/* 
   Unix SMB/CIFS implementation.
   Samba utility functions
   Copyright (C) Andrew Tridgell 1992-2001
   Copyright (C) Simo Sorce 2001
   Copyright (C) Jeremy Allison 2005
   
   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"

#ifndef MAXUNI
#define MAXUNI 1024
#endif

/* these 3 tables define the unicode case handling.  They are loaded
   at startup either via mmap() or read() from the lib directory */
static uint8 *valid_table;
static bool initialized;

/* Copy into a smb_ucs2_t from a possibly unaligned buffer. Return the copied smb_ucs2_t */
#define COPY_UCS2_CHAR(dest,src) (((unsigned char *)(dest))[0] = ((unsigned char *)(src))[0],\
				((unsigned char *)(dest))[1] = ((unsigned char *)(src))[1], (dest))


/* return an ascii version of a ucs2 character */
#define UCS2_TO_CHAR(c) (((c) >> UCS2_SHIFT) & 0xff)


/**
 * Destroy global objects allocated by load_case_tables()
 **/
void gfree_case_tables(void)
{
	if ( valid_table ) {
		unmap_file(valid_table, 0x10000);
		valid_table = NULL;
	}
	initialized = false;
}

/**
 * Load the valid character map table from <tt>valid.dat</tt> or
 * create from the configured codepage.
 *
 * This function is called whenever the configuration is reloaded.
 * However, the valid character table is not changed if it's loaded
 * from a file, because we can't unmap files.
 **/

static void init_valid_table(void)
{
	if (valid_table) {
		return;
	}

	valid_table = (uint8 *)map_file(data_path("valid.dat"), 0x10000);
	if (!valid_table) {
		smb_panic("Could not load valid.dat file required for mangle method=hash");
		return;
	}
}

/*******************************************************************
 Write a string in (little-endian) unicode format. src is in
 the current DOS codepage. len is the length in bytes of the
 string pointed to by dst.

 if null_terminate is True then null terminate the packet (adds 2 bytes)

 the return value is the length in bytes consumed by the string, including the
 null termination if applied
********************************************************************/

size_t dos_PutUniCode(char *dst,const char *src, size_t len, bool null_terminate)
{
	int flags = null_terminate ? STR_UNICODE|STR_NOALIGN|STR_TERMINATE
				   : STR_UNICODE|STR_NOALIGN;
	return push_ucs2(NULL, dst, src, len, flags);
}


/*******************************************************************
 Skip past a unicode string, but not more than len. Always move
 past a terminating zero if found.
********************************************************************/

char *skip_unibuf(char *src, size_t len)
{
	char *srcend = src + len;

	while (src < srcend && SVAL(src,0)) {
		src += 2;
	}

	if(!SVAL(src,0)) {
		src += 2;
	}

	return src;
}

/* Converts a string from internal samba format to unicode
 */

int rpcstr_push(void *dest, const char *src, size_t dest_len, int flags)
{
	return push_ucs2(NULL, dest, src, dest_len, flags|STR_UNICODE|STR_NOALIGN);
}

/* Converts a string from internal samba format to unicode. Always terminates.
 * Actually just a wrapper round push_ucs2_talloc().
 */

int rpcstr_push_talloc(TALLOC_CTX *ctx, smb_ucs2_t **dest, const char *src)
{
	size_t size;
	if (push_ucs2_talloc(ctx, dest, src, &size))
		return size;
	else
		return -1;
}

/*******************************************************************
 Determine if a character is valid in a 8.3 name.
********************************************************************/

bool isvalid83_w(smb_ucs2_t c)
{
	init_valid_table();
	return valid_table[SVAL(&c,0)] != 0;
}

/*******************************************************************
 Count the number of two-byte pairs in a UTF16 string.
********************************************************************/

size_t strlen_w(const smb_ucs2_t *src)
{
	size_t len;
	smb_ucs2_t c;

	for(len = 0; *(COPY_UCS2_CHAR(&c,src)); src++, len++) {
		;
	}

	return len;
}

/*******************************************************************
 Count up to max number of characters in a smb_ucs2_t string.
********************************************************************/

size_t strnlen_w(const smb_ucs2_t *src, size_t max)
{
	size_t len;
	smb_ucs2_t c;

	for(len = 0; (len < max) && *(COPY_UCS2_CHAR(&c,src)); src++, len++) {
		;
	}

	return len;
}

/*******************************************************************
 Wide strchr().
********************************************************************/

smb_ucs2_t *strchr_w(const smb_ucs2_t *s, smb_ucs2_t c)
{
	smb_ucs2_t cp;
	while (*(COPY_UCS2_CHAR(&cp,s))) {
		if (c == cp) {
			return (smb_ucs2_t *)s;
		}
		s++;
	}
	if (c == cp) {
		return (smb_ucs2_t *)s;
	}

	return NULL;
}

smb_ucs2_t *strchr_wa(const smb_ucs2_t *s, char c)
{
	return strchr_w(s, UCS2_CHAR(c));
}

/*******************************************************************
 Wide strrchr().
********************************************************************/

smb_ucs2_t *strrchr_w(const smb_ucs2_t *s, smb_ucs2_t c)
{
	smb_ucs2_t cp;
	const smb_ucs2_t *p = s;
	int len = strlen_w(s);

	if (len == 0) {
		return NULL;
	}
	p += (len - 1);
	do {
		if (c == *(COPY_UCS2_CHAR(&cp,p))) {
			return (smb_ucs2_t *)p;
		}
	} while (p-- != s);
	return NULL;
}

/*******************************************************************
 Wide version of strrchr that returns after doing strrchr 'n' times.
********************************************************************/

smb_ucs2_t *strnrchr_w(const smb_ucs2_t *s, smb_ucs2_t c, unsigned int n)
{
	smb_ucs2_t cp;
	const smb_ucs2_t *p = s;
	int len = strlen_w(s);

	if (len == 0 || !n) {
		return NULL;
	}
	p += (len - 1);
	do {
		if (c == *(COPY_UCS2_CHAR(&cp,p))) {
			n--;
		}

		if (!n) {
			return (smb_ucs2_t *)p;
		}
	} while (p-- != s);
	return NULL;
}

/*******************************************************************
 Wide strstr().
********************************************************************/

smb_ucs2_t *strstr_w(const smb_ucs2_t *s, const smb_ucs2_t *ins)
{
	smb_ucs2_t *r;
	size_t inslen;

	if (!s || !*s || !ins || !*ins) {
		return NULL;
	}

	inslen = strlen_w(ins);
	r = (smb_ucs2_t *)s;

	while ((r = strchr_w(r, *ins))) {
		if (strncmp_w(r, ins, inslen) == 0) {
			return r;
		}
		r++;
	}

	return NULL;
}

/*******************************************************************
 Convert a string to lower case.
 return True if any char is converted

 This is unsafe for any string involving a UTF16 character
********************************************************************/

bool strlower_w(smb_ucs2_t *s)
{
	smb_ucs2_t cp;
	bool ret = False;

	while (*(COPY_UCS2_CHAR(&cp,s))) {
		smb_ucs2_t v = tolower_m(cp);
		if (v != cp) {
			COPY_UCS2_CHAR(s,&v);
			ret = True;
		}
		s++;
	}
	return ret;
}

/*******************************************************************
 Convert a string to upper case.
 return True if any char is converted

 This is unsafe for any string involving a UTF16 character
********************************************************************/

bool strupper_w(smb_ucs2_t *s)
{
	smb_ucs2_t cp;
	bool ret = False;
	while (*(COPY_UCS2_CHAR(&cp,s))) {
		smb_ucs2_t v = toupper_m(cp);
		if (v != cp) {
			COPY_UCS2_CHAR(s,&v);
			ret = True;
		}
		s++;
	}
	return ret;
}

/*******************************************************************
 Convert a string to "normal" form.
********************************************************************/

void strnorm_w(smb_ucs2_t *s, int case_default)
{
	if (case_default == CASE_UPPER) {
		strupper_w(s);
	} else {
		strlower_w(s);
	}
}

int strcmp_w(const smb_ucs2_t *a, const smb_ucs2_t *b)
{
	smb_ucs2_t cpa, cpb;

	while ((*(COPY_UCS2_CHAR(&cpb,b))) && (*(COPY_UCS2_CHAR(&cpa,a)) == cpb)) {
		a++;
		b++;
	}
	return (*(COPY_UCS2_CHAR(&cpa,a)) - *(COPY_UCS2_CHAR(&cpb,b)));
	/* warning: if *a != *b and both are not 0 we return a random
		greater or lesser than 0 number not realted to which
		string is longer */
}

int strncmp_w(const smb_ucs2_t *a, const smb_ucs2_t *b, size_t len)
{
	smb_ucs2_t cpa, cpb;
	size_t n = 0;

	while ((n < len) && (*(COPY_UCS2_CHAR(&cpb,b))) && (*(COPY_UCS2_CHAR(&cpa,a)) == cpb)) {
		a++;
		b++;
		n++;
	}
	return (len - n)?(*(COPY_UCS2_CHAR(&cpa,a)) - *(COPY_UCS2_CHAR(&cpb,b))):0;
}

/*******************************************************************
 Case insensitive string comparison.
********************************************************************/

int strcasecmp_w(const smb_ucs2_t *a, const smb_ucs2_t *b)
{
	smb_ucs2_t cpa, cpb;

	while ((*COPY_UCS2_CHAR(&cpb,b)) && toupper_m(*(COPY_UCS2_CHAR(&cpa,a))) == toupper_m(cpb)) {
		a++;
		b++;
	}
	return (tolower_m(*(COPY_UCS2_CHAR(&cpa,a))) - tolower_m(*(COPY_UCS2_CHAR(&cpb,b))));
}

/*******************************************************************
 Case insensitive string comparison, length limited.
********************************************************************/

int strncasecmp_w(const smb_ucs2_t *a, const smb_ucs2_t *b, size_t len)
{
	smb_ucs2_t cpa, cpb;
	size_t n = 0;

	while ((n < len) && *COPY_UCS2_CHAR(&cpb,b) && (toupper_m(*(COPY_UCS2_CHAR(&cpa,a))) == toupper_m(cpb))) {
		a++;
		b++;
		n++;
	}
	return (len - n)?(tolower_m(*(COPY_UCS2_CHAR(&cpa,a))) - tolower_m(*(COPY_UCS2_CHAR(&cpb,b)))):0;
}

/*******************************************************************
 Duplicate string.
********************************************************************/

smb_ucs2_t *strdup_w(const smb_ucs2_t *src)
{
	smb_ucs2_t *dest;
	size_t len = strlen_w(src);
	dest = SMB_MALLOC_ARRAY(smb_ucs2_t, len + 1);
	if (!dest) {
		DEBUG(0,("strdup_w: out of memory!\n"));
		return NULL;
	}

	memcpy(dest, src, len * sizeof(smb_ucs2_t));
	dest[len] = 0;
	return dest;
}
/*
  The *_wa() functions take a combination of 7 bit ascii
  and wide characters They are used so that you can use string
  functions combining C string constants with ucs2 strings

  The char* arguments must NOT be multibyte - to be completely sure
  of this only pass string constants */

int strcmp_wa(const smb_ucs2_t *a, const char *b)
{
	smb_ucs2_t cp = 0;

	while (*b && *(COPY_UCS2_CHAR(&cp,a)) == UCS2_CHAR(*b)) {
		a++;
		b++;
	}
	return (*(COPY_UCS2_CHAR(&cp,a)) - UCS2_CHAR(*b));
}

/*************************************************************
 ascii only toupper - saves the need for smbd to be in C locale.
*************************************************************/

int toupper_ascii(int c)
{
	smb_ucs2_t uc = toupper_m(UCS2_CHAR(c));
	return UCS2_TO_CHAR(uc);
}

/*************************************************************
 ascii only tolower - saves the need for smbd to be in C locale.
*************************************************************/

int tolower_ascii(int c)
{
	smb_ucs2_t uc = tolower_m(UCS2_CHAR(c));
	return UCS2_TO_CHAR(uc);
}

/*************************************************************
 ascii only isupper - saves the need for smbd to be in C locale.
*************************************************************/

int isupper_ascii(int c)
{
	return isupper_m(UCS2_CHAR(c));
}

/*************************************************************
 ascii only islower - saves the need for smbd to be in C locale.
*************************************************************/

int islower_ascii(int c)
{
	return islower_m(UCS2_CHAR(c));
}