src/shared/efivars.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <dirent.h>
   4 #include <errno.h>
   5 #include <fcntl.h>
   6 #include <limits.h>
   7 #include <linux/fs.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <sys/stat.h>
  12 #include <unistd.h>
  13
  14 #include "sd-id128.h"
  15
  16 #include "alloc-util.h"
  17 #include "chattr-util.h"
  18 #include "dirent-util.h"
  19 #include "efivars.h"
  20 #include "fd-util.h"
  21 #include "io-util.h"
  22 #include "macro.h"
  23 #include "parse-util.h"
  24 #include "stdio-util.h"
  25 #include "strv.h"
  26 #include "time-util.h"
  27 #include "utf8.h"
  28 #include "util.h"
  29 #include "virt.h"
  30
  31 #if ENABLE_EFI
  32
  33 #define LOAD_OPTION_ACTIVE            0x00000001
  34 #define MEDIA_DEVICE_PATH                   0x04
  35 #define MEDIA_HARDDRIVE_DP                  0x01
  36 #define MEDIA_FILEPATH_DP                   0x04
  37 #define SIGNATURE_TYPE_GUID                 0x02
  38 #define MBR_TYPE_EFI_PARTITION_TABLE_HEADER 0x02
  39 #define END_DEVICE_PATH_TYPE                0x7f
  40 #define END_ENTIRE_DEVICE_PATH_SUBTYPE      0xff
  41 #define EFI_OS_INDICATIONS_BOOT_TO_FW_UI    0x0000000000000001
  42
  43 struct boot_option {
  44         uint32_t attr;
  45         uint16_t path_len;
  46         uint16_t title[];
  47 } _packed_;
  48
  49 struct drive_path {
  50         uint32_t part_nr;
  51         uint64_t part_start;
  52         uint64_t part_size;
  53         char signature[16];
  54         uint8_t mbr_type;
  55         uint8_t signature_type;
  56 } _packed_;
  57
  58 struct device_path {
  59         uint8_t type;
  60         uint8_t sub_type;
  61         uint16_t length;
  62         union {
  63                 uint16_t path[0];
  64                 struct drive_path drive;
  65         };
  66 } _packed_;
  67
  68 bool is_efi_boot(void) {
  69         if (detect_container() > 0)
  70                 return false;
  71
  72         return access("/sys/firmware/efi/", F_OK) >= 0;
  73 }
  74
  75 static int read_flag(const char *varname) {
  76         _cleanup_free_ void *v = NULL;
  77         uint8_t b;
  78         size_t s;
  79         int r;
  80
  81         if (!is_efi_boot()) /* If this is not an EFI boot, assume the queried flags are zero */
  82                 return 0;
  83
  84         r = efi_get_variable(EFI_VENDOR_GLOBAL, varname, NULL, &v, &s);
  85         if (r < 0)
  86                 return r;
  87
  88         if (s != 1)
  89                 return -EINVAL;
  90
  91         b = *(uint8_t *)v;
  92         return !!b;
  93 }
  94
  95 bool is_efi_secure_boot(void) {
  96         return read_flag("SecureBoot") > 0;
  97 }
  98
  99 bool is_efi_secure_boot_setup_mode(void) {
 100         return read_flag("SetupMode") > 0;
 101 }
 102
 103 int efi_reboot_to_firmware_supported(void) {
 104         _cleanup_free_ void *v = NULL;
 105         uint64_t b;
 106         size_t s;
 107         int r;
 108
 109         if (!is_efi_boot())
 110                 return -EOPNOTSUPP;
 111
 112         r = efi_get_variable(EFI_VENDOR_GLOBAL, "OsIndicationsSupported", NULL, &v, &s);
 113         if (r == -ENOENT) /* variable doesn't exist? it's not supported then */
 114                 return -EOPNOTSUPP;
 115         if (r < 0)
 116                 return r;
 117         if (s != sizeof(uint64_t))
 118                 return -EINVAL;
 119
 120         b = *(uint64_t*) v;
 121         if (!(b & EFI_OS_INDICATIONS_BOOT_TO_FW_UI))
 122                 return -EOPNOTSUPP; /* bit unset? it's not supported then */
 123
 124         return 0;
 125 }
 126
 127 static int get_os_indications(uint64_t *os_indication) {
 128         _cleanup_free_ void *v = NULL;
 129         size_t s;
 130         int r;
 131
 132         /* Let's verify general support first */
