/*
	a simple TCP connector
*/

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <fcntl.h>
#include <netdb.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>

#include "stty.h"

#define PORT		5800
#define BUFF_SIZE	4096

extern int errno;

#define max(x,y)	((x) > (y) ? (x) : (y))

void errorf (char *fmt, ...)
{
	va_list args;
	
	va_start (args, fmt);
	vfprintf (stderr, fmt, args);
	exit (1);
}

int main (int argc, char **argv)
{
	fd_set readset;
	struct sockaddr_in my_addr;
	struct hostent *host;
	int sock, n, fd, fdmax, port = PORT, quit = 0, echar = 0;
	char buff[BUFF_SIZE], device[128], *s;

	*device = 0;
	if (argc < 2)
		errorf ("tcpconn: error: hostname required\n" \
			"Usage: tcpconn [-d pty] [-p port] hostname[:port]\n");
	for (n = 1; *argv[n] == '-'; n++)
		switch (argv[n][1])
		{
			case 'e' :
				echar = argv[n][2] ? argv[n][2] : 28;
				break;

			case 'd' :
				strcpy (device, argv[n][2] ? &argv[n][2] : argv[++n]);
				break;

			case 'p' :
				port = argv[n][2] ? atoi(argv[n] + 2) : atoi(argv[++n]);
				break;

			case 'h' :
				errorf ("Usage: tcpconn [-d pty] [-p port] hostname[:port]\n");
		}

	if ((s = strtok(argv[n], ":")) == NULL)
		errorf ("invalid hostname\n");
	host = gethostbyname(s);
	
	if ((s = strtok(NULL, ":")) != NULL)
		port = atoi(s);

	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
		errorf ("can't create client socket (%s)\n", strerror(errno));
	
	bzero (&my_addr, sizeof(my_addr));
	my_addr.sin_family = AF_INET;
	my_addr.sin_addr = *(struct in_addr *) host->h_addr_list[0];
	my_addr.sin_port = htons(port);

	if (connect(sock, (struct sockaddr *) &my_addr, sizeof(my_addr)) < 0)
		errorf ("can't connect to server (%s)\n", strerror(errno));

	if (*device)
	{
		if ((fd = open(device, O_RDWR)) < 0)
			errorf ("can't open device %s (%s)", device, strerror(errno));

		dup2 (fd, STDIN_FILENO);
		dup2 (fd, STDOUT_FILENO);
	}
	else if (isatty(STDIN_FILENO))
	{
		stty_initstore ();
		stty_raw (STDIN_FILENO);
		atexit (stty_orig);
	}

	fdmax = max(STDIN_FILENO, sock);

	while (!quit)
	{
		FD_ZERO (&readset);
		FD_SET (STDIN_FILENO, &readset);
		FD_SET (sock, &readset);

		if (select(fdmax + 1, &readset, NULL, NULL, NULL) < 0)
			errorf ("select failed (%s)\n", strerror(errno));

		if (FD_ISSET(STDIN_FILENO, &readset))
		{
			if ((n = read(STDIN_FILENO, buff, BUFF_SIZE)) <= 0)
				quit = 1;
			else if (n == 1 && echar && *buff == echar)
				quit = 1;
			else
				write (sock, buff, n);
		}

		if (FD_ISSET(sock, &readset))
		{
			if ((n = read(sock, buff, BUFF_SIZE)) <= 0)
				quit = 1;
			else
				write (STDOUT_FILENO, buff, n);
		}
	}

	close (sock);
	printf ("\r\n");

	return (0);
}