xref: /openbsd-src/lib/libcurses/tinfo/read_termcap.c (revision c7ef0cfc17afcba97172c25e1e3a943e893bc632)
1 /* $OpenBSD: read_termcap.c,v 1.24 2023/10/17 09:52:09 nicm Exp $ */
2 
3 /****************************************************************************
4  * Copyright 2018-2021,2023 Thomas E. Dickey                                *
5  * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
6  *                                                                          *
7  * Permission is hereby granted, free of charge, to any person obtaining a  *
8  * copy of this software and associated documentation files (the            *
9  * "Software"), to deal in the Software without restriction, including      *
10  * without limitation the rights to use, copy, modify, merge, publish,      *
11  * distribute, distribute with modifications, sublicense, and/or sell       *
12  * copies of the Software, and to permit persons to whom the Software is    *
13  * furnished to do so, subject to the following conditions:                 *
14  *                                                                          *
15  * The above copyright notice and this permission notice shall be included  *
16  * in all copies or substantial portions of the Software.                   *
17  *                                                                          *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
21  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
24  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
25  *                                                                          *
26  * Except as contained in this notice, the name(s) of the above copyright   *
27  * holders shall not be used in advertising or otherwise to promote the     *
28  * sale, use or other dealings in this Software without prior written       *
29  * authorization.                                                           *
30  ****************************************************************************/
31 
32 /****************************************************************************
33  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
34  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
35  *     and: Thomas E. Dickey                        1996-on                 *
36  ****************************************************************************/
37 
38 /*
39  * Termcap compatibility support
40  *
41  * If your OS integrator didn't install a terminfo database, you can call
42  * _nc_read_termcap_entry() to support reading and translating capabilities
43  * from the system termcap file.  This is a kludge; it will bulk up and slow
44  * down every program that uses ncurses, and translated termcap entries cannot
45  * use full terminfo capabilities.  Don't use it unless you absolutely have to;
46  * instead, get your system people to run tic(1) from root on the terminfo
47  * master included with ncurses to translate it into a terminfo database.
48  *
49  * If USE_GETCAP is enabled, we use what is effectively a copy of the 4.4BSD
50  * getcap code to fetch entries.  There are disadvantages to this; mainly that
51  * getcap(3) does its own resolution, meaning that entries read in in this way
52  * can't reference the terminfo tree.  The only thing it buys is faster startup
53  * time, getcap(3) is much faster than our tic parser.
54  */
55 
56 #include <curses.priv.h>
57 
58 #include <ctype.h>
59 #include <sys/types.h>
60 #include <tic.h>
61 
62 MODULE_ID("$Id: read_termcap.c,v 1.24 2023/10/17 09:52:09 nicm Exp $")
63 
64 #if !PURE_TERMINFO
65 
66 #define TC_SUCCESS     0
67 #define TC_NOT_FOUND  -1
68 #define TC_SYS_ERR    -2
69 #define TC_REF_LOOP   -3
70 #define TC_UNRESOLVED -4	/* this is not returned by BSD cgetent */
71 
72 static const char *
get_termpath(void)73 get_termpath(void)
74 {
75     const char *result;
76 
77     if (!use_terminfo_vars() || (result = getenv("TERMPATH")) == 0)
78 	result = TERMPATH;
79     TR(TRACE_DATABASE, ("TERMPATH is %s", result));
80     return result;
81 }
82 
83 /*
84  * Note:
85  * getcap(), cgetent(), etc., are BSD functions.  A copy of those was added to
86  * this file in November 1995, derived from the BSD4.4 Lite sources.
87  *
88  * The initial adaptation uses 518 lines from that source.
89  * The current source (in 2009) uses 183 lines of BSD4.4 Lite (441 ignoring
90  * whitespace).
91  */
92 #if USE_GETCAP
93 
94 #if HAVE_BSD_CGETENT
95 #define _nc_cgetcap   cgetcap
96 #define _nc_cgetent(buf, oline, db_array, name) cgetent(buf, db_array, name)
97 #define _nc_cgetmatch cgetmatch
98 #define _nc_cgetset   cgetset
99 #else
100 static int _nc_cgetmatch(char *, const char *);
101 static int _nc_getent(char **, unsigned *, int *, int, char **, int, const char
102 		      *, int, char *);
103 static int _nc_nfcmp(const char *, char *);
104 
105 /*-
106  * Copyright (c) 1992, 1993
107  *	The Regents of the University of California.  All rights reserved.
108  *
109  * This code is derived from software contributed to Berkeley by
110  * Casey Leedom of Lawrence Livermore National Laboratory.
111  *
112  * Redistribution and use in source and binary forms, with or without
113  * modification, are permitted provided that the following conditions
114  * are met:
115  * 1. Redistributions of source code must retain the above copyright
116  *    notice, this list of conditions and the following disclaimer.
117  * 2. Redistributions in binary form must reproduce the above copyright
118  *    notice, this list of conditions and the following disclaimer in the
119  *    documentation and/or other materials provided with the distribution.
120  * 3. Neither the name of the University nor the names of its contributors
121  *    may be used to endorse or promote products derived from this software
122  *    without specific prior written permission.
123  *
124  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
125  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
126  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
127  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
128  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
129  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
130  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
131  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
132  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
133  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
134  * SUCH DAMAGE.
