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File: [cvs.NetBSD.org] / src / libexec / telnetd / slc.c (download)

Revision 1.15, Fri Nov 24 19:46:58 2006 UTC (13 years, 10 months ago) by christos
Branch: MAIN
CVS Tags: yamt-pf42-baseX, yamt-pf42-base4, yamt-pf42-base3, yamt-pf42-base2, yamt-pf42-base, yamt-pf42, yamt-pagecache-tag8, yamt-pagecache-base9, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, yamt-pagecache-base5, yamt-pagecache-base4, yamt-pagecache-base3, yamt-pagecache-base2, yamt-pagecache-base, yamt-pagecache, wrstuden-revivesa-base-3, wrstuden-revivesa-base-2, wrstuden-revivesa-base-1, wrstuden-revivesa-base, wrstuden-revivesa, wrstuden-fixsa-newbase, wrstuden-fixsa-base-1, wrstuden-fixsa-base, wrstuden-fixsa, tls-maxphys-base, tls-maxphys, tls-earlyentropy-base, tls-earlyentropy, riastradh-xf86-video-intel-2-7-1-pre-2-21-15, riastradh-drm2-base3, riastradh-drm2-base2, riastradh-drm2-base1, riastradh-drm2-base, riastradh-drm2, prg-localcount2-base3, prg-localcount2-base2, prg-localcount2-base1, prg-localcount2-base, prg-localcount2, phil-wifi-base, phil-wifi-20200421, phil-wifi-20200411, phil-wifi-20200406, phil-wifi-20191119, phil-wifi-20190609, phil-wifi, pgoyette-localcount-base, pgoyette-localcount-20170426, pgoyette-localcount-20170320, pgoyette-localcount-20170107, pgoyette-localcount-20161104, pgoyette-localcount-20160806, pgoyette-localcount-20160726, pgoyette-localcount, pgoyette-compat-merge-20190127, pgoyette-compat-base, pgoyette-compat-20190127, pgoyette-compat-20190118, pgoyette-compat-1226, pgoyette-compat-1126, pgoyette-compat-1020, pgoyette-compat-0930, pgoyette-compat-0906, pgoyette-compat-0728, pgoyette-compat-0625, pgoyette-compat-0521, pgoyette-compat-0502, pgoyette-compat-0422, pgoyette-compat-0415, pgoyette-compat-0407, pgoyette-compat-0330, pgoyette-compat-0322, pgoyette-compat-0315, pgoyette-compat, perseant-stdc-iso10646-base, perseant-stdc-iso10646, netbsd-9-base, netbsd-9-0-RELEASE, netbsd-9-0-RC2, netbsd-9-0-RC1, netbsd-9, netbsd-8-base, netbsd-8-2-RELEASE, netbsd-8-1-RELEASE, netbsd-8-1-RC1, netbsd-8-0-RELEASE, netbsd-8-0-RC2, netbsd-8-0-RC1, netbsd-8, netbsd-7-nhusb-base-20170116, netbsd-7-nhusb-base, netbsd-7-nhusb, netbsd-7-base, netbsd-7-2-RELEASE, netbsd-7-1-RELEASE, netbsd-7-1-RC2, netbsd-7-1-RC1, netbsd-7-1-2-RELEASE, netbsd-7-1-1-RELEASE, netbsd-7-1, netbsd-7-0-RELEASE, netbsd-7-0-RC3, netbsd-7-0-RC2, netbsd-7-0-RC1, netbsd-7-0-2-RELEASE, netbsd-7-0-1-RELEASE, netbsd-7-0, netbsd-7, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-5-RELEASE, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-6-RELEASE, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, netbsd-5-base, netbsd-5-2-RELEASE, netbsd-5-2-RC1, netbsd-5-2-3-RELEASE, netbsd-5-2-2-RELEASE, netbsd-5-2-1-RELEASE, netbsd-5-2, netbsd-5-1-RELEASE, netbsd-5-1-RC4, netbsd-5-1-RC3, netbsd-5-1-RC2, netbsd-5-1-RC1, netbsd-5-1-5-RELEASE, netbsd-5-1-4-RELEASE, netbsd-5-1-3-RELEASE, netbsd-5-1-2-RELEASE, netbsd-5-1-1-RELEASE, netbsd-5-1, netbsd-5-0-RELEASE, netbsd-5-0-RC4, netbsd-5-0-RC3, netbsd-5-0-RC2, netbsd-5-0-RC1, netbsd-5-0-2-RELEASE, netbsd-5-0-1-RELEASE, netbsd-5-0, netbsd-5, netbsd-4-base, netbsd-4-0-RELEASE, netbsd-4-0-RC5, netbsd-4-0-RC4, netbsd-4-0-RC3, netbsd-4-0-RC2, netbsd-4-0-RC1, netbsd-4-0-1-RELEASE, netbsd-4-0, netbsd-4, mjf-devfs2-base, mjf-devfs2, matt-premerge-20091211, matt-nb8-mediatek-base, matt-nb8-mediatek, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, matt-nb5-pq3-base, matt-nb5-pq3, matt-nb5-mips64-u2-k2-k4-k7-k8-k9, matt-nb5-mips64-u1-k1-k5, matt-nb5-mips64-premerge-20101231, matt-nb5-mips64-premerge-20091211, matt-nb5-mips64-k15, matt-nb5-mips64, matt-nb4-mips64-k7-u2a-k9b, matt-mips64-premerge-20101231, matt-mips64-base2, matt-mips64-base, matt-mips64, matt-armv6-prevmlocking, matt-armv6-nbase, matt-armv6-base, matt-armv6, localcount-20160914, keiichi-mipv6-base, keiichi-mipv6, jym-xensuspend-nbase, jym-xensuspend-base, jym-xensuspend, is-mlppp-base, is-mlppp, hpcarm-cleanup-nbase, hpcarm-cleanup-base, hpcarm-cleanup, cube-autoconf-base, cube-autoconf, cherry-xenmp-base, cherry-xenmp, bouyer-socketcan-base1, bouyer-socketcan-base, bouyer-socketcan, bouyer-quota2-nbase, bouyer-quota2-base, bouyer-quota2, agc-symver-base, agc-symver, HEAD
Changes since 1.14: +3 -3 lines

