path: root/login-utils/agetty.c

/* agetty.c - another getty program for Linux. By W. Z. Venema 1989
   Ported to Linux by Peter Orbaek <poe@daimi.aau.dk>
   This program is freely distributable. The entire man-page used to
   be here. Now read the real man-page agetty.8 instead.

   -f option added by Eric Rasmussen <ear@usfirst.org> - 12/28/95
   
   1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL>
   - added Native Language Support

   1999-05-05 Thorsten Kranzkowski <dl8bcu@gmx.net>
   - enable hardware flow control before displaying /etc/issue
   
*/

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <termio.h>
#include <signal.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdarg.h>
#include <ctype.h>
#include <utmp.h>
#include <getopt.h>
#include <time.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include "xstrncpy.h"
#include "nls.h"
#include "pathnames.h"

#ifdef __linux__
#include <sys/param.h>
#define USE_SYSLOG
#endif

 /* If USE_SYSLOG is undefined all diagnostics go directly to /dev/console. */

#ifdef	USE_SYSLOG
#include <syslog.h>
#endif

 /*
  * Some heuristics to find out what environment we are in: if it is not
  * System V, assume it is SunOS 4.
  */

#ifdef LOGIN_PROCESS			/* defined in System V utmp.h */
#define	SYSV_STYLE			/* select System V style getty */
#endif

 /*
  * Things you may want to modify.
  * 
  * If ISSUE is not defined, agetty will never display the contents of the
  * /etc/issue file. You will not want to spit out large "issue" files at the
  * wrong baud rate. Relevant for System V only.
  * 
  * You may disagree with the default line-editing etc. characters defined
  * below. Note, however, that DEL cannot be used for interrupt generation
  * and for line editing at the same time.
  */

#ifdef	SYSV_STYLE
#define	ISSUE "/etc/issue"		/* displayed before the login prompt */
#include <sys/utsname.h>
#include <time.h>
#endif

#define LOGIN " login: "		/* login prompt */

/* Some shorthands for control characters. */

#define CTL(x)		(x ^ 0100)	/* Assumes ASCII dialect */
#define	CR		CTL('M')	/* carriage return */
#define	NL		CTL('J')	/* line feed */
#define	BS		CTL('H')	/* back space */
#define	DEL		CTL('?')	/* delete */

/* Defaults for line-editing etc. characters; you may want to change this. */

#define DEF_ERASE	DEL		/* default erase character */
#define DEF_INTR	CTL('C')	/* default interrupt character */
#define DEF_QUIT	CTL('\\')	/* default quit char */
#define DEF_KILL	CTL('U')	/* default kill char */
#define DEF_EOF		CTL('D')	/* default EOF char */
#define DEF_EOL		0
#define DEF_SWITCH	0		/* default switch char */

 /*
  * SunOS 4.1.1 termio is broken. We must use the termios stuff instead,
  * because the termio -> termios translation does not clear the termios
  * CIBAUD bits. Therefore, the tty driver would sometimes report that input
  * baud rate != output baud rate. I did not notice that problem with SunOS
  * 4.1. We will use termios where available, and termio otherwise.
  */

/* linux 0.12 termio is broken too, if we use it c_cc[VERASE] isn't set
   properly, but all is well if we use termios?! */

#ifdef	TCGETS
#undef	TCGETA
#undef	TCSETA
#undef	TCSETAW
#define	termio	termios
#define	TCGETA	TCGETS
#define	TCSETA	TCSETS
#define	TCSETAW	TCSETSW
#endif

#ifndef MAXHOSTNAMELEN
# ifdef HOST_NAME_MAX
#  define MAXHOSTNAMELEN HOST_NAME_MAX
# else
#  define MAXHOSTNAMELEN 64
# endif
#endif

 /*
  * When multiple baud rates are specified on the command line, the first one
  * we will try is the first one specified.
  */

#define	FIRST_SPEED	0

/* Storage for command-line options. */

#define	MAX_SPEED	10		/* max. nr. of baud rates */

struct options {
    int     flags;			/* toggle switches, see below */
    int     timeout;			/* time-out period */
    char   *login;			/* login program */
    char   *tty;			/* name of tty */
    char   *initstring;			/* modem init string */
    char   *issue;			/* alternative issue file */
    int     numspeed;			/* number of baud rates to try */
    int     speeds[MAX_SPEED];		/* baud rates to be tried */
    int     eightbits;			/* assume 8bit-clean tty */
};

#define	F_PARSE		(1<<0)		/* process modem status messages */
#define	F_ISSUE		(1<<1)		/* display /etc/issue */
#define	F_RTSCTS	(1<<2)		/* enable RTS/CTS flow control */
#define F_LOCAL		(1<<3)		/* force local */
#define F_INITSTRING    (1<<4)		/* initstring is set */
#define F_WAITCRLF	(1<<5)		/* wait for CR or LF */
#define F_CUSTISSUE	(1<<6)		/* give alternative issue file */
#define F_NOPROMPT	(1<<7)		/* don't ask for login name! */

