+++ /dev/null
-/***
- 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 <avahi-common/error.h>
-#include <avahi-common/domain.h>
-#include <avahi-common/rlist.h>
-#include <avahi-common/address.h>
-
-#include "browse.h"
-#include "log.h"
-#include "querier.h"
-#include "domain-util.h"
-#include "rr-util.h"
-
-#define AVAHI_LOOKUPS_PER_BROWSER_MAX 15
-
-struct AvahiSRBLookup {
- AvahiSRecordBrowser *record_browser;
-
- unsigned ref;
-
- AvahiIfIndex interface;
- AvahiProtocol protocol;
- AvahiLookupFlags flags;
-
- AvahiKey *key;
-
- AvahiWideAreaLookup *wide_area;
- AvahiMulticastLookup *multicast;
-
- AvahiRList *cname_lookups;
-
- AVAHI_LLIST_FIELDS(AvahiSRBLookup, lookups);
-};
-
-static void lookup_handle_cname(AvahiSRBLookup *l, AvahiIfIndex interface, AvahiProtocol protocol, AvahiLookupFlags flags, AvahiRecord *r);
-static void lookup_drop_cname(AvahiSRBLookup *l, AvahiIfIndex interface, AvahiProtocol protocol, AvahiLookupFlags flags, AvahiRecord *r);
-
-static void transport_flags_from_domain(AvahiServer *s, AvahiLookupFlags *flags, const char *domain) {
- assert(flags);
- assert(domain);
-
- assert(!((*flags & AVAHI_LOOKUP_USE_MULTICAST) && (*flags & AVAHI_LOOKUP_USE_WIDE_AREA)));
-
- if (*flags & (AVAHI_LOOKUP_USE_MULTICAST|AVAHI_LOOKUP_USE_WIDE_AREA))
- return;
-
- if (!s->wide_area_lookup_engine ||
- !avahi_wide_area_has_servers(s->wide_area_lookup_engine) ||
- avahi_domain_ends_with(domain, AVAHI_MDNS_SUFFIX_LOCAL) ||
- avahi_domain_ends_with(domain, AVAHI_MDNS_SUFFIX_ADDR_IPV4) ||
- avahi_domain_ends_with(domain, AVAHI_MDNS_SUFFIX_ADDR_IPV6))
- *flags |= AVAHI_LOOKUP_USE_MULTICAST;
- else
- *flags |= AVAHI_LOOKUP_USE_WIDE_AREA;
-}
-
-static AvahiSRBLookup* lookup_new(
- AvahiSRecordBrowser *b,
- AvahiIfIndex interface,
- AvahiProtocol protocol,
- AvahiLookupFlags flags,
- AvahiKey *key) {
-
- AvahiSRBLookup *l;
-
- assert(b);
- assert(AVAHI_IF_VALID(interface));
- assert(AVAHI_PROTO_VALID(protocol));
-
- if (b->n_lookups >= AVAHI_LOOKUPS_PER_BROWSER_MAX)
- /* We don't like cyclic CNAMEs */
- return NULL;
-
- if (!(l = avahi_new(AvahiSRBLookup, 1)))
- return NULL;
-
- l->ref = 1;
- l->record_browser = b;
- l->interface = interface;
- l->protocol = protocol;
- l->key = avahi_key_ref(key);
- l->wide_area = NULL;
- l->multicast = NULL;
- l->cname_lookups = NULL;
- l->flags = flags;
-
- transport_flags_from_domain(b->server, &l->flags, key->name);
-
- AVAHI_LLIST_PREPEND(AvahiSRBLookup, lookups, b->lookups, l);
-
- b->n_lookups ++;
-
- return l;
-}
-
-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 AvahiSRBLookup* lookup_ref(AvahiSRBLookup *l) {
- assert(l);
- assert(l->ref >= 1);
-
- l->ref++;
- return l;
-}
-
-static AvahiSRBLookup *lookup_find(
- AvahiSRecordBrowser *b,
- AvahiIfIndex interface,
- AvahiProtocol protocol,
- AvahiLookupFlags flags,
- AvahiKey *key) {
-
- AvahiSRBLookup *l;
-
- assert(b);
-
- for (l = b->lookups; l; l = l->lookups_next) {
-
- if ((l->interface == AVAHI_IF_UNSPEC || l->interface == interface) &&
- (l->interface == AVAHI_PROTO_UNSPEC || l->protocol == protocol) &&
- l->flags == flags &&
- avahi_key_equal(l->key, key))
-
- return l;
- }
-
- return NULL;
-}
