ovn-northd: Add flows in DHCP_OPTIONS pipeline to support renew requests

ovn-northd adds the flows to send the DHCPv4 packets to ovn-controller
only with the match ip4.src = 0.0.0.0 and ip4.dst = 255.255.255.255.

When a DHCPv4 lease is about to expire, before sending a DHCPDISCOVER
packet, the client can send a DHCPREQUEST packet to renew its ip
with ip4.src set to its offered ip and ip4.dst set to the DHCP server
ip or broadcast ip.

This patch supports this missing scenario by adding the necessary
flows in DHCP_OPTIONS ingress pipeline.

Signed-off-by: Numan Siddique <nusiddiq@redhat.com>
Signed-off-by: Russell Bryant <russell@ovn.org>

1 files changed, 75 insertions, 9 deletions

diff --git a/tests/ovn.at b/tests/ovn.at
index 126574c52..7ace71597 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -3705,8 +3705,17 @@ as hv1 ovs-vsctl show
 # This shell function sends a DHCP request packet
 # test_dhcp INPORT SRC_MAC DHCP_TYPE OFFER_IP ...
 test_dhcp() {
-    local inport=$1 src_mac=$2 dhcp_type=$3 offer_ip=$4
-    local request=ffffffffffff${src_mac}080045100110000000008011000000000000ffffffff
+    local inport=$1 src_mac=$2 dhcp_type=$3 offer_ip=$4 use_ip=$5
+    shift; shift; shift; shift; shift;
+    if test $use_ip != 0; then
+        src_ip=$1
+        dst_ip=$2
+        shift; shift;
+    else
+        src_ip=`ip_to_hex 0 0 0 0`
+        dst_ip=`ip_to_hex 255 255 255 255`
+    fi
+    local request=ffffffffffff${src_mac}0800451001100000000080110000${src_ip}${dst_ip}
     # udp header and dhcp header
     request=${request}0044004300fc0000
     request=${request}010106006359aa760000000000000000000000000000000000000000${src_mac}
@@ -3726,7 +3735,7 @@ test_dhcp() {
     request=${request}3501${dhcp_type}ff
 
     if test $offer_ip != 0; then
-        local srv_mac=$5 srv_ip=$6 expected_dhcp_opts=$7
+        local srv_mac=$1 srv_ip=$2 expected_dhcp_opts=$3
         # total IP length will be the IP length of the request packet
         # (which is 272 in our case) + 8 (padding bytes) + (expected_dhcp_opts / 2)
         ip_len=`expr 280 + ${#expected_dhcp_opts} / 2`
@@ -3762,7 +3771,6 @@ test_dhcp() {
         reply=${reply}3501${dhcp_reply_type}${expected_dhcp_opts}00000000ff00000000
         echo $reply >> $inport.expected
     else
-        shift; shift; shift; shift;
         for outport; do
             echo $request >> $outport.expected
         done
@@ -3808,7 +3816,7 @@ as hv1 ovs-ofctl dump-flows br-int
 offer_ip=`ip_to_hex 10 0 0 4`
 server_ip=`ip_to_hex 10 0 0 1`
 expected_dhcp_opts=330400000e100104ffffff0003040a00000136040a000001
-test_dhcp 1 f00000000001 01 $offer_ip ff1000000001 $server_ip $expected_dhcp_opts
+test_dhcp 1 f00000000001 01 $offer_ip 0 ff1000000001 $server_ip $expected_dhcp_opts
 
 # NXT_RESUMEs should be 1.
 OVS_WAIT_UNTIL([test 1 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])
@@ -3831,7 +3839,7 @@ rm -f 2.expected
 offer_ip=`ip_to_hex 10 0 0 6`
 server_ip=`ip_to_hex 10 0 0 1`
 expected_dhcp_opts=330400000e100104ffffff0003040a00000136040a000001
-test_dhcp 2 f00000000002 03 $offer_ip ff1000000001 $server_ip $expected_dhcp_opts
+test_dhcp 2 f00000000002 03 $offer_ip 0 ff1000000001 $server_ip $expected_dhcp_opts
 
 # NXT_RESUMEs should be 2.
 OVS_WAIT_UNTIL([test 2 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])
@@ -3853,7 +3861,7 @@ rm -f 2.expected
 # ls1-lp1 (vif1-tx.pcap) should receive the DHCPv4 request packet twice,
 # one from ovn-controller and the other from "ovs-ofctl resume."
 offer_ip=0
-test_dhcp 2 f00000000002 08 $offer_ip 1 1
+test_dhcp 2 f00000000002 08 $offer_ip 0 1 1
 
 # NXT_RESUMEs should be 3.
 OVS_WAIT_UNTIL([test 3 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])
@@ -3869,11 +3877,11 @@ rm -f 2.expected
 # Send DHCPv4 packet on ls2-lp1. It doesn't have any DHCPv4 options defined.
 # ls2-lp2 (vif4-tx.pcap) should receive the DHCPv4 request packet once.
 
