CAN-binder/low-can-binding/can/can-message.cpp

   1 /*
   2  * Copyright (C) 2015, 2016 "IoT.bzh"
   3  * Author "Romain Forlot" <romain.forlot@iot.bzh>
   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 #include "can-message.hpp"
  19
  20 #include <cstring>
  21
  22 #include "../binding/low-can-hat.hpp"
  23
  24 ///
  25 /// @brief Class constructor
  26 ///
  27 /// Constructor about can_message_t class.
  28 ///
  29 can_message_t::can_message_t()
  30         : maxdlen_{0}, id_{0}, length_{0}, format_{can_message_format_t::ERROR}, rtr_flag_{false}, flags_{0}
  31 {}
  32
  33 can_message_t::can_message_t(uint8_t maxdlen,
  34         uint32_t id,
  35         uint8_t length,
  36         can_message_format_t format,
  37         bool rtr_flag,
  38         uint8_t flags,
  39         std::vector<uint8_t> data)
  40         :  maxdlen_{maxdlen},
  41         id_{id},
  42         length_{length},
  43         format_{format},
  44         rtr_flag_{rtr_flag},
  45         flags_{flags},
  46         data_{data}
  47 {}
  48
  49 ///
  50 /// @brief Retrieve id_ member value.
  51 ///
  52 /// @return id_ class member
  53 ///
  54 uint32_t can_message_t::get_id() const
  55 {
  56         return id_;
  57 }
  58
  59 ///
  60 /// @brief Retrieve RTR flag member.
  61 ///
  62 /// @return rtr_flags_ class member
  63 ///
  64 bool can_message_t::get_rtr_flag_() const
  65 {
  66         return rtr_flag_;
  67 }
  68
  69 ///
  70 /// @brief Retrieve format_ member value.
  71 ///
  72 /// @return format_ class member
  73 ///
  74 can_message_format_t can_message_t::get_format() const
  75 {
  76         if (format_ != can_message_format_t::STANDARD || format_ != can_message_format_t::EXTENDED)
  77                 return can_message_format_t::ERROR;
  78         return format_;
  79 }
  80
  81 ///
  82 /// @brief Retrieve flags_ member value.
  83 ///
  84 /// @return flags_ class member
  85 ///
  86 uint8_t can_message_t::get_flags() const
  87 {
  88         return flags_;
  89 }
  90
  91 ///
  92 /// @brief Retrieve data_ member value.
  93 ///
  94 /// @return pointer to the first element
  95 ///  of class member data_
  96 ///
  97 const uint8_t* can_message_t::get_data() const
  98 {
  99         return data_.data();
 100 }
 101
 102 ///
 103 /// @brief Retrieve data_ member whole vector
 104 ///
 105 /// @return the vector as is
 106 ///
 107 const std::vector<uint8_t> can_message_t::get_data_vector() const
 108 {
 109         return data_;
 110 }
 111
 112 ///
 113 /// @brief Retrieve length_ member value.
 114 ///
 115 /// @return length_ class member
 116 ///
 117 uint8_t can_message_t::get_length() const
 118 {
 119         return length_;
 120 }
 121
 122 ///
 123 /// @brief Control whether the object is correctly initialized
 124 ///  to be sent over the CAN bus
 125 ///
 126 /// @return true if object correctly initialized and false if not.
 127 ///
 128 bool can_message_t::is_correct_to_send()
 129 {
 130         if (id_ != 0 && length_ != 0 && format_ != can_message_format_t::ERROR)
 131         {
 132                 int i;
 133                 for(i=0;i<CAN_MESSAGE_SIZE;i++)
 134                         if(data_[i] != 0)
 135                                 return true;
 136         }
 137         return false;
 138 }
 139
 140 ///
 141 /// @brief Set format_ member value.
 142 ///
 143 /// Preferred way to initialize these members by using
 144 /// convert_from_canfd_frame method.
 145 ///
 146 /// @param[in] new_format - class member
 147 ///
 148 void can_message_t::set_format(const can_message_format_t new_format)
 149 {
 150         if(new_format == can_message_format_t::STANDARD || new_format == can_message_format_t::EXTENDED || new_format == can_message_format_t::ERROR)
 151                 format_ = new_format;
 152         else
 153                 ERROR(binder_interface, "%s: Can set format, wrong format chosen", __FUNCTION__);
 154 }
 155
 156 /// @brief Take a canfd_frame struct to initialize class members
 157 ///
 158 /// This is the preferred way to initialize class members.
 159 ///
 160 /// @param[in] frame - canfd_frame to convert coming from a read of CAN socket
 161 /// @param[in] nbytes - bytes read from socket read operation.
 162 ///
 163 /// @return A can_message_t object fully initialized with canfd_frame values.
 164 ///
 165 can_message_t can_message_t::convert_from_frame(const struct canfd_frame& frame, size_t nbytes)
 166 {
 167         uint8_t maxdlen, length, flags = (uint8_t)NULL;
 168         uint32_t id;
 169         can_message_format_t format;
 170         bool rtr_flag;
 171         std::vector<uint8_t> data;
 172
 173         switch(nbytes)
 174         {
 175                 case CANFD_MTU:
 176                         DEBUG(binder_interface, "%s: Got an CAN FD frame", __FUNCTION__);
 177                         maxdlen = CANFD_MAX_DLEN;
 178                         break;
 179                 case CAN_MTU:
 180                         DEBUG(binder_interface, "%s: Got a legacy CAN frame", __FUNCTION__);
 181                         maxdlen = CAN_MAX_DLEN;
 182                         break;
 183                 default:
 184                         ERROR(binder_interface, "%s: unsupported CAN frame", __FUNCTION__);
 185                         break;
 186         }
 187
 188         if (frame.can_id & CAN_ERR_FLAG)
 189         {
 190                 format = can_message_format_t::ERROR;
 191                 id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
 192         }
 193         else if (frame.can_id & CAN_EFF_FLAG)
 194         {
 195                 format = can_message_format_t::EXTENDED;
 196                 id = frame.can_id & CAN_EFF_MASK;
 197         }
 198         else
 199         {
 200                 format = can_message_format_t::STANDARD;
 201                 id = frame.can_id & CAN_SFF_MASK;
 202         }
 203
 204         /* Overwrite length_ if RTR flags is detected.
