sortix--sortix/kernel/sockopt.cpp

/*
 * Copyright (c) 2014 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * sockopt.cpp
 * getsockopt() and setsockopt() utility functions.
 */

#include <errno.h>
#include <stddef.h>
#include <stdint.h>

#include <sortix/kernel/ioctx.h>
#include <sortix/kernel/sockopt.h>

namespace Sortix {

bool sockopt_fetch_uintmax(uintmax_t* optval_ptr, ioctx_t* ctx,
                           const void* option_value, size_t option_size)
{
	uintmax_t optval;

	if ( option_size == 0 )
	{
		optval = 0;
	}
	else if ( option_size == 1 )
	{
		uint8_t truncated;
		if ( !ctx->copy_from_src(&truncated, option_value, sizeof(truncated)) )
			return false;
		optval = truncated;
	}
	else if ( option_size == 2 )
	{
		uint16_t truncated;
		if ( !ctx->copy_from_src(&truncated, option_value, sizeof(truncated)) )
			return false;
		optval = truncated;
	}
	else if ( option_size == 4 )
	{
		uint32_t truncated;
		if ( !ctx->copy_from_src(&truncated, option_value, sizeof(truncated)) )
			return false;
		optval = truncated;
	}
	else if ( option_size == 8 )
	{
		uint64_t truncated;
		if ( !ctx->copy_from_src(&truncated, option_value, sizeof(truncated)) )
			return false;
		optval = truncated;
	}
#if UINT64_MAX < UINTMAX_MAX
	#error "Add support for your large uintmax_t"
#endif
	else
	{
		return errno = EINVAL, false;
	}

	return *optval_ptr = optval, true;
}

bool sockopt_return_uintmax(uintmax_t optval, ioctx_t* ctx,
                            void* option_value, size_t* option_size_ptr)
{
	size_t option_size;
	if ( !ctx->copy_from_src(&option_size, option_size_ptr, sizeof(option_size)) )
		return false;

	if ( /*0 <= option_size &&*/ option_size < 1 )
	{
		option_size = 0;
	}
	else if ( 1 <= option_size && option_size < 2 )
	{
		if ( UINT8_MAX < optval )
			return errno = ERANGE, false;
		uint8_t value = optval;
		option_size = sizeof(value);
		if ( !ctx->copy_to_dest(option_value, &value, sizeof(value)) )
			return false;
	}
	else if ( 2 <= option_size && option_size < 4 )
	{
		if ( UINT16_MAX < optval )
			return errno = ERANGE, false;
		uint16_t value = optval;
		option_size = sizeof(value);
		if ( !ctx->copy_to_dest(option_value, &value, sizeof(value)) )
			return false;
	}
	else if ( 4 <= option_size && option_size < 8 )
	{
		if ( UINT32_MAX < optval )
			return errno = ERANGE, false;
		uint32_t value = optval;
		option_size = sizeof(value);
		if ( !ctx->copy_to_dest(option_value, &value, sizeof(value)) )
			return false;
	}
	else if ( 8 <= option_size /* && option_size < 16 */ )
	{
#if UINT64_MAX < UINTMAX_MAX
	#error "Add support for your large uintmax_t"
#endif
		uint64_t value = optval;
		option_size = sizeof(value);
		if ( !ctx->copy_to_dest(option_value, &value, sizeof(value)) )
			return false;
	}

	if ( !ctx->copy_to_dest(option_size_ptr, &option_size, sizeof(option_size)) )
		return false;

	return true;
}

} // namespace Sortix