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Doug Zongker512536a2010-02-17 16:11:44 -08001/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17// See imgdiff.c in this directory for a description of the patch file
18// format.
19
20#include <stdio.h>
Mark Salyzynf3bb31c2014-03-14 09:39:48 -070021#include <sys/cdefs.h>
Doug Zongker512536a2010-02-17 16:11:44 -080022#include <sys/stat.h>
23#include <errno.h>
Elliott Hughescd3c55a2015-01-29 20:50:08 -080024#include <malloc.h>
Doug Zongker512536a2010-02-17 16:11:44 -080025#include <unistd.h>
26#include <string.h>
27
28#include "zlib.h"
Sen Jiangc48cb5e2016-02-04 16:23:21 +080029#include "openssl/sha.h"
Doug Zongker512536a2010-02-17 16:11:44 -080030#include "applypatch.h"
31#include "imgdiff.h"
32#include "utils.h"
33
Sen Jiang0cce9cd2016-01-22 20:49:07 +080034int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
35 const unsigned char* patch_data, ssize_t patch_size,
36 SinkFn sink, void* token) {
37 Value patch = {VAL_BLOB, patch_size,
38 reinterpret_cast<char*>(const_cast<unsigned char*>(patch_data))};
39 return ApplyImagePatch(
40 old_data, old_size, &patch, sink, token, nullptr, nullptr);
41}
42
Doug Zongker512536a2010-02-17 16:11:44 -080043/*
44 * Apply the patch given in 'patch_filename' to the source data given
45 * by (old_data, old_size). Write the patched output to the 'output'
46 * file, and update the SHA context with the output data as well.
47 * Return 0 on success.
48 */
Sen Jiang0cce9cd2016-01-22 20:49:07 +080049int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
Doug Zongkerc4351c72010-02-22 14:46:32 -080050 const Value* patch,
Doug Zongkera3ccba62012-08-20 15:28:02 -070051 SinkFn sink, void* token, SHA_CTX* ctx,
52 const Value* bonus_data) {
Doug Zongkerc4351c72010-02-22 14:46:32 -080053 ssize_t pos = 12;
54 char* header = patch->data;
55 if (patch->size < 12) {
56 printf("patch too short to contain header\n");
57 return -1;
Doug Zongker512536a2010-02-17 16:11:44 -080058 }
59
Doug Zongkerc4351c72010-02-22 14:46:32 -080060 // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
61 // (IMGDIFF1, which is no longer supported, used CHUNK_NORMAL and
62 // CHUNK_GZIP.)
63 if (memcmp(header, "IMGDIFF2", 8) != 0) {
64 printf("corrupt patch file header (magic number)\n");
Doug Zongker512536a2010-02-17 16:11:44 -080065 return -1;
Doug Zongker512536a2010-02-17 16:11:44 -080066 }
Doug Zongker512536a2010-02-17 16:11:44 -080067
Doug Zongkerc4351c72010-02-22 14:46:32 -080068 int num_chunks = Read4(header+8);
69
70 int i;
71 for (i = 0; i < num_chunks; ++i) {
72 // each chunk's header record starts with 4 bytes.
73 if (pos + 4 > patch->size) {
74 printf("failed to read chunk %d record\n", i);
75 return -1;
76 }
77 int type = Read4(patch->data + pos);
78 pos += 4;
79
80 if (type == CHUNK_NORMAL) {
81 char* normal_header = patch->data + pos;
82 pos += 24;
83 if (pos > patch->size) {
84 printf("failed to read chunk %d normal header data\n", i);
85 return -1;
86 }
87
88 size_t src_start = Read8(normal_header);
89 size_t src_len = Read8(normal_header+8);
90 size_t patch_offset = Read8(normal_header+16);
91
Sen Jiang0cce9cd2016-01-22 20:49:07 +080092 if (src_start + src_len > static_cast<size_t>(old_size)) {
93 printf("source data too short\n");
94 return -1;
95 }
Doug Zongkerc4351c72010-02-22 14:46:32 -080096 ApplyBSDiffPatch(old_data + src_start, src_len,
97 patch, patch_offset, sink, token, ctx);
98 } else if (type == CHUNK_RAW) {
99 char* raw_header = patch->data + pos;
100 pos += 4;
101 if (pos > patch->size) {
102 printf("failed to read chunk %d raw header data\n", i);
103 return -1;
104 }
105
106 ssize_t data_len = Read4(raw_header);
107
108 if (pos + data_len > patch->size) {
109 printf("failed to read chunk %d raw data\n", i);
110 return -1;
111 }
Sen Jiangc48cb5e2016-02-04 16:23:21 +0800112 if (ctx) SHA1_Update(ctx, patch->data + pos, data_len);
Doug Zongkerc4351c72010-02-22 14:46:32 -0800113 if (sink((unsigned char*)patch->data + pos,
114 data_len, token) != data_len) {
115 printf("failed to write chunk %d raw data\n", i);
116 return -1;
117 }
118 pos += data_len;
119 } else if (type == CHUNK_DEFLATE) {
120 // deflate chunks have an additional 60 bytes in their chunk header.
