from.c

性能优秀的SIP Proxy

/*
 * $Id: from.c,v 1.12 2006/04/10 12:53:47 bogdan_iancu Exp $
 *
 * Copyright (C) 2005 Voice Sistem SRL
 *
 * This file is part of openser, a free SIP server.
 *
 * UAC OpenSER-module 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.
 *
 * UAC OpenSER-module 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:
 * ---------
 *  2005-01-31  first version (ramona)
 *  2005-08-12  encoded old FROM URI stored in RR hdr and not in FROM anymore;
 *              some TM callbacks replaced with RR callback - more efficient;
 *              XOR used to mix together old and new URI
 *              (bogdan)
 *  2006-03-03  new display name is added even if there is no previous one
 *              (bogdan)
 *  2006-03-03  the RR parameter is encrypted via XOR with a password
 *              (bogdan)
 */


#include <ctype.h>

#include "../../parser/parse_from.h"
#include "../../mem/mem.h"
#include "../../data_lump.h"
#include "../tm/h_table.h"
#include "../tm/tm_load.h"
#include "../rr/api.h"

#include "from.h"

extern str rr_param;
extern str uac_passwd;
extern int from_restore_mode;
extern struct tm_binds uac_tmb;
extern struct rr_binds uac_rrb;

static char enc_table64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
		"abcdefghijklmnopqrstuvwxyz0123456789+/";

static int dec_table64[256];

static void restore_from_reply(struct cell* t, int type, struct tmcb_params *p);
static void restore_to_reply(struct cell* t, int type, struct tmcb_params *p);

#define text3B64_len(_l)   ( ( ((_l)+2)/3 ) << 2 )


void init_from_replacer()
{
	int i;

	for( i=0 ; i<256 ; i++)
		dec_table64[i] = -1;
	for ( i=0 ; i<64; i++)
		dec_table64[(unsigned char)enc_table64[i]] = i;
	}


static inline int encode_from( str *src, str *dst )
{
	static char buf[text3B64_len(MAX_URI_SIZE)];
	int  idx;
	int  left;
	int  block;
	int  i,r;
	char *p;

	dst->len = text3B64_len( src->len );
	dst->s = buf;
	if (dst->len>text3B64_len(MAX_URI_SIZE))
	{
		LOG(L_ERR,"ERROR:uac:encode_from: uri too long\n");
		return -1;
	}

	for ( idx=0, p=buf ; idx<src->len ; idx+=3)
	{
		left = src->len - idx -1 ;
		left = (left>1? 2 : left);

		/* Collect 1 to 3 bytes to encode */
		block = 0;
		for ( i=0,r= 16 ; i<=left ; i++,r-=8 )
		{
			block += ((unsigned char)src->s[idx+i]) << r;
		}

		/* Encode into 2-4 chars appending '=' if not enough data left.*/
		*(p++) = enc_table64[(block >> 18) & 0x3f];
		*(p++) = enc_table64[(block >> 12) & 0x3f];
		*(p++) = left > 0 ? enc_table64[(block >> 6) & 0x3f] : '-';
		*(p++) = left > 1 ? enc_table64[block & 0x3f] : '-';
	}

	return 0;
}


static inline int decode_from( str *src , str *dst)
{
	static char buf[MAX_URI_SIZE];
	int block;
	int n;
	int idx;
	int end;
	int i,j;
	char c;

	/* Count '-' at end and disregard them */
	for( n=0,i=src->len-1; src->s[i]=='-'; i--)
		n++;

	dst->len = ((src->len * 6) >> 3) - n;
	dst->s = buf;
	if (dst->len>MAX_URI_SIZE)
	{
		LOG(L_ERR,"ERROR:uac:decode_from: uri too long\n");
		return -1;
	}

	end = src->len - n;
	for ( i=0,idx=0 ; i<end ; idx+=3 )
	{
		/* Assemble three bytes into an int from four "valid" characters */
		block = 0;
		for ( j=0; j<4 && i<end ; j++)
		{
			c = dec_table64[(unsigned char)src->s[i++]];
			if ( c<0 )
			{
				LOG(L_ERR,"ERROR:uac:decode_from: invalid base64 string "
					"\"%.*s\"\n",src->len,src->s);
				return -1;
			}
			block += c << (18 - 6*j);
		}

		/* Add the bytes */
		for ( j=0,n=16 ; j<3 && idx+j< dst->len; j++,n-=8 )
			buf[idx+j] = (char) ((block >> n) & 0xff);
	}

	return 0;
}


static inline struct lump* get_fdisplay_anchor(struct sip_msg *msg,
												struct to_body *from, str *dsp)
{
	struct lump* l;
	char *p1;
	char *p2;

	/* is URI quoted or not? */
	p1 = msg->from->name.s + msg->from->name.len;
	for( p2=from->uri.s-1 ; p2>=p1 && *p2!='<' ; p2--);

	if (*p2=='<') {
		/* is quoted */
		l = anchor_lump( msg, p2 - msg->buf, 0, 0);
		if (l==0) {
			LOG(L_ERR,"ERROR:uac:get_fdisplay_anchor: unable to build lump "
				"anchor\n");
			return 0;
		}
		dsp->s[dsp->len++] = ' ';
		return l;
	}

