/*

 * Copyright (c) 1980 Regents of the University of California.

 * 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. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *	This product includes software developed by the University of

 *	California, Berkeley and its contributors.

 * 4. Neither the name of the University nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.

 */

/*

 * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL>

 * - added Native Language Support

 *

 * 2000-07-30 Per Andreas Buer <per@linpro.no> - added "q"-option

 */

/*

 * tcpscript - Modified from script - 2007 Lluis Batlle i Rossell

 */

#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <termios.h>

#include <sys/ioctl.h>

#include <sys/time.h>

#include <sys/signal.h>

#include <sys/socket.h>

#include <netinet/in.h>

#ifdef __linux__

#include <unistd.h>

#include <string.h>

#endif

#define HAVE_openpty

#define _PATH_BSHELL "/bin/sh"

#ifdef HAVE_openpty

#include <pty.h>

#endif

void finish(int);

void done(void);

void fail(void);

void resize(int);

void fixtty(void);

void getmaster(void);

void getslave(void);

void doinput(void);

void dooutput(void);

void doshell(void);

char	*shell;

int	master;

int	slave;

int	child;

int	subchild;

char	*fname;

struct	termios tt;

struct	winsize win;

int	lb;

int	l;

#ifndef HAVE_openpty

char	line[] = "/dev/ptyXX";

#endif

char	*cflg = NULL;

int	qflg = 0;

int	tcp_port = 4000;

int	limit_conns = 1;

enum {

    MAXCONNS = 10

};

static char *progname;

static void

die_if_link(char *fn) {

	struct stat s;

	if (lstat(fn, &s) == 0 && (S_ISLNK(s.st_mode) || s.st_nlink > 1)) {

		fprintf(stderr,

			"Warning: `%s' is a link.\n"

			  "Use `%s [options] %s' if you really "

			  "want to use it.\n"

			  "Script not started.\n",

			fn, progname, fn);

		exit(1);

	}

}

/*

 * script -t prints time delays as floating point numbers

 * The example program (scriptreplay) that we provide to handle this

 * timing output is a perl script, and does not handle numbers in

 * locale format (not even when "use locale;" is added).

 * So, since these numbers are not for human consumption, it seems

 * easiest to set LC_NUMERIC here.

 */

int

main(int argc, char **argv) {

	extern int optind;

	char *p;

	int ch;

	progname = argv[0];

	if ((p = strrchr(progname, '/')) != NULL)

		progname = p+1;

	if (argc == 2) {

		if (!strcmp(argv[1], "-V") || !strcmp(argv[1], "--version")) {

			printf("%s, modification of 'script', by %s\n",

			       progname, "Lluis Batlle i Rossell 2007");

			return 0;

		}

	}

	while ((ch = getopt(argc, argv, "c:qp:l:")) != -1)

		switch((char)ch) {

		case 'c':

			cflg = optarg;

			break;

		case 'p':

			tcp_port = atoi(optarg);

			break;

		case 'l':

			limit_conns = atoi(optarg);

			break;

		case 'q':

			qflg++;

			break;

		case '?':

		default:

			fprintf(stderr,

			exit(1);

		}

	argc -= optind;

	argv += optind;

	shell = getenv("SHELL");

	if (shell == NULL)

		shell = _PATH_BSHELL;

	getmaster();

	fixtty();

	(void) signal(SIGCHLD, finish);

	child = fork();

	if (child < 0) {

		perror("fork");

		fail();

	}

	if (child == 0) {

		subchild = child = fork();

		if (child < 0) {

			perror("fork");

			fail();

		}

		if (child)

			dooutput();

		else

			doshell();

	} else

		(void) signal(SIGWINCH, resize);

	doinput();

	return 0;

}

void

doinput() {

	register int cc;

	char ibuf[BUFSIZ];

	while ((cc = read(0, ibuf, BUFSIZ)) > 0)

		(void) write(master, ibuf, cc);

	done();

}

#include <sys/wait.h>

void

finish(int dummy) {

	int status;

	register int pid;

	register int die = 0;

	while ((pid = wait3(&status, WNOHANG, 0)) > 0)

		if (pid == child)

			die = 1;

	if (die)

		done();

}

void

resize(int dummy) {

	/* transmit window change information to the child */

	(void) ioctl(0, TIOCGWINSZ, (char *)&win);

	(void) ioctl(slave, TIOCSWINSZ, (char *)&win);

	kill(child, SIGWINCH);

}

void fatal()

{

    exit(-1);

}

int set_reusable(int s)

{

    int boolean = 1;

    int res;

    res = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &boolean, sizeof(boolean));

    if (res != 0)

        perror("Setsockopt REUSE failed"), fatal();

}

int listen_tcp()

{

    int s;

    struct sockaddr_in addr;

    int res;

    s = socket(PF_INET, SOCK_STREAM, 0);

    if (s == -1)

        perror("Failed socket()"), fatal();

    set_reusable(s);

    addr.sin_family = AF_INET;

    addr.sin_port = htons(tcp_port);

    addr.sin_addr.s_addr = INADDR_ANY;

    res = bind(s, (struct sockaddr *) &addr, sizeof(addr));

    if (s != 0)

        perror("Failed bind()"), fatal();

    res = listen(s, 1);

    if (s != 0)

        perror("Failed listen()"), fatal();

    if (!qflg)

        printf("Listening on port %i\n", tcp_port);

    return s;

