X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-core%2Fcache.c;h=454aac53a5efa068be431b00285b068373d93ea4;hb=9c0f9c65093cfa53d45f9b68782321eb8063a032;hp=924b8c958d83c84e3aa2b1a2b4b0c92f3e092bbe;hpb=4f0a5e7572a4257894b4bfede42c26d65152609e;p=catta diff --git a/avahi-core/cache.c b/avahi-core/cache.c index 924b8c9..454aac5 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 @@ -25,14 +23,14 @@ #include #include +#include #include #include #include "cache.h" #include "log.h" - -#define AVAHI_MAX_CACHE_ENTRIES 200 +#include "rr-util.h" static void remove_entry(AvahiCache *c, AvahiCacheEntry *e) { AvahiCacheEntry *t; @@ -52,17 +50,18 @@ static void remove_entry(AvahiCache *c, AvahiCacheEntry *e) { /* Remove from linked list */ AVAHI_LLIST_REMOVE(AvahiCacheEntry, entry, c->entries, e); - + if (e->time_event) avahi_time_event_free(e->time_event); - avahi_browser_notify(c->server, c->interface, e->record, AVAHI_BROWSER_REMOVE); + 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); + assert(c->n_entries >= 1); + --c->n_entries; } AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *iface) { @@ -73,7 +72,7 @@ AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *iface) { avahi_log_error(__FILE__": Out of memory."); return NULL; /* OOM */ } - + c->server = server; c->interface = iface; @@ -85,7 +84,9 @@ AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *iface) { AVAHI_LLIST_HEAD_INIT(AvahiCacheEntry, c->entries); c->n_entries = 0; - + + c->last_rand_timestamp = 0; + return c; } @@ -95,45 +96,45 @@ void avahi_cache_free(AvahiCache *c) { while (c->entries) remove_entry(c, c->entries); assert(c->n_entries == 0); - + avahi_hashmap_free(c->hashmap); - + avahi_free(c); } -AvahiCacheEntry *avahi_cache_lookup_key(AvahiCache *c, AvahiKey *k) { +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 = 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; } @@ -153,7 +154,7 @@ static void* lookup_record_callback(AvahiCache *c, AvahiKey *pattern, AvahiCache return NULL; } -AvahiCacheEntry *avahi_cache_lookup_record(AvahiCache *c, AvahiRecord *r) { +static AvahiCacheEntry *lookup_record(AvahiCache *c, AvahiRecord *r) { assert(c); assert(r); @@ -165,52 +166,58 @@ 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); */ - if (e->state == AVAHI_CACHE_FINAL) { - remove_entry(e->cache, e); + 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); */ - } else { - unsigned 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: - ; - } + 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_is_subscribed(e->cache->server, e->cache->interface, e->record->key)) { -/* avahi_log_debug("Requesting cache entry update at %i%% for %s.", percent, txt); */ - avahi_interface_post_query(e->cache->interface, e->record->key, 1); - } + /* 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); */ @@ -219,7 +226,7 @@ static void elapse_func(AvahiTimeEvent *t, void *userdata) { 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 @@ -228,31 +235,39 @@ static void update_time_event(AvahiCache *c, AvahiCacheEntry *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 */ - usec = left + (AvahiUsec) ((double) (right-left) * rand() / (RAND_MAX+1.0)); - + 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) { +static void expire_in_one_second(AvahiCache *c, AvahiCacheEntry *e, AvahiCacheEntryState state) { assert(c); assert(e); - - e->state = AVAHI_CACHE_FINAL; + + e->state = state; gettimeofday(&e->expiry, NULL); avahi_timeval_add(&e->expiry, 1000000); /* 1s */ update_time_event(c, e); @@ -260,7 +275,7 @@ static void expire_in_one_second(AvahiCache *c, AvahiCacheEntry *e) { void avahi_cache_update(AvahiCache *c, AvahiRecord *r, int cache_flush, const AvahiAddress *a) { /* char *txt; */ - + assert(c); assert(r && r->ref >= 1); @@ -271,8 +286,8 @@ void avahi_cache_update(AvahiCache *c, AvahiRecord *r, int cache_flush, const Av AvahiCacheEntry *e; - if ((e = avahi_cache_lookup_record(c, r))) - expire_in_one_second(c, e); + if ((e = lookup_record(c, r))) + expire_in_one_second(c, e, AVAHI_CACHE_GOODBYE_FINAL); } else { AvahiCacheEntry *e = NULL, *first; @@ -282,8 +297,8 @@ void avahi_cache_update(AvahiCache *c, AvahiRecord *r, int cache_flush, const Av /* This is an update request */ - if ((first = avahi_cache_lookup_key(c, r->key))) { - + if ((first = lookup_key(c, r->key))) { + if (cache_flush) { /* For unique entries drop all entries older than one second */ @@ -293,37 +308,37 @@ void avahi_cache_update(AvahiCache *c, AvahiRecord *r, int cache_flush, const Av t = avahi_timeval_diff(&now, &e->timestamp); if (t > 1000000) - expire_in_one_second(c, e); + 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_MAX_CACHE_ENTRIES) + if (c->n_entries >= c->server->config.n_cache_entries_max) return; if (!(e = avahi_new(AvahiCacheEntry, 1))) { @@ -345,9 +360,9 @@ void avahi_cache_update(AvahiCache *c, AvahiRecord *r, int cache_flush, const Av c->n_entries++; /* Notify subscribers */ - avahi_browser_notify(c->server, c->interface, e->record, AVAHI_BROWSER_NEW); - } - + 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); @@ -377,7 +392,7 @@ static void dump_callback(void* key, void* data, void* userdata) { if (!(t = avahi_record_to_string(e->record))) continue; /* OOM */ - + dump_data->callback(t, dump_data->userdata); avahi_free(t); } @@ -402,7 +417,7 @@ int avahi_cache_dump(AvahiCache *c, AvahiDumpCallback callback, void* userdata) int avahi_cache_entry_half_ttl(AvahiCache *c, AvahiCacheEntry *e) { struct timeval now; unsigned age; - + assert(c); assert(e); @@ -411,7 +426,7 @@ int avahi_cache_entry_half_ttl(AvahiCache *c, AvahiCacheEntry *e) { 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; } @@ -421,3 +436,78 @@ void avahi_cache_flush(AvahiCache *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); + } +}