+/// This is the preferred way to initialize class members.
+///
+/// @param[in] frame - can_frame to convert coming from a read of CAN socket
+/// @param[in] nbytes - bytes read from socket read operation.
+///
+/// @return A can_message_t object fully initialized with can_frame values.
+can_message_t can_message_t::convert_from_frame(const struct can_frame& frame, size_t nbytes, uint64_t timestamp)
+{
+ uint8_t maxdlen = 0, length = 0, flags = 0;
+ uint32_t id;
+ can_message_format_t format;
+ bool rtr_flag;
+ std::vector<uint8_t> data;
+
+ if(nbytes <= CAN_MTU)
+ {
+ AFB_DEBUG("Got a legacy CAN frame");
+ maxdlen = CAN_MAX_DLEN;
+ }
+ else
+ {
+ AFB_ERROR("unsupported CAN frame");
+ }
+
+ if (frame.can_id & CAN_ERR_FLAG)
+ {
+ format = can_message_format_t::INVALID;
+ id = frame.can_id & (CAN_ERR_MASK|CAN_ERR_FLAG);
+ }
+ else if (frame.can_id & CAN_EFF_FLAG)
+ {
+ format = can_message_format_t::EXTENDED;
+ id = frame.can_id & CAN_EFF_MASK;
+ }
+ else
+ {
+ format = can_message_format_t::STANDARD;
+ id = frame.can_id & CAN_SFF_MASK;
+ }
+
+ /* Overwrite length_ if RTR flags is detected.
+ * standard CAN frames may have RTR enabled. There are no ERR frames with RTR */
+ if (frame.can_id & CAN_RTR_FLAG)
+ {
+ rtr_flag = true;
+ if(frame.can_dlc && frame.can_dlc <= CAN_MAX_DLC)
+ {
+ if(rtr_flag)
+ length = frame.can_dlc& 0xF;
+ else
+ {
+ length = (frame.can_dlc > maxdlen) ? maxdlen : frame.can_dlc;
+ }
+ }
+ }
+ else
+ {
+ length = (frame.can_dlc > maxdlen) ? maxdlen : frame.can_dlc;
+
+ if (data.capacity() < maxdlen)
+ data.reserve(maxdlen);
+ int i;
+
+ data.clear();
+ /* maxdlen_ is now set at CAN_MAX_DLEN or CANFD_MAX_DLEN, respectively 8 and 64 bytes*/
+ for(i=0;i<maxdlen;i++)
+ {
+ data.push_back(frame.data[i]);
+ };
+
+// AFB_DEBUG("Found id: %X, format: %X, length: %X, data %02X%02X%02X%02X%02X%02X%02X%02X",
+// id, (uint8_t)format, length, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);
+ }
+
+ return can_message_t(maxdlen, id, length, format, rtr_flag, flags, data, timestamp);
+}
+