1 /****************************************************************************
2  * Copyright (c) 1998-2004,2005 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 
40 #include <curses.priv.h>
41 
42 #include <tic.h>
43 #include <term_entry.h>
44 
45 MODULE_ID("$Id: read_entry.c,v 1.81 2005/06/02 22:04:32 tom Exp $")
46 #ifdef __MirBSD__
47 __RCSID("$MirOS: src/lib/libncurses/src/ncurses/tinfo/read_entry.c,v 1.6 2009/09/06 12:46:46 tg Exp $");
48 #endif
49 
50 #if !HAVE_TELL
51 #define tell(fd) lseek(fd, 0, SEEK_CUR)		/* lseek() is POSIX, but not tell() */
52 #endif
53 
54 #define TYPE_CALLOC(type,elts) typeCalloc(type, (unsigned)(elts))
55 
56 /*
57  *	int
58  *	_nc_read_file_entry(filename, ptr)
59  *
60  *	Read the compiled terminfo entry in the given file into the
61  *	structure pointed to by ptr, allocating space for the string
62  *	table.
63  */
64 
65 #undef  BYTE
66 #define BYTE(p,n)	(unsigned char)((p)[n])
67 
68 #define IS_NEG1(p)	((BYTE(p,0) == 0377) && (BYTE(p,1) == 0377))
69 #define IS_NEG2(p)	((BYTE(p,0) == 0376) && (BYTE(p,1) == 0377))
70 #define LOW_MSB(p)	(BYTE(p,0) + 256*BYTE(p,1))
71 
72 static bool have_tic_directory = FALSE;
73 static bool keep_tic_directory = FALSE;
74 
75 /*
76  * Record the "official" location of the terminfo directory, according to
77  * the place where we're writing to, or the normal default, if not.
78  */
79 NCURSES_EXPORT(const char *)
_nc_tic_dir(const char * path)80 _nc_tic_dir(const char *path)
81 {
82     static const char *result = TERMINFO;
83 
84     if (!keep_tic_directory) {
85 	if (path != 0) {
86 	    result = path;
87 	    have_tic_directory = TRUE;
88 	} else if (!have_tic_directory && use_terminfo_vars()) {
89 	    char *envp;
90 	    if ((envp = getenv("TERMINFO")) != 0)
91 		return _nc_tic_dir(envp);
92 	}
93     }
94     return result;
95 }
96 
97 /*
98  * Special fix to prevent the terminfo directory from being moved after tic
99  * has chdir'd to it.  If we let it be changed, then if $TERMINFO has a
100  * relative path, we'll lose track of the actual directory.
101  */
102 NCURSES_EXPORT(void)
_nc_keep_tic_dir(const char * path)103 _nc_keep_tic_dir(const char *path)
104 {
105     _nc_tic_dir(path);
106     keep_tic_directory = TRUE;
107 }
108 
109 static void
convert_shorts(char * buf,short * Numbers,int count)110 convert_shorts(char *buf, short *Numbers, int count)
111 {
112     int i;
113     for (i = 0; i < count; i++) {
114 	if (IS_NEG1(buf + 2 * i))
115 	    Numbers[i] = ABSENT_NUMERIC;
116 	else if (IS_NEG2(buf + 2 * i))
117 	    Numbers[i] = CANCELLED_NUMERIC;
118 	else
119 	    Numbers[i] = LOW_MSB(buf + 2 * i);
120 	TR(TRACE_DATABASE, ("get Numbers[%d]=%d", i, Numbers[i]));
121     }
122 }
123 
124 static void
convert_strings(char * buf,char ** Strings,int count,int size,char * table)125 convert_strings(char *buf, char **Strings, int count, int size, char *table)
126 {
127     int i;
128     char *p;
129 
130     for (i = 0; i < count; i++) {
131 	if (IS_NEG1(buf + 2 * i)) {
132 	    Strings[i] = ABSENT_STRING;
133 	} else if (IS_NEG2(buf + 2 * i)) {
134 	    Strings[i] = CANCELLED_STRING;