/* Storage for things detected while the login name was read. */

struct chardata {
    int     erase;			/* erase character */
    int     kill;			/* kill character */
    int     eol;			/* end-of-line character */
    int     parity;			/* what parity did we see */
    int     capslock;			/* upper case without lower case */
};

/* Initial values for the above. */

struct chardata init_chardata = {
    DEF_ERASE,				/* default erase character */
    DEF_KILL,				/* default kill character */
    13,					/* default eol char */
    0,					/* space parity */
    0,					/* no capslock */
};

struct Speedtab {
    long    speed;
    int     code;
};

static struct Speedtab speedtab[] = {
    { 50, B50 },
    { 75, B75 },
    { 110, B110 },
    { 134, B134 },
    { 150, B150 },
    { 200, B200 },
    { 300, B300 },
    { 600, B600 },
    { 1200, B1200 },
    { 1800, B1800 },
    { 2400, B2400 },
    { 4800, B4800 },
    { 9600, B9600 },
#ifdef	B19200
    { 19200, B19200 },
#endif
#ifdef	B38400
    { 38400, B38400 },
#endif
#ifdef	EXTA
    { 19200, EXTA },
#endif
#ifdef	EXTB
    { 38400, EXTB },
#endif
#ifdef B57600
    { 57600, B57600 },
#endif
#ifdef B115200
    { 115200, B115200 },
#endif
#ifdef B230400
    { 230400, B230400 },
#endif
    { 0, 0 },
};

#define P_(s) s
int main P_((int argc, char **argv));
void parse_args P_((int argc, char **argv, struct options *op));
void parse_speeds P_((struct options *op, char *arg));
void update_utmp P_((char *line));
void open_tty P_((char *tty, struct termio *tp, int local));
void termio_init P_((struct termio *tp, int speed, struct options *op));
void auto_baud P_((struct termio *tp));
void do_prompt P_((struct options *op, struct termio *tp));
void next_speed P_((struct termio *tp, struct options *op));
char *get_logname P_((struct options *op, struct chardata *cp, struct termio *tp));
void termio_final P_((struct options *op, struct termio *tp, struct chardata *cp));
int caps_lock P_((char *s));
int bcode P_((char *s));
void usage P_((void));
void error P_((const char *, ...));
#undef P_

/* The following is used for understandable diagnostics. */

char *progname;

/* Fake hostname for ut_host specified on command line. */
char *fakehost = NULL;

/* ... */
#ifdef DEBUGGING
#define debug(s) fprintf(dbf,s); fflush(dbf)
FILE *dbf;
#else
#define debug(s) /* nothing */
#endif

int
main(argc, argv)
     int     argc;
     char  **argv;
{
    char   *logname = NULL;		/* login name, given to /bin/login */
    struct chardata chardata;		/* set by get_logname() */
    struct termio termio;		/* terminal mode bits */
    static struct options options = {
	F_ISSUE,			/* show /etc/issue (SYSV_STYLE) */
	0,				/* no timeout */
	_PATH_LOGIN,			/* default login program */
	"tty1",				/* default tty line */
	"",				/* modem init string */
	ISSUE,				/* default issue file */
	0,				/* no baud rates known yet */
    };

       setlocale(LC_ALL, "");
       bindtextdomain(PACKAGE, LOCALEDIR);
       textdomain(PACKAGE);
    
    /* The BSD-style init command passes us a useless process name. */

#ifdef	SYSV_STYLE
       {
	       char *ptr;
	       progname = argv[0];
	       if ((ptr = strrchr(argv[0], '/')))
		       progname = ++ptr;
       }
#else
       progname = "agetty";
#endif

#ifdef DEBUGGING
	dbf = fopen("/dev/ttyp0", "w");

	{	int i;
	
		for(i = 1; i < argc; i++) {
			debug(argv[i]);
		}
	}
#endif

    /* Parse command-line arguments. */

    parse_args(argc, argv, &options);

#ifdef __linux__
	setsid();
#endif
	
    /* Update the utmp file. */

#ifdef	SYSV_STYLE
    update_utmp(options.tty);
#endif

    debug("calling open_tty\n");
    /* Open the tty as standard { input, output, error }. */
    open_tty(options.tty, &termio, options.flags & F_LOCAL);

#ifdef __linux__
	{
		int iv;
		
		iv = getpid();
		(void) ioctl(0, TIOCSPGRP, &iv);
	}
#endif
    /* Initialize the termio settings (raw mode, eight-bit, blocking i/o). */
    debug("calling termio_init\n");
    termio_init(&termio, options.speeds[FIRST_SPEED], &options);

