text: /*
     Unix SMB/CIFS implementation.
     Name mangling
     Copyright (C) Andrew Tridgell 1992-2002
     Copyright (C) Simo Sorce 2001
     Copyright (C) Andrew Bartlett 2002
     Copyright (C) Jeremy Allison 2007
  
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 3 of the License, or
     (at your option) any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
  
  #include "includes.h"
  #include "smbd/globals.h"
  
  /* -------------------------------------------------------------------------- **
   * Other stuff...
   *
   * magic_char     - This is the magic char used for mangling.  It's
   *                  global.  There is a call to lp_magicchar() in server.c
   *                  that is used to override the initial value.
   *
   * MANGLE_BASE    - This is the number of characters we use for name mangling.
   *
   * basechars      - The set characters used for name mangling.  This
   *                  is static (scope is this file only).
   *
   * mangle()       - Macro used to select a character from basechars (i.e.,
   *                  mangle(n) will return the nth digit, modulo MANGLE_BASE).
   *
   * chartest       - array 0..255.  The index range is the set of all possible
   *                  values of a byte.  For each byte value, the content is a
   *                  two nibble pair.  See BASECHAR_MASK below.
   *
   * ct_initialized - False until the chartest array has been initialized via
   *                  a call to init_chartest().
   *
   * BASECHAR_MASK  - Masks the upper nibble of a one-byte value.
   *
   * isbasecahr()   - Given a character, check the chartest array to see
   *                  if that character is in the basechars set.  This is
   *                  faster than using strchr_m().
   *
   */
  
  static const char basechars[43]="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
  #define MANGLE_BASE       (sizeof(basechars)/sizeof(char)-1)
  
  #define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
  #define BASECHAR_MASK 0xf0
  #define isbasechar(C) ( (chartest[ ((C) & 0xff) ]) & BASECHAR_MASK )
  
  /* -------------------------------------------------------------------- */
  
  static NTSTATUS has_valid_83_chars(const smb_ucs2_t *s, bool allow_wildcards)
  {
  	if (!*s) {
  		return NT_STATUS_INVALID_PARAMETER;
  	}
  
  	if (!allow_wildcards && ms_has_wild_w(s)) {
  		return NT_STATUS_UNSUCCESSFUL;
  	}
  
  	while (*s) {
  		if(!isvalid83_w(*s)) {
  			return NT_STATUS_UNSUCCESSFUL;
  		}
  		s++;
  	}
  
  	return NT_STATUS_OK;
  }
  
  static NTSTATUS has_illegal_chars(const smb_ucs2_t *s, bool allow_wildcards)
  {
  	if (!allow_wildcards && ms_has_wild_w(s)) {
  		return NT_STATUS_UNSUCCESSFUL;
  	}
  
  	while (*s) {
  		if (*s <= 0x1f) {
  			/* Control characters. */
  			return NT_STATUS_UNSUCCESSFUL;
  		}
  		switch(*s) {
  			case UCS2_CHAR('\\'):
  			case UCS2_CHAR('/'):
  			case UCS2_CHAR('|'):
  			case UCS2_CHAR(':'):
  				return NT_STATUS_UNSUCCESSFUL;
  		}
  		s++;
  	}
  
  	return NT_STATUS_OK;
  }
  
  /* return False if something fail and
   * return 2 alloced unicode strings that contain prefix and extension
   */
  
  static NTSTATUS mangle_get_prefix(const smb_ucs2_t *ucs2_string, smb_ucs2_t **prefix,
  		smb_ucs2_t **extension, bool allow_wildcards)
  {
  	size_t ext_len;
  	smb_ucs2_t *p;
  
