netcode-revival: trace the online-path XNet/Xam calls

Adds an 'xnet trace' log to the online-path functions (XNetGetTitleXnAddr,
XNetGetEthernetLinkStatus, QosListen/QosLookup, CreateKey, Connect,
GetConnectStatus, XamUserGetSigninState/Info, XamShowSigninUI, privilege)
gated on the xnet_trace cvar (default on during bring-up, rate-limited for
the polling signin-state calls). Running the game and clicking the online
flow now shows exactly which gate the party/EA path hits, so we can fix the
real check instead of guessing at the reverse-engineered globals.

src/kernel/xam/xam_net.cpp

@@ -15,6 +15,7 @@
 #include <cstring>
 
 #include <rex/chrono/clock.h>
+#include <rex/cvar.h>
 #include <rex/kernel/xam/module.h>
 #include <rex/kernel/xam/private.h>
 #include <rex/kernel/xboxkrnl/error.h>
@@ -48,6 +49,15 @@ namespace xam {
 using namespace rex::system;
 using namespace rex::system::xam;
 
+// netcode-revival: trace the online-path calls so a run shows exactly which
+// XNet/Xam gates the game hits (party/Ea Nation debugging). Default on during
+// the revival bring-up; disable with xnet_trace=false before any release.
+REXCVAR_DEFINE_BOOL(xnet_trace, true, "Kernel",
+                    "Log online-path XNet/Xam calls (netcode debugging)");
+bool XnetTrace() {
+  return REXCVAR_GET(xnet_trace);
+}
+
 // https://github.com/G91/TitanOffLine/blob/1e692d9bb9dfac386d08045ccdadf4ae3227bb5e/xkelib/xam/xamNet.h
 enum {
   XNCALLER_INVALID = 0x0,
@@ -498,6 +508,10 @@ u32 NetDll_XNetGetTitleXnAddr_entry(u32 caller, ppc_ptr_t<XNADDR> addr_ptr) {
   std::memset(addr_ptr->abOnline, 0, 20);
   // 0x60 = the game's "online" status bits (not the standard 0-3 enum; the
   // game checks (status & 0x60) everywhere it means "connected to LIVE").
+  if (XnetTrace()) {
+    REXLOG_INFO("xnet trace: XNetGetTitleXnAddr(caller={}) -> status 0x60 (online)",
+                caller);
+  }
   return 0x60;
 }
 
@@ -576,6 +590,10 @@ u32 NetDll_XNetGetEthernetLinkStatus_entry(u32 caller) {
   // machine only reaches the EA-Nation/online path when the link is up
   // (sub_82A1AAE8 returns the online server IP only if this is non-zero),
   // so returning 0 left it frozen on "connecting to EA Nation" forever.
+  if (XnetTrace()) {
+    REXLOG_INFO("xnet trace: XNetGetEthernetLinkStatus(caller={}) -> active 100Mbps",
+                caller);
+  }
   return XEthernetStatus::XNET_ETHERNET_LINK_ACTIVE |
          XEthernetStatus::XNET_ETHERNET_LINK_100MBPS;
 }
@@ -639,6 +657,10 @@ u32 NetDll_XNetQosListen_entry(u32 caller, mapped_void id, mapped_void data, u32
   (void)data_size;
   (void)r7;
   (void)flags;
+  if (XnetTrace()) {
+    REXLOG_INFO("xnet trace: XNetQosListen(caller={}, flags={}) -> ok (advertise)",
+                caller, flags);
+  }
   return 0;
 }
 
@@ -696,6 +718,11 @@ u32 NetDll_XNetQosLookup_entry(u32 caller, u32 cxna, mapped_void apxna, mapped_v
   }
   qos->count = qos->count_pending = n;
 
+  if (XnetTrace()) {
+    REXLOG_INFO("xnet trace: XNetQosLookup(caller={}) -> {} session(s) found",
+                caller, n);
+  }
+
   if (apxnqosResults) {
     *apxnqosResults = qos_guest;
   }
@@ -713,6 +740,9 @@ u32 NetDll_XNetCreateKey_entry(u32 caller, mapped_void key) {
   if (!key) {
     return X_ERROR_INVALID_PARAMETER;
   }
+  if (XnetTrace()) {
+    REXLOG_INFO("xnet trace: XNetCreateKey(caller={})", caller);
+  }
   uint8_t* out = static_cast<uint8_t*>(key);
   uint64_t r = XnetNextRand();
   for (int i = 0; i < 16; ++i) {
@@ -726,6 +756,9 @@ u32 NetDll_XNetCreateKey_entry(u32 caller, mapped_void key) {
 
