sortix--sortix/kernel/hostname.cpp

/*******************************************************************************

    Copyright(C) Jonas 'Sortie' Termansen 2014.

    This file is part of Sortix.

    Sortix 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, either version 3 of the License, or (at your option) any later
    version.

    Sortix 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
    Sortix. If not, see <http://www.gnu.org/licenses/>.

    hostname.cpp
    System calls for managing the hostname of the current system.

*******************************************************************************/

#include <errno.h>
#include <string.h>

#include <sortix/limits.h>

#include <sortix/kernel/copy.h>
#include <sortix/kernel/kernel.h>
#include <sortix/kernel/kthread.h>
#include <sortix/kernel/syscall.h>

namespace Sortix {

static kthread_mutex_t hostname_lock = KTHREAD_MUTEX_INITIALIZER;

static char hostname[HOST_NAME_MAX + 1] = "sortix";
static size_t hostname_length = 6;

int sys_gethostname(char* dst_name, size_t dst_name_size)
{
	if ( dst_name_size == 0 )
		return errno = EINVAL, -1;
	size_t dst_name_length = dst_name_size - 1;
	ScopedLock lock(&hostname_lock);
	if ( dst_name_length < hostname_length )
		errno = ERANGE;
	if ( hostname_length < dst_name_length )
		dst_name_length = hostname_length;
	if ( !CopyToUser(dst_name, hostname, dst_name_length) )
		return -1;
	char nul = '\0';
	if ( !CopyToUser(dst_name + dst_name_length, &nul, 1) )
		return -1;
	return 0;
}

int sys_sethostname(const char* src_name, size_t src_name_size)
{
	char new_hostname[HOST_NAME_MAX + 1];
	if ( sizeof(new_hostname) < src_name_size )
		return errno = EINVAL, -1;
	if ( !CopyFromUser(new_hostname, src_name, src_name_size) )
		return -1;
	size_t new_hostname_length = strnlen(new_hostname, sizeof(new_hostname));
	if ( HOST_NAME_MAX < new_hostname_length )
		return errno = EINVAL, -1;
	new_hostname[new_hostname_length] = '\0';
	ScopedLock lock(&hostname_lock);
	memcpy(hostname, new_hostname, new_hostname_length + 1);
	hostname_length = new_hostname_length;
	return 0;
}

} // namespace Sortix