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/* Copyright (C) 2019 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.
*/
/**
*
* \author Giuseppe Longo <giuseppe@glongo.it>
*
* Implements the sip.method sticky buffer
*
*/
#include "suricata-common.h"
#include "threads.h"
#include "decode.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-engine-prefilter.h"
#include "detect-content.h"
#include "detect-pcre.h"
#include "flow.h"
#include "flow-var.h"
#include "flow-util.h"
#include "util-debug.h"
#include "util-unittest.h"
#include "util-unittest-helper.h"
#include "util-spm.h"
#include "app-layer.h"
#include "app-layer-parser.h"
#include "detect-sip-method.h"
#include "stream-tcp.h"
#include "rust.h"
#include "app-layer-sip.h"
#define KEYWORD_NAME "sip.method"
#define KEYWORD_DOC "sip-keywords.html#sip-method"
#define BUFFER_NAME "sip.method"
#define BUFFER_DESC "sip request method"
static int g_buffer_id = 0;
static int DetectSipMethodSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
if (DetectBufferSetActiveList(de_ctx, s, g_buffer_id) < 0)
return -1;
if (DetectSignatureSetAppProto(s, ALPROTO_SIP) < 0)
return -1;
return 0;
}
static bool DetectSipMethodValidateCallback(const Signature *s, const char **sigerror)
{
for (uint32_t x = 0; x < s->init_data->buffer_index; x++) {
if (s->init_data->buffers[x].id != (uint32_t)g_buffer_id)
continue;
const SigMatch *sm = s->init_data->buffers[x].head;
for (; sm != NULL; sm = sm->next) {
if (sm->type != DETECT_CONTENT)
continue;
const DetectContentData *cd = (const DetectContentData *)sm->ctx;
if (cd->content && cd->content_len) {
if (cd->content[cd->content_len - 1] == 0x20) {
*sigerror = "sip.method pattern with trailing space";
SCLogError("%s", *sigerror);
return true;
} else if (cd->content[0] == 0x20) {
*sigerror = "sip.method pattern with leading space";
SCLogError("%s", *sigerror);
return true;
} else if (cd->content[cd->content_len - 1] == 0x09) {
*sigerror = "sip.method pattern with trailing tab";
SCLogError("%s", *sigerror);
return true;
} else if (cd->content[0] == 0x09) {
*sigerror = "sip.method pattern with leading tab";
SCLogError("%s", *sigerror);
return true;
}
}
}
}
return true;
}
static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Flow *_f,
const uint8_t _flow_flags, void *txv, const int list_id)
{
InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
if (buffer->inspect == NULL) {
const uint8_t *b = NULL;
uint32_t b_len = 0;
if (rs_sip_tx_get_method(txv, &b, &b_len) != 1)
return NULL;
if (b == NULL || b_len == 0)
return NULL;
InspectionBufferSetup(det_ctx, list_id, buffer, b, b_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
void DetectSipMethodRegister(void)
{
/* sip.method sticky buffer */
sigmatch_table[DETECT_AL_SIP_METHOD].name = KEYWORD_NAME;
sigmatch_table[DETECT_AL_SIP_METHOD].desc = "sticky buffer to match on the SIP method buffer";
sigmatch_table[DETECT_AL_SIP_METHOD].url = "/rules/" KEYWORD_DOC;
sigmatch_table[DETECT_AL_SIP_METHOD].Setup = DetectSipMethodSetup;
sigmatch_table[DETECT_AL_SIP_METHOD].flags |= SIGMATCH_NOOPT;
DetectAppLayerInspectEngineRegister2(BUFFER_NAME, ALPROTO_SIP,
SIG_FLAG_TOSERVER, 0,
DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOSERVER, 2,
PrefilterGenericMpmRegister, GetData, ALPROTO_SIP,
1);
DetectBufferTypeSetDescriptionByName(BUFFER_NAME, BUFFER_DESC);
DetectBufferTypeRegisterValidateCallback(BUFFER_NAME,
DetectSipMethodValidateCallback);
g_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
SCLogDebug("registering " BUFFER_NAME " rule option");
}
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