    /* write the modem init string and DON'T flush the buffers */
    if (options.flags & F_INITSTRING) {
	debug("writing init string\n");
	write(1, options.initstring, strlen(options.initstring));
    }

    if (!(options.flags & F_LOCAL)) {
	/* go to blocking write mode unless -L is specified */
	fcntl(1, F_SETFL, fcntl(1, F_GETFL, 0) & ~O_NONBLOCK);
    }

    /* Optionally detect the baud rate from the modem status message. */
    debug("before autobaud\n");
    if (options.flags & F_PARSE)
	auto_baud(&termio);

    /* Set the optional timer. */
    if (options.timeout)
	(void) alarm((unsigned) options.timeout);

    /* optionally wait for CR or LF before writing /etc/issue */
    if (options.flags & F_WAITCRLF) {
	char ch;

	debug("waiting for cr-lf\n");
	while(read(0, &ch, 1) == 1) {
	    ch &= 0x7f;   /* strip "parity bit" */
#ifdef DEBUGGING
	    fprintf(dbf, "read %c\n", ch);
#endif
	    if (ch == '\n' || ch == '\r') break;
	}
    }

    chardata = init_chardata;
    if (!(options.flags & F_NOPROMPT)) {
	/* Read the login name. */
	debug("reading login name\n");
	while ((logname = get_logname(&options, &chardata, &termio)) == 0)
	  next_speed(&termio, &options);
    }

    /* Disable timer. */

    if (options.timeout)
	(void) alarm(0);

    /* Finalize the termio settings. */

    termio_final(&options, &termio, &chardata);

    /* Now the newline character should be properly written. */

    (void) write(1, "\n", 1);

    /* Let the login program take care of password validation. */

    (void) execl(options.login, options.login, "--", logname, NULL);
    error(_("%s: can't exec %s: %m"), options.tty, options.login);
    exit(0);  /* quiet GCC */
}

/* parse-args - parse command-line arguments */

void
parse_args(argc, argv, op)
     int     argc;
     char  **argv;
     struct options *op;
{
    extern char *optarg;		/* getopt */
    extern int optind;			/* getopt */
    int     c;

    while (isascii(c = getopt(argc, argv, "8I:LH:f:hil:mt:wn"))) {
	switch (c) {
	case '8':
	    op->eightbits = 1;
	    break;
	case 'I':
	    if (!(op->initstring = malloc(strlen(optarg)+1))) {
		error(_("can't malloc initstring"));
		break;
	    }
	    {
		char ch, *p, *q;
		int i;

		/* copy optarg into op->initstring decoding \ddd
		   octal codes into chars */
		q = op->initstring;
		p = optarg;
		while (*p) {
		    if (*p == '\\') {		/* know \\ means \ */
			p++;
			if (*p == '\\') {
			    ch = '\\';
			    p++;
			} else {		/* handle \000 - \177 */
			    ch = 0;
			    for (i = 1; i <= 3; i++) {
				if (*p >= '0' && *p <= '7') {
				    ch <<= 3;
				    ch += *p - '0';
				    p++;
				} else 
				  break;
			    }
			}
			*q++ = ch;
		    } else {
			*q++ = *p++;
		    }
		}
		*q = '\0';
	    }
	    op->flags |= F_INITSTRING;
	    break;

	case 'L':				/* force local */
 	    op->flags |= F_LOCAL;
 	    break;
	case 'H':                               /* fake login host */
	    fakehost = optarg;
	    break;
	case 'f':				/* custom issue file */
	    op->flags |= F_CUSTISSUE;
	    op->issue = optarg;
	    break;
	case 'h':				/* enable h/w flow control */
	    op->flags |= F_RTSCTS;
	    break;
	case 'i':				/* do not show /etc/issue */
	    op->flags &= ~F_ISSUE;
	    break;
	case 'l':
	    op->login = optarg;			/* non-default login program */
	    break;
	case 'm':				/* parse modem status message */
	    op->flags |= F_PARSE;
	    break;
	case 'n':
	    op->flags |= F_NOPROMPT;
	    break;
	case 't':				/* time out */
	    if ((op->timeout = atoi(optarg)) <= 0)
		error(_("bad timeout value: %s"), optarg);
	    break;
	case 'w':
	    op->flags |= F_WAITCRLF;
	    break;
	default:
	    usage();
	}
    }
	debug("after getopt loop\n");
    if (argc < optind + 2)			/* check parameter count */
	usage();

    /* we loosen up a bit and accept both "baudrate tty" and "tty baudrate" */
    if('0' <= argv[optind][0] && argv[optind][0] <= '9') {
	/* a number first, assume it's a speed (BSD style) */
	parse_speeds(op, argv[optind++]);	/* baud rate(s) */
	op->tty = argv[optind];			/* tty name */
    } else {
	op->tty = argv[optind++];		/* tty name */
	parse_speeds(op, argv[optind]);		/* baud rate(s) */
    }

    optind++;
    if (argc > optind && argv[optind])
	setenv ("TERM", argv[optind], 1);

