xref: /openbsd/lib/libcurses/tinfo/read_entry.c (revision 771fbea0)
1 /* $OpenBSD: read_entry.c,v 1.17 2015/12/03 11:29:55 nicm Exp $ */
2 
3 /****************************************************************************
4  * Copyright (c) 1998-2007,2008 Free Software Foundation, Inc.              *
5  *                                                                          *
6  * Permission is hereby granted, free of charge, to any person obtaining a  *
7  * copy of this software and associated documentation files (the            *
8  * "Software"), to deal in the Software without restriction, including      *
9  * without limitation the rights to use, copy, modify, merge, publish,      *
10  * distribute, distribute with modifications, sublicense, and/or sell       *
11  * copies of the Software, and to permit persons to whom the Software is    *
12  * furnished to do so, subject to the following conditions:                 *
13  *                                                                          *
14  * The above copyright notice and this permission notice shall be included  *
15  * in all copies or substantial portions of the Software.                   *
16  *                                                                          *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
20  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
21  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
22  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
23  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
24  *                                                                          *
25  * Except as contained in this notice, the name(s) of the above copyright   *
26  * holders shall not be used in advertising or otherwise to promote the     *
27  * sale, use or other dealings in this Software without prior written       *
28  * authorization.                                                           *
29  ****************************************************************************/
30 
31 /****************************************************************************
32  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
33  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
34  *     and: Thomas E. Dickey                        1996-on                 *
35  ****************************************************************************/
36 
37 /*
38  *	read_entry.c -- Routine for reading in a compiled terminfo file
39  */
40 
41 #include <curses.priv.h>
42 #include <hashed_db.h>
43 
44 #include <tic.h>
45 #include <term_entry.h>
46 
47 MODULE_ID("$Id: read_entry.c,v 1.17 2015/12/03 11:29:55 nicm Exp $")
48 
49 #define TYPE_CALLOC(type,elts) typeCalloc(type, (unsigned)(elts))
50 
51 #if USE_DATABASE
52 static void
53 convert_shorts(char *buf, short *Numbers, int count)
54 {
55     int i;
56     for (i = 0; i < count; i++) {
57 	if (IS_NEG1(buf + 2 * i))
58 	    Numbers[i] = ABSENT_NUMERIC;
59 	else if (IS_NEG2(buf + 2 * i))
60 	    Numbers[i] = CANCELLED_NUMERIC;
61 	else
62 	    Numbers[i] = LOW_MSB(buf + 2 * i);
63 	TR(TRACE_DATABASE, ("get Numbers[%d]=%d", i, Numbers[i]));
64     }
65 }
66 
67 static void
68 convert_strings(char *buf, char **Strings, int count, int size, char *table)
69 {
70     int i;
71     char *p;
72 
73     for (i = 0; i < count; i++) {
74 	if (IS_NEG1(buf + 2 * i)) {
75 	    Strings[i] = ABSENT_STRING;
76 	} else if (IS_NEG2(buf + 2 * i)) {
77 	    Strings[i] = CANCELLED_STRING;
78 	} else if ((int) LOW_MSB(buf + 2 * i) > size) {
79 	    Strings[i] = ABSENT_STRING;
80 	} else {
81 	    Strings[i] = (LOW_MSB(buf + 2 * i) + table);
82 	    TR(TRACE_DATABASE, ("Strings[%d] = %s", i, _nc_visbuf(Strings[i])));
83 	}
84 
85 	/* make sure all strings are NUL terminated */
86 	if (VALID_STRING(Strings[i])) {
87 	    for (p = Strings[i]; p <= table + size; p++)
88 		if (*p == '\0')
89 		    break;
90 	    /* if there is no NUL, ignore the string */
91 	    if (p > table + size)
92 		Strings[i] = ABSENT_STRING;
93 	}
94     }
95 }
96 
97 static int
98 fake_read(char *src, int *offset, int limit, char *dst, unsigned want)