121 char* deflate_header = patch->data + pos;
122 pos += 60;
123 if (pos > patch->size) {
124 printf("failed to read chunk %d deflate header data\n", i);
125 return -1;
126 }
127
128 size_t src_start = Read8(deflate_header);
129 size_t src_len = Read8(deflate_header+8);
130 size_t patch_offset = Read8(deflate_header+16);
131 size_t expanded_len = Read8(deflate_header+24);
132 size_t target_len = Read8(deflate_header+32);
133 int level = Read4(deflate_header+40);
134 int method = Read4(deflate_header+44);
135 int windowBits = Read4(deflate_header+48);
136 int memLevel = Read4(deflate_header+52);
137 int strategy = Read4(deflate_header+56);
138
Sen Jiang0cce9cd2016-01-22 20:49:07 +0800139 if (src_start + src_len > static_cast<size_t>(old_size)) {
140 printf("source data too short\n");
141 return -1;
142 }
143
Doug Zongkerc4351c72010-02-22 14:46:32 -0800144 // Decompress the source data; the chunk header tells us exactly
145 // how big we expect it to be when decompressed.
146
Doug Zongkera3ccba62012-08-20 15:28:02 -0700147 // Note: expanded_len will include the bonus data size if
148 // the patch was constructed with bonus data. The
149 // deflation will come up 'bonus_size' bytes short; these
150 // must be appended from the bonus_data value.
151 size_t bonus_size = (i == 1 && bonus_data != NULL) ? bonus_data->size : 0;
152
Tao Baoba9a42a2015-06-23 23:23:33 -0700153 unsigned char* expanded_source = reinterpret_cast<unsigned char*>(malloc(expanded_len));
Doug Zongkerc4351c72010-02-22 14:46:32 -0800154 if (expanded_source == NULL) {
Mark Salyzynf3bb31c2014-03-14 09:39:48 -0700155 printf("failed to allocate %zu bytes for expanded_source\n",
Doug Zongkerc4351c72010-02-22 14:46:32 -0800156 expanded_len);
157 return -1;
158 }
159
160 z_stream strm;
161 strm.zalloc = Z_NULL;
162 strm.zfree = Z_NULL;
163 strm.opaque = Z_NULL;
164 strm.avail_in = src_len;
165 strm.next_in = (unsigned char*)(old_data + src_start);
166 strm.avail_out = expanded_len;
167 strm.next_out = expanded_source;
168
169 int ret;
170 ret = inflateInit2(&strm, -15);
171 if (ret != Z_OK) {
172 printf("failed to init source inflation: %d\n", ret);
173 return -1;
174 }
175
176 // Because we've provided enough room to accommodate the output
177 // data, we expect one call to inflate() to suffice.
178 ret = inflate(&strm, Z_SYNC_FLUSH);
179 if (ret != Z_STREAM_END) {
180 printf("source inflation returned %d\n", ret);
181 return -1;
182 }
Doug Zongkera3ccba62012-08-20 15:28:02 -0700183 // We should have filled the output buffer exactly, except
184 // for the bonus_size.
185 if (strm.avail_out != bonus_size) {
Mark Salyzynf3bb31c2014-03-14 09:39:48 -0700186 printf("source inflation short by %zu bytes\n", strm.avail_out-bonus_size);
Doug Zongkerc4351c72010-02-22 14:46:32 -0800187 return -1;
188 }
189 inflateEnd(&strm);
190
Doug Zongkera3ccba62012-08-20 15:28:02 -0700191 if (bonus_size) {
192 memcpy(expanded_source + (expanded_len - bonus_size),
193 bonus_data->data, bonus_size);
194 }
195
Doug Zongkerc4351c72010-02-22 14:46:32 -0800196 // Next, apply the bsdiff patch (in memory) to the uncompressed
197 // data.
198 unsigned char* uncompressed_target_data;
199 ssize_t uncompressed_target_size;
200 if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
201 patch, patch_offset,
202 &uncompressed_target_data,
203 &uncompressed_target_size) != 0) {
204 return -1;
205 }
206
207 // Now compress the target data and append it to the output.
208
209 // we're done with the expanded_source data buffer, so we'll
210 // reuse that memory to receive the output of deflate.
211 unsigned char* temp_data = expanded_source;
212 ssize_t temp_size = expanded_len;
213 if (temp_size < 32768) {
214 // ... unless the buffer is too small, in which case we'll
215 // allocate a fresh one.
216 free(temp_data);
Tao Baoba9a42a2015-06-23 23:23:33 -0700217 temp_data = reinterpret_cast<unsigned char*>(malloc(32768));
Doug Zongkerc4351c72010-02-22 14:46:32 -0800218 temp_size = 32768;
219 }
220
221 // now the deflate stream
222 strm.zalloc = Z_NULL;
223 strm.zfree = Z_NULL;
224 strm.opaque = Z_NULL;
225 strm.avail_in = uncompressed_target_size;
226 strm.next_in = uncompressed_target_data;
227 ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
228 do {
229 strm.avail_out = temp_size;
230 strm.next_out = temp_data;
231 ret = deflate(&strm, Z_FINISH);
232 ssize_t have = temp_size - strm.avail_out;
233
234 if (sink(temp_data, have, token) != have) {
235 printf("failed to write %ld compressed bytes to output\n",
236 (long)have);
237 return -1;
238 }
Sen Jiangc48cb5e2016-02-04 16:23:21 +0800239 if (ctx) SHA1_Update(ctx, temp_data, have);
Doug Zongkerc4351c72010-02-22 14:46:32 -0800240 } while (ret != Z_STREAM_END);
241 deflateEnd(&strm);
242
243 free(temp_data);
244 free(uncompressed_target_data);
245 } else {
246 printf("patch chunk %d is unknown type %d\n", i, type);
247 return -1;
248 }
249 }
250
251 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800252}