lib/efi_loader/efi_file.c

   1 /*
   2  *  EFI utils
   3  *
   4  *  Copyright (c) 2017 Rob Clark
   5  *
   6  *  SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <charset.h>
  11 #include <efi_loader.h>
  12 #include <malloc.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 /* NOTE: despite what you would expect, 'file_name' is actually a path.
 131  * With windoze style backlashes, ofc.
 132  */
 133 static struct efi_file_handle *file_open(struct file_system *fs,
 134                 struct file_handle *parent, s16 *file_name, u64 mode)
 135 {
 136         struct file_handle *fh;
 137         char f0[MAX_UTF8_PER_UTF16] = {0};
 138         int plen = 0;
 139         int flen = 0;
 140
 141         if (file_name) {
 142                 utf16_to_utf8((u8 *)f0, (u16 *)file_name, 1);
 143                 flen = utf16_strlen((u16 *)file_name);
 144         }
 145
 146         /* we could have a parent, but also an absolute path: */
 147         if (f0[0] == '\\') {
 148                 plen = 0;
 149         } else if (parent) {
 150                 plen = strlen(parent->path) + 1;
 151         }
 152
 153         /* +2 is for null and '/' */
 154         fh = calloc(1, sizeof(*fh) + plen + (flen * MAX_UTF8_PER_UTF16) + 2);
 155
 156         fh->base = efi_file_handle_protocol;
 157         fh->fs = fs;
 158
 159         if (parent) {
 160                 char *p = fh->path;
 161
 162                 if (plen > 0) {
 163                         strcpy(p, parent->path);
 164                         p += plen - 1;
 165                         *p++ = '/';
 166                 }
 167
 168                 utf16_to_utf8((u8 *)p, (u16 *)file_name, flen);
 169
 170                 if (sanitize_path(fh->path))
 171                         goto error;
 172
 173                 /* check if file exists: */
 174                 if (set_blk_dev(fh))
 175                         goto error;
 176
 177                 if (!((mode & EFI_FILE_MODE_CREATE) || fs_exists(fh->path)))
 178                         goto error;
 179
 180                 /* figure out if file is a directory: */
 181                 fh->isdir = is_dir(fh);
 182         } else {
 183                 fh->isdir = 1;
 184                 strcpy(fh->path, "");
 185         }
 186
 187         return &fh->base;
 188
 189 error:
 190         free(fh);
 191         return NULL;
 192 }
 193
 194 static efi_status_t EFIAPI efi_file_open(struct efi_file_handle *file,
 195                 struct efi_file_handle **new_handle,
 196                 s16 *file_name, u64 open_mode, u64 attributes)
 197 {
 198         struct file_handle *fh = to_fh(file);
 199
 200         EFI_ENTRY("%p, %p, \"%ls\", %llx, %llu", file, new_handle, file_name,
 201                   open_mode, attributes);
 202
 203         *new_handle = file_open(fh->fs, fh, file_name, open_mode);
 204         if (!*new_handle)
 205                 return EFI_EXIT(EFI_NOT_FOUND);
 206
 207         return EFI_EXIT(EFI_SUCCESS);
 208 }
 209
 210 static efi_status_t file_close(struct file_handle *fh)
 211 {
 212         fs_closedir(fh->dirs);
 213         free(fh);
 214         return EFI_SUCCESS;
 215 }
 216
 217 static efi_status_t EFIAPI efi_file_close(struct efi_file_handle *file)
 218 {
 219         struct file_handle *fh = to_fh(file);
 220         EFI_ENTRY("%p", file);
 221         return EFI_EXIT(file_close(fh));
 222 }
 223
 224 static efi_status_t EFIAPI efi_file_delete(struct efi_file_handle *file)
 225 {
 226         struct file_handle *fh = to_fh(file);
 227         EFI_ENTRY("%p", file);
 228         file_close(fh);
 229         return EFI_EXIT(EFI_WARN_DELETE_FAILURE);
 230 }
 231
 232 static efi_status_t file_read(struct file_handle *fh, u64 *buffer_size,
 233                 void *buffer)
 234 {
 235         loff_t actread;
 236
 237         if (fs_read(fh->path, (ulong)buffer, fh->offset,
 238                     *buffer_size, &actread))
 239                 return EFI_DEVICE_ERROR;
 240
 241         *buffer_size = actread;
 242         fh->offset += actread;
 243
 244         return EFI_SUCCESS;
 245 }
 246
 247 static efi_status_t dir_read(struct file_handle *fh, u64 *buffer_size,
 248                 void *buffer)
 249 {
 250         struct efi_file_info *info = buffer;
 251         struct fs_dirent *dent;
 252         unsigned int required_size;
 253
 254         if (!fh->dirs) {
 255                 assert(fh->offset == 0);
 256                 fh->dirs = fs_opendir(fh->path);
 257                 if (!fh->dirs)
 258                         return EFI_DEVICE_ERROR;
 259         }
 260
 261         /*
 262          * So this is a bit awkward.  Since fs layer is stateful and we
 263          * can't rewind an entry, in the EFI_BUFFER_TOO_SMALL case below
 264          * we might have to return without consuming the dent.. so we
 265          * have to stash it for next call.
