sobredirect/passthru.c

/*
    Copyright (C) 2006 AbsoluteValue Systems, Inc.  All Rights Reserved.

    Originally written and maintained by: Solomon Peachy <pizza@shaftnet.org>
    Local redirection & Debugging code by: Mark Mathews <mark@linux-wlan.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */
#include "common.h"

#include <errno.h>
#include <sys/types.h>

#include <sys/stat.h>
#include <sys/poll.h>

#include <sys/time.h>

#include <sys/socket.h>

#include <sys/ioctl.h>
#include <fcntl.h>
#include <signal.h>

#include <string.h>

#include <syslog.h>
#include <ctype.h>

struct sob_config {
	uint32_t baud;
	uint32_t stopbits;
	uint32_t databits;
	uint8_t parity;
	uint8_t flow;
};

/* ================================================================ */

static void dump_config(char *prefix, struct sob_config *cfg) 
{
	syslog(LOG_INFO, "%s Serial %d-%d%c%d Flow %c", 
	       prefix, 
	       cfg->baud, cfg->databits, cfg->parity, cfg->stopbits,
	       cfg->flow);
}


void printhelp() {
	fprintf(stderr, "  Serial to Serial forwarder and sniffer\n\n");
	fprintf(stderr, "\t-d <serialdev> -s <commsparams> [ -x | -r ]\n");
	fprintf(stderr, "\t-D <serialdev> -S <commsparams> [ -X | -R ]\n");
	fprintf(stderr, "commsparams:  <baud>-<databits><parity><stopbits>\n");
	fprintf(stderr, "\n");
}

static int run = 1;

int main (int argc, char **argv)
{
	struct sob_config sob_cfg1;
	struct sob_config sob_cfg2;

	/* Basic communications parameters */

	int modem_lines = 0;

	int hw_flow = 0;
	int sw_flow = 0;
	int hw_flow2 = 0;
	int sw_flow2 = 0;

	char *ser_dev1 = NULL;
	char *ser_dev2 = NULL;

	int ser_fd1;
	int ser_fd2;

	char *comm_params1 = NULL;
	char *comm_params2 = NULL;

	struct termios ser_cfg1;
	struct termios ser_cfg2;

	int daemonize = 0;

	int i;

	/* Parse command line */
	while(1) {
		int c;
		c = getopt(argc, argv, "hd:s:D:S:xrXR");
		if (c == -1) break;
		switch (c) {
		case 'h':
			printhelp();
			exit(0);
		case 'd':
			ser_dev1 = optarg;
			break;
		case 'D':
			ser_dev2 = optarg;
			break;
		case 's':
			comm_params1 = optarg;
			break;
		case 'S':
			comm_params2 = optarg;
			break;
		case 'x':
			sw_flow = 1;
			break;
		case 'r':
			hw_flow = 1;
			break;
		case 'X':
			sw_flow2 = 1;
			break;
		case 'R':
			hw_flow2 = 1;
			break;

		default:
			fprintf(stderr, "getopt returned bogus option '%c'\n", c);
			return 1;
		}
	}

	if (!ser_dev1 || !ser_dev2 || !comm_params1 || !comm_params2) {
		fprintf(stderr, "ERROR:  missing command-line arguments.\n\n");
		printhelp();
		return 2;
	}

	if (hw_flow && sw_flow) {
		fprintf(stderr, "ERROR:  can't use both hardware and software flow control.\n\n");
		printhelp();
		return 10;
	}

	if (hw_flow2 && sw_flow2) {
		fprintf(stderr, "ERROR:  can't use both hardware and software flow control.\n\n");
		printhelp();
		return 10;
	}

	if (hw_flow)
		sob_cfg1.flow = 'H';
	else if (sw_flow)
		sob_cfg1.flow = 'S';
	else
		sob_cfg1.flow = 'N';

	if (hw_flow2)
		sob_cfg2.flow = 'H';
	else if (sw_flow2)
		sob_cfg2.flow = 'S';
	else
		sob_cfg2.flow = 'N';

	/* Parse serial parameters #1 */
	i = sscanf(comm_params1, "%d-%d%c%d", &sob_cfg1.baud, &sob_cfg1.databits, 
		   &sob_cfg1.parity, &sob_cfg1.stopbits);
	if (i < 4) {
		fprintf(stderr, "Invalid commparameters (%s)\n", comm_params1);
		printhelp();
		return 6;
	}
	sob_cfg1.parity &= ~0x20;  /* Case insensitive */

	/* Parse serial parameters #2 */
	i = sscanf(comm_params2, "%d-%d%c%d", &sob_cfg2.baud, &sob_cfg2.databits, 
		   &sob_cfg2.parity, &sob_cfg2.stopbits);
	if (i < 4) {
		fprintf(stderr, "Invalid commparameters (%s)\n", comm_params2);
		printhelp();
		return 6;
	}
	sob_cfg2.parity &= ~0x20;  /* Case insensitive */

	/* Open serial port #1 */
	ser_fd1 = open(ser_dev1, O_RDWR|O_NONBLOCK|O_NOCTTY|O_ASYNC);
	if (ser_fd1 < 0) {
		perror("Could not open serial device #1");
		return 5;
	}

	if (!isatty(ser_fd1)) {
		perror("Not a TTY\n");
		return 999;
	}

	/* Set serial Parameters #1*/
	i = setserial(&ser_cfg1, ser_fd1, sob_cfg1.baud, sob_cfg1.databits, 
		      sob_cfg1.parity, sob_cfg1.stopbits, 
		      hw_flow, sw_flow, modem_lines);
	if (i > 0) {
		printhelp();
		return 7;
	}

	if (i < 0) {
		perror("Could not initialize serial device");
		return 8;
	}

	/* Turn off Break #1*/
	i = ioctl(ser_fd1, TIOCCBRK);
	if (i < 0) {
		perror("Could not turn off BREAK");
		return 18;
	}

	/* Open serial port #2 */
	ser_fd2 = open(ser_dev2, O_RDWR|O_NONBLOCK|O_NOCTTY|O_ASYNC);
	if (ser_fd2 < 0) {
		perror("Could not open serial device #2");
		return 5;
	}

	if (!isatty(ser_fd2)) {
		perror("Not a TTY\n");
		return 999;
	}

	/* Set serial Parameters #2*/
	i = setserial(&ser_cfg2, ser_fd2, sob_cfg2.baud, sob_cfg2.databits, 
		      sob_cfg2.parity, sob_cfg2.stopbits, 
		      hw_flow2, sw_flow2, modem_lines);
	if (i > 0) {
		printhelp();
		return 7;
	}

	if (i < 0) {
		perror("Could not initialize serial device");
		return 8;
	}

	/* Turn off Break #2*/
	i = ioctl(ser_fd2, TIOCCBRK);
	if (i < 0) {
		perror("Could not turn off BREAK");
		return 18;
	}

	/* Ignore sigpipes */
	signal(SIGPIPE, SIG_IGN);

	if (daemonize)   daemon(0, 0);

	/* And at this point, start! */
	openlog("sob", LOG_PID, LOG_DAEMON);

	struct pollfd pfds[2];
	
	/* Set up the poll */
	pfds[0].fd = ser_fd1;
	pfds[0].revents = 0;
	pfds[0].events = POLLIN|POLLPRI;
	pfds[1].fd = ser_fd2;
	pfds[1].revents = 0;
	pfds[1].events = POLLIN|POLLPRI;

	syslog(LOG_INFO, "serialsnif bound and active");
	dump_config("Local config#1: ", &sob_cfg1);
	dump_config("Local config#2: ", &sob_cfg2);

#define TV_FLATTEN(__tv__)  ((__tv__.tv_sec * 1000000) + __tv__.tv_usec)

	/* Now we can run */
	while (run) {

		pfds[0].revents = 0;
		pfds[1].revents = 0;

		i = poll(pfds, 2, 1000);

		/* If the poll timed out, just do it again */
		if (i == 0) {
			continue;
		}

		/* Handle serial port reset */
		if (pfds[0].revents & (POLLERR|POLLHUP|POLLNVAL)) {
			syslog(LOG_ERR, "Serial port #1 reset, purging buffers (%d)\n", pfds[0].revents);

			tcflush(ser_fd1, TCIOFLUSH);

			close(ser_fd1);
			ser_fd1 = open(ser_dev1,O_RDWR|O_NONBLOCK|O_NOCTTY|O_ASYNC);

			if (ser_fd1 < 0) {
				syslog(LOG_CRIT, "Could not open serial device, terminating: %m");
				return 5;
			}

			i = tcsetattr(ser_fd1, TCSANOW, &ser_cfg1);
			if (i < 0) {
				syslog(LOG_CRIT, "Could not initialize serial device: %m");
			}
			pfds[1].fd = ser_fd1;
			continue;
		}
		if (pfds[1].revents & (POLLERR|POLLHUP|POLLNVAL)) {
			syslog(LOG_ERR, "Serial port #2 reset, purging buffers (%d)\n", pfds[1].revents);

			tcflush(ser_fd2, TCIOFLUSH);

			close(ser_fd2);
			ser_fd2 = open(ser_dev1,O_RDWR|O_NONBLOCK|O_NOCTTY|O_ASYNC);

			if (ser_fd2 < 0) {
				syslog(LOG_CRIT, "Could not open serial device, terminating: %m");
				return 5;
			}

			i = tcsetattr(ser_fd2, TCSANOW, &ser_cfg2);
			if (i < 0) {
				syslog(LOG_CRIT, "Could not initialize serial device: %m");
			}
			pfds[1].fd = ser_fd2;
			continue;
		}

		/* Handle the serial port IN */
		if (pfds[0].revents & (POLLIN|POLLPRI)) {
			uint8_t c;

			while ((i = read(ser_fd1, &c, sizeof(c))) > 0) {
				char buf[20];
				write(ser_fd2, &c, sizeof(c));
				sprintf(buf, "1> 0x%02x '%c'\n", c, isprint(c)? c : '.' );
				write(fileno(stdout), buf, strlen(buf));
			}
		}
		if (pfds[1].revents & (POLLIN|POLLPRI)) {
			uint8_t c;

			while ((i = read(ser_fd2, &c, sizeof(c))) > 0) {
				char buf[20];
				write(ser_fd1, &c, sizeof(c));
				sprintf(buf, "2> 0x%02x '%c'\n", c, isprint(c)? c : '.' );
				write(fileno(stdout), buf, strlen(buf));
			}
		}
	}
	
	/* Clean up */
	syslog(LOG_INFO, "sobredird shutting down");

	tcflush(ser_fd1, TCIOFLUSH);
	tcflush(ser_fd2, TCIOFLUSH);
	close(ser_fd1);
	close(ser_fd2);

	closelog();

	return 0;
}