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-rw-r--r--applypatch/applypatch.c1048
1 files changed, 0 insertions, 1048 deletions
diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c
deleted file mode 100644
index 2358d4292..000000000
--- a/applypatch/applypatch.c
+++ /dev/null
@@ -1,1048 +0,0 @@
-/*
- * 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 <stdbool.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(const 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; store the file contents and associated
-// metadata in *file.
-//
-// Return 0 on success.
-int LoadFileContents(const char* filename, FileContents* file) {
- 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);
-
- SHA_hash(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 (%zu bytes of %zu) 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 %zu 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 | O_SYNC, 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;
- }
- if (fsync(fd) != 0) {
- printf("fsync of \"%s\" failed: %s\n", filename, strerror(errno));
- return -1;
- }
- if (close(fd) != 0) {
- printf("close of \"%s\" failed: %s\n", filename, strerror(errno));
- return -1;
- }
-
- 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 %zu of %zu 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;
- int fd = open(partition, O_RDWR | O_SYNC);
- if (fd < 0) {
- printf("failed to open %s: %s\n", partition, strerror(errno));
- return -1;
- }
- int attempt;
-
- for (attempt = 0; attempt < 2; ++attempt) {
- if (TEMP_FAILURE_RETRY(lseek(fd, start, SEEK_SET)) == -1) {
- printf("failed seek on %s: %s\n",
- partition, strerror(errno));
- return -1;
- }
- while (start < len) {
- size_t to_write = len - start;
- if (to_write > 1<<20) to_write = 1<<20;
-
- ssize_t written = TEMP_FAILURE_RETRY(write(fd, data+start, to_write));
- if (written == -1) {
- printf("failed write writing to %s: %s\n", partition, strerror(errno));
- return -1;
- }
- start += written;
- }
- if (fsync(fd) != 0) {
- printf("failed to sync to %s (%s)\n",
- partition, strerror(errno));
- return -1;
- }
- if (close(fd) != 0) {
- printf("failed to close %s (%s)\n",
- partition, strerror(errno));
- return -1;
- }
- fd = open(partition, O_RDONLY);
- if (fd < 0) {
- printf("failed to reopen %s for verify (%s)\n",
- partition, strerror(errno));
- return -1;
- }
-
- // drop caches so our subsequent verification read
- // won't just be reading the cache.
- sync();
- int dc = open("/proc/sys/vm/drop_caches", O_WRONLY);
- if (TEMP_FAILURE_RETRY(write(dc, "3\n", 2)) == -1) {
- printf("write to /proc/sys/vm/drop_caches failed: %s\n", strerror(errno));
- } else {
- printf(" caches dropped\n");
- }
- close(dc);
- sleep(1);
-
- // verify
- if (TEMP_FAILURE_RETRY(lseek(fd, 0, SEEK_SET)) == -1) {
- printf("failed to seek back to beginning of %s: %s\n",
- partition, strerror(errno));
- return -1;
- }
- 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);
-
- size_t so_far = 0;
- while (so_far < to_read) {
- ssize_t read_count =
- TEMP_FAILURE_RETRY(read(fd, buffer+so_far, to_read-so_far));
- if (read_count == -1) {
- printf("verify read error %s at %zu: %s\n",
- partition, p, strerror(errno));
- return -1;
- }
- if ((size_t)read_count < to_read) {
- printf("short verify read %s at %zu: %zd %zu %s\n",
- partition, p, read_count, to_read, strerror(errno));
- }
- so_far += read_count;
- }
-
- if (memcmp(buffer, data+p, to_read)) {
- printf("verification failed starting at %zu\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 (close(fd) != 0) {
- printf("error closing %s (%s)\n", partition, strerror(errno));
- return -1;
- }
- sync();
- 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) != 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) != 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(const 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 = TEMP_FAILURE_RETRY(write(fd, data+done, len-done));
- if (wrote == -1) {
- 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(const 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_bavail;
-}
-
-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) == 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);
- }
-
- 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) < 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 | O_SYNC,
- 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) {
- if (fsync(output) != 0) {
- printf("failed to fsync file \"%s\" (%s)\n", outname, strerror(errno));
- result = 1;
- }
- if (close(output) != 0) {
- printf("failed to close file \"%s\" (%s)\n", outname, strerror(errno));
- result = 1;
- }
- }
-
- 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;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 12:16:20 +0100