 133         r = efi_reboot_to_firmware_supported();
 134         if (r < 0)
 135                 return r;
 136
 137         r = efi_get_variable(EFI_VENDOR_GLOBAL, "OsIndications", NULL, &v, &s);
 138         if (r == -ENOENT) {
 139                 /* Some firmware implementations that do support OsIndications and report that with
 140                  * OsIndicationsSupported will remove the OsIndications variable when it is unset. Let's pretend it's 0
 141                  * then, to hide this implementation detail. Note that this call will return -ENOENT then only if the
 142                  * support for OsIndications is missing entirely, as determined by efi_reboot_to_firmware_supported()
 143                  * above. */
 144                 *os_indication = 0;
 145                 return 0;
 146         } else if (r < 0)
 147                 return r;
 148         else if (s != sizeof(uint64_t))
 149                 return -EINVAL;
 150
 151         *os_indication = *(uint64_t *)v;
 152         return 0;
 153 }
 154
 155 int efi_get_reboot_to_firmware(void) {
 156         int r;
 157         uint64_t b;
 158
 159         r = get_os_indications(&b);
 160         if (r < 0)
 161                 return r;
 162
 163         return !!(b & EFI_OS_INDICATIONS_BOOT_TO_FW_UI);
 164 }
 165
 166 int efi_set_reboot_to_firmware(bool value) {
 167         int r;
 168         uint64_t b, b_new;
 169
 170         r = get_os_indications(&b);
 171         if (r < 0)
 172                 return r;
 173
 174         if (value)
 175                 b_new = b | EFI_OS_INDICATIONS_BOOT_TO_FW_UI;
 176         else
 177                 b_new = b & ~EFI_OS_INDICATIONS_BOOT_TO_FW_UI;
 178
 179         /* Avoid writing to efi vars store if we can due to firmware bugs. */
 180         if (b != b_new)
 181                 return efi_set_variable(EFI_VENDOR_GLOBAL, "OsIndications", &b_new, sizeof(uint64_t));
 182
 183         return 0;
 184 }
 185
 186 int efi_get_variable(
 187                 sd_id128_t vendor,
 188                 const char *name,
 189                 uint32_t *attribute,
 190                 void **value,
 191                 size_t *size) {
 192
 193         _cleanup_close_ int fd = -1;
 194         _cleanup_free_ char *p = NULL;
 195         uint32_t a;
 196         ssize_t n;
 197         struct stat st;
 198         _cleanup_free_ void *buf = NULL;
 199
 200         assert(name);
 201         assert(value);
 202         assert(size);
 203
 204         if (asprintf(&p,
 205                      "/sys/firmware/efi/efivars/%s-%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 206                      name, SD_ID128_FORMAT_VAL(vendor)) < 0)
 207                 return -ENOMEM;
 208
 209         fd = open(p, O_RDONLY|O_NOCTTY|O_CLOEXEC);
 210         if (fd < 0)
 211                 return -errno;
 212
 213         if (fstat(fd, &st) < 0)
 214                 return -errno;
 215         if (st.st_size < 4)
 216                 return -EIO;
 217         if (st.st_size > 4*1024*1024 + 4)
 218                 return -E2BIG;
 219
 220         n = read(fd, &a, sizeof(a));
 221         if (n < 0)
 222                 return -errno;
 223         if (n != sizeof(a))
 224                 return -EIO;
 225
 226         buf = malloc(st.st_size - 4 + 2);
 227         if (!buf)
 228                 return -ENOMEM;
 229
 230         n = read(fd, buf, (size_t) st.st_size - 4);
 231         if (n < 0)
 232                 return -errno;
 233         if (n != (ssize_t) st.st_size - 4)
 234                 return -EIO;
 235
 236         /* Always NUL terminate (2 bytes, to protect UTF-16) */
 237         ((char*) buf)[st.st_size - 4] = 0;
 238         ((char*) buf)[st.st_size - 4 + 1] = 0;
 239
 240         *value = TAKE_PTR(buf);
 241         *size = (size_t) st.st_size - 4;
