applypatch/imgpatch.c - platform/bootable/recovery - Git at Google

 /*
  * Copyright (C) 2009 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.
  */

 // See imgdiff.c in this directory for a description of the patch file
 // format.

 #include <stdio.h>
 #include <sys/cdefs.h>
 #include <sys/stat.h>
 #include <errno.h>
 #include <unistd.h>
 #include <string.h>

 #include "zlib.h"
 #include "mincrypt/sha.h"
 #include "applypatch.h"
 #include "imgdiff.h"
 #include "utils.h"

 /*
  * Apply the patch given in 'patch_filename' to the source data given
  * by (old_data, old_size).  Write the patched output to the 'output'
  * file, and update the SHA context with the output data as well.
  * Return 0 on success.
  */
 int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size __unused,
                     const Value* patch,
                     SinkFn sink, void* token, SHA_CTX* ctx,
                     const Value* bonus_data) {
     ssize_t pos = 12;
     char* header = patch->data;
     if (patch->size < 12) {
         printf("patch too short to contain header\n");
         return -1;
     }

     // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
     // (IMGDIFF1, which is no longer supported, used CHUNK_NORMAL and
     // CHUNK_GZIP.)
     if (memcmp(header, "IMGDIFF2", 8) != 0) {
         printf("corrupt patch file header (magic number)\n");
         return -1;
     }

     int num_chunks = Read4(header+8);

     int i;
     for (i = 0; i < num_chunks; ++i) {
         // each chunk's header record starts with 4 bytes.
         if (pos + 4 > patch->size) {
             printf("failed to read chunk %d record\n", i);
             return -1;
         }
         int type = Read4(patch->data + pos);
         pos += 4;

         if (type == CHUNK_NORMAL) {
             char* normal_header = patch->data + pos;
             pos += 24;
             if (pos > patch->size) {
                 printf("failed to read chunk %d normal header data\n", i);
                 return -1;
             }

             size_t src_start = Read8(normal_header);
             size_t src_len = Read8(normal_header+8);
             size_t patch_offset = Read8(normal_header+16);

             ApplyBSDiffPatch(old_data + src_start, src_len,
                              patch, patch_offset, sink, token, ctx);
         } else if (type == CHUNK_RAW) {
             char* raw_header = patch->data + pos;
             pos += 4;
             if (pos > patch->size) {
                 printf("failed to read chunk %d raw header data\n", i);
                 return -1;
             }

             ssize_t data_len = Read4(raw_header);

             if (pos + data_len > patch->size) {
                 printf("failed to read chunk %d raw data\n", i);
                 return -1;
             }
             if (ctx) SHA_update(ctx, patch->data + pos, data_len);
             if (sink((unsigned char*)patch->data + pos,
                      data_len, token) != data_len) {
                 printf("failed to write chunk %d raw data\n", i);
                 return -1;
             }
             pos += data_len;
         } else if (type == CHUNK_DEFLATE) {
             // deflate chunks have an additional 60 bytes in their chunk header.
             char* deflate_header = patch->data + pos;
             pos += 60;
             if (pos > patch->size) {
                 printf("failed to read chunk %d deflate header data\n", i);
                 return -1;
             }

             size_t src_start = Read8(deflate_header);
             size_t src_len = Read8(deflate_header+8);
             size_t patch_offset = Read8(deflate_header+16);
             size_t expanded_len = Read8(deflate_header+24);
             size_t target_len = Read8(deflate_header+32);
             int level = Read4(deflate_header+40);
             int method = Read4(deflate_header+44);
             int windowBits = Read4(deflate_header+48);
             int memLevel = Read4(deflate_header+52);
             int strategy = Read4(deflate_header+56);

             // Decompress the source data; the chunk header tells us exactly
             // how big we expect it to be when decompressed.

             // Note: expanded_len will include the bonus data size if
             // the patch was constructed with bonus data.  The
             // deflation will come up 'bonus_size' bytes short; these
             // must be appended from the bonus_data value.
             size_t bonus_size = (i == 1 && bonus_data != NULL) ? bonus_data->size : 0;

             unsigned char* expanded_source = malloc(expanded_len);
             if (expanded_source == NULL) {
                 printf("failed to allocate %zu bytes for expanded_source\n",
                        expanded_len);
                 return -1;
             }

             z_stream strm;
             strm.zalloc = Z_NULL;
             strm.zfree = Z_NULL;
             strm.opaque = Z_NULL;
             strm.avail_in = src_len;
             strm.next_in = (unsigned char*)(old_data + src_start);
             strm.avail_out = expanded_len;
             strm.next_out = expanded_source;

             int ret;
             ret = inflateInit2(&strm, -15);
             if (ret != Z_OK) {
                 printf("failed to init source inflation: %d\n", ret);
                 return -1;
             }

