/*********************************************************************************************************
* Software License Agreement (BSD License)                                                               *
* Author: Sebastien Decugis <sdecugis@nict.go.jp>							 *
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* Copyright (c) 2009, WIDE Project and NICT								 *
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/* Peers facility.
 *
 * DPR / DPA messages management
 *
 * See peer-api.h and peer.h for more information on the functions 
 *
 */

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

/* Dictionary objects for PSM */
static dict_object_t * dict_DPR = NULL;
static dict_object_t * dict_DPA = NULL;

int _peer_dpr_dpa_init(void)
{
	CHECK_FCT( dict_search( DICT_COMMAND, CMD_BY_NAME, "Disconnect-Peer-Request", &dict_DPR, ENOENT) );
	CHECK_FCT( dict_search( DICT_COMMAND, CMD_BY_NAME, "Disconnect-Peer-Answer",  &dict_DPA, ENOENT) );
	
	return 0;
}

int _peer_dpr_dpa_fini(void)
{
	/* nothing special to do */
	return 0;
}

/***********************************************************************/
/*  Diameter Base Protocol: Disconnect-Peer messages                   */
/***********************************************************************/
/* Create a DPR message */
int _peer_dpr_create( _peer_t * peer, msg_t ** dpr, uint32_t cause )
{
	
	TRACE_ENTRY("%p %p %u", peer, dpr, cause);
	
	/* NULL is not allowed */
	CHECK_PARAMS( peer && dpr && cause );
	
	/* Create an empty DPR */
	CHECK_FCT( msg_new( dict_DPR, 0, dpr ) );
	
	/* Add standard Origin-Host, Origin-Realm and Origin-State-Id AVPs */
	CHECK_FCT( msg_add_origin( *dpr, 1 ) );
	
	/* Add the Disconnect-Cause AVP */
	{
		dict_object_t * dict = NULL;
		msg_avp_t * avp = NULL;
		avp_value_t val;
		
		/* Find the model for this AVP */
		CHECK_FCT(  dict_search( DICT_AVP, AVP_BY_NAME, "Disconnect-Cause", &dict, ENOENT )  );
		
		/* Create the AVP */
		CHECK_FCT( msg_avp_new( dict, 0, &avp ) );
		
		/* Set its value */
		memset(&val, 0, sizeof(val));
		val.u32 = cause;
		CHECK_FCT( msg_avp_setvalue( avp, &val ) );

		/* Add it to the message */
		CHECK_FCT( msg_avp_add( *dpr, MSG_BRW_LAST_CHILD, avp ) );
		
	}
	
	/* Set the DPR header: end-to-end id ( hop-by-hop is set when sending ) */
	{
		msg_data_t * dpr_data = NULL;
		CHECK_FCT(  msg_data( *dpr, &dpr_data )  );
		
		dpr_data->msg_eteid = msg_get_eteid();
	}
	
	/* Make sure the DPR message is valid -- mostly for debug here... */
	CHECK_FCT(  msg_parse_rules( *dpr, NULL )  );
	
	/* The DPR is now ready */
	TRACE_DEBUG(FULL, "DPR Ready");
	msg_dump_walk(FULL, *dpr);
	
	return 0;
}

/* Parse a received DPR */
int _peer_dpr_parse( msg_t * dpr, _peer_t * peer )
{
	msg_avp_t * avp = NULL;
	
	CHECK_PARAMS(  VALIDATE_PEER( peer ) && dpr  );

	CHECK_FCT(  msg_browse(dpr, MSG_BRW_FIRST_CHILD, &avp, NULL)  );

	/* Now loop on all AVPs -- we will break when last AVP was parsed */
	while (avp) {
		msg_avp_data_t * avpdata;

		CHECK_FCT(  msg_avp_data( avp, &avpdata )  );

		if (avpdata->avp_flags & AVP_FLAG_VENDOR) {
			/* Ignore all vendor-specific AVPs in DPR ... because we don't support any currently */
			TRACE_DEBUG(FULL, "Ignored a vendor AVP in DPR");
			msg_dump_one(FULL, avp);
			goto next;
		}

		if (avpdata->avp_data == NULL) {
			/* Ignore if the data is not set -- this is more like a sanity check */
			TRACE_DEBUG(FULL, "Ignored an AVP with unset value in DPR");
			msg_dump_one(FULL, avp);
			ASSERT(0); /* To check if this really happens, and understand why... */
			goto next;
		}

		switch (avpdata->avp_code) {
			case AC_ORIGIN_HOST: /* Origin-Host */
				/* Verify that the advertized Origin-Host is conform to the peer name */
				if (strncasecmp(peer->p_diamid, (char *)avpdata->avp_data->os.data, avpdata->avp_data->os.len)) {
					log_error("DPR Received from '%s' with invalid Origin-Host value.\n", peer->p_diamid);
					msg_dump_one(0, avp);
					return EBADMSG;
				}
				break;

			case AC_ORIGIN_REALM: /* Origin-Realm */
				/* Verify that the advertized Origin-Realm is conform to the peer realm */
				if (strncasecmp(peer->p_realm, (char *)avpdata->avp_data->os.data, avpdata->avp_data->os.len)) {
					log_error("DPR Received with invalid Origin-Realm value.\n");
					msg_dump_one(0, avp);
					return EBADMSG;
				}
				break;

			case AC_ORIGIN_STATE_ID: /* Origin-State-Id */
				/* Check if the remote peer has lost its state, in which case we must close the connection */
				if ( peer->p_orstate != avpdata->avp_data->u32 ) {
					/* The easiest way here is to return an error, this should never happen anyway */
					log_error("DPR received from '%s' with a new Origin-State-Id value.\n", peer->p_diamid);
					msg_dump_one(0, avp);
					return EBADMSG;
				}
				break;

