src/snaprestore.m

   1 #import <Foundation/Foundation.h>
   2 #import <Foundation/NSFileManager.h>
   3 #import <sys/snapshot.h>
   4 #import <getopt.h>
   5
   6 typedef char io_string_t[512];
   7 typedef mach_port_t io_object_t;
   8 typedef io_object_t io_registry_entry_t;
   9 io_registry_entry_t IORegistryEntryFromPath(mach_port_t master, const io_string_t path);
  10 CFTypeRef IORegistryEntryCreateCFProperty(io_registry_entry_t entry, CFStringRef key, CFAllocatorRef allocator, uint32_t options);
  11 kern_return_t IOObjectRelease(io_object_t object);
  12
  13 @interface LSApplicationWorkspace : NSObject
  14 + (id)defaultWorkspace;
  15 - (BOOL)_LSPrivateRebuildApplicationDatabasesForSystemApps:(BOOL)arg1 internal:(BOOL)arg2 user:(BOOL)arg3;
  16 - (BOOL)registerApplicationDictionary:(NSDictionary *)applicationDictionary;
  17 - (BOOL)registerBundleWithInfo:(NSDictionary *)bundleInfo options:(NSDictionary *)options type:(unsigned long long)arg3 progress:(id)arg4 ;
  18 - (BOOL)registerApplication:(NSURL *)url;
  19 - (BOOL)registerPlugin:(NSURL *)url;
  20 - (BOOL)unregisterApplication:(NSURL *)url;
  21 - (NSArray *)installedPlugins;
  22 -(void)_LSPrivateSyncWithMobileInstallation;
  23 @end
  24
  25 void usage(char *name) {
  26         printf(
  27                 "Usage: %s [volume] [snapshot]\n", name);
  28 }
  29
  30 NSString *bootsnapshot() {
  31         NSMutableString *outString = [@"com.apple.os.update-" mutableCopy];
  32         const UInt8 *bytes;
  33         CFIndex length;
  34         CFDataRef manifestHash, rootSnapshotName;
  35
  36         io_registry_entry_t chosen = IORegistryEntryFromPath(0, "IODeviceTree:/chosen");
  37
  38         rootSnapshotName = IORegistryEntryCreateCFProperty(chosen, CFSTR("root-snapshot-name"), kCFAllocatorDefault, 0);
  39
  40         if (rootSnapshotName != NULL && CFGetTypeID(rootSnapshotName) == CFDataGetTypeID()) {
  41                 CFStringRef snapshotString = CFStringCreateFromExternalRepresentation(kCFAllocatorDefault, rootSnapshotName, kCFStringEncodingUTF8);
  42                 CFRelease(rootSnapshotName);
  43                 char buffer[100];
  44                 const char *ptr = CFStringGetCStringPtr(snapshotString, kCFStringEncodingUTF8);
  45                 if (ptr == NULL) {
  46                         if (CFStringGetCString(snapshotString, buffer, 100, kCFStringEncodingUTF8))
  47                                 ptr = buffer;
  48                 }
  49                 return [NSString stringWithUTF8String:ptr];
  50         } else {
  51                 manifestHash = (CFDataRef)IORegistryEntryCreateCFProperty(chosen, CFSTR("boot-manifest-hash"), kCFAllocatorDefault, 0);
  52                 IOObjectRelease(chosen);
  53
  54                 if (manifestHash == NULL || CFGetTypeID(manifestHash) != CFDataGetTypeID()) {
  55                         fprintf(stderr, "Unable to read boot-manifest-hash or root-snapshot-name\n");
  56                         exit(1);
  57                 }
  58
  59                 length = CFDataGetLength(manifestHash);
  60                 bytes = CFDataGetBytePtr(manifestHash);
  61                 CFRelease(manifestHash);
  62
  63                 for (int i = 0; i < length; i++)
  64                         [outString appendFormat:@"%02X", bytes[i]];
  65         }
  66
  67         return outString;
  68 }
  69
  70 int restore(const char *vol, const char *snap) {
  71         int fd = open(vol, O_RDONLY, 0);
  72
  73         int ret = fs_snapshot_revert(fd, snap, 0);
  74         return ret;
  75 }
  76
  77 int mount(const char *vol, const char *snap, const char *mnt) {
