kamailio/ut.h

/*
 *$Id$
 *
 * - various general purpose functions
 *
 * 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:
 *    [email protected]
 *
 * 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
 * ------
 * 2003-01-18 un_escape function introduced for convenience of code needing
 *            the complex&slow feature of unescaping
 */


#ifndef ut_h
#define ut_h


#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>


#include "dprint.h"
#include "str.h"


struct sip_msg;

/* returns string beginning and length without insignificant chars */
#define trim_len( _len, _begin, _mystr ) \
	do{ 	static char _c; \
		(_len)=(_mystr).len; \
		while ((_len) && ((_c=(_mystr).s[(_len)-1])==0 || _c=='\r' || \
					_c=='\n' || _c==' ' || _c=='\t' )) \
			(_len)--; \
		(_begin)=(_mystr).s; \
		while ((_len) && ((_c=*(_begin))==' ' || _c=='\t')) { \
			(_len)--;\
			(_begin)++; \
		} \
	}while(0)

#define trim_r( _mystr ) \
	do{	static char _c; \
		while( ((_mystr).len) && ( ((_c=(_mystr).s[(_mystr).len-1]))==0 ||\
									_c=='\r' || _c=='\n' ) \
				) \
			(_mystr).len--; \
	}while(0)


#define  translate_pointer( _new_buf , _org_buf , _p) \
	( (_p)?(_new_buf + (_p-_org_buf)):(0) )

#define via_len(_via) \
	((_via)->bsize-((_via)->name.s-\
		((_via)->hdr.s+(_via)->hdr.len)))

#define via_s(_via,_p_msg) \
	translate_pointer((_p_msg)->orig,(_p_msg)->buf,(_via)->name.s)


/* char to hex conversion table */
static char fourbits2char[16] = { '0', '1', '2', '3', '4', '5',
	'6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };


/* converts a str to an u. short, returns the u. short and sets *err on
 * error and if err!=null
  */
static inline unsigned short str2s(unsigned char* str, unsigned int len,
									int *err)
{
	unsigned short ret;
	int i;
	unsigned char *limit;
	unsigned char *init;

	/*init*/
	ret=i=0;
	limit=str+len;
	init=str;

	for(;str<limit ;str++){
		if ( (*str <= '9' ) && (*str >= '0') ){
				ret=ret*10+*str-'0';
				i++;
				if (i>5) goto error_digits;
		}else{
				//error unknown char
				goto error_char;
		}
	}
	if (err) *err=0;
	return ret;

error_digits:
	DBG("str2s: ERROR: too many letters in [%.*s]\n", (int)len, init);
	if (err) *err=1;
	return 0;
error_char:
	DBG("str2s: ERROR: unexpected char %c in %.*s\n", *str, (int)len, init);
	if (err) *err=1;
	return 0;
}



static inline int btostr( char *p,  unsigned char val)
{
	unsigned int a,b,i =0;

	if ( (a=val/100)!=0 )
		*(p+(i++)) = a+'0';         /*first digit*/
	if ( (b=val%100/10)!=0 || a)
		*(p+(i++)) = b+'0';        /*second digit*/
	*(p+(i++)) = '0'+val%10;              /*third digit*/

	return i;
}



/* faster memchr version */
static inline char* q_memchr(char* p, int c, unsigned int size)
{
	char* end;

	end=p+size;
	for(;p<end;p++){
		if (*p==(unsigned char)c) return p;
	}
	return 0;
}
	

inline static int reverse_hex2int( char *c, int len )
{
	char *pc;
	int r;
	char mychar;

	r=0;
	for (pc=c+len-1; len>0; pc--, len--) {
		r <<= 4 ;
		mychar=*pc;
		if ( mychar >='0' && mychar <='9') r+=mychar -'0';
		else if (mychar >='a' && mychar <='f') r+=mychar -'a'+10;
		else if (mychar  >='A' && mychar <='F') r+=mychar -'A'+10;
		else return -1;
	}
	return r;
}

inline static int int2reverse_hex( char **c, int *size, int nr )
{
	unsigned short digit;

	if (*size && nr==0) {
		**c = '0';
		(*c)++;
		(*size)--;
		return 1;
	}

	while (*size && nr ) {
		digit = nr & 0xf ;
		**c= digit >= 10 ? digit + 'a' - 10 : digit + '0';
		nr >>= 4;
		(*c)++;
		(*size)--;
	}
	return nr ? -1 /* number not processed; too little space */ : 1;
}

