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 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 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);
}
AvahiSDomainBrowser *avahi_s_domain_browser_prepare(
AvahiServer *server,
AvahiIfIndex interface,
AvahiProtocol protocol,
const char *domain,
AvahiDomainBrowserType type,
AvahiLookupFlags flags,
AvahiSDomainBrowserCallback callback,
void* userdata) {
static const char * const type_table[AVAHI_DOMAIN_BROWSER_MAX] = {
"b",
"db",
"r",
"dr",
"lb"
};
AvahiSDomainBrowser *b;
AvahiKey *k = NULL;
char n[AVAHI_DOMAIN_NAME_MAX];
int r;
assert(server);
assert(callback);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, type < AVAHI_DOMAIN_BROWSER_MAX, AVAHI_ERR_INVALID_FLAGS);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS);
if (!domain)
domain = server->domain_name;
if ((r = avahi_service_name_join(n, sizeof(n), type_table[type], "_dns-sd._udp", domain)) < 0) {
avahi_server_set_errno(server, r);
return NULL;
}
if (!(b = avahi_new(AvahiSDomainBrowser, 1))) {
avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
return NULL;
}
b->ref = 1;
b->server = server;
b->callback = callback;
b->userdata = userdata;
b->record_browser = NULL;
b->type = type;
b->all_for_now_scheduled = 0;
b->defer_event = NULL;
AVAHI_LLIST_PREPEND(AvahiSDomainBrowser, browser, server->domain_browsers, b);
if (!(k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_PTR))) {
avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
goto fail;
}
if (!(b->record_browser = avahi_s_record_browser_prepare(server, interface, protocol, k, flags, record_browser_callback, b)))
goto fail;
avahi_key_unref(k);
if (type == AVAHI_DOMAIN_BROWSER_BROWSE && b->server->config.browse_domains)
b->defer_event = avahi_time_event_new(server->time_event_queue, NULL, defer_callback, b);
return b;
fail:
if (k)
avahi_key_unref(k);
avahi_s_domain_browser_free(b);
return NULL;
}
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);
}
AvahiSServiceResolver *avahi_s_service_resolver_new(
AvahiServer *server,
AvahiIfIndex interface,
AvahiProtocol protocol,
const char *name,
const char *type,
const char *domain,
AvahiProtocol aprotocol,
AvahiLookupFlags flags,
AvahiSServiceResolverCallback callback,
void* userdata) {
AvahiSServiceResolver *r;
AvahiKey *k;
char n[AVAHI_DOMAIN_NAME_MAX];
int ret;
assert(server);
assert(type);
assert(callback);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(aprotocol), AVAHI_ERR_INVALID_PROTOCOL);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !name || avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST|AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), AVAHI_ERR_INVALID_FLAGS);
if (!domain)
domain = server->domain_name;
if ((ret = avahi_service_name_join(n, sizeof(n), name, type, domain)) < 0) {
avahi_server_set_errno(server, ret);
return NULL;
}
if (!(r = avahi_new(AvahiSServiceResolver, 1))) {
avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
return NULL;
}
r->server = server;
r->service_name = avahi_strdup(name);
r->service_type = avahi_normalize_name_strdup(type);
r->domain_name = avahi_normalize_name_strdup(domain);
r->callback = callback;
r->userdata = userdata;
r->address_protocol = aprotocol;
r->srv_record = r->txt_record = r->address_record = NULL;
r->srv_flags = r->txt_flags = r->address_flags = 0;
r->interface = interface;
r->protocol = protocol;
r->user_flags = flags;
r->record_browser_a = r->record_browser_aaaa = r->record_browser_srv = r->record_browser_txt = NULL;
r->time_event = NULL;
AVAHI_LLIST_PREPEND(AvahiSServiceResolver, resolver, server->service_resolvers, r);
k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV);
