suricata/src/detect-http-method.c

/* 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.
 */

/**
 * \ingroup httplayer
 *
 * @{
 */


/**
 * \file
 *
 * \author Brian Rectanus <brectanu@gmail.com>
 *
 * Implements the http_method keyword
 */

#include "suricata-common.h"
#include "threads.h"
#include "debug.h"
#include "decode.h"
#include "detect.h"

#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-engine-state.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 "detect-http-method.h"
#include "stream-tcp.h"


static int DetectHttpMethodSetup(DetectEngineCtx *, Signature *, char *);
void DetectHttpMethodRegisterTests(void);
void DetectHttpMethodFree(void *);

/**
 * \brief Registration function for keyword: http_method
 */
void DetectHttpMethodRegister(void)
{
    sigmatch_table[DETECT_AL_HTTP_METHOD].name = "http_method";
    sigmatch_table[DETECT_AL_HTTP_METHOD].desc = "content modifier to match only on the HTTP method-buffer";
    sigmatch_table[DETECT_AL_HTTP_METHOD].url = "https://redmine.openinfosecfoundation.org/projects/suricata/wiki/HTTP-keywords#http_method";
    sigmatch_table[DETECT_AL_HTTP_METHOD].Match = NULL;
    sigmatch_table[DETECT_AL_HTTP_METHOD].AppLayerMatch = NULL;
    sigmatch_table[DETECT_AL_HTTP_METHOD].Setup = DetectHttpMethodSetup;
    sigmatch_table[DETECT_AL_HTTP_METHOD].Free  = DetectHttpMethodFree;
    sigmatch_table[DETECT_AL_HTTP_METHOD].RegisterTests = DetectHttpMethodRegisterTests;
    sigmatch_table[DETECT_AL_HTTP_METHOD].flags |= SIGMATCH_NOOPT;
    sigmatch_table[DETECT_AL_HTTP_METHOD].flags |= SIGMATCH_PAYLOAD;

    SCLogDebug("registering http_method rule option");
}

/**
 * \brief This function is used to add the parsed "http_method" option
 *        into the current signature.
 *
 * \param de_ctx Pointer to the Detection Engine Context.
 * \param s      Pointer to the Current Signature.
 * \param str    Pointer to the user provided option string.
 *
 * \retval  0 on Success.
 * \retval -1 on Failure.
 */
static int DetectHttpMethodSetup(DetectEngineCtx *de_ctx, Signature *s, char *str)
{
    return DetectEngineContentModifierBufferSetup(de_ctx, s, str,
                                                  DETECT_AL_HTTP_METHOD,
                                                  DETECT_SM_LIST_HMDMATCH,
                                                  ALPROTO_HTTP,
                                                  NULL);
}

/**
 * \brief this function will free memory associated with DetectContentData
 *
 * \param id_d pointer to DetectContentData
 */
void DetectHttpMethodFree(void *ptr)
{
    DetectContentData *data = (DetectContentData *)ptr;

    if (data->content != NULL)
        SCFree(data->content);
    SCFree(data);
}

/**
 *  \retval 1 valid
 *  \retval 0 invalid
 */
int DetectHttpMethodValidateRule(const Signature *s)
{
    if (s->alproto != ALPROTO_HTTP)
        return 1;

    if (s->sm_lists[DETECT_SM_LIST_HMDMATCH] != NULL) {
        const SigMatch *sm = s->sm_lists[DETECT_SM_LIST_HMDMATCH];
        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) {
                    SCLogError(SC_ERR_INVALID_SIGNATURE, "http_method pattern with trailing space");
                    return 0;
                } else if (cd->content[0] == 0x20) {
                    SCLogError(SC_ERR_INVALID_SIGNATURE, "http_method pattern with leading space");
                    return 0;
                } else if (cd->content[cd->content_len-1] == 0x09) {
                    SCLogError(SC_ERR_INVALID_SIGNATURE, "http_method pattern with trailing tab");
                    return 0;
                } else if (cd->content[0] == 0x09) {
                    SCLogError(SC_ERR_INVALID_SIGNATURE, "http_method pattern with leading tab");
                    return 0;
                }
            }
        }
    }
    return 1;
}

