1 /****************************************************************************
2  * Copyright (c) 1998-2010,2011 Free Software Foundation, Inc.              *
3  *                                                                          *
4  * Permission is hereby granted, free of charge, to any person obtaining a  *
5  * copy of this software and associated documentation files (the            *
6  * "Software"), to deal in the Software without restriction, including      *
7  * without limitation the rights to use, copy, modify, merge, publish,      *
8  * distribute, distribute with modifications, sublicense, and/or sell       *
9  * copies of the Software, and to permit persons to whom the Software is    *
10  * furnished to do so, subject to the following conditions:                 *
11  *                                                                          *
12  * The above copyright notice and this permission notice shall be included  *
13  * in all copies or substantial portions of the Software.                   *
14  *                                                                          *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
24  * holders shall not be used in advertising or otherwise to promote the     *
25  * sale, use or other dealings in this Software without prior written       *
26  * authorization.                                                           *
27  ****************************************************************************/
28 
29 /****************************************************************************
30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32  *     and: Thomas E. Dickey                        1996-on                 *
33  ****************************************************************************/
34 
35 /*
36  *	read_entry.c -- Routine for reading in a compiled terminfo file
37  */
38 
39 #include <curses.priv.h>
40 #include <hashed_db.h>
41 
42 #include <tic.h>
43 
44 MODULE_ID("$Id: read_entry.c,v 1.108 2011/02/26 15:36:06 tom Exp $")
45 
46 #define TYPE_CALLOC(type,elts) typeCalloc(type, (unsigned)(elts))
47 
48 #if USE_DATABASE
49 static void
50 convert_shorts(char *buf, short *Numbers, int count)
51 {
52     int i;
53     for (i = 0; i < count; i++) {
54 	if (IS_NEG1(buf + 2 * i))
55 	    Numbers[i] = ABSENT_NUMERIC;
56 	else if (IS_NEG2(buf + 2 * i))
57 	    Numbers[i] = CANCELLED_NUMERIC;
58 	else
59 	    Numbers[i] = (short) LOW_MSB(buf + 2 * i);
60 	TR(TRACE_DATABASE, ("get Numbers[%d]=%d", i, Numbers[i]));
61     }
62 }
63 
64 static void
65 convert_strings(char *buf, char **Strings, int count, int size, char *table)
66 {
67     int i;
68     char *p;
69 
70     for (i = 0; i < count; i++) {
71 	if (IS_NEG1(buf + 2 * i)) {
72 	    Strings[i] = ABSENT_STRING;
73 	} else if (IS_NEG2(buf + 2 * i)) {
74 	    Strings[i] = CANCELLED_STRING;
75 	} else if ((int) LOW_MSB(buf + 2 * i) > size) {
76 	    Strings[i] = ABSENT_STRING;
77 	} else {
78 	    Strings[i] = (LOW_MSB(buf + 2 * i) + table);
79 	    TR(TRACE_DATABASE, ("Strings[%d] = %s", i, _nc_visbuf(Strings[i])));
80 	}
81 
82 	/* make sure all strings are NUL terminated */
83 	if (VALID_STRING(Strings[i])) {
84 	    for (p = Strings[i]; p <= table + size; p++)
85 		if (*p == '\0')
86 		    break;
87 	    /* if there is no NUL, ignore the string */
88 	    if (p > table + size)
89 		Strings[i] = ABSENT_STRING;
90 	}
91     }
92 }
93 
94 static int
95 fake_read(char *src, int *offset, int limit, char *dst, unsigned want)
96 {
97     int have = (limit - *offset);
98 
99     if (have > 0) {
100 	if ((int) want > have)
101 	    want = (unsigned) have;
102 	memcpy(dst, src + *offset, want);
103 	*offset += (int) want;
104     } else {
105 	want = 0;
106     }
107     return (int) want;
108 }
109 
