leviathan-driver 0.3.0

//! Windows Filtering Platform (WFP) Network Filter
//!
//! Implements network packet filtering using WFP callouts.
//!
//! # Capabilities
//! - Inspect/block network connections (TCP/UDP)
//! - Deep packet inspection (DPI)
//! - Application-aware firewall
//! - Network traffic monitoring
//! - Implement custom network policies
//!
//! # WFP Layers
//! WFP provides multiple layers for filtering at different points:
//! - INBOUND/OUTBOUND_IPPACKET: Raw IP packets
//! - INBOUND/OUTBOUND_TRANSPORT: TCP/UDP layer
//! - ALE_AUTH_CONNECT/RECV_ACCEPT: Connection authorization
//! - STREAM: TCP stream data
//!
//! # Use Cases
//! - Host-based firewall
//! - Network intrusion detection (NIDS)
//! - Application control (block specific apps)
//! - Data exfiltration prevention
//! - VPN/proxy implementation

use core::sync::atomic::{AtomicBool, Ordering};
use core::ptr;
use wdk::println;
use wdk_sys::{NTSTATUS, PVOID, STATUS_SUCCESS, HANDLE, GUID};

// WFP types not available in wdk-sys 0.5 default bindings.
// These are placeholder type definitions for the WFP filtering framework.
// Enable WFP feature flags in wdk-sys if/when they become available.

/// FWP action type
#[allow(non_camel_case_types)]
pub type FWP_ACTION_TYPE = u32;
/// FWP classify output
#[allow(non_camel_case_types)]
pub type FWP_CLASSIFY_OUT = u8; // placeholder
/// FWP incoming values
#[allow(non_camel_case_types)]
pub type FWP_INCOMING_VALUES = u8; // placeholder
/// FWPS incoming metadata values
#[allow(non_camel_case_types)]
pub type FWPS_INCOMING_METADATA_VALUES = u8; // placeholder
/// FWPS callout structure
#[allow(non_camel_case_types)]
pub type FWPS_CALLOUT = u8; // placeholder
/// FWPS filter structure
#[allow(non_camel_case_types)]
pub type FWPS_FILTER = u8; // placeholder
/// FWPS callout notify type
#[allow(non_camel_case_types)]
pub type FWPS_CALLOUT_NOTIFY_TYPE = u32;
/// FWPM callout structure
#[allow(non_camel_case_types)]
pub type FWPM_CALLOUT = u8; // placeholder
/// FWPM filter structure
#[allow(non_camel_case_types)]
pub type FWPM_FILTER = u8; // placeholder
/// FWPM sublayer structure
#[allow(non_camel_case_types)]
pub type FWPM_SUBLAYER = u8; // placeholder
/// FWPM display data
#[allow(non_camel_case_types)]
pub type FWPM_DISPLAY_DATA0 = u8; // placeholder
/// FWP byte blob
#[allow(non_camel_case_types)]
pub type FWP_BYTE_BLOB = u8; // placeholder

/// FWP action types
pub const FWP_ACTION_PERMIT: FWP_ACTION_TYPE = 0x00000001;
pub const FWP_ACTION_BLOCK: FWP_ACTION_TYPE = 0x00000002;
pub const FWP_ACTION_CONTINUE: FWP_ACTION_TYPE = 0x00000003;

/// Classify out flag
pub const FWPS_CLASSIFY_OUT_FLAG_ABSORB: u32 = 0x00000001;

/// RPC authentication
pub const RPC_C_AUTHN_WINNT: u32 = 10;

/// Flag indicating if WFP callouts are registered
static REGISTERED: AtomicBool = AtomicBool::new(false);

/// Engine handle for WFP operations
static mut ENGINE_HANDLE: HANDLE = ptr::null_mut();

/// Callout IDs for unregistration
static mut CALLOUT_IDS: [u32; 4] = [0; 4];

/// Our custom sublayer GUID
/// {A1B2C3D4-E5F6-7890-ABCD-EF1234567890}
pub const SUBLAYER_GUID: GUID = GUID {
    Data1: 0xA1B2C3D4,
    Data2: 0xE5F6,
    Data3: 0x7890,
    Data4: [0xAB, 0xCD, 0xEF, 0x12, 0x34, 0x56, 0x78, 0x90],
};

/// Outbound IPv4 callout GUID
pub const CALLOUT_OUTBOUND_IPV4_GUID: GUID = GUID {
    Data1: 0x11111111,
    Data2: 0x1111,
    Data3: 0x1111,
    Data4: [0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11],
};

/// Inbound IPv4 callout GUID
pub const CALLOUT_INBOUND_IPV4_GUID: GUID = GUID {
    Data1: 0x22222222,
    Data2: 0x2222,
    Data3: 0x2222,
    Data4: [0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22],
};

/// ALE Connect callout GUID (application layer)
pub const CALLOUT_ALE_CONNECT_GUID: GUID = GUID {
    Data1: 0x33333333,
    Data2: 0x3333,
    Data3: 0x3333,
    Data4: [0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33],
};

/// ALE Recv Accept callout GUID
pub const CALLOUT_ALE_RECV_GUID: GUID = GUID {
    Data1: 0x44444444,
    Data2: 0x4444,
    Data3: 0x4444,
    Data4: [0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44],
};

/// Network action to take on traffic
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum NetworkAction {
    /// Allow the traffic
    Permit,
    /// Block the traffic
    Block,
    /// Continue to next filter
    Continue,
}

/// Connection information for logging/decisions
#[derive(Debug)]
pub struct ConnectionInfo {
    pub local_addr: [u8; 4],
    pub local_port: u16,
    pub remote_addr: [u8; 4],
    pub remote_port: u16,
    pub protocol: u8,
    pub process_id: u32,
    pub direction: Direction,
}

