[ovs-dev] [vlan-maint 2/2] vswitchd: Make the MAC entry aging time configurable.

Ben Pfaff blp at nicira.com
Mon Jan 23 22:43:53 UTC 2012


NICS-11.
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
 lib/learning-switch.c |    6 ++++--
 lib/mac-learning.c    |   41 ++++++++++++++++++++++++++++++++++-------
 lib/mac-learning.h    |   10 +++++++---
 ofproto/ofproto.c     |    4 ++--
 vswitchd/bridge.c     |   14 ++++++++++++--
 vswitchd/vswitch.xml  |    6 ++++++
 6 files changed, 65 insertions(+), 16 deletions(-)

diff --git a/lib/learning-switch.c b/lib/learning-switch.c
index ca97054..5b1996c 100644
--- a/lib/learning-switch.c
+++ b/lib/learning-switch.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -96,7 +96,9 @@ lswitch_create(struct rconn *rconn, const struct lswitch_config *cfg)
     sw->max_idle = cfg->max_idle;
     sw->datapath_id = 0;
     sw->last_features_request = time_now() - 1;
-    sw->ml = cfg->mode == LSW_LEARN ? mac_learning_create() : NULL;
+    sw->ml = (cfg->mode == LSW_LEARN
+              ? mac_learning_create(MAC_ENTRY_DEFAULT_IDLE_TIME)
+              : NULL);
     sw->action_normal = cfg->mode == LSW_NORMAL;
 
     flow_wildcards_init_exact(&sw->wc);
diff --git a/lib/mac-learning.c b/lib/mac-learning.c
index b7320e8..5efa44d 100644
--- a/lib/mac-learning.c
+++ b/lib/mac-learning.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2012 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,12 +36,12 @@ VLOG_DEFINE_THIS_MODULE(mac_learning);
 COVERAGE_DEFINE(mac_learning_learned);
 COVERAGE_DEFINE(mac_learning_expired);
 
-/* Returns the number of seconds since 'e' was last learned. */
+/* Returns the number of seconds since 'e' (within 'ml') was last learned. */
 int
-mac_entry_age(const struct mac_entry *e)
+mac_entry_age(const struct mac_learning *ml, const struct mac_entry *e)
 {
     time_t remaining = e->expires - time_now();
-    return MAC_ENTRY_IDLE_TIME - remaining;
+    return ml->idle_time - remaining;
 }
 
 static uint32_t
@@ -115,9 +115,18 @@ free_mac_entry(struct mac_learning *ml, struct mac_entry *e)
     list_push_front(&ml->free, &e->lru_node);
 }
 
-/* Creates and returns a new MAC learning table. */
+static unsigned int
+normalize_idle_time(unsigned int idle_time)
+{
+    return (idle_time < 15 ? 15
+            : idle_time > 3600 ? 3600
+            : idle_time);
+}
+
+/* Creates and returns a new MAC learning table with an initial MAC aging
+ * timeout of 'idle_time' seconds. */
 struct mac_learning *
-mac_learning_create(void)
+mac_learning_create(unsigned int idle_time)
 {
     struct mac_learning *ml;
     int i;
@@ -134,6 +143,7 @@ mac_learning_create(void)
     }
     ml->secret = random_uint32();
     ml->flood_vlans = NULL;
+    ml->idle_time = normalize_idle_time(idle_time);
     return ml;
 }
 
@@ -164,6 +174,23 @@ mac_learning_set_flood_vlans(struct mac_learning *ml, unsigned long *bitmap)
     return ret;
 }
 
+/* Changes the MAC agin timeout of 'ml' to 'idle_time' seconds. */
+void
+mac_learning_set_idle_time(struct mac_learning *ml, unsigned int idle_time)
+{
+    idle_time = normalize_idle_time(idle_time);
+    if (idle_time != ml->idle_time) {
+        struct mac_entry *e;
+        int delta;
+
+        delta = (int) idle_time - (int) ml->idle_time;
+        LIST_FOR_EACH (e, lru_node, &ml->lrus) {
+            e->expires += delta;
+        }
+        ml->idle_time = idle_time;
+    }
+}
+
 static bool
 is_learning_vlan(const struct mac_learning *ml, uint16_t vlan)
 {
@@ -222,7 +249,7 @@ mac_learning_learn(struct mac_learning *ml,
         /* Make the entry most-recently-used. */
         list_remove(&e->lru_node);
         list_push_back(&ml->lrus, &e->lru_node);
-        e->expires = time_now() + MAC_ENTRY_IDLE_TIME;
+        e->expires = time_now() + ml->idle_time;
         if (lock_type == GRAT_ARP_LOCK_SET) {
             e->grat_arp_lock = time_now() + MAC_GRAT_ARP_LOCK_TIME;
         }
diff --git a/lib/mac-learning.h b/lib/mac-learning.h
index 9c59fa0..9a5a52e 100644
--- a/lib/mac-learning.h
+++ b/lib/mac-learning.h
@@ -22,6 +22,8 @@
 #include "packets.h"
 #include "tag.h"
 
