/***
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/domain.h>
#include <avahi-common/timeval.h>
#include "avahi-common/avahi-malloc.h"
#include "probe-sched.h"
#include "log.h"
#include "rr-util.h"
#define AVAHI_PROBE_HISTORY_MSEC 150
#define AVAHI_PROBE_DEFER_MSEC 50
typedef struct AvahiProbeJob AvahiProbeJob;
struct AvahiProbeJob {
AvahiProbeScheduler *scheduler;
AvahiTimeEvent *time_event;
int chosen; /* Use for packet assembling */
int done;
struct timeval delivery;
AvahiRecord *record;
AVAHI_LLIST_FIELDS(AvahiProbeJob, jobs);
};
struct AvahiProbeScheduler {
AvahiInterface *interface;
AvahiTimeEventQueue *time_event_queue;
AVAHI_LLIST_HEAD(AvahiProbeJob, jobs);
AVAHI_LLIST_HEAD(AvahiProbeJob, history);
};
static AvahiProbeJob* job_new(AvahiProbeScheduler *s, AvahiRecord *record, int done) {
AvahiProbeJob *pj;
assert(s);
assert(record);
if (!(pj = avahi_new(AvahiProbeJob, 1))) {
avahi_log_error(__FILE__": Out of memory");
return NULL; /* OOM */
}
pj->scheduler = s;
pj->record = avahi_record_ref(record);
pj->time_event = NULL;
pj->chosen = 0;
if ((pj->done = done))
AVAHI_LLIST_PREPEND(AvahiProbeJob, jobs, s->history, pj);
else
AVAHI_LLIST_PREPEND(AvahiProbeJob, jobs, s->jobs, pj);
return pj;
}
static void job_free(AvahiProbeScheduler *s, AvahiProbeJob *pj) {
assert(pj);
if (pj->time_event)
avahi_time_event_free(pj->time_event);
if (pj->done)
AVAHI_LLIST_REMOVE(AvahiProbeJob, jobs, s->history, pj);
else
AVAHI_LLIST_REMOVE(AvahiProbeJob, jobs, s->jobs, pj);
avahi_record_unref(pj->record);
avahi_free(pj);
}
static void elapse_callback(AvahiTimeEvent *e, void* data);
static void job_set_elapse_time(AvahiProbeScheduler *s, AvahiProbeJob *pj, unsigned msec, unsigned jitter) {
struct timeval tv;
assert(s);
assert(pj);
avahi_elapse_time(&tv, msec, jitter);
if (pj->time_event)
avahi_time_event_update(pj->time_event, &tv);
else
pj->time_event = avahi_time_event_new(s->time_event_queue, &tv, elapse_callback, pj);
}
static void job_mark_done(AvahiProbeScheduler *s, AvahiProbeJob *pj) {
assert(s);
assert(pj);
assert(!pj->done);
AVAHI_LLIST_REMOVE(AvahiProbeJob, jobs, s->jobs, pj);
AVAHI_LLIST_PREPEND(AvahiProbeJob, jobs, s->history, pj);
pj->done = 1;
job_set_elapse_time(s, pj, AVAHI_PROBE_HISTORY_MSEC, 0);
gettimeofday(&pj->delivery, NULL);
}
AvahiProbeScheduler *avahi_probe_scheduler_new(AvahiInterface *i) {
AvahiProbeScheduler *s;
assert(i);
if (!(s = avahi_new(AvahiProbeScheduler, 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(AvahiProbeJob, s->jobs);
AVAHI_LLIST_HEAD_INIT(AvahiProbeJob, s->history);
return s;
}
void avahi_probe_scheduler_free(AvahiProbeScheduler *s) {
assert(s);
avahi_probe_scheduler_clear(s);
avahi_free(s);
}
void avahi_probe_scheduler_clear(AvahiProbeScheduler *s) {
assert(s);
while (s->jobs)
job_free(s, s->jobs);
while (s->history)
job_free(s, s->history);
}
static int packet_add_probe_query(AvahiProbeScheduler *s, AvahiDnsPacket *p, AvahiProbeJob *pj) {
size_t size;
AvahiKey *k;
int b;
assert(s);
assert(p);
assert(pj);
assert(!pj->chosen);
/* Estimate the size for this record */
size =
avahi_key_get_estimate_size(pj->record->key) +
avahi_record_get_estimate_size(pj->record);
/* Too large */
if (size > avahi_dns_packet_space(p))
return 0;
/* Create the probe query */
if (!(k = avahi_key_new(pj->record->key->name, pj->record->key->clazz, AVAHI_DNS_TYPE_ANY)))
return 0; /* OOM */
b = !!avahi_dns_packet_append_key(p, k, 0);
assert(b);
/* Mark this job for addition to the packet */
pj->chosen = 1;
/* Scan for more jobs whith matching key pattern */
for (pj = s->jobs; pj; pj = pj->jobs_next) {
if (pj->chosen)
continue;
/* Does the record match the probe? */
if (k->clazz != pj->record->key->clazz || !avahi_domain_equal(k->name, pj->record->key->name))
continue;
/* This job wouldn't fit in */
if (avahi_record_get_estimate_size(pj->record) > avahi_dns_packet_space(p))