135 	} else if (LOW_MSB(buf + 2 * i) > size) {
136 	    Strings[i] = ABSENT_STRING;
137 	} else {
138 	    Strings[i] = (LOW_MSB(buf + 2 * i) + table);
139 	    TR(TRACE_DATABASE, ("Strings[%d] = %s", i, _nc_visbuf(Strings[i])));
140 	}
141 
142 	/* make sure all strings are NUL terminated */
143 	if (VALID_STRING(Strings[i])) {
144 	    for (p = Strings[i]; p <= table + size; p++)
145 		if (*p == '\0')
146 		    break;
147 	    /* if there is no NUL, ignore the string */
148 	    if (p > table + size)
149 		Strings[i] = ABSENT_STRING;
150 	}
151     }
152 }
153 
154 #define read_shorts(fd, buf, count) \
155 	(read(fd, buf, (unsigned) (count)*2) == (int) (count)*2)
156 
157 #define even_boundary(value) \
158     if ((value) % 2 != 0) read(fd, buf, 1)
159 
160 static int
read_termtype(int fd,TERMTYPE * ptr)161 read_termtype(int fd, TERMTYPE *ptr)
162 /* return 1 if read, 0 if not found or garbled */
163 {
164     int name_size, bool_count, num_count, str_count, str_size;
165     int i;
166     char buf[MAX_ENTRY_SIZE + 1];
167     unsigned want, have;
168 
169     TR(TRACE_DATABASE, ("READ termtype header @%ld", (long) tell(fd)));
170 
171     memset(ptr, 0, sizeof(*ptr));
172 
173     /* grab the header */
174     if (!read_shorts(fd, buf, 6)
175 	|| LOW_MSB(buf) != MAGIC) {
176 	return (0);
177     }
178 
179     name_size = LOW_MSB(buf + 2);
180     bool_count = LOW_MSB(buf + 4);
181     num_count = LOW_MSB(buf + 6);
182     str_count = LOW_MSB(buf + 8);
183     str_size = LOW_MSB(buf + 10);
184 
185     TR(TRACE_DATABASE,
186        ("TERMTYPE name_size=%d, bool=%d/%d, num=%d/%d str=%d/%d(%d)",
187 	name_size, bool_count, BOOLCOUNT, num_count, NUMCOUNT,
188 	str_count, STRCOUNT, str_size));
189     if (name_size < 0
190 	|| bool_count < 0
191 	|| num_count < 0
192 	|| str_count < 0
193 	|| str_size < 0) {
194 	return (0);
195     }
196 
197     if (str_size) {
198 	/* try to allocate space for the string table */
199 	if (str_count * 2 >= (int) sizeof(buf)
200 	    || (ptr->str_table = typeMalloc(char, (unsigned) str_size)) == 0) {
201 	    return (0);
202 	}
203     } else {
204 	str_count = 0;
205     }
206 
207     /* grab the name (a null-terminated string) */
208     want = min(MAX_NAME_SIZE, (unsigned) name_size);
209     if ((have = read(fd, buf, want)) != want) {
210 	memset(buf + have, 0, want - have);
211     }
212     buf[want] = '\0';
213     ptr->term_names = TYPE_CALLOC(char, strlen(buf) + 1);
214     if (ptr->term_names == NULL) {
215 	return (0);
216     }
217     (void) strcpy(ptr->term_names, buf);
218     if (have > MAX_NAME_SIZE)
219 	lseek(fd, (off_t) (have - MAX_NAME_SIZE), 1);
220 
221     /* grab the booleans */
222     if ((ptr->Booleans = TYPE_CALLOC(char, max(BOOLCOUNT, bool_count))) == 0
223 	|| read(fd, ptr->Booleans, (unsigned) bool_count) < bool_count) {
224 	return (0);
225     }
226 
227     /*
228      * If booleans end on an odd byte, skip it.  The machine they
229      * originally wrote terminfo on must have been a 16-bit
230      * word-oriented machine that would trap out if you tried a
231      * word access off a 2-byte boundary.
