| /* |
| * 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(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 (%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; |
| int fd = open(partition, O_RDWR); |
| if (fd < 0) { |
| printf("failed to open %s: %s\n", partition, strerror(errno)); |
| return -1; |
| } |
| int attempt; |
| |
| for (attempt = 0; attempt < 2; ++attempt) { |
| lseek(fd, start, SEEK_SET); |
| while (start < len) { |
| size_t to_write = len - start; |
| if (to_write > 1<<20) to_write = 1<<20; |
| |
| ssize_t written = write(fd, data+start, to_write); |
| if (written < 0) { |
| if (errno == EINTR) { |
| written = 0; |
| } else { |
| printf("failed write writing to %s (%s)\n", |
| partition, strerror(errno)); |
| return -1; |
| } |
| } |
| start += written; |
| } |
| fsync(fd); |
| |
| // 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); |
| write(dc, "3\n", 2); |
| close(dc); |
| sleep(1); |
| printf(" caches dropped\n"); |
| |
| // verify |
| lseek(fd, 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); |
| |
| size_t so_far = 0; |
| while (so_far < to_read) { |
| ssize_t read_count = read(fd, buffer+so_far, to_read-so_far); |
| if (read_count < 0) { |
| if (errno == EINTR) { |
| read_count = 0; |
| } else { |
| printf("verify read error %s at %d: %s\n", |
| partition, p, strerror(errno)); |
| return -1; |
| } |
| } |
| if ((size_t)read_count < to_read) { |
| printf("short verify read %s at %d: %d %d %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 %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 (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(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) == 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, ©_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, |
| ©_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; |
| } |