ckutio.c

linux终端仿真程序

    conbgt(0);				/* See if we're in the background */
    congm();				/* Get console modes */

    (VOID) signal(SIGALRM,SIG_IGN);	/* Ignore alarms */
#ifndef SIGUSR1				/* User-defined signals */
#define SIGUSR1 30
#endif /* SIGUSR1 */

#ifndef SIGUSR2
#define SIGUSR2 31
#endif /* SIGUSR2 */

    (VOID) signal(SIGUSR1,SIG_IGN);	/* Ignore user-defined signals */
    (VOID) signal(SIGUSR2,SIG_IGN);	/*  */

#ifdef SIGDANGER			/* Ignore danger signals */
/*
  This signal is sent when the system is low on swap space.  Processes
  that don't handle it are candidates for termination.  If swap space doesn't
  clear out enough, we still might be terminated via kill() -- nothing we can
  do about that!  Conceivably, this could be improved by installing a real
  signal handler that warns the user, but that would be pretty complicated,
  since we are not always in control of the screen -- e.g. during remote-mode
  file transfer.
*/
    (VOID) signal(SIGDANGER,SIG_IGN);	/* e.g. on RS/6000 AIX */
#endif /* SIGDANGER */

#ifdef SIGPIPE
/*
  This one comes when a TCP/IP connection is broken by the remote.
  We prefer to catch this situation by examining error codes from write().
*/
    (VOID) signal(SIGPIPE,SIG_IGN);
#endif /* SIGPIPE */

#ifdef ultrix
    gtty(0,&vanilla);			/* Get sgtty info */
    iniflags = fcntl(0,F_GETFL,0);	/* Get flags */
#else
#ifdef AUX
    set42sig();				/* Don't ask! ([e-mail]) */
#endif /* AUX */
#endif /* ultrix */

    ttgwsiz();				/* Get window (screen) dimensions. */

#ifdef Plan9
    if (!backgrd) {
    	consctlfd = open("/dev/consctl", O_WRONLY);
    	/*noisefd = open("/dev/noise", O_WRONLY)*/
    }
    ckxech = 1;
#endif /* Plan9 */

    return(0);
}

/*  S Y S C L E A N U P  --  System-dependent program cleanup.  */

int
syscleanup() {
#ifdef ultrix
    stty(0,&vanilla);                   /* Get sgtty info */
    fcntl(0,F_SETFL,iniflags);		/* Restore flags */
#endif /* ultrix */
    /* No need to call anything in the suid package here, right? */
    return(0);
}

/*  T T O P E N  --  Open a tty for exclusive access.  */

/*
  Call with:
    ttname: character string - device name or network host name.
    lcl:
  If called with lcl < 0, sets value of lcl as follows:
  0: the terminal named by ttname is the job's controlling terminal.
  1: the terminal named by ttname is not the job's controlling terminal.
  But watch out: if a line is already open, or if requested line can't
  be opened, then lcl remains (and is returned as) -1.
    modem:
  Less than zero: ttname is a network host name.
  Zero or greater: ttname is a terminal device name.    
  Zero means a local connection (don't use modem signals).
  Positive means use modem signals.  
   timo:
  0 = no timer.
  nonzero = number of seconds to wait for open() to return before timing out.

  Returns:
    0 on success
   -5 if device is in use
   -4 if access to device is denied
   -3 if access to lock directory denied
   -2 upon timeout waiting for device to open
   -1 on other error
*/
static int ttotmo = 0;			/* Timeout flag */
/* Flag kept here to avoid being clobbered by longjmp.  */

int
ttopen(ttname,lcl,modem,timo) char *ttname; int *lcl, modem, timo; {

#ifdef BSD44
#define ctermid(x) strcpy(x,"")
#else
#ifdef SVORPOSIX
#ifndef CIE
    extern char *ctermid();		/* Wish they all had this! */
#else					/* CIE Regulus */
#define ctermid(x) strcpy(x,"")
#endif /* CIE */
#endif /* SVORPOSIX */
#endif /* BSD44 */

#ifdef ultrix
    int temp = 0;
#endif /* ultrix */

    char *x;				/* Worker string pointer */

#ifndef MINIX
    extern char* ttyname();
#endif /* MINIX */
    char cname[DEVNAMLEN+4];

#ifndef pdp11
#define NAMEFD	 /* Feature to allow name to be an open file descriptor */
#endif /* pdp11 */

