init

5 files changed, 1807 insertions, 0 deletions

diff --git a/src/conf.rs b/src/conf.rs
new file mode 100644
index 0000000..b6e49a0
--- /dev/null
+++ b/src/conf.rs
@@ -0,0 +1,692 @@
+use std::{fmt::Write, str::FromStr};
+
+use ipnet::IpNet;
+
+use super::Key;
+
+const FIELD_PRIVATE_KEY: &str = "PrivateKey";
+const FIELD_LISTEN_PORT: &str = "ListenPort";
+const FIELD_FWMARK: &str = "FwMark";
+const FIELD_PUBLIC_KEY: &str = "PublicKey";
+const FIELD_PRE_SHARED_KEY: &str = "PresharedKey";
+const FIELD_ALLOWED_IPS: &str = "AllowedIPs";
+const FIELD_ENDPOINT: &str = "Endpoint";
+const FIELD_PERSISTENT_KEEPALIVE: &str = "PersistentKeepalive";
+
+// wg-quick fields
+const FIELD_ADDRESS: &str = "Address";
+const FIELD_DNS: &str = "DNS";
+
+macro_rules! header {
+    ($dest:expr, $h:expr) => {
+        writeln!($dest, "[{}]", $h).unwrap();
+    };
+}
+
+macro_rules! field {
+    ($dest:expr, $n:expr, $v:expr) => {
+        writeln!($dest, "{} = {}", $n, $v).unwrap();
+    };
+}
+
+macro_rules! field_csv {
+    ($dest:expr, $n:expr, $v:expr) => {
+        if !$v.is_empty() {
+            write!($dest, "{} = ", $n).unwrap();
+            let mut comma = false;
+            for e in $v.iter() {
+                if comma {
+                    write!($dest, ", ").unwrap();
+                } else {
+                    comma = true;
+                }
+                write!($dest, "{}", e).unwrap();
+            }
+            writeln!($dest).unwrap();
+        }
+    };
+}
+
+macro_rules! field_opt {
+    ($dest:expr, $n:expr, $v:expr) => {
+        if let Some(ref v) = $v {
+            field!($dest, $n, v);
+        }
+    };
+}
+
+#[derive(Debug, Clone)]
+pub struct WgInterface {
+    pub private_key: Key,
+    pub address: Vec<IpNet>,
+    pub listen_port: Option<u16>,
+    pub fw_mark: Option<u32>,
+    pub dns: Option<String>,
+}
+
+#[derive(Debug, Clone)]
+pub struct WgPeer {
+    pub public_key: Key,
+    pub preshared_key: Option<Key>,
+    pub allowed_ips: Vec<IpNet>,
+    pub endpoint: Option<String>,
+    pub keep_alive: Option<u16>,
+}
+
+impl WgPeer {
+    pub fn builder(public_key: Key) -> WgPeerBuilder {
+        WgPeerBuilder::new(public_key)
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct WgConf {
+    pub interface: WgInterface,
+    pub peers: Vec<WgPeer>,
+}
+
+impl WgConf {
+    pub fn builder() -> WgConfBuilder {
+        WgConfBuilder::new()
+    }
+}
+
+#[derive(Debug)]
+pub struct WgPeerBuilder {
+    pub public_key: Key,
+    pub preshared_key: Option<Key>,
+    pub allowed_ips: Vec<IpNet>,
+    pub endpoint: Option<String>,
+    pub keep_alive: Option<u16>,
+}
+
+impl WgPeerBuilder {
+    pub fn new(public_key: Key) -> WgPeerBuilder {
+        WgPeerBuilder {
+            public_key,
+            preshared_key: None,
+            allowed_ips: Vec::new(),
+            endpoint: None,
+            keep_alive: None,
+        }
+    }
+
+    pub fn preshared_key(mut self, preshared_key: Key) -> Self {
+        self.preshared_key = Some(preshared_key);
+        self
+    }
+
+    pub fn allowed_ip(mut self, allowed_ip: IpNet) -> Self {
+        self.allowed_ips.push(allowed_ip);
+        self
+    }
+
+    pub fn allowed_ips(mut self, allowed_ips: impl IntoIterator<Item = IpNet>) -> Self {
+        self.allowed_ips.extend(allowed_ips);
+        self
+    }
+
+    pub fn endpoint(mut self, endpoint: impl Into<String>) -> Self {
+        self.endpoint = Some(endpoint.into());
+        self
+    }
+
+    pub fn endpoint_opt(mut self, endpoint: Option<impl Into<String>>) -> Self {
+        if let Some(endpoint) = endpoint {
+            self.endpoint = Some(endpoint.into());
+        }
+        self
+    }
+
+    pub fn keep_alive(mut self, keep_alive: u16) -> Self {
+        self.keep_alive = Some(keep_alive);
+        self
+    }
+
+    pub fn build(self) -> WgPeer {
+        WgPeer {
+            public_key: self.public_key,
+            preshared_key: self.preshared_key,
+            allowed_ips: self.allowed_ips,
+            endpoint: self.endpoint,
+            keep_alive: self.keep_alive,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct WgConfBuilder {
+    private_key: Option<Key>,
+    address: Vec<IpNet>,
+    listen_port: Option<u16>,
+    fw_mark: Option<u32>,
+    dns: Option<String>,
+    peers: Vec<WgPeer>,
+}
+
+impl WgConfBuilder {
+    pub fn new() -> Self {
+        WgConfBuilder {
+            private_key: None,
+            address: Vec::new(),
+            listen_port: None,
+            fw_mark: None,
+            dns: None,
+            peers: Vec::new(),
+        }
+    }
+
+    pub fn private_key(mut self, private_key: Key) -> Self {
+        self.private_key = Some(private_key);
+        self
+    }
+
+    pub fn address(mut self, address: impl Into<IpNet>) -> Self {
+        self.address.push(address.into());
+        self
+    }
+
+    pub fn addresses(mut self, addresses: impl IntoIterator<Item = IpNet>) -> Self {
+        self.address.extend(addresses);
+        self
+    }
+
+    pub fn listen_port(mut self, listen_port: u16) -> Self {
+        self.listen_port = Some(listen_port);
+        self
+    }
+
+    pub fn fw_mark(mut self, fw_mark: u32) -> Self {
+        self.fw_mark = Some(fw_mark);
+        self
+    }
+
+    pub fn dns(mut self, dns: impl Into<String>) -> Self {
+        self.dns = Some(dns.into());
+        self
+    }
+
+    pub fn dns_opt(mut self, dns: Option<impl Into<String>>) -> Self {
+        if let Some(dns) = dns {
