From 114ca5e976d46bb7285c993879a2837146701386 Mon Sep 17 00:00:00 2001
Message-Id: <114ca5e976d46bb7285c993879a2837146701386.1593090759.git.lorenzo.bianconi@redhat.com>
From: Gabriele Cerami <gcerami@redhat.com>
Date: Sat, 13 Jun 2020 10:20:23 +0100
Subject: [PATCH] Honour router_preference for solicited RA
Replies to router solicitation follow a different flow than periodic RA.
This flow currently does not honour the router_preference configuration.
This patch modifies the flow to honour the flag, and send
router-preference indications in the reply RA following RFC4191
specifications
Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1804576
Signed-off-by: Gabriele Cerami <gcerami@redhat.com>
Signed-off-by: Numan Siddique <numans@ovn.org>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
AUTHORS.rst | 1 +
ovn/lib/actions.c | 29 +++++++++++++++++++++++++++--
ovn/lib/ovn-l7.h | 5 +++++
ovn/northd/ovn-northd.c | 6 ++++++
tests/ovn.at | 26 ++++++++++++++++----------
5 files changed, 55 insertions(+), 12 deletions(-)
--- a/AUTHORS.rst
+++ b/AUTHORS.rst
@@ -145,6 +145,7 @@ Frédéric Tobias Christ fch
Frode Nordahl frode.nordahl@gmail.com
FUJITA Tomonori fujita.tomonori@lab.ntt.co.jp
Gabe Beged-Dov gabe@begeddov.com
+Gabriele Cerami gcerami@redhat.com
Gaetano Catalli gaetano.catalli@gmail.com
Gal Sagie gal.sagie@gmail.com
Genevieve LEsperance glesperance@pivotal.io
--- a/ovn/lib/actions.c
+++ b/ovn/lib/actions.c
@@ -2298,6 +2298,12 @@ parse_put_nd_ra_opts(struct action_conte
}
break;
+ case ND_RA_FLAG_PRF:
+ ok = (c->string && (!strcmp(c->string, "MEDIUM") ||
+ !strcmp(c->string, "HIGH") ||
+ !strcmp(c->string, "LOW")));
+ break;
+
case ND_OPT_SOURCE_LINKADDR:
ok = c->format == LEX_F_ETHERNET;
slla_present = true;
@@ -2352,9 +2358,22 @@ encode_put_nd_ra_option(const struct ovn
{
struct ovs_ra_msg *ra = ofpbuf_at(ofpacts, ra_offset, sizeof *ra);
if (!strcmp(c->string, "dhcpv6_stateful")) {
- ra->mo_flags = IPV6_ND_RA_FLAG_MANAGED_ADDR_CONFIG;
+ ra->mo_flags |= IPV6_ND_RA_FLAG_MANAGED_ADDR_CONFIG;
} else if (!strcmp(c->string, "dhcpv6_stateless")) {
- ra->mo_flags = IPV6_ND_RA_FLAG_OTHER_ADDR_CONFIG;
+ ra->mo_flags |= IPV6_ND_RA_FLAG_OTHER_ADDR_CONFIG;
+ }
+ break;
+ }
+
+ case ND_RA_FLAG_PRF:
+ {
+ struct ovs_ra_msg *ra = ofpbuf_at(ofpacts, ra_offset, sizeof *ra);
+ if (!strcmp(c->string, "LOW")) {
+ ra->mo_flags |= IPV6_ND_RA_OPT_PRF_LOW;
+ } else if (!strcmp(c->string, "HIGH")) {
+ ra->mo_flags |= IPV6_ND_RA_OPT_PRF_HIGH;
+ } else {
+ ra->mo_flags |= IPV6_ND_RA_OPT_PRF_NORMAL;
}
break;
}
@@ -2435,6 +2454,12 @@ encode_PUT_ND_RA_OPTS(const struct ovnac
encode_put_nd_ra_option(o, ofpacts, ra_offset);
}
+ /* RFC4191 section 2.2 */
+ struct ovs_ra_msg *new_ra = ofpbuf_at(ofpacts, ra_offset, sizeof *new_ra);
+ if (ntohs(new_ra->router_lifetime) == 0) {
+ new_ra->mo_flags &= IPV6_ND_RA_OPT_PRF_RESET_MASK;
+ }
+
encode_finish_controller_op(oc_offset, ofpacts);
}
--- a/ovn/lib/ovn-l7.h
+++ b/ovn/lib/ovn-l7.h
@@ -295,6 +295,9 @@ nd_ra_opts_destroy(struct hmap *nd_ra_op
