Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 1 | /* |
| 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 | #define LOG_TAG "backup_data" |
| 18 | |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 19 | #include <stdio.h> |
| 20 | #include <string.h> |
| 21 | #include <unistd.h> |
| 22 | |
Mark Salyzyn | 52eb4e0 | 2016-09-28 16:15:30 -0700 | [diff] [blame] | 23 | #include <androidfw/BackupHelpers.h> |
| 24 | #include <log/log.h> |
| 25 | #include <utils/ByteOrder.h> |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 26 | |
| 27 | namespace android { |
| 28 | |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 29 | static const bool kIsDebug = false; |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 30 | |
| 31 | /* |
| 32 | * File Format (v1): |
| 33 | * |
| 34 | * All ints are stored little-endian. |
| 35 | * |
| 36 | * - An app_header_v1 struct. |
| 37 | * - The name of the package, utf-8, null terminated, padded to 4-byte boundary. |
| 38 | * - A sequence of zero or more key/value paires (entities), each with |
| 39 | * - A entity_header_v1 struct |
| 40 | * - The key, utf-8, null terminated, padded to 4-byte boundary. |
| 41 | * - The value, padded to 4 byte boundary |
| 42 | */ |
| 43 | |
| 44 | const static int ROUND_UP[4] = { 0, 3, 2, 1 }; |
| 45 | |
| 46 | static inline size_t |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 47 | padding_extra(size_t n) |
| 48 | { |
| 49 | return ROUND_UP[n % 4]; |
| 50 | } |
| 51 | |
| 52 | BackupDataWriter::BackupDataWriter(int fd) |
| 53 | :m_fd(fd), |
| 54 | m_status(NO_ERROR), |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 55 | m_entityCount(0) |
| 56 | { |
Christopher Tate | b048c33 | 2014-02-21 12:50:21 -0800 | [diff] [blame] | 57 | m_pos = (ssize_t) lseek(fd, 0, SEEK_CUR); |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 58 | if (kIsDebug) ALOGI("BackupDataWriter(%d) @ %ld", fd, (long)m_pos); |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 59 | } |
| 60 | |
| 61 | BackupDataWriter::~BackupDataWriter() |
| 62 | { |
| 63 | } |
| 64 | |
| 65 | // Pad out anything they've previously written to the next 4 byte boundary. |
| 66 | status_t |
| 67 | BackupDataWriter::write_padding_for(int n) |
| 68 | { |
| 69 | ssize_t amt; |
| 70 | ssize_t paddingSize; |
| 71 | |
| 72 | paddingSize = padding_extra(n); |
| 73 | if (paddingSize > 0) { |
| 74 | uint32_t padding = 0xbcbcbcbc; |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 75 | if (kIsDebug) ALOGI("writing %zd padding bytes for %d", paddingSize, n); |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 76 | amt = write(m_fd, &padding, paddingSize); |
| 77 | if (amt != paddingSize) { |
| 78 | m_status = errno; |
| 79 | return m_status; |
| 80 | } |
| 81 | m_pos += amt; |
| 82 | } |
| 83 | return NO_ERROR; |
| 84 | } |
| 85 | |
| 86 | status_t |
| 87 | BackupDataWriter::WriteEntityHeader(const String8& key, size_t dataSize) |
| 88 | { |
| 89 | if (m_status != NO_ERROR) { |
| 90 | return m_status; |
| 91 | } |
| 92 | |
| 93 | ssize_t amt; |
| 94 | |
| 95 | amt = write_padding_for(m_pos); |
| 96 | if (amt != 0) { |
| 97 | return amt; |
| 98 | } |
| 99 | |
| 100 | String8 k; |
| 101 | if (m_keyPrefix.length() > 0) { |
| 102 | k = m_keyPrefix; |
| 103 | k += ":"; |
