xref: /freebsd/libexec/getty/main.c (revision b6de9e91bd2c47efaeec72a08642f8fd99cc7b20)
1 /*-
2  * Copyright (c) 1980, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1980, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)from: main.c	8.1 (Berkeley) 6/20/93";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif /* not lint */
47 
48 #include <sys/param.h>
49 #include <sys/ioctl.h>
50 #include <sys/time.h>
51 #include <sys/resource.h>
52 #include <sys/stat.h>
53 #include <sys/ttydefaults.h>
54 #include <sys/utsname.h>
55 
56 #include <ctype.h>
57 #include <errno.h>
58 #include <fcntl.h>
59 #include <locale.h>
60 #include <libutil.h>
61 #include <setjmp.h>
62 #include <signal.h>
63 #include <stdlib.h>
64 #include <string.h>
65 #include <syslog.h>
66 #include <termios.h>
67 #include <time.h>
68 #include <unistd.h>
69 
70 #include "gettytab.h"
71 #include "extern.h"
72 #include "pathnames.h"
73 
74 /*
75  * Set the amount of running time that getty should accumulate
76  * before deciding that something is wrong and exit.
77  */
78 #define GETTY_TIMEOUT	60 /* seconds */
79 
80 #undef CTRL
81 #define CTRL(x)  (x&037)
82 
83 /* defines for auto detection of incoming PPP calls (->PAP/CHAP) */
84 
85 #define PPP_FRAME           0x7e  /* PPP Framing character */
86 #define PPP_STATION         0xff  /* "All Station" character */
87 #define PPP_ESCAPE          0x7d  /* Escape Character */
88 #define PPP_CONTROL         0x03  /* PPP Control Field */
89 #define PPP_CONTROL_ESCAPED 0x23  /* PPP Control Field, escaped */
90 #define PPP_LCP_HI          0xc0  /* LCP protocol - high byte */
91 #define PPP_LCP_LOW         0x21  /* LCP protocol - low byte */
92 
93 /* original mode; flags've been reset using values from <sys/ttydefaults.h> */
94 struct termios omode;
95 /* current mode */
96 struct termios tmode;
97 
98 int crmod, digit, lower, upper;
99 
100 char	hostname[MAXHOSTNAMELEN];
101 char	name[MAXLOGNAME*3];
102 char	dev[] = _PATH_DEV;
103 char	ttyn[32];
104 
105 #define	OBUFSIZ		128
106 #define	TABBUFSIZ	512
107 
108 char	defent[TABBUFSIZ];
109 char	tabent[TABBUFSIZ];
110 const	char *tname;
111 
112 char	*env[128];
113 
114 char partab[] = {
115 	0001,0201,0201,0001,0201,0001,0001,0201,
116 	0202,0004,0003,0205,0005,0206,0201,0001,
117 	0201,0001,0001,0201,0001,0201,0201,0001,
118 	0001,0201,0201,0001,0201,0001,0001,0201,
119 	0200,0000,0000,0200,0000,0200,0200,0000,
120 	0000,0200,0200,0000,0200,0000,0000,0200,
121 	0000,0200,0200,0000,0200,0000,0000,0200,
122 	0200,0000,0000,0200,0000,0200,0200,0000,
123 	0200,0000,0000,0200,0000,0200,0200,0000,
124 	0000,0200,0200,0000,0200,0000,0000,0200,
125 	0000,0200,0200,0000,0200,0000,0000,0200,
126 	0200,0000,0000,0200,0000,0200,0200,0000,
127 	0000,0200,0200,0000,0200,0000,0000,0200,
128 	0200,0000,0000,0200,0000,0200,0200,0000,
129 	0200,0000,0000,0200,0000,0200,0200,0000,
130 	0000,0200,0200,0000,0200,0000,0000,0201
131 };
132 
133 #define	ERASE	tmode.c_cc[VERASE]
134 #define	KILL	tmode.c_cc[VKILL]
135 #define	EOT	tmode.c_cc[VEOF]
136 
137 #define	puts	Gputs
138 
139 static void	defttymode(void);
140 static void	dingdong(int);
141 static void	dogettytab(void);
142 static int	getname(void);
143 static void	interrupt(int);
144 static void	oflush(void);
145 static void	prompt(void);
146 static void	putchr(int);
147 static void	putf(const char *);
148 static void	putpad(const char *);
149 static void	puts(const char *);
150 static void	timeoverrun(int);
151 static char	*getline(int);
152 static void	setttymode(int);
153 static int	opentty(const char *, int);
154 
155 jmp_buf timeout;
156 
157 static void
158 dingdong(int signo __unused)
159 {
160 	alarm(0);
161 	longjmp(timeout, 1);
162 }
163 
164 jmp_buf	intrupt;
165 
166 static void
167 interrupt(int signo __unused)
168 {
169 	longjmp(intrupt, 1);
170 }
171 
172 /*
173  * Action to take when getty is running too long.