+struct mac_learning;
+
 #define MAC_HASH_BITS 10
 #define MAC_HASH_MASK (MAC_HASH_SIZE - 1)
 #define MAC_HASH_SIZE (1u << MAC_HASH_BITS)
@@ -29,7 +31,7 @@
 #define MAC_MAX 2048
 
 /* Time, in seconds, before expiring a mac_entry due to inactivity. */
-#define MAC_ENTRY_IDLE_TIME 300
+#define MAC_ENTRY_DEFAULT_IDLE_TIME 300
 
 /* Time, in seconds, to lock an entry updated by a gratuitous ARP to avoid
  * relearning based on a reflection from a bond slave. */
@@ -53,7 +55,7 @@ struct mac_entry {
     tag_type tag;               /* Tag for this learning entry. */
 };
 
-int mac_entry_age(const struct mac_entry *);
+int mac_entry_age(const struct mac_learning *, const struct mac_entry *);
 
 /* MAC learning table. */
 struct mac_learning {
@@ -64,12 +66,14 @@ struct mac_learning {
     struct mac_entry entries[MAC_MAX]; /* All entries. */
     uint32_t secret;            /* Secret for randomizing hash table. */
     unsigned long *flood_vlans; /* Bitmap of learning disabled VLANs. */
+    unsigned int idle_time;     /* Max age before deleting an entry. */
 };
 
-struct mac_learning *mac_learning_create(void);
+struct mac_learning *mac_learning_create(unsigned int idle_time);
 void mac_learning_destroy(struct mac_learning *);
 bool mac_learning_set_flood_vlans(struct mac_learning *,
                                   unsigned long *bitmap);
+void mac_learning_set_idle_time(struct mac_learning *, unsigned int idle_time);
 tag_type mac_learning_learn(struct mac_learning *,
                             const uint8_t src[ETH_ADDR_LEN], uint16_t vlan,
                             uint16_t src_port, enum grat_arp_lock_type
diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 9bcef2c..37e2ad9 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2009, 2010, 2011, 2012 Nicira Networks.
  * Copyright (c) 2010 Jean Tourrilhes - HP-Labs.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -515,7 +515,7 @@ ofproto_create(const char *datapath, const char *datapath_type,
     } else {
         p->ofhooks = &default_ofhooks;
         p->aux = p;
-        p->ml = mac_learning_create();
+        p->ml = mac_learning_create(MAC_ENTRY_DEFAULT_IDLE_TIME);
     }
 
     /* Pick final datapath ID. */
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index fb2ad83..b2303d0 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -1584,7 +1584,8 @@ bridge_unixctl_fdb_show(struct unixctl_conn *conn,
         }
         ds_put_format(&ds, "%5d  %4d  "ETH_ADDR_FMT"  %3d\n",
                       br->ports[e->port]->ifaces[0]->dp_ifidx,
-                      e->vlan, ETH_ADDR_ARGS(e->mac), mac_entry_age(e));
+                      e->vlan, ETH_ADDR_ARGS(e->mac),
+                      mac_entry_age(br->ml, e));
     }
     unixctl_command_reply(conn, 200, ds_cstr(&ds));
     ds_destroy(&ds);
@@ -1714,7 +1715,7 @@ bridge_create(const struct ovsrec_bridge *br_cfg)
 
     br->name = xstrdup(br_cfg->name);
     br->cfg = br_cfg;
-    br->ml = mac_learning_create();
+    br->ml = mac_learning_create(MAC_ENTRY_DEFAULT_IDLE_TIME);
     eth_addr_nicira_random(br->default_ea);
 
     hmap_init(&br->ifaces);
@@ -1867,6 +1868,8 @@ bridge_reconfigure_one(struct bridge *br)
     struct svec snoops, old_snoops;
     struct shash_node *node;
     enum ofproto_fail_mode fail_mode;
+    const char *idle_time_str;
+    int idle_time;
     size_t i;
 
     /* Collect old ports. */
@@ -1946,6 +1949,13 @@ bridge_reconfigure_one(struct bridge *br)
     }
     ofproto_set_fail_mode(br->ofproto, fail_mode);
 
+    /* Set the MAC learning aging timeout. */
+    idle_time_str = bridge_get_other_config(br->cfg, "mac-aging-time");
+    idle_time = (idle_time_str && atoi(idle_time_str)
+                 ? atoi(idle_time_str)
+                 : MAC_ENTRY_DEFAULT_IDLE_TIME);
+    mac_learning_set_idle_time(br->ml, idle_time);
+
     /* Delete all flows if we're switching from connected to standalone or vice
      * versa.  (XXX Should we delete all flows if we are switching from one
      * controller to another?) */
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 2f77669..c574434 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -437,6 +437,12 @@
             does not have QoS configured, or if the port does not have a queue
             with the specified ID, the default queue is used instead.
           </dd>
+          <dt><code>mac-aging-time</code></dt>
+          <dd>
+            A positive integer specifying the maximum number of seconds to
+            retain a MAC learning entry for which no packets have been seen.
+            The default is currently 300 seconds (5 minutes).
+          </dd>
         </dl>
       </column>
     </group>
-- 
1.7.2.5




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