135  */
136 
137 /* static char sccsid[] = "@(#)getcap.c	8.3 (Berkeley) 3/25/94"; */
138 
139 #define	BFRAG		1024
140 #define	BSIZE		1024
141 #define	MAX_RECURSION	32	/* maximum getent recursion */
142 
143 static size_t topreclen;	/* toprec length */
144 static char *toprec;		/* Additional record specified by cgetset() */
145 static int gottoprec;		/* Flag indicating retrieval of toprecord */
146 
147 /*
148  * Cgetset() allows the addition of a user specified buffer to be added to the
149  * database array, in effect "pushing" the buffer on top of the virtual
150  * database.  0 is returned on success, -1 on failure.
151  */
152 static int
_nc_cgetset(const char * ent)153 _nc_cgetset(const char *ent)
154 {
155     if (ent == 0) {
156 	FreeIfNeeded(toprec);
157 	toprec = 0;
158 	topreclen = 0;
159 	return (0);
160     }
161     topreclen = strlen(ent);
162     if ((toprec = typeMalloc(char, topreclen + 1)) == 0) {
163 	errno = ENOMEM;
164 	return (-1);
165     }
166     gottoprec = 0;
167     _nc_STRCPY(toprec, ent, topreclen);
168     return (0);
169 }
170 
171 /*
172  * Cgetcap searches the capability record buf for the capability cap with type
173  * `type'.  A pointer to the value of cap is returned on success, 0 if the
174  * requested capability couldn't be found.
175  *
176  * Specifying a type of ':' means that nothing should follow cap (:cap:).  In
177  * this case a pointer to the terminating ':' or NUL will be returned if cap is
178  * found.
179  *
180  * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
181  * return 0.
182  */
183 static char *
_nc_cgetcap(char * buf,const char * cap,int type)184 _nc_cgetcap(char *buf, const char *cap, int type)
185 {
186     register const char *cp;
187     register char *bp;
188 
189     bp = buf;
190     for (;;) {
191 	/*
192 	 * Skip past the current capability field - it is either the
193 	 * name field if this is the first time through the loop, or
194 	 * the remainder of a field whose name failed to match cap.
195 	 */
196 	for (;;) {
197 	    if (*bp == '\0')
198 		return (0);
199 	    else if (*bp++ == ':')
200 		break;
201 	}
202 
203 	/*
204 	 * Try to match (cap, type) in buf.
205 	 */
206 	for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
207 	    continue;
208 	if (*cp != '\0')
209 	    continue;
210 	if (*bp == '@')
211 	    return (0);
212 	if (type == ':') {
213 	    if (*bp != '\0' && *bp != ':')
214 		continue;
215 	    return (bp);
216 	}
217 	if (*bp != type)
218 	    continue;
219 	bp++;
220 	return (*bp == '@' ? 0 : bp);
221     }
222     /* NOTREACHED */
223 }
224 
225 /*
226  * Cgetent extracts the capability record name from the NULL terminated file
227  * array db_array and returns a pointer to a malloc'd copy of it in buf.  Buf
228  * must be retained through all subsequent calls to cgetcap, cgetnum, cgetflag,
229  * and cgetstr, but may then be freed.
230  *
231  * Returns:
232  *
233  * positive #    on success (i.e., the index in db_array)
234  * TC_NOT_FOUND  if the requested record couldn't be found
235  * TC_SYS_ERR    if a system error was encountered (e.g.,couldn't open a file)
236  * TC_REF_LOOP   if a potential reference loop is detected
237  * TC_UNRESOLVED if we had too many recurrences to resolve
238  */
239 static int
_nc_cgetent(char ** buf,int * oline,char ** db_array,const char * name)240 _nc_cgetent(char **buf, int *oline, char **db_array, const char *name)
241 {
242     unsigned dummy;
243 
244     return (_nc_getent(buf, &dummy, oline, 0, db_array, -1, name, 0, 0));
245 }
246 
247 /*
248  * Getent implements the functions of cgetent.  If fd is non-negative,
249  * *db_array has already been opened and fd is the open file descriptor.  We
250  * do this to save time and avoid using up file descriptors for tc=
251  * recursions.
252  *
253  * Getent returns the same success/failure codes as cgetent.  On success, a
254  * pointer to a malloc'd capability record with all tc= capabilities fully
255  * expanded and its length (not including trailing ASCII NUL) are left in
256  * *cap and *len.
257  *
258  * Basic algorithm:
259  *	+ Allocate memory incrementally as needed in chunks of size BFRAG
260  *	  for capability buffer.
261  *	+ Recurse for each tc=name and interpolate result.  Stop when all
262  *	  names interpolated, a name can't be found, or depth exceeds
263  *	  MAX_RECURSION.
264  */
265 #define DOALLOC(size) typeRealloc(char, size, record)
266 static int
_nc_getent(char ** cap,unsigned * len,int * beginning,int in_array,char ** db_array,int fd,const char * name,int depth,char * nfield)267 _nc_getent(
268 	      char **cap,	/* termcap-content */
269 	      unsigned *len,	/* length, needed for recursion */
270 	      int *beginning,	/* line-number at match */
271 	      int in_array,	/* index in 'db_array[] */
272 	      char **db_array,	/* list of files to search */
273 	      int fd,
274 	      const char *name,
275 	      int depth,
276 	      char *nfield)
277 {
278     register char *r_end, *rp;
279     int myfd = FALSE;
280     char *record = 0;
281     int tc_not_resolved;
282     int current;
283     int lineno;
284 
285     /*
286      * Return with ``loop detected'' error if we've recurred more than
287      * MAX_RECURSION times.
