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 length_ member value.
 104 ///
 105 /// @return length_ class member
 106 ///
 107 uint8_t can_message_t::get_length() const
 108 {
 109         return length_;
 110 }
 111
 112 ///
 113 /// @brief Control whether the object is correctly initialized
 114 ///  to be sent over the CAN bus
 115 ///
 116 /// @return true if object correctly initialized and false if not.
 117 ///
 118 bool can_message_t::is_correct_to_send()
 119 {
 120         if (id_ != 0 && length_ != 0 && format_ != can_message_format_t::ERROR)
 121         {
 122                 int i;
 123                 for(i=0;i<CAN_MESSAGE_SIZE;i++)
 124                         if(data_[i] != 0)
 125                                 return true;
 126         }
 127         return false;
 128 }
 129
 130 ///
 131 /// @brief Set format_ member value.
 132 ///
 133 /// Preferred way to initialize these members by using
 134 /// convert_from_canfd_frame method.
 135 ///
 136 /// @param[in] new_format - class member
 137 ///
 138 void can_message_t::set_format(const can_message_format_t new_format)
 139 {
 140         if(new_format == can_message_format_t::STANDARD || new_format == can_message_format_t::EXTENDED || new_format == can_message_format_t::ERROR)
 141                 format_ = new_format;
 142         else
 143                 ERROR(binder_interface, "%s: Can set format, wrong format chosen", __FUNCTION__);
 144 }
 145
 146 /// @brief Take a canfd_frame struct to initialize class members
 147 ///
 148 /// This is the preferred way to initialize class members.
 149 ///
 150 /// @param[in] frame - canfd_frame to convert coming from a read of CAN socket
 151 /// @param[in] nbytes - bytes read from socket read operation.
 152 ///
 153 /// @return A can_message_t object fully initialized with canfd_frame values.
 154 ///
 155 can_message_t can_message_t::convert_from_frame(const struct canfd_frame& frame, size_t nbytes)
 156 {
 157         uint8_t maxdlen, length, flags = (uint8_t)NULL;
 158         uint32_t id;
 159         can_message_format_t format;
 160         bool rtr_flag;
 161         std::vector<uint8_t> data;
 162
 163         switch(nbytes)
 164         {
 165                 case CANFD_MTU:
 166                         DEBUG(binder_interface, "%s: Got an CAN FD frame", __FUNCTION__);
 167                         maxdlen = CANFD_MAX_DLEN;
 168                         break;
 169                 case CAN_MTU:
 170                         DEBUG(binder_interface, "%s: Got a legacy CAN frame", __FUNCTION__);
 171                         maxdlen = CAN_MAX_DLEN;
 172                         break;
 173                 default:
 174                         ERROR(binder_interface, "%s: unsupported CAN frame", __FUNCTION__);
 175                         break;
 176         }
 177
 178         if (frame.can_id & CAN_ERR_FLAG)
 179         {
 180                 format = can_message_format_t::ERROR;
 181                 id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
 182         }
 183         else if (frame.can_id & CAN_EFF_FLAG)
 184         {
 185                 format = can_message_format_t::EXTENDED;
 186                 id = frame.can_id & CAN_EFF_MASK;
 187         }
 188         else
 189         {
 190                 format = can_message_format_t::STANDARD;
 191                 id = frame.can_id & CAN_SFF_MASK;
 192         }
 193
 194         /* Overwrite length_ if RTR flags is detected.