+            self.dns = Some(dns.into());
+        }
+        self
+    }
+
+    pub fn peer(mut self, peer: WgPeer) -> Self {
+        self.peers.push(peer);
+        self
+    }
+
+    pub fn peers(mut self, peers: impl IntoIterator<Item = WgPeer>) -> Self {
+        self.peers.extend(peers);
+        self
+    }
+
+    pub fn build(self) -> WgConf {
+        WgConf {
+            interface: WgInterface {
+                private_key: self.private_key.unwrap_or_else(Key::generate_private),
+                address: self.address,
+                listen_port: self.listen_port,
+                fw_mark: self.fw_mark,
+                dns: self.dns,
+            },
+            peers: self.peers,
+        }
+    }
+}
+
+#[derive(Default)]
+struct PartialConf {
+    interface: Option<WgInterface>,
+    peers: Vec<WgPeer>,
+}
+
+pub fn parse_conf(conf: &str) -> anyhow::Result<WgConf> {
+    let mut iter = conf.lines().filter_map(|l| {
+        // remove whitespace on the sides
+        let l = l.trim();
+        // remove the comment
+        let (l, _) = l.rsplit_once("#").unwrap_or((l, ""));
+        if l.is_empty() {
+            None
+        } else {
+            Some(l)
+        }
+    });
+
+    let mut partial = PartialConf::default();
+    parse_partial(&mut partial, &mut iter)?;
+
+    match partial.interface {
+        Some(interface) => Ok(WgConf {
+            interface,
+            peers: partial.peers,
+        }),
+        None => Err(anyhow::anyhow!("no interface found")),
+    }
+}
+
+pub fn serialize_conf(conf: &WgConf) -> String {
+    let mut conf_str = String::new();
+    header!(conf_str, "Interface");
+    field!(conf_str, FIELD_PRIVATE_KEY, conf.interface.private_key);
+    field_csv!(conf_str, FIELD_ADDRESS, conf.interface.address);
+    field_opt!(conf_str, FIELD_LISTEN_PORT, conf.interface.listen_port);
+    field_opt!(conf_str, FIELD_FWMARK, conf.interface.fw_mark);
+    field_opt!(conf_str, FIELD_DNS, conf.interface.dns);
+    for peer in conf.peers.iter() {
+        writeln!(conf_str).unwrap();
+        header!(conf_str, "Peer");
+        field!(conf_str, FIELD_PUBLIC_KEY, peer.public_key);
+        field_opt!(conf_str, FIELD_PRE_SHARED_KEY, peer.preshared_key);
+        field_csv!(conf_str, FIELD_ALLOWED_IPS, peer.allowed_ips);
+        field_opt!(conf_str, FIELD_ENDPOINT, peer.endpoint);
+        field_opt!(conf_str, FIELD_PERSISTENT_KEEPALIVE, peer.keep_alive);
+    }
+    conf_str
+}
+
+fn parse_partial<'s, I: Iterator<Item = &'s str>>(
+    cfg: &mut PartialConf,
+    iter: &mut I,
+) -> anyhow::Result<()> {
+    match iter.next() {
+        Some("[Interface]") => parse_interface(cfg, iter),
+        Some("[Peer]") => parse_peer(cfg, iter),
+        Some(line) => Err(anyhow::anyhow!("unexpected line: {}", line)),
+        None => Err(anyhow::anyhow!("unexpected end of file")),
+    }
+}
+
+fn parse_interface<'s, I: Iterator<Item = &'s str>>(
+    cfg: &mut PartialConf,
+    iter: &mut I,
+) -> anyhow::Result<()> {
+    let mut private_key = None;
+    let mut address = Vec::new();
+    let mut listen_port = None;
+    let mut fw_mark = None;
+    let mut dns = None;
+    let mut peer_next = false;
+
+    if cfg.interface.is_some() {
+        anyhow::bail!("cannot have more than one interface");
+    }
+
+    while let Some(line) = iter.next() {
+        if line == "[Peer]" {
+            peer_next = true;
+            break;
+        }
+
+        let (key, value) = parse_key_value(line)?;
+        match key {
+            FIELD_PRIVATE_KEY => private_key = Some(value.parse()?),
+            FIELD_LISTEN_PORT => listen_port = Some(value.parse()?),
+            FIELD_FWMARK => fw_mark = Some(value.parse()?),
+            FIELD_ADDRESS => address = parse_csv(value)?,
+            FIELD_DNS => dns = Some(value.to_string()),
+            _ => anyhow::bail!("unexpected key: {}", key),
+        }
+    }
+
+    cfg.interface = Some(WgInterface {
+        private_key: private_key.ok_or_else(|| anyhow::anyhow!("interface missing private key"))?,
+        address,
+        listen_port,
+        fw_mark,
+        dns,
+    });
+
+    if peer_next {
+        parse_peer(cfg, iter)
+    } else {
+        Ok(())
+    }
+}
+
+fn parse_peer<'s, I: Iterator<Item = &'s str>>(
+    cfg: &mut PartialConf,
+    iter: &mut I,
+) -> anyhow::Result<()> {
+    let mut public_key = None;
+    let mut preshared_key = None;
+    let mut allowed_ips = Vec::new();
+    let mut endpoint = None;
+    let mut keep_alive = None;
+    let mut interface_next = false;
+    let mut peer_next = false;
+
+    while let Some(line) = iter.next() {
+        if line == "[Interface]" {
+            interface_next = true;
+            break;
+        }
+        if line == "[Peer]" {
+            peer_next = true;
+            break;
+        }
+
+        let (key, value) = parse_key_value(line)?;
+        match key {
+            FIELD_PUBLIC_KEY => public_key = Some(value.parse()?),
+            FIELD_PRE_SHARED_KEY => preshared_key = Some(value.parse()?),
+            FIELD_ALLOWED_IPS => allowed_ips = parse_csv(value)?,
+            FIELD_ENDPOINT => endpoint = Some(value.to_string()),
+            FIELD_PERSISTENT_KEEPALIVE => keep_alive = Some(value.parse()?),
+            _ => anyhow::bail!("unexpected key: {}", key),
+        }
+    }
+
+    cfg.peers.push(WgPeer {
+        public_key: public_key.ok_or_else(|| anyhow::anyhow!("peer missing public key"))?,
+        preshared_key,
+        allowed_ips,