 242
 243         if (attribute)
 244                 *attribute = a;
 245
 246         return 0;
 247 }
 248
 249 int efi_get_variable_string(sd_id128_t vendor, const char *name, char **p) {
 250         _cleanup_free_ void *s = NULL;
 251         size_t ss = 0;
 252         int r;
 253         char *x;
 254
 255         r = efi_get_variable(vendor, name, NULL, &s, &ss);
 256         if (r < 0)
 257                 return r;
 258
 259         x = utf16_to_utf8(s, ss);
 260         if (!x)
 261                 return -ENOMEM;
 262
 263         *p = x;
 264         return 0;
 265 }
 266
 267 int efi_set_variable(
 268                 sd_id128_t vendor,
 269                 const char *name,
 270                 const void *value,
 271                 size_t size) {
 272
 273         struct var {
 274                 uint32_t attr;
 275                 char buf[];
 276         } _packed_ * _cleanup_free_ buf = NULL;
 277         _cleanup_free_ char *p = NULL;
 278         _cleanup_close_ int fd = -1;
 279         bool saved_flags_valid = false;
 280         unsigned saved_flags;
 281         int r;
 282
 283         assert(name);
 284         assert(value || size == 0);
 285
 286         if (asprintf(&p,
 287                      "/sys/firmware/efi/efivars/%s-%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 288                      name, SD_ID128_FORMAT_VAL(vendor)) < 0)
 289                 return -ENOMEM;
 290
 291         /* Newer efivarfs protects variables that are not in a whitelist with FS_IMMUTABLE_FL by default, to protect
 292          * them for accidental removal and modification. We are not changing these variables accidentally however,
 293          * hence let's unset the bit first. */
 294
 295         r = chattr_path(p, 0, FS_IMMUTABLE_FL, &saved_flags);
 296         if (r < 0 && r != -ENOENT)
 297                 log_debug_errno(r, "Failed to drop FS_IMMUTABLE_FL flag from '%s', ignoring: %m", p);
 298
 299         saved_flags_valid = r >= 0;
 300
 301         if (size == 0) {
 302                 if (unlink(p) < 0) {
 303                         r = -errno;
 304                         goto finish;
 305                 }
 306
 307                 return 0;
 308         }
 309
 310         fd = open(p, O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC, 0644);
 311         if (fd < 0) {
 312                 r = -errno;
 313                 goto finish;
 314         }
 315
 316         buf = malloc(sizeof(uint32_t) + size);
 317         if (!buf) {
 318                 r = -ENOMEM;
 319                 goto finish;
 320         }
 321
 322         buf->attr = EFI_VARIABLE_NON_VOLATILE|EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS;
 323         memcpy(buf->buf, value, size);
 324
 325         r = loop_write(fd, buf, sizeof(uint32_t) + size, false);
 326         if (r < 0)
 327                 goto finish;
 328
 329         r = 0;
 330
 331 finish:
 332         if (saved_flags_valid) {
 333                 int q;
 334
 335                 /* Restore the original flags field, just in case */
 336                 if (fd < 0)
 337                         q = chattr_path(p, saved_flags, FS_IMMUTABLE_FL, NULL);
 338                 else
 339                         q = chattr_fd(fd, saved_flags, FS_IMMUTABLE_FL, NULL);
 340                 if (q < 0)
 341                         log_debug_errno(q, "Failed to restore FS_IMMUTABLE_FL on '%s', ignoring: %m", p);
 342         }
 343
 344         return r;
 345 }
 346
 347 int efi_set_variable_string(sd_id128_t vendor, const char *name, const char *v) {
 348         _cleanup_free_ char16_t *u16 = NULL;
 349
 350         u16 = utf8_to_utf16(v, strlen(v));
 351         if (!u16)
 352                 return -ENOMEM;
 353
 354         return efi_set_variable(vendor, name, u16, (char16_strlen(u16) + 1) * sizeof(char16_t));
