Update UAPI semantics for remove

18 files changed, 288 insertions, 140 deletions

diff --git a/src/configuration/config.rs b/src/configuration/config.rs
index b1c0121..50fdfb8 100644
--- a/src/configuration/config.rs
+++ b/src/configuration/config.rs
@@ -19,16 +19,16 @@ pub struct PeerState {
     pub last_handshake_time_nsec: u64,
     pub public_key: PublicKey,
     pub allowed_ips: Vec<(IpAddr, u32)>,
-    pub preshared_key: Option<[u8; 32]>,
+    pub preshared_key: [u8; 32], // 0^32 is the "default value"
 }
 
-pub struct WireguardConfig<T: tun::Tun, B: bind::Platform> {
+pub struct WireguardConfig<T: tun::Tun, B: bind::PlatformBind> {
     wireguard: Wireguard<T, B>,
     network: Mutex<Option<B::Owner>>,
 }
 
-impl<T: tun::Tun, B: bind::Platform> WireguardConfig<T, B> {
-    fn new(wg: Wireguard<T, B>) -> WireguardConfig<T, B> {
+impl<T: tun::Tun, B: bind::PlatformBind> WireguardConfig<T, B> {
+    pub fn new(wg: Wireguard<T, B>) -> WireguardConfig<T, B> {
         WireguardConfig {
             wireguard: wg,
             network: Mutex::new(None),
@@ -110,7 +110,7 @@ pub trait Configuration {
     /// # Returns
     ///
     /// An error if no such peer exists
-    fn set_preshared_key(&self, peer: &PublicKey, psk: Option<[u8; 32]>) -> Option<ConfigError>;
+    fn set_preshared_key(&self, peer: &PublicKey, psk: [u8; 32]) -> Option<ConfigError>;
 
     /// Update the endpoint of the
     ///
@@ -170,7 +170,7 @@ pub trait Configuration {
     fn get_fwmark(&self) -> Option<u32>;
 }
 
-impl<T: tun::Tun, B: bind::Platform> Configuration for WireguardConfig<T, B> {
+impl<T: tun::Tun, B: bind::PlatformBind> Configuration for WireguardConfig<T, B> {
     fn get_fwmark(&self) -> Option<u32> {
         self.network
             .lock()
@@ -246,7 +246,7 @@ impl<T: tun::Tun, B: bind::Platform> Configuration for WireguardConfig<T, B> {
         false
     }
 
-    fn set_preshared_key(&self, peer: &PublicKey, psk: Option<[u8; 32]>) -> Option<ConfigError> {
+    fn set_preshared_key(&self, peer: &PublicKey, psk: [u8; 32]) -> Option<ConfigError> {
         if self.wireguard.set_psk(*peer, psk) {
             None
         } else {
@@ -308,16 +308,18 @@ impl<T: tun::Tun, B: bind::Platform> Configuration for WireguardConfig<T, B> {
                 .duration_since(SystemTime::UNIX_EPOCH)
                 .unwrap_or(Duration::from_secs(0)); // any time before epoch is mapped to epoch
 
-            // extract state into PeerState
-            state.push(PeerState {
-                preshared_key: self.wireguard.get_psk(&p.pk),
-                rx_bytes: p.rx_bytes.load(Ordering::Relaxed),
-                tx_bytes: p.tx_bytes.load(Ordering::Relaxed),
-                allowed_ips: p.router.list_allowed_ips(),
-                last_handshake_time_nsec: last_handshake.subsec_nanos() as u64,
-                last_handshake_time_sec: last_handshake.as_secs(),
-                public_key: p.pk,
-            })
+            if let Some(psk) = self.wireguard.get_psk(&p.pk) {
+                // extract state into PeerState
+                state.push(PeerState {
+                    preshared_key: psk,
+                    rx_bytes: p.rx_bytes.load(Ordering::Relaxed),
+                    tx_bytes: p.tx_bytes.load(Ordering::Relaxed),
+                    allowed_ips: p.router.list_allowed_ips(),
+                    last_handshake_time_nsec: last_handshake.subsec_nanos() as u64,
+                    last_handshake_time_sec: last_handshake.as_secs(),
+                    public_key: p.pk,
+                })
+            }
         }
         state
     }
diff --git a/src/configuration/mod.rs b/src/configuration/mod.rs
index 26f0c6e..dc1d93a 100644
--- a/src/configuration/mod.rs
+++ b/src/configuration/mod.rs
@@ -1,6 +1,6 @@
 mod config;
 mod error;
-mod uapi;
+pub mod uapi;
 
