SystemConfiguration.fproj/SCPUnlock.c

   1 /*
   2  * Copyright (c) 2000, 2001, 2004-2010, 2013, 2015, 2016, 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  * Modification History
  26  *
  27  * June 1, 2001                 Allan Nathanson <ajn@apple.com>
  28  * - public API conversion
  29  *
  30  * November 9, 2000             Allan Nathanson <ajn@apple.com>
  31  * - initial revision
  32  */
  33
  34 #include "SCPreferencesInternal.h"
  35 #include "SCHelper_client.h"
  36
  37 #include <unistd.h>
  38 #include <pthread.h>
  39
  40
  41 static Boolean
  42 __SCPreferencesUnlock_helper(SCPreferencesRef prefs)
  43 {
  44         Boolean                 ok;
  45         SCPreferencesPrivateRef prefsPrivate    = (SCPreferencesPrivateRef)prefs;
  46         uint32_t                status          = kSCStatusOK;
  47
  48         if (prefsPrivate->helper_port == MACH_PORT_NULL) {
  49                 // if no helper
  50                 goto fail;
  51         }
  52
  53         // have the helper "unlock" the prefs
  54 //      status = kSCStatusOK;
  55         ok = _SCHelperExec(prefsPrivate->helper_port,
  56                            SCHELPER_MSG_PREFS_UNLOCK,
  57                            NULL,
  58                            &status,
  59                            NULL);
  60         if (!ok) {
  61                 goto fail;
  62         }
  63
  64         if (status != kSCStatusOK) {
  65                 goto error;
  66         }
  67
  68         __SCPreferencesUpdateLockedState(prefs, FALSE);
  69         return TRUE;
  70
  71     fail :
  72
  73         // close helper
  74         if (prefsPrivate->helper_port != MACH_PORT_NULL) {
  75                 _SCHelperClose(&prefsPrivate->helper_port);
  76         }
  77
  78         status = kSCStatusAccessError;
  79
  80     error :
  81
  82         // return error
  83         _SCErrorSet(status);
  84         return FALSE;
  85 }
  86
  87
  88 static void
  89 reportDelay(SCPreferencesRef prefs, struct timeval *delay)
  90 {
  91         SCPreferencesPrivateRef prefsPrivate    = (SCPreferencesPrivateRef)prefs;
  92
  93         SC_log(LOG_ERR,
  94                "SCPreferences(%@:%@) lock held for %d.%3.3d seconds",
  95                prefsPrivate->name,
  96                prefsPrivate->prefsID,
  97                (int)delay->tv_sec,
  98                delay->tv_usec / 1000);
  99         return;
 100 }
 101
 102
 103 Boolean
 104 SCPreferencesUnlock(SCPreferencesRef prefs)
 105 {
 106         struct timeval          lockElapsed;
 107         struct timeval          lockEnd;
 108         SCPreferencesPrivateRef prefsPrivate    = (SCPreferencesPrivateRef)prefs;
 109
 110         if (prefs == NULL) {
 111                 /* sorry, you must provide a session */
 112                 _SCErrorSet(kSCStatusNoPrefsSession);
 113                 return FALSE;
 114         }
 115
 116         if (!prefsPrivate->locked) {
 117                 /* sorry, you don't have the lock */
 118                 _SCErrorSet(kSCStatusNeedLock);
 119                 return FALSE;
 120         }
 121
 122         if (prefsPrivate->authorizationData != NULL) {
 123                 return __SCPreferencesUnlock_helper(prefs);
 124         }
 125
 126         pthread_mutex_lock(&prefsPrivate->lock);
 127
 128         if (prefsPrivate->sessionNoO_EXLOCK != NULL) {
 129                 // Note: closing the session removes the temporary "lock" key
 130                 CFRelease(prefsPrivate->sessionNoO_EXLOCK);
 131                 prefsPrivate->sessionNoO_EXLOCK = NULL;
 132         }
 133
 134         if (prefsPrivate->lockFD != -1) {
 135                 if (prefsPrivate->lockPath != NULL) {
 136                         unlink(prefsPrivate->lockPath);
 137                 }
 138                 close(prefsPrivate->lockFD);
 139                 prefsPrivate->lockFD = -1;
 140         }
 141
 142         (void)gettimeofday(&lockEnd, NULL);
 143         timersub(&lockEnd, &prefsPrivate->lockTime, &lockElapsed);
 144         if (lockElapsed.tv_sec > 0) {
 145                 // if we held the lock for more than 1 second
 146                 reportDelay(prefs, &lockElapsed);
 147         }
 148
 149         SC_log(LOG_DEBUG, "SCPreferences() unlock: %s",
 150                prefsPrivate->newPath ? prefsPrivate->newPath : prefsPrivate->path);
 151
 152         __SCPreferencesUpdateLockedState(prefs, FALSE);
 153
 154         pthread_mutex_unlock(&prefsPrivate->lock);
 155         return TRUE;
 156 }