110 #define Read(buf, count) fake_read(buffer, &offset, limit, buf, count)
111 
112 #define read_shorts(buf, count) \
113 	(Read(buf, (unsigned) (count)*2) == (int) (count)*2)
114 
115 #define even_boundary(value) \
116     if ((value) % 2 != 0) Read(buf, 1)
117 
118 NCURSES_EXPORT(int)
119 _nc_read_termtype(TERMTYPE *ptr, char *buffer, int limit)
120 /* return 1 if read, 0 if not found or garbled */
121 {
122     int offset = 0;
123     int name_size, bool_count, num_count, str_count, str_size;
124     int i;
125     char buf[MAX_ENTRY_SIZE + 1];
126     char *string_table;
127     unsigned want, have;
128 
129     TR(TRACE_DATABASE, ("READ termtype header @%d", offset));
130 
131     memset(ptr, 0, sizeof(*ptr));
132 
133     /* grab the header */
134     if (!read_shorts(buf, 6)
135 	|| !IS_TIC_MAGIC(buf)) {
136 	return (TGETENT_NO);
137     }
138 
139     name_size = LOW_MSB(buf + 2);
140     bool_count = LOW_MSB(buf + 4);
141     num_count = LOW_MSB(buf + 6);
142     str_count = LOW_MSB(buf + 8);
143     str_size = LOW_MSB(buf + 10);
144 
145     TR(TRACE_DATABASE,
146        ("TERMTYPE name_size=%d, bool=%d/%d, num=%d/%d str=%d/%d(%d)",
147 	name_size, bool_count, BOOLCOUNT, num_count, NUMCOUNT,
148 	str_count, STRCOUNT, str_size));
149     if (name_size < 0
150 	|| bool_count < 0
151 	|| num_count < 0
152 	|| str_count < 0
153 	|| str_size < 0) {
154 	return (TGETENT_NO);
155     }
156 
157     want = (unsigned) (str_size + name_size + 1);
158     if (str_size) {
159 	/* try to allocate space for the string table */
160 	if (str_count * 2 >= (int) sizeof(buf)
161 	    || (string_table = typeMalloc(char, want)) == 0) {
162 	    return (TGETENT_NO);
163 	}
164     } else {
165 	str_count = 0;
166 	if ((string_table = typeMalloc(char, want)) == 0) {
167 	    return (TGETENT_NO);
168 	}
169     }
170 
171     /* grab the name (a null-terminated string) */
172     want = min(MAX_NAME_SIZE, (unsigned) name_size);
173     ptr->str_table = string_table;
174     ptr->term_names = string_table;
175     if ((have = (unsigned) Read(ptr->term_names, want)) != want) {
176 	memset(ptr->term_names + have, 0, want - have);
177     }
178     ptr->term_names[want] = '\0';
179     string_table += (want + 1);
180 
181     if (have > MAX_NAME_SIZE)
182 	offset = (int) (have - MAX_NAME_SIZE);
183 
184     /* grab the booleans */
185     if ((ptr->Booleans = TYPE_CALLOC(NCURSES_SBOOL,
186 				     max(BOOLCOUNT, bool_count))) == 0
187 	|| Read(ptr->Booleans, (unsigned) bool_count) < bool_count) {
188 	return (TGETENT_NO);
189     }
190 
191     /*
192      * If booleans end on an odd byte, skip it.  The machine they
193      * originally wrote terminfo on must have been a 16-bit
194      * word-oriented machine that would trap out if you tried a
195      * word access off a 2-byte boundary.
196      */
197     even_boundary(name_size + bool_count);
198 
199     /* grab the numbers */
200     if ((ptr->Numbers = TYPE_CALLOC(short, max(NUMCOUNT, num_count))) == 0
201 	|| !read_shorts(buf, num_count)) {
202 	return (TGETENT_NO);
203     }
204     convert_shorts(buf, ptr->Numbers, num_count);
205 
206     if ((ptr->Strings = TYPE_CALLOC(char *, max(STRCOUNT, str_count))) == 0)
207 	  return (TGETENT_NO);
208 
209     if (str_count) {
210 	/* grab the string offsets */
211 	if (!read_shorts(buf, str_count)) {
212 	    return (TGETENT_NO);
213 	}
214 	/* finally, grab the string table itself */
215 	if (Read(string_table, (unsigned) str_size) != str_size)
216 	    return (TGETENT_NO);
217 	convert_strings(buf, ptr->Strings, str_count, str_size, string_table);
218     }
219 #if NCURSES_XNAMES
220 
221     ptr->num_Booleans = BOOLCOUNT;
222     ptr->num_Numbers = NUMCOUNT;
223     ptr->num_Strings = STRCOUNT;
224 
225     /*
226      * Read extended entries, if any, after the normal end of terminfo data.