             // Because we've provided enough room to accommodate the output
             // data, we expect one call to inflate() to suffice.
             ret = inflate(&strm, Z_SYNC_FLUSH);
             if (ret != Z_STREAM_END) {
                 printf("source inflation returned %d\n", ret);
                 return -1;
             }
             // We should have filled the output buffer exactly, except
             // for the bonus_size.
             if (strm.avail_out != bonus_size) {
                 printf("source inflation short by %zu bytes\n", strm.avail_out-bonus_size);
                 return -1;
             }
             inflateEnd(&strm);

             if (bonus_size) {
                 memcpy(expanded_source + (expanded_len - bonus_size),
                        bonus_data->data, bonus_size);
             }

             // Next, apply the bsdiff patch (in memory) to the uncompressed
             // data.
             unsigned char* uncompressed_target_data;
             ssize_t uncompressed_target_size;
             if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
                                     patch, patch_offset,
                                     &uncompressed_target_data,
                                     &uncompressed_target_size) != 0) {
                 return -1;
             }

             // Now compress the target data and append it to the output.

             // we're done with the expanded_source data buffer, so we'll
             // reuse that memory to receive the output of deflate.
             unsigned char* temp_data = expanded_source;
             ssize_t temp_size = expanded_len;
             if (temp_size < 32768) {
                 // ... unless the buffer is too small, in which case we'll
                 // allocate a fresh one.
                 free(temp_data);
                 temp_data = malloc(32768);
                 temp_size = 32768;
             }

             // now the deflate stream
             strm.zalloc = Z_NULL;
             strm.zfree = Z_NULL;
             strm.opaque = Z_NULL;
             strm.avail_in = uncompressed_target_size;
             strm.next_in = uncompressed_target_data;
             ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
             do {
                 strm.avail_out = temp_size;
                 strm.next_out = temp_data;
                 ret = deflate(&strm, Z_FINISH);
                 ssize_t have = temp_size - strm.avail_out;

                 if (sink(temp_data, have, token) != have) {
                     printf("failed to write %ld compressed bytes to output\n",
                            (long)have);
                     return -1;
                 }
                 if (ctx) SHA_update(ctx, temp_data, have);
             } while (ret != Z_STREAM_END);
             deflateEnd(&strm);

             free(temp_data);
             free(uncompressed_target_data);
         } else {
             printf("patch chunk %d is unknown type %d\n", i, type);
             return -1;
         }
     }

     return 0;
 }
	/*
	* Copyright (C) 2009 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.
	*/

	// See imgdiff.c in this directory for a description of the patch file
	// format.

	#include <stdio.h>
	#include <sys/cdefs.h>
	#include <sys/stat.h>
	#include <errno.h>
	#include <unistd.h>
	#include <string.h>

	#include "zlib.h"
	#include "mincrypt/sha.h"
	#include "applypatch.h"
	#include "imgdiff.h"
	#include "utils.h"

	/*
	* Apply the patch given in 'patch_filename' to the source data given
	* by (old_data, old_size). Write the patched output to the 'output'
	* file, and update the SHA context with the output data as well.
	* Return 0 on success.
	*/
	int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size __unused,
	const Value* patch,
	SinkFn sink, void* token, SHA_CTX* ctx,
	const Value* bonus_data) {
	ssize_t pos = 12;
	char* header = patch->data;
	if (patch->size < 12) {
	printf("patch too short to contain header\n");
	return -1;
	}

	// IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
	// (IMGDIFF1, which is no longer supported, used CHUNK_NORMAL and
	// CHUNK_GZIP.)
	if (memcmp(header, "IMGDIFF2", 8) != 0) {
	printf("corrupt patch file header (magic number)\n");
	return -1;
	}

	int num_chunks = Read4(header+8);

	int i;
	for (i = 0; i < num_chunks; ++i) {
	// each chunk's header record starts with 4 bytes.
	if (pos + 4 > patch->size) {
	printf("failed to read chunk %d record\n", i);
	return -1;
	}
	int type = Read4(patch->data + pos);
	pos += 4;

	if (type == CHUNK_NORMAL) {
	char* normal_header = patch->data + pos;
	pos += 24;
	if (pos > patch->size) {
	printf("failed to read chunk %d normal header data\n", i);
	return -1;
	}

	size_t src_start = Read8(normal_header);
	size_t src_len = Read8(normal_header+8);
	size_t patch_offset = Read8(normal_header+16);

