[ovs-dev] [patch v4] conntrack: ignore port for ICMP/ICMPv6 NAT.

[Darrell Ball]

From: solomon <liwei.solomon at gmail.com>

ICMP/ICMPv6 fails, if the src/dst port is set in a common NAT rule.
For example:
actions=ct(nat(dst=172.16.1.100:5000),commit,table=40)

Fixes: 4cd0481c9e8b ("conntrack: Fix wasted work for ICMP NAT.")
CC: Darrell Ball <dlu998 at gmail.com>
Signed-off-by: solomon <liwei.solomon at gmail.com>
Signed-off-by: Darrell Ball <dlu998 at gmail.com>
Co-authored-by: Darrell Ball <dlu998 at gmail.com>
---

v4: Fix corrupted test.
v3: Add co-author tag.
v2: Add a test.

 lib/conntrack.c         |  8 ++++++--
 tests/system-traffic.at | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/lib/conntrack.c b/lib/conntrack.c
index 1d4d9ad..aa76fbd 100644
--- a/lib/conntrack.c
+++ b/lib/conntrack.c
@@ -2089,10 +2089,14 @@ nat_select_range_tuple(struct conntrack *ct, const struct conn *conn,
     while (true) {
         if (conn->nat_info->nat_action & NAT_ACTION_SRC) {
             nat_conn->rev_key.dst.addr = ct_addr;
-            nat_conn->rev_key.dst.port = htons(port);
+            if (pat_enabled) {
+                nat_conn->rev_key.dst.port = htons(port);
+            }
         } else {
             nat_conn->rev_key.src.addr = ct_addr;
-            nat_conn->rev_key.src.port = htons(port);
+            if (pat_enabled) {
+                nat_conn->rev_key.src.port = htons(port);
+            }
         }
 
         uint32_t conn_hash = conn_key_hash(&nat_conn->rev_key,
diff --git a/tests/system-traffic.at b/tests/system-traffic.at
index 79d12fe..d23ee89 100644
--- a/tests/system-traffic.at
+++ b/tests/system-traffic.at
@@ -3994,6 +3994,54 @@ tcp,orig=(src=10.1.1.1,dst=10.1.1.2,sport=<cleared>,dport=<cleared>),reply=(src=
 OVS_TRAFFIC_VSWITCHD_STOP
 AT_CLEANUP
 
+AT_SETUP([conntrack - SNAT with port range using ICMP])
+dnl Check PAT is not attempted on ICMP packets causing corrupted packets.
+CHECK_CONNTRACK()
+CHECK_CONNTRACK_NAT()
+OVS_TRAFFIC_VSWITCHD_START()
+
+ADD_NAMESPACES(at_ns0, at_ns1)
+
+ADD_VETH(p0, at_ns0, br0, "10.1.1.1/24")
+NS_CHECK_EXEC([at_ns0], [ip link set dev p0 address 80:88:88:88:88:88])
+ADD_VETH(p1, at_ns1, br0, "10.1.1.2/24")
+
+dnl Allow any traffic from ns0->ns1. Only allow nd, return traffic from ns1->ns0.
+AT_DATA([flows.txt], [dnl
+in_port=1,ip,action=ct(commit,zone=1,nat(src=10.1.1.240-10.1.1.255:20000)),2
+in_port=2,ct_state=-trk,ip,action=ct(table=0,zone=1,nat)
+in_port=2,ct_state=+trk,ct_zone=1,action=1
+dnl
+dnl ARP
+priority=100 arp arp_op=1 action=move:OXM_OF_ARP_TPA[[]]->NXM_NX_REG2[[]],resubmit(,8),goto_table:10
+priority=10 arp action=normal
+priority=0,action=drop
+dnl
+dnl MAC resolution table for IP in reg2, stores mac in OXM_OF_PKT_REG0
+table=8,reg2=0x0a0101f0/0xfffffff0,action=load:0x808888888888->OXM_OF_PKT_REG0[[]]
+table=8,priority=0,action=load:0->OXM_OF_PKT_REG0[[]]
+dnl ARP responder mac filled in at OXM_OF_PKT_REG0, or 0 for normal action.
+dnl TPA IP in reg2.
+dnl Swaps the fields of the ARP message to turn a query to a response.
+table=10 priority=100 arp xreg0=0 action=normal
+table=10 priority=10,arp,arp_op=1,action=load:2->OXM_OF_ARP_OP[[]],move:OXM_OF_ARP_SHA[[]]->OXM_OF_ARP_THA[[]],move:OXM_OF_PKT_REG0[[0..47]]->OXM_OF_ARP_SHA[[]],move:OXM_OF_ARP_SPA[[]]->OXM_OF_ARP_TPA[[]],move:NXM_NX_REG2[[]]->OXM_OF_ARP_SPA[[]],move:NXM_OF_ETH_SRC[[]]->NXM_OF_ETH_DST[[]],move:OXM_OF_PKT_REG0[[0..47]]->NXM_OF_ETH_SRC[[]],move:NXM_OF_IN_PORT[[]]->NXM_NX_REG3[[0..15]],load:0->NXM_OF_IN_PORT[[]],output:NXM_NX_REG3[[0..15]]
+table=10 priority=0 action=drop
+])
+
+AT_CHECK([ovs-ofctl --bundle add-flows br0 flows.txt])
+
+dnl ICMP requests from p0->p1 should work fine.
+NS_CHECK_EXEC([at_ns0], [ping -c 1 10.1.1.2 | FORMAT_PING], [0], [dnl
+1 packets transmitted, 1 received, 0% packet loss, time 0ms
+])
+
+AT_CHECK([ovs-appctl dpctl/dump-conntrack | FORMAT_CT(10.1.1.2) | sed -e 's/dst=10.1.1.2[[45]][[0-9]]/dst=10.1.1.2XX/'], [0], [dnl
+icmp,orig=(src=10.1.1.1,dst=10.1.1.2,id=<cleared>,type=8,code=0),reply=(src=10.1.1.2,dst=10.1.1.2XX,id=<cleared>,type=0,code=0),zone=1
+])
+
+OVS_TRAFFIC_VSWITCHD_STOP
+AT_CLEANUP
+
 AT_SETUP([conntrack - SNAT with port range with exhaustion])
 CHECK_CONNTRACK()
 CHECK_CONNTRACK_NAT()
-- 
1.9.1