X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-core%2Fcache.c;h=c0745795a5d51adc400ce31b5d14c5b4914600e0;hb=908e491f7d55209acfbb2595ab1ef5b24502d641;hp=0307b8e58cf18f877af45d2440f046f2aba3d293;hpb=c58379bde376cb2298fca14f83a86626f1b76f2f;p=catta

diff --git a/avahi-core/cache.c b/avahi-core/cache.c
index 0307b8e..c074579 100644
--- a/avahi-core/cache.c
+++ b/avahi-core/cache.c
@@ -1,18 +1,16 @@
-/* $Id$ */
-
 /***
   This file is part of avahi.
- 
+
   avahi is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.
- 
+
   avahi is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
   Public License for more details.
- 
+
   You should have received a copy of the GNU Lesser General Public
   License along with avahi; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
@@ -24,97 +22,121 @@
 #endif
 
 #include <string.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include <avahi-common/timeval.h>
+#include <avahi-common/malloc.h>
 
-#include "util.h"
 #include "cache.h"
+#include "log.h"
+#include "rr-util.h"
+
+#define AVAHI_CACHE_ENTRIES_MAX 500
 
 static void remove_entry(AvahiCache *c, AvahiCacheEntry *e) {
     AvahiCacheEntry *t;
 
-    g_assert(c);
-    g_assert(e);
+    assert(c);
+    assert(e);
 
-/*     g_message("removing from cache: %p %p", c, e); */
+/*     avahi_log_debug("removing from cache: %p %p", c, e); */
 
     /* Remove from hash table */
-    t = g_hash_table_lookup(c->hash_table, e->record->key);
+    t = avahi_hashmap_lookup(c->hashmap, e->record->key);
     AVAHI_LLIST_REMOVE(AvahiCacheEntry, by_key, t, e);
     if (t)
-        g_hash_table_replace(c->hash_table, t->record->key, t);
+        avahi_hashmap_replace(c->hashmap, t->record->key, t);
     else
-        g_hash_table_remove(c->hash_table, e->record->key);
+        avahi_hashmap_remove(c->hashmap, e->record->key);
 
     /* Remove from linked list */
     AVAHI_LLIST_REMOVE(AvahiCacheEntry, entry, c->entries, e);
-        
+
     if (e->time_event)
-        avahi_time_event_queue_remove(c->server->time_event_queue, e->time_event);
+        avahi_time_event_free(e->time_event);
 
-    avahi_subscription_notify(c->server, c->interface, e->record, AVAHI_SUBSCRIPTION_REMOVE);
+    avahi_multicast_lookup_engine_notify(c->server->multicast_lookup_engine, c->interface, e->record, AVAHI_BROWSER_REMOVE);
 
     avahi_record_unref(e->record);
-    
-    g_free(e);
+
+    avahi_free(e);
+
+    assert(c->n_entries >= 1);
+    --c->n_entries;
 }
 
 AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *iface) {
     AvahiCache *c;
-    g_assert(server);
+    assert(server);
+
+    if (!(c = avahi_new(AvahiCache, 1))) {
+        avahi_log_error(__FILE__": Out of memory.");
+        return NULL; /* OOM */
+    }
 
-    c = g_new(AvahiCache, 1);
     c->server = server;
     c->interface = iface;
-    c->hash_table = g_hash_table_new((GHashFunc) avahi_key_hash, (GEqualFunc) avahi_key_equal);
+
+    if (!(c->hashmap = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL))) {
+        avahi_log_error(__FILE__": Out of memory.");
+        avahi_free(c);
+        return NULL; /* OOM */
+    }
 
     AVAHI_LLIST_HEAD_INIT(AvahiCacheEntry, c->entries);
-    
+    c->n_entries = 0;
+
+    c->last_rand_timestamp = 0;
+
     return c;
 }
 
 void avahi_cache_free(AvahiCache *c) {
-    g_assert(c);
+    assert(c);
 
     while (c->entries)
         remove_entry(c, c->entries);
-    
-    g_hash_table_destroy(c->hash_table);
-    
-    g_free(c);
+    assert(c->n_entries == 0);
+
+    avahi_hashmap_free(c->hashmap);
+
+    avahi_free(c);
 }
 
-AvahiCacheEntry *avahi_cache_lookup_key(AvahiCache *c, AvahiKey *k) {
-    g_assert(c);
-    g_assert(k);
+static AvahiCacheEntry *lookup_key(AvahiCache *c, AvahiKey *k) {
+    assert(c);
+    assert(k);
+
+    assert(!avahi_key_is_pattern(k));
 
-    g_assert(!avahi_key_is_pattern(k));
-    
-    return g_hash_table_lookup(c->hash_table, k);
+    return avahi_hashmap_lookup(c->hashmap, k);
 }
 
-gpointer avahi_cache_walk(AvahiCache *c, AvahiKey *pattern, AvahiCacheWalkCallback cb, gpointer userdata) {
-    gpointer ret;
-    
-    g_assert(c);
-    g_assert(pattern);
-    g_assert(cb);
-    
+void* avahi_cache_walk(AvahiCache *c, AvahiKey *pattern, AvahiCacheWalkCallback cb, void* userdata) {
+    void* ret;
+
+    assert(c);
+    assert(pattern);
+    assert(cb);
+
     if (avahi_key_is_pattern(pattern)) {
         AvahiCacheEntry *e, *n;
-        
+
         for (e = c->entries; e; e = n) {
             n = e->entry_next;
-            
+
             if (avahi_key_pattern_match(pattern, e->record->key))
                 if ((ret = cb(c, pattern, e, userdata)))
                     return ret;
         }
-        
+
     } else {
         AvahiCacheEntry *e, *n;
 
-        for (e = avahi_cache_lookup_key(c, pattern); e; e = n) {
+        for (e = lookup_key(c, pattern); e; e = n) {
             n = e->by_key_next;
-                
+
             if ((ret = cb(c, pattern, e, userdata)))
                 return ret;
         }
@@ -123,10 +145,10 @@ gpointer avahi_cache_walk(AvahiCache *c, AvahiKey *pattern, AvahiCacheWalkCallba
     return NULL;
 }
 
-static gpointer lookup_record_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, void *userdata) {
-    g_assert(c);
-    g_assert(pattern);
-    g_assert(e);
+static void* lookup_record_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, void *userdata) {
+    assert(c);
+    assert(pattern);
+    assert(e);
 
     if (avahi_record_equal_no_ttl(e->record, userdata))
         return e;
@@ -134,239 +156,363 @@ static gpointer lookup_record_callback(AvahiCache *c, AvahiKey *pattern, AvahiCa
     return NULL;
 }
 
-AvahiCacheEntry *avahi_cache_lookup_record(AvahiCache *c, AvahiRecord *r) {
-    g_assert(c);
-    g_assert(r);
+static AvahiCacheEntry *lookup_record(AvahiCache *c, AvahiRecord *r) {
+    assert(c);
+    assert(r);
 
     return avahi_cache_walk(c, r->key, lookup_record_callback, r);
 }
 
-static void next_expiry(AvahiCache *c, AvahiCacheEntry *e, guint percent);
+static void next_expiry(AvahiCache *c, AvahiCacheEntry *e, unsigned percent);
 
 static void elapse_func(AvahiTimeEvent *t, void *userdata) {
     AvahiCacheEntry *e = userdata;
-    
-    g_assert(t);
-    g_assert(e);
-
-    if (e->state == AVAHI_CACHE_FINAL) {
-        remove_entry(e->cache, e);
-        g_message("Removing entry from cache due to expiration");
-    } else {
-        guint percent = 0;
-    
-        switch (e->state) {
-            case AVAHI_CACHE_VALID:
-                e->state = AVAHI_CACHE_EXPIRY1;
-                percent = 85;
-                break;
-                
-            case AVAHI_CACHE_EXPIRY1:
-                e->state = AVAHI_CACHE_EXPIRY2;
-                percent = 90;
-                break;
-            case AVAHI_CACHE_EXPIRY2:
-                e->state = AVAHI_CACHE_EXPIRY3;
-                percent = 95;
-                break;
-                
-            case AVAHI_CACHE_EXPIRY3:
-                e->state = AVAHI_CACHE_FINAL;
-                percent = 100;
-                break;
-
-            default:
-                ;
-        }
+/*     char *txt; */
+    unsigned percent = 0;
+
+    assert(t);
+    assert(e);
+
+/*     txt = avahi_record_to_string(e->record); */
+
+    switch (e->state) {
+
+        case AVAHI_CACHE_EXPIRY_FINAL:
+        case AVAHI_CACHE_POOF_FINAL:
+        case AVAHI_CACHE_GOODBYE_FINAL:
+        case AVAHI_CACHE_REPLACE_FINAL:
+
+            remove_entry(e->cache, e);
+
+            e = NULL;
+/*         avahi_log_debug("Removing entry from cache due to expiration (%s)", txt); */
+            break;
+
+        case AVAHI_CACHE_VALID:
+        case AVAHI_CACHE_POOF:
+            e->state = AVAHI_CACHE_EXPIRY1;
+            percent = 85;
+            break;
+
+        case AVAHI_CACHE_EXPIRY1:
+            e->state = AVAHI_CACHE_EXPIRY2;
+            percent = 90;
+            break;
+        case AVAHI_CACHE_EXPIRY2:
+            e->state = AVAHI_CACHE_EXPIRY3;
+            percent = 95;
+            break;
+
+        case AVAHI_CACHE_EXPIRY3:
+            e->state = AVAHI_CACHE_EXPIRY_FINAL;
+            percent = 100;
+            break;
+    }
 
-        g_assert(percent > 0);
+    if (e) {
 
-        g_message("Requesting cache entry update at %i%%.", percent);
+        assert(percent > 0);
 
-        /* Request a cache update, if we are subscribed to this entry */
-        if (avahi_is_subscribed(e->cache->server, e->record->key))
-            avahi_interface_post_query(e->cache->interface, e->record->key, TRUE);
+        /* Request a cache update if we are subscribed to this entry */
+        if (avahi_querier_shall_refresh_cache(e->cache->interface, e->record->key))
+            avahi_interface_post_query(e->cache->interface, e->record->key, 0, NULL);
 
         /* Check again later */
         next_expiry(e->cache, e, percent);
+
     }
+
+/*     avahi_free(txt); */
 }
 
 static void update_time_event(AvahiCache *c, AvahiCacheEntry *e) {
-    g_assert(c);
-    g_assert(e);
-    
+    assert(c);
+    assert(e);
+
     if (e->time_event)
-        avahi_time_event_queue_update(c->server->time_event_queue, e->time_event, &e->expiry);
+        avahi_time_event_update(e->time_event, &e->expiry);
     else
-        e->time_event = avahi_time_event_queue_add(c->server->time_event_queue, &e->expiry, elapse_func, e);
+        e->time_event = avahi_time_event_new(c->server->time_event_queue, &e->expiry, elapse_func, e);
 }
 
-static void next_expiry(AvahiCache *c, AvahiCacheEntry *e, guint percent) {
-    gulong usec;
+static void next_expiry(AvahiCache *c, AvahiCacheEntry *e, unsigned percent) {
+    AvahiUsec usec, left, right;
+    time_t now;
+
+    assert(c);
+    assert(e);
+    assert(percent > 0 && percent <= 100);
+
+    usec = (AvahiUsec) e->record->ttl * 10000;
+
+    left = usec * percent;
+    right = usec * (percent+2); /* 2% jitter */
+
+    now = time(NULL);
 
-    g_assert(c);
-    g_assert(e);
-    g_assert(percent > 0 && percent <= 100);
+    if (now >= c->last_rand_timestamp + 10) {
+        c->last_rand = rand();
+        c->last_rand_timestamp = now;
+    }
+
+    usec = left + (AvahiUsec) ((double) (right-left) * c->last_rand / (RAND_MAX+1.0));
 
     e->expiry = e->timestamp;
+    avahi_timeval_add(&e->expiry, usec);
 
-    usec = e->record->ttl * 10000;
+/*     g_message("wake up in +%lu seconds", e->expiry.tv_sec - e->timestamp.tv_sec); */
 
-    /* 2% jitter */
-    usec = g_random_int_range(usec*percent, usec*(percent+2));
-    
-    g_time_val_add(&e->expiry, usec);
     update_time_event(c, e);
 }
 
-void avahi_cache_update(AvahiCache *c, AvahiRecord *r, gboolean unique, const AvahiAddress *a) {
-    AvahiCacheEntry *e, *t;
-    gchar *txt;
-    
-    g_assert(c);
-    g_assert(r && r->ref >= 1);
+static void expire_in_one_second(AvahiCache *c, AvahiCacheEntry *e, AvahiCacheEntryState state) {
+    assert(c);
+    assert(e);
 
-    g_message("cache update: %s", (txt = avahi_record_to_string(r)));
-    g_free(txt);
+    e->state = state;
+    gettimeofday(&e->expiry, NULL);
+    avahi_timeval_add(&e->expiry, 1000000); /* 1s */
+    update_time_event(c, e);
+}
 
-    if (r->ttl == 0) {
+void avahi_cache_update(AvahiCache *c, AvahiRecord *r, int cache_flush, const AvahiAddress *a) {
+/*     char *txt; */
+
+    assert(c);
+    assert(r && r->ref >= 1);
+
+/*     txt = avahi_record_to_string(r); */
 
+    if (r->ttl == 0) {
         /* This is a goodbye request */
 
-        if ((e = avahi_cache_lookup_record(c, r))) {
+        AvahiCacheEntry *e;
 
-            e->state = AVAHI_CACHE_FINAL;
-            g_get_current_time(&e->timestamp);
-            e->expiry = e->timestamp;
-            g_time_val_add(&e->expiry, 1000000); /* 1s */
-            update_time_event(c, e);
-        }
+        if ((e = lookup_record(c, r)))
+            expire_in_one_second(c, e, AVAHI_CACHE_GOODBYE_FINAL);
 
     } else {
+        AvahiCacheEntry *e = NULL, *first;
+        struct timeval now;
+
+        gettimeofday(&now, NULL);
 
         /* This is an update request */
 
-        if ((t = e = avahi_cache_lookup_key(c, r->key))) {
-        
-            if (unique) {
-                
-                /* For unique records, remove all entries but one */
-                while (e->by_key_next)
-                    remove_entry(c, e->by_key_next);
-                
-            } else {
-                
-                /* For non-unique record, look for exactly the same entry */
-                for (; e; e = e->by_key_next)
-                    if (avahi_record_equal_no_ttl(e->record, r))
-                        break;
+        if ((first = lookup_key(c, r->key))) {
+
+            if (cache_flush) {
+
+                /* For unique entries drop all entries older than one second */
+                for (e = first; e; e = e->by_key_next) {
+                    AvahiUsec t;
+
+                    t = avahi_timeval_diff(&now, &e->timestamp);
+
+                    if (t > 1000000)
+                        expire_in_one_second(c, e, AVAHI_CACHE_REPLACE_FINAL);
+                }
             }
+
+            /* Look for exactly the same entry */
+            for (e = first; e; e = e->by_key_next)
+                if (avahi_record_equal_no_ttl(e->record, r))
+                    break;
         }
-    
+
         if (e) {
-            
-/*         g_message("found matching cache entry"); */
-            
-            /* We are the first in the linked list so let's replace the hash table key with the new one */
+
+/*             avahi_log_debug("found matching cache entry");  */
+
+            /* We need to update the hash table key if we replace the
+             * record */
             if (e->by_key_prev == NULL)
-                g_hash_table_replace(c->hash_table, r->key, e);
-            
-            /* Notify subscribers */
-            if (!avahi_record_equal_no_ttl(e->record, r))
-                avahi_subscription_notify(c->server, c->interface, r, AVAHI_SUBSCRIPTION_CHANGE);    
-            
+                avahi_hashmap_replace(c->hashmap, r->key, e);
+
             /* Update the record */
             avahi_record_unref(e->record);
             e->record = avahi_record_ref(r);
-            
+
+/*             avahi_log_debug("cache: updating %s", txt);   */
+
         } else {
             /* No entry found, therefore we create a new one */
-            
-/*         g_message("couldn't find matching cache entry"); */
-            
-            e = g_new(AvahiCacheEntry, 1);
+
+/*             avahi_log_debug("cache: couldn't find matching cache entry for %s", txt);   */
+
+            if (c->n_entries >= AVAHI_CACHE_ENTRIES_MAX)
+                return;
+
+            if (!(e = avahi_new(AvahiCacheEntry, 1))) {
+                avahi_log_error(__FILE__": Out of memory");
+                return;
+            }
+
             e->cache = c;
             e->time_event = NULL;
             e->record = avahi_record_ref(r);
 
             /* Append to hash table */
-            AVAHI_LLIST_PREPEND(AvahiCacheEntry, by_key, t, e);
-            g_hash_table_replace(c->hash_table, e->record->key, t);
+            AVAHI_LLIST_PREPEND(AvahiCacheEntry, by_key, first, e);
+            avahi_hashmap_replace(c->hashmap, e->record->key, first);
 
             /* Append to linked list */
             AVAHI_LLIST_PREPEND(AvahiCacheEntry, entry, c->entries, e);
 
+            c->n_entries++;
+
             /* Notify subscribers */
-            avahi_subscription_notify(c->server, c->interface, e->record, AVAHI_SUBSCRIPTION_NEW);
-        } 
-        
+            avahi_multicast_lookup_engine_notify(c->server->multicast_lookup_engine, c->interface, e->record, AVAHI_BROWSER_NEW);
+        }
+
         e->origin = *a;
-        g_get_current_time(&e->timestamp);
+        e->timestamp = now;
         next_expiry(c, e, 80);
         e->state = AVAHI_CACHE_VALID;
+        e->cache_flush = cache_flush;
     }
+
+/*     avahi_free(txt);  */
 }
 
-static gpointer drop_key_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, gpointer userdata) {
-    g_assert(c);
-    g_assert(pattern);
-    g_assert(e);
+struct dump_data {
+    AvahiDumpCallback callback;
+    void* userdata;
+};
 
-    remove_entry(c, e);
-    return NULL;
+static void dump_callback(void* key, void* data, void* userdata) {
+    AvahiCacheEntry *e = data;
+    AvahiKey *k = key;
+    struct dump_data *dump_data = userdata;
+
+    assert(k);
+    assert(e);
+    assert(data);
+
+    for (; e; e = e->by_key_next) {
+        char *t;
+
+        if (!(t = avahi_record_to_string(e->record)))
+            continue; /* OOM */
+
+        dump_data->callback(t, dump_data->userdata);
+        avahi_free(t);
+    }
 }
 
-void avahi_cache_drop_key(AvahiCache *c, AvahiKey *k) {
-    g_assert(c);
-    g_assert(k);
+int avahi_cache_dump(AvahiCache *c, AvahiDumpCallback callback, void* userdata) {
+    struct dump_data data;
+
+    assert(c);
+    assert(callback);
+
+    callback(";;; CACHE DUMP FOLLOWS ;;;", userdata);
+
+    data.callback = callback;
+    data.userdata = userdata;
 
-    avahi_cache_walk(c, k, drop_key_callback, NULL);
+    avahi_hashmap_foreach(c->hashmap, dump_callback, &data);
+
+    return 0;
 }
 
-void avahi_cache_drop_record(AvahiCache *c, AvahiRecord *r) {
-    AvahiCacheEntry *e;
-    
-    g_assert(c);
-    g_assert(r);
+int avahi_cache_entry_half_ttl(AvahiCache *c, AvahiCacheEntry *e) {
+    struct timeval now;
+    unsigned age;
+
+    assert(c);
+    assert(e);
+
+    gettimeofday(&now, NULL);
+
+    age = (unsigned) (avahi_timeval_diff(&now, &e->timestamp)/1000000);
+
+/*     avahi_log_debug("age: %lli, ttl/2: %u", age, e->record->ttl);  */
+
+    return age >= e->record->ttl/2;
+}
 
-    if ((e = avahi_cache_lookup_record(c, r))) 
-        remove_entry(c, e);
+void avahi_cache_flush(AvahiCache *c) {
+    assert(c);
+
+    while (c->entries)
+        remove_entry(c, c->entries);
 }
 
-static void func(gpointer key, gpointer data, gpointer userdata) {
-    AvahiCacheEntry *e = data;
-    AvahiKey *k = key;
-    gchar *t;
-
-    g_assert(k);
-    g_assert(e);
-    
-    t = avahi_record_to_string(e->record);
-    fprintf((FILE*) userdata, "%s\n", t);
-    g_free(t);
+/*** Passive observation of failure ***/
+
+static void* start_poof_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, void *userdata) {
+    AvahiAddress *a = userdata;
+    struct timeval now;
+
+    assert(c);
+    assert(pattern);
+    assert(e);
+    assert(a);
+
+    gettimeofday(&now, NULL);
+
+    switch (e->state) {
+        case AVAHI_CACHE_VALID:
+
+            /* The entry was perfectly valid till, now, so let's enter
+             * POOF mode */
+
+            e->state = AVAHI_CACHE_POOF;
+            e->poof_address = *a;
+            e->poof_timestamp = now;
+            e->poof_num = 0;
+
+            break;
+
+        case AVAHI_CACHE_POOF:
+            if (avahi_timeval_diff(&now, &e->poof_timestamp) < 1000000)
+              break;
+
+            e->poof_timestamp = now;
+            e->poof_address = *a;
+            e->poof_num ++;
+
+            /* This is the 4th time we got no response, so let's
+             * fucking remove this entry. */
+            if (e->poof_num > 3)
+              expire_in_one_second(c, e, AVAHI_CACHE_POOF_FINAL);
+            break;
+
+        default:
+            ;
+    }
+
+    return NULL;
 }
 
-void avahi_cache_dump(AvahiCache *c, FILE *f) {
-    g_assert(c);
-    g_assert(f);
+void avahi_cache_start_poof(AvahiCache *c, AvahiKey *key, const AvahiAddress *a) {
+    assert(c);
+    assert(key);
 
-    fprintf(f, ";;; CACHE DUMP FOLLOWS ;;;\n");
-    g_hash_table_foreach(c->hash_table, func, f);
+    avahi_cache_walk(c, key, start_poof_callback, (void*) a);
 }
 
-gboolean avahi_cache_entry_half_ttl(AvahiCache *c, AvahiCacheEntry *e) {
-    GTimeVal now;
-    guint age;
-    
-    g_assert(c);
-    g_assert(e);
+void avahi_cache_stop_poof(AvahiCache *c, AvahiRecord *record, const AvahiAddress *a) {
+    AvahiCacheEntry *e;
 
-    g_get_current_time(&now);
+    assert(c);
+    assert(record);
+    assert(a);
 
-    age = avahi_timeval_diff(&now, &e->timestamp)/1000000;
+    if (!(e = lookup_record(c, record)))
+        return;
 
-    g_message("age: %u, ttl/2: %u", age, e->record->ttl);
-    
-    return age >= e->record->ttl/2;
+    /* This function is called for each response suppression
+       record. If the matching cache entry is in POOF state and the
+       query address is the same, we put it back into valid mode */
+
+    if (e->state == AVAHI_CACHE_POOF || e->state == AVAHI_CACHE_POOF_FINAL)
+        if (avahi_address_cmp(a, &e->poof_address) == 0) {
+            e->state = AVAHI_CACHE_VALID;
+            next_expiry(c, e, 80);
+        }
 }
+
+
+