int main()

in canutils/candump/candump.c [224:817]


int main(int argc, char **argv)
{
	fd_set rdfs;
	int s[MAXSOCK];
	unsigned char timestamp = 0;
	unsigned char hwtimestamp = 0;
	unsigned char down_causes_exit = 1;
	unsigned char dropmonitor = 0;
	unsigned char extra_msg_info = 0;
	unsigned char silent = SILENT_INI;
	unsigned char silentani = 0;
	unsigned char color = 0;
	unsigned char view = 0;
	unsigned char log = 0;
	unsigned char logfrmt = 0;
	int count = 0;
	int rcvbuf_size = 0;
	int opt;
	int currmax, numfilter;
	int join_filter;
	char *ptr, *nptr;
	struct sockaddr_can addr;
	char ctrlmsg[CMSG_SPACE(sizeof(struct timeval) + 3*sizeof(struct timespec) + sizeof(__u32))];
	struct iovec iov;
	struct msghdr msg;
	struct cmsghdr *cmsg;
	struct can_filter *rfilter;
	can_err_mask_t err_mask;
	struct canfd_frame frame;
	int nbytes, i, maxdlen;
	struct ifreq ifr;
	struct timeval tv, last_tv;
	struct timeval timeout, timeout_config = { 0, 0 }, *timeout_current = NULL;
	FILE *logfile = NULL;

#if 0 /* NuttX doesn't support these signals */
	signal(SIGTERM, sigterm);
	signal(SIGHUP, sigterm);
#endif
	signal(SIGINT, sigterm);

	last_tv.tv_sec  = 0;
	last_tv.tv_usec = 0;

	while ((opt = getopt(argc, argv, "t:HciaSs:lDdxLn:r:heT:?")) != -1) {
		switch (opt) {
		case 't':
			timestamp = optarg[0];
			if ((timestamp != 'a') && (timestamp != 'A') &&
			    (timestamp != 'd') && (timestamp != 'z')) {
				fprintf(stderr, "%s: unknown timestamp mode '%c' - ignored\n",
				       basename(argv[0]), optarg[0]);
				timestamp = 0;
			}
			break;

		case 'H':
			hwtimestamp = 1;
			break;

		case 'c':
			color++;
			break;

		case 'i':
			view |= CANLIB_VIEW_BINARY;
			break;

		case 'a':
			view |= CANLIB_VIEW_ASCII;
			break;

		case 'S':
			view |= CANLIB_VIEW_SWAP;
			break;

		case 'e':
			view |= CANLIB_VIEW_ERROR;
			break;

		case 's':
			silent = atoi(optarg);
			if (silent > SILENT_ON) {
				print_usage(basename(argv[0]));
				exit(1);
			}
			break;

		case 'l':
			log = 1;
			break;

		case 'D':
			down_causes_exit = 0;
			break;

		case 'd':
			dropmonitor = 1;
			break;

		case 'x':
			extra_msg_info = 1;
			break;

		case 'L':
			logfrmt = 1;
			break;

		case 'n':
			count = atoi(optarg);
			if (count < 1) {
				print_usage(basename(argv[0]));
				exit(1);
			}
			break;

		case 'r':
			rcvbuf_size = atoi(optarg);
			if (rcvbuf_size < 1) {
				print_usage(basename(argv[0]));
				exit(1);
			}
			break;

		case 'T':
			errno = 0;
			timeout_config.tv_usec = strtol(optarg, NULL, 0);
			if (errno != 0) {
				print_usage(basename(argv[0]));
				exit(1);
			}
			timeout_config.tv_sec = timeout_config.tv_usec / 1000;
			timeout_config.tv_usec = (timeout_config.tv_usec % 1000) * 1000;
			timeout_current = &timeout;
			break;
		default:
			print_usage(basename(argv[0]));
			exit(1);
			break;
		}
	}

	if (optind == argc) {
		print_usage(basename(argv[0]));
		exit(0);
	}

	if (logfrmt && view) {
		fprintf(stderr, "Log file format selected: Please disable ASCII/BINARY/SWAP options!\n");
		exit(0);
	}

	if (silent == SILENT_INI) {
		if (log) {
			fprintf(stderr, "Disabled standard output while logging.\n");
			silent = SILENT_ON; /* disable output on stdout */
		} else
			silent = SILENT_OFF; /* default output */
	}

	currmax = argc - optind; /* find real number of CAN devices */

	if (currmax > MAXSOCK) {
		fprintf(stderr, "More than %d CAN devices given on commandline!\n", MAXSOCK);
		return 1;
	}

	for (i=0; i < currmax; i++) {

		ptr = argv[optind+i];
		nptr = strchr(ptr, ',');

#ifdef DEBUG
		printf("open %d '%s'.\n", i, ptr);
#endif

		s[i] = socket(PF_CAN, SOCK_RAW, CAN_RAW);
		if (s[i] < 0) {
			perror("socket");
			return 1;
		}

		if (nptr)
			nbytes = nptr - ptr;  /* interface name is up the first ',' */
		else
			nbytes = strlen(ptr); /* no ',' found => no filter definitions */

		if (nbytes >= IFNAMSIZ) {
			fprintf(stderr, "name of CAN device '%s' is too long!\n", ptr);
			return 1;
		}

		if (nbytes > max_devname_len)
			max_devname_len = nbytes; /* for nice printing */

		addr.can_family = AF_CAN;

		memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name));
		strncpy(ifr.ifr_name, ptr, nbytes);

#ifdef DEBUG
		printf("using interface name '%s'.\n", ifr.ifr_name);
#endif

		if (strcmp(ANYDEV, ifr.ifr_name)) {
			if (ioctl(s[i], SIOCGIFINDEX, &ifr) < 0) {
				perror("SIOCGIFINDEX");
				exit(1);
			}
			addr.can_ifindex = ifr.ifr_ifindex;
		} else
			addr.can_ifindex = 0; /* any can interface */

		if (nptr) {

			/* found a ',' after the interface name => check for filters */

			/* determine number of filters to alloc the filter space */
			numfilter = 0;
			ptr = nptr;
			while (ptr) {
				numfilter++;
				ptr++; /* hop behind the ',' */
				ptr = strchr(ptr, ','); /* exit condition */
			}

			rfilter = malloc(sizeof(struct can_filter) * numfilter);
			if (!rfilter) {
				fprintf(stderr, "Failed to create filter space!\n");
				return 1;
			}

			numfilter = 0;
			err_mask = 0;
			join_filter = 0;

			while (nptr) {

				ptr = nptr+1; /* hop behind the ',' */
				nptr = strchr(ptr, ','); /* update exit condition */

				if (sscanf(ptr, "%" SCNx32 ":%" SCNx32,
					   &rfilter[numfilter].can_id,
					   &rfilter[numfilter].can_mask) == 2) {
 					rfilter[numfilter].can_mask &= ~CAN_ERR_FLAG;
					if (*(ptr+8) == ':')
						rfilter[numfilter].can_id |= CAN_EFF_FLAG;
					numfilter++;
				} else if (sscanf(ptr, "%" SCNx32 "~%" SCNx32,
						  &rfilter[numfilter].can_id,
						  &rfilter[numfilter].can_mask) == 2) {
 					rfilter[numfilter].can_id |= CAN_INV_FILTER;
 					rfilter[numfilter].can_mask &= ~CAN_ERR_FLAG;
					if (*(ptr+8) == '~')
						rfilter[numfilter].can_id |= CAN_EFF_FLAG;
					numfilter++;
				} else if (*ptr == 'j' || *ptr == 'J') {
					join_filter = 1;
				} else if (sscanf(ptr, "#%" SCNx32, &err_mask) != 1) {
					fprintf(stderr, "Error in filter option parsing: '%s'\n", ptr);
					return 1;
				}
			}

			if (err_mask)
				setsockopt(s[i], SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
					   &err_mask, sizeof(err_mask));

			if (join_filter && setsockopt(s[i], SOL_CAN_RAW, CAN_RAW_JOIN_FILTERS,
						      &join_filter, sizeof(join_filter)) < 0) {
				perror("setsockopt CAN_RAW_JOIN_FILTERS not supported by your Linux Kernel");
				return 1;
			}

			if (numfilter)
				setsockopt(s[i], SOL_CAN_RAW, CAN_RAW_FILTER,
					   rfilter, numfilter * sizeof(struct can_filter));

			free(rfilter);

		} /* if (nptr) */

		/* try to switch the socket into CAN FD mode */
		setsockopt(s[i], SOL_CAN_RAW, CAN_RAW_FD_FRAMES, &canfd_on, sizeof(canfd_on));

		if (rcvbuf_size) {

			int curr_rcvbuf_size;
			socklen_t curr_rcvbuf_size_len = sizeof(curr_rcvbuf_size);

			/* try SO_RCVBUFFORCE first, if we run with CAP_NET_ADMIN */
			if (setsockopt(s[i], SOL_SOCKET, SO_RCVBUFFORCE,
				       &rcvbuf_size, sizeof(rcvbuf_size)) < 0) {
#ifdef DEBUG
				printf("SO_RCVBUFFORCE failed so try SO_RCVBUF ...\n");
#endif
				if (setsockopt(s[i], SOL_SOCKET, SO_RCVBUF,
					       &rcvbuf_size, sizeof(rcvbuf_size)) < 0) {
					perror("setsockopt SO_RCVBUF");
					return 1;
				}

				if (getsockopt(s[i], SOL_SOCKET, SO_RCVBUF,
					       &curr_rcvbuf_size, &curr_rcvbuf_size_len) < 0) {
					perror("getsockopt SO_RCVBUF");
					return 1;
				}

				/* Only print a warning the first time we detect the adjustment */
				/* n.b.: The wanted size is doubled in Linux in net/sore/sock.c */
				if (!i && curr_rcvbuf_size < rcvbuf_size*2)
					fprintf(stderr, "The socket receive buffer size was "
						"adjusted due to /proc/sys/net/core/rmem_max.\n");
			}
		}

		if (timestamp || log || logfrmt) {

			if (hwtimestamp) {
				const int timestamping_flags = (SOF_TIMESTAMPING_SOFTWARE | \
								SOF_TIMESTAMPING_RX_SOFTWARE | \
								SOF_TIMESTAMPING_RAW_HARDWARE);

				if (setsockopt(s[i], SOL_SOCKET, SO_TIMESTAMPING,
						&timestamping_flags, sizeof(timestamping_flags)) < 0) {
					perror("setsockopt SO_TIMESTAMPING is not supported by your Linux kernel");
					return 1;
				}
			} else {
				const int timestamp_on = 1;

				if (setsockopt(s[i], SOL_SOCKET, SO_TIMESTAMP,
					       &timestamp_on, sizeof(timestamp_on)) < 0) {
					perror("setsockopt SO_TIMESTAMP");
					return 1;
				}
			}
		}

		if (dropmonitor) {

			const int dropmonitor_on = 1;

			if (setsockopt(s[i], SOL_SOCKET, SO_RXQ_OVFL,
				       &dropmonitor_on, sizeof(dropmonitor_on)) < 0) {
				perror("setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
				return 1;
			}
		}

		if (bind(s[i], (struct sockaddr *)&addr, sizeof(addr)) < 0) {
			perror("bind");
			return 1;
		}
	}

	if (log) {
		time_t currtime;
		struct tm now;
		char fname[83]; /* suggested by -Wformat-overflow= */

		if (time(&currtime) == (time_t)-1) {
			perror("time");
			return 1;
		}

		localtime_r(&currtime, &now);

		sprintf(fname, "candump-%04d-%02d-%02d_%02d%02d%02d.log",
			now.tm_year + 1900,
			now.tm_mon + 1,
			now.tm_mday,
			now.tm_hour,
			now.tm_min,
			now.tm_sec);

		if (silent != SILENT_ON)
			fprintf(stderr, "Warning: Console output active while logging!\n");

		fprintf(stderr, "Enabling Logfile '%s'\n", fname);

		logfile = fopen(fname, "w");
		if (!logfile) {
			perror("logfile");
			return 1;
		}
	}

	/* these settings are static and can be held out of the hot path */
	iov.iov_base = &frame;
	msg.msg_name = &addr;
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	msg.msg_control = &ctrlmsg;

	while (running) {

		FD_ZERO(&rdfs);
		for (i=0; i<currmax; i++)
			FD_SET(s[i], &rdfs);

		if (timeout_current)
			*timeout_current = timeout_config;

		if ((select(s[currmax-1]+1, &rdfs, NULL, NULL, timeout_current)) <= 0) {
			//perror("select");
			running = 0;
			continue;
		}

		for (i=0; i<currmax; i++) {  /* check all CAN RAW sockets */

			if (FD_ISSET(s[i], &rdfs)) {

				int idx;

				/* these settings may be modified by recvmsg() */
				iov.iov_len = sizeof(frame);
				msg.msg_namelen = sizeof(addr);
				msg.msg_controllen = sizeof(ctrlmsg);
				msg.msg_flags = 0;

				nbytes = recvmsg(s[i], &msg, 0);
				idx = idx2dindex(addr.can_ifindex, s[i]);

				if (nbytes < 0) {
					if ((errno == ENETDOWN) && !down_causes_exit) {
						fprintf(stderr, "%s: interface down\n", devname[idx]);
						continue;
					}
					perror("read");
					return 1;
				}

				if ((size_t)nbytes == CAN_MTU)
					maxdlen = CAN_MAX_DLEN;
				else if ((size_t)nbytes == CANFD_MTU)
					maxdlen = CANFD_MAX_DLEN;
				else {
					fprintf(stderr, "read: incomplete CAN frame\n");
					return 1;
				}

				if (count && (--count == 0))
					running = 0;

				for (cmsg = CMSG_FIRSTHDR(&msg);
				     cmsg && (cmsg->cmsg_level == SOL_SOCKET);
				     cmsg = CMSG_NXTHDR(&msg,cmsg)) {
					if (cmsg->cmsg_type == SO_TIMESTAMP) {
						memcpy(&tv, CMSG_DATA(cmsg), sizeof(tv));
					} else if (cmsg->cmsg_type == SO_TIMESTAMPING) {

						struct timespec *stamp = (struct timespec *)CMSG_DATA(cmsg);

						/*
						 * stamp[0] is the software timestamp
						 * stamp[1] is deprecated
						 * stamp[2] is the raw hardware timestamp
						 * See chapter 2.1.2 Receive timestamps in
						 * linux/Documentation/networking/timestamping.txt
						 */
						tv.tv_sec = stamp[2].tv_sec;
						tv.tv_usec = stamp[2].tv_nsec/1000;
					} else if (cmsg->cmsg_type == SO_RXQ_OVFL)
						memcpy(&dropcnt[i], CMSG_DATA(cmsg), sizeof(__u32));
				}

				/* check for (unlikely) dropped frames on this specific socket */
				if (dropcnt[i] != last_dropcnt[i]) {

