tequilaOS/platform_bootable_recovery
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
platform_bootable_recovery/applypatch/applypatch.c
Doug Zongker 044a0b4d49 recovery: try to write EMMC partitions more reliably 
Nexus 4 has flash errors that manifest during large writes (eg, of the
radio partition).  Writes of some blocks seem to be dropped silently,
without any errors being returned to the user level.

Make two changes to the partition-writing code:

- break it up into 1MB writes instead of writing partitions with a
  single fwrite() call.  Pause for 50ms in between every chunk.

- read the partition back after writing and verify that we read what
  we wrote.  Drop caches before reading so we (hopefully) are reading
  off the actual flash and not some cache.

Neither of these should be necessary.

Bug: 9602014

Change-Id: Ice2e24dd4c11f1a57968277b5eb1468c772f6f63
2013-07-08 12:59:22 -07:00

1021 lines
34 KiB
C
Raw Blame History

/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include "mincrypt/sha.h"
#include "applypatch.h"
#include "mtdutils/mtdutils.h"
#include "edify/expr.h"
static int LoadPartitionContents(const char* filename, FileContents* file);
static ssize_t FileSink(unsigned char* data, ssize_t len, void* token);
static int GenerateTarget(FileContents* source_file,
const Value* source_patch_value,
FileContents* copy_file,
const Value* copy_patch_value,
const char* source_filename,
const char* target_filename,
const uint8_t target_sha1[SHA_DIGEST_SIZE],
size_t target_size,
const Value* bonus_data);
static int mtd_partitions_scanned = 0;
// Read a file into memory; optionally (retouch_flag == RETOUCH_DO_MASK) mask
// the retouched entries back to their original value (such that SHA-1 checks
// don't fail due to randomization); store the file contents and associated
// metadata in *file.
//
// Return 0 on success.
int LoadFileContents(const char* filename, FileContents* file,
int retouch_flag) {
file->data = NULL;
// A special 'filename' beginning with "MTD:" or "EMMC:" means to
// load the contents of a partition.
if (strncmp(filename, "MTD:", 4) == 0 ||
strncmp(filename, "EMMC:", 5) == 0) {
return LoadPartitionContents(filename, file);
}
if (stat(filename, &file->st) != 0) {
printf("failed to stat \"%s\": %s\n", filename, strerror(errno));
return -1;
}
file->size = file->st.st_size;
file->data = malloc(file->size);
FILE* f = fopen(filename, "rb");
if (f == NULL) {
printf("failed to open \"%s\": %s\n", filename, strerror(errno));
free(file->data);
file->data = NULL;
return -1;
}
ssize_t bytes_read = fread(file->data, 1, file->size, f);
if (bytes_read != file->size) {
printf("short read of \"%s\" (%ld bytes of %ld)\n",
filename, (long)bytes_read, (long)file->size);
free(file->data);
file->data = NULL;
return -1;
}
fclose(f);
// apply_patch[_check] functions are blind to randomization. Randomization
// is taken care of in [Undo]RetouchBinariesFn. If there is a mismatch
// within a file, this means the file is assumed "corrupt" for simplicity.
if (retouch_flag) {
int32_t desired_offset = 0;
if (retouch_mask_data(file->data, file->size,
&desired_offset, NULL) != RETOUCH_DATA_MATCHED) {
printf("error trying to mask retouch entries\n");
free(file->data);
file->data = NULL;
return -1;
}
}
SHA(file->data, file->size, file->sha1);
return 0;
}
static size_t* size_array;
// comparison function for qsort()ing an int array of indexes into
// size_array[].
static int compare_size_indices(const void* a, const void* b) {
int aa = *(int*)a;
int bb = *(int*)b;
if (size_array[aa] < size_array[bb]) {
return -1;
} else if (size_array[aa] > size_array[bb]) {
return 1;
} else {
return 0;
}
}
// Load the contents of an MTD or EMMC partition into the provided
// FileContents. filename should be a string of the form
// "MTD:<partition_name>:<size_1>:<sha1_1>:<size_2>:<sha1_2>:..." (or
// "EMMC:<partition_device>:..."). The smallest size_n bytes for
// which that prefix of the partition contents has the corresponding
// sha1 hash will be loaded. It is acceptable for a size value to be
// repeated with different sha1s. Will return 0 on success.
