SystemConfiguration.fproj/CaptiveNetwork.c

   1 /*
   2  * Copyright (c) 2009, 2010, 2012, 2013, 2015, 2018 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25 #include <sys/types.h>
  26 #include <sys/param.h>
  27 #include <sys/stat.h>
  28 #include <dlfcn.h>
  29 #include <mach-o/dyld_priv.h>
  30 #include <sys/codesign.h>
  31
  32 #include <SystemConfiguration/CaptiveNetwork.h>
  33 #include <SystemConfiguration/SCPrivate.h>
  34
  35
  36 #pragma mark -
  37 #pragma mark CaptiveNetwork.framework APIs (exported through the SystemConfiguration.framework)
  38
  39
  40 const CFStringRef kCNNetworkInfoKeySSIDData    = CFSTR("SSIDDATA");
  41 const CFStringRef kCNNetworkInfoKeySSID        = CFSTR("SSID");
  42 const CFStringRef kCNNetworkInfoKeyBSSID       = CFSTR("BSSID");
  43
  44
  45 static void *
  46 __loadCaptiveNetwork(void) {
  47         static void             *image  = NULL;
  48         static dispatch_once_t  once;
  49
  50         dispatch_once(&once, ^{
  51                 image = _SC_dlopen("/System/Library/PrivateFrameworks/CaptiveNetwork.framework/CaptiveNetwork");
  52         });
  53
  54         return image;
  55 }
  56
  57
  58 Boolean
  59 CNSetSupportedSSIDs(CFArrayRef ssidArray)
  60 {
  61         static typeof (CNSetSupportedSSIDs) *dyfunc = NULL;
  62         if (!dyfunc) {
  63                 void *image = __loadCaptiveNetwork();
  64                 if (image) dyfunc = dlsym(image, "__CNSetSupportedSSIDs");
  65         }
  66         return dyfunc ? dyfunc(ssidArray) : FALSE;
  67 }
  68
  69
  70 Boolean
  71 CNMarkPortalOnline(CFStringRef interfaceName)
  72 {
  73         static typeof (CNMarkPortalOnline) *dyfunc = NULL;
  74         if (!dyfunc) {
  75                 void *image = __loadCaptiveNetwork();
  76                 if (image) dyfunc = dlsym(image, "__CNMarkPortalOnline");
  77         }
  78         return dyfunc ? dyfunc(interfaceName) : FALSE;
  79 }
  80
  81
  82 Boolean
  83 CNMarkPortalOffline(CFStringRef interfaceName)
  84 {
  85         static typeof (CNMarkPortalOffline) *dyfunc = NULL;
  86         if (!dyfunc) {
  87                 void *image = __loadCaptiveNetwork();
  88                 if (image) dyfunc = dlsym(image, "__CNMarkPortalOffline");
  89         }
  90         return dyfunc ? dyfunc(interfaceName) : FALSE;
  91 }
  92
  93 CFArrayRef
  94 CNCopySupportedInterfaces(void)
  95 {
  96         static typeof (CNCopySupportedInterfaces) *dyfunc = NULL;
  97         if (!dyfunc) {
  98                 void *image = __loadCaptiveNetwork();
  99                 if (image) dyfunc = dlsym(image, "__CNCopySupportedInterfaces");
 100         }
 101         return dyfunc ? dyfunc() : NULL;
 102 }
 103
 104 #if     TARGET_OS_IPHONE
 105
 106 #define CN_COPY_ENTITLEMENT CFSTR("com.apple.developer.networking.wifi-info")
 107
 108 static CFDictionaryRef
 109 __CopyEntitlementsForPID(pid_t pid)
 110 {
 111         uint8_t *buffer = NULL;
 112         size_t bufferlen = 0L;
 113         int64_t datalen = 0L;
 114         CFDataRef cfdata = NULL;
 115         struct csheader {
 116                 uint32_t magic;
 117                 uint32_t length;
 118         } csheader = { 0, 0 };
 119         int error = -1;
 120         CFPropertyListRef plist = NULL;
 121
 122         /*
 123          * Get the length of the actual entitlement data
 124          */
 125         error = csops(pid, CS_OPS_ENTITLEMENTS_BLOB, &csheader, sizeof(csheader));
 126
 127         if (error == -1 && errno == ERANGE) {
 128                 bufferlen = ntohl(csheader.length);
 129                 if (bufferlen > 1024 * 1024 || bufferlen < 8) {
 130                         errno = EINVAL;
 131                         goto out;
 132                 }
