lib/efi_loader/efi_file.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  EFI utils
   4  *
   5  *  Copyright (c) 2017 Rob Clark
   6  */
   7
   8 #include <common.h>
   9 #include <charset.h>
  10 #include <efi_loader.h>
  11 #include <malloc.h>
  12 #include <mapmem.h>
  13 #include <fs.h>
  14
  15 /* GUID for file system information */
  16 const efi_guid_t efi_file_system_info_guid = EFI_FILE_SYSTEM_INFO_GUID;
  17
  18 struct file_system {
  19         struct efi_simple_file_system_protocol base;
  20         struct efi_device_path *dp;
  21         struct blk_desc *desc;
  22         int part;
  23 };
  24 #define to_fs(x) container_of(x, struct file_system, base)
  25
  26 struct file_handle {
  27         struct efi_file_handle base;
  28         struct file_system *fs;
  29         loff_t offset;       /* current file position/cursor */
  30         int isdir;
  31
  32         /* for reading a directory: */
  33         struct fs_dir_stream *dirs;
  34         struct fs_dirent *dent;
  35
  36         char path[0];
  37 };
  38 #define to_fh(x) container_of(x, struct file_handle, base)
  39
  40 static const struct efi_file_handle efi_file_handle_protocol;
  41
  42 static char *basename(struct file_handle *fh)
  43 {
  44         char *s = strrchr(fh->path, '/');
  45         if (s)
  46                 return s + 1;
  47         return fh->path;
  48 }
  49
  50 static int set_blk_dev(struct file_handle *fh)
  51 {
  52         return fs_set_blk_dev_with_part(fh->fs->desc, fh->fs->part);
  53 }
  54
  55 static int is_dir(struct file_handle *fh)
  56 {
  57         struct fs_dir_stream *dirs;
  58
  59         set_blk_dev(fh);
  60         dirs = fs_opendir(fh->path);
  61         if (!dirs)
  62                 return 0;
  63
  64         fs_closedir(dirs);
  65
  66         return 1;
  67 }
  68
  69 /*
  70  * Normalize a path which may include either back or fwd slashes,
  71  * double slashes, . or .. entries in the path, etc.
  72  */
  73 static int sanitize_path(char *path)
  74 {
  75         char *p;
  76
  77         /* backslash to slash: */
  78         p = path;
  79         while ((p = strchr(p, '\\')))
  80                 *p++ = '/';
  81
  82         /* handle double-slashes: */
  83         p = path;
  84         while ((p = strstr(p, "//"))) {
  85                 char *src = p + 1;
  86                 memmove(p, src, strlen(src) + 1);
  87         }
  88
  89         /* handle extra /.'s */
  90         p = path;
  91         while ((p = strstr(p, "/."))) {
  92                 /*
  93                  * You'd be tempted to do this *after* handling ".."s
  94                  * below to avoid having to check if "/." is start of
  95                  * a "/..", but that won't have the correct results..
  96                  * for example, "/foo/./../bar" would get resolved to
  97                  * "/foo/bar" if you did these two passes in the other
  98                  * order
  99                  */
 100                 if (p[2] == '.') {
 101                         p += 2;
 102                         continue;
 103                 }
 104                 char *src = p + 2;
 105                 memmove(p, src, strlen(src) + 1);
 106         }
 107
 108         /* handle extra /..'s: */
 109         p = path;
 110         while ((p = strstr(p, "/.."))) {
 111                 char *src = p + 3;
 112
 113                 p--;
 114
 115                 /* find beginning of previous path entry: */
 116                 while (true) {
 117                         if (p < path)
 118                                 return -1;
 119                         if (*p == '/')
 120                                 break;
 121                         p--;
 122                 }
 123
 124                 memmove(p, src, strlen(src) + 1);
 125         }
 126
 127         return 0;
 128 }
 129
 130 /**
 131  * file_open() - open a file handle
 132  *
 133  * @fs:                 file system
 134  * @parent:             directory relative to which the file is to be opened
 135  * @file_name:          path of the file to be opened. '\', '.', or '..' may
 136  *                      be used as modifiers. A leading backslash indicates an
 137  *                      absolute path.
