| // SPDX-License-Identifier: LGPL-2.1-or-later |
| /* |
| * |
| * BlueZ - Bluetooth protocol stack for Linux |
| * |
| * Copyright (C) 2015 Intel Corporation. All rights reserved. |
| * |
| * |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif |
| |
| #define _GNU_SOURCE |
| #include <stdio.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <stdint.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <sys/param.h> |
| #include <sys/uio.h> |
| |
| #include "peripheral/efivars.h" |
| |
| #define SYSFS_EFIVARS "/sys/firmware/efi/efivars" |
| |
| typedef struct { |
| uint32_t data1; |
| uint16_t data2; |
| uint16_t data3; |
| uint8_t data4[8]; |
| } efi_guid_t; |
| |
| #define VENDOR_GUID \ |
| (efi_guid_t) { 0xd5f9d775, 0x1a09, 0x4e89, \ |
| { 0x96, 0xcf, 0x1d, 0x19, 0x55, 0x4d, 0xa6, 0x67 } } |
| |
| static void efivars_pathname(const char *name, char *pathname, size_t size) |
| { |
| static efi_guid_t guid = VENDOR_GUID; |
| |
| snprintf(pathname, size - 1, |
| "%s/%s-%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x", |
| SYSFS_EFIVARS, name, guid.data1, guid.data2, guid.data3, |
| guid.data4[0], guid.data4[1], guid.data4[2], guid.data4[3], |
| guid.data4[4], guid.data4[5], guid.data4[6], guid.data4[7]); |
| } |
| |
| int efivars_read(const char *name, uint32_t *attributes, |
| void *data, size_t size) |
| { |
| char pathname[PATH_MAX]; |
| struct iovec iov[2]; |
| uint32_t attr; |
| ssize_t len; |
| int fd; |
| |
| efivars_pathname(name, pathname, PATH_MAX); |
| |
| fd = open(pathname, O_RDONLY | O_CLOEXEC); |
| if (fd < 0) |
| return -EIO; |
| |
| iov[0].iov_base = &attr; |
| iov[0].iov_len = sizeof(attr); |
| iov[1].iov_base = data; |
| iov[1].iov_len = size; |
| |
| len = readv(fd, iov, 2); |
| |
| close(fd); |
| |
| if (len < 0) |
| return -EIO; |
| |
| if (attributes) |
| *attributes = attr; |
| |
| return 0; |
| } |
| |
| int efivars_write(const char *name, uint32_t attributes, |
| const void *data, size_t size) |
| { |
| char pathname[PATH_MAX]; |
| void *buf; |
| ssize_t written; |
| int fd; |
| |
| efivars_pathname(name, pathname, PATH_MAX); |
| |
| buf = malloc(size + sizeof(attributes)); |
| if (!buf) |
| return -ENOMEM; |
| |
| fd = open(pathname, O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0644); |
| if (fd < 0) { |
| free(buf); |
| return -EIO; |
| } |
| |
| memcpy(buf, &attributes, sizeof(attributes)); |
| memcpy(buf + sizeof(attributes), data, size); |
| |
| written = write(fd, buf, size + sizeof(attributes)); |
| |
| close(fd); |
| free(buf); |
| |
| if (written < 0) |
| return -EIO; |
| |
| return 0; |
| } |