288      */
289     if (depth > MAX_RECURSION)
290 	return (TC_REF_LOOP);
291 
292     /*
293      * Check if we have a top record from cgetset().
294      */
295     if (depth == 0 && toprec != 0 && _nc_cgetmatch(toprec, name) == 0) {
296 	if ((record = DOALLOC(topreclen + BFRAG)) == 0) {
297 	    errno = ENOMEM;
298 	    return (TC_SYS_ERR);
299 	}
300 	_nc_STRCPY(record, toprec, topreclen + BFRAG);
301 	rp = record + topreclen + 1;
302 	r_end = rp + BFRAG;
303 	current = in_array;
304     } else {
305 	int foundit;
306 
307 	/*
308 	 * Allocate first chunk of memory.
309 	 */
310 	if ((record = DOALLOC(BFRAG)) == 0) {
311 	    errno = ENOMEM;
312 	    return (TC_SYS_ERR);
313 	}
314 	rp = r_end = record + BFRAG;
315 	foundit = FALSE;
316 
317 	/*
318 	 * Loop through database array until finding the record.
319 	 */
320 	for (current = in_array; db_array[current] != 0; current++) {
321 	    int eof = FALSE;
322 
323 	    /*
324 	     * Open database if not already open.
325 	     */
326 	    if (fd >= 0) {
327 		(void) lseek(fd, (off_t) 0, SEEK_SET);
328 	    } else if ((_nc_access(db_array[current], R_OK) < 0)
329 		       || (fd = safe_open2(db_array[current], O_RDONLY)) < 0) {
330 		/* No error on unfound file. */
331 		if (errno == ENOENT)
332 		    continue;
333 		free(record);
334 		return (TC_SYS_ERR);
335 	    } else {
336 		myfd = TRUE;
337 	    }
338 	    lineno = 0;
339 
340 	    /*
341 	     * Find the requested capability record ...
342 	     */
343 	    {
344 		char buf[2048];
345 		register char *b_end = buf;
346 		register char *bp = buf;
347 		register int c;
348 
349 		/*
350 		 * Loop invariants:
351 		 *      There is always room for one more character in record.
352 		 *      R_end always points just past end of record.
353 		 *      Rp always points just past last character in record.
354 		 *      B_end always points just past last character in buf.
355 		 *      Bp always points at next character in buf.
356 		 */
357 
358 		for (;;) {
359 		    int first = lineno + 1;
360 
361 		    /*
362 		     * Read in a line implementing (\, newline)
363 		     * line continuation.
364 		     */
365 		    rp = record;
366 		    for (;;) {
367 			if (bp >= b_end) {
368 			    int n;
369 
370 			    n = (int) read(fd, buf, sizeof(buf));
371 			    if (n <= 0) {
372 				if (myfd)
373 				    (void) close(fd);
374 				if (n < 0) {
375 				    free(record);
376 				    return (TC_SYS_ERR);
377 				}
378 				fd = -1;
379 				eof = TRUE;
380 				break;
381 			    }
382 			    b_end = buf + n;
383 			    bp = buf;
384 			}
385 
386 			c = *bp++;
387 			if (c == '\n') {
388 			    lineno++;
389 			    /*
390 			     * Unlike BSD 4.3, this ignores a backslash at the
391 			     * end of a comment-line.  That makes it consistent
392 			     * with the rest of ncurses -TD
393 			     */
394 			    if (rp == record
395 				|| *record == '#'
396 				|| *(rp - 1) != '\\')
397 				break;
398 			}
399 			*rp++ = (char) c;
400 
401 			/*
402 			 * Enforce loop invariant: if no room
403 			 * left in record buffer, try to get
404 			 * some more.
405 			 */
406 			if (rp >= r_end) {
407 			    unsigned pos;
408 			    size_t newsize;
409 
410 			    pos = (unsigned) (rp - record);
411 			    newsize = (size_t) (r_end - record + BFRAG);
412 			    record = DOALLOC(newsize);
413 			    if (record == 0) {
414 				if (myfd)
415 				    (void) close(fd);
416 				errno = ENOMEM;
417 				return (TC_SYS_ERR);
418 			    }
419 			    r_end = record + newsize;
420 			    rp = record + pos;
421 			}
422 		    }
423 		    /* loop invariant lets us do this */
424 		    *rp++ = '\0';
425 
426 		    /*
427 		     * If encountered eof check next file.
428 		     */
429 		    if (eof)
430 			break;
431 
432 		    /*
433 		     * Toss blank lines and comments.
434 		     */
435 		    if (*record == '\0' || *record == '#')
436 			continue;
437 
438 		    /*
439 		     * See if this is the record we want ...
440 		     */
441 		    if (_nc_cgetmatch(record, name) == 0
442 			&& (nfield == 0
443 			    || !_nc_nfcmp(nfield, record))) {
444 			foundit = TRUE;
445 			*beginning = first;
446 			break;	/* found it! */
447 		    }
448 		}
449 	    }
450 	    if (foundit)
451 		break;
452 	}
453 
454 	if (!foundit) {
455 	    free(record);
456 	    return (TC_NOT_FOUND);
457 	}
458     }
459 
460     /*
461      * Got the capability record, but now we have to expand all tc=name
462      * references in it ...