 138  * @mode:               bit mask indicating the access mode (read, write,
 139  *                      create)
 140  * @attributes:         attributes for newly created file
 141  * Returns:             handle to the opened file or NULL
 142  */
 143 static struct efi_file_handle *file_open(struct file_system *fs,
 144                 struct file_handle *parent, s16 *file_name, u64 mode,
 145                 u64 attributes)
 146 {
 147         struct file_handle *fh;
 148         char f0[MAX_UTF8_PER_UTF16] = {0};
 149         int plen = 0;
 150         int flen = 0;
 151
 152         if (file_name) {
 153                 utf16_to_utf8((u8 *)f0, (u16 *)file_name, 1);
 154                 flen = u16_strlen((u16 *)file_name);
 155         }
 156
 157         /* we could have a parent, but also an absolute path: */
 158         if (f0[0] == '\\') {
 159                 plen = 0;
 160         } else if (parent) {
 161                 plen = strlen(parent->path) + 1;
 162         }
 163
 164         /* +2 is for null and '/' */
 165         fh = calloc(1, sizeof(*fh) + plen + (flen * MAX_UTF8_PER_UTF16) + 2);
 166
 167         fh->base = efi_file_handle_protocol;
 168         fh->fs = fs;
 169
 170         if (parent) {
 171                 char *p = fh->path;
 172
 173                 if (plen > 0) {
 174                         strcpy(p, parent->path);
 175                         p += plen - 1;
 176                         *p++ = '/';
 177                 }
 178
 179                 utf16_to_utf8((u8 *)p, (u16 *)file_name, flen);
 180
 181                 if (sanitize_path(fh->path))
 182                         goto error;
 183
 184                 /* check if file exists: */
 185                 if (set_blk_dev(fh))
 186                         goto error;
 187
 188                 if ((mode & EFI_FILE_MODE_CREATE) &&
 189                     (attributes & EFI_FILE_DIRECTORY)) {
 190                         if (fs_mkdir(fh->path))
 191                                 goto error;
 192                 } else if (!((mode & EFI_FILE_MODE_CREATE) ||
 193                              fs_exists(fh->path)))
 194                         goto error;
 195
 196                 /* figure out if file is a directory: */
 197                 fh->isdir = is_dir(fh);
 198         } else {
 199                 fh->isdir = 1;
 200                 strcpy(fh->path, "");
 201         }
 202
 203         return &fh->base;
 204
 205 error:
 206         free(fh);
 207         return NULL;
 208 }
 209
 210 static efi_status_t EFIAPI efi_file_open(struct efi_file_handle *file,
 211                 struct efi_file_handle **new_handle,
 212                 s16 *file_name, u64 open_mode, u64 attributes)
 213 {
 214         struct file_handle *fh = to_fh(file);
 215         efi_status_t ret;
 216
 217         EFI_ENTRY("%p, %p, \"%ls\", %llx, %llu", file, new_handle, file_name,
 218                   open_mode, attributes);
 219
 220         /* Check parameters */
 221         if (!file || !new_handle || !file_name) {
 222                 ret = EFI_INVALID_PARAMETER;
 223                 goto out;
 224         }
 225         if (open_mode != EFI_FILE_MODE_READ &&
 226             open_mode != (EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE) &&
 227             open_mode != (EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE |
 228                          EFI_FILE_MODE_CREATE)) {
 229                 ret = EFI_INVALID_PARAMETER;
 230                 goto out;
 231         }
 232         /*
 233          * The UEFI spec requires that attributes are only set in create mode.
 234          * The SCT does not care about this and sets EFI_FILE_DIRECTORY in
 235          * read mode. EDK2 does not check that attributes are zero if not in
 236          * create mode.
