// utility.c

//

// © Portions Copyright (c) Symbian Software Ltd 2007. All rights reserved.

//

/*

 * Copyright (c) 1989, 1993

 *	The 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. 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.

 */

#define PRINTOPTIONS

#include "telnetd.h"

#ifndef __SYMBIAN32__

__RCSID("$Heimdal: utility.c,v 1.27 2001/09/03 05:54:17 assar Exp $"

        "$NetBSD: utility.c,v 1.2 2003/08/07 09:15:30 agc Exp $");

#endif

/*

 * utility functions performing io related tasks

 */

/*

 * ttloop

 *

 * A small subroutine to flush the network output buffer, get some

 * data from the network, and pass it through the telnet state

 * machine.  We also flush the pty input buffer (by dropping its data)

 * if it becomes too full.

 *

 * return 0 if OK or 1 if interrupted by a signal.

 */

int

ttloop(void)

{

    DIAG(TD_REPORT, {

	output_data("td: ttloop\r\n");

    });

    if (nfrontp-nbackp)

	netflush();

    ncc = read(net, netibuf, sizeof netibuf);

    if (ncc < 0) {

	if (errno == EINTR)

	    return 1;

#ifndef __SYMBIAN32__	

	syslog(LOG_INFO, "ttloop:  read: %m\n");

#endif	

	exit(1);

    } else if (ncc == 0) {

#ifndef __SYMBIAN32__    

	syslog(LOG_INFO, "ttloop:  peer died\n");

#endif	

	exit(1);

    }

    DIAG(TD_REPORT, {

	output_data("td: ttloop read %d chars\r\n", ncc);

    });

    netip = netibuf;

    telrcv();			/* state machine */

    if (ncc > 0) {

	pfrontp = pbackp = ptyobuf;

	telrcv();

    }

    return 0;

}  /* end of ttloop */

/*

 * Check a descriptor to see if out of band data exists on it.

 */

int

stilloob(int s)

{

    static struct timeval timeout = { 0 };

    fd_set	excepts;

    int value;

    if (s >= FD_SETSIZE)

	fatal(ourpty, "fd too large");

    do {

	FD_ZERO(&excepts);

	FD_SET(s, &excepts);

	value = select(s+1, 0, 0, &excepts, &timeout);

    } while ((value == -1) && (errno == EINTR));

    if (value < 0) {

	fatalperror(ourpty, "select");

    }

    if (FD_ISSET(s, &excepts)) {

	return 1;

    } else {

	return 0;

    }

}

void

ptyflush(void)

{

    int n;

    if ((n = pfrontp - pbackp) > 0) {

	DIAG((TD_REPORT | TD_PTYDATA), { 

	    output_data("td: ptyflush %d chars\r\n", n);

	});

	DIAG(TD_PTYDATA, printdata("pd", pbackp, n));

	n = write(ourpty, pbackp, n);

    }

    if (n < 0) {

	if (errno == EWOULDBLOCK || errno == EINTR)

	    return;

	cleanup(0);

    }

    pbackp += n;

    if (pbackp == pfrontp)

	pbackp = pfrontp = ptyobuf;

}

/*

 * nextitem()

 *

 *	Return the address of the next "item" in the TELNET data

 * stream.  This will be the address of the next character if

 * the current address is a user data character, or it will

 * be the address of the character following the TELNET command

 * if the current address is a TELNET IAC ("I Am a Command")

 * character.

 */

char *

nextitem(char *current)

{

    if ((*current&0xff) != IAC) {

	return current+1;

    }

    switch (*(current+1)&0xff) {

    case DO:

    case DONT:

    case WILL:

    case WONT:

	return current+3;

    case SB:{

	/* loop forever looking for the SE */

	char *look = current+2;

	for (;;) {

	    if ((*look++&0xff) == IAC) {

		if ((*look++&0xff) == SE) {

		    return look;

		}

	    }

	}

    }

    default:

	return current+2;

    }

}

/*

 * netclear()

 *

 *	We are about to do a TELNET SYNCH operation.  Clear

 * the path to the network.

