| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <unistd.h> |
| |
| #include "alloc-util.h" |
| #include "dirent-util.h" |
| #include "efi-api.h" |
| #include "efivars.h" |
| #include "fd-util.h" |
| #include "sort-util.h" |
| #include "stat-util.h" |
| #include "stdio-util.h" |
| #include "utf8.h" |
| |
| #if ENABLE_EFI |
| |
| #define LOAD_OPTION_ACTIVE 0x00000001 |
| #define MEDIA_DEVICE_PATH 0x04 |
| #define MEDIA_HARDDRIVE_DP 0x01 |
| #define MEDIA_FILEPATH_DP 0x04 |
| #define SIGNATURE_TYPE_GUID 0x02 |
| #define MBR_TYPE_EFI_PARTITION_TABLE_HEADER 0x02 |
| #define END_DEVICE_PATH_TYPE 0x7f |
| #define END_ENTIRE_DEVICE_PATH_SUBTYPE 0xff |
| |
| #define EFI_OS_INDICATIONS_BOOT_TO_FW_UI UINT64_C(0x0000000000000001) |
| |
| #define boot_option__contents \ |
| { \ |
| uint32_t attr; \ |
| uint16_t path_len; \ |
| uint16_t title[]; \ |
| } |
| |
| struct boot_option boot_option__contents; |
| struct boot_option__packed boot_option__contents _packed_; |
| assert_cc(offsetof(struct boot_option, title) == offsetof(struct boot_option__packed, title)); |
| /* sizeof(struct boot_option) != sizeof(struct boot_option__packed), so |
| * the *size* of the structure should not be used anywhere below. */ |
| |
| struct drive_path { |
| uint32_t part_nr; |
| uint64_t part_start; |
| uint64_t part_size; |
| char signature[16]; |
| uint8_t mbr_type; |
| uint8_t signature_type; |
| } _packed_; |
| |
| #define device_path__contents \ |
| { \ |
| uint8_t type; \ |
| uint8_t sub_type; \ |
| uint16_t length; \ |
| union { \ |
| uint16_t path[0]; \ |
| struct drive_path drive; \ |
| }; \ |
| } |
| |
| struct device_path device_path__contents; |
| struct device_path__packed device_path__contents _packed_; |
| assert_cc(sizeof(struct device_path) == sizeof(struct device_path__packed)); |
| |
| int efi_reboot_to_firmware_supported(void) { |
| _cleanup_free_ void *v = NULL; |
| static int cache = -1; |
| uint64_t b; |
| size_t s; |
| int r; |
| |
| if (cache > 0) |
| return 0; |
| if (cache == 0) |
| return -EOPNOTSUPP; |
| |
| if (!is_efi_boot()) |
| goto not_supported; |
| |
| r = efi_get_variable(EFI_GLOBAL_VARIABLE(OsIndicationsSupported), NULL, &v, &s); |
| if (r == -ENOENT) |
| goto not_supported; /* variable doesn't exist? it's not supported then */ |
| if (r < 0) |
| return r; |
| if (s != sizeof(uint64_t)) |
| return -EINVAL; |
| |
| b = *(uint64_t*) v; |
| if (!(b & EFI_OS_INDICATIONS_BOOT_TO_FW_UI)) |
| goto not_supported; /* bit unset? it's not supported then */ |
| |
| cache = 1; |
| return 0; |
| |
| not_supported: |
| cache = 0; |
| return -EOPNOTSUPP; |
| } |
| |
| static int get_os_indications(uint64_t *ret) { |
| static struct stat cache_stat = {}; |
| _cleanup_free_ void *v = NULL; |
| static uint64_t cache; |
| struct stat new_stat; |
| size_t s; |
| int r; |
| |
| assert(ret); |
| |
| /* Let's verify general support first */ |
| r = efi_reboot_to_firmware_supported(); |
| if (r < 0) |
| return r; |
| |
| /* stat() the EFI variable, to see if the mtime changed. If it did we need to cache again. */ |
| if (stat(EFIVAR_PATH(EFI_GLOBAL_VARIABLE(OsIndications)), &new_stat) < 0) { |
| if (errno != ENOENT) |
| return -errno; |
| |
| /* Doesn't exist? Then we can exit early (also see below) */ |
| *ret = 0; |
| return 0; |
| |
| } else if (stat_inode_unmodified(&new_stat, &cache_stat)) { |
| /* inode didn't change, we can return the cached value */ |
| *ret = cache; |
| return 0; |
| } |
| |
| r = efi_get_variable(EFI_GLOBAL_VARIABLE(OsIndications), NULL, &v, &s); |
| if (r == -ENOENT) { |
| /* Some firmware implementations that do support OsIndications and report that with |
| * OsIndicationsSupported will remove the OsIndications variable when it is unset. Let's |
| * pretend it's 0 then, to hide this implementation detail. Note that this call will return |
| * -ENOENT then only if the support for OsIndications is missing entirely, as determined by |
| * efi_reboot_to_firmware_supported() above. */ |
| *ret = 0; |
| return 0; |
| } |
| if (r < 0) |
| return r; |
| if (s != sizeof(uint64_t)) |
| return -EINVAL; |
| |
| cache_stat = new_stat; |
| *ret = cache = *(uint64_t *)v; |
| return 0; |
| } |
| |
| int efi_get_reboot_to_firmware(void) { |
| int r; |
| uint64_t b; |
| |
| r = get_os_indications(&b); |
| if (r < 0) |
| return r; |
| |
| return !!(b & EFI_OS_INDICATIONS_BOOT_TO_FW_UI); |
| } |
| |
| int efi_set_reboot_to_firmware(bool value) { |
| int r; |
| uint64_t b, b_new; |
| |
| r = get_os_indications(&b); |
| if (r < 0) |
| return r; |
| |
| b_new = UPDATE_FLAG(b, EFI_OS_INDICATIONS_BOOT_TO_FW_UI, value); |
| |
| /* Avoid writing to efi vars store if we can due to firmware bugs. */ |
| if (b != b_new) |
| return efi_set_variable(EFI_GLOBAL_VARIABLE(OsIndications), &b_new, sizeof(uint64_t)); |
| |
| return 0; |
| } |
| |
| static ssize_t utf16_size(const uint16_t *s, size_t buf_len_bytes) { |
| size_t l = 0; |
| |
| /* Returns the size of the string in bytes without the terminating two zero bytes */ |
| |
| while (l < buf_len_bytes / sizeof(uint16_t)) { |
| if (s[l] == 0) |
| return (l + 1) * sizeof(uint16_t); |
| l++; |
| } |
| |
| return -EINVAL; /* The terminator was not found */ |
| } |
| |
| struct guid { |
| uint32_t u1; |
| uint16_t u2; |
| uint16_t u3; |
| uint8_t u4[8]; |
| } _packed_; |
| |
| static void efi_guid_to_id128(const void *guid, sd_id128_t *id128) { |
| uint32_t u1; |
| uint16_t u2, u3; |
| const struct guid *uuid = guid; |
| |
| memcpy(&u1, &uuid->u1, sizeof(uint32_t)); |
| id128->bytes[0] = (u1 >> 24) & 0xff; |
| id128->bytes[1] = (u1 >> 16) & 0xff; |
| id128->bytes[2] = (u1 >> 8) & 0xff; |
| id128->bytes[3] = u1 & 0xff; |
| memcpy(&u2, &uuid->u2, sizeof(uint16_t)); |
| id128->bytes[4] = (u2 >> 8) & 0xff; |
| id128->bytes[5] = u2 & 0xff; |
| memcpy(&u3, &uuid->u3, sizeof(uint16_t)); |
| id128->bytes[6] = (u3 >> 8) & 0xff; |
| id128->bytes[7] = u3 & 0xff; |
| memcpy(&id128->bytes[8], uuid->u4, sizeof(uuid->u4)); |
| } |
| |
| int efi_get_boot_option( |
| uint16_t id, |
| char **ret_title, |
| sd_id128_t *ret_part_uuid, |
| char **ret_path, |
| bool *ret_active) { |
| |
| char variable[STRLEN(EFI_GLOBAL_VARIABLE_STR("Boot")) + 4 + 1]; |
| _cleanup_free_ uint8_t *buf = NULL; |