 355 }
 356
 357 static size_t utf16_size(const uint16_t *s) {
 358         size_t l = 0;
 359
 360         while (s[l] > 0)
 361                 l++;
 362
 363         return (l+1) * sizeof(uint16_t);
 364 }
 365
 366 static void efi_guid_to_id128(const void *guid, sd_id128_t *id128) {
 367         struct uuid {
 368                 uint32_t u1;
 369                 uint16_t u2;
 370                 uint16_t u3;
 371                 uint8_t u4[8];
 372         } _packed_;
 373         const struct uuid *uuid = guid;
 374
 375         id128->bytes[0] = (uuid->u1 >> 24) & 0xff;
 376         id128->bytes[1] = (uuid->u1 >> 16) & 0xff;
 377         id128->bytes[2] = (uuid->u1 >> 8) & 0xff;
 378         id128->bytes[3] = (uuid->u1) & 0xff;
 379         id128->bytes[4] = (uuid->u2 >> 8) & 0xff;
 380         id128->bytes[5] = (uuid->u2) & 0xff;
 381         id128->bytes[6] = (uuid->u3 >> 8) & 0xff;
 382         id128->bytes[7] = (uuid->u3) & 0xff;
 383         memcpy(&id128->bytes[8], uuid->u4, sizeof(uuid->u4));
 384 }
 385
 386 int efi_get_boot_option(
 387                 uint16_t id,
 388                 char **title,
 389                 sd_id128_t *part_uuid,
 390                 char **path,
 391                 bool *active) {
 392
 393         char boot_id[9];
 394         _cleanup_free_ uint8_t *buf = NULL;
 395         size_t l;
 396         struct boot_option *header;
 397         size_t title_size;
 398         _cleanup_free_ char *s = NULL, *p = NULL;
 399         sd_id128_t p_uuid = SD_ID128_NULL;
 400         int r;
 401
 402         if (!is_efi_boot())
 403                 return -EOPNOTSUPP;
 404
 405         xsprintf(boot_id, "Boot%04X", id);
 406         r = efi_get_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, (void **)&buf, &l);
 407         if (r < 0)
 408                 return r;
 409         if (l < sizeof(struct boot_option))
 410                 return -ENOENT;
 411
 412         header = (struct boot_option *)buf;
 413         title_size = utf16_size(header->title);
 414         if (title_size > l - offsetof(struct boot_option, title))
 415                 return -EINVAL;
 416
 417         if (title) {
 418                 s = utf16_to_utf8(header->title, title_size);
 419                 if (!s)
 420                         return -ENOMEM;
 421         }
 422
 423         if (header->path_len > 0) {
 424                 uint8_t *dbuf;
 425                 size_t dnext, doff;
 426
 427                 doff = offsetof(struct boot_option, title) + title_size;
 428                 dbuf = buf + doff;
 429                 if (header->path_len > l - doff)
 430                         return -EINVAL;
 431
 432                 dnext = 0;
 433                 while (dnext < header->path_len) {
 434                         struct device_path *dpath;
 435
 436                         dpath = (struct device_path *)(dbuf + dnext);
 437                         if (dpath->length < 4)
 438                                 break;
 439
 440                         /* Type 0x7F – End of Hardware Device Path, Sub-Type 0xFF – End Entire Device Path */
 441                         if (dpath->type == END_DEVICE_PATH_TYPE && dpath->sub_type == END_ENTIRE_DEVICE_PATH_SUBTYPE)
 442                                 break;
 443
 444                         dnext += dpath->length;
 445
 446                         /* Type 0x04 – Media Device Path */
 447                         if (dpath->type != MEDIA_DEVICE_PATH)
 448                                 continue;
 449
 450                         /* Sub-Type 1 – Hard Drive */
 451                         if (dpath->sub_type == MEDIA_HARDDRIVE_DP) {
 452                                 /* 0x02 – GUID Partition Table */
 453                                 if (dpath->drive.mbr_type != MBR_TYPE_EFI_PARTITION_TABLE_HEADER)
