X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fmac-learning.c;h=7dcce4154fe06306b71580260d782d17c6b0c67c;hb=HEAD;hp=f9f4db3d4bfbd2e9a2846c5d5a4861a70ebf6496;hpb=8e2e7a5d54779ac8ee880fdef612c6eaa9ce5667;p=sliver-openvswitch.git

diff --git a/lib/mac-learning.c b/lib/mac-learning.c
index f9f4db3d4..7dcce4154 100644
--- a/lib/mac-learning.c
+++ b/lib/mac-learning.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,6 @@
 #include <config.h>
 #include "mac-learning.h"
 
-#include <assert.h>
 #include <inttypes.h>
 #include <stdlib.h>
 
@@ -26,29 +25,27 @@
 #include "hash.h"
 #include "list.h"
 #include "poll-loop.h"
-#include "tag.h"
 #include "timeval.h"
+#include "unaligned.h"
 #include "util.h"
 #include "vlan-bitmap.h"
-#include "vlog.h"
-
-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
-mac_table_hash(const uint8_t mac[ETH_ADDR_LEN], uint16_t vlan)
+mac_table_hash(const struct mac_learning *ml, const uint8_t mac[ETH_ADDR_LEN],
+               uint16_t vlan)
 {
-    return hash_bytes(mac, ETH_ADDR_LEN, vlan);
+    return hash_mac(mac, vlan, ml->secret);
 }
 
 static struct mac_entry *
@@ -57,34 +54,15 @@ mac_entry_from_lru_node(struct list *list)
     return CONTAINER_OF(list, struct mac_entry, lru_node);
 }
 
-/* Returns a tag that represents that 'mac' is on an unknown port in 'vlan'.
- * (When we learn where 'mac' is in 'vlan', this allows flows that were
- * flooded to be revalidated.) */
-static tag_type
-make_unknown_mac_tag(const struct mac_learning *ml,
-                     const uint8_t mac[ETH_ADDR_LEN], uint16_t vlan)
-{
-    uint32_t h = hash_int(ml->secret, mac_table_hash(mac, vlan));
-    return tag_create_deterministic(h);
-}
-
-static struct list *
-mac_table_bucket(const struct mac_learning *ml,
-                 const uint8_t mac[ETH_ADDR_LEN],
-                 uint16_t vlan)
-{
-    uint32_t hash = mac_table_hash(mac, vlan);
-    const struct list *list = &ml->table[hash & MAC_HASH_BITS];
-    return (struct list *) list;
-}
-
 static struct mac_entry *
-search_bucket(struct list *bucket, const uint8_t mac[ETH_ADDR_LEN],
-              uint16_t vlan)
+mac_entry_lookup(const struct mac_learning *ml,
+                 const uint8_t mac[ETH_ADDR_LEN], uint16_t vlan)
 {
     struct mac_entry *e;
-    LIST_FOR_EACH (e, hash_node, bucket) {
-        if (eth_addr_equals(e->mac, mac) && e->vlan == vlan) {
+
+    HMAP_FOR_EACH_WITH_HASH (e, hmap_node, mac_table_hash(ml, mac, vlan),
+                             &ml->table) {
+        if (e->vlan == vlan && eth_addr_equals(e->mac, mac)) {
             return e;
         }
     }
@@ -96,6 +74,7 @@ search_bucket(struct list *bucket, const uint8_t mac[ETH_ADDR_LEN],
  * and return false. */
 static bool
 get_lru(struct mac_learning *ml, struct mac_entry **e)
+    OVS_REQ_RDLOCK(ml->rwlock)
 {
     if (!list_is_empty(&ml->lrus)) {
         *e = mac_entry_from_lru_node(ml->lrus.next);
@@ -106,34 +85,60 @@ get_lru(struct mac_learning *ml, struct mac_entry **e)
     }
 }
 
-/* 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 and an initial maximum of MAC_DEFAULT_MAX
+ * entries. */
 struct mac_learning *
-mac_learning_create(void)
+mac_learning_create(unsigned int idle_time)
 {
     struct mac_learning *ml;
-    int i;
 
     ml = xmalloc(sizeof *ml);
     list_init(&ml->lrus);
-    list_init(&ml->free);
-    for (i = 0; i < MAC_HASH_SIZE; i++) {
-        list_init(&ml->table[i]);
-    }
-    for (i = 0; i < MAC_MAX; i++) {
-        struct mac_entry *s = &ml->entries[i];
-        list_push_front(&ml->free, &s->lru_node);
-    }
+    hmap_init(&ml->table);
     ml->secret = random_uint32();
     ml->flood_vlans = NULL;
+    ml->idle_time = normalize_idle_time(idle_time);
+    ml->max_entries = MAC_DEFAULT_MAX;
+    ml->need_revalidate = false;
+    ovs_refcount_init(&ml->ref_cnt);
+    ovs_rwlock_init(&ml->rwlock);
     return ml;
 }
 