fix spelling of accommodate; from Zapher.

/*	$NetBSD: slc.c,v 1.15 2006/11/24 19:46:58 christos Exp $	*/

/*
 * 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.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)slc.c	8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: slc.c,v 1.15 2006/11/24 19:46:58 christos Exp $");
#endif
#endif /* not lint */

#include "telnetd.h"

#ifdef	LINEMODE
/*
 * local varibles
 */
static unsigned char	*def_slcbuf = (unsigned char *)0;
static int		def_slclen = 0;
static int		slcchange;	/* change to slc is requested */
static unsigned char	*slcptr;	/* pointer into slc buffer */
static unsigned char	slcbuf[NSLC*6];	/* buffer for slc negotiation */

void default_slc(void);
void process_slc(u_int, u_int, cc_t);

/*
 * send_slc
 *
 * Write out the current special characters to the client.
 */
void
send_slc(void)
{
	int i;

	/*
	 * Send out list of triplets of special characters
	 * to client.  We only send info on the characters
	 * that are currently supported.
	 */
	for (i = 1; i <= NSLC; i++) {
		if ((slctab[i].defset.flag & SLC_LEVELBITS) == SLC_NOSUPPORT)
			continue;
		add_slc((unsigned char)i, slctab[i].current.flag,
							slctab[i].current.val);
	}

}  /* end of send_slc */

/*
 * default_slc
 *
 * Set pty special characters to all the defaults.
 */
void
default_slc(void)
{
	int i;

	for (i = 1; i <= NSLC; i++) {
		slctab[i].current.val = slctab[i].defset.val;
		if (slctab[i].current.val == (cc_t)(_POSIX_VDISABLE))
			slctab[i].current.flag = SLC_NOSUPPORT;
		else
			slctab[i].current.flag = slctab[i].defset.flag;
		if (slctab[i].sptr) {
			*(slctab[i].sptr) = slctab[i].defset.val;
		}
	}
	slcchange = 1;

}  /* end of default_slc */
#endif	/* LINEMODE */

/*
 * get_slc_defaults
 *
 * Initialize the slc mapping table.
 */
void
get_slc_defaults(void)
{
	int i;

	init_termbuf();

	for (i = 1; i <= NSLC; i++) {
		slctab[i].defset.flag =
			spcset(i, &slctab[i].defset.val, &slctab[i].sptr);
		slctab[i].current.flag = SLC_NOSUPPORT;
		slctab[i].current.val = 0;
	}

}  /* end of get_slc_defaults */

#ifdef	LINEMODE
/*
 * add_slc
 *
 * Add an slc triplet to the slc buffer.
 */
void
add_slc(char func, char flag, cc_t val)
{

	if ((*slcptr++ = (unsigned char)func) == 0xff)
		*slcptr++ = 0xff;

	if ((*slcptr++ = (unsigned char)flag) == 0xff)
		*slcptr++ = 0xff;

	if ((*slcptr++ = (unsigned char)val) == 0xff)
		*slcptr++ = 0xff;

