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 || !file || !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         if ((!(open_mode & EFI_FILE_MODE_CREATE) && attributes) ||
 233             (attributes & (EFI_FILE_READ_ONLY | ~EFI_FILE_VALID_ATTR))) {
 234                 ret = EFI_INVALID_PARAMETER;
 235                 goto out;
 236         }
 237
 238         /* Open file */
 239         *new_handle = file_open(fh->fs, fh, file_name, open_mode, attributes);
 240         if (*new_handle)
 241                 ret = EFI_SUCCESS;
 242         else
 243                 ret = EFI_NOT_FOUND;
 244 out:
 245         return EFI_EXIT(ret);
 246 }
 247
 248 static efi_status_t file_close(struct file_handle *fh)
 249 {
 250         fs_closedir(fh->dirs);
 251         free(fh);
 252         return EFI_SUCCESS;
 253 }
 254
 255 static efi_status_t EFIAPI efi_file_close(struct efi_file_handle *file)
 256 {
 257         struct file_handle *fh = to_fh(file);
 258         EFI_ENTRY("%p", file);
 259         return EFI_EXIT(file_close(fh));
 260 }
 261
 262 static efi_status_t EFIAPI efi_file_delete(struct efi_file_handle *file)
 263 {
 264         struct file_handle *fh = to_fh(file);
 265         efi_status_t ret = EFI_SUCCESS;
 266
 267         EFI_ENTRY("%p", file);
 268
 269         if (set_blk_dev(fh)) {
 270                 ret = EFI_DEVICE_ERROR;
 271                 goto error;
 272         }
 273
 274         if (fs_unlink(fh->path))
 275                 ret = EFI_DEVICE_ERROR;
 276         file_close(fh);
 277
 278 error:
 279         return EFI_EXIT(ret);
 280 }
 281
 282 static efi_status_t file_read(struct file_handle *fh, u64 *buffer_size,
 283                 void *buffer)
 284 {
 285         loff_t actread;
 286         /* fs_read expects buffer address, not pointer */
 287         uintptr_t buffer_addr = (uintptr_t)map_to_sysmem(buffer);
 288
 289         if (fs_read(fh->path, buffer_addr, fh->offset,
 290                     *buffer_size, &actread))
 291                 return EFI_DEVICE_ERROR;
 292
 293         *buffer_size = actread;
 294         fh->offset += actread;
 295
 296         return EFI_SUCCESS;
 297 }
 298
 299 static efi_status_t dir_read(struct file_handle *fh, u64 *buffer_size,
 300                 void *buffer)
 301 {
 302         struct efi_file_info *info = buffer;
 303         struct fs_dirent *dent;
 304         unsigned int required_size;
 305
 306         if (!fh->dirs) {
 307                 assert(fh->offset == 0);
 308                 fh->dirs = fs_opendir(fh->path);
 309                 if (!fh->dirs)
 310                         return EFI_DEVICE_ERROR;
 311         }
 312
 313         /*
 314          * So this is a bit awkward.  Since fs layer is stateful and we
 315          * can't rewind an entry, in the EFI_BUFFER_TOO_SMALL case below
 316          * we might have to return without consuming the dent.. so we
 317          * have to stash it for next call.