 266          */
 267         if (fh->dent) {
 268                 dent = fh->dent;
 269                 fh->dent = NULL;
 270         } else {
 271                 dent = fs_readdir(fh->dirs);
 272         }
 273
 274
 275         if (!dent) {
 276                 /* no more files in directory: */
 277                 /* workaround shim.efi bug/quirk.. as find_boot_csv()
 278                  * loops through directory contents, it initially calls
 279                  * read w/ zero length buffer to find out how much mem
 280                  * to allocate for the EFI_FILE_INFO, then allocates,
 281                  * and then calls a 2nd time.  If we return size of
 282                  * zero the first time, it happily passes that to
 283                  * AllocateZeroPool(), and when that returns NULL it
 284                  * thinks it is EFI_OUT_OF_RESOURCES.  So on first
 285                  * call return a non-zero size:
 286                  */
 287                 if (*buffer_size == 0)
 288                         *buffer_size = sizeof(*info);
 289                 else
 290                         *buffer_size = 0;
 291                 return EFI_SUCCESS;
 292         }
 293
 294         /* check buffer size: */
 295         required_size = sizeof(*info) + 2 * (strlen(dent->name) + 1);
 296         if (*buffer_size < required_size) {
 297                 *buffer_size = required_size;
 298                 fh->dent = dent;
 299                 return EFI_BUFFER_TOO_SMALL;
 300         }
 301
 302         *buffer_size = required_size;
 303         memset(info, 0, required_size);
 304
 305         info->size = required_size;
 306         info->file_size = dent->size;
 307         info->physical_size = dent->size;
 308
 309         if (dent->type == FS_DT_DIR)
 310                 info->attribute |= EFI_FILE_DIRECTORY;
 311
 312         ascii2unicode((u16 *)info->file_name, dent->name);
 313
 314         fh->offset++;
 315
 316         return EFI_SUCCESS;
 317 }
 318
 319 static efi_status_t EFIAPI efi_file_read(struct efi_file_handle *file,
 320                                          efi_uintn_t *buffer_size, void *buffer)
 321 {
 322         struct file_handle *fh = to_fh(file);
 323         efi_status_t ret = EFI_SUCCESS;
 324         u64 bs;
 325
 326         EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
 327
 328         if (!buffer_size || !buffer) {
 329                 ret = EFI_INVALID_PARAMETER;
 330                 goto error;
 331         }
 332
 333         if (set_blk_dev(fh)) {
 334                 ret = EFI_DEVICE_ERROR;
 335                 goto error;
 336         }
 337
 338         bs = *buffer_size;
 339         if (fh->isdir)
 340                 ret = dir_read(fh, &bs, buffer);
 341         else
 342                 ret = file_read(fh, &bs, buffer);
 343         if (bs <= SIZE_MAX)
 344                 *buffer_size = bs;
 345         else
 346                 *buffer_size = SIZE_MAX;
 347
 348 error:
 349         return EFI_EXIT(ret);
 350 }
 351
 352 static efi_status_t EFIAPI efi_file_write(struct efi_file_handle *file,
 353                                           efi_uintn_t *buffer_size,
 354                                           void *buffer)
 355 {
 356         struct file_handle *fh = to_fh(file);
 357         efi_status_t ret = EFI_SUCCESS;
 358         loff_t actwrite;
 359
 360         EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
 361
 362         if (set_blk_dev(fh)) {
 363                 ret = EFI_DEVICE_ERROR;
 364                 goto error;
 365         }
 366
 367         if (fs_write(fh->path, (ulong)buffer, fh->offset, *buffer_size,
 368                      &actwrite)) {
 369                 ret = EFI_DEVICE_ERROR;
 370                 goto error;
 371         }
 372
 373         *buffer_size = actwrite;
 374         fh->offset += actwrite;
 375
 376 error:
 377         return EFI_EXIT(ret);
 378 }
 379
 380 static efi_status_t EFIAPI efi_file_getpos(struct efi_file_handle *file,
 381                                            efi_uintn_t *pos)
 382 {
 383         struct file_handle *fh = to_fh(file);
 384
 385         EFI_ENTRY("%p, %p", file, pos);
 386
 387         if (fh->offset <= SIZE_MAX) {
 388                 *pos = fh->offset;
 389                 return EFI_EXIT(EFI_SUCCESS);
 390         } else {
 391                 return EFI_EXIT(EFI_DEVICE_ERROR);
 392         }