174  */
175 static void
176 timeoverrun(int signo __unused)
177 {
178 
179 	syslog(LOG_ERR, "getty exiting due to excessive running time");
180 	exit(1);
181 }
182 
183 int
184 main(int argc, char *argv[])
185 {
186 	extern	char **environ;
187 	int first_sleep = 1, first_time = 1;
188 	struct rlimit limit;
189 	int rval;
190 
191 	signal(SIGINT, SIG_IGN);
192 	signal(SIGQUIT, SIG_IGN);
193 
194 	openlog("getty", LOG_ODELAY|LOG_CONS|LOG_PID, LOG_AUTH);
195 	gethostname(hostname, sizeof(hostname) - 1);
196 	hostname[sizeof(hostname) - 1] = '\0';
197 	if (hostname[0] == '\0')
198 		strcpy(hostname, "Amnesiac");
199 
200 	/*
201 	 * Limit running time to deal with broken or dead lines.
202 	 */
203 	(void)signal(SIGXCPU, timeoverrun);
204 	limit.rlim_max = RLIM_INFINITY;
205 	limit.rlim_cur = GETTY_TIMEOUT;
206 	(void)setrlimit(RLIMIT_CPU, &limit);
207 
208 	gettable("default", defent);
209 	gendefaults();
210 	tname = "default";
211 	if (argc > 1)
212 		tname = argv[1];
213 
214 	/*
215 	 * The following is a work around for vhangup interactions
216 	 * which cause great problems getting window systems started.
217 	 * If the tty line is "-", we do the old style getty presuming
218 	 * that the file descriptors are already set up for us.
219 	 * J. Gettys - MIT Project Athena.
220 	 */
221 	if (argc <= 2 || strcmp(argv[2], "-") == 0)
222 	    strcpy(ttyn, ttyname(STDIN_FILENO));
223 	else {
224 	    strcpy(ttyn, dev);
225 	    strncat(ttyn, argv[2], sizeof(ttyn)-sizeof(dev));
226 	    if (strcmp(argv[0], "+") != 0) {
227 		chown(ttyn, 0, 0);
228 		chmod(ttyn, 0600);
229 		revoke(ttyn);
230 
231 		/*
232 		 * Do the first scan through gettytab.
233 		 * Terminal mode parameters will be wrong until
234 		 * defttymode() called, but they're irrelevant for
235 		 * the initial setup of the terminal device.
236 		 */
237 		dogettytab();
238 
239 		/*
240 		 * Init or answer modem sequence has been specified.
