e2sim/ASN1c/asn_codecs.h

   1 /*****************************************************************************
   2 #                                                                            *
   3 # Copyright 2019 AT&T Intellectual Property                                  *
   4 #                                                                            *
   5 # Licensed under the Apache License, Version 2.0 (the "License");            *
   6 # you may not use this file except in compliance with the License.           *
   7 # You may obtain a copy of the License at                                    *
   8 #                                                                            *
   9 #      http://www.apache.org/licenses/LICENSE-2.0                            *
  10 #                                                                            *
  11 # Unless required by applicable law or agreed to in writing, software        *
  12 # distributed under the License is distributed on an "AS IS" BASIS,          *
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   *
  14 # See the License for the specific language governing permissions and        *
  15 # limitations under the License.                                             *
  16 #                                                                            *
  17 ******************************************************************************/
  18
  19 /*
  20  * Copyright (c) 2003-2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
  21  * Redistribution and modifications are permitted subject to BSD license.
  22  */
  23 #ifndef ASN_CODECS_H
  24 #define ASN_CODECS_H
  25
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29
  30 struct asn_TYPE_descriptor_s;   /* Forward declaration */
  31
  32 /*
  33  * This structure defines a set of parameters that may be passed
  34  * to every ASN.1 encoder or decoder function.
  35  * WARNING: if max_stack_size member is set, and you are calling the
  36  *   function pointers of the asn_TYPE_descriptor_t directly,
  37  *   this structure must be ALLOCATED ON THE STACK!
  38  *   If you can't always satisfy this requirement, use ber_decode(),
  39  *   xer_decode() and uper_decode() functions instead.
  40  */
  41 typedef struct asn_codec_ctx_s {
  42         /*
  43          * Limit the decoder routines to use no (much) more stack than a given
  44          * number of bytes. Most of decoders are stack-based, and this
  45          * would protect against stack overflows if the number of nested
  46          * encodings is high.
  47          * The OCTET STRING, BIT STRING and ANY BER decoders are heap-based,
  48          * and are safe from this kind of overflow.
  49          * A value from getrlimit(RLIMIT_STACK) may be used to initialize
  50          * this variable. Be careful in multithreaded environments, as the
  51          * stack size is rather limited.
  52          */
  53         size_t  max_stack_size; /* 0 disables stack bounds checking */
  54 } asn_codec_ctx_t;
  55
  56 /*
  57  * Type of the return value of the encoding functions (der_encode, xer_encode).
  58  */
  59 typedef struct asn_enc_rval_s {
  60         /*
  61          * Number of bytes encoded.
  62          * -1 indicates failure to encode the structure.
  63          * In this case, the members below this one are meaningful.
  64          */
  65         ssize_t encoded;
  66
  67         /*
  68          * Members meaningful when (encoded == -1), for post mortem analysis.
  69          */
  70
  71         /* Type which cannot be encoded */
  72         const struct asn_TYPE_descriptor_s *failed_type;
  73
  74         /* Pointer to the structure of that type */
  75         const void *structure_ptr;
  76 } asn_enc_rval_t;
  77 #define ASN__ENCODE_FAILED do {                                 \
  78         asn_enc_rval_t tmp_error;                               \
  79         tmp_error.encoded = -1;                                 \
  80         tmp_error.failed_type = td;                             \
  81         tmp_error.structure_ptr = sptr;                         \
  82         ASN_DEBUG("Failed to encode element %s", td ? td->name : "");   \
  83         return tmp_error;                                       \
  84 } while(0)
  85 #define ASN__ENCODED_OK(rval) do {                              \
  86         rval.structure_ptr = 0;                                 \
  87         rval.failed_type = 0;                                   \
  88         return rval;                                            \
  89 } while(0)
  90
  91 /*
  92  * Type of the return value of the decoding functions (ber_decode, xer_decode)
  93  *
  94  * Please note that the number of consumed bytes is ALWAYS meaningful,
  95  * even if code==RC_FAIL. This is to indicate the number of successfully
  96  * decoded bytes, hence providing a possibility to fail with more diagnostics
  97  * (i.e., print the offending remainder of the buffer).
  98  */
  99 enum asn_dec_rval_code_e {
 100         RC_OK,          /* Decoded successfully */
 101         RC_WMORE,       /* More data expected, call again */
 102         RC_FAIL         /* Failure to decode data */
 103 };
 104 typedef struct asn_dec_rval_s {
 105         enum asn_dec_rval_code_e code;  /* Result code */
 106         size_t consumed;                /* Number of bytes consumed */
 107 } asn_dec_rval_t;
 108 #define ASN__DECODE_FAILED do {                                 \
 109         asn_dec_rval_t tmp_error;                               \
 110         tmp_error.code = RC_FAIL;                               \
 111         tmp_error.consumed = 0;                                 \
 112         ASN_DEBUG("Failed to decode element %s", td ? td->name : "");   \
 113         return tmp_error;                                       \
 114 } while(0)
 115 #define ASN__DECODE_STARVED do {                                \
 116         asn_dec_rval_t tmp_error;                               \
 117         tmp_error.code = RC_WMORE;                              \
 118         tmp_error.consumed = 0;                                 \
 119         return tmp_error;                                       \
 120 } while(0)
 121
 122 #ifdef __cplusplus
 123 }
 124 #endif
 125
 126 #endif  /* ASN_CODECS_H */