freebsd-nq/contrib/ofed/libibverbs/sysfs.c

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/*
* Copyright (c) 2006 Cisco Systems, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#define _GNU_SOURCE
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <sys/sysctl.h>
#include "ibverbs.h"
static const char *sysfs_path;
const char *ibv_get_sysfs_path(void)
{
const char *env = NULL;
if (sysfs_path)
return sysfs_path;
/*
* Only follow use path passed in through the calling user's
* environment if we're not running SUID.
*/
if (getuid() == geteuid())
env = getenv("SYSFS_PATH");
if (env) {
int len;
char *dup;
sysfs_path = dup = strndup(env, IBV_SYSFS_PATH_MAX);
len = strlen(dup);
while (len > 0 && dup[len - 1] == '/') {
--len;
dup[len] = '\0';
}
} else
sysfs_path = "/sys";
return sysfs_path;
}
int ibv_read_sysfs_file(const char *dir, const char *file,
char *buf, size_t size)
{
char *path, *s;
int fd;
size_t len;
if (asprintf(&path, "%s/%s", dir, file) < 0)
return -1;
for (s = &path[0]; *s != '\0'; s++)
if (*s == '/')
*s = '.';
len = size;
if (sysctlbyname(&path[1], buf, &len, NULL, 0) == -1)
return -1;
free(path);
if (len > 0 && buf[len - 1] == '\n')
buf[--len] = '\0';
return len;
}