#ifdef NAMEFD
    char *p;
    debug(F101,"ttopen telnetfd","",telnetfd);
#endif /* NAMEFD */

    debug(F111,"ttopen entry modem",ttname,modem);
    debug(F101," ttyfd","",ttyfd);
    debug(F101," lcl","",*lcl);

#ifdef MAXNAMLEN
    debug(F100,"ttopen MAXNAMLEN defined","",0);
#else
    debug(F100,"ttopen MAXNAMLEN *NOT* defined","",0);
#endif

#ifdef BSD4
    debug(F100,"ttopen BSD4 defined","",0);
#else
    debug(F100,"ttopen BSD4 *NOT* defined","",0);
#endif

#ifdef BSD42
    debug(F100,"ttopen BSD42 defined","",0);
#else
    debug(F100,"ttopen BSD42 *NOT* defined","",0);
#endif /* BSD42 */

#ifdef MYREAD
    debug(F100,"ttopen MYREAD defined","",0);
#else
    debug(F100,"ttopen MYREAD *NOT* defined","",0);
#endif /* MYREAD */

    ttpmsk = 0xff;
    if (ttyfd > -1) {			/* if device already opened */
        if (strncmp(ttname,ttnmsv,DEVNAMLEN)) /* are new & old names equal? */
          ttclos(ttyfd);		/* no, close old ttname, open new */
        else 				/* else same, ignore this call, */
	  return(0);			/* and return. */
    }

#ifdef	NETCONN
    if (modem < 0) {			/* modem < 0 = special code for net */
	int x;
	ttmdm = modem;
	modem = -modem;			/* Positive network type number */
	fdflag = 0;			/* Stdio not redirected. */
	netconn = 1;			/* And it's a network connection */
	debug(F111,"ttopen net",ttname,modem);
#ifdef NAMEFD
	for (p = ttname; isdigit(*p); p++) ; /* Check for all digits */
 	if (*p == '\0' && (telnetfd || x25fd)) { /* Avoid X.121 addresses */
	    ttyfd = atoi(ttname);	/* Is there a way to test it's open? */
	    ttfdflg = 1;		/* We got an open file descriptor */
	    debug(F111,"ttopen got open network fd",ttname,ttyfd);
	    strncpy(ttnmsv,ttname,DEVNAMLEN); /* Remember the "name". */
	    x = 1;			/* Return code is "good". */
	    if (telnetfd) {
		ttnet = NET_TCPB;
		ttnproto = NP_TELNET;
#ifdef SUNX25
	    } else if (x25fd) {
		ttnet = NET_SX25;
		ttnproto = NP_NONE;
#endif /* SUNX25 */		
	    }
	} else {			/* Host name or address given */
#endif /* NAMEFD */
	    x = netopen(ttname, lcl, modem); /* (see ckcnet.h) */
	    if (x > -1) {
		strncpy(ttnmsv,ttname,DEVNAMLEN);
	    } else netconn = 0;
#ifdef NAMEFD
	}
#endif /* NAMEFD */

#ifdef sony_news			/* Sony NEWS */
	if (ioctl(ttyfd,TIOCKGET,&km_ext) < 0) { /* Get Kanji mode */
	    perror("ttopen error getting Kanji mode (network)");
	    debug(F111,"ttopen error getting Kanji mode","network",0);
	    km_ext = -1;		/* Make sure this stays undefined. */
	}
#endif /* sony_news */

	xlocal = *lcl = 1;		/* Network connections are local. */
	debug(F101,"ttopen net x","",x);
#ifdef COMMENT
/* Let netopen() do this */
	if (x > -1 && !x25fd)
	  x = tn_ini();			/* Initialize TELNET protocol */
#endif /* COMMENT */
	return(x);
    } else {				/* Terminal device */
#endif	/* NETCONN */

#ifdef NAMEFD
/*
  This code lets you give Kermit an open file descriptor for a serial
  communication device, rather than a device name.  Kermit assumes that the
  line is already open, locked, conditioned with the right parameters, etc.
*/
	for (p = ttname; isdigit(*p); p++) ; /* Check for all digits */
	if (*p == '\0') {
	    ttyfd = atoi(ttname);	/* Is there a way to test it's open? */
	    debug(F111,"ttopen got open fd",ttname,ttyfd);
	    strncpy(ttnmsv,ttname,DEVNAMLEN); /* Remember the "name". */
	    xlocal = *lcl = 1;		/* Assume it's local. */
	    netconn = 0;		/* Assume it's not a network. */
	    tvtflg = 0;			/* Might need to initialize modes. */
	    ttmdm = modem;		/* Remember modem type. */
	    fdflag = 0;			/* Stdio not redirected. */
	    ttfdflg = 1;		/* Flag we were opened this way. */

