Update year

ATTRIBUTIONS.md

@@ -3,7 +3,7 @@
 ## ASIO C++ Library
 - **Name:** ASIO (standalone)
 - **Website:** https://think-async.com/Asio/
-- **Copyright:** (c) 2003-2025 Christopher M. Kohlhoff
+- **Copyright:** (c) 2003-2026 Christopher M. Kohlhoff
 - **License:** Boost Software License, Version 1.0
 - **License Text:** See `third_party/asio/LICENSE_1_0.txt`
 
@@ -12,14 +12,14 @@ This project uses the standalone version of the ASIO C++ library for asynchronou
 ## CXXOPTS C++ Library
 - **Name:** cxxopts
 - **Website:** https://github.com/jarro2783/cxxopts/
-- **Copyright:** (c) 2014-2025 Christopher M. Kohlhoff
+- **Copyright:** (c) 2014-2026 Christopher M. Kohlhoff
 - **License:** MIT License
 - **License Text:** See `third_party/cxxopts/LICENSE_1_0.txt`
 
 ## Wintun C++ Library
 - **Name:** wintun
 - **Website:** https://www.wintun.net/
-- **Copyright:** (c) 2018-2025 WireGuard LLC
+- **Copyright:** (c) 2018-2026 WireGuard LLC
 - **License:** MIT License OR GPL-2.0 License
 - **License Text:** See `third_party/wintun/`
 - **Utilized Under:** MIT License

CMakeLists.txt

@@ -6,7 +6,7 @@ cmake_minimum_required(VERSION 3.16)
 # If MAJOR is 0, and MINOR > 0, Version is BETA
 
 project(ColumnLynx
-    VERSION 1.0.0
+    VERSION 1.0.1
     LANGUAGES CXX
 )
 
@@ -50,7 +50,7 @@ endif()
 FetchContent_Declare(
     Sodium
     GIT_REPOSITORY https://github.com/robinlinden/libsodium-cmake.git
-    GIT_TAG e5b985ad0dd235d8c4307ea3a385b45e76c74c6a  # Last updated at 2025-04-13
+    GIT_TAG e5b985ad0dd235d8c4307ea3a385b45e76c74c6a
 )
 
 set(SODIUM_DISABLE_TESTS ON CACHE BOOL "" FORCE)

README.md

@@ -57,7 +57,9 @@ openssl pkey -in key.pem -pubout -outform DER | tail -c 32 | xxd -p -c 32
 
 You can then set these keys accordingly in the **server_config** and **client_config** files.
 
-### Creating the Tun Interface (Linux Server ONLY)
+### Server Setup (Linux Server ONLY)
+
+#### Creating the Tun Interface
 
 In order for the VPN server to work, you need to create the Tun interface that the VPN will use.
 
