From 0c710269dad33dab3c954525f3bba2eea1e4aaf8 Mon Sep 17 00:00:00 2001
From: Federico Cecchetto <fedecek3@gmail.com>
Date: Sat, 26 Feb 2022 16:07:45 +0100
Subject: [PATCH] Fix getaddrinfo hook

---
 src/client/component/demonware.cpp | 35 +++++++++++++++++++++++++-----
 src/common/utils/memory.cpp        |  8 +++++++
 src/common/utils/memory.hpp        |  2 ++
 3 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/src/client/component/demonware.cpp b/src/client/component/demonware.cpp
index 7d4c5b56..b745023b 100644
--- a/src/client/component/demonware.cpp
+++ b/src/client/component/demonware.cpp
@@ -129,19 +129,43 @@ namespace demonware
 					server = udp_servers.find(name);
 				}
 
-				const auto result = getaddrinfo(name, service, hints, res);
-
 				if (!server)
 				{
-					return result;
+					return getaddrinfo(name, service, hints, res);
 				}
 
-				auto address = reinterpret_cast<sockaddr_in*>(res[0]->ai_addr);
-				address->sin_addr.s_addr = server->get_address();
+				const auto address = utils::memory::get_allocator()->allocate<sockaddr>();
+				const auto ai = utils::memory::get_allocator()->allocate<addrinfo>();
+
+				auto in_addr = reinterpret_cast<sockaddr_in*>(address);
+				in_addr->sin_addr.s_addr = server->get_address();
+				in_addr->sin_family = AF_INET;
+
+				ai->ai_family = AF_INET;
+				ai->ai_socktype = SOCK_STREAM;
+				ai->ai_addr = address;
+				ai->ai_addrlen = sizeof(sockaddr);
+				ai->ai_next = nullptr;
+				ai->ai_flags = 0;
+				ai->ai_protocol = 0;
+				ai->ai_canonname = const_cast<char*>(name);
+
+				*res = ai;
 
 				return 0;
 			}
 
+			void freeaddrinfo_stub(addrinfo* ai)
+			{
+				if (!utils::memory::get_allocator()->find(ai))
+				{
+					return freeaddrinfo(ai);
+				}
+
+				utils::memory::get_allocator()->free(ai->ai_addr);
+				utils::memory::get_allocator()->free(ai);
+			}
+
 			int getpeername_stub(const SOCKET s, sockaddr* addr, socklen_t* addrlen)
 			{
 				auto* server = find_server(s);
@@ -500,6 +524,7 @@ namespace demonware
 				if (function == "#20") return io::sendto_stub;
 				if (function == "#52") return io::gethostbyname_stub;
 				if (function == "getaddrinfo") return io::getaddrinfo_stub;
+				if (function == "freeaddrinfo") return io::freeaddrinfo_stub;
 			}
 
 			if (function == "InternetGetConnectedState")
diff --git a/src/common/utils/memory.cpp b/src/common/utils/memory.cpp
index 52d46771..99a03916 100644
--- a/src/common/utils/memory.cpp
+++ b/src/common/utils/memory.cpp
@@ -62,6 +62,14 @@ namespace utils
 		return data;
 	}
 
+	bool memory::allocator::find(const void* data)
+	{
+		std::lock_guard _(this->mutex_);
+
+		const auto j = std::find(this->pool_.begin(), this->pool_.end(), data);
+		return j != this->pool_.end();
+	}
+
 	void* memory::allocate(const size_t length)
 	{
 		return calloc(length, 1);
diff --git a/src/common/utils/memory.hpp b/src/common/utils/memory.hpp
index 5af5645e..01f9554f 100644
--- a/src/common/utils/memory.hpp
+++ b/src/common/utils/memory.hpp
@@ -37,6 +37,8 @@ namespace utils
 
 			char* duplicate_string(const std::string& string);
 
+			bool find(const void* data);
+
 		private:
 			std::mutex mutex_;
 			std::vector<void*> pool_;