cpl_proxy.h

用来作为linux中SIP SERVER,完成VOIP网络电话中服务器的功能

/*
 * $Id: cpl_proxy.h,v 1.22.2.2 2005/06/21 17:52:13 andrei Exp $
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of ser, a free SIP server.
 *
 * ser 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
 *
 * For a license to use the ser software under conditions
 * other than those described here, or to purchase support for this
 * software, please contact iptel.org by e-mail at the following addresses:
 *    [e-mail]
 *
 * ser 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * History:
 * -------
 * 2003-07-29: file created (bogdan)
 * 2004-06-14: flag CPL_IS_STATEFUL is set now immediately after the 
 *             transaction is created (bogdan)
 */

#include "../tm/h_table.h"
#include "../../parser/contact/parse_contact.h"


#define duplicate_str( _orig_ , _new_ ) \
	do {\
		(_new_) = (str*)shm_malloc(sizeof(str)+(_orig_)->len);\
		if (!(_new_)) goto mem_error;\
		(_new_)->len = (_orig_)->len;\
		(_new_)->s = (char*)((_new_))+sizeof(str);\
		memcpy((_new_)->s,(_orig_)->s,(_orig_)->len);\
	} while(0)

#define search_and_duplicate_hdr( _intr_ , _field_ , _name_ , _sfoo_ ) \
	do {\
		if (!(_intr_)->_field_) {\
			if (!(_intr_)->msg->_field_) { \
				if (parse_headers((_intr_)->msg,_name_,0)==-1) {\
					LOG(L_ERR,"ERROR:run_proxy: bad %u hdr\n",_name_);\
					goto runtime_error;\
				} else if ( !(_intr_)->msg->_field_) {\
					(_intr_)->_field_ = STR_NOT_FOUND;\
				} else {\
					(_sfoo_) = &((_intr_)->msg->_field_->body);\
					duplicate_str( (_sfoo_) , (_intr_)->_field_ );\
				}\
			} else {\
				(_sfoo_) = &((_intr_)->msg->_field_->body);\
				duplicate_str( (_sfoo_) , (_intr_)->_field_ );\
			}\
		} else {\
			(_sfoo_) = (_intr_)->_field_;\
			duplicate_str( (_sfoo_) , (_intr_)->_field_ );\
		}\
	}while(0)



static inline int parse_q(str *q, unsigned int *prio)
{
	if (q->s[0]=='0')
		*prio=0;
	else if (q->s[0]=='1')
		*prio=10;
	else
		goto error;
	if (q->s[1]!='.')
		goto error;
	if (q->s[2]<'0' || q->s[2]>'9')
		goto error;
	*prio += q->s[2] - '0';
	if (*prio>10)
		goto error;

	return 0;
error:
	LOG(L_ERR,"ERROR:cpl-c:parse_q:bad q param <%.*s>\n",q->len,q->s);
	return -1;
}



static inline int add_contacts_to_loc_set(struct sip_msg* msg,
													struct location **loc_set)
{
	struct sip_uri uri;
	struct contact *contacts;
	unsigned int prio;

	/* we need to have the contact header */
	if (msg->contact==0) {
		/* find and parse the Contact header */
		if ((parse_headers(msg, HDR_CONTACT, 0)==-1) || (msg->contact==0) ) {
			LOG(L_ERR,"ERROR:cpl-c:add_contacts_to_loc_set: error parsing or "
				"no Contact hdr found!\n");
			goto error;
		}
	}

	/* extract from contact header the all the addresses */
	if (parse_contact( msg->contact )!=0) {
		LOG(L_ERR,"ERROR:cpl-c:add_contacts_to_loc_set: unable to parse "
			"Contact hdr!\n");
		goto error;
	}

	/* in contact hdr, in parsed attr, we should have a list of contacts */
	if ( msg->contact->parsed ) {
		contacts = ((struct contact_body*)msg->contact->parsed)->contacts;
		for( ; contacts ; contacts=contacts->next) {
			/* check if the contact is a valid sip uri */
			if (parse_uri( contacts->uri.s, contacts->uri.len , &uri)!=0) {
				continue;
			}
			/* convert the q param to int value (if any) */
			if (contacts->q) {
				if (parse_q( &(contacts->q->body), &prio )!=0)
					continue;
			} else {
				prio = 10; /* set default to minimum */
			}
			/* add the uri to location set */
			if (add_location( loc_set, &contacts->uri,prio, CPL_LOC_DUPL)!=0) {
				LOG(L_ERR,"ERROR:cpl-c:add_contacts_to_loc_set: unable to add "
				"<%.*s>\n",contacts->uri.len,contacts->uri.s);
			}
		}
	}

	return 0;
error:
	return -1;
}



static void reply_callback( struct cell* t, int type, struct tmcb_params* ps)
{
	struct cpl_interpreter *intr = (struct cpl_interpreter*)(*(ps->param));
	struct location        *loc  = 0;
	int rez;

