ndpi: use helpers to register packet keywords

Register ndpi-protocol and ndpi-risk through SCDetectHelperKeywordRegister
and install their packet callbacks with the new companion function. This
removes direct sigmatch_table writes while retaining the keyword metadata,
flags, setup functions, and match callbacks.

Note: Check the registration helper's UINT16_MAX failure result before installing
the packet callback.

Related to ticket: 7499

plugins/ndpi/ndpi.c

@@ -533,34 +533,36 @@ static void EveCallback(ThreadVars *tv, const Packet *p, Flow *f, SCJsonBuilder
 
 static void NdpInitRiskKeyword(void)
 {
-    /* SCSigTableAppLiteElmt and SCDetectHelperKeywordRegister don't yet
-     * support all the fields required to register the nDPI keywords,
-     * missing the (packet) Match callback,
-     * so we'll just register with an empty keyword specifier to get
-     * the ID, then fill in the ID. */
-    ndpi_protocol_keyword_id = SCDetectHelperNewKeywordId();
+    const SCSigTableAppLiteElmt protocol_kw = {
+        .name = "ndpi-protocol",
+        .desc = "match on the detected nDPI protocol",
+        .url = "/rules/ndpi-protocol.html",
+        .flags = SIGMATCH_QUOTES_OPTIONAL | SIGMATCH_HANDLE_NEGATION,
+        .Setup = DetectnDPIProtocolSetup,
+        .Free = DetectnDPIProtocolFree,
+    };
+    ndpi_protocol_keyword_id = SCDetectHelperKeywordRegister(&protocol_kw);
+    if (ndpi_protocol_keyword_id == UINT16_MAX) {
+        FatalError("Failed to register ndpi-protocol keyword");
+    }
+    SCDetectHelperKeywordPacketMatchRegister(
+            ndpi_protocol_keyword_id, DetectnDPIProtocolPacketMatch);
     SCLogDebug("Registered new ndpi-protocol keyword with ID %" PRIu32, ndpi_protocol_keyword_id);
 
-    sigmatch_table[ndpi_protocol_keyword_id].name = "ndpi-protocol";
-    sigmatch_table[ndpi_protocol_keyword_id].desc = "match on the detected nDPI protocol";
-    sigmatch_table[ndpi_protocol_keyword_id].url = "/rules/ndpi-protocol.html";
-    sigmatch_table[ndpi_protocol_keyword_id].Match = DetectnDPIProtocolPacketMatch;
-    sigmatch_table[ndpi_protocol_keyword_id].Setup = DetectnDPIProtocolSetup;
-    sigmatch_table[ndpi_protocol_keyword_id].Free = DetectnDPIProtocolFree;
-    sigmatch_table[ndpi_protocol_keyword_id].flags =
-            (SIGMATCH_QUOTES_OPTIONAL | SIGMATCH_HANDLE_NEGATION);
-
-    ndpi_risk_keyword_id = SCDetectHelperNewKeywordId();
+    const SCSigTableAppLiteElmt risk_kw = {
+        .name = "ndpi-risk",
+        .desc = "match on the detected nDPI risk",
+        .url = "/rules/ndpi-risk.html",
+        .flags = SIGMATCH_QUOTES_OPTIONAL | SIGMATCH_HANDLE_NEGATION,
+        .Setup = DetectnDPIRiskSetup,
+        .Free = DetectnDPIRiskFree,
+    };
+    ndpi_risk_keyword_id = SCDetectHelperKeywordRegister(&risk_kw);
+    if (ndpi_risk_keyword_id == UINT16_MAX) {
+        FatalError("Failed to register ndpi-risk keyword");
+    }
+    SCDetectHelperKeywordPacketMatchRegister(ndpi_risk_keyword_id, DetectnDPIRiskPacketMatch);
     SCLogDebug("Registered new ndpi-risk keyword with ID %" PRIu32, ndpi_risk_keyword_id);
-
-    sigmatch_table[ndpi_risk_keyword_id].name = "ndpi-risk";
-    sigmatch_table[ndpi_risk_keyword_id].desc = "match on the detected nDPI risk";
-    sigmatch_table[ndpi_risk_keyword_id].url = "/rules/ndpi-risk.html";
-    sigmatch_table[ndpi_risk_keyword_id].Match = DetectnDPIRiskPacketMatch;
-    sigmatch_table[ndpi_risk_keyword_id].Setup = DetectnDPIRiskSetup;
-    sigmatch_table[ndpi_risk_keyword_id].Free = DetectnDPIRiskFree;
-    sigmatch_table[ndpi_risk_keyword_id].flags =
-            (SIGMATCH_QUOTES_OPTIONAL | SIGMATCH_HANDLE_NEGATION);
 }
 
 static void NdpiInit(void)