Michael Ryleev | 7a2bc37 | 2016-03-08 15:16:11 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 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 | #include <errno.h> |
| 17 | #include <fcntl.h> |
| 18 | #include <inttypes.h> |
| 19 | #include <stdbool.h> |
| 20 | #include <stdlib.h> |
| 21 | #include <string.h> |
| 22 | #include <sys/stat.h> |
| 23 | #include <sys/syscall.h> |
| 24 | #include <sys/types.h> |
| 25 | #include <unistd.h> |
| 26 | |
| 27 | #include "log.h" |
| 28 | #include "ipc.h" |
| 29 | #include "storage.h" |
| 30 | |
| 31 | #define FD_TBL_SIZE 64 |
| 32 | #define MAX_READ_SIZE 4096 |
| 33 | |
| 34 | enum sync_state { |
| 35 | SS_UNUSED = -1, |
| 36 | SS_CLEAN = 0, |
| 37 | SS_DIRTY = 1, |
| 38 | }; |
| 39 | |
| 40 | static int ssdir_fd = -1; |
| 41 | static const char *ssdir_name; |
| 42 | |
| 43 | static enum sync_state fs_state; |
| 44 | static enum sync_state dir_state; |
| 45 | static enum sync_state fd_state[FD_TBL_SIZE]; |
| 46 | |
| 47 | static struct { |
| 48 | struct storage_file_read_resp hdr; |
| 49 | uint8_t data[MAX_READ_SIZE]; |
| 50 | } read_rsp; |
| 51 | |
| 52 | static uint32_t insert_fd(int open_flags, int fd) |
| 53 | { |
| 54 | uint32_t handle = fd; |
| 55 | |
| 56 | if (open_flags & O_CREAT) { |
| 57 | dir_state = SS_DIRTY; |
| 58 | } |
| 59 | |
| 60 | if (handle < FD_TBL_SIZE) { |
| 61 | fd_state[fd] = SS_CLEAN; /* fd clean */ |
| 62 | if (open_flags & O_TRUNC) { |
| 63 | fd_state[fd] = SS_DIRTY; /* set fd dirty */ |
| 64 | } |
| 65 | } else { |
| 66 | ALOGW("%s: untracked fd %u\n", __func__, fd); |
| 67 | if (open_flags & (O_TRUNC | O_CREAT)) { |
| 68 | fs_state = SS_DIRTY; |
| 69 | } |
| 70 | } |
| 71 | return handle; |
| 72 | } |
| 73 | |
| 74 | static int lookup_fd(uint32_t handle, bool dirty) |
| 75 | { |
| 76 | if (dirty) { |
| 77 | if (handle < FD_TBL_SIZE) { |
| 78 | fd_state[handle] = SS_DIRTY; |
| 79 | } else { |
| 80 | fs_state = SS_DIRTY; |
| 81 | } |
| 82 | } |
| 83 | return handle; |
| 84 | } |
| 85 | |
| 86 | static int remove_fd(uint32_t handle) |
| 87 | { |
| 88 | if (handle < FD_TBL_SIZE) { |
| 89 | fd_state[handle] = SS_UNUSED; /* set to uninstalled */ |
| 90 | } |
| 91 | return handle; |
| 92 | } |
| 93 | |
| 94 | static enum storage_err translate_errno(int error) |
| 95 | { |
| 96 | enum storage_err result; |
| 97 | switch (error) { |
| 98 | case 0: |
| 99 | result = STORAGE_NO_ERROR; |
| 100 | break; |
| 101 | case EBADF: |
| 102 | case EINVAL: |
| 103 | case ENOTDIR: |
| 104 | case EISDIR: |
| 105 | case ENAMETOOLONG: |
| 106 | result = STORAGE_ERR_NOT_VALID; |
| 107 | break; |
| 108 | case ENOENT: |
| 109 | result = STORAGE_ERR_NOT_FOUND; |
| 110 | break; |
| 111 | case EEXIST: |
| 112 | result = STORAGE_ERR_EXIST; |
| 113 | break; |
| 114 | case EPERM: |
| 115 | case EACCES: |
| 116 | result = STORAGE_ERR_ACCESS; |
| 117 | break; |
| 118 | default: |
| 119 | result = STORAGE_ERR_GENERIC; |
| 120 | break; |
| 121 | } |
| 122 | |
| 123 | return result; |
| 124 | } |
| 125 | |
| 126 | static ssize_t write_with_retry(int fd, const void *buf_, size_t size, off_t offset) |
| 127 | { |
| 128 | ssize_t rc; |
| 129 | const uint8_t *buf = buf_; |
| 130 | |