			case AC_DISCONNECT_CAUSE: /* Disconnect-Cause */
				switch (avpdata->avp_data->u32) {
					case ACV_DC_REBOOTING: /* REBOOTING */
						/* we will just try reconnection afterwards, as if no DPR was received */
						break;
						
					case ACV_DC_BUSY: /* BUSY */
					case ACV_DC_NOT_FRIEND: /* DO_NOT_WANT_TO_TALK_TO_YOU */
						/* We add the flag to the peer so that the PSM does not attempt reconnecting */
						peer->p_flags |= PEERFL_DISABLE_AFTER_SHUTDOWN;
						break;
						
					default: /* unknown cause... ignore */
						log_normal("Received DPR from '%s' with unkown cause (%u).\n", peer->p_diamid, avpdata->avp_data->u32);
				}
				break;

			default: /* Other AVP */
				TRACE_DEBUG(FULL, "Ignored AVP in DPR");
				msg_dump_one(FULL, avp);
		}

next:			
		/* Go to next AVP */
		CHECK_FCT( msg_browse(avp, MSG_BRW_NEXT, &avp, NULL) );
	}
	
	return 0;
}

/* Create an answer */
int _peer_dpa_create( _peer_t * peer, msg_t ** dpa, uint32_t eteid, uint32_t hbhid )
{
	TRACE_ENTRY("%p %p %u %u", peer, dpa, eteid, hbhid);
	
	/* NULL is not allowed */
	CHECK_PARAMS( dpa );
	
	/* Create an empty DPA */
	CHECK_FCT( msg_new( dict_DPA, 0, dpa ) );
	
	/* Note: the Result-Code AVP will be added later outside this function */
	
	/* Add standard Origin-Host, Origin-Realm and Origin-State-Id AVPs */
	CHECK_FCT( msg_add_origin( *dpa, 1 ) );
	
	/* Set the DPA header: end-to-end id */
	{
		msg_data_t * dpa_data = NULL;
		
		CHECK_FCT(  msg_data( *dpa, &dpa_data )  );
		
		dpa_data->msg_eteid = eteid;
		dpa_data->msg_hbhid = hbhid;
	}
	
	return 0;
}

/* Parse a received answer */
int _peer_dpa_parse( msg_t * dpa, _peer_t * peer )
{
	msg_avp_t * avp = NULL;
	uint32_t errorcode = 0;
	
	CHECK_PARAMS(  VALIDATE_PEER( peer ) && dpa  );

	CHECK_FCT(  msg_browse(dpa, MSG_BRW_FIRST_CHILD, &avp, NULL)  );

	/* Now loop on all AVPs -- we will break when last AVP was parsed */
	while (avp) {
		msg_avp_data_t * avpdata;

		CHECK_FCT(  msg_avp_data( avp, &avpdata )  );

		if (avpdata->avp_flags & AVP_FLAG_VENDOR) {
			/* Ignore all vendor-specific AVPs ... because we don't support any currently */
			TRACE_DEBUG(FULL, "Ignored a vendor AVP in DPA");
			msg_dump_one(FULL, avp);
			goto next;
		}

		if (avpdata->avp_data == NULL) {
			/* Ignore if the data is not set -- this is more like a sanity check */
			TRACE_DEBUG(FULL, "Ignored an AVP with unset value in DPA");
			msg_dump_one(FULL, avp);
			ASSERT(0); /* To check if this really happens, and understand why... */
			goto next;
		}

		switch (avpdata->avp_code) {
			case AC_ORIGIN_HOST: /* Origin-Host */
				/* Check that the remote peer is what we expect */
				if (strncasecmp(peer->p_diamid, (char *)avpdata->avp_data->os.data, avpdata->avp_data->os.len)) {
					log_error("The DPA received from peer '%s' contains invalid Origin-Host (bad IP?), resetting connection", peer->p_diamid);
					msg_dump_one(0, avp);
					return EBADMSG;
				}
				break;

			case AC_ORIGIN_REALM: /* Origin-Realm */
				/* Verify that the advertized Origin-Realm is conform to the peer realm */
				if (strncasecmp(peer->p_realm, (char *)avpdata->avp_data->os.data, avpdata->avp_data->os.len)) {
					log_error("DPA received with invalid Origin-Realm value.\n");
					msg_dump_one(0, avp);
					return EBADMSG;
				}
				break;

			case AC_ORIGIN_STATE_ID: /* Origin-State-Id */
				/* Check if the remote peer has lost its state, in which case we must close the connection */
				if ( peer->p_orstate != avpdata->avp_data->u32 ) {
					/* The easiest way here is to return an error, this should never happen anyway */
					log_error("DPA received from '%s' with a new Origin-State-Id value.\n", peer->p_diamid);
					msg_dump_one(0, avp);
					return EBADMSG;
				}
				break;

			case AC_RESULT_CODE: /* Result-Code */
				errorcode = avpdata->avp_data->u32;
				break;
				
			case AC_ERROR_MESSAGE: /* Error-Message */
				log_normal("The DPA received from peer '%s' contains an Error-Message AVP", peer->p_diamid);
				msg_dump_one(INFO, avp);
				break;

			default: /* Other AVP */
				TRACE_DEBUG(FULL, "Ignored AVP in DPA");
				msg_dump_one(FULL, avp);
		}

next:			
		/* Go to next AVP */
		CHECK_FCT( msg_browse(avp, MSG_BRW_NEXT, &avp, NULL) );
	}
	
	/* Ok, now check the error code */
	if ( errorcode != ER_DIAMETER_SUCCESS ) {
		/* We do not allow another error code here */
		log_error("Received DPA with Result-Code value %u from %s.\n", errorcode, peer->p_diamid);
		return EBADMSG;
	}
	
	return 0;
}