 205          * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
 206         if (frame.can_id & CAN_RTR_FLAG)
 207         {
 208                 rtr_flag = true;
 209                 if(frame.len && frame.len <= CAN_MAX_DLC)
 210                 {
 211                         if(rtr_flag)
 212                                 length = frame.len& 0xF;
 213                         else
 214                         {
 215                                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 216                         }
 217                 }
 218         }
 219         else
 220         {
 221                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 222
 223                 /* Flags field only present for CAN FD frames*/
 224                 if(maxdlen == CANFD_MAX_DLEN)
 225                                 flags = frame.flags & 0xF;
 226
 227                 if (data.capacity() < maxdlen)
 228                         data.reserve(maxdlen);
 229                                 int i;
 230
 231                         data.clear();
 232                         /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
 233                         for(i=0;i<maxdlen;i++)
 234                         {
 235                                 data.push_back(frame.data[i]);
 236                         };
 237
 238                 DEBUG(binder_interface, "%s: Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X", __FUNCTION__,
 239                                                                 id, (uint8_t)format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
 240         }
 241
 242         return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data);
 243 }
 244
 245 can_message_t can_message_t::convert_from_frame(const struct can_frame& frame, size_t nbytes)
 246 {
 247         uint8_t maxdlen, length, flags = (uint8_t)NULL;
 248         uint32_t id;
 249         can_message_format_t format;
 250         bool rtr_flag;
 251         std::vector<uint8_t> data;
 252
 253         if(nbytes <= CAN_MTU)
 254         {
 255                         DEBUG(binder_interface, "%s: Got a legacy CAN frame", __FUNCTION__);
 256                         maxdlen = CAN_MAX_DLEN;
 257         }
 258         else
 259         {
 260                         ERROR(binder_interface, "%s: unsupported CAN frame", __FUNCTION__);
 261         }
 262
 263         if (frame.can_id & CAN_ERR_FLAG)
 264         {
 265                 format = can_message_format_t::ERROR;
 266                 id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
 267         }
 268         else if (frame.can_id & CAN_EFF_FLAG)
 269         {
 270                 format = can_message_format_t::EXTENDED;
 271                 id = frame.can_id & CAN_EFF_MASK;
 272         }
 273         else
 274         {
 275                 format = can_message_format_t::STANDARD;
 276                 id = frame.can_id & CAN_SFF_MASK;
 277         }
 278
 279         /* Overwrite length_ if RTR flags is detected.
 280          * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
 281         if (frame.can_id & CAN_RTR_FLAG)
 282         {
 283                 rtr_flag = true;
 284                 if(frame.can_dlc && frame.can_dlc <= CAN_MAX_DLC)
 285                 {
 286                         if(rtr_flag)
 287                                 length = frame.can_dlc& 0xF;
 288                         else
 289                         {
 290                                 length = (frame.can_dlc > maxdlen) ? maxdlen : frame.can_dlc;
 291                         }
 292                 }
 293         }
 294         else
 295         {
 296                 length = (frame.can_dlc > maxdlen) ? maxdlen : frame.can_dlc;
 297
 298                 if (data.capacity() < maxdlen)
 299                         data.reserve(maxdlen);
 300                                 int i;
 301
 302                         data.clear();
 303                         /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
 304                         for(i=0;i<maxdlen;i++)
 305                         {
 306                                 data.push_back(frame.data[i]);
 307                         };
 308
 309 //              DEBUG(binder_interface, "%s: Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X", __FUNCTION__,
 310 //                                                              id, (uint8_t)format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
 311         }
 312
 313         return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data);
 314 }
 315
 316 ///
 317 /// @brief Take all initialized class's members and build an
 318 /// canfd_frame struct that can be use to send a CAN message over
 319 /// the bus.
 320 ///
 321 /// @return canfd_frame struct built from class members.
 322 ///
 323 struct canfd_frame can_message_t::convert_to_canfd_frame()
 324 {
 325         canfd_frame frame;
 326
 327         if(is_correct_to_send())
 328         {
 329                 frame.can_id = get_id();
 330                 frame.len = get_length();
 331                 ::memcpy(frame.data, get_data(), length_);
 332         }
 333         else
 334                 ERROR(binder_interface, "%s: can_message_t not correctly initialized to be sent", __FUNCTION__);
 335
 336         return frame;
 337 }
 338
 339 struct can_frame can_message_t::convert_to_can_frame()
 340 {
 341         can_frame frame;
 342
 343         if(is_correct_to_send())
 344         {
 345                 frame.can_id = get_id();
 346                 frame.can_dlc = get_length();
 347                 ::memcpy(frame.data, get_data(), length_);
 348         }
 349         else
 350                 ERROR(binder_interface, "%s: can_message_t not correctly initialized to be sent", __FUNCTION__);
 351
 352         return frame;
 353 }