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/*
* Copyright (c) 2003-2017 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 */
const struct asn_TYPE_descriptor_s *failed_type;
/* Pointer to the structure of that type */
const 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 */