}  /* end of add_slc */

/*
 * start_slc
 *
 * Get ready to process incoming slc's and respond to them.
 *
 * The parameter getit is non-zero if it is necessary to grab a copy
 * of the terminal control structures.
 */
void
start_slc(int getit)
{

	slcchange = 0;
	if (getit)
		init_termbuf();
	(void)snprintf((char *)slcbuf, sizeof slcbuf, "%c%c%c%c",
					IAC, SB, TELOPT_LINEMODE, LM_SLC);
	slcptr = slcbuf + 4;

}  /* end of start_slc */

/*
 * end_slc
 *
 * Finish up the slc negotiation.  If something to send, then send it.
 */
int
end_slc(unsigned char **bufp)
{
	int len;

	/*
	 * If a change has occurred, store the new terminal control
	 * structures back to the terminal driver.
	 */
	if (slcchange) {
		set_termbuf();
	}

	/*
	 * If the pty state has not yet been fully processed and there is a
	 * deferred slc request from the client, then do not send any
	 * sort of slc negotiation now.  We will respond to the client's
	 * request very soon.
	 */
	if (def_slcbuf && (terminit() == 0)) {
		return(0);
	}

	if (slcptr > (slcbuf + 4)) {
		if (bufp) {
			*bufp = &slcbuf[4];
			return(slcptr - slcbuf - 4);
		} else {
			(void) snprintf((char *)slcptr,
			    sizeof(slcbuf) - (slcptr - slcbuf), "%c%c",
			    IAC, SE);
			slcptr += 2;
			len = slcptr - slcbuf;
			writenet(slcbuf, len);
			netflush();  /* force it out immediately */
			DIAG(TD_OPTIONS, printsub('>', slcbuf+2, len-2););
		}
	}
	return (0);

}  /* end of end_slc */

/*
 * process_slc
 *
 * Figure out what to do about the client's slc
 */
void
process_slc(u_int func, u_int flag, cc_t val)
{
	int hislevel, mylevel, ack;

	/*
	 * Ensure that we know something about this function
	 */
	if (func > NSLC) {
		add_slc(func, SLC_NOSUPPORT, 0);
		return;
	}

	/*
	 * Process the special case requests of 0 SLC_DEFAULT 0
	 * and 0 SLC_VARIABLE 0.  Be a little forgiving here, don't
	 * worry about whether the value is actually 0 or not.
	 */
	if (func == 0) {
		if ((flag = flag & SLC_LEVELBITS) == SLC_DEFAULT) {
			default_slc();
			send_slc();
		} else if (flag == SLC_VARIABLE) {
			send_slc();
		}
		return;
	}

	/*
	 * Appears to be a function that we know something about.  So
	 * get on with it and see what we know.
	 */

	hislevel = flag & SLC_LEVELBITS;
	mylevel = slctab[func].current.flag & SLC_LEVELBITS;
	ack = flag & SLC_ACK;
	/*
	 * ignore the command if:
	 * the function value and level are the same as what we already have;
	 * or the level is the same and the ack bit is set
	 */
	if (hislevel == mylevel && (val == slctab[func].current.val || ack)) {
		return;
	} else if (ack) {
		/*
		 * If we get here, we got an ack, but the levels don't match.
		 * This shouldn't happen.  If it does, it is probably because
		 * we have sent two requests to set a variable without getting
		 * a response between them, and this is the first response.
		 * So, ignore it, and wait for the next response.
		 */
		return;
	} else {
		change_slc(func, flag, val);
	}

}  /* end of process_slc */

/*
 * change_slc
 *
 * Process a request to change one of our special characters.
 * Compare client's request with what we are capable of supporting.
 */
void
change_slc(int func, int flag, cc_t val)
{
	int hislevel, mylevel;

	hislevel = flag & SLC_LEVELBITS;
	mylevel = slctab[func].defset.flag & SLC_LEVELBITS;
	/*
	 * If client is setting a function to NOSUPPORT
	 * or DEFAULT, then we can easily and directly
	 * accommodate the request.
	 */
	if (hislevel == SLC_NOSUPPORT) {
		slctab[func].current.flag = flag;
		slctab[func].current.val = (cc_t)_POSIX_VDISABLE;
		flag |= SLC_ACK;
		add_slc(func, flag, val);
		return;
	}
	if (hislevel == SLC_DEFAULT) {
		/*
		 * Special case here.  If client tells us to use
		 * the default on a function we don't support, then
		 * return NOSUPPORT instead of what we may have as a
		 * default level of DEFAULT.
		 */
		if (mylevel == SLC_DEFAULT) {
			slctab[func].current.flag = SLC_NOSUPPORT;
		} else {
			slctab[func].current.flag = slctab[func].defset.flag;
		}
		slctab[func].current.val = slctab[func].defset.val;
		add_slc(func, slctab[func].current.flag,
						slctab[func].current.val);
		return;
	}