+        endpoint,
+        keep_alive,
+    });
+
+    if interface_next {
+        parse_interface(cfg, iter)
+    } else if peer_next {
+        parse_peer(cfg, iter)
+    } else {
+        Ok(())
+    }
+}
+
+fn parse_key_value<'s>(line: &'s str) -> anyhow::Result<(&'s str, &'s str)> {
+    line.split_once("=")
+        .map(|(k, v)| (k.trim(), v.trim()))
+        .ok_or_else(|| anyhow::anyhow!("invalid line: {}", line))
+}
+
+fn parse_csv<
+    'v,
+    T: FromStr<Err = impl std::error::Error + std::marker::Sync + std::marker::Send + 'static>,
+>(
+    value: &'v str,
+) -> anyhow::Result<Vec<T>> {
+    let mut values = Vec::new();
+    for v in value.split(',').map(str::trim) {
+        values.push(v.parse()?);
+    }
+    Ok(values)
+}
+
+#[cfg(test)]
+mod tests {
+    use std::net::Ipv4Addr;
+
+    use ipnet::{IpNet, Ipv4Net};
+
+    use crate::Key;
+
+    use super::{WgConfBuilder, WgPeerBuilder};
+
+    const TEST_CONF_1: &str = r#"
+            [Interface]
+            PrivateKey = yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=
+            ListenPort = 51820
+
+            [Peer]
+            PublicKey = xTIBA5rboUvnH4htodjb6e697QjLERt1NAB4mZqp8Dg=
+            Endpoint = 192.95.5.67:1234
+            AllowedIPs = 10.192.122.3/32, 10.192.124.1/24
+
+            [Peer]
+            PublicKey = TrMvSoP4jYQlY6RIzBgbssQqY3vxI2Pi+y71lOWWXX0=
+            Endpoint = [2607:5300:60:6b0::c05f:543]:2468
+            AllowedIPs = 10.192.122.4/32, 192.168.0.0/16
+
+            [Peer]
+            PublicKey = gN65BkIKy1eCE9pP1wdc8ROUtkHLF2PfAqYdyYBz6EA=
+            Endpoint = test.wireguard.com:18981
+
+            AllowedIPs = 10.10.10.230/32
+            PersistentKeepalive = 54
+"#;
+
+    const TEST_CONF_2: &str = r#"
+            [Peer]
+            PublicKey = xTIBA5rboUvnH4htodjb6e697QjLERt1NAB4mZqp8Dg=
+            Endpoint = 192.95.5.67:1234
+            AllowedIPs = 10.192.122.3/32, 10.192.124.1/24
+
+            [Peer]
+            PublicKey = TrMvSoP4jYQlY6RIzBgbssQqY3vxI2Pi+y71lOWWXX0=
+            Endpoint = [2607:5300:60:6b0::c05f:543]:2468
+            AllowedIPs = 10.192.122.4/32, 192.168.0.0/16
+
+            [Interface]
+            PrivateKey = yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=
+            ListenPort = 51820
+
+            [Peer]
+            PublicKey = gN65BkIKy1eCE9pP1wdc8ROUtkHLF2PfAqYdyYBz6EA=
+            Endpoint = test.wireguard.com:18981
+
+            AllowedIPs = 10.10.10.230/32
+            PersistentKeepalive = 54
+"#;
+
+    const TEST_CONF_3: &str = r#"
+            [Interface]
+            PrivateKey = yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=
+            ListenPort = 51820
+
+            [Interface]
+            PrivateKey = yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=
+            ListenPort = 51821
+
+            [Peer]
+            PublicKey = gN65BkIKy1eCE9pP1wdc8ROUtkHLF2PfAqYdyYBz6EA=
+            Endpoint = test.wireguard.com:18981
+            AllowedIPs = 10.10.10.230/32
+"#;
+
+    const TEST_CONF_4: &str = "";
+
+    const TEST_CONF_5: &str = r#"
+            PublicKey = 1
+
+            [Interface]
+            PrivateKey = yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=
+            ListenPort = 51820
+
+            [Peer]
+            PublicKey = gN65BkIKy1eCE9pP1wdc8ROUtkHLF2PfAqYdyYBz6EA=
+            Endpoint = test.wireguard.com:18981
+            AllowedIPs = 10.10.10.230/32
+"#;
+
+    const TEST_CONF_6: &str = r#"
+            [Interface]
+            PrivateKey = yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=
+            ListenPort = 51820
+            Unknown = 1
+
+            [Peer]
+            PublicKey = gN65BkIKy1eCE9pP1wdc8ROUtkHLF2PfAqYdyYBz6EA=
+            Endpoint = test.wireguard.com:18981
+            AllowedIPs = 10.10.10.230/32
+"#;
+
+    const TEST_CONF_7: &str = r#"
+            [Interface]
+            PrivateKey = yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=
+            ListenPort = 51820
+"#;
+
+    #[test]
+    fn parse_config() {
+        parse_config_1_and_2(TEST_CONF_1);
+    }
+
+    #[test]
+    fn parse_config_out_of_order_interface() {
+        parse_config_1_and_2(TEST_CONF_2);
+    }
+
+    #[test]
+    #[should_panic]
+    fn parse_config_duplicate_interface() {
+        super::parse_conf(TEST_CONF_3).unwrap();
+    }
+
+    #[test]
+    #[should_panic]
+    fn parse_config_empty() {
+        super::parse_conf(TEST_CONF_4).unwrap();
+    }
+
+    #[test]
+    #[should_panic]
+    fn parse_config_out_of_order_field() {
+        super::parse_conf(TEST_CONF_5).unwrap();
+    }
+
+    #[test]
+    #[should_panic]
+    fn parse_config_unkown_field() {
+        super::parse_conf(TEST_CONF_6).unwrap();
+    }
+
+    #[test]
+    fn parse_config_no_peers() {
+        let cfg = super::parse_conf(TEST_CONF_7).unwrap();
+
+        assert_eq!(
+            "yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=",
+            cfg.interface.private_key.to_string(),
+        );
+        assert_eq!(Some(51820), cfg.interface.listen_port);
+        assert_eq!(None, cfg.interface.fw_mark);
+
+        assert_eq!(0, cfg.peers.len());
+    }
+
+    fn parse_config_1_and_2(conf_str: &str) {
+        let cfg = super::parse_conf(conf_str).unwrap();
+
+        assert_eq!(
+            "yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=",
+            cfg.interface.private_key.to_string()
+        );
+        assert_eq!(Some(51820), cfg.interface.listen_port);
