static void lookup_drop_cname(AvahiSRBLookup *l, AvahiIfIndex interface, AvahiProtocol protocol, AvahiLookupFlags flags, AvahiRecord *r) {
AvahiKey *k;
AvahiSRBLookup *n = NULL;
AvahiRList *rl;
assert(r->key->clazz == AVAHI_DNS_CLASS_IN);
assert(r->key->type == AVAHI_DNS_TYPE_CNAME);
k = avahi_key_new(r->data.ptr.name, l->record_browser->key->clazz, l->record_browser->key->type);
for (rl = l->cname_lookups; rl; rl = rl->rlist_next) {
n = rl->data;
assert(n);
if ((n->interface == AVAHI_IF_UNSPEC || n->interface == interface) &&
(n->interface == AVAHI_PROTO_UNSPEC || n->protocol == protocol) &&
n->flags == flags &&
avahi_key_equal(n->key, k))
break;
}
avahi_key_unref(k);
if (rl) {
l->cname_lookups = avahi_rlist_remove_by_link(l->cname_lookups, rl);
lookup_unref(n);
}
}
static int lookup_go(AvahiSRBLookup *l) {
int n = 0;
assert(l);
if (l->record_browser->dead)
return 0;
lookup_ref(l);
/* Browse the cache for the root request */
n = lookup_scan_cache(l);
/* Start the lookup */
if (!l->record_browser->dead && l->ref > 1) {
if ((l->flags & AVAHI_LOOKUP_USE_MULTICAST) || n == 0)
/* We do no start a query if the cache contained entries and we're on wide area */
if (lookup_start(l) < 0)
n = -1;
}
lookup_unref(l);
return n;
}
static void lookup_unref(AvahiSRBLookup *l) {
assert(l);
assert(l->ref >= 1);
if (--l->ref >= 1)
return;
AVAHI_LLIST_REMOVE(AvahiSRBLookup, lookups, l->record_browser->lookups, l);
l->record_browser->n_lookups --;
if (l->wide_area) {
avahi_wide_area_lookup_free(l->wide_area);
l->wide_area = NULL;
}
if (l->multicast) {
avahi_multicast_lookup_free(l->multicast);
l->multicast = NULL;
}
while (l->cname_lookups) {
lookup_unref(l->cname_lookups->data);
l->cname_lookups = avahi_rlist_remove_by_link(l->cname_lookups, l->cname_lookups);
}
avahi_key_unref(l->key);
avahi_free(l);
}
static void lookup_llmnr_callback(
AvahiLLMNRLookupEngine *e,
AvahiIfIndex interface,
AvahiProtocol protocol,
AvahiBrowserEvent event,
AvahiLookupResultFlags flags,
AvahiRecord *r,
void *userdata) {
AvahiSRBLookup *l = userdata;
AvahiSRecordBrowser *b;
assert(e);
assert(l);
/* assert(AVAHI_IF_VALID(idx) && idx != -1);
assert(AVAHI_PROTO_VALID(protocol) && protocol != -1);*/
b = l->record_browser;
if (b->dead)
return;
lookup_ref(l);
switch(event) {
case AVAHI_BROWSER_NEW:
assert(r);
if (r->key->clazz == AVAHI_DNS_CLASS_IN &&
r->key->type == AVAHI_DNS_TYPE_CNAME)
lookup_handle_cname(l, interface, protocol, b->flags, r);
else
/* We are discrading packets originating from our own interface/s
or should we accept them? TODO AVAHI_LOOKUP_RESULT_LOCAL*/
b->callback(b, interface, protocol, event, r, flags, b->userdata);
break;
case AVAHI_BROWSER_REMOVE:
case AVAHI_BROWSER_CACHE_EXHAUSTED:
abort();
case AVAHI_BROWSER_ALL_FOR_NOW:
b->callback(b, interface, protocol, event, NULL, flags, b->userdata);
break;
case AVAHI_BROWSER_FAILURE:
/* This event states that LLMNR query has been sent three times on specified
interface and protocol and we don't have any records available */
/*b->callback(b, interface, protocol, event, NULL, flags, b->userdata);
lookup_ref(l);*/
abort();
}
lookup_unref(l);
}
static void lookup_wide_area_callback(
AvahiWideAreaLookupEngine *e,
AvahiBrowserEvent event,
AvahiLookupResultFlags flags,
AvahiRecord *r,
void *userdata) {
AvahiSRBLookup *l = userdata;
AvahiSRecordBrowser *b;
assert(e);
assert(l);