241 		 */
242 		if (IC || AC) {
243 			if (!opentty(ttyn, O_RDWR|O_NONBLOCK))
244 				exit(1);
245 			defttymode();
246 			setttymode(1);
247 		}
248 
249 		if (IC) {
250 			if (getty_chat(IC, CT, DC) > 0) {
251 				syslog(LOG_ERR, "modem init problem on %s", ttyn);
252 				(void)tcsetattr(STDIN_FILENO, TCSANOW, &tmode);
253 				exit(1);
254 			}
255 		}
256 
257 		if (AC) {
258 			int i, rfds;
259 			struct timeval to;
260 
261         		rfds = 1 << 0;	/* FD_SET */
262         		to.tv_sec = RT;
263         		to.tv_usec = 0;
264         		i = select(32, (fd_set*)&rfds, (fd_set*)NULL,
265         			       (fd_set*)NULL, RT ? &to : NULL);
266         		if (i < 0) {
267 				syslog(LOG_ERR, "select %s: %m", ttyn);
268 			} else if (i == 0) {
269 				syslog(LOG_NOTICE, "recycle tty %s", ttyn);
270 				(void)tcsetattr(STDIN_FILENO, TCSANOW, &tmode);
271 				exit(0);  /* recycle for init */
272 			}
273 			i = getty_chat(AC, CT, DC);
274 			if (i > 0) {
275 				syslog(LOG_ERR, "modem answer problem on %s", ttyn);
276 				(void)tcsetattr(STDIN_FILENO, TCSANOW, &tmode);
277 				exit(1);
278 			}
279 		} else { /* maybe blocking open */
280 			if (!opentty(ttyn, O_RDWR | (NC ? O_NONBLOCK : 0 )))
281 				exit(1);
282 		}
283 	    }
284 	}
285 
286 	defttymode();
287 	for (;;) {
288 
289 		/*
290 		 * if a delay was specified then sleep for that
291 		 * number of seconds before writing the initial prompt
292 		 */
293 		if (first_sleep && DE) {
294 		    sleep(DE);
295 		    /* remove any noise */
296 		    (void)tcflush(STDIN_FILENO, TCIOFLUSH);
297 		}
298 		first_sleep = 0;
299 
300 		setttymode(0);
301 		if (AB) {
302 			tname = autobaud();
303 			dogettytab();
304 			continue;
305 		}
306 		if (PS) {
307 			tname = portselector();
308 			dogettytab();
309 			continue;
310 		}
311 		if (CL && *CL)
312 			putpad(CL);
313 		edithost(HE);
314 
315 		/* if this is the first time through this, and an
316 		   issue file has been given, then send it */
317 		if (first_time && IF) {
318 			int fd;
319 
320 			if ((fd = open(IF, O_RDONLY)) != -1) {
321 				char * cp;
322 
323 				while ((cp = getline(fd)) != NULL) {
324 					  putf(cp);
325 				}
326 				close(fd);
327 			}
328 		}
329 		first_time = 0;
330 
331 		if (IM && *IM && !(PL && PP))
332 			putf(IM);
333 		if (setjmp(timeout)) {
334 			cfsetispeed(&tmode, B0);
335 			cfsetospeed(&tmode, B0);
336 			(void)tcsetattr(STDIN_FILENO, TCSANOW, &tmode);
337 			exit(1);
338 		}
339 		if (TO) {
340 			signal(SIGALRM, dingdong);
341 			alarm(TO);
342 		}
343 
344 		rval = 0;
345 		if (AL) {
346 			const char *p = AL;
347 			char *q = name;
348 
349 			while (*p && q < &name[sizeof name - 1]) {
350 				if (isupper(*p))
351 					upper = 1;
352 				else if (islower(*p))
353 					lower = 1;
354 				else if (isdigit(*p))
355 					digit = 1;
356 				*q++ = *p++;
357 			}
358 		} else if (!(PL && PP))
359 			rval = getname();
360 		if (rval == 2 || (PL && PP)) {
361 			oflush();
362 			alarm(0);
363 			limit.rlim_max = RLIM_INFINITY;
364 			limit.rlim_cur = RLIM_INFINITY;
365 			(void)setrlimit(RLIMIT_CPU, &limit);
366 			execle(PP, "ppplogin", ttyn, (char *) 0, env);
367 			syslog(LOG_ERR, "%s: %m", PP);
368 			exit(1);
369 		} else if (rval || AL) {
370 			int i;
371 
372 			oflush();
373 			alarm(0);
374 			signal(SIGALRM, SIG_DFL);
375 			if (name[0] == '\0')
376 				continue;
377 			if (name[0] == '-') {
378 				puts("user names may not start with '-'.");
379 				continue;
380 			}
381 			if (!(upper || lower || digit)) {
382 				if (AL) {
383 					syslog(LOG_ERR,
384 					    "invalid auto-login name: %s", AL);
385 					exit(1);
386 				} else
387 					continue;
388 			}
389 			set_flags(2);
390 			if (crmod) {
391 				tmode.c_iflag |= ICRNL;
392 				tmode.c_oflag |= ONLCR;