r->record_browser_srv = avahi_s_record_browser_new(server, interface, protocol, k, flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
avahi_key_unref(k);
if (!r->record_browser_srv) {
avahi_s_service_resolver_free(r);
return NULL;
}
if (!(flags & AVAHI_LOOKUP_NO_TXT)) {
k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_TXT);
r->record_browser_txt = avahi_s_record_browser_new(server, interface, protocol, k, flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
avahi_key_unref(k);
if (!r->record_browser_txt) {
avahi_s_service_resolver_free(r);
return NULL;
}
}
start_timeout(r);
return r;
}
static void record_browser_callback(
AvahiSRecordBrowser*rr,
AvahiIfIndex interface,
AvahiProtocol protocol,
AvahiBrowserEvent event,
AvahiRecord *record,
AvahiLookupResultFlags flags,
void* userdata) {
AvahiSServiceResolver *r = userdata;
assert(rr);
assert(r);
if (rr == r->record_browser_aaaa || rr == r->record_browser_a)
r->address_flags = flags;
else if (rr == r->record_browser_srv)
r->srv_flags = flags;
else if (rr == r->record_browser_txt)
r->txt_flags = flags;
switch (event) {
case AVAHI_BROWSER_NEW: {
int changed = 0;
assert(record);
if (r->interface > 0 && interface > 0 && interface != r->interface)
return;
if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
return;
if (r->interface <= 0)
r->interface = interface;
if (r->protocol == AVAHI_PROTO_UNSPEC)
r->protocol = protocol;
switch (record->key->type) {
case AVAHI_DNS_TYPE_SRV:
if (!r->srv_record) {
r->srv_record = avahi_record_ref(record);
changed = 1;
if (r->record_browser_a) {
avahi_s_record_browser_free(r->record_browser_a);
r->record_browser_a = NULL;
}
if (r->record_browser_aaaa) {
avahi_s_record_browser_free(r->record_browser_aaaa);
r->record_browser_aaaa = NULL;
}
if (!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS)) {
if (r->address_protocol == AVAHI_PROTO_INET || r->address_protocol == AVAHI_PROTO_UNSPEC) {
AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_A);
r->record_browser_a = avahi_s_record_browser_new(r->server, r->interface, r->protocol, k, r->user_flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
avahi_key_unref(k);
}
if (r->address_protocol == AVAHI_PROTO_INET6 || r->address_protocol == AVAHI_PROTO_UNSPEC) {
AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_AAAA);
r->record_browser_aaaa = avahi_s_record_browser_new(r->server, r->interface, r->protocol, k, r->user_flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
avahi_key_unref(k);
}
}
}
break;
case AVAHI_DNS_TYPE_TXT:
assert(!(r->user_flags & AVAHI_LOOKUP_NO_TXT));
if (!r->txt_record) {
r->txt_record = avahi_record_ref(record);
changed = 1;
}
break;
case AVAHI_DNS_TYPE_A:
case AVAHI_DNS_TYPE_AAAA:
assert(!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS));
if (!r->address_record) {
r->address_record = avahi_record_ref(record);
changed = 1;
}
break;
default:
abort();
}
if (changed &&
r->srv_record &&
(r->txt_record || (r->user_flags & AVAHI_LOOKUP_NO_TXT)) &&
(r->address_record || (r->user_flags & AVAHI_LOOKUP_NO_ADDRESS)))
finish(r, AVAHI_RESOLVER_FOUND);
break;
}
case AVAHI_BROWSER_REMOVE:
assert(record);
switch (record->key->type) {
case AVAHI_DNS_TYPE_SRV:
if (r->srv_record && avahi_record_equal_no_ttl(record, r->srv_record)) {
avahi_record_unref(r->srv_record);
r->srv_record = NULL;
if (r->record_browser_a) {
avahi_s_record_browser_free(r->record_browser_a);
r->record_browser_a = NULL;
}
if (r->record_browser_aaaa) {
avahi_s_record_browser_free(r->record_browser_aaaa);
r->record_browser_aaaa = NULL;
}
/** Look for a replacement */
avahi_s_record_browser_restart(r->record_browser_srv);
start_timeout(r);
}
break;
case AVAHI_DNS_TYPE_TXT:
assert(!(r->user_flags & AVAHI_LOOKUP_NO_TXT));
if (r->txt_record && avahi_record_equal_no_ttl(record, r->txt_record)) {