 use super::platform::Endpoint;
 use super::platform::{bind, tun};
diff --git a/src/configuration/uapi/get.rs b/src/configuration/uapi/get.rs
index 9b05421..0874cfc 100644
--- a/src/configuration/uapi/get.rs
+++ b/src/configuration/uapi/get.rs
@@ -1,6 +1,8 @@
 use hex::FromHex;
 use subtle::ConstantTimeEq;
 
+use log;
+
 use super::Configuration;
 use std::io;
 
@@ -8,9 +10,11 @@ pub fn serialize<C: Configuration, W: io::Write>(writer: &mut W, config: &C) ->
     let mut write = |key: &'static str, value: String| {
         debug_assert!(value.is_ascii());
         debug_assert!(key.is_ascii());
+        log::trace!("UAPI: return : {} = {}", key, value);
         writer.write(key.as_ref())?;
         writer.write(b"=")?;
-        writer.write(value.as_ref())
+        writer.write(value.as_ref())?;
+        writer.write(b"\n")
     };
 
     // serialize interface
@@ -40,9 +44,7 @@ pub fn serialize<C: Configuration, W: io::Write>(writer: &mut W, config: &C) ->
             p.last_handshake_time_nsec.to_string(),
         )?;
         write("public_key", hex::encode(p.public_key.as_bytes()))?;
-        if let Some(psk) = p.preshared_key {
-            write("preshared_key", hex::encode(psk))?;
-        }
+        write("preshared_key", hex::encode(p.preshared_key))?;
         for (ip, cidr) in p.allowed_ips {
             write("allowed_ip", ip.to_string() + "/" + &cidr.to_string())?;
         }
diff --git a/src/configuration/uapi/mod.rs b/src/configuration/uapi/mod.rs
index 117d970..4261e7d 100644
--- a/src/configuration/uapi/mod.rs
+++ b/src/configuration/uapi/mod.rs
@@ -1,6 +1,7 @@
 mod get;
 mod set;
 
+use log;
 use std::io::{Read, Write};
 
 use super::{ConfigError, Configuration};
@@ -10,10 +11,9 @@ use set::LineParser;
 
 const MAX_LINE_LENGTH: usize = 256;
 
-pub fn process<R: Read, W: Write, C: Configuration>(reader: &mut R, writer: &mut W, config: &C) {
-    fn operation<R: Read, W: Write, C: Configuration>(
-        reader: &mut R,
-        writer: &mut W,
+pub fn handle<S: Read + Write, C: Configuration>(stream: &mut S, config: &C) {
+    fn operation<S: Read + Write, C: Configuration>(
+        stream: &mut S,
         config: &C,
     ) -> Result<(), ConfigError> {
         // read string up to maximum length (why is this not in std?)
@@ -23,6 +23,7 @@ pub fn process<R: Read, W: Write, C: Configuration>(reader: &mut R, writer: &mut
             while let Ok(_) = reader.read_exact(&mut m) {
                 let c = m[0] as char;
                 if c == '\n' {
+                    log::trace!("UAPI, line: {}", l);
                     return Ok(l);
                 };
                 l.push(c);
@@ -43,12 +44,16 @@ pub fn process<R: Read, W: Write, C: Configuration>(reader: &mut R, writer: &mut
         };
 