463      */
464     {
465 	register char *newicap, *s;
466 	register int newilen;
467 	unsigned ilen;
468 	int diff, iret, tclen, oline;
469 	char *icap = 0, *scan, *tc, *tcstart, *tcend;
470 
471 	/*
472 	 * Loop invariants:
473 	 *      There is room for one more character in record.
474 	 *      R_end points just past end of record.
475 	 *      Rp points just past last character in record.
476 	 *      Scan points at remainder of record that needs to be
477 	 *      scanned for tc=name constructs.
478 	 */
479 	scan = record;
480 	tc_not_resolved = FALSE;
481 	for (;;) {
482 	    if ((tc = _nc_cgetcap(scan, "tc", '=')) == 0) {
483 		break;
484 	    }
485 
486 	    /*
487 	     * Find end of tc=name and stomp on the trailing `:'
488 	     * (if present) so we can use it to call ourselves.
489 	     */
490 	    s = tc;
491 	    while (*s != '\0') {
492 		if (*s++ == ':') {
493 		    *(s - 1) = '\0';
494 		    break;
495 		}
496 	    }
497 	    tcstart = tc - 3;
498 	    tclen = (int) (s - tcstart);
499 	    tcend = s;
500 
501 	    icap = 0;
502 	    iret = _nc_getent(&icap, &ilen, &oline, current, db_array, fd,
503 			      tc, depth + 1, 0);
504 	    newicap = icap;	/* Put into a register. */
505 	    newilen = (int) ilen;
506 	    if (iret != TC_SUCCESS) {
507 		/* an error */
508 		if (iret < TC_NOT_FOUND) {
509 		    if (myfd)
510 			(void) close(fd);
511 		    free(record);
512 		    FreeIfNeeded(icap);
513 		    return (iret);
514 		}
515 		if (iret == TC_UNRESOLVED) {
516 		    tc_not_resolved = TRUE;
517 		    /* couldn't resolve tc */
518 		} else if (iret == TC_NOT_FOUND) {
519 		    *(s - 1) = ':';
520 		    scan = s - 1;
521 		    tc_not_resolved = TRUE;
522 		    continue;
523 		}
524 	    }
525 
526 	    /* not interested in name field of tc'ed record */
527 	    s = newicap;
528 	    while (*s != '\0' && *s++ != ':') ;
529 	    newilen -= (int) (s - newicap);
530 	    newicap = s;
531 
532 	    /* make sure interpolated record is `:'-terminated */
533 	    s += newilen;
534 	    if (*(s - 1) != ':') {
535 		*s = ':';	/* overwrite NUL with : */
536 		newilen++;
537 	    }
538 
539 	    /*
540 	     * Make sure there's enough room to insert the
541 	     * new record.
542 	     */
543 	    diff = newilen - tclen;
544 	    if (diff >= r_end - rp) {
545 		unsigned pos, tcpos, tcposend;
546 		size_t newsize;
547 
548 		pos = (unsigned) (rp - record);
549 		newsize = (size_t) (r_end - record + diff + BFRAG);
550 		tcpos = (unsigned) (tcstart - record);
551 		tcposend = (unsigned) (tcend - record);
552 		record = DOALLOC(newsize);
553 		if (record == 0) {
554 		    if (myfd)
555 			(void) close(fd);
556 		    free(icap);
557 		    errno = ENOMEM;
558 		    return (TC_SYS_ERR);
559 		}
560 		r_end = record + newsize;
561 		rp = record + pos;
562 		tcstart = record + tcpos;
563 		tcend = record + tcposend;
564 	    }
565 
566 	    /*
567 	     * Insert tc'ed record into our record.
568 	     */
569 	    s = tcstart + newilen;
570 	    memmove(s, tcend, (size_t) (rp - tcend));
571 	    memmove(tcstart, newicap, (size_t) newilen);
572 	    rp += diff;
573 	    free(icap);
574 
575 	    /*
576 	     * Start scan on `:' so next cgetcap works properly
577 	     * (cgetcap always skips first field).
578 	     */
579 	    scan = s - 1;
580 	}
581     }
582 
583     /*
584      * Close file (if we opened it), give back any extra memory, and
585      * return capability, length and success.
586      */
587     if (myfd)
588 	(void) close(fd);
589     *len = (unsigned) (rp - record - 1);	/* don't count NUL */
590     if (r_end > rp) {
591 	if ((record = DOALLOC((size_t) (rp - record))) == 0) {
592 	    errno = ENOMEM;
593 	    return (TC_SYS_ERR);
594 	}
595     }
596 
597     *cap = record;
598     if (tc_not_resolved) {
599 	return (TC_UNRESOLVED);
600     }
601     return (current);
602 }
603 
604 /*
605  * Cgetmatch will return 0 if name is one of the names of the capability
606  * record buf, -1 if not.
607  */
608 static int
_nc_cgetmatch(char * buf,const char * name)609 _nc_cgetmatch(char *buf, const char *name)
610 {
611     register const char *np;
612     register char *bp;
613 
614     /*
615      * Start search at beginning of record.
616      */
617     bp = buf;
618     for (;;) {
619 	/*
620 	 * Try to match a record name.
621 	 */
622 	np = name;
623 	for (;;) {
624 	    if (*np == '\0') {
625 		if (*bp == '|' || *bp == ':' || *bp == '\0')
626 		    return (0);
627 		else
628 		    break;
629 	    } else if (*bp++ != *np++) {
630 		break;
631 	    }
632 	}
633 
634 	/*
635 	 * Match failed, skip to next name in record.