+        assert_eq!(None, cfg.interface.fw_mark);
+
+        assert_eq!(3, cfg.peers.len());
+
+        let peer = &cfg.peers[0];
+        assert_eq!(
+            "xTIBA5rboUvnH4htodjb6e697QjLERt1NAB4mZqp8Dg=",
+            peer.public_key.to_string()
+        );
+        assert_eq!(None, peer.preshared_key);
+        assert_eq!(2, peer.allowed_ips.len());
+        assert_eq!(Some("192.95.5.67:1234"), peer.endpoint.as_deref());
+        assert_eq!(None, peer.keep_alive);
+
+        let peer = &cfg.peers[1];
+        assert_eq!(
+            "TrMvSoP4jYQlY6RIzBgbssQqY3vxI2Pi+y71lOWWXX0=",
+            peer.public_key.to_string()
+        );
+        assert_eq!(None, peer.preshared_key);
+        assert_eq!(2, peer.allowed_ips.len());
+        assert_eq!(
+            Some("[2607:5300:60:6b0::c05f:543]:2468"),
+            peer.endpoint.as_deref()
+        );
+        assert_eq!(None, peer.keep_alive);
+
+        let peer = &cfg.peers[2];
+        assert_eq!(
+            "gN65BkIKy1eCE9pP1wdc8ROUtkHLF2PfAqYdyYBz6EA=",
+            peer.public_key.to_string()
+        );
+        assert_eq!(None, peer.preshared_key);
+        assert_eq!(1, peer.allowed_ips.len());
+        assert_eq!(Some("test.wireguard.com:18981"), peer.endpoint.as_deref());
+        assert_eq!(Some(54), peer.keep_alive);
+    }
+
+    #[test]
+    fn serialize_no_peers() {
+        let key = Key::decode("yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=").unwrap();
+        let conf = WgConfBuilder::new()
+            .fw_mark(10)
+            .listen_port(6000)
+            .dns("dns.example.com")
+            .address(IpNet::V4(
+                Ipv4Net::new(Ipv4Addr::new(10, 0, 0, 5), 24).unwrap(),
+            ))
+            .private_key(key)
+            .build();
+        let serialized = super::serialize_conf(&conf);
+
+        assert_eq!(
+            r#"[Interface]
+PrivateKey = yAnz5TF+lXXJte14tji3zlMNq+hd2rYUIgJBgB3fBmk=
+Address = 10.0.0.5/24
+ListenPort = 6000
+FwMark = 10
+DNS = dns.example.com
+"#,
+            serialized
+        );
+    }
+
+    #[test]
+    fn serialize_with_peers() {
+        let key1 = Key::decode("xTIBA5rboUvnH4htodjb6e697QjLERt1NAB4mZqp8Dg=").unwrap();
+        let key2 = Key::decode("TrMvSoP4jYQlY6RIzBgbssQqY3vxI2Pi+y71lOWWXX0=").unwrap();
+        let key3 = Key::decode("gN65BkIKy1eCE9pP1wdc8ROUtkHLF2PfAqYdyYBz6EA=").unwrap();
+
+        let conf = WgConfBuilder::new()
+            .private_key(key1)
+            .listen_port(51820)
+            .dns("dns.example.com")
+            .peer(
+                WgPeerBuilder::new(key2)
+                    .keep_alive(10)
+                    .endpoint("test.wireguard.com:18981")
+                    .allowed_ip(ipnet::IpNet::V4(
+                        Ipv4Net::new(Ipv4Addr::new(10, 0, 0, 2), 24).unwrap(),
+                    ))
+                    .build(),
+            )
+            .peer(
+                WgPeerBuilder::new(key3)
+                    .allowed_ip(ipnet::IpNet::V4(
+                        Ipv4Net::new(Ipv4Addr::new(10, 0, 0, 3), 24).unwrap(),
+                    ))
+                    .build(),
+            )
+            .build();
+
+        let serialized = super::serialize_conf(&conf);
+
+        assert_eq!(
+            r#"[Interface]
+PrivateKey = xTIBA5rboUvnH4htodjb6e697QjLERt1NAB4mZqp8Dg=
+ListenPort = 51820
+DNS = dns.example.com
+
+[Peer]
+PublicKey = TrMvSoP4jYQlY6RIzBgbssQqY3vxI2Pi+y71lOWWXX0=
+AllowedIPs = 10.0.0.2/24
+Endpoint = test.wireguard.com:18981
+PersistentKeepalive = 10
+
+[Peer]
+PublicKey = gN65BkIKy1eCE9pP1wdc8ROUtkHLF2PfAqYdyYBz6EA=
+AllowedIPs = 10.0.0.3/24
+"#,
+            serialized
+        );
+    }
+}
diff --git a/src/key.rs b/src/key.rs
new file mode 100644
index 0000000..19bc127
--- /dev/null
+++ b/src/key.rs
@@ -0,0 +1,372 @@
+use base64::Engine;
+use netlink_packet_wireguard::constants::WG_KEY_LEN;
+use rand::{rngs::OsRng, RngCore};
+
+// Code from: https://git.zx2c4.com/wireguard-tools/tree/contrib/embeddable-wg-library/wireguard.c
+
+type Fe = [i64; 16];
+
+#[derive(Debug)]
+pub struct KeyDecodeError;
+
+impl std::fmt::Display for KeyDecodeError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Key decode error")
+    }
+}
+
+impl std::error::Error for KeyDecodeError {}
+
+#[derive(Clone, Default, Copy, PartialEq, Eq, Hash)]
+pub struct Key([u8; WG_KEY_LEN]);
+
+impl Key {
+    pub fn into_array(self) -> [u8; WG_KEY_LEN] {
+        self.0
+    }
+
+    pub fn as_array(&self) -> &[u8; WG_KEY_LEN] {
+        &self.0
+    }
+
+    pub fn as_slice(&self) -> &[u8] {
+        &self.0
+    }
+
+    pub fn encode(&self) -> String {
+        base64::engine::general_purpose::STANDARD.encode(&self.0)
+    }
+
+    pub fn decode(encoded: &str) -> Result<Self, KeyDecodeError> {
+        let decoded = base64::engine::general_purpose::STANDARD
+            .decode(encoded)
+            .map_err(|_| KeyDecodeError)?;
+        if decoded.len() != WG_KEY_LEN {
+            return Err(KeyDecodeError);
+        }
+        let mut key = [0u8; WG_KEY_LEN];
+        key.copy_from_slice(&decoded);
+        Ok(Key(key))
+    }
+
+    pub fn generate_pub_priv() -> (Self, Self) {
+        let private_key = Self::generate_private();
+        let public_key = Self::generate_public(&private_key);
+        (public_key, private_key)
+    }
+
+    pub fn generate_public(private: &Key) -> Self {
+        let mut r: i32 = Default::default();
+        let mut public_key: [u8; WG_KEY_LEN] = Default::default();
