+++ /dev/null
-/***
- 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"
-
-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);
- --c->n_entries;
-}
-
-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 >= 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, 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;
- 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_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);
- }
-}
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