         // read operation line
-        match readline(reader)?.as_str() {
-            "get=1" => serialize(writer, config).map_err(|_| ConfigError::IOError),
+        match readline(stream)?.as_str() {
+            "get=1" => {
+                log::debug!("UAPI, Get operation");
+                serialize(stream, config).map_err(|_| ConfigError::IOError)
+            }
             "set=1" => {
+                log::debug!("UAPI, Set operation");
                 let mut parser = LineParser::new(config);
                 loop {
-                    let ln = readline(reader)?;
+                    let ln = readline(stream)?;
                     if ln == "" {
                         break Ok(());
                     };
@@ -61,17 +66,17 @@ pub fn process<R: Read, W: Write, C: Configuration>(reader: &mut R, writer: &mut
     }
 
     // process operation
-    let res = operation(reader, writer, config);
-    log::debug!("{:?}", res);
+    let res = operation(stream, config);
+    log::debug!("UAPI, Result of operation: {:?}", res);
 
     // return errno
-    let _ = writer.write("errno=".as_ref());
-    let _ = writer.write(
+    let _ = stream.write("errno=".as_ref());
+    let _ = stream.write(
         match res {
             Err(e) => e.errno().to_string(),
             Ok(()) => "0".to_owned(),
         }
         .as_ref(),
     );
-    let _ = writer.write("\n\n".as_ref());
+    let _ = stream.write("\n\n".as_ref());
 }
diff --git a/src/configuration/uapi/set.rs b/src/configuration/uapi/set.rs
index 4c2c554..e449edd 100644
--- a/src/configuration/uapi/set.rs
+++ b/src/configuration/uapi/set.rs
@@ -1,18 +1,27 @@
 use hex::FromHex;
+use std::net::{IpAddr, SocketAddr};
 use subtle::ConstantTimeEq;
 use x25519_dalek::{PublicKey, StaticSecret};
 
 use super::{ConfigError, Configuration};
 
-#[derive(Copy, Clone)]
 enum ParserState {
-    Peer {
-        public_key: PublicKey,
-        update_only: bool,
-    },
+    Peer(ParsedPeer),
     Interface,
 }
 
+struct ParsedPeer {
+    public_key: PublicKey,
+    update_only: bool,
+    allowed_ips: Vec<(IpAddr, u32)>,
+    remove: bool,
+    preshared_key: Option<[u8; 32]>,
+    replace_allowed_ips: bool,
+    persistent_keepalive_interval: Option<u64>,
+    protocol_version: Option<usize>,
+    endpoint: Option<SocketAddr>,
+}
+
 pub struct LineParser<'a, C: Configuration> {
     config: &'a C,
     state: ParserState,
@@ -28,45 +37,71 @@ impl<'a, C: Configuration> LineParser<'a, C> {
 
     fn new_peer(value: &str) -> Result<ParserState, ConfigError> {
         match <[u8; 32]>::from_hex(value) {
-            Ok(pk) => Ok(ParserState::Peer {
+            Ok(pk) => Ok(ParserState::Peer(ParsedPeer {
                 public_key: PublicKey::from(pk),
+                remove: false,
                 update_only: false,
-            }),
+                allowed_ips: vec![],
+                preshared_key: None,
+                replace_allowed_ips: false,
+                persistent_keepalive_interval: None,
+                protocol_version: None,
+                endpoint: None,
+            })),
             Err(_) => Err(ConfigError::InvalidHexValue),
         }
     }
 
