[ovs-dev] [PATCH ovn] controller: configure only matching encaps between chassis

[Vladislav Odintsov]

Previously tunnels encap on a chassis was based on the remote chassis
"best" encap type. Suppose we have 2 chassis: one with STT, another with
GENEVE. In this case on chassis 1 there was configured STT tunnel, and
GENEVE on another one. No traffic could be sent between these chassis.

With this approach it was impossible to change encap type
for chassis one-by-one, because different tunnel types were
configured on different edges of the link.
Suppose we have 2 chassis: one with STT and VXLAN configured encaps,
another with GENEVE and STT. In
this case on chassis 1 there was configured STT tunnel (best of VXLAN
and STT) and GENEVE on another one ("best" of GENEVE and STT).
No traffic could be sent between these chassis. Though the common STT
could be used.

Now we configure only matching encaps between nodes.

Signed-off-by: Vladislav Odintsov <odivlad at gmail.com>
---
 controller/encaps.c         | 23 ++++++++++++++++++-----
 controller/ovn-controller.h |  3 ++-
 tests/ovn-controller.at     | 14 +++++++++++---
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/controller/encaps.c b/controller/encaps.c
index fc93bf1ee..200b4405d 100644
--- a/controller/encaps.c
+++ b/controller/encaps.c
@@ -248,15 +248,26 @@ exit:
     smap_destroy(&options);
 }
 
+static bool
+chassis_has_type(const struct sbrec_chassis *chassis, uint32_t tun_type) {
+    for (int i =0; i < chassis->n_encaps; i++) {
+        if (get_tunnel_type(chassis->encaps[i]->type) == tun_type) {
+            return true;
+        }
+    }
+    return false;
+}
+
 struct sbrec_encap *
-preferred_encap(const struct sbrec_chassis *chassis_rec)
+preferred_encap(const struct sbrec_chassis *chassis_rec,
+                const struct sbrec_chassis *this_chassis)
 {
     struct sbrec_encap *best_encap = NULL;
     uint32_t best_type = 0;
 
     for (int i = 0; i < chassis_rec->n_encaps; i++) {
         uint32_t tun_type = get_tunnel_type(chassis_rec->encaps[i]->type);
-        if (tun_type > best_type) {
+        if (tun_type > best_type && chassis_has_type(this_chassis, tun_type)) {
             best_type = tun_type;
             best_encap = chassis_rec->encaps[i];
         }
@@ -270,9 +281,11 @@ preferred_encap(const struct sbrec_chassis *chassis_rec)
  * as there are VTEP of that type (differentiated by remote_ip) on that chassis.
  */
 static int
-chassis_tunnel_add(const struct sbrec_chassis *chassis_rec, const struct sbrec_sb_global *sbg, struct tunnel_ctx *tc)
+chassis_tunnel_add(const struct sbrec_chassis *chassis_rec,
+                   const struct sbrec_sb_global *sbg, struct tunnel_ctx *tc,
+                   const struct sbrec_chassis *this_chassis)
 {
-    struct sbrec_encap *encap = preferred_encap(chassis_rec);
+    struct sbrec_encap *encap = preferred_encap(chassis_rec, this_chassis);
     int tuncnt = 0;
 
     if (!encap) {
@@ -390,7 +403,7 @@ encaps_run(struct ovsdb_idl_txn *ovs_idl_txn,
                 continue;
             }
 
-            if (chassis_tunnel_add(chassis_rec, sbg, &tc) == 0) {
+            if (chassis_tunnel_add(chassis_rec, sbg, &tc, this_chassis) == 0) {
                 VLOG_INFO("Creating encap for '%s' failed", chassis_rec->name);
                 continue;
             }
diff --git a/controller/ovn-controller.h b/controller/ovn-controller.h
index 78a53312f..ea48a36cb 100644
--- a/controller/ovn-controller.h
+++ b/controller/ovn-controller.h
@@ -43,7 +43,8 @@ struct ct_zone_pending_entry {
 const struct ovsrec_bridge *get_bridge(const struct ovsrec_bridge_table *,
                                        const char *br_name);
 
-struct sbrec_encap *preferred_encap(const struct sbrec_chassis *);
+struct sbrec_encap *preferred_encap(const struct sbrec_chassis *,
+                                    const struct sbrec_chassis *);
 
 uint32_t get_tunnel_type(const char *name);
 
diff --git a/tests/ovn-controller.at b/tests/ovn-controller.at
index 4ae218ed6..3d27ddd2f 100644
--- a/tests/ovn-controller.at
+++ b/tests/ovn-controller.at
@@ -263,9 +263,8 @@ check_tunnel_property () {
     test "`ovs-vsctl get interface ovn-fakech-0 $1`" = "$2"
 }
 
-# Start off with a remote chassis supporting STT
-ovn-sbctl chassis-add fakechassis stt 192.168.0.2
-OVS_WAIT_UNTIL([check_tunnel_property type stt])
+# create "empty" chassis. vxlan is used here as a stub
+ovn-sbctl chassis-add fakechassis vxlan 192.168.0.2
 
 # See if we switch to Geneve as the first choice when it is available
 # With multi-VTEP support we support tunnels with different IPs to the
@@ -278,6 +277,15 @@ OVS_WAIT_UNTIL([check_tunnel_property type stt])
 encap_uuid=$(ovn-sbctl add chassis fakechassis encaps @encap -- --id=@encap create encap type=geneve ip="192.168.0.2")
 OVS_WAIT_UNTIL([check_tunnel_property type geneve])
 
+# change geneve to stt and check that tun interface was deleted and there is
+# no stt encap on the second chassis, only vxlan
+ovn-sbctl set encap ${encap_uuid} type=stt
+OVS_WAIT_WHILE([check_tunnel_property type stt])
+OVS_WAIT_UNTIL([check_tunnel_property type vxlan])
+
+# change back to geneve
+ovn-sbctl set encap ${encap_uuid} type=geneve
+
 # Check that changes within an encap row are propagated
 ovn-sbctl set encap ${encap_uuid} ip=192.168.0.2
 OVS_WAIT_UNTIL([check_tunnel_property options:remote_ip "\"192.168.0.2\""])
-- 
2.30.0