detect: add http.user_agent sticky buffer

diff --git a/src/detect-engine-hua.c b/src/detect-engine-hua.c
index 1e9cd0c934cea2fe91bc16f3257617186fe5371c..613c3bc940226bd22daf46f61622ef282dca6ceb 100644 (file)
--- a/src/detect-engine-hua.c
+++ b/src/detect-engine-hua.c
@@ -61,97 +61,6 @@
 #include "detect-engine-hua.h"
 #include "util-validate.h"
 
-/** \brief HTTP UA Mpm prefilter callback
- *
- *  \param det_ctx detection engine thread ctx
- *  \param p packet to inspect
- *  \param f flow to inspect
- *  \param txv tx to inspect
- *  \param pectx inspection context
- */
-static void PrefilterTxUA(DetectEngineThreadCtx *det_ctx, const void *pectx,
-        Packet *p, Flow *f, void *txv,
-        const uint64_t idx, const uint8_t flags)
-{
-    SCEnter();
-
-    const MpmCtx *mpm_ctx = (MpmCtx *)pectx;
-    htp_tx_t *tx = (htp_tx_t *)txv;
-
-    if (tx->request_headers == NULL)
-        return;
-
-    htp_header_t *h = (htp_header_t *)htp_table_get_c(tx->request_headers,
-                                                      "User-Agent");
-    if (h == NULL || h->value == NULL) {
-        SCLogDebug("HTTP UA header not present in this request");
-        return;
-    }
-
-    const uint32_t buffer_len = bstr_len(h->value);
-    const uint8_t *buffer = bstr_ptr(h->value);
-
-    if (buffer_len >= mpm_ctx->minlen) {
-        (void)mpm_table[mpm_ctx->mpm_type].Search(mpm_ctx,
-                &det_ctx->mtcu, &det_ctx->pmq, buffer, buffer_len);
-    }
-}
-
-int PrefilterTxUARegister(DetectEngineCtx *de_ctx,
-        SigGroupHead *sgh, MpmCtx *mpm_ctx)
-{
-    SCEnter();
-
-    return PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxUA,
-        ALPROTO_HTTP, HTP_REQUEST_HEADERS,
-        mpm_ctx, NULL, "http_user_agent");
-}
-
-/**
- * \brief Do the http_user_agent content inspection for a signature.
- *
- * \param de_ctx  Detection engine context.
- * \param det_ctx Detection engine thread context.
- * \param s       Signature to inspect.
- * \param f       Flow.
- * \param flags   App layer flags.
- * \param state   App layer state.
- *
- * \retval 0 No match.
- * \retval 1 Match.
- */
-int DetectEngineInspectHttpUA(ThreadVars *tv,
-        DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx,
-        const Signature *s, const SigMatchData *smd,
-        Flow *f, uint8_t flags, void *alstate, void *txv, uint64_t tx_id)
-{
-    htp_tx_t *tx = (htp_tx_t *)txv;
-    htp_header_t *h = (htp_header_t *)htp_table_get_c(tx->request_headers,
-                                                      "User-Agent");
-    if (h == NULL) {
-        SCLogDebug("HTTP user agent header not present in this request");
-        goto end;
-    }
-
-    det_ctx->buffer_offset = 0;
-    det_ctx->discontinue_matching = 0;
-    det_ctx->inspection_recursion_counter = 0;
-    int r = DetectEngineContentInspection(de_ctx, det_ctx, s, smd,
-                                          f,
-                                          (uint8_t *)bstr_ptr(h->value),
-                                          bstr_len(h->value),
-                                          0, DETECT_CI_FLAGS_SINGLE,
-                                          DETECT_ENGINE_CONTENT_INSPECTION_MODE_STATE, NULL);
-    if (r == 1)
-        return DETECT_ENGINE_INSPECT_SIG_MATCH;
-
- end:
-    if (AppLayerParserGetStateProgress(IPPROTO_TCP, ALPROTO_HTTP, tx, flags) > HTP_REQUEST_HEADERS)
-        return DETECT_ENGINE_INSPECT_SIG_CANT_MATCH;
-    else
-        return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
-}
-
 /***********************************Unittests**********************************/
 
 #ifdef UNITTESTS

diff --git a/src/detect-engine-register.h b/src/detect-engine-register.h
index e9585ef38ba6cfcb324359bb3846049159a9ed05..462e87332b5ff895204f8ad43dd0077fa3f7902c 100644 (file)
--- a/src/detect-engine-register.h
+++ b/src/detect-engine-register.h
@@ -133,6 +133,7 @@ enum {
     DETECT_AL_HTTP_STAT_MSG,
     DETECT_AL_HTTP_STAT_CODE,
     DETECT_AL_HTTP_USER_AGENT,
+    DETECT_HTTP_UA,
     DETECT_AL_HTTP_HOST,
     DETECT_AL_HTTP_RAW_HOST,
     DETECT_AL_HTTP_REQUEST_LINE,

diff --git a/src/detect-http-ua.c b/src/detect-http-ua.c
index 1e43f48ee8d2cfcc0dc0887304196269f095f77d..30432c7c178aeb06db2f201950bd21e709218960 100644 (file)
--- a/src/detect-http-ua.c
+++ b/src/detect-http-ua.c
@@ -39,6 +39,7 @@
 #include "detect-engine.h"
 #include "detect-engine-mpm.h"
 #include "detect-engine-state.h"
+#include "detect-engine-prefilter.h"
 #include "detect-content.h"
 #include "detect-pcre.h"
 