     pub fn parse_line(&mut self, key: &str, value: &str) -> Result<(), ConfigError> {
-        // add the peer if not update_only
-        let flush_peer = |st: ParserState| -> ParserState {
-            match st {
-                ParserState::Peer {
-                    public_key,
-                    update_only: false,
-                } => {
-                    self.config.add_peer(&public_key);
-                    ParserState::Peer {
-                        public_key,
-                        update_only: true,
-                    }
+        // flush peer updates to configuration
+        fn flush_peer<C: Configuration>(config: &C, peer: &ParsedPeer) -> Option<ConfigError> {
+            if peer.remove {
+                config.remove_peer(&peer.public_key);
+                return None;
+            }
+
+            if !peer.update_only {
+                config.add_peer(&peer.public_key);
+            }
+
+            for (ip, masklen) in &peer.allowed_ips {
+                config.add_allowed_ip(&peer.public_key, *ip, *masklen);
+            }
+
+            if let Some(psk) = peer.preshared_key {
+                config.set_preshared_key(&peer.public_key, psk);
+            }
+
+            if let Some(secs) = peer.persistent_keepalive_interval {
+                config.set_persistent_keepalive_interval(&peer.public_key, secs);
+            }
+
+            if let Some(version) = peer.protocol_version {
+                if version == 0 || version > config.get_protocol_version() {
+                    return Some(ConfigError::UnsupportedProtocolVersion);
                 }
-                _ => st,
             }
+
+            if let Some(endpoint) = peer.endpoint {
+                config.set_endpoint(&peer.public_key, endpoint);
+            };
+
+            None
         };
 
         // parse line and update parser state
-        self.state = match self.state {
+        match self.state {
             // configure the interface
             ParserState::Interface => match key {
                 // opt: set private key
                 "private_key" => match <[u8; 32]>::from_hex(value) {
                     Ok(sk) => {
-                        self.config.set_private_key(if sk == [0u8; 32] {
+                        self.config.set_private_key(if sk.ct_eq(&[0u8; 32]).into() {
                             None
                         } else {
                             Some(StaticSecret::from(sk))
                         });
-                        Ok(self.state)
+                        Ok(())
                     }
                     Err(_) => Err(ConfigError::InvalidHexValue),
                 },
@@ -75,7 +110,7 @@ impl<'a, C: Configuration> LineParser<'a, C> {
                 "listen_port" => match value.parse() {
                     Ok(port) => {
                         self.config.set_listen_port(Some(port));
-                        Ok(self.state)
+                        Ok(())
                     }
                     Err(_) => Err(ConfigError::InvalidPortNumber),
                 },
@@ -85,7 +120,7 @@ impl<'a, C: Configuration> LineParser<'a, C> {
                     Ok(fwmark) => {
                         self.config
                             .set_fwmark(if fwmark == 0 { None } else { Some(fwmark) });
-                        Ok(self.state)
+                        Ok(())
                     }
                     Err(_) => Err(ConfigError::InvalidFwmark),
                 },
@@ -96,51 +131,47 @@ impl<'a, C: Configuration> LineParser<'a, C> {
                         for p in self.config.get_peers() {
                             self.config.remove_peer(&p.public_key)
                         }
-                        Ok(self.state)
+                        Ok(())
                     }
                     _ => Err(ConfigError::UnsupportedValue),
                 },
 
                 // opt: transition to peer configuration
-                "public_key" => Self::new_peer(value),
+                "public_key" => {
+                    self.state = Self::new_peer(value)?;
+                    Ok(())
+                }
 
                 // unknown key
                 _ => Err(ConfigError::InvalidKey),
             },
 
             // configure peers
-            ParserState::Peer { public_key, .. } => match key {
+            ParserState::Peer(ref mut peer) => match key {
                 // opt: new peer
                 "public_key" => {
-                    flush_peer(self.state);
-                    Self::new_peer(value)
+                    flush_peer(self.config, &peer);
+                    self.state = Self::new_peer(value)?;
+                    Ok(())
                 }
 
                 // opt: remove peer
                 "remove" => {
-                    self.config.remove_peer(&public_key);
-                    Ok(self.state)
+                    peer.remove = true;
+                    Ok(())
                 }
 
                 // opt: update only
-                "update_only" => Ok(ParserState::Peer {
-                    public_key,
-                    update_only: true,
-                }),
+                "update_only" => {
+                    peer.update_only = true;
+                    Ok(())
+                }
 
