[ovs-dev] [CCC 3/3] vswitchd: Don't act as learning switch in secure mode with no controllers

[Justin Pettit]

Don't act as a learning switch when the fail-mode is "secure" and no
controllers are defined.  This allows the bridge to come up in a state
where it won't pass any traffic until a controller has told it to do so.

Note that "secure" means that it won't add a rule to do normal
processing, but it doesn't flush any existing flows.
---
 ofproto/ofproto.c    |    6 ++++++
 ofproto/ofproto.h    |    1 +
 vswitchd/bridge.c    |   21 +++++++++++++--------
 vswitchd/vswitch.xml |    5 +++--
 4 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 44daabf..28c1b8d 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -883,6 +883,12 @@ ofproto_has_controller(const struct ofproto *ofproto)
     return !hmap_is_empty(&ofproto->controllers);
 }
 
+enum ofproto_fail_mode
+ofproto_get_fail_mode(struct ofproto *p)
+{
+    return p->fail_mode;
+}
+
 void
 ofproto_get_listeners(const struct ofproto *ofproto, struct svec *listeners)
 {
diff --git a/ofproto/ofproto.h b/ofproto/ofproto.h
index 56c54f5..0a9164e 100644
--- a/ofproto/ofproto.h
+++ b/ofproto/ofproto.h
@@ -121,6 +121,7 @@ int ofproto_set_stp(struct ofproto *, bool enable_stp);
 /* Configuration querying. */
 uint64_t ofproto_get_datapath_id(const struct ofproto *);
 bool ofproto_has_controller(const struct ofproto *);
+enum ofproto_fail_mode ofproto_get_fail_mode(struct ofproto *);
 void ofproto_get_listeners(const struct ofproto *, struct svec *);
 void ofproto_get_snoops(const struct ofproto *, struct svec *);
 void ofproto_get_all_flows(struct ofproto *p, struct ds *);
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index fad9b01..4116424 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -1553,14 +1553,19 @@ bridge_reconfigure_remotes(struct bridge *br,
         /* Clear out controllers. */
         ofproto_set_controllers(br->ofproto, NULL, 0);
 
-        /* Set up a flow that matches every packet and directs them to
-         * OFPP_NORMAL (which goes to us). */
-        memset(&action, 0, sizeof action);
-        action.type = htons(OFPAT_OUTPUT);
-        action.output.len = htons(sizeof action);
-        action.output.port = htons(OFPP_NORMAL);
-        memset(&flow, 0, sizeof flow);
-        ofproto_add_flow(br->ofproto, &flow, OVSFW_ALL, 0, &action, 1, 0);
+        /* If there are no controllers and the bridge is in standalone
+         * mode, set up a flow that matches every packet and directs
+         * them to OFPP_NORMAL (which goes to us).  Otherwise, the
+         * switch is in secure mode and we won't pass any traffic until
+         * a controller has been defined and it tells us to do so. */
+        if (ofproto_get_fail_mode(br->ofproto) == OFPROTO_FAIL_STANDALONE) {
+            memset(&action, 0, sizeof action);
+            action.type = htons(OFPAT_OUTPUT);
+            action.output.len = htons(sizeof action);
+            action.output.port = htons(OFPP_NORMAL);
+            memset(&flow, 0, sizeof flow);
+            ofproto_add_flow(br->ofproto, &flow, OVSFW_ALL, 0, &action, 1, 0);
+        }
     } else {
         struct ofproto_controller *ocs;
         size_t i;
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index f5e010b..af85477 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -151,8 +151,9 @@
               standalone behavior.</dd>
             <dt><code>secure</code></dt>
             <dd>Open vSwitch will not set up flows on its own when the
-              controller connection fails.  It will continue retry
-              connecting to the controller forever.</dd>
+              controller connection fails or when no controllers are
+              defined.  The bridge will continue to retry connecting to
+              any defined controllers forever.</dd>
           </dl>
         </p>
         <p>If this value is unset, the default is implementation-specific.</p>
-- 
1.7.1