-test_dhcp 3 f00000000003 01 0 4
+test_dhcp 3 f00000000003 01 0 4 0
 
 # Send DHCPv4 packet on ls2-lp2. "router" DHCPv4 option is not defined for
 # this lport.
-test_dhcp 4 f00000000004 01 0 3
+test_dhcp 4 f00000000004 01 0 3 0
 
 # NXT_RESUMEs should be 3.
 OVS_WAIT_UNTIL([test 3 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])
@@ -3881,6 +3889,64 @@ OVS_WAIT_UNTIL([test 3 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])
 OVN_CHECK_PACKETS([hv1/vif3-tx.pcap], [3.expected])
 OVN_CHECK_PACKETS([hv1/vif4-tx.pcap], [4.expected])
 
+# Send DHCPREQUEST with ip4.src set to 10.0.0.6 and ip4.dst set to 10.0.0.1.
+offer_ip=`ip_to_hex 10 0 0 6`
+server_ip=`ip_to_hex 10 0 0 1`
+expected_dhcp_opts=330400000e100104ffffff0003040a00000136040a000001
+src_ip=$offer_ip
+dst_ip=$server_ip
+test_dhcp 2 f00000000002 03 $offer_ip 1 $src_ip $dst_ip ff1000000001 $server_ip $expected_dhcp_opts
+
+# NXT_RESUMEs should be 4.
+OVS_WAIT_UNTIL([test 4 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])
+
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/vif2-tx.pcap > 2.packets
+cat 2.expected | cut -c -48 > expout
+AT_CHECK([cat 2.packets | cut -c -48], [0], [expout])
+# Skipping the IPv4 checksum.
+cat 2.expected | cut -c 53- > expout
+AT_CHECK([cat 2.packets | cut -c 53-], [0], [expout])
+
+reset_pcap_file hv1-vif1 hv1/vif1
+reset_pcap_file hv1-vif2 hv1/vif2
+rm -f 1.expected
+rm -f 2.expected
+
+# Send DHCPREQUEST with ip4.src set to 10.0.0.6 and ip4.dst set to 255.255.255.255.
+offer_ip=`ip_to_hex 10 0 0 6`
+server_ip=`ip_to_hex 10 0 0 1`
+expected_dhcp_opts=330400000e100104ffffff0003040a00000136040a000001
+src_ip=$offer_ip
+dst_ip=`ip_to_hex 255 255 255 255`
+test_dhcp 2 f00000000002 03 $offer_ip 1 $src_ip $dst_ip ff1000000001 $server_ip $expected_dhcp_opts
+
+# NXT_RESUMEs should be 5.
+OVS_WAIT_UNTIL([test 5 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])
+
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/vif2-tx.pcap > 2.packets
+cat 2.expected | cut -c -48 > expout
+AT_CHECK([cat 2.packets | cut -c -48], [0], [expout])
+# Skipping the IPv4 checksum.
+cat 2.expected | cut -c 53- > expout
+AT_CHECK([cat 2.packets | cut -c 53-], [0], [expout])
+
+reset_pcap_file hv1-vif1 hv1/vif1
+reset_pcap_file hv1-vif2 hv1/vif2
+rm -f 1.expected
+rm -f 2.expected
+
+# Send DHCPREQUEST with ip4.src set to 10.0.0.6 and ip4.dst set to 10.0.0.4.
+# The packet should not be received by ovn-controller.
+src_ip=`ip_to_hex 10 0 0 6`
+dst_ip=`ip_to_hex 10 0 0 4`
+test_dhcp 2 f00000000002 03 0 1 $src_ip $dst_ip 1
+
+# NXT_RESUMEs should be 5.
+OVS_WAIT_UNTIL([test 5 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])
+
+# vif1-tx.pcap should have received the DHCPv4 request packet
+OVN_CHECK_PACKETS([hv1/vif1-tx.pcap], [1.expected])
+
 as hv1
 OVS_APP_EXIT_AND_WAIT([ovn-controller])
 OVS_APP_EXIT_AND_WAIT([ovs-vswitchd])