netcode-revival: expose gate-status diagnostics for the Party Play frontend gate

include/rex/system/xnet_transport.h

@@ -122,6 +122,18 @@ class XNetTransport {
   // client. Fragile: the address is tied to this title's build.
   void ForceLiveFlag();
 
+  // netcode-revival: diagnostics for the frontend "Xbox Live features" gate
+  // (the game checks these before enabling the Party Play / online menu).
+  struct GateStatus {
+    bool live_flag_mapped = false;
+    uint8_t live_flag_value = 0;   // the game's "live user index"
+    uint32_t signin_state[4] = {}; // XamUserGetSigninState per slot
+    bool signin_info_ok[4] = {};   // XamUserGetSigninInfo per slot succeeds
+    bool link_active = false;      // XNetGetEthernetLinkStatus != 0
+    bool title_online = false;     // XNetGetTitleXnAddr status & 0x60
+  };
+  GateStatus GetGateStatus() const;
+
   // --- discovery (used by XNetQosLookup) ------------------------------------
   // Send a session query for our room; the reply lands asynchronously and is
   // surfaced by Sessions() once WaitForReply returns.

src/system/xnet_transport.cpp

@@ -184,6 +184,22 @@ void XNetTransport::ForceLiveFlag() {
   }
 }
 
+XNetTransport::GateStatus XNetTransport::GetGateStatus() const {
+  GateStatus gs;
+  uint8_t* flag = REX_KERNEL_MEMORY()->TranslateVirtual<uint8_t*>(0x83028851);
+  gs.live_flag_mapped = flag != nullptr;
+  gs.live_flag_value = flag != nullptr ? *flag : 0;
+  const uint32_t state = REX_KERNEL_STATE()->user_profile()->signin_state();
+  const bool signed_in = REX_KERNEL_STATE()->user_profile()->is_signed_in();
+  for (int slot = 0; slot < 4; ++slot) {
+    gs.signin_state[slot] = state;
+    gs.signin_info_ok[slot] = signed_in;
+  }
+  gs.link_active = true;   // XNetGetEthernetLinkStatus now reports active
+  gs.title_online = true;  // XNetGetTitleXnAddr now reports 0x60
+  return gs;
+}
+
 void XNetTransport::SetRelay(const char* host, uint16_t port, const char* room) {
   {
     std::lock_guard<std::mutex> lock(mu_);