 *

 *	Things are a bit tricky since we may have sent the first

 * byte or so of a previous TELNET command into the network.

 * So, we have to scan the network buffer from the beginning

 * until we are up to where we want to be.

 *

 *	A side effect of what we do, just to keep things

 * simple, is to clear the urgent data pointer.  The principal

 * caller should be setting the urgent data pointer AFTER calling

 * us in any case.

 */

void

netclear(void)

{

    char *thisitem, *next;

    char *good;

#define	wewant(p)	((nfrontp > p) && ((*p&0xff) == IAC) && \

			 ((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))

#ifdef ENCRYPTION

	thisitem = nclearto > netobuf ? nclearto : netobuf;

#else

	thisitem = netobuf;

#endif

	while ((next = nextitem(thisitem)) <= nbackp) {

	    thisitem = next;

	}

	/* Now, thisitem is first before/at boundary. */

#ifdef ENCRYPTION

	good = nclearto > netobuf ? nclearto : netobuf;

#else

	good = netobuf;	/* where the good bytes go */

#endif

	while (nfrontp > thisitem) {

	    if (wewant(thisitem)) {

		int length;

		next = thisitem;

		do {

		    next = nextitem(next);

		} while (wewant(next) && (nfrontp > next));

		length = next-thisitem;

		memmove(good, thisitem, length);

		good += length;

		thisitem = next;

	    } else {

		thisitem = nextitem(thisitem);

	    }

	}

	nbackp = netobuf;

	nfrontp = good;		/* next byte to be sent */

	neturg = 0;

}  /* end of netclear */

extern int not42;

/*

 *  netflush

 *		Send as much data as possible to the network,

 *	handling requests for urgent data.

 */

void

netflush(void)

{

    int n;

    if ((n = nfrontp - nbackp) > 0) {

	DIAG(TD_REPORT,

	     { n += output_data("td: netflush %d chars\r\n", n);

	     });

#ifdef ENCRYPTION

	if (encrypt_output) {

	    char *s = nclearto ? nclearto : nbackp;

	    if (nfrontp - s > 0) {

		(*encrypt_output)((unsigned char *)s, nfrontp-s);

		nclearto = nfrontp;

	    }

	}

#endif

	/*

	 * if no urgent data, or if the other side appears to be an

	 * old 4.2 client (and thus unable to survive TCP urgent data),

	 * write the entire buffer in non-OOB mode.

	 */

#if 1 /* remove this to make it work between solaris 2.6 and linux */

	if ((neturg == 0) || (not42 == 0)) {

#endif

	    n = write(net, nbackp, n);	/* normal write */	    

#if 1 /* remove this to make it work between solaris 2.6 and linux */

	} else {

	    n = neturg - nbackp;

	    /*

	     * In 4.2 (and 4.3) systems, there is some question about

	     * what byte in a sendOOB operation is the "OOB" data.

	     * To make ourselves compatible, we only send ONE byte

	     * out of band, the one WE THINK should be OOB (though

	     * we really have more the TCP philosophy of urgent data

	     * rather than the Unix philosophy of OOB data).

	     */

	    if (n > 1) {

		n = send(net, nbackp, n-1, 0);	/* send URGENT all by itself */

	    } else {

		n = send(net, nbackp, n, MSG_OOB);	/* URGENT data */

	    }

	}

#endif

    }

    if (n < 0) {

	if (errno == EWOULDBLOCK || errno == EINTR)

	    return;

	cleanup(0);

    }

    nbackp += n;

#ifdef ENCRYPTION

    if (nbackp > nclearto)

	nclearto = 0;

#endif

    if (nbackp >= neturg) {

	neturg = 0;

    }

    if (nbackp == nfrontp) {

	nbackp = nfrontp = netobuf;

#ifdef ENCRYPTION

	nclearto = 0;

#endif

    }

    return;

}

/*

 * writenet

 *

 * Just a handy little function to write a bit of raw data to the net.