	/* not quoted - more complicated....must place the closing bracket */
	l = anchor_lump( msg, (from->uri.s+from->uri.len) - msg->buf, 0, 0);
	if (l==0) {
		LOG(L_ERR,"ERROR:uac:get_fdisplay_anchor: unable to build lump "
			"anchor\n");
		return 0;
	}
	p1 = (char*)pkg_malloc(1);
	if (p1==0) {
		LOG(L_ERR,"ERROR:uac:get_fdisplay_anchor: no more pkg mem \n");
		return 0;
	}
	*p1 = '>';
	if (insert_new_lump_after( l, p1, 1, 0)==0) {
		LOG(L_ERR,"ERROR:uac:get_fdisplay_anchor: insert lump failed\n");
		pkg_free(p1);
		return 0;
	}
	/* build anchor for display */
	l = anchor_lump( msg, from->uri.s - msg->buf, 0, 0);
	if (l==0) {
		LOG(L_ERR,"ERROR:uac:get_fdisplay_anchor: unable to build lump "
			"anchor\n");
		return 0;
	}
	dsp->s[dsp->len++] = ' ';
	dsp->s[dsp->len++] = '<';
	return l;
}


/*
 * relace from uri and/or from display name
 */
int replace_from( struct sip_msg *msg, str *from_dsp, str *from_uri)
{
	static char buf_s[MAX_URI_SIZE];
	struct to_body *from;
	struct lump* l;
	str replace;
	char *p;
	str param;
	str buf;
	int i;

	/* consistency check! in AUTO mode, do NOT allow FROM changing
	 * in sequential request */
	if (from_restore_mode==FROM_AUTO_RESTORE && from_uri && from_uri->len) {
		if ( msg->to==0 && (parse_headers(msg,HDR_TO_F,0)!=0 || msg->to==0) ) {
			LOG(L_ERR,"ERROR:uac:replace_from: failed to parse TO hdr\n");
			goto error;
		}
		if (get_to(msg)->tag_value.len!=0) {
			LOG(L_ERR,"ERROR:uac:replace_from: decline FROM replacing in "
				"sequential request in auto mode (has TO tag)\n");
			goto error;
		}
	}

	/* parse original from hdr */
	if (parse_from_header(msg)<0 )
	{
		LOG(L_ERR,"ERROR:uac:replace_from: failed to find/parse FROM hdr\n");
		goto error;
	}
	from = (struct to_body*)msg->from->parsed;
	/* some validity checks */
	if (from->param_lst==0)
	{
		LOG(L_ERR,"ERROR:uac:replace_from: broken FROM hdr; no tag param\n");
		goto error;
	}

	/* first deal with display name */
	if (from_dsp)
	{
		/* must be replaced/ removed */
		l = 0;
		/* first remove the existing display */
		if ( from->display.len)
		{
			DBG("DEBUG:uac:replace_from: removing display [%.*s]\n",
				from->display.len,from->display.s);
			/* build del lump */
			l = del_lump( msg, from->display.s-msg->buf, from->display.len, 0);
			if (l==0)
			{
				LOG(L_ERR,"ERROR:uac:replace_from: display del lump failed\n");
				goto error;
			}
		}
		/* some new display to set? */
		if (from_dsp->len)
		{
			/* add the new display exactly over the deleted one */
			buf.s = pkg_malloc( from_dsp->len + 2 );
			if (buf.s==0)
			{
				LOG(L_ERR,"ERROR:uac:replace_from: no more pkg mem\n");
				goto error;
			}
			memcpy( buf.s, from_dsp->s, from_dsp->len);
			buf.len =  from_dsp->len;
			if (l==0 && (l=get_fdisplay_anchor(msg,from,&buf))==0)
			{
				LOG(L_ERR,"ERROR:uac:replace_from: failed to insert anchor\n");
				goto error;
			}
			if (insert_new_lump_after( l, buf.s, buf.len, 0)==0)
			{
				LOG(L_ERR,"ERROR:uac:replace_from: insert new "
					"display lump failed\n");
				pkg_free(buf.s);
				goto error;
			}
		}
	}

	/* now handle the URI */
	if (from_uri==0 || from_uri->len==0 )
		/* do not touch URI part */
		return 0;

	DBG("DEBUG:uac:replace_from: uri to replace [%.*s]\n",
		from->uri.len, from->uri.s);
	DBG("DEBUG:uac:replace_from: replacement uri is [%.*s]\n",
		from_uri->len, from_uri->s);

	/* build del/add lumps */
	if ((l=del_lump( msg, from->uri.s-msg->buf, from->uri.len, 0))==0)
	{
		LOG(L_ERR,"ERROR:uac:replace_from: del lump failed\n");
		goto error;
	}
	p = pkg_malloc( from_uri->len);