Lib.Net: Proper resolver errors when isConnectedToNetwork is disabled (#4081)

* Force resolver errors when not connected to network

Error values are based on real hardware testing.
sceNetResolverGetError is based on libSceNet decompilation.

* Update net_resolver.h

src/core/libraries/network/net.cpp

@@ -887,6 +887,10 @@ int PS4_SYSV_ABI sceNetEpollWait(OrbisNetId epollid, OrbisNetEpollEvent* events,
             }
 
             file->resolver->Resolve();
+            if (file->resolver->resolution_error != ORBIS_OK) {
+                // Resolution failed, shouldn't appear.
+                continue;
+            }
 
             const auto it =
                 std::ranges::find_if(epoll->events, [&](auto& el) { return el.first == rid; });
@@ -1402,8 +1406,21 @@ int PS4_SYSV_ABI sceNetResolverDestroy(OrbisNetId resolverid) {
 }
 
 int PS4_SYSV_ABI sceNetResolverGetError(OrbisNetId resolverid, s32* status) {
-    LOG_ERROR(Lib_Net, "(STUBBED) called rid = {}", resolverid);
+    if (!status) {
-    *status = 0;
+        LOG_ERROR(Lib_Net, "status == nullptr");
+        *sceNetErrnoLoc() = ORBIS_NET_EINVAL;
+        return ORBIS_NET_ERROR_EINVAL;
+    }
+
+    auto file = FDTable::Instance()->GetResolver(resolverid);
+    if (!file) {
+        LOG_ERROR(Lib_Net, "invalid resolverid {}", resolverid);
+        *sceNetErrnoLoc() = ORBIS_NET_EBADF;
+        return ORBIS_NET_ERROR_EBADF;
+    }
+
+    *status = file->resolver->resolution_error;
+    LOG_INFO(Lib_Net, "called rid = {}, error = {:#x}", resolverid, static_cast<u32>(*status));
     return ORBIS_OK;
 }
 
@@ -1425,10 +1442,17 @@ int PS4_SYSV_ABI sceNetResolverStartNtoa(OrbisNetId resolverid, const char* host
 
     auto file = FDTable::Instance()->GetResolver(resolverid);
     if (!file) {
+        LOG_ERROR(Lib_Net, "invalid resolverid {}", resolverid);
         *sceNetErrnoLoc() = ORBIS_NET_EBADF;
         return ORBIS_NET_ERROR_EBADF;
     }
 
+    if (!Config::getIsConnectedToNetwork()) {
+        *sceNetErrnoLoc() = ORBIS_NET_RESOLVER_ENODNS;
+        file->resolver->resolution_error = ORBIS_NET_ERROR_RESOLVER_ENODNS;
+        return ORBIS_NET_ERROR_RESOLVER_ENODNS;
+    }
+
     if ((flags & ORBIS_NET_RESOLVER_ASYNC) != 0) {
         return file->resolver->ResolveAsync(hostname, addr, timeout, retry, flags);
     }

src/core/libraries/network/net_resolver.cpp

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "common/assert.h"
+#include "common/config.h"
 #include "common/singleton.h"
 #include "common/types.h"
 #include "core/libraries/error_codes.h"
@@ -26,11 +27,16 @@ int Resolver::ResolveAsync(const char* hostname, OrbisNetInAddr* addr, int timeo
 }
 
 void Resolver::Resolve() {
+    if (!Config::getIsConnectedToNetwork()) {
+        resolution_error = ORBIS_NET_ERROR_RESOLVER_ENODNS;
+        return;
+    }
+
     if (async_resolution) {
         auto* netinfo = Common::Singleton<NetUtil::NetUtilInternal>::Instance();
         auto ret = netinfo->ResolveHostname(async_resolution->hostname, async_resolution->addr);
-
+        // Resolver errors are stored as ORBIS_NET_ERROR values.
-        resolution_error = ret;
+        resolution_error = -ret | ORBIS_NET_ERROR_BASE;
     } else {
         LOG_ERROR(Lib_Net, "async resolution has not been set-up");
     }

src/core/libraries/network/net_resolver.h

@@ -18,6 +18,8 @@ public:
     int ResolveAsync(const char* hostname, OrbisNetInAddr* addr, int timeout, int retry, int flags);
     void Resolve();
 
+    int resolution_error = ORBIS_OK;
+
 private:
     struct AsyncResolution {
         const char* hostname;
@@ -31,7 +33,6 @@ private:
     int poolid;
     int flags;
     std::optional<AsyncResolution> async_resolution{};
-    int resolution_error = ORBIS_OK;
     std::mutex m_mutex;
 };