avahi_record_unref(r->txt_record);
r->txt_record = NULL;
/** Look for a replacement */
avahi_s_record_browser_restart(r->record_browser_txt);
start_timeout(r);
}
break;
case AVAHI_DNS_TYPE_A:
case AVAHI_DNS_TYPE_AAAA:
assert(!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS));
if (r->address_record && avahi_record_equal_no_ttl(record, r->address_record)) {
avahi_record_unref(r->address_record);
r->address_record = NULL;
/** Look for a replacement */
if (r->record_browser_aaaa)
avahi_s_record_browser_restart(r->record_browser_aaaa);
if (r->record_browser_a)
avahi_s_record_browser_restart(r->record_browser_a);
start_timeout(r);
}
break;
default:
abort();
}
break;
case AVAHI_BROWSER_CACHE_EXHAUSTED:
case AVAHI_BROWSER_ALL_FOR_NOW:
break;
case AVAHI_BROWSER_FAILURE:
if (rr == r->record_browser_a && r->record_browser_aaaa) {
/* We were looking for both AAAA and A, and the other query is still living, so we'll not die */
avahi_s_record_browser_free(r->record_browser_a);
r->record_browser_a = NULL;
break;
}
if (rr == r->record_browser_aaaa && r->record_browser_a) {
/* We were looking for both AAAA and A, and the other query is still living, so we'll not die */
avahi_s_record_browser_free(r->record_browser_aaaa);
r->record_browser_aaaa = NULL;
break;
}
/* Hmm, everything's lost, tell the user */
if (r->record_browser_srv)
avahi_s_record_browser_free(r->record_browser_srv);
if (r->record_browser_txt)
avahi_s_record_browser_free(r->record_browser_txt);
if (r->record_browser_a)
avahi_s_record_browser_free(r->record_browser_a);
if (r->record_browser_aaaa)
avahi_s_record_browser_free(r->record_browser_aaaa);
r->record_browser_srv = r->record_browser_txt = r->record_browser_a = r->record_browser_aaaa = NULL;
finish(r, AVAHI_RESOLVER_FAILURE);
break;
}
}
AvahiSAddressResolver *avahi_s_address_resolver_new(
AvahiServer *server,
AvahiIfIndex interface,
AvahiProtocol protocol,
const AvahiAddress *address,
AvahiLookupFlags flags,
AvahiSAddressResolverCallback callback,
void* userdata) {
AvahiSAddressResolver *r;
AvahiKey *k;
char n[AVAHI_DOMAIN_NAME_MAX];
assert(server);
assert(address);
assert(callback);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, address->proto == AVAHI_PROTO_INET || address->proto == AVAHI_PROTO_INET6, AVAHI_ERR_INVALID_PROTOCOL);
AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST|AVAHI_LOOKUP_USE_LLMNR), AVAHI_ERR_INVALID_FLAGS);
avahi_reverse_lookup_name(address, n, sizeof(n));
if (!(k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_PTR))) {
avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
return NULL;
}
if (!(r = avahi_new(AvahiSAddressResolver, 1))) {
avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
avahi_key_unref(k);
return NULL;
}
r->server = server;
r->address = *address;
r->callback = callback;
r->userdata = userdata;
r->ptr_record = NULL;
r->interface = interface;
r->protocol = protocol;
r->flags = 0;
r->retry_with_multicast = 0;
r->retry_with_llmnr = 0;
r->llmnr_has_record = 0;
r->key = k;
r->record_browser = NULL;
AVAHI_LLIST_PREPEND(AvahiSAddressResolver, resolver, server->address_resolvers, r);
r->time_event = NULL;
if (!(flags & (AVAHI_LOOKUP_USE_MULTICAST|AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_LLMNR))) {
if (!server->wide_area.wide_area_lookup_engine || !avahi_wide_area_has_servers(server->wide_area.wide_area_lookup_engine))
flags |= AVAHI_LOOKUP_USE_LLMNR;
else {
flags |= AVAHI_LOOKUP_USE_WIDE_AREA;
r->retry_with_llmnr = 1;
}
r->retry_with_multicast = 1;
}
r->record_browser = avahi_s_record_browser_new(server, interface, protocol, k, flags, record_browser_callback, r);
if (!r->record_browser) {
avahi_s_address_resolver_free(r);
return NULL;
}
start_timeout(r);
return r;
}
