From 6c68b07a673e307eb44a9442fa93c5e6d79f3b52 Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Mon, 28 Aug 2023 11:48:25 -0400
Subject: [PATCH] sfdnsres: ensure lp1 is not resolved

---
 src/core/hle/service/sockets/nsd.cpp      | 11 +++++++++--
 src/core/hle/service/sockets/sfdnsres.cpp | 12 ++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/core/hle/service/sockets/nsd.cpp b/src/core/hle/service/sockets/nsd.cpp
index bac21752a..491b76d48 100644
--- a/src/core/hle/service/sockets/nsd.cpp
+++ b/src/core/hle/service/sockets/nsd.cpp
@@ -19,6 +19,12 @@ enum class ServerEnvironmentType : u8 {
     Dp,
 };
 
+// This is nn::nsd::EnvironmentIdentifier
+struct EnvironmentIdentifier {
+    std::array<u8, 8> identifier;
+};
+static_assert(sizeof(EnvironmentIdentifier) == 0x8);
+
 NSD::NSD(Core::System& system_, const char* name) : ServiceFramework{system_, name} {
     // clang-format off
     static const FunctionInfo functions[] = {
@@ -101,8 +107,9 @@ void NSD::ResolveEx(HLERequestContext& ctx) {
 }
 
 void NSD::GetEnvironmentIdentifier(HLERequestContext& ctx) {
-    const std::string environment_identifier = "lp1";
-    ctx.WriteBuffer(environment_identifier);
+    constexpr EnvironmentIdentifier lp1 = {
+        .identifier = {'l', 'p', '1', '\0', '\0', '\0', '\0', '\0'}};
+    ctx.WriteBuffer(lp1);
 
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(ResultSuccess);
diff --git a/src/core/hle/service/sockets/sfdnsres.cpp b/src/core/hle/service/sockets/sfdnsres.cpp
index 22e4a6f49..c657c4efd 100644
--- a/src/core/hle/service/sockets/sfdnsres.cpp
+++ b/src/core/hle/service/sockets/sfdnsres.cpp
@@ -150,6 +150,12 @@ static std::pair<u32, GetAddrInfoError> GetHostByNameRequestImpl(HLERequestConte
     const std::string host = Common::StringFromBuffer(host_buffer);
     // For now, ignore options, which are in input buffer 1 for GetHostByNameRequestWithOptions.
 
+    // Prevent resolution of Nintendo servers
+    if (host.find("srv.nintendo.net") != std::string::npos) {
+        LOG_WARNING(Network, "Resolution of hostname {} requested, returning EAI_AGAIN", host);
+        return {0, GetAddrInfoError::AGAIN};
+    }
+
     auto res = Network::GetAddressInfo(host, /*service*/ std::nullopt);
     if (!res.has_value()) {
         return {0, Translate(res.error())};
@@ -261,6 +267,12 @@ static std::pair<u32, GetAddrInfoError> GetAddrInfoRequestImpl(HLERequestContext
     const auto host_buffer = ctx.ReadBuffer(0);
     const std::string host = Common::StringFromBuffer(host_buffer);
 
+    // Prevent resolution of Nintendo servers
+    if (host.find("srv.nintendo.net") != std::string::npos) {
+        LOG_WARNING(Network, "Resolution of hostname {} requested, returning EAI_AGAIN", host);
+        return {0, GetAddrInfoError::AGAIN};
+    }
+
     std::optional<std::string> service = std::nullopt;
     if (ctx.CanReadBuffer(1)) {
         const std::span<const u8> service_buffer = ctx.ReadBuffer(1);