                 // opt: set preshared key
                 "preshared_key" => match <[u8; 32]>::from_hex(value) {
                     Ok(psk) => {
-                        let st = flush_peer(self.state);
-                        self.config.set_preshared_key(
-                            &public_key,
-                            if psk.ct_eq(&[0u8; 32]).into() {
-                                None
-                            } else {
-                                Some(psk)
-                            },
-                        );
-                        Ok(st)
+                        peer.preshared_key = Some(psk);
+                        Ok(())
                     }
                     Err(_) => Err(ConfigError::InvalidHexValue),
                 },
@@ -148,9 +179,8 @@ impl<'a, C: Configuration> LineParser<'a, C> {
                 // opt: set endpoint
                 "endpoint" => match value.parse() {
                     Ok(endpoint) => {
-                        let st = flush_peer(self.state);
-                        self.config.set_endpoint(&public_key, endpoint);
-                        Ok(st)
+                        peer.endpoint = Some(endpoint);
+                        Ok(())
                     }
                     Err(_) => Err(ConfigError::InvalidSocketAddr),
                 },
@@ -158,19 +188,17 @@ impl<'a, C: Configuration> LineParser<'a, C> {
                 // opt: set persistent keepalive interval
                 "persistent_keepalive_interval" => match value.parse() {
                     Ok(secs) => {
-                        let st = flush_peer(self.state);
-                        self.config
-                            .set_persistent_keepalive_interval(&public_key, secs);
-                        Ok(st)
+                        peer.persistent_keepalive_interval = Some(secs);
+                        Ok(())
                     }
                     Err(_) => Err(ConfigError::InvalidKeepaliveInterval),
                 },
 
                 // opt replace allowed ips
                 "replace_allowed_ips" => {
-                    let st = flush_peer(self.state);
-                    self.config.replace_allowed_ips(&public_key);
-                    Ok(st)
+                    peer.replace_allowed_ips = true;
+                    peer.allowed_ips.clear();
+                    Ok(())
                 }
 
                 // opt add allowed ips
@@ -180,9 +208,8 @@ impl<'a, C: Configuration> LineParser<'a, C> {
                     let cidr = split.next().and_then(|x| x.parse().ok());
                     match (addr, cidr) {
                         (Some(addr), Some(cidr)) => {
-                            let st = flush_peer(self.state);
-                            self.config.add_allowed_ip(&public_key, addr, cidr);
-                            Ok(st)
+                            peer.allowed_ips.push((addr, cidr));
+                            Ok(())
                         }
                         _ => Err(ConfigError::InvalidAllowedIp),
                     }
@@ -193,11 +220,8 @@ impl<'a, C: Configuration> LineParser<'a, C> {
                     let parse_res: Result<usize, _> = value.parse();
                     match parse_res {
                         Ok(version) => {
-                            if version == 0 || version > self.config.get_protocol_version() {
-                                Err(ConfigError::UnsupportedProtocolVersion)
-                            } else {
-                                Ok(self.state)
-                            }
+                            peer.protocol_version = Some(version);
+                            Ok(())
                         }
                         Err(_) => Err(ConfigError::UnsupportedProtocolVersion),
                     }
@@ -206,8 +230,6 @@ impl<'a, C: Configuration> LineParser<'a, C> {
                 // unknown key
                 _ => Err(ConfigError::InvalidKey),
             },
-        }?;
-
-        Ok(())
+        }
     }
 }
diff --git a/src/main.rs b/src/main.rs
index 4d34b39..e17a127 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -10,21 +10,35 @@ mod configuration;
 mod platform;
 mod wireguard;
 
-use platform::tun;
+use platform::tun::PlatformTun;
+use platform::uapi::PlatformUAPI;
+use platform::*;
 
-use configuration::WireguardConfig;
+use std::sync::Arc;
+use std::thread;
+use std::time::Duration;
 
 fn main() {
-    /*
-    let (mut readers, writer, mtu) = platform::TunInstance::create("test").unwrap();
-    let wg = wireguard::Wireguard::new(readers, writer, mtu);
-    */
-}
+    let name = "wg0";
+
+    let _ = env_logger::builder().is_test(true).try_init();
+
+    // create UAPI socket
+    let uapi = plt::UAPI::bind(name).unwrap();
+
+    // create TUN device
+    let (readers, writer, mtu) = plt::Tun::create(name).unwrap();
+
+    // create WireGuard device
+    let wg: wireguard::Wireguard<plt::Tun, plt::Bind> =
+        wireguard::Wireguard::new(readers, writer, mtu);
 