-/* Destroys MAC learning table 'ml'. */
-void
-mac_learning_destroy(struct mac_learning *ml)
+struct mac_learning *
+mac_learning_ref(const struct mac_learning *ml_)
 {
+    struct mac_learning *ml = CONST_CAST(struct mac_learning *, ml_);
     if (ml) {
+        ovs_refcount_ref(&ml->ref_cnt);
+    }
+    return ml;
+}
+
+/* Unreferences (and possibly destroys) MAC learning table 'ml'. */
+void
+mac_learning_unref(struct mac_learning *ml)
+{
+    if (ml && ovs_refcount_unref(&ml->ref_cnt) == 1) {
+        struct mac_entry *e, *next;
+
+        HMAP_FOR_EACH_SAFE (e, next, hmap_node, &ml->table) {
+            hmap_remove(&ml->table, &e->hmap_node);
+            free(e);
+        }
+        hmap_destroy(&ml->table);
+
         bitmap_free(ml->flood_vlans);
+        ovs_rwlock_destroy(&ml->rwlock);
         free(ml);
     }
 }
@@ -154,10 +159,37 @@ mac_learning_set_flood_vlans(struct mac_learning *ml,
     }
 }
 
+/* Changes the MAC aging 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;
+    }
+}
+
+/* Sets the maximum number of entries in 'ml' to 'max_entries', adjusting it
+ * to be within a reasonable range. */
+void
+mac_learning_set_max_entries(struct mac_learning *ml, size_t max_entries)
+{
+    ml->max_entries = (max_entries < 10 ? 10
+                       : max_entries > 1000 * 1000 ? 1000 * 1000
+                       : max_entries);
+}
+
 static bool
 is_learning_vlan(const struct mac_learning *ml, uint16_t vlan)
 {
-    return vlan_bitmap_contains(ml->flood_vlans, vlan);
+    return !ml->flood_vlans || !bitmap_is_set(ml->flood_vlans, vlan);
 }
 
 /* Returns true if 'src_mac' may be learned on 'vlan' for 'ml'.
@@ -185,48 +217,46 @@ mac_learning_insert(struct mac_learning *ml,
                     const uint8_t src_mac[ETH_ADDR_LEN], uint16_t vlan)
 {
     struct mac_entry *e;
-    struct list *bucket;
 
-    bucket = mac_table_bucket(ml, src_mac, vlan);
-    e = search_bucket(bucket, src_mac, vlan);
+    e = mac_entry_lookup(ml, src_mac, vlan);
     if (!e) {
-        if (!list_is_empty(&ml->free)) {
-            e = mac_entry_from_lru_node(ml->free.next);
-        } else {
-            e = mac_entry_from_lru_node(ml->lrus.next);
-            list_remove(&e->hash_node);
+        uint32_t hash = mac_table_hash(ml, src_mac, vlan);
+
+        if (hmap_count(&ml->table) >= ml->max_entries) {
+            get_lru(ml, &e);
+            mac_learning_expire(ml, e);
         }
-        list_push_front(bucket, &e->hash_node);
+
+        e = xmalloc(sizeof *e);
+        hmap_insert(&ml->table, &e->hmap_node, hash);
         memcpy(e->mac, src_mac, ETH_ADDR_LEN);
         e->vlan = vlan;
-        e->tag = 0;
         e->grat_arp_lock = TIME_MIN;
+        e->port.p = NULL;
+    } else {
+        list_remove(&e->lru_node);
     }
 
     /* Mark 'e' as 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;
 
     return e;
 }
 
-/* Changes 'e''s tag to a new, randomly selected one, and returns the tag that
- * would have been previously used for this entry's MAC and VLAN (either before
- * 'e' was inserted, if it is new, or otherwise before its port was updated.)
+/* Changes 'e''s tag to a new, randomly selected one.  Causes
+ * mac_learning_run() to flag for revalidation the tag that would have been
+ * previously used for this entry's MAC and VLAN (either before 'e' was
+ * inserted, if it is new, or otherwise before its port was updated.)
  *
  * The client should call this function after obtaining a MAC learning entry
  * from mac_learning_insert(), if the entry is either new or if its learned
  * port has changed. */
-tag_type
-mac_learning_changed(struct mac_learning *ml, struct mac_entry *e)
+void
+mac_learning_changed(struct mac_learning *ml)
 {
-    tag_type old_tag = e->tag;
-
     COVERAGE_INC(mac_learning_learned);
-
-    e->tag = tag_create_random();
-    return old_tag ? old_tag : make_unknown_mac_tag(ml, e->mac, e->vlan);
+    ml->need_revalidate = true;
 }
 