 237          *
 238          * So here we only check attributes in create mode and do not check
 239          * that they are zero otherwise.
 240          */
 241         if ((open_mode & EFI_FILE_MODE_CREATE) &&
 242             (attributes & (EFI_FILE_READ_ONLY | ~EFI_FILE_VALID_ATTR))) {
 243                 ret = EFI_INVALID_PARAMETER;
 244                 goto out;
 245         }
 246
 247         /* Open file */
 248         *new_handle = file_open(fh->fs, fh, file_name, open_mode, attributes);
 249         if (*new_handle)
 250                 ret = EFI_SUCCESS;
 251         else
 252                 ret = EFI_NOT_FOUND;
 253 out:
 254         return EFI_EXIT(ret);
 255 }
 256
 257 static efi_status_t file_close(struct file_handle *fh)
 258 {
 259         fs_closedir(fh->dirs);
 260         free(fh);
 261         return EFI_SUCCESS;
 262 }
 263
 264 static efi_status_t EFIAPI efi_file_close(struct efi_file_handle *file)
 265 {
 266         struct file_handle *fh = to_fh(file);
 267         EFI_ENTRY("%p", file);
 268         return EFI_EXIT(file_close(fh));
 269 }
 270
 271 static efi_status_t EFIAPI efi_file_delete(struct efi_file_handle *file)
 272 {
 273         struct file_handle *fh = to_fh(file);
 274         efi_status_t ret = EFI_SUCCESS;
 275
 276         EFI_ENTRY("%p", file);
 277
 278         if (set_blk_dev(fh)) {
 279                 ret = EFI_DEVICE_ERROR;
 280                 goto error;
 281         }
 282
 283         if (fs_unlink(fh->path))
 284                 ret = EFI_DEVICE_ERROR;
 285         file_close(fh);
 286
 287 error:
 288         return EFI_EXIT(ret);
 289 }
 290
 291 static efi_status_t file_read(struct file_handle *fh, u64 *buffer_size,
 292                 void *buffer)
 293 {
 294         loff_t actread;
 295
 296         if (fs_read(fh->path, map_to_sysmem(buffer), fh->offset,
 297                     *buffer_size, &actread))
 298                 return EFI_DEVICE_ERROR;
 299
 300         *buffer_size = actread;
 301         fh->offset += actread;
 302
 303         return EFI_SUCCESS;
 304 }
 305
 306 static efi_status_t dir_read(struct file_handle *fh, u64 *buffer_size,
 307                 void *buffer)
 308 {
 309         struct efi_file_info *info = buffer;
 310         struct fs_dirent *dent;
 311         unsigned int required_size;
 312
 313         if (!fh->dirs) {
 314                 assert(fh->offset == 0);
 315                 fh->dirs = fs_opendir(fh->path);
 316                 if (!fh->dirs)
 317                         return EFI_DEVICE_ERROR;
 318         }
 319
 320         /*
 321          * So this is a bit awkward.  Since fs layer is stateful and we
 322          * can't rewind an entry, in the EFI_BUFFER_TOO_SMALL case below
 323          * we might have to return without consuming the dent.. so we
 324          * have to stash it for next call.