-
-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_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 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);
-}
-
-static int lookup_start(AvahiSRBLookup *l) {
- assert(l);
-
- assert(!(l->flags & AVAHI_LOOKUP_USE_WIDE_AREA) != !(l->flags & AVAHI_LOOKUP_USE_MULTICAST));
- assert(!l->wide_area && !l->multicast);
-
- if (l->flags & AVAHI_LOOKUP_USE_WIDE_AREA) {
-
- if (!(l->wide_area = avahi_wide_area_lookup_new(l->record_browser->server->wide_area_lookup_engine, l->key, lookup_wide_area_callback, l)))
- return -1;
-
- } else {
- assert(l->flags & AVAHI_LOOKUP_USE_MULTICAST);
-
- if (!(l->multicast = avahi_multicast_lookup_new(l->record_browser->server->multicast_lookup_engine, l->interface, l->protocol, l->key, lookup_multicast_callback, l)))
- return -1;
- }
-
- return 0;
-}
-
-static int lookup_scan_cache(AvahiSRBLookup *l) {
- int n = 0;
-
- assert(l);
-
- assert(!(l->flags & AVAHI_LOOKUP_USE_WIDE_AREA) != !(l->flags & AVAHI_LOOKUP_USE_MULTICAST));
-
-
- if (l->flags & AVAHI_LOOKUP_USE_WIDE_AREA) {
- n = (int) avahi_wide_area_scan_cache(l->record_browser->server->wide_area_lookup_engine, l->key, lookup_wide_area_callback, l);
-
- } else {
- assert(l->flags & AVAHI_LOOKUP_USE_MULTICAST);
- n = (int) avahi_multicast_lookup_engine_scan_cache(l->record_browser->server->multicast_lookup_engine, l->interface, l->protocol, l->key, lookup_multicast_callback, l);
- }
-
- return n;
-}
-
-static AvahiSRBLookup* lookup_add(AvahiSRecordBrowser *b, AvahiIfIndex interface, AvahiProtocol protocol, AvahiLookupFlags flags, AvahiKey *key) {
- AvahiSRBLookup *l;
-
- assert(b);
- assert(!b->dead);
-
- if ((l = lookup_find(b, interface, protocol, flags, key)))
- return lookup_ref(l);
-
- if (!(l = lookup_new(b, interface, protocol, flags, key)))
- return NULL;
-
- return l;
-}
-
-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_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_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 void defer_callback(AVAHI_GCC_UNUSED AvahiTimeEvent *e, void *userdata) {
- AvahiSRecordBrowser *b = userdata;
- int n;
-
- assert(b);
- assert(!b->dead);
-
- /* Remove the defer timeout */
- if (b->defer_time_event) {
- avahi_time_event_free(b->defer_time_event);
- b->defer_time_event = NULL;
- }
-
- /* Create initial query */
- assert(!b->root_lookup);
- b->root_lookup = lookup_add(b, b->interface, b->protocol, b->flags, b->key);
- assert(b->root_lookup);
-
- n = lookup_go(b->root_lookup);
-
- if (b->dead)
- return;
-
- if (n < 0) {
- /* sending of the initial query failed */
-
- avahi_server_set_errno(b->server, AVAHI_ERR_FAILURE);
-
- b->callback(
- b, b->interface, b->protocol, AVAHI_BROWSER_FAILURE, NULL,
- b->flags & AVAHI_LOOKUP_USE_WIDE_AREA ? AVAHI_LOOKUP_RESULT_WIDE_AREA : AVAHI_LOOKUP_RESULT_MULTICAST,
- b->userdata);
-
- browser_cancel(b);
- return;
- }
-
- /* Tell the client that we're done with the cache */
- b->callback(
- b, b->interface, b->protocol, AVAHI_BROWSER_CACHE_EXHAUSTED, NULL,
- b->flags & AVAHI_LOOKUP_USE_WIDE_AREA ? AVAHI_LOOKUP_RESULT_WIDE_AREA : AVAHI_LOOKUP_RESULT_MULTICAST,
- b->userdata);
-
