From d7b024a24ee249c3ce6bf593499fdb6a79d78706 Mon Sep 17 00:00:00 2001

Message-Id: <d7b024a24ee249c3ce6bf593499fdb6a79d78706.1575382494.git.lorenzo.bianconi@redhat.com>

From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

Date: Thu, 28 Nov 2019 14:48:35 +0200

Subject: [PATCH 1/2] Add support to Default Router Preference (PRF) - RFC 4191

Introduce support for Default Router Preference (PRF) in IPv6 Router

Advertisement according to RFC 4191

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

Signed-off-by: Numan Siddique <numans@ovn.org>

---

 ovn/controller/pinctrl.c | 20 +++++++++++++++++---

 ovn/lib/ovn-l7.h         |  4 ++++

 ovn/northd/ovn-northd.c  |  8 ++++++++

 ovn/ovn-nb.xml           | 12 ++++++++++++

 tests/ovn.at             | 13 +++++++++----

 5 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/ovn/controller/pinctrl.c b/ovn/controller/pinctrl.c

index fa9c827c1..ea0551c21 100644

--- a/ovn/controller/pinctrl.c

+++ b/ovn/controller/pinctrl.c

@@ -2267,10 +2267,10 @@ ipv6_ra_update_config(const struct sbrec_port_binding *pb)

         goto fail;

     }

     if (!strcmp(address_mode, "dhcpv6_stateless")) {

-        config->mo_flags = IPV6_ND_RA_FLAG_OTHER_ADDR_CONFIG;

+        config->mo_flags |= IPV6_ND_RA_FLAG_OTHER_ADDR_CONFIG;

         config->la_flags |= IPV6_ND_RA_OPT_PREFIX_AUTONOMOUS;

     } else if (!strcmp(address_mode, "dhcpv6_stateful")) {

-        config->mo_flags = IPV6_ND_RA_FLAG_MANAGED_ADDR_CONFIG;

+        config->mo_flags |= IPV6_ND_RA_FLAG_MANAGED_ADDR_CONFIG;

     } else if (!strcmp(address_mode, "slaac")) {

         config->la_flags |= IPV6_ND_RA_OPT_PREFIX_AUTONOMOUS;

     } else {

@@ -2278,6 +2278,13 @@ ipv6_ra_update_config(const struct sbrec_port_binding *pb)

         goto fail;

     }

+    const char *prf = smap_get(&pb->options, "ipv6_ra_prf");

+    if (!strcmp(prf, "HIGH")) {

+        config->mo_flags |= IPV6_ND_RA_OPT_PRF_HIGH;

+    } else if (!strcmp(prf, "LOW")) {

+        config->mo_flags |= IPV6_ND_RA_OPT_PRF_LOW;

+    }

+

     const char *prefixes = smap_get(&pb->options, "ipv6_ra_prefixes");

     if (prefixes && !extract_ip_addresses(prefixes, &config->prefixes)) {

         VLOG_WARN("Invalid IPv6 prefixes: %s", prefixes);

@@ -2427,10 +2434,17 @@ ipv6_ra_send(struct rconn *swconn, struct ipv6_ra_state *ra)

     uint64_t packet_stub[128 / 8];

     struct dp_packet packet;

+    uint16_t router_lt = IPV6_ND_RA_LIFETIME;

+

+    if (!router_lt) {

+        /* Reset PRF to MEDIUM if router lifetime is not set */

+        ra->config->mo_flags &= ~IPV6_ND_RA_OPT_PRF_LOW;

+    }

+

     dp_packet_use_stub(&packet, packet_stub, sizeof packet_stub);

     compose_nd_ra(&packet, ra->config->eth_src, ra->config->eth_dst,

             &ra->config->ipv6_src, &ra->config->ipv6_dst,

-            255, ra->config->mo_flags, htons(IPV6_ND_RA_LIFETIME), 0, 0,

+            255, ra->config->mo_flags, htons(router_lt), 0, 0,

             ra->config->mtu);

     for (int i = 0; i < ra->config->prefixes.n_ipv6_addrs; i++) {

diff --git a/ovn/lib/ovn-l7.h b/ovn/lib/ovn-l7.h

index 5fc370bf5..fd898b0dc 100644

--- a/ovn/lib/ovn-l7.h

+++ b/ovn/lib/ovn-l7.h

@@ -287,6 +287,10 @@ nd_ra_opts_destroy(struct hmap *nd_ra_opts)