99 {
100     int have = (limit - *offset);
101 
102     if (have > 0) {
103 	if ((int) want > have)
104 	    want = have;
105 	memcpy(dst, src + *offset, want);
106 	*offset += want;
107     } else {
108 	want = 0;
109     }
110     return (int) want;
111 }
112 
113 #define Read(buf, count) fake_read(buffer, &offset, limit, buf, count)
114 
115 #define read_shorts(buf, count) \
116 	(Read(buf, (unsigned) (count)*2) == (int) (count)*2)
117 
118 #define even_boundary(value) \
119     if ((value) % 2 != 0) Read(buf, 1)
120 
121 NCURSES_EXPORT(int)
122 _nc_read_termtype(TERMTYPE *ptr, char *buffer, int limit)
123 /* return 1 if read, 0 if not found or garbled */
124 {
125     int offset = 0;
126     int name_size, bool_count, num_count, str_count, str_size;
127     int i;
128     char buf[MAX_ENTRY_SIZE + 1];
129     char *string_table;
130     unsigned want, have;
131 
132     TR(TRACE_DATABASE, ("READ termtype header @%d", offset));
133 
134     memset(ptr, 0, sizeof(*ptr));
135 
136     /* grab the header */
137     if (!read_shorts(buf, 6)
138 	|| !IS_TIC_MAGIC(buf)) {
139 	return (TGETENT_NO);
140     }
141 
142     name_size = LOW_MSB(buf + 2);
143     bool_count = LOW_MSB(buf + 4);
144     num_count = LOW_MSB(buf + 6);
145     str_count = LOW_MSB(buf + 8);
146     str_size = LOW_MSB(buf + 10);
147 
148     TR(TRACE_DATABASE,
149        ("TERMTYPE name_size=%d, bool=%d/%d, num=%d/%d str=%d/%d(%d)",
150 	name_size, bool_count, BOOLCOUNT, num_count, NUMCOUNT,
151 	str_count, STRCOUNT, str_size));
152     if (name_size < 0
153 	|| bool_count < 0
154 	|| num_count < 0
155 	|| str_count < 0
156 	|| str_size < 0) {
157 	return (TGETENT_NO);
158     }
159 
160     want = str_size + name_size + 1;
161     if (str_size) {
162 	/* try to allocate space for the string table */
163 	if (str_count * 2 >= (int) sizeof(buf)
164 	    || (string_table = typeMalloc(char, want)) == 0) {
165 	    return (TGETENT_NO);
166 	}
167     } else {
168 	str_count = 0;
169 	if ((string_table = typeMalloc(char, want)) == 0) {
170 	    return (TGETENT_NO);
171 	}
172     }
173 
174     /* grab the name (a null-terminated string) */
175     want = min(MAX_NAME_SIZE, (unsigned) name_size);
176     ptr->str_table = string_table;
177     ptr->term_names = string_table;
178     if ((have = Read(ptr->term_names, want)) != want) {
179 	memset(ptr->term_names + have, 0, want - have);
180     }
181     ptr->term_names[want] = '\0';
182     string_table += (want + 1);
183 
184     if (have > MAX_NAME_SIZE)
185 	offset = (have - MAX_NAME_SIZE);
186 
187     /* grab the booleans */
188     if ((ptr->Booleans = TYPE_CALLOC(NCURSES_SBOOL,
189 				     max(BOOLCOUNT, bool_count))) == 0
190 	|| Read(ptr->Booleans, (unsigned) bool_count) < bool_count) {
191 	return (TGETENT_NO);
192     }
193 
194     /*
195      * If booleans end on an odd byte, skip it.  The machine they
196      * originally wrote terminfo on must have been a 16-bit
197      * word-oriented machine that would trap out if you tried a
198      * word access off a 2-byte boundary.
199      */
200     even_boundary(name_size + bool_count);
201 
202     /* grab the numbers */
203     if ((ptr->Numbers = TYPE_CALLOC(short, max(NUMCOUNT, num_count))) == 0
204 	|| !read_shorts(buf, num_count)) {
205 	return (TGETENT_NO);
206     }
207     convert_shorts(buf, ptr->Numbers, num_count);
208 
209     if ((ptr->Strings = TYPE_CALLOC(char *, max(STRCOUNT, str_count))) == 0)
210 	  return (TGETENT_NO);
211 
212     if (str_count) {
213 	/* grab the string offsets */
214 	if (!read_shorts(buf, str_count)) {
215 	    return (TGETENT_NO);
216 	}
217 	/* finally, grab the string table itself */
218 	if (Read(string_table, (unsigned) str_size) != str_size)
219 	    return (TGETENT_NO);
220 	convert_strings(buf, ptr->Strings, str_count, str_size, string_table);
221     }
222 #if NCURSES_XNAMES
223 
224     ptr->num_Booleans = BOOLCOUNT;
225     ptr->num_Numbers = NUMCOUNT;
226     ptr->num_Strings = STRCOUNT;
227 
228     /*
229      * Read extended entries, if any, after the normal end of terminfo data.
