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/** BEGIN COPYRIGHT BLOCK
* Copyright (C) 2001 Sun Microsystems, Inc. Used by permission.
* Copyright (C) 2005 Red Hat, Inc.
* All rights reserved.
* END COPYRIGHT BLOCK **/
#ifndef __attrec_h
#define __attrec_h
/*
* Description (attrec.h)
*
* This file describes the encoding and decoding of attribute
* records. Attribute records consist of a sequence of items
* of the form:
*
* <tag><length><contents>
*
* The <tag> is an integer code which identifies a particular
* attribute. The <length> is the integer length in bytes of
* the <contents>. The encoding of the contents is determined
* by the <tag>, and is application-specific.
*
* Primitive data types currently supported are unsigned
* integers (USI) and null-terminated strings (NTS). The
* encoding of USI values less than 128 is simply an octet
* containing the value. For values 128 or greater, the first
* octet is 0x80 plus the length of the value, in octets.
* This octet is followed by the indicated number of octets,
* containing the USI value, with the most significant bits in
* the first octet, and the least significant bits in the last
* octet.
*
* Examples of USI encoding:
*
* Value Encoding (each value is an octet)
* 4 0x04
* 127 0x7f
* -1 (this is not a USI)
* 128 0x81 0x80
* 1023 0x82 0x03 0xff
*
* The encoding of a null-terminated string (NTS) is simply the
* sequence of octets which comprise the string, including the
* terminating null (0x00) octet. The terminating null octet is
* the only null value in the string. The character set used to
* encode the other string octets is ASCII.
*/
#include "usi.h"
NSPR_BEGIN_EXTERN_C
/* Define a type to reference an attribute record */
typedef unsigned char * ATR_t;
/*
* Description (USILENGTH)
*
* This macro returns the length of the USI encoding for a specified
* unsigned integer value. The length is the number of octets
* required. It will be greater than zero, and less than or equal
* to USIALLOC(). This is a partial inline optimization of
* USI_Length().
*/
#define USILENGTH(val) (((USI_t)(val) <= 0x7f) ? 1 : USI_Length((USI_t)(val)))
/*
* Description (USIALLOC)
*
* This macro returns the maximum length of an unsigned integer
* encoding.
*/
#define USIALLOC() (5)
/*
* Description (USIENCODE)
*
* This macro encodes a USI value into a specified buffer. It
* returns a pointer to the first octet after the encoding.
* This is a partial inline optimization for USI_Encode().
*/
#define USIENCODE(cp, val) (((USI_t)(val) <= 0x7f) ? (*(cp) = (val), (cp)+1) \
: USI_Encode((cp), (val)))
/*
* Description (USIINSERT)
*
* This macro performs a variation of USIENCODE which always
* generates the maximum-sized USI encoding, i.e. the number of
* octets indicated by USIALLOC().
*/
#define USIINSERT(cp, val) USI_Insert((ATR_t)(cp), (USI_t)(val))
/*
* Description (USIDECODE)
*
* This macro decodes a USI value from a specified buffer. It
* returns a pointer to the first octet after the encoding.
* This is a partial inline optimization for USI_Decode().
*/
#define USIDECODE(cp, pval) \
((*(cp) & 0x80) ? USI_Decode((cp), (pval)) \
: (((pval) ? (*(pval) = *(cp)) : 0), (cp)+1))
/* Define a type to reference a null-terminated string */
typedef unsigned char * NTS_t;
/*
* Decription (NTSLENGTH)
*
* Return the length, in octets, of a null-terminated string.
* It includes the terminating null octet.
*/
#define NTSLENGTH(nts) ((nts) ? strlen((char *)(nts)) + 1 : 1)
/*
* Description (NTSENCODE)
*
* This macro copies a null-terminated string to a specified
* attribute record buffer. It returns a pointer to the octet
* following the NTS in the buffer.
*/
#define NTSENCODE(cp, nts) \
((ATR_t)memccpy((void *)(cp), \
(void *)((nts) ? (NTS_t)(nts) : (NTS_t)""), \
0, NTSLENGTH(nts)))
/*
* Description (NTSDECODE)
*
* This macro decodes a null-terminated string in a specified
* attribute record buffer into a dynamically allocated buffer.
* It returns a pointer to the first octet after the NTS in the
* attribute record buffer.
*/
#define NTSDECODE(cp, pnts) NTS_Decode((cp), (pnts))
/* Functions in attrec.c */
extern int NTS_Length(NTS_t ntsp);
extern ATR_t NTS_Decode(ATR_t cp, NTS_t * pnts);
extern ATR_t NTS_Encode(ATR_t cp, NTS_t nts);
extern ATR_t USI_Decode(ATR_t cp, USI_t * pval);
extern ATR_t USI_Encode(ATR_t cp, USI_t val);
extern ATR_t USI_Insert(ATR_t cp, USI_t val);
extern int USI_Length(USI_t val);
NSPR_END_EXTERN_C
#endif /* __attrec_h */
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