 133                 buffer = malloc(bufferlen);
 134                 if (buffer == NULL) {
 135                         goto out;
 136                 }
 137                 error = csops(pid, CS_OPS_ENTITLEMENTS_BLOB, buffer, bufferlen);
 138                 if (error < 0) {
 139                         goto out;
 140                 }
 141         }
 142
 143         datalen = bufferlen - sizeof(csheader);
 144
 145         if (error == 0 && buffer && datalen > 0) {
 146                 cfdata = CFDataCreateWithBytesNoCopy(kCFAllocatorDefault, buffer + sizeof(csheader), datalen, kCFAllocatorNull);
 147                 if (cfdata == NULL) {
 148                         goto out;
 149                 }
 150
 151                 plist = CFPropertyListCreateWithData(NULL, cfdata, kCFPropertyListImmutable, NULL, NULL);
 152                 if (!plist) {
 153                         SC_log(LOG_ERR, "Could not decode entitlements for pid %d", pid);
 154                 }
 155         }
 156         else {
 157                 SC_log(LOG_ERR, "Could not get valid codesigning data for pid %d. Error %d", pid, error);
 158         }
 159 out:
 160         if (error < 0) {
 161                 SC_log(LOG_ERR, "Error getting entitlements for pid %d: %s", pid, strerror(errno));
 162         }
 163         if (cfdata != NULL) {
 164                 CFRelease(cfdata);
 165         }
 166         if (buffer != NULL) {
 167                 free(buffer);
 168         }
 169         if (plist && !isA_CFDictionary(plist)) {
 170                 SC_log(LOG_ERR, "Could not decode entitlements for pid %d as a dictionary.", pid);
 171                 CFRelease(plist);
 172                 plist = NULL;
 173         }
 174
 175         return plist;
 176 }
 177
 178 static Boolean
 179 __isApplicationEntitled(void)
 180 {
 181         if (dyld_get_program_sdk_version() >= DYLD_IOS_VERSION_12_0) {
 182                 /* application is linked on or after iOS 12.0 SDK so it must have the entitlement */
 183                 CFTypeRef entitlement = NULL;
 184                 CFDictionaryRef entitlements = __CopyEntitlementsForPID(getpid());
 185                 if (entitlements != NULL) {
 186                         Boolean entitled = FALSE;
 187                         entitlement = CFDictionaryGetValue(entitlements, CN_COPY_ENTITLEMENT);
 188                         if(isA_CFBoolean(entitlement)) {
 189                                 entitled = CFBooleanGetValue(entitlement);
 190                         }
 191                         CFRelease(entitlements);
 192                         return entitled;
 193                 }
 194                 /* application is linked on or after iOS 12.0 SDK but missing entitlement */
 195                 return FALSE;
 196         }
 197         /* application is linked before iOS 12.0 SDK */
 198         return TRUE;
 199 }
 200
 201 #endif /* TARGET_OS_IPHONE */
 202
 203 CFDictionaryRef
 204 CNCopyCurrentNetworkInfo(CFStringRef    interfaceName)
 205 {
 206 #if     TARGET_OS_IPHONE && !TARGET_OS_IOSMAC
 207         if (__isApplicationEntitled() == FALSE) {
 208                 SC_log(LOG_DEBUG, "Application does not have %@ entitlement", CN_COPY_ENTITLEMENT);
 209                 return NULL;
 210         }
 211         static typeof (CNCopyCurrentNetworkInfo) *dyfunc = NULL;
 212         if (!dyfunc) {
 213                 void *image = __loadCaptiveNetwork();
 214                 if (image) dyfunc = dlsym(image, "__CNCopyCurrentNetworkInfo");
 215         }
 216         return dyfunc ? dyfunc(interfaceName) : NULL;
 217 #else   // TARGET_OS_IPHONE && !TARGET_OS_IOSMAC
 218 #pragma unused(interfaceName)
 219         return NULL;
 220 #endif  // TARGET_OS_IPHONE && !TARGET_OS_IOSMAC
 221 }
 222