break;
/* Mark this job for addition to the packet */
pj->chosen = 1;
}
avahi_key_unref(k);
return 1;
}
static void elapse_callback(AVAHI_GCC_UNUSED AvahiTimeEvent *e, void* data) {
AvahiProbeJob *pj = data, *next;
AvahiProbeScheduler *s;
AvahiDnsPacket *p;
unsigned n;
assert(pj);
s = pj->scheduler;
if (pj->done) {
/* Lets remove it from the history */
job_free(s, pj);
return;
}
if (!(p = avahi_dns_packet_new_query(s->interface->hardware->mtu)))
return; /* OOM */
n = 1;
/* Add the import probe */
if (!packet_add_probe_query(s, p, pj)) {
size_t size;
AvahiKey *k;
int b;
avahi_dns_packet_free(p);
/* The probe didn't fit in the package, so let's allocate a larger one */
size =
avahi_key_get_estimate_size(pj->record->key) +
avahi_record_get_estimate_size(pj->record) +
AVAHI_DNS_PACKET_HEADER_SIZE;
if (!(p = avahi_dns_packet_new_query(size + AVAHI_DNS_PACKET_EXTRA_SIZE)))
return; /* OOM */
if (!(k = avahi_key_new(pj->record->key->name, pj->record->key->clazz, AVAHI_DNS_TYPE_ANY))) {
avahi_dns_packet_free(p);
return; /* OOM */
}
b = avahi_dns_packet_append_key(p, k, 0) && avahi_dns_packet_append_record(p, pj->record, 0, 0);
avahi_key_unref(k);
if (b) {
avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_NSCOUNT, 1);
avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_QDCOUNT, 1);
avahi_interface_send_packet(s->interface, p);
} else
avahi_log_warn("Probe record too large, cannot send");
avahi_dns_packet_free(p);
job_mark_done(s, pj);
return;
}
/* Try to fill up packet with more probes, if available */
for (pj = s->jobs; pj; pj = pj->jobs_next) {
if (pj->chosen)
continue;
if (!packet_add_probe_query(s, p, pj))
break;
n++;
}
avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_QDCOUNT, n);
n = 0;
/* Now add the chosen records to the authorative section */
for (pj = s->jobs; pj; pj = next) {
next = pj->jobs_next;
if (!pj->chosen)
continue;
if (!avahi_dns_packet_append_record(p, pj->record, 0, 0)) {
/* avahi_log_warn("Bad probe size estimate!"); */
/* Unmark all following jobs */
for (; pj; pj = pj->jobs_next)
pj->chosen = 0;
break;
}
job_mark_done(s, pj);
n ++;
}
avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_NSCOUNT, n);
/* Send it now */
avahi_interface_send_packet(s->interface, p);
avahi_dns_packet_free(p);
}
static AvahiProbeJob* find_scheduled_job(AvahiProbeScheduler *s, AvahiRecord *record) {
AvahiProbeJob *pj;
assert(s);
assert(record);
for (pj = s->jobs; pj; pj = pj->jobs_next) {
assert(!pj->done);
if (avahi_record_equal_no_ttl(pj->record, record))
return pj;
}
return NULL;
}
static AvahiProbeJob* find_history_job(AvahiProbeScheduler *s, AvahiRecord *record) {
AvahiProbeJob *pj;
assert(s);
assert(record);
for (pj = s->history; pj; pj = pj->jobs_next) {
assert(pj->done);
if (avahi_record_equal_no_ttl(pj->record, record)) {
/* Check whether this entry is outdated */
if (avahi_age(&pj->delivery) > AVAHI_PROBE_HISTORY_MSEC*1000) {
/* it is outdated, so let's remove it */
job_free(s, pj);
return NULL;
}
return pj;
}
}
return NULL;
}
int avahi_probe_scheduler_post(AvahiProbeScheduler *s, AvahiRecord *record, int immediately) {
AvahiProbeJob *pj;
struct timeval tv;
assert(s);
assert(record);
assert(!avahi_key_is_pattern(record->key));
if ((pj = find_history_job(s, record)))
return 0;
avahi_elapse_time(&tv, immediately ? 0 : AVAHI_PROBE_DEFER_MSEC, 0);
if ((pj = find_scheduled_job(s, record))) {
if (avahi_timeval_compare(&tv, &pj->delivery) < 0) {
/* If the new entry should be scheduled earlier, update the old entry */
pj->delivery = tv;
avahi_time_event_update(pj->time_event, &pj->delivery);
}
return 1;
} else {
/* Create a new job and schedule it */
if (!(pj = job_new(s, record, 0)))
return 0; /* OOM */
pj->delivery = tv;
pj->time_event = avahi_time_event_new(s->time_event_queue, &pj->delivery, elapse_callback, pj);
/* avahi_log_debug("Accepted new probe job."); */
return 1;
}
}