#ifdef DO_DEVFS_FIDDLING
    /*
     * some devfs junk, following Goswin Brederlow:
     *   turn ttyS<n> into tts/<n>
     *   turn tty<n> into vc/<n>
     */
    if (op->tty && strlen(op->tty) < 90) {
	    char dev_name[100];
	    struct stat st;

	    if (strncmp(op->tty, "ttyS", 4) == 0) {
		    strcpy(dev_name, "/dev/");
		    strcat(dev_name, op->tty);
		    if (stat(dev_name, &st) < 0) {
			    strcpy(dev_name, "/dev/tts/");
			    strcat(dev_name, op->tty + 4);
			    if (stat(dev_name, &st) == 0)
				    op->tty = strdup(dev_name + 5);
		    }
	    } else if (strncmp(op->tty, "tty", 3) == 0) {
		    strcpy(dev_name, "/dev/");
		    strncat(dev_name, op->tty, 90);
		    if (stat(dev_name, &st) < 0) {
			    strcpy(dev_name, "/dev/vc/");
			    strcat(dev_name, op->tty + 3);
			    if (stat(dev_name, &st) == 0)
				    op->tty = strdup(dev_name + 5);
		    }
	    }
    }
#endif

    debug("exiting parseargs\n");
}

/* parse_speeds - parse alternate baud rates */

void
parse_speeds(op, arg)
     struct options *op;
     char   *arg;
{
    char   *cp;

	debug("entered parse_speeds\n");
    for (cp = strtok(arg, ","); cp != 0; cp = strtok((char *) 0, ",")) {
	if ((op->speeds[op->numspeed++] = bcode(cp)) <= 0)
	    error(_("bad speed: %s"), cp);
	if (op->numspeed >= MAX_SPEED)
	    error(_("too many alternate speeds"));
    }
    debug("exiting parsespeeds\n");
}

#ifdef	SYSV_STYLE

/* update_utmp - update our utmp entry */
void
update_utmp(line)
     char   *line;
{
    struct  utmp ut;
    time_t  t;
    int     mypid = getpid();
    struct  utmp *utp;

    /*
     * The utmp file holds miscellaneous information about things started by
     * /sbin/init and other system-related events. Our purpose is to update
     * the utmp entry for the current process, in particular the process type
     * and the tty line we are listening to. Return successfully only if the
     * utmp file can be opened for update, and if we are able to find our
     * entry in the utmp file.
     */

    utmpname(_PATH_UTMP);
    setutent();

    /* Find mypid in utmp. Earlier code here tested only
       utp->ut_type != INIT_PROCESS, so maybe the >= here should be >.
       The present code is taken from login.c, so if this is changed,
       maybe login has to be changed as well. */
    while ((utp = getutent()))
	    if (utp->ut_pid == mypid
		&& utp->ut_type >= INIT_PROCESS
		&& utp->ut_type <= DEAD_PROCESS)
		    break;

    if (utp) {
	memcpy(&ut, utp, sizeof(ut));
    } else {
	/* some inits don't initialize utmp... */
	memset(&ut, 0, sizeof(ut));
	strncpy(ut.ut_id, line + 3, sizeof(ut.ut_id));
    }
	
    strncpy(ut.ut_user, "LOGIN", sizeof(ut.ut_user));
    strncpy(ut.ut_line, line, sizeof(ut.ut_line));
    if (fakehost)
	strncpy(ut.ut_host, fakehost, sizeof(ut.ut_host));
    time(&t);
    ut.ut_time = t;
    ut.ut_type = LOGIN_PROCESS;
    ut.ut_pid = mypid;

    pututline(&ut);
    endutent();

    {
#ifdef HAVE_UPDWTMP
	updwtmp(_PATH_WTMP, &ut);
#else
	int ut_fd;
	int lf;

	if ((lf = open(_PATH_WTMPLOCK, O_CREAT|O_WRONLY, 0660)) >= 0) {
	    flock(lf, LOCK_EX);
	    if ((ut_fd = open(_PATH_WTMP, O_APPEND|O_WRONLY)) >= 0) {
		write(ut_fd, &ut, sizeof(ut));
		close(ut_fd);
	    }
	    flock(lf, LOCK_UN);
	    close(lf);
	}
#endif
    }
}

#endif

/* open_tty - set up tty as standard { input, output, error } */
void
open_tty(tty, tp, local)
     char   *tty;
     struct termio *tp;
     int    local;
{
    /* Get rid of the present standard { output, error} if any. */

    (void) close(1);
    (void) close(2);
    errno = 0;					/* ignore above errors */

    /* Set up new standard input, unless we are given an already opened port. */

    if (strcmp(tty, "-")) {
	struct stat st;

	/* Sanity checks... */

	if (chdir("/dev"))
	    error(_("/dev: chdir() failed: %m"));
	if (stat(tty, &st) < 0)
	    error("/dev/%s: %m", tty);
	if ((st.st_mode & S_IFMT) != S_IFCHR)
	    error(_("/dev/%s: not a character device"), tty);

