ncurses/ncurses/tinfo/read_entry.c - nest-cam/4320010/ncurses - Git at Google

 /****************************************************************************
  * Copyright (c) 1998-2014,2015 Free Software Foundation, Inc.              *
  *                                                                          *
  * Permission is hereby granted, free of charge, to any person obtaining a  *
  * copy of this software and associated documentation files (the            *
  * "Software"), to deal in the Software without restriction, including      *
  * without limitation the rights to use, copy, modify, merge, publish,      *
  * distribute, distribute with modifications, sublicense, and/or sell       *
  * copies of the Software, and to permit persons to whom the Software is    *
  * furnished to do so, subject to the following conditions:                 *
  *                                                                          *
  * The above copyright notice and this permission notice shall be included  *
  * in all copies or substantial portions of the Software.                   *
  *                                                                          *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
  *                                                                          *
  * Except as contained in this notice, the name(s) of the above copyright   *
  * holders shall not be used in advertising or otherwise to promote the     *
  * sale, use or other dealings in this Software without prior written       *
  * authorization.                                                           *
  ****************************************************************************/

 /****************************************************************************
  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
  *     and: Thomas E. Dickey                        1996-on                 *
  ****************************************************************************/

 /*
  *	read_entry.c -- Routine for reading in a compiled terminfo file
  */

 #include <curses.priv.h>
 #include <hashed_db.h>

 #include <tic.h>

 MODULE_ID("$Id: read_entry.c,v 1.129 2015/06/27 16:16:40 tom Exp $")

 #define TYPE_CALLOC(type,elts) typeCalloc(type, (unsigned)(elts))

 #define MyNumber(n) (short) LOW_MSB(n)

 #if NCURSES_USE_DATABASE
 static void
 convert_shorts(char *buf, short *Numbers, int count)
 {
     int i;
     for (i = 0; i < count; i++) {
 	if (IS_NEG1(buf + 2 * i))
 	    Numbers[i] = ABSENT_NUMERIC;
 	else if (IS_NEG2(buf + 2 * i))
 	    Numbers[i] = CANCELLED_NUMERIC;
 	else
 	    Numbers[i] = MyNumber(buf + 2 * i);
 	TR(TRACE_DATABASE, ("get Numbers[%d]=%d", i, Numbers[i]));
     }
 }

 static void
 convert_strings(char *buf, char **Strings, int count, int size, char *table)
 {
     int i;
     char *p;

     for (i = 0; i < count; i++) {
 	if (IS_NEG1(buf + 2 * i)) {
 	    Strings[i] = ABSENT_STRING;
 	} else if (IS_NEG2(buf + 2 * i)) {
 	    Strings[i] = CANCELLED_STRING;
 	} else if (MyNumber(buf + 2 * i) > size) {
 	    Strings[i] = ABSENT_STRING;
 	} else {
 	    Strings[i] = (MyNumber(buf + 2 * i) + table);
 	    TR(TRACE_DATABASE, ("Strings[%d] = %s", i, _nc_visbuf(Strings[i])));
 	}

 	/* make sure all strings are NUL terminated */
 	if (VALID_STRING(Strings[i])) {
 	    for (p = Strings[i]; p <= table + size; p++)
 		if (*p == '\0')
 		    break;
 	    /* if there is no NUL, ignore the string */
 	    if (p > table + size)
 		Strings[i] = ABSENT_STRING;
 	}
     }
 }

 static int
 fake_read(char *src, int *offset, int limit, char *dst, unsigned want)
 {
     int have = (limit - *offset);

     if (have > 0) {
 	if ((int) want > have)
 	    want = (unsigned) have;
 	memcpy(dst, src + *offset, (size_t) want);
 	*offset += (int) want;
     } else {
 	want = 0;
     }
     return (int) want;
 }

 #define Read(buf, count) fake_read(buffer, &offset, limit, (char *) buf, (unsigned) count)

 #define read_shorts(buf, count) \
 	(Read(buf, (count)*2) == (int) (count)*2)

 #define even_boundary(value) \
     if ((value) % 2 != 0) Read(buf, 1)
 #endif

 NCURSES_EXPORT(void)
 _nc_init_termtype(TERMTYPE *const tp)
 {
     unsigned i;

 #if NCURSES_XNAMES
     tp->num_Booleans = BOOLCOUNT;
     tp->num_Numbers = NUMCOUNT;
     tp->num_Strings = STRCOUNT;
     tp->ext_Booleans = 0;
     tp->ext_Numbers = 0;
     tp->ext_Strings = 0;
 #endif
     if (tp->Booleans == 0)
 	TYPE_MALLOC(NCURSES_SBOOL, BOOLCOUNT, tp->Booleans);
     if (tp->Numbers == 0)
 	TYPE_MALLOC(short, NUMCOUNT, tp->Numbers);
     if (tp->Strings == 0)
 	TYPE_MALLOC(char *, STRCOUNT, tp->Strings);

     for_each_boolean(i, tp)
 	tp->Booleans[i] = FALSE;

     for_each_number(i, tp)
 	tp->Numbers[i] = ABSENT_NUMERIC;

     for_each_string(i, tp)
 	tp->Strings[i] = ABSENT_STRING;
 }

 #if NCURSES_USE_DATABASE
 #if NCURSES_XNAMES
 static bool
 valid_shorts(char *buffer, int limit)
 {
     bool result = FALSE;
     int n;
     for (n = 0; n < limit; ++n) {
 	if (MyNumber(buffer + (n * 2)) > 0) {
 	    result = TRUE;
 	    break;
 	}
     }
     return result;
 }
 #endif

 /*
  * Return TGETENT_YES if read, TGETENT_NO if not found or garbled.
  */
 NCURSES_EXPORT(int)
 _nc_read_termtype(TERMTYPE *ptr, char *buffer, int limit)
 {
     int offset = 0;
     int name_size, bool_count, num_count, str_count, str_size;
     int i;
     char buf[MAX_ENTRY_SIZE + 2];
     char *string_table;
     unsigned want, have;

     TR(TRACE_DATABASE, ("READ termtype header @%d", offset));

     memset(ptr, 0, sizeof(*ptr));

     /* grab the header */
     if (!read_shorts(buf, 6)
 	|| !IS_TIC_MAGIC(buf)) {
 	return (TGETENT_NO);
     }

     name_size = MyNumber(buf + 2);
     bool_count = MyNumber(buf + 4);
     num_count = MyNumber(buf + 6);
     str_count = MyNumber(buf + 8);
     str_size = MyNumber(buf + 10);

     TR(TRACE_DATABASE,
        ("TERMTYPE name_size=%d, bool=%d/%d, num=%d/%d str=%d/%d(%d)",
 	name_size, bool_count, BOOLCOUNT, num_count, NUMCOUNT,
 	str_count, STRCOUNT, str_size));
     if (name_size < 0
 	|| bool_count < 0
 	|| num_count < 0
 	|| str_count < 0
 	|| str_size < 0) {
 	return (TGETENT_NO);
     }

     want = (unsigned) (str_size + name_size + 1);
     if (str_size) {
 	/* try to allocate space for the string table */
 	if (str_count * 2 >= MAX_ENTRY_SIZE
 	    || (string_table = typeMalloc(char, want)) == 0) {
 	    return (TGETENT_NO);
 	}
     } else {
 	str_count = 0;
 	if ((string_table = typeMalloc(char, want)) == 0) {
 	    return (TGETENT_NO);
 	}
     }

     /* grab the name (a null-terminated string) */
     want = min(MAX_NAME_SIZE, (unsigned) name_size);
     ptr->str_table = string_table;
     ptr->term_names = string_table;
     if ((have = (unsigned) Read(ptr->term_names, want)) != want) {
 	memset(ptr->term_names + have, 0, (size_t) (want - have));
     }
     ptr->term_names[want] = '\0';
     string_table += (want + 1);

     if (have > MAX_NAME_SIZE)
 	offset = (int) (have - MAX_NAME_SIZE);

     /* grab the booleans */
     if ((ptr->Booleans = TYPE_CALLOC(NCURSES_SBOOL,
 				     max(BOOLCOUNT, bool_count))) == 0
 	|| Read(ptr->Booleans, (unsigned) bool_count) < bool_count) {
 	return (TGETENT_NO);
     }

     /*
      * If booleans end on an odd byte, skip it.  The machine they
      * originally wrote terminfo on must have been a 16-bit
      * word-oriented machine that would trap out if you tried a
      * word access off a 2-byte boundary.
      */
     even_boundary(name_size + bool_count);

     /* grab the numbers */
     if ((ptr->Numbers = TYPE_CALLOC(short, max(NUMCOUNT, num_count))) == 0
 	|| !read_shorts(buf, num_count)) {
 	return (TGETENT_NO);
     }
     convert_shorts(buf, ptr->Numbers, num_count);

     if ((ptr->Strings = TYPE_CALLOC(char *, max(STRCOUNT, str_count))) == 0) {
 	return (TGETENT_NO);
     }

     if (str_count) {
 	/* grab the string offsets */
 	if (!read_shorts(buf, str_count)) {
 	    return (TGETENT_NO);
 	}
 	/* finally, grab the string table itself */
 	if (Read(string_table, (unsigned) str_size) != str_size) {
 	    return (TGETENT_NO);
 	}
 	convert_strings(buf, ptr->Strings, str_count, str_size, string_table);
     }
 #if NCURSES_XNAMES

     ptr->num_Booleans = BOOLCOUNT;
     ptr->num_Numbers = NUMCOUNT;
     ptr->num_Strings = STRCOUNT;

     /*
      * Read extended entries, if any, after the normal end of terminfo data.
      */
     even_boundary(str_size);
     TR(TRACE_DATABASE, ("READ extended_header @%d", offset));
     if (_nc_user_definable && read_shorts(buf, 5) && valid_shorts(buf, 5)) {
 	int ext_bool_count = MyNumber(buf + 0);
 	int ext_num_count = MyNumber(buf + 2);
 	int ext_str_count = MyNumber(buf + 4);
 	int ext_str_size = MyNumber(buf + 6);
 	int ext_str_limit = MyNumber(buf + 8);
 	unsigned need = (unsigned) (ext_bool_count + ext_num_count + ext_str_count);
 	int base = 0;

 	if (need >= (MAX_ENTRY_SIZE / 2)
 	    || ext_str_size >= MAX_ENTRY_SIZE
 	    || ext_str_limit >= MAX_ENTRY_SIZE
 	    || ext_bool_count < 0
 	    || ext_num_count < 0
 	    || ext_str_count < 0
 	    || ext_str_size < 0
 	    || ext_str_limit < 0) {
 	    return (TGETENT_NO);
 	}

 	ptr->num_Booleans = UShort(BOOLCOUNT + ext_bool_count);
 	ptr->num_Numbers = UShort(NUMCOUNT + ext_num_count);
 	ptr->num_Strings = UShort(STRCOUNT + ext_str_count);

 	TYPE_REALLOC(NCURSES_SBOOL, ptr->num_Booleans, ptr->Booleans);
 	TYPE_REALLOC(short, ptr->num_Numbers, ptr->Numbers);
 	TYPE_REALLOC(char *, ptr->num_Strings, ptr->Strings);

 	TR(TRACE_DATABASE, ("extended header is %d/%d/%d(%d:%d)",
 			    ext_bool_count, ext_num_count, ext_str_count,
 			    ext_str_size, ext_str_limit));

 	TR(TRACE_DATABASE, ("READ %d extended-booleans @%d",
 			    ext_bool_count, offset));
 	if ((ptr->ext_Booleans = UShort(ext_bool_count)) != 0) {
 	    if (Read(ptr->Booleans + BOOLCOUNT, (unsigned)
 		     ext_bool_count) != ext_bool_count) {
 		return (TGETENT_NO);
 	    }
 	}
 	even_boundary(ext_bool_count);

 	TR(TRACE_DATABASE, ("READ %d extended-numbers @%d",
 			    ext_num_count, offset));
 	if ((ptr->ext_Numbers = UShort(ext_num_count)) != 0) {
 	    if (!read_shorts(buf, ext_num_count)) {
 		return (TGETENT_NO);
 	    }
 	    TR(TRACE_DATABASE, ("Before converting extended-numbers"));
 	    convert_shorts(buf, ptr->Numbers + NUMCOUNT, ext_num_count);
 	}

 	TR(TRACE_DATABASE, ("READ extended-offsets @%d", offset));
 	if ((unsigned) (ext_str_count + (int) need) >= (MAX_ENTRY_SIZE / 2)) {
 	    return (TGETENT_NO);
 	}
 	if ((ext_str_count || need)
 	    && !read_shorts(buf, ext_str_count + (int) need)) {
 	    return (TGETENT_NO);
 	}

 	TR(TRACE_DATABASE, ("READ %d bytes of extended-strings @%d",
 			    ext_str_limit, offset));

 	if (ext_str_limit) {
 	    ptr->ext_str_table = typeMalloc(char, (size_t) ext_str_limit);
 	    if (ptr->ext_str_table == 0) {
 		return (TGETENT_NO);
 	    }
 	    if (Read(ptr->ext_str_table, (unsigned) ext_str_limit) != ext_str_limit) {
 		return (TGETENT_NO);
 	    }
 	    TR(TRACE_DATABASE, ("first extended-string is %s", _nc_visbuf(ptr->ext_str_table)));
 	}

 	if ((ptr->ext_Strings = UShort(ext_str_count)) != 0) {
 	    TR(TRACE_DATABASE,
 	       ("Before computing extended-string capabilities str_count=%d, ext_str_count=%d",
 		str_count, ext_str_count));
 	    convert_strings(buf, ptr->Strings + str_count, ext_str_count,
 			    ext_str_limit, ptr->ext_str_table);
 	    for (i = ext_str_count - 1; i >= 0; i--) {
 		TR(TRACE_DATABASE, ("MOVE from [%d:%d] %s",
 				    i, i + str_count,
 				    _nc_visbuf(ptr->Strings[i + str_count])));
 		ptr->Strings[i + STRCOUNT] = ptr->Strings[i + str_count];
 		if (VALID_STRING(ptr->Strings[i + STRCOUNT]))
 		    base += (int) (strlen(ptr->Strings[i + STRCOUNT]) + 1);
 		TR(TRACE_DATABASE, ("... to    [%d] %s",
 				    i + STRCOUNT,
 				    _nc_visbuf(ptr->Strings[i + STRCOUNT])));
 	    }
 	}

 	if (need) {
 	    if (ext_str_count >= (MAX_ENTRY_SIZE / 2)) {
 		return (TGETENT_NO);
 	    }
 	    if ((ptr->ext_Names = TYPE_CALLOC(char *, need)) == 0) {
 		return (TGETENT_NO);
 	    }
 	    TR(TRACE_DATABASE,
 	       ("ext_NAMES starting @%d in extended_strings, first = %s",
 		base, _nc_visbuf(ptr->ext_str_table + base)));
 	    convert_strings(buf + (2 * ext_str_count),
 			    ptr->ext_Names,
 			    (int) need,
 			    ext_str_limit, ptr->ext_str_table + base);
 	}

 	TR(TRACE_DATABASE,
 	   ("...done reading terminfo bool %d(%d) num %d(%d) str %d(%d)",
 	    ptr->num_Booleans, ptr->ext_Booleans,
 	    ptr->num_Numbers, ptr->ext_Numbers,
 	    ptr->num_Strings, ptr->ext_Strings));

 	TR(TRACE_DATABASE, ("extend: num_Booleans:%d", ptr->num_Booleans));
     } else
 #endif /* NCURSES_XNAMES */
     {
 	TR(TRACE_DATABASE, ("...done reading terminfo bool %d num %d str %d",
 			    bool_count, num_count, str_count));
 #if NCURSES_XNAMES
 	TR(TRACE_DATABASE, ("normal: num_Booleans:%d", ptr->num_Booleans));
 #endif
     }

     for (i = bool_count; i < BOOLCOUNT; i++)
 	ptr->Booleans[i] = FALSE;
     for (i = num_count; i < NUMCOUNT; i++)
 	ptr->Numbers[i] = ABSENT_NUMERIC;
     for (i = str_count; i < STRCOUNT; i++)
 	ptr->Strings[i] = ABSENT_STRING;

     return (TGETENT_YES);
 }

 /*
  *	int
  *	_nc_read_file_entry(filename, ptr)
  *
  *	Read the compiled terminfo entry in the given file into the
  *	structure pointed to by ptr, allocating space for the string
  *	table.
  */
 NCURSES_EXPORT(int)
 _nc_read_file_entry(const char *const filename, TERMTYPE *ptr)
 /* return 1 if read, 0 if not found or garbled */
 {
     FILE *fp = 0;
     int code;
     int limit;
     char buffer[MAX_ENTRY_SIZE + 1];

     if (_nc_access(filename, R_OK) < 0
 	|| (fp = fopen(filename, "rb")) == 0) {
 	TR(TRACE_DATABASE, ("cannot open terminfo %s (errno=%d)", filename, errno));
 	code = TGETENT_NO;
     } else {
 	if ((limit = (int) fread(buffer, sizeof(char), sizeof(buffer), fp))
 	    > 0) {

 	    TR(TRACE_DATABASE, ("read terminfo %s", filename));
 	    if ((code = _nc_read_termtype(ptr, buffer, limit)) == TGETENT_NO) {
 		_nc_free_termtype(ptr);
 	    }
 	} else {
 	    code = TGETENT_NO;
 	}
 	fclose(fp);
     }

     return (code);
 }

 #if USE_HASHED_DB
 /*
  * Return if if we can build the filename of a ".db" file.
  */
 static bool
 make_db_filename(char *filename, unsigned limit, const char *const path)
 {
     static const char suffix[] = DBM_SUFFIX;

     size_t lens = sizeof(suffix) - 1;
     size_t size = strlen(path);
     size_t test = lens + size;
     bool result = FALSE;

     if (test < limit) {
 	if (size >= lens
 	    && !strcmp(path + size - lens, suffix))
 	    _nc_STRCPY(filename, path, limit);
 	else
 	    _nc_SPRINTF(filename, _nc_SLIMIT(limit) "%s%s", path, suffix);
 	result = TRUE;
     }
     return result;
 }
 #endif

 /*
  * Return true if we can build the name of a filesystem entry.
  */
 static bool
 make_dir_filename(char *filename,
 		  unsigned limit,
 		  const char *const path,
 		  const char *name)
 {
     bool result = FALSE;

 #if NCURSES_USE_TERMCAP
     if (_nc_is_dir_path(path))
 #endif
     {
 	unsigned need = (unsigned) (LEAF_LEN + 3 + strlen(path) + strlen(name));

 	if (need <= limit) {
 	    _nc_SPRINTF(filename, _nc_SLIMIT(limit)
 			"%s/" LEAF_FMT "/%s", path, *name, name);
 	    result = TRUE;
 	}
     }
     return result;
 }

 /*
  * Build a terminfo pathname and try to read the data.  Returns TGETENT_YES on
  * success, TGETENT_NO on failure.
  */
 static int
 _nc_read_tic_entry(char *filename,
 		   unsigned limit,
 		   const char *const path,
 		   const char *name,
 		   TERMTYPE *const tp)
 {
     int code = TGETENT_NO;

 #if USE_HASHED_DB
     DB *capdbp;

     if (make_db_filename(filename, limit, path)
 	&& (capdbp = _nc_db_open(filename, FALSE)) != 0) {

 	DBT key, data;
 	int reccnt = 0;
 	char *save = strdup(name);

 	memset(&key, 0, sizeof(key));
 	key.data = save;
 	key.size = strlen(save);

 	/*
 	 * This lookup could return termcap data, which we do not want.  We are
 	 * looking for compiled (binary) terminfo data.
 	 *
 	 * cgetent uses a two-level lookup.  On the first it uses the given
 	 * name to return a record containing only the aliases for an entry.
 	 * On the second (using that list of aliases as a key), it returns the
 	 * content of the terminal description.  We expect second lookup to
 	 * return data beginning with the same set of aliases.
 	 *
 	 * For compiled terminfo, the list of aliases in the second case will
 	 * be null-terminated.  A termcap entry will not be, and will run on
 	 * into the description.  So we can easily distinguish between the two
 	 * (source/binary) by checking the lengths.
 	 */
 	while (_nc_db_get(capdbp, &key, &data) == 0) {
 	    int used = (int) data.size - 1;
 	    char *have = (char *) data.data;

 	    if (*have++ == 0) {
 		if (data.size > key.size
 		    && IS_TIC_MAGIC(have)) {
 		    code = _nc_read_termtype(tp, have, used);
 		    if (code == TGETENT_NO) {
 			_nc_free_termtype(tp);
 		    }
 		}
 		break;
 	    }

 	    /*
 	     * Just in case we have a corrupt database, do not waste time with
 	     * it.
 	     */
 	    if (++reccnt >= 3)
 		break;

 	    /*
 	     * Prepare for the second level.
 	     */
 	    key.data = have;
 	    key.size = used;
 	}

 	free(save);
     } else			/* may be either filesystem or flat file */
 #endif
     if (make_dir_filename(filename, limit, path, name)) {
 	code = _nc_read_file_entry(filename, tp);
     }
 #if NCURSES_USE_TERMCAP
     else if (code != TGETENT_YES) {
 	code = _nc_read_termcap_entry(name, tp);
 	_nc_SPRINTF(filename, _nc_SLIMIT(PATH_MAX)
 		    "%.*s", PATH_MAX - 1, _nc_get_source());
     }
 #endif
     return code;
 }
 #endif /* NCURSES_USE_DATABASE */

 /*
  *	_nc_read_entry(char *name, char *filename, TERMTYPE *tp)
  *
  *	Find and read the compiled entry for a given terminal type,
  *	if it exists.  We take pains here to make sure no combination
  *	of environment variables and terminal type name can be used to
  *	overrun the file buffer.
  */

 NCURSES_EXPORT(int)
 _nc_read_entry(const char *const name, char *const filename, TERMTYPE *const tp)
 {
     int code = TGETENT_NO;

     _nc_SPRINTF(filename, _nc_SLIMIT(PATH_MAX)
 		"%.*s", PATH_MAX - 1, name);

     if (strlen(name) == 0
 	|| strcmp(name, ".") == 0
 	|| strcmp(name, "..") == 0
 	|| _nc_pathlast(name) != 0
 	|| strchr(name, NCURSES_PATHSEP) != 0) {
 	TR(TRACE_DATABASE, ("illegal or missing entry name '%s'", name));
     } else {
 #if NCURSES_USE_DATABASE
 	DBDIRS state;
 	int offset;
 	const char *path;

 	_nc_first_db(&state, &offset);
 	code = TGETENT_ERR;
 	while ((path = _nc_next_db(&state, &offset)) != 0) {
 	    TR(TRACE_DATABASE, ("_nc_read_tic_entry path=%s, name=%s", path, name));
 	    code = _nc_read_tic_entry(filename, PATH_MAX, path, name, tp);
 	    if (code == TGETENT_YES) {
 		_nc_last_db();
 		break;
 	    }
 	}
 #elif NCURSES_USE_TERMCAP
 	if (code != TGETENT_YES) {
 	    code = _nc_read_termcap_entry(name, tp);
 	    _nc_SPRINTF(filename, _nc_SLIMIT(PATH_MAX)
 			"%.*s", PATH_MAX - 1, _nc_get_source());
 	}
 #endif
     }
     return code;
 }
	/****************************************************************************
	* Copyright (c) 1998-2014,2015 Free Software Foundation, Inc. *
	* *
	* Permission is hereby granted, free of charge, to any person obtaining a *
	* copy of this software and associated documentation files (the *
	* "Software"), to deal in the Software without restriction, including *
	* without limitation the rights to use, copy, modify, merge, publish, *
	* distribute, distribute with modifications, sublicense, and/or sell *
	* copies of the Software, and to permit persons to whom the Software is *
	* furnished to do so, subject to the following conditions: *
	* *
	* The above copyright notice and this permission notice shall be included *
	* in all copies or substantial portions of the Software. *
	* *
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
	* IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
	* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
	* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
	* THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
	* *
	* Except as contained in this notice, the name(s) of the above copyright *
	* holders shall not be used in advertising or otherwise to promote the *
	* sale, use or other dealings in this Software without prior written *
	* authorization. *
	****************************************************************************/

	/****************************************************************************
	* Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 *
	* and: Eric S. Raymond <esr@snark.thyrsus.com> *
	* and: Thomas E. Dickey 1996-on *
	****************************************************************************/

	/*
	* read_entry.c -- Routine for reading in a compiled terminfo file
	*/

	#include <curses.priv.h>
	#include <hashed_db.h>

	#include <tic.h>

	MODULE_ID("$Id: read_entry.c,v 1.129 2015/06/27 16:16:40 tom Exp $")

	#define TYPE_CALLOC(type,elts) typeCalloc(type, (unsigned)(elts))

	#define MyNumber(n) (short) LOW_MSB(n)

	#if NCURSES_USE_DATABASE
	static void
	convert_shorts(char buf, short Numbers, int count)
	{
	int i;
	for (i = 0; i < count; i++) {
	if (IS_NEG1(buf + 2 * i))
	Numbers[i] = ABSENT_NUMERIC;
	else if (IS_NEG2(buf + 2 * i))
	Numbers[i] = CANCELLED_NUMERIC;
	else
	Numbers[i] = MyNumber(buf + 2 * i);
	TR(TRACE_DATABASE, ("get Numbers[%d]=%d", i, Numbers[i]));
	}
	}

	static void
	convert_strings(char buf, char Strings, int count, int size, char table)
	{
	int i;
	char *p;

	for (i = 0; i < count; i++) {
	if (IS_NEG1(buf + 2 * i)) {
	Strings[i] = ABSENT_STRING;
	} else if (IS_NEG2(buf + 2 * i)) {
	Strings[i] = CANCELLED_STRING;
	} else if (MyNumber(buf + 2 * i) > size) {
	Strings[i] = ABSENT_STRING;
	} else {
	Strings[i] = (MyNumber(buf + 2 * i) + table);
	TR(TRACE_DATABASE, ("Strings[%d] = %s", i, _nc_visbuf(Strings[i])));
	}

	/* make sure all strings are NUL terminated */
	if (VALID_STRING(Strings[i])) {
	for (p = Strings[i]; p <= table + size; p++)
	if (*p == '\0')
	break;
	/* if there is no NUL, ignore the string */
	if (p > table + size)
	Strings[i] = ABSENT_STRING;
	}
	}
	}

	static int
	fake_read(char src, int offset, int limit, char *dst, unsigned want)
	{
	int have = (limit - *offset);

	if (have > 0) {
	if ((int) want > have)
	want = (unsigned) have;
	memcpy(dst, src + *offset, (size_t) want);
	*offset += (int) want;
	} else {
	want = 0;
	}
	return (int) want;
	}

	#define Read(buf, count) fake_read(buffer, &offset, limit, (char *) buf, (unsigned) count)

	#define read_shorts(buf, count) \
	(Read(buf, (count)2) == (int) (count)2)

	#define even_boundary(value) \
	if ((value) % 2 != 0) Read(buf, 1)
	#endif

	NCURSES_EXPORT(void)
	_nc_init_termtype(TERMTYPE *const tp)
	{
	unsigned i;

	#if NCURSES_XNAMES
	tp->num_Booleans = BOOLCOUNT;
	tp->num_Numbers = NUMCOUNT;
	tp->num_Strings = STRCOUNT;
	tp->ext_Booleans = 0;
	tp->ext_Numbers = 0;
	tp->ext_Strings = 0;
	#endif
	if (tp->Booleans == 0)
	TYPE_MALLOC(NCURSES_SBOOL, BOOLCOUNT, tp->Booleans);
	if (tp->Numbers == 0)
	TYPE_MALLOC(short, NUMCOUNT, tp->Numbers);
	if (tp->Strings == 0)
	TYPE_MALLOC(char *, STRCOUNT, tp->Strings);

	for_each_boolean(i, tp)
	tp->Booleans[i] = FALSE;

	for_each_number(i, tp)
	tp->Numbers[i] = ABSENT_NUMERIC;

	for_each_string(i, tp)
	tp->Strings[i] = ABSENT_STRING;
	}

	#if NCURSES_USE_DATABASE
	#if NCURSES_XNAMES
	static bool
	valid_shorts(char *buffer, int limit)
	{
	bool result = FALSE;
	int n;
	for (n = 0; n < limit; ++n) {
	if (MyNumber(buffer + (n * 2)) > 0) {
	result = TRUE;
	break;
	}
	}
	return result;
	}
	#endif

	/*
	* Return TGETENT_YES if read, TGETENT_NO if not found or garbled.
	*/
	NCURSES_EXPORT(int)
	_nc_read_termtype(TERMTYPE ptr, char buffer, int limit)
	{
	int offset = 0;
	int name_size, bool_count, num_count, str_count, str_size;
	int i;
	char buf[MAX_ENTRY_SIZE + 2];
	char *string_table;
	unsigned want, have;

	TR(TRACE_DATABASE, ("READ termtype header @%d", offset));

	memset(ptr, 0, sizeof(*ptr));

	/* grab the header */
	if (!read_shorts(buf, 6)
	\|\| !IS_TIC_MAGIC(buf)) {
	return (TGETENT_NO);
	}

	name_size = MyNumber(buf + 2);
	bool_count = MyNumber(buf + 4);
	num_count = MyNumber(buf + 6);
	str_count = MyNumber(buf + 8);
	str_size = MyNumber(buf + 10);

	TR(TRACE_DATABASE,
	("TERMTYPE name_size=%d, bool=%d/%d, num=%d/%d str=%d/%d(%d)",
	name_size, bool_count, BOOLCOUNT, num_count, NUMCOUNT,
	str_count, STRCOUNT, str_size));
	if (name_size < 0
	\|\| bool_count < 0
	\|\| num_count < 0
	\|\| str_count < 0
	\|\| str_size < 0) {
	return (TGETENT_NO);
	}

	want = (unsigned) (str_size + name_size + 1);
	if (str_size) {
	/* try to allocate space for the string table */
	if (str_count * 2 >= MAX_ENTRY_SIZE
	\|\| (string_table = typeMalloc(char, want)) == 0) {
	return (TGETENT_NO);
	}
	} else {
	str_count = 0;
	if ((string_table = typeMalloc(char, want)) == 0) {
	return (TGETENT_NO);
	}
	}

	/* grab the name (a null-terminated string) */
	want = min(MAX_NAME_SIZE, (unsigned) name_size);
	ptr->str_table = string_table;
	ptr->term_names = string_table;
	if ((have = (unsigned) Read(ptr->term_names, want)) != want) {
	memset(ptr->term_names + have, 0, (size_t) (want - have));
	}
	ptr->term_names[want] = '\0';
	string_table += (want + 1);

	if (have > MAX_NAME_SIZE)
	offset = (int) (have - MAX_NAME_SIZE);

	/* grab the booleans */
	if ((ptr->Booleans = TYPE_CALLOC(NCURSES_SBOOL,
	max(BOOLCOUNT, bool_count))) == 0
	\|\| Read(ptr->Booleans, (unsigned) bool_count) < bool_count) {
	return (TGETENT_NO);
	}

	/*
	* If booleans end on an odd byte, skip it. The machine they
	* originally wrote terminfo on must have been a 16-bit
	* word-oriented machine that would trap out if you tried a
	* word access off a 2-byte boundary.
	*/
	even_boundary(name_size + bool_count);

	/* grab the numbers */
	if ((ptr->Numbers = TYPE_CALLOC(short, max(NUMCOUNT, num_count))) == 0
	\|\| !read_shorts(buf, num_count)) {
	return (TGETENT_NO);
	}
	convert_shorts(buf, ptr->Numbers, num_count);

	if ((ptr->Strings = TYPE_CALLOC(char *, max(STRCOUNT, str_count))) == 0) {
	return (TGETENT_NO);
	}

	if (str_count) {
	/* grab the string offsets */
	if (!read_shorts(buf, str_count)) {
	return (TGETENT_NO);
	}
	/* finally, grab the string table itself */
	if (Read(string_table, (unsigned) str_size) != str_size) {
	return (TGETENT_NO);
	}
	convert_strings(buf, ptr->Strings, str_count, str_size, string_table);
	}
	#if NCURSES_XNAMES

	ptr->num_Booleans = BOOLCOUNT;
	ptr->num_Numbers = NUMCOUNT;
	ptr->num_Strings = STRCOUNT;

	/*
	* Read extended entries, if any, after the normal end of terminfo data.
	*/
	even_boundary(str_size);
	TR(TRACE_DATABASE, ("READ extended_header @%d", offset));
	if (_nc_user_definable && read_shorts(buf, 5) && valid_shorts(buf, 5)) {
	int ext_bool_count = MyNumber(buf + 0);
	int ext_num_count = MyNumber(buf + 2);
	int ext_str_count = MyNumber(buf + 4);
	int ext_str_size = MyNumber(buf + 6);
	int ext_str_limit = MyNumber(buf + 8);
	unsigned need = (unsigned) (ext_bool_count + ext_num_count + ext_str_count);
	int base = 0;

	if (need >= (MAX_ENTRY_SIZE / 2)
	\|\| ext_str_size >= MAX_ENTRY_SIZE
	\|\| ext_str_limit >= MAX_ENTRY_SIZE
	\|\| ext_bool_count < 0
	\|\| ext_num_count < 0
	\|\| ext_str_count < 0
	\|\| ext_str_size < 0
	\|\| ext_str_limit < 0) {
	return (TGETENT_NO);
	}

	ptr->num_Booleans = UShort(BOOLCOUNT + ext_bool_count);
	ptr->num_Numbers = UShort(NUMCOUNT + ext_num_count);
	ptr->num_Strings = UShort(STRCOUNT + ext_str_count);

	TYPE_REALLOC(NCURSES_SBOOL, ptr->num_Booleans, ptr->Booleans);
	TYPE_REALLOC(short, ptr->num_Numbers, ptr->Numbers);
	TYPE_REALLOC(char *, ptr->num_Strings, ptr->Strings);

	TR(TRACE_DATABASE, ("extended header is %d/%d/%d(%d:%d)",
	ext_bool_count, ext_num_count, ext_str_count,
	ext_str_size, ext_str_limit));

	TR(TRACE_DATABASE, ("READ %d extended-booleans @%d",
	ext_bool_count, offset));
	if ((ptr->ext_Booleans = UShort(ext_bool_count)) != 0) {
	if (Read(ptr->Booleans + BOOLCOUNT, (unsigned)
	ext_bool_count) != ext_bool_count) {
	return (TGETENT_NO);
	}
	}
	even_boundary(ext_bool_count);

	TR(TRACE_DATABASE, ("READ %d extended-numbers @%d",
	ext_num_count, offset));
	if ((ptr->ext_Numbers = UShort(ext_num_count)) != 0) {
	if (!read_shorts(buf, ext_num_count)) {
	return (TGETENT_NO);
	}
	TR(TRACE_DATABASE, ("Before converting extended-numbers"));
	convert_shorts(buf, ptr->Numbers + NUMCOUNT, ext_num_count);
	}

	TR(TRACE_DATABASE, ("READ extended-offsets @%d", offset));
	if ((unsigned) (ext_str_count + (int) need) >= (MAX_ENTRY_SIZE / 2)) {
	return (TGETENT_NO);
	}
	if ((ext_str_count \|\| need)
	&& !read_shorts(buf, ext_str_count + (int) need)) {
	return (TGETENT_NO);
	}

	TR(TRACE_DATABASE, ("READ %d bytes of extended-strings @%d",
	ext_str_limit, offset));

	if (ext_str_limit) {
	ptr->ext_str_table = typeMalloc(char, (size_t) ext_str_limit);
	if (ptr->ext_str_table == 0) {
	return (TGETENT_NO);
	}
	if (Read(ptr->ext_str_table, (unsigned) ext_str_limit) != ext_str_limit) {
	return (TGETENT_NO);
	}
	TR(TRACE_DATABASE, ("first extended-string is %s", _nc_visbuf(ptr->ext_str_table)));
	}

	if ((ptr->ext_Strings = UShort(ext_str_count)) != 0) {
	TR(TRACE_DATABASE,
	("Before computing extended-string capabilities str_count=%d, ext_str_count=%d",
	str_count, ext_str_count));
	convert_strings(buf, ptr->Strings + str_count, ext_str_count,
	ext_str_limit, ptr->ext_str_table);
	for (i = ext_str_count - 1; i >= 0; i--) {
	TR(TRACE_DATABASE, ("MOVE from [%d:%d] %s",
	i, i + str_count,
	_nc_visbuf(ptr->Strings[i + str_count])));
	ptr->Strings[i + STRCOUNT] = ptr->Strings[i + str_count];
	if (VALID_STRING(ptr->Strings[i + STRCOUNT]))
	base += (int) (strlen(ptr->Strings[i + STRCOUNT]) + 1);
	TR(TRACE_DATABASE, ("... to [%d] %s",
	i + STRCOUNT,
	_nc_visbuf(ptr->Strings[i + STRCOUNT])));
	}
	}

	if (need) {
	if (ext_str_count >= (MAX_ENTRY_SIZE / 2)) {
	return (TGETENT_NO);
	}
	if ((ptr->ext_Names = TYPE_CALLOC(char *, need)) == 0) {
	return (TGETENT_NO);
	}
	TR(TRACE_DATABASE,
	("ext_NAMES starting @%d in extended_strings, first = %s",
	base, _nc_visbuf(ptr->ext_str_table + base)));
	convert_strings(buf + (2 * ext_str_count),
	ptr->ext_Names,
	(int) need,
	ext_str_limit, ptr->ext_str_table + base);
	}

	TR(TRACE_DATABASE,
	("...done reading terminfo bool %d(%d) num %d(%d) str %d(%d)",
	ptr->num_Booleans, ptr->ext_Booleans,
	ptr->num_Numbers, ptr->ext_Numbers,
	ptr->num_Strings, ptr->ext_Strings));

	TR(TRACE_DATABASE, ("extend: num_Booleans:%d", ptr->num_Booleans));
	} else
	#endif /* NCURSES_XNAMES */
	{
	TR(TRACE_DATABASE, ("...done reading terminfo bool %d num %d str %d",
	bool_count, num_count, str_count));
	#if NCURSES_XNAMES
	TR(TRACE_DATABASE, ("normal: num_Booleans:%d", ptr->num_Booleans));
	#endif
	}

	for (i = bool_count; i < BOOLCOUNT; i++)
	ptr->Booleans[i] = FALSE;
	for (i = num_count; i < NUMCOUNT; i++)
	ptr->Numbers[i] = ABSENT_NUMERIC;
	for (i = str_count; i < STRCOUNT; i++)
	ptr->Strings[i] = ABSENT_STRING;

	return (TGETENT_YES);
	}

	/*
	* int
	* _nc_read_file_entry(filename, ptr)
	*
	* Read the compiled terminfo entry in the given file into the
	* structure pointed to by ptr, allocating space for the string
	* table.
	*/
	NCURSES_EXPORT(int)
	_nc_read_file_entry(const char const filename, TERMTYPE ptr)
	/* return 1 if read, 0 if not found or garbled */
	{
	FILE *fp = 0;
	int code;
	int limit;
	char buffer[MAX_ENTRY_SIZE + 1];

	if (_nc_access(filename, R_OK) < 0
	\|\| (fp = fopen(filename, "rb")) == 0) {
	TR(TRACE_DATABASE, ("cannot open terminfo %s (errno=%d)", filename, errno));
	code = TGETENT_NO;
	} else {
	if ((limit = (int) fread(buffer, sizeof(char), sizeof(buffer), fp))
	> 0) {

	TR(TRACE_DATABASE, ("read terminfo %s", filename));
	if ((code = _nc_read_termtype(ptr, buffer, limit)) == TGETENT_NO) {
	_nc_free_termtype(ptr);
	}
	} else {
	code = TGETENT_NO;
	}
	fclose(fp);
	}

	return (code);
	}

	#if USE_HASHED_DB
	/*
	* Return if if we can build the filename of a ".db" file.
	*/
	static bool
	make_db_filename(char filename, unsigned limit, const char const path)
	{
	static const char suffix[] = DBM_SUFFIX;

	size_t lens = sizeof(suffix) - 1;
	size_t size = strlen(path);
	size_t test = lens + size;
	bool result = FALSE;

	if (test < limit) {
	if (size >= lens
	&& !strcmp(path + size - lens, suffix))
	_nc_STRCPY(filename, path, limit);
	else
	_nc_SPRINTF(filename, _nc_SLIMIT(limit) "%s%s", path, suffix);
	result = TRUE;
	}
	return result;
	}
	#endif

	/*
	* Return true if we can build the name of a filesystem entry.
	*/
	static bool
	make_dir_filename(char *filename,
	unsigned limit,
	const char *const path,
	const char *name)
	{
	bool result = FALSE;

	#if NCURSES_USE_TERMCAP
	if (_nc_is_dir_path(path))
	#endif
	{
	unsigned need = (unsigned) (LEAF_LEN + 3 + strlen(path) + strlen(name));

	if (need <= limit) {
	_nc_SPRINTF(filename, _nc_SLIMIT(limit)
	"%s/" LEAF_FMT "/%s", path, *name, name);
	result = TRUE;
	}
	}
	return result;
	}

	/*
	* Build a terminfo pathname and try to read the data. Returns TGETENT_YES on
	* success, TGETENT_NO on failure.
	*/
	static int
	_nc_read_tic_entry(char *filename,
	unsigned limit,
	const char *const path,
	const char *name,
	TERMTYPE *const tp)
	{
	int code = TGETENT_NO;

	#if USE_HASHED_DB
	DB *capdbp;

	if (make_db_filename(filename, limit, path)
	&& (capdbp = _nc_db_open(filename, FALSE)) != 0) {

	DBT key, data;
	int reccnt = 0;
	char *save = strdup(name);

	memset(&key, 0, sizeof(key));
	key.data = save;
	key.size = strlen(save);

	/*
	* This lookup could return termcap data, which we do not want. We are
	* looking for compiled (binary) terminfo data.
	*
	* cgetent uses a two-level lookup. On the first it uses the given
	* name to return a record containing only the aliases for an entry.
	* On the second (using that list of aliases as a key), it returns the
	* content of the terminal description. We expect second lookup to
	* return data beginning with the same set of aliases.
	*
	* For compiled terminfo, the list of aliases in the second case will
	* be null-terminated. A termcap entry will not be, and will run on
	* into the description. So we can easily distinguish between the two
	* (source/binary) by checking the lengths.
	*/
	while (_nc_db_get(capdbp, &key, &data) == 0) {
	int used = (int) data.size - 1;
	char have = (char ) data.data;

	if (*have++ == 0) {
	if (data.size > key.size
	&& IS_TIC_MAGIC(have)) {
	code = _nc_read_termtype(tp, have, used);
	if (code == TGETENT_NO) {
	_nc_free_termtype(tp);
	}
	}
	break;
	}

	/*
	* Just in case we have a corrupt database, do not waste time with
	* it.
	*/
	if (++reccnt >= 3)
	break;

	/*
	* Prepare for the second level.
	*/
	key.data = have;
	key.size = used;
	}

	free(save);
	} else /* may be either filesystem or flat file */
	#endif
	if (make_dir_filename(filename, limit, path, name)) {
	code = _nc_read_file_entry(filename, tp);
	}
	#if NCURSES_USE_TERMCAP
	else if (code != TGETENT_YES) {
	code = _nc_read_termcap_entry(name, tp);
	_nc_SPRINTF(filename, _nc_SLIMIT(PATH_MAX)
	"%.*s", PATH_MAX - 1, _nc_get_source());
	}
	#endif
	return code;
	}
	#endif /* NCURSES_USE_DATABASE */

	/*
	* _nc_read_entry(char name, char filename, TERMTYPE *tp)
	*
	* Find and read the compiled entry for a given terminal type,
	* if it exists. We take pains here to make sure no combination
	* of environment variables and terminal type name can be used to
	* overrun the file buffer.
	*/

	NCURSES_EXPORT(int)
	_nc_read_entry(const char const name, char const filename, TERMTYPE *const tp)
	{
	int code = TGETENT_NO;

	_nc_SPRINTF(filename, _nc_SLIMIT(PATH_MAX)
	"%.*s", PATH_MAX - 1, name);

	if (strlen(name) == 0
	\|\| strcmp(name, ".") == 0
	\|\| strcmp(name, "..") == 0
	\|\| _nc_pathlast(name) != 0
	\|\| strchr(name, NCURSES_PATHSEP) != 0) {
	TR(TRACE_DATABASE, ("illegal or missing entry name '%s'", name));
	} else {
	#if NCURSES_USE_DATABASE
	DBDIRS state;
	int offset;
	const char *path;

	_nc_first_db(&state, &offset);
	code = TGETENT_ERR;
	while ((path = _nc_next_db(&state, &offset)) != 0) {
	TR(TRACE_DATABASE, ("_nc_read_tic_entry path=%s, name=%s", path, name));
	code = _nc_read_tic_entry(filename, PATH_MAX, path, name, tp);
	if (code == TGETENT_YES) {
	_nc_last_db();
	break;
	}
	}
	#elif NCURSES_USE_TERMCAP
	if (code != TGETENT_YES) {
	code = _nc_read_termcap_entry(name, tp);
	_nc_SPRINTF(filename, _nc_SLIMIT(PATH_MAX)
	"%.*s", PATH_MAX - 1, _nc_get_source());
	}
	#endif
	}
	return code;
	}