636 	 */
637 	bp--;			/* a '|' or ':' may have stopped the match */
638 	for (;;) {
639 	    if (*bp == '\0' || *bp == ':')
640 		return (-1);	/* match failed totally */
641 	    else if (*bp++ == '|')
642 		break;		/* found next name */
643 	}
644     }
645 }
646 
647 /*
648  * Compare name field of record.
649  */
650 static int
_nc_nfcmp(const char * nf,char * rec)651 _nc_nfcmp(const char *nf, char *rec)
652 {
653     char *cp, tmp;
654     int ret;
655 
656     for (cp = rec; *cp != ':'; cp++) ;
657 
658     tmp = *(cp + 1);
659     *(cp + 1) = '\0';
660     ret = strcmp(nf, rec);
661     *(cp + 1) = tmp;
662 
663     return (ret);
664 }
665 #endif /* HAVE_BSD_CGETENT */
666 
667 /*
668  * Since ncurses provides its own 'tgetent()', we cannot use the native one.
669  * So we reproduce the logic to get down to cgetent() -- or our cut-down
670  * version of that -- to circumvent the problem of configuring against the
671  * termcap library.
672  */
673 #define USE_BSD_TGETENT 1
674 
675 #if USE_BSD_TGETENT
676 /*
677  * Copyright (c) 1980, 1993
678  *	The Regents of the University of California.  All rights reserved.
679  *
680  * Redistribution and use in source and binary forms, with or without
681  * modification, are permitted provided that the following conditions
682  * are met:
683  * 1. Redistributions of source code must retain the above copyright
684  *    notice, this list of conditions and the following disclaimer.
685  * 2. Redistributions in binary form must reproduce the above copyright
686  *    notice, this list of conditions and the following disclaimer in the
687  *    documentation and/or other materials provided with the distribution.
688  * 3. All advertising materials mentioning features or use of this software
689  *    must display the following acknowledgment:
690  *	This product includes software developed by the University of
691  *	California, Berkeley and its contributors.
692  * 4. Neither the name of the University nor the names of its contributors
693  *    may be used to endorse or promote products derived from this software
694  *    without specific prior written permission.
695  *
696  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
697  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
698  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
699  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
700  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
701  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
702  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
703  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
704  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
705  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
706  * SUCH DAMAGE.
707  */
708 
709 /* static char sccsid[] = "@(#)termcap.c	8.1 (Berkeley) 6/4/93" */
710 
711 #define	PBUFSIZ		512	/* max length of filename path */
712 #define	PVECSIZ		32	/* max number of names in path */
713 #define TBUFSIZ (2048*2)
714 
715 /*
716  * On entry, srcp points to a non ':' character which is the beginning of the
717  * token, if any.  We'll try to return a string that doesn't end with a ':'.
718  */
719 static char *
get_tc_token(char ** srcp,int * endp)720 get_tc_token(char **srcp, int *endp)
721 {
722     int ch;
723     bool found = FALSE;
724     char *s, *base;
725     char *tok = 0;
726 
727     *endp = TRUE;
728     for (s = base = *srcp; *s != '\0';) {
729 	ch = *s++;
730 	if (ch == '\\') {
731 	    if (*s == '\0') {
732 		break;
733 	    } else if (*s++ == '\n') {
734 		while (isspace(UChar(*s)))
735 		    s++;
736 	    } else {
737 		found = TRUE;
738 	    }
739 	} else if (ch == ':') {
740 	    if (found) {
741 		tok = base;
742 		s[-1] = '\0';
743 		*srcp = s;
744 		*endp = FALSE;
745 		break;
746 	    }
747 	    base = s;
748 	} else if (isgraph(UChar(ch))) {
749 	    found = TRUE;
750 	}
751     }
752 
753     /* malformed entry may end without a ':' */
754     if (tok == 0 && found) {
755 	tok = base;
756     }
757 
758     return tok;
759 }
760 
761 static char *
copy_tc_token(char * dst,const char * src,size_t len)762 copy_tc_token(char *dst, const char *src, size_t len)
763 {
764     int ch;
765 
766     while ((ch = *src++) != '\0') {
767 	if (ch == '\\' && *src == '\n') {
768 	    while (isspace(UChar(*src)))
769 		src++;
770 	    continue;
771 	}
772 	if (--len == 0) {
773 	    dst = 0;
774 	    break;
775 	}
776 	*dst++ = (char) ch;
777     }
778     return dst;
779 }
780 
781 /*
782  * Get an entry for terminal name in buffer bp from the termcap file.
783  */
784 static int
_nc_tgetent(char * bp,char ** sourcename,int * lineno,const char * name)785 _nc_tgetent(char *bp, char **sourcename, int *lineno, const char *name)
786 {
787     static char *the_source;
788 
789     register char *p;
790     register char *cp;
791     char *dummy = NULL;
792     CGETENT_CONST char **fname;
793     char *home;
794     int i;
795     char pathbuf[PBUFSIZ];	/* holds raw path of filenames */
796     CGETENT_CONST char *pathvec[PVECSIZ];	/* point to names in pathbuf */
797     const char *termpath;
798     string_desc desc;
799 
800     *lineno = 1;
801     fname = pathvec;
802     p = pathbuf;
803     cp = use_terminfo_vars()? getenv("TERMCAP") : NULL;
804 
805     /*
806      * TERMCAP can have one of two things in it.  It can be the name of a file
807      * to use instead of /etc/termcap.  In this case it better start with a
808      * "/".  Or it can be an entry to use so we don't have to read the file.
