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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Copyright (C) 2018 Huaxintong Semiconductor Technology Co.,Ltd. All rights
* reserved.
* Author: Ge Song <ge.song@hxt-semitech.com>
*/
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <linux/fs.h>
#include <sys/ioctl.h>
#include "efivar.h"
#include "log/log.h"
#include "talloc/talloc.h"
static const char *efivarfs_path;
inline void set_efivarfs_path(const char *path)
{
efivarfs_path = path;
}
inline const char *get_efivarfs_path(void)
{
return efivarfs_path;
}
int efi_del_variable(void *ctx, const char *guidstr,
const char *name)
{
int fd, flag, errno_value;
int rc = -1;
const char *dir;
char *path;
dir = get_efivarfs_path();
if (!dir)
return -1;
path = talloc_asprintf(ctx, "%s%s-%s", dir, name, guidstr);
if (!path)
return -1;
fd = open(path, O_RDONLY|O_NONBLOCK);
if (fd == -1)
goto err;
rc = ioctl(fd, FS_IOC_GETFLAGS, &flag);
if (rc == -1)
goto err;
flag &= ~FS_IMMUTABLE_FL;
rc = ioctl(fd, FS_IOC_SETFLAGS, &flag);
if (rc == -1)
goto err;
close(fd);
rc = unlink(path);
err:
errno_value = errno;
if (fd > 0)
close(fd);
errno = errno_value;
return rc;
}
int efi_get_variable(void *ctx, const char *guidstr, const char *name,
uint8_t **data, size_t *data_size, uint32_t *attributes)
{
int fd, errno_value;
int rc = -1;
void *p, *buf;
size_t bufsize = 4096;
size_t filesize = 0;
ssize_t sz;
const char *dir;
char *path;
dir = get_efivarfs_path();
if (!dir)
return EFAULT;
path = talloc_asprintf(ctx, "%s%s-%s", dir, name, guidstr);
if (!path)
return ENOMEM;
fd = open(path, O_RDONLY|O_NONBLOCK);
if (fd < 0)
goto err;
buf = talloc_size(ctx, bufsize);
if (!buf)
goto err;
do {
p = buf + filesize;
sz = read(fd, p, bufsize);
if (sz < 0 && errno == EAGAIN) {
continue;
} else if (sz == 0) {
break;
}
filesize += sz;
} while (1);
*attributes = *(uint32_t *)buf;
*data = (uint8_t *)(buf + sizeof(uint32_t));
*data_size = strlen(buf + sizeof(uint32_t));
rc = 0;
err:
errno_value = errno;
if (fd > 0)
close(fd);
errno = errno_value;
return rc;
}
int efi_set_variable(void *ctx, const char *guidstr, const char *name,
uint8_t *data, size_t data_size, uint32_t attributes)
{
int rc = -1, errno_value;
int fd = -1;
ssize_t len;
const char *dir;
char *path;
void *buf;
size_t bufsize;
mode_t mask = 0644;
dir = get_efivarfs_path();
if (!dir)
return EFAULT;
path = talloc_asprintf(ctx, "%s%s-%s", dir, name, guidstr);
if (!path)
return ENOMEM;
if (!access(path, F_OK)) {
rc = efi_del_variable(ctx, guidstr, name);
if (rc < 0) {
goto err;
}
}
fd = open(path, O_CREAT|O_WRONLY, mask);
if (fd < 0)
goto err;
bufsize = sizeof(uint32_t) + data_size;
buf = talloc_size(ctx, bufsize);
if (!buf)
goto err;
*(uint32_t *)buf = attributes;
memcpy(buf + sizeof(uint32_t), data, data_size);
len = write(fd, buf, bufsize);
if ((size_t)len != bufsize)
goto err;
else
rc = 0;
err:
errno_value = errno;
if (fd > 0)
close(fd);
errno = errno_value;
return rc;
}
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