sys_term.c

这是关于远程登陆TELNET 的源代码 已经测试过的。

/*
 * Copyright (c) 1989 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.
 */

/*
 * From: @(#)sys_term.c	5.16 (Berkeley) 3/22/91
 */
char st_rcsid[] = 
  "$Id: sys_term.c,v 1.17 1999/12/17 14:28:47 dholland Exp $";

#include <utmp.h>

#include "telnetd.h"
#include "pathnames.h"
#include "logout.h"
#include "logwtmp.h"

#if defined(__GLIBC__) && (__GLIBC__ >= 2)
/* mmm, nonstandard */
#include <pty.h>
#else
int openpty(int *, int *, char *, struct termios *, struct winsize *);
#endif

#define ARCH64 ((sizeof(void *)) == 8)
#define ARCH32 ((sizeof(void *)) == 4)

#if defined(AUTHENTICATE)
#include <libtelnet/auth.h>
#endif

static struct termios termbuf, termbuf2;	/* pty control structure */

/*static int cleanopen(char *line);*/

/*
 * init_termbuf()
 * copy_termbuf(cp)
 * set_termbuf()
 *
 * These three routines are used to get and set the "termbuf" structure
 * to and from the kernel.  init_termbuf() gets the current settings.
 * copy_termbuf() hands in a new "termbuf" to write to the kernel, and
 * set_termbuf() writes the structure into the kernel.
 */

void init_termbuf(void) {
    tcgetattr(pty, &termbuf);
    termbuf2 = termbuf;
}

#if defined(LINEMODE) && defined(TIOCPKT_IOCTL)
/*
 * ?
 */
void copy_termbuf(char *cp, int len) {
    if (len > sizeof(termbuf)) len = sizeof(termbuf);
    bcopy(cp, (char *)&termbuf, len);
    termbuf2 = termbuf;
}
#endif /* defined(LINEMODE) && defined(TIOCPKT_IOCTL) */

void set_termbuf(void) {
    if (memcmp(&termbuf, &termbuf2, sizeof(termbuf))) {
	tcsetattr(pty, TCSANOW, &termbuf);
    }
}


/*
 * spcset(func, valp, valpp)
 *
 * This function takes various special characters (func), and
 * sets *valp to the current value of that character, and
 * *valpp to point to where in the "termbuf" structure that
 * value is kept.
 *
 * It returns the SLC_ level of support for this function.
 */


int spcset(int func, cc_t *valp, cc_t **valpp) {

#define	setval(a, b)	*valp = termbuf.c_cc[a]; \
			*valpp = &termbuf.c_cc[a]; \
			return(b);
#define	defval(a) *valp = ((cc_t)a); *valpp = (cc_t *)0; return(SLC_DEFAULT);

    switch(func) {
    case SLC_EOF:
	setval(VEOF, SLC_VARIABLE);
    case SLC_EC:
	setval(VERASE, SLC_VARIABLE);
    case SLC_EL:
	setval(VKILL, SLC_VARIABLE);
    case SLC_IP:
	setval(VINTR, SLC_VARIABLE|SLC_FLUSHIN|SLC_FLUSHOUT);
    case SLC_ABORT:
	setval(VQUIT, SLC_VARIABLE|SLC_FLUSHIN|SLC_FLUSHOUT);
    case SLC_XON:
#ifdef VSTART
	setval(VSTART, SLC_VARIABLE);
#else
	defval(0x13);
#endif
    case SLC_XOFF:
#ifdef	VSTOP
	setval(VSTOP, SLC_VARIABLE);
#else
	defval(0x11);
#endif
    case SLC_EW:
#ifdef	VWERASE
	setval(VWERASE, SLC_VARIABLE);
#else
	defval(0);
#endif
    case SLC_RP:
#ifdef	VREPRINT
	setval(VREPRINT, SLC_VARIABLE);
#else
	defval(0);
#endif
    case SLC_LNEXT:
#ifdef	VLNEXT
	setval(VLNEXT, SLC_VARIABLE);
#else
	defval(0);
#endif
    case SLC_AO:
#if	!defined(VDISCARD) && defined(VFLUSHO)
# define VDISCARD VFLUSHO
#endif
#ifdef	VDISCARD
	setval(VDISCARD, SLC_VARIABLE|SLC_FLUSHOUT);
#else
	defval(0);
#endif
    case SLC_SUSP:
#ifdef	VSUSP
	setval(VSUSP, SLC_VARIABLE|SLC_FLUSHIN);
#else
	defval(0);
#endif
#ifdef	VEOL
    case SLC_FORW1:
	setval(VEOL, SLC_VARIABLE);
#endif
#ifdef	VEOL2
    case SLC_FORW2:
	setval(VEOL2, SLC_VARIABLE);
#endif
    case SLC_AYT:
#ifdef	VSTATUS
	setval(VSTATUS, SLC_VARIABLE);
#else
	defval(0);
#endif
	
    case SLC_BRK:
    case SLC_SYNCH:
    case SLC_EOR:
	defval(0);
	
    default:
	*valp = 0;
	*valpp = 0;
	return(SLC_NOSUPPORT);
    }
}

/*
 * getpty()
 *
 * Allocate a pty.  As a side effect, the external character
 * array "line" contains the name of the slave side.
 *
 * Returns the file descriptor of the opened pty.
 */
static char linedata[PATH_MAX];
char *line = linedata;

static int ptyslavefd=-1;

int getpty(void) {
    int masterfd;

    if (openpty(&masterfd, &ptyslavefd, line, NULL, NULL)) {
	return -1;
    }
    return masterfd;
}

