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/* Copyright (C) 2007-2010 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* 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
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/**
* \file
*
* \author Victor Julien <victor@inliniac.net>
* \author Pablo Rincon Crespo <pablo.rincon.crespo@gmail.com>
*
* bs is a bruteforce search. It will try to search the pattern
* from all characters until the available text len is less
* than the length of the pattern. It needs no context but it
* time cost is not good.
*/
#include "suricata-common.h"
#include "suricata.h"
#include "util-debug.h"
#include "util-spm-bs.h"
/**
* \brief Basic search improved. Limits are better handled, so
* it doesn't start searches that wont fit in the remaining buffer
*
* \param haystack pointer to the buffer to search in
* \param haystack_len length limit of the buffer
* \param neddle pointer to the pattern we ar searching for
* \param needle_len length limit of the needle
*
* \retval ptr to start of the match; NULL if no match
*/
uint8_t *BasicSearch(const uint8_t *haystack, uint32_t haystack_len, const uint8_t *needle, uint16_t needle_len)
{
SCEnter();
const uint8_t *h, *n;
const uint8_t *hmax = haystack + haystack_len;
const uint8_t *nmax = needle + needle_len;
if (needle_len == 0 || needle_len > haystack_len) {
SCReturnPtr(NULL, "uint8_t");
}
//PrintRawDataFp(stdout,needle,needle_len);
//PrintRawDataFp(stdout,haystack,haystack_len);
for (n = needle; nmax - n <= hmax - haystack; haystack++) {
if (*haystack != *n) {
continue;
}
SCLogDebug("*haystack == *n, %c == %c", *haystack, *n);
/* one byte needles */
if (needle_len == 1) {
SCReturnPtr((uint8_t *)haystack, "uint8_t");
}
for (h = haystack+1, n++; nmax - n <= hmax - haystack; h++, n++) {
if (*h != *n) {
break;
}
SCLogDebug("*haystack == *n, %c == %c", *haystack, *n);
/* if we run out of needle we fully matched */
if (n == nmax - 1) {
SCReturnPtr((uint8_t *)haystack, "uint8_t");
}
}
n = needle;
}
SCReturnPtr(NULL, "uint8_t");
}
/**
* \brief Basic search case less
*
* \param haystack pointer to the buffer to search in
* \param haystack_len length limit of the buffer
* \param neddle pointer to the pattern we ar searching for
* \param needle_len length limit of the needle
*
* \retval ptr to start of the match; NULL if no match
*/
uint8_t *BasicSearchNocase(const uint8_t *haystack, uint32_t haystack_len, const uint8_t *needle, uint16_t needle_len)
{
const uint8_t *h, *n;
const uint8_t *hmax = haystack + haystack_len;
const uint8_t *nmax = needle + needle_len;
if (needle_len == 0 || needle_len > haystack_len)
return NULL;
for (n = needle; nmax - n <= hmax - haystack; haystack++) {
if (u8_tolower(*haystack) != u8_tolower(*n)) {
continue;
}
/* one byte needles */
if (needle_len == 1) {
return (uint8_t *)haystack;
}
for (h = haystack+1, n++; nmax - n <= hmax - h ; h++, n++) {
if (u8_tolower(*h) != u8_tolower(*n)) {
break;
}
/* if we run out of needle we fully matched */
if (n == nmax - 1) {
return (uint8_t *)haystack;
}
}
n = needle;
}
return NULL;
}
void BasicSearchInit (void)
{
/* nothing no more */
}
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