/*
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

/*!
 * \file
 * \brief Kamailio core ::
 * \ingroup core
 * Module: \ref core
 */


#include <string.h>
#include <stdlib.h>
#include <sys/time.h>

#include "receive.h"
#include "globals.h"
#include "dprint.h"
#include "route.h"
#include "parser/msg_parser.h"
#include "forward.h"
#include "action.h"
#include "mem/mem.h"
#include "stats.h"
#include "ip_addr.h"
#include "script_cb.h"
#include "nonsip_hooks.h"
#include "dset.h"
#include "usr_avp.h"
#ifdef WITH_XAVP
#include "xavp.h"
#endif
#include "select_buf.h"

#include "tcp_server.h" /* for tcpconn_add_alias */
#include "tcp_options.h" /* for access to tcp_accept_aliases*/
#include "cfg/cfg.h"
#include "core_stats.h"

#ifdef DEBUG_DMALLOC
#include <mem/dmalloc.h>
#endif

unsigned int msg_no=0;
/* address preset vars */
str default_global_address={0,0};
str default_global_port={0,0};
str default_via_address={0,0};
str default_via_port={0,0};

/**
 * increment msg_no and return the new value
 */
unsigned int inc_msg_no(void)
{
	return ++msg_no;
}

/**
 *
 */
int sip_check_fline(char* buf, unsigned int len)
{
	char *p;
	int m;

	m = 0;
	for(p=buf; p<buf+len; p++) {
		/* first check if is a reply - starts with SIP/2.0 */
		if(m==0) {
			if(*p==' ' || *p=='\t' || *p=='\r' || *p=='\n') continue;
			if(buf+len-p<10) return -1;
			if(strncmp(p, "SIP/2.0 ", 8)==0) {
				LM_DBG("first line indicates a SIP reply\n");
				return 0;
			}
			m=1;
		} else {
			/* check if a request - before end of first line is SIP/2.0 */
			if(*p!='\r' && *p!='\n') continue;
			if(p-10>=buf) {
				if(strncmp(p-8, " SIP/2.0", 8)==0) {
					LM_DBG("first line indicates a SIP request\n");
					return 0;
				}
			}
			return -1;
		}
	}
	return -1;
}

/** Receive message
 *  WARNING: buf must be 0 terminated (buf[len]=0) or some things might
 * break (e.g.: modules/textops)
 */
int receive_msg(char* buf, unsigned int len, struct receive_info* rcv_info)
{
	struct sip_msg* msg;
	struct run_act_ctx ctx;
	int ret;
#ifdef STATS
	int skipped = 1;
	struct timeval tvb, tve;
	struct timezone tz;
	unsigned int diff;
#endif
	str inb;
	sr_net_info_t netinfo;

	if(sr_event_enabled(SREV_NET_DATA_RECV)) {
		if(sip_check_fline(buf, len)==0) {
			memset(&netinfo, 0, sizeof(sr_net_info_t));
			netinfo.data.s = buf;
			netinfo.data.len = len;
			netinfo.rcv = rcv_info;
			sr_event_exec(SREV_NET_DATA_RECV, (void*)&netinfo);
		}
	}

	inb.s = buf;
	inb.len = len;
	sr_event_exec(SREV_NET_DATA_IN, (void*)&inb);
	len = inb.len;

	msg=pkg_malloc(sizeof(struct sip_msg));
	if (msg==0) {
		LM_ERR("no mem for sip_msg\n");
		goto error00;
	}
	msg_no++;
	/* number of vias parsed -- good for diagnostic info in replies */
	via_cnt=0;

	memset(msg,0, sizeof(struct sip_msg)); /* init everything to 0 */
	/* fill in msg */
	msg->buf=buf;
	msg->len=len;
	/* zero termination (termination of orig message bellow not that
	 * useful as most of the work is done with scratch-pad; -jiri  */
	/* buf[len]=0; */ /* WARNING: zero term removed! */
	msg->rcv=*rcv_info;
	msg->id=msg_no;
	msg->pid=my_pid();
	msg->set_global_address=default_global_address;
	msg->set_global_port=default_global_port;

	if(likely(sr_msg_time==1)) msg_set_time(msg);

	if (parse_msg(buf,len, msg)!=0){
		if(sr_event_exec(SREV_RCV_NOSIP, (void*)msg)!=0) {
			LOG(cfg_get(core, core_cfg, corelog),
				"core parsing of SIP message failed (%s:%d/%d)\n",
				ip_addr2a(&msg->rcv.src_ip), (int)msg->rcv.src_port,
				(int)msg->rcv.proto);
			sr_core_ert_run(msg, SR_CORE_ERT_RECEIVE_PARSE_ERROR);
		}
		goto error02;
	}
	LM_DBG("After parse_msg...\n");

	/* set log prefix */
	log_prefix_set(msg);

	/* ... clear branches from previous message */
	clear_branches();

	if (msg->first_line.type==SIP_REQUEST){
		ruri_mark_new(); /* ruri is usable for forking (not consumed yet) */
		if (!IS_SIP(msg)){
			if ((ret=nonsip_msg_run_hooks(msg))!=NONSIP_MSG_ACCEPT){
				if (unlikely(ret==NONSIP_MSG_ERROR))
					goto error03;
				goto end; /* drop the message */
			}
		}
		/* sanity checks */
		if ((msg->via1==0) || (msg->via1->error!=PARSE_OK)){
			/* no via, send back error ? */
			LM_ERR("no via found in request\n");
			STATS_BAD_MSG();
			goto error02;
		}
		/* check if necessary to add receive?->moved to forward_req */
		/* check for the alias stuff */
#ifdef USE_TCP
		if (msg->via1->alias && cfg_get(tcp, tcp_cfg, accept_aliases) &&
				(((rcv_info->proto==PROTO_TCP) && !tcp_disable)
#ifdef USE_TLS
					|| ((rcv_info->proto==PROTO_TLS) && !tls_disable)
#endif
				)
			){
			if (tcpconn_add_alias(rcv_info->proto_reserved1, msg->via1->port,
									rcv_info->proto)!=0){
				LM_ERR("tcp alias failed\n");
				/* continue */
			}
		}
#endif