 195          * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
 196         if (frame.can_id & CAN_RTR_FLAG)
 197         {
 198                 rtr_flag = true;
 199                 if(frame.len && frame.len <= CAN_MAX_DLC)
 200                 {
 201                         if(rtr_flag)
 202                                 length = frame.len& 0xF;
 203                         else
 204                         {
 205                                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 206                         }
 207                 }
 208         }
 209         else
 210         {
 211                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 212
 213                 /* Flags field only present for CAN FD frames*/
 214                 if(maxdlen == CANFD_MAX_DLEN)
 215                                 flags = frame.flags & 0xF;
 216
 217                 if (data.capacity() < maxdlen)
 218                         data.reserve(maxdlen);
 219                                 int i;
 220
 221                         data.clear();
 222                         /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
 223                         for(i=0;i<maxdlen;i++)
 224                         {
 225                                 data.push_back(frame.data[i]);
 226                         };
 227
 228                 DEBUG(binder_interface, "%s: Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X", __FUNCTION__,
 229                                                                 id, (uint8_t)format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
 230         }
 231
 232         return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data);
 233 }
 234
 235 can_message_t can_message_t::convert_from_frame(const struct can_frame& frame, size_t nbytes)
 236 {
 237         uint8_t maxdlen, length, flags = (uint8_t)NULL;
 238         uint32_t id;
 239         can_message_format_t format;
 240         bool rtr_flag;
 241         std::vector<uint8_t> data;
 242
 243         if(nbytes <= CAN_MTU)
 244         {
 245                         DEBUG(binder_interface, "%s: Got a legacy CAN frame", __FUNCTION__);
 246                         maxdlen = CAN_MAX_DLEN;
 247         }
 248         else
 249         {
 250                         ERROR(binder_interface, "%s: unsupported CAN frame", __FUNCTION__);
 251         }
 252
 253         if (frame.can_id & CAN_ERR_FLAG)
 254         {
 255                 format = can_message_format_t::ERROR;
 256                 id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
 257         }
 258         else if (frame.can_id & CAN_EFF_FLAG)
 259         {
 260                 format = can_message_format_t::EXTENDED;
 261                 id = frame.can_id & CAN_EFF_MASK;
 262         }
 263         else
 264         {
 265                 format = can_message_format_t::STANDARD;
 266                 id = frame.can_id & CAN_SFF_MASK;
 267         }
 268
 269         /* Overwrite length_ if RTR flags is detected.
 270          * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
 271         if (frame.can_id & CAN_RTR_FLAG)
 272         {
 273                 rtr_flag = true;
 274                 if(frame.can_dlc && frame.can_dlc <= CAN_MAX_DLC)
 275                 {
 276                         if(rtr_flag)
 277                                 length = frame.can_dlc& 0xF;
 278                         else
 279                         {
 280                                 length = (frame.can_dlc > maxdlen) ? maxdlen : frame.can_dlc;
 281                         }
 282                 }
 283         }
 284         else
 285         {
 286                 length = (frame.can_dlc > maxdlen) ? maxdlen : frame.can_dlc;
 287
 288                 if (data.capacity() < maxdlen)
 289                         data.reserve(maxdlen);
 290                                 int i;
 291
 292                         data.clear();
 293                         /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
 294                         for(i=0;i<maxdlen;i++)
 295                         {
 296                                 data.push_back(frame.data[i]);
 297                         };
 298
 299 //              DEBUG(binder_interface, "%s: Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X", __FUNCTION__,
 300 //                                                              id, (uint8_t)format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
 301         }
 302
 303         return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data);
 304 }
 305
 306 ///
 307 /// @brief Take all initialized class's members and build an
 308 /// canfd_frame struct that can be use to send a CAN message over
 309 /// the bus.
 310 ///
 311 /// @return canfd_frame struct built from class members.
 312 ///
 313 struct canfd_frame can_message_t::convert_to_canfd_frame()
 314 {
 315         canfd_frame frame;
 316
 317         if(is_correct_to_send())
 318         {
 319                 frame.can_id = get_id();
 320                 frame.len = get_length();
 321                 ::memcpy(frame.data, get_data(), length_);
 322         }
 323         else
 324                 ERROR(binder_interface, "%s: can_message_t not correctly initialized to be sent", __FUNCTION__);
 325
 326         return frame;
 327 }
 328
 329 struct can_frame can_message_t::convert_to_can_frame()
 330 {
 331         can_frame frame;
 332
 333         if(is_correct_to_send())
 334         {
 335                 frame.can_id = get_id();
 336                 frame.can_dlc = get_length();
 337                 ::memcpy(frame.data, get_data(), length_);
 338         }
 339         else
 340                 ERROR(binder_interface, "%s: can_message_t not correctly initialized to be sent", __FUNCTION__);
 341
 342         return frame;
 343 }