[ovs-dev] [PATCH] connect: Add min_backoff parameter to the Manager table

Pryima, Anton Serhiyovych (Contractor) AntonSerhiyovych_Pryima at comcast.com
Wed Oct 6 19:42:03 UTC 2021


To adjust the minimum number of connection attempts by
ovsdb-server to the cloud controller (to avoid ddos when controller
was down and then up)

Was carefully tested within product's codestack

Signed-off-by: Anton Pryima <apryim702 at cable.comcast.com>

diff --git a/lib/jsonrpc.c b/lib/jsonrpc.c
index c8ce5362e..f7c5f17c1 100644
--- a/lib/jsonrpc.c
+++ b/lib/jsonrpc.c
@@ -1306,6 +1306,16 @@ jsonrpc_session_set_max_backoff(struct jsonrpc_session *s, int max_backoff)
     reconnect_set_backoff(s->reconnect, 0, max_backoff);
 }

+/* Sets 'min_backoff and 'max_backoff' as the minimum and maximum time,
+ * in milliseconds, to wait after a connection attempt fails before attempting
+ * to connect again. */
+void
+jsonrpc_session_set_backoff(struct jsonrpc_session *s, int min_backoff,
+                            int max_backoff)
+{
+    reconnect_set_backoff(s->reconnect, min_backoff, max_backoff);
+}
+
 /* Sets the "probe interval" for 's' to 'probe_interval', in milliseconds.  If
  * this is zero, it disables the connection keepalive feature.  Otherwise, if
  * 's' is idle for 'probe_interval' milliseconds then 's' will send an echo
diff --git a/lib/jsonrpc.h b/lib/jsonrpc.h
index 2aa97d3fe..cece97f3b 100644
--- a/lib/jsonrpc.h
+++ b/lib/jsonrpc.h
@@ -141,6 +141,8 @@ void jsonrpc_session_reset_backoff(struct jsonrpc_session *);

 void jsonrpc_session_set_max_backoff(struct jsonrpc_session *,
                                      int max_backoff);
+void jsonrpc_session_set_backoff(struct jsonrpc_session *,
+                                     int min_backoff, int max_backoff);
 void jsonrpc_session_set_probe_interval(struct jsonrpc_session *,
                                         int probe_interval);
 void jsonrpc_session_set_dscp(struct jsonrpc_session *,
diff --git a/lib/reconnect.c b/lib/reconnect.c
index a929ddfd2..e23763fb8 100644
--- a/lib/reconnect.c
+++ b/lib/reconnect.c
@@ -551,7 +551,8 @@ reconnect_deadline__(const struct reconnect *fsm)
         return fsm->state_entered + fsm->backoff;

     case S_CONNECTING:
-        return fsm->state_entered + MAX(1000, fsm->backoff);
+        return fsm->state_entered + MAX(1000, MAX(fsm->min_backoff,
+                                                  fsm->backoff));

     case S_ACTIVE:
         if (fsm->probe_interval) {
diff --git a/ovsdb/jsonrpc-server.c b/ovsdb/jsonrpc-server.c
index 351c39d8a..8e283bf0c 100644
--- a/ovsdb/jsonrpc-server.c
+++ b/ovsdb/jsonrpc-server.c
@@ -212,6 +212,7 @@ ovsdb_jsonrpc_default_options(const char *target)
 {
     struct ovsdb_jsonrpc_options *options = xzalloc(sizeof *options);
     options->max_backoff = RECONNECT_DEFAULT_MAX_BACKOFF;
+    options->min_backoff = RECONNECT_DEFAULT_MIN_BACKOFF;
     options->probe_interval = (stream_or_pstream_needs_probes(target)
                                ? RECONNECT_DEFAULT_PROBE_INTERVAL
                                : 0);
@@ -577,7 +578,8 @@ static void
 ovsdb_jsonrpc_session_set_options(struct ovsdb_jsonrpc_session *session,
                                   const struct ovsdb_jsonrpc_options *options)
 {
-    jsonrpc_session_set_max_backoff(session->js, options->max_backoff);
+    jsonrpc_session_set_backoff(session->js, options->min_backoff,
+                                options->max_backoff);
     jsonrpc_session_set_probe_interval(session->js, options->probe_interval);
     jsonrpc_session_set_dscp(session->js, options->dscp);
 }
diff --git a/ovsdb/jsonrpc-server.h b/ovsdb/jsonrpc-server.h
index e0653aa39..b157c2860 100644
--- a/ovsdb/jsonrpc-server.h
+++ b/ovsdb/jsonrpc-server.h
@@ -34,6 +34,7 @@ void ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *);
 /* Options for a remote. */
 struct ovsdb_jsonrpc_options {
     int max_backoff;            /* Maximum reconnection backoff, in msec. */
+    int min_backoff;            /* Minimum reconnection backoff, in msec. */
     int probe_interval;         /* Max idle time before probing, in msec. */
     bool read_only;             /* Only read-only transactions are allowed. */
     int dscp;                   /* Dscp value for manager connections */
diff --git a/ovsdb/ovsdb-server.c b/ovsdb/ovsdb-server.c
index b34d97e29..2696643a2 100644
--- a/ovsdb/ovsdb-server.c
+++ b/ovsdb/ovsdb-server.c
@@ -948,7 +948,7 @@ add_manager_options(struct shash *remotes, const struct ovsdb_row *row)
 {
     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
     struct ovsdb_jsonrpc_options *options;
-    long long int max_backoff, probe_interval;
+    long long int max_backoff, min_backoff, probe_interval;
     bool read_only;
     const char *target, *dscp_string, *role;

@@ -962,6 +962,9 @@ add_manager_options(struct shash *remotes, const struct ovsdb_row *row)
     if (ovsdb_util_read_integer_column(row, "max_backoff", &max_backoff)) {
         options->max_backoff = max_backoff;
     }
+    if (ovsdb_util_read_integer_column(row, "min_backoff", &min_backoff)) {
+        options->min_backoff = min_backoff;
+    }
     if (ovsdb_util_read_integer_column(row, "inactivity_probe",
                                        &probe_interval)) {
         options->probe_interval = probe_interval;
diff --git a/vswitchd/vswitch.ovsschema b/vswitchd/vswitch.ovsschema
index 4873cfde7..457925d91 100644
--- a/vswitchd/vswitch.ovsschema
+++ b/vswitchd/vswitch.ovsschema
@@ -1,6 +1,6 @@
 {"name": "Open_vSwitch",
- "version": "8.3.0",
- "cksum": "3781850481 26690",
+ "version": "8.4.0",
+ "cksum": "542313912 26846",
  "tables": {
    "Open_vSwitch": {
      "columns": {
@@ -625,6 +625,10 @@
          "type": {"key": {"type": "integer",
                           "minInteger": 1000},
                   "min": 0, "max": 1}},
+       "min_backoff": {
+         "type": {"key": {"type": "integer",
+                          "minInteger": 1000},
+                  "min": 0, "max": 1}},
        "inactivity_probe": {
          "type": {"key": "integer", "min": 0, "max": 1}},
        "connection_mode": {
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 026b5e2ca..4ccfe7f55 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -5668,6 +5668,11 @@ ovs-vsctl add-port br0 p0 -- set Interface p0 type=patch options:peer=p1 \
         Default is implementation-specific.
       </column>

+      <column name="min_backoff">
+        Minimum number of milliseconds to wait between connection attempts.
+        Default is implementation-specific.
+      </column>
+
       <column name="inactivity_probe">
         Maximum number of milliseconds of idle time on connection to the client
         before sending an inactivity probe message.  If Open vSwitch does not


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