809      * In this case it has to already have the newlines crunched out.  If
810      * TERMCAP does not hold a file name then a path of names is searched
811      * instead.  The path is found in the TERMPATH variable, or becomes
812      * "$HOME/.termcap /etc/termcap" if no TERMPATH exists.
813      */
814     _nc_str_init(&desc, pathbuf, sizeof(pathbuf));
815     if (cp == NULL) {
816 	_nc_safe_strcpy(&desc, get_termpath());
817     } else if (!_nc_is_abs_path(cp)) {	/* TERMCAP holds an entry */
818 	if ((termpath = get_termpath()) != 0) {
819 	    _nc_safe_strcat(&desc, termpath);
820 	} else {
821 	    char temp[PBUFSIZ];
822 	    temp[0] = 0;
823 	    if ((home = getenv("HOME")) != 0 && *home != '\0'
824 		&& strchr(home, ' ') == 0
825 		&& strlen(home) < sizeof(temp) - 10) {	/* setup path */
826 		_nc_SPRINTF(temp, _nc_SLIMIT(sizeof(temp))
827 			    "%s/", home);	/* $HOME first */
828 	    }
829 	    /* if no $HOME look in current directory */
830 	    _nc_STRCAT(temp, ".termcap", sizeof(temp));
831 	    _nc_safe_strcat(&desc, temp);
832 	    _nc_safe_strcat(&desc, " ");
833 	    _nc_safe_strcat(&desc, get_termpath());
834 	}
835     } else {			/* user-defined name in TERMCAP */
836 	_nc_safe_strcat(&desc, cp);	/* still can be tokenized */
837     }
838 
839     *fname++ = pathbuf;		/* tokenize path into vector of names */
840     while (*++p) {
841 	if (*p == ' ' || *p == NCURSES_PATHSEP) {
842 	    *p = '\0';
843 	    while (*++p)
844 		if (*p != ' ' && *p != NCURSES_PATHSEP)
845 		    break;
846 	    if (*p == '\0')
847 		break;
848 	    *fname++ = p;
849 	    if (fname >= pathvec + PVECSIZ) {
850 		fname--;
851 		break;
852 	    }
853 	}
854     }
855     *fname = 0;			/* mark end of vector */
856 #if !HAVE_BSD_CGETENT
857     (void) _nc_cgetset(0);
858 #endif
859     if (_nc_is_abs_path(cp)) {
860 	if (_nc_cgetset(cp) < 0) {
861 	    return (TC_SYS_ERR);
862 	}
863     }
864 
865     i = _nc_cgetent(&dummy, lineno, pathvec, name);
866 
867     /* ncurses' termcap-parsing routines cannot handle multiple adjacent
868      * empty fields, and mistakenly use the last valid cap entry instead of
869      * the first (breaks tc= includes)
870      */
871     *bp = '\0';
872     if (i >= 0) {
873 	char *pd, *ps, *tok;
874 	int endflag = FALSE;
875 	char *list[1023];
876 	size_t n, count = 0;
877 
878 	pd = bp;
879 	ps = dummy;
880 	while (!endflag && (tok = get_tc_token(&ps, &endflag)) != 0) {
881 	    bool ignore = FALSE;
882 
883 	    for (n = 1; n < count; n++) {
884 		char *s = list[n];
885 		if (s[0] == tok[0]
886 		    && s[1] == tok[1]) {
887 		    ignore = TRUE;
888 		    break;
889 		}
890 	    }
891 	    if (ignore != TRUE) {
892 		list[count++] = tok;
893 		pd = copy_tc_token(pd, tok, (size_t) (TBUFSIZ - (2 + pd - bp)));
894 		if (pd == 0) {
895 		    i = -1;
896 		    break;
897 		}
898 		*pd++ = ':';
899 		*pd = '\0';
900 	    }
901 	}
902     }
903 
904     FreeIfNeeded(dummy);
905     FreeIfNeeded(the_source);
906     the_source = 0;
907 
908     /* This is not related to the BSD cgetent(), but to fake up a suitable
909      * filename for ncurses' error reporting.  (If we are not using BSD
910      * cgetent, then it is the actual filename).
911      */
912     if (i >= 0) {
913 #if HAVE_BSD_CGETENT
914 	char temp[PATH_MAX];
915 
916 	_nc_str_init(&desc, temp, sizeof(temp));
917 	_nc_safe_strcpy(&desc, pathvec[i]);
918 	_nc_safe_strcat(&desc, ".db");
919 	if (_nc_access(temp, R_OK) == 0) {
920 	    _nc_safe_strcpy(&desc, pathvec[i]);
921 	}
922 	if ((the_source = strdup(temp)) != 0)
923 	    *sourcename = the_source;
924 #else
925 	if ((the_source = strdup(pathvec[i])) != 0)
926 	    *sourcename = the_source;
927 #endif
928     }
929 
930     return (i);
931 }
932 #endif /* USE_BSD_TGETENT */
933 #endif /* USE_GETCAP */
934 
935 #define MAXPATHS	32
936 
937 /*
938  * Add a filename to the list in 'termpaths[]', checking that we really have
939  * a right to open the file.