#ifdef sony_news			/* Sony NEWS */
	    /* Get device Kanji mode */
	    if (ioctl(ttyfd,TIOCKGET,&km_ext) < 0) {
		perror("ttopen error getting Kanji mode");
		debug(F101,"ttopen error getting Kanji mode","",0);
		km_ext = -1;		/* Make sure this stays undefined. */
	    }
#endif /* sony_news */
	    return(0);			/* Return success */
	}
#endif /* NAMEFD */
#ifdef NETCONN
    }
#endif /* NETCONN */

/* Here we have to open a serial device of the given name. */

    occt = signal(SIGINT, cctrap);	/* Set Control-C trap, save old one */

    tvtflg = 0;			/* Flag for use by ttvt(). */
				/* 0 = ttvt not called yet for this device */

    fdflag = (!isatty(0) || !isatty(1)); /* Flag for stdio redirected */
    debug(F101,"ttopen fdflag","",fdflag);

    ttmdm = modem;                      /* Make this available to other fns */
    xlocal = *lcl;                      /* Make this available to other fns */

/* Code for handling bidirectional tty lines goes here. */
/* Use specified method for turning off logins and suppressing getty. */

#ifdef ACUCNTRL
    /* Should put call to priv_on() here, but that would be very risky! */
    acucntrl("disable",ttname);         /* acucntrl() program. */
    /* and priv_off() here... */
#else
#ifdef ATT7300
    if ((attmodem & DOGETY) == 0)       /* offgetty() program. */
      attmodem |= offgetty(ttname);	/* Remember response.  */
#endif /* ATT7300 */
#endif /* ACUCNTRL */

/*
 In the following section, we open the tty device for read/write.
 If a modem has been specified via "set modem" prior to "set line"
 then the O_NDELAY parameter is used in the open, provided this symbol
 is defined (e.g. in fcntl.h), so that the program does not hang waiting
 for carrier (which in most cases won't be present because a connection
 has not been dialed yet).  O_NDELAY is removed later on in ttopen().  It
 would make more sense to first determine if the line is local before
 doing this, but because ttyname() requires a file descriptor, we have
 to open it first.  See do_open().

 Now open the device using the desired treatment of carrier.
 If carrier is REQUIRED, then open could hang forever, so an optional
 timer is provided.  If carrier is not required, the timer should never
 go off, and should do no harm...
*/
    ttotmo = 0;				/* Flag no timeout */
    if (timo > 0) {
	int xx;
	saval = signal(SIGALRM,timerh);	/* Timed, set up timer. */
	xx = alarm(timo);		/* Timed open() */
	debug(F101,"ttopen alarm","",xx);
	if (
#ifdef CK_POSIX_SIG
	    sigsetjmp(sjbuf,1)
#else
	    setjmp(sjbuf)
#endif /* CK_POSIX_SIG */
	    ) {
	    ttotmo = 1;			/* Flag timeout. */
	} else ttyfd = do_open(ttname);
	ttimoff();
	debug(F111,"ttopen","modem",modem);
	debug(F101," ttyfd","",ttyfd);
	debug(F101," alarm return","",ttotmo);
    } else ttyfd = do_open(ttname);
    debug(F111,"ttopen ttyfd",ttname,ttyfd);
    if (ttyfd < 0) {			/* If couldn't open, fail. */
#ifdef ATT7300
	if (attmodem & DOGETY)		/* was getty(1m) running before us? */
	  ongetty(ttnmsv);		/* yes, restart on tty line */
	attmodem &= ~DOGETY;		/* no phone in use, getty restored */
#else
#ifdef ACUCNTRL
        /* Should put call to priv_on() here, but that would be risky! */
	acucntrl("enable",ttname);	/* acucntrl() program. */	
	/* and priv_off() here... */
#endif /* ACUNTRL */
#endif /* ATT7300 */

	signal(SIGINT,occt);		/* Put old Ctrl-C trap back. */
	if (errno == EACCES) {		/* Device is protected against user */
	    perror(ttname);		/* Print message */
	    debug(F111,"ttopen tty access denied",ttname,errno);
	    return(-4);
	} else return(ttotmo ? -2 : -1);
    }

