SystemConfiguration.fproj/SCPCommit.c

   1 /*
   2  * Copyright(c) 2000-2003 Apple Computer, 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 <SystemConfiguration/SystemConfiguration.h>
  35 #include <SystemConfiguration/SCPrivate.h>
  36 #include "SCPreferencesInternal.h"
  37
  38 #include <fcntl.h>
  39 #include <unistd.h>
  40 #include <sys/errno.h>
  41
  42 static ssize_t
  43 writen(int d, const void *buf, size_t nbytes)
  44 {
  45         size_t          left    = nbytes;
  46         const void      *p      = buf;
  47
  48         while (left > 0) {
  49                 ssize_t n;
  50
  51                 n = write(d, p, left);
  52                 if (n >= 0) {
  53                         left -= n;
  54                         p    += n;
  55                 } else {
  56                         if (errno != EINTR) {
  57                                 return -1;
  58                         }
  59                 }
  60         }
  61         return nbytes;
  62 }
  63
  64
  65 Boolean
  66 SCPreferencesCommitChanges(SCPreferencesRef prefs)
  67 {
  68         SCPreferencesPrivateRef prefsPrivate    = (SCPreferencesPrivateRef)prefs;
  69         Boolean                 wasLocked;
  70
  71         if (prefs == NULL) {
  72                 /* sorry, you must provide a session */
  73                 _SCErrorSet(kSCStatusNoPrefsSession);
  74                 return FALSE;
  75         }
  76
  77         /*
  78          * Determine if the we have exclusive access to the preferences
  79          * and acquire the lock if necessary.
  80          */
  81         wasLocked = prefsPrivate->locked;
  82         if (!wasLocked) {
  83                 if (!SCPreferencesLock(prefs, TRUE)) {
  84                         SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges SCPreferencesLock() failed"));
  85                         return FALSE;
  86                 }
  87         }
  88
  89         /*
  90          * if necessary, apply changes
  91          */
  92         if (prefsPrivate->changed) {
  93                 int             fd;
  94                 CFDataRef       newPrefs;
  95                 char *          path;
  96                 int             pathLen;
  97                 struct stat     statBuf;
  98                 char *          thePath;
  99
 100                 if (stat(prefsPrivate->path, &statBuf) == -1) {
 101                         if (errno == ENOENT) {
 102                                 bzero(&statBuf, sizeof(statBuf));
 103                                 statBuf.st_mode = 0644;
 104                                 statBuf.st_uid  = geteuid();
 105                                 statBuf.st_gid  = getegid();
 106                         } else {
 107                                 SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges stat() failed: %s"), strerror(errno));
 108                                 goto error;
 109                         }
 110                 }
 111
 112                 /* create the (new) preferences file */
 113                 path = prefsPrivate->newPath ? prefsPrivate->newPath : prefsPrivate->path;
 114                 pathLen = strlen(path) + sizeof("-new");
 115                 thePath = CFAllocatorAllocate(NULL, pathLen, 0);
 116                 snprintf(thePath, pathLen, "%s-new", path);
 117
 118                 /* open the (new) preferences file */
 119             reopen :
 120                 fd = open(thePath, O_WRONLY|O_CREAT, statBuf.st_mode);
 121                 if (fd == -1) {
 122                         if ((errno == ENOENT) &&
 123                             ((prefsPrivate->prefsID == NULL) || !CFStringHasPrefix(prefsPrivate->prefsID, CFSTR("/")))) {
 124                                 char    *ch;
 125
 126                                 ch = strrchr(thePath, '/');
 127                                 if (ch != NULL) {
 128                                         int     status;
 129
 130                                         *ch = '\0';
 131                                         status = mkdir(thePath, 0755);
 132                                         *ch = '/';
 133                                         if (status == 0) {
 134                                                 goto reopen;
 135                                         }
 136                                 }
 137                         }
 138                         SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges open() failed: %s"), strerror(errno));
 139                         CFAllocatorDeallocate(NULL, thePath);
 140                         goto error;
 141                 }
 142
 143                 /* preserve permissions */
 144                 (void) fchown(fd, statBuf.st_uid, statBuf.st_gid);
 145                 (void) fchmod(fd, statBuf.st_mode);
 146
 147                 /* write the new preferences */