	/*	skip: */
		LM_DBG("preparing to run routing scripts...\n");
#ifdef  STATS
		gettimeofday( & tvb, &tz );
#endif
		/* execute pre-script callbacks, if any; -jiri */
		/* if some of the callbacks said not to continue with
		 * script processing, don't do so
		 * if we are here basic sanity checks are already done
		 * (like presence of at least one via), so you can count
		 * on via1 being parsed in a pre-script callback --andrei
		*/
		if (exec_pre_script_cb(msg, REQUEST_CB_TYPE)==0 )
		{
			STATS_REQ_FWD_DROP();
			goto end; /* drop the request */
		}

		set_route_type(REQUEST_ROUTE);
		/* exec the routing script */
		if (run_top_route(main_rt.rlist[DEFAULT_RT], msg, 0)<0){
			LM_WARN("error while trying script\n");
			goto error_req;
		}

#ifdef STATS
		gettimeofday( & tve, &tz );
		diff = (tve.tv_sec-tvb.tv_sec)*1000000+(tve.tv_usec-tvb.tv_usec);
		stats->processed_requests++;
		stats->acc_req_time += diff;
		LM_DBG("successfully ran routing scripts...(%d usec)\n", diff);
		STATS_RX_REQUEST( msg->first_line.u.request.method_value );
#endif

		/* execute post request-script callbacks */
		exec_post_script_cb(msg, REQUEST_CB_TYPE);
	}else if (msg->first_line.type==SIP_REPLY){
		/* sanity checks */
		if ((msg->via1==0) || (msg->via1->error!=PARSE_OK)){
			/* no via, send back error ? */
			LM_ERR("no via found in reply\n");
			STATS_BAD_RPL();
			goto error02;
		}

#ifdef STATS
		gettimeofday( & tvb, &tz );
		STATS_RX_RESPONSE ( msg->first_line.u.reply.statuscode / 100 );
#endif

		/* execute pre-script callbacks, if any; -jiri */
		/* if some of the callbacks said not to continue with
		 * script processing, don't do so
		 * if we are here basic sanity checks are already done
		 * (like presence of at least one via), so you can count
		 * on via1 being parsed in a pre-script callback --andrei
		*/
		if (exec_pre_script_cb(msg, ONREPLY_CB_TYPE)==0 )
		{
			STATS_RPL_FWD_DROP();
			goto end; /* drop the reply */
		}

		/* exec the onreply routing script */
		if (onreply_rt.rlist[DEFAULT_RT]){
			set_route_type(CORE_ONREPLY_ROUTE);
			ret=run_top_route(onreply_rt.rlist[DEFAULT_RT], msg, &ctx);
#ifndef NO_ONREPLY_ROUTE_ERROR
			if (unlikely(ret<0)){
				LM_WARN("error while trying onreply script\n");
				goto error_rpl;
			}else
#endif /* NO_ONREPLY_ROUTE_ERROR */
			if (unlikely(ret==0 || (ctx.run_flags&DROP_R_F))){
				STATS_RPL_FWD_DROP();
				goto skip_send_reply; /* drop the message, no error */
			}
		}
		/* send the msg */
		forward_reply(msg);
	skip_send_reply:
#ifdef STATS
		gettimeofday( & tve, &tz );
		diff = (tve.tv_sec-tvb.tv_sec)*1000000+(tve.tv_usec-tvb.tv_usec);
		stats->processed_responses++;
		stats->acc_res_time+=diff;
		LM_DBG("successfully ran reply processing...(%d usec)\n", diff);
#endif

		/* execute post reply-script callbacks */
		exec_post_script_cb(msg, ONREPLY_CB_TYPE);
	}

end:
#ifdef STATS
	skipped = 0;
#endif
	ksr_msg_env_reset();
	LM_DBG("cleaning up\n");
	free_sip_msg(msg);
	pkg_free(msg);
#ifdef STATS
	if (skipped) STATS_RX_DROPS;
#endif
	/* reset log prefix */
	log_prefix_set(NULL);
	return 0;

#ifndef NO_ONREPLY_ROUTE_ERROR
error_rpl:
	/* execute post reply-script callbacks */
	exec_post_script_cb(msg, ONREPLY_CB_TYPE);
	goto error02;
#endif /* NO_ONREPLY_ROUTE_ERROR */
error_req:
	LM_DBG("error:...\n");
	/* execute post request-script callbacks */
	exec_post_script_cb(msg, REQUEST_CB_TYPE);
error03:
error02:
	free_sip_msg(msg);
	pkg_free(msg);
error00:
	ksr_msg_env_reset();
	STATS_RX_DROPS;
	/* reset log prefix */
	log_prefix_set(NULL);
	return -1;
}

/**
 * clean up msg environment, such as avp and xavp lists
 */
void ksr_msg_env_reset(void)
{
	reset_avps();
#ifdef WITH_XAVP
	xavp_reset_list();
#endif

}