#define ND_RA_FLAG_ADDR_MODE 0
+/* all small numbers seems to be all already taken but nothing guarantees this
+ * code will not be assigned by IANA to another option */
+#define ND_RA_FLAG_PRF 255
/* Default values of various IPv6 Neighbor Discovery protocol options and
@@ -316,11 +319,13 @@ nd_ra_opts_destroy(struct hmap *nd_ra_op
#define IPV6_ND_RA_OPT_PRF_NORMAL 0x00
#define IPV6_ND_RA_OPT_PRF_HIGH 0x08
#define IPV6_ND_RA_OPT_PRF_LOW 0x18
+#define IPV6_ND_RA_OPT_PRF_RESET_MASK 0xe7
static inline void
nd_ra_opts_init(struct hmap *nd_ra_opts)
{
nd_ra_opt_add(nd_ra_opts, "addr_mode", ND_RA_FLAG_ADDR_MODE, "str");
+ nd_ra_opt_add(nd_ra_opts, "router_preference", ND_RA_FLAG_PRF, "str");
nd_ra_opt_add(nd_ra_opts, "slla", ND_OPT_SOURCE_LINKADDR, "mac");
nd_ra_opt_add(nd_ra_opts, "prefix", ND_OPT_PREFIX_INFORMATION, "ipv6");
nd_ra_opt_add(nd_ra_opts, "mtu", ND_OPT_MTU, "uint32");
--- a/ovn/northd/ovn-northd.c
+++ b/ovn/northd/ovn-northd.c
@@ -8551,6 +8551,12 @@ build_lrouter_flows(struct hmap *datapat
ds_put_format(&actions, ", mtu = %u", mtu);
}
+ const char *prf = smap_get_def(
+ &op->nbrp->ipv6_ra_configs, "router_preference", "MEDIUM");
+ if (strcmp(prf, "MEDIUM")) {
+ ds_put_format(&actions, ", router_preference = \"%s\"", prf);
+ }
+
bool add_rs_response_flow = false;
for (size_t i = 0; i < op->lrp_networks.n_ipv6_addrs; i++) {
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -1326,14 +1326,14 @@ log(severity=notice);
Syntax error at `;' expecting verdict.
# put_nd_ra_opts
-reg1[0] = put_nd_ra_opts(addr_mode = "slaac", mtu = 1500, prefix = aef0::/64, slla = ae:01:02:03:04:05);
- encodes as controller(userdata=00.00.00.08.00.00.00.00.00.01.de.10.00.00.00.40.86.00.00.00.ff.00.ff.ff.00.00.00.00.00.00.00.00.05.01.00.00.00.00.05.dc.03.04.40.c0.ff.ff.ff.ff.ff.ff.ff.ff.00.00.00.00.ae.f0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.01.01.ae.01.02.03.04.05,pause)
+reg1[0] = put_nd_ra_opts(addr_mode = "slaac", mtu = 1500, router_preference = "HIGH", prefix = aef0::/64, slla = ae:01:02:03:04:05);
+ encodes as controller(userdata=00.00.00.08.00.00.00.00.00.01.de.10.00.00.00.40.86.00.00.00.ff.08.ff.ff.00.00.00.00.00.00.00.00.05.01.00.00.00.00.05.dc.03.04.40.c0.ff.ff.ff.ff.ff.ff.ff.ff.00.00.00.00.ae.f0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.01.01.ae.01.02.03.04.05,pause)
has prereqs ip6
-reg1[0] = put_nd_ra_opts(addr_mode = "dhcpv6_stateful", slla = ae:01:02:03:04:10, mtu = 1450);
+reg1[0] = put_nd_ra_opts(addr_mode = "dhcpv6_stateful", router_preference = "MEDIUM", slla = ae:01:02:03:04:10, mtu = 1450);
encodes as controller(userdata=00.00.00.08.00.00.00.00.00.01.de.10.00.00.00.40.86.00.00.00.ff.80.ff.ff.00.00.00.00.00.00.00.00.01.01.ae.01.02.03.04.10.05.01.00.00.00.00.05.aa,pause)
has prereqs ip6
-reg1[0] = put_nd_ra_opts(addr_mode = "dhcpv6_stateless", slla = ae:01:02:03:04:06, prefix = aef0::/64);
