fsck_hfs/dfalib/uuid.c

   1 #include <fcntl.h>
   2 #include <util.h>
   3 #include <unistd.h>
   4 #include <string.h>
   5 #include <sys/mount.h>
   6 #include <uuid/uuid.h>
   7 #include <IOKit/IOBSD.h>
   8 #include <IOKit/IOKitLib.h>
   9 #include <IOKit/storage/IOMedia.h>
  10
  11 extern char debug;
  12 extern void plog(const char *, ...);
  13
  14 /*
  15  * Given a uuid string, look up the BSD device and open it.
  16  * This code comes from DanM.
  17  *
  18  * Essentially, it is given a UUID string (from the journal header),
  19  * and then looks it up via IOKit.  From there, it then gets the
  20  * BSD name (e.g., /dev/dsik3), and opens it read-only.
  21  *
  22  * It returns the file descriptor, or -1 on error.
  23  */
  24 int
  25 OpenDeviceByUUID(void *uuidp, char **namep)
  26 {
  27     char devname[ MAXPATHLEN ];
  28     CFStringRef devname_string;
  29     int fd = -1;
  30     CFMutableDictionaryRef matching;
  31     io_service_t media;
  32     uuid_string_t uuid_cstring;
  33     CFStringRef uuid_string;
  34
  35     memcpy(&uuid_cstring, uuidp, sizeof(uuid_cstring));
  36
  37     uuid_string = CFStringCreateWithCString( kCFAllocatorDefault, uuid_cstring, kCFStringEncodingUTF8 );
  38     if ( uuid_string ) {
  39         matching = IOServiceMatching( kIOMediaClass );
  40         if ( matching ) {
  41             CFDictionarySetValue( matching, CFSTR( kIOMediaUUIDKey ), uuid_string );
  42             media = IOServiceGetMatchingService( kIOMasterPortDefault, matching );
  43             if ( media ) {
  44                 devname_string = IORegistryEntryCreateCFProperty( media, CFSTR( kIOBSDNameKey ), kCFAllocatorDefault, 0 );
  45                 if ( devname_string ) {
  46                     if ( CFStringGetCString( devname_string, devname, sizeof( devname ), kCFStringEncodingUTF8 ) ) {
  47                         if (debug)
  48                                 plog("external journal device name = `%s'\n", devname);
  49
  50                         fd = opendev( devname, O_RDONLY, 0, NULL );
  51                         if (fd != -1 && namep != NULL) {
  52                                 *namep = strdup(devname);
  53                         }
  54                     }
  55                     CFRelease( devname_string );
  56                 }
  57                 IOObjectRelease( media );
  58             }
  59             /* do not CFRelease( matching ); */
  60         }
  61         CFRelease( uuid_string );
  62     }
  63
  64     return fd;
  65 }