230      */
231     even_boundary(str_size);
232     TR(TRACE_DATABASE, ("READ extended_header @%d", offset));
233     if (_nc_user_definable && read_shorts(buf, 5)) {
234 	int ext_bool_count = LOW_MSB(buf + 0);
235 	int ext_num_count = LOW_MSB(buf + 2);
236 	int ext_str_count = LOW_MSB(buf + 4);
237 	int ext_str_size = LOW_MSB(buf + 6);
238 	int ext_str_limit = LOW_MSB(buf + 8);
239 	unsigned need = (ext_bool_count + ext_num_count + ext_str_count);
240 	int base = 0;
241 
242 	if (need >= sizeof(buf)
243 	    || ext_str_size >= (int) sizeof(buf)
244 	    || ext_str_limit >= (int) sizeof(buf)
245 	    || ext_bool_count < 0
246 	    || ext_num_count < 0
247 	    || ext_str_count < 0
248 	    || ext_str_size < 0
249 	    || ext_str_limit < 0)
250 	    return (TGETENT_NO);
251 
252 	ptr->num_Booleans = BOOLCOUNT + ext_bool_count;
253 	ptr->num_Numbers = NUMCOUNT + ext_num_count;
254 	ptr->num_Strings = STRCOUNT + ext_str_count;
255 
256 	ptr->Booleans = typeRealloc(NCURSES_SBOOL, ptr->num_Booleans, ptr->Booleans);
257 	ptr->Numbers = typeRealloc(short, ptr->num_Numbers, ptr->Numbers);
258 	ptr->Strings = typeRealloc(char *, ptr->num_Strings, ptr->Strings);
259 
260 	TR(TRACE_DATABASE, ("extended header is %d/%d/%d(%d:%d)",
261 			    ext_bool_count, ext_num_count, ext_str_count,
262 			    ext_str_size, ext_str_limit));
263 
264 	TR(TRACE_DATABASE, ("READ %d extended-booleans @%d",
265 			    ext_bool_count, offset));
266 	if ((ptr->ext_Booleans = ext_bool_count) != 0) {
267 	    if (Read(ptr->Booleans + BOOLCOUNT, (unsigned)
268 		     ext_bool_count) != ext_bool_count)
269 		return (TGETENT_NO);
270 	}
271 	even_boundary(ext_bool_count);
272 
273 	TR(TRACE_DATABASE, ("READ %d extended-numbers @%d",
274 			    ext_num_count, offset));
275 	if ((ptr->ext_Numbers = ext_num_count) != 0) {
276 	    if (!read_shorts(buf, ext_num_count))
277 		return (TGETENT_NO);
278 	    TR(TRACE_DATABASE, ("Before converting extended-numbers"));
279 	    convert_shorts(buf, ptr->Numbers + NUMCOUNT, ext_num_count);
280 	}
281 
282 	TR(TRACE_DATABASE, ("READ extended-offsets @%d", offset));
283 	if ((ext_str_count || need)
284 	    && !read_shorts(buf, ext_str_count + need))
285 	    return (TGETENT_NO);
286 
287 	TR(TRACE_DATABASE, ("READ %d bytes of extended-strings @%d",
288 			    ext_str_limit, offset));
289 
290 	if (ext_str_limit) {
291 	    if ((ptr->ext_str_table = typeMalloc(char, ext_str_limit)) == 0)
292 		  return (TGETENT_NO);
293 	    if (Read(ptr->ext_str_table, (unsigned) ext_str_limit) != ext_str_limit)
294 		return (TGETENT_NO);
295 	    TR(TRACE_DATABASE, ("first extended-string is %s", _nc_visbuf(ptr->ext_str_table)));
296 	}
297 
298 	if ((ptr->ext_Strings = ext_str_count) != 0) {
299 	    TR(TRACE_DATABASE,
300 	       ("Before computing extended-string capabilities str_count=%d, ext_str_count=%d",
301 		str_count, ext_str_count));
302 	    convert_strings(buf, ptr->Strings + str_count, ext_str_count,
303 			    ext_str_limit, ptr->ext_str_table);
304 	    for (i = ext_str_count - 1; i >= 0; i--) {
305 		TR(TRACE_DATABASE, ("MOVE from [%d:%d] %s",
306 				    i, i + str_count,
307 				    _nc_visbuf(ptr->Strings[i + str_count])));
308 		ptr->Strings[i + STRCOUNT] = ptr->Strings[i + str_count];
