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Diffstat (limited to 'include/libaccess/attrec.h')
| -rw-r--r-- | include/libaccess/attrec.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/include/libaccess/attrec.h b/include/libaccess/attrec.h new file mode 100644 index 00000000..267c32ff --- /dev/null +++ b/include/libaccess/attrec.h @@ -0,0 +1,157 @@ +/** BEGIN COPYRIGHT BLOCK + * Copyright 2001 Sun Microsystems, Inc. + * Portions copyright 1999, 2001-2003 Netscape Communications Corporation. + * 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 */ |