 /* Looks up MAC 'dst' for VLAN 'vlan' in 'ml' and returns the associated MAC
@@ -235,8 +265,7 @@ mac_learning_changed(struct mac_learning *ml, struct mac_entry *e)
  * '*tag'. */
 struct mac_entry *
 mac_learning_lookup(const struct mac_learning *ml,
-                    const uint8_t dst[ETH_ADDR_LEN], uint16_t vlan,
-                    tag_type *tag)
+                    const uint8_t dst[ETH_ADDR_LEN], uint16_t vlan)
 {
     if (eth_addr_is_multicast(dst)) {
         /* No tag because the treatment of multicast destinations never
@@ -247,56 +276,65 @@ mac_learning_lookup(const struct mac_learning *ml,
          * rarely that we revalidate every flow when it changes. */
         return NULL;
     } else {
-        struct mac_entry *e = search_bucket(mac_table_bucket(ml, dst, vlan),
-                                            dst, vlan);
-        assert(e == NULL || e->tag != 0);
-        if (tag) {
-            /* Tag either the learned port or the lack thereof. */
-            *tag |= e ? e->tag : make_unknown_mac_tag(ml, dst, vlan);
-        }
+        struct mac_entry *e = mac_entry_lookup(ml, dst, vlan);
+
+        ovs_assert(e == NULL || e->port.p != NULL);
         return e;
     }
 }
 
-/* Expires 'e' from the 'ml' hash table.  'e' must not already be on the free
- * list. */
+/* Expires 'e' from the 'ml' hash table. */
 void
 mac_learning_expire(struct mac_learning *ml, struct mac_entry *e)
 {
-    list_remove(&e->hash_node);
+    hmap_remove(&ml->table, &e->hmap_node);
     list_remove(&e->lru_node);
-    list_push_front(&ml->free, &e->lru_node);
+    free(e);
 }
 
-/* Expires all the mac-learning entries in 'ml'.  The tags in 'ml' are
- * discarded, so the client is responsible for revalidating any flows that
- * depend on 'ml', if necessary. */
+/* Expires all the mac-learning entries in 'ml'.  If not NULL, the tags in 'ml'
+ * are added to 'tags'.  Otherwise the tags in 'ml' are discarded.  The client
+ * is responsible for revalidating any flows that depend on 'ml', if
+ * necessary. */
 void
 mac_learning_flush(struct mac_learning *ml)
 {
     struct mac_entry *e;
     while (get_lru(ml, &e)){
+        ml->need_revalidate = true;
         mac_learning_expire(ml, e);
     }
+    hmap_shrink(&ml->table);
 }
 
-void
-mac_learning_run(struct mac_learning *ml, struct tag_set *set)
+/* Does periodic work required by 'ml'.  Returns true if something changed that
+ * may require flow revalidation. */
+bool
+mac_learning_run(struct mac_learning *ml)
 {
+    bool need_revalidate;
     struct mac_entry *e;
-    while (get_lru(ml, &e) && time_now() >= e->expires) {
+
+    while (get_lru(ml, &e)
+           && (hmap_count(&ml->table) > ml->max_entries
+               || time_now() >= e->expires)) {
         COVERAGE_INC(mac_learning_expired);
-        if (set) {
-            tag_set_add(set, e->tag);
-        }
+        ml->need_revalidate = true;
         mac_learning_expire(ml, e);
     }
+
+    need_revalidate = ml->need_revalidate;
+    ml->need_revalidate = false;
+    return need_revalidate;
 }
 
 void
 mac_learning_wait(struct mac_learning *ml)
 {
-    if (!list_is_empty(&ml->lrus)) {
+    if (hmap_count(&ml->table) > ml->max_entries
+        || ml->need_revalidate) {
+        poll_immediate_wake();
+    } else if (!list_is_empty(&ml->lrus)) {
         struct mac_entry *e = mac_entry_from_lru_node(ml->lrus.next);
         poll_timer_wait_until(e->expires * 1000LL);
     }