232      */
233     even_boundary(name_size + bool_count);
234 
235     /* grab the numbers */
236     if ((ptr->Numbers = TYPE_CALLOC(short, max(NUMCOUNT, num_count))) == 0
237 	|| !read_shorts(fd, buf, num_count)) {
238 	return (0);
239     }
240     convert_shorts(buf, ptr->Numbers, num_count);
241 
242     if ((ptr->Strings = TYPE_CALLOC(char *, max(STRCOUNT, str_count))) == 0)
243 	  return (0);
244 
245     if (str_count) {
246 	/* grab the string offsets */
247 	if (!read_shorts(fd, buf, str_count)) {
248 	    return (0);
249 	}
250 	/* finally, grab the string table itself */
251 	if (read(fd, ptr->str_table, (unsigned) str_size) != str_size)
252 	    return (0);
253 	convert_strings(buf, ptr->Strings, str_count, str_size, ptr->str_table);
254     }
255 #if NCURSES_XNAMES
256 
257     ptr->num_Booleans = BOOLCOUNT;
258     ptr->num_Numbers = NUMCOUNT;
259     ptr->num_Strings = STRCOUNT;
260 
261     /*
262      * Read extended entries, if any, after the normal end of terminfo data.
263      */
264     even_boundary(str_size);
265     TR(TRACE_DATABASE, ("READ extended_header @%ld", (long) tell(fd)));
266     if (_nc_user_definable && read_shorts(fd, buf, 5)) {
267 	int ext_bool_count = LOW_MSB(buf + 0);
268 	int ext_num_count = LOW_MSB(buf + 2);
269 	int ext_str_count = LOW_MSB(buf + 4);
270 	int ext_str_size = LOW_MSB(buf + 6);
271 	int ext_str_limit = LOW_MSB(buf + 8);
272 	unsigned need = (ext_bool_count + ext_num_count + ext_str_count);
273 	int base = 0;
274 
275 	if (need >= sizeof(buf)
276 	    || ext_str_size >= (int) sizeof(buf)
277 	    || ext_str_limit >= (int) sizeof(buf)
278 	    || ext_bool_count < 0
279 	    || ext_num_count < 0
280 	    || ext_str_count < 0
281 	    || ext_str_size < 0
282 	    || ext_str_limit < 0)
283 	    return (0);
284 
285 	ptr->num_Booleans = BOOLCOUNT + ext_bool_count;
286 	ptr->num_Numbers = NUMCOUNT + ext_num_count;
287 	ptr->num_Strings = STRCOUNT + ext_str_count;
288 
289 	ptr->Booleans = typeRealloc(char, ptr->num_Booleans, ptr->Booleans);
290 	ptr->Numbers = typeRealloc(short, ptr->num_Numbers, ptr->Numbers);
291 	ptr->Strings = typeRealloc(char *, ptr->num_Strings, ptr->Strings);
292 
293 	TR(TRACE_DATABASE, ("extended header is %d/%d/%d(%d:%d)",
294 			    ext_bool_count, ext_num_count, ext_str_count,
295 			    ext_str_size, ext_str_limit));
296 
297 	TR(TRACE_DATABASE, ("READ %d extended-booleans @%ld",
298 			    ext_bool_count, (long) tell(fd)));
299 	if ((ptr->ext_Booleans = ext_bool_count) != 0) {
300 	    if (read(fd, ptr->Booleans + BOOLCOUNT, (unsigned)
301 		     ext_bool_count) != ext_bool_count)
302 		return (0);
303 	}
304 	even_boundary(ext_bool_count);
305 
306 	TR(TRACE_DATABASE, ("READ %d extended-numbers @%ld",
307 			    ext_num_count, (long) tell(fd)));
308 	if ((ptr->ext_Numbers = ext_num_count) != 0) {
309 	    if (!read_shorts(fd, buf, ext_num_count))
310 		return (0);
311 	    TR(TRACE_DATABASE, ("Before converting extended-numbers"));
312 	    convert_shorts(buf, ptr->Numbers + NUMCOUNT, ext_num_count);
313 	}
314 
315 	TR(TRACE_DATABASE, ("READ extended-offsets @%ld", (long) tell(fd)));
316 	if ((ext_str_count || need)
317 	    && !read_shorts(fd, buf, ext_str_count + need))
318 	    return (0);
319 
320 	TR(TRACE_DATABASE, ("READ %d bytes of extended-strings @%ld",
