sys_term.c

经典的unix下telnetd代码

/*
 * 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 "telnetd.h"

/* RCSID("$KTH: sys_term.c,v 1.100 2001/04/24 23:11:43 assar Exp $"); */

#if defined(_CRAY) || (defined(__hpux) && !defined(HAVE_UTMPX_H))
# define PARENT_DOES_UTMP
#endif

#ifdef HAVE_UTMP_H
#include <utmp.h>
#endif

#ifdef HAVE_UTMPX_H
#include <utmpx.h>
#endif

#ifdef HAVE_UTMPX_H
struct	utmpx wtmp;
#elif defined(HAVE_UTMP_H)
struct	utmp wtmp;
#endif /* HAVE_UTMPX_H */

#ifdef HAVE_STRUCT_UTMP_UT_HOST
int	utmp_len = sizeof(wtmp.ut_host);
#else
int	utmp_len = MAXHOSTNAMELEN;
#endif

#ifndef UTMP_FILE
#ifdef _PATH_UTMP
#define UTMP_FILE _PATH_UTMP
#else
#define UTMP_FILE "/etc/utmp"
#endif
#endif

#if !defined(WTMP_FILE) && defined(_PATH_WTMP)
#define WTMP_FILE _PATH_WTMP
#endif

#ifndef PARENT_DOES_UTMP
#ifdef WTMP_FILE
char	wtmpf[] = WTMP_FILE;
#else
char	wtmpf[]	= "/usr/adm/wtmp";
#endif
char	utmpf[] = UTMP_FILE;
#else /* PARENT_DOES_UTMP */
#ifdef WTMP_FILE
char	wtmpf[] = WTMP_FILE;
#else
char	wtmpf[]	= "/etc/wtmp";
#endif
#endif /* PARENT_DOES_UTMP */

#ifdef HAVE_TMPDIR_H
#include <tmpdir.h>
#endif	/* CRAY */

#ifdef	STREAMSPTY

#ifdef HAVE_SAC_H
#include <sac.h>
#endif

#ifdef HAVE_SYS_STROPTS_H
#include <sys/stropts.h>
#endif

#endif /* STREAMSPTY */

#ifdef	HAVE_SYS_STREAM_H
#ifdef  HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#ifdef __hpux
#undef SE
#endif
#include <sys/stream.h>
#endif
#if !(defined(__sgi) || defined(__linux) || defined(_AIX)) && defined(HAVE_SYS_TTY)
#include <sys/tty.h>
#endif
#ifdef	t_erase
#undef	t_erase
#undef	t_kill
#undef	t_intrc
#undef	t_quitc
#undef	t_startc
#undef	t_stopc
#undef	t_eofc
#undef	t_brkc
#undef	t_suspc
#undef	t_dsuspc
#undef	t_rprntc
#undef	t_flushc
#undef	t_werasc
#undef	t_lnextc
#endif

#ifdef HAVE_TERMIOS_H
#include <termios.h>
#else
#ifdef HAVE_TERMIO_H
#include <termio.h>
#endif
#endif

#ifdef HAVE_UTIL_H
#include <util.h>
#endif

# ifndef	TCSANOW
#  ifdef TCSETS
#   define	TCSANOW		TCSETS
#   define	TCSADRAIN	TCSETSW
#   define	tcgetattr(f, t)	ioctl(f, TCGETS, (char *)t)
#  else
#   ifdef TCSETA
#    define	TCSANOW		TCSETA
#    define	TCSADRAIN	TCSETAW
#    define	tcgetattr(f, t)	ioctl(f, TCGETA, (char *)t)
#   else
#    define	TCSANOW		TIOCSETA
#    define	TCSADRAIN	TIOCSETAW
#    define	tcgetattr(f, t)	ioctl(f, TIOCGETA, (char *)t)
#   endif
#  endif
#  define	tcsetattr(f, a, t)	ioctl(f, a, t)
#  define	cfsetospeed(tp, val)	(tp)->c_cflag &= ~CBAUD; \
(tp)->c_cflag |= (val)
#  define	cfgetospeed(tp)		((tp)->c_cflag & CBAUD)
#  ifdef CIBAUD
#   define	cfsetispeed(tp, val)	(tp)->c_cflag &= ~CIBAUD; \
     (tp)->c_cflag |= ((val)<<IBSHIFT)
#   define	cfgetispeed(tp)		(((tp)->c_cflag & CIBAUD)>>IBSHIFT)
#  else
#   define	cfsetispeed(tp, val)	(tp)->c_cflag &= ~CBAUD; \
     (tp)->c_cflag |= (val)
#   define	cfgetispeed(tp)		((tp)->c_cflag & CBAUD)
#  endif
# endif /* TCSANOW */
     struct termios termbuf, termbuf2;	/* pty control structure */
# ifdef  STREAMSPTY
     static int ttyfd = -1;
     int really_stream = 0;
# endif

     char *new_login = NULL;

/*
 * 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)
{
# ifdef  STREAMSPTY
    if (really_stream)
	tcgetattr(ttyfd, &termbuf);
    else
# endif
	tcgetattr(ourpty, &termbuf);
    termbuf2 = termbuf;
}

void
set_termbuf(void)
{
    /*
     * Only make the necessary changes.
	 */
    if (memcmp(&termbuf, &termbuf2, sizeof(termbuf)))
# ifdef  STREAMSPTY
	if (really_stream)
	    tcsetattr(ttyfd, TCSANOW, &termbuf);
	else
# endif
	    tcsetattr(ourpty, 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);
    }
}

