)
+
+ # session should still exist
+ sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
+ self.assertEqual(len(sessions) - start_sessnum, 1)
+
+ # send FIN+ACK packet out -> in - will cause session to be wiped
+ # but won't create a new session
+ p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
+ IP(src=self.pg1.remote_ip4, dst=service_ip) /
+ TCP(sport=33898, dport=80, flags="FA", seq=300, ack=101))
+ self.pg1.add_stream(p)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
self.assertEqual(len(sessions) - start_sessnum, 0)
+ self.pg0.assert_nothing_captured(0)
def test_tcp_session_close_in(self):
""" Close TCP session from inside network """