support online pac, see https://github.com/shadowsocks/shadowsocks-csharp/issues/163

shadowsocks-csharp/Controller/PACServer.cs

@@ -71,7 +71,10 @@ namespace Shadowsocks.Controller
                 }
                 if (hostMatch && pathMatch)
                 {
-                    SendResponse(firstPacket, length, socket, useSocks);
+                    if (_config.useOnlinePac && !string.IsNullOrEmpty(_config.pacUrl))
+                        RedirectToOnlinePAC(firstPacket, length, socket, useSocks);
+                    else
+                        SendResponse(firstPacket, length, socket, useSocks);
                     return true;
                 }
                 return false;
@@ -121,6 +124,30 @@ namespace Shadowsocks.Controller
             }
         }
 
+        private void RedirectToOnlinePAC(byte[] firstPacket, int length, Socket socket, bool useSocks)
+        {
+            try
+            {
+                string friendlyMessage = "Redirect to online pac " + _config.pacUrl;
+                string text = String.Format(@"HTTP/1.1 302 Found
+Server: Shadowsocks
+Content-Type: text/html; charset=utf-8
+Location: {0}
+Content-Length: {1}
+Connection: Close
+
+", _config.pacUrl, System.Text.Encoding.UTF8.GetBytes(friendlyMessage).Length) + friendlyMessage;
+                byte[] response = System.Text.Encoding.UTF8.GetBytes(text);
+                socket.BeginSend(response, 0, response.Length, 0, new AsyncCallback(SendCallback), socket);
+                Util.Utils.ReleaseMemory();
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine(e);
+                socket.Close();
+            }
+        }
+
         public void SendResponse(byte[] firstPacket, int length, Socket socket, bool useSocks)
         {
             try

shadowsocks-csharp/Controller/ShadowsocksController.cs

@@ -192,6 +192,28 @@ namespace Shadowsocks.Controller
             }
         }
 
+        public void SavePACUrl(string pacUrl)
+        {
+            _config.pacUrl = pacUrl;
+            UpdateSystemProxy();
+            SaveConfig(_config);
+            if (ConfigChanged != null)
+            {
+                ConfigChanged(this, new EventArgs());
+            }
+        }
+
+        public void UseOnlinePAC(bool useOnlinePac)
+        {
+            _config.useOnlinePac = useOnlinePac;
+            UpdateSystemProxy();
+            SaveConfig(_config);
+            if (ConfigChanged != null)
+            {
+                ConfigChanged(this, new EventArgs());
+            }
+        }
+
         protected void Reload()
         {
             // some logic in configuration updated the config when saving, we need to read it again

shadowsocks-csharp/Data/cn.txt

@@ -40,6 +40,11 @@ New server=未配置的服务器
 
 QRCode=二维码
 
+# PAC Url Form
+
+Update Online PAC URL=更新在线 PAC 网址
+PAC Url=PAC 网址
+
 # Messages
 
 Shadowsocks Error: {0}=Shadowsocks 错误: {0}
@@ -63,4 +68,5 @@ No QRCode found. Try to zoom in or move it to the center of the screen.=未发
 Failed to decode QRCode=无法解析二维码
 Failed to update registry=无法修改注册表
 System Proxy On: =系统代理已启用：
-Running: Port {0}=正在运行：端口 {0}
+Running: Port {0}=正在运行：端口 {0}
+PAC Url can not be blank=PAC 网址不能为空

shadowsocks-csharp/Model/Configuration.cs

@@ -17,6 +17,8 @@ namespace Shadowsocks.Model
         public bool shareOverLan;
         public bool isDefault;
         public int localPort;
+        public string pacUrl;
+        public bool useOnlinePac;
 
         private static string CONFIG_FILE = "gui-config.json";
 

shadowsocks-csharp/View/MenuViewController.cs

@@ -35,7 +35,10 @@ namespace Shadowsocks.View
         private MenuItem ServersItem;
         private MenuItem globalModeItem;
         private MenuItem PACModeItem;
+        private MenuItem localPACItem;
+        private MenuItem onlinePACItem;
         private ConfigForm configForm;
+        private PACUrlForm pacUrlForm;
         private string _urlToOpen;
 