	ApplyBSDiffPatch(old_data + src_start, src_len,
	patch, patch_offset, sink, token, ctx);
	} else if (type == CHUNK_RAW) {
	char* raw_header = patch->data + pos;
	pos += 4;
	if (pos > patch->size) {
	printf("failed to read chunk %d raw header data\n", i);
	return -1;
	}

	ssize_t data_len = Read4(raw_header);

	if (pos + data_len > patch->size) {
	printf("failed to read chunk %d raw data\n", i);
	return -1;
	}
	if (ctx) SHA_update(ctx, patch->data + pos, data_len);
	if (sink((unsigned char*)patch->data + pos,
	data_len, token) != data_len) {
	printf("failed to write chunk %d raw data\n", i);
	return -1;
	}
	pos += data_len;
	} else if (type == CHUNK_DEFLATE) {
	// deflate chunks have an additional 60 bytes in their chunk header.
	char* deflate_header = patch->data + pos;
	pos += 60;
	if (pos > patch->size) {
	printf("failed to read chunk %d deflate header data\n", i);
	return -1;
	}

	size_t src_start = Read8(deflate_header);
	size_t src_len = Read8(deflate_header+8);
	size_t patch_offset = Read8(deflate_header+16);
	size_t expanded_len = Read8(deflate_header+24);
	size_t target_len = Read8(deflate_header+32);
	int level = Read4(deflate_header+40);
	int method = Read4(deflate_header+44);
	int windowBits = Read4(deflate_header+48);
	int memLevel = Read4(deflate_header+52);
	int strategy = Read4(deflate_header+56);

	// Decompress the source data; the chunk header tells us exactly
	// how big we expect it to be when decompressed.

	// Note: expanded_len will include the bonus data size if
	// the patch was constructed with bonus data. The
	// deflation will come up 'bonus_size' bytes short; these
	// must be appended from the bonus_data value.
	size_t bonus_size = (i == 1 && bonus_data != NULL) ? bonus_data->size : 0;

	unsigned char* expanded_source = malloc(expanded_len);
	if (expanded_source == NULL) {
	printf("failed to allocate %zu bytes for expanded_source\n",
	expanded_len);
	return -1;
	}

	z_stream strm;
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = src_len;
	strm.next_in = (unsigned char*)(old_data + src_start);
	strm.avail_out = expanded_len;
	strm.next_out = expanded_source;

	int ret;
	ret = inflateInit2(&strm, -15);
	if (ret != Z_OK) {
	printf("failed to init source inflation: %d\n", ret);
	return -1;
	}

	// Because we've provided enough room to accommodate the output
	// data, we expect one call to inflate() to suffice.
	ret = inflate(&strm, Z_SYNC_FLUSH);
	if (ret != Z_STREAM_END) {
	printf("source inflation returned %d\n", ret);
	return -1;
	}
	// We should have filled the output buffer exactly, except
	// for the bonus_size.
	if (strm.avail_out != bonus_size) {
	printf("source inflation short by %zu bytes\n", strm.avail_out-bonus_size);
	return -1;
	}
	inflateEnd(&strm);

	if (bonus_size) {
	memcpy(expanded_source + (expanded_len - bonus_size),
	bonus_data->data, bonus_size);
	}

	// Next, apply the bsdiff patch (in memory) to the uncompressed
	// data.
	unsigned char* uncompressed_target_data;
	ssize_t uncompressed_target_size;
	if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
	patch, patch_offset,
	&uncompressed_target_data,
	&uncompressed_target_size) != 0) {
	return -1;
	}

	// Now compress the target data and append it to the output.

	// we're done with the expanded_source data buffer, so we'll
	// reuse that memory to receive the output of deflate.
	unsigned char* temp_data = expanded_source;
	ssize_t temp_size = expanded_len;
	if (temp_size < 32768) {
	// ... unless the buffer is too small, in which case we'll
	// allocate a fresh one.
	free(temp_data);
	temp_data = malloc(32768);
	temp_size = 32768;
	}

	// now the deflate stream
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = uncompressed_target_size;
	strm.next_in = uncompressed_target_data;
	ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
	do {
	strm.avail_out = temp_size;
	strm.next_out = temp_data;
	ret = deflate(&strm, Z_FINISH);
	ssize_t have = temp_size - strm.avail_out;

	if (sink(temp_data, have, token) != have) {
	printf("failed to write %ld compressed bytes to output\n",
	(long)have);
	return -1;
	}
	if (ctx) SHA_update(ctx, temp_data, have);
	} while (ret != Z_STREAM_END);
	deflateEnd(&strm);

	free(temp_data);
	free(uncompressed_target_data);
	} else {
	printf("patch chunk %d is unknown type %d\n", i, type);
	return -1;
	}
	}

	return 0;
	}