| 104 | k += key; |
| 105 | } else { |
| 106 | k = key; |
| 107 | } |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 108 | if (kIsDebug) { |
Tomasz Wasilczyk | ade0631 | 2023-08-10 23:54:44 +0000 | [diff] [blame] | 109 | ALOGD("Writing header: prefix='%s' key='%s' dataSize=%zu", m_keyPrefix.c_str(), |
| 110 | key.c_str(), dataSize); |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 111 | } |
| 112 | |
| 113 | entity_header_v1 header; |
| 114 | ssize_t keyLen; |
| 115 | |
| 116 | keyLen = k.length(); |
| 117 | |
| 118 | header.type = tolel(BACKUP_HEADER_ENTITY_V1); |
| 119 | header.keyLen = tolel(keyLen); |
| 120 | header.dataSize = tolel(dataSize); |
| 121 | |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 122 | if (kIsDebug) ALOGI("writing entity header, %zu bytes", sizeof(entity_header_v1)); |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 123 | amt = write(m_fd, &header, sizeof(entity_header_v1)); |
| 124 | if (amt != sizeof(entity_header_v1)) { |
| 125 | m_status = errno; |
| 126 | return m_status; |
| 127 | } |
| 128 | m_pos += amt; |
| 129 | |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 130 | if (kIsDebug) ALOGI("writing entity header key, %zd bytes", keyLen+1); |
Tomasz Wasilczyk | ade0631 | 2023-08-10 23:54:44 +0000 | [diff] [blame] | 131 | amt = write(m_fd, k.c_str(), keyLen+1); |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 132 | if (amt != keyLen+1) { |
| 133 | m_status = errno; |
| 134 | return m_status; |
| 135 | } |
| 136 | m_pos += amt; |
| 137 | |
| 138 | amt = write_padding_for(keyLen+1); |
| 139 | |
| 140 | m_entityCount++; |
| 141 | |
| 142 | return amt; |
| 143 | } |
| 144 | |
| 145 | status_t |
| 146 | BackupDataWriter::WriteEntityData(const void* data, size_t size) |
| 147 | { |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 148 | if (kIsDebug) ALOGD("Writing data: size=%lu", (unsigned long) size); |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 149 | |
| 150 | if (m_status != NO_ERROR) { |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 151 | if (kIsDebug) { |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 152 | ALOGD("Not writing data - stream in error state %d (%s)", m_status, strerror(m_status)); |
| 153 | } |
| 154 | return m_status; |
| 155 | } |
| 156 | |
| 157 | // We don't write padding here, because they're allowed to call this several |
| 158 | // times with smaller buffers. We write it at the end of WriteEntityHeader |
| 159 | // instead. |
| 160 | ssize_t amt = write(m_fd, data, size); |
| 161 | if (amt != (ssize_t)size) { |
| 162 | m_status = errno; |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 163 | if (kIsDebug) ALOGD("write returned error %d (%s)", m_status, strerror(m_status)); |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 164 | return m_status; |
| 165 | } |
| 166 | m_pos += amt; |
| 167 | return NO_ERROR; |
| 168 | } |
| 169 | |
| 170 | void |
| 171 | BackupDataWriter::SetKeyPrefix(const String8& keyPrefix) |
| 172 | { |
| 173 | m_keyPrefix = keyPrefix; |
| 174 | } |
| 175 | |
| 176 | |
| 177 | BackupDataReader::BackupDataReader(int fd) |
| 178 | :m_fd(fd), |
| 179 | m_done(false), |
| 180 | m_status(NO_ERROR), |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 181 | m_entityCount(0) |
