On Thu, Jul 23, 2020 at 10:57 AM Han Zhou <hz...@ovn.org> wrote: > Support a new logical router option "always_learn_from_arp_request" that > controls > behavior when handling ARP requests or IPv4 ND-NS packets. > > "true" - Always learn the MAC/IP binding and add a new MAC_Binding entry > (default behavior) > > "false" - If there is a MAC_binding for that IP and the MAC is different, > or, > if TPA of ARP request belongs to any router port on this router, then > update/add that MAC/IP binding. Otherwise, don't update/add entries. > > Reported-by: Girish Moodalbail <gmoodalb...@nvidia.com> > Reported-at: > https://mail.openvswitch.org/pipermail/ovs-discuss/2020-May/049995.html > Signed-off-by: Han Zhou <hz...@ovn.org> >
Hi Han, I just gave a quick look. I'll review properly tomorrow. I just have a few small comments now. I think it's good to add a few tests in ovn-northd.at to make sure that ovn-northd programs the flows as expected. Thanks Numan --- > northd/ovn-northd.8.xml | 109 > ++++++++++++++++++++++++++++++++++++++++-------- > northd/ovn-northd.c | 96 +++++++++++++++++++++++++++++++++++------- > ovn-nb.xml | 27 ++++++++++++ > tests/ovn.at | 18 ++++++++ > 4 files changed, 217 insertions(+), 33 deletions(-) > > diff --git a/northd/ovn-northd.8.xml b/northd/ovn-northd.8.xml > index 9f2c70f..30936ab 100644 > --- a/northd/ovn-northd.8.xml > +++ b/northd/ovn-northd.8.xml > @@ -1537,58 +1537,126 @@ output; > <p> > For each router port <var>P</var> that owns IP address > <var>A</var>, > which belongs to subnet <var>S</var> with prefix length > <var>L</var>, > - a priority-100 flow is added which matches > - <code>inport == <var>P</var> && > - arp.spa == <var>S</var>/<var>L</var> && arp.op == > 1</code> > - (ARP request) with the > - following actions: > + if the option <code>always_learn_from_arp_request</code> is > + <code>true</code> for this router, a priority-100 flow is added > which > + matches <code>inport == <var>P</var> && arp.spa == > + <var>S</var>/<var>L</var> && arp.op == 1</code> (ARP > request) > + with the following actions: > + </p> > + > + <pre> > +reg9[2] = lookup_arp(inport, arp.spa, arp.sha); > +next; > + </pre> > + > + <p> > + If the option <code>always_learn_from_arp_request</code> is > + <code>false</code>, the following two flows are added. > + </p> > + > + <p> > + A priority-110 flow is added which matches <code>inport == > + <var>P</var> && arp.spa == <var>S</var>/<var>L</var> > + && arp.tpa == <var>A</var> && arp.op == 1</code> > + (ARP request) with the following actions: > </p> > > <pre> > reg9[2] = lookup_arp(inport, arp.spa, arp.sha); > +reg9[3] = 1; > +next; > + </pre> > + > + <p> > + A priority-100 flow is added which matches <code>inport == > + <var>P</var> && arp.spa == <var>S</var>/<var>L</var> > + && arp.op == 1</code> (ARP request) with the following > + actions: > + </p> > + > + <pre> > +reg9[2] = lookup_arp(inport, arp.spa, arp.sha); > +reg9[3] = lookup_arp_ip(inport, arp.spa); > next; > </pre> > > <p> > If the logical router port <var>P</var> is a distributed gateway > router port, additional match > - <code>is_chassis_resident(cr-<var>P</var>)</code> is added so > that > - the resident gateway chassis handles the neighbor lookup. > + <code>is_chassis_resident(cr-<var>P</var>)</code> is added for > all > + these flows. > </p> > </li> > > <li> > <p> > A priority-100 flow which matches on ARP reply packets and > applies > - the actions: > + the actions if the option > <code>always_learn_from_arp_request</code> > + is <code>true</code>: > </p> > > <pre> > reg9[2] = lookup_arp(inport, arp.spa, arp.sha); > next; > </pre> > + > + <p> > + If the option <code>always_learn_from_arp_request</code> > + is <code>false</code>, the above actions will be: > + </p> > + > + <pre> > +reg9[2] = lookup_arp(inport, arp.spa, arp.sha); > +reg9[3] = 1; > +next; > + </pre> > + > </li> > > <li> > <p> > A priority-100 flow which matches on IPv6 Neighbor Discovery > - advertisement packet and applies the actions: > + advertisement packet and applies the actions if the option > + <code>always_learn_from_arp_request</code> is <code>true</code>: > </p> > > <pre> > reg9[2] = lookup_nd(inport, nd.target, nd.tll); > next; > </pre> > + > + <p> > + If the option <code>always_learn_from_arp_request</code> > + is <code>false</code>, the above actions will be: > + </p> > + > + <pre> > +reg9[2] = lookup_nd(inport, nd.target, nd.tll); > +reg9[3] = 1; > +next; > + </pre> > </li> > > <li> > <p> > A priority-100 flow which matches on IPv6 Neighbor Discovery > - solicitation packet and applies the actions: > + solicitation packet and applies the actions if the option > + <code>always_learn_from_arp_request</code> is <code>true</code>: > + </p> > + > + <pre> > +reg9[2] = lookup_nd(inport, ip6.src, nd.sll); > +next; > + </pre> > + > + <p> > + If the option <code>always_learn_from_arp_request</code> > + is <code>false</code>, the above actions will be: > </p> > > <pre> > reg9[2] = lookup_nd(inport, ip6.src, nd.sll); > +reg9[3] = lookup_nd_ip(inport, ip6.src); > next; > </pre> > </li> > @@ -1604,21 +1672,28 @@ next; > > <p> > This table adds flows to learn the mac bindings from the ARP and > - IPv6 Neighbor Solicitation/Advertisement packets if ARP/ND lookup > - failed in the previous table. > + IPv6 Neighbor Solicitation/Advertisement packets if it is needed > + according to the lookup results from the previous stage. > </p> > > <p> > reg9[2] will be <code>1</code> if the > <code>lookup_arp/lookup_nd</code> > - in the previous table was successful, or if there was no need to do > the > - lookup. > + in the previous table was successful or skipped, meaning no need > + to learn mac binding from the packet. > + </p> > + > + <p> > + reg9[3] will be <code>1</code> if the > + <code>lookup_arp_ip/lookup_nd_ip</code> in the previous table was > + successful or skipped, meaning it is ok to learn mac binding from > + the packet (if reg9[2] is 0). > </p> > > <ul> > <li> > - A priority-100 flow with the match > - <code>reg9[2] == 1</code> and advances the packet > - to the next table as there is no need to learn the neighbor. > + A priority-100 flow with the match <code>reg9[2] == 1 || reg9[3] > == > + 0</code> and advances the packet to the next table as there is no > need > + to learn the neighbor. > </li> > > <li> > diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c > index 425f522..b5e7c08 100644 > --- a/northd/ovn-northd.c > +++ b/northd/ovn-northd.c > @@ -221,6 +221,7 @@ enum ovn_stage { > /* Register to store the result of check_pkt_larger action. */ > #define REGBIT_PKT_LARGER "reg9[1]" > #define REGBIT_LOOKUP_NEIGHBOR_RESULT "reg9[2]" > +#define REGBIT_LOOKUP_NEIGHBOR_IP_RESULT "reg9[3]" > > /* Register to store the eth address associated to a router port for > packets > * received in S_ROUTER_IN_ADMISSION. > @@ -8242,36 +8243,62 @@ build_lrouter_flows(struct hmap *datapaths, struct > hmap *ports, > * For ARP packets, table LOOKUP_NEIGHBOR does a lookup for the > * (arp.spa, arp.sha) in the mac binding table using the > 'lookup_arp' > * action and stores the result in REGBIT_LOOKUP_NEIGHBOR_RESULT > bit. > + * If "always_learn_from_arp_request" is set to false, it will > also > + * lookup for the (arp.spa) in the mac binding table using the > + * "lookup_arp_ip" action for ARP request packets, and stores the > + * result in REGBIT_LOOKUP_NEIGHBOR_IP_RESULT bit; or set that bit > + * to "1" directly for ARP response packets. > * > * For IPv6 ND NA packets, table LOOKUP_NEIGHBOR does a lookup > * for the (nd.target, nd.tll) in the mac binding table using the > * 'lookup_nd' action and stores the result in > - * REGBIT_LOOKUP_NEIGHBOR_RESULT bit. > + * REGBIT_LOOKUP_NEIGHBOR_RESULT bit. If > + * "always_learn_from_arp_request" is set to false, > + * REGBIT_LOOKUP_NEIGHBOR_IP_RESULT bit is set. > * > * For IPv6 ND NS packets, table LOOKUP_NEIGHBOR does a lookup > * for the (ip6.src, nd.sll) in the mac binding table using the > * 'lookup_nd' action and stores the result in > - * REGBIT_LOOKUP_NEIGHBOR_RESULT bit. > + * REGBIT_LOOKUP_NEIGHBOR_RESULT bit. If > + * "always_learn_from_arp_request" is set to false, it will also > lookup > + * for the (ip6.src) in the mac binding table using the > "lookup_nd_ip" > + * action and stores the result in > REGBIT_LOOKUP_NEIGHBOR_IP_RESULT > + * bit. > * > * Table LEARN_NEIGHBOR learns the mac-binding using the action > - * - 'put_arp/put_nd' only if REGBIT_LOOKUP_NEIGHBOR_RESULT bit > - * is not set. > + * - 'put_arp/put_nd'. Learning mac-binding is skipped if > + * REGBIT_LOOKUP_NEIGHBOR_RESULT bit is set or > + * REGBIT_LOOKUP_NEIGHBOR_IP_RESULT is not set. > * > * */ > > /* Flows for LOOKUP_NEIGHBOR. */ > + bool learn_from_arp_request = smap_get_bool(&od->nbr->options, > + "always_learn_from_arp_request", true); > + ds_clear(&actions); > + ds_put_format(&actions, REGBIT_LOOKUP_NEIGHBOR_RESULT > + " = lookup_arp(inport, arp.spa, arp.sha); %snext;", > + learn_from_arp_request ? "" : > + REGBIT_LOOKUP_NEIGHBOR_IP_RESULT" = 1; "); > ovn_lflow_add(lflows, od, S_ROUTER_IN_LOOKUP_NEIGHBOR, 100, > - "arp.op == 2", > - REGBIT_LOOKUP_NEIGHBOR_RESULT" = " > - "lookup_arp(inport, arp.spa, arp.sha); next;"); > + "arp.op == 2", ds_cstr(&actions)); > > + ds_clear(&actions); > + ds_put_format(&actions, REGBIT_LOOKUP_NEIGHBOR_RESULT > + " = lookup_nd(inport, nd.target, nd.tll); %snext;", > + learn_from_arp_request ? "" : > + REGBIT_LOOKUP_NEIGHBOR_IP_RESULT" = 1; "); > ovn_lflow_add(lflows, od, S_ROUTER_IN_LOOKUP_NEIGHBOR, 