/*********************************************************************************************************
* Software License Agreement (BSD License)                                                               *
* Author: Sebastien Decugis <sdecugis@nict.go.jp>							 *
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/* Peers facility.
 *
 * This file contains the code of a dummy security module to exchange data with a remote peer before identity is known.
 *
 */

#include "waaad-internal.h"
#include "peer-internal.h"	

/* State change callback */
static int _peer_secini_state_change (sec_pss_t newstate, sec_pss_t oldstate, sec_session_t * session, void ** ext_session)
{
	TRACE_ENTRY("%d %d %p %p", newstate, oldstate, session, ext_session);
	
	/* We don't need to save a session state in this module, so do not do anything here */
	return 0;
}

/* Sending data: we just write the buffer unmodified on the connection object */
static int _peer_secini_send (sec_session_t * session, void ** ext_session, void * data, size_t length)
{
	ssize_t ret = 0;
	size_t sent = 0;
	int  stream = -1;
	
	TRACE_ENTRY("%p %p %p %d", session, ext_session, data, length);
	
	if (!session || !session->conn) {
		TRACE_DEBUG(INFO, "Invalid argument");
		return EINVAL;
	}
	
	while (sent < length) {
		switch (session->proto) {
			case IPPROTO_TCP:
				ret = (*session->cbs.tcp.send_data) (session, ((char *)data) + sent, length - sent);
				break;

#ifndef DISABLE_SCTP				
			case IPPROTO_SCTP:
				ret = (*session->cbs.sctp.send_data) (session, &stream, ((char *)data) + sent, length - sent);
				break;
#endif /* DISABLE_SCTP */
			
			default:
				TRACE_DEBUG(INFO, "Invalid proto");
				return EINVAL;
		}
				
		if (ret == -1) {
			ret = errno;
			TRACE_DEBUG(INFO, "The send_data callback failed: %s", strerror(ret));
			return ret;
		}
		sent += ret;
	}
	
	return 0;
}

/* Receive from a TCP connection: rebuild the message boundaries */
static int _peer_secini_recv_tcp (sec_session_t * session, void ** data, size_t *length)
{
	unsigned char header[4];
	unsigned char * newmsg;
	ssize_t ret = 0;
	size_t	received = 0;
	
	/* First, receive only a message header. */
	while (received < sizeof(header)) {
		ret = (*session->cbs.tcp.recv_data) (session, &header[received], sizeof(header) - received);
		if (ret == 0) {
			/* Shutdown in progress */
			TRACE_DEBUG(INFO, "The recv_data function returned 0");
			return ENOTCONN;
		}
		
		CHECK_SYS(ret); /* in case of <0 value */
		
		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 */
	CHECK_MALLOC(  newmsg = malloc( *length )  );
	
	memcpy(newmsg, header, sizeof(header));
	while (received < *length) {
		pthread_cleanup_push(cleanup_buffer, newmsg); /* In case we are canceled, clean the partialy built buffer */
		ret = (*session->cbs.tcp.recv_data) (session, newmsg + received, (*length) - received);
		pthread_cleanup_pop(0);
	
		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;
			CHECK_SYS_DO( -1, );
			free(newmsg);
			return ret;
		}
		received += ret;
	}
	
	/* We have received a full message, return it */
	*data = (void *) newmsg;
	
	return 0;
}

#ifndef DISABLE_SCTP
/* Receive from a SCTP connection: the message boundaries are preserved, so we have very few to do here */
static int _peer_secini_recv_sctp (sec_session_t * session, void ** data, size_t *length)
{
	ssize_t ret = 0;
	uint16_t stream = 0;
	
	ret = (*session->cbs.sctp.recv_data) (session, &stream, data, length);
	if (ret == 0) {
		/* Shutdown in progress */
		TRACE_DEBUG(INFO, "The recv_data function returned 0");
		return ENOTCONN;
	}
	CHECK_SYS(ret);
	
	TRACE_DEBUG(FULL, "Received a message of %d bytes on stream %d", *length, stream);
	return 0;
}
#endif /* DISABLE_SCTP */

/* We just receive the buffer on the connection object, and rebuild a message (boundaries are lost with TCP) */
int _peer_secini_recv (sec_session_t * session, void ** ext_session, void ** data, size_t *length)
{
	TRACE_ENTRY("%p %p %p %p", session, ext_session, data, length);
	
	CHECK_PARAMS(session && session->conn && data && length);
	
	switch (session->proto) {
		case IPPROTO_TCP:
			CHECK_FCT( _peer_secini_recv_tcp(session, data, length) );
			break;

#ifndef DISABLE_SCTP
		case IPPROTO_SCTP:
			CHECK_FCT( _peer_secini_recv_sctp(session, data, length) );
			break;
#endif /* DISABLE_SCTP */

		default:
			TRACE_DEBUG(INFO, "Invalid proto");
			return EINVAL;
	}
	
	return 0;
}


sec_module_t _peer_secini_mod = {
	.sec_insecid 		= 0,
	.sec_is_supported_peer 	= NULL,
	.sec_state_change 	= _peer_secini_state_change,
	.sec_send_protect 	= _peer_secini_send,
	.sec_recv_unprotect 	= _peer_secini_recv
};