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/*
* Embedded Linux library
* Copyright (C) 2012 Intel Corporation
* Copyright (C) 2023 Cruise LLC
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#define _GNU_SOURCE
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include "sysctl.h"
#include "useful.h"
#include "util.h"
#include "private.h"
static int sysctl_write(const char *file, const void *value, size_t len)
{
int fd;
ssize_t r;
fd = L_TFR(open(file, O_WRONLY));
if (unlikely(fd < 0))
return -errno;
r = L_TFR(write(fd, value, len));
if (r < 0)
r = -errno;
else
r = 0;
close(fd);
return r;
}
static int sysctl_read(const char *file, void *dest, size_t len)
{
int fd;
ssize_t r;
fd = L_TFR(open(file, O_RDONLY));
if (unlikely(fd < 0))
return -errno;
r = L_TFR(read(fd, dest, len));
if (unlikely(r < 0))
r = -errno;
close(fd);
return r;
}
LIB_EXPORT int l_sysctl_get_u32(uint32_t *out_v, const char *format, ...)
{
_auto_(l_free) char *filename = NULL;
va_list ap;
char valuestr[64];
int r;
va_start(ap, format);
filename = l_strdup_vprintf(format, ap);
va_end(ap);
r = sysctl_read(filename, valuestr, sizeof(valuestr) - 1);
if (r < 0)
return r;
while (r > 0 && L_IN_SET(valuestr[r - 1], '\n', '\r', '\t', ' '))
r--;
valuestr[r] = '\0';
return l_safe_atou32(valuestr, out_v);
}
LIB_EXPORT int l_sysctl_set_u32(uint32_t v, const char *format, ...)
{
_auto_(l_free) char *filename = NULL;
va_list ap;
char valuestr[64];
size_t len;
va_start(ap, format);
filename = l_strdup_vprintf(format, ap);
va_end(ap);
len = snprintf(valuestr, sizeof(valuestr), "%u", v);
return sysctl_write(filename, valuestr, len);
}
LIB_EXPORT int l_sysctl_get_char(char *out_c, const char *format, ...)
{
_auto_(l_free) char *filename = NULL;
va_list ap;
va_start(ap, format);
filename = l_strdup_vprintf(format, ap);
va_end(ap);
return sysctl_read(filename, out_c, sizeof(char));
}
LIB_EXPORT int l_sysctl_set_char(char c, const char *format, ...)
{
_auto_(l_free) char *filename = NULL;
va_list ap;
va_start(ap, format);
filename = l_strdup_vprintf(format, ap);
va_end(ap);
return sysctl_write(filename, &c, sizeof(char));
}
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