| 131 | while (size > 0) { |
| 132 | rc = TEMP_FAILURE_RETRY(pwrite(fd, buf, size, offset)); |
| 133 | if (rc < 0) |
| 134 | return rc; |
| 135 | size -= rc; |
| 136 | buf += rc; |
| 137 | offset += rc; |
| 138 | } |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | static ssize_t read_with_retry(int fd, void *buf_, size_t size, off_t offset) |
| 143 | { |
| 144 | ssize_t rc; |
| 145 | size_t rcnt = 0; |
| 146 | uint8_t *buf = buf_; |
| 147 | |
| 148 | while (size > 0) { |
| 149 | rc = TEMP_FAILURE_RETRY(pread(fd, buf, size, offset)); |
| 150 | if (rc < 0) |
| 151 | return rc; |
| 152 | if (rc == 0) |
| 153 | break; |
| 154 | size -= rc; |
| 155 | buf += rc; |
| 156 | offset += rc; |
| 157 | rcnt += rc; |
| 158 | } |
| 159 | return rcnt; |
| 160 | } |
| 161 | |
| 162 | int storage_file_delete(struct storage_msg *msg, |
| 163 | const void *r, size_t req_len) |
| 164 | { |
| 165 | char *path = NULL; |
| 166 | const struct storage_file_delete_req *req = r; |
| 167 | |
| 168 | if (req_len < sizeof(*req)) { |
| 169 | ALOGE("%s: invalid request length (%zd < %zd)\n", |
| 170 | __func__, req_len, sizeof(*req)); |
| 171 | msg->result = STORAGE_ERR_NOT_VALID; |
| 172 | goto err_response; |
| 173 | } |
| 174 | |
| 175 | size_t fname_len = strlen(req->name); |
| 176 | if (fname_len != req_len - sizeof(*req)) { |
| 177 | ALOGE("%s: invalid filename length (%zd != %zd)\n", |
| 178 | __func__, fname_len, req_len - sizeof(*req)); |
| 179 | msg->result = STORAGE_ERR_NOT_VALID; |
| 180 | goto err_response; |
| 181 | } |
| 182 | |
| 183 | int rc = asprintf(&path, "%s/%s", ssdir_name, req->name); |
| 184 | if (rc < 0) { |
| 185 | ALOGE("%s: asprintf failed\n", __func__); |
| 186 | msg->result = STORAGE_ERR_GENERIC; |
| 187 | goto err_response; |
| 188 | } |
| 189 | |
| 190 | dir_state = SS_DIRTY; |
| 191 | rc = unlink(path); |
| 192 | if (rc < 0) { |
| 193 | rc = errno; |
| 194 | if (errno == ENOENT) { |
| 195 | ALOGV("%s: error (%d) unlinking file '%s'\n", |
| 196 | __func__, rc, path); |
| 197 | } else { |
| 198 | ALOGE("%s: error (%d) unlinking file '%s'\n", |
| 199 | __func__, rc, path); |
| 200 | } |
| 201 | msg->result = translate_errno(rc); |
| 202 | goto err_response; |
| 203 | } |
| 204 | |
| 205 | ALOGV("%s: \"%s\"\n", __func__, path); |
| 206 | msg->result = STORAGE_NO_ERROR; |
| 207 | |
| 208 | err_response: |
| 209 | if (path) |
| 210 | free(path); |
| 211 | return ipc_respond(msg, NULL, 0); |
| 212 | } |
| 213 | |
| 214 | |
| 215 | int storage_file_open(struct storage_msg *msg, |
| 216 | const void *r, size_t req_len) |
| 217 | { |
| 218 | char *path = NULL; |
| 219 | const struct storage_file_open_req *req = r; |
| 220 | struct storage_file_open_resp resp = {0}; |
| 221 | |
| 222 | if (req_len < sizeof(*req)) { |
| 223 | ALOGE("%s: invalid request length (%zd < %zd)\n", |
| 224 | __func__, req_len, sizeof(*req)); |
| 225 | msg->result = STORAGE_ERR_NOT_VALID; |
| 226 | goto err_response; |
| 227 | } |
| 228 | |
| 229 | size_t fname_len = strlen(req->name); |
| 230 | if (fname_len != req_len - sizeof(*req)) { |
| 231 | ALOGE("%s: invalid filename length (%zd != %zd)\n", |
| 232 | __func__, fname_len, req_len - sizeof(*req)); |
| 233 | msg->result = STORAGE_ERR_NOT_VALID; |
| 234 | goto err_response; |
| 235 | } |
| 236 | |
| 237 | int rc = asprintf(&path, "%s/%s", ssdir_name, req->name); |
| 238 | if (rc < 0) { |
| 239 | ALOGE("%s: asprintf failed\n", __func__); |
| 240 | msg->result = STORAGE_ERR_GENERIC; |
| 241 | goto err_response; |
| 242 | } |
| 243 | |
| 244 | int open_flags = O_RDWR; |
| 245 | |
| 246 | if (req->flags & STORAGE_FILE_OPEN_TRUNCATE) |
| 247 | open_flags |= O_TRUNC; |
| 248 | |
| 249 | if (req->flags & STORAGE_FILE_OPEN_CREATE) { |
| 250 | /* open or create */ |
| 251 | if (req->flags & STORAGE_FILE_OPEN_CREATE_EXCLUSIVE) { |
| 252 | /* create exclusive */ |
| 253 | open_flags |= O_CREAT | O_EXCL; |
| 254 | rc = TEMP_FAILURE_RETRY(open(path, open_flags, S_IRUSR | S_IWUSR)); |
| 255 | } else { |
| 256 | /* try open first */ |
| 257 | rc = TEMP_FAILURE_RETRY(open(path, open_flags, S_IRUSR | S_IWUSR)); |
| 258 | if (rc == -1 && errno == ENOENT) { |
| 259 | /* then try open with O_CREATE */ |
| 260 | open_flags |= O_CREAT; |
| 261 | rc = TEMP_FAILURE_RETRY(open(path, open_flags, S_IRUSR | S_IWUSR)); |
| 262 | } |
| 263 | |
| 264 | } |
| 265 | } else { |
| 266 | /* open an existing file */ |
| 267 | rc = TEMP_FAILURE_RETRY(open(path, open_flags, S_IRUSR | S_IWUSR)); |
| 268 | } |
| 269 | |
| 270 | if (rc < 0) { |
| 271 | rc = errno; |
| 272 | if (errno == EEXIST || errno == ENOENT) { |
| 273 | ALOGV("%s: failed to open file \"%s\": %s\n", |
| 274 | __func__, path, strerror(errno)); |
| 275 | } else { |
| 276 | ALOGE("%s: failed to open file \"%s\": %s\n", |
| 277 | __func__, path, strerror(errno)); |
| 278 | } |
| 279 | msg->result = translate_errno(rc); |
| 280 | goto err_response; |
| 281 | } |
| 282 | free(path); |
| 283 | |
| 284 | /* at this point rc contains storage file fd */ |
| 285 | msg->result = STORAGE_NO_ERROR; |
| 286 | resp.handle = insert_fd(open_flags, rc); |
| 287 | ALOGV("%s: \"%s\": fd = %u: handle = %d\n", |
| 288 | __func__, path, rc, resp.handle); |
| 289 | |
| 290 | return ipc_respond(msg, &resp, sizeof(resp)); |
| 291 | |
| 292 | err_response: |
| 293 | if (path) |
| 294 | free(path); |
| 295 | return ipc_respond(msg, NULL, 0); |
| 296 | } |
| 297 | |
| 298 | int storage_file_close(struct storage_msg *msg, |
| 299 | const void *r, size_t req_len) |
| 300 | { |
| 301 | const struct storage_file_close_req *req = r; |
| 302 | |
| 303 | if (req_len != sizeof(*req)) { |
| 304 | ALOGE("%s: invalid request length (%zd != %zd)\n", |
| 305 | __func__, req_len, sizeof(*req)); |
| 306 | msg->result = STORAGE_ERR_NOT_VALID; |
| 307 | goto err_response; |
| 308 | } |
| 309 | |
| 310 | int fd = remove_fd(req->handle); |
| 311 | ALOGV("%s: handle = %u: fd = %u\n", __func__, req->handle, fd); |
| 312 | |
| 313 | int rc = fsync(fd); |
| 314 | if (rc < 0) { |
| 315 | rc = errno; |
| 316 | ALOGE("%s: fsync failed for fd=%u: %s\n", |
| 317 | __func__, fd, strerror(errno)); |
| 318 | msg->result = translate_errno(rc); |
| 319 | goto err_response; |
| 320 | } |
| 321 | |
| 322 | rc = close(fd); |
| 323 | if (rc < 0) { |
| 324 | rc = errno; |
| 325 | ALOGE("%s: close failed for fd=%u: %s\n", |
| 326 | __func__, fd, strerror(errno)); |
| 327 | msg->result = translate_errno(rc); |
| 328 | goto err_response; |
| 329 | } |
| 330 | |
| 331 | msg->result = STORAGE_NO_ERROR; |
| 332 | |
| 333 | err_response: |
| 334 | return ipc_respond(msg, NULL, 0); |
| 335 | } |
| 336 | |
| 337 | |
| 338 | int storage_file_write(struct storage_msg *msg, |
| 339 | const void *r, size_t req_len) |
| 340 | { |
| 341 | int rc; |
| 342 | const struct storage_file_write_req *req = r; |
| 343 | |
| 344 | if (req_len < sizeof(*req)) { |
| 345 | ALOGE("%s: invalid request length (%zd < %zd)\n", |
| 346 | __func__, req_len, sizeof(*req)); |
| 347 | msg->result = STORAGE_ERR_NOT_VALID; |
| 348 | goto err_response; |
| 349 | } |
| 350 | |
| 351 | int fd = lookup_fd(req->handle, true); |
| 352 | if (write_with_retry(fd, &req->data[0], req_len - sizeof(*req), |
| 353 | req->offset) < 0) { |
| 354 | rc = errno; |
| 355 | ALOGW("%s: error writing file (fd=%d): %s\n", |
| 356 | __func__, fd, strerror(errno)); |
| 357 | msg->result = translate_errno(rc); |
| 358 | goto err_response; |
| 359 | } |
| 360 | |
| 361 | msg->result = STORAGE_NO_ERROR; |
| 362 | |
| 363 | err_response: |
| 364 | return ipc_respond(msg, NULL, 0); |
| 365 | } |
| 366 | |
| 367 | |
| 368 | int storage_file_read(struct storage_msg *msg, |
| 369 | const void *r, size_t req_len) |
| 370 | { |
| 371 | int rc; |
| 372 | const struct storage_file_read_req *req = r; |
| 373 | |
| 374 | if (req_len != sizeof(*req)) { |
| 375 | ALOGE("%s: invalid request length (%zd != %zd)\n", |
| 376 | __func__, req_len, sizeof(*req)); |
| 377 | msg->result = STORAGE_ERR_NOT_VALID; |
| 378 | goto err_response; |
| 379 | } |
| 380 | |
| 381 | if (req->size > MAX_READ_SIZE) { |
| 382 | ALOGW("%s: request is too large (%zd > %zd) - refusing\n", |
| 383 | __func__, req->size, MAX_READ_SIZE); |
| 384 | msg->result = STORAGE_ERR_NOT_VALID; |
| 385 | goto err_response; |
| 386 | } |
| 387 | |
| 388 | int fd = lookup_fd(req->handle, false); |
| 389 | ssize_t read_res = read_with_retry(fd, read_rsp.hdr.data, req->size, |
| 390 | (off_t)req->offset); |
| 391 | if (read_res < 0) { |
| 392 | rc = errno; |
| 393 | ALOGW("%s: error reading file (fd=%d): %s\n", |
| 394 | __func__, fd, strerror(errno)); |
| 395 | msg->result = translate_errno(rc); |
| 396 | goto err_response; |
| 397 | } |
| 398 | |
| 399 | msg->result = STORAGE_NO_ERROR; |
| 400 | return ipc_respond(msg, &read_rsp, read_res + sizeof(read_rsp.hdr)); |
| 401 | |
| 402 | err_response: |
| 403 | return ipc_respond(msg, NULL, 0); |
| 404 | } |
| 405 | |
| 406 | |
| 407 | int storage_file_get_size(struct storage_msg *msg, |
| 408 | const void *r, size_t req_len) |
| 409 | { |
| 410 | const struct storage_file_get_size_req *req = r; |
| 411 | struct storage_file_get_size_resp resp = {0}; |
| 412 | |
| 413 | if (req_len != sizeof(*req)) { |
| 414 | ALOGE("%s: invalid request length (%zd != %zd)\n", |
| 415 | __func__, req_len, sizeof(*req)); |
| 416 | msg->result = STORAGE_ERR_NOT_VALID; |
| 417 | goto err_response; |
| 418 | } |
| 419 | |
| 420 | struct stat stat; |
| 421 | int fd = lookup_fd(req->handle, false); |
| 422 | int rc = fstat(fd, &stat); |
| 423 | if (rc < 0) { |
| 424 | rc = errno; |
| 425 | ALOGE("%s: error stat'ing file (fd=%d): %s\n", |
| 426 | __func__, fd, strerror(errno)); |
| 427 | msg->result = translate_errno(rc); |
| 428 | goto err_response; |
| 429 | } |
| 430 | |
| 431 | resp.size = stat.st_size; |
| 432 | msg->result = STORAGE_NO_ERROR; |
| 433 | return ipc_respond(msg, &resp, sizeof(resp)); |
| 434 | |
| 435 | err_response: |
| 436 | return ipc_respond(msg, NULL, 0); |
| 437 | } |
| 438 | |
| 439 | |
| 440 | int storage_file_set_size(struct storage_msg *msg, |
| 441 | const void *r, size_t req_len) |
| 442 | { |
| 443 | const struct storage_file_set_size_req *req = r; |
| 444 | |
| 445 | if (req_len != sizeof(*req)) { |
| 446 | ALOGE("%s: invalid request length (%zd != %zd)\n", |
| 447 | __func__, req_len, sizeof(*req)); |
| 448 | msg->result = STORAGE_ERR_NOT_VALID; |
| 449 | goto err_response; |
| 450 | } |
| 451 | |
| 452 | int fd = lookup_fd(req->handle, true); |
| 453 | int rc = TEMP_FAILURE_RETRY(ftruncate(fd, req->size)); |
| 454 | if (rc < 0) { |
| 455 | rc = errno; |
| 456 | ALOGE("%s: error truncating file (fd=%d): %s\n", |
| 457 | __func__, fd, strerror(errno)); |
| 458 | msg->result = translate_errno(rc); |
| 459 | goto err_response; |
| 460 | } |
| 461 | |
| 462 | msg->result = STORAGE_NO_ERROR; |
| 463 | |
| 464 | err_response: |
| 465 | return ipc_respond(msg, NULL, 0); |
| 466 | } |
| 467 | |
| 468 | int storage_init(const char *dirname) |
| 469 | { |
| 470 | fs_state = SS_CLEAN; |
| 471 | dir_state = SS_CLEAN; |
| 472 | for (uint i = 0; i < FD_TBL_SIZE; i++) { |
| 473 | fd_state[i] = SS_UNUSED; /* uninstalled */ |
| 474 | } |
| 475 | |
| 476 | ssdir_fd = open(dirname, O_RDONLY); |
| 477 | if (ssdir_fd < 0) { |
| 478 | ALOGE("failed to open ss root dir \"%s\": %s\n", |
| 479 | dirname, strerror(errno)); |
| 480 | return -1; |
| 481 | } |
| 482 | ssdir_name = dirname; |
| 483 | return 0; |
| 484 | } |
| 485 | |
| 486 | int storage_sync_checkpoint(void) |
| 487 | { |
| 488 | int rc; |
| 489 | |
| 490 | /* sync fd table and reset it to clean state first */ |
| 491 | for (uint fd = 0; fd < FD_TBL_SIZE; fd++) { |
| 492 | if (fd_state[fd] == SS_DIRTY) { |
| 493 | if (fs_state == SS_CLEAN) { |
| 494 | /* need to sync individual fd */ |
| 495 | rc = fsync(fd); |
| 496 | if (rc < 0) { |
| 497 | ALOGE("fsync for fd=%d failed: %s\n", fd, strerror(errno)); |
| 498 | return rc; |
| 499 | } |
| 500 | } |
| 501 | fd_state[fd] = SS_CLEAN; /* set to clean */ |
| 502 | } |
| 503 | } |
| 504 | |
| 505 | /* check if we need to sync the directory */ |
| 506 | if (dir_state == SS_DIRTY) { |
| 507 | if (fs_state == SS_CLEAN) { |
| 508 | rc = fsync(ssdir_fd); |
| 509 | if (rc < 0) { |
| 510 | ALOGE("fsync for ssdir failed: %s\n", strerror(errno)); |
| 511 | return rc; |
| 512 | } |
| 513 | } |
| 514 | dir_state = SS_CLEAN; /* set to clean */ |
| 515 | } |
| 516 | |
| 517 | /* check if we need to sync the whole fs */ |
| 518 | if (fs_state == SS_DIRTY) { |
| 519 | rc = syscall(SYS_syncfs, ssdir_fd); |
| 520 | if (rc < 0) { |
| 521 | ALOGE("syncfs failed: %s\n", strerror(errno)); |
| 522 | return rc; |
| 523 | } |
| 524 | fs_state = SS_CLEAN; |
| 525 | } |
| 526 | |
| 527 | return 0; |
| 528 | } |
| 529 | |