#ifdef UNITTESTS /* UNITTESTS */

#include "stream-tcp-reassemble.h"

/** \test Check a signature with content */
int DetectHttpMethodTest01(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;
    de_ctx->sig_list = SigInit(de_ctx,
                               "alert tcp any any -> any any "
                               "(msg:\"Testing http_method\"; "
                               "content:\"GET\"; "
                               "http_method; sid:1;)");

    if (de_ctx->sig_list != NULL) {
        result = 1;
    } else {
        printf("sig parse failed: ");
    }

 end:
    if (de_ctx != NULL)
        SigCleanSignatures(de_ctx);
    if (de_ctx != NULL)
        DetectEngineCtxFree(de_ctx);
    return result;
}

/** \test Check a signature without content (fail) */
int DetectHttpMethodTest02(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;
    de_ctx->sig_list = SigInit(de_ctx,
                               "alert tcp any any -> any any "
                               "(msg:\"Testing http_method\"; "
                               "http_method; sid:1;)");

    if (de_ctx->sig_list == NULL) {
        result = 1;
    }

 end:
    if (de_ctx != NULL)
        SigCleanSignatures(de_ctx);
    if (de_ctx != NULL)
        DetectEngineCtxFree(de_ctx);
    return result;
}

/** \test Check a signature with parameter (fail) */
int DetectHttpMethodTest03(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;
    de_ctx->sig_list = SigInit(de_ctx,
                               "alert tcp any any -> any any "
                               "(msg:\"Testing http_method\"; "
                               "content:\"foobar\"; "
                               "http_method:\"GET\"; sid:1;)");

    if (de_ctx->sig_list == NULL) {
        result = 1;
    }

 end:
    if (de_ctx != NULL)
        SigCleanSignatures(de_ctx);
    if (de_ctx != NULL)
        DetectEngineCtxFree(de_ctx);
    return result;
}

/** \test Check a signature with fast_pattern (should work) */
int DetectHttpMethodTest04(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;
    de_ctx->sig_list = SigInit(de_ctx,
                               "alert tcp any any -> any any "
                               "(msg:\"Testing http_method\"; "
                               "content:\"GET\"; "
                               "fast_pattern; "
                               "http_method; sid:1;)");

    if (de_ctx->sig_list != NULL) {
        result = 1;
    }

 end:
    if (de_ctx != NULL)
        SigCleanSignatures(de_ctx);
    if (de_ctx != NULL)
        DetectEngineCtxFree(de_ctx);
    return result;
}

/** \test Check a signature with rawbytes (fail) */
int DetectHttpMethodTest05(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;
    de_ctx->sig_list = SigInit(de_ctx,
                               "alert tcp any any -> any any "
                               "(msg:\"Testing http_method\"; "
                               "content:\"GET\"; "
                               "rawbytes; "
                               "http_method; sid:1;)");

    if (de_ctx->sig_list == NULL) {
        result = 1;
    }

 end:
    if (de_ctx != NULL)
        SigCleanSignatures(de_ctx);
    if (de_ctx != NULL)
        DetectEngineCtxFree(de_ctx);
    return result;
}

/** \test setting the nocase flag */
static int DetectHttpMethodTest12(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;

    if (DetectEngineAppendSig(de_ctx, "alert http any any -> any any "
                               "(content:\"one\"; http_method; nocase; sid:1;)") == NULL) {
        printf("DetectEngineAppend == NULL: ");
        goto end;
    }
    if (DetectEngineAppendSig(de_ctx, "alert http any any -> any any "
                               "(content:\"one\"; nocase; http_method; sid:2;)") == NULL) {
        printf("DetectEngineAppend == NULL: ");
        goto end;
    }

    if (de_ctx->sig_list->sm_lists[DETECT_SM_LIST_HMDMATCH] == NULL) {
        printf("de_ctx->sig_list->sm_lists[DETECT_SM_LIST_HMDMATCH] == NULL: ");
        goto end;
    }