@@ -62,26 +63,39 @@
 static int DetectHttpUASetup(DetectEngineCtx *, Signature *, const char *);
 static void DetectHttpUARegisterTests(void);
 static int g_http_ua_buffer_id = 0;
+static int DetectHttpUserAgentSetup(DetectEngineCtx *, Signature *, const char *);
+static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms,
+        Flow *_f, const uint8_t _flow_flags,
+        void *txv, const int list_id);
 
 /**
  * \brief Registers the keyword handlers for the "http_user_agent" keyword.
  */
 void DetectHttpUARegister(void)
 {
+    /* http_user_agent content modifier */
     sigmatch_table[DETECT_AL_HTTP_USER_AGENT].name = "http_user_agent";
     sigmatch_table[DETECT_AL_HTTP_USER_AGENT].desc = "content modifier to match only on the HTTP User-Agent header";
     sigmatch_table[DETECT_AL_HTTP_USER_AGENT].url = DOC_URL DOC_VERSION "/rules/http-keywords.html#http-user-agent";
     sigmatch_table[DETECT_AL_HTTP_USER_AGENT].Setup = DetectHttpUASetup;
     sigmatch_table[DETECT_AL_HTTP_USER_AGENT].RegisterTests = DetectHttpUARegisterTests;
-
     sigmatch_table[DETECT_AL_HTTP_USER_AGENT].flags |= SIGMATCH_NOOPT;
 
-    DetectAppLayerMpmRegister("http_user_agent", SIG_FLAG_TOSERVER, 2,
-            PrefilterTxUARegister);
+    /* http.user_agent sticky buffer */
+    sigmatch_table[DETECT_HTTP_UA].name = "http.user_agent";
+    sigmatch_table[DETECT_HTTP_UA].desc = "sticky buffer to match specifically and only on the HTTP User Agent buffer";
+    sigmatch_table[DETECT_HTTP_UA].url = DOC_URL DOC_VERSION "/rules/http-keywords.html#http-user-agent";
+    sigmatch_table[DETECT_HTTP_UA].Setup = DetectHttpUserAgentSetup;
+    sigmatch_table[DETECT_HTTP_UA].flags |= SIGMATCH_NOOPT;
+
+    DetectAppLayerInspectEngineRegister2("http_user_agent", ALPROTO_HTTP,
+            SIG_FLAG_TOSERVER, HTP_REQUEST_HEADERS,
+            DetectEngineInspectBufferGeneric, GetData);
 
-    DetectAppLayerInspectEngineRegister("http_user_agent",
-            ALPROTO_HTTP, SIG_FLAG_TOSERVER, HTP_REQUEST_HEADERS,
-            DetectEngineInspectHttpUA);
+    DetectAppLayerMpmRegister2("http_user_agent", SIG_FLAG_TOSERVER, 2,
+            PrefilterGenericMpmRegister, GetData, ALPROTO_HTTP,
+            HTP_REQUEST_HEADERS);
 
     DetectBufferTypeSetDescriptionByName("http_user_agent",
             "http user agent");
@@ -110,6 +124,51 @@ int DetectHttpUASetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)
                                                   ALPROTO_HTTP);
 }
 
+/**
+ * \brief this function setup the http.user_agent 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 DetectHttpUserAgentSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
+{
+    if (DetectBufferSetActiveList(s, g_http_ua_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)
+{
+    InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
+    if (buffer->inspect == NULL) {
+        htp_tx_t *tx = (htp_tx_t *)txv;
+
+        if (tx->request_headers == NULL)
+            return NULL;
+
+        htp_header_t *h = (htp_header_t *)htp_table_get_c(tx->request_headers,
+                "User-Agent");
+        if (h == NULL || h->value == NULL) {
+            SCLogDebug("HTTP UA header not present in this request");
+            return NULL;
+        }
+
+        const uint32_t data_len = bstr_len(h->value);
+        const uint8_t *data = bstr_ptr(h->value);
+
+        InspectionBufferSetup(buffer, data, data_len);
+        InspectionBufferApplyTransforms(buffer, transforms);
+    }
+
+    return buffer;
+}
 /************************************Unittests*********************************/
 
 #ifdef UNITTESTS