[ovs-dev] [External] : [PATCH ovn v2] ovn-northd.c: Add proxy ARP support to OVN
Numan Siddique
numans at ovn.org
Mon Jun 14 20:17:40 UTC 2021
On Mon, Jun 14, 2021 at 5:19 AM Brendan Doyle <brendan.doyle at oracle.com> wrote:
>
> Hi,
>
> Just wondering how to move this along. It's been in the queue a while now.
> The product I'm working on requires this feature and If I can't get it
> upstream
> I'll need to look at other options.
Hi Brendan,
Sorry for the late reply. For some reason the patch doesn't apply to me.
Please see below for a few comments.
>
>
> Thanks
>
> Brendan
>
> On 04/06/2021 15:51, Brendan Doyle wrote:
> > From 07ecd5d00f82658e094132102575d8d576161a6b Mon Sep 17 00:00:00 2001
> > From: Brendan Doyle <brendan.doyle at oracle.com>
> > Date: Fri, 28 May 2021 10:01:17 -0700
> > Subject: [PATCH ovn] ovn-northd.c: Add proxy ARP support to OVN
> >
> > This patch provides the ability to configure proxy ARP IPs on a Logical
> > Switch Router port. The IPs are added as Options for router ports. This
> > provides a useful feature where traffic for a service must be sent to an
> > address in a logical network address space, but the service is provided
> > in a different network. For example an NFS service is provide to Logical
> > networks at an address in their Logical network space, but the NFS
> > server resides in a physical network. A Logical switch Router port can
> > be configured to respond to ARP requests sent to the service "Logical
> > address", the Logical Router/Gateway can then be configured to forward
> > the traffic to the underlay/physical network.
> >
> > Signed-off-by: Brendan Doyle <brendan.doyle at oracle.com>
> > ---
> > northd/ovn-northd.c | 44 ++++++++++++++++++++++
> > ovn-nb.xml | 9 +++++
> > tests/ovn.at | 103
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 156 insertions(+)
> >
> > diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
> > index 0e5092a..9b686d9 100644
> > --- a/northd/ovn-northd.c
> > +++ b/northd/ovn-northd.c
> > @@ -6943,6 +6943,7 @@ build_lswitch_arp_nd_responder_known_ips(struct
> > ovn_port *op,
> > struct ds *match)
> > {
> > if (op->nbsp) {
> > + const char *arp_proxy;
> > if (!strcmp(op->nbsp->type, "virtual")) {
> > /* Handle
> > * - GARPs for virtual ip which belongs to a logical port
> > @@ -7096,6 +7097,49 @@ build_lswitch_arp_nd_responder_known_ips(struct
> > ovn_port *op,
> > }
> > }
> > }
> > +
> > + /*
> > + * Add responses for ARP proxies.
> > + */
> > + arp_proxy = smap_get(&op->nbsp->options,"arp_proxy");
In my opinion instead of defining these proxy IPs in the logical
switch port options,
it is better to define them in the router port as generally a router
would handle proxy arps (correct me if I'm wrong here).
I'd suggest to add a new column "proxy_ips" (or something more appropriate)
in the Logical_Router_Port and this column would point to an address set.
CMS can define the list of IPs in the address set. ovn-northd can add
a logical flow like
match = "inport == <router_port> && arp.tpa == $proxy_ip, action = {....}
This would result in just one logical flow.
CMS would do something like
addr_set_uuid=$(ovn-nbctl create address_set name=proxy_arps
addresses="10.0.0.4, 10.0.0.5")
ovn-nbctl set logical_router_port <router_port> proxy_ip=$addr_set_uuid
What do you think ?
Thanks
Numan
> > + if (arp_proxy && op->peer) {
> > + char *ips, *ip, *rest;
> > + int i = 0;
> > +
> > + ips = xstrdup(arp_proxy);
> > + rest = ips;
> > +
> > + /*
> > + * Match rule on all proxy ARP IPs.