| size_t l; |
| struct boot_option *header; |
| ssize_t title_size; |
| _cleanup_free_ char *s = NULL, *p = NULL; |
| sd_id128_t p_uuid = SD_ID128_NULL; |
| int r; |
| |
| if (!is_efi_boot()) |
| return -EOPNOTSUPP; |
| |
| xsprintf(variable, EFI_GLOBAL_VARIABLE_STR("Boot%04X"), id); |
| r = efi_get_variable(variable, NULL, (void **)&buf, &l); |
| if (r < 0) |
| return r; |
| if (l < offsetof(struct boot_option, title)) |
| return -ENOENT; |
| |
| header = (struct boot_option *)buf; |
| title_size = utf16_size(header->title, l - offsetof(struct boot_option, title)); |
| if (title_size < 0) |
| return title_size; |
| |
| if (ret_title) { |
| s = utf16_to_utf8(header->title, title_size); |
| if (!s) |
| return -ENOMEM; |
| } |
| |
| if (header->path_len > 0) { |
| uint8_t *dbuf; |
| size_t dnext, doff; |
| |
| doff = offsetof(struct boot_option, title) + title_size; |
| dbuf = buf + doff; |
| if (header->path_len > l - doff) |
| return -EINVAL; |
| |
| dnext = 0; |
| while (dnext < header->path_len) { |
| struct device_path *dpath; |
| |
| dpath = (struct device_path *)(dbuf + dnext); |
| if (dpath->length < 4) |
| break; |
| |
| /* Type 0x7F – End of Hardware Device Path, Sub-Type 0xFF – End Entire Device Path */ |
| if (dpath->type == END_DEVICE_PATH_TYPE && dpath->sub_type == END_ENTIRE_DEVICE_PATH_SUBTYPE) |
| break; |
| |
| dnext += dpath->length; |
| |
| /* Type 0x04 – Media Device Path */ |
| if (dpath->type != MEDIA_DEVICE_PATH) |
| continue; |
| |
| /* Sub-Type 1 – Hard Drive */ |
| if (dpath->sub_type == MEDIA_HARDDRIVE_DP) { |
| /* 0x02 – GUID Partition Table */ |
| if (dpath->drive.mbr_type != MBR_TYPE_EFI_PARTITION_TABLE_HEADER) |
| continue; |
| |
| /* 0x02 – GUID signature */ |
| if (dpath->drive.signature_type != SIGNATURE_TYPE_GUID) |
| continue; |
| |
| if (ret_part_uuid) |
| efi_guid_to_id128(dpath->drive.signature, &p_uuid); |
| continue; |
| } |
| |
| /* Sub-Type 4 – File Path */ |
| if (dpath->sub_type == MEDIA_FILEPATH_DP && !p && ret_path) { |
| p = utf16_to_utf8(dpath->path, dpath->length-4); |
| if (!p) |
| return -ENOMEM; |
| |
| efi_tilt_backslashes(p); |
| continue; |
| } |
| } |
| } |
| |
| if (ret_title) |
| *ret_title = TAKE_PTR(s); |
| if (ret_part_uuid) |
| *ret_part_uuid = p_uuid; |
| if (ret_path) |
| *ret_path = TAKE_PTR(p); |
| if (ret_active) |
| *ret_active = header->attr & LOAD_OPTION_ACTIVE; |
| |
| return 0; |
| } |
| |
| static void to_utf16(uint16_t *dest, const char *src) { |
| int i; |
| |
| for (i = 0; src[i] != '\0'; i++) |
| dest[i] = src[i]; |
| dest[i] = '\0'; |
| } |
| |
| static void id128_to_efi_guid(sd_id128_t id, void *guid) { |
| struct guid uuid = { |
| .u1 = id.bytes[0] << 24 | id.bytes[1] << 16 | id.bytes[2] << 8 | id.bytes[3], |
| .u2 = id.bytes[4] << 8 | id.bytes[5], |
| .u3 = id.bytes[6] << 8 | id.bytes[7], |
| }; |
| memcpy(uuid.u4, id.bytes+8, sizeof(uuid.u4)); |
| memcpy(guid, &uuid, sizeof(uuid)); |
| } |
| |
| static uint16_t *tilt_slashes(uint16_t *s) { |
| for (uint16_t *p = s; *p; p++) |
| if (*p == '/') |
| *p = '\\'; |
| |
| return s; |
| } |
| |
| int efi_add_boot_option( |
