t_msgbuilder.c

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

/*
 * $Id: t_msgbuilder.c,v 1.40 2004/11/09 15:15:12 andrei Exp $
 *
 * message printing
 *
 * 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:
 * ----------
 * 2003-01-27  next baby-step to removing ZT - PRESERVE_ZT (jiri)
 * 2003-02-13  build_uac_request uses proto (andrei)
 * 2003-02-28  scratchpad compatibility abandoned (jiri)
 * 2003-04-14  build_local no longer checks reply status as it
 *             is now called before reply status is updated to
 *             avoid late ACK sending (jiri)
 * 2003-10-02  added via_builder set host/port support (andrei)
 * 2004-02-11  FIFO/CANCEL + alignments (hash=f(callid,cseq)) (uli+jiri)
 * 2004-02-13: t->is_invite and t->local replaced with flags (bogdan)
 */

#include "defs.h"


#include "../../comp_defs.h"
#include "../../hash_func.h"
#include "../../globals.h"
#include "t_funcs.h"
#include "../../dprint.h"
#include "../../config.h"
#include "../../parser/parser_f.h"
#include "../../ut.h"
#include "../../parser/msg_parser.h"
#include "../../parser/contact/parse_contact.h"
#include "t_msgbuilder.h"
#include "uac.h"


#define ROUTE_PREFIX "Route: "
#define ROUTE_PREFIX_LEN (sizeof(ROUTE_PREFIX) - 1)

#define ROUTE_SEPARATOR ", "
#define ROUTE_SEPARATOR_LEN (sizeof(ROUTE_SEPARATOR) - 1)

#define  append_mem_block(_d,_s,_len) \
		do{\
			memcpy((_d),(_s),(_len));\
			(_d) += (_len);\
		}while(0);

#define append_str(_p,_str) \
	do{  \
		memcpy((_p), (_str).s, (_str).len); \
		(_p)+=(_str).len;  \
 	} while(0);

/* Build a local request based on a previous request; main
   customers of this function are local ACK and local CANCEL
 */
char *build_local(struct cell *Trans,unsigned int branch,
	unsigned int *len, char *method, int method_len, str *to)
{
	char                *cancel_buf, *p, *via;
	unsigned int         via_len;
	struct hdr_field    *hdr;
	char branch_buf[MAX_BRANCH_PARAM_LEN];
	int branch_len;
	str branch_str;
	struct hostport hp;

#ifdef _OBSO
	if ( Trans->uac[branch].last_received<100)
	{
		DBG("DEBUG: build_local: no response ever received"
			" : dropping local request! \n");
		goto error;
	}
#endif

	/* method, separators, version: "CANCEL sip:[e-mail] SIP/2.0" */
	*len=SIP_VERSION_LEN + method_len + 2 /* spaces */ + CRLF_LEN;
	*len+=Trans->uac[branch].uri.len;

	/*via*/
	if (!t_calc_branch(Trans,  branch, 
		branch_buf, &branch_len ))
		goto error;
	branch_str.s=branch_buf;
	branch_str.len=branch_len;
	set_hostport(&hp, (is_local(Trans))?0:(Trans->uas.request));
	via=via_builder(&via_len, Trans->uac[branch].request.dst.send_sock,
		&branch_str, 0, Trans->uac[branch].request.dst.proto, &hp );
	if (!via)
	{
		LOG(L_ERR, "ERROR: build_local: "
			"no via header got from builder\n");
		goto error;
	}
	*len+= via_len;
	/*headers*/
	*len+=Trans->from.len+Trans->callid.len+to->len+
		+Trans->cseq_n.len+1+method_len+CRLF_LEN; 


	/* copy'n'paste Route headers */
	if (!is_local(Trans)) {
		for ( hdr=Trans->uas.request->headers ; hdr ; hdr=hdr->next )
			 if (hdr->type==HDR_ROUTE)
				*len+=hdr->len;
	}

	/* User Agent */
	if (server_signature) {
		*len += USER_AGENT_LEN + CRLF_LEN;
	}
	/* Content Length, EoM */
	*len+=CONTENT_LENGTH_LEN+1 + CRLF_LEN + CRLF_LEN;

	cancel_buf=shm_malloc( *len+1 );
	if (!cancel_buf)
	{
		LOG(L_ERR, "ERROR: build_local: cannot allocate memory\n");
		goto error01;
	}
	p = cancel_buf;

	append_mem_block( p, method, method_len );
	append_mem_block( p, " ", 1 );
	append_str( p, Trans->uac[branch].uri );
	append_mem_block( p, " " SIP_VERSION CRLF, 1+SIP_VERSION_LEN+CRLF_LEN );

	/* insert our via */
	append_mem_block(p,via,via_len);

	/*other headers*/
	append_str( p, Trans->from );
	append_str( p, Trans->callid );
	append_str( p, *to );

	append_str( p, Trans->cseq_n );
	append_mem_block( p, " ", 1 );
	append_mem_block( p, method, method_len );
	append_mem_block( p, CRLF, CRLF_LEN );

	if (!is_local(Trans))  {
		for ( hdr=Trans->uas.request->headers ; hdr ; hdr=hdr->next )
			if(hdr->type==HDR_ROUTE) {
				append_mem_block(p, hdr->name.s, hdr->len );
			}
	}