	/* Open the tty as standard input. */

	(void) close(0);
	errno = 0;				/* ignore close(2) errors */

	debug("open(2)\n");
	if (open(tty, O_RDWR|O_NONBLOCK, 0) != 0)
	    error(_("/dev/%s: cannot open as standard input: %m"), tty);

    } else {

	/*
	 * Standard input should already be connected to an open port. Make
	 * sure it is open for read/write.
	 */

	if ((fcntl(0, F_GETFL, 0) & O_RDWR) != O_RDWR)
	    error(_("%s: not open for read/write"), tty);
    }

    /* Set up standard output and standard error file descriptors. */
    debug("duping\n");
    if (dup(0) != 1 || dup(0) != 2)		/* set up stdout and stderr */
	error(_("%s: dup problem: %m"), tty);	/* we have a problem */

    /*
     * The following ioctl will fail if stdin is not a tty, but also when
     * there is noise on the modem control lines. In the latter case, the
     * common course of action is (1) fix your cables (2) give the modem more
     * time to properly reset after hanging up. SunOS users can achieve (2)
     * by patching the SunOS kernel variable "zsadtrlow" to a larger value;
     * 5 seconds seems to be a good value.
     */

    if (ioctl(0, TCGETA, tp) < 0)
	error("%s: ioctl: %m", tty);

    /*
     * It seems to be a terminal. Set proper protections and ownership. Mode
     * 0622 is suitable for SYSV <4 because /bin/login does not change
     * protections. SunOS 4 login will change the protections to 0620 (write
     * access for group tty) after the login has succeeded.
     */

    /*
     * Let us use 0600 for Linux for the period between getty and login
     */

    (void) chown(tty, 0, 0);			/* root, sys */
    (void) chmod(tty, 0600);			/* 0622: crw--w--w- */
    errno = 0;					/* ignore above errors */
}

/* termio_init - initialize termio settings */

char gbuf[1024];
char area[1024];

void
termio_init(tp, speed, op)
     struct termio *tp;
     int     speed;
     struct options *op;
{

    /*
     * Initial termio settings: 8-bit characters, raw-mode, blocking i/o.
     * Special characters are set after we have read the login name; all
     * reads will be done in raw mode anyway. Errors will be dealt with
     * lateron.
     */
#ifdef __linux__
    /* flush input and output queues, important for modems! */
    (void) ioctl(0, TCFLSH, TCIOFLUSH);
#endif

    tp->c_cflag = CS8 | HUPCL | CREAD | speed;
    if (op->flags & F_LOCAL) {
	tp->c_cflag |= CLOCAL;
    }

    tp->c_iflag = tp->c_lflag = tp->c_oflag = tp->c_line = 0;
    tp->c_cc[VMIN] = 1;
    tp->c_cc[VTIME] = 0;

    /* Optionally enable hardware flow control */

#ifdef	CRTSCTS
    if (op->flags & F_RTSCTS)
	tp->c_cflag |= CRTSCTS;
#endif

    (void) ioctl(0, TCSETA, tp);

    /* go to blocking input even in local mode */
    fcntl(0, F_SETFL, fcntl(0, F_GETFL, 0) & ~O_NONBLOCK);

    debug("term_io 2\n");
}

/* auto_baud - extract baud rate from modem status message */
void
auto_baud(tp)
     struct termio *tp;
{
    int     speed;
    int     vmin;
    unsigned iflag;
    char    buf[BUFSIZ];
    char   *bp;
    int     nread;

    /*
     * This works only if the modem produces its status code AFTER raising
     * the DCD line, and if the computer is fast enough to set the proper
     * baud rate before the message has gone by. We expect a message of the
     * following format:
     * 
     * <junk><number><junk>
     * 
     * The number is interpreted as the baud rate of the incoming call. If the
     * modem does not tell us the baud rate within one second, we will keep
     * using the current baud rate. It is advisable to enable BREAK
     * processing (comma-separated list of baud rates) if the processing of
     * modem status messages is enabled.
     */

    /*
     * Use 7-bit characters, don't block if input queue is empty. Errors will
     * be dealt with lateron.
     */

    iflag = tp->c_iflag;
    tp->c_iflag |= ISTRIP;			/* enable 8th-bit stripping */
    vmin = tp->c_cc[VMIN];
    tp->c_cc[VMIN] = 0;				/* don't block if queue empty */
    (void) ioctl(0, TCSETA, tp);

    /*
     * Wait for a while, then read everything the modem has said so far and
     * try to extract the speed of the dial-in call.
     */

    (void) sleep(1);
    if ((nread = read(0, buf, sizeof(buf) - 1)) > 0) {
	buf[nread] = '\0';
	for (bp = buf; bp < buf + nread; bp++) {
	    if (isascii(*bp) && isdigit(*bp)) {
		if ((speed = bcode(bp))) {
		    tp->c_cflag &= ~CBAUD;
		    tp->c_cflag |= speed;
		}
		break;
	    }
	}
    }
    /* Restore terminal settings. Errors will be dealt with lateron. */

    tp->c_iflag = iflag;
    tp->c_cc[VMIN] = vmin;
    (void) ioctl(0, TCSETA, tp);
}

/* do_prompt - show login prompt, optionally preceded by /etc/issue contents */
void
do_prompt(op, tp)
     struct options *op;
     struct termio *tp;
{
#ifdef	ISSUE
    FILE    *fd;
    int     oflag;
    int     c;
    struct utsname uts;

    (void) uname(&uts);
#endif

    (void) write(1, "\r\n", 2);			/* start a new line */
#ifdef	ISSUE					/* optional: show /etc/issue */
    if ((op->flags & F_ISSUE) && (fd = fopen(op->issue, "r"))) {
	oflag = tp->c_oflag;			/* save current setting */
	tp->c_oflag |= (ONLCR | OPOST);		/* map NL in output to CR-NL */
	(void) ioctl(0, TCSETAW, tp);


	while ((c = getc(fd)) != EOF)
	{
	    if (c == '\\')
	      {
		c = getc(fd);
		
		switch (c)
		  {
		  case 's':
		    (void) printf ("%s", uts.sysname);
		    break;
		    
		  case 'n':
		    (void) printf ("%s", uts.nodename);
		    break;
		    
		  case 'r':
		    (void) printf ("%s", uts.release);
		    break;
		    
		  case 'v':
		    (void) printf ("%s", uts.version);
		    break;
		    
		  case 'm':
		    (void) printf ("%s", uts.machine);
		    break;

		  case 'o':
		   {
		     char domainname[MAXHOSTNAMELEN+1];
#ifdef HAVE_GETDOMAINNAME
		     if (getdomainname(domainname, sizeof(domainname)))
#endif
			 strcpy(domainname, "unknown_domain");
		     domainname[sizeof(domainname)-1] = '\0';
		     printf ("%s", domainname);
		   }
		  break;

		  case 'O':
		   {
			char *dom = "unknown_domain";
			char host[MAXHOSTNAMELEN+1];
			struct addrinfo hints, *info = NULL;

			memset(&hints, 0, sizeof(hints));
			hints.ai_flags = AI_CANONNAME;

			if (gethostname(host, sizeof(host)) ||
			    getaddrinfo(host, NULL, &hints, &info) ||
			    info == NULL)
				fputs(dom, stdout);
			else {
				char *canon;

				if (info->ai_canonname &&
				    (canon = strchr(info->ai_canonname, '.')))
					dom = canon + 1;
				fputs(dom, stdout);
				freeaddrinfo(info);
			}
		   }
		  break;

		  case 'd':
		  case 't':
		    {
		      char *weekday[] = { "Sun", "Mon", "Tue", "Wed", "Thu",
					  "Fri", "Sat" };
		      char *month[] = { "Jan", "Feb", "Mar", "Apr", "May",
					"Jun", "Jul", "Aug", "Sep", "Oct",
					"Nov", "Dec" };
		      time_t now;
		      struct tm *tm;

		      (void) time (&now);
		      tm = localtime(&now);

		      if (c == 'd')
			(void) printf ("%s %s %d  %d",
				weekday[tm->tm_wday], month[tm->tm_mon],
				tm->tm_mday, 
				tm->tm_year < 70 ? tm->tm_year + 2000 :
				tm->tm_year + 1900);
		      else
			(void) printf ("%02d:%02d:%02d",
				tm->tm_hour, tm->tm_min, tm->tm_sec);
		      
		      break;
		    }

		  case 'l':
		      (void) printf ("%s", op->tty);
		      break;

		  case 'b':
		    {
			int i;

			for (i = 0; speedtab[i].speed; i++) {
			    if (speedtab[i].code == (tp->c_cflag & CBAUD)) {
				printf("%ld", speedtab[i].speed);
				break;
			    }
			}
			break;
		    }
		  case 'u':
		  case 'U':
		    {
		      int users = 0;
		      struct utmp *ut;
		      setutent();
		      while ((ut = getutent()))
		        if (ut->ut_type == USER_PROCESS)
			  users++;
		      endutent();
		      printf ("%d ", users);
		      if (c == 'U')
		        printf ((users == 1) ? _("user") : _("users"));
		      break;
		    }
		  default:
		    (void) putchar(c);
		  }
	      }
	    else
	      (void) putchar(c);
	}
	fflush(stdout);

	tp->c_oflag = oflag;			/* restore settings */
	(void) ioctl(0, TCSETAW, tp);		/* wait till output is gone */
	(void) fclose(fd);
    }
#endif
    {
	char hn[MAXHOSTNAMELEN+1];
	if (gethostname(hn, sizeof(hn)) == 0)
	    write(1, hn, strlen(hn));
    }
    (void) write(1, LOGIN, sizeof(LOGIN) - 1);	/* always show login prompt */
}