| uint16_t id, |
| const char *title, |
| uint32_t part, |
| uint64_t pstart, |
| uint64_t psize, |
| sd_id128_t part_uuid, |
| const char *path) { |
| |
| size_t size, title_len, path_len; |
| _cleanup_free_ char *buf = NULL; |
| struct boot_option *option; |
| struct device_path *devicep; |
| char variable[STRLEN(EFI_GLOBAL_VARIABLE_STR("Boot")) + 4 + 1]; |
| |
| if (!is_efi_boot()) |
| return -EOPNOTSUPP; |
| |
| title_len = (strlen(title)+1) * 2; |
| path_len = (strlen(path)+1) * 2; |
| |
| buf = malloc0(offsetof(struct boot_option, title) + title_len + |
| sizeof(struct drive_path) + |
| sizeof(struct device_path) + path_len); |
| if (!buf) |
| return -ENOMEM; |
| |
| /* header */ |
| option = (struct boot_option *)buf; |
| option->attr = LOAD_OPTION_ACTIVE; |
| option->path_len = offsetof(struct device_path, drive) + sizeof(struct drive_path) + |
| offsetof(struct device_path, path) + path_len + |
| offsetof(struct device_path, path); |
| to_utf16(option->title, title); |
| size = offsetof(struct boot_option, title) + title_len; |
| |
| /* partition info */ |
| devicep = (struct device_path *)(buf + size); |
| devicep->type = MEDIA_DEVICE_PATH; |
| devicep->sub_type = MEDIA_HARDDRIVE_DP; |
| devicep->length = offsetof(struct device_path, drive) + sizeof(struct drive_path); |
| memcpy(&devicep->drive.part_nr, &part, sizeof(uint32_t)); |
| memcpy(&devicep->drive.part_start, &pstart, sizeof(uint64_t)); |
| memcpy(&devicep->drive.part_size, &psize, sizeof(uint64_t)); |
| id128_to_efi_guid(part_uuid, devicep->drive.signature); |
| devicep->drive.mbr_type = MBR_TYPE_EFI_PARTITION_TABLE_HEADER; |
| devicep->drive.signature_type = SIGNATURE_TYPE_GUID; |
| size += devicep->length; |
| |
| /* path to loader */ |
| devicep = (struct device_path *)(buf + size); |
| devicep->type = MEDIA_DEVICE_PATH; |
| devicep->sub_type = MEDIA_FILEPATH_DP; |
| devicep->length = offsetof(struct device_path, path) + path_len; |
| to_utf16(devicep->path, path); |
| tilt_slashes(devicep->path); |
| size += devicep->length; |
| |
| /* end of path */ |
| devicep = (struct device_path *)(buf + size); |
| devicep->type = END_DEVICE_PATH_TYPE; |
| devicep->sub_type = END_ENTIRE_DEVICE_PATH_SUBTYPE; |
| devicep->length = offsetof(struct device_path, path); |
| size += devicep->length; |
| |
| xsprintf(variable, EFI_GLOBAL_VARIABLE_STR("Boot%04X"), id); |
| return efi_set_variable(variable, buf, size); |
| } |
| |
| int efi_remove_boot_option(uint16_t id) { |
| char variable[STRLEN(EFI_GLOBAL_VARIABLE_STR("Boot")) + 4 + 1]; |
| |
| if (!is_efi_boot()) |
| return -EOPNOTSUPP; |
| |
| xsprintf(variable, EFI_GLOBAL_VARIABLE_STR("Boot%04X"), id); |
| return efi_set_variable(variable, NULL, 0); |
| } |
| |
| int efi_get_boot_order(uint16_t **ret_order) { |
| _cleanup_free_ void *buf = NULL; |
| size_t l; |
| int r; |
| |
| assert(ret_order); |
| |
| if (!is_efi_boot()) |
| return -EOPNOTSUPP; |
| |
| r = efi_get_variable(EFI_GLOBAL_VARIABLE(BootOrder), NULL, &buf, &l); |
| if (r < 0) |
| return r; |
| |
| if (l <= 0) |
| return -ENOENT; |
| |
| if (l % sizeof(uint16_t) > 0 || |
