4 files changed, 52 insertions, 11 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 1662ec63d..e74e6a668 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -400,6 +400,7 @@ add_library(core STATIC
     hle/service/hid/controllers/xpad.h
     hle/service/lbl/lbl.cpp
     hle/service/lbl/lbl.h
+    hle/service/ldn/errors.h
     hle/service/ldn/ldn.cpp
     hle/service/ldn/ldn.h
     hle/service/ldr/ldr.cpp
diff --git a/src/core/hle/service/am/am.cpp b/src/core/hle/service/am/am.cpp
index bb77c2569..8e1fe9438 100644
--- a/src/core/hle/service/am/am.cpp
+++ b/src/core/hle/service/am/am.cpp
@@ -1047,20 +1047,21 @@ void IStorageAccessor::Write(Kernel::HLERequestContext& ctx) {
 
     const u64 offset{rp.Pop<u64>()};
     const std::vector<u8> data{ctx.ReadBuffer()};
+    const std::size_t size{std::min(data.size(), backing.GetSize() - offset)};
 
-    LOG_DEBUG(Service_AM, "called, offset={}, size={}", offset, data.size());
+    LOG_DEBUG(Service_AM, "called, offset={}, size={}", offset, size);
 
-    if (data.size() > backing.GetSize() - offset) {
+    if (offset > backing.GetSize()) {
         LOG_ERROR(Service_AM,
                   "offset is out of bounds, backing_buffer_sz={}, data_size={}, offset={}",
-                  backing.GetSize(), data.size(), offset);
+                  backing.GetSize(), size, offset);
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(ERR_SIZE_OUT_OF_BOUNDS);
         return;
     }
 
-    std::memcpy(backing.GetData().data() + offset, data.data(), data.size());
+    std::memcpy(backing.GetData().data() + offset, data.data(), size);
 
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(RESULT_SUCCESS);
@@ -1070,11 +1071,11 @@ void IStorageAccessor::Read(Kernel::HLERequestContext& ctx) {
     IPC::RequestParser rp{ctx};
 
     const u64 offset{rp.Pop<u64>()};
-    const std::size_t size{ctx.GetWriteBufferSize()};
+    const std::size_t size{std::min(ctx.GetWriteBufferSize(), backing.GetSize() - offset)};
 
     LOG_DEBUG(Service_AM, "called, offset={}, size={}", offset, size);
 
-    if (size > backing.GetSize() - offset) {
+    if (offset > backing.GetSize()) {
         LOG_ERROR(Service_AM, "offset is out of bounds, backing_buffer_sz={}, size={}, offset={}",
                   backing.GetSize(), size, offset);
 
diff --git a/src/core/hle/service/ldn/errors.h b/src/core/hle/service/ldn/errors.h
new file mode 100644
index 000000000..a718c5c66
--- /dev/null
+++ b/src/core/hle/service/ldn/errors.h
@@ -0,0 +1,13 @@
+// Copyright 2021 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/result.h"
+
+namespace Service::LDN {
+
+constexpr ResultCode ERROR_DISABLED{ErrorModule::LDN, 22};
+
+} // namespace Service::LDN
diff --git a/src/core/hle/service/ldn/ldn.cpp b/src/core/hle/service/ldn/ldn.cpp
index ee908f399..c630d93cd 100644
--- a/src/core/hle/service/ldn/ldn.cpp
+++ b/src/core/hle/service/ldn/ldn.cpp
@@ -6,6 +6,7 @@
 
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/result.h"
+#include "core/hle/service/ldn/errors.h"
 #include "core/hle/service/ldn/ldn.h"
 #include "core/hle/service/sm/sm.h"
 
@@ -103,7 +104,7 @@ public:
         : ServiceFramework{system_, "IUserLocalCommunicationService"} {
         // clang-format off
         static const FunctionInfo functions[] = {
-            {0, nullptr, "GetState"},
+            {0, &IUserLocalCommunicationService::GetState, "GetState"},
             {1, nullptr, "GetNetworkInfo"},
             {2, nullptr, "GetIpv4Address"},
             {3, nullptr, "GetDisconnectReason"},
@@ -138,13 +139,38 @@ public:
         RegisterHandlers(functions);
     }
 
-    void Initialize2(Kernel::HLERequestContext& ctx) {
+    void GetState(Kernel::HLERequestContext& ctx) {
         LOG_WARNING(Service_LDN, "(STUBBED) called");
-        // Result success seem make this services start network and continue.
-        // If we just pass result error then it will stop and maybe try again and again.
+
+        IPC::ResponseBuilder rb{ctx, 3};
+
+        // Indicate a network error, as we do not actually emulate LDN
+        rb.Push(static_cast<u32>(State::Error));
+
+        rb.Push(RESULT_SUCCESS);
+    }
+
+    void Initialize2(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_LDN, "called");
+
+        is_initialized = true;
+
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(RESULT_UNKNOWN);
+        rb.Push(RESULT_SUCCESS);
     }
+
+private:
+    enum class State {
+        None,
+        Initialized,
+        AccessPointOpened,
+        AccessPointCreated,
+        StationOpened,
+        StationConnected,
+        Error,
+    };
+
+    bool is_initialized{};
 };
 
 class LDNS final : public ServiceFramework<LDNS> {