 325          */
 326         if (fh->dent) {
 327                 dent = fh->dent;
 328                 fh->dent = NULL;
 329         } else {
 330                 dent = fs_readdir(fh->dirs);
 331         }
 332
 333
 334         if (!dent) {
 335                 /* no more files in directory: */
 336                 /* workaround shim.efi bug/quirk.. as find_boot_csv()
 337                  * loops through directory contents, it initially calls
 338                  * read w/ zero length buffer to find out how much mem
 339                  * to allocate for the EFI_FILE_INFO, then allocates,
 340                  * and then calls a 2nd time.  If we return size of
 341                  * zero the first time, it happily passes that to
 342                  * AllocateZeroPool(), and when that returns NULL it
 343                  * thinks it is EFI_OUT_OF_RESOURCES.  So on first
 344                  * call return a non-zero size:
 345                  */
 346                 if (*buffer_size == 0)
 347                         *buffer_size = sizeof(*info);
 348                 else
 349                         *buffer_size = 0;
 350                 return EFI_SUCCESS;
 351         }
 352
 353         /* check buffer size: */
 354         required_size = sizeof(*info) + 2 * (strlen(dent->name) + 1);
 355         if (*buffer_size < required_size) {
 356                 *buffer_size = required_size;
 357                 fh->dent = dent;
 358                 return EFI_BUFFER_TOO_SMALL;
 359         }
 360
 361         *buffer_size = required_size;
 362         memset(info, 0, required_size);
 363
 364         info->size = required_size;
 365         info->file_size = dent->size;
 366         info->physical_size = dent->size;
 367
 368         if (dent->type == FS_DT_DIR)
 369                 info->attribute |= EFI_FILE_DIRECTORY;
 370
 371         ascii2unicode((u16 *)info->file_name, dent->name);
 372
 373         fh->offset++;
 374
 375         return EFI_SUCCESS;
 376 }
 377
 378 static efi_status_t EFIAPI efi_file_read(struct efi_file_handle *file,
 379                                          efi_uintn_t *buffer_size, void *buffer)
 380 {
 381         struct file_handle *fh = to_fh(file);
 382         efi_status_t ret = EFI_SUCCESS;
 383         u64 bs;
 384
 385         EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
 386
 387         if (!buffer_size || !buffer) {
 388                 ret = EFI_INVALID_PARAMETER;
 389                 goto error;
 390         }
 391
 392         if (set_blk_dev(fh)) {
 393                 ret = EFI_DEVICE_ERROR;
 394                 goto error;
 395         }
 396
 397         bs = *buffer_size;
 398         if (fh->isdir)
 399                 ret = dir_read(fh, &bs, buffer);
 400         else
 401                 ret = file_read(fh, &bs, buffer);
 402         if (bs <= SIZE_MAX)
 403                 *buffer_size = bs;
 404         else
 405                 *buffer_size = SIZE_MAX;
 406
 407 error:
 408         return EFI_EXIT(ret);
 409 }
 410
 411 static efi_status_t EFIAPI efi_file_write(struct efi_file_handle *file,
 412                                           efi_uintn_t *buffer_size,
 413                                           void *buffer)
 414 {
 415         struct file_handle *fh = to_fh(file);
 416         efi_status_t ret = EFI_SUCCESS;
 417         loff_t actwrite;
 418
 419         EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
 420
 421         if (set_blk_dev(fh)) {
 422                 ret = EFI_DEVICE_ERROR;
 423                 goto error;
 424         }
 425
 426         if (fs_write(fh->path, map_to_sysmem(buffer), fh->offset, *buffer_size,
 427                      &actwrite)) {
 428                 ret = EFI_DEVICE_ERROR;
 429                 goto error;
 430         }
 431
 432         *buffer_size = actwrite;
 433         fh->offset += actwrite;
 434
 435 error:
 436         return EFI_EXIT(ret);
 437 }
 438
 439 static efi_status_t EFIAPI efi_file_getpos(struct efi_file_handle *file,
 440                                            efi_uintn_t *pos)
 441 {
 442         struct file_handle *fh = to_fh(file);
 443
 444         EFI_ENTRY("%p, %p", file, pos);
 445
 446         if (fh->offset <= SIZE_MAX) {
 447                 *pos = fh->offset;
 448                 return EFI_EXIT(EFI_SUCCESS);
 449         } else {
 450                 return EFI_EXIT(EFI_DEVICE_ERROR);
 451         }
