SystemConfiguration.fproj/helper/SCHelper_client.c

   1 /*
   2  * Copyright (c) 2005-2008, 2010, 2011, 2013, 2015 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 #include <fcntl.h>
  25 #include <paths.h>
  26 #include <signal.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include <sys/param.h>
  32 #include <sys/types.h>
  33 #include <sys/socket.h>
  34 #include <sys/un.h>
  35 #include <sys/wait.h>
  36 #include <mach/mach.h>
  37 #include <mach/mach_error.h>
  38 #include <servers/bootstrap.h>
  39 #include <bootstrap_priv.h>
  40 #include <pthread.h>
  41
  42 #include <CoreFoundation/CoreFoundation.h>
  43 #include <SystemConfiguration/SCPrivate.h>
  44
  45 #include "SCHelper_client.h"
  46 #include "helper.h"             // MiG generated file
  47
  48
  49 #define HELPER                                  "SCHelper"
  50 #define HELPER_LEN                              (sizeof(HELPER) - 1)
  51
  52 #define SUFFIX_SYM                              "~sym"
  53 #define SUFFIX_SYM_LEN                          (sizeof(SUFFIX_SYM) - 1)
  54
  55
  56 static pthread_mutex_t  _helper_lock    = PTHREAD_MUTEX_INITIALIZER;
  57 static mach_port_t      _helper_server  = MACH_PORT_NULL;
  58
  59
  60 static mach_port_t
  61 __SCHelperServerPort(kern_return_t *status)
  62 {
  63         mach_port_t     server  = MACH_PORT_NULL;
  64         char            *server_name;
  65
  66         server_name = getenv("SCHELPER_SERVER");
  67         if (!server_name) {
  68                 server_name = SCHELPER_SERVER;
  69         }
  70
  71 #ifdef  BOOTSTRAP_PRIVILEGED_SERVER
  72         *status = bootstrap_look_up2(bootstrap_port,
  73                                      server_name,
  74                                      &server,
  75                                      0,
  76                                      BOOTSTRAP_PRIVILEGED_SERVER);
  77 #else   // BOOTSTRAP_PRIVILEGED_SERVER
  78         *status = bootstrap_look_up(bootstrap_port, server_name, &server);
  79 #endif  // BOOTSTRAP_PRIVILEGED_SERVER
  80
  81         switch (*status) {
  82                 case BOOTSTRAP_SUCCESS :
  83                         /* service currently registered, "a good thing" (tm) */
  84                         return server;
  85                 case BOOTSTRAP_NOT_PRIVILEGED :
  86                         /* the service is not privileged */
  87                         break;
  88                 case BOOTSTRAP_UNKNOWN_SERVICE :
  89                         /* service not currently registered, try again later */
  90                         break;
  91                 default :
  92 #ifdef  DEBUG
  93                         SC_log(LOG_INFO, "bootstrap_look_up() failed: status=%s",
  94                                bootstrap_strerror(*status));
  95 #endif  /* DEBUG */
  96                         break;
  97         }
  98
  99         return MACH_PORT_NULL;
 100 }
 101
 102
 103 __private_extern__
 104 Boolean
 105 _SCHelperOpen(CFDataRef authorizationData, mach_port_t *helper_port)
 106 {
 107         kern_return_t           kr;
 108         Boolean                 ok;
 109         mach_port_t             server;
 110         uint32_t                status  = 0;
 111
 112         *helper_port = MACH_PORT_NULL;
 113
 114         // open a new session with the server
 115         server = _helper_server;
 116         while (TRUE) {
 117                 if (server != MACH_PORT_NULL) {
 118                         kr = helperinit(server,
 119                                         helper_port,
 120                                         &status);
 121                         if (kr == KERN_SUCCESS) {
 122                                 break;
 123                         }
 124
 125                         // our [cached] server port is not valid
 126                         if (kr != MACH_SEND_INVALID_DEST) {
 127                                 // if we got an unexpected error, don't retry
 128                                 status = kr;
 129                                 break;
 130                         }
 131                 }
 132
 133                 pthread_mutex_lock(&_helper_lock);
 134                 if (_helper_server != MACH_PORT_NULL) {
 135                         if (server == _helper_server) {
 136                                 // if the server we tried returned the error
 137                                 (void)mach_port_deallocate(mach_task_self(), _helper_server);
 138                                 _helper_server = __SCHelperServerPort(&kr);
 139                                 if (_helper_server == MACH_PORT_NULL) {
 140                                         status = kr;
 141                                 }
 142                         } else {
 143                                 // another thread has refreshed the SCHelper server port
 144                         }
 145                 } else {
 146                         _helper_server = __SCHelperServerPort(&kr);
 147                         if (_helper_server == MACH_PORT_NULL) {
 148                                 status = kr;
 149                         }