    DetectContentData *hmd1 = (DetectContentData *)de_ctx->sig_list->sm_lists_tail[DETECT_SM_LIST_HMDMATCH]->ctx;
    DetectContentData *hmd2 = (DetectContentData *)de_ctx->sig_list->next->sm_lists_tail[DETECT_SM_LIST_HMDMATCH]->ctx;

    if (!(hmd1->flags & DETECT_CONTENT_NOCASE)) {
        printf("nocase flag not set on sig 1: ");
        goto end;
    }

    if (!(hmd2->flags & DETECT_CONTENT_NOCASE)) {
        printf("nocase flag not set on sig 2: ");
        goto end;
    }
    result = 1;

 end:
    SigCleanSignatures(de_ctx);
    DetectEngineCtxFree(de_ctx);
    return result;
}

/** \test Check a signature with method + within and pcre with /M (should work) */
int DetectHttpMethodTest13(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;
    de_ctx->sig_list = SigInit(de_ctx,
                               "alert tcp any any -> any any "
                               "(msg:\"Testing http_method\"; "
                               "pcre:\"/HE/M\"; "
                               "content:\"AD\"; "
                               "within:2; http_method; sid:1;)");

    if (de_ctx->sig_list != NULL) {
        result = 1;
    }

 end:
    if (de_ctx != NULL)
        SigCleanSignatures(de_ctx);
    if (de_ctx != NULL)
        DetectEngineCtxFree(de_ctx);
    return result;
}

/** \test Check a signature with method + within and pcre without /M (should fail) */
int DetectHttpMethodTest14(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;
    de_ctx->sig_list = SigInit(de_ctx,
                               "alert tcp any any -> any any "
                               "(msg:\"Testing http_method\"; "
                               "pcre:\"/HE/\"; "
                               "content:\"AD\"; "
                               "http_method; within:2; sid:1;)");

    if (de_ctx->sig_list != NULL) {
        result = 1;
    }

 end:
    if (de_ctx != NULL)
        SigCleanSignatures(de_ctx);
    if (de_ctx != NULL)
        DetectEngineCtxFree(de_ctx);
    return result;
}

/** \test Check a signature with method + within and pcre with /M (should work) */
int DetectHttpMethodTest15(void)
{
    DetectEngineCtx *de_ctx = NULL;
    int result = 0;

    if ( (de_ctx = DetectEngineCtxInit()) == NULL)
        goto end;

    de_ctx->flags |= DE_QUIET;
    de_ctx->sig_list = SigInit(de_ctx,
                               "alert tcp any any -> any any "
                               "(msg:\"Testing http_method\"; "
                               "pcre:\"/HE/M\"; "
                               "content:\"AD\"; "
                               "http_method; within:2; sid:1;)");

    if (de_ctx->sig_list != NULL) {
        result = 1;
    }

 end:
    if (de_ctx != NULL)
        SigCleanSignatures(de_ctx);
    if (de_ctx != NULL)
        DetectEngineCtxFree(de_ctx);
    return result;
}
/** \test Check a signature with an known request method */
static int DetectHttpMethodSigTest01(void)
{
    int result = 0;
    Flow f;
    uint8_t httpbuf1[] = "GET / HTTP/1.0\r\n"
                         "Host: foo.bar.tld\r\n"
                         "\r\n";
    uint32_t httplen1 = sizeof(httpbuf1) - 1; /* minus the \0 */
    TcpSession ssn;
    Packet *p = NULL;
    Signature *s = NULL;
    ThreadVars th_v;
    DetectEngineThreadCtx *det_ctx;
    HtpState *http_state = NULL;
    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();

    memset(&th_v, 0, sizeof(th_v));
    memset(&f, 0, sizeof(f));
    memset(&ssn, 0, sizeof(ssn));

    p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);

    FLOW_INITIALIZE(&f);
    f.protoctx = (void *)&ssn;
    f.proto = IPPROTO_TCP;
    f.flags |= FLOW_IPV4;

    p->flow = &f;
    p->flowflags |= FLOW_PKT_TOSERVER;
    p->flowflags |= FLOW_PKT_ESTABLISHED;
    p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
    f.alproto = ALPROTO_HTTP;

    StreamTcpInitConfig(TRUE);

    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
    if (de_ctx == NULL) {
        goto end;
    }

    de_ctx->flags |= DE_QUIET;

    s = de_ctx->sig_list = SigInit(de_ctx,
                                   "alert tcp any any -> any any "
                                   "(msg:\"Testing http_method\"; "
                                   "content:\"GET\"; "
                                   "http_method; sid:1;)");
    if (s == NULL) {
        goto end;
    }

    s = s->next = SigInit(de_ctx,
                          "alert tcp any any -> any any "
                          "(msg:\"Testing http_method\"; "
                          "content:\"POST\"; "
                          "http_method; sid:2;)");
    if (s == NULL) {
        goto end;
    }

    SigGroupBuild(de_ctx);
    DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);

    FLOWLOCK_WRLOCK(&f);
    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_HTTP,
                                STREAM_TOSERVER, httpbuf1, httplen1);
    if (r != 0) {
        SCLogDebug("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
        FLOWLOCK_UNLOCK(&f);
        goto end;
    }
    FLOWLOCK_UNLOCK(&f);

    http_state = f.alstate;
    if (http_state == NULL) {
        SCLogDebug("no http state: ");
        goto end;
    }

    SigMatchSignatures(&th_v, de_ctx, det_ctx, p);

    if (!(PacketAlertCheck(p, 1))) {
        goto end;
    }
    if (PacketAlertCheck(p, 2)) {
        goto end;
    }

    result = 1;

end:
    if (alp_tctx != NULL)
        AppLayerParserThreadCtxFree(alp_tctx);
    if (de_ctx != NULL) SigGroupCleanup(de_ctx);
    if (de_ctx != NULL) SigCleanSignatures(de_ctx);
    if (de_ctx != NULL) DetectEngineCtxFree(de_ctx);

    StreamTcpFreeConfig(TRUE);
    FLOW_DESTROY(&f);
    UTHFreePackets(&p, 1);
    return result;
}

/** \test Check a signature with an unknown request method */
static int DetectHttpMethodSigTest02(void)
{
    int result = 0;
    Flow f;
    uint8_t httpbuf1[] = "FOO / HTTP/1.0\r\n"
                         "Host: foo.bar.tld\r\n"
                         "\r\n";
    uint32_t httplen1 = sizeof(httpbuf1) - 1; /* minus the \0 */
    TcpSession ssn;
    Packet *p = NULL;
    Signature *s = NULL;
    ThreadVars th_v;
    DetectEngineThreadCtx *det_ctx = NULL;
    HtpState *http_state = NULL;
    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();

    memset(&th_v, 0, sizeof(th_v));
    memset(&f, 0, sizeof(f));
    memset(&ssn, 0, sizeof(ssn));

    p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);

    FLOW_INITIALIZE(&f);
    f.protoctx = (void *)&ssn;
    f.proto = IPPROTO_TCP;
    f.flags |= FLOW_IPV4;

    p->flow = &f;
    p->flowflags |= FLOW_PKT_TOSERVER;
    p->flowflags |= FLOW_PKT_ESTABLISHED;
    p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
    f.alproto = ALPROTO_HTTP;

    StreamTcpInitConfig(TRUE);

    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
    if (de_ctx == NULL) {
        goto end;
    }

    de_ctx->flags |= DE_QUIET;

    s = de_ctx->sig_list = SigInit(de_ctx,
                                   "alert tcp any any -> any any "
                                   "(msg:\"Testing http_method\"; "
                                   "content:\"FOO\"; "
                                   "http_method; sid:1;)");
    if (s == NULL) {
        goto end;
    }

    s = s->next = SigInit(de_ctx,
                          "alert tcp any any -> any any "
                          "(msg:\"Testing http_method\"; "
                          "content:\"BAR\"; "
                          "http_method; sid:2;)");
    if (s == NULL) {
        goto end;
    }

    SigGroupBuild(de_ctx);
    DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);

    FLOWLOCK_WRLOCK(&f);
    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_HTTP,
                                STREAM_TOSERVER, httpbuf1, httplen1);
    if (r != 0) {
        SCLogDebug("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
        FLOWLOCK_UNLOCK(&f);
        goto end;
    }
    FLOWLOCK_UNLOCK(&f);

    http_state = f.alstate;
    if (http_state == NULL) {
        SCLogDebug("no http state: ");
        goto end;
    }

    SigMatchSignatures(&th_v, de_ctx, det_ctx, p);

    if (!(PacketAlertCheck(p, 1))) {
        goto end;
    }
    if (PacketAlertCheck(p, 2)) {
        goto end;
    }

    result = 1;

end:
    if (alp_tctx != NULL)
        AppLayerParserThreadCtxFree(alp_tctx);
    if (de_ctx != NULL) SigGroupCleanup(de_ctx);
    if (de_ctx != NULL) SigCleanSignatures(de_ctx);
    if (det_ctx != NULL) DetectEngineThreadCtxDeinit(&th_v, (void *) det_ctx);
    if (de_ctx != NULL) DetectEngineCtxFree(de_ctx);

    StreamTcpFreeConfig(TRUE);
    FLOW_DESTROY(&f);
    UTHFreePackets(&p, 1);
    return result;
}

/** \test Check a signature against an unparsable request */
static int DetectHttpMethodSigTest03(void)
{
    int result = 0;
    Flow f;
    uint8_t httpbuf1[] = " ";
    uint32_t httplen1 = sizeof(httpbuf1) - 1; /* minus the \0 */
    TcpSession ssn;
    Packet *p = NULL;
    Signature *s = NULL;
    ThreadVars th_v;
    DetectEngineThreadCtx *det_ctx;
    HtpState *http_state = NULL;
    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();

    memset(&th_v, 0, sizeof(th_v));
    memset(&f, 0, sizeof(f));
    memset(&ssn, 0, sizeof(ssn));

    p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);

    FLOW_INITIALIZE(&f);
    f.protoctx = (void *)&ssn;
    f.proto = IPPROTO_TCP;
    f.flags |= FLOW_IPV4;

    p->flow = &f;
    p->flowflags |= FLOW_PKT_TOSERVER;
    p->flowflags |= FLOW_PKT_ESTABLISHED;
    p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
    f.alproto = ALPROTO_HTTP;

    StreamTcpInitConfig(TRUE);

    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
    if (de_ctx == NULL) {
        goto end;
    }

    de_ctx->flags |= DE_QUIET;

    s = de_ctx->sig_list = SigInit(de_ctx,
                                   "alert tcp any any -> any any "
                                   "(msg:\"Testing http_method\"; "
                                   "content:\"GET\"; "
                                   "http_method; sid:1;)");
    if (s == NULL) {
        SCLogDebug("Bad signature");
        goto end;
    }

    SigGroupBuild(de_ctx);
    DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);

    FLOWLOCK_WRLOCK(&f);
    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_HTTP,
                                STREAM_TOSERVER, httpbuf1, httplen1);
    if (r != 0) {
        SCLogDebug("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
        FLOWLOCK_UNLOCK(&f);
        goto end;
    }
    FLOWLOCK_UNLOCK(&f);

    http_state = f.alstate;
    if (http_state == NULL) {
        SCLogDebug("no http state: ");
        goto end;
    }

    SigMatchSignatures(&th_v, de_ctx, det_ctx, p);

    if (PacketAlertCheck(p, 1)) {
        goto end;
    }

    result = 1;

end:
    if (alp_tctx != NULL)
        AppLayerParserThreadCtxFree(alp_tctx);
    if (de_ctx != NULL) SigGroupCleanup(de_ctx);
    if (de_ctx != NULL) SigCleanSignatures(de_ctx);
    if (de_ctx != NULL) DetectEngineCtxFree(de_ctx);

    StreamTcpFreeConfig(TRUE);
    FLOW_DESTROY(&f);
    UTHFreePackets(&p, 1);
    return result;
}

/** \test Check a signature with an request method and negation of the same */
static int DetectHttpMethodSigTest04(void)
{
    int result = 0;
    Flow f;
    uint8_t httpbuf1[] = "GET / HTTP/1.0\r\n"
                         "Host: foo.bar.tld\r\n"
                         "\r\n";
    uint32_t httplen1 = sizeof(httpbuf1) - 1; /* minus the \0 */
    TcpSession ssn;
    Packet *p = NULL;
    Signature *s = NULL;
    ThreadVars th_v;
    DetectEngineThreadCtx *det_ctx = NULL;
    HtpState *http_state = NULL;
    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();

    memset(&th_v, 0, sizeof(th_v));
    memset(&f, 0, sizeof(f));
    memset(&ssn, 0, sizeof(ssn));

    p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);

    FLOW_INITIALIZE(&f);
    f.protoctx = (void *)&ssn;
    f.proto = IPPROTO_TCP;
    f.flags |= FLOW_IPV4;

    p->flow = &f;
    p->flowflags |= FLOW_PKT_TOSERVER;
    p->flowflags |= FLOW_PKT_ESTABLISHED;
    p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
    f.alproto = ALPROTO_HTTP;

    StreamTcpInitConfig(TRUE);

    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
    if (de_ctx == NULL) {
        goto end;
    }

    de_ctx->flags |= DE_QUIET;

    s = de_ctx->sig_list = SigInit(de_ctx,
            "alert tcp any any -> any any (msg:\"Testing http_method\"; "
            "content:\"GET\"; http_method; sid:1;)");
    if (s == NULL) {
        goto end;
    }

    s = s->next = SigInit(de_ctx,
            "alert tcp any any -> any any (msg:\"Testing http_method\"; "
            "content:!\"GET\"; http_method; sid:2;)");
    if (s == NULL) {
        goto end;
    }

    SigGroupBuild(de_ctx);
    DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);

    FLOWLOCK_WRLOCK(&f);
    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_HTTP,
                                STREAM_TOSERVER, httpbuf1, httplen1);
    if (r != 0) {
        SCLogDebug("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
        FLOWLOCK_UNLOCK(&f);
        goto end;
    }
    FLOWLOCK_UNLOCK(&f);

    http_state = f.alstate;
    if (http_state == NULL) {
        SCLogDebug("no http state: ");
        goto end;
    }

    SigMatchSignatures(&th_v, de_ctx, det_ctx, p);

    if (!(PacketAlertCheck(p, 1))) {
        printf("sid 1 didn't match but should have: ");
        goto end;
    }
    if (PacketAlertCheck(p, 2)) {
        printf("sid 2 matched but shouldn't have: ");
        goto end;
    }

    result = 1;

end:
    if (alp_tctx != NULL)
        AppLayerParserThreadCtxFree(alp_tctx);
    if (de_ctx != NULL) {
        SigGroupCleanup(de_ctx);
        SigCleanSignatures(de_ctx);
    }
    if (det_ctx != NULL) {
        DetectEngineThreadCtxDeinit(&th_v, (void *) det_ctx);
    }
    if (de_ctx != NULL) {
        DetectEngineCtxFree(de_ctx);
    }

    StreamTcpFreeConfig(TRUE);
    FLOW_DESTROY(&f);
    UTHFreePackets(&p, 1);
    return result;
}

#endif /* UNITTESTS */

/**
 * \brief this function registers unit tests for DetectHttpMethod
 */
void DetectHttpMethodRegisterTests(void)
{
#ifdef UNITTESTS /* UNITTESTS */
    SCLogDebug("Registering tests for DetectHttpMethod...");
    UtRegisterTest("DetectHttpMethodTest01", DetectHttpMethodTest01);
    UtRegisterTest("DetectHttpMethodTest02", DetectHttpMethodTest02);
    UtRegisterTest("DetectHttpMethodTest03", DetectHttpMethodTest03);
    UtRegisterTest("DetectHttpMethodTest04", DetectHttpMethodTest04);
    UtRegisterTest("DetectHttpMethodTest05", DetectHttpMethodTest05);
    UtRegisterTest("DetectHttpMethodTest12 -- nocase flag",
                   DetectHttpMethodTest12);
    UtRegisterTest("DetectHttpMethodTest13", DetectHttpMethodTest13);
    UtRegisterTest("DetectHttpMethodTest14", DetectHttpMethodTest14);
    UtRegisterTest("DetectHttpMethodTest15", DetectHttpMethodTest15);
    UtRegisterTest("DetectHttpMethodSigTest01", DetectHttpMethodSigTest01);
    UtRegisterTest("DetectHttpMethodSigTest02", DetectHttpMethodSigTest02);
    UtRegisterTest("DetectHttpMethodSigTest03", DetectHttpMethodSigTest03);
    UtRegisterTest("DetectHttpMethodSigTest04", DetectHttpMethodSigTest04);
#endif /* UNITTESTS */
}

/**
 * @}
 */