| 182 | { |
| 183 | memset(&m_header, 0, sizeof(m_header)); |
Christopher Tate | b048c33 | 2014-02-21 12:50:21 -0800 | [diff] [blame] | 184 | m_pos = (ssize_t) lseek(fd, 0, SEEK_CUR); |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 185 | if (kIsDebug) ALOGI("BackupDataReader(%d) @ %ld", fd, (long)m_pos); |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 186 | } |
| 187 | |
| 188 | BackupDataReader::~BackupDataReader() |
| 189 | { |
| 190 | } |
| 191 | |
| 192 | status_t |
| 193 | BackupDataReader::Status() |
| 194 | { |
| 195 | return m_status; |
| 196 | } |
| 197 | |
| 198 | #define CHECK_SIZE(actual, expected) \ |
| 199 | do { \ |
| 200 | if ((actual) != (expected)) { \ |
| 201 | if ((actual) == 0) { \ |
| 202 | m_status = EIO; \ |
| 203 | m_done = true; \ |
| 204 | } else { \ |
| 205 | m_status = errno; \ |
| 206 | ALOGD("CHECK_SIZE(a=%ld e=%ld) failed at line %d m_status='%s'", \ |
| 207 | long(actual), long(expected), __LINE__, strerror(m_status)); \ |
| 208 | } \ |
| 209 | return m_status; \ |
| 210 | } \ |
| 211 | } while(0) |
| 212 | #define SKIP_PADDING() \ |
| 213 | do { \ |
| 214 | status_t err = skip_padding(); \ |
| 215 | if (err != NO_ERROR) { \ |
| 216 | ALOGD("SKIP_PADDING FAILED at line %d", __LINE__); \ |
| 217 | m_status = err; \ |
| 218 | return err; \ |
| 219 | } \ |
| 220 | } while(0) |
| 221 | |
| 222 | status_t |
| 223 | BackupDataReader::ReadNextHeader(bool* done, int* type) |
| 224 | { |
| 225 | *done = m_done; |
| 226 | if (m_status != NO_ERROR) { |
| 227 | return m_status; |
| 228 | } |
| 229 | |
| 230 | int amt; |
| 231 | |
| 232 | amt = skip_padding(); |
| 233 | if (amt == EIO) { |
| 234 | *done = m_done = true; |
| 235 | return NO_ERROR; |
| 236 | } |
| 237 | else if (amt != NO_ERROR) { |
| 238 | return amt; |
| 239 | } |
| 240 | amt = read(m_fd, &m_header, sizeof(m_header)); |
| 241 | *done = m_done = (amt == 0); |
| 242 | if (*done) { |
| 243 | return NO_ERROR; |
| 244 | } |
| 245 | CHECK_SIZE(amt, sizeof(m_header)); |
| 246 | m_pos += sizeof(m_header); |
| 247 | if (type) { |
| 248 | *type = m_header.type; |
| 249 | } |
| 250 | |
| 251 | // validate and fix up the fields. |
| 252 | m_header.type = fromlel(m_header.type); |
| 253 | switch (m_header.type) |
| 254 | { |
| 255 | case BACKUP_HEADER_ENTITY_V1: |
| 256 | { |
| 257 | m_header.entity.keyLen = fromlel(m_header.entity.keyLen); |
| 258 | if (m_header.entity.keyLen <= 0) { |
| 259 | ALOGD("Entity header at %d has keyLen<=0: 0x%08x\n", (int)m_pos, |
| 260 | (int)m_header.entity.keyLen); |
| 261 | m_status = EINVAL; |
| 262 | } |
| 263 | m_header.entity.dataSize = fromlel(m_header.entity.dataSize); |
| 264 | m_entityCount++; |
| 265 | |
| 266 | // read the rest of the header (filename) |
| 267 | size_t size = m_header.entity.keyLen; |
| 268 | char* buf = m_key.lockBuffer(size); |
| 269 | if (buf == NULL) { |
| 270 | m_status = ENOMEM; |
| 271 | return m_status; |
| 272 | } |
| 273 | int amt = read(m_fd, buf, size+1); |
| 274 | CHECK_SIZE(amt, (int)size+1); |
| 275 | m_key.unlockBuffer(size); |
| 276 | m_pos += size+1; |
| 277 | SKIP_PADDING(); |
| 278 | m_dataEndPos = m_pos + m_header.entity.dataSize; |
| 279 | |
| 280 | break; |
| 281 | } |
| 282 | default: |
| 283 | ALOGD("Chunk header at %d has invalid type: 0x%08x", |
