smtp: use configured FTP ports in probing parser

To allow users to configure more than port 21

Ticket: 6591

src/app-layer-detect-proto.c

@@ -460,6 +460,21 @@ static AppLayerProtoDetectProbingParserPort *AppLayerProtoDetectGetProbingParser
     SCReturnPtr(pp_port, "AppLayerProtoDetectProbingParserPort *");
 }
 
+bool AppLayerProtoDetectHasProbingParsers(uint8_t ipproto, uint16_t port, AppProto alproto)
+{
+    AppLayerProtoDetectProbingParserPort *p =
+            AppLayerProtoDetectGetProbingParsers(alpd_ctx.ctx_pp, ipproto, port);
+    if (p == NULL)
+        return false;
+    AppLayerProtoDetectProbingParserElement *dp = p->dp;
+    while (dp) {
+        if (dp->alproto == alproto) {
+            return true;
+        }
+        dp = dp->next;
+    }
+    return false;
+}
 
 /**
  * \brief Call the probing expectation to see if there is some for this flow.

src/app-layer-detect-proto.h

@@ -198,6 +198,8 @@ void AppLayerRegisterExpectationProto(uint8_t proto, AppProto alproto);
 
 void AppProtoDetectListNames(void);
 
+bool AppLayerProtoDetectHasProbingParsers(uint8_t ipproto, uint16_t port, AppProto alproto);
+
 /***** Unittests *****/
 
 #ifdef UNITTESTS

src/app-layer-smtp.c

@@ -1684,7 +1684,7 @@ static int SMTPStateGetEventInfoById(
 static AppProto SMTPClientProbingParserCheckPort(
         const Flow *f, uint8_t direction, const uint8_t *input, uint32_t len, uint8_t *rdir)
 {
-    if (f->dp == 21) {
+    if (AppLayerProtoDetectHasProbingParsers(IPPROTO_TCP, f->dp, ALPROTO_FTP)) {
         return ALPROTO_FAILED;
     }
     return ALPROTO_SMTP;