 393 }
 394
 395 static efi_status_t EFIAPI efi_file_setpos(struct efi_file_handle *file,
 396                 efi_uintn_t pos)
 397 {
 398         struct file_handle *fh = to_fh(file);
 399         efi_status_t ret = EFI_SUCCESS;
 400
 401         EFI_ENTRY("%p, %zu", file, pos);
 402
 403         if (fh->isdir) {
 404                 if (pos != 0) {
 405                         ret = EFI_UNSUPPORTED;
 406                         goto error;
 407                 }
 408                 fs_closedir(fh->dirs);
 409                 fh->dirs = NULL;
 410         }
 411
 412         if (pos == ~0ULL) {
 413                 loff_t file_size;
 414
 415                 if (set_blk_dev(fh)) {
 416                         ret = EFI_DEVICE_ERROR;
 417                         goto error;
 418                 }
 419
 420                 if (fs_size(fh->path, &file_size)) {
 421                         ret = EFI_DEVICE_ERROR;
 422                         goto error;
 423                 }
 424
 425                 pos = file_size;
 426         }
 427
 428         fh->offset = pos;
 429
 430 error:
 431         return EFI_EXIT(ret);
 432 }
 433
 434 static efi_status_t EFIAPI efi_file_getinfo(struct efi_file_handle *file,
 435                                             const efi_guid_t *info_type,
 436                                             efi_uintn_t *buffer_size,
 437                                             void *buffer)
 438 {
 439         struct file_handle *fh = to_fh(file);
 440         efi_status_t ret = EFI_SUCCESS;
 441
 442         EFI_ENTRY("%p, %p, %p, %p", file, info_type, buffer_size, buffer);
 443
 444         if (!guidcmp(info_type, &efi_file_info_guid)) {
 445                 struct efi_file_info *info = buffer;
 446                 char *filename = basename(fh);
 447                 unsigned int required_size;
 448                 loff_t file_size;
 449
 450                 /* check buffer size: */
 451                 required_size = sizeof(*info) + 2 * (strlen(filename) + 1);
 452                 if (*buffer_size < required_size) {
 453                         *buffer_size = required_size;
 454                         ret = EFI_BUFFER_TOO_SMALL;
 455                         goto error;
 456                 }
 457
 458                 if (set_blk_dev(fh)) {
 459                         ret = EFI_DEVICE_ERROR;
 460                         goto error;
 461                 }
 462
 463                 if (fs_size(fh->path, &file_size)) {
 464                         ret = EFI_DEVICE_ERROR;
 465                         goto error;
 466                 }
 467
 468                 memset(info, 0, required_size);
 469
 470                 info->size = required_size;
 471                 info->file_size = file_size;
 472                 info->physical_size = file_size;
 473
 474                 if (fh->isdir)
 475                         info->attribute |= EFI_FILE_DIRECTORY;
 476
 477                 ascii2unicode((u16 *)info->file_name, filename);
 478         } else if (!guidcmp(info_type, &efi_file_system_info_guid)) {
 479                 struct efi_file_system_info *info = buffer;
 480                 disk_partition_t part;
 481                 efi_uintn_t required_size;
 482                 int r;
 483
 484                 if (fh->fs->part >= 1)
 485                         r = part_get_info(fh->fs->desc, fh->fs->part, &part);
 486                 else
 487                         r = part_get_info_whole_disk(fh->fs->desc, &part);
 488                 if (r < 0) {
 489                         ret = EFI_DEVICE_ERROR;
 490                         goto error;
 491                 }
 492                 required_size = sizeof(info) + 2 *
 493                                 (strlen((const char *)part.name) + 1);
 494                 if (*buffer_size < required_size) {
 495                         *buffer_size = required_size;
 496                         ret = EFI_BUFFER_TOO_SMALL;
 497                         goto error;
 498                 }
 499
 500                 memset(info, 0, required_size);
 501
 502                 info->size = required_size;
 503                 info->read_only = true;
 504                 info->volume_size = part.size * part.blksz;
 505                 info->free_space = 0;
 506                 info->block_size = part.blksz;
 507                 /*
 508                  * TODO: The volume label is not available in U-Boot.