309 		if (VALID_STRING(ptr->Strings[i + STRCOUNT]))
310 		    base += (strlen(ptr->Strings[i + STRCOUNT]) + 1);
311 		TR(TRACE_DATABASE, ("... to    [%d] %s",
312 				    i + STRCOUNT,
313 				    _nc_visbuf(ptr->Strings[i + STRCOUNT])));
314 	    }
315 	}
316 
317 	if (need) {
318 	    if (ext_str_count >= (MAX_ENTRY_SIZE * 2))
319 		  return (TGETENT_NO);
320 	    if ((ptr->ext_Names = TYPE_CALLOC(char *, need)) == 0)
321 		  return (TGETENT_NO);
322 	    TR(TRACE_DATABASE,
323 	       ("ext_NAMES starting @%d in extended_strings, first = %s",
324 		base, _nc_visbuf(ptr->ext_str_table + base)));
325 	    convert_strings(buf + (2 * ext_str_count),
326 			    ptr->ext_Names,
327 			    (int) need,
328 			    ext_str_limit, ptr->ext_str_table + base);
329 	}
330 
331 	T(("...done reading terminfo bool %d(%d) num %d(%d) str %d(%d)",
332 	   ptr->num_Booleans, ptr->ext_Booleans,
333 	   ptr->num_Numbers, ptr->ext_Numbers,
334 	   ptr->num_Strings, ptr->ext_Strings));
335 
336 	TR(TRACE_DATABASE, ("extend: num_Booleans:%d", ptr->num_Booleans));
337     } else
338 #endif /* NCURSES_XNAMES */
339     {
340 	T(("...done reading terminfo bool %d num %d str %d",
341 	   bool_count, num_count, str_count));
342 #if NCURSES_XNAMES
343 	TR(TRACE_DATABASE, ("normal: num_Booleans:%d", ptr->num_Booleans));
344 #endif
345     }
346 
347     for (i = bool_count; i < BOOLCOUNT; i++)
348 	ptr->Booleans[i] = FALSE;
349     for (i = num_count; i < NUMCOUNT; i++)
350 	ptr->Numbers[i] = ABSENT_NUMERIC;
351     for (i = str_count; i < STRCOUNT; i++)
352 	ptr->Strings[i] = ABSENT_STRING;
353 
354     return (TGETENT_YES);
355 }
356 
357 /*
358  *	int
359  *	_nc_read_file_entry(filename, ptr)
360  *
361  *	Read the compiled terminfo entry in the given file into the
362  *	structure pointed to by ptr, allocating space for the string
363  *	table.
364  */
365 NCURSES_EXPORT(int)
366 _nc_read_file_entry(const char *const filename, TERMTYPE *ptr)
367 /* return 1 if read, 0 if not found or garbled */
368 {
369     int code, fd = -1;
370     int limit;
371     char buffer[MAX_ENTRY_SIZE + 1];
372 
373     if (_nc_access(filename, R_OK) < 0
374 	|| (fd = open(filename, O_RDONLY | O_BINARY)) < 0) {
375 	T(("cannot open terminfo %s (errno=%d)", filename, errno));
376 	code = TGETENT_NO;
377     } else {
378 	if ((limit = read(fd, buffer, sizeof(buffer))) > 0) {
379 
380 	    T(("read terminfo %s", filename));
381 	    if ((code = _nc_read_termtype(ptr, buffer, limit)) == TGETENT_NO) {
382 		_nc_free_termtype(ptr);
383 	    }
384 	} else {
385 	    code = TGETENT_NO;
386 	}
387 	close(fd);
388     }
389 
390     return (code);
391 }
392 
393 /*
394  * Build a terminfo pathname and try to read the data.  Returns TGETENT_YES on
395  * success, TGETENT_NO on failure.
396  */
397 static int
398 _nc_read_tic_entry(char *filename,
399 		   unsigned limit,
400 		   const char *const path,
401 		   const char *name,
402 		   TERMTYPE *const tp)
403 {
404     int result = TGETENT_NO;
405 
406     /*
407      * If we are looking in a directory, assume the entry is a file under that,
408      * according to the normal rules.
409      *
410      * FIXME - add caseless-filename fixup.
