diff options
Diffstat (limited to 'trunk/avahi-core/response-sched.c')
| -rw-r--r-- | trunk/avahi-core/response-sched.c | 516 |
1 files changed, 0 insertions, 516 deletions
diff --git a/trunk/avahi-core/response-sched.c b/trunk/avahi-core/response-sched.c deleted file mode 100644 index ef10eca..0000000 --- a/trunk/avahi-core/response-sched.c +++ /dev/null @@ -1,516 +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 <stdlib.h> - -#include <avahi-common/timeval.h> -#include <avahi-common/malloc.h> - -#include "response-sched.h" -#include "log.h" -#include "rr-util.h" - -/* Local packets are supressed this long after sending them */ -#define AVAHI_RESPONSE_HISTORY_MSEC 500 - -/* Local packets are deferred this long before sending them */ -#define AVAHI_RESPONSE_DEFER_MSEC 20 - -/* Additional jitter for deferred packets */ -#define AVAHI_RESPONSE_JITTER_MSEC 100 - -/* Remote packets can suppress local traffic as long as this value */ -#define AVAHI_RESPONSE_SUPPRESS_MSEC 700 - -typedef struct AvahiResponseJob AvahiResponseJob; - -typedef enum { - AVAHI_SCHEDULED, - AVAHI_DONE, - AVAHI_SUPPRESSED -} AvahiResponseJobState; - -struct AvahiResponseJob { - AvahiResponseScheduler *scheduler; - AvahiTimeEvent *time_event; - - AvahiResponseJobState state; - struct timeval delivery; - - AvahiRecord *record; - int flush_cache; - AvahiAddress querier; - int querier_valid; - - AVAHI_LLIST_FIELDS(AvahiResponseJob, jobs); -}; - -struct AvahiResponseScheduler { - AvahiInterface *interface; - AvahiTimeEventQueue *time_event_queue; - - AVAHI_LLIST_HEAD(AvahiResponseJob, jobs); - AVAHI_LLIST_HEAD(AvahiResponseJob, history); - AVAHI_LLIST_HEAD(AvahiResponseJob, suppressed); -}; - -static AvahiResponseJob* job_new(AvahiResponseScheduler *s, AvahiRecord *record, AvahiResponseJobState state) { - AvahiResponseJob *rj; - - assert(s); - assert(record); - - if (!(rj = avahi_new(AvahiResponseJob, 1))) { - avahi_log_error(__FILE__": Out of memory"); - return NULL; - } - - rj->scheduler = s; - rj->record = avahi_record_ref(record); - rj->time_event = NULL; - rj->flush_cache = 0; - rj->querier_valid = 0; - - if ((rj->state = state) == AVAHI_SCHEDULED) - AVAHI_LLIST_PREPEND(AvahiResponseJob, jobs, s->jobs, rj); - else if (rj->state == AVAHI_DONE) - AVAHI_LLIST_PREPEND(AvahiResponseJob, jobs, s->history, rj); - else /* rj->state == AVAHI_SUPPRESSED */ - AVAHI_LLIST_PREPEND(AvahiResponseJob, jobs, s->suppressed, rj); - - return rj; -} - -static void job_free(AvahiResponseScheduler *s, AvahiResponseJob *rj) { - assert(s); - assert(rj); - - if (rj->time_event) - avahi_time_event_free(rj->time_event); - - if (rj->state == AVAHI_SCHEDULED) - AVAHI_LLIST_REMOVE(AvahiResponseJob, jobs, s->jobs, rj); - else if (rj->state == AVAHI_DONE) - AVAHI_LLIST_REMOVE(AvahiResponseJob, jobs, s->history, rj); - else /* rj->state == AVAHI_SUPPRESSED */ - AVAHI_LLIST_REMOVE(AvahiResponseJob, jobs, s->suppressed, rj); - - avahi_record_unref(rj->record); - avahi_free(rj); -} - -static void elapse_callback(AvahiTimeEvent *e, void* data); - -static void job_set_elapse_time(AvahiResponseScheduler *s, AvahiResponseJob *rj, unsigned msec, unsigned jitter) { - struct timeval tv; - - assert(s); - assert(rj); - - avahi_elapse_time(&tv, msec, jitter); - - if (rj->time_event) - avahi_time_event_update(rj->time_event, &tv); - else - rj->time_event = avahi_time_event_new(s->time_event_queue, &tv, elapse_callback, rj); -} - -static