227      */
228     even_boundary(str_size);
229     TR(TRACE_DATABASE, ("READ extended_header @%d", offset));
230     if (_nc_user_definable && read_shorts(buf, 5)) {
231 	int ext_bool_count = LOW_MSB(buf + 0);
232 	int ext_num_count = LOW_MSB(buf + 2);
233 	int ext_str_count = LOW_MSB(buf + 4);
234 	int ext_str_size = LOW_MSB(buf + 6);
235 	int ext_str_limit = LOW_MSB(buf + 8);
236 	unsigned need = (unsigned) (ext_bool_count + ext_num_count + ext_str_count);
237 	int base = 0;
238 
239 	if (need >= sizeof(buf)
240 	    || ext_str_size >= (int) sizeof(buf)
241 	    || ext_str_limit >= (int) sizeof(buf)
242 	    || ext_bool_count < 0
243 	    || ext_num_count < 0
244 	    || ext_str_count < 0
245 	    || ext_str_size < 0
246 	    || ext_str_limit < 0)
247 	    return (TGETENT_NO);
248 
249 	ptr->num_Booleans = UShort(BOOLCOUNT + ext_bool_count);
250 	ptr->num_Numbers = UShort(NUMCOUNT + ext_num_count);
251 	ptr->num_Strings = UShort(STRCOUNT + ext_str_count);
252 
253 	ptr->Booleans = typeRealloc(NCURSES_SBOOL, ptr->num_Booleans, ptr->Booleans);
254 	ptr->Numbers = typeRealloc(short, ptr->num_Numbers, ptr->Numbers);
255 	ptr->Strings = typeRealloc(char *, ptr->num_Strings, ptr->Strings);
256 
257 	TR(TRACE_DATABASE, ("extended header is %d/%d/%d(%d:%d)",
258 			    ext_bool_count, ext_num_count, ext_str_count,
259 			    ext_str_size, ext_str_limit));
260 
261 	TR(TRACE_DATABASE, ("READ %d extended-booleans @%d",
262 			    ext_bool_count, offset));
263 	if ((ptr->ext_Booleans = UShort(ext_bool_count)) != 0) {
264 	    if (Read(ptr->Booleans + BOOLCOUNT, (unsigned)
265 		     ext_bool_count) != ext_bool_count)
266 		return (TGETENT_NO);
267 	}
268 	even_boundary(ext_bool_count);
269 
270 	TR(TRACE_DATABASE, ("READ %d extended-numbers @%d",
271 			    ext_num_count, offset));
272 	if ((ptr->ext_Numbers = UShort(ext_num_count)) != 0) {
273 	    if (!read_shorts(buf, ext_num_count))
274 		return (TGETENT_NO);
275 	    TR(TRACE_DATABASE, ("Before converting extended-numbers"));
276 	    convert_shorts(buf, ptr->Numbers + NUMCOUNT, ext_num_count);
277 	}
278 
279 	TR(TRACE_DATABASE, ("READ extended-offsets @%d", offset));
280 	if ((ext_str_count || need)
281 	    && !read_shorts(buf, ext_str_count + (int) need))
282 	    return (TGETENT_NO);
283 
284 	TR(TRACE_DATABASE, ("READ %d bytes of extended-strings @%d",
285 			    ext_str_limit, offset));
286 
287 	if (ext_str_limit) {
288 	    ptr->ext_str_table = typeMalloc(char, (size_t) ext_str_limit);
289 	    if (ptr->ext_str_table == 0)
290 		return (TGETENT_NO);
291 	    if (Read(ptr->ext_str_table, (unsigned) ext_str_limit) != ext_str_limit)
292 		return (TGETENT_NO);
293 	    TR(TRACE_DATABASE, ("first extended-string is %s", _nc_visbuf(ptr->ext_str_table)));
294 	}
295 
296 	if ((ptr->ext_Strings = UShort(ext_str_count)) != 0) {
297 	    TR(TRACE_DATABASE,
298 	       ("Before computing extended-string capabilities str_count=%d, ext_str_count=%d",
299 		str_count, ext_str_count));
300 	    convert_strings(buf, ptr->Strings + str_count, ext_str_count,
301 			    ext_str_limit, ptr->ext_str_table);
302 	    for (i = ext_str_count - 1; i >= 0; i--) {
303 		TR(TRACE_DATABASE, ("MOVE from [%d:%d] %s",
304 				    i, i + str_count,
305 				    _nc_visbuf(ptr->Strings[i + str_count])));
306 		ptr->Strings[i + STRCOUNT] = ptr->Strings[i + str_count];
307 		if (VALID_STRING(ptr->Strings[i + STRCOUNT]))