411      */
412     unsigned need = 4 + strlen(path) + strlen(name);
413     if (need <= limit) {
414 	    (void) snprintf(filename, limit, "%s/" LEAF_FMT "/%s", path, *name, name);
415 	    if (_nc_is_dir_path(path))
416 		    result = _nc_read_file_entry(filename, tp);
417     }
418 
419 #if USE_HASHED_DB
420     else {
421 	static const char suffix[] = DBM_SUFFIX;
422 	DB *capdbp;
423 	unsigned lens = sizeof(suffix) - 1;
424 	unsigned size = strlen(path);
425 	unsigned need = lens + size;
426 
427 	if (need <= limit) {
428 	    if (size >= lens
429 		&& !strcmp(path + size - lens, suffix))
430 		(void) strlcpy(filename, path, limit);
431 	    else
432 		(void) snprintf(filename, limit, "%s%s", path, suffix);
433 
434 	    /*
435 	     * It would be nice to optimize the dbopen/close activity, as
436 	     * done in the cgetent implementation for tc= clauses.  However,
437 	     * since we support multiple database locations, we cannot do
438 	     * that.
439 	     */
440 	    if ((capdbp = _nc_db_open(filename, FALSE)) != 0) {
441 		DBT key, data;
442 		int reccnt = 0;
443 		char *save = strdup(name);
444 
445 		memset(&key, 0, sizeof(key));
446 		key.data = save;
447 		key.size = strlen(save);
448 
449 		/*
450 		 * This lookup could return termcap data, which we do not want.
451 		 * We are looking for compiled (binary) terminfo data.
452 		 *
453 		 * cgetent uses a two-level lookup.  On the first it uses the
454 		 * given name to return a record containing only the aliases
455 		 * for an entry.  On the second (using that list of aliases as
456 		 * a key), it returns the content of the terminal description.
457 		 * We expect second lookup to return data beginning with the
458 		 * same set of aliases.
459 		 *
460 		 * For compiled terminfo, the list of aliases in the second
461 		 * case will be null-terminated.  A termcap entry will not be,
462 		 * and will run on into the description.  So we can easily
463 		 * distinguish between the two (source/binary) by checking the
464 		 * lengths.
465 		 */
466 		while (_nc_db_get(capdbp, &key, &data) == 0) {
467 		    int used = data.size - 1;
468 		    char *have = (char *) data.data;
469 
470 		    if (*have++ == 0) {
471 			if (data.size > key.size
472 			    && IS_TIC_MAGIC(have)) {
473 			    result = _nc_read_termtype(tp, have, used);
474 			    if (result == TGETENT_NO) {
475 				_nc_free_termtype(tp);
476 			    }
477 			}
478 			break;
479 		    }
480 
481 		    /*
482 		     * Just in case we have a corrupt database, do not waste
483 		     * time with it.
484 		     */
485 		    if (++reccnt >= 3)
486 			break;
487 
488 		    /*
489 		     * Prepare for the second level.
490 		     */
491 		    key.data = have;
492 		    key.size = used;
493 		}
494 
495 		_nc_db_close(capdbp);
496 		free(save);
497 	    }
498 	}
499     }
500 #endif
501     return result;
502 }
503 #endif /* USE_DATABASE */
504 
505 /*
506  *	_nc_read_entry(char *name, char *filename, TERMTYPE *tp)
507  *
508  *	Find and read the compiled entry for a given terminal type,
509  *	if it exists.  We take pains here to make sure no combination
510  *	of environment variables and terminal type name can be used to
511  *	overrun the file buffer.
512  */
513 
514 NCURSES_EXPORT(int)
515 _nc_read_entry(const char *const name, char *const filename, TERMTYPE *const tp)
516 {
517     int code = TGETENT_NO;
518 
519     snprintf(filename, PATH_MAX, "%s", name);
520     if (strlen(name) == 0
521 	|| strcmp(name, ".") == 0
522 	|| strcmp(name, "..") == 0
523 	|| _nc_pathlast(name) != 0
524 	|| strchr(name, NCURSES_PATHSEP) != 0) {
525 	T(("illegal or missing entry name '%s'", name));
526     } else {
527 #if USE_DATABASE
528 	DBDIRS state = dbdTIC;
529 	int offset = 0;
530 	const char *path;
531 
532 	while ((path = _nc_next_db(&state, &offset)) != 0) {
533 	    code = _nc_read_tic_entry(filename, PATH_MAX, path, name, tp);
534 	    if (code == TGETENT_YES) {
535 		_nc_last_db();
536 		break;
537 	    }
538 	}
539 #endif
540 #if USE_TERMCAP
541 	if (code != TGETENT_YES) {
542 	    code = _nc_read_termcap_entry(name, tp);
543 	    snprintf(filename, PATH_MAX, "%s", _nc_get_source());
544 	}
545 #endif
546     }
547     return code;
548 }
549