/*********************************************************************************************************
* Software License Agreement (BSD License)                                                               *
* Author: Sebastien Decugis <sdecugis@nict.go.jp>							 *
*													 *
* Copyright (c) 2008, WIDE Project and NICT								 *
* All rights reserved.											 *
* 													 *
* Redistribution and use of this software 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.								 *
* 													 *
* * Neither the name of the WIDE Project or NICT nor the 						 *
*   names of its contributors may be used to endorse or 						 *
*   promote products derived from this software without 						 *
*   specific prior written permission of WIDE Project and 						 *
*   NICT.												 *
* 													 *
* 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.								 *
*********************************************************************************************************/

/* Code of the recv_unprotect callback function.
 * See <waaad/security-api.h> for more information.
 */

#include "sec_nosec.h"

/* We just receive the buffer "as is" on the connection object, and rebuild a message (boundaries are lost with TCP) */

int sns_recv_unprotect (sec_session_t * session, void ** ext_session, void ** data, size_t *length)
{
	unsigned char header[4];
	unsigned char * newmsg;
	ssize_t ret = 0;
	size_t	received = 0;
	
	TRACE_ENTRY("%p %p %p %p", session, ext_session, data, length);
	
	if (!session || !session->recv_data || !data || !length) {
		TRACE_DEBUG(INFO, "Invalid argument");
		return EINVAL;
	}
	
	/* First, receive only a message header. */
	while (received < sizeof(header)) {
		ret = (*session->recv_data) (session->conn, &header[received], sizeof(header) - received);
		if (ret == 0) {
			/* Shutdown in progress */
			TRACE_DEBUG(INFO, "The recv_data function returned 0");
			return ENOTCONN;
		}
		if (ret < 0) {
			/* Error */
			ret = errno;
			TRACE_DEBUG(INFO, "The recv_data function failed: %s", strerror(ret));
			return ret;
		}
		received += ret;
	}
	
	*length = (size_t)header[1] << 16 + (size_t)header[2] << 8 + (size_t)header[3];
	
	/* Check the received word is a valid begining of a Diameter message */
	if ((header[0] != MSG_VERSION)	/* MSG_VERSION defined in <waaad/message-api.h> */
	   || (*length > DIAMETER_MSG_SIZE_MAX)) { /* to avoid too big mallocs */
		/* The message is suspect */
		TRACE_DEBUG(INFO, "Received suspect message header: ver = %d, size = %d", (int)header[0], *length);
		return EBADMSG;
	}
	
	/* Ok, now we can really receive the data */
	newmsg = malloc( *length );
	if (newmsg == NULL) {
		log_error("Memory allocation failed: %s\n", strerror(errno));
		TRACE_DEBUG(INFO, "malloc failed");
		return ENOMEM;
	}
	
	memcpy(newmsg, header, sizeof(header));
	while (received < *length) {
		ret = (*session->recv_data) (session->conn, newmsg + received, (*length) - received);
		if (ret == 0) {
			/* Shutdown in progress */
			TRACE_DEBUG(INFO, "The recv_data function returned 0");
			free(newmsg);
			return ENOTCONN;
		}
		if (ret < 0) {
			/* Error */
			ret = errno;
			TRACE_DEBUG(INFO, "The recv_data function failed: %s", strerror(ret));
			free(newmsg);
			return ret;
		}
		received += ret;
	}
	
	/* We have received a full message, return it */
	*data = (void *) newmsg;
	
	return 0;
}