SystemConfiguration.fproj/helper/SCHelper_client.c

   1 /*
   2  * Copyright (c) 2005-2007, 2010 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
  41 #include <CoreFoundation/CoreFoundation.h>
  42 #include <SystemConfiguration/SCPrivate.h>
  43
  44 #include "SCHelper_client.h"
  45 #include "helper.h"             // MiG generated file
  46
  47
  48 #define HELPER                                  "SCHelper"
  49 #define HELPER_LEN                              (sizeof(HELPER) - 1)
  50
  51 #define SUFFIX_SYM                              "~sym"
  52 #define SUFFIX_SYM_LEN                          (sizeof(SUFFIX_SYM) - 1)
  53
  54
  55 static pthread_mutex_t  _helper_lock    = PTHREAD_MUTEX_INITIALIZER;
  56 static mach_port_t      _helper_server  = MACH_PORT_NULL;
  57
  58
  59 static mach_port_t
  60 __SCHelperServerPort(kern_return_t *status)
  61 {
  62         mach_port_t     server  = MACH_PORT_NULL;
  63         char            *server_name;
  64
  65         server_name = getenv("SCHELPER_SERVER");
  66         if (!server_name) {
  67                 server_name = SCHELPER_SERVER;
  68         }
  69
  70 #ifdef  BOOTSTRAP_PRIVILEGED_SERVER
  71         *status = bootstrap_look_up2(bootstrap_port,
  72                                      server_name,
  73                                      &server,
  74                                      0,
  75                                      BOOTSTRAP_PRIVILEGED_SERVER);
  76 #else   // BOOTSTRAP_PRIVILEGED_SERVER
  77         *status = bootstrap_look_up(bootstrap_port, server_name, &server);
  78 #endif  // BOOTSTRAP_PRIVILEGED_SERVER
  79
  80         switch (*status) {
  81                 case BOOTSTRAP_SUCCESS :
  82                         /* service currently registered, "a good thing" (tm) */
  83                         return server;
  84                 case BOOTSTRAP_NOT_PRIVILEGED :
  85                         /* the service is not privileged */
  86                         break;
  87                 case BOOTSTRAP_UNKNOWN_SERVICE :
  88                         /* service not currently registered, try again later */
  89                         break;
  90                 default :
  91 #ifdef  DEBUG
  92                         SCLog(_sc_verbose, LOG_DEBUG,
  93                               CFSTR("__SCHelperServerPort 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                 SCLog(TRUE, LOG_ERR,
 163                       CFSTR("_SCHelperOpen: could not contact server: %s"),
 164                       SCErrorString(status));
 165                 return FALSE;
 166         }
 167
 168         ok = _SCHelperExec(*helper_port, SCHELPER_MSG_AUTH, authorizationData, &status, NULL);
 169         if (!ok) {
 170                 SCLog(TRUE, LOG_INFO, CFSTR("_SCHelperOpen: could not send authorization"));
 171                 goto error;
 172         }
 173
 174         ok = (status == 0);
 175         if (!ok) {
 176                 SCLog(TRUE, LOG_INFO, CFSTR("could not start \"" HELPER "\", status = %u"), status);
 177                 goto error;
 178         }
 179
 180         return TRUE;
 181
 182     error :
 183
 184         if (*helper_port != MACH_PORT_NULL) {
 185                 (void)mach_port_deallocate(mach_task_self(), *helper_port);
 186                 *helper_port = MACH_PORT_NULL;
 187         }
 188
 189         return FALSE;
 190
 191 }
 192
 193
 194 __private_extern__
 195 void
 196 _SCHelperClose(mach_port_t *helper_port)
 197 {
 198         if (!_SCHelperExec(*helper_port, SCHELPER_MSG_EXIT, NULL, NULL, NULL)) {
 199                 SCLog(TRUE, LOG_INFO, CFSTR("_SCHelperOpen: could not send exit request"));
 200         }
 201
 202         if (*helper_port != MACH_PORT_NULL) {
 203                 (void)mach_port_deallocate(mach_task_self(), *helper_port);
 204                 *helper_port = MACH_PORT_NULL;
 205         }
 206
 207         return;
 208 }
 209
 210
 211 Boolean
 212 _SCHelperExec(mach_port_t port, uint32_t msgID, CFDataRef data, uint32_t *status, CFDataRef *reply)
 213 {
 214         kern_return_t           kr;
 215         CFDataRef               myData          = NULL;
 216         xmlDataOut_t            replyRef        = NULL;         /* raw bytes */
 217         mach_msg_type_number_t  replyLen        = 0;
 218         uint32_t                replyStatus     = 0;
 219
 220         kr = helperexec(port,
 221                         msgID,
 222                         (data != NULL) ? (void *)CFDataGetBytePtr(data) : NULL,
 223                         (data != NULL) ? CFDataGetLength(data)  : 0,
 224                         &replyStatus,
 225                         &replyRef,
 226                         &replyLen);
 227         if (kr != KERN_SUCCESS) {
 228                 if (replyRef != NULL) {
 229                         (void) vm_deallocate(mach_task_self(), (vm_address_t)replyRef, replyLen);
 230                 }
 231
 232                 if (kr != MACH_SEND_INVALID_DEST) {
 233                         // if we got an unexpected error
 234                         SCLog(TRUE, LOG_ERR, CFSTR("_SCHelperExec() failed: %s"), mach_error_string(kr));
 235                 }
 236                 _SCErrorSet(kr);
 237
 238                 return FALSE;
 239         }
 240
 241         // un-serialize the reply
 242         if (replyRef != NULL) {
 243                 if (!_SCUnserializeData(&myData, replyRef, replyLen)) {
 244                         return FALSE;
 245                 }
 246         }
 247
 248         if (status != NULL) {
 249                 *status = replyStatus;
 250         }
 251
 252         if (reply != NULL) {
 253                 *reply = myData;
 254         } else if (myData != NULL) {
 255                 SCLog(TRUE, LOG_DEBUG, CFSTR("_SCHelperExec() data available with no place to go"));
 256                 CFRelease(myData);
 257         }
 258
 259         return TRUE;
 260 }