/* Copyright (C) 2007-2022 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.

 */

/**

 * \ingroup httplayer

 *

 * @{

 */

/**

 * \file

 *

 * \author Victor Julien <victor@inliniac.net>

 *

 * Implements support for the http_response_line keyword.

 */

#include "suricata-common.h"

#include "threads.h"

#include "decode.h"

#include "detect.h"

#include "detect-parse.h"

#include "detect-engine.h"

#include "detect-engine-buffer.h"

#include "detect-engine-mpm.h"

#include "detect-engine-state.h"

#include "detect-engine-prefilter.h"

#include "detect-engine-content-inspection.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 "app-layer-htp.h"

#include "stream-tcp.h"

#include "detect-http-response-line.h"

static int DetectHttpResponseLineSetup(DetectEngineCtx *, Signature *, const char *);

#ifdef UNITTESTS

static void DetectHttpResponseLineRegisterTests(void);

#endif

static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,

        const DetectEngineTransforms *transforms,

        Flow *_f, const uint8_t _flow_flags,

        void *txv, const int list_id);

static int g_http_response_line_id = 0;

static InspectionBuffer *GetData2(DetectEngineThreadCtx *det_ctx,

        const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,

        const int list_id)

{

    SCEnter();

    InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);

    if (buffer->inspect == NULL) {

        uint32_t b_len = 0;

        const uint8_t *b = NULL;

        if (SCHttp2TxGetResponseLine(txv, &b, &b_len) != 1)

            return NULL;

        if (b == NULL || b_len == 0)

            return NULL;

        InspectionBufferSetupAndApplyTransforms(det_ctx, list_id, buffer, b, b_len, transforms);

    }

    return buffer;

}

/**

 * \brief Registers the keyword handlers for the "http_response_line" keyword.

 */

void DetectHttpResponseLineRegister(void)

{

    sigmatch_table[DETECT_HTTP_RESPONSE_LINE].name = "http.response_line";

    sigmatch_table[DETECT_HTTP_RESPONSE_LINE].alias = "http_response_line";

    sigmatch_table[DETECT_HTTP_RESPONSE_LINE].desc =

            "content modifier to match only on the HTTP response line";

    sigmatch_table[DETECT_HTTP_RESPONSE_LINE].url = "/rules/http-keywords.html#http-response-line";

    sigmatch_table[DETECT_HTTP_RESPONSE_LINE].Setup = DetectHttpResponseLineSetup;

#ifdef UNITTESTS

    sigmatch_table[DETECT_HTTP_RESPONSE_LINE].RegisterTests = DetectHttpResponseLineRegisterTests;

#endif

    sigmatch_table[DETECT_HTTP_RESPONSE_LINE].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;

    DetectAppLayerInspectEngineRegister("http_response_line", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT,

            HTP_RESPONSE_PROGRESS_LINE, DetectEngineInspectBufferGeneric, GetData);

    DetectAppLayerMpmRegister("http_response_line", SIG_FLAG_TOCLIENT, 2,

            PrefilterGenericMpmRegister, GetData, ALPROTO_HTTP1, HTP_RESPONSE_PROGRESS_LINE);

    DetectAppLayerInspectEngineRegister("http_response_line", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT,

            HTTP2StateDataServer, DetectEngineInspectBufferGeneric, GetData2);

    DetectAppLayerMpmRegister("http_response_line", SIG_FLAG_TOCLIENT, 2,

            PrefilterGenericMpmRegister, GetData2, ALPROTO_HTTP2, HTTP2StateDataServer);

    DetectBufferTypeSetDescriptionByName("http_response_line",

            "http response line");

    g_http_response_line_id = DetectBufferTypeGetByName("http_response_line");

}

/**

 * \brief The setup function for the http_response_line keyword for a signature.

 *

 * \param de_ctx Pointer to the detection engine context.

 * \param s      Pointer to the signature for the current Signature being

 *               parsed from the rules.

 * \param m      Pointer to the head of the SigMatch for the current rule

 *               being parsed.

 * \param arg    Pointer to the string holding the keyword value.

 *

 * \retval  0 On success

 * \retval -1 On failure

 */

static int DetectHttpResponseLineSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)

{

    if (SCDetectBufferSetActiveList(de_ctx, s, g_http_response_line_id) < 0)

        return -1;

    if (SCDetectSignatureSetAppProto(s, ALPROTO_HTTP) < 0)

        return -1;

    return 0;

}

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) {

        htp_tx_t *tx = (htp_tx_t *)txv;

        if (unlikely(htp_tx_response_line(tx) == NULL)) {

            return NULL;

        }

        const uint32_t data_len = (uint32_t)bstr_len(htp_tx_response_line(tx));

        const uint8_t *data = bstr_ptr(htp_tx_response_line(tx));

        InspectionBufferSetupAndApplyTransforms(

                det_ctx, list_id, buffer, data, data_len, transforms);

    }

    return buffer;

}

/************************************Unittests*********************************/

#ifdef UNITTESTS

#include "stream-tcp-reassemble.h"

/**

 * \test Test that a signature containing a http_response_line is correctly parsed

 *       and the keyword is registered.

 */

static int DetectHttpResponseLineTest01(void)

{

    DetectEngineCtx *de_ctx = DetectEngineCtxInit();

    FAIL_IF_NULL(de_ctx);

    de_ctx->flags |= DE_QUIET;

    de_ctx->sig_list = SigInit(de_ctx, "alert tcp any any -> any any "

                               "(http_response_line; content:\"200 OK\"; sid:1;)");

    FAIL_IF_NULL(de_ctx->sig_list);

    DetectEngineCtxFree(de_ctx);

    PASS;

}

void DetectHttpResponseLineRegisterTests(void)

{

    UtRegisterTest("DetectHttpResponseLineTest01", DetectHttpResponseLineTest01);

}

#endif /* UNITTESTS */

/**

 * @}

 */