 318          */
 319         if (fh->dent) {
 320                 dent = fh->dent;
 321                 fh->dent = NULL;
 322         } else {
 323                 dent = fs_readdir(fh->dirs);
 324         }
 325
 326
 327         if (!dent) {
 328                 /* no more files in directory: */
 329                 /* workaround shim.efi bug/quirk.. as find_boot_csv()
 330                  * loops through directory contents, it initially calls
 331                  * read w/ zero length buffer to find out how much mem
 332                  * to allocate for the EFI_FILE_INFO, then allocates,
 333                  * and then calls a 2nd time.  If we return size of
 334                  * zero the first time, it happily passes that to
 335                  * AllocateZeroPool(), and when that returns NULL it
 336                  * thinks it is EFI_OUT_OF_RESOURCES.  So on first
 337                  * call return a non-zero size:
 338                  */
 339                 if (*buffer_size == 0)
 340                         *buffer_size = sizeof(*info);
 341                 else
 342                         *buffer_size = 0;
 343                 return EFI_SUCCESS;
 344         }
 345
 346         /* check buffer size: */
 347         required_size = sizeof(*info) + 2 * (strlen(dent->name) + 1);
 348         if (*buffer_size < required_size) {
 349                 *buffer_size = required_size;
 350                 fh->dent = dent;
 351                 return EFI_BUFFER_TOO_SMALL;
 352         }
 353
 354         *buffer_size = required_size;
 355         memset(info, 0, required_size);
 356
 357         info->size = required_size;
 358         info->file_size = dent->size;
 359         info->physical_size = dent->size;
 360
 361         if (dent->type == FS_DT_DIR)
 362                 info->attribute |= EFI_FILE_DIRECTORY;
 363
 364         ascii2unicode((u16 *)info->file_name, dent->name);
 365
 366         fh->offset++;
 367
 368         return EFI_SUCCESS;
 369 }
 370
 371 static efi_status_t EFIAPI efi_file_read(struct efi_file_handle *file,
 372                                          efi_uintn_t *buffer_size, void *buffer)
 373 {
 374         struct file_handle *fh = to_fh(file);
 375         efi_status_t ret = EFI_SUCCESS;
 376         u64 bs;
 377
 378         EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
 379
 380         if (!buffer_size || !buffer) {
 381                 ret = EFI_INVALID_PARAMETER;
 382                 goto error;
 383         }
 384
 385         if (set_blk_dev(fh)) {
 386                 ret = EFI_DEVICE_ERROR;
 387                 goto error;
 388         }
 389
 390         bs = *buffer_size;
 391         if (fh->isdir)
 392                 ret = dir_read(fh, &bs, buffer);
 393         else
 394                 ret = file_read(fh, &bs, buffer);
 395         if (bs <= SIZE_MAX)
 396                 *buffer_size = bs;
 397         else
 398                 *buffer_size = SIZE_MAX;
 399
 400 error:
 401         return EFI_EXIT(ret);
 402 }
 403
 404 static efi_status_t EFIAPI efi_file_write(struct efi_file_handle *file,
 405                                           efi_uintn_t *buffer_size,
 406                                           void *buffer)
 407 {
 408         struct file_handle *fh = to_fh(file);
 409         efi_status_t ret = EFI_SUCCESS;
 410         loff_t actwrite;
 411
 412         EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
 413
 414         if (set_blk_dev(fh)) {
 415                 ret = EFI_DEVICE_ERROR;
 416                 goto error;
 417         }
 418
 419         if (fs_write(fh->path, (ulong)buffer, fh->offset, *buffer_size,
 420                      &actwrite)) {
 421                 ret = EFI_DEVICE_ERROR;
 422                 goto error;
 423         }
 424
 425         *buffer_size = actwrite;
 426         fh->offset += actwrite;
 427
 428 error:
 429         return EFI_EXIT(ret);
 430 }
 431
 432 static efi_status_t EFIAPI efi_file_getpos(struct efi_file_handle *file,
 433                                            efi_uintn_t *pos)
 434 {
 435         struct file_handle *fh = to_fh(file);
 436
 437         EFI_ENTRY("%p, %p", file, pos);
 438
 439         if (fh->offset <= SIZE_MAX) {
 440                 *pos = fh->offset;
 441                 return EFI_EXIT(EFI_SUCCESS);
 442         } else {
 443                 return EFI_EXIT(EFI_DEVICE_ERROR);
 444         }