#ifdef	LINEMODE
/*
 * tty_flowmode()	Find out if flow control is enabled or disabled.
 * tty_linemode()	Find out if linemode (external processing) is enabled.
 * tty_setlinemod(on)	Turn on/off linemode.
 * tty_isecho()		Find out if echoing is turned on.
 * tty_setecho(on)	Enable/disable character echoing.
 * tty_israw()		Find out if terminal is in RAW mode.
 * tty_binaryin(on)	Turn on/off BINARY on input.
 * tty_binaryout(on)	Turn on/off BINARY on output.
 * tty_isediting()	Find out if line editing is enabled.
 * tty_istrapsig()	Find out if signal trapping is enabled.
 * tty_setedit(on)	Turn on/off line editing.
 * tty_setsig(on)	Turn on/off signal trapping.
 * tty_issofttab()	Find out if tab expansion is enabled.
 * tty_setsofttab(on)	Turn on/off soft tab expansion.
 * tty_islitecho()	Find out if typed control chars are echoed literally
 * tty_setlitecho()	Turn on/off literal echo of control chars
 * tty_tspeed(val)	Set transmit speed to val.
 * tty_rspeed(val)	Set receive speed to val.
 */

int tty_flowmode(void) {
    return (termbuf.c_iflag & IXON ? 1 : 0);
}

int tty_linemode(void) {
    return (termbuf.c_lflag & EXTPROC);
}

void tty_setlinemode(int on) {
#ifdef TIOCEXT
    set_termbuf();
    ioctl(pty, TIOCEXT, (char *)&on);
    init_termbuf();
#else	/* !TIOCEXT */
# ifdef	EXTPROC
    if (on) termbuf.c_lflag |= EXTPROC;
    else termbuf.c_lflag &= ~EXTPROC;
# endif
#endif	/* TIOCEXT */
}

int tty_isecho(void) {
    return (termbuf.c_lflag & ECHO);
}
#endif	/* LINEMODE */

void tty_setecho(int on) {
    if (on) termbuf.c_lflag |= ECHO;
    else termbuf.c_lflag &= ~ECHO;
}

#if defined(LINEMODE) && defined(KLUDGELINEMODE)
int tty_israw(void) {
    return(!(termbuf.c_lflag & ICANON));
}
#endif	/* defined(LINEMODE) && defined(KLUDGELINEMODE) */

void tty_binaryin(int on) {
    if (on) {
	termbuf.c_iflag &= ~ISTRIP;
    }
    else {
	termbuf.c_iflag |= ISTRIP;
    }
}

void tty_binaryout(int on) {
    if (on) {
	termbuf.c_cflag &= ~(CSIZE|PARENB);
	termbuf.c_cflag |= CS8;
	termbuf.c_oflag &= ~OPOST;
    } 
    else {
	termbuf.c_cflag &= ~CSIZE;
	termbuf.c_cflag |= CS7|PARENB;
	termbuf.c_oflag |= OPOST;
    }
}

int tty_isbinaryin(void) {
    return (!(termbuf.c_iflag & ISTRIP));
}

int tty_isbinaryout(void) {
    return (!(termbuf.c_oflag&OPOST));
}

#ifdef	LINEMODE
int tty_isediting(void) {
    return(termbuf.c_lflag & ICANON);
}

int tty_istrapsig(void) {
    return(termbuf.c_lflag & ISIG);
}

void tty_setedit(int on) {
    if (on) termbuf.c_lflag |= ICANON;
    else termbuf.c_lflag &= ~ICANON;
}

void tty_setsig(int on) {
    if (on) termbuf.c_lflag |= ISIG;
    else termbuf.c_lflag &= ~ISIG;
}
#endif	/* LINEMODE */

int tty_issofttab(void) {
#ifdef OXTABS
    return (termbuf.c_oflag & OXTABS);
#endif
#ifdef TABDLY
    return ((termbuf.c_oflag & TABDLY) == TAB3);
#endif
}

void tty_setsofttab(int on) {
    if (on) {
#ifdef	OXTABS
	termbuf.c_oflag |= OXTABS;
#endif
#ifdef	TABDLY
	termbuf.c_oflag &= ~TABDLY;
	termbuf.c_oflag |= TAB3;
#endif
    } 
    else {
#ifdef	OXTABS
	termbuf.c_oflag &= ~OXTABS;
#endif
#ifdef	TABDLY
	termbuf.c_oflag &= ~TABDLY;
	termbuf.c_oflag |= TAB0;
#endif
    }
}

int tty_islitecho(void) {
    return (!(termbuf.c_lflag & ECHOCTL));
}

void tty_setlitecho(int on) {
    if (on) termbuf.c_lflag &= ~ECHOCTL;
    else termbuf.c_lflag |= ECHOCTL;
}

int tty_iscrnl(void) {
    return (termbuf.c_iflag & ICRNL);
}