void job_mark_done(AvahiResponseScheduler *s, AvahiResponseJob *rj) { - assert(s); - assert(rj); - - assert(rj->state == AVAHI_SCHEDULED); - - AVAHI_LLIST_REMOVE(AvahiResponseJob, jobs, s->jobs, rj); - AVAHI_LLIST_PREPEND(AvahiResponseJob, jobs, s->history, rj); - - rj->state = AVAHI_DONE; - - job_set_elapse_time(s, rj, AVAHI_RESPONSE_HISTORY_MSEC, 0); - - gettimeofday(&rj->delivery, NULL); -} - -AvahiResponseScheduler *avahi_response_scheduler_new(AvahiInterface *i) { - AvahiResponseScheduler *s; - assert(i); - - if (!(s = avahi_new(AvahiResponseScheduler, 1))) { - avahi_log_error(__FILE__": Out of memory"); - return NULL; - } - - s->interface = i; - s->time_event_queue = i->monitor->server->time_event_queue; - - AVAHI_LLIST_HEAD_INIT(AvahiResponseJob, s->jobs); - AVAHI_LLIST_HEAD_INIT(AvahiResponseJob, s->history); - AVAHI_LLIST_HEAD_INIT(AvahiResponseJob, s->suppressed); - - return s; -} - -void avahi_response_scheduler_free(AvahiResponseScheduler *s) { - assert(s); - - avahi_response_scheduler_clear(s); - avahi_free(s); -} - -void avahi_response_scheduler_clear(AvahiResponseScheduler *s) { - assert(s); - - while (s->jobs) - job_free(s, s->jobs); - while (s->history) - job_free(s, s->history); - while (s->suppressed) - job_free(s, s->suppressed); -} - -static void enumerate_aux_records_callback(AVAHI_GCC_UNUSED AvahiServer *s, AvahiRecord *r, int flush_cache, void* userdata) { - AvahiResponseJob *rj = userdata; - - assert(r); - assert(rj); - - avahi_response_scheduler_post(rj->scheduler, r, flush_cache, rj->querier_valid ? &rj->querier : NULL, 0); -} - -static int packet_add_response_job(AvahiResponseScheduler *s, AvahiDnsPacket *p, AvahiResponseJob *rj) { - assert(s); - assert(p); - assert(rj); - - /* Try to add this record to the packet */ - if (!avahi_dns_packet_append_record(p, rj->record, rj->flush_cache, 0)) - return 0; - - /* Ok, this record will definitely be sent, so schedule the - * auxilliary packets, too */ - avahi_server_enumerate_aux_records(s->interface->monitor->server, s->interface, rj->record, enumerate_aux_records_callback, rj); - job_mark_done(s, rj); - - return 1; -} - -static void send_response_packet(AvahiResponseScheduler *s, AvahiResponseJob *rj) { - AvahiDnsPacket *p; - unsigned n; - - assert(s); - assert(rj); - - if (!(p = avahi_dns_packet_new_response(s->interface->hardware->mtu, 1))) - return; /* OOM */ - n = 1; - - /* Put it in the packet. */ - if (packet_add_response_job(s, p, rj)) { - - /* Try to fill up packet with more responses, if available */ - while (s->jobs) { - - if (!packet_add_response_job(s, p, s->jobs)) - break; - - n++; - } - - } else { - size_t size; - - avahi_dns_packet_free(p); - - /* OK, the packet was too small, so create one that fits */ - size = avahi_record_get_estimate_size(rj->record) + AVAHI_DNS_PACKET_HEADER_SIZE; - - if (size > AVAHI_DNS_PACKET_SIZE_MAX) - size = AVAHI_DNS_PACKET_SIZE_MAX; - - if (!