 445 }
 446
 447 static efi_status_t EFIAPI efi_file_setpos(struct efi_file_handle *file,
 448                 efi_uintn_t pos)
 449 {
 450         struct file_handle *fh = to_fh(file);
 451         efi_status_t ret = EFI_SUCCESS;
 452
 453         EFI_ENTRY("%p, %zu", file, pos);
 454
 455         if (fh->isdir) {
 456                 if (pos != 0) {
 457                         ret = EFI_UNSUPPORTED;
 458                         goto error;
 459                 }
 460                 fs_closedir(fh->dirs);
 461                 fh->dirs = NULL;
 462         }
 463
 464         if (pos == ~0ULL) {
 465                 loff_t file_size;
 466
 467                 if (set_blk_dev(fh)) {
 468                         ret = EFI_DEVICE_ERROR;
 469                         goto error;
 470                 }
 471
 472                 if (fs_size(fh->path, &file_size)) {
 473                         ret = EFI_DEVICE_ERROR;
 474                         goto error;
 475                 }
 476
 477                 pos = file_size;
 478         }
 479
 480         fh->offset = pos;
 481
 482 error:
 483         return EFI_EXIT(ret);
 484 }
 485
 486 static efi_status_t EFIAPI efi_file_getinfo(struct efi_file_handle *file,
 487                                             const efi_guid_t *info_type,
 488                                             efi_uintn_t *buffer_size,
 489                                             void *buffer)
 490 {
 491         struct file_handle *fh = to_fh(file);
 492         efi_status_t ret = EFI_SUCCESS;
 493
 494         EFI_ENTRY("%p, %p, %p, %p", file, info_type, buffer_size, buffer);
 495
 496         if (!guidcmp(info_type, &efi_file_info_guid)) {
 497                 struct efi_file_info *info = buffer;
 498                 char *filename = basename(fh);
 499                 unsigned int required_size;
 500                 loff_t file_size;
 501
 502                 /* check buffer size: */
 503                 required_size = sizeof(*info) + 2 * (strlen(filename) + 1);
 504                 if (*buffer_size < required_size) {
 505                         *buffer_size = required_size;
 506                         ret = EFI_BUFFER_TOO_SMALL;
 507                         goto error;
 508                 }
 509
 510                 if (set_blk_dev(fh)) {
 511                         ret = EFI_DEVICE_ERROR;
 512                         goto error;
 513                 }
 514
 515                 if (fs_size(fh->path, &file_size)) {
 516                         ret = EFI_DEVICE_ERROR;
 517                         goto error;
 518                 }
 519
 520                 memset(info, 0, required_size);
 521
 522                 info->size = required_size;
 523                 info->file_size = file_size;
 524                 info->physical_size = file_size;
 525
 526                 if (fh->isdir)
 527                         info->attribute |= EFI_FILE_DIRECTORY;
 528
 529                 ascii2unicode((u16 *)info->file_name, filename);
 530         } else if (!guidcmp(info_type, &efi_file_system_info_guid)) {
 531                 struct efi_file_system_info *info = buffer;
 532                 disk_partition_t part;
 533                 efi_uintn_t required_size;
 534                 int r;
 535
 536                 if (fh->fs->part >= 1)
 537                         r = part_get_info(fh->fs->desc, fh->fs->part, &part);
 538                 else
 539                         r = part_get_info_whole_disk(fh->fs->desc, &part);
 540                 if (r < 0) {
 541                         ret = EFI_DEVICE_ERROR;
 542                         goto error;
 543                 }
 544                 required_size = sizeof(info) + 2 *
 545                                 (strlen((const char *)part.name) + 1);
 546                 if (*buffer_size < required_size) {
 547                         *buffer_size = required_size;
 548                         ret = EFI_BUFFER_TOO_SMALL;
 549                         goto error;
 550                 }
 551
 552                 memset(info, 0, required_size);
 553
 554                 info->size = required_size;
 555                 info->read_only = true;
 556                 info->volume_size = part.size * part.blksz;
 557                 info->free_space = 0;
 558                 info->block_size = part.blksz;
 559                 /*
 560                  * TODO: The volume label is not available in U-Boot.