         public MenuViewController(ShadowsocksController controller)
@@ -151,10 +154,15 @@ namespace Shadowsocks.View
                     CreateMenuItem("Show QRCode...", new EventHandler(this.QRCodeItem_Click)),
                     CreateMenuItem("Scan QRCode from Screen...", new EventHandler(this.ScanQRCodeItem_Click))
                 }),
-                new MenuItem("-"),
-                CreateMenuItem("Edit PAC File...", new EventHandler(this.EditPACFileItem_Click)),
-                CreateMenuItem("Update PAC from GFWList", new EventHandler(this.UpdatePACFromGFWListItem_Click)),
-                CreateMenuItem("Edit User Rule for GFWList...", new EventHandler(this.EditUserRuleFileForGFWListItem_Click)),
+                CreateMenuGroup("PAC", new MenuItem[] {
+                    this.localPACItem = CreateMenuItem("Local PAC", new EventHandler(this.LocalPACItem_Click)),
+                    this.onlinePACItem = CreateMenuItem("Online PAC", new EventHandler(this.OnlinePACItem_Click)),
+                    new MenuItem("-"),
+                    CreateMenuItem("Edit PAC File...", new EventHandler(this.EditPACFileItem_Click)),
+                    CreateMenuItem("Update PAC from GFWList", new EventHandler(this.UpdatePACFromGFWListItem_Click)),
+                    CreateMenuItem("Edit User Rule for GFWList...", new EventHandler(this.EditUserRuleFileForGFWListItem_Click)),
+                    CreateMenuItem("Update Online PAC URL", new EventHandler(this.UpdateOnlinePACURLItem_Click)),
+                }),
                 new MenuItem("-"),
                 this.AutoStartupItem = CreateMenuItem("Start on Boot", new EventHandler(this.AutoStartupItem_Click)),
                 this.ShareOverLANItem = CreateMenuItem("Allow Clients from LAN", new EventHandler(this.ShareOverLANItem_Click)),
@@ -240,6 +248,9 @@ namespace Shadowsocks.View
             PACModeItem.Checked = !config.global;
             ShareOverLANItem.Checked = config.shareOverLan;
             AutoStartupItem.Checked = AutoStartup.Check();
+            onlinePACItem.Enabled = !string.IsNullOrEmpty(config.pacUrl);
+            onlinePACItem.Checked = onlinePACItem.Enabled && config.useOnlinePac;
+            localPACItem.Checked = !onlinePACItem.Checked;
         }
 
         private void UpdateServersMenu()
@@ -481,5 +492,51 @@ namespace Shadowsocks.View
 				MessageBox.Show(I18N.GetString("Failed to update registry"));
 			}
 		}
+
+        private void LocalPACItem_Click(object sender, EventArgs e)
+        {
+            if (!localPACItem.Checked)
+            {
+                localPACItem.Checked = true;
+                onlinePACItem.Checked = false;
+                controller.UseOnlinePAC(false);
+            }
+        }
+
+        private void OnlinePACItem_Click(object sender, EventArgs e)
+        {
+            if (!onlinePACItem.Checked)
+            {
+                localPACItem.Checked = false;
+                onlinePACItem.Checked = true;
+                controller.UseOnlinePAC(true);
+            }
+        }
+
+        private void showPACUrlForm()
+        {
+            if (pacUrlForm != null)
+            {
+                pacUrlForm.Activate();
+            }
+            else
+            {
+                pacUrlForm = new PACUrlForm(controller);
+                pacUrlForm.Show();
+                pacUrlForm.FormClosed += pacUrlForm_FormClosed;
+            }
+        }
+
+        private void pacUrlForm_FormClosed(object sender, FormClosedEventArgs e)
+        {
+            pacUrlForm = null;
+            Util.Utils.ReleaseMemory();
+            ShowFirstTimeBalloon();
+        }
+
+        private void UpdateOnlinePACURLItem_Click(object sender, EventArgs e)
+        {
+            showPACUrlForm();
+        }
     }
 }