940  */
941 #if !USE_GETCAP
942 static int
add_tc(char * termpaths[],char * path,int count)943 add_tc(char *termpaths[], char *path, int count)
944 {
945     char *save = strchr(path, NCURSES_PATHSEP);
946     if (save != 0)
947 	*save = '\0';
948     if (count < MAXPATHS
949 	&& _nc_access(path, R_OK) == 0) {
950 	termpaths[count++] = path;
951 	TR(TRACE_DATABASE, ("Adding termpath %s", path));
952     }
953     termpaths[count] = 0;
954     if (save != 0)
955 	*save = NCURSES_PATHSEP;
956     return count;
957 }
958 #define ADD_TC(path, count) filecount = add_tc(termpaths, path, count)
959 #endif /* !USE_GETCAP */
960 
961 NCURSES_EXPORT(int)
_nc_read_termcap_entry(const char * const tn,TERMTYPE2 * const tp)962 _nc_read_termcap_entry(const char *const tn, TERMTYPE2 *const tp)
963 {
964     int found = TGETENT_NO;
965     ENTRY *ep;
966 #if USE_GETCAP_CACHE
967     char cwd_buf[PATH_MAX];
968 #endif
969 #if USE_GETCAP
970     char *p, tc[TBUFSIZ];
971     char *tc_buf = 0;
972 #define MY_SIZE sizeof(tc) - 1
973     int status;
974     static char *source;
975     static int lineno;
976 
977     TR(TRACE_DATABASE, ("read termcap entry for %s", tn));
978 
979     if (strlen(tn) == 0
980 	|| strcmp(tn, ".") == 0
981 	|| strcmp(tn, "..") == 0
982 	|| _nc_pathlast(tn) != 0) {
983 	TR(TRACE_DATABASE, ("illegal or missing entry name '%s'", tn));
984 	return TGETENT_NO;
985     }
986 
987     if (use_terminfo_vars() && (p = getenv("TERMCAP")) != 0
988 	&& !_nc_is_abs_path(p) && _nc_name_match(p, tn, "|:")) {
989 	/* TERMCAP holds a termcap entry */
990 	tc_buf = strdup(p);
991 	_nc_set_source("TERMCAP");
992     } else {
993 	/* we're using getcap(3) */
994 	if ((status = _nc_tgetent(tc, &source, &lineno, tn)) < 0)
995 	    return (status == TC_NOT_FOUND ? TGETENT_NO : TGETENT_ERR);
996 
997 	_nc_curr_line = lineno;
998 	_nc_set_source(source);
999 	tc_buf = tc;
1000     }
1001     if (tc_buf == 0)
1002 	return (TGETENT_ERR);
1003     _nc_read_entry_source((FILE *) 0, tc_buf, FALSE, TRUE, NULLHOOK);
1004     if (tc_buf != tc)
1005 	free(tc_buf);
1006 #else
1007     /*
1008      * Here is what the 4.4BSD termcap(3) page prescribes:
1009      *
1010      * It will look in the environment for a TERMCAP variable.  If found, and
1011      * the value does not begin with a slash, and the terminal type name is the
1012      * same as the environment string TERM, the TERMCAP string is used instead
1013      * of reading a termcap file.  If it does begin with a slash, the string is
1014      * used as a path name of the termcap file to search.  If TERMCAP does not
1015      * begin with a slash and name is different from TERM, tgetent() searches
1016      * the files $HOME/.termcap and /usr/share/misc/termcap, in that order,
1017      * unless the environment variable TERMPATH exists, in which case it
1018      * specifies a list of file pathnames (separated by spaces or colons) to be
1019      * searched instead.
1020      *
1021      * It goes on to state:
1022      *
1023      * Whenever multiple files are searched and a tc field occurs in the
1024      * requested entry, the entry it names must be found in the same file or
1025      * one of the succeeding files.
1026      *
1027      * However, this restriction is relaxed in ncurses; tc references to
1028      * previous files are permitted.
1029      *
1030      * This routine returns 1 if an entry is found, 0 if not found, and -1 if
1031      * the database is not accessible.
1032      */
1033     FILE *fp;
1034     char *tc, *termpaths[MAXPATHS];
1035     int filecount = 0;
1036     int j, k;
1037     bool use_buffer = FALSE;
1038     bool normal = TRUE;
1039     char *tc_buf = 0;
1040     char pathbuf[PATH_MAX];
1041     char *copied = 0;
1042     char *cp;
1043     struct stat test_stat[MAXPATHS];
1044 
1045     termpaths[filecount] = 0;
1046     if (use_terminfo_vars() && (tc = getenv("TERMCAP")) != 0) {
1047 	if (_nc_is_abs_path(tc)) {	/* interpret as a filename */
1048 	    ADD_TC(tc, 0);
1049 	    normal = FALSE;
1050 	} else if (_nc_name_match(tc, tn, "|:")) {	/* treat as a capability file */
1051 	    tc_buf = strdup(tc);
1052 	    use_buffer = (tc_buf != 0);
1053 	    normal = FALSE;
1054 	}
1055     }
1056 
1057     if (normal) {		/* normal case */
1058 	char envhome[PATH_MAX], *h;
1059 
1060 	if ((copied = strdup(get_termpath())) != 0) {
1061 	    for (cp = copied; *cp; cp++) {
1062 		if (*cp == NCURSES_PATHSEP)
1063 		    *cp = '\0';
1064 		else if (cp == copied || cp[-1] == '\0') {
1065 		    ADD_TC(cp, filecount);
1066 		}
1067 	    }
1068 	}
1069 #define PRIVATE_CAP "%.*s/.termcap"
1070 
1071 	if (use_terminfo_vars() && (h = getenv("HOME")) != NULL && *h != '\0'
1072 	    && (strlen(h) + sizeof(PRIVATE_CAP)) < PATH_MAX) {
1073 	    /* user's .termcap, if any, should override it */
1074 	    _nc_STRCPY(envhome, h, sizeof(envhome));
1075 	    _nc_SPRINTF(pathbuf, _nc_SLIMIT(sizeof(pathbuf))
1076 			PRIVATE_CAP,
1077 			(int) (sizeof(pathbuf) - sizeof(PRIVATE_CAP)),
1078 			envhome);
1079 	    ADD_TC(pathbuf, filecount);
1080 	}
1081     }
1082 
1083     /*
1084      * Probably /etc/termcap is a symlink to /usr/share/misc/termcap.
