e2sim/e2apv1sim/src/ASN1/asn/per/binary_integer.hpp

   1 #pragma once
   2 /******************************************************************************
   3 *
   4 *   Copyright (c) 2019 AT&T Intellectual Property.
   5 *   Copyright (c) 2018-2019 Nokia.
   6 *
   7 *   Licensed under the Apache License, Version 2.0 (the "License");
   8 *   you may not use this file except in compliance with the License.
   9 *   You may obtain a copy of the License at
  10 *
  11 *       http://www.apache.org/licenses/LICENSE-2.0
  12 *
  13 *   Unless required by applicable law or agreed to in writing, software
  14 *   distributed under the License is distributed on an "AS IS" BASIS,
  15 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16 *   See the License for the specific language governing permissions and
  17 *   limitations under the License.
  18 *
  19 ******************************************************************************/
  20
  21 // Standard Includes: ANSI C/C++, MSA, and Third-Party Libraries
  22
  23 // Local Includes: Application specific classes, functions, and libraries
  24 #include "asn/per/common.hpp"
  25 #include "asn/per/length.hpp"
  26
  27 namespace asn {
  28 namespace per {
  29
  30 template <class Range, class Enable = void>
  31 struct BinaryIntegerLength;
  32
  33 /***************************************************************************************
  34 * Encoding of a non-negative-binary-integer (X.691 10.3)
  35 ***************************************************************************************/
  36 template <class Range>
  37 struct NonnegativeBinaryInteger
  38 {
  39         static void inline run(u64 val, EncoderCtx& ctx)
  40         {
  41                 if(val)
  42                 {
  43                         size_t const len = sizeof(val) - (__builtin_clzll(val) >> 3);
  44
  45                         BinaryIntegerLength< Range >::run(ctx, len);
  46                         Tools::bit_accessor::padByte(ctx.refBuffer());
  47
  48                         u8 buff[len];
  49                         size_t shift = (len - 1) << 3;
  50                         for(size_t i = 0; i < len; ++i)
  51                         {
  52                                 buff[i] = static_cast<uint8_t>(val >> shift);
  53                                 shift -= 8;
  54                         }
  55
  56                         ctx.refBuffer().putBytes(buff, len);
  57                 }
  58                 else
  59                 {
  60                         BinaryIntegerLength< Range >::run(ctx, 1);
  61                         Tools::bit_accessor::padByte(ctx.refBuffer());
  62                         ctx.refBuffer().putByte(0);
  63                 }
  64         }
  65         template<typename T>
  66         static void inline run(T& retval, DecoderCtx& ctx, bool extended_val)
  67         {
  68                 retval = 0;
  69                 size_t len = (size_t)BinaryIntegerLength< Range >::run(ctx, extended_val);
  70                 Tools::bit_accessor::padByte(ctx.refBuffer());
  71                 u8 const* data = ctx.refBuffer().getBytes(len);
  72
  73                 if (data)
  74                 {
  75                         for (size_t i = 0; i < len; ++i)
  76                         {
  77                                 retval = retval << 8;
  78                                 retval |= data[i];
  79                         }
  80                 }
  81         }
  82 };
  83
  84 /***************************************************************************************
  85 * Encoding of a 2's-complement-binary-integer (X.691 10.4)
  86 ***************************************************************************************/
  87
  88 template <class IE>
  89 struct TwosComplementBinaryInteger
  90 {
  91         static void inline run(IE const& ie, EncoderCtx& ctx)
  92         {
  93                 Tools::bit_accessor::padByte(ctx.refBuffer());
  94
  95                 u64 val = ie.get();
  96                 u64 tval = val;
  97                 u64 mask = static_cast<u64>(-128);
  98                 u8 len = 1;
  99                 u8 i = 7;
 100
 101                 u8 buf[8];
 102
 103                 while (len < 8)
 104                 {
 105                         buf[i] = static_cast<u8>(tval);
 106                         if (!(val & mask) || (val & mask) == mask)
 107                                 break;
 108                         mask = mask << 8;
 109                         tval = tval >> 8;
 110                         len++;
 111                         i--;
 112                 }
 113
 114                 ctx.refBuffer().putByte(len) && ctx.refBuffer().putBytes(&buf[i], len);
 115         }
 116         static void inline run(IE& ie, DecoderCtx& ctx)
 117         {
 118                 Tools::bit_accessor::padByte(ctx.refBuffer());
 119
 120                 u8 const* data = nullptr;
 121                 typename IE::value_type val = 0;
 122
 123                 u8 const* len = ctx.refBuffer().getBytes(1);
 124
 125                 if (len && (*len) <= 8 && (data = ctx.refBuffer().getBytes(*len)))
 126                 {
 127                         for (u8 i = 0; i < *len; ++i)
 128                         {
 129                                 val = val << 8;
 130                                 val |= data[i];
 131                         }
 132                 }
 133                 ie.set(val);
 134         }
 135 };
 136
 137 /***************************************************************************************
 138 * Encoding of a normally small non-negativebinary integer (X.691 10.6)
 139 ***************************************************************************************/
 140 template <class IE, typename TValue = typename IE::value_type>
 141 struct NormallySmallNonnegativeBinaryInteger
 142 {
 143         static void inline run(IE const& ie, EncoderCtx& ctx, typename IE::constraint_t::boundary_type val)
 144         {
 145                 if (val <= 63)
 146                 {
 147                         Tools::bit_accessor::put(static_cast<u8>(val), 7, ctx.refBuffer()); //7 bits ('0' indicator + value)
 148                 }
 149                 else
 150                 {
 151                         Tools::bit_accessor::put(1, 1, ctx.refBuffer()); //1 bit ('1' indicator)
 152                         NonnegativeBinaryInteger<typename IE::constraint_t>::run(val, ctx);
 153                 }
 154         }
 155         static TValue inline run(DecoderCtx& ctx)
 156         {
 157                 u8 ext = Tools::bit_accessor::get(1, ctx.refBuffer());
 158                 if (ext) {
 159                         TValue rval = 0;
 160                         NonnegativeBinaryInteger<typename IE::constraint_t>::run(rval, ctx, true);
 161                         return rval;
 162                 }
 163                 return Tools::bit_accessor::get(6, ctx.refBuffer());
 164         }
 165 };
 166
 167 } //namespace per
 168 } //namespace asn