shadowsocks-csharp/View/PACUrlForm.Designer.cs

@@ -0,0 +1,105 @@
+namespace Shadowsocks.View
+{
+    partial class PACUrlForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.PACUrlTextBox = new System.Windows.Forms.TextBox();
+            this.PACUrlLabel = new System.Windows.Forms.Label();
+            this.OkButton = new System.Windows.Forms.Button();
+            this.CancelButton = new System.Windows.Forms.Button();
+            this.SuspendLayout();
+            // 
+            // PACUrlTextBox
+            // 
+            this.PACUrlTextBox.Location = new System.Drawing.Point(61, 12);
+            this.PACUrlTextBox.MaxLength = 256;
+            this.PACUrlTextBox.Name = "PACUrlTextBox";
+            this.PACUrlTextBox.Size = new System.Drawing.Size(245, 20);
+            this.PACUrlTextBox.TabIndex = 4;
+            this.PACUrlTextBox.WordWrap = false;
+            // 
+            // PACUrlLabel
+            // 
+            this.PACUrlLabel.AutoSize = true;
+            this.PACUrlLabel.Location = new System.Drawing.Point(6, 15);
+            this.PACUrlLabel.Name = "PACUrlLabel";
+            this.PACUrlLabel.Size = new System.Drawing.Size(44, 13);
+            this.PACUrlLabel.TabIndex = 3;
+            this.PACUrlLabel.Text = "PAC Url";
+            // 
+            // OkButton
+            // 
+            this.OkButton.Location = new System.Drawing.Point(150, 50);
+            this.OkButton.Name = "OkButton";
+            this.OkButton.Size = new System.Drawing.Size(75, 23);
+            this.OkButton.TabIndex = 5;
+            this.OkButton.Text = "OK";
+            this.OkButton.UseVisualStyleBackColor = true;
+            this.OkButton.Click += new System.EventHandler(this.OkButton_Click);
+            // 
+            // CancelButton
+            // 
+            this.CancelButton.Location = new System.Drawing.Point(231, 50);
+            this.CancelButton.Name = "CancelButton";
+            this.CancelButton.Size = new System.Drawing.Size(75, 23);
+            this.CancelButton.TabIndex = 6;
+            this.CancelButton.Text = "Cancel";
+            this.CancelButton.UseVisualStyleBackColor = true;
+            this.CancelButton.Click += new System.EventHandler(this.CancelButton_Click);
+            // 
+            // PACUrlForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.AutoSize = true;
+            this.AutoSizeMode = System.Windows.Forms.AutoSizeMode.GrowAndShrink;
+            this.ClientSize = new System.Drawing.Size(327, 88);
+            this.Controls.Add(this.CancelButton);
+            this.Controls.Add(this.OkButton);
+            this.Controls.Add(this.PACUrlTextBox);
+            this.Controls.Add(this.PACUrlLabel);
+            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
+            this.MaximizeBox = false;
+            this.MinimizeBox = false;
+            this.Name = "PACUrlForm";
+            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
+            this.Text = "Update Online PAC URL";
+            this.Load += new System.EventHandler(this.PACUrlForm_Load);
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private System.Windows.Forms.TextBox PACUrlTextBox;
+        private System.Windows.Forms.Label PACUrlLabel;
+        private System.Windows.Forms.Button OkButton;
+        private System.Windows.Forms.Button CancelButton;
+    }
+}

shadowsocks-csharp/View/PACUrlForm.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Text;
+using System.Windows.Forms;
+using Shadowsocks.Controller;
+using Shadowsocks.Model;
+using Shadowsocks.Properties;
+
+namespace Shadowsocks.View
+{
+    public partial class PACUrlForm : Form
+    {
+        private ShadowsocksController controller;
+        private string orig_pacUrl;
+
+        public PACUrlForm(ShadowsocksController controller)
+        {
+            this.Font = System.Drawing.SystemFonts.MessageBoxFont;
+            InitializeComponent();
+
+            UpdateTexts();
+            this.Icon = Icon.FromHandle(Resources.ssw128.GetHicon());
+
+            this.controller = controller;
+            controller.ConfigChanged += controller_ConfigChanged;
+        }
+
+        private void UpdateTexts()
+        {
+            OkButton.Text = I18N.GetString("OK");
+            CancelButton.Text = I18N.GetString("Cancel");
+            PACUrlLabel.Text = I18N.GetString("PAC Url");
+            this.Text = I18N.GetString("Update Online PAC URL");
+        }
+
+        private void controller_ConfigChanged(object sender, EventArgs e)
+        {
+            orig_pacUrl = PACUrlTextBox.Text = controller.GetConfiguration().pacUrl;
+        }
+
+        private void PACUrlForm_Load(object sender, EventArgs e)
+        {
+            PACUrlTextBox.Text = controller.GetConfiguration().pacUrl;
+        }
+
+        private void OkButton_Click(object sender, EventArgs e)
+        {
+            string pacUrl = PACUrlTextBox.Text.Trim();
+            if (string.IsNullOrEmpty(pacUrl))
+            {
+                MessageBox.Show(I18N.GetString("PAC Url can not be blank"));
+                return;
+            }
+            if (pacUrl != this.orig_pacUrl)
+            {
+                controller.SavePACUrl(pacUrl);
+            }
+            this.Close();
+        }
+
+        private void CancelButton_Click(object sender, EventArgs e)
+        {
+            this.Close();
+        }
+    }
+}

shadowsocks-csharp/View/PACUrlForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

shadowsocks-csharp/shadowsocks-csharp.csproj

@@ -162,6 +162,12 @@
     <Compile Include="Controller\ShadowsocksController.cs" />
     <Compile Include="Controller\SystemProxy.cs" />
     <Compile Include="View\MenuViewController.cs" />
+    <Compile Include="View\PACUrlForm.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="View\PACUrlForm.Designer.cs">
+      <DependentUpon>PACUrlForm.cs</DependentUpon>
+    </Compile>
     <Compile Include="View\QRCodeForm.cs">
       <SubType>Form</SubType>
     </Compile>
@@ -180,6 +186,9 @@
       <SubType>Designer</SubType>
       <LastGenOutput>Resources.Designer.cs</LastGenOutput>
     </EmbeddedResource>
+    <EmbeddedResource Include="View\PACUrlForm.resx">
+      <DependentUpon>PACUrlForm.cs</DependentUpon>
+    </EmbeddedResource>
     <EmbeddedResource Include="View\QRCodeForm.resx">
       <DependentUpon>QRCodeForm.cs</DependentUpon>
     </EmbeddedResource>