-/*
-fn test_wg_configuration() {
-    let (mut readers, writer, mtu) = platform::dummy::
+    // wrap in configuration interface and start UAPI server
+    let cfg = configuration::WireguardConfig::new(wg);
+    loop {
+        let mut stream = uapi.accept().unwrap();
+        configuration::uapi::handle(&mut stream.0, &cfg);
+    }
 
-    let wg = wireguard::Wireguard::new(readers, writer, mtu);
+    thread::sleep(Duration::from_secs(600));
 }
-*/
diff --git a/src/platform/bind.rs b/src/platform/bind.rs
index 1a234c7..1055f37 100644
--- a/src/platform/bind.rs
+++ b/src/platform/bind.rs
@@ -37,7 +37,7 @@ pub trait Owner: Send {
 
 /// On some platforms the application can itself bind to a socket.
 /// This enables configuration using the UAPI interface.
-pub trait Platform: Bind {
+pub trait PlatformBind: Bind {
     type Owner: Owner;
 
     /// Bind to a new port, returning the reader/writer and
diff --git a/src/platform/dummy/bind.rs b/src/platform/dummy/bind.rs
index 2c30486..b42483a 100644
--- a/src/platform/dummy/bind.rs
+++ b/src/platform/dummy/bind.rs
@@ -216,7 +216,7 @@ impl Owner for VoidOwner {
     }
 }
 
-impl Platform for PairBind {
+impl PlatformBind for PairBind {
     type Owner = VoidOwner;
     fn bind(_port: u16) -> Result<(Vec<Self::Reader>, Self::Writer, Self::Owner), Self::Error> {
         Err(BindError::Disconnected)
diff --git a/src/platform/dummy/tun.rs b/src/platform/dummy/tun.rs
index 185b328..569bf1c 100644
--- a/src/platform/dummy/tun.rs
+++ b/src/platform/dummy/tun.rs
@@ -192,7 +192,7 @@ impl TunTest {
     }
 }
 
-impl Platform for TunTest {
+impl PlatformTun for TunTest {
     fn create(_name: &str) -> Result<(Vec<Self::Reader>, Self::Writer, Self::MTU), Self::Error> {
         Err(TunError::Disconnected)
     }
diff --git a/src/platform/linux/mod.rs b/src/platform/linux/mod.rs
index 7d6a61c..82731de 100644
--- a/src/platform/linux/mod.rs
+++ b/src/platform/linux/mod.rs
@@ -1,5 +1,7 @@
 mod tun;
+mod uapi;
 mod udp;
 
-pub use tun::LinuxTun;
-pub use udp::LinuxBind;
+pub use tun::LinuxTun as Tun;
+pub use uapi::LinuxUAPI as UAPI;
+pub use udp::LinuxBind as Bind;
diff --git a/src/platform/linux/tun.rs b/src/platform/linux/tun.rs
index 090569a..0bbae81 100644
--- a/src/platform/linux/tun.rs
+++ b/src/platform/linux/tun.rs
@@ -125,7 +125,7 @@ impl Tun for LinuxTun {
     type MTU = LinuxTunMTU;
 }
 