- encodes as controller(userdata=00.00.00.08.00.00.00.00.00.01.de.10.00.00.00.40.86.00.00.00.ff.40.ff.ff.00.00.00.00.00.00.00.00.01.01.ae.01.02.03.04.06.03.04.40.c0.ff.ff.ff.ff.ff.ff.ff.ff.00.00.00.00.ae.f0.00.00.00.00.00.00.00.00.00.00.00.00.00.00,pause)
+reg1[0] = put_nd_ra_opts(addr_mode = "dhcpv6_stateless", router_preference = "LOW", slla = ae:01:02:03:04:06, prefix = aef0::/64);
+ encodes as controller(userdata=00.00.00.08.00.00.00.00.00.01.de.10.00.00.00.40.86.00.00.00.ff.58.ff.ff.00.00.00.00.00.00.00.00.01.01.ae.01.02.03.04.06.03.04.40.c0.ff.ff.ff.ff.ff.ff.ff.ff.00.00.00.00.ae.f0.00.00.00.00.00.00.00.00.00.00.00.00.00.00,pause)
has prereqs ip6
reg1[0] = put_nd_ra_opts(addr_mode = "slaac", mtu = 1500, prefix = aef0::/64);
slla option not present
@@ -10075,13 +10075,16 @@ reset_pcap_file hv1-vif1 hv1/vif1
reset_pcap_file hv1-vif2 hv1/vif2
reset_pcap_file hv1-vif3 hv1/vif3
-# Set the MTU to 1500
+# Set the MTU to 1500, send_periodic to false, preference to LOW
ovn-nbctl --wait=hv set Logical_Router_Port lrp0 ipv6_ra_configs:mtu=1500
+ovn-nbctl --wait=hv set Logical_Router_Port lrp0 ipv6_ra_configs:send_periodic="false"
+ovn-nbctl --wait=hv set Logical_Router_Port lrp0 ipv6_ra_configs:router_preference="LOW"
# Make sure that ovn-controller has installed the corresponding OF Flow.
OVS_WAIT_UNTIL([test 1 = `as hv1 ovs-ofctl dump-flows br-int | grep -c "ipv6_dst=ff02::2,nw_ttl=255,icmp_type=133,icmp_code=0"`])
-addr_mode=00
+# addr_mode byte also includes router preference information
+addr_mode=18
default_prefix_option_config=030440c0ffffffffffffffff00000000
src_mac=fa163e000003
src_lla=fe80000000000000f8163efffe000003
@@ -10106,12 +10109,14 @@ reset_pcap_file hv1-vif1 hv1/vif1
reset_pcap_file hv1-vif2 hv1/vif2
reset_pcap_file hv1-vif3 hv1/vif3
-# Set the address mode to dhcpv6_stateful
+# Set the address mode to dhcpv6_stateful, router_preference to HIGH
ovn-nbctl --wait=hv set Logical_Router_Port lrp0 ipv6_ra_configs:address_mode=dhcpv6_stateful
+ovn-nbctl --wait=hv set Logical_Router_Port lrp0 ipv6_ra_configs:router_preference="HIGH"
# Make sure that ovn-controller has installed the corresponding OF Flow.
OVS_WAIT_UNTIL([test 1 = `as hv1 ovs-ofctl dump-flows br-int | grep -c "ipv6_dst=ff02::2,nw_ttl=255,icmp_type=133,icmp_code=0"`])
-addr_mode=80
+# addr_mode byte also includes router preference information
+addr_mode=88
default_prefix_option_config=03044080ffffffffffffffff00000000
src_mac=fa163e000004
src_lla=fe80000000000000f8163efffe000004
@@ -10136,8 +10141,9 @@ reset_pcap_file hv1-vif1 hv1/vif1
reset_pcap_file hv1-vif2 hv1/vif2
reset_pcap_file hv1-vif3 hv1/vif3
-# Set the address mode to dhcpv6_stateless
+# Set the address mode to dhcpv6_stateless, reset router preference to default
ovn-nbctl --wait=hv set Logical_Router_Port lrp0 ipv6_ra_configs:address_mode=dhcpv6_stateless
+ovn-nbctl --wait=hv set Logical_Router_Port lrp0 ipv6_ra_configs:router_preference="MEDIUM"
# Make sure that ovn-controller has installed the corresponding OF Flow.
OVS_WAIT_UNTIL([test 1 = `as hv1 ovs-ofctl dump-flows br-int | grep -c "ipv6_dst=ff02::2,nw_ttl=255,icmp_type=133,icmp_code=0"`])