HttpProxyService: Forward https, modify http

UmlautAdaptarr/Services/HttpProxyService.cs

@@ -1,47 +1,78 @@
 using System.Net;
+using System.Net.Sockets;
+using System.Text;
 
 namespace UmlautAdaptarr.Services
 {
     public class HttpProxyService : IHostedService
     {
-        private HttpListener _listener;
+        private TcpListener _listener;
-        private readonly IHttpClientFactory _clientFactory;
         private readonly ILogger<HttpProxyService> _logger;
-        private const int PROXY_PORT = 5006; // TODO move to appsettings.json
+        private readonly int _proxyPort = 5006; // TODO move to appsettings.json
+        private readonly IHttpClientFactory _clientFactory;
 
-        public HttpProxyService(IHttpClientFactory clientFactory, ILogger<HttpProxyService> logger)
+        public HttpProxyService(ILogger<HttpProxyService> logger, IHttpClientFactory clientFactory)
         {
-            _clientFactory = clientFactory;
             _logger = logger;
+            _clientFactory = clientFactory;
         }
 
-        private async Task HandleRequests()
+        private async Task HandleRequests(CancellationToken stoppingToken)
         {
-            while (_listener.IsListening)
+            while (!stoppingToken.IsCancellationRequested)
             {
+                var clientSocket = await _listener.AcceptSocketAsync();
+                _ = Task.Run(() => ProcessRequest(clientSocket), stoppingToken);
+            }
+        }
+
+        private async Task ProcessRequest(Socket clientSocket)
+        {
+            using var clientStream = new NetworkStream(clientSocket, ownsSocket: true);
+            var buffer = new byte[8192];
+            var bytesRead = await clientStream.ReadAsync(buffer, 0, buffer.Length);
+            var requestString = Encoding.ASCII.GetString(buffer, 0, bytesRead);
+
+            if (requestString.StartsWith("CONNECT"))
+            {
+                // Handle HTTPS CONNECT request
+                await HandleHttpsConnect(requestString, clientStream, clientSocket);
+            }
+            else
+            {
+                // Handle HTTP request
+                await HandleHttp(requestString, clientStream, clientSocket);
+            }
+        }
+
+        private async Task HandleHttpsConnect(string requestString, NetworkStream clientStream, Socket clientSocket)
+        {
+            var targetInfo = ParseTargetInfo(requestString);
+            if (targetInfo.host != "prowlarr.servarr.com")
+            {
+                _logger.LogWarning($"Indexer {targetInfo.host} needs to be set to http:// instead of https://");
+            }
+            using var targetSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
             try
             {
-                    var context = await _listener.GetContextAsync();
+                await targetSocket.ConnectAsync(targetInfo.host, targetInfo.port);
-                    await ProcessRequest(context);
+                await clientStream.WriteAsync(Encoding.ASCII.GetBytes("HTTP/1.1 200 Connection Established\r\n\r\n"));
+                using var targetStream = new NetworkStream(targetSocket, ownsSocket: true);
+                await RelayTraffic(clientStream, targetStream);
             }
             catch (Exception ex)
             {
-                    _logger.LogError($"Error handling request: {ex.Message}");
+                _logger.LogError($"Failed to connect to target: {ex.Message}");
-                }
+                clientSocket.Close();
             }
         }
 
-        private async Task ProcessRequest(HttpListenerContext context)
+        private async Task HandleHttp(string requestString, NetworkStream clientStream, Socket clientSocket)
         {
-            var request = context.Request;
-            var response = context.Response;
-
             try
             {
-                var originalUri = new Uri(request.RawUrl);
+                var uri = new Uri(requestString.Split(' ')[1]);
-                var modifiedUri = "http://localhost:5005/_/" + originalUri.Host + originalUri.PathAndQuery; // TODO read port from appsettings?
+                var modifiedUri = $"http://localhost:5005/_/{uri.Host}{uri.PathAndQuery}";  // TODO read port from appsettings?
-
-                // Act as a proxy and forward the modified request to internal endpoints
                 using var client = _clientFactory.CreateClient();
                 var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, modifiedUri);
                 var result = await client.SendAsync(httpRequestMessage);
@@ -49,36 +80,60 @@ namespace UmlautAdaptarr.Services
                 if (result.IsSuccessStatusCode)
                 {
                     var responseData = await result.Content.ReadAsByteArrayAsync();
-                    response.ContentLength64 = responseData.Length;
+                    await clientStream.WriteAsync(Encoding.ASCII.GetBytes($"HTTP/1.1 200 OK\r\nContent-Length: {responseData.Length}\r\n\r\n"));
-                    await response.OutputStream.WriteAsync(responseData);
+                    await clientStream.WriteAsync(responseData);
                 }
                 else
                 {
-                    response.StatusCode = (int)result.StatusCode;
+                    await clientStream.WriteAsync(Encoding.ASCII.GetBytes($"HTTP/1.1 {result.StatusCode}\r\n\r\n"));
                 }
             }
             catch (Exception ex)
             {
                 _logger.LogError($"HTTP Proxy error: {ex.Message}");
-                response.StatusCode = 500;
+                await clientStream.WriteAsync(Encoding.ASCII.GetBytes("HTTP/1.1 500 Internal Server Error\r\n\r\n"));
             }
             finally
             {
-                response.OutputStream.Close();
+                clientSocket.Close();
             }
         }
+
+        private (string host, int port) ParseTargetInfo(string requestLine)
+        {
+            var parts = requestLine.Split(' ')[1].Split(':');
+            return (parts[0], int.Parse(parts[1]));
+        }
+
+        private async Task RelayTraffic(NetworkStream clientStream, NetworkStream targetStream)
+        {
+            var clientToTargetTask = RelayStream(clientStream, targetStream);
+            var targetToClientTask = RelayStream(targetStream, clientStream);
+            await Task.WhenAll(clientToTargetTask, targetToClientTask);
+        }
+
+        private async Task RelayStream(NetworkStream input, NetworkStream output)
+        {
+            byte[] buffer = new byte[8192];
+            int bytesRead;
+            while ((bytesRead = await input.ReadAsync(buffer.AsMemory(0, buffer.Length))) > 0)
+            {
+                await output.WriteAsync(buffer.AsMemory(0, bytesRead));
+                await output.FlushAsync();
+            }
+        }
+
         public Task StartAsync(CancellationToken cancellationToken)
         {
-            _listener = new HttpListener();
+            _listener = new TcpListener(IPAddress.Any, _proxyPort);
-            _listener.Prefixes.Add($"http://*:{PROXY_PORT}/");
             _listener.Start();
-            Task.Run(HandleRequests, cancellationToken);
+            Task.Run(() => HandleRequests(cancellationToken), cancellationToken);
             return Task.CompletedTask;
         }
+
         public Task StopAsync(CancellationToken cancellationToken)
         {
             _listener.Stop();
-            _listener.Close();
             return Task.CompletedTask;
         }
     }