+        let mut z: [u8; WG_KEY_LEN] = private.0;
+        let mut a = fe_new_one(1);
+        let mut b = fe_new_one(9);
+        let mut c = fe_new_one(0);
+        let mut d = fe_new_one(1);
+        let mut e = fe_new_default();
+        let mut f = fe_new_default();
+
+        clamp_key(&mut z);
+
+        for i in (0..=254i32).rev() {
+            r = ((z[(i >> 3) as usize] >> (i & 7)) & 1) as i32;
+            cswap(&mut a, &mut b, r);
+            cswap(&mut c, &mut d, r);
+            add(&mut e, &a, &c);
+            {
+                let a_clone = a;
+                subtract(&mut a, &a_clone, &c);
+            }
+            add(&mut c, &b, &d);
+            {
+                let b_clone = b;
+                subtract(&mut b, &b_clone, &d);
+            }
+            multmod(&mut d, &e, &e);
+            multmod(&mut f, &a, &a);
+            {
+                let a_clone = a;
+                multmod(&mut a, &c, &a_clone);
+            }
+            multmod(&mut c, &b, &e);
+            add(&mut e, &a, &c);
+            {
+                let a_clone = a;
+                subtract(&mut a, &a_clone, &c);
+            }
+            multmod(&mut b, &a, &a);
+            subtract(&mut c, &d, &f);
+            //multmod(&mut a, &c, (const fe){ 0xdb41, 1 });
+            multmod(&mut a, &c, &fe_new_two(0xdb41, 1));
+            {
+                let a_clone = a;
+                add(&mut a, &a_clone, &d);
+            }
+            {
+                let c_clone = c;
+                multmod(&mut c, &c_clone, &a);
+            }
+            multmod(&mut a, &d, &f);
+            multmod(&mut d, &b, &fe_new_one(9));
+            multmod(&mut b, &e, &e);
+            cswap(&mut a, &mut b, r);
+            cswap(&mut c, &mut d, r);
+        }
+        {
+            let c_clone = c;
+            invert(&mut c, &c_clone);
+        }
+        {
+            let a_clone = a;
+            multmod(&mut a, &a_clone, &c);
+        }
+        pack(&mut public_key, &a);
+
+        memzero_explicit(&mut r);
+        memzero_explicit(&mut z);
+        memzero_explicit(&mut a);
+        memzero_explicit(&mut b);
+        memzero_explicit(&mut c);
+        memzero_explicit(&mut d);
+        memzero_explicit(&mut e);
+        memzero_explicit(&mut f);
+
+        Self(public_key)
+    }
+
+    pub fn generate_private() -> Self {
+        let mut preshared = Self::generate_preshared();
+        clamp_key(&mut preshared.0);
+        preshared
+    }
+
+    pub fn generate_preshared() -> Self {
+        let mut key = [0u8; WG_KEY_LEN];
+        OsRng.fill_bytes(&mut key);
+        Self(key)
+    }
+}
+
+impl From<&[u8; WG_KEY_LEN]> for Key {
+    fn from(k: &[u8; WG_KEY_LEN]) -> Self {
+        Self(*k)
+    }
+}
+
+impl From<[u8; WG_KEY_LEN]> for Key {
+    fn from(k: [u8; WG_KEY_LEN]) -> Self {
+        Self(k)
+    }
+}
+
+impl std::str::FromStr for Key {
+    type Err = KeyDecodeError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Key::decode(s)
+    }
+}
+
+impl std::fmt::Debug for Key {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut buf = [0; WG_KEY_LEN * 2];
+        let len = base64::engine::general_purpose::STANDARD
+            .encode_slice(&self.0, &mut buf)
+            .expect("base64 should encode");
+        let b64 = std::str::from_utf8(&buf[..len]).expect("base64 should be valid utf-8");
+        f.debug_tuple("Key").field(&b64).finish()
+    }
+}
+
+impl std::fmt::Display for Key {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut buf = [0; WG_KEY_LEN * 2];
+        let len = base64::engine::general_purpose::STANDARD
+            .encode_slice(&self.0, &mut buf)
+            .expect("base64 should encode");
+        let b64 = std::str::from_utf8(&buf[..len]).expect("base64 should be valid utf-8");
+        f.write_str(b64)
+    }
+}
+
+impl serde::Serialize for Key {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str(&self.encode())
+    }
+}
+
+impl<'de> serde::Deserialize<'de> for Key {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        Key::decode(&s).map_err(serde::de::Error::custom)
+    }
+}
+
+fn fe_new_default() -> Fe {
+    Default::default()
+}
+
+fn fe_new_one(x: i64) -> Fe {
+    let mut fe = fe_new_default();
+    fe[0] = x;
+    fe
+}
+
+fn fe_new_two(x: i64, y: i64) -> Fe {
+    let mut fe = fe_new_default();
+    fe[0] = x;
+    fe[1] = y;
+    fe
+}
+
+fn clamp_key(key: &mut [u8]) {
+    key[31] = (key[31] & 127) | 64;
+    key[0] &= 248;
+}
+
+fn carry(o: &mut Fe) {
+    for i in 0..16 {
+        let x = if i == 15 { 38 } else { 1 };
+        o[(i + 1) % 16] += x * (o[i] >> 16);
+        o[i] &= 0xffff;
+    }
+}
+
+fn cswap(p: &mut Fe, q: &mut Fe, mut b: i32) {
+    let mut t: i64 = 0;
+    let mut c: i64 = !i64::from(b).wrapping_sub(1);
+
+    for i in 0..16 {
+        t = c & (p[i] ^ q[i]);
+        p[i] ^= t;
+        q[i] ^= t;
+    }
+
+    memzero_explicit(&mut t);
+    memzero_explicit(&mut c);
+    memzero_explicit(&mut b);
+}
+
+fn pack(o: &mut [u8; WG_KEY_LEN], n: &Fe) {
+    let mut b: i32 = 0;
+    let mut t: Fe = fe_new_default();
+    let mut m: Fe = fe_new_default();
+
+    t.copy_from_slice(n);
+    carry(&mut t);
+    carry(&mut t);
+    carry(&mut t);
+    for _ in 0..2 {
+        m[0] = t[0] - 0xffed;
+        for i in 1..15 {
+            m[i] = t[i] - 0xffff - ((m[i - 1] >> 16) & 1);
+            m[i - 1] &= 0xffff;
+        }
+        m[15] = t[15] - 0x7fff - ((m[14] >> 16) & 1);
