text: /*
   * cansend.c - simple command line tool to send CAN-frames via CAN_RAW sockets
   *
   * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of Volkswagen nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * Alternatively, provided that this notice is retained in full, this
   * software may be distributed under the terms of the GNU General
   * Public License ("GPL") version 2, in which case the provisions of the
   * GPL apply INSTEAD OF those given above.
   *
   * The provided data structures and external interfaces from this code
   * are not restricted to be used by modules with a GPL compatible license.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
   * DAMAGE.
   *
   * Send feedback to <linux-can@vger.kernel.org>
   *
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #include <net/if.h>
  #include <sys/ioctl.h>
  #include <sys/socket.h>
  
  #include <linux/can.h>
  #include <linux/can/raw.h>
  
  #include "lib.h"
  
  int main(int argc, char **argv)
  {
  	int s; /* can raw socket */ 
  	int required_mtu;
  	int mtu;
  	int enable_canfd = 1;
  	struct sockaddr_can addr;
  	struct canfd_frame frame;
  	struct ifreq ifr;
  
  	/* check command line options */
  	if (argc != 3) {
  		fprintf(stderr, "Usage: %s <device> <can_frame>.\n", argv[0]);
  		return 1;
  	}
  
  	/* parse CAN frame */
  	required_mtu = parse_canframe(argv[2], &frame);
  	if (!required_mtu){
  		fprintf(stderr, "\nWrong CAN-frame format! Try:\n\n");
  		fprintf(stderr, "    <can_id>#{R|data}          for CAN 2.0 frames\n");
  		fprintf(stderr, "    <can_id>##<flags>{data}    for CAN FD frames\n\n");
  		fprintf(stderr, "<can_id> can have 3 (SFF) or 8 (EFF) hex chars\n");
  		fprintf(stderr, "{data} has 0..8 (0..64 CAN FD) ASCII hex-values (optionally");
  		fprintf(stderr, " separated by '.')\n");
  		fprintf(stderr, "<flags> a single ASCII Hex value (0 .. F) which defines");
  		fprintf(stderr, " canfd_frame.flags\n\n");
  		fprintf(stderr, "e.g. 5A1#11.2233.44556677.88 / 123#DEADBEEF / 5AA# / ");
  		fprintf(stderr, "123##1 / 213##311\n     1F334455#1122334455667788 / 123#R ");
  		fprintf(stderr, "for remote transmission request.\n\n");
  		return 1;
  	}
  
  	/* open socket */
  	if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0) {
  		perror("socket");
  		return 1;
  	}
  
  	strncpy(ifr.ifr_name, argv[1], IFNAMSIZ - 1);
  	ifr.ifr_name[IFNAMSIZ - 1] = '\0';
  	ifr.ifr_ifindex = if_nametoindex(ifr.ifr_name);
  	if (!ifr.ifr_ifindex) {
  		perror("if_nametoindex");
  		return 1;
  	}
  
  	addr.can_family = AF_CAN;
  	addr.can_ifindex = ifr.ifr_ifindex;
  
  	if (required_mtu > CAN_MTU) {
  
  		/* check if the frame fits into the CAN netdevice */
  		if (ioctl(s, SIOCGIFMTU, &ifr) < 0) {
  			perror("SIOCGIFMTU");
  			return 1;
  		}
  		mtu = ifr.ifr_mtu;
  
  		if (mtu != CANFD_MTU) {
  			printf("CAN interface ist not CAN FD capable - sorry.\n");
  			return 1;
  		}
  
  		/* interface is ok - try to switch the socket into CAN FD mode */
  		if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FD_FRAMES,
  			       &enable_canfd, sizeof(enable_canfd))){
  			printf("error when enabling CAN FD support\n");
  			return 1;
  		}
  
  		/* ensure discrete CAN FD length values 0..8, 12, 16, 20, 24, 32, 64 */
  		frame.len = can_dlc2len(can_len2dlc(frame.len));
  	}
  
  	/* disable default receive filter on this RAW socket */
  	/* This is obsolete as we do not read from the socket at all, but for */
  	/* this reason we can remove the receive list in the Kernel to save a */
  	/* little (really a very little!) CPU usage.                          */
  	setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);
  
  	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
  		perror("bind");
  		return 1;
  	}
  
  	/* send frame */
  	if (write(s, &frame, required_mtu) != required_mtu) {
  		perror("write");
  		return 1;
  	}
  
  	close(s);
  
  	return 0;
  }
  