 452 }
 453
 454 static efi_status_t EFIAPI efi_file_setpos(struct efi_file_handle *file,
 455                 efi_uintn_t pos)
 456 {
 457         struct file_handle *fh = to_fh(file);
 458         efi_status_t ret = EFI_SUCCESS;
 459
 460         EFI_ENTRY("%p, %zu", file, pos);
 461
 462         if (fh->isdir) {
 463                 if (pos != 0) {
 464                         ret = EFI_UNSUPPORTED;
 465                         goto error;
 466                 }
 467                 fs_closedir(fh->dirs);
 468                 fh->dirs = NULL;
 469         }
 470
 471         if (pos == ~0ULL) {
 472                 loff_t file_size;
 473
 474                 if (set_blk_dev(fh)) {
 475                         ret = EFI_DEVICE_ERROR;
 476                         goto error;
 477                 }
 478
 479                 if (fs_size(fh->path, &file_size)) {
 480                         ret = EFI_DEVICE_ERROR;
 481                         goto error;
 482                 }
 483
 484                 pos = file_size;
 485         }
 486
 487         fh->offset = pos;
 488
 489 error:
 490         return EFI_EXIT(ret);
 491 }
 492
 493 static efi_status_t EFIAPI efi_file_getinfo(struct efi_file_handle *file,
 494                                             const efi_guid_t *info_type,
 495                                             efi_uintn_t *buffer_size,
 496                                             void *buffer)
 497 {
 498         struct file_handle *fh = to_fh(file);
 499         efi_status_t ret = EFI_SUCCESS;
 500
 501         EFI_ENTRY("%p, %pUl, %p, %p", file, info_type, buffer_size, buffer);
 502
 503         if (!guidcmp(info_type, &efi_file_info_guid)) {
 504                 struct efi_file_info *info = buffer;
 505                 char *filename = basename(fh);
 506                 unsigned int required_size;
 507                 loff_t file_size;
 508
 509                 /* check buffer size: */
 510                 required_size = sizeof(*info) + 2 * (strlen(filename) + 1);
 511                 if (*buffer_size < required_size) {
 512                         *buffer_size = required_size;
 513                         ret = EFI_BUFFER_TOO_SMALL;
 514                         goto error;
 515                 }
 516
 517                 if (set_blk_dev(fh)) {
 518                         ret = EFI_DEVICE_ERROR;
 519                         goto error;
 520                 }
 521
 522                 if (fs_size(fh->path, &file_size)) {
 523                         ret = EFI_DEVICE_ERROR;
 524                         goto error;
 525                 }
 526
 527                 memset(info, 0, required_size);
 528
 529                 info->size = required_size;
 530                 info->file_size = file_size;
 531                 info->physical_size = file_size;
 532
 533                 if (fh->isdir)
 534                         info->attribute |= EFI_FILE_DIRECTORY;
 535
 536                 ascii2unicode((u16 *)info->file_name, filename);
 537         } else if (!guidcmp(info_type, &efi_file_system_info_guid)) {
 538                 struct efi_file_system_info *info = buffer;
 539                 disk_partition_t part;
 540                 efi_uintn_t required_size;
 541                 int r;
 542
 543                 if (fh->fs->part >= 1)
 544                         r = part_get_info(fh->fs->desc, fh->fs->part, &part);
 545                 else
 546                         r = part_get_info_whole_disk(fh->fs->desc, &part);
 547                 if (r < 0) {
 548                         ret = EFI_DEVICE_ERROR;
 549                         goto error;
 550                 }
 551                 required_size = sizeof(info) + 2 *
 552                                 (strlen((const char *)part.name) + 1);
 553                 if (*buffer_size < required_size) {
 554                         *buffer_size = required_size;
 555                         ret = EFI_BUFFER_TOO_SMALL;
 556                         goto error;
 557                 }
 558
 559                 memset(info, 0, required_size);
 560
 561                 info->size = required_size;
 562                 info->read_only = true;
 563                 info->volume_size = part.size * part.blksz;
 564                 info->free_space = 0;
 565                 info->block_size = part.blksz;
 566                 /*
 567                  * TODO: The volume label is not available in U-Boot.
