detect-http-uri.c

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/* Copyright (C) 2007-2018 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 Gerardo Iglesias  <iglesiasg@gmail.com>
 * \author Victor Julien <victor@inliniac.net>
 */
 
#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-prefilter.h"
#include "detect-content.h"
#include "detect-pcre.h"
#include "detect-urilen.h"
 
#include "flow.h"
#include "flow-var.h"
 
#include "util-debug.h"
#include "util-unittest.h"
#include "util-spm.h"
#include "util-print.h"
 
#include "app-layer.h"
 
#include "app-layer-htp.h"
#include "detect-http-uri.h"
#include "stream-tcp.h"
 
#ifdef UNITTESTS
static void DetectHttpUriRegisterTests(void);
#endif
static void DetectHttpUriSetupCallback(const DetectEngineCtx *de_ctx, Signature *s);
static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
        const DetectEngineTransforms *transforms,
        Flow *_f, const uint8_t _flow_flags,
        void *txv, const int list_id);
static InspectionBuffer *GetData2(DetectEngineThreadCtx *det_ctx,
        const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,
        const int list_id);
static int DetectHttpUriSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str);
static int DetectHttpRawUriSetup(DetectEngineCtx *, Signature *, const char *);
static void DetectHttpRawUriSetupCallback(const DetectEngineCtx *de_ctx, Signature *s);
static InspectionBuffer *GetRawData(DetectEngineThreadCtx *det_ctx,
        const DetectEngineTransforms *transforms,
        Flow *_f, const uint8_t _flow_flags,
        void *txv, const int list_id);
static int DetectHttpRawUriSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str);
 
static int g_http_raw_uri_buffer_id = 0;
static int g_http_uri_buffer_id = 0;
 
/**
 * \brief Registration function for keywords: http_uri and http.uri
 */
void DetectHttpUriRegister (void)
{
    /* http_uri content modifier */
    sigmatch_table[DETECT_HTTP_URI_CM].name = "http_uri";
    sigmatch_table[DETECT_HTTP_URI_CM].desc =
            "content modifier to match specifically and only on the HTTP uri-buffer";
    sigmatch_table[DETECT_HTTP_URI_CM].url = "/rules/http-keywords.html#http-uri-and-http-uri-raw";
    sigmatch_table[DETECT_HTTP_URI_CM].Setup = DetectHttpUriSetup;
#ifdef UNITTESTS
    sigmatch_table[DETECT_HTTP_URI_CM].RegisterTests = DetectHttpUriRegisterTests;
#endif
    sigmatch_table[DETECT_HTTP_URI_CM].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_CONTENT_MODIFIER;
    sigmatch_table[DETECT_HTTP_URI_CM].alternative = DETECT_HTTP_URI;
 
    /* http.uri sticky buffer */
    sigmatch_table[DETECT_HTTP_URI].name = "http.uri";
    sigmatch_table[DETECT_HTTP_URI].alias = "http.uri.normalized";
    sigmatch_table[DETECT_HTTP_URI].desc = "sticky buffer to match specifically and only on the normalized HTTP URI buffer";
    sigmatch_table[DETECT_HTTP_URI].url = "/rules/http-keywords.html#http-uri-and-http-uri-raw";
    sigmatch_table[DETECT_HTTP_URI].Setup = DetectHttpUriSetupSticky;
    sigmatch_table[DETECT_HTTP_URI].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER;
 
    DetectAppLayerInspectEngineRegister("http_uri", ALPROTO_HTTP1, SIG_FLAG_TOSERVER,
            HTP_REQUEST_PROGRESS_LINE, DetectEngineInspectBufferGeneric, GetData);
 
    DetectAppLayerMpmRegister("http_uri", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
            GetData, ALPROTO_HTTP1, HTP_REQUEST_PROGRESS_LINE);
 
    DetectAppLayerInspectEngineRegister("http_uri", ALPROTO_HTTP2, SIG_FLAG_TOSERVER,
            HTTP2StateDataClient, DetectEngineInspectBufferGeneric, GetData2);
 
    DetectAppLayerMpmRegister("http_uri", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
            GetData2, ALPROTO_HTTP2, HTTP2StateDataClient);
 
    DetectBufferTypeSetDescriptionByName("http_uri",
            "http request uri");
 
    DetectBufferTypeRegisterSetupCallback("http_uri",
            DetectHttpUriSetupCallback);
 
    DetectBufferTypeRegisterValidateCallback("http_uri", DetectUrilenValidateContent);
 
    g_http_uri_buffer_id = DetectBufferTypeGetByName("http_uri");
 
    /* http_raw_uri content modifier */
    sigmatch_table[DETECT_HTTP_RAW_URI].name = "http_raw_uri";
    sigmatch_table[DETECT_HTTP_RAW_URI].desc = "content modifier to match on the raw HTTP uri";
    sigmatch_table[DETECT_HTTP_RAW_URI].url = "/rules/http-keywords.html#http_uri-and-http_raw-uri";
    sigmatch_table[DETECT_HTTP_RAW_URI].Setup = DetectHttpRawUriSetup;
    sigmatch_table[DETECT_HTTP_RAW_URI].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_CONTENT_MODIFIER;
    sigmatch_table[DETECT_HTTP_RAW_URI].alternative = DETECT_HTTP_URI_RAW;
 
    /* http.uri.raw sticky buffer */
    sigmatch_table[DETECT_HTTP_URI_RAW].name = "http.uri.raw";
    sigmatch_table[DETECT_HTTP_URI_RAW].desc = "sticky buffer to match specifically and only on the raw HTTP URI buffer";
    sigmatch_table[DETECT_HTTP_URI_RAW].url = "/rules/http-keywords.html#http-uri-and-http-raw-uri";
    sigmatch_table[DETECT_HTTP_URI_RAW].Setup = DetectHttpRawUriSetupSticky;
    sigmatch_table[DETECT_HTTP_URI_RAW].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER;
 