  78         int fd = open(vol, O_RDONLY, 0);
  79
  80         BOOL isDir;
  81         NSFileManager *fileManager = [NSFileManager defaultManager];
  82                 if(![fileManager fileExistsAtPath:[NSString stringWithUTF8String:mnt] isDirectory:&isDir])
  83                         if(![fileManager createDirectoryAtPath:[NSString stringWithUTF8String:mnt] withIntermediateDirectories:YES attributes:nil error:NULL])
  84                                 NSLog(@"Error: Create folder failed %s", mnt);
  85
  86         int ret = fs_snapshot_mount(fd, mnt, snap, 0);
  87
  88         return ret;
  89 }
  90
  91 NSMutableSet *findApps(const char *root, const char *mnt) {
  92         NSMutableString *rootApplications = [NSMutableString stringWithUTF8String:root];
  93         rootApplications = [[rootApplications stringByAppendingString:@"/Applications"] mutableCopy];
  94
  95         NSMutableString *mntApplications = [NSMutableString stringWithUTF8String:mnt];
  96         mntApplications = [[mntApplications stringByAppendingString:@"/Applications"] mutableCopy];
  97
  98         NSArray *rootApps = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:rootApplications error:nil];
  99         NSArray *mntApps = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:mntApplications error:nil];
 100
 101         NSMutableSet *ret = [[NSMutableSet alloc] init];
 102         for (NSString *app in rootApps) {
 103                 if (![mntApps containsObject:app]) {
 104                         [ret addObject:[@"/Applications/" stringByAppendingString:app]];
 105                 }
 106         }
 107
 108         return ret;
 109 }
 110
 111 int unregisterPath(NSString *path) {
 112         path = [path stringByResolvingSymlinksInPath];
 113         NSURL *url = [NSURL fileURLWithPath:path];
 114         LSApplicationWorkspace *workspace = [LSApplicationWorkspace defaultWorkspace];
 115         return [workspace unregisterApplication:url];
 116 }
 117
 118 int rename(const char *vol, const char *snap) {
 119         int fd = open(vol, O_RDONLY, 0);
 120
 121         int ret = fs_snapshot_rename(fd, snap, [bootsnapshot() UTF8String], 0);
 122         return ret;
 123 }
 124
 125 int clean() {
 126         NSArray *extrafiles = @[@"/var/lib", @"/var/cache"];
 127         NSError *error = nil;
 128         for (NSString *path in extrafiles) {
 129                 [[NSFileManager defaultManager] removeItemAtPath:path error:&error];
 130         }
 131         return 0;
 132 }
 133
 134 int main(int argc, char *argv[]) {
 135         if (argc != 3) {
 136                 usage(argv[0]);
 137                 return 0;
 138         }
 139
 140         char *vol = argv[1];
 141         char *snap = argv[2];
 142         char *mnt = "/tmp/rootfsmnt";
 143
 144         printf("Restoring snapshot %s...\n", snap);
 145         restore(vol, snap);
 146         printf("Restored snapshot...\n");
 147         printf("Mounting rootfs...\n");
 148         mount(vol, snap, mnt);
 149         printf("Mounted %s at %s\n", snap, mnt);
 150         NSMutableSet *appSet = findApps(vol, mnt);
 151         if ([appSet count]) {
 152                 for (NSString *app in appSet) {
 153                         printf("unregistering %s\n", [app UTF8String]);
 154                         unregisterPath(app);
 155                 }
 156         }
 157         printf("Cleaning up /var\n");
 158         clean();
 159         printf("Renaming snapshot...\n");
 160         rename(vol, snap);
 161         printf("Restoring %s on %s has succeeded\n", snap, vol);
 162         return 0;
 163 }