(p = avahi_dns_packet_new_response(size, 1))) - return; /* OOM */ - - if (!packet_add_response_job(s, p, rj)) { - avahi_dns_packet_free(p); - - avahi_log_warn("Record too large, cannot send"); - job_mark_done(s, rj); - return; - } - } - - avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ANCOUNT, n); - avahi_interface_send_packet(s->interface, p); - avahi_dns_packet_free(p); -} - -static void elapse_callback(AVAHI_GCC_UNUSED AvahiTimeEvent *e, void* data) { - AvahiResponseJob *rj = data; - - assert(rj); - - if (rj->state == AVAHI_DONE || rj->state == AVAHI_SUPPRESSED) - job_free(rj->scheduler, rj); /* Lets drop this entry */ - else - send_response_packet(rj->scheduler, rj); -} - -static AvahiResponseJob* find_scheduled_job(AvahiResponseScheduler *s, AvahiRecord *record) { - AvahiResponseJob *rj; - - assert(s); - assert(record); - - for (rj = s->jobs; rj; rj = rj->jobs_next) { - assert(rj->state == AVAHI_SCHEDULED); - - if (avahi_record_equal_no_ttl(rj->record, record)) - return rj; - } - - return NULL; -} - -static AvahiResponseJob* find_history_job(AvahiResponseScheduler *s, AvahiRecord *record) { - AvahiResponseJob *rj; - - assert(s); - assert(record); - - for (rj = s->history; rj; rj = rj->jobs_next) { - assert(rj->state == AVAHI_DONE); - - if (avahi_record_equal_no_ttl(rj->record, record)) { - /* Check whether this entry is outdated */ - -/* avahi_log_debug("history age: %u", (unsigned) (avahi_age(&rj->delivery)/1000)); */ - - if (avahi_age(&rj->delivery)/1000 > AVAHI_RESPONSE_HISTORY_MSEC) { - /* it is outdated, so let's remove it */ - job_free(s, rj); - return NULL; - } - - return rj; - } - } - - return NULL; -} - -static AvahiResponseJob* find_suppressed_job(AvahiResponseScheduler *s, AvahiRecord *record, const AvahiAddress *querier) { - AvahiResponseJob *rj; - - assert(s); - assert(record); - assert(querier); - - for (rj = s->suppressed; rj; rj = rj->jobs_next) { - assert(rj->state == AVAHI_SUPPRESSED); - assert(rj->querier_valid); - - if (avahi_record_equal_no_ttl(rj->record, record) && - avahi_address_cmp(&rj->querier, querier) == 0) { - /* Check whether this entry is outdated */ - - if (avahi_age(&rj->delivery) > AVAHI_RESPONSE_SUPPRESS_MSEC*1000) { - /* it is outdated, so let's remove it */ - job_free(s, rj); - return NULL; - } - - return rj; - } - } - - return NULL; -} - -int avahi_response_scheduler_post(AvahiResponseScheduler *s, AvahiRecord *record, int flush_cache, const AvahiAddress *querier, int immediately) { - AvahiResponseJob *rj; - struct timeval tv; -/* char *t; */ - - assert(s); - assert(record); - - assert(!avahi_key_is_pattern(record->key)); - -/* t = avahi_record_to_string(record); */ -/* avahi_log_debug("post %i %s", immediately, t); */ -/* avahi_free(t); */ - - /* Check whether this response is suppressed */ - if (querier && - (rj = find_suppressed_job(s, record, querier)) && - avahi_record_is_goodbye(record) == avahi_record_is_goodbye(rj->record) && - rj->record->ttl >= record->ttl/2) { - -/* avahi_log_debug("Response suppressed by known answer suppression."); */ - return 0; - } - - /* Check if we already sent this response recently */ - if ((rj = find_history_job(s, record))) { - - if (avahi_record_is_goodbye(record) == avahi_record_is_goodbye(rj->record) && - rj->record->ttl >= record->ttl/2 && - (rj->flush_cache || !flush_cache)) { -/* avahi_log_debug("Response suppressed by local duplicate suppression (history)"); */ - return 0; - } - - /* Outdated ... */ - job_free(s, rj); - } - - avahi_elapse_time(&tv, immediately ? 0 : AVAHI_RESPONSE_DEFER_MSEC, immediately ? 