Add RTR frames to TCP messages

doc/protocol.md

@@ -74,6 +74,22 @@ Send a single CAN frame without cyclic transmission
     // ID: 1AAAAAAA, Length: 2, Data: 0x01 0xF1
     < send 1AAAAAAA 2 1 F1 > 
 
+#### Send a single Remote-transfer-request frame ####
+This command is used to send a single RTR CAN frame.
+
+    < sendrtr can_id can_dlc >
+
+Example:
+Send a single CAN frame without cyclic transmission
+
+    // ID: 123, DLC 0
+    < sendrtr 123 0 > 
+
+    // ID: 1AAAAAAA, DLC 2
+    < sendrtr 1AAAAAAA 2 > 
+
+Note that DLC may cause collisions on CAN bus. Check CiA application note 802
+
 ### Commands for reception ###
 The commands for reception are 'subscribe' , 'unsubscribe' and 'filter'.
 
@@ -169,7 +185,16 @@ Example:
 Reception of a CAN frame with CAN ID 0x123 , data length 4 and data 0x11, 0x22, 0x33 and 0x44 at time 23.424242>
 
     < frame 123 23.424242 11 22 33 44 >
+
+#### RTR frame transmission ####
+CAN RTR messages received in raw mode:
+    < rtr can_id seconds.useconds can_dlc >
 
+Example:
+Reception of a RTR frame with CAN ID 0x123 , data length 4 at time 23.424242
+
+    < rtr 123 23.424242 4 >
+
 #### Switch to BCM mode ####
 With '< bcmmode >' it is possible to switch back to BCM mode.
 

doc/raspberrypi.md

@@ -0,0 +1,77 @@
+Running on Raspberry PI
+===================
+
+For this example used adapter-board: https://www.waveshare.com/rs485-can-hat.htm you can find it on aliexpress too.
+After flashing Raspberry image to SD card modify 'config.txt', uncomment this line:
+
+	dtparam=spi=on
+
+Add this line:
+
+	dtoverlay=mcp2515-can0,oscillator=12000000,interrupt=25,spimaxfrequency=5000000
+
+Save file and create empty 'SSH' file if you want to remotely login over ethenet to pi.
+For Windows (10+) use:
+
+	ssh raspberrypi.local -l pi
+
+Password: raspberry
+
+You can check if CAN driver initialized successfully with:
+
+	dmesg | grep -i '\(can\|spi\)'
+
+Prepare something needed for build
+
+	sudo apt-get install libconfig-dev
+
+Now lets clone socketcand to sd card and build it
+
+	cd boot
+	sudo git clone https://github.com/linux-can/socketcand.git
+	cd socketcand
+	sudo ./autogen.sh
+	sudo ./configure
+	sudo make
+
+Now you can install it into system
+
+	sudo make install
+
+After that you may want to make it run on boot as service, run this command to edit it
+
+	sudo systemctl edit --force --full socketcand.service
+
+Replace content with this rescription:
+
+	[Unit]
+	Description=CAN ethernet
+	After=server.service multi-user.target
+
+	[Service]
+	ExecStart=
+	ExecStart=-/usr/local/bin/socketcand -i can0
+	Restart=always
+	TimeoutSec=10
+
+	[Install]
+	WantedBy=multi-user.target
+
+Try to start it with
+
+	sudo systemctl daemon-reload
+	sudo systemctl start socketcand.service
+
+And listen on UDP default port 42000 for discovery message.
+
+	<CANBeacon name="raspberrypi" type="SocketCAN" description="socketcand">
+	<URL>can://192.168.1.221:29536</URL><Bus name="can0"/></CANBeacon>
+
+Note that it should say 'can0' and not 'vcan0'. 
+If everything ok so far, what is quite suprisingly, then run this command to activate service on boot.
+
+	sudo systemctl enable socketcand.service
+	sudo reboot
+
+Check for discovery again.
+Now you can connect to IP: raspberrypi.local on TCP port 29536 (default) to start working with remote CAN. Check protocol file for commands and its description.

