#include <unistd.h>

#include <string.h>

#include <fcntl.h>

#include "util.h"

#include "utf8.h"

#include "efivars.h"

#ifdef 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

struct boot_option {

uint32_t attr;

uint16_t path_len;

uint16_t title[];

} _packed_;

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_;

struct device_path {

uint8_t type;

uint8_t sub_type;

uint16_t length;

union {

uint16_t path[0];

struct drive_path drive;

};

} _packed_;

bool is_efi_boot(void) {

return access("/sys/firmware/efi", F_OK) >= 0;

}

static int read_flag(const char *varname) {

int r;

_cleanup_free_ void *v = NULL;

size_t s;

uint8_t b;

r = efi_get_variable(EFI_VENDOR_GLOBAL, varname, NULL, &v, &s);

if (r < 0)

return r;

if (s != 1)

return -EINVAL;

b = *(uint8_t *)v;

r = b > 0;

return r;

}

int is_efi_secure_boot(void) {

return read_flag("SecureBoot");

}

int is_efi_secure_boot_setup_mode(void) {

return read_flag("SetupMode");

}

int efi_get_variable(

sd_id128_t vendor,

const char *name,

uint32_t *attribute,

void **value,

size_t *size) {

_cleanup_close_ int fd = -1;

_cleanup_free_ char *p = NULL;

uint32_t a;

ssize_t n;

struct stat st;

_cleanup_free_ void *buf;

assert(name);

assert(value);

assert(size);

if (asprintf(&p,

"/sys/firmware/efi/efivars/%s-%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",

name, SD_ID128_FORMAT_VAL(vendor)) < 0)

return -ENOMEM;

fd = open(p, O_RDONLY|O_NOCTTY|O_CLOEXEC);

if (fd < 0)

return -errno;

if (fstat(fd, &st) < 0)

return -errno;

if (st.st_size < 4)

return -EIO;

if (st.st_size > 4*1024*1024 + 4)

return -E2BIG;

n = read(fd, &a, sizeof(a));

if (n < 0)

return -errno;

if (n != sizeof(a))

return -EIO;

buf = malloc(st.st_size - 4 + 2);

if (!buf)

return -ENOMEM;

n = read(fd, buf, (size_t) st.st_size - 4);

if (n < 0)

return -errno;

if (n != (ssize_t) st.st_size - 4)

return -EIO;

/* Always NUL terminate (2 bytes, to protect UTF-16) */

((char*) buf)[st.st_size - 4] = 0;

((char*) buf)[st.st_size - 4 + 1] = 0;

*value = buf;

buf = NULL;

*size = (size_t) st.st_size - 4;

if (attribute)

*attribute = a;

return 0;

}

int efi_set_variable(

sd_id128_t vendor,

const char *name,

const void *value,

size_t size) {

struct var {

uint32_t attr;

char buf[];

} _packed_ * _cleanup_free_ buf = NULL;

_cleanup_free_ char *p = NULL;

_cleanup_close_ int fd = -1;

assert(name);

if (asprintf(&p,

"/sys/firmware/efi/efivars/%s-%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",

name, SD_ID128_FORMAT_VAL(vendor)) < 0)

return -ENOMEM;

if (size == 0) {

if (unlink(p) < 0)

return -errno;

return 0;

}

fd = open(p, O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC, 0644);

if (fd < 0)

return -errno;

buf = malloc(sizeof(uint32_t) + size);

if (!buf)

return -ENOMEM;

buf->attr = EFI_VARIABLE_NON_VOLATILE|EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS;

memcpy(buf->buf, value, size);

return loop_write(fd, buf, sizeof(uint32_t) + size, false);

}

int efi_get_variable_string(sd_id128_t vendor, const char *name, char **p) {

_cleanup_free_ void *s = NULL;

size_t ss = 0;

int r;

char *x;

r = efi_get_variable(vendor, name, NULL, &s, &ss);

if (r < 0)

return r;

x = utf16_to_utf8(s, ss);

if (!x)

return -ENOMEM;

*p = x;

return 0;

}

static size_t utf16_size(const uint16_t *s) {

size_t l = 0;

while (s[l] > 0)

l++;

return (l+1) * sizeof(uint16_t);

}

static void efi_guid_to_id128(const void *guid, sd_id128_t *id128) {

struct uuid {

uint32_t u1;

uint16_t u2;

uint16_t u3;

uint8_t u4[8];

} _packed_;

const struct uuid *uuid = guid;

id128->bytes[0] = (uuid->u1 >> 24) & 0xff;

id128->bytes[1] = (uuid->u1 >> 16) & 0xff;

id128->bytes[2] = (uuid->u1 >> 8) & 0xff;

id128->bytes[3] = (uuid->u1) & 0xff;

id128->bytes[4] = (uuid->u2 >> 8) & 0xff;

id128->bytes[5] = (uuid->u2) & 0xff;

id128->bytes[6] = (uuid->u3 >> 8) & 0xff;

id128->bytes[7] = (uuid->u3) & 0xff;

memcpy(&id128->bytes[8], uuid->u4, sizeof(uuid->u4));

}

int efi_get_boot_option(

uint16_t id,

char **title,

sd_id128_t *part_uuid,

char **path,

bool *active) {

char boot_id[9];

_cleanup_free_ uint8_t *buf = NULL;

size_t l;

struct boot_option *header;

size_t title_size;

_cleanup_free_ char *s = NULL, *p = NULL;

sd_id128_t p_uuid = SD_ID128_NULL;

int r;

xsprintf(boot_id, "Boot%04X", id);

r = efi_get_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, (void **)&buf, &l);

if (r < 0)

return r;

if (l < sizeof(struct boot_option))

return -ENOENT;

header = (struct boot_option *)buf;

title_size = utf16_size(header->title);

if (title_size > l - offsetof(struct boot_option, title))

return -EINVAL;

if (title) {

s = utf16_to_utf8(header->title, title_size);

if (!s)

return -ENOMEM;

}

if (header->path_len > 0) {

uint8_t *dbuf;

size_t dnext;

dbuf = buf + offsetof(struct boot_option, title) + title_size;

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 (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 && path) {

p = utf16_to_utf8(dpath->path, dpath->length-4);

efi_tilt_backslashes(p);

continue;

}

}

}

if (title) {

*title = s;

s = NULL;

}

if (part_uuid)

*part_uuid = p_uuid;

if (path) {

*path = p;

p = NULL;

}

if (active)

*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';

}

struct guid {

uint32_t u1;

uint16_t u2;

uint16_t u3;

uint8_t u4[8];

} _packed_;

static void id128_to_efi_guid(sd_id128_t id, void *guid) {

struct guid *uuid = guid;

uuid->u1 = id.bytes[0] << 24 | id.bytes[1] << 16 | id.bytes[2] << 8 | id.bytes[3];

uuid->u2 = id.bytes[4] << 8 | id.bytes[5];

uuid->u3 = id.bytes[6] << 8 | id.bytes[7];

memcpy(uuid->u4, id.bytes+8, sizeof(uuid->u4));

}

static uint16_t *tilt_slashes(uint16_t *s) {

uint16_t *p;

for (p = s; *p; p++)

if (*p == '/')

*p = '\\';

return s;

}

char *efi_tilt_backslashes(char *s) {

char *p;

for (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) {

char boot_id[9];

size_t size;

size_t title_len;

size_t path_len;

struct boot_option *option;

struct device_path *devicep;

_cleanup_free_ char *buf = NULL;

title_len = (strlen(title)+1) * 2;

path_len = (strlen(path)+1) * 2;

buf = calloc(sizeof(struct boot_option) + title_len +

sizeof(struct drive_path) +

sizeof(struct device_path) + path_len, 1);

