/**************************************************************************** * libs/libc/misc/lib_ioctl.c * * Copyright (C) 2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include "libc.h" #if defined(CONFIG_LIBC_IOCTL_VARIADIC) && CONFIG_NFILE_DESCRIPTORS > 0 /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: ioctl * * Description: * Perform device specific operations. * * Input Parameters: * fd File/socket descriptor of device * req The ioctl command * ... A third argument of type unsigned long is expected * * Returned Value: * >=0 on success (positive non-zero values are cmd-specific) * -1 on failure with errno set properly: * * EBADF * 'fd' is not a valid descriptor. * EFAULT * 'arg' references an inaccessible memory area. * EINVAL * 'cmd' or 'arg' is not valid. * ENOTTY * 'fd' is not associated with a character special device. * ENOTTY * The specified request does not apply to the kind of object that the * descriptor 'fd' references. * ****************************************************************************/ int ioctl(int fd, int req, ...) { unsigned long arg; va_list ap; /* Get the unsigned long argument. * * REVISIT: This could be the cause of the crash down the road if the * actual size of the argument is anything other than sizeof(unsigned long). * Most small integers will be promoted to 'int'. ARM should pass the * following test with all three types having sizeof(type) == 4 bytes. * 'float' should also be tested. But 'long long' and 'double' are out of * the question! Don't try to pass them. * * And what will happen if no third argument is passed? In most cases, * this should just result in a garbage value for arg. But you may * discover cases where something worse happens! */ DEBUGASSERT(sizeof(int) == sizeof(unsigned long) && sizeof(FAR void *) == sizeof(unsigned long)); va_start(ap, req); arg = va_arg(ap, unsigned long); va_end(ap); /* Then let fs_ioctl() to the real work */ return fs_ioctl(fd, req, arg); } #endif /* CONFIG_LIBC_IOCTL_VARIADIC && CONFIG_NFILE_DESCRIPTORS > 0 */