393 			}
394 #if REALLY_OLD_TTYS
395 			if (upper || UC)
396 				tmode.sg_flags |= LCASE;
397 			if (lower || LC)
398 				tmode.sg_flags &= ~LCASE;
399 #endif
400 			if (tcsetattr(STDIN_FILENO, TCSANOW, &tmode) < 0) {
401 				syslog(LOG_ERR, "tcsetattr %s: %m", ttyn);
402 				exit(1);
403 			}
404 			signal(SIGINT, SIG_DFL);
405 			for (i = 0; environ[i] != (char *)0; i++)
406 				env[i] = environ[i];
407 			makeenv(&env[i]);
408 
409 			limit.rlim_max = RLIM_INFINITY;
410 			limit.rlim_cur = RLIM_INFINITY;
411 			(void)setrlimit(RLIMIT_CPU, &limit);
412 			execle(LO, "login", AL ? "-fp" : "-p", name,
413 			    (char *) 0, env);
414 			syslog(LOG_ERR, "%s: %m", LO);
415 			exit(1);
416 		}
417 		alarm(0);
418 		signal(SIGALRM, SIG_DFL);
419 		signal(SIGINT, SIG_IGN);
420 		if (NX && *NX) {
421 			tname = NX;
422 			dogettytab();
423 		}
424 	}
425 }
426 
427 static int
428 opentty(const char *tty, int flags)
429 {
430 	int i;
431 	int failopenlogged = 0;
432 
433 	while ((i = open(tty, flags)) == -1)
434 	{
435 		if (!failopenlogged) {
436 			syslog(LOG_ERR, "open %s: %m", tty);
437 			failopenlogged = 1;
438 		}
439 		sleep(60);
440 	}
441 	if (login_tty(i) < 0) {
442 		if (daemon(0,0) < 0) {
443 			syslog(LOG_ERR,"daemon: %m");
444 			close(i);
445 			return 0;
446 		}
447 		if (login_tty(i) < 0) {
448 			syslog(LOG_ERR, "login_tty %s: %m", tty);
449 			close(i);
450 			return 0;
451 		}
452 	}
453 	return 1;
454 }
455 
456 static void
457 defttymode()
458 {
459 
460 	/* Start with default tty settings. */
461 	if (tcgetattr(STDIN_FILENO, &tmode) < 0) {
462 		syslog(LOG_ERR, "tcgetattr %s: %m", ttyn);
463 		exit(1);
464 	}
465 	omode = tmode; /* fill c_cc for dogettytab() */
466 	dogettytab();
467 	/*
468 	 * Don't rely on the driver too much, and initialize crucial
469 	 * things according to <sys/ttydefaults.h>.  Avoid clobbering
470 	 * the c_cc[] settings however, the console drivers might wish
471 	 * to leave their idea of the preferred VERASE key value
472 	 * there.
473 	 */
474 	tmode.c_iflag = TTYDEF_IFLAG;
475 	tmode.c_oflag = TTYDEF_OFLAG;
476 	tmode.c_lflag = TTYDEF_LFLAG;
477 	tmode.c_cflag = TTYDEF_CFLAG;
478 	if (NC)
479 		tmode.c_cflag |= CLOCAL;
480 	omode = tmode;
481 }
482 
483 static void
484 setttymode(int raw)
485 {
486 	int off = 0;
487 
488 	(void)tcflush(STDIN_FILENO, TCIOFLUSH);	/* clear out the crap */
489 	ioctl(STDIN_FILENO, FIONBIO, &off);	/* turn off non-blocking mode */
490 	ioctl(STDIN_FILENO, FIOASYNC, &off);	/* ditto for async mode */
491 
492 	if (IS)
493 		cfsetispeed(&tmode, speed(IS));
494 	else if (SP)
495 		cfsetispeed(&tmode, speed(SP));
496 	if (OS)
497 		cfsetospeed(&tmode, speed(OS));
498 	else if (SP)
499 		cfsetospeed(&tmode, speed(SP));
500 	set_flags(0);
501 	setchars();
502 	if (raw)
503 		cfmakeraw(&tmode);
504 	if (tcsetattr(STDIN_FILENO, TCSANOW, &tmode) < 0) {
505 		syslog(LOG_ERR, "tcsetattr %s: %m", ttyn);
506 		exit(1);
507 	}
508 }
509 
510 
511 static int
512 getname(void)
513 {
514 	int c;
515 	char *np;
516 	unsigned char cs;
517 	int ppp_state = 0;
518 	int ppp_connection = 0;
519 
520 	/*
521 	 * Interrupt may happen if we use CBREAK mode
522 	 */
523 	if (setjmp(intrupt)) {
524 		signal(SIGINT, SIG_IGN);
525 		return (0);
526 	}
527 	signal(SIGINT, interrupt);
528 	set_flags(1);
529 	prompt();
530 	oflush();
531 	if (PF > 0) {
532 		sleep(PF);
533 		PF = 0;
534 	}
535 	if (tcsetattr(STDIN_FILENO, TCSANOW, &tmode) < 0) {
536 		syslog(LOG_ERR, "%s: %m", ttyn);
537 		exit(1);
538 	}
539 	crmod = digit = lower = upper = 0;
540 	np = name;
541 	for (;;) {
542 		oflush();
543 		if (read(STDIN_FILENO, &cs, 1) <= 0)
544 			exit(0);
545 		if ((c = cs&0177) == 0)
546 			return (0);
547 
548 		/* PPP detection state machine..
