[ovs-dev] [PATCH ovn] ovn-northd.c: Add proxy ARP support to OVN
Dan Williams
dcbw at redhat.com
Thu Jun 3 15:59:50 UTC 2021
On Wed, 2021-06-02 at 17:02 +0100, Brendan Doyle wrote:
> From a9d3140845175edb7644b2d0d82a95bd6cf94662 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 | 38 +++++++++++++++++++
> ovn-nb.xml | 9 +++++
> tests/ovn.at | 103
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 150 insertions(+)
>
> diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
> index 0e5092a..a377e83 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 +7097,43 @@ 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");
> + if (arp_proxy && op->peer) {
> + char *ips, *ip, *rest;
> +
> + ips = xstrdup(arp_proxy);
> + rest = ips;
> +
> + while ((ip = strtok_r(rest,",", &rest))) {
> + ds_clear(match);
> + ds_put_format(match, "arp.tpa == %s && arp.op == 1",
> ip);
> +
> + 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; "
> + "arp.spa = %s; "
I think you can collapse the two lines above into:
"arp.tpa <-> arp.spa; "
and get rid of one %s. For an example, see build_lrouter_arp_flow().
In fact, you might be able to reduce the number of lflows down to one
by doing something like the following, since now your action is
constant due to the <->.
int i = 0;
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, ")");
An example of that is in build_port_security_ipv6_nd_flow().
---
General comment, this will need a ddlog counterpart too. I'm not an
expert there, so I'll leave it to the OVN team to help. But you could
use Ilya's lrouter arp flow patch as a reference:
http://patchwork.ozlabs.org/project/ovn/patch/20210507162256.3661118-1-i.maximets@ovn.org/
Looking at that patch, you might need to update the ovn-northd.8
manpage as well?
Thanks!
Dan
> + "outport = inport; "
> + "flags.loopback = 1; "
> + "output;",
> + op->peer->lrp_networks.ea_s,
> + op->peer->lrp_networks.ea_s,
> + ip);
> +
> + 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..c675cc9 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
> +2
> +])
> +
> +# 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
> +])
> --
> 1.8.3.1
>
> _______________________________________________
> dev mailing list
> dev at openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>
More information about the dev
mailing list