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/*-
* Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
* Redistribution and modifications are permitted subject to BSD license.
*/
/*
* This file contains the declaration structure called "ASN.1 Type Definition",
* which holds all information necessary for encoding and decoding routines.
* This structure even contains pointer to these encoding and decoding routines
* for each defined ASN.1 type.
*/
#ifndef _CONSTR_TYPE_H
#define _CONSTR_TYPE_H
#include <ber_tlv_length.h>
#include <ber_tlv_tag.h>
struct asn_TYPE_descriptor_s; /* Forward declaration */
struct asn_TYPE_member_s; /* Forward declaration */
/*
* This type provides the context information for various ASN.1 routines,
* primarily ones doing decoding. A member _asn_ctx of this type must be
* included into certain target language's structures, such as compound types.
*/
typedef struct asn_struct_ctx_s {
int phase; /* Decoding phase */
int step; /* Elementary step of a phase */
ber_tlv_len_t left; /* Number of bytes left, -1 for indefinite */
void *ptr; /* Decoder-specific stuff (stack elements) */
} asn_struct_ctx_t;
/*
* This structure defines a context 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!
*/
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 __er = { -1, td, sptr }; \
return __er; \
} while(0)
#include <ber_decoder.h>
#include <der_encoder.h>
#include <xer_encoder.h>
#include <constraints.h>
/*
* Free the structure according to its specification.
* If (free_contents_only) is set, the wrapper structure itself (struct_ptr)
* will not be freed. (It may be useful in case the structure is allocated
* statically or arranged on the stack, yet its elements are allocated
* dynamically.)
*/
typedef void (asn_struct_free_f)(
struct asn_TYPE_descriptor_s *type_descriptor,
void *struct_ptr, int free_contents_only);
/*
* Print the structure according to its specification.
*/
typedef int (asn_struct_print_f)(
struct asn_TYPE_descriptor_s *type_descriptor,
const void *struct_ptr,
int level, /* Indentation level */
asn_app_consume_bytes_f *callback, void *app_key);
/*
* Return the outmost tag of the type.
* If the type is untagged CHOICE, the dynamic operation is performed.
* NOTE: This function pointer type is only useful internally.
* Do not use it in your application.
*/
typedef ber_tlv_tag_t (asn_outmost_tag_f)(
struct asn_TYPE_descriptor_s *type_descriptor,
const void *struct_ptr, int tag_mode, ber_tlv_tag_t tag);
/* The instance of the above function type; used internally. */
asn_outmost_tag_f asn_TYPE_outmost_tag;
/*
* The definitive description of the destination language's structure.
*/
typedef struct asn_TYPE_descriptor_s {
char *name; /* A name of the ASN.1 type */
/*
* Generalized functions for dealing with the specific type.
* May be directly invoked by applications.
*/
asn_struct_free_f *free_struct; /* Free the structure */
asn_struct_print_f *print_struct; /* Human readable output */
asn_constr_check_f *check_constraints; /* Constraints validator */
ber_type_decoder_f *ber_decoder; /* Free-form BER decoder */
der_type_encoder_f *der_encoder; /* Canonical DER encoder */
int (*xer_decoder);/* PLACEHOLDER */ /* Free-form XER decoder */
xer_type_encoder_f *xer_encoder; /* [Canonical] XER encoder */
/*
* Functions used internally. Should not be used by applications.
*/
asn_outmost_tag_f *outmost_tag; /* <optional, internal> */
/*
* Tags that are expected to occur.
*/
ber_tlv_tag_t *tags; /* Effective tags sequence for this type */
int tags_count; /* Number of tags which are expected */
ber_tlv_tag_t *all_tags;/* Every tag for BER/containment */
int all_tags_count; /* Number of tags */
/*
* An ASN.1 production type members (members of SEQUENCE, SET, CHOICE).
*/
struct asn_TYPE_member_s *elements;
int elements_count;
/*
* Additional information describing the type, used by appropriate
* functions above.
*/
void *specifics;
} asn_TYPE_descriptor_t;
/*
* This type describes an element of the constructed type,
* i.e. SEQUENCE, SET, CHOICE, etc.
*/
enum asn_TYPE_flags_e {
ATF_NOFLAGS,
ATF_POINTER = 0x01, /* Represented by the pointer */
ATF_OPEN_TYPE = 0x02 /* ANY type, without meaningful tag */
};
typedef struct asn_TYPE_member_s {
enum asn_TYPE_flags_e flags; /* Element's presentation flags */
int optional; /* Following optional members, including current */
int memb_offset; /* Offset of the element */
ber_tlv_tag_t tag; /* Outmost (most immediate) tag */
int tag_mode; /* IMPLICIT/no/EXPLICIT tag at current level */
asn_TYPE_descriptor_t *type; /* Member type descriptor */
asn_constr_check_f *memb_constraints; /* Constraints validator */
char *name; /* ASN.1 identifier of the element */
} asn_TYPE_member_t;
/*
* BER tag to element number mapping.
*/
typedef struct asn_TYPE_tag2member_s {
ber_tlv_tag_t el_tag; /* Outmost tag of the member */
int el_no; /* Index of the associated member, base 0 */
int toff_first; /* First occurence of the el_tag, relative */
int toff_last; /* Last occurence of the el_tag, relatvie */
} asn_TYPE_tag2member_t;
/*
* This function is a wrapper around (td)->print_struct, which prints out
* the contents of the target language's structure (struct_ptr) into the
* file pointer (stream) in human readable form.
* RETURN VALUES:
* 0: The structure is printed.
* -1: Problem dumping the structure.
* (See also xer_fprint() in xer_encoder.h)
*/
int asn_fprint(FILE *stream, /* Destination stream descriptor */
asn_TYPE_descriptor_t *td, /* ASN.1 type descriptor */
const void *struct_ptr); /* Structure to be printed */
#endif /* _CONSTR_TYPE_H_ */
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