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);

devicep->drive.part_nr = part;

devicep->drive.part_start = pstart;

devicep->drive.part_size = psize;

devicep->drive.signature_type = SIGNATURE_TYPE_GUID;

devicep->drive.mbr_type = MBR_TYPE_EFI_PARTITION_TABLE_HEADER;

id128_to_efi_guid(part_uuid, devicep->drive.signature);

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(boot_id, "Boot%04X", id);

return efi_set_variable(EFI_VENDOR_GLOBAL, boot_id, buf, size);

}

int efi_remove_boot_option(uint16_t id) {

char boot_id[9];

xsprintf(boot_id, "Boot%04X", id);

return efi_set_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, 0);

}

int efi_get_boot_order(uint16_t **order) {

_cleanup_free_ void *buf = NULL;

size_t l;

int r;

r = efi_get_variable(EFI_VENDOR_GLOBAL, "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;

*order = buf;

buf = NULL;

return (int) (l / sizeof(uint16_t));

}

int efi_set_boot_order(uint16_t *order, size_t n) {

return efi_set_variable(EFI_VENDOR_GLOBAL, "BootOrder", order, n * sizeof(uint16_t));

}

static int boot_id_hex(const char s[4]) {

int i;

int id = 0;

for (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 void *_a, const void *_b) {

const uint16_t *a = _a, *b = _b;

return (int)*a - (int)*b;

}

int efi_get_boot_options(uint16_t **options) {

_cleanup_closedir_ DIR *dir = NULL;

struct dirent *de;

_cleanup_free_ uint16_t *list = NULL;

size_t alloc = 0;

int count = 0;

assert(options);

dir = opendir("/sys/firmware/efi/efivars/");

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, "-8be4df61-93ca-11d2-aa0d-00e098032b8c") != 0)

continue;

id = boot_id_hex(de->d_name + 4);

if (id < 0)

continue;

if (!GREEDY_REALLOC(list, alloc, count + 1))

return -ENOMEM;

list[count++] = id;

}

qsort_safe(list, count, sizeof(uint16_t), cmp_uint16);

*options = list;

list = NULL;

return count;

}

static int read_usec(sd_id128_t vendor, const char *name, usec_t *u) {

_cleanup_free_ char *j = NULL;

int r;

uint64_t x = 0;

assert(name);

assert(u);

r = efi_get_variable_string(EFI_VENDOR_LOADER, name, &j);

if (r < 0)

return r;

r = safe_atou64(j, &x);

if (r < 0)

return r;

*u = x;

return 0;

}

int efi_loader_get_boot_usec(usec_t *firmware, usec_t *loader) {

uint64_t x, y;

int r;

assert(firmware);

assert(loader);

r = read_usec(EFI_VENDOR_LOADER, "LoaderTimeInitUSec", &x);

if (r < 0)

return r;

r = read_usec(EFI_VENDOR_LOADER, "LoaderTimeExecUSec", &y);

if (r < 0)

return r;

if (y == 0 || y < x)

return -EIO;

if (y > USEC_PER_HOUR)

return -EIO;

*firmware = x;

*loader = y;

return 0;

}

int efi_loader_get_device_part_uuid(sd_id128_t *u) {

_cleanup_free_ char *p = NULL;

int r, parsed[16];

r = efi_get_variable_string(EFI_VENDOR_LOADER, "LoaderDevicePartUUID", &p);

if (r < 0)

return r;

if (sscanf(p, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",

&parsed[0], &parsed[1], &parsed[2], &parsed[3],

&parsed[4], &parsed[5], &parsed[6], &parsed[7],

&parsed[8], &parsed[9], &parsed[10], &parsed[11],

&parsed[12], &parsed[13], &parsed[14], &parsed[15]) != 16)

return -EIO;

if (u) {

unsigned i;

for (i = 0; i < ELEMENTSOF(parsed); i++)

u->bytes[i] = parsed[i];

}

return 0;

}

#endif