socketcandcl.c

@@ -342,6 +342,25 @@ inline void state_connected()
 						}
 					}
 				}
+				if (!strncmp("< rtr ", buf, 6)) {
+					//send RTR frame only
+					sscanf(buf, "< %*s %x %*d.%*d %hhu >", &frame.can_id, &frame.can_dlc);
+
+					frame.can_id |= CAN_RTR_FLAG;
+					char *s = buf + 6;
+					for (; ++s;) {
+						if (*s == ' ') {
+							break;
+						}
+					}
+					if ((s - buf - 7) > 4)
+						frame.can_id |= CAN_EFF_FLAG;
+
+					ret = write(raw_socket, &frame, sizeof(struct can_frame));
+					if (ret < sizeof(struct can_frame)) {
+						perror("Writing CAN frame to can socket\n");
+					}
+				}
 			} else {
 				ret = read(server_socket, &buf, 0);
 				if(ret == -1) {
@@ -372,21 +391,26 @@ inline void state_connected()
 				} else {
 					if(frame.can_id & CAN_ERR_FLAG) {
 						/* TODO implement */
-					} else if(frame.can_id & CAN_RTR_FLAG) {
-						/* TODO implement */
 					} else {
-						int i;
-						if(frame.can_id & CAN_EFF_FLAG) {
-							ret = sprintf(buf, "< send %08X %d ",
-								      frame.can_id & CAN_EFF_MASK, frame.can_dlc);
+						if (frame.can_id & CAN_RTR_FLAG) {
+							if (frame.can_id & CAN_EFF_FLAG) {
+								ret = sprintf(buf, "< sendrtr %08X %hhu >", frame.can_id & CAN_EFF_MASK, frame.can_dlc);
+							} else {
+								ret = sprintf(buf, "< sendrtr %03X %hhu >", frame.can_id & CAN_SFF_MASK, frame.can_dlc);
+							}
 						} else {
-							ret = sprintf(buf, "< send %03X %d ",
-								      frame.can_id & CAN_SFF_MASK, frame.can_dlc);
-						}
-						for(i=0; i<frame.can_dlc; i++) {
-							ret += sprintf(buf+ret, "%02x ", frame.data[i]);
+							int i;
+							if (frame.can_id & CAN_EFF_FLAG) {
+								ret = sprintf(buf, "< send %08X %hhu ", frame.can_id & CAN_EFF_MASK, frame.can_dlc);
+							} else {
+								ret = sprintf(buf, "< send %03X %hhu ", frame.can_id & CAN_SFF_MASK, frame.can_dlc);
+							}
+							for (i = 0; i < frame.can_dlc; i++) {
+								ret += sprintf(buf + ret, "%02x ", frame.data[i]);
+							}
+							sprintf(buf + ret, " >");
+
 						}
-						sprintf(buf+ret, " >");
 
 						const size_t len = strlen(buf);
 						ret = send(server_socket, buf, len, 0);

state_bcm.c

@@ -196,7 +196,24 @@ void state_bcm() {
 				       (struct sockaddr*)&caddr, sizeof(caddr));
 			}
 			/* Add a send job */
-		} else if(!strncmp("< add ", buf, 6)) {
+		} else if (!strncmp("< sendrtr ", buf, 10)) {
+			//send RTR frame only
+			items = sscanf(buf, "< %*s %x %hhu >", &msg.msg_head.can_id, &msg.frame.can_dlc);
+			if ((items < 2) || (msg.frame.can_dlc > CAN_MAX_DLEN)) {
+				PRINT_ERROR("Syntax error in sendrtr command\n")
+				return;
+			}
+
+			msg.msg_head.can_id |= CAN_RTR_FLAG;
+
+			if (element_length(buf, 2) == 8)
+				msg.msg_head.can_id |= CAN_EFF_FLAG; //extended
+
+			if (!ioctl(sc, SIOCGIFINDEX, &ifr)) {
+				caddr.can_ifindex = ifr.ifr_ifindex;
+				sendto(sc, &msg, sizeof(msg), 0, (struct sockaddr*) &caddr, sizeof(caddr));
+			}
+		} else if (!strncmp("< add ", buf, 6)) {
 			items = sscanf(buf, "< %*s %lu %lu %x %hhu "
 				       "%hhx %hhx %hhx %hhx %hhx %hhx "
 				       "%hhx %hhx >",

state_raw.c

@@ -120,8 +120,13 @@ void state_raw() {
 				canid_t class = frame.can_id  & CAN_EFF_MASK;
 				ret = sprintf(buf, "< error %03X %ld.%06ld >", class, tv.tv_sec, tv.tv_usec);
 				send(client_socket, buf, strlen(buf), 0);
-			} else if(frame.can_id & CAN_RTR_FLAG) {
-				/* TODO implement */
+			} else if (frame.can_id & CAN_RTR_FLAG) {
+				if (frame.can_id & CAN_EFF_FLAG) {
+					ret = sprintf(buf, "< rtr %08X %ld.%06ld %hhu >", frame.can_id & CAN_EFF_MASK, tv.tv_sec, tv.tv_usec, frame.can_dlc);
+				} else {
+					ret = sprintf(buf, "< rtr %03X %ld.%06ld %hhu >", frame.can_id & CAN_SFF_MASK, tv.tv_sec, tv.tv_usec, frame.can_dlc);
+				}
+				send(client_socket, buf, strlen(buf), 0);
 			} else {
 				if(frame.can_id & CAN_EFF_FLAG) {
 					ret = sprintf(buf, "< frame %08X %ld.%06ld ", frame.can_id & CAN_EFF_MASK, tv.tv_sec, tv.tv_usec);
@@ -187,6 +192,23 @@ void state_raw() {
 					return;
 				}
 
+			} else if (!strncmp("< sendrtr ", buf, 10)) {
+				//send RTR frame only
+				items = sscanf(buf, "< %*s %x %hhu >", &frame.can_id, &frame.can_dlc);
+				if ((items < 2) || (frame.can_dlc > CAN_MAX_DLEN)) {
+					PRINT_ERROR("Syntax error in sendrtr command\n")
+					return;
+				}
+
+				frame.can_id |= CAN_RTR_FLAG;
+
+				if (element_length(buf, 2) == 8)
+					frame.can_id |= CAN_EFF_FLAG; //extended
+				ret = send(raw_socket, &frame, sizeof(struct can_frame), 0);
+				if (ret == -1) {
+					state = STATE_SHUTDOWN;
+					return;
+				}
 			} else {
 				PRINT_ERROR("unknown command '%s'\n", buf);
 				strcpy(buf, "< error unknown command >");