 561                  * Use the partition name as substitute.
 562                  */
 563                 ascii2unicode((u16 *)info->volume_label,
 564                               (const char *)part.name);
 565         } else {
 566                 ret = EFI_UNSUPPORTED;
 567         }
 568
 569 error:
 570         return EFI_EXIT(ret);
 571 }
 572
 573 static efi_status_t EFIAPI efi_file_setinfo(struct efi_file_handle *file,
 574                                             const efi_guid_t *info_type,
 575                                             efi_uintn_t buffer_size,
 576                                             void *buffer)
 577 {
 578         EFI_ENTRY("%p, %p, %zu, %p", file, info_type, buffer_size, buffer);
 579
 580         return EFI_EXIT(EFI_UNSUPPORTED);
 581 }
 582
 583 static efi_status_t EFIAPI efi_file_flush(struct efi_file_handle *file)
 584 {
 585         EFI_ENTRY("%p", file);
 586         return EFI_EXIT(EFI_SUCCESS);
 587 }
 588
 589 static const struct efi_file_handle efi_file_handle_protocol = {
 590         .rev = EFI_FILE_PROTOCOL_REVISION,
 591         .open = efi_file_open,
 592         .close = efi_file_close,
 593         .delete = efi_file_delete,
 594         .read = efi_file_read,
 595         .write = efi_file_write,
 596         .getpos = efi_file_getpos,
 597         .setpos = efi_file_setpos,
 598         .getinfo = efi_file_getinfo,
 599         .setinfo = efi_file_setinfo,
 600         .flush = efi_file_flush,
 601 };
 602
 603 struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp)
 604 {
 605         struct efi_simple_file_system_protocol *v;
 606         struct efi_file_handle *f;
 607         efi_status_t ret;
 608
 609         v = efi_fs_from_path(fp);
 610         if (!v)
 611                 return NULL;
 612
 613         EFI_CALL(ret = v->open_volume(v, &f));
 614         if (ret != EFI_SUCCESS)
 615                 return NULL;
 616
 617         /* skip over device-path nodes before the file path: */
 618         while (fp && !EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH))
 619                 fp = efi_dp_next(fp);
 620
 621         while (fp) {
 622                 struct efi_device_path_file_path *fdp =
 623                         container_of(fp, struct efi_device_path_file_path, dp);
 624                 struct efi_file_handle *f2;
 625
 626                 if (!EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH)) {
 627                         printf("bad file path!\n");
 628                         f->close(f);
 629                         return NULL;
 630                 }
 631
 632                 EFI_CALL(ret = f->open(f, &f2, (s16 *)fdp->str,
 633                                        EFI_FILE_MODE_READ, 0));
 634                 if (ret != EFI_SUCCESS)
 635                         return NULL;
 636
 637                 fp = efi_dp_next(fp);
 638
 639                 EFI_CALL(f->close(f));
 640                 f = f2;
 641         }
 642
 643         return f;
 644 }
 645
 646 static efi_status_t EFIAPI
 647 efi_open_volume(struct efi_simple_file_system_protocol *this,
 648                 struct efi_file_handle **root)
 649 {
 650         struct file_system *fs = to_fs(this);
 651
 652         EFI_ENTRY("%p, %p", this, root);
 653
 654         *root = file_open(fs, NULL, NULL, 0, 0);
 655
 656         return EFI_EXIT(EFI_SUCCESS);
 657 }
 658
 659 struct efi_simple_file_system_protocol *
 660 efi_simple_file_system(struct blk_desc *desc, int part,
 661                        struct efi_device_path *dp)
 662 {
 663         struct file_system *fs;
 664
 665         fs = calloc(1, sizeof(*fs));
 666         fs->base.rev = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
 667         fs->base.open_volume = efi_open_volume;
 668         fs->desc = desc;
 669         fs->part = part;
 670         fs->dp = dp;
 671
 672         return &fs->base;
 673 }