 454                                         continue;
 455
 456                                 /* 0x02 – GUID signature */
 457                                 if (dpath->drive.signature_type != SIGNATURE_TYPE_GUID)
 458                                         continue;
 459
 460                                 if (part_uuid)
 461                                         efi_guid_to_id128(dpath->drive.signature, &p_uuid);
 462                                 continue;
 463                         }
 464
 465                         /* Sub-Type 4 – File Path */
 466                         if (dpath->sub_type == MEDIA_FILEPATH_DP && !p && path) {
 467                                 p = utf16_to_utf8(dpath->path, dpath->length-4);
 468                                 if (!p)
 469                                         return  -ENOMEM;
 470
 471                                 efi_tilt_backslashes(p);
 472                                 continue;
 473                         }
 474                 }
 475         }
 476
 477         if (title)
 478                 *title = TAKE_PTR(s);
 479         if (part_uuid)
 480                 *part_uuid = p_uuid;
 481         if (path)
 482                 *path = TAKE_PTR(p);
 483         if (active)
 484                 *active = !!(header->attr & LOAD_OPTION_ACTIVE);
 485
 486         return 0;
 487 }
 488
 489 static void to_utf16(uint16_t *dest, const char *src) {
 490         int i;
 491
 492         for (i = 0; src[i] != '\0'; i++)
 493                 dest[i] = src[i];
 494         dest[i] = '\0';
 495 }
 496
 497 struct guid {
 498         uint32_t u1;
 499         uint16_t u2;
 500         uint16_t u3;
 501         uint8_t u4[8];
 502 } _packed_;
 503
 504 static void id128_to_efi_guid(sd_id128_t id, void *guid) {
 505         struct guid *uuid = guid;
 506
 507         uuid->u1 = id.bytes[0] << 24 | id.bytes[1] << 16 | id.bytes[2] << 8 | id.bytes[3];
 508         uuid->u2 = id.bytes[4] << 8 | id.bytes[5];
 509         uuid->u3 = id.bytes[6] << 8 | id.bytes[7];
 510         memcpy(uuid->u4, id.bytes+8, sizeof(uuid->u4));
 511 }
 512
 513 static uint16_t *tilt_slashes(uint16_t *s) {
 514         uint16_t *p;
 515
 516         for (p = s; *p; p++)
 517                 if (*p == '/')
 518                         *p = '\\';
 519
 520         return s;
 521 }
 522
 523 int efi_add_boot_option(
 524                 uint16_t id,
 525                 const char *title,
 526                 uint32_t part,
 527                 uint64_t pstart,
 528                 uint64_t psize,
 529                 sd_id128_t part_uuid,
 530                 const char *path) {
 531
 532         size_t size, title_len, path_len;
 533         _cleanup_free_ char *buf = NULL;
 534         struct boot_option *option;
 535         struct device_path *devicep;
 536         char boot_id[9];
 537
 538         if (!is_efi_boot())
 539                 return -EOPNOTSUPP;
 540
 541         title_len = (strlen(title)+1) * 2;
 542         path_len = (strlen(path)+1) * 2;
 543
 544         buf = malloc0(sizeof(struct boot_option) + title_len +
 545                       sizeof(struct drive_path) +
 546                       sizeof(struct device_path) + path_len);
 547         if (!buf)
 548                 return -ENOMEM;
 549
 550         /* header */
 551         option = (struct boot_option *)buf;
 552         option->attr = LOAD_OPTION_ACTIVE;
 553         option->path_len = offsetof(struct device_path, drive) + sizeof(struct drive_path) +
 554                            offsetof(struct device_path, path) + path_len +
 555                            offsetof(struct device_path, path);
 556         to_utf16(option->title, title);
 557         size = offsetof(struct boot_option, title) + title_len;
 558