+        b = ((m[15] >> 16) & 1) as i32;
+        m[14] &= 0xffff;
+        cswap(&mut t, &mut m, 1 - b);
+    }
+    for i in 0..16 {
+        o[2 * i] = (t[i] & 0xff) as u8;
+        o[2 * i + 1] = (t[i] >> 8) as u8;
+    }
+
+    memzero_explicit(&mut m);
+    memzero_explicit(&mut t);
+    memzero_explicit(&mut b);
+}
+
+fn add(o: &mut Fe, a: &Fe, b: &Fe) {
+    for i in 0..16 {
+        o[i] = a[i] + b[i];
+    }
+}
+
+fn subtract(o: &mut Fe, a: &Fe, b: &Fe) {
+    for i in 0..16 {
+        o[i] = a[i] - b[i];
+    }
+}
+
+fn multmod(o: &mut Fe, a: &Fe, b: &Fe) {
+    let mut t: [i64; 31] = [0; 31];
+
+    for i in 0..16 {
+        for j in 0..16 {
+            t[i + j] += a[i] * b[j];
+        }
+    }
+    for i in 0..15 {
+        t[i] += 38 * t[i + 16];
+    }
+    o.copy_from_slice(&t[..16]);
+    carry(o);
+    carry(o);
+
+    memzero_explicit(&mut t);
+}
+
+fn invert(o: &mut Fe, i: &Fe) {
+    let mut c: Fe = fe_new_default();
+
+    c.copy_from_slice(i);
+    for a in (0..=253).rev() {
+        {
+            let c_clone = c;
+            multmod(&mut c, &c_clone, &c_clone);
+        }
+        if a != 2 && a != 4 {
+            {
+                let c_clone = c;
+                multmod(&mut c, &c_clone, i);
+            }
+        }
+    }
+    o.copy_from_slice(&c);
+
+    memzero_explicit(&mut c);
+}
+
+fn memzero_explicit<T>(v: &mut T) {
+    unsafe {
+        let zeroed = std::mem::zeroed();
+        std::ptr::write_volatile(v as *mut _, zeroed);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Key;
+
+    #[test]
+    fn decode_encode_key() {
+        let key = "6F5rOtYE5A2KcXTKf9jdzWa9Y/kuV5gPS3LcKlxmOnY=";
+        let key = super::Key::decode(key).unwrap();
+        let key = key.encode();
+        assert_eq!(key, "6F5rOtYE5A2KcXTKf9jdzWa9Y/kuV5gPS3LcKlxmOnY=");
+    }
+
+    #[test]
+    fn generate_public_key() {
+        assert_eq!(
+            Key::decode("3D5lgnI9ztvnuyWDm7dlBDgm6xr0+WVWPoo6HIfzHRU=").unwrap(),
+            Key::generate_public(
+                &Key::decode("+Op7voRskU0Zm2fHFR/5tVE+PJtnwn6cbnme71jXt0E=").unwrap()
+            )
+        );
+
+        assert_eq!(
+            Key::decode("//eq/raPUE4+sOlTlozx76XEE+W8L0bUqNfyg9IpX0Q=").unwrap(),
+            Key::generate_public(
+                &Key::decode("8OD8QPWH/a0D5LmbWVnb7bwFq4Fghy/QUEFkIhyL/EI=").unwrap()
+            )
+        );
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..c47d618
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,401 @@
+mod conf;
+mod key;
+mod setup;
+mod view;
+
+use std::borrow::Cow;
+
+use futures::{StreamExt, TryStreamExt};
+use genetlink::{GenetlinkError, GenetlinkHandle};
+use netlink_packet_core::{NetlinkMessage, NetlinkPayload, NLM_F_ACK, NLM_F_DUMP, NLM_F_REQUEST};
+use netlink_packet_generic::GenlMessage;
+use netlink_packet_route::{
+    link::{InfoKind, LinkAttribute, LinkInfo},
+    route::RouteScope,
+};
+use netlink_packet_wireguard::{nlas::WgDeviceAttrs, Wireguard, WireguardCmd};
+use rtnetlink::Handle;
+
+pub use conf::*;
+pub use key::*;
+pub use setup::*;
+pub use view::*;
+
+pub use ipnet;
+
+pub type Result<T, E = Error> = std::result::Result<T, E>;
+
+#[derive(Debug)]
+pub struct Error {
+    inner: Option<Box<dyn std::error::Error + Send + Sync + 'static>>,
+    message: Option<Cow<'static, str>>,
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match (self.message.as_ref(), self.inner.as_ref()) {
+            (Some(message), Some(inner)) => write!(f, "{}: {}", message, inner),
+            (Some(message), None) => write!(f, "{}", message),
+            (None, Some(inner)) => write!(f, "{}", inner),
+            (None, None) => write!(f, "Unknown error"),
+        }
+    }
+}
+
+impl std::error::Error for Error {}
+
+impl From<std::io::Error> for Error {
+    fn from(inner: std::io::Error) -> Self {
+        Self {
+            inner: Some(Box::new(inner)),
+            message: None,
+        }
+    }
+}
+
+impl From<GenetlinkError> for Error {
+    fn from(inner: GenetlinkError) -> Self {
+        Self {
+            inner: Some(Box::new(inner)),
+            message: None,
+        }
+    }
+}
+
+impl From<rtnetlink::Error> for Error {
+    fn from(inner: rtnetlink::Error) -> Self {
+        Self {
+            inner: Some(Box::new(inner)),
+            message: None,
+        }
+    }
+}
+
+impl Error {
+    pub(crate) fn with_message<E>(inner: E, message: impl Into<Cow<'static, str>>) -> Self
+    where
+        E: std::error::Error + Send + Sync + 'static,
+    {
+        Self {
+            inner: Some(Box::new(inner)),
+            message: Some(message.into()),
+        }
+    }
+
+    pub(crate) fn message(message: impl Into<Cow<'static, str>>) -> Self {
+        Self {
+            inner: None,
+            message: Some(message.into()),
+        }
+    }
+}
+
+struct Link {
+    pub name: String,
+    pub ifindex: u32,
+}
+
+pub struct WireGuard {
+    rt_handle: Handle,
+    gen_handle: GenetlinkHandle,
+}
+
+#[allow(clippy::await_holding_refcell_ref)]
+impl WireGuard {
+    pub async fn new() -> Result<Self> {
+        let (rt_connection, rt_handle, _) = rtnetlink::new_connection()?;
+        tokio::spawn(rt_connection);
+        let (gen_connection, gen_handle, _) = genetlink::new_connection()?;
+        tokio::spawn(gen_connection);
+
+        Ok(Self {
+            rt_handle,
+            gen_handle,
+        })
+    }
+
+    pub async fn create_device(
+        &mut self,
+        device_name: &str,