549 		   Look for sequences:
550 		   PPP_FRAME, PPP_STATION, PPP_ESCAPE, PPP_CONTROL_ESCAPED or
551 		   PPP_FRAME, PPP_STATION, PPP_CONTROL (deviant from RFC)
552 		   See RFC1662.
553 		   Derived from code from Michael Hancock, <michaelh@cet.co.jp>
554 		   and Erik 'PPP' Olson, <eriko@wrq.com>
555 		 */
556 
557 		if (PP && (cs == PPP_FRAME)) {
558 			ppp_state = 1;
559 		} else if (ppp_state == 1 && cs == PPP_STATION) {
560 			ppp_state = 2;
561 		} else if (ppp_state == 2 && cs == PPP_ESCAPE) {
562 			ppp_state = 3;
563 		} else if ((ppp_state == 2 && cs == PPP_CONTROL)
564 			|| (ppp_state == 3 && cs == PPP_CONTROL_ESCAPED)) {
565 			ppp_state = 4;
566 		} else if (ppp_state == 4 && cs == PPP_LCP_HI) {
567 			ppp_state = 5;
568 		} else if (ppp_state == 5 && cs == PPP_LCP_LOW) {
569 			ppp_connection = 1;
570 			break;
571 		} else {
572 			ppp_state = 0;
573 		}
574 
575 		if (c == EOT || c == CTRL('d'))
576 			exit(0);
577 		if (c == '\r' || c == '\n' || np >= &name[sizeof name-1]) {
578 			putf("\r\n");
579 			break;
580 		}
581 		if (islower(c))
582 			lower = 1;
583 		else if (isupper(c))
584 			upper = 1;
585 		else if (c == ERASE || c == '\b' || c == 0177) {
586 			if (np > name) {
587 				np--;
588 				if (cfgetospeed(&tmode) >= 1200)
589 					puts("\b \b");
590 				else
591 					putchr(cs);
592 			}
593 			continue;
594 		} else if (c == KILL || c == CTRL('u')) {
595 			putchr('\r');
596 			if (cfgetospeed(&tmode) < 1200)
597 				putchr('\n');
598 			/* this is the way they do it down under ... */
599 			else if (np > name)
600 				puts("                                     \r");
601 			prompt();
602 			digit = lower = upper = 0;
603 			np = name;
604 			continue;
605 		} else if (isdigit(c))
606 			digit = 1;
607 		if (IG && (c <= ' ' || c > 0176))
608 			continue;
609 		*np++ = c;
610 		putchr(cs);
611 	}
612 	signal(SIGINT, SIG_IGN);
613 	*np = 0;
614 	if (c == '\r')
615 		crmod = 1;
616 	if ((upper && !lower && !LC) || UC)
617 		for (np = name; *np; np++)
618 			if (isupper(*np))
619 				*np = tolower(*np);
620 	return (1 + ppp_connection);
621 }
622 
623 static void
624 putpad(const char *s)
625 {
626 	int pad = 0;
627 	speed_t ospeed = cfgetospeed(&tmode);
628 
629 	if (isdigit(*s)) {
630 		while (isdigit(*s)) {
631 			pad *= 10;
632 			pad += *s++ - '0';
633 		}
634 		pad *= 10;
635 		if (*s == '.' && isdigit(s[1])) {
636 			pad += s[1] - '0';
637 			s += 2;
638 		}
639 	}
640 
641 	puts(s);
642 	/*
643 	 * If no delay needed, or output speed is
644 	 * not comprehensible, then don't try to delay.