 559         /* partition info */
 560         devicep = (struct device_path *)(buf + size);
 561         devicep->type = MEDIA_DEVICE_PATH;
 562         devicep->sub_type = MEDIA_HARDDRIVE_DP;
 563         devicep->length = offsetof(struct device_path, drive) + sizeof(struct drive_path);
 564         devicep->drive.part_nr = part;
 565         devicep->drive.part_start = pstart;
 566         devicep->drive.part_size = psize;
 567         devicep->drive.signature_type = SIGNATURE_TYPE_GUID;
 568         devicep->drive.mbr_type = MBR_TYPE_EFI_PARTITION_TABLE_HEADER;
 569         id128_to_efi_guid(part_uuid, devicep->drive.signature);
 570         size += devicep->length;
 571
 572         /* path to loader */
 573         devicep = (struct device_path *)(buf + size);
 574         devicep->type = MEDIA_DEVICE_PATH;
 575         devicep->sub_type = MEDIA_FILEPATH_DP;
 576         devicep->length = offsetof(struct device_path, path) + path_len;
 577         to_utf16(devicep->path, path);
 578         tilt_slashes(devicep->path);
 579         size += devicep->length;
 580
 581         /* end of path */
 582         devicep = (struct device_path *)(buf + size);
 583         devicep->type = END_DEVICE_PATH_TYPE;
 584         devicep->sub_type = END_ENTIRE_DEVICE_PATH_SUBTYPE;
 585         devicep->length = offsetof(struct device_path, path);
 586         size += devicep->length;
 587
 588         xsprintf(boot_id, "Boot%04X", id);
 589         return efi_set_variable(EFI_VENDOR_GLOBAL, boot_id, buf, size);
 590 }
 591
 592 int efi_remove_boot_option(uint16_t id) {
 593         char boot_id[9];
 594
 595         if (!is_efi_boot())
 596                 return -EOPNOTSUPP;
 597
 598         xsprintf(boot_id, "Boot%04X", id);
 599         return efi_set_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, 0);
 600 }
 601
 602 int efi_get_boot_order(uint16_t **order) {
 603         _cleanup_free_ void *buf = NULL;
 604         size_t l;
 605         int r;
 606
 607         if (!is_efi_boot())
 608                 return -EOPNOTSUPP;
 609
 610         r = efi_get_variable(EFI_VENDOR_GLOBAL, "BootOrder", NULL, &buf, &l);
 611         if (r < 0)
 612                 return r;
 613
 614         if (l <= 0)
 615                 return -ENOENT;
 616
 617         if (l % sizeof(uint16_t) > 0 ||
 618             l / sizeof(uint16_t) > INT_MAX)
 619                 return -EINVAL;
 620
 621         *order = TAKE_PTR(buf);
 622         return (int) (l / sizeof(uint16_t));
 623 }
 624
 625 int efi_set_boot_order(uint16_t *order, size_t n) {
 626
 627         if (!is_efi_boot())
 628                 return -EOPNOTSUPP;
 629
 630         return efi_set_variable(EFI_VENDOR_GLOBAL, "BootOrder", order, n * sizeof(uint16_t));
 631 }
 632
 633 static int boot_id_hex(const char s[4]) {
 634         int id = 0, i;
 635
 636         for (i = 0; i < 4; i++)
 637                 if (s[i] >= '0' && s[i] <= '9')
 638                         id |= (s[i] - '0') << (3 - i) * 4;
 639                 else if (s[i] >= 'A' && s[i] <= 'F')
 640                         id |= (s[i] - 'A' + 10) << (3 - i) * 4;
 641                 else
 642                         return -EINVAL;
 643
 644         return id;
 645 }
 646
 647 static int cmp_uint16(const uint16_t *a, const uint16_t *b) {
 648         return CMP(*a, *b);
 649 }
 650
 651 int efi_get_boot_options(uint16_t **options) {
 652         _cleanup_closedir_ DIR *dir = NULL;
 653         _cleanup_free_ uint16_t *list = NULL;
 654         struct dirent *de;
 655         size_t alloc = 0;
 656         int count = 0;
 657
 658         assert(options);
 659
 660         if (!is_efi_boot())
 661                 return -EOPNOTSUPP;
 662
 663         dir = opendir("/sys/firmware/efi/efivars/");
 664         if (!dir)
 665                 return -errno;
 666