}

void remove_element(int index, int *array, int total)

{

    int i;

    for (i = index; i < (total - 1); ++i)

        array[i] = array[i+1];

}

void

dooutput() {

	int cc;

	char obuf[BUFSIZ];

    int accept_socket;

    int conns[MAXCONNS];

    int nconns;

    int i;

	(void) close(0);

#ifdef HAVE_openpty

	(void) close(slave);

#endif

    fd_set read_set;

    fd_set should_read_set;

    fd_set tcp_set;

    accept_socket = listen_tcp();

    FD_ZERO(&should_read_set);

    FD_SET(accept_socket, &should_read_set);

    FD_SET(master, &should_read_set);

    nconns = 0;

	for (;;) {

        int max;

        read_set = should_read_set;

        /* Calculate max fd */

        max = accept_socket;

        if (master > max)

            max = master;

        for (i = 0; i < nconns; ++i)

            if (conns[i] > max)

                max = conns[i];

        select(max + 1, &read_set, 0, 0, 0);

        if (FD_ISSET(master, &read_set))

        {

            cc = read(master, obuf, sizeof (obuf));

            if (cc <= 0)

                break;

            /* Write to the terminal output */

            (void) write(1, obuf, cc);

            /* Broadcast messages */

            for (i = 0; i < nconns; ++i)

                (void) write(conns[i], obuf, cc);

        }

        for (i = 0; i < nconns; ++i)

        {

            if (FD_ISSET(conns[i], &read_set))

            {

                int size;

                size = read(conns[i], obuf, sizeof(obuf));

                if (size == 0)

                {

                    close(conns[i]);

                    FD_CLR(conns[i], &should_read_set);

                    remove_element(i, conns, nconns);

                    nconns--;

                }

            }

        }

        if (FD_ISSET(accept_socket, &read_set))

        {

            int s;

            s = accept(accept_socket, 0, 0);

            if (s == -1)

            {

                perror("accept() failed");

                break;

            }

            if (nconns < (MAXCONNS - 1) && nconns < limit_conns)

            {

                FD_SET(s, &should_read_set);

                conns[nconns] = s;

                nconns++;

            } else

                close(s);

        }

	}

    close(accept_socket);

    for (i = 0; i < nconns; ++i)

        close(conns[i]);

	done();

}

void

doshell() {

	char *shname;

#if 0

	int t;

	t = open(_PATH_TTY, O_RDWR);

	if (t >= 0) {

		(void) ioctl(t, TIOCNOTTY, (char *)0);

		(void) close(t);

	}

#endif

	getslave();

	(void) close(master);

	(void) dup2(slave, 0);

	(void) dup2(slave, 1);

	(void) dup2(slave, 2);

	(void) close(slave);

	shname = strrchr(shell, '/');

	if (shname)

		shname++;

	else

		shname = shell;

	if (cflg)

		execl(shell, shname, "-c", cflg, 0);

	else

		execl(shell, shname, "-i", 0);

	perror(shell);

	fail();

}

void

fixtty() {

	struct termios rtt;

	rtt = tt;

	cfmakeraw(&rtt);

	rtt.c_lflag &= ~ECHO;

	(void) tcsetattr(0, TCSAFLUSH, &rtt);

}

void

fail() {

	(void) kill(0, SIGTERM);

	done();

}

void

done() {

	time_t tvec;

	if (subchild) {

		(void) close(master);

	} else {

		(void) tcsetattr(0, TCSAFLUSH, &tt);

	}

	exit(0);

}

void

getmaster() {

#ifdef HAVE_openpty

	(void) tcgetattr(0, &tt);

	(void) ioctl(0, TIOCGWINSZ, (char *)&win);

	if (openpty(&master, &slave, NULL, &tt, &win) < 0) {

		fprintf(stderr, "openpty failed\n");

		fail();

	}

#else

	char *pty, *bank, *cp;

	struct stat stb;

	pty = &line[strlen("/dev/ptyp")];

	for (bank = "pqrs"; *bank; bank++) {

		line[strlen("/dev/pty")] = *bank;

		*pty = '0';

		if (stat(line, &stb) < 0)

			break;

		for (cp = "0123456789abcdef"; *cp; cp++) {

			*pty = *cp;

			master = open(line, O_RDWR);

			if (master >= 0) {

				char *tp = &line[strlen("/dev/")];

				int ok;

				/* verify slave side is usable */

				*tp = 't';

				ok = access(line, R_OK|W_OK) == 0;

				*tp = 'p';

				if (ok) {

					(void) tcgetattr(0, &tt);

				    	(void) ioctl(0, TIOCGWINSZ, 

						(char *)&win);

					return;

				}

				(void) close(master);

			}

		}

	}

	fprintf(stderr, "Out of pty's\n");

	fail();

#endif /* not HAVE_openpty */

}

void

getslave() {

#ifndef HAVE_openpty

	line[strlen("/dev/")] = 't';

	slave = open(line, O_RDWR);

	if (slave < 0) {

		perror(line);

		fail();

	}

	(void) tcsetattr(slave, TCSAFLUSH, &tt);

	(void) ioctl(slave, TIOCSWINSZ, (char *)&win);

#endif

	(void) setsid();

	(void) ioctl(slave, TIOCSCTTY, 0);

}