/* next_speed - select next baud rate */
void
next_speed(tp, op)
     struct termio *tp;
     struct options *op;
{
    static int baud_index = FIRST_SPEED;/* current speed index */

    baud_index = (baud_index + 1) % op->numspeed;
    tp->c_cflag &= ~CBAUD;
    tp->c_cflag |= op->speeds[baud_index];
    (void) ioctl(0, TCSETA, tp);
}

/* get_logname - get user name, establish parity, speed, erase, kill, eol */

char   *get_logname(op, cp, tp)
     struct options *op;
     struct chardata *cp;
     struct termio *tp;
{
    static char logname[BUFSIZ];
    char   *bp;
    char    c;				/* input character, full eight bits */
    char    ascval;			/* low 7 bits of input character */
    int     bits;			/* # of "1" bits per character */
    int     mask;			/* mask with 1 bit up */
    static char *erase[] = {		/* backspace-space-backspace */
	"\010\040\010",			/* space parity */
	"\010\040\010",			/* odd parity */
	"\210\240\210",			/* even parity */
	"\210\240\210",			/* no parity */
    };

    /* Initialize kill, erase, parity etc. (also after switching speeds). */

    *cp = init_chardata;

    /* Flush pending input (esp. after parsing or switching the baud rate). */

    (void) sleep(1);
    (void) ioctl(0, TCFLSH, TCIFLUSH);

    /* Prompt for and read a login name. */

    for (*logname = 0; *logname == 0; /* void */ ) {

	/* Write issue file and prompt, with "parity" bit == 0. */

	do_prompt(op, tp);

	/* Read name, watch for break, parity, erase, kill, end-of-line. */

	for (bp = logname, cp->eol = 0; cp->eol == 0; /* void */ ) {

	    /* Do not report trivial EINTR/EIO errors. */

	    if (read(0, &c, 1) < 1) {
		if (errno == EINTR || errno == EIO)
		    exit(0);
		error(_("%s: read: %m"), op->tty);
	    }
	    /* Do BREAK handling elsewhere. */

	    if ((c == 0) && op->numspeed > 1)
		return (0);
	    /* Do parity bit handling. */

	    if (op->eightbits) {
		ascval = c;
	    } else if (c != (ascval = (c & 0177))) {	/* "parity" bit on */
		for (bits = 1, mask = 1; mask & 0177; mask <<= 1)
		    if (mask & ascval)
			bits++;			/* count "1" bits */
		cp->parity |= ((bits & 1) ? 1 : 2);
	    }
	    /* Do erase, kill and end-of-line processing. */

	    switch (ascval) {
	    case CR:
	    case NL:
		*bp = 0;			/* terminate logname */
		cp->eol = ascval;		/* set end-of-line char */
		break;
	    case BS:
	    case DEL:
	    case '#':
		cp->erase = ascval;		/* set erase character */
		if (bp > logname) {
		    (void) write(1, erase[cp->parity], 3);
		    bp--;
		}
		break;
	    case CTL('U'):
	    case '@':
		cp->kill = ascval;		/* set kill character */
		while (bp > logname) {
		    (void) write(1, erase[cp->parity], 3);
		    bp--;
		}
		break;
	    case CTL('D'):
		exit(0);
	    default:
		if (!isascii(ascval) || !isprint(ascval)) {
		     /* ignore garbage characters */ ;
		} else if (bp - logname >= sizeof(logname) - 1) {
		    error(_("%s: input overrun"), op->tty);
		} else {
		    (void) write(1, &c, 1);	/* echo the character */
		    *bp++ = ascval;		/* and store it */
		}
		break;
	    }
	}
    }
    /* Handle names with upper case and no lower case. */

    if ((cp->capslock = caps_lock(logname))) {
	for (bp = logname; *bp; bp++)
	    if (isupper(*bp))
		*bp = tolower(*bp);		/* map name to lower case */
    }
    return (logname);
}

/* termio_final - set the final tty mode bits */
void
termio_final(op, tp, cp)
     struct options *op;
     struct termio *tp;
     struct chardata *cp;
{
    /* General terminal-independent stuff. */

    tp->c_iflag |= IXON | IXOFF;		/* 2-way flow control */
    tp->c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK| ECHOKE;
      /* no longer| ECHOCTL | ECHOPRT*/
    tp->c_oflag |= OPOST;
    /* tp->c_cflag = 0; */
    tp->c_cc[VINTR] = DEF_INTR;			/* default interrupt */
    tp->c_cc[VQUIT] = DEF_QUIT;			/* default quit */
    tp->c_cc[VEOF] = DEF_EOF;			/* default EOF character */
    tp->c_cc[VEOL] = DEF_EOL;
#ifdef __linux__
    tp->c_cc[VSWTC] = DEF_SWITCH;		/* default switch character */
#else
    tp->c_cc[VSWTCH] = DEF_SWITCH;		/* default switch character */
#endif