	/*
	 * Client wants us to change to a new value or he
	 * is telling us that he can't change to our value.
	 * Some of the slc's we support and can change,
	 * some we do support but can't change,
	 * and others we don't support at all.
	 * If we can change it then we have a pointer to
	 * the place to put the new value, so change it,
	 * otherwise, continue the negotiation.
	 */
	if (slctab[func].sptr) {
		/*
		 * We can change this one.
		 */
		slctab[func].current.val = val;
		*(slctab[func].sptr) = val;
		slctab[func].current.flag = flag;
		flag |= SLC_ACK;
		slcchange = 1;
		add_slc(func, flag, val);
	} else {
		/*
		* It is not possible for us to support this
		* request as he asks.
		*
		* If our level is DEFAULT, then just ack whatever was
		* sent.
		*
		* If he can't change and we can't change,
		* then degenerate to NOSUPPORT.
		*
		* Otherwise we send our level back to him, (CANTCHANGE
		* or NOSUPPORT) and if CANTCHANGE, send
		* our value as well.
		*/
		if (mylevel == SLC_DEFAULT) {
			slctab[func].current.flag = flag;
			slctab[func].current.val = val;
			flag |= SLC_ACK;
		} else if (hislevel == SLC_CANTCHANGE &&
				    mylevel == SLC_CANTCHANGE) {
			flag &= ~SLC_LEVELBITS;
			flag |= SLC_NOSUPPORT;
			slctab[func].current.flag = flag;
		} else {
			flag &= ~SLC_LEVELBITS;
			flag |= mylevel;
			slctab[func].current.flag = flag;
			if (mylevel == SLC_CANTCHANGE) {
				slctab[func].current.val =
					slctab[func].defset.val;
				val = slctab[func].current.val;
			}
		}
		add_slc(func, flag, val);
	}

}  /* end of change_slc */

#if VEOF == VMIN
cc_t oldeofc = '\004';
#endif

/*
 * check_slc
 *
 * Check the special characters in use and notify the client if any have
 * changed.  Only those characters that are capable of being changed are
 * likely to have changed.  If a local change occurs, kick the support level
 * and flags up to the defaults.
 */
void
check_slc(void)
{
	int i;

	for (i = 1; i <= NSLC; i++) {
#if VEOF == VMIN
		/*
		 * In a perfect world this would be a neat little
		 * function.  But in this world, we should not notify
		 * client of changes to the VEOF char when
		 * ICANON is off, because it is not representing
		 * a special character.
		 */
		if (i == SLC_EOF) {
			if (!tty_isediting())
				continue;
			else if (slctab[i].sptr)
				oldeofc = *(slctab[i].sptr);
		}
#endif	/* VEOF == VMIN */
		if (slctab[i].sptr &&
				(*(slctab[i].sptr) != slctab[i].current.val)) {
			slctab[i].current.val = *(slctab[i].sptr);
			if (*(slctab[i].sptr) == (cc_t)_POSIX_VDISABLE)
				slctab[i].current.flag = SLC_NOSUPPORT;
			else
				slctab[i].current.flag = slctab[i].defset.flag;
			add_slc((unsigned char)i, slctab[i].current.flag,
						slctab[i].current.val);
		}
	}
}  /* check_slc */

/*
 * do_opt_slc
 *
 * Process an slc option buffer.  Defer processing of incoming slc's
 * until after the terminal state has been processed.  Save the first slc
 * request that comes along, but discard all others.
 *
 * ptr points to the beginning of the buffer, len is the length.
 */
void
do_opt_slc(unsigned char *ptr, int len)
{
	unsigned char func, flag;
	cc_t val;
	unsigned char *end = ptr + len;

	if (terminit()) {  /* go ahead */
		while (ptr < end) {
			func = *ptr++;
			if (ptr >= end) break;
			flag = *ptr++;
			if (ptr >= end) break;
			val = (cc_t)*ptr++;

			process_slc((u_int)func, (u_int)flag, val);

		}
	} else {
		/*
		 * save this slc buffer if it is the first, otherwise dump
		 * it.
		 */
		if (def_slcbuf == (unsigned char *)0) {
			def_slclen = len;
			def_slcbuf = (unsigned char *)malloc((unsigned)len);
			if (def_slcbuf == (unsigned char *)0)
				return;  /* too bad */
			memcpy(def_slcbuf, ptr, len);
		}
	}

}  /* end of do_opt_slc */

/*
 * deferslc
 *
 * Do slc stuff that was deferred.
 */
void
deferslc(void)
{
	if (def_slcbuf) {
		start_slc(1);
		do_opt_slc(def_slcbuf, def_slclen);
		(void) end_slc(0);
		free(def_slcbuf);
		def_slcbuf = (unsigned char *)0;
		def_slclen = 0;
	}

}  /* end of deferslc */

#endif	/* LINEMODE */