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 "../low-can-binding.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, "ERROR: Can set format, wrong format chosen");
 144 }
 145
 146 ///
 147 /// @brief Take a canfd_frame struct to initialize class members
 148 ///
 149 /// This is the preferred way to initialize class members.
 150 ///
 151 /// @param[in] frame - canfd_frame to convert coming from a read of CAN socket
 152 /// @param[in] nbytes - bytes read from socket read operation.
 153 ///
 154 /// @return A can_message_t object fully initialized with canfd_frame values.
 155 ///
 156 can_message_t can_message_t::convert_from_canfd_frame(const struct canfd_frame& frame, size_t nbytes)
 157 {
 158         uint8_t maxdlen, length, flags = (uint8_t)NULL;
 159         uint32_t id;
 160         can_message_format_t format;
 161         bool rtr_flag;
 162         std::vector<uint8_t> data;
 163
 164         switch(nbytes)
 165         {
 166                 case CANFD_MTU:
 167                         DEBUG(binder_interface, "set_max_data_length: Got an CAN FD frame");
 168                         maxdlen = CANFD_MAX_DLEN;
 169                         break;
 170                 case CAN_MTU:
 171                         DEBUG(binder_interface, "set_max_data_length: Got a legacy CAN frame");
 172                         maxdlen = CAN_MAX_DLEN;
 173                         break;
 174                 default:
 175                         ERROR(binder_interface, "set_max_data_length: unsupported CAN frame");
 176                         break;
 177         }
 178
 179         if (frame.can_id & CAN_ERR_FLAG)
 180                 format = can_message_format_t::ERROR;
 181         else if (frame.can_id & CAN_EFF_FLAG)
 182                 format = can_message_format_t::EXTENDED;
 183         else
 184                 format = can_message_format_t::STANDARD;
 185
 186         switch(format)
 187         {
 188                 case can_message_format_t::STANDARD:
 189                         id = frame.can_id & CAN_SFF_MASK;
 190                         break;
 191                 case can_message_format_t::EXTENDED:
 192                         id = frame.can_id & CAN_EFF_MASK;
 193                         break;
 194                 case can_message_format_t::ERROR:
 195                         id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
 196                         break;
 197                 default:
 198                         ERROR(binder_interface, "ERROR: Can set id, not a compatible format or format not set prior to set id.");
 199                         break;
 200         }
 201
 202         /* Overwrite length_ if RTR flags is detected.
 203          * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
 204         if (frame.can_id & CAN_RTR_FLAG)
 205         {
 206                 rtr_flag = true;
 207                 if(frame.len && frame.len <= CAN_MAX_DLC)
 208                 {
 209                         if(rtr_flag)
 210                                 length = frame.len& 0xF;
 211                         else
 212                         {
 213                                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 214                         }
 215                 }
 216         }
 217         else
 218         {
 219                 length = (frame.len > maxdlen) ? maxdlen : frame.len;
 220
 221                 /* Flags field only present for CAN FD frames*/
 222                 if(maxdlen == CANFD_MAX_DLEN)
 223                                 flags = frame.flags & 0xF;
 224
 225                 if (data.capacity() < maxdlen)
 226                         data.reserve(maxdlen);
 227                                 int i;
 228
 229                         data.clear();
 230                         /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
 231                         for(i=0;i<maxdlen;i++)
 232                         {
 233                                 data.push_back(frame.data[i]);
 234                         };
 235
 236                 DEBUG(binder_interface, "convert_from_canfd_frame: Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X",
 237                                                                 id, (uint8_t)format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
 238         }
 239
 240         return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data);
 241 }
 242
 243 ///
 244 /// @brief Take all initialized class's members and build an
 245 /// canfd_frame struct that can be use to send a CAN message over
 246 /// the bus.
 247 ///
 248 /// @return canfd_frame struct built from class members.
 249 ///
 250 canfd_frame can_message_t::convert_to_canfd_frame()
 251 {
 252         canfd_frame frame;
 253
 254         if(is_correct_to_send())
 255         {
 256                 frame.can_id = get_id();
 257                 frame.len = get_length();
 258                 ::memcpy(frame.data, get_data(), length_);
 259         }
 260         else
 261                 ERROR(binder_interface, "can_message_t not correctly initialized to be sent");
 262
 263         return frame;
 264 }