 150                 }
 151                 server = _helper_server;
 152                 pthread_mutex_unlock(&_helper_lock);
 153
 154                 if (server == MACH_PORT_NULL) {
 155                         // if SCHelper server not available
 156                         break;
 157                 }
 158         }
 159         __MACH_PORT_DEBUG(TRUE, "*** _SCHelperOpen", *helper_port);
 160
 161         if (*helper_port == MACH_PORT_NULL) {
 162                 SC_log(LOG_NOTICE, "could not contact \"" HELPER "\": %s",
 163                       SCErrorString(status));
 164                 return FALSE;
 165         }
 166
 167         ok = _SCHelperExec(*helper_port, SCHELPER_MSG_AUTH, authorizationData, &status, NULL);
 168         if (!ok) {
 169                 SC_log(LOG_NOTICE, "could not send authorization");
 170                 goto error;
 171         }
 172
 173         ok = (status == 0);
 174         if (!ok) {
 175                 SC_log(LOG_NOTICE, "could not start \"" HELPER "\", status = %u", status);
 176                 goto error;
 177         }
 178
 179         return TRUE;
 180
 181     error :
 182
 183         if (*helper_port != MACH_PORT_NULL) {
 184                 (void)mach_port_deallocate(mach_task_self(), *helper_port);
 185                 *helper_port = MACH_PORT_NULL;
 186         }
 187
 188         return FALSE;
 189
 190 }
 191
 192
 193 __private_extern__
 194 void
 195 _SCHelperClose(mach_port_t *helper_port)
 196 {
 197         if (!_SCHelperExec(*helper_port, SCHELPER_MSG_EXIT, NULL, NULL, NULL)) {
 198                 SC_log(LOG_INFO, "could not send exit request");
 199         }
 200
 201         if (*helper_port != MACH_PORT_NULL) {
 202                 (void)mach_port_deallocate(mach_task_self(), *helper_port);
 203                 *helper_port = MACH_PORT_NULL;
 204         }
 205
 206         return;
 207 }
 208
 209
 210 static CFDataRef
 211 _SCHelperExecCopyBacktrace()
 212 {
 213         static Boolean          loggingEnabled  = FALSE;
 214         static dispatch_once_t  once;
 215         CFDataRef               traceData       = NULL;
 216
 217         dispatch_once(&once, ^{
 218                 if(getenv("ENABLE_SCHELPER_BACKTRACES")) {
 219                         loggingEnabled = TRUE;
 220                 }
 221         });
 222
 223         if (loggingEnabled) {
 224                 CFStringRef     backtrace;
 225
 226                 backtrace = _SC_copyBacktrace();
 227                 if (backtrace != NULL) {
 228                         _SCSerializeString(backtrace, &traceData, NULL, NULL);
 229                         CFRelease(backtrace);
 230                 }
 231         }
 232
 233         return traceData;
 234 }
 235
 236
 237 Boolean
 238 _SCHelperExec(mach_port_t port, uint32_t msgID, CFDataRef data, uint32_t *status, CFDataRef *reply)
 239 {
 240         kern_return_t           kr;
 241         CFDataRef               myData          = NULL;
 242         xmlDataOut_t            replyRef        = NULL;         /* raw bytes */
 243         mach_msg_type_number_t  replyLen        = 0;
 244         uint32_t                replyStatus     = 0;
 245         CFDataRef               traceData;
 246
 247         traceData = _SCHelperExecCopyBacktrace();
 248
 249         kr = helperexec(port,
 250                         msgID,
 251                         (data != NULL) ? (void *)CFDataGetBytePtr(data) : NULL,
 252                         (data != NULL) ? (mach_msg_type_number_t)CFDataGetLength(data) : 0,
 253                         (traceData != NULL) ? (void *)CFDataGetBytePtr(traceData) : NULL,
 254                         (traceData != NULL) ? (mach_msg_type_number_t)CFDataGetLength(traceData) : 0,
 255                         &replyStatus,
 256                         &replyRef,
 257                         &replyLen);
 258
 259         if (traceData != NULL) {
 260                 CFRelease(traceData);
 261         }
 262
 263         if (kr != KERN_SUCCESS) {
 264                 if (replyRef != NULL) {
 265                         (void) vm_deallocate(mach_task_self(), (vm_address_t)replyRef, replyLen);
 266                 }
 267
 268                 if (kr != MACH_SEND_INVALID_DEST) {
 269                         // if we got an unexpected error
 270                         SC_log(LOG_NOTICE, "_SCHelperExec() failed: %s", mach_error_string(kr));
 271                 }
 272                 _SCErrorSet(kr);
 273
 274                 return FALSE;
 275         }
 276
 277         // un-serialize the reply
 278         if (replyRef != NULL) {
 279                 if (!_SCUnserializeData(&myData, replyRef, replyLen)) {
 280                         return FALSE;
 281                 }
 282         }
 283
 284         if (status != NULL) {
 285                 *status = replyStatus;
 286         }
 287
 288         if (reply != NULL) {
 289                 *reply = myData;
 290         } else if (myData != NULL) {
 291                 SC_log(LOG_INFO, "data available with no place to go");
 292                 CFRelease(myData);
 293         }
 294
 295         return TRUE;
 296 }