mDNSMacOSX/mdns_objects/mdns_managed_defaults.c

   1 /*
   2  * Copyright (c) 2020 Apple Inc. All rights reserved.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     https://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "mdns_managed_defaults.h"
  18
  19 #include "mdns_helpers.h"
  20
  21 #include <CoreUtils/CoreUtils.h>
  22
  23 //======================================================================================================================
  24 // MARK: - Internals
  25
  26 // Managed defaults is currently only for iOS-like OSes.
  27 #if !defined(TARGET_OS_IOS_LIKE_DEVICE)
  28         #error "TARGET_OS_IOS_LIKE_DEVICE is not defined"
  29 #endif
  30
  31 MDNS_LOG_CATEGORY_DEFINE(managed_defaults, "managed_defaults");
  32
  33 //======================================================================================================================
  34 // MARK: - Local Prototypes
  35
  36 #if TARGET_OS_IOS_LIKE_DEVICE
  37 static CFURLRef
  38 _mdns_managed_defaults_create_domain_url(const char *domain, OSStatus *out_error);
  39
  40 static CFReadStreamRef
  41 _mdns_managed_defaults_create_opened_read_stream(CFURLRef url, OSStatus *out_error);
  42
  43 static CFDictionaryRef
  44 _mdns_managed_defaults_create_dictionary_from_stream(CFReadStreamRef stream, OSStatus *out_error);
  45 #endif
  46
  47 static int64_t
  48 _mdns_managed_defaults_get_int64(CFDictionaryRef defaults, CFStringRef key, OSStatus *out_error);
  49
  50 #define _assign_null_safe(PTR, VALUE)   \
  51         do {                                                            \
  52                 if ((PTR)) {                                    \
  53                         *(PTR) = (VALUE);                       \
  54                 }                                                               \
  55         } while(0)
  56
  57 //======================================================================================================================
  58 // MARK: - Public Functions
  59
  60 #if TARGET_OS_IOS_LIKE_DEVICE
  61 CFDictionaryRef
  62 mdns_managed_defaults_create(const char * const domain, OSStatus * const out_error)
  63 {
  64         CFDictionaryRef result = NULL;
  65         OSStatus err, tmp_err;
  66         CFURLRef url = _mdns_managed_defaults_create_domain_url(domain, &tmp_err);
  67         require_action_quiet(url, exit, err = tmp_err; os_log_error(_mdns_managed_defaults_log(),
  68                 "Failed to create URL -- domain: %{public}s, error: %{mdns:err}ld", domain, (long)err));
  69
  70         CFReadStreamRef stream = _mdns_managed_defaults_create_opened_read_stream(url, &tmp_err);
  71         require_action_quiet(stream, exit, err = tmp_err; os_log_error(_mdns_managed_defaults_log(),
  72                 "Failed to create read stream -- url: %{public}@, error: %{mdns:err}ld", url, (long)err));
  73
  74         CFDictionaryRef plist = _mdns_managed_defaults_create_dictionary_from_stream(stream, &tmp_err);
  75         ForgetCF(&stream);
  76         require_action_quiet(plist, exit, err = tmp_err; os_log_error(_mdns_managed_defaults_log(),
  77                 "Failed to create dictionary -- url: %{public}@, error: %{mdns:err}ld", url, (long)err));
  78
  79         result = plist;
  80         err = kNoErr;
  81
  82 exit:
  83         ForgetCF(&url);
  84         _assign_null_safe(out_error, err);
  85         return result;
  86 }
  87 #else
  88 CFDictionaryRef
  89 mdns_managed_defaults_create(__unused const char * const domain, OSStatus * const out_error)
  90 {
  91         os_log_info(_mdns_managed_defaults_log(), "Managed defaults is not supported on this OS");
  92         _assign_null_safe(out_error, kUnsupportedErr);
  93         return NULL;
  94 }
  95 #endif // TARGET_OS_IOS_LIKE_DEVICE
  96
  97 //======================================================================================================================
  98
  99 int
 100 mdns_managed_defaults_get_int_clamped(const CFDictionaryRef defaults, const CFStringRef key, const int fallback_value,
 101         OSStatus * const out_error)
 102 {
 103         int result;
 104         OSStatus err;
 105         const int64_t value = _mdns_managed_defaults_get_int64(defaults, key, &err);
 106         require_noerr_action_quiet(err, exit, result = fallback_value);
 107
 108         result = (int)Clamp(value, INT_MIN, INT_MAX);
 109
 110 exit:
