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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 <sys/stat.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;
}
static int efi_open(const char *name, const char *guidstr, int flags,
mode_t mode, char **path)
{
int fd;
*path = NULL;
if (!get_efivarfs_path())
return -1;
*path = talloc_asprintf(NULL, "%s%s-%s", get_efivarfs_path(), name, guidstr);
if (!*path)
return -1;
flags = flags ? flags : O_RDONLY | O_NONBLOCK;
fd = open(*path, flags, mode);
if (fd < 0) {
pb_log("%s: open failed %s: %s\n", __func__, *path,
strerror(errno));
talloc_free(*path);
*path = NULL;
return -1;
}
return fd;
}
int efi_del_variable(const char *guidstr, const char *name)
{
int fd, flag;
int rc = -1;
char *path;
fd = efi_open(name, guidstr, 0, 0, &path);
if (fd < 0)
return -1;
rc = ioctl(fd, FS_IOC_GETFLAGS, &flag);
if (rc == -1)
goto exit;
flag &= ~FS_IMMUTABLE_FL;
rc = ioctl(fd, FS_IOC_SETFLAGS, &flag);
if (rc == -1)
goto exit;
close(fd);
fd = 0;
rc = unlink(path);
exit:
talloc_free(path);
close(fd);
return rc;
}
int efi_get_variable(void *ctx, const char *guidstr, const char *name,
struct efi_data **efi_data)
{
int fd;
int rc = -1;
char *p;
char buf[4096];
ssize_t total;
ssize_t count;
char *path;
*efi_data = NULL;
fd = efi_open(name, guidstr, 0, 0, &path);
if (fd < 0)
return -1;
for (p = buf, total = 0; ; p = buf + count) {
count = read(fd, p, sizeof(buf) - total);
if (count < 0) {
if (errno == EAGAIN || errno == EWOULDBLOCK)
continue;
pb_log("%s: read failed %s: (%ld) %s\n", __func__, path,
count, strerror(errno));
goto exit;
}
if (p >= (buf + sizeof(buf))) {
pb_log("%s: buffer full %s: (%ld)\n", __func__, path,
sizeof(buf));
goto exit;
}
if (count == 0)
break;
total += count;
};
*efi_data = (void*)talloc_zero_array(ctx, char,
sizeof (struct efi_data) + total);
(*efi_data)->attributes = *(uint32_t *)buf;
(*efi_data)->data_size = total;
(*efi_data)->data = (*efi_data)->fill;
memcpy((*efi_data)->data, buf + sizeof (uint32_t), total);
rc = 0;
exit:
talloc_free(path);
close(fd);
return rc;
}
int efi_set_variable(const char *guidstr, const char *name,
const struct efi_data *efi_data)
{
int rc = -1;
int fd;
ssize_t count;
void *buf;
size_t bufsize;
char *path;
efi_del_variable(guidstr, name);
fd = efi_open(name, guidstr, O_CREAT | O_WRONLY,
S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH, &path);
if (fd < 0)
return -1;
bufsize = sizeof(uint32_t) + efi_data->data_size;
buf = talloc_size(path, bufsize);
if (!buf)
goto exit;
*(uint32_t *)buf = efi_data->attributes;
memcpy(buf + sizeof(uint32_t), efi_data->data, efi_data->data_size);
count = write(fd, buf, bufsize);
if ((size_t)count != bufsize) {
pb_log("%s: write failed %s: (%ld) %s\n", __func__, name,
count, strerror(errno));
goto exit;
}
rc = 0;
exit:
talloc_free(path);
close(fd);
return rc;
}
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