  	*extension = 0;
  	*prefix = strdup_w(ucs2_string);
  	if (!*prefix) {
  		return NT_STATUS_NO_MEMORY;
  	}
  	if ((p = strrchr_w(*prefix, UCS2_CHAR('.')))) {
  		ext_len = strlen_w(p+1);
  		if ((ext_len > 0) && (ext_len < 4) && (p != *prefix) &&
  		    (NT_STATUS_IS_OK(has_valid_83_chars(p+1,allow_wildcards)))) /* check extension */ {
  			*p = 0;
  			*extension = strdup_w(p+1);
  			if (!*extension) {
  				SAFE_FREE(*prefix);
  				return NT_STATUS_NO_MEMORY;
  			}
  		}
  	}
  	return NT_STATUS_OK;
  }
  
  /* ************************************************************************** **
   * Return NT_STATUS_UNSUCCESSFUL if a name is a special msdos reserved name.
   * or contains illegal characters.
   *
   *  Input:  fname - String containing the name to be tested.
   *
   *  Output: NT_STATUS_UNSUCCESSFUL, if the condition above is true.
   *
   *  Notes:  This is a static function called by is_8_3(), below.
   *
   * ************************************************************************** **
   */
  
  static NTSTATUS is_valid_name(const smb_ucs2_t *fname, bool allow_wildcards, bool only_8_3)
  {
  	smb_ucs2_t *str, *p;
  	size_t num_ucs2_chars;
  	NTSTATUS ret = NT_STATUS_OK;
  
  	if (!fname || !*fname)
  		return NT_STATUS_INVALID_PARAMETER;
  
  	/* . and .. are valid names. */
  	if (strcmp_wa(fname, ".")==0 || strcmp_wa(fname, "..")==0)
  		return NT_STATUS_OK;
  
  	if (only_8_3) {
  		ret = has_valid_83_chars(fname, allow_wildcards);
  		if (!NT_STATUS_IS_OK(ret))
  			return ret;
  	}
  
  	ret = has_illegal_chars(fname, allow_wildcards);
  	if (!NT_STATUS_IS_OK(ret))
  		return ret;
  
  	/* Name can't end in '.' or ' ' */
  	num_ucs2_chars = strlen_w(fname);
  	if (fname[num_ucs2_chars-1] == UCS2_CHAR('.') || fname[num_ucs2_chars-1] == UCS2_CHAR(' ')) {
  		return NT_STATUS_UNSUCCESSFUL;
  	}
  
  	str = strdup_w(fname);
  
  	/* Truncate copy after the first dot. */
  	p = strchr_w(str, UCS2_CHAR('.'));
  	if (p) {
  		*p = 0;
  	}
  
  	strupper_w(str);
  	p = &str[1];
  
  	switch(str[0])
  	{
  	case UCS2_CHAR('A'):
  		if(strcmp_wa(p, "UX") == 0)
  			ret = NT_STATUS_UNSUCCESSFUL;
  		break;
  	case UCS2_CHAR('C'):
  		if((strcmp_wa(p, "LOCK$") == 0)
  		|| (strcmp_wa(p, "ON") == 0)
  		|| (strcmp_wa(p, "OM1") == 0)
  		|| (strcmp_wa(p, "OM2") == 0)
  		|| (strcmp_wa(p, "OM3") == 0)
  		|| (strcmp_wa(p, "OM4") == 0)
  		)
  			ret = NT_STATUS_UNSUCCESSFUL;
  		break;
  	case UCS2_CHAR('L'):
  		if((strcmp_wa(p, "PT1") == 0)
  		|| (strcmp_wa(p, "PT2") == 0)
  		|| (strcmp_wa(p, "PT3") == 0)
  		)
  			ret = NT_STATUS_UNSUCCESSFUL;
  		break;
  	case UCS2_CHAR('N'):
  		if(strcmp_wa(p, "UL") == 0)
  			ret = NT_STATUS_UNSUCCESSFUL;
  		break;
  	case UCS2_CHAR('P'):
  		if(strcmp_wa(p, "RN") == 0)
  			ret = NT_STATUS_UNSUCCESSFUL;
  		break;
  	default:
  		break;
  	}
  
  	SAFE_FREE(str);
  	return ret;
  }
  
  static NTSTATUS is_8_3_w(const smb_ucs2_t *fname, bool allow_wildcards)
  {
  	smb_ucs2_t *pref = 0, *ext = 0;
  	size_t plen;
  	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
  
  	if (!fname || !*fname)
  		return NT_STATUS_INVALID_PARAMETER;
  
  	if (strlen_w(fname) > 12)
  		return NT_STATUS_UNSUCCESSFUL;
  
  	if (strcmp_wa(fname, ".") == 0 || strcmp_wa(fname, "..") == 0)
  		return NT_STATUS_OK;
  
  	/* Name cannot start with '.' */
  	if (*fname == UCS2_CHAR('.'))
  		return NT_STATUS_UNSUCCESSFUL;
  
  	if (!NT_STATUS_IS_OK(is_valid_name(fname, allow_wildcards, True)))
  		goto done;
  
  	if (!NT_STATUS_IS_OK(mangle_get_prefix(fname, &pref, &ext, allow_wildcards)))
  		goto done;
  	plen = strlen_w(pref);
  
  	if (strchr_wa(pref, '.'))
  		goto done;
  	if (plen < 1 || plen > 8)
  		goto done;
  	if (ext && (strlen_w(ext) > 3))
  		goto done;
  
  	ret = NT_STATUS_OK;
  
  done:
  	SAFE_FREE(pref);
  	SAFE_FREE(ext);
  	return ret;
  }
  
  static bool is_8_3(const char *fname, bool check_case, bool allow_wildcards,
  		   const struct share_params *p)
  {
  	const char *f;
  	smb_ucs2_t *ucs2name;
  	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
  	size_t size;
  	char magic_char;
  
  	magic_char = lp_magicchar(p);
  
  	if (!fname || !*fname)
  		return False;
  	if ((f = strrchr(fname, '/')) == NULL)
  		f = fname;
  	else
  		f++;
  
  	if (strlen(f) > 12)
  		return False;
  
  	if (!push_ucs2_talloc(NULL, &ucs2name, f, &size)) {
  		DEBUG(0,("is_8_3: internal error push_ucs2_talloc() failed!\n"));
  		goto done;
  	}
  
  	ret = is_8_3_w(ucs2name, allow_wildcards);
  
  done:
  	TALLOC_FREE(ucs2name);
  
  	if (!NT_STATUS_IS_OK(ret)) {
  		return False;
  	}
  
  	return True;
  }
  
  /* -------------------------------------------------------------------------- **
   * Functions...
   */
  
  /* ************************************************************************** **
   * Initialize the static character test array.
   *
   *  Input:  none
   *
   *  Output: none
   *
   *  Notes:  This function changes (loads) the contents of the <chartest>
   *          array.  The scope of <chartest> is this file.
   *
   * ************************************************************************** **
   */
  
  static void init_chartest( void )
  {
  	const unsigned char *s;
  
  	chartest = SMB_MALLOC_ARRAY(unsigned char, 256);
  
  	SMB_ASSERT(chartest != NULL);
  	memset(chartest, '\0', 256);
  
  	for( s = (const unsigned char *)basechars; *s; s++ ) {
  		chartest[*s] |= BASECHAR_MASK;
  	}
  }
  
  /* ************************************************************************** **
   * Return True if the name *could be* a mangled name.
   *
   *  Input:  s - A path name - in UNIX pathname format.
   *
   *  Output: True if the name matches the pattern described below in the
   *          notes, else False.
   *
   *  Notes:  The input name is *not* tested for 8.3 compliance.  This must be
   *          done separately.  This function returns true if the name contains
   *          a magic character followed by excactly two characters from the
   *          basechars list (above), which in turn are followed either by the
   *          nul (end of string) byte or a dot (extension) or by a '/' (end of
   *          a directory name).
   *
   * ************************************************************************** **
   */
  
  static bool is_mangled(const char *s, const struct share_params *p)
  {
  	char *magic;
  	char magic_char;
  
  	magic_char = lp_magicchar(p);
  
  	if (chartest == NULL) {
  		init_chartest();
  	}
  
  	magic = strchr_m( s, magic_char );
  	while( magic && magic[1] && magic[2] ) {         /* 3 chars, 1st is magic. */
  		if( ('.' == magic[3] || '/' == magic[3] || !(magic[3]))          /* Ends with '.' or nul or '/' ?  */
  				&& isbasechar( toupper_ascii(magic[1]) )           /* is 2nd char basechar?  */
  				&& isbasechar( toupper_ascii(magic[2]) ) )         /* is 3rd char basechar?  */
  			return( True );                           /* If all above, then true, */
  		magic = strchr_m( magic+1, magic_char );      /*    else seek next magic. */
  	}
  	return( False );
  }
  
  /***************************************************************************
   Initializes or clears the mangled cache.
  ***************************************************************************/
  
  static void mangle_reset( void )
  {
  	/* We could close and re-open the tdb here... should we ? The old code did
  	   the equivalent... JRA. */
  }
  
  /***************************************************************************
   Add a mangled name into the cache.
   If the extension of the raw name maps directly to the
   extension of the mangled name, then we'll store both names
   *without* extensions.  That way, we can provide consistent
   reverse mangling for all names that match.  The test here is
   a bit more careful than the one done in earlier versions of
   mangle.c:
  
      - the extension must exist on the raw name,
      - it must be all lower case
      - it must match the mangled extension (to prove that no
        mangling occurred).
    crh 07-Apr-1998
  **************************************************************************/
  
  static void cache_mangled_name( const char mangled_name[13],
  				const char *raw_name )
  {
  	TDB_DATA data_val;
  	char mangled_name_key[13];
  	char *s1 = NULL;
  	char *s2 = NULL;
  
  	/* If the cache isn't initialized, give up. */
  	if( !tdb_mangled_cache )
  		return;
  
  	/* Init the string lengths. */
  	safe_strcpy(mangled_name_key, mangled_name, sizeof(mangled_name_key)-1);
  
  	/* See if the extensions are unmangled.  If so, store the entry
  	 * without the extension, thus creating a "group" reverse map.
  	 */
  	s1 = strrchr( mangled_name_key, '.' );
  	if( s1 && (s2 = strrchr( raw_name, '.' )) ) {
  		size_t i = 1;
  		while( s1[i] && (tolower_ascii( s1[i] ) == s2[i]) )
  			i++;
  		if( !s1[i] && !s2[i] ) {
  			/* Truncate at the '.' */
  			*s1 = '\0';
  			/*
  			 * DANGER WILL ROBINSON - this
  			 * is changing a const string via
  			 * an aliased pointer ! Remember to
  			 * put it back once we've used it.
  			 * JRA
  			 */
  			*s2 = '\0';
  		}
  	}
  
  	/* Allocate a new cache entry.  If the allocation fails, just return. */
  	data_val = string_term_tdb_data(raw_name);
  	if (tdb_store_bystring(tdb_mangled_cache, mangled_name_key, data_val, TDB_REPLACE) != 0) {
  		DEBUG(0,("cache_mangled_name: Error storing entry %s -> %s\n", mangled_name_key, raw_name));
  	} else {
  		DEBUG(5,("cache_mangled_name: Stored entry %s -> %s\n", mangled_name_key, raw_name));
  	}
  	/* Restore the change we made to the const string. */
  	if (s2) {
  		*s2 = '.';
  	}
  }
  
  /* ************************************************************************** **
   * Check for a name on the mangled name stack
   *
   *  Input:  s - Input *and* output string buffer.
   *	    maxlen - space in i/o string buffer.
   *  Output: True if the name was found in the cache, else False.
   *
   *  Notes:  If a reverse map is found, the function will overwrite the string
   *          space indicated by the input pointer <s>.  This is frightening.
   *          It should be rewritten to return NULL if the long name was not
   *          found, and a pointer to the long name if it was found.
   *
   * ************************************************************************** **
   */
  
  static bool lookup_name_from_8_3(TALLOC_CTX *ctx,
  				const char *in,
  				char **out, /* talloced on the given context. */
  				const struct share_params *p)
  {
  	TDB_DATA data_val;
  	char *saved_ext = NULL;
  	char *s = talloc_strdup(ctx, in);
  	char magic_char;
  
  	magic_char = lp_magicchar(p);
  
  	/* If the cache isn't initialized, give up. */
  	if(!s || !tdb_mangled_cache ) {
  		TALLOC_FREE(s);
  		return False;
  	}
  
  	data_val = tdb_fetch_bystring(tdb_mangled_cache, s);
  
  	/* If we didn't find the name *with* the extension, try without. */
  	if(data_val.dptr == NULL || data_val.dsize == 0) {
  		char *ext_start = strrchr( s, '.' );
  		if( ext_start ) {
  			if((saved_ext = talloc_strdup(ctx,ext_start)) == NULL) {
  				TALLOC_FREE(s);
  				return False;
  			}
  
  			*ext_start = '\0';
  			data_val = tdb_fetch_bystring(tdb_mangled_cache, s);
  			/*
  			 * At this point s is the name without the
  			 * extension. We re-add the extension if saved_ext
  			 * is not null, before freeing saved_ext.
  			 */
  		}
  	}
  
  	/* Okay, if we haven't found it we're done. */
  	if(data_val.dptr == NULL || data_val.dsize == 0) {
  		TALLOC_FREE(saved_ext);
  		TALLOC_FREE(s);
  		return False;
  	}
  
  	/* If we *did* find it, we need to talloc it on the given ctx. */
  	if (saved_ext) {
  		*out = talloc_asprintf(ctx, "%s%s",
  					(char *)data_val.dptr,
  					saved_ext);
  	} else {
  		*out = talloc_strdup(ctx, (char *)data_val.dptr);
  	}
  
  	TALLOC_FREE(s);
  	TALLOC_FREE(saved_ext);
  	SAFE_FREE(data_val.dptr);
  
  	return *out ? True : False;
  }
  
  /*****************************************************************************
   Do the actual mangling to 8.3 format.
  *****************************************************************************/
  
  static bool to_8_3(char magic_char, const char *in, char out[13], int default_case)
  {
  	int csum;
  	char *p;
  	char extension[4];
  	char base[9];
  	int baselen = 0;
  	int extlen = 0;
  	char *s = SMB_STRDUP(in);
  
  	extension[0] = 0;
  	base[0] = 0;
  
  	if (!s) {
  		return False;
  	}
  
  	p = strrchr(s,'.');
  	if( p && (strlen(p+1) < (size_t)4) ) {
  		bool all_normal = ( strisnormal(p+1, default_case) ); /* XXXXXXXXX */
  
  		if( all_normal && p[1] != 0 ) {
  			*p = 0;
  			csum = str_checksum( s );
  			*p = '.';
  		} else
  			csum = str_checksum(s);
  	} else
  		csum = str_checksum(s);
  
  	strupper_m( s );
  
  	if( p ) {
  		if( p == s )
  			safe_strcpy( extension, "___", 3 );
  		else {
  			*p++ = 0;
  			while( *p && extlen < 3 ) {
  				if ( *p != '.') {
  					extension[extlen++] = p[0];
  				}
  				p++;
  			}
  			extension[extlen] = 0;
  		}
  	}
  
  	p = s;
  
  	while( *p && baselen < 5 ) {
  		if (isbasechar(*p)) {
  			base[baselen++] = p[0];
  		}
  		p++;
  	}
  	base[baselen] = 0;
  
  	csum = csum % (MANGLE_BASE*MANGLE_BASE);
  
  	memcpy(out, base, baselen);
  	out[baselen] = magic_char;
  	out[baselen+1] = mangle( csum/MANGLE_BASE );
  	out[baselen+2] = mangle( csum );
  
  	if( *extension ) {
  		out[baselen+3] = '.';
  		safe_strcpy(&out[baselen+4], extension, 3);
  	}
  
  	SAFE_FREE(s);
  	return True;
  }
  
  static bool must_mangle(const char *name,
  			const struct share_params *p)
  {
  	smb_ucs2_t *name_ucs2 = NULL;
  	NTSTATUS status;
  	size_t converted_size;
  	char magic_char;
  
  	magic_char = lp_magicchar(p);
  
  	if (!push_ucs2_talloc(NULL, &name_ucs2, name, &converted_size)) {
  		DEBUG(0, ("push_ucs2_talloc failed!\n"));
  		return False;
  	}
  	status = is_valid_name(name_ucs2, False, False);
  	TALLOC_FREE(name_ucs2);
  	/* We return true if we *must* mangle, so if it's
  	 * a valid name (status == OK) then we must return
  	 * false. Bug #6939. */
  	return !NT_STATUS_IS_OK(status);
  }
  
  /*****************************************************************************
   * Convert a filename to DOS format.  Return True if successful.
   *  Input:  in        Incoming name.
   *
   *          out       8.3 DOS name.
   *
   *          cache83 - If False, the mangled name cache will not be updated.
   *                    This is usually used to prevent that we overwrite
   *                    a conflicting cache entry prematurely, i.e. before
   *                    we know whether the client is really interested in the
   *                    current name.  (See PR#13758).  UKD.
   *
   * ****************************************************************************
   */
  
  static bool hash_name_to_8_3(const char *in,
  			char out[13],
  			bool cache83,
  			int default_case,
  			const struct share_params *p)
  {
  	smb_ucs2_t *in_ucs2 = NULL;
  	size_t converted_size;
  	char magic_char;
  
  	magic_char = lp_magicchar(p);
  
  	DEBUG(5,("hash_name_to_8_3( %s, cache83 = %s)\n", in,
  		 cache83 ? "True" : "False"));
  
  	if (!push_ucs2_talloc(NULL, &in_ucs2, in, &converted_size)) {
  		DEBUG(0, ("push_ucs2_talloc failed!\n"));
  		return False;
  	}
  
  	/* If it's already 8.3, just copy. */
  	if (NT_STATUS_IS_OK(is_valid_name(in_ucs2, False, False)) &&
  				NT_STATUS_IS_OK(is_8_3_w(in_ucs2, False))) {
  		TALLOC_FREE(in_ucs2);
  		safe_strcpy(out, in, 12);
  		return True;
  	}
  
  	TALLOC_FREE(in_ucs2);
  	if (!to_8_3(magic_char, in, out, default_case)) {
  		return False;
  	}
  
  	cache_mangled_name(out, in);
  
  	DEBUG(5,("hash_name_to_8_3(%s) ==> [%s]\n", in, out));
  	return True;
  }
  
  /*
    the following provides the abstraction layer to make it easier
    to drop in an alternative mangling implementation
  */
  static const struct mangle_fns mangle_hash_fns = {
  	mangle_reset,
  	is_mangled,
  	must_mangle,
  	is_8_3,
  	lookup_name_from_8_3,
  	hash_name_to_8_3
  };
  
  /* return the methods for this mangling implementation */
  const struct mangle_fns *mangle_hash_init(void)
  {
  	mangle_reset();
  
  	/* Create the in-memory tdb using our custom hash function. */
  	tdb_mangled_cache = tdb_open_ex("mangled_cache", 1031, TDB_INTERNAL,
  				(O_RDWR|O_CREAT), 0644, NULL, fast_string_hash);
  
  	return &mangle_hash_fns;
  }
  