	/* User Agent header */
	if (server_signature) {
		append_mem_block(p,USER_AGENT CRLF, USER_AGENT_LEN+CRLF_LEN );
	}
	/* Content Length, EoM */
	append_mem_block(p, CONTENT_LENGTH "0" CRLF CRLF ,
		CONTENT_LENGTH_LEN+1 + CRLF_LEN + CRLF_LEN);
	*p=0;

	pkg_free(via);
	return cancel_buf;
error01:
	pkg_free(via);
error:
	return NULL;
}


struct rte {
	rr_t* ptr;
	struct rte* next;
};

  	 
static inline void free_rte_list(struct rte* list)
{
	struct rte* ptr;
	
	while(list) {
		ptr = list;
		list = list->next;
		pkg_free(ptr);
	}
}


static inline int process_routeset(struct sip_msg* msg, str* contact, struct rte** list, str* ruri, str* next_hop)
{
	struct hdr_field* ptr;
	rr_t* p;
	struct rte* t, *head;
	struct sip_uri puri;
	
	ptr = msg->record_route;
	head = 0;
	while(ptr) {
		if (ptr->type == HDR_RECORDROUTE) {
			if (parse_rr(ptr) < 0) {
				LOG(L_ERR, "process_routeset: Error while parsing Record-Route header\n");
				return -1;
			}
			
			p = (rr_t*)ptr->parsed;
			while(p) {
				t = (struct rte*)pkg_malloc(sizeof(struct rte));
				if (!t) {
					LOG(L_ERR, "process_routeset: No memory left\n");
					free_rte_list(head);
					return -1;
				}
				t->ptr = p;
				t->next = head;
				head = t;
				p = p->next;
			}
		}
		ptr = ptr->next;
	}
	
	if (head) {
		if (parse_uri(head->ptr->nameaddr.uri.s, head->ptr->nameaddr.uri.len, &puri) == -1) {
			LOG(L_ERR, "process_routeset: Error while parsing URI\n");
			free_rte_list(head);
			return -1;
		}
		
		if (puri.lr.s) {
			     /* Next hop is loose router */
			*ruri = *contact;
			*next_hop = head->ptr->nameaddr.uri;
		} else {
			     /* Next hop is strict router */
			*ruri = head->ptr->nameaddr.uri;
			*next_hop = *ruri;
			t = head;
			head = head->next;
			pkg_free(t);
		}
	} else {
		     /* No routes */
		*ruri = *contact;
		*next_hop = *contact;
	}
	
	*list = head;
	return 0;
}


static inline int calc_routeset_len(struct rte* list, str* contact)
{
	struct rte* ptr;
	int ret;
	
	if (list || contact) {
		ret = ROUTE_PREFIX_LEN + CRLF_LEN;
	} else {
		return 0;
	}
	
	ptr = list;
	while(ptr) {
		if (ptr != list) {
			ret += ROUTE_SEPARATOR_LEN;
		}
		ret += ptr->ptr->len;
		ptr = ptr->next;
	}
	
	if (contact) {
		if (list) ret += ROUTE_SEPARATOR_LEN;
		ret += 2 + contact->len;
	}
	
	return ret;
}


     /*
      * Print the route set
      */
static inline char* print_rs(char* p, struct rte* list, str* contact)
{
	struct rte* ptr;
	
	if (list || contact) {
		memapp(p, ROUTE_PREFIX, ROUTE_PREFIX_LEN);
	} else {
		return p;
	}
	
	ptr = list;
	while(ptr) {
		if (ptr != list) {
			memapp(p, ROUTE_SEPARATOR, ROUTE_SEPARATOR_LEN);
		}
		
		memapp(p, ptr->ptr->nameaddr.name.s, ptr->ptr->len);
		ptr = ptr->next;
	}
	
	if (contact) {
		if (list) memapp(p, ROUTE_SEPARATOR, ROUTE_SEPARATOR_LEN);
		*p++ = '<';
		append_str(p, *contact);
		*p++ = '>';
	}
	
	memapp(p, CRLF, CRLF_LEN);
	return p;
}


     /*
      * Parse Contact header field body and extract URI
      * Does not parse headers !
      */
static inline int get_contact_uri(struct sip_msg* msg, str* uri)
{
	contact_t* c;
	
	uri->len = 0;
	if (!msg->contact) return 1;
	
	if (parse_contact(msg->contact) < 0) {
		LOG(L_ERR, "get_contact_uri: Error while parsing Contact body\n");
		return -1;
	}
	
	c = ((contact_body_t*)msg->contact->parsed)->contacts;
	
	if (!c) {
		LOG(L_ERR, "get_contact_uri: Empty body or * contact\n");
		return -2;
	}
	
	*uri = c->uri;
	return 0;
}



     /*
      * The function creates an ACK to 200 OK. Route set will be created
      * and parsed and next_hop parameter will contain uri the which the
      * request should be send. The function is used by tm when it generates
      * local ACK to 200 OK (on behalf of applications using uac
      */
char *build_dlg_ack(struct sip_msg* rpl, struct cell *Trans, unsigned int branch,
		    str* to, unsigned int *len, str *next_hop)
{
	char *req_buf, *p, *via;
	unsigned int via_len;
	char branch_buf[MAX_BRANCH_PARAM_LEN];
	int branch_len;
	str branch_str;
	struct hostport hp;
	struct rte* list;
	str contact, ruri, *cont;
	struct socket_info* send_sock;
	union sockaddr_union to_su;
	
	if (get_contact_uri(rpl, &contact) < 0) {
		return 0;
	}
	
	if (process_routeset(rpl, &contact, &list, &ruri, next_hop) < 0) {