-impl Platform for LinuxTun {
+impl PlatformTun for LinuxTun {
     fn create(name: &str) -> Result<(Vec<Self::Reader>, Self::Writer, Self::MTU), Self::Error> {
         // construct request struct
         let mut req = Ifreq {
diff --git a/src/platform/linux/uapi.rs b/src/platform/linux/uapi.rs
new file mode 100644
index 0000000..fdf2bf0
--- /dev/null
+++ b/src/platform/linux/uapi.rs
@@ -0,0 +1,31 @@
+use super::super::uapi::*;
+
+use std::fs;
+use std::io;
+use std::os::unix::net::{UnixListener, UnixStream};
+
+const SOCK_DIR: &str = "/var/run/wireguard/";
+
+pub struct LinuxUAPI {}
+
+impl PlatformUAPI for LinuxUAPI {
+    type Error = io::Error;
+    type Bind = UnixListener;
+
+    fn bind(name: &str) -> Result<UnixListener, io::Error> {
+        let socket_path = format!("{}{}.sock", SOCK_DIR, name);
+        let _ = fs::create_dir_all(SOCK_DIR);
+        let _ = fs::remove_file(&socket_path);
+        UnixListener::bind(socket_path)
+    }
+}
+
+impl BindUAPI for UnixListener {
+    type Stream = UnixStream;
+    type Error = io::Error;
+
+    fn accept(&self) -> Result<UnixStream, io::Error> {
+        let (stream, _) = self.accept()?;
+        Ok(stream)
+    }
+}
diff --git a/src/platform/linux/udp.rs b/src/platform/linux/udp.rs
index 52e4c45..d3d61b6 100644
--- a/src/platform/linux/udp.rs
+++ b/src/platform/linux/udp.rs
@@ -1,26 +1,82 @@
 use super::super::bind::*;
 use super::super::Endpoint;
 
-use std::net::SocketAddr;
+use std::io;
+use std::net::{SocketAddr, UdpSocket};
+use std::sync::Arc;
 
-pub struct LinuxEndpoint {}
+#[derive(Clone)]
+pub struct LinuxBind(Arc<UdpSocket>);
 
-pub struct LinuxBind {}
+pub struct LinuxOwner(Arc<UdpSocket>);
 
-impl Endpoint for LinuxEndpoint {
+impl Endpoint for SocketAddr {
     fn clear_src(&mut self) {}
 
     fn from_address(addr: SocketAddr) -> Self {
-        LinuxEndpoint {}
+        addr
     }
 
     fn into_address(&self) -> SocketAddr {
-        "127.0.0.1:6060".parse().unwrap()
+        *self
     }
 }
 
-/*
-impl Bind for PlatformBind {
-    type Endpoint = PlatformEndpoint;
+impl Reader<SocketAddr> for LinuxBind {
+    type Error = io::Error;
+
+    fn read(&self, buf: &mut [u8]) -> Result<(usize, SocketAddr), Self::Error> {
+        self.0.recv_from(buf)
+    }
+}
+
+impl Writer<SocketAddr> for LinuxBind {
+    type Error = io::Error;
+
+    fn write(&self, buf: &[u8], dst: &SocketAddr) -> Result<(), Self::Error> {
+        self.0.send_to(buf, dst)?;
+        Ok(())
+    }
+}
+
+impl Owner for LinuxOwner {
+    type Error = io::Error;
+
+    fn get_port(&self) -> u16 {
+        1337
+    }
+
+    fn get_fwmark(&self) -> Option<u32> {
+        None
+    }
+
+    fn set_fwmark(&mut self, value: Option<u32>) -> Option<Self::Error> {
+        None
+    }
+}
+
+impl Drop for LinuxOwner {
+    fn drop(&mut self) {}
+}
+
+impl Bind for LinuxBind {
+    type Error = io::Error;
+    type Endpoint = SocketAddr;
+    type Reader = LinuxBind;
+    type Writer = LinuxBind;
+}
+
+impl PlatformBind for LinuxBind {
+    type Owner = LinuxOwner;
+
+    fn bind(port: u16) -> Result<(Vec<Self::Reader>, Self::Writer, Self::Owner), Self::Error> {
+        let socket = UdpSocket::bind(format!("0.0.0.0:{}", port))?;
+        let socket = Arc::new(socket);
+
+        Ok((
+            vec![LinuxBind(socket.clone())],
+            LinuxBind(socket.clone()),
+            LinuxOwner(socket),
+        ))
+    }
 }
-*/
diff --git a/src/platform/mod.rs b/src/platform/mod.rs
index ecd559a..99707e3 100644
--- a/src/platform/mod.rs
+++ b/src/platform/mod.rs
@@ -2,14 +2,15 @@ mod endpoint;
 
 pub mod bind;
 pub mod tun;
+pub mod uapi;
 
 pub use endpoint::Endpoint;
 