 #define IPV6_ND_RA_OPT_PREFIX_VALID_LIFETIME        0xffffffff

 #define IPV6_ND_RA_OPT_PREFIX_PREFERRED_LIFETIME    0xffffffff

+#define IPV6_ND_RA_OPT_PRF_NORMAL                   0x00

+#define IPV6_ND_RA_OPT_PRF_HIGH                     0x08

+#define IPV6_ND_RA_OPT_PRF_LOW                      0x18

+

 static inline void

 nd_ra_opts_init(struct hmap *nd_ra_opts)

 {

diff --git a/ovn/northd/ovn-northd.c b/ovn/northd/ovn-northd.c

index 0e6f8f621..1bcf34369 100644

--- a/ovn/northd/ovn-northd.c

+++ b/ovn/northd/ovn-northd.c

@@ -6755,6 +6755,14 @@ copy_ra_to_sb(struct ovn_port *op, const char *address_mode)

     smap_add(&options, "ipv6_ra_src_eth", op->lrp_networks.ea_s);

+    const char *prf = smap_get(&op->nbrp->ipv6_ra_configs,

+                               "router_preference");

+    if (!prf || (strcmp(prf, "HIGH") && strcmp(prf, "LOW"))) {

+        smap_add(&options, "ipv6_ra_prf", "MEDIUM");

+    } else {

+        smap_add(&options, "ipv6_ra_prf", prf);

+    }

+

     sbrec_port_binding_set_options(op->sb, &options);

     smap_destroy(&options);

 }

diff --git a/ovn/ovn-nb.xml b/ovn/ovn-nb.xml

index 6f6e06777..16851dba1 100644

--- a/ovn/ovn-nb.xml

+++ b/ovn/ovn-nb.xml

@@ -1859,6 +1859,18 @@

       </column>

+      <column name="ipv6_ra_configs" key="router_preference">

+        Default Router Preference (PRF) indicates whether to prefer this

+        router over other default routers (RFC 4191).

+        Possible values are:

+

+        

+          
HIGH: mapped to 0x01 in RA PRF field

+          
MEDIUM: mapped to 0x00 in RA PRF field

+          
LOW: mapped to 0x11 in RA PRF field

+        

+      </column>

+

       <column name="ipv6_ra_configs" key="mtu">

         The recommended MTU for the link. Default is 0, which means no MTU

         Option will be included in RA packet replied by ovn-controller.

diff --git a/tests/ovn.at b/tests/ovn.at

index 33989e697..78524256f 100644

--- a/tests/ovn.at

+++ b/tests/ovn.at

@@ -11488,23 +11488,28 @@ ra_test 000005dc 00 0 0 c0 40 aef00000000000000000000000000000

 ovn-nbctl --wait=hv set Logical_Router_port ro-sw networks='aef0\:\:1/64 fd0f\:\:1/48'

 ra_test 000005dc 00 0 0 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

+# Test PRF for default gw

+ovn-nbctl --wait=hv set Logical_Router_port ro-sw ipv6_ra_configs:router_preference="LOW"

+ra_test 000005dc 18 0 0 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

+

 # Now test for RDNSS

 ovn-nbctl --wait=hv set Logical_Router_port ro-sw ipv6_ra_configs:rdnss='aef0::11'

 dns_addr=aef00000000000000000000000000011

-ra_test 000005dc 00 $dns_addr 0 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

+ra_test 000005dc 18 $dns_addr 0 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

 # Now test for DNSSL

 ovn-nbctl --wait=hv set Logical_Router_port ro-sw ipv6_ra_configs:dnssl="aa.bb.cc"

+ovn-nbctl --wait=hv set Logical_Router_port ro-sw ipv6_ra_configs:router_preference="HIGH"

 dnssl=02616102626202636300000000000000

-ra_test 000005dc 00 $dns_addr $dnssl c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

+ra_test 000005dc 08 $dns_addr $dnssl c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

 ## Test a different address mode now

 ovn-nbctl --wait=hv set Logical_Router_Port ro-sw ipv6_ra_configs:address_mode=dhcpv6_stateful

-ra_test 000005dc 80 $dns_addr $dnssl 80 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

+ra_test 000005dc 88 $dns_addr $dnssl 80 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

 # And the other address mode

 ovn-nbctl --wait=hv set Logical_Router_Port ro-sw ipv6_ra_configs:address_mode=dhcpv6_stateless

-ra_test 000005dc 40 $dns_addr $dnssl c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

+ra_test 000005dc 48 $dns_addr $dnssl c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000

 OVN_CLEANUP([hv1],[hv2])

 AT_CLEANUP

-- 

2.21.0