@@ -69,6 +71,88 @@ sudo ip link set dev lynx0 mtu 1420
 sudo ip link set dev lynx0 up
 ```
 
+#### Creating the systemd service
+
+It is highly recommended to **run the server as a systemd service**, as systemd is the primary service manager on Linux.
+
+**1. Create a file for the service**
+```bash
+sudo touch /etc/systemd/system/columnlynx.service
+```
+
+**2. Open the file in your editor of choice**
+```bash
+sudo nano /etc/systemd/system/columnlynx.service
+# OR
+sudo vim /etc/systemd/system/columnlynx.service
+# OR any other editor of your choice...
+```
+
+**3. Configure the service**
+
+**Replace** the **ExecStart** and **WorkingDirectory** paths with the paths where your binaries are stored.
+
+If you configured your tun interface to belong to a custom user, you may also replace the **User** and **Group** with that user, however you must ensure that that user owns the **tun interface**, **config directory in /etc/columnlynx** and the **working directory**.
+
+This is a **simple example** for the **root user** and the executable in **/opt/columnlynx**:
+
+```
+[Unit]
+Description=ColumnLynx Server Service
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/opt/columnlynx/columnlynx_server
+WorkingDirectory=/opt/columnlynx
+User=root
+Group=root
+Restart=on-failure
+StandardOutput=append:/var/log/columnlynx.log
+StandardError=append:/var/log/columnlynx.err
+
+[Install]
+WantedBy=multi-user.target
+```
+
+**4. Reload systemd and enable the service**
+
+```bash
+sudo systemctl daemon-reload
+sudo systemctl enable columnlynx.service
+sudo systemctl start columnlynx.service
+```
+
+#### Set firewall rules
+
+This part greatly depends on your firewall of choice. Generally you just need to **allow port 48042 on both TCP and UDP** (Both IPv4 and IPv6).
+
+This example is for **UFW**:
+
+```bash
+sudo ufw allow 48042
+sudo ufw reload
+```
+
+
+#### IPTables rules for forwarding (Optional)
+
+In addition to creating the interface, you'll also need to make some **iptables** rules if you want to be able to **send traffic to foreign networks** (more like a *commercial VPN*).
+
+You can do these as such (example with NFT IPTABLES):
+
+- Enable the **generic IPv4 forwarding**:
+```bash
+sudo sysctl net.ipv4.ip_forward=1
+```
+- Create the masquerade (**Replace the IP subnet** with your own that you set in the config and **replace the interface** with your server's main (NOT *lynx0*) interface):
+```bash
+sudo nft add table nat
+sudo nft add chain nat postroute { type nat hook postrouting priority 100 \; }
+sudo nft add rule nat postroute ip saddr 10.10.0.0/24 oifname "eth0" masquerade
+```
+
+
 ### Server
  
 "**server_config**" is a file that contains the server configuration, **one variable per line**. These are the current configuration available variables:

include/columnlynx/client/net/tcp/tcp_client.hpp

@@ -1,5 +1,5 @@
 // tcp_client.hpp - TCP Client for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/client/net/udp/udp_client.hpp

@@ -1,5 +1,5 @@
 // udp_client.hpp - UDP Client for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/libsodium_wrapper.hpp

@@ -1,5 +1,5 @@
 // libsodium_wrapper.hpp - Libsodium Wrapper for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/protocol_structs.hpp

@@ -1,5 +1,5 @@
 // protocol_structs.hpp - Network Protocol Structures
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/session_registry.hpp

@@ -1,5 +1,5 @@
 // session_registry.hpp - Session Registry for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/tcp/net_helper.hpp

@@ -1,5 +1,5 @@
 // net_helper.hpp - Network Helper Functions for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/tcp/tcp_message_handler.hpp

@@ -1,5 +1,5 @@
 // tcp_message_handler.hpp - TCP Message Handler for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/tcp/tcp_message_type.hpp

@@ -1,5 +1,5 @@
 // tcp_message_type.hpp - TCP Message Types for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/udp/udp_message_type.hpp

@@ -1,5 +1,5 @@
 // udp_message_type.hpp - UDP Message Types for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/net/virtual_interface.hpp

@@ -1,5 +1,5 @@
 // virtual_interface.hpp - Virtual Interface for Network Communication
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/panic_handler.hpp

@@ -1,5 +1,5 @@
 // panic_handler.hpp - Panic Handler for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/common/utils.hpp

@@ -1,5 +1,5 @@
 // utils.hpp - Utility functions for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once
@@ -29,6 +29,9 @@ namespace ColumnLynx {
 }
 
 namespace ColumnLynx::Utils {
+    // Converts unix milliseconds to a local ISO 8601 formatted string; Defaults to local time; Will use UTC if local is false.
