incubator-nuttx/libc/unistd/lib_sethostname.c

133 lines
5.0 KiB
C

/****************************************************************************
* libc/unistd/lib_gethostname.c
*
* Copyright (C) 2015 Stavros Polymenis. All rights reserved.
* Copyright (C) 2015, 2016 Gregory Nutt. All rights reserved.
* Author: Stavros Polymenis <sp@orbitalfox.com>
* Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <unistd.h>
#include <nuttx/irq.h>
/* This file is only compiled if network support is enabled */
#ifdef CONFIG_NET
/* Further, in the protected and kernel build modes where kernel and
* application code are separated, the hostname is a common system property
* and must reside only in the kernel. In that case, this accessor
* function only be called from user space is only via a kernel system call.
*/
#if (!defined(CONFIG_BUILD_PROTECTED) && !defined(CONFIG_BUILD_KERNEL)) || \
defined(__KERNEL__)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef MIN
# define MIN(a,b) ((a) < (b) ? (a) : (b))
#endif
#ifndef MAX
# define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/* This is the system hostname (defined in lib_gethostname). */
extern char g_hostname[HOST_NAME_MAX + 1];
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sethostname
*
* Description:
*
* sethostname() sets the hostname to the value given in the character
* array name. The len argument specifies the number of bytes in name.
* (Thus, name does not require a terminating null byte.)
*
* Conforming To
* SVr4, 4.4BSD (these interfaces first appeared in 4.2BSD). POSIX.1-2001
* specifies gethostname() but not sethostname().
*
* Input Parameters:
* name - The user buffer to providing the new host name.
* namelen - The size of the user buffer in bytes.
*
* Returned Value:
* Upon successful completion, 0 will be returned; otherwise, -1 will be
* returned. No errors are defined; errno variable is not set.
*
****************************************************************************/
int sethostname(FAR const char *name, size_t size)
{
irqstate_t flags;
/* Save the new host name, truncating to HOST_NAME_MAX if necessary. This
* internal copy is always NUL terminated. The hostname is global resource.
* There is a microscopic possibility that it could be accessed while we
* are setting it.
*/
flags = enter_critical_section();
strncpy(g_hostname, name, MIN(HOST_NAME_MAX, size));
g_hostname[HOST_NAME_MAX] = '\0';
leave_critical_section(flags);
return 0;
}
#endif /* CONFIG_NET */
#endif /* (!CONFIG_BUILD_PROTECTED && !CONFIG_BUILD_KERNEL) || __KERNEL__ */