diff options
Diffstat (limited to 'trunk/avahi-core/cache.c')
| -rw-r--r-- | trunk/avahi-core/cache.c | 508 |
1 files changed, 0 insertions, 508 deletions
diff --git a/trunk/avahi-core/cache.c b/trunk/avahi-core/cache.c deleted file mode 100644 index 4ba88b5..0000000 --- a/trunk/avahi-core/cache.c +++ /dev/null @@ -1,508 +0,0 @@ -/* $Id$ */ - -/*** - 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 - USA. -***/ - -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#include <string.h> -#include <stdlib.h> -#include <time.h> - -#include <avahi-common/timeval.h> -#include <avahi-common/malloc.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; - - assert(c); - assert(e); - -/* avahi_log_debug("removing from cache: %p %p", c, e); */ - - /* Remove from hash table */ - t = avahi_hashmap_lookup(c->hashmap, e->record->key); - AVAHI_LLIST_REMOVE(AvahiCacheEntry, by_key, t, e); - if (t) - avahi_hashmap_replace(c->hashmap, t->record->key, t); - else - 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_free(e->time_event); - - avahi_multicast_lookup_engine_notify(c->server->multicast_lookup_engine, c->interface, e->record, AVAHI_BROWSER_REMOVE); - - avahi_record_unref(e->record); - - avahi_free(e); - - assert(c->n_entries-- >= 1); -} - -AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *iface) { - AvahiCache *c; - assert(server); - - if (!(c = avahi_new(AvahiCache, 1))) { - avahi_log_error(__FILE__": Out of memory."); - return NULL; /* OOM */ - } - - c->server = server; - c->interface = iface; - - 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) { - assert(c); - - while (c->entries) - remove_entry(c, c->entries); - assert(c->n_entries == 0); - - avahi_hashmap_free(c->hashmap); - - avahi_free(c); -} - -static AvahiCacheEntry *lookup_key(AvahiCache *c, AvahiKey *k) { - assert(c); - assert(k); - - assert(!avahi_key_is_pattern(k)); - - return avahi_hashmap_lookup(c->hashmap, k); -} - -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 = lookup_key(c, pattern); e; e = n) { - n = e->by_key_next; - - if ((ret = cb(c, pattern, e, userdata))) - return ret; - } - } - - return NULL; -} - -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; -} - -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, unsigned percent); - -static void elapse_func(AvahiTimeEvent *t, void *userdata) { - AvahiCacheEntry *e = userdata; -/* 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) { - - assert(percent > 0); - - /* 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) { - assert(c); - assert(e); - - if (e->time_event) - avahi_time_event_update(e->time_event, &e->expiry); - else - 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, 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); - - 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); - -/* g_message("wake up in +%lu seconds", e->expiry.tv_sec - e->timestamp.tv_sec); */ - - update_time_event(c, e); -} - -static void expire_in_one_second(AvahiCache *c, AvahiCacheEntry *e, AvahiCacheEntryState state) { - assert(c); - assert(e); - - e->state = state; - gettimeofday(&e->expiry, NULL); - avahi_timeval_add(&e->expiry, 1000000); /* 1s */ - update_time_event(c, e); -} - -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 */ - - AvahiCacheEntry *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 ((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) { - -/* 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) - 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 */ - -/* 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, 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_multicast_lookup_engine_notify(c->server->multicast_lookup_engine, c->interface, e->record, AVAHI_BROWSER_NEW); - } - - e->origin = *a; - e->timestamp = now; - next_expiry(c, e, 80); - e->state = AVAHI_CACHE_VALID; - e->cache_flush = cache_flush; - } - -/* avahi_free(txt); */ -} - -struct dump_data { - AvahiDumpCallback callback; - void* userdata; -}; - -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); - } -} - -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_hashmap_foreach(c->hashmap, dump_callback, &data); - - return 0; -} - -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; -} - -void avahi_cache_flush(AvahiCache *c) { - assert(c); - - while (c->entries) - remove_entry(c, c->entries); -} - -/*** Passive observation of failure ***/ - -static void* start_poof_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, void *userdata) { - AvahiAddress *a = userdata; - - assert(c); - assert(pattern); - assert(e); - assert(a); - - 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; - - break; - - case AVAHI_CACHE_POOF: - - /* This is the second time we got no response, so let's - * fucking remove this entry. */ - - expire_in_one_second(c, e, AVAHI_CACHE_POOF_FINAL); - break; - - default: - ; - } - - return NULL; -} - -void avahi_cache_start_poof(AvahiCache *c, AvahiKey *key, const AvahiAddress *a) { - assert(c); - assert(key); - - avahi_cache_walk(c, key, start_poof_callback, (void*) a); -} - -void avahi_cache_stop_poof(AvahiCache *c, AvahiRecord *record, const AvahiAddress *a) { - AvahiCacheEntry *e; - - 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); - } -} - - - |