ladish/daemon/escape.c

135 lines
3.3 KiB
C

/* -*- Mode: C ; c-basic-offset: 2 -*- */
/*
* LADI Session Handler (ladish)
*
* Copyright (C) 2009, 2010 Nedko Arnaudov <nedko@arnaudov.name>
*
**************************************************************************
* This file contains implementation of the escape helper functions
**************************************************************************
*
* LADI Session Handler 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 2 of the License, or
* (at your option) any later version.
*
* LADI Session Handler 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 LADI Session Handler. If not, see <http://www.gnu.org/licenses/>
* or write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "escape.h"
static char hex_digits[] = "0123456789ABCDEF";
#define HEX_TO_INT(hexchar) ((hexchar) <= '9' ? hexchar - '0' : 10 + (hexchar - 'A'))
void escape(const char ** src_ptr, char ** dst_ptr, unsigned int flags)
{
const char * src;
char * dst;
src = *src_ptr;
dst = *dst_ptr;
while (*src != 0)
{
switch (*src)
{
case '/': /* used as separator for address components */
case '\'':
case '>':
case '%':
if ((flags & LADISH_ESCAPE_FLAG_OTHER) == 0)
{
break;
}
/* fall through intentionally, some compilers are parsing comments */
case '<': /* invalid attribute value char (XML spec) */
case '&': /* invalid attribute value char (XML spec) */
case '"': /* we store attribute values in double quotes - invalid attribute value char (XML spec) */
if ((flags & LADISH_ESCAPE_FLAG_XML_ATTR) == 0)
{
break;
}
dst[0] = '%';
dst[1] = hex_digits[*src >> 4];
dst[2] = hex_digits[*src & 0x0F];
dst += 3;
src++;
continue;
}
*dst++ = *src++;
}
*src_ptr = src;
*dst_ptr = dst;
}
void escape_simple(const char * src_ptr, char * dst_ptr, unsigned int flags)
{
escape(&src_ptr, &dst_ptr, flags);
*dst_ptr = 0;
}
size_t unescape(const char * src, size_t src_len, char * dst)
{
size_t dst_len;
dst_len = 0;
while (src_len)
{
if (src_len >= 3 &&
src[0] == '%' &&
((src[1] >= '0' && src[1] <= '9') ||
(src[1] >= 'A' && src[1] <= 'F')) &&
((src[2] >= '0' && src[2] <= '9') ||
(src[2] >= 'A' && src[2] <= 'F')))
{
*dst = (HEX_TO_INT(src[1]) << 4) | HEX_TO_INT(src[2]);
//lash_info("unescaping %c%c%c to '%c'", src[0], src[1], src[2], *dst);
src_len -= 3;
src += 3;
}
else
{
*dst = *src;
src_len--;
src++;
}
dst++;
dst_len++;
}
return dst_len;
}
void unescape_simple(char * buffer)
{
unescape(buffer, strlen(buffer) + 1, buffer);
}
char * unescape_dup(const char * src)
{
size_t len;
char * dst;
len = strlen(src) + 1;
dst = malloc(len);
if (dst != NULL)
{
unescape(src, len, dst);
}
return dst;
}