#[derive(Debug, Clone, Copy)]
pub enum Direction {
    Inbound,
    Outbound,
}

/// Blocked IP addresses/ranges
/// In production, use a proper data structure (hash set, trie)
const BLOCKED_IPS: &[[u8; 4]] = &[
    // Example: Block some IPs
    // [192, 168, 1, 100],
];

/// Blocked ports (common malware C2 ports)
const BLOCKED_PORTS: &[u16] = &[
    4444,  // Metasploit default
    5555,  // Common RAT
    6666,  // Common malware
    31337, // Elite/Back Orifice
];

/// Register WFP callouts and filters
///
/// # Safety
/// Must be called from DriverEntry at PASSIVE_LEVEL
/// Note: WFP types are not available in wdk-sys 0.5 default bindings.
/// This function is a placeholder that logs the intent.
pub unsafe fn register(_device_object: PVOID) -> Result<(), NTSTATUS> {
    if REGISTERED.load(Ordering::SeqCst) {
        return Ok(());
    }

    // WFP types (FWPM_SUBLAYER, FWPS_CALLOUT, FwpmEngineOpen, etc.) are not
    // available in wdk-sys 0.5 without WFP feature flags.
    // The network filter is disabled by default (features::ENABLE_NETWORK_FILTER = false).
    println!("[Leviathan] WFP network filter registration skipped - not available in wdk-sys 0.5");
    println!("[Leviathan] To enable: add WFP feature flags to wdk-sys dependency");

    REGISTERED.store(true, Ordering::SeqCst);
    Ok(())
}

/// Unregister WFP callouts and filters
///
/// # Safety
/// Must be called from driver unload
pub unsafe fn unregister() {
    if !REGISTERED.load(Ordering::SeqCst) {
        return;
    }

    REGISTERED.store(false, Ordering::SeqCst);
    println!("[Leviathan] WFP network filter unregistered");
}

/// Add our custom sublayer to WFP (placeholder)
unsafe fn add_sublayer(_engine_handle: HANDLE) -> Result<(), NTSTATUS> {
    Ok(())
}

/// Register WFP callouts with the filter engine (placeholder)
unsafe fn register_callouts(_device_object: PVOID) -> Result<(), NTSTATUS> {
    Ok(())
}

/// Add filters that use our callouts (placeholder)
unsafe fn add_filters(_engine_handle: HANDLE) -> Result<(), NTSTATUS> {
    Ok(())
}

/// Classify callback for outbound traffic (placeholder)
unsafe extern "C" fn classify_outbound(
    _fixed_values: *const FWP_INCOMING_VALUES,
    _meta_values: *const FWPS_INCOMING_METADATA_VALUES,
    _layer_data: PVOID,
    _context: PVOID,
    _filter: *const FWPS_FILTER,
    _flow_context: u64,
    _classify_out: *mut FWP_CLASSIFY_OUT,
) {
    // Placeholder - would inspect traffic and set action type
}

/// Classify callback for inbound traffic (placeholder)
unsafe extern "C" fn classify_inbound(
    _fixed_values: *const FWP_INCOMING_VALUES,
    _meta_values: *const FWPS_INCOMING_METADATA_VALUES,
    _layer_data: PVOID,
    _context: PVOID,
    _filter: *const FWPS_FILTER,
    _flow_context: u64,
    _classify_out: *mut FWP_CLASSIFY_OUT,
) {
    // Placeholder - would inspect traffic and set action type
}

/// Classify callback for ALE connect (application-aware, placeholder)
unsafe extern "C" fn classify_ale_connect(
    _fixed_values: *const FWP_INCOMING_VALUES,
    _meta_values: *const FWPS_INCOMING_METADATA_VALUES,
    _layer_data: PVOID,
    _context: PVOID,
    _filter: *const FWPS_FILTER,
    _flow_context: u64,
    _classify_out: *mut FWP_CLASSIFY_OUT,
) {
    // Placeholder - would inspect application connections
}

/// Notify callback for filter events (placeholder)
unsafe extern "C" fn notify_callout(
    _notify_type: FWPS_CALLOUT_NOTIFY_TYPE,
    _filter_key: *const GUID,
    _filter: *const FWPS_FILTER,
) -> NTSTATUS {
    STATUS_SUCCESS
}

/// Check outbound traffic against policy
fn check_outbound_policy() -> NetworkAction {
    // In production:
    // 1. Extract destination IP and port
    // 2. Check against blocklists
    // 3. Check process against application policy
    // 4. Perform reputation lookup

    NetworkAction::Permit
}

/// Check inbound traffic against policy
fn check_inbound_policy() -> NetworkAction {
    // In production:
    // 1. Check source IP against known threats
    // 2. Verify port is expected to be open
    // 3. Rate limiting for DDoS protection

    NetworkAction::Permit
}

/// Check if an IP address is blocked
#[allow(dead_code)]
fn is_blocked_ip(ip: &[u8; 4]) -> bool {
    for blocked in BLOCKED_IPS {
        if ip == blocked {
            return true;
        }
    }
    false
}

/// Check if a port is blocked
#[allow(dead_code)]
fn is_blocked_port(port: u16) -> bool {
    BLOCKED_PORTS.contains(&port)
}

/// Log a connection for audit purposes
#[allow(dead_code)]
fn log_connection(info: &ConnectionInfo, action: NetworkAction) {
    println!(
        "[Leviathan] {:?} {:?} -> {:?} (PID: {}) = {:?}",
        info.direction,
        info.local_addr,
        info.remote_addr,
        info.process_id,
        action
    );
}

/// Format an IP address as a string
fn format_ip(ip: &[u8; 4]) -> [u8; 15] {
    let mut buf = [b' '; 15];
    // Simplified - would format properly
    buf[0] = ip[0];
    buf
}