100, > "nd_na", > - REGBIT_LOOKUP_NEIGHBOR_RESULT" = " > - "lookup_nd(inport, nd.target, nd.tll); next;"); > + ds_cstr(&actions)); > > + ds_clear(&actions); > + ds_put_format(&actions, REGBIT_LOOKUP_NEIGHBOR_RESULT > + " = lookup_nd(inport, ip6.src, nd.sll); %snext;", > + learn_from_arp_request ? "" : > + REGBIT_LOOKUP_NEIGHBOR_IP_RESULT > + " = lookup_nd_ip(inport, ip6.src); "); > ovn_lflow_add(lflows, od, S_ROUTER_IN_LOOKUP_NEIGHBOR, 100, > "nd_ns", > - REGBIT_LOOKUP_NEIGHBOR_RESULT" = " > - "lookup_nd(inport, ip6.src, nd.sll); next;"); > + ds_cstr(&actions)); > > /* For other packet types, we can skip neighbor learning. > * So set REGBIT_LOOKUP_NEIGHBOR_RESULT to 1. */ > @@ -8280,8 +8307,12 @@ build_lrouter_flows(struct hmap *datapaths, struct > hmap *ports, > > /* Flows for LEARN_NEIGHBOR. */ > /* Skip Neighbor learning if not required. */ > + ds_clear(&match); > + ds_put_format(&match, REGBIT_LOOKUP_NEIGHBOR_RESULT" == 1%s", > + learn_from_arp_request ? "" : > + " || "REGBIT_LOOKUP_NEIGHBOR_IP_RESULT" == 0"); > ovn_lflow_add(lflows, od, S_ROUTER_IN_LEARN_NEIGHBOR, 100, > - REGBIT_LOOKUP_NEIGHBOR_RESULT" == 1", "next;"); > + ds_cstr(&match), "next;"); > > ovn_lflow_add(lflows, od, S_ROUTER_IN_LEARN_NEIGHBOR, 90, > "arp", "put_arp(inport, arp.spa, arp.sha); next;"); > @@ -8298,8 +8329,37 @@ build_lrouter_flows(struct hmap *datapaths, struct > hmap *ports, > continue; > } > > + bool learn_from_arp_request = smap_get_bool(&op->od->nbr->options, > + "always_learn_from_arp_request", true); > + > /* Check if we need to learn mac-binding from ARP requests. */ > for (int i = 0; i < op->lrp_networks.n_ipv4_addrs; i++) { > + if (!learn_from_arp_request) { > + /* ARP request to this address should always get learned, > + * so add a priority-110 flow to set > + * REGBIT_LOOKUP_NEIGHBOR_IP_RESULT to 1. */ > + ds_clear(&match); > + ds_put_format(&match, > + "inport == %s && arp.spa == %s/%u && " > + "arp.tpa == %s && arp.op == 1", > + op->json_key, > + op->lrp_networks.ipv4_addrs[i].network_s, > + op->lrp_networks.ipv4_addrs[i].plen, > + op->lrp_networks.ipv4_addrs[i].addr_s); > + if (op->od->l3dgw_port && op == op->od->l3dgw_port > + && op->od->l3redirect_port) { > + ds_put_format(&match, " && is_chassis_resident(%s)", > + op->od->l3redirect_port->json_key); > + } > + const char *actions_s = REGBIT_LOOKUP_NEIGHBOR_RESULT > + " = lookup_arp(inport, arp.spa, > arp.sha); " > + REGBIT_LOOKUP_NEIGHBOR_IP_RESULT" = 1;" > + " next;"; > + ovn_lflow_add_with_hint(lflows, op->od, > + S_ROUTER_IN_LOOKUP_NEIGHBOR, 110, > + ds_cstr(&match), actions_s, > + &op->nbrp->header_); > + } > ds_clear(&match); > ds_put_format(&match, > "inport == %s && arp.spa == %s/%u && arp.op == > 1", > @@ -8311,12 +8371,16 @@ build_lrouter_flows(struct hmap *datapaths, struct > hmap *ports, > ds_put_format(&match, " && is_chassis_resident(%s)", > op->od->l3redirect_port->json_key); > } > + ds_clear(&actions); > + ds_put_format(&actions, REGBIT_LOOKUP_NEIGHBOR_RESULT > + " = lookup_arp(inport, arp.spa, arp.sha); > %snext;", > + learn_from_arp_request ? "" : > + REGBIT_LOOKUP_NEIGHBOR_IP_RESULT > + " = lookup_arp_ip(inport, arp.spa); "); > ovn_lflow_add_with_hint(lflows, op->od, > S_ROUTER_IN_LOOKUP_NEIGHBOR, 100, > - ds_cstr(&match), > - REGBIT_LOOKUP_NEIGHBOR_RESULT" = " > - "lookup_arp(inport, arp.spa, > arp.sha); " > - "next;", &op->nbrp->header_); > + ds_cstr(&match), ds_cstr(&actions), > + &op->nbrp->header_); > } > } > > diff --git a/ovn-nb.xml b/ovn-nb.xml > index e8450aa..415d30a 100644 > --- a/ovn-nb.xml > +++ b/ovn-nb.xml > @@ -1859,6 +1859,33 @@ > send traffic between each other. > </p> > </column> > + <column name="options" key="always_learn_from_arp_request" > type='{"type": "boolean"}'> > + <p> > + This option controls the behavior when handling IPv4 ARP > requests or > + IPv6 ND-NS packets - whether a dynamic neighbor (MAC binding) > entry > + is added/updated. > + </p> > + > + <p> > + <code>true</code> - Always learn the MAC-IP binding, and > add/update > + the MAC binding entry. > + </p> > + > + <p> > + <code>false</code> - If there is a MAC binding for that IP and > the > + MAC is different, or, if TPA of ARP request belongs to any > router > + port on this router, then update/add that MAC-IP binding. > Otherwise, > + don't update/add entries. > + </p> > + > + <p> > + It is <code>true</code> by default. It is recommended to set to > + <code>false</code> when a large number of logical routers are > + connected to the same logical switch but most of them never > need to > + send traffic between each other, to reduce the size of the MAC > + binding table. > + </p> > + </column> > </group> > > <group title="Common Columns"> > diff --git a/tests/ovn.at b/tests/ovn.at > index 67fb754..fc811b4 100644 > --- a/tests/ovn.at > +++ b/tests/ovn.at > @@ -4031,6 +4031,18 @@ ip_to_hex() { > sha=f00000000011 > spa=`ip_to_hex 192 168 1 100` > tpa=$spa > + > +# When always_learn_from_arp_request=false, the new mac-binding will not > be learned > +# through GARP request. > +ovn-nbctl --wait=hv set logical_router lr0 > options:always_learn_from_arp_request=false > + > +test_arp 11 $sha $spa $tpa > +sleep 1 > Instead of sleep, I think it's good to run "ovn-nbctl --wait-hv sync" > +AT_CHECK([ovn-sbctl find mac_binding ip="192.168.1.100"], [0], []) > + > +# When always_learn_from_arp_request=true, the new mac-binding will be > learned. > +ovn-nbctl --wait=hv set logical_router lr0 > options:always_learn_from_arp_request=true > + > test_arp 11 $sha $spa $tpa > OVS_WAIT_UNTIL([test `ovn-sbctl find mac_binding ip="192.168.1.100" | wc > -l` -gt 0]) > ovn-nbctl --wait=hv sync > @@ -4045,6 +4057,12 @@ test_ip 21 $smac $dmac $sip $dip 11 > > # lp12 send GARP request to announce ownership of 192.168.1.100. > > +# Even when always_learn_from_arp_request=false, the existing mac-binding > should be > +# updated through GARP request. > +ovn-nbctl --wait=hv set logical_router lr0 > options:always_learn_from_arp_request=false > +ovn-sbctl lflow-list > +as hv2 ovs-ofctl dump-flows br-int > + > sha=f00000000012 > test_arp 12 $sha $spa $tpa > OVS_WAIT_UNTIL([ovn-sbctl find mac_binding ip="192.168.1.100" | grep > f0:00:00:00:00:12]) > -- > 2.1.0 > > _______________________________________________ > dev mailing list > d...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev