-/* $Id$ */
-
/***
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
#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"
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);
- g_assert(!avahi_key_is_pattern(k));
-
- return g_hash_table_lookup(c->hash_table, k);
+ assert(!avahi_key_is_pattern(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;
}
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;
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);
+/* 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;
+ }
- 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:
- ;
- }
+ if (e) {
- g_assert(percent > 0);
+ assert(percent > 0);
- /* Request a cache update, if we are subscribed to this entry */
- if (avahi_is_subscribed(e->cache->server, e->record->key)) {
- g_message("Requesting cache entry update at %i%%.", percent);
- 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 >= c->server->config.n_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);
- avahi_cache_walk(c, k, drop_key_callback, NULL);
+ data.callback = callback;
+ data.userdata = userdata;
+
+ 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);
- if ((e = avahi_cache_lookup_record(c, r)))
- remove_entry(c, e);
+/* avahi_log_debug("age: %lli, ttl/2: %u", age, e->record->ttl); */
+
+ return age >= e->record->ttl/2;
}
-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);
+void avahi_cache_flush(AvahiCache *c) {
+ assert(c);
+
+ while (c->entries)
+ remove_entry(c, c->entries);
}
-void avahi_cache_dump(AvahiCache *c, FILE *f) {
- g_assert(c);
- g_assert(f);
+/*** 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;
- fprintf(f, ";;; CACHE DUMP FOLLOWS ;;;\n");
- g_hash_table_foreach(c->hash_table, func, f);
+ 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;
}
-gboolean avahi_cache_entry_half_ttl(AvahiCache *c, AvahiCacheEntry *e) {
- GTimeVal now;
- guint age;
-
- g_assert(c);
- g_assert(e);
+void avahi_cache_start_poof(AvahiCache *c, AvahiKey *key, const AvahiAddress *a) {
+ assert(c);
+ assert(key);
- g_get_current_time(&now);
+ avahi_cache_walk(c, key, start_poof_callback, (void*) a);
+}
- age = avahi_timeval_diff(&now, &e->timestamp)/1000000;
+void avahi_cache_stop_poof(AvahiCache *c, AvahiRecord *record, const AvahiAddress *a) {
+ AvahiCacheEntry *e;
- g_message("age: %u, ttl/2: %u", age, e->record->ttl);
-
- return age >= e->record->ttl/2;
+ assert(c);
+ assert(record);
+ assert(a);
+
+ if (!(e = lookup_record(c, record)))
+ return;
+
+ /* 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);
+ }
}
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