firewall: share the generic app hook name helper

Mapping an app-layer progress state to its generic request-/response-
hook alias was hardcoded in multiple places.

This commit adds a wrapper to unify it to a single function.
It returns the config-form (hyphenated) name, or NULL for an
intermediate state.

Ticket: 8770
(cherry picked from commit 1aa0259876)

src/detect-engine-analyzer.c

@@ -2110,11 +2110,8 @@ int FirewallAnalyzer(const DetectEngineCtx *de_ctx)
             const char *name =
                     AppLayerParserGetStateNameById(IPPROTO_TCP, a, state, STREAM_TOSERVER);
             if (name == NULL) {
-                if (state == 0)
-                    name = "request-started";
-                else if (state == complete_state_ts)
-                    name = "request-complete";
-                else
+                name = DetectFirewallAppGenericHookName(state, complete_state_ts, STREAM_TOSERVER);
+                if (name == NULL)
                     name = "unknown";
             }
 
@@ -2136,11 +2133,8 @@ int FirewallAnalyzer(const DetectEngineCtx *de_ctx)
             const char *name =
                     AppLayerParserGetStateNameById(IPPROTO_TCP, a, state, STREAM_TOCLIENT);
             if (name == NULL) {
-                if (state == 0)
-                    name = "response-started";
-                else if (state == complete_state_tc)
-                    name = "response-complete";
-                else
+                name = DetectFirewallAppGenericHookName(state, complete_state_tc, STREAM_TOCLIENT);
+                if (name == NULL)
                     name = "unknown";
             }
             char table_name[128];

src/detect-parse.c

@@ -1141,6 +1141,20 @@ static bool IsBuiltIn(const char *n)
     return false;
 }
 
+/**
+ * \brief Generic start/complete hook alias for an app progress state, in config
+ *        form (hyphens), or NULL for intermediate states.
+ */
+const char *DetectFirewallAppGenericHookName(
+        const uint8_t state, const uint8_t complete_state, const int direction)
+{
+    if (state == 0)
+        return (direction == STREAM_TOSERVER) ? "request-started" : "response-started";
+    if (state == complete_state)
+        return (direction == STREAM_TOSERVER) ? "request-complete" : "response-complete";
+    return NULL;
+}
+
 /** \brief register app hooks as generic lists
  *
  *  Register each hook in each app protocol as:

src/detect-parse.h

@@ -118,6 +118,9 @@ void DetectRegisterAppLayerHookLists(void);
 
 const char *ActionScopeToString(enum ActionScope s);
 
+const char *DetectFirewallAppGenericHookName(
+        const uint8_t state, const uint8_t complete_state, const int direction);
+
 struct DetectFirewallPolicy;
 void DetectFirewallPolicyToString(const struct DetectFirewallPolicy *p, char *out, size_t out_size);
 int DetectFirewallInitDefaultPolicies(DetectEngineCtx *);