| 284 | (int)(m_pos - sizeof(m_header)), (int)m_header.type); |
| 285 | m_status = EINVAL; |
| 286 | } |
Mark Salyzyn | 00adb86 | 2014-03-19 11:00:06 -0700 | [diff] [blame] | 287 | |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 288 | return m_status; |
| 289 | } |
| 290 | |
| 291 | bool |
| 292 | BackupDataReader::HasEntities() |
| 293 | { |
| 294 | return m_status == NO_ERROR && m_header.type == BACKUP_HEADER_ENTITY_V1; |
| 295 | } |
| 296 | |
| 297 | status_t |
| 298 | BackupDataReader::ReadEntityHeader(String8* key, size_t* dataSize) |
| 299 | { |
| 300 | if (m_status != NO_ERROR) { |
| 301 | return m_status; |
| 302 | } |
| 303 | if (m_header.type != BACKUP_HEADER_ENTITY_V1) { |
| 304 | return EINVAL; |
| 305 | } |
| 306 | *key = m_key; |
| 307 | *dataSize = m_header.entity.dataSize; |
| 308 | return NO_ERROR; |
| 309 | } |
| 310 | |
| 311 | status_t |
| 312 | BackupDataReader::SkipEntityData() |
| 313 | { |
| 314 | if (m_status != NO_ERROR) { |
| 315 | return m_status; |
| 316 | } |
| 317 | if (m_header.type != BACKUP_HEADER_ENTITY_V1) { |
| 318 | return EINVAL; |
| 319 | } |
| 320 | if (m_header.entity.dataSize > 0) { |
| 321 | int pos = lseek(m_fd, m_dataEndPos, SEEK_SET); |
| 322 | if (pos == -1) { |
| 323 | return errno; |
| 324 | } |
| 325 | m_pos = pos; |
| 326 | } |
| 327 | SKIP_PADDING(); |
| 328 | return NO_ERROR; |
| 329 | } |
| 330 | |
| 331 | ssize_t |
| 332 | BackupDataReader::ReadEntityData(void* data, size_t size) |
| 333 | { |
| 334 | if (m_status != NO_ERROR) { |
| 335 | return -1; |
| 336 | } |
| 337 | int remaining = m_dataEndPos - m_pos; |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 338 | if (kIsDebug) { |
Andreas Gampe | 25df5fb | 2014-11-07 22:24:57 -0800 | [diff] [blame] | 339 | ALOGD("ReadEntityData size=%zu m_pos=0x%zx m_dataEndPos=0x%zx remaining=%d\n", |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 340 | size, m_pos, m_dataEndPos, remaining); |
| 341 | } |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 342 | if (remaining <= 0) { |
| 343 | return 0; |
| 344 | } |
| 345 | if (((int)size) > remaining) { |
| 346 | size = remaining; |
| 347 | } |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 348 | if (kIsDebug) { |
Andreas Gampe | 25df5fb | 2014-11-07 22:24:57 -0800 | [diff] [blame] | 349 | ALOGD(" reading %zu bytes", size); |
Andreas Gampe | 2204f0b | 2014-10-21 23:04:54 -0700 | [diff] [blame] | 350 | } |
Adam Lesinski | 16c4d15 | 2014-01-24 13:27:13 -0800 | [diff] [blame] | 351 | int amt = read(m_fd, data, size); |
| 352 | if (amt < 0) { |
| 353 | m_status = errno; |
| 354 | return -1; |
| 355 | } |
| 356 | if (amt == 0) { |
| 357 | m_status = EIO; |
| 358 | m_done = true; |
| 359 | } |
| 360 | m_pos += amt; |
| 361 | return amt; |
| 362 | } |
| 363 | |
| 364 | status_t |
| 365 | BackupDataReader::skip_padding() |
| 366 | { |
| 367 | ssize_t amt; |
| 368 | ssize_t paddingSize; |
| 369 | |
| 370 | paddingSize = padding_extra(m_pos); |
| 371 | if (paddingSize > 0) { |
| 372 | uint32_t padding; |
| 373 | amt = read(m_fd, &padding, paddingSize); |
| 374 | CHECK_SIZE(amt, paddingSize); |
| 375 | m_pos += amt; |
| 376 | } |
| 377 | return NO_ERROR; |
| 378 | } |
| 379 | |
| 380 | |
| 381 | } // namespace android |