> > + */
> > + ds_clear(match);
> > + ds_put_cstr(match, "arp.op == 1 && (");
> > + while ((ip = strtok_r(rest,",", &rest))) {
> > + if (i++ > 0) {
> > + ds_put_cstr(match, " || ");
> > + };
> > + ds_put_format(match, "arp.tpa == %s", ip);
> > + }
> > + ds_put_cstr(match, ")");
> > +
> > + ds_clear(actions);
> > + ds_put_format(actions,
> > + "eth.dst = eth.src; "
> > + "eth.src = %s; "
> > + "arp.op = 2; /* ARP reply */ "
> > + "arp.tha = arp.sha; "
> > + "arp.sha = %s; "
> > + "arp.tpa <-> arp.spa; "
> > + "outport = inport; "
> > + "flags.loopback = 1; "
> > + "output;",
> > + op->peer->lrp_networks.ea_s,
> > + op->peer->lrp_networks.ea_s);
> > +
> > + ovn_lflow_add_with_hint(lflows, op->od,
> > S_SWITCH_IN_ARP_ND_RSP,
> > + 50, ds_cstr(match), ds_cstr(actions),
> > &op->nbsp->header_);
> > + free(ips);
> > + }
> > }
> > }
> >
> > diff --git a/ovn-nb.xml b/ovn-nb.xml
> > index 02fd216..4b6c183 100644
> > --- a/ovn-nb.xml
> > +++ b/ovn-nb.xml
> > @@ -848,6 +848,15 @@
> > </dd>
> > </dl>
> > </column>
> > +
> > + <column name="options" key="arp_proxy">
> > + Optional. A comma separated list IPv4 addresses that this
> > + logical switch <code>router</code> port will reply to ARP
> > requests.
> > + Example: <code>169.254.239.254,169.254.239.2</code>. The
> > + <ref column="options" key="router-port"/>'s logical router
> > should
> > + have a route to forward packets sent to configured proxy
> > ARP IPs to
> > + an appropriate destination.
> > + </column>
> > </group>
> >
> > <group title="Options for localnet ports">
> > diff --git a/tests/ovn.at b/tests/ovn.at
> > index 2c3c36d..4befe4a 100644
> > --- a/tests/ovn.at
> > +++ b/tests/ovn.at
> > @@ -26527,3 +26527,106 @@ AT_CHECK([test $(ovn-appctl -t
> > ovn-controller coverage/read-counter lflow_run) =
> > OVN_CLEANUP([hv1])
> > AT_CLEANUP
> > ])
> > +
> > +OVN_FOR_EACH_NORTHD([
> > +AT_SETUP([ovn -- proxy-arp: 1 HVs, 1 LSs, 1 lport/LS, 1 LR])
> > +AT_KEYWORDS([proxy-arp])
> > +ovn_start
> > +
> > +# Logical network:
> > +# One LR - lr1 has switch ls1 (192.16.1.0/24) connected to it,
> > +# and and one HV with IP 192.16.1.6.
> > +
> > +ovn-nbctl lr-add lr1
> > +ovn-nbctl ls-add ls1
> > +
> > +# Connect ls1 to lr1
> > +ovn-nbctl lrp-add lr1 ls1 00:00:00:01:02:f1 192.16.1.1/24
> > +ovn-nbctl lsp-add ls1 rp-ls1 -- set Logical_Switch_Port rp-ls1 \
> > + type=router options:router-port=ls1 addresses=\"00:00:00:01:02:f1\"
> > +
> > +# Create logical port ls1-lp1 in ls1
> > +ovn-nbctl lsp-add ls1 ls1-lp1 \
> > +-- lsp-set-addresses ls1-lp1 "00:00:00:01:02:03 192.16.1.6"
> > +
> > +
> > +# Create one hypervisor and create OVS ports corresponding to logical
> > ports.
> > +net_add n1
> > +
> > +sim_add pa-hv
> > +as pa-hv
> > +ovs-vsctl add-br br-phys
> > +ovn_attach n1 br-phys 192.16.0.1
> > +
> > +# Note: tx/rx are with respect to the LS port, so
> > +# tx on switch port is HV rx, etc.
> > +ovs-vsctl -- add-port br-int vif1 -- \
> > + set interface vif1 external-ids:iface-id=ls1-lp1 \
> > + options:tx_pcap=pa-hv/vif1-tx.pcap \
> > + options:rxq_pcap=pa-hv/vif1-rx.pcap \
> > + ofport-request=1
> > +
> > +# And proxy ARP flows for 69.254.239.254 and 169.254.239.2
> > +# and check that SB flows have been added.
> > +ovn-nbctl --wait=hv add Logical_Switch_Port rp-ls1 \
> > +options arp_proxy='"169.254.239.254,169.254.239.2"'
> > +ovn-sbctl dump-flows > sbflows
> > +AT_CAPTURE_FILE([sbflows])
> > +
> > +AT_CHECK([ovn-sbctl dump-flows | grep ls_in_arp_rsp | grep
> > "169.254.239.2" | wc -l], [0], [dnl
> > +1
> > +])
> > +
> > +# Remove and check that the flows have been removed
> > +ovn-nbctl --wait=hv remove Logical_Switch_Port rp-ls1 options
> > arp_proxy='"169.254.239.254,169.254.239.2"'
> > +
> > +AT_CHECK([ovn-sbctl dump-flows | grep ls_in_arp_rsp | grep
> > "169.254.239.2" | wc -l], [0], [dnl
> > +0
> > +])
> > +
> > +# Add the flows back send arp request and check we see an ARP response
> > +ovn-nbctl --wait=hv add Logical_Switch_Port rp-ls1 \
> > +options arp_proxy='"169.254.239.254,169.254.239.2"'
> > +
> > +ls1_p1_mac=00:00:00:01:02:03
> > +ls1_p1_ip=192.16.1.6
> > +
> > +ls1_ro_mac=00:00:00:01:02:f1
> > +ls1_ro_ip=192.168.1.1
> > +
> > +proxy_ip1=169.254.239.254
> > +proxy_ip2=169.254.239.2
> > +
> > +bcast_mac=ff:ff:ff:ff:ff:ff
> > +
> > +# Send ARP request for 169.254.239.254
> > +packet="inport==\"ls1-lp1\" && eth.src==$ls1_p1_mac &&
> > eth.dst==$bcast_mac &&
> > + arp.op==1 && arp.sha==$ls1_p1_mac && arp.spa==$ls1_p1_ip &&
> > + arp.tha==$bcast_mac && arp.tpa==$proxy_ip1"
> > +
> > +as pa-hv ovs-appctl -t ovn-controller inject-pkt "$packet"
> > +
> > +ovs-ofctl dump-flows br-int| grep 169.254.239.254 | grep priority=50
> > > debug1
> > +AT_CAPTURE_FILE([debug1])
> > +
> > +
> > +# Check if packet hit the ARP reply ovs flow
> > +AT_CHECK([ovs-ofctl dump-flows br-int | \
> > + grep "169.254.239.254" | \
> > + grep "priority=50" | \
> > + grep "arp_op=1" | \
> > + grep "n_packets=1" | wc -l], [0], [dnl
> > +1
> > +])
> > +
> > +# Check that the HV gets an ARP reply
> > +expected="eth.src==$ls1_ro_mac && eth.dst==$ls1_p1_mac &&
> > + arp.op==2 && arp.sha==$ls1_ro_mac && arp.spa==$proxy_ip1 &&
> > + arp.tha==$ls1_p1_mac && arp.tpa==$ls1_p1_ip"
> > +echo $expected | ovstest test-ovn expr-to-packets > expected
> > +
> > +OVN_CHECK_PACKETS([pa-hv/vif1-tx.pcap], [expected])
> > +
> > +OVN_CLEANUP([pa-hv])
> > +AT_CLEANUP
> > +])
>
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