| l / sizeof(uint16_t) > INT_MAX) |
| return -EINVAL; |
| |
| *ret_order = TAKE_PTR(buf); |
| return (int) (l / sizeof(uint16_t)); |
| } |
| |
| int efi_set_boot_order(const uint16_t *order, size_t n) { |
| |
| if (!is_efi_boot()) |
| return -EOPNOTSUPP; |
| |
| return efi_set_variable(EFI_GLOBAL_VARIABLE(BootOrder), order, n * sizeof(uint16_t)); |
| } |
| |
| static int boot_id_hex(const char s[static 4]) { |
| int id = 0; |
| |
| assert(s); |
| |
| for (int i = 0; i < 4; i++) |
| if (s[i] >= '0' && s[i] <= '9') |
| id |= (s[i] - '0') << (3 - i) * 4; |
| else if (s[i] >= 'A' && s[i] <= 'F') |
| id |= (s[i] - 'A' + 10) << (3 - i) * 4; |
| else |
| return -EINVAL; |
| |
| return id; |
| } |
| |
| static int cmp_uint16(const uint16_t *a, const uint16_t *b) { |
| return CMP(*a, *b); |
| } |
| |
| int efi_get_boot_options(uint16_t **ret_options) { |
| _cleanup_closedir_ DIR *dir = NULL; |
| _cleanup_free_ uint16_t *list = NULL; |
| int count = 0; |
| |
| assert(ret_options); |
| |
| if (!is_efi_boot()) |
| return -EOPNOTSUPP; |
| |
| dir = opendir(EFIVAR_PATH(".")); |
| if (!dir) |
| return -errno; |
| |
| FOREACH_DIRENT(de, dir, return -errno) { |
| int id; |
| |
| if (strncmp(de->d_name, "Boot", 4) != 0) |
| continue; |
| |
| if (strlen(de->d_name) != 45) |
| continue; |
| |
| if (strcmp(de->d_name + 8, EFI_GLOBAL_VARIABLE_STR("")) != 0) /* generate variable suffix using macro */ |
| continue; |
| |
| id = boot_id_hex(de->d_name + 4); |
| if (id < 0) |
| continue; |
| |
| if (!GREEDY_REALLOC(list, count + 1)) |
| return -ENOMEM; |
| |
| list[count++] = id; |
| } |
| |
| typesafe_qsort(list, count, cmp_uint16); |
| |
| *ret_options = TAKE_PTR(list); |
| |
| return count; |
| } |
| |
| bool efi_has_tpm2(void) { |
| static int cache = -1; |
| |
| /* Returns whether the system has a TPM2 chip which is known to the EFI firmware. */ |
| |
| if (cache >= 0) |
| return cache; |
| |
| /* First, check if we are on an EFI boot at all. */ |
| if (!is_efi_boot()) { |
| cache = 0; |
| return cache; |
| } |
| |
| /* Then, check if the ACPI table "TPM2" exists, which is the TPM2 event log table, see: |
| * https://trustedcomputinggroup.org/wp-content/uploads/TCG_ACPIGeneralSpecification_v1.20_r8.pdf |
| * This table exists whenever the firmware is hooked up to TPM2. */ |
| cache = access("/sys/firmware/acpi/tables/TPM2", F_OK) >= 0; |
| if (cache) |
| return cache; |
| |
| if (errno != ENOENT) |
| log_debug_errno(errno, "Unable to test whether /sys/firmware/acpi/tables/TPM2 exists, assuming it doesn't: %m"); |
| |
| /* As the last try, check if the EFI firmware provides the EFI_TCG2_FINAL_EVENTS_TABLE |
| * stored in EFI configuration table, see: |
| * https://trustedcomputinggroup.org/wp-content/uploads/EFI-Protocol-Specification-rev13-160330final.pdf |
| */ |
| cache = access("/sys/kernel/security/tpm0/binary_bios_measurements", F_OK) >= 0; |
| if (!cache && errno != ENOENT) |
| log_debug_errno(errno, "Unable to test whether /sys/kernel/security/tpm0/binary_bios_measurements exists, assuming it doesn't: %m"); |
| |
| return cache; |
| } |
| |
| #endif |