 148                 newPrefs = CFPropertyListCreateXMLData(NULL, prefsPrivate->prefs);
 149                 if (!newPrefs) {
 150                         _SCErrorSet(kSCStatusFailed);
 151                         SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges CFPropertyListCreateXMLData() failed"));
 152                         SCLog(_sc_verbose, LOG_ERR, CFSTR("  prefs = %s"), path);
 153                         CFAllocatorDeallocate(NULL, thePath);
 154                         (void) close(fd);
 155                         goto error;
 156                 }
 157                 if (writen(fd, (void *)CFDataGetBytePtr(newPrefs), CFDataGetLength(newPrefs)) == -1) {
 158                         _SCErrorSet(errno);
 159                         SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges write() failed: %s"), strerror(errno));
 160                         SCLog(_sc_verbose, LOG_ERR, CFSTR("  path = %s"), thePath);
 161                         (void) unlink(thePath);
 162                         CFAllocatorDeallocate(NULL, thePath);
 163                         (void) close(fd);
 164                         CFRelease(newPrefs);
 165                         goto error;
 166                 }
 167                 if (fsync(fd) == -1) {
 168                         _SCErrorSet(errno);
 169                         SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges fsync() failed: %s"), strerror(errno));
 170                         SCLog(_sc_verbose, LOG_ERR, CFSTR("  path = %s"), thePath);
 171                         (void) unlink(thePath);
 172                         CFAllocatorDeallocate(NULL, thePath);
 173                         (void) close(fd);
 174                         CFRelease(newPrefs);
 175                         goto error;
 176                 }
 177                 if (close(fd) == -1) {
 178                         _SCErrorSet(errno);
 179                         SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges close() failed: %s"), strerror(errno));
 180                         SCLog(_sc_verbose, LOG_ERR, CFSTR("  path = %s"), thePath);
 181                         (void) unlink(thePath);
 182                         CFAllocatorDeallocate(NULL, thePath);
 183                         CFRelease(newPrefs);
 184                         goto error;
 185                 }
 186                 CFRelease(newPrefs);
 187
 188                 /* rename new->old */
 189                 if (rename(thePath, path) == -1) {
 190                         _SCErrorSet(errno);
 191                         SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges rename() failed: %s"), strerror(errno));
 192                         SCLog(_sc_verbose, LOG_ERR, CFSTR("  path = %s --> %s"), thePath, path);
 193                         CFAllocatorDeallocate(NULL, thePath);
 194                         goto error;
 195                 }
 196                 CFAllocatorDeallocate(NULL, thePath);
 197
 198                 if (prefsPrivate->newPath) {
 199                         /* prefs file saved in "new" directory */
 200                         (void) unlink(prefsPrivate->path);
 201                         (void) symlink(prefsPrivate->newPath, prefsPrivate->path);
 202                         CFAllocatorDeallocate(NULL, prefsPrivate->path);
 203                         prefsPrivate->path = path;
 204                         prefsPrivate->newPath = NULL;
 205                 }
 206
 207                 /* update signature */
 208                 if (stat(path, &statBuf) == -1) {
 209                         _SCErrorSet(errno);
 210                         SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges stat() failed: %s"), strerror(errno));
 211                         SCLog(_sc_verbose, LOG_ERR, CFSTR("  path = %s"), thePath);
 212                         goto error;
 213                 }
 214                 CFRelease(prefsPrivate->signature);
 215                 prefsPrivate->signature = __SCPSignatureFromStatbuf(&statBuf);
 216         }
 217
 218         if (!prefsPrivate->isRoot) {
 219                 /* CONFIGD REALLY NEEDS NON-ROOT WRITE ACCESS */
 220                 goto perUser;
 221         }
 222
 223         /* post notification */
 224         if (!SCDynamicStoreNotifyValue(prefsPrivate->session,
 225                                        prefsPrivate->sessionKeyCommit)) {
 226                 SCLog(_sc_verbose, LOG_ERR, CFSTR("SCPreferencesCommitChanges SCDynamicStoreNotifyValue() failed"));
 227                 _SCErrorSet(kSCStatusFailed);
 228                 goto error;
 229         }
 230
 231     perUser :
 232
 233         if (!wasLocked) (void) SCPreferencesUnlock(prefs);
 234         prefsPrivate->changed = FALSE;
 235         return TRUE;
 236
 237     error :
 238
 239         if (!wasLocked) (void) SCPreferencesUnlock(prefs);
 240         return FALSE;
 241 }