 509                  * Use the partition name as substitute.
 510                  */
 511                 ascii2unicode((u16 *)info->volume_label,
 512                               (const char *)part.name);
 513         } else {
 514                 ret = EFI_UNSUPPORTED;
 515         }
 516
 517 error:
 518         return EFI_EXIT(ret);
 519 }
 520
 521 static efi_status_t EFIAPI efi_file_setinfo(struct efi_file_handle *file,
 522                                             const efi_guid_t *info_type,
 523                                             efi_uintn_t buffer_size,
 524                                             void *buffer)
 525 {
 526         EFI_ENTRY("%p, %p, %zu, %p", file, info_type, buffer_size, buffer);
 527
 528         return EFI_EXIT(EFI_UNSUPPORTED);
 529 }
 530
 531 static efi_status_t EFIAPI efi_file_flush(struct efi_file_handle *file)
 532 {
 533         EFI_ENTRY("%p", file);
 534         return EFI_EXIT(EFI_SUCCESS);
 535 }
 536
 537 static const struct efi_file_handle efi_file_handle_protocol = {
 538         .rev = EFI_FILE_PROTOCOL_REVISION,
 539         .open = efi_file_open,
 540         .close = efi_file_close,
 541         .delete = efi_file_delete,
 542         .read = efi_file_read,
 543         .write = efi_file_write,
 544         .getpos = efi_file_getpos,
 545         .setpos = efi_file_setpos,
 546         .getinfo = efi_file_getinfo,
 547         .setinfo = efi_file_setinfo,
 548         .flush = efi_file_flush,
 549 };
 550
 551 struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp)
 552 {
 553         struct efi_simple_file_system_protocol *v;
 554         struct efi_file_handle *f;
 555         efi_status_t ret;
 556
 557         v = efi_fs_from_path(fp);
 558         if (!v)
 559                 return NULL;
 560
 561         EFI_CALL(ret = v->open_volume(v, &f));
 562         if (ret != EFI_SUCCESS)
 563                 return NULL;
 564
 565         /* skip over device-path nodes before the file path: */
 566         while (fp && !EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH))
 567                 fp = efi_dp_next(fp);
 568
 569         while (fp) {
 570                 struct efi_device_path_file_path *fdp =
 571                         container_of(fp, struct efi_device_path_file_path, dp);
 572                 struct efi_file_handle *f2;
 573
 574                 if (!EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH)) {
 575                         printf("bad file path!\n");
 576                         f->close(f);
 577                         return NULL;
 578                 }
 579
 580                 EFI_CALL(ret = f->open(f, &f2, (s16 *)fdp->str,
 581                                        EFI_FILE_MODE_READ, 0));
 582                 if (ret != EFI_SUCCESS)
 583                         return NULL;
 584
 585                 fp = efi_dp_next(fp);
 586
 587                 EFI_CALL(f->close(f));
 588                 f = f2;
 589         }
 590
 591         return f;
 592 }
 593
 594 static efi_status_t EFIAPI
 595 efi_open_volume(struct efi_simple_file_system_protocol *this,
 596                 struct efi_file_handle **root)
 597 {
 598         struct file_system *fs = to_fs(this);
 599
 600         EFI_ENTRY("%p, %p", this, root);
 601
 602         *root = file_open(fs, NULL, NULL, 0);
 603
 604         return EFI_EXIT(EFI_SUCCESS);
 605 }
 606
 607 struct efi_simple_file_system_protocol *
 608 efi_simple_file_system(struct blk_desc *desc, int part,
 609                        struct efi_device_path *dp)
 610 {
 611         struct file_system *fs;
 612
 613         fs = calloc(1, sizeof(*fs));
 614         fs->base.rev = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
 615         fs->base.open_volume = efi_open_volume;
 616         fs->desc = desc;
 617         fs->part = part;
 618         fs->dp = dp;
 619
 620         return &fs->base;
 621 }