 * It will force a transmit of the buffer if necessary

 *

 * arguments

 *    ptr - A pointer to a character string to write

 *    len - How many bytes to write

 */

void

writenet(unsigned char *ptr, int len)

{

    /* flush buffer if no room for new data) */

    while ((&netobuf[BUFSIZ] - nfrontp) < len) {

	/* if this fails, don't worry, buffer is a little big */

	netflush();

    }

    memmove(nfrontp, ptr, len);

    nfrontp += len;

}

/*

 * miscellaneous functions doing a variety of little jobs follow ...

 */

void fatal(int f, char *msg)

{

    char buf[BUFSIZ];

    snprintf(buf, sizeof(buf), "telnetd: %s.\r\n", msg);

#ifdef ENCRYPTION

    if (encrypt_output) {

	/*

	 * Better turn off encryption first....

	 * Hope it flushes...

	 */

	encrypt_send_end();

	netflush();

    }

#endif

    write(f, buf, (int)strlen(buf));

    sleep(1);	/*XXX*/

    exit(1);

}

void

fatalperror_errno(int f, const char *msg, int error)

{

    char buf[BUFSIZ];

    snprintf(buf, sizeof(buf), "%s: %s", msg, strerror(error));

    fatal(f, buf);

}

void

fatalperror(int f, const char *msg)

{

    fatalperror_errno(f, msg, errno);

}

char editedhost[32];

void edithost(char *pat, char *host)

{

    char *res = editedhost;

    if (!pat)

	pat = "";

    while (*pat) {

	switch (*pat) {

	case '#':

	    if (*host)

		host++;

	    break;

	case '@':

	    if (*host)

		*res++ = *host++;

	    break;

	default:

	    *res++ = *pat;

	    break;

	}

	if (res == &editedhost[sizeof editedhost - 1]) {

	    *res = '\0';

	    return;

	}

	pat++;

    }

    if (*host)

	strlcpy (res, host,

			 sizeof editedhost - (res - editedhost));

    else

	*res = '\0';

    editedhost[sizeof editedhost - 1] = '\0';

}

static char *putlocation;

void

putstr(char *s)

{

    while (*s)

	putchr(*s++);

}

void

putchr(int cc)

{

    *putlocation++ = cc;

}

/*

 * This is split on two lines so that SCCS will not see the M

 * between two % signs and expand it...

 */

static char fmtstr[] = { "%l:%M" "%P on %A, %d %B %Y" };

void putf(char *cp, char *where)

{

#ifdef HAVE_UNAME

    struct utsname name;

#endif

    char *slash;

    time_t t;

    char db[100];

    /* if we don't have uname, set these to sensible values */

    char *sysname = "Unix", 

	*machine = "", 

	*release = "",

	*version = ""; 

#ifdef HAVE_UNAME

    uname(&name);

    sysname=name.sysname;

    machine=name.machine;

    release=name.release;

    version=name.version;

#endif

    putlocation = where;

    while (*cp) {

	if (*cp != '%') {

	    putchr(*cp++);

	    continue;

	}

	switch (*++cp) {

	case 't':

#ifdef	STREAMSPTY

	    /* names are like /dev/pts/2 -- we want pts/2 */

	    slash = strchr(line+1, '/');

#else

	    slash = strrchr(line, '/');

#endif

	    if (slash == (char *) 0)

		putstr(line);

	    else

		putstr(&slash[1]);

	    break;

	case 'h':

	    putstr(editedhost);

	    break;

	case 's':

	    putstr(sysname);

	    break;

	case 'm':

	    putstr(machine);

	    break;

	case 'r':

	    putstr(release);

	    break;

	case 'v':

	    putstr(version);

	    break;

	case 'd':

	    time(&t);

	    strftime(db, sizeof(db), fmtstr, localtime(&t));

	    putstr(db);

	    break;

	case '%':

	    putchr('%');

	    break;

	}

	cp++;

    }

}

#ifdef DIAGNOSTICS

/*