    /* Account for special characters seen in input. */

    if (cp->eol == CR) {
	tp->c_iflag |= ICRNL;			/* map CR in input to NL */
	tp->c_oflag |= ONLCR;			/* map NL in output to CR-NL */
    }
    tp->c_cc[VERASE] = cp->erase;		/* set erase character */
    tp->c_cc[VKILL] = cp->kill;			/* set kill character */

    /* Account for the presence or absence of parity bits in input. */

    switch (cp->parity) {
    case 0:					/* space (always 0) parity */
	break;
    case 1:					/* odd parity */
	tp->c_cflag |= PARODD;
	/* FALLTHROUGH */
    case 2:					/* even parity */
	tp->c_cflag |= PARENB;
	tp->c_iflag |= INPCK | ISTRIP;
	/* FALLTHROUGH */
    case (1 | 2):				/* no parity bit */
	tp->c_cflag &= ~CSIZE;
	tp->c_cflag |= CS7;
	break;
    }
    /* Account for upper case without lower case. */

    if (cp->capslock) {
	tp->c_iflag |= IUCLC;
	tp->c_lflag |= XCASE;
	tp->c_oflag |= OLCUC;
    }
    /* Optionally enable hardware flow control */

#ifdef	CRTSCTS
    if (op->flags & F_RTSCTS)
	tp->c_cflag |= CRTSCTS;
#endif

    /* Finally, make the new settings effective */

    if (ioctl(0, TCSETA, tp) < 0)
	error("%s: ioctl: TCSETA: %m", op->tty);
}

/* caps_lock - string contains upper case without lower case */
int
caps_lock(s)
     char   *s;
{
    int     capslock;

    for (capslock = 0; *s; s++) {
	if (islower(*s))
	    return (0);
	if (capslock == 0)
	    capslock = isupper(*s);
    }
    return (capslock);
}

/* bcode - convert speed string to speed code; return 0 on failure */
int
bcode(s)
     char   *s;
{
    struct Speedtab *sp;
    long    speed = atol(s);

    for (sp = speedtab; sp->speed; sp++)
	if (sp->speed == speed)
	    return (sp->code);
    return (0);
}

/* usage - explain */

void
usage()
{
    fprintf(stderr, _("Usage: %s [-8hiLmw] [-l login_program] [-t timeout] [-I initstring] [-H login_host] baud_rate,... line [termtype]\nor\t[-hiLmw] [-l login_program] [-t timeout] [-I initstring] [-H login_host] line baud_rate,... [termtype]\n"), progname);
    exit(1);
}

/* error - report errors to console or syslog; only understands %s and %m */

#define	str2cpy(b,s1,s2)	strcat(strcpy(b,s1),s2)

void
error(const char *fmt, ...) {
    va_list ap;
#ifndef	USE_SYSLOG
    int     fd;
#endif
    char    buf[BUFSIZ];
    char   *bp;

    /*
     * If the diagnostic is reported via syslog(3), the process name is
     * automatically prepended to the message. If we write directly to
     * /dev/console, we must prepend the process name ourselves.
     */

#ifdef USE_SYSLOG
    buf[0] = '\0';
    bp = buf;
#else
    (void) str2cpy(buf, progname, ": ");
    bp = buf + strlen(buf);
#endif

    /*
     * %s expansion is done by hand. On a System V Release 2 system without
     * shared libraries and without syslog(3), linking with the the stdio
     * library would make the program three times as big...
     *
     * %m expansion is done here as well. Too bad syslog(3) does not have a
     * vsprintf() like interface.
     */

    va_start(ap, fmt);
    while (*fmt && bp < &buf[BUFSIZ-1]) {
	if (strncmp(fmt, "%s", 2) == 0) {
	    xstrncpy(bp, va_arg(ap, char *), &buf[BUFSIZ-1] - bp);
	    bp += strlen(bp);
	    fmt += 2;
	} else if (strncmp(fmt, "%m", 2) == 0) {
	    xstrncpy(bp, strerror(errno), &buf[BUFSIZ-1] - bp);
	    bp += strlen(bp);
	    fmt += 2;
	} else {
	    *bp++ = *fmt++;
	}
    }
    *bp = 0;
    va_end(ap);

    /*
     * Write the diagnostic directly to /dev/console if we do not use the
     * syslog(3) facility.
     */

#ifdef	USE_SYSLOG
    (void) openlog(progname, LOG_PID, LOG_AUTHPRIV);
    (void) syslog(LOG_ERR, "%s", buf);
    closelog();
#else
    /* Terminate with CR-LF since the console mode is unknown. */
    (void) strcat(bp, "\r\n");
    if ((fd = open("/dev/console", 1)) >= 0) {
	(void) write(fd, buf, strlen(buf));
	(void) close(fd);
    }
#endif
    (void) sleep((unsigned) 10);		/* be kind to init(8) */
    exit(1);
}