321 			    ext_str_limit, (long) tell(fd)));
322 
323 	if (ext_str_limit) {
324 	    if ((ptr->ext_str_table = typeMalloc(char, ext_str_limit)) == 0)
325 		  return (0);
326 	    if (read(fd, ptr->ext_str_table, (unsigned) ext_str_limit) != ext_str_limit)
327 		return (0);
328 	    TR(TRACE_DATABASE, ("first extended-string is %s", _nc_visbuf(ptr->ext_str_table)));
329 	}
330 
331 	if ((ptr->ext_Strings = ext_str_count) != 0) {
332 	    TR(TRACE_DATABASE,
333 	       ("Before computing extended-string capabilities str_count=%d, ext_str_count=%d",
334 		str_count, ext_str_count));
335 	    convert_strings(buf, ptr->Strings + str_count, ext_str_count,
336 			    ext_str_limit, ptr->ext_str_table);
337 	    for (i = ext_str_count - 1; i >= 0; i--) {
338 		TR(TRACE_DATABASE, ("MOVE from [%d:%d] %s",
339 				    i, i + str_count,
340 				    _nc_visbuf(ptr->Strings[i + str_count])));
341 		ptr->Strings[i + STRCOUNT] = ptr->Strings[i + str_count];
342 		if (VALID_STRING(ptr->Strings[i + STRCOUNT]))
343 		    base += (strlen(ptr->Strings[i + STRCOUNT]) + 1);
344 		TR(TRACE_DATABASE, ("... to    [%d] %s",
345 				    i + STRCOUNT,
346 				    _nc_visbuf(ptr->Strings[i + STRCOUNT])));
347 	    }
348 	}
349 
350 	if (need) {
351 	    if ((ptr->ext_Names = TYPE_CALLOC(char *, need)) == 0)
352 		  return (0);
353 	    TR(TRACE_DATABASE,
354 	       ("ext_NAMES starting @%d in extended_strings, first = %s",
355 		base, _nc_visbuf(ptr->ext_str_table + base)));
356 	    convert_strings(buf + (2 * ext_str_count),
357 			    ptr->ext_Names,
358 			    (int) need,
359 			    ext_str_limit, ptr->ext_str_table + base);
360 	}
361 
362 	T(("...done reading terminfo bool %d(%d) num %d(%d) str %d(%d)",
363 	   ptr->num_Booleans, ptr->ext_Booleans,
364 	   ptr->num_Numbers, ptr->ext_Numbers,
365 	   ptr->num_Strings, ptr->ext_Strings));
366 
367 	TR(TRACE_DATABASE, ("extend: num_Booleans:%d", ptr->num_Booleans));
368     } else
369 #endif /* NCURSES_XNAMES */
370     {
371 	T(("...done reading terminfo bool %d num %d str %d",
372 	   bool_count, num_count, str_count));
373 #if NCURSES_XNAMES
374 	TR(TRACE_DATABASE, ("normal: num_Booleans:%d", ptr->num_Booleans));
375 #endif
376     }
377 
378     for (i = bool_count; i < BOOLCOUNT; i++)
379 	ptr->Booleans[i] = FALSE;
380     for (i = num_count; i < NUMCOUNT; i++)
381 	ptr->Numbers[i] = ABSENT_NUMERIC;
382     for (i = str_count; i < STRCOUNT; i++)
383 	ptr->Strings[i] = ABSENT_STRING;
384 
385     return (1);
386 }
387 
388 NCURSES_EXPORT(int)
_nc_read_file_entry(const char * const filename,TERMTYPE * ptr)389 _nc_read_file_entry(const char *const filename, TERMTYPE *ptr)
390 /* return 1 if read, 0 if not found or garbled */
391 {
392     int code, fd = -1;
393 
394     if (_nc_read_bsd_terminfo_file(filename, ptr) == 1)
395 	return (1);
396 
397     if (_nc_access(filename, R_OK) < 0
398 	|| (fd = open(filename, O_RDONLY | O_BINARY)) < 0) {
399 	T(("cannot open terminfo %s (errno=%d)", filename, errno));
400 	code = 0;
401     } else {
402 	T(("read terminfo %s", filename));
403 	if ((code = read_termtype(fd, ptr)) == 0) {
404 	    _nc_free_termtype(ptr);
405 	}
406 	close(fd);
407     }
408 
409     return (code);
410 }
411 
412 /*
413  * Build a terminfo pathname and try to read the data.  Returns 1 on success,
414  * 0 on failure.