//
// This complexity is needed because if an OTA installation is
// interrupted, the partition might contain either the source or the
// target data, which might be of different lengths. We need to know
// the length in order to read from a partition (there is no
// "end-of-file" marker), so the caller must specify the possible
// lengths and the hash of the data, and we'll do the load expecting
// to find one of those hashes.
enum PartitionType { MTD, EMMC };
static int LoadPartitionContents(const char* filename, FileContents* file) {
char* copy = strdup(filename);
const char* magic = strtok(copy, ":");
enum PartitionType type;
if (strcmp(magic, "MTD") == 0) {
type = MTD;
} else if (strcmp(magic, "EMMC") == 0) {
type = EMMC;
} else {
printf("LoadPartitionContents called with bad filename (%s)\n",
filename);
return -1;
}
const char* partition = strtok(NULL, ":");
int i;
int colons = 0;
for (i = 0; filename[i] != '\0'; ++i) {
if (filename[i] == ':') {
++colons;
}
}
if (colons < 3 || colons%2 == 0) {
printf("LoadPartitionContents called with bad filename (%s)\n",
filename);
}
int pairs = (colons-1)/2; // # of (size,sha1) pairs in filename
int* index = malloc(pairs * sizeof(int));
size_t* size = malloc(pairs * sizeof(size_t));
char** sha1sum = malloc(pairs * sizeof(char*));
for (i = 0; i < pairs; ++i) {
const char* size_str = strtok(NULL, ":");
size[i] = strtol(size_str, NULL, 10);
if (size[i] == 0) {
printf("LoadPartitionContents called with bad size (%s)\n", filename);
return -1;
}
sha1sum[i] = strtok(NULL, ":");
index[i] = i;
}
// sort the index[] array so it indexes the pairs in order of
// increasing size.
size_array = size;
qsort(index, pairs, sizeof(int), compare_size_indices);
MtdReadContext* ctx = NULL;
FILE* dev = NULL;
switch (type) {
case MTD:
if (!mtd_partitions_scanned) {
mtd_scan_partitions();
mtd_partitions_scanned = 1;
}
const MtdPartition* mtd = mtd_find_partition_by_name(partition);
if (mtd == NULL) {
printf("mtd partition \"%s\" not found (loading %s)\n",
partition, filename);
return -1;
}
ctx = mtd_read_partition(mtd);
if (ctx == NULL) {
printf("failed to initialize read of mtd partition \"%s\"\n",
partition);
return -1;
}
break;
case EMMC:
dev = fopen(partition, "rb");
if (dev == NULL) {
printf("failed to open emmc partition \"%s\": %s\n",
partition, strerror(errno));
return -1;
}
}
SHA_CTX sha_ctx;
SHA_init(&sha_ctx);
uint8_t parsed_sha[SHA_DIGEST_SIZE];
// allocate enough memory to hold the largest size.
file->data = malloc(size[index[pairs-1]]);
char* p = (char*)file->data;
file->size = 0; // # bytes read so far
for (i = 0; i < pairs; ++i) {
// Read enough additional bytes to get us up to the next size
// (again, we're trying the possibilities in order of increasing
// size).
size_t next = size[index[i]] - file->size;
size_t read = 0;
if (next > 0) {
switch (type) {
case MTD:
read = mtd_read_data(ctx, p, next);
break;
case EMMC:
read = fread(p, 1, next, dev);
break;
}
if (next != read) {
printf("short read (%d bytes of %d) for partition \"%s\"\n",
read, next, partition);
free(file->data);
file->data = NULL;
return -1;
}
SHA_update(&sha_ctx, p, read);
file->size += read;
}
// Duplicate the SHA context and finalize the duplicate so we can
// check it against this pair's expected hash.
SHA_CTX temp_ctx;
memcpy(&temp_ctx, &sha_ctx, sizeof(SHA_CTX));
const uint8_t* sha_so_far = SHA_final(&temp_ctx);
if (ParseSha1(sha1sum[index[i]], parsed_sha) != 0) {
printf("failed to parse sha1 %s in %s\n",
sha1sum[index[i]], filename);
free(file->data);
file->data = NULL;
return -1;
}
if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_SIZE) == 0) {
// we have a match. stop reading the partition; we'll return
// the data we've read so far.
printf("partition read matched size %d sha %s\n",
size[index[i]], sha1sum[index[i]]);
break;
}
p += read;
}
switch (type) {
case MTD:
mtd_read_close(ctx);
break;
case EMMC:
fclose(dev);
break;
}
if (i == pairs) {
// Ran off the end of the list of (size,sha1) pairs without
// finding a match.
printf("contents of partition \"%s\" didn't match %s\n",
partition, filename);
free(file->data);
file->data = NULL;
return -1;
}
const uint8_t* sha_final = SHA_final(&sha_ctx);
for (i = 0; i < SHA_DIGEST_SIZE; ++i) {
file->sha1[i] = sha_final[i];
}
// Fake some stat() info.
file->st.st_mode = 0644;
file->st.st_uid = 0;
file->st.st_gid = 0;
free(copy);
free(index);
free(size);
free(sha1sum);
return 0;
}
// Save the contents of the given FileContents object under the given
// filename. Return 0 on success.
int SaveFileContents(const char* filename, const FileContents* file) {
int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
if (fd < 0) {
printf("failed to open \"%s\" for write: %s\n",
filename, strerror(errno));
return -1;
}
ssize_t bytes_written = FileSink(file->data, file->size, &fd);
if (bytes_written != file->size) {
printf("short write of \"%s\" (%ld bytes of %ld) (%s)\n",
filename, (long)bytes_written, (long)file->size,
strerror(errno));
close(fd);
return -1;
}
fsync(fd);
close(fd);
if (chmod(filename, file->st.st_mode) != 0) {
printf("chmod of \"%s\" failed: %s\n", filename, strerror(errno));
return -1;
}
if (chown(filename, file->st.st_uid, file->st.st_gid) != 0) {
printf("chown of \"%s\" failed: %s\n", filename, strerror(errno));
return -1;
}
return 0;
}
// Write a memory buffer to 'target' partition, a string of the form
// "MTD:<partition>[:...]" or "EMMC:<partition_device>:". Return 0 on
// success.
int WriteToPartition(unsigned char* data, size_t len,
const char* target) {
char* copy = strdup(target);
const char* magic = strtok(copy, ":");
enum PartitionType type;
if (strcmp(magic, "MTD") == 0) {
type = MTD;
} else if (strcmp(magic, "EMMC") == 0) {
type = EMMC;
} else {
printf("WriteToPartition called with bad target (%s)\n", target);
return -1;
}
const char* partition = strtok(NULL, ":");
if (partition == NULL) {
printf("bad partition target name \"%s\"\n", target);
return -1;
}
switch (type) {
case MTD:
if (!mtd_partitions_scanned) {
mtd_scan_partitions();
mtd_partitions_scanned = 1;
}
const MtdPartition* mtd = mtd_find_partition_by_name(partition);
if (mtd == NULL) {
printf("mtd partition \"%s\" not found for writing\n",
partition);
return -1;
}
MtdWriteContext* ctx = mtd_write_partition(mtd);
if (ctx == NULL) {
printf("failed to init mtd partition \"%s\" for writing\n",
partition);
return -1;
}
size_t written = mtd_write_data(ctx, (char*)data, len);
if (written != len) {
printf("only wrote %d of %d bytes to MTD %s\n",
written, len, partition);
mtd_write_close(ctx);
return -1;
}
if (mtd_erase_blocks(ctx, -1) < 0) {
printf("error finishing mtd write of %s\n", partition);
mtd_write_close(ctx);
return -1;
}
if (mtd_write_close(ctx)) {
printf("error closing mtd write of %s\n", partition);
return -1;
}
break;
case EMMC:
{
size_t start = 0;
int success = 0;
FILE* f = fopen(partition, "r+b");
if (f == NULL) {
printf("failed to open %s: %s\n", partition, strerror(errno));
return -1;
}
int attempt;
for (attempt = 0; attempt < 3; ++attempt) {
printf("write %s attempt %d start at %d\n", partition, attempt+1, start);
fseek(f, start, SEEK_SET);
while (start < len) {
size_t to_write = len - start;
if (to_write > (1<<20)) to_write = 1<<20;
if (fwrite(data+start, 1, to_write, f) != to_write) {
printf("short write writing to %s (%s)\n",
partition, strerror(errno));
return -1;
}
start += to_write;
if (start < len) {
usleep(50000); // 50 ms
}
}
// drop caches so our subsequent verification read
// won't just be reading the cache.
sync();
FILE* dc = fopen("/proc/sys/vm/drop_caches", "w");
fwrite("3\n", 2, 1, dc);
fclose(dc);
sleep(1);
printf(" caches dropped\n");
// verify
fseek(f, 0, SEEK_SET);
unsigned char buffer[4096];
start = len;
size_t p;
for (p = 0; p < len; p += sizeof(buffer)) {
size_t to_read = len - p;
if (to_read > sizeof(buffer)) to_read = sizeof(buffer);
if (fread(buffer, 1, to_read, f) != to_read) {
printf("short verify read %s at %d: %s\n",
partition, p, strerror(errno));
start = p;
break;
}
if (memcmp(buffer, data+p, to_read)) {
printf("verification failed starting at %d\n", p);
start = p;
break;
}
}
if (start == len) {
printf("verification read succeeded (attempt %d)\n", attempt+1);
success = true;
break;
}
}
if (!success) {
printf("failed to verify after all attempts\n");
return -1;
}
if (fclose(f) != 0) {
printf("error closing %s (%s)\n", partition, strerror(errno));
return -1;
}
break;
}
}
free(copy);
return 0;
}
// Take a string 'str' of 40 hex digits and parse it into the 20
// byte array 'digest'. 'str' may contain only the digest or be of
// the form "<digest>:<anything>". Return 0 on success, -1 on any
// error.
int ParseSha1(const char* str, uint8_t* digest) {
int i;
const char* ps = str;
uint8_t* pd = digest;
for (i = 0; i < SHA_DIGEST_SIZE * 2; ++i, ++ps) {
int digit;
if (*ps >= '0' && *ps <= '9') {
digit = *ps - '0';
} else if (*ps >= 'a' && *ps <= 'f') {
digit = *ps - 'a' + 10;
} else if (*ps >= 'A' && *ps <= 'F') {
digit = *ps - 'A' + 10;
} else {
return -1;
}
if (i % 2 == 0) {
*pd = digit << 4;
} else {
*pd |= digit;
++pd;
}
}
if (*ps != '\0') return -1;
return 0;
}
// Search an array of sha1 strings for one matching the given sha1.
// Return the index of the match on success, or -1 if no match is
// found.
int FindMatchingPatch(uint8_t* sha1, char* const * const patch_sha1_str,
int num_patches) {
int i;
uint8_t patch_sha1[SHA_DIGEST_SIZE];
for (i = 0; i < num_patches; ++i) {
if (ParseSha1(patch_sha1_str[i], patch_sha1) == 0 &&
memcmp(patch_sha1, sha1, SHA_DIGEST_SIZE) == 0) {
return i;
}
}
return -1;
}
// Returns 0 if the contents of the file (argv[2]) or the cached file
// match any of the sha1's on the command line (argv[3:]). Returns
// nonzero otherwise.
int applypatch_check(const char* filename,
int num_patches, char** const patch_sha1_str) {
FileContents file;
file.data = NULL;
// It's okay to specify no sha1s; the check will pass if the
// LoadFileContents is successful. (Useful for reading
// partitions, where the filename encodes the sha1s; no need to
// check them twice.)
if (LoadFileContents(filename, &file, RETOUCH_DO_MASK) != 0 ||
(num_patches > 0 &&
FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0)) {
printf("file \"%s\" doesn't have any of expected "
"sha1 sums; checking cache\n", filename);
free(file.data);
file.data = NULL;
// If the source file is missing or corrupted, it might be because
// we were killed in the middle of patching it. A copy of it
// should have been made in CACHE_TEMP_SOURCE. If that file
// exists and matches the sha1 we're looking for, the check still
// passes.
if (LoadFileContents(CACHE_TEMP_SOURCE, &file, RETOUCH_DO_MASK) != 0) {
printf("failed to load cache file\n");
return 1;
}
if (FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0) {
printf("cache bits don't match any sha1 for \"%s\"\n", filename);
free(file.data);
return 1;
}
}
free(file.data);
return 0;
}
int ShowLicenses() {
ShowBSDiffLicense();
return 0;
}
ssize_t FileSink(unsigned char* data, ssize_t len, void* token) {
int fd = *(int *)token;
ssize_t done = 0;
ssize_t wrote;
while (done < (ssize_t) len) {
wrote = write(fd, data+done, len-done);
if (wrote <= 0) {
printf("error writing %d bytes: %s\n", (int)(len-done), strerror(errno));
return done;
}
done += wrote;
}
return done;
}
typedef struct {
unsigned char* buffer;
ssize_t size;
ssize_t pos;
} MemorySinkInfo;
ssize_t MemorySink(unsigned char* data, ssize_t len, void* token) {
MemorySinkInfo* msi = (MemorySinkInfo*)token;
if (msi->size - msi->pos < len) {
return -1;
}
memcpy(msi->buffer + msi->pos, data, len);
msi->pos += len;
return len;
}
// Return the amount of free space (in bytes) on the filesystem
// containing filename. filename must exist. Return -1 on error.
size_t FreeSpaceForFile(const char* filename) {
struct statfs sf;
if (statfs(filename, &sf) != 0) {
printf("failed to statfs %s: %s\n", filename, strerror(errno));
return -1;
}
return sf.f_bsize * sf.f_bfree;
}
int CacheSizeCheck(size_t bytes) {
if (MakeFreeSpaceOnCache(bytes) < 0) {
printf("unable to make %ld bytes available on /cache\n", (long)bytes);
return 1;
} else {
return 0;
}
}
static void print_short_sha1(const uint8_t sha1[SHA_DIGEST_SIZE]) {
int i;
const char* hex = "0123456789abcdef";
for (i = 0; i < 4; ++i) {
putchar(hex[(sha1[i]>>4) & 0xf]);
putchar(hex[sha1[i] & 0xf]);
}
}
// This function applies binary patches to files in a way that is safe
// (the original file is not touched until we have the desired
// replacement for it) and idempotent (it's okay to run this program
// multiple times).
//
// - if the sha1 hash of <target_filename> is <target_sha1_string>,
// does nothing and exits successfully.
//
// - otherwise, if the sha1 hash of <source_filename> is one of the
// entries in <patch_sha1_str>, the corresponding patch from
// <patch_data> (which must be a VAL_BLOB) is applied to produce a
// new file (the type of patch is automatically detected from the
// blob daat). If that new file has sha1 hash <target_sha1_str>,
// moves it to replace <target_filename>, and exits successfully.
// Note that if <source_filename> and <target_filename> are not the
// same, <source_filename> is NOT deleted on success.
// <target_filename> may be the string "-" to mean "the same as
// source_filename".
//
// - otherwise, or if any error is encountered, exits with non-zero
// status.
//
// <source_filename> may refer to a partition to read the source data.
// See the comments for the LoadPartition Contents() function above
// for the format of such a filename.
int applypatch(const char* source_filename,
const char* target_filename,
const char* target_sha1_str,
size_t target_size,
int num_patches,
char** const patch_sha1_str,
Value** patch_data,
Value* bonus_data) {
printf("patch %s: ", source_filename);
if (target_filename[0] == '-' &&
target_filename[1] == '\0') {
target_filename = source_filename;
}
uint8_t target_sha1[SHA_DIGEST_SIZE];
if (ParseSha1(target_sha1_str, target_sha1) != 0) {
printf("failed to parse tgt-sha1 \"%s\"\n", target_sha1_str);
return 1;
}
FileContents copy_file;
FileContents source_file;
copy_file.data = NULL;
source_file.data = NULL;
const Value* source_patch_value = NULL;
const Value* copy_patch_value = NULL;
// We try to load the target file into the source_file object.
if (LoadFileContents(target_filename, &source_file,
RETOUCH_DO_MASK) == 0) {
if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) {
// The early-exit case: the patch was already applied, this file
// has the desired hash, nothing for us to do.
printf("already ");
print_short_sha1(target_sha1);
putchar('\n');
free(source_file.data);
return 0;
}
}
if (source_file.data == NULL ||
(target_filename != source_filename &&
strcmp(target_filename, source_filename) != 0)) {
// Need to load the source file: either we failed to load the
// target file, or we did but it's different from the source file.
free(source_file.data);
source_file.data = NULL;
LoadFileContents(source_filename, &source_file,
RETOUCH_DO_MASK);
}
if (source_file.data != NULL) {
int to_use = FindMatchingPatch(source_file.sha1,
patch_sha1_str, num_patches);
if (to_use >= 0) {
source_patch_value = patch_data[to_use];
}
}
if (source_patch_value == NULL) {
free(source_file.data);
source_file.data = NULL;
printf("source file is bad; trying copy\n");
if (LoadFileContents(CACHE_TEMP_SOURCE, &copy_file,
RETOUCH_DO_MASK) < 0) {
// fail.
printf("failed to read copy file\n");
return 1;
}
int to_use = FindMatchingPatch(copy_file.sha1,
patch_sha1_str, num_patches);
if (to_use >= 0) {
copy_patch_value = patch_data[to_use];
}
if (copy_patch_value == NULL) {
// fail.
printf("copy file doesn't match source SHA-1s either\n");
free(copy_file.data);
return 1;
}
}
int result = GenerateTarget(&source_file, source_patch_value,
&copy_file, copy_patch_value,
source_filename, target_filename,
target_sha1, target_size, bonus_data);
free(source_file.data);
free(copy_file.data);
return result;
}
static int GenerateTarget(FileContents* source_file,
const Value* source_patch_value,
FileContents* copy_file,
const Value* copy_patch_value,
const char* source_filename,
const char* target_filename,
const uint8_t target_sha1[SHA_DIGEST_SIZE],
size_t target_size,
const Value* bonus_data) {
int retry = 1;
SHA_CTX ctx;
int output;
MemorySinkInfo msi;
FileContents* source_to_use;
char* outname;
int made_copy = 0;
// assume that target_filename (eg "/system/app/Foo.apk") is located
// on the same filesystem as its top-level directory ("/system").
// We need something that exists for calling statfs().
char target_fs[strlen(target_filename)+1];
char* slash = strchr(target_filename+1, '/');
if (slash != NULL) {
int count = slash - target_filename;
strncpy(target_fs, target_filename, count);
target_fs[count] = '\0';
} else {
strcpy(target_fs, target_filename);
}
do {
// Is there enough room in the target filesystem to hold the patched
// file?
if (strncmp(target_filename, "MTD:", 4) == 0 ||
strncmp(target_filename, "EMMC:", 5) == 0) {
// If the target is a partition, we're actually going to
// write the output to /tmp and then copy it to the
// partition. statfs() always returns 0 blocks free for
// /tmp, so instead we'll just assume that /tmp has enough
// space to hold the file.
// We still write the original source to cache, in case
// the partition write is interrupted.
if (MakeFreeSpaceOnCache(source_file->size) < 0) {
printf("not enough free space on /cache\n");
return 1;
}
if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) {
printf("failed to back up source file\n");
return 1;
}
made_copy = 1;
retry = 0;
} else {
int enough_space = 0;
if (retry > 0) {
size_t free_space = FreeSpaceForFile(target_fs);
enough_space =
(free_space > (256 << 10)) && // 256k (two-block) minimum
(free_space > (target_size * 3 / 2)); // 50% margin of error
if (!enough_space) {
printf("target %ld bytes; free space %ld bytes; retry %d; enough %d\n",
(long)target_size, (long)free_space, retry, enough_space);
}
}
if (!enough_space) {
retry = 0;
}
if (!enough_space && source_patch_value != NULL) {
// Using the original source, but not enough free space. First
// copy the source file to cache, then delete it from the original
// location.
if (strncmp(source_filename, "MTD:", 4) == 0 ||
strncmp(source_filename, "EMMC:", 5) == 0) {
// It's impossible to free space on the target filesystem by
// deleting the source if the source is a partition. If
// we're ever in a state where we need to do this, fail.
printf("not enough free space for target but source "
"is partition\n");
return 1;
}
if (MakeFreeSpaceOnCache(source_file->size) < 0) {
printf("not enough free space on /cache\n");
return 1;
}
if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) {
printf("failed to back up source file\n");
return 1;
}
made_copy = 1;
unlink(source_filename);
size_t free_space = FreeSpaceForFile(target_fs);
printf("(now %ld bytes free for target) ", (long)free_space);
}
}
const Value* patch;
if (source_patch_value != NULL) {
source_to_use = source_file;
patch = source_patch_value;
} else {
source_to_use = copy_file;
patch = copy_patch_value;
}
if (patch->type != VAL_BLOB) {
printf("patch is not a blob\n");
return 1;
}
SinkFn sink = NULL;
void* token = NULL;
output = -1;
outname = NULL;
if (strncmp(target_filename, "MTD:", 4) == 0 ||
strncmp(target_filename, "EMMC:", 5) == 0) {
// We store the decoded output in memory.
msi.buffer = malloc(target_size);
if (msi.buffer == NULL) {
printf("failed to alloc %ld bytes for output\n",
(long)target_size);
return 1;
}
msi.pos = 0;
msi.size = target_size;
sink = MemorySink;
token = &msi;
} else {
// We write the decoded output to "<tgt-file>.patch".
outname = (char*)malloc(strlen(target_filename) + 10);
strcpy(outname, target_filename);
strcat(outname, ".patch");
output = open(outname, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
if (output < 0) {
printf("failed to open output file %s: %s\n",
outname, strerror(errno));
return 1;
}
sink = FileSink;
token = &output;
}
char* header = patch->data;
ssize_t header_bytes_read = patch->size;
SHA_init(&ctx);
int result;
if (header_bytes_read >= 8 &&
memcmp(header, "BSDIFF40", 8) == 0) {
result = ApplyBSDiffPatch(source_to_use->data, source_to_use->size,
patch, 0, sink, token, &ctx);
} else if (header_bytes_read >= 8 &&
memcmp(header, "IMGDIFF2", 8) == 0) {
result = ApplyImagePatch(source_to_use->data, source_to_use->size,
patch, sink, token, &ctx, bonus_data);
} else {
printf("Unknown patch file format\n");
return 1;
}
if (output >= 0) {
fsync(output);
close(output);
}
if (result != 0) {
if (retry == 0) {
printf("applying patch failed\n");
return result != 0;
} else {
printf("applying patch failed; retrying\n");
}
if (outname != NULL) {
unlink(outname);
}
} else {
// succeeded; no need to retry
break;
}
} while (retry-- > 0);
const uint8_t* current_target_sha1 = SHA_final(&ctx);
if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_SIZE) != 0) {
printf("patch did not produce expected sha1\n");
return 1;
} else {
printf("now ");
print_short_sha1(target_sha1);
putchar('\n');
}
if (output < 0) {
// Copy the temp file to the partition.
if (WriteToPartition(msi.buffer, msi.pos, target_filename) != 0) {
printf("write of patched data to %s failed\n", target_filename);
return 1;
}
free(msi.buffer);
} else {
// Give the .patch file the same owner, group, and mode of the
// original source file.
if (chmod(outname, source_to_use->st.st_mode) != 0) {
printf("chmod of \"%s\" failed: %s\n", outname, strerror(errno));
return 1;
}
if (chown(outname, source_to_use->st.st_uid,
source_to_use->st.st_gid) != 0) {
printf("chown of \"%s\" failed: %s\n", outname, strerror(errno));
return 1;
}
// Finally, rename the .patch file to replace the target file.
if (rename(outname, target_filename) != 0) {
printf("rename of .patch to \"%s\" failed: %s\n",
target_filename, strerror(errno));
return 1;
}
}
// If this run of applypatch created the copy, and we're here, we
// can delete it.
if (made_copy) unlink(CACHE_TEMP_SOURCE);
// Success!
return 0;
}
Reference in a new issue View git blame Copy permalink