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},
  31          id_{0},
  32          length_{0},
  33          format_{can_message_format_t::INVALID},
  34          rtr_flag_{false},
  35          flags_{0},
  36          timestamp_{0},
  37          sub_id_{-1}
  38 {}
  39
  40 can_message_t::can_message_t(uint8_t maxdlen,
  41         uint32_t id,
  42         uint8_t length,
  43         can_message_format_t format,
  44         bool rtr_flag,
  45         uint8_t flags,
  46         std::vector<uint8_t>& data,
  47         uint64_t timestamp)
  48         :  maxdlen_{maxdlen},
  49         id_{id},
  50         length_{length},
  51         format_{format},
  52         rtr_flag_{rtr_flag},
  53         flags_{flags},
  54         data_{data},
  55         timestamp_{timestamp},
  56         sub_id_{-1}
  57 {}
  58
  59 ///
  60 /// @brief Retrieve id_ member value.
  61 ///
  62 /// @return id_ class member
  63 ///
  64 uint32_t can_message_t::get_id() const
  65 {
  66         return id_;
  67 }
  68
  69 int can_message_t::get_sub_id() const
  70 {
  71         return sub_id_;
  72 }
  73
  74 ///
  75 /// @brief Retrieve RTR flag member.
  76 ///
  77 /// @return rtr_flags_ class member
  78 ///
  79 bool can_message_t::get_rtr_flag_() const
  80 {
  81         return rtr_flag_;
  82 }
  83
  84 ///
  85 /// @brief Retrieve format_ member value.
  86 ///
  87 /// @return format_ class member. Default to INVALID.
  88 ///
  89 can_message_format_t can_message_t::get_format() const
  90 {
  91         if (format_ != can_message_format_t::STANDARD || format_ != can_message_format_t::EXTENDED)
  92                 return can_message_format_t::INVALID;
  93         return format_;
  94 }
  95
  96 ///
  97 /// @brief Retrieve flags_ member value.
  98 ///
  99 /// @return flags_ class member
 100 ///
 101 uint8_t can_message_t::get_flags() const
 102 {
 103         return flags_;
 104 }
 105
 106 ///
 107 /// @brief Retrieve data_ member value.
 108 ///
 109 /// @return pointer to the first element
 110 ///  of class member data_
 111 ///
 112 const uint8_t* can_message_t::get_data() const
 113 {
 114         return data_.data();
 115 }
 116
 117 ///
 118 /// @brief Retrieve data_ member whole vector
 119 ///
 120 /// @return the vector as is
 121 ///
 122 const std::vector<uint8_t> can_message_t::get_data_vector() const
 123 {
 124         return data_;
 125 }
 126
 127 ///
 128 /// @brief Retrieve length_ member value.
 129 ///
 130 /// @return length_ class member
 131 ///
 132 uint8_t can_message_t::get_length() const
 133 {
 134         return length_;
 135 }
 136
 137 void can_message_t::set_sub_id(int sub_id)
 138 {
 139         sub_id_ = sub_id;
 140 }
 141
 142 uint64_t can_message_t::get_timestamp() const
 143 {
 144         return timestamp_;
 145 }
 146
 147 void can_message_t::set_timestamp(uint64_t timestamp)
 148 {
 149         timestamp_ = timestamp;
 150 }
 151
 152 /// @brief Control whether the object is correctly initialized
 153 ///  to be sent over the CAN bus
 154 ///
 155 /// @return True if object correctly initialized and false if not.
 156 bool can_message_t::is_correct_to_send()
 157 {
 158         if (id_ != 0 && length_ != 0 && format_ != can_message_format_t::INVALID)
 159         {
 160                 int i;
 161                 for(i=0;i<CAN_MESSAGE_SIZE;i++)
 162                         if(data_[i] != 0)
 163                                 return true;
 164         }
 165         return false;
 166 }
 167
 168 /// @brief Set format_ member value.
 169 ///
 170 /// Preferred way to initialize these members by using
 171 /// convert_from_canfd_frame method.
 172 ///
 173 /// @param[in] new_format - class member
 174 void can_message_t::set_format(const can_message_format_t new_format)
 175 {
 176         if(new_format == can_message_format_t::STANDARD || new_format == can_message_format_t::EXTENDED || new_format == can_message_format_t::INVALID)
 177                 format_ = new_format;
 178         else
 179                 AFB_ERROR("Can set format, wrong format chosen");
 180 }
 181
 182 /// @brief Take a canfd_frame struct to initialize class members
 183 ///
 184 /// This is the preferred way to initialize class members.
 185 ///
 186 /// @param[in] frame - canfd_frame to convert coming from a read of CAN socket
 187 /// @param[in] nbytes - bytes read from socket read operation.
 188 ///
 189 /// @return A can_message_t object fully initialized with canfd_frame values.
 190 can_message_t can_message_t::convert_from_frame(const struct canfd_frame& frame, size_t nbytes, uint64_t timestamp)
 191 {
 192         uint8_t maxdlen, length, flags = (uint8_t)NULL;
 193         uint32_t id;
 194         can_message_format_t format;
 195         bool rtr_flag;
 196         std::vector<uint8_t> data;
 197
 198         switch(nbytes)
 199         {
 200                 case CANFD_MTU:
 201                         AFB_DEBUG("Got an CAN FD frame");
 202                         maxdlen = CANFD_MAX_DLEN;
 203                         break;
 204                 case CAN_MTU:
 205                         AFB_DEBUG("Got a legacy CAN frame");
 206                         maxdlen = CAN_MAX_DLEN;
 207                         break;
 208                 default:
 209                         AFB_ERROR("unsupported CAN frame");
 210                         break;
 211         }
 212
 213         if (frame.can_id & CAN_ERR_FLAG)
 214         {
 215                 format = can_message_format_t::INVALID;
 216                 id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
 217         }
 218         else if (frame.can_id & CAN_EFF_FLAG)
 219         {
 220                 format = can_message_format_t::EXTENDED;
 221                 id = frame.can_id & CAN_EFF_MASK;
 222         }
 223         else
 224         {
 225                 format = can_message_format_t::STANDARD;
 226                 id = frame.can_id & CAN_SFF_MASK;
 227         }
 228
 229         /* Overwrite length_ if RTR flags is detected.