#ifdef _CRAY
/*
 * getnpty()
 *
 * Return the number of pty's configured into the system.
 */
int
getnpty()
{
#ifdef _SC_CRAY_NPTY
    int numptys;

    if ((numptys = sysconf(_SC_CRAY_NPTY)) != -1)
	return numptys;
    else
#endif /* _SC_CRAY_NPTY */
	return 128;
}
#endif /* CRAY */

/*
 * 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 Xline[] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
char *line = Xline;

int	slavefd = -1;

#ifdef	_CRAY
char myline[] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
#endif	/* CRAY */

#if !defined(HAVE_PTSNAME) && defined(STREAMSPTY)
static char *ptsname(int fd)
{
#ifdef HAVE_TTYNAME
    return ttyname(fd);
#else
    return NULL;
#endif
}
#endif

int getpty(int *ptynum)
{
#if defined(__osf__) || defined(HAVE_OPENPTY)
    int master;
    int slave;
    if(openpty(&master, &slave, line, 0, 0) == 0){
	slavefd = slave;
	return master;
    }
    return -1;
#else
#ifdef HAVE__GETPTY
    int master, slave;
    char *p;
    p = _getpty(&master, O_RDWR, 0600, 1);
    if(p == NULL)
	return -1;
    strlcpy(line, p, sizeof(Xline));
    return master;
#else

    int p;
    char *cp, *p1, *p2;
    int i;
#if SunOS == 40
    int dummy;
#endif
#if 0 /* && defined(HAVE_OPENPTY) */
    int master;
    int slave;
    if(openpty(&master, &slave, line, 0, 0) == 0){
	close(slave);
	return master;
    }
#else
#ifdef	STREAMSPTY
    char *clone[] = { "/dev/ptc", "/dev/ptmx", "/dev/ptm", 
		      "/dev/ptym/clone", 0 };

    char **q;
    for(q=clone; *q; q++){
	p=open(*q, O_RDWR);
	if(p >= 0){
#ifdef HAVE_GRANTPT
	    grantpt(p);
#endif
#ifdef HAVE_UNLOCKPT
	    unlockpt(p);
#endif
	    strlcpy(line, ptsname(p), sizeof(Xline));
	    really_stream = 1;
	    return p;
	}
    }
#endif /* STREAMSPTY */
#ifndef _CRAY

#ifndef	__hpux
    snprintf(line, sizeof(Xline), "/dev/ptyXX");
    p1 = &line[8];
    p2 = &line[9];
#else
    snprintf(line, sizeof(Xline), "/dev/ptym/ptyXX");
    p1 = &line[13];
    p2 = &line[14];
#endif

	
    for (cp = "pqrstuvwxyzPQRST"; *cp; cp++) {
	struct stat stb;

	*p1 = *cp;
	*p2 = '0';
	/*
	 * This stat() check is just to keep us from
	 * looping through all 256 combinations if there
	 * aren't that many ptys available.
	 */
	if (stat(line, &stb) < 0)
	    break;
	for (i = 0; i < 16; i++) {
	    *p2 = "0123456789abcdef"[i];
	    p = open(line, O_RDWR);
	    if (p > 0) {
#ifndef	__hpux
		line[5] = 't';
#else
		for (p1 = &line[8]; *p1; p1++)
		    *p1 = *(p1+1);
		line[9] = 't';
#endif
		chown(line, 0, 0);
		chmod(line, 0600);
#if SunOS == 40
		if (ioctl(p, TIOCGPGRP, &dummy) == 0
		    || errno != EIO) {
		    chmod(line, 0666);
		    close(p);
		    line[5] = 'p';
		} else
#endif /* SunOS == 40 */
		    return(p);
	    }
	}
    }
#else	/* CRAY */
    extern lowpty, highpty;
    struct stat sb;

    for (*ptynum = lowpty; *ptynum <= highpty; (*ptynum)++) {
	snprintf(myline, sizeof(myline), "/dev/pty/%03d", *ptynum);
	p = open(myline, 2);
	if (p < 0)
	    continue;
	snprintf(line, sizeof(Xline), "/dev/ttyp%03d", *ptynum);
	/*
	 * Here are some shenanigans to make sure that there
	 * are no listeners lurking on the line.
	 */
	if(stat(line, &sb) < 0) {
	    close(p);
	    continue;
	}
	if(sb.st_uid || sb.st_gid || sb.st_mode != 0600) {
	    chown(line, 0, 0);
	    chmod(line, 0600);
	    close(p);
	    p = open(myline, 2);
	    if (p < 0)
		continue;
	}
	/*
	 * Now it should be safe...check for accessability.
	 */
	if (access(line, 6) == 0)
	    return(p);
	else {
	    /* no tty side to pty so skip it */
	    close(p);
	}
    }
#endif	/* CRAY */
#endif	/* STREAMSPTY */
#endif /* OPENPTY */
    return(-1);
#endif
}


int
tty_isecho(void)
{
    return (termbuf.c_lflag & ECHO);
}

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

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

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

int
tty_israw(void)
{
    return(!(termbuf.c_lflag & ICANON));
}

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));
}


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)
{
# ifdef	ECHOCTL
    return (!(termbuf.c_lflag & ECHOCTL));
# endif
# ifdef	TCTLECH
    return (!(termbuf.c_lflag & TCTLECH));
# endif
# if	!defined(ECHOCTL) && !defined(TCTLECH)
    return (0);	/* assumes ctl chars are echoed '^x' */
# endif
}

void