308 		    base += (int) (strlen(ptr->Strings[i + STRCOUNT]) + 1);
309 		TR(TRACE_DATABASE, ("... to    [%d] %s",
310 				    i + STRCOUNT,
311 				    _nc_visbuf(ptr->Strings[i + STRCOUNT])));
312 	    }
313 	}
314 
315 	if (need) {
316 	    if (ext_str_count >= (MAX_ENTRY_SIZE * 2))
317 		return (TGETENT_NO);
318 	    if ((ptr->ext_Names = TYPE_CALLOC(char *, need)) == 0)
319 		  return (TGETENT_NO);
320 	    TR(TRACE_DATABASE,
321 	       ("ext_NAMES starting @%d in extended_strings, first = %s",
322 		base, _nc_visbuf(ptr->ext_str_table + base)));
323 	    convert_strings(buf + (2 * ext_str_count),
324 			    ptr->ext_Names,
325 			    (int) need,
326 			    ext_str_limit, ptr->ext_str_table + base);
327 	}
328 
329 	T(("...done reading terminfo bool %d(%d) num %d(%d) str %d(%d)",
330 	   ptr->num_Booleans, ptr->ext_Booleans,
331 	   ptr->num_Numbers, ptr->ext_Numbers,
332 	   ptr->num_Strings, ptr->ext_Strings));
333 
334 	TR(TRACE_DATABASE, ("extend: num_Booleans:%d", ptr->num_Booleans));
335     } else
336 #endif /* NCURSES_XNAMES */
337     {
338 	T(("...done reading terminfo bool %d num %d str %d",
339 	   bool_count, num_count, str_count));
340 #if NCURSES_XNAMES
341 	TR(TRACE_DATABASE, ("normal: num_Booleans:%d", ptr->num_Booleans));
342 #endif
343     }
344 
345     for (i = bool_count; i < BOOLCOUNT; i++)
346 	ptr->Booleans[i] = FALSE;
347     for (i = num_count; i < NUMCOUNT; i++)
348 	ptr->Numbers[i] = ABSENT_NUMERIC;
349     for (i = str_count; i < STRCOUNT; i++)
350 	ptr->Strings[i] = ABSENT_STRING;
351 
352     return (TGETENT_YES);
353 }
354 
355 /*
356  *	int
357  *	_nc_read_file_entry(filename, ptr)
358  *
359  *	Read the compiled terminfo entry in the given file into the
360  *	structure pointed to by ptr, allocating space for the string
361  *	table.
362  */
363 NCURSES_EXPORT(int)
364 _nc_read_file_entry(const char *const filename, TERMTYPE *ptr)
365 /* return 1 if read, 0 if not found or garbled */
366 {
367     FILE *fp = 0;
368     int code;
369     int limit;
370     char buffer[MAX_ENTRY_SIZE + 1];
371 
372     if (_nc_access(filename, R_OK) < 0
373 	|| (fp = fopen(filename, "rb")) == 0) {
374 	T(("cannot open terminfo %s (errno=%d)", filename, errno));
375 	code = TGETENT_NO;
376     } else {
377 	if ((limit = (int) fread(buffer, sizeof(char), sizeof(buffer), fp))
378 	    > 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 	fclose(fp);
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     unsigned need = (unsigned) (LEAF_LEN + 3 + strlen(path) + strlen(name));
411     if (need <= limit)
412 	(void) sprintf(filename, "%s/" LEAF_FMT "/%s", path, *name, name);
413 
414     if (_nc_is_dir_path(path))
415 	result = _nc_read_file_entry(filename, tp);
416 #if USE_HASHED_DB
417     else {
418 	static const char suffix[] = DBM_SUFFIX;
419 	DB *capdbp;
420 	unsigned lens = sizeof(suffix) - 1;
421 	unsigned size = strlen(path);
422 	unsigned test = lens + size;
423 
424 	if (test < limit) {
425 	    if (size >= lens
426 		&& !strcmp(path + size - lens, suffix))
427 		(void) strcpy(filename, path);
428 	    else
429 		(void) sprintf(filename, "%s%s", path, suffix);
430 
431 	    /*
432 	     * It would be nice to optimize the dbopen/close activity, as
433 	     * done in the cgetent implementation for tc= clauses.  However,
434 	     * since we support multiple database locations, we cannot do
435 	     * that.
436 	     */
437 	    if ((capdbp = _nc_db_open(filename, FALSE)) != 0) {
438 		DBT key, data;
439 		int reccnt = 0;
440 		char *save = strdup(name);
441 
442 		memset(&key, 0, sizeof(key));
443 		key.data = save;
444 		key.size = strlen(save);
445 
446 		/*
447 		 * This lookup could return termcap data, which we do not want.
448 		 * We are looking for compiled (binary) terminfo data.
449 		 *
450 		 * cgetent uses a two-level lookup.  On the first it uses the
451 		 * given name to return a record containing only the aliases
452 		 * for an entry.  On the second (using that list of aliases as
453 		 * a key), it returns the content of the terminal description.
454 		 * We expect second lookup to return data beginning with the
455 		 * same set of aliases.
456 		 *
457 		 * For compiled terminfo, the list of aliases in the second
458 		 * case will be null-terminated.  A termcap entry will not be,
459 		 * and will run on into the description.  So we can easily
460 		 * distinguish between the two (source/binary) by checking the
461 		 * lengths.
462 		 */
463 		while (_nc_db_get(capdbp, &key, &data) == 0) {
464 		    int used = data.size - 1;
465 		    char *have = (char *) data.data;
466 
467 		    if (*have++ == 0) {
468 			if (data.size > key.size
469 			    && IS_TIC_MAGIC(have)) {
470 			    result = _nc_read_termtype(tp, have, used);
471 			    if (result == TGETENT_NO) {
472 				_nc_free_termtype(tp);
473 			    }
474 			}
475 			break;
476 		    }
477 
478 		    /*
479 		     * Just in case we have a corrupt database, do not waste
480 		     * time with it.
481 		     */
482 		    if (++reccnt >= 3)
483 			break;
484 
485 		    /*
486 		     * Prepare for the second level.
487 		     */
488 		    key.data = have;
489 		    key.size = used;
490 		}
491 
492 		_nc_db_close(capdbp);
493 		free(save);
494 	    }
495 	}
496     }
497 #endif
498     return result;
499 }
500 #endif /* USE_DATABASE */
501 
502 /*
503  *	_nc_read_entry(char *name, char *filename, TERMTYPE *tp)
504  *
505  *	Find and read the compiled entry for a given terminal type,
506  *	if it exists.  We take pains here to make sure no combination
507  *	of environment variables and terminal type name can be used to
508  *	overrun the file buffer.
509  */
510 
511 NCURSES_EXPORT(int)
512 _nc_read_entry(const char *const name, char *const filename, TERMTYPE *const tp)
513 {
514     int code = TGETENT_NO;
515 
516     sprintf(filename, "%.*s", PATH_MAX - 1, name);
517     if (strlen(name) == 0
518 	|| strcmp(name, ".") == 0
519 	|| strcmp(name, "..") == 0
520 	|| _nc_pathlast(name) != 0
521 	|| strchr(name, NCURSES_PATHSEP) != 0) {
522 	T(("illegal or missing entry name '%s'", name));
523     } else {
524 #if USE_DATABASE
525 	DBDIRS state = dbdTIC;
526 	int offset = 0;
527 	const char *path;
528 
529 	while ((path = _nc_next_db(&state, &offset)) != 0) {
530 	    code = _nc_read_tic_entry(filename, PATH_MAX, path, name, tp);
531 	    if (code == TGETENT_YES) {
532 		_nc_last_db();
533 		break;
534 	    }
535 	}
536 #endif
537 #if USE_TERMCAP
538 	if (code != TGETENT_YES) {
539 	    code = _nc_read_termcap_entry(name, tp);
540 	    sprintf(filename, "%.*s", PATH_MAX - 1, _nc_get_source());
541 	}
542 #endif
543     }
544     return code;
545 }
546