From 7db52b4b2e8f2bf3f98aac5f148b7c2fdd4cc52b Mon Sep 17 00:00:00 2001
From: hieudoanm <hieumdoan@gmail.com>
Date: Mon, 10 Feb 2025 00:46:57 +0700
Subject: [PATCH] Update README

---
 README.md                        |   2 +-
 docs/README.md                   |   2 +-
 languages/cplusplus/Makefile     |   5 ++
 languages/cplusplus/README.md    |   1 +
 languages/cplusplus/example.http |   1 +
 languages/cplusplus/main.cpp     | 107 +++++++++++++++++++++++++++++++
 6 files changed, 116 insertions(+), 2 deletions(-)
 create mode 100644 languages/cplusplus/Makefile
 create mode 100644 languages/cplusplus/README.md
 create mode 100644 languages/cplusplus/example.http
 create mode 100644 languages/cplusplus/main.cpp

diff --git a/README.md b/README.md
index 1bb69ae..2fcfda9 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Reverse Proxy
 
-- C++ (In Progress)
+- [C++](https://cplusplus.com/)
 - [Go](https://go.dev/)
 - [Node.js](https://nodejs.org/en)
 - [Python](https://python.org)
diff --git a/docs/README.md b/docs/README.md
index 1bb69ae..2fcfda9 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -1,6 +1,6 @@
 # Reverse Proxy
 
-- C++ (In Progress)
+- [C++](https://cplusplus.com/)
 - [Go](https://go.dev/)
 - [Node.js](https://nodejs.org/en)
 - [Python](https://python.org)
diff --git a/languages/cplusplus/Makefile b/languages/cplusplus/Makefile
new file mode 100644
index 0000000..0764f29
--- /dev/null
+++ b/languages/cplusplus/Makefile
@@ -0,0 +1,5 @@
+build:
+	g++ main.cpp -o main
+
+start:
+	./main
diff --git a/languages/cplusplus/README.md b/languages/cplusplus/README.md
new file mode 100644
index 0000000..63c3dff
--- /dev/null
+++ b/languages/cplusplus/README.md
@@ -0,0 +1 @@
+# C++
diff --git a/languages/cplusplus/example.http b/languages/cplusplus/example.http
new file mode 100644
index 0000000..8b40776
--- /dev/null
+++ b/languages/cplusplus/example.http
@@ -0,0 +1 @@
+GET http://localhost:8080/?target=http://jsonplaceholder.typicode.com/todos/1
diff --git a/languages/cplusplus/main.cpp b/languages/cplusplus/main.cpp
new file mode 100644
index 0000000..2e4cebe
--- /dev/null
+++ b/languages/cplusplus/main.cpp
@@ -0,0 +1,107 @@
+#include <boost/beast.hpp>
+#include <boost/asio.hpp>
+#include <iostream>
+#include <string>
+
+namespace beast = boost::beast;
+namespace http = beast::http;
+namespace net = boost::asio;
+using tcp = net::ip::tcp;
+
+// Extract target host and path from query
+bool parse_target_url(const std::string& request, std::string& host, std::string& path) {
+    size_t pos = request.find("?target=http://");
+    if (pos == std::string::npos) return false;
+
+    std::string target = request.substr(pos + 9);
+    size_t path_start = target.find("/");
+    if (path_start == std::string::npos) {
+        host = target;
+        path = "/";
+    } else {
+        host = target.substr(0, path_start);
+        path = target.substr(path_start);
+    }
+    return true;
+}
+
+// Forward HTTP request to the target server
+std::string forward_request(const std::string& host, const std::string& path, net::io_context& ioc) {
+    try {
+        tcp::resolver resolver(ioc);
+        tcp::socket socket(ioc);
+
+        // Resolve domain and connect
+        auto endpoints = resolver.resolve(host, "80");
+        net::connect(socket, endpoints);
+
+        // Create HTTP GET request
+        http::request<http::string_body> req{http::verb::get, path, 11};
+        req.set(http::field::host, host);
+        req.set(http::field::user_agent, BOOST_BEAST_VERSION_STRING);
+
+        // Send request
+        http::write(socket, req);
+
+        // Receive response
+        beast::flat_buffer buffer;
+        http::response<http::dynamic_body> res;
+        http::read(socket, buffer, res);
+
+        // Convert response body to string
+        std::ostringstream response_stream;
+        response_stream << res;
+
+        return response_stream.str();
+    } catch (std::exception& e) {
+        return "HTTP/1.1 502 Bad Gateway\r\n\r\nError: " + std::string(e.what());
+    }
+}
+
+// Handle client requests
+void handle_client(tcp::socket client_socket) {
+    beast::flat_buffer buffer;
+    http::request<http::string_body> req;
+
+    try {
+        // Read HTTP request from client
+        http::read(client_socket, buffer, req);
+        std::string request_text = req.target().to_string();
+
+        // Extract target host & path from query
+        std::string host, path;
+        if (!parse_target_url(request_text, host, path)) {
+            std::string error_response = "HTTP/1.1 400 Bad Request\r\n\r\nMissing target URL";
+            http::write(client_socket, http::response<http::string_body>{http::status::bad_request, 11, error_response});
+            return;
+        }
+
+        // Forward request to target server
+        net::io_context ioc;
+        std::string response = forward_request(host, path, ioc);
+
+        // Send response back to client
+        http::write(client_socket, http::response<http::string_body>{http::status::ok, 11, response});
+    } catch (std::exception& e) {
+        std::cerr << "Error: " << e.what() << "\n";
+    }
+}
+
+// Main function to start the proxy server
+int main() {
+    try {
+        net::io_context ioc;
+        tcp::acceptor acceptor(ioc, {tcp::v4(), 8080});
+        std::cout << "Reverse Proxy running on port 8080...\n";
+
+        while (true) {
+            tcp::socket socket(ioc);
+            acceptor.accept(socket);
+            std::thread(handle_client, std::move(socket)).detach();
+        }
+    } catch (std::exception& e) {
+        std::cerr << "Error: " << e.what() << "\n";
+    }
+
+    return 0;
+}