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suricata/src/util-mpm-ac-ks-small.c

102 lines
3.5 KiB
C

/* Copyright (C) 2013-2014 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 Ken Steele <suricata@tilera.com>
* Included by util-mpm-ac-ks.c with different SLOAD, SINDEX and
* FUNC_NAME
*
*/
/* Only included into util-mpm-ac-ks.c, which defines FUNC_NAME
*
*/
#ifdef FUNC_NAME
/* This function handles (ctx->state_count < 32767) */
uint32_t FUNC_NAME(const SCACTileSearchCtx *ctx, MpmThreadCtx *mpm_thread_ctx,
PrefilterRuleStore *pmq, const uint8_t *buf, uint32_t buflen)
{
uint32_t i = 0;
int matches = 0;
uint8_t mpm_bitarray[ctx->mpm_bitarray_size];
memset(mpm_bitarray, 0, ctx->mpm_bitarray_size);
const uint8_t* restrict xlate = ctx->translate_table;
STYPE *state_table = (STYPE*)ctx->state_table;
STYPE state = 0;
int c = xlate[buf[0]];
/* If buflen at least 4 bytes and buf 4-byte aligned. */
if (buflen >= (4 + EXTRA) && ((uintptr_t)buf & 0x3) == 0) {
BUF_TYPE data = *(BUF_TYPE* restrict)(&buf[0]);
uint64_t index = 0;
/* Process 4*floor(buflen/4) bytes. */
i = 0;
while ((i + EXTRA) < (buflen & ~0x3)) {
BUF_TYPE data1 = *(BUF_TYPE* restrict)(&buf[i + 4]);
index = SINDEX(index, state);
state = SLOAD(state_table + index + c);
c = xlate[BYTE1(data)];
if (unlikely(SCHECK(state))) {
matches = CheckMatch(ctx, pmq, buf, buflen, state, i, matches, mpm_bitarray);
}
i++;
index = SINDEX(index, state);
state = SLOAD(state_table + index + c);
c = xlate[BYTE2(data)];
if (unlikely(SCHECK(state))) {
matches = CheckMatch(ctx, pmq, buf, buflen, state, i, matches, mpm_bitarray);
}
i++;
index = SINDEX(index, state);
state = SLOAD(state_table + index + c);
c = xlate[BYTE3(data)];
if (unlikely(SCHECK(state))) {
matches = CheckMatch(ctx, pmq, buf, buflen, state, i, matches, mpm_bitarray);
}
data = data1;
i++;
index = SINDEX(index, state);
state = SLOAD(state_table + index + c);
c = xlate[BYTE0(data)];
if (unlikely(SCHECK(state))) {
matches = CheckMatch(ctx, pmq, buf, buflen, state, i, matches, mpm_bitarray);
}
i++;
}
}
/* Process buflen % 4 bytes. */
for (; i < buflen; i++) {
size_t index = 0 ;
index = SINDEX(index, state);
state = SLOAD(state_table + index + c);
if (likely(i+1 < buflen))
c = xlate[buf[i+1]];
if (unlikely(SCHECK(state))) {
matches = CheckMatch(ctx, pmq, buf, buflen, state, i, matches, mpm_bitarray);
}
} /* for (i = 0; i < buflen; i++) */
return matches;
}
#endif /* FUNC_NAME */