/* double output length assumed ; does NOT zero-terminate */
inline static int string2hex( 
	/* input */ unsigned char *str, int len,
	/* output */ char *hex )
{
	int orig_len;

	if (len==0) {
		*hex='0';
		return 1;
	}

	orig_len=len;
	while ( len ) {

		*hex=fourbits2char[(*str) >> 4];
		hex++;
		*hex=fourbits2char[(*str) & 0xf];
		hex++;
		len--;
		str++;

	}
	return orig_len-len;
}

/* portable sleep in microseconds (no interrupt handling now) */

inline static void sleep_us( unsigned int nusecs )
{
	struct timeval tval;
	tval.tv_sec=nusecs/100000;
	tval.tv_usec=nusecs%1000000;
	select(0, NULL, NULL, NULL, &tval );
}

inline static int hex2int(char hex_digit)
{
	if (hex_digit>='0' && hex_digit<='9')
		return hex_digit-'0';
	if (hex_digit>='a' && hex_digit<='f')
		return hex_digit-'a'+10;
	if (hex_digit>='A' && hex_digit<='F')
		return hex_digit-'A'+10;
	/* no valid hex digit ... */
	LOG(L_ERR, "ERROR: hex2int: '%c' is no hex char\n", hex_digit );
	return -1;
}

/* Un-escape URI user  -- it takes a pointer to original user
   str, as well as the new, unescaped one, which MUST have
   an allocated buffer linked to the 'str' structure ;
   (the buffer can be allocated with the same length as
   the original string -- the output string is always
   shorter (if escaped characters occur) or same-long
   as the original one).

   only printeable characters are permitted

	<0 is returned on an uneascaping error, length of the
	unescaped string otherwise
*/
inline static int un_escape(str *user, str *new_user ) 
{
 	int i, j, value;
	int hi, lo;

	if( new_user==0 || new_user->s==0) {
		LOG(L_CRIT, "BUG: un_escape: called with invalid param\n");
		return -1;
	}

	new_user->len = 0;
	j = 0;

	for (i = 0; i < user->len; i++) {
		if (user->s[i] == '%') {
			if (i + 2 >= user->len) {
				LOG(L_ERR, "ERROR: un_escape: escape sequence too short in"
					" '%.*s' @ %d\n",
					user->len, user->s, i );
				goto error;
			}
			hi=hex2int(user->s[i + 1]);
			if (hi<0) {
				LOG(L_ERR, "ERROR: un_escape: non-hex high digit in an escape sequence in"
					" '%.*s' @ %d\n",
					user->len, user->s, i+1 );
				goto error;
			}
			lo=hex2int(user->s[i + 2]);
			if (lo<0) {
				LOG(L_ERR, "ERROR: non-hex low digit in an escape sequence in "
					"'%.*s' @ %d\n",
					user->len, user->s, i+2 );
				goto error;
			}
			value=(hi<<4)+lo;
			if (value < 32 || value > 126) {
				LOG(L_ERR, "ERROR: non-ASCII escaped character in '%.*s' @ %d\n",
					user->len, user->s, i );
				goto error;
			}
			new_user->s[j] = value;
			i+=2; /* consume the two hex digits, for cycle will move to the next char */
		} else {
			new_user->s[j] = user->s[i];
		}
        j++; /* good -- we translated another character */
	}
	new_user->len = j;
	return j;

error:
	new_user->len = j;
	return -1;
} 

#endif