/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see .
***/
#include
#include
#include
#include "util.h"
#include "utf8.h"
#include "efivars.h"
bool is_efiboot(void) {
return access("/sys/firmware/efi", F_OK) >= 0;
}
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;
void *r;
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 (int) n;
if (n != sizeof(a))
return -EIO;
r = malloc(st.st_size - 4 + 2);
if (!r)
return -ENOMEM;
n = read(fd, r, (size_t) st.st_size - 4);
if (n < 0) {
free(r);
return (int) -n;
}
if (n != (ssize_t) st.st_size - 4) {
free(r);
return -EIO;
}
/* Always NUL terminate (2 bytes, to protect UTF-16) */
((char*) r)[st.st_size - 4] = 0;
((char*) r)[st.st_size - 4 + 1] = 0;
*value = r;
*size = (size_t) st.st_size - 4;
if (attribute)
*attribute = a;
return 0;
}
char *efi_get_variable_string(sd_id128_t vendor, const char *name) {
_cleanup_free_ void *s = NULL;
size_t ss;
int err;
err = efi_get_variable(vendor, name, NULL, &s, &ss);
if (err < 0)
return NULL;
return utf16_to_utf8(s, ss);
}
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(uint32_t id, uint32_t *attributes, char **title, sd_id128_t *part_uuid, char **path, char **data, size_t *data_size) {
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_;
char boot_id[32];
_cleanup_free_ char *buf = NULL;
size_t l;
struct boot_option *header;
size_t title_size;
char *s = NULL;
char *p = NULL;
sd_id128_t p_uuid = SD_ID128_NULL;
char *d = NULL;
size_t d_size = 0;
int err;
snprintf(boot_id, sizeof(boot_id), "Boot%04X", id);
err = efi_get_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, (void **)&buf, &l);
if (err < 0)
return err;
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;
s = utf16_to_utf8(header->title, title_size);
if (!s) {
err = -ENOMEM;
goto err;
}
if (header->path_len > 0) {
char *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 == 0x7f && dpath->sub_type == 0xff)
break;
dnext += dpath->length;
/* Type 0x04 – Media Device Path */
if (dpath->type != 0x04)
continue;
/* Sub-Type 1 – Hard Drive */
if (dpath->sub_type == 0x01) {
/* 0x02 – GUID Partition Table */
if (dpath->drive.mbr_type != 0x02)
continue;
/* 0x02 – GUID signature */
if (dpath->drive.signature_type != 0x02)
continue;
efi_guid_to_id128(dpath->drive.signature, &p_uuid);
continue;
}
/* Sub-Type 4 – File Path */
if (dpath->sub_type == 0x04) {
p = utf16_to_utf8(dpath->path, dpath->length-4);
continue;
}
}
}
*title = s;
if (part_uuid)
*part_uuid = p_uuid;
if (path)
*path = p;
if (data)
*data = d;
if (data_size)
*data_size = d_size;
return 0;
err:
free(s);
free(p);
free(d);
return err;
}
int efi_get_boot_order(uint16_t **order, size_t *count) {
void *buf;
size_t l;
int err;
err = efi_get_variable(EFI_VENDOR_GLOBAL, "BootOrder", NULL, &buf, &l);
if (err < 0)
return err;
if (l == 0) {
free(buf);
return -ENOENT;
}
if ((l % sizeof(uint16_t) > 0)) {
free(buf);
return -EINVAL;
}
*order = buf;
*count = l / sizeof(uint16_t);
return 0;
}
static int read_usec(sd_id128_t vendor, const char *name, usec_t *u) {
_cleanup_free_ void *i = NULL;
_cleanup_free_ char *j = NULL;
size_t is;
int r;
uint64_t x;
assert(name);
assert(u);
r = efi_get_variable(EFI_VENDOR_LOADER, name, NULL, &i, &is);
if (r < 0)
return r;
j = utf16_to_utf8(i, is);
if (!j)
return -ENOMEM;
r = safe_atou64(j, &x);
if (r < 0)
return r;
*u = x;
return 0;
}
static int 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_get_boot_timestamps(const dual_timestamp *n, dual_timestamp *firmware, dual_timestamp *loader) {
usec_t x, y, a;
int r;
dual_timestamp _n;
assert(firmware);
assert(loader);
if (!n) {
dual_timestamp_get(&_n);
n = &_n;
}
r = get_boot_usec(&x, &y);
if (r < 0)
return r;
/* Let's convert this to timestamps where the firmware
* began/loader began working. To make this more confusing:
* since usec_t is unsigned and the kernel's monotonic clock
* begins at kernel initialization we'll actually initialize
* the monotonic timestamps here as negative of the actual
* value. */
firmware->monotonic = y;
loader->monotonic = y - x;
a = n->monotonic + firmware->monotonic;
firmware->realtime = n->realtime > a ? n->realtime - a : 0;
a = n->monotonic + loader->monotonic;
loader->realtime = n->realtime > a ? n->realtime - a : 0;
return 0;
}
int efi_get_loader_device_part_uuid(sd_id128_t *u) {
_cleanup_free_ void *s = NULL;
_cleanup_free_ char *p = NULL;
size_t ss;
int r, parsed[16];
unsigned i;
assert(u);
r = efi_get_variable(EFI_VENDOR_LOADER, "LoaderDevicePartUUID", NULL, &s, &ss);
if (r < 0)
return r;
p = utf16_to_utf8(s, ss);
if (!p)
return -ENOMEM;
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;
for (i = 0; i < ELEMENTSOF(parsed); i++)
u->bytes[i] = parsed[i];
return 0;
}