/*-

 * Copyright (c) 2003, 2004, 2005 Lev Walkin <vlm@lionet.info>.

 * All rights reserved.

 * Redistribution and modifications are permitted subject to BSD license.

 */

#ifndef	_ASN_CODECS_H_

#define	_ASN_CODECS_H_

#ifdef __cplusplus

extern "C" {

#endif

struct asn_TYPE_descriptor_s;	/* Forward declaration */

/*

 * This structure defines a set of parameters that may be passed

 * to every ASN.1 encoder or decoder function.

 * WARNING: if max_stack_size member is set, and you are calling the

 *   function pointers of the asn_TYPE_descriptor_t directly,

 *   this structure must be ALLOCATED ON THE STACK!

 *   If you can't always satisfy this requirement, use ber_decode(),

 *   xer_decode() and uper_decode() functions instead.

 */

typedef struct asn_codec_ctx_s {

	/*

	 * Limit the decoder routines to use no (much) more stack than a given

	 * number of bytes. Most of decoders are stack-based, and this

	 * would protect against stack overflows if the number of nested

	 * encodings is high.

	 * The OCTET STRING, BIT STRING and ANY BER decoders are heap-based,

	 * and are safe from this kind of overflow.

	 * A value from getrlimit(RLIMIT_STACK) may be used to initialize

	 * this variable. Be careful in multithreaded environments, as the

	 * stack size is rather limited.

	 */

	size_t  max_stack_size; /* 0 disables stack bounds checking */

} asn_codec_ctx_t;

/*

 * Type of the return value of the encoding functions (der_encode, xer_encode).

 */

typedef struct asn_enc_rval_s {

	/*

	 * Number of bytes encoded.

	 * -1 indicates failure to encode the structure.

	 * In this case, the members below this one are meaningful.

	 */

	ssize_t encoded;

	/*

	 * Members meaningful when (encoded == -1), for post mortem analysis.

	 */

	/* Type which cannot be encoded */

	struct asn_TYPE_descriptor_s *failed_type;

	/* Pointer to the structure of that type */

	void *structure_ptr;

} asn_enc_rval_t;

#define	_ASN_ENCODE_FAILED do {					\

	asn_enc_rval_t tmp_error;				\

	tmp_error.encoded = -1;					\

	tmp_error.failed_type = td;				\

	tmp_error.structure_ptr = sptr;				\

	ASN_DEBUG("Failed to encode element %s", td ? td->name : "");	\

	return tmp_error;					\

} while(0)

#define	_ASN_ENCODED_OK(rval) do {				\

	rval.structure_ptr = 0;					\

	rval.failed_type = 0;					\

	return rval;						\

} while(0)

/*

 * Type of the return value of the decoding functions (ber_decode, xer_decode)

 * 

 * Please note that the number of consumed bytes is ALWAYS meaningful,

 * even if code==RC_FAIL. This is to indicate the number of successfully

 * decoded bytes, hence providing a possibility to fail with more diagnostics

 * (i.e., print the offending remainder of the buffer).

 */

enum asn_dec_rval_code_e {

	RC_OK,		/* Decoded successfully */

	RC_WMORE,	/* More data expected, call again */

	RC_FAIL		/* Failure to decode data */

};

typedef struct asn_dec_rval_s {

	enum asn_dec_rval_code_e code;	/* Result code */

	size_t consumed;		/* Number of bytes consumed */

} asn_dec_rval_t;

#define	_ASN_DECODE_FAILED do {					\

	asn_dec_rval_t tmp_error;				\

	tmp_error.code = RC_FAIL;				\

	tmp_error.consumed = 0;					\

	ASN_DEBUG("Failed to decode element %s", td ? td->name : "");	\

	return tmp_error;					\

} while(0)

#define	_ASN_DECODE_STARVED do {				\

	asn_dec_rval_t tmp_error;				\

	tmp_error.code = RC_WMORE;				\

	tmp_error.consumed = 0;					\

	return tmp_error;					\

} while(0)

#ifdef __cplusplus

}

#endif

#endif	/* _ASN_CODECS_H_ */