					__u32 frames = dropcnt[i] - last_dropcnt[i];

					if (silent != SILENT_ON)
						printf("DROPCOUNT: dropped %" PRId32 " CAN frame%s on '%s' socket (total drops %" PRId32 ")\n",
						       (uint32_t)frames, (frames > 1)?"s":"", devname[idx], (uint32_t)dropcnt[i]);

					if (log)
						fprintf(logfile, "DROPCOUNT: dropped %" PRId32 " CAN frame%s on '%s' socket (total drops %" PRId32 ")\n",
							(uint32_t)frames, (frames > 1)?"s":"", devname[idx], (uint32_t)dropcnt[i]);

					last_dropcnt[i] = dropcnt[i];
				}

				/* once we detected a EFF frame indent SFF frames accordingly */
				if (frame.can_id & CAN_EFF_FLAG)
					view |= CANLIB_VIEW_INDENT_SFF;

				if (log) {
					char buf[CL_CFSZ]; /* max length */

					/* log CAN frame with absolute timestamp & device */
					sprint_canframe(buf, &frame, 0, maxdlen);
					fprintf(logfile, "(%010ju.%06ld) %*s %s\n",
						(uintmax_t)tv.tv_sec, tv.tv_usec,
						max_devname_len, devname[idx], buf);
				}

				if ((logfrmt) && (silent == SILENT_OFF)){
					char buf[CL_CFSZ]; /* max length */

					/* print CAN frame in log file style to stdout */
					sprint_canframe(buf, &frame, 0, maxdlen);
					printf("(%010ju.%06ld) %*s %s\n",
					       (uintmax_t)tv.tv_sec, tv.tv_usec,
					       max_devname_len, devname[idx], buf);
					goto out_fflush; /* no other output to stdout */
				}

				if (silent != SILENT_OFF){
					if (silent == SILENT_ANI) {
						printf("%c\b", anichar[silentani%=MAXANI]);
						silentani++;
					}
					goto out_fflush; /* no other output to stdout */
				}

				printf(" %s", (color>2)?col_on[idx%MAXCOL]:"");

				switch (timestamp) {

				case 'a': /* absolute with timestamp */
					printf("(%010ju.%06ld) ",
						   (uintmax_t)tv.tv_sec, tv.tv_usec);
					break;

				case 'A': /* absolute with date */
				{
					struct tm tm;
					char timestring[25];

					tm = *localtime(&tv.tv_sec);
					strftime(timestring, 24, "%Y-%m-%d %H:%M:%S", &tm);
					printf("(%s.%06ld) ", timestring, tv.tv_usec);
				}
				break;

				case 'd': /* delta */
				case 'z': /* starting with zero */
				{
					struct timeval diff;

					if (last_tv.tv_sec == 0)   /* first init */
						last_tv = tv;
					diff.tv_sec  = tv.tv_sec  - last_tv.tv_sec;
					diff.tv_usec = tv.tv_usec - last_tv.tv_usec;
					if (diff.tv_usec < 0)
						diff.tv_sec--, diff.tv_usec += 1000000;
					if (diff.tv_sec < 0)
						diff.tv_sec = diff.tv_usec = 0;
					printf("(%03ju.%06ld) ",
						   (uintmax_t)diff.tv_sec, diff.tv_usec);

					if (timestamp == 'd')
						last_tv = tv; /* update for delta calculation */
				}
				break;

				default: /* no timestamp output */
					break;
				}

				printf(" %s", (color && (color<3))?col_on[idx%MAXCOL]:"");
				printf("%*s", max_devname_len, devname[idx]);

				if (extra_msg_info) {

					if (msg.msg_flags & MSG_DONTROUTE)
						printf ("  TX %s", extra_m_info[frame.flags & 3]);
					else
						printf ("  RX %s", extra_m_info[frame.flags & 3]);
				}

				printf("%s  ", (color==1)?col_off:"");

				fprint_long_canframe(stdout, &frame, NULL, view, maxdlen);

				printf("%s", (color>1)?col_off:"");
				printf("\n");
			}

		out_fflush:
			fflush(stdout);
		}
	}

	for (i=0; i<currmax; i++)
		close(s[i]);

	if (log)
		fclose(logfile);

	return 0;
}