#ifdef Plan9
    /* take this opportunity to open the control channel */
    if (p9openttyctl(ttname) < 0)
#else
    /* Make sure it's a real tty. */
    if (!isatty(ttyfd) && strcmp(ttname,"/dev/null"))
#endif /* Plan9 */
      {
	fprintf(stderr,"%s is not a terminal device\n",ttname);
	debug(F110,"ttopen not a tty",ttname,0);
	close(ttyfd);
	ttyfd = -1;
	signal(SIGINT,occt);
	return(-1);
    }

#ifdef aegis
	/* Apollo C runtime claims that console pads are tty devices, which
	 * is reasonable, but they aren't any good for packet transfer. */
	ios_$inq_type_uid((short)ttyfd, ttyuid, st);
	if (st.all != status_$ok) {
	    fprintf(stderr, "problem getting tty object type: ");
	    error_$print(st);
	} else if (ttyuid != sio_$uid) { /* reject non-SIO lines */
	    close(ttyfd); ttyfd = -1;
	    errno = ENOTTY; perror(ttname);
	    signal(SIGINT,occt);
	    return(-1);
	}
#endif /* aegis */

    strncpy(ttnmsv,ttname,DEVNAMLEN);   /*  Keep copy of name locally. */

/* Caller wants us to figure out if line is controlling tty */

    if (*lcl < 0) {
	int x0 = 0, x1 = 0;
        if (strcmp(ttname,CTTNAM) == 0) {   /* "/dev/tty" always remote */
            xlocal = 0;
	    debug(F111," ttname=CTTNAM",ttname,xlocal);

    /* If any of 0, 1, or 2 not redirected, we can use ttyname() to get */
    /* the name of the controlling terminal... */

/*
  Warning: on some UNIX systems (SVR4?), ttyname() reportedly opens /dev but
  never closes it.  If it is called often enough, we run out of file
  descriptors and subsequent open()'s of other devices or files can fail.
*/

        } else if ((x0 = isatty(0)) || (x1 = isatty(1)) || isatty(2)) {
#ifndef MINIX
	    if (x0)
	      x = ttyname(0);		/* and compare it with the */
	    else if (x1)		/* tty device name. */
	      x = ttyname(1);
	    else x = ttyname(2);
            strncpy(cname,x,DEVNAMLEN); /* (copy from internal static buf) */
	    debug(F110," cname",x,0);
#ifdef BEBOX
            x = ttnmsv;			/* ttyname() is broken */
#else
            x = ttyname(ttyfd);         /* Get real name of ttname. */
#endif /* BEBOX */		
	    if (x) {
		if (*x) {
		    xlocal = (strncmp(x,cname,DEVNAMLEN) == 0) ? 0 : 1;
		    debug(F111," ttyname",x,xlocal);
		}
	    } else xlocal = 1;
#else
	    xlocal = 1;			/* Can't do this test in MINIX */
#endif /* MINIX */
        } else {                        /* Else, if stdin redirected... */
#ifdef SVORPOSIX
/* System V provides nice ctermid() function to get name of controlling tty */
            ctermid(cname);             /* Get name of controlling terminal */
            debug(F110," ctermid",cname,0);

            x = ttyname(ttyfd);         /* Compare with name of comm line. */
#ifdef BEBOX
            xlocal = 1;			/* ttyname always returns /dev/tty */
#else
            xlocal = (strncmp(x,cname,DEVNAMLEN) == 0) ? 0 : 1;
#endif /* BEBOX */		
            debug(F111," ttyname",x,xlocal);
#else
/* Just assume local */
            xlocal = 1;
#endif /* SVORPOSIX */
            debug(F101," redirected stdin","",xlocal);
        }
    }

#ifndef NOFDZERO
/* Note, the following code was added so that Unix "idle-line" snoopers */
/* would not think Kermit was idle when it was transferring files, and */
/* maybe log people out. */
    if (xlocal == 0) {			/* Remote mode */
	if (fdflag == 0) {		/* Standard i/o is not redirected */
	    debug(F100,"ttopen setting ttyfd = 0","",0);
#ifdef LYNXOS
	    /* On Lynx OS, fd 0 is open for read only. */
	    dup2(ttyfd,0);
#endif /* LYNXOS */
	    close(ttyfd);		/* Use file descriptor 0 */
	    ttyfd = 0;
	} else {			/* Standard i/o is redirected */
	    debug(F101,"ttopen stdio redirected","",ttyfd);
	}
    }
#endif /* NOFDZERO */

/* Now check if line is locked -- if so fail, else lock for ourselves */
/* Note: After having done this, don't forget to delete the lock if you */