+        descriptor: DeviceDescriptor,
+    ) -> Result<()> {
+        tracing::trace!("Creating device {}", device_name);
+        self.link_create(device_name).await?;
+        let link = self.link_get_by_name(device_name).await?;
+        self.link_up(link.ifindex).await?;
+        self.setup_device(device_name, descriptor).await?;
+        tracing::trace!("Created device");
+        Ok(())
+    }
+
+    pub async fn reload_device(
+        &mut self,
+        device_name: &str,
+        descriptor: DeviceDescriptor,
+    ) -> Result<()> {
+        tracing::trace!("Reloading device {}", device_name);
+        self.setup_device(device_name, descriptor).await?;
+        tracing::trace!("Reloaded device");
+        Ok(())
+    }
+
+    pub async fn remove_device(&self, device_name: &str) -> Result<()> {
+        tracing::trace!("Removing device {}", device_name);
+        let link = self.link_get_by_name(device_name).await?;
+        self.link_down(link.ifindex).await?;
+        self.link_delete(link.ifindex).await?;
+        tracing::trace!("Removed device");
+        Ok(())
+    }
+
+    pub async fn view_device(&mut self, device_name: &str) -> Result<DeviceView> {
+        let genlmsg: GenlMessage<Wireguard> = GenlMessage::from_payload(Wireguard {
+            cmd: WireguardCmd::GetDevice,
+            nlas: vec![WgDeviceAttrs::IfName(device_name.to_string())],
+        });
+        let mut nlmsg = NetlinkMessage::from(genlmsg);
+        nlmsg.header.flags = NLM_F_REQUEST | NLM_F_DUMP;
+
+        let mut resp = self.gen_handle.request(nlmsg).await?;
+        while let Some(result) = resp.next().await {
+            let rx_packet = result.map_err(|e| Error::with_message(e, "Error decoding packet"))?;
+            match rx_packet.payload {
+                NetlinkPayload::InnerMessage(genlmsg) => {
+                    return device_view_from_payload(genlmsg.payload);
+                }
+                NetlinkPayload::Error(e) => {
+                    return Err(Error::message(format!("Error: {:?}", e)));
+                }
+                _ => (),
+            };
+        }
+        unreachable!();
+    }
+
+    pub async fn view_device_if_exists(&mut self, device_name: &str) -> Result<Option<DeviceView>> {
+        let device_names = self.list_device_names().await?;
+        if device_names.iter().any(|name| name == device_name) {
+            Ok(Some(self.view_device(device_name).await?))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub async fn view_devices(&mut self) -> Result<Vec<DeviceView>> {
+        let device_names = self.list_device_names().await?;
+        let mut devices = Vec::with_capacity(device_names.len());
+        for name in device_names {
+            let device = self.view_device(&name).await?;
+            devices.push(device);
+        }
+        Ok(devices)
+    }
+
+    pub async fn list_device_names(&self) -> Result<Vec<String>> {
+        Ok(self
+            .link_list()
+            .await?
+            .into_iter()
+            .map(|link| link.name)
+            .collect())
+    }
+
+    async fn setup_device(
+        &mut self,
+        device_name: &str,
+        descriptor: DeviceDescriptor,
+    ) -> Result<()> {
+        tracing::trace!("Setting up device {}", device_name);
+
+        let link = self.link_get_by_name(device_name).await?;
+        for addr in descriptor.addresses.iter() {
+            self.link_add_address(link.ifindex, *addr).await?;
+        }
+
+        let message = descriptor.into_wireguard(device_name.to_string());
+        let genlmsg: GenlMessage<Wireguard> = GenlMessage::from_payload(message);
+        let mut nlmsg = NetlinkMessage::from(genlmsg);
+        nlmsg.header.flags = NLM_F_REQUEST | NLM_F_ACK;
+
+        let mut stream = self.gen_handle.request(nlmsg).await?;
+        while (stream.next().await).is_some() {}
+        tracing::trace!("Device setup");
+
+        Ok(())
+    }
+
+    async fn link_create(&self, name: &str) -> Result<()> {
+        let mut msg = self.rt_handle.link().add().replace();
+        msg.message_mut()
+            .attributes
+            .push(LinkAttribute::LinkInfo(vec![LinkInfo::Kind(
+                InfoKind::Wireguard,
+            )]));
+        msg.message_mut()
+            .attributes
+            .push(LinkAttribute::IfName(name.to_string()));
+        msg.execute().await?;
+        Ok(())
+    }
+
+    async fn link_delete(&self, ifindex: u32) -> Result<()> {
+        self.rt_handle.link().del(ifindex).execute().await?;
+        Ok(())
+    }
+
+    async fn link_up(&self, ifindex: u32) -> Result<()> {
+        tracing::trace!("Bringing up interface {}", ifindex);
+        self.rt_handle.link().set(ifindex).up().execute().await?;
+        Ok(())
+    }
+
+    async fn link_down(&self, ifindex: u32) -> Result<()> {
+        tracing::trace!("Bringing down interface {}", ifindex);
+        self.rt_handle.link().set(ifindex).down().execute().await?;
+        Ok(())
+    }
+
+    async fn link_add_address(&self, ifindex: u32, net: ipnet::IpNet) -> Result<()> {
+        tracing::trace!("Adding address {} to {}", net, ifindex);
+        self.rt_handle
+            .address()
+            .add(ifindex, net.addr(), net.prefix_len())
+            .replace()
+            .execute()
+            .await?;
+        Ok(())
+    }
+
+    //TODO: return Result<Option<Link>>?
+    async fn link_get_by_name(&self, name: &str) -> Result<Link> {
+        let link = self
+            .link_list()
+            .await?