 // netcode-revival: accept + (Phase 1) register the session key.
 u32 NetDll_XNetRegisterKey_entry(u32 caller, mapped_void key) {
+  if (XnetTrace()) {
+    REXLOG_INFO("xnet trace: XNetRegisterKey(caller={})", caller);
+  }
   (void)key;
   return 0;
 }
@@ -737,6 +770,10 @@ u32 NetDll_XNetUnregisterKey_entry(u32 caller, mapped_void key) {
 
 // netcode-revival: connecting to a peer is reported as established.
 u32 NetDll_XNetConnect_entry(u32 caller, ppc_ptr_t<XNADDR> xn_addr) {
+  if (XnetTrace()) {
+    REXLOG_INFO("xnet trace: XNetConnect(caller={}, peer=10.80.0.{})",
+                caller, xn_addr ? (ntohl(xn_addr->ina.s_addr) & 0xFFu) : 0);
+  }
   (void)xn_addr;
   return 0;
 }
@@ -744,6 +781,9 @@ u32 NetDll_XNetConnect_entry(u32 caller, ppc_ptr_t<XNADDR> xn_addr) {
 // https://learn.microsoft.com/en-us/previous-versions/windows/desktop/xna/xnetgetconnectstatus
 // INT XNetGetConnectStatus(const XNADDR* pxna, INT* pxncs)
 u32 NetDll_XNetGetConnectStatus_entry(u32 caller, ppc_ptr_t<XNADDR> xn_addr, mapped_void status_ptr) {
+  if (XnetTrace()) {
+    REXLOG_INFO("xnet trace: XNetGetConnectStatus(caller={}) -> CONNECTED", caller);
+  }
   (void)xn_addr;
   if (status_ptr) {
     const uint32_t connected = 2;  // XNET_CONNECT_STATUS_CONNECTED

src/kernel/xam/xam_user.cpp

@@ -43,6 +43,8 @@ using namespace rex::system::xam;
 
 extern std::atomic<int> xam_dialogs_shown_;
 
+REXCVAR_DECLARE(bool, xnet_trace);
+
 i32 XamUserGetXUID_entry(u32 user_index, u32 type_mask, mapped_u64 xuid_ptr) {
   assert_true(type_mask == 1 || type_mask == 2 || type_mask == 3 || type_mask == 4 ||
               type_mask == 7);
@@ -82,6 +84,17 @@ u32 XamUserGetSigninState_entry(u32 user_index) {
       signin_state = user_profile->signin_state();
     }
   }
+  if (REXCVAR_GET(xnet_trace)) {
+    // Rate-limited: the frontend polls this frequently.
+    static double last_log = 0.0;
+    const double now =
+        double(std::chrono::steady_clock::now().time_since_epoch().count()) / 1e9;
+    if (now - last_log >= 0.5) {
+      last_log = now;
+      REXLOG_INFO("xam trace: XamUserGetSigninState(user={}) -> {}", user_index,
+                  signin_state);
+    }
+  }
   return signin_state;
 }
 
@@ -113,6 +126,10 @@ i32 XamUserGetSigninInfo_entry(u32 user_index, u32 flags, ppc_ptr_t<X_USER_SIGNI
   info->xuid = user_profile->xuid();
   info->signin_state = user_profile->signin_state();
   rex::string::util_copy_truncating(info->name, user_profile->name(), rex::countof(info->name));
+  if (REXCVAR_GET(xnet_trace)) {
+    REXLOG_INFO("xam trace: XamUserGetSigninInfo(user={}, flags={}) -> signin_state={}",
+                user_index, flags, user_profile->signin_state());
+  }
   return X_E_SUCCESS;
 }
 
@@ -538,6 +555,8 @@ u32 XamUserAreUsersFriends_entry(u32 user_index, u32 unk1, u32 unk2, mapped_u32
 }
 
 u32 XamShowSigninUI_entry(u32 unk, u32 unk_mask) {
+  REXLOG_INFO("xam trace: XamShowSigninUI(unk={}, mask={}) - game asked for sign-in",
+              unk, unk_mask);
   // Mask values vary. Probably matching user types? Local/remote?
   KernelState* kernel_state = REX_KERNEL_STATE();