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 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 (!(p = avahi_dns_packet_new_response(size + AVAHI_DNS_PACKET_EXTRA_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_MDNS);
avahi_dns_packet_free(p);
}
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 (size > AVAHI_DNS_PACKET_SIZE_MAX)
size = AVAHI_DNS_PACKET_SIZE_MAX;
if (!(p = avahi_dns_packet_new_query(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);
}