1085      * Avoid reading the same file twice.
1086      */
1087 #if HAVE_LINK
1088     for (j = 0; j < filecount; j++) {
1089 	bool omit = FALSE;
1090 	if (stat(termpaths[j], &test_stat[j]) != 0
1091 	    || !S_ISREG(test_stat[j].st_mode)) {
1092 	    omit = TRUE;
1093 	} else {
1094 	    for (k = 0; k < j; k++) {
1095 		if (test_stat[k].st_dev == test_stat[j].st_dev
1096 		    && test_stat[k].st_ino == test_stat[j].st_ino) {
1097 		    omit = TRUE;
1098 		    break;
1099 		}
1100 	    }
1101 	}
1102 	if (omit) {
1103 	    TR(TRACE_DATABASE, ("Path %s is a duplicate", termpaths[j]));
1104 	    for (k = j + 1; k < filecount; k++) {
1105 		termpaths[k - 1] = termpaths[k];
1106 		test_stat[k - 1] = test_stat[k];
1107 	    }
1108 	    --filecount;
1109 	    --j;
1110 	}
1111     }
1112 #endif
1113 
1114     /* parse the sources */
1115     if (use_buffer) {
1116 	_nc_set_source("TERMCAP");
1117 
1118 	/*
1119 	 * We don't suppress warning messages here.  The presumption is
1120 	 * that since it is just a single entry, they won't be a pain.
1121 	 */
1122 	_nc_read_entry_source((FILE *) 0, tc_buf, FALSE, FALSE, NULLHOOK);
1123 	free(tc_buf);
1124     } else {
1125 	int i;
1126 
1127 	for (i = 0; i < filecount; i++) {
1128 
1129 	    TR(TRACE_DATABASE, ("Looking for %s in %s", tn, termpaths[i]));
1130 	    if (_nc_access(termpaths[i], R_OK) == 0
1131 		&& (fp = safe_fopen(termpaths[i], "r")) != (FILE *) 0) {
1132 		_nc_set_source(termpaths[i]);
1133 
1134 		/*
1135 		 * Suppress warning messages.  Otherwise you get 400 lines of
1136 		 * crap from archaic termcap files as ncurses complains about
1137 		 * all the obsolete capabilities.
1138 		 */
1139 		_nc_read_entry_source(fp, (char *) 0, FALSE, TRUE, NULLHOOK);
1140 
1141 		(void) fclose(fp);
1142 	    }
1143 	}
1144     }
1145     if (copied != 0)
1146 	free(copied);
1147 #endif /* USE_GETCAP */
1148 
1149     if (_nc_head == 0)
1150 	return (TGETENT_ERR);
1151 
1152     /* resolve all use references */
1153     if (_nc_resolve_uses2(TRUE, FALSE) != TRUE)
1154 	return (TGETENT_ERR);
1155 
1156     /* find a terminal matching tn, if we can */
1157 #if USE_GETCAP_CACHE
1158     if (getcwd(cwd_buf, sizeof(cwd_buf)) != 0) {
1159 	_nc_set_writedir((char *) 0);	/* note: this does a chdir */
1160 #endif
1161 	for_entry_list(ep) {
1162 	    if (_nc_name_match(ep->tterm.term_names, tn, "|:")) {
1163 		/*
1164 		 * Make a local copy of the terminal capabilities, delinked
1165 		 * from the list.
1166 		 */
1167 		*tp = ep->tterm;
1168 		_nc_free_entry(_nc_head, &(ep->tterm));
1169 
1170 		/*
1171 		 * OK, now try to write the type to user's terminfo directory.
1172 		 * Next time he loads this, it will come through terminfo.
1173 		 *
1174 		 * Advantage:  Second and subsequent fetches of this entry will
1175 		 * be very fast.
1176 		 *
1177 		 * Disadvantage:  After the first time a termcap type is loaded
1178 		 * by its user, editing it in the /etc/termcap file, or in
1179 		 * TERMCAP, or in a local ~/.termcap, will be ineffective
1180 		 * unless the terminfo entry is explicitly removed.
1181 		 */
1182 #if USE_GETCAP_CACHE
1183 		(void) _nc_write_entry(tp);
1184 #endif
1185 		found = TGETENT_YES;
1186 		break;
1187 	    }
1188 	}
1189 #if USE_GETCAP_CACHE
1190 	chdir(cwd_buf);
1191     }
1192 #endif
1193 
1194     return (found);
1195 }
1196 #else
1197 extern
1198 NCURSES_EXPORT(void)
1199 _nc_read_termcap(void);
1200 NCURSES_EXPORT(void)
1201 _nc_read_termcap(void)
1202 {
1203 }
1204 #endif /* PURE_TERMINFO */
1205