645 	 */
646 	if (pad == 0 || ospeed <= 0)
647 		return;
648 
649 	/*
650 	 * Round up by a half a character frame, and then do the delay.
651 	 * Too bad there are no user program accessible programmed delays.
652 	 * Transmitting pad characters slows many terminals down and also
653 	 * loads the system.
654 	 */
655 	pad = (pad * ospeed + 50000) / 100000;
656 	while (pad--)
657 		putchr(*PC);
658 }
659 
660 static void
661 puts(const char *s)
662 {
663 	while (*s)
664 		putchr(*s++);
665 }
666 
667 char	outbuf[OBUFSIZ];
668 int	obufcnt = 0;
669 
670 static void
671 putchr(int cc)
672 {
673 	char c;
674 
675 	c = cc;
676 	if (!NP) {
677 		c |= partab[c&0177] & 0200;
678 		if (OP)
679 			c ^= 0200;
680 	}
681 	if (!UB) {
682 		outbuf[obufcnt++] = c;
683 		if (obufcnt >= OBUFSIZ)
684 			oflush();
685 	} else
686 		write(STDOUT_FILENO, &c, 1);
687 }
688 
689 static void
690 oflush(void)
691 {
692 	if (obufcnt)
693 		write(STDOUT_FILENO, outbuf, obufcnt);
694 	obufcnt = 0;
695 }
696 
697 static void
698 prompt(void)
699 {
700 
701 	putf(LM);
702 	if (CO)
703 		putchr('\n');
704 }
705 
706 
707 static char *
708 getline(int fd)
709 {
710 	int i = 0;
711 	static char linebuf[512];
712 
713 	/*
714 	 * This is certainly slow, but it avoids having to include
715 	 * stdio.h unnecessarily. Issue files should be small anyway.
716 	 */
717 	while (i < (sizeof linebuf - 3) && read(fd, linebuf+i, 1)==1) {
718 		if (linebuf[i] == '\n') {
719 			/* Don't rely on newline mode, assume raw */
720 			linebuf[i++] = '\r';
721 			linebuf[i++] = '\n';
722 			linebuf[i] = '\0';
723 			return linebuf;
724 		}
725 		++i;
726 	}
727 	linebuf[i] = '\0';
728 	return i ? linebuf : 0;
729 }
730 
731 static void
732 putf(const char *cp)
733 {
734 	extern char editedhost[];
735 	time_t t;
736 	char *slash, db[100];
737 
738 	static struct utsname kerninfo;
739 
740 	if (!*kerninfo.sysname)
741 		uname(&kerninfo);
742 
743 	while (*cp) {
744 		if (*cp != '%') {
745 			putchr(*cp++);
746 			continue;
747 		}
748 		switch (*++cp) {
749 
750 		case 't':
751 			slash = strrchr(ttyn, '/');
752 			if (slash == (char *) 0)
753 				puts(ttyn);
754 			else
755 				puts(&slash[1]);
756 			break;
757 
758 		case 'h':
759 			puts(editedhost);
760 			break;
761 
762 		case 'd': {
763 			t = (time_t)0;
764 			(void)time(&t);
765 			if (Lo)
766 				(void)setlocale(LC_TIME, Lo);
767 			(void)strftime(db, sizeof(db), DF, localtime(&t));
768 			puts(db);
769 			break;
770 
771 		case 's':
772 			puts(kerninfo.sysname);
773 			break;
774 
775 		case 'm':
776 			puts(kerninfo.machine);
777 			break;
778 
779 		case 'r':
780 			puts(kerninfo.release);
781 			break;
782 
783 		case 'v':
784 			puts(kerninfo.version);
785 			break;
786 		}
787 
788 		case '%':
789 			putchr('%');
790 			break;
791 		}
792 		cp++;
793 	}
794 }
795 
796 /*
797  * Read a gettytab database entry and perform necessary quirks.
798  */
799 static void
800 dogettytab()
801 {
802 
803 	/* Read the database entry. */
804 	gettable(tname, tabent);
805 
806 	/*
807 	 * Avoid inheriting the parity values from the default entry
808 	 * if any of them is set in the current entry.
809 	 * Mixing different parity settings is unreasonable.
810 	 */
811 	if (OPset || EPset || APset || NPset)
812 		OPset = EPset = APset = NPset = 1;
813 
814 	/* Fill in default values for unset capabilities. */
815 	setdefaults();
816 }
817