+    std::string unixMillisToISO8601(uint64_t unixMillis, bool local = true);
+
     // General log function. Use for logging important information.
     void log(const std::string &msg);
     // General warning function. Use for logging important warnings.

include/columnlynx/server/net/tcp/tcp_connection.hpp

@@ -1,5 +1,5 @@
 // tcp_connection.hpp - TCP Connection for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/server/net/tcp/tcp_server.hpp

@@ -1,5 +1,5 @@
 // tcp_server.hpp - TCP Server for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

include/columnlynx/server/net/udp/udp_server.hpp

@@ -1,5 +1,5 @@
 // udp_server.hpp - UDP Server for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #pragma once

src/client/main.cpp

@@ -1,5 +1,5 @@
 // main.cpp - Client entry point for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <asio.hpp>
@@ -68,7 +68,7 @@ int main(int argc, char** argv) {
     if (optionsObj.count("help")) {
         std::cout << options.help() << std::endl;
         std::cout << "This software is licensed under the GPLv2-only license OR the GPLv3 license.\n";
-        std::cout << "Copyright (C) 2025, The ColumnLynx Contributors.\n";
+        std::cout << "Copyright (C) 2026, The ColumnLynx Contributors.\n";
         std::cout << "This software is provided under ABSOLUTELY NO WARRANTY, to the extent permitted by law.\n";
         return 0;
     }
@@ -110,6 +110,10 @@ int main(int argc, char** argv) {
         aesKey->fill(0); // Defualt zeroed state until modified by handshake
         std::shared_ptr<uint64_t> sessionID = std::make_shared<uint64_t>(0);
 
+        if (insecureMode) {
+            warn("You have started the client with the --ignore-whitelist. This means that the client will NOT attempt to verify the server's public key. This is INSECURE and SHOULDN'T be used!");
+        }
+
         asio::io_context io;
         auto client = std::make_shared<ColumnLynx::Net::TCP::TCPClient>(io, host, port, sodiumWrapper, aesKey, sessionID, insecureMode, configPath, tun);
         auto udpClient = std::make_shared<ColumnLynx::Net::UDP::UDPClient>(io, host, port, aesKey, sessionID, tun);

src/client/net/tcp/tcp_client.cpp

@@ -1,5 +1,5 @@
 // tcp_client.cpp - TCP Client for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/client/net/tcp/tcp_client.hpp>

src/client/net/udp/udp_client.cpp

@@ -1,5 +1,5 @@
 // udp_client.cpp - UDP Client for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/client/net/udp/udp_client.hpp>

src/common/libsodium_wrapper.cpp

@@ -1,5 +1,5 @@
 // libsodium_wrapper.cpp - Libsodium Wrapper for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/libsodium_wrapper.hpp>

src/common/session_registry.cpp

@@ -1,5 +1,5 @@
 // session_registry.cpp - Session Registry for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/net/session_registry.hpp>

src/common/tcp_message_handler.cpp

@@ -1,5 +1,5 @@
 // tcp_message_handler.cpp - TCP Message Handler for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/net/tcp/tcp_message_handler.hpp>

src/common/utils.cpp

@@ -1,29 +1,65 @@
 // utils.cpp - Utility functions for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/utils.hpp>
 
 namespace ColumnLynx::Utils {
+    std::string unixMillisToISO8601(uint64_t unixMillis, bool local) {
+        using namespace std::chrono;
+
+        // Convert milliseconds since epoch to system_clock::time_point
+        system_clock::time_point tp = system_clock::time_point(milliseconds(unixMillis));
+
+        // Convert to time_t for localtime conversion
+        std::time_t tt = system_clock::to_time_t(tp);
+        std::tm localTm;
+
+        if (local) {
+#ifdef _WIN32
+        localtime_s(&localTm, &tt);
+#else
+        localtime_r(&tt, &localTm);
+#endif
+        } else {
+#ifdef _WIN32
+        gmtime_s(&localTm, &tt);
+#else
+        gmtime_r(&tt, &localTm);
+#endif
+        }
+
+        // Format the time to ISO 8601
+        char buffer[30];
+        std::strftime(buffer, sizeof(buffer), "%Y-%m-%dT%H:%M:%S", &localTm);
+
+        // Append milliseconds
+        auto ms = duration_cast<milliseconds>(tp.time_since_epoch()) % 1000;
+        char iso8601[34];
+        std::snprintf(iso8601, sizeof(iso8601), "%s.%03lld", buffer, static_cast<long long>(ms.count()));
+
+        return std::string(iso8601);
+    }
+
     void log(const std::string &msg) {
         uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
-        std::cout << "\033[0m[" << std::to_string(now) << " LOG] " << msg << std::endl;
+        std::cout << "\033[0m[" << unixMillisToISO8601(now) << " LOG] " << msg << std::endl;
     }
 
     void warn(const std::string &msg) {
         uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
-        std::cerr << "\033[33m[" << std::to_string(now) << " WARN] " << msg << "\033[0m" << std::endl;
+        std::cerr << "\033[33m[" << unixMillisToISO8601(now) << " WARN] " << msg << "\033[0m" << std::endl;
     }
 
     void error(const std::string &msg) {
         uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
-        std::cerr << "\033[31m[" << std::to_string(now) << " ERROR] " << msg << "\033[0m" << std::endl;
+        std::cerr << "\033[31m[" << unixMillisToISO8601(now) << " ERROR] " << msg << "\033[0m" << std::endl;
     }
 
     void debug(const std::string &msg) {
 #if DEBUG || _DEBUG
         uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
-        std::cerr << "\033[95m[" << std::to_string(now) << " DEBUG] " << msg << "\033[0m" << std::endl;
+        std::cerr << "\033[95m[" << unixMillisToISO8601(now) << " DEBUG] " << msg << "\033[0m" << std::endl;
 #else
         return;
 #endif
@@ -49,7 +85,7 @@ namespace ColumnLynx::Utils {
     }
 
     std::string getVersion() {
-        return "1.0.0";
+        return "1.0.1";
     }
 
     unsigned short serverPort() {

src/common/virtual_interface.cpp

@@ -1,5 +1,5 @@
 // virtual_interface.cpp - Virtual Interface for Network Communication
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/common/net/virtual_interface.hpp>

src/server/main.cpp

@@ -1,5 +1,5 @@
 // main.cpp - Server entry point for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <asio.hpp>
@@ -55,7 +55,7 @@ int main(int argc, char** argv) {
         if (optionsObj.count("help")) {
             std::cout << options.help() << std::endl;
             std::cout << "This software is licensed under the GPLv2-only license OR the GPLv3 license.\n";
-            std::cout << "Copyright (C) 2025, The ColumnLynx Contributors.\n";
+            std::cout << "Copyright (C) 2026, The ColumnLynx Contributors.\n";
             std::cout << "This software is provided under ABSOLUTELY NO WARRANTY, to the extent permitted by law.\n";
             return 0;
         }
@@ -153,15 +153,28 @@ int main(int argc, char** argv) {
             }
 
             const uint8_t* ip = packet.data();
-            uint32_t dstIP = ntohl(*(uint32_t*)(ip + 16)); // IPv4 destination address offset in IPv6-mapped header
+            uint32_t srcIP = ntohl(*(uint32_t*)(ip + 12)); // IPv4 source address offset
+            uint32_t dstIP = ntohl(*(uint32_t*)(ip + 16)); // IPv4 destination address offset
         
-            auto session = SessionRegistry::getInstance().getByIP(dstIP);
-            if (!session) {
-                Utils::warn("TUN: No session found for destination IP " + VirtualInterface::ipv4ToString(dstIP));
+            // First, check if destination IP is a registered client (e.g., server responding to client or client-to-client)
+            auto dstSession = SessionRegistry::getInstance().getByIP(dstIP);
+            if (dstSession) {
+                // Destination is a registered client, forward to that client's session
+                udpServer->sendData(dstSession->sessionID, std::string(packet.begin(), packet.end()));
                 continue;
             }
 
-            udpServer->sendData(session->sessionID, std::string(packet.begin(), packet.end()));
+            // Destination is not a registered client, check if source is (for external routing)
+            auto srcSession = SessionRegistry::getInstance().getByIP(srcIP);
+            if (srcSession) {
+                // Source is a registered client, write to TUN interface to forward to external destination
+                tun->writePacket(packet);
+                continue;
+            }
+
+            // Neither source nor destination is registered, drop the packet
+            Utils::warn("TUN: No session found for source IP " + VirtualInterface::ipv4ToString(srcIP) + 
+                       " or destination IP " + VirtualInterface::ipv4ToString(dstIP));
         }
 
         log("Shutting down server...");

src/server/net/tcp/tcp_connection.cpp

@@ -1,5 +1,5 @@
 // tcp_connection.cpp - TCP Connection for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/server/net/tcp/tcp_connection.hpp>

src/server/net/tcp/tcp_server.cpp

@@ -1,5 +1,5 @@
 // tcp_server.cpp - TCP Server for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/server/net/tcp/tcp_server.hpp>

src/server/net/udp/udp_server.cpp

@@ -1,5 +1,5 @@
 // udp_server.cpp - UDP Server for ColumnLynx
-// Copyright (C) 2025 DcruBro
+// Copyright (C) 2026 DcruBro
 // Distributed under the terms of the GNU General Public License, either version 2 only or version 3. See LICENSES/ for details.
 
 #include <columnlynx/server/net/udp/udp_server.hpp>