From e982dd50d0396499d7e83f929eb6b548d52cbd9f Mon Sep 17 00:00:00 2001
From: Philippe Antoine <pantoine@oisf.net>
Date: Thu, 29 Jan 2026 21:21:11 +0100
Subject: [PATCH] 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 | 15 +++++++++++++++
 src/app-layer-detect-proto.h |  2 ++
 src/app-layer-smtp.c         |  2 +-
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/app-layer-detect-proto.c b/src/app-layer-detect-proto.c
index 0be4bcfc39..5036589999 100644
--- a/src/app-layer-detect-proto.c
+++ b/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.
diff --git a/src/app-layer-detect-proto.h b/src/app-layer-detect-proto.h
index 276eeea736..4e9147ca40 100644
--- a/src/app-layer-detect-proto.h
+++ b/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
diff --git a/src/app-layer-smtp.c b/src/app-layer-smtp.c
index 00f9bc14ab..285c495f40 100644
--- a/src/app-layer-smtp.c
+++ b/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;