pgsql: fix probing functions

Some non-pgsql traffic seen by Suricata is mistankenly identified as
pgsql, as the probing function is too generic. Now, if the parser sees
an unknown message type, even if it looks like pgsql, it will fail.

Bug OISF#6080

rust/src/pgsql/pgsql.rs

@@ -151,7 +151,7 @@ impl Default for PgsqlState {
         Self::new()
     }
 }
-    
+
 impl PgsqlState {
     pub fn new() -> Self {
         Self {
@@ -563,8 +563,20 @@ pub unsafe extern "C" fn rs_pgsql_probing_parser_ts(
     if input_len >= 1 && !input.is_null() {
 
         let slice: &[u8] = build_slice!(input, input_len as usize);
-        if probe_ts(slice) {
-            return ALPROTO_PGSQL;
+
+        match parser::parse_request(slice) {
+            Ok((_, request)) => {
+                if let PgsqlFEMessage::UnknownMessageType(_) = request {
+                    return ALPROTO_FAILED;
+                }
+                return ALPROTO_PGSQL;
+            }
+            Err(Err::Incomplete(_)) => {
+                return ALPROTO_UNKNOWN;
+            }
+            Err(_e) => {
+                return ALPROTO_FAILED;
+            }
         }
     }
     return ALPROTO_UNKNOWN;
@@ -584,7 +596,10 @@ pub unsafe extern "C" fn rs_pgsql_probing_parser_tc(
         }
 
         match parser::pgsql_parse_response(slice) {
-            Ok((_, _response)) => {
+            Ok((_, response)) => {
+                if let PgsqlBEMessage::UnknownMessageType(_) = response {
+                    return ALPROTO_FAILED;
+                }
                 return ALPROTO_PGSQL;
             }
             Err(Err::Incomplete(_)) => {