 230          * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
 231         if (frame.can_id & CAN_RTR_FLAG)
 232         {
 233                 rtr_flag = true;
 234                 if(frame.len && frame.len <= CAN_MAX_DLC)
 235                 {
 236                         if(rtr_flag)
 237                                 length = frame.len& 0xF;
 238                         else
 239                         {
 240                                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 241                         }
 242                 }
 243         }
 244         else
 245         {
 246                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 247
 248                 /* Flags field only present for CAN FD frames*/
 249                 if(maxdlen == CANFD_MAX_DLEN)
 250                                 flags = frame.flags & 0xF;
 251
 252                 if (data.capacity() < maxdlen)
 253                         data.reserve(maxdlen);
 254                                 int i;
 255
 256                         data.clear();
 257                         /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
 258                         for(i=0;i<maxdlen;i++)
 259                         {
 260                                 data.push_back(frame.data[i]);
 261                         };
 262
 263                 AFB_DEBUG("Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X",
 264                                                                 id, (uint8_t)format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
 265         }
 266
 267         return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data, timestamp);
 268 }
 269
 270 /// @brief Take a can_frame struct to initialize class members
 271 ///
 272 /// This is the preferred way to initialize class members.
 273 ///
 274 /// @param[in] frame - can_frame to convert coming from a read of CAN socket
 275 /// @param[in] nbytes - bytes read from socket read operation.
 276 ///
 277 /// @return A can_message_t object fully initialized with can_frame values.
 278 can_message_t can_message_t::convert_from_frame(const struct can_frame& frame, size_t nbytes, uint64_t timestamp)
 279 {
 280         uint8_t maxdlen, length, flags = (uint8_t)NULL;
 281         uint32_t id;
 282         can_message_format_t format;
 283         bool rtr_flag;
 284         std::vector<uint8_t> data;
 285
 286         if(nbytes <= CAN_MTU)
 287         {
 288                         AFB_DEBUG("Got a legacy CAN frame");
 289                         maxdlen = CAN_MAX_DLEN;
 290         }
 291         else
 292         {
 293                         AFB_ERROR("unsupported CAN frame");
 294         }
 295
 296         if (frame.can_id & CAN_ERR_FLAG)
 297         {
 298                 format = can_message_format_t::INVALID;
 299                 id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
 300         }
 301         else if (frame.can_id & CAN_EFF_FLAG)
 302         {
 303                 format = can_message_format_t::EXTENDED;
 304                 id = frame.can_id & CAN_EFF_MASK;
 305         }
 306         else
 307         {
 308                 format = can_message_format_t::STANDARD;
 309                 id = frame.can_id & CAN_SFF_MASK;
 310         }
 311
 312         /* Overwrite length_ if RTR flags is detected.
 313          * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
 314         if (frame.can_id & CAN_RTR_FLAG)
 315         {
 316                 rtr_flag = true;
 317                 if(frame.can_dlc && frame.can_dlc <= CAN_MAX_DLC)
 318                 {
 319                         if(rtr_flag)
 320                                 length = frame.can_dlc& 0xF;
 321                         else
 322                         {
 323                                 length = (frame.can_dlc > maxdlen) ? maxdlen : frame.can_dlc;
 324                         }
 325                 }
 326         }
 327         else
 328         {
 329                 length = (frame.can_dlc > maxdlen) ? maxdlen : frame.can_dlc;
 330
 331                 if (data.capacity() < maxdlen)
 332                         data.reserve(maxdlen);
 333                                 int i;
 334
 335                         data.clear();
 336                         /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
 337                         for(i=0;i<maxdlen;i++)
 338                         {
 339                                 data.push_back(frame.data[i]);
 340                         };
 341
 342 //              AFB_DEBUG("Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X",
 343 //                                                              id, (uint8_t)format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
 344         }
 345
 346         return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data, timestamp);
 347 }
 348
 349 /// @brief Take all initialized class's members and build an
 350 /// canfd_frame struct that can be use to send a CAN message over
 351 /// the bus.
 352 ///
 353 /// @return canfd_frame struct built from class members.
 354 struct canfd_frame can_message_t::convert_to_canfd_frame()
 355 {
 356         canfd_frame frame;
 357
 358         if(is_correct_to_send())
 359         {
 360                 frame.can_id = get_id();
 361                 frame.len = get_length();
 362                 ::memcpy(frame.data, get_data(), length_);
 363         }
 364         else
 365                 AFB_ERROR("can_message_t not correctly initialized to be sent");
 366
 367         return frame;
 368 }
 369
 370 /// @brief Take all initialized class's members and build an
 371 /// can_frame struct that can be use to send a CAN message over
 372 /// the bus.
 373 ///
 374 /// @return can_frame struct built from class members.
 375 struct can_frame can_message_t::convert_to_can_frame()
 376 {
 377         can_frame frame;
 378
 379         if(is_correct_to_send())
 380         {
 381                 frame.can_id = get_id();
 382                 frame.can_dlc = get_length();
 383                 ::memcpy(frame.data, get_data(), length_);
 384         }
 385         else
 386                 AFB_ERROR("can_message_t not correctly initialized to be sent");
 387
 388         return frame;
 389 }