SystemConfiguration.fproj/helper/SCHelper_client.c

   1 /*
   2  * Copyright (c) 2005-2008, 2010, 2011, 2013 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                         SCLog(_sc_verbose, LOG_DEBUG,
  94                               CFSTR("__SCHelperServerPort bootstrap_look_up() failed: status=%s"),
  95                               bootstrap_strerror(*status));
  96 #endif  /* DEBUG */
  97                         break;
  98         }
  99
 100         return MACH_PORT_NULL;
 101 }
 102
 103
 104 __private_extern__
 105 Boolean
 106 _SCHelperOpen(CFDataRef authorizationData, mach_port_t *helper_port)
 107 {
 108         kern_return_t           kr;
 109         Boolean                 ok;
 110         mach_port_t             server;
 111         uint32_t                status  = 0;
 112
 113         *helper_port = MACH_PORT_NULL;
 114
 115         // open a new session with the server
 116         server = _helper_server;
 117         while (TRUE) {
 118                 if (server != MACH_PORT_NULL) {
 119                         kr = helperinit(server,
 120                                         helper_port,
 121                                         &status);
 122                         if (kr == KERN_SUCCESS) {
 123                                 break;
 124                         }
 125
 126                         // our [cached] server port is not valid
 127                         if (kr != MACH_SEND_INVALID_DEST) {
 128                                 // if we got an unexpected error, don't retry
 129                                 status = kr;
 130                                 break;
 131                         }
 132                 }
 133
 134                 pthread_mutex_lock(&_helper_lock);
 135                 if (_helper_server != MACH_PORT_NULL) {
 136                         if (server == _helper_server) {
 137                                 // if the server we tried returned the error
 138                                 (void)mach_port_deallocate(mach_task_self(), _helper_server);
 139                                 _helper_server = __SCHelperServerPort(&kr);
 140                                 if (_helper_server == MACH_PORT_NULL) {
 141                                         status = kr;
 142                                 }
 143                         } else {
 144                                 // another thread has refreshed the SCHelper server port
 145                         }
 146                 } else {
 147                         _helper_server = __SCHelperServerPort(&kr);
 148                         if (_helper_server == MACH_PORT_NULL) {
 149                                 status = kr;
 150                         }
 151                 }
 152                 server = _helper_server;
 153                 pthread_mutex_unlock(&_helper_lock);
 154
 155                 if (server == MACH_PORT_NULL) {
 156                         // if SCHelper server not available
 157                         break;
 158                 }
 159         }
 160         __MACH_PORT_DEBUG(TRUE, "*** _SCHelperOpen", *helper_port);
 161
 162         if (*helper_port == MACH_PORT_NULL) {
 163                 SCLog(TRUE, LOG_ERR,
 164                       CFSTR("_SCHelperOpen: could not contact server: %s"),
 165                       SCErrorString(status));
 166                 return FALSE;
 167         }
 168
 169         ok = _SCHelperExec(*helper_port, SCHELPER_MSG_AUTH, authorizationData, &status, NULL);
 170         if (!ok) {
 171                 SCLog(TRUE, LOG_INFO, CFSTR("_SCHelperOpen: could not send authorization"));
 172                 goto error;
 173         }
 174
 175         ok = (status == 0);
 176         if (!ok) {
 177                 SCLog(TRUE, LOG_INFO, CFSTR("could not start \"" HELPER "\", status = %u"), status);
 178                 goto error;
 179         }
 180
 181         return TRUE;
 182
 183     error :
 184
 185         if (*helper_port != MACH_PORT_NULL) {
 186                 (void)mach_port_deallocate(mach_task_self(), *helper_port);
 187                 *helper_port = MACH_PORT_NULL;
 188         }
 189
 190         return FALSE;
 191
 192 }
 193
 194
 195 __private_extern__
 196 void
 197 _SCHelperClose(mach_port_t *helper_port)
 198 {
 199         if (!_SCHelperExec(*helper_port, SCHELPER_MSG_EXIT, NULL, NULL, NULL)) {
 200                 SCLog(TRUE, LOG_INFO, CFSTR("_SCHelperOpen: could not send exit request"));
 201         }
 202
 203         if (*helper_port != MACH_PORT_NULL) {
 204                 (void)mach_port_deallocate(mach_task_self(), *helper_port);
 205                 *helper_port = MACH_PORT_NULL;
 206         }
 207
 208         return;
 209 }
 210
 211
 212 static CFDataRef
 213 _SCHelperExecCopyBacktrace()
 214 {
 215         static Boolean          loggingEnabled  = FALSE;
 216         static dispatch_once_t  once;
 217         CFDataRef               traceData       = NULL;
 218
 219         dispatch_once(&once, ^{
 220                 if(getenv("ENABLE_SCHELPER_BACKTRACES")) {
 221                         loggingEnabled = TRUE;
 222                 }
 223         });
 224
 225         if (loggingEnabled) {
 226                 CFStringRef     backtrace;
 227
 228                 backtrace = _SC_copyBacktrace();
 229                 if (backtrace != NULL) {
 230                         _SCSerializeString(backtrace, &traceData, NULL, NULL);
 231                         CFRelease(backtrace);
 232                 }
 233         }
 234
 235         return traceData;
 236 }
 237
 238
 239 Boolean
 240 _SCHelperExec(mach_port_t port, uint32_t msgID, CFDataRef data, uint32_t *status, CFDataRef *reply)
 241 {
 242         kern_return_t           kr;
 243         CFDataRef               myData          = NULL;
 244         xmlDataOut_t            replyRef        = NULL;         /* raw bytes */
 245         mach_msg_type_number_t  replyLen        = 0;
 246         uint32_t                replyStatus     = 0;
 247         CFDataRef               traceData;
 248
 249         traceData = _SCHelperExecCopyBacktrace();
 250
 251         kr = helperexec(port,
 252                         msgID,
 253                         (data != NULL) ? (void *)CFDataGetBytePtr(data) : NULL,
 254                         (data != NULL) ? (mach_msg_type_number_t)CFDataGetLength(data) : 0,
 255                         (traceData != NULL) ? (void *)CFDataGetBytePtr(traceData) : NULL,
 256                         (traceData != NULL) ? (mach_msg_type_number_t)CFDataGetLength(traceData) : 0,
 257                         &replyStatus,
 258                         &replyRef,
 259                         &replyLen);
 260
 261         if (traceData != NULL) {
 262                 CFRelease(traceData);
 263         }
 264
 265         if (kr != KERN_SUCCESS) {
 266                 if (replyRef != NULL) {
 267                         (void) vm_deallocate(mach_task_self(), (vm_address_t)replyRef, replyLen);
 268                 }
 269
 270                 if (kr != MACH_SEND_INVALID_DEST) {
 271                         // if we got an unexpected error
 272                         SCLog(TRUE, LOG_ERR, CFSTR("_SCHelperExec() failed: %s"), mach_error_string(kr));
 273                 }
 274                 _SCErrorSet(kr);
 275
 276                 return FALSE;
 277         }
 278
 279         // un-serialize the reply
 280         if (replyRef != NULL) {
 281                 if (!_SCUnserializeData(&myData, replyRef, replyLen)) {
 282                         return FALSE;
 283                 }
 284         }
 285
 286         if (status != NULL) {
 287                 *status = replyStatus;
 288         }
 289
 290         if (reply != NULL) {
 291                 *reply = myData;
 292         } else if (myData != NULL) {
 293                 SCLog(TRUE, LOG_DEBUG, CFSTR("_SCHelperExec() data available with no place to go"));
 294                 CFRelease(myData);
 295         }
 296
 297         return TRUE;
 298 }