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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <stdio.h>
     18 #include <errno.h>
     19 #include <stdarg.h>
     20 #include <stdlib.h>
     21 #include <string.h>
     22 #include <sys/types.h>
     23 #include <sys/stat.h>
     24 #include <fcntl.h>
     25 #include <unistd.h>
     26 #include <cryptfs.h>
     27 
     28 #include "edify/expr.h"
     29 #include "bootloader.h"
     30 
     31 Value* WriteBootloaderFn(const char* name, State* state, int argc, Expr* argv[])
     32 {
     33     int result = -1;
     34     Value* img;
     35     Value* xloader_loc;
     36     Value* sbl_loc;
     37 
     38     if (argc != 3) {
     39         return ErrorAbort(state, "%s() expects 3 args, got %d", name, argc);
     40     }
     41 
     42     if (ReadValueArgs(state, argv, 3, &img, &xloader_loc, &sbl_loc) < 0) {
     43         return NULL;
     44     }
     45 
     46     if(img->type != VAL_BLOB ||
     47        xloader_loc->type != VAL_STRING ||
     48        sbl_loc->type != VAL_STRING) {
     49       FreeValue(img);
     50       FreeValue(xloader_loc);
     51       FreeValue(sbl_loc);
     52       return ErrorAbort(state, "%s(): argument types are incorrect", name);
     53     }
     54 
     55     result = update_bootloader(img->data, img->size,
     56                                xloader_loc->data, sbl_loc->data);
     57     FreeValue(img);
     58     FreeValue(xloader_loc);
     59     FreeValue(sbl_loc);
     60     return StringValue(strdup(result == 0 ? "t" : ""));
     61 }
     62 
     63 /*
     64  * The size of the userdata partition for HSPA Galaxy Nexus devices is incorrect
     65  * in the partition as it comes from the factory.  Updating the bootloader fixes
     66  * the partition table, and makes the size of the userdata partition 1 sector
     67  * smaller.  However, if the user had encrypted their device with the original
     68  * incorrect size of the partition table, the crypto footer has saved that
     69  * size, and tries to map that much data when decrypting.  However, with the
     70  * new partition table, that size is too big to be mapped, and the kernel
     71  * throws an error, and the user can't decrypt and boot the device after the
     72  * OTA is installed.  Oops!
     73  *
     74  * The fix here is to recognize a crypto footer that has the wrong size, and
     75  * update it to the new correct size.  This program should be run as part of
     76  * the recovery script for HSPA Galaxy Nexus devices.
     77  */
     78 
     79 #define BAD_SIZE  0x01b14fdfULL
     80 #define GOOD_SIZE 0x01b14fdeULL
     81 
     82 #define HSPA_PRIME_KEY_PARTITION "/dev/block/platform/omap/omap_hsmmc.0/by-name/metadata"
     83 
     84 Value* FsSizeFixFn(const char* name, State* state, int argc, Expr* argv[])
     85 {
     86     struct crypt_mnt_ftr ftr;
     87     int fd;
     88 
     89     if (argc != 0) {
     90         return ErrorAbort(state, "%s() expects 0 args, got %d", name, argc);
     91     }
     92 
     93     if ((fd = open(HSPA_PRIME_KEY_PARTITION, O_RDWR)) == -1) {
     94         return ErrorAbort(state, "%s() Cannot open %s\n", name, HSPA_PRIME_KEY_PARTITION);
     95     }
     96 
     97     if (read(fd, &ftr, sizeof(ftr)) != sizeof(ftr)) {
     98         close(fd);
     99         return ErrorAbort(state, "%s() Cannot read crypto footer %s\n", name, HSPA_PRIME_KEY_PARTITION);
    100     }
    101 
    102    if ((ftr.magic == CRYPT_MNT_MAGIC) && (ftr.fs_size == BAD_SIZE)) {
    103         ftr.fs_size = GOOD_SIZE;
    104         if (lseek(fd, 0, SEEK_SET) == 0) {
    105             if (write(fd, &ftr, sizeof(ftr)) == sizeof(ftr)) {
    106                 fsync(fd); /* Make sure it gets to the disk */
    107                 fprintf(stderr, "Footer updated\n");
    108                 close(fd);
    109                 return StringValue(strdup("t"));
    110             }
    111         }
    112         close(fd);
    113         return ErrorAbort(state, "%s() Cannot seek or write crypto footer %s\n", name, HSPA_PRIME_KEY_PARTITION);
    114     }
    115 
    116     /* Nothing to do */
    117     fprintf(stderr, "Footer doesn't need updating\n");
    118     close(fd);
    119     return StringValue(strdup("t"));
    120 }
    121 
    122 void Register_librecovery_updater_tuna() {
    123     fprintf(stderr, "installing samsung updater extensions\n");
    124 
    125     RegisterFunction("samsung.write_bootloader", WriteBootloaderFn);
    126     RegisterFunction("samsung.fs_size_fix", FsSizeFixFn);
    127 }
    128