 #[cfg(target_os = "linux")]
-mod linux;
+pub mod linux;
 
 #[cfg(test)]
 pub mod dummy;
 
 #[cfg(target_os = "linux")]
-pub use linux::LinuxTun as TunInstance;
+pub use linux as plt;
diff --git a/src/platform/tun.rs b/src/platform/tun.rs
index f49d4af..c92304a 100644
--- a/src/platform/tun.rs
+++ b/src/platform/tun.rs
@@ -56,6 +56,6 @@ pub trait Tun: Send + Sync + 'static {
 }
 
 /// On some platforms the application can create the TUN device itself.
-pub trait Platform: Tun {
+pub trait PlatformTun: Tun {
     fn create(name: &str) -> Result<(Vec<Self::Reader>, Self::Writer, Self::MTU), Self::Error>;
 }
diff --git a/src/platform/uapi.rs b/src/platform/uapi.rs
new file mode 100644
index 0000000..6922a9c
--- /dev/null
+++ b/src/platform/uapi.rs
@@ -0,0 +1,16 @@
+use std::error::Error;
+use std::io::{Read, Write};
+
+pub trait BindUAPI {
+    type Stream: Read + Write;
+    type Error: Error;
+
+    fn accept(&self) -> Result<Self::Stream, Self::Error>;
+}
+
+pub trait PlatformUAPI {
+    type Error: Error;
+    type Bind: BindUAPI;
+
+    fn bind(name: &str) -> Result<Self::Bind, Self::Error>;
+}
diff --git a/src/wireguard/handshake/device.rs b/src/wireguard/handshake/device.rs
index f65692c..02e6929 100644
--- a/src/wireguard/handshake/device.rs
+++ b/src/wireguard/handshake/device.rs
@@ -178,13 +178,10 @@ impl Device {
     /// # Returns
     ///
     /// The call might fail if the public key is not found
-    pub fn set_psk(&mut self, pk: PublicKey, psk: Option<Psk>) -> Result<(), ConfigError> {
+    pub fn set_psk(&mut self, pk: PublicKey, psk: Psk) -> Result<(), ConfigError> {
         match self.pk_map.get_mut(pk.as_bytes()) {
             Some(mut peer) => {
-                peer.psk = match psk {
-                    Some(v) => v,
-                    None => [0u8; 32],
-                };
+                peer.psk = psk;
                 Ok(())
             }
             _ => Err(ConfigError::new("No such public key")),
@@ -466,8 +463,8 @@ mod tests {
         dev1.add(pk2).unwrap();
         dev2.add(pk1).unwrap();
 
-        dev1.set_psk(pk2, Some(psk)).unwrap();
-        dev2.set_psk(pk1, Some(psk)).unwrap();
+        dev1.set_psk(pk2, psk).unwrap();
+        dev2.set_psk(pk1, psk).unwrap();
 
         (pk1, dev1, pk2, dev2)
     }
diff --git a/src/wireguard/wireguard.rs b/src/wireguard/wireguard.rs
index 77be9f8..c0a8d9d 100644
--- a/src/wireguard/wireguard.rs
+++ b/src/wireguard/wireguard.rs
@@ -201,7 +201,7 @@ impl<T: Tun, B: Bind> Wireguard<T, B> {
             .map(|sk| StaticSecret::from(sk.to_bytes()))
     }
 
-    pub fn set_psk(&self, pk: PublicKey, psk: Option<[u8; 32]>) -> bool {
+    pub fn set_psk(&self, pk: PublicKey, psk: [u8; 32]) -> bool {
         self.state.handshake.write().set_psk(pk, psk).is_ok()
     }
     pub fn get_psk(&self, pk: &PublicKey) -> Option<[u8; 32]> {