 568                  * Use the partition name as substitute.
 569                  */
 570                 ascii2unicode((u16 *)info->volume_label,
 571                               (const char *)part.name);
 572         } else {
 573                 ret = EFI_UNSUPPORTED;
 574         }
 575
 576 error:
 577         return EFI_EXIT(ret);
 578 }
 579
 580 static efi_status_t EFIAPI efi_file_setinfo(struct efi_file_handle *file,
 581                                             const efi_guid_t *info_type,
 582                                             efi_uintn_t buffer_size,
 583                                             void *buffer)
 584 {
 585         EFI_ENTRY("%p, %p, %zu, %p", file, info_type, buffer_size, buffer);
 586
 587         return EFI_EXIT(EFI_UNSUPPORTED);
 588 }
 589
 590 static efi_status_t EFIAPI efi_file_flush(struct efi_file_handle *file)
 591 {
 592         EFI_ENTRY("%p", file);
 593         return EFI_EXIT(EFI_SUCCESS);
 594 }
 595
 596 static const struct efi_file_handle efi_file_handle_protocol = {
 597         .rev = EFI_FILE_PROTOCOL_REVISION,
 598         .open = efi_file_open,
 599         .close = efi_file_close,
 600         .delete = efi_file_delete,
 601         .read = efi_file_read,
 602         .write = efi_file_write,
 603         .getpos = efi_file_getpos,
 604         .setpos = efi_file_setpos,
 605         .getinfo = efi_file_getinfo,
 606         .setinfo = efi_file_setinfo,
 607         .flush = efi_file_flush,
 608 };
 609
 610 struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp)
 611 {
 612         struct efi_simple_file_system_protocol *v;
 613         struct efi_file_handle *f;
 614         efi_status_t ret;
 615
 616         v = efi_fs_from_path(fp);
 617         if (!v)
 618                 return NULL;
 619
 620         EFI_CALL(ret = v->open_volume(v, &f));
 621         if (ret != EFI_SUCCESS)
 622                 return NULL;
 623
 624         /* skip over device-path nodes before the file path: */
 625         while (fp && !EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH))
 626                 fp = efi_dp_next(fp);
 627
 628         while (fp) {
 629                 struct efi_device_path_file_path *fdp =
 630                         container_of(fp, struct efi_device_path_file_path, dp);
 631                 struct efi_file_handle *f2;
 632
 633                 if (!EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH)) {
 634                         printf("bad file path!\n");
 635                         f->close(f);
 636                         return NULL;
 637                 }
 638
 639                 EFI_CALL(ret = f->open(f, &f2, (s16 *)fdp->str,
 640                                        EFI_FILE_MODE_READ, 0));
 641                 if (ret != EFI_SUCCESS)
 642                         return NULL;
 643
 644                 fp = efi_dp_next(fp);
 645
 646                 EFI_CALL(f->close(f));
 647                 f = f2;
 648         }
 649
 650         return f;
 651 }
 652
 653 static efi_status_t EFIAPI
 654 efi_open_volume(struct efi_simple_file_system_protocol *this,
 655                 struct efi_file_handle **root)
 656 {
 657         struct file_system *fs = to_fs(this);
 658
 659         EFI_ENTRY("%p, %p", this, root);
 660
 661         *root = file_open(fs, NULL, NULL, 0, 0);
 662
 663         return EFI_EXIT(EFI_SUCCESS);
 664 }
 665
 666 struct efi_simple_file_system_protocol *
 667 efi_simple_file_system(struct blk_desc *desc, int part,
 668                        struct efi_device_path *dp)
 669 {
 670         struct file_system *fs;
 671
 672         fs = calloc(1, sizeof(*fs));
 673         fs->base.rev = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
 674         fs->base.open_volume = efi_open_volume;
 675         fs->desc = desc;
 676         fs->part = part;
 677         fs->dp = dp;
 678
 679         return &fs->base;
 680 }