415  */
416 static int
_nc_read_tic_entry(char * const filename,const char * const dir,const char * ttn,TERMTYPE * const tp)417 _nc_read_tic_entry(char *const filename,
418 		   const char *const dir, const char *ttn, TERMTYPE *const tp)
419 {
420     int need = 2 + strlen(dir) + strlen(ttn);
421 
422     if (need > PATH_MAX)
423 	return 0;
424     (void) sprintf(filename, "%s/%s", dir, ttn);
425     return _nc_read_file_entry(filename, tp);
426 }
427 
428 /*
429  * Process the list of :-separated directories, looking for the terminal type.
430  * We don't use strtok because it does not show us empty tokens.
431  */
432 static int
_nc_read_terminfo_dirs(const char * dirs,char * const filename,const char * const ttn,TERMTYPE * const tp)433 _nc_read_terminfo_dirs(const char *dirs, char *const filename, const char *const
434 		       ttn, TERMTYPE *const tp)
435 {
436     char *list, *a;
437     const char *b;
438     int code = 0;
439 
440     /* we'll modify the argument, so we must copy */
441     if ((b = a = list = strdup(dirs)) == NULL)
442 	return (0);
443 
444     for (;;) {
445 	int c = *a;
446 	if (c == 0 || c == NCURSES_PATHSEP) {
447 	    *a = 0;
448 	    if ((b + 1) >= a)
449 		b = TERMINFO;
450 	    if (_nc_read_tic_entry(filename, b, ttn, tp) == 1) {
451 		code = 1;
452 		break;
453 	    }
454 	    b = a + 1;
455 	    if (c == 0)
456 		break;
457 	}
458 	a++;
459     }
460 
461     free(list);
462     return (code);
463 }
464 
465 /*
466  *	_nc_read_entry(char *tn, char *filename, TERMTYPE *tp)
467  *
468  *	Find and read the compiled entry for a given terminal type,
469  *	if it exists.  We take pains here to make sure no combination
470  *	of environment variables and terminal type name can be used to
471  *	overrun the file buffer.
472  */
473 
474 NCURSES_EXPORT(int)
_nc_read_entry(const char * const tn,char * const filename,TERMTYPE * const tp)475 _nc_read_entry(const char *const tn, char *const filename, TERMTYPE *const tp)
476 {
477     char *envp;
478     char ttn[PATH_MAX];
479 
480     if (strlen(tn) == 0
481 	|| strcmp(tn, ".") == 0
482 	|| strcmp(tn, "..") == 0
483 	|| _nc_pathlast(tn) != 0) {
484 	T(("illegal or missing entry name '%s'", tn));
485 	return 0;
486     }
487 
488     /* First check the BSD terminfo.db file */
489     if (_nc_read_bsd_terminfo_entry(tn, filename, tp) == 1)
490 	return (1);
491 
492     /* truncate the terminal name to prevent buffer overflow */
493     (void) sprintf(ttn, "%c/%.*s", *tn, (int) sizeof(ttn) - 3, tn);
494 
495     /* This is System V behavior, in conjunction with our requirements for
496      * writing terminfo entries.
497      */
498     if (have_tic_directory
499 	&& _nc_read_tic_entry(filename, _nc_tic_dir(0), ttn, tp) == 1)
500 	return 1;
501 
502     if (use_terminfo_vars()) {
503 	if ((envp = getenv("TERMINFO")) != 0
504 	    && _nc_read_tic_entry(filename, _nc_tic_dir(envp), ttn, tp) == 1)
505 	    return 1;
506 
507 	/* this is an ncurses extension */
508 	if ((envp = _nc_home_terminfo()) != 0) {
509 	    if (_nc_read_tic_entry(filename, envp, ttn, tp) == 1) {
510 		return 1;
511 	    }
512 	}
513 
514 	/* this is an ncurses extension */
515 	if ((envp = getenv("TERMINFO_DIRS")) != 0)
516 	    return _nc_read_terminfo_dirs(envp, filename, ttn, tp);
517     }
518 
519     /* Try the system directory.  Note that the TERMINFO_DIRS value, if
520      * defined by the configure script, begins with a ":", which will be
521      * interpreted as TERMINFO.
522      */
523 #ifdef TERMINFO_DIRS
524     return _nc_read_terminfo_dirs(TERMINFO_DIRS, filename, ttn, tp);
525 #else
526     return _nc_read_tic_entry(filename, TERMINFO, ttn, tp);
527 #endif
528 }
529