mDNSShared/dnssd_clientstub_apple.c

   1 /*
   2  * Copyright (c) 2020 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are met:
   6  *
   7  * 1.  Redistributions of source code must retain the above copyright notice,
   8  *     this list of conditions and the following disclaimer.
   9  * 2.  Redistributions in binary form must reproduce the above copyright notice,
  10  *     this list of conditions and the following disclaimer in the documentation
  11  *     and/or other materials provided with the distribution.
  12  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of its
  13  *     contributors may be used to endorse or promote products derived from this
  14  *     software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  19  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "dnssd_clientstub_apple.h"
  29 #include "dns_sd_private.h"
  30
  31 #include <CoreUtils/CommonServices.h>
  32 #include <CoreUtils/DebugServices.h>
  33 #include <os/lock.h>
  34
  35 static xpc_object_t             g_defaults_dict = NULL;
  36 static os_unfair_lock   g_defaults_lock = OS_UNFAIR_LOCK_INIT;
  37
  38 DNSServiceErrorType DNSSD_API
  39 DNSServiceSetResolverDefaults(const void * const plist_data_ptr, const size_t plist_data_len, bool require_privacy)
  40 {
  41         DNSServiceErrorType err;
  42     require_action_quiet(plist_data_len <= (32 * CUBytesPerKibiByte), exit, err = kDNSServiceErr_Invalid);
  43
  44     const xpc_object_t new_dict = xpc_dictionary_create(NULL, NULL, 0);
  45     require_action_quiet(new_dict, exit, err = kDNSServiceErr_NoMemory);
  46
  47     xpc_dictionary_set_bool(new_dict, kDNSServiceDefaultsKey_RequirePrivacy, require_privacy);
  48         if (plist_data_ptr && (plist_data_len > 0)) {
  49         xpc_dictionary_set_data(new_dict, kDNSServiceDefaultsKey_ResolverConfigPListData, plist_data_ptr,
  50             plist_data_len);
  51         }
  52         os_unfair_lock_lock(&g_defaults_lock);
  53         xpc_object_t old_dict = g_defaults_dict;
  54         g_defaults_dict = new_dict;
  55         os_unfair_lock_unlock(&g_defaults_lock);
  56
  57         xpc_forget(&old_dict);
  58         err = kDNSServiceErr_NoError;
  59
  60 exit:
  61         return err;
  62 }
  63
  64 xpc_object_t
  65 DNSServiceGetRetainedResolverDefaults(void)
  66 {
  67         os_unfair_lock_lock(&g_defaults_lock);
  68         const xpc_object_t dict_copy = g_defaults_dict ? xpc_retain(g_defaults_dict) : NULL;
  69         os_unfair_lock_unlock(&g_defaults_lock);
  70         return dict_copy;
  71 }