    DetectAppLayerInspectEngineRegister("http_raw_uri", ALPROTO_HTTP1, SIG_FLAG_TOSERVER,
            HTP_REQUEST_PROGRESS_LINE, DetectEngineInspectBufferGeneric, GetRawData);
 
    DetectAppLayerMpmRegister("http_raw_uri", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
            GetRawData, ALPROTO_HTTP1, HTP_REQUEST_PROGRESS_LINE);
 
    // no difference between raw and decoded uri for HTTP2
    DetectAppLayerInspectEngineRegister("http_raw_uri", ALPROTO_HTTP2, SIG_FLAG_TOSERVER,
            HTTP2StateDataClient, DetectEngineInspectBufferGeneric, GetData2);
 
    DetectAppLayerMpmRegister("http_raw_uri", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
            GetData2, ALPROTO_HTTP2, HTTP2StateDataClient);
 
    DetectBufferTypeSetDescriptionByName("http_raw_uri",
            "raw http uri");
 
    DetectBufferTypeRegisterSetupCallback("http_raw_uri",
            DetectHttpRawUriSetupCallback);
 
    DetectBufferTypeRegisterValidateCallback("http_raw_uri", DetectUrilenValidateContent);
 
    g_http_raw_uri_buffer_id = DetectBufferTypeGetByName("http_raw_uri");
}
 
/**
 * \brief this function setups the http_uri modifier keyword used in the rule
 *
 * \param de_ctx   Pointer to the Detection Engine Context
 * \param s        Pointer to the Signature to which the current keyword belongs
 * \param str      Should hold an empty string always
 *
 * \retval  0 On success
 * \retval -1 On failure
 */
 
int DetectHttpUriSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
    return DetectEngineContentModifierBufferSetup(
            de_ctx, s, str, DETECT_HTTP_URI_CM, g_http_uri_buffer_id, ALPROTO_HTTP1);
}
 
static void DetectHttpUriSetupCallback(const DetectEngineCtx *de_ctx,
                                       Signature *s)
{
    SCLogDebug("callback invoked by %u", s->id);
    DetectUrilenApplyToContent(s, g_http_uri_buffer_id);
}
 
/**
 * \brief this function setup the http.uri keyword used in the rule
 *
 * \param de_ctx   Pointer to the Detection Engine Context
 * \param s        Pointer to the Signature to which the current keyword belongs
 * \param str      Should hold an empty string always
 *
 * \retval 0       On success
 */
static int DetectHttpUriSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
    if (SCDetectBufferSetActiveList(de_ctx, s, g_http_uri_buffer_id) < 0)
        return -1;
    if (DetectSignatureSetAppProto(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)
{
    SCEnter();
 
    InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
    if (!buffer->initialized) {
        htp_tx_t *tx = (htp_tx_t *)txv;
        bstr *request_uri_normalized = (bstr *)htp_tx_normalized_uri(tx);
        if (request_uri_normalized == NULL)
            return NULL;
 
        const uint32_t data_len = (uint32_t)bstr_len(request_uri_normalized);
        const uint8_t *data = bstr_ptr(request_uri_normalized);
 
        InspectionBufferSetupAndApplyTransforms(
                det_ctx, list_id, buffer, data, data_len, transforms);
    }
 
    return buffer;
}
 
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->initialized) {
        uint32_t b_len = 0;
        const uint8_t *b = NULL;
 
        if (SCHttp2TxGetUri(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 Sets up the http_raw_uri modifier keyword.
 *
 * \param de_ctx Pointer to the Detection Engine Context.
 * \param s      Pointer to the Signature to which the current keyword belongs.
 * \param arg    Should hold an empty string always.
 *
 * \retval  0 On success.
 * \retval -1 On failure.
 */
static int DetectHttpRawUriSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)
{
    return DetectEngineContentModifierBufferSetup(
            de_ctx, s, arg, DETECT_HTTP_RAW_URI, g_http_raw_uri_buffer_id, ALPROTO_HTTP1);
}
 
static void DetectHttpRawUriSetupCallback(const DetectEngineCtx *de_ctx,
                                          Signature *s)
{
    SCLogDebug("callback invoked by %u", s->id);
    DetectUrilenApplyToContent(s, g_http_raw_uri_buffer_id);
}
 
/**
 * \brief this function setup the http.uri.raw keyword used in the rule
 *
 * \param de_ctx   Pointer to the Detection Engine Context
 * \param s        Pointer to the Signature to which the current keyword belongs
 * \param str      Should hold an empty string always
 *
 * \retval 0       On success
 */
static int DetectHttpRawUriSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
    if (SCDetectBufferSetActiveList(de_ctx, s, g_http_raw_uri_buffer_id) < 0)
        return -1;
    if (DetectSignatureSetAppProto(s, ALPROTO_HTTP) < 0)
        return -1;
    return 0;
}
 
static InspectionBuffer *GetRawData(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->initialized) {
        htp_tx_t *tx = (htp_tx_t *)txv;
        if (unlikely(htp_tx_request_uri(tx) == NULL)) {
            return NULL;
        }
        const uint32_t data_len = (uint32_t)bstr_len(htp_tx_request_uri(tx));
        const uint8_t *data = bstr_ptr(htp_tx_request_uri(tx));
 
        InspectionBufferSetupAndApplyTransforms(
                det_ctx, list_id, buffer, data, data_len, transforms);
    }
 
    return buffer;
}
 
#ifdef UNITTESTS /* UNITTESTS */
#include "tests/detect-http-uri.c"
#endif /* UNITTESTS */
 
/**
 * @}
 */