 111         _assign_null_safe(out_error, err);
 112         return result;
 113 }
 114
 115 //======================================================================================================================
 116 // MARK: - Private Functions
 117
 118 #if TARGET_OS_IOS_LIKE_DEVICE
 119 static CFURLRef
 120 _mdns_managed_defaults_create_domain_url(const char * const domain, OSStatus * const out_error)
 121 {
 122         OSStatus err;
 123         CFURLRef result = NULL;
 124         char *path_cstr = NULL;
 125         asprintf(&path_cstr, "/Library/Managed Preferences/mobile/%s.plist", domain);
 126         require_action_quiet(path_cstr, exit, err = kNoMemoryErr);
 127
 128         CFStringRef path = CFStringCreateWithCStringNoCopy(NULL, path_cstr, kCFStringEncodingUTF8, kCFAllocatorMalloc);
 129         require_action_quiet(path, exit, ForgetMem(&path_cstr); err = kNoResourcesErr);
 130         path_cstr = NULL;
 131
 132         CFURLRef url = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, path, kCFURLPOSIXPathStyle, false);
 133         ForgetCF(&path);
 134         require_action_quiet(url, exit, err = kNoResourcesErr);
 135
 136         result = url;
 137         err = kNoErr;
 138
 139 exit:
 140         _assign_null_safe(out_error, err);
 141         return result;
 142 }
 143
 144 //======================================================================================================================
 145
 146 static CFReadStreamRef
 147 _mdns_managed_defaults_create_opened_read_stream(const CFURLRef url, OSStatus * const out_error)
 148 {
 149         OSStatus err;
 150         CFReadStreamRef result = NULL;
 151         CFReadStreamRef stream = CFReadStreamCreateWithFile(kCFAllocatorDefault, url);
 152         require_action_quiet(stream, exit, err = kNoResourcesErr);
 153
 154         const Boolean ok = CFReadStreamOpen(stream);
 155         require_action_quiet(ok, exit, ForgetCF(&stream); err = kOpenErr);
 156
 157         result = stream;
 158         err = kNoErr;
 159
 160 exit:
 161         _assign_null_safe(out_error, err);
 162         return result;
 163 }
 164
 165 //======================================================================================================================
 166
 167 static OSStatus
 168 _mdns_get_cferror_code(CFErrorRef error);
 169
 170 static CFDictionaryRef
 171 _mdns_managed_defaults_create_dictionary_from_stream(const CFReadStreamRef stream, OSStatus * const out_error)
 172 {
 173         OSStatus err;
 174         CFErrorRef error = NULL;
 175         CFDictionaryRef result = NULL;
 176         CFPropertyListRef plist = CFPropertyListCreateWithStream(NULL, stream, 0, kCFPropertyListImmutable, NULL, &error);
 177         require_action_quiet(plist, exit, err = _mdns_get_cferror_code(error); os_log_error(_mdns_managed_defaults_log(),
 178                 "CFPropertyListCreateWithStream failed: %{public}@", error));
 179         require_action_quiet(CFIsType(plist, CFDictionary), exit, ForgetCF(&plist); err = kTypeErr);
 180
 181         result = plist;
 182         err = kNoErr;
 183
 184 exit:
 185         ForgetCF(&error);
 186         _assign_null_safe(out_error, err);
 187         return result;
 188 }
 189
 190 static OSStatus
 191 _mdns_get_cferror_code(const CFErrorRef error)
 192 {
 193         return (error ? ((OSStatus)CFErrorGetCode(error)) : kUnknownErr);
 194 }
 195 #endif // TARGET_OS_IOS_LIKE_DEVICE
 196
 197 //======================================================================================================================
 198
 199 static int64_t
 200 _mdns_managed_defaults_get_int64(const CFDictionaryRef defaults, const CFStringRef key, OSStatus * const out_error)
 201 {
 202         OSStatus err;
 203         int64_t result = 0;
 204         const CFNumberRef number = CFDictionaryGetValue(defaults, key);
 205         require_action_quiet(number != NULL, exit, err = kNotFoundErr);
 206         require_action_quiet(CFIsType(number, CFNumber), exit, err = kTypeErr);
 207         require_action_quiet(!CFNumberIsFloatType(number), exit, err = kTypeErr);
 208
 209         int64_t value;
 210         const Boolean ok = CFNumberGetValue(number, kCFNumberSInt64Type, &value);
 211         require_action_quiet(ok, exit, err = kUnknownErr);
 212
 213         result = value;
 214         err = kNoErr;
 215
 216 exit:
 217         _assign_null_safe(out_error, err);
 218         return result;
 219 }