0 : AVAHI_RESPONSE_JITTER_MSEC); - - if ((rj = find_scheduled_job(s, record))) { -/* avahi_log_debug("Response suppressed by local duplicate suppression (scheduled)"); */ - - /* Update a little ... */ - - /* Update the time if the new is prior to the old */ - if (avahi_timeval_compare(&tv, &rj->delivery) < 0) { - rj->delivery = tv; - avahi_time_event_update(rj->time_event, &rj->delivery); - } - - /* Update the flush cache bit */ - if (flush_cache) - rj->flush_cache = 1; - - /* Update the querier field */ - if (!querier || (rj->querier_valid && avahi_address_cmp(querier, &rj->querier) != 0)) - rj->querier_valid = 0; - - /* Update record data (just for the TTL) */ - avahi_record_unref(rj->record); - rj->record = avahi_record_ref(record); - - return 1; - } else { -/* avahi_log_debug("Accepted new response job."); */ - - /* Create a new job and schedule it */ - if (!(rj = job_new(s, record, AVAHI_SCHEDULED))) - return 0; /* OOM */ - - rj->delivery = tv; - rj->time_event = avahi_time_event_new(s->time_event_queue, &rj->delivery, elapse_callback, rj); - rj->flush_cache = flush_cache; - - if ((rj->querier_valid = !!querier)) - rj->querier = *querier; - - return 1; - } -} - -void avahi_response_scheduler_incoming(AvahiResponseScheduler *s, AvahiRecord *record, int flush_cache) { - AvahiResponseJob *rj; - assert(s); - - /* This function is called whenever an incoming response was - * receieved. We drop scheduled responses which match here. The - * keyword is "DUPLICATE ANSWER SUPPRESION". */ - - if ((rj = find_scheduled_job(s, record))) { - - if ((!rj->flush_cache || flush_cache) && /* flush cache bit was set correctly */ - avahi_record_is_goodbye(record) == avahi_record_is_goodbye(rj->record) && /* both goodbye packets, or both not */ - record->ttl >= rj->record->ttl/2) { /* sensible TTL */ - - /* A matching entry was found, so let's mark it done */ -/* avahi_log_debug("Response suppressed by distributed duplicate suppression"); */ - job_mark_done(s, rj); - } - - return; - } - - if ((rj = find_history_job(s, record))) { - /* Found a history job, let's update it */ - avahi_record_unref(rj->record); - rj->record = avahi_record_ref(record); - } else - /* Found no existing history job, so let's create a new one */ - if (!(rj = job_new(s, record, AVAHI_DONE))) - return; /* OOM */ - - rj->flush_cache = flush_cache; - rj->querier_valid = 0; - - gettimeofday(&rj->delivery, NULL); - job_set_elapse_time(s, rj, AVAHI_RESPONSE_HISTORY_MSEC, 0); -} - -void avahi_response_scheduler_suppress(AvahiResponseScheduler *s, AvahiRecord *record, const AvahiAddress *querier) { - AvahiResponseJob *rj; - - assert(s); - assert(record); - assert(querier); - - if ((rj = find_scheduled_job(s, record))) { - - if (rj->querier_valid && avahi_address_cmp(querier, &rj->querier) == 0 && /* same originator */ - avahi_record_is_goodbye(record) == avahi_record_is_goodbye(rj->record) && /* both goodbye packets, or both not */ - record->ttl >= rj->record->ttl/2) { /* sensible TTL */ - - /* A matching entry was found, so let's drop it */ -/* avahi_log_debug("Known answer suppression active!"); */ - job_free(s, rj); - } - } - - if ((rj = find_suppressed_job(s, record, querier))) { - - /* Let's update the old entry */ - avahi_record_unref(rj->record); - rj->record = avahi_record_ref(record); - - } else { - - /* Create a new entry */ - if (!(rj = job_new(s, record, AVAHI_SUPPRESSED))) - return; /* OOM */ - rj->querier_valid = 1; - rj->querier = *querier; - } - - gettimeofday(&rj->delivery, NULL); - job_set_elapse_time(s, rj, AVAHI_RESPONSE_SUPPRESS_MSEC, 0); -} - -void avahi_response_scheduler_force(AvahiResponseScheduler *s) { - assert(s); - - /* Send all scheduled responses immediately */ - while (s->jobs) - send_response_packet(s, s->jobs); -} |