 667         FOREACH_DIRENT(de, dir, return -errno) {
 668                 int id;
 669
 670                 if (strncmp(de->d_name, "Boot", 4) != 0)
 671                         continue;
 672
 673                 if (strlen(de->d_name) != 45)
 674                         continue;
 675
 676                 if (strcmp(de->d_name + 8, "-8be4df61-93ca-11d2-aa0d-00e098032b8c") != 0)
 677                         continue;
 678
 679                 id = boot_id_hex(de->d_name + 4);
 680                 if (id < 0)
 681                         continue;
 682
 683                 if (!GREEDY_REALLOC(list, alloc, count + 1))
 684                         return -ENOMEM;
 685
 686                 list[count++] = id;
 687         }
 688
 689         typesafe_qsort(list, count, cmp_uint16);
 690
 691         *options = TAKE_PTR(list);
 692
 693         return count;
 694 }
 695
 696 static int read_usec(sd_id128_t vendor, const char *name, usec_t *u) {
 697         _cleanup_free_ char *j = NULL;
 698         int r;
 699         uint64_t x = 0;
 700
 701         assert(name);
 702         assert(u);
 703
 704         r = efi_get_variable_string(EFI_VENDOR_LOADER, name, &j);
 705         if (r < 0)
 706                 return r;
 707
 708         r = safe_atou64(j, &x);
 709         if (r < 0)
 710                 return r;
 711
 712         *u = x;
 713         return 0;
 714 }
 715
 716 int efi_loader_get_boot_usec(usec_t *firmware, usec_t *loader) {
 717         uint64_t x, y;
 718         int r;
 719
 720         assert(firmware);
 721         assert(loader);
 722
 723         if (!is_efi_boot())
 724                 return -EOPNOTSUPP;
 725
 726         r = read_usec(EFI_VENDOR_LOADER, "LoaderTimeInitUSec", &x);
 727         if (r < 0)
 728                 return r;
 729
 730         r = read_usec(EFI_VENDOR_LOADER, "LoaderTimeExecUSec", &y);
 731         if (r < 0)
 732                 return r;
 733
 734         if (y == 0 || y < x)
 735                 return -EIO;
 736
 737         if (y > USEC_PER_HOUR)
 738                 return -EIO;
 739
 740         *firmware = x;
 741         *loader = y;
 742
 743         return 0;
 744 }
 745
 746 int efi_loader_get_device_part_uuid(sd_id128_t *u) {
 747         _cleanup_free_ char *p = NULL;
 748         int r, parsed[16];
 749
 750         if (!is_efi_boot())
 751                 return -EOPNOTSUPP;
 752
 753         r = efi_get_variable_string(EFI_VENDOR_LOADER, "LoaderDevicePartUUID", &p);
 754         if (r < 0)
 755                 return r;
 756
 757         if (sscanf(p, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 758                    &parsed[0], &parsed[1], &parsed[2], &parsed[3],
 759                    &parsed[4], &parsed[5], &parsed[6], &parsed[7],
 760                    &parsed[8], &parsed[9], &parsed[10], &parsed[11],
 761                    &parsed[12], &parsed[13], &parsed[14], &parsed[15]) != 16)
 762                 return -EIO;
 763
 764         if (u) {
 765                 unsigned i;
 766
 767                 for (i = 0; i < ELEMENTSOF(parsed); i++)
 768                         u->bytes[i] = parsed[i];
 769         }
 770
 771         return 0;
 772 }
 773
 774 bool efi_loader_entry_name_valid(const char *s) {
 775         if (isempty(s))
 776                 return false;
 777
 778         if (strlen(s) > FILENAME_MAX) /* Make sure entry names fit in filenames */
 779                 return false;
 780
 781         return in_charset(s, ALPHANUMERICAL "-");
 782 }
 783
 784 int efi_loader_get_entries(char ***ret) {
 785         _cleanup_free_ char16_t *entries = NULL;
 786         _cleanup_strv_free_ char **l = NULL;
 787         size_t size, i, start;
 788         int r;
 789
 790         assert(ret);
 791
 792         if (!is_efi_boot())
 793                 return -EOPNOTSUPP;
 794