assert(l->ref >= 1);
b = l->record_browser;
if (b->dead)
return;
lookup_ref(l);
switch (event) {
case AVAHI_BROWSER_NEW:
assert(r);
if (r->key->clazz == AVAHI_DNS_CLASS_IN &&
r->key->type == AVAHI_DNS_TYPE_CNAME)
/* It's a CNAME record, so let's follow it. We only follow it on wide area DNS! */
lookup_handle_cname(l, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_LOOKUP_USE_WIDE_AREA, r);
else {
/* It's a normal record, so let's call the user callback */
assert(avahi_key_equal(r->key, l->key));
b->callback(b, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, event, r, flags, b->userdata);
}
break;
case AVAHI_BROWSER_REMOVE:
case AVAHI_BROWSER_CACHE_EXHAUSTED:
/* Not defined for wide area DNS */
abort();
case AVAHI_BROWSER_ALL_FOR_NOW:
case AVAHI_BROWSER_FAILURE:
b->callback(b, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, event, NULL, flags, b->userdata);
break;
}
lookup_unref(l);
}
static void browser_cancel(AvahiSRecordBrowser *b) {
assert(b);
if (b->root_lookup) {
lookup_unref(b->root_lookup);
b->root_lookup = NULL;
}
if (b->defer_time_event) {
avahi_time_event_free(b->defer_time_event);
b->defer_time_event = NULL;
}
}
static void lookup_handle_cname(AvahiSRBLookup *l, AvahiIfIndex interface, AvahiProtocol protocol, AvahiLookupFlags flags, AvahiRecord *r) {
AvahiKey *k;
AvahiSRBLookup *n;
assert(l);
assert(r);
assert(r->key->clazz == AVAHI_DNS_CLASS_IN);
assert(r->key->type == AVAHI_DNS_TYPE_CNAME);
k = avahi_key_new(r->data.ptr.name, l->record_browser->key->clazz, l->record_browser->key->type);
n = lookup_add(l->record_browser, interface, protocol, flags, k);
avahi_key_unref(k);
if (!n) {
avahi_log_debug(__FILE__": Failed to create SRBLookup.");
return;
}
l->cname_lookups = avahi_rlist_prepend(l->cname_lookups, lookup_ref(n));
lookup_go(n);
lookup_unref(n);
}
static void lookup_multicast_callback(
AvahiMulticastLookupEngine *e,
AvahiIfIndex interface,
AvahiProtocol protocol,
AvahiBrowserEvent event,
AvahiLookupResultFlags flags,
AvahiRecord *r,
void *userdata) {
AvahiSRBLookup *l = userdata;
AvahiSRecordBrowser *b;
assert(e);
assert(l);
b = l->record_browser;
if (b->dead)
return;
lookup_ref(l);
switch (event) {
case AVAHI_BROWSER_NEW:
assert(r);
if (r->key->clazz == AVAHI_DNS_CLASS_IN &&
r->key->type == AVAHI_DNS_TYPE_CNAME)
/* It's a CNAME record, so let's follow it. We allow browsing on both multicast and wide area. */
lookup_handle_cname(l, interface, protocol, b->flags, r);
else {
/* It's a normal record, so let's call the user callback */
if (avahi_server_is_record_local(b->server, interface, protocol, r))
flags |= AVAHI_LOOKUP_RESULT_LOCAL;
b->callback(b, interface, protocol, event, r, flags, b->userdata);
}
break;
case AVAHI_BROWSER_REMOVE:
assert(r);
if (r->key->clazz == AVAHI_DNS_CLASS_IN &&
r->key->type == AVAHI_DNS_TYPE_CNAME)
/* It's a CNAME record, so let's drop that query! */
lookup_drop_cname(l, interface, protocol, 0, r);
else {
/* It's a normal record, so let's call the user callback */
assert(avahi_key_equal(b->key, l->key));
b->callback(b, interface, protocol, event, r, flags, b->userdata);
}
break;
case AVAHI_BROWSER_ALL_FOR_NOW:
b->callback(b, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, event, NULL, flags, b->userdata);
break;
case AVAHI_BROWSER_CACHE_EXHAUSTED:
case AVAHI_BROWSER_FAILURE:
/* Not defined for multicast DNS */
abort();
}
lookup_unref(l);
}