- if (!b->dead && b->root_lookup && b->root_lookup->flags & AVAHI_LOOKUP_USE_WIDE_AREA && n > 0) {
-
- /* If we do wide area lookups and the the cache contained
- * entries, we assume that it is complete, and tell the user
- * so by firing ALL_FOR_NOW. */
-
- b->callback(b, b->interface, b->protocol, AVAHI_BROWSER_ALL_FOR_NOW, NULL, AVAHI_LOOKUP_RESULT_WIDE_AREA, b->userdata);
- }
-}
-
-void avahi_s_record_browser_restart(AvahiSRecordBrowser *b) {
- assert(b);
- assert(!b->dead);
-
- browser_cancel(b);
-
- /* Request a new iteration of the cache scanning */
- if (!b->defer_time_event) {
- b->defer_time_event = avahi_time_event_new(b->server->time_event_queue, NULL, defer_callback, b);
- assert(b->defer_time_event);
- }
-}
-
-AvahiSRecordBrowser *avahi_s_record_browser_new(
- AvahiServer *server,
- AvahiIfIndex interface,
- AvahiProtocol protocol,
- AvahiKey *key,
- AvahiLookupFlags flags,
- AvahiSRecordBrowserCallback callback,
- void* userdata) {
-
- AvahiSRecordBrowser *b;
-
- assert(server);
- assert(key);
- 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_key_is_pattern(key), AVAHI_ERR_IS_PATTERN);
- AVAHI_CHECK_VALIDITY_RETURN_NULL(server, avahi_key_is_valid(key), AVAHI_ERR_INVALID_KEY);
- AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS);
- AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !(flags & AVAHI_LOOKUP_USE_WIDE_AREA) || !(flags & AVAHI_LOOKUP_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS);
-
- if (!(b = avahi_new(AvahiSRecordBrowser, 1))) {
- avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
- return NULL;
- }
-
- b->dead = 0;
- b->server = server;
- b->interface = interface;
- b->protocol = protocol;
- b->key = avahi_key_ref(key);
- b->flags = flags;
- b->callback = callback;
- b->userdata = userdata;
- b->n_lookups = 0;
- AVAHI_LLIST_HEAD_INIT(AvahiSRBLookup, b->lookups);
- b->root_lookup = NULL;
-
- AVAHI_LLIST_PREPEND(AvahiSRecordBrowser, browser, server->record_browsers, b);
-
- /* The currently cached entries are scanned a bit later, and than we will start querying, too */
- b->defer_time_event = avahi_time_event_new(server->time_event_queue, NULL, defer_callback, b);
- assert(b->defer_time_event);
-
- return b;
-}
-
-void avahi_s_record_browser_free(AvahiSRecordBrowser *b) {
- assert(b);
- assert(!b->dead);
-
- b->dead = 1;
- b->server->need_browser_cleanup = 1;
-
- browser_cancel(b);
-}
-
-void avahi_s_record_browser_destroy(AvahiSRecordBrowser *b) {
- assert(b);
-
- browser_cancel(b);
-
- AVAHI_LLIST_REMOVE(AvahiSRecordBrowser, browser, b->server->record_browsers, b);
-
- avahi_key_unref(b->key);
-
- avahi_free(b);
-}
-
-void avahi_browser_cleanup(AvahiServer *server) {
- AvahiSRecordBrowser *b;
- AvahiSRecordBrowser *n;
-
- assert(server);
-
- while (server->need_browser_cleanup) {
- server->need_browser_cleanup = 0;
-
- for (b = server->record_browsers; b; b = n) {
- n = b->browser_next;
-
- if (b->dead)
- avahi_s_record_browser_destroy(b);
- }
- }
-
- if (server->wide_area_lookup_engine)
- avahi_wide_area_cleanup(server->wide_area_lookup_engine);
- avahi_multicast_lookup_engine_cleanup(server->multicast_lookup_engine);
-}
-
projects / catta / blobdiff