 795         r = efi_get_variable(EFI_VENDOR_LOADER, "LoaderEntries", NULL, (void**) &entries, &size);
 796         if (r < 0)
 797                 return r;
 798
 799         /* The variable contains a series of individually NUL terminated UTF-16 strings. */
 800
 801         for (i = 0, start = 0;; i++) {
 802                 _cleanup_free_ char *decoded = NULL;
 803                 bool end;
 804
 805                 /* Is this the end of the variable's data? */
 806                 end = i * sizeof(char16_t) >= size;
 807
 808                 /* Are we in the middle of a string? (i.e. not at the end of the variable, nor at a NUL terminator?) If
 809                  * so, let's go to the next entry. */
 810                 if (!end && entries[i] != 0)
 811                         continue;
 812
 813                 /* We reached the end of a string, let's decode it into UTF-8 */
 814                 decoded = utf16_to_utf8(entries + start, (i - start) * sizeof(char16_t));
 815                 if (!decoded)
 816                         return -ENOMEM;
 817
 818                 if (efi_loader_entry_name_valid(decoded)) {
 819                         r = strv_consume(&l, TAKE_PTR(decoded));
 820                         if (r < 0)
 821                                 return r;
 822                 } else
 823                         log_debug("Ignoring invalid loader entry '%s'.", decoded);
 824
 825                 /* We reached the end of the variable */
 826                 if (end)
 827                         break;
 828
 829                 /* Continue after the NUL byte */
 830                 start = i + 1;
 831         }
 832
 833         *ret = TAKE_PTR(l);
 834         return 0;
 835 }
 836
 837 int efi_loader_get_features(uint64_t *ret) {
 838         _cleanup_free_ void *v = NULL;
 839         size_t s;
 840         int r;
 841
 842         if (!is_efi_boot()) {
 843                 *ret = 0;
 844                 return 0;
 845         }
 846
 847         r = efi_get_variable(EFI_VENDOR_LOADER, "LoaderFeatures", NULL, &v, &s);
 848         if (r == -ENOENT) {
 849                 _cleanup_free_ char *info = NULL;
 850
 851                 /* The new (v240+) LoaderFeatures variable is not supported, let's see if it's systemd-boot at all */
 852                 r = efi_get_variable_string(EFI_VENDOR_LOADER, "LoaderInfo", &info);
 853                 if (r < 0) {
 854                         if (r != -ENOENT)
 855                                 return r;
 856
 857                         /* Variable not set, definitely means not systemd-boot */
 858
 859                 } else if (first_word(info, "systemd-boot")) {
 860
 861                         /* An older systemd-boot version. Let's hardcode the feature set, since it was pretty
 862                          * static in all its versions. */
 863
 864                         *ret = EFI_LOADER_FEATURE_CONFIG_TIMEOUT |
 865                                 EFI_LOADER_FEATURE_ENTRY_DEFAULT |
 866                                 EFI_LOADER_FEATURE_ENTRY_ONESHOT;
 867
 868                         return 0;
 869                 }
 870
 871                 /* No features supported */
 872                 *ret = 0;
 873                 return 0;
 874         }
 875         if (r < 0)
 876                 return r;
 877
 878         if (s != sizeof(uint64_t)) {
 879                 log_debug("LoaderFeatures EFI variable doesn't have the right size.");
 880                 return -EINVAL;
 881         }
 882
 883         memcpy(ret, v, sizeof(uint64_t));
 884         return 0;
 885 }
 886
 887 #endif
 888
 889 char *efi_tilt_backslashes(char *s) {
 890         char *p;
 891
 892         for (p = s; *p; p++)
 893                 if (*p == '\\')
 894                         *p = '/';
 895
 896         return s;
 897 }