You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
suricata/src/detect-ftp-completion-code.c

106 lines
3.3 KiB
C

/* Copyright (C) 2025 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 Jeff Lucovsky <jlucovsky@oisf.net>
*
* Implements the ftp.completion-code sticky buffer
*
*/
#include "suricata-common.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-buffer.h"
#include "detect-engine-helper.h"
#include "detect-ftp-completion-code.h"
#include "app-layer.h"
#include "app-layer-ftp.h"
#include "flow.h"
#include "util-debug.h"
#define KEYWORD_NAME "ftp.completion_code"
#define KEYWORD_DOC "ftp-keywords.html#ftp-completion_code"
#define BUFFER_NAME "ftp.completion_code"
#define BUFFER_DESC "ftp completion code"
static int g_ftp_ccode_buffer_id = 0;
static int DetectFtpCompletionCodeSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
if (SCDetectBufferSetActiveList(de_ctx, s, g_ftp_ccode_buffer_id) < 0)
return -1;
if (DetectSignatureSetAppProto(s, ALPROTO_FTP) < 0)
return -1;
return 0;
}
static bool DetectFTPCompletionCodeGetData(DetectEngineThreadCtx *_det_ctx, const void *txv,
uint8_t _flow_flags, uint32_t index, const uint8_t **buffer, uint32_t *buffer_len)
{
FTPTransaction *tx = (FTPTransaction *)txv;
if (tx->command_descriptor.command_code == FTP_COMMAND_UNKNOWN)
return false;
if (!TAILQ_EMPTY(&tx->response_list)) {
uint32_t count = 0;
FTPResponseWrapper *wrapper;
TAILQ_FOREACH (wrapper, &tx->response_list, next) {
DEBUG_VALIDATE_BUG_ON(wrapper->response == NULL);
if (index == count) {
*buffer = (const uint8_t *)wrapper->response->code;
*buffer_len = wrapper->response->code_length;
return true;
}
count++;
}
}
*buffer = NULL;
*buffer_len = 0;
return false;
}
void DetectFtpCompletionCodeRegister(void)
{
/* ftp.completion_code sticky buffer */
sigmatch_table[DETECT_FTP_COMPLETION_CODE].name = KEYWORD_NAME;
sigmatch_table[DETECT_FTP_COMPLETION_CODE].desc =
"sticky buffer to match on the FTP completion code buffer";
sigmatch_table[DETECT_FTP_COMPLETION_CODE].url = "/rules/" KEYWORD_DOC;
sigmatch_table[DETECT_FTP_COMPLETION_CODE].Setup = DetectFtpCompletionCodeSetup;
sigmatch_table[DETECT_FTP_COMPLETION_CODE].flags |= SIGMATCH_NOOPT;
DetectAppLayerMultiRegister(
BUFFER_NAME, ALPROTO_FTP, SIG_FLAG_TOCLIENT, 0, DetectFTPCompletionCodeGetData, 2);
DetectBufferTypeSetDescriptionByName(BUFFER_NAME, BUFFER_DESC);
g_ftp_ccode_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
SCLogDebug("registering " BUFFER_NAME " rule option");
}