	if (intr==0) {
		LOG(L_WARN,"WARNING:cpl-c:reply_callback: param=0 for callback %d,"
			" transaction=%p \n",type,t);
		return;
	}

	if (type&TMCB_RESPONSE_OUT) {
		/* the purpose of the final reply is to trash down the interpreter
		 * structure! it's the safest place to do that, since this callback
		 * it's called only once per transaction for final codes (>=200) ;-) */
		if (ps->code>=200) {
			DBG("DEBUG:cpl-c:final_reply: code=%d  -------------->\n"
				" --------------------------> final reply received\n",
			ps->code);
			/* CPL interpretation done, call established -> destroy */
			free_cpl_interpreter( intr );
			/* set to zero the param callback*/
			*(ps->param) = 0;
		}
		return;
	} else if (!type&TMCB_ON_FAILURE) {
		LOG(L_ERR,"BUG:cpl-c:reply_callback: unknown type %d\n",type);
		goto exit;
	}

	DBG("DEBUG:cpl-c:negativ_reply: ------------------------------>\n"
		" ---------------------------------> negativ reply received\n");

	intr->flags |= CPL_PROXY_DONE;
	intr->msg = ps->req;

	/* if it's a redirect-> do I have to added to the location set ? */
	if (intr->proxy.recurse && (ps->code)/100==3) {
		DBG("DEBUG:cpl-c:negativ_reply: recurse level %d processing..\n",
				intr->proxy.recurse);
		intr->proxy.recurse--;
		/* get the locations from the Contact */
		add_contacts_to_loc_set( ps->rpl, &(intr->loc_set));
		switch (intr->proxy.ordering) {
			case SEQUENTIAL_VAL:
				/* update the last_to_proxy to last location from set */
				if (intr->proxy.last_to_proxy==0) {
					/* the pointer went through entire old set -> set it to the
					 * updated set, from the beginning  */
					if (intr->loc_set==0)
						/* the updated set is also empty -> proxy ended */
						break;
					intr->proxy.last_to_proxy = intr->loc_set;
				}
				while(intr->proxy.last_to_proxy->next)
					intr->proxy.last_to_proxy=intr->proxy.last_to_proxy->next;
				break;
			case PARALLEL_VAL:
				/* push the whole new location set to be proxy */
				intr->proxy.last_to_proxy = intr->loc_set;
				break;
			case FIRSTONLY_VAL:
				intr->proxy.last_to_proxy = 0;
				break;
		}
	}

	/* the current proxying failed -> do I have another location to try ?
	 * This applies only for SERIAL forking or if RECURSE is set */
	if (intr->proxy.last_to_proxy) {
		/* continue proxying */
		DBG("DEBUG:cpl-c:failed_reply: resuming proxying....\n");
		switch (intr->proxy.ordering) {
			case PARALLEL_VAL:
				/* I get here only if I got a 3xx and RECURSE in on ->
				 * forward to all location from location set */
				intr->proxy.last_to_proxy = 0;
				cpl_proxy_to_loc_set(intr->msg,&(intr->loc_set),intr->flags );
				break;
			case SEQUENTIAL_VAL:
				/* place a new branch to the next location from loc. set*/
				loc = remove_first_location( &(intr->loc_set) );
				/*print_location_set(intr->loc_set);*/
				/* update (if necessary) the last_to_proxy location  */
				if (intr->proxy.last_to_proxy==loc)
					intr->proxy.last_to_proxy = 0;
				cpl_proxy_to_loc_set(intr->msg,&loc,intr->flags );
				break;
			default:
				LOG(L_CRIT,"BUG:cpl_c:failed_reply: unexpected ordering found "
					"when continuing proxying (%d)\n",intr->proxy.ordering);
				goto exit;
		}
		/* nothing more to be done */
		return;
	} else {
		/* done with proxying.... -> process the final response */
		DBG("DEBUG:cpl-c:failed_reply:final_reply: got a final %d\n",ps->code);
		intr->ip = 0;
		if (ps->code==486 || ps->code==600) {
			/* busy response */
			intr->ip = intr->proxy.busy;
		} else if (ps->code==408) {
			/* request timeout -> no response */
			intr->ip = intr->proxy.noanswer;
		} else if (((ps->code)/100)==3) {
			/* redirection */
			/* add to the location list all the addresses from Contact */
			add_contacts_to_loc_set( ps->rpl, &(intr->loc_set));
			print_location_set( intr->loc_set );
			intr->ip = intr->proxy.redirect;
		} else {
			/* generic failure */
			intr->ip = intr->proxy.failure;
		}

		if (intr->ip==0)
			intr->ip = (intr->proxy.default_)?
				intr->proxy.default_:DEFAULT_ACTION;
		if (intr->ip!=DEFAULT_ACTION)
			intr->ip = get_first_child( intr->ip );