+            .into_iter()
+            .find(|link| link.name == name)
+            .ok_or_else(|| Error::message(format!("Link {} not found", name)))?;
+        tracing::debug!("device {} has index {}", name, link.ifindex);
+        Ok(link)
+    }
+
+    async fn link_list(&self) -> Result<Vec<Link>> {
+        let mut links = Vec::new();
+        let mut link_stream = self.rt_handle.link().get().execute();
+        while let Some(link) = link_stream.try_next().await? {
+            let mut is_wireguard = false;
+            let mut link_name = None;
+            for nla in link.attributes {
+                match nla {
+                    LinkAttribute::IfName(name) => link_name = Some(name),
+                    LinkAttribute::LinkInfo(infos) => {
+                        for info in infos {
+                            if let netlink_packet_route::link::LinkInfo::Kind(kind) = info {
+                                if kind == netlink_packet_route::link::InfoKind::Wireguard {
+                                    is_wireguard = true;
+                                    break;
+                                }
+                            }
+                        }
+                    }
+                    _ => {}
+                }
+                if is_wireguard && link_name.is_some() {
+                    links.push(Link {
+                        name: link_name.unwrap(),
+                        ifindex: link.header.index,
+                    });
+                    break;
+                }
+            }
+        }
+        Ok(links)
+    }
+
+    #[allow(unused)]
+    async fn route_add(&self, ifindex: u32, net: ipnet::IpNet) -> Result<()> {
+        tracing::trace!("Adding route {} to {}", net, ifindex);
+        let request = self
+            .rt_handle
+            .route()
+            .add()
+            .scope(RouteScope::Link)
+            .output_interface(ifindex)
+            .replace();
+
+        match net.addr() {
+            std::net::IpAddr::V4(ip) => {
+                request
+                    .v4()
+                    .destination_prefix(ip, net.prefix_len())
+                    .execute()
+                    .await
+            }
+            std::net::IpAddr::V6(ip) => {
+                request
+                    .v6()
+                    .destination_prefix(ip, net.prefix_len())
+                    .execute()
+                    .await
+            }
+        }?;
+
+        Ok(())
+    }
+}
+
+pub async fn create_device(
+    device_name: impl AsRef<str>,
+    device_descriptor: DeviceDescriptor,
+) -> Result<()> {
+    tracing::info!("creating device {}", device_name.as_ref());
+    tracing::debug!("device descriptor: {:#?}", device_descriptor);
+    let mut wireguard = WireGuard::new().await?;
+    wireguard
+        .create_device(device_name.as_ref(), device_descriptor)
+        .await
+}
+
+pub async fn reload_device(
+    device_name: impl AsRef<str>,
+    device_descriptor: DeviceDescriptor,
+) -> Result<()> {
+    tracing::info!("reloading device {}", device_name.as_ref());
+    tracing::debug!("device descriptor: {:#?}", device_descriptor);
+    let mut wireguard = WireGuard::new().await?;
+    wireguard
+        .reload_device(device_name.as_ref(), device_descriptor)
+        .await
+}
+
+pub async fn device_exists(name: impl AsRef<str>) -> Result<bool> {
+    tracing::info!("checking if device {} exists", name.as_ref());
+    let mut wireguard = WireGuard::new().await?;
+    wireguard
+        .view_device_if_exists(name.as_ref())
+        .await
+        .map(|x| x.is_some())
+}
+
+pub async fn remove_device(name: impl AsRef<str>) -> Result<()> {
+    tracing::info!("removing device {}", name.as_ref());
+    let wireguard = WireGuard::new().await?;
+    wireguard.remove_device(name.as_ref()).await
+}
+
+pub async fn view_device(name: impl AsRef<str>) -> Result<DeviceView> {
+    tracing::info!("viewing device {}", name.as_ref());
+    let mut wireguard = WireGuard::new().await?;
+    wireguard.view_device(name.as_ref()).await
+}
+
+pub async fn view_device_if_exists(name: impl AsRef<str>) -> Result<Option<DeviceView>> {
+    tracing::info!("viewing device {}", name.as_ref());
+    let mut wireguard = WireGuard::new().await?;
+    wireguard.view_device_if_exists(name.as_ref()).await
+}
+
+pub async fn list_device_names() -> Result<Vec<String>> {
+    tracing::info!("listing device names");
+    let wireguard = WireGuard::new().await?;
+    wireguard.list_device_names().await
+}
diff --git a/src/setup.rs b/src/setup.rs
new file mode 100644
index 0000000..e7d454c
--- /dev/null
+++ b/src/setup.rs
@@ -0,0 +1,212 @@
+use std::net::{IpAddr, SocketAddr};
+
+use ipnet::IpNet;
+use netlink_packet_wireguard::{
+    constants::{AF_INET, AF_INET6, WGDEVICE_F_REPLACE_PEERS, WGPEER_F_REPLACE_ALLOWEDIPS},
+    nlas::{WgAllowedIp, WgAllowedIpAttrs, WgDeviceAttrs, WgPeer, WgPeerAttrs},
+    Wireguard, WireguardCmd,
+};
+
+use super::Key;
+
+#[derive(Debug)]
+pub struct PeerDescriptor {
+    pub(super) public_key: Key,
+    pub(super) preshared_key: Option<Key>,
+    pub(super) endpoint: Option<SocketAddr>,
+    pub(super) keepalive: Option<u16>,
+    pub(super) allowed_ips: Option<Vec<IpNet>>,
+}
+
+impl PeerDescriptor {
+    pub fn new(public_key: Key) -> Self {
+        Self {
+            public_key,
+            preshared_key: None,
+            endpoint: None,
+            keepalive: None,
+            allowed_ips: None,
+        }
+    }
+
+    pub fn preshared_key_optional(mut self, preshared_key: Option<Key>) -> Self {
+        self.preshared_key = preshared_key;
+        self
+    }
+
+    pub fn preshared_key(mut self, preshared_key: Key) -> Self {
+        self.preshared_key = Some(preshared_key);
+        self
+    }
+
+    pub fn endpoint_optional(mut self, endpoint: Option<SocketAddr>) -> Self {
+        self.endpoint = endpoint;
+        self
+    }
+
+    pub fn endpoint(mut self, endpoint: SocketAddr) -> Self {
+        self.endpoint = Some(endpoint);
+        self
+    }
+
+    pub fn keepalive_optional(mut self, keepalive: Option<u16>) -> Self {
+        self.keepalive = keepalive;
+        self
+    }
+
+    pub fn keepalive(mut self, keepalive: u16) -> Self {
+        self.keepalive = Some(keepalive);
+        self
+    }
+
+    pub fn allowed_ip_optