postinst.mm

   1 #include <dirent.h>
   2 #include <strings.h>
   3
   4 #include <Sources.h>
   5
   6 #include <sys/stat.h>
   7 #include <sys/sysctl.h>
   8 #include <sys/types.h>
   9
  10 #include <Menes/ObjectHandle.h>
  11
  12 void Finish(const char *finish) {
  13     if (finish == NULL)
  14         return;
  15
  16     const char *cydia(getenv("CYDIA"));
  17     if (cydia == NULL)
  18         return;
  19
  20     int fd([[[[NSString stringWithUTF8String:cydia] componentsSeparatedByString:@" "] objectAtIndex:0] intValue]);
  21
  22     FILE *fout(fdopen(fd, "w"));
  23     fprintf(fout, "finish:%s\n", finish);
  24     fclose(fout);
  25 }
  26
  27 static bool setnsfpn(const char *path) {
  28     return system([[NSString stringWithFormat:@"/usr/libexec/cydia/setnsfpn %s", path] UTF8String]) == 0;
  29 }
  30
  31 static bool MoveStash() {
  32     struct stat stat;
  33
  34     if (lstat("/var/stash", &stat) == -1)
  35         return errno == ENOENT;
  36     else if (S_ISLNK(stat.st_mode))
  37         return true;
  38     else if (!S_ISDIR(stat.st_mode))
  39         return false;
  40
  41     if (lstat("/var/db/stash", &stat) == -1) {
  42         if (errno == ENOENT)
  43             goto move;
  44         else return false;
  45     } else if (S_ISLNK(stat.st_mode))
  46         // XXX: this is fixable
  47         return false;
  48     else if (!S_ISDIR(stat.st_mode))
  49         return false;
  50     else {
  51         if (!setnsfpn("/var/db/stash"))
  52             return false;
  53         if (system("mv -t /var/stash /var/db/stash/*") != 0)
  54             return false;
  55         if (rmdir("/var/db/stash") == -1)
  56             return false;
  57     } move:
  58
  59     if (!setnsfpn("/var/stash"))
  60         return false;
  61
  62     if (rename("/var/stash", "/var/db/stash") == -1)
  63         return false;
  64     if (symlink("/var/db/stash", "/var/stash") != -1)
  65         return true;
  66     if (rename("/var/db/stash", "/var/stash") != -1)
  67         return false;
  68
  69     fprintf(stderr, "/var/stash misplaced -- DO NOT REBOOT\n");
  70     return false;
  71 }
  72
  73 static bool FixProtections() {
  74     const char *path("/var/lib");
  75     mkdir(path, 0755);
  76     if (!setnsfpn(path)) {
  77         fprintf(stderr, "failed to setnsfpn %s\n", path);
  78         return false;
  79     }
  80
  81     return true;
  82 }
  83
  84 static void FixPermissions() {
  85     DIR *stash(opendir("/var/stash"));
  86     if (stash == NULL)
  87         return;
  88
  89     while (dirent *entry = readdir(stash)) {
  90         const char *folder(entry->d_name);
  91         if (strlen(folder) != 8)
  92             continue;
  93         if (strncmp(folder, "_.", 2) != 0)
  94             continue;
  95
  96         char path[1024];
  97         sprintf(path, "/var/stash/%s", folder);
  98
  99         struct stat stat;
 100         if (lstat(path, &stat) == -1)
 101             continue;
 102         if (!S_ISDIR(stat.st_mode))
 103             continue;
 104
 105         chmod(path, 0755);
 106     }
 107
 108     closedir(stash);
 109 }
 110
 111 #define APPLICATIONS "/Applications"
 112 static bool FixApplications() {
 113     char target[1024];
 114     ssize_t length(readlink(APPLICATIONS, target, sizeof(target)));
 115     if (length == -1)
 116         return false;
 117
 118     if (length >= sizeof(target)) // >= "just in case" (I'm nervous)
 119         return false;
 120     target[length] = '\0';
 121
 122     if (strlen(target) != 30)
 123         return false;
 124     if (memcmp(target, "/var/stash/Applications.", 24) != 0)
 125         return false;
 126     if (strchr(target + 24, '/') != NULL)
 127         return false;
 128
 129     struct stat stat;
 130     if (lstat(target, &stat) == -1)
 131         return false;
 132     if (!S_ISDIR(stat.st_mode))
 133         return false;
 134
 135     char temp[] = "/var/stash/_.XXXXXX";
 136     if (mkdtemp(temp) == NULL)
 137         return false;
 138
 139     if (false) undo: {
 140         unlink(temp);
 141         return false;
 142     }
 143
 144     if (chmod(temp, 0755) == -1)
 145         goto undo;
 146
 147     char destiny[strlen(temp) + 32];
 148     sprintf(destiny, "%s%s", temp, APPLICATIONS);
 149
 150     if (unlink(APPLICATIONS) == -1)
 151         goto undo;
 152
 153     if (rename(target, destiny) == -1) {
 154         if (symlink(target, APPLICATIONS) == -1)
 155             fprintf(stderr, "/Applications damaged -- DO NOT REBOOT\n");
 156         goto undo;
 157     } else {
 158         bool success;
 159         if (symlink(destiny, APPLICATIONS) != -1)
 160             success = true;
 161         else {
 162             fprintf(stderr, "/var/stash/Applications damaged -- DO NOT REBOOT\n");
 163             success = false;
 164         }
 165
 166         // unneccessary, but feels better (I'm nervous)
 167         symlink(destiny, target);
 168
 169         [@APPLICATIONS writeToFile:[NSString stringWithFormat:@"%s.lnk", temp] atomically:YES encoding:NSNonLossyASCIIStringEncoding error:NULL];
 170         return success;
 171     }
 172 }
 173
 174 int main(int argc, const char *argv[]) {
 175     if (argc < 2 || strcmp(argv[1], "configure") != 0)
 176         return 0;
 177
 178     NSAutoreleasePool *pool([[NSAutoreleasePool alloc] init]);
 179
 180     bool restart(false);
 181
 182     if (kCFCoreFoundationVersionNumber >= 1000) {
 183         if (!FixProtections())
 184             return 1;
 185         if (MoveStash())
 186             restart = true;
 187         else {
 188             fprintf(stderr, "failed to move stash\n");
 189             return 1;
 190         }
 191     }
 192
 193     #define OldCache_ "/var/root/Library/Caches/com.saurik.Cydia"
 194     if (access(OldCache_, F_OK) == 0)
 195         system("rm -rf " OldCache_);
 196
 197     #define NewCache_ "/var/mobile/Library/Caches/com.saurik.Cydia"
 198     system("cd /; su -c 'mkdir -p " NewCache_ "' mobile");
 199     if (access(NewCache_ "/lists", F_OK) != 0 && errno == ENOENT)
 200         system("cp -at " NewCache_ " /var/lib/apt/lists");
 201     system("chown -R 501.501 " NewCache_);
 202
 203     #define OldLibrary_ "/var/lib/cydia"
 204
 205     #define NewLibrary_ "/var/mobile/Library/Cydia"
 206     system("cd /; su -c 'mkdir -p " NewLibrary_ "' mobile");
 207
 208     #define Cytore_ "/metadata.cb0"
 209
 210     if (access(NewLibrary_ Cytore_, F_OK) != 0 && errno == ENOENT) {
 211         if (access(NewCache_ Cytore_, F_OK) == 0)
 212             system("mv -f " NewCache_ Cytore_ " " NewLibrary_);
 213         else if (access(OldLibrary_ Cytore_, F_OK) == 0)
 214             system("mv -f " OldLibrary_ Cytore_ " " NewLibrary_);
 215         chown(NewLibrary_ Cytore_, 501, 501);
 216     }
 217
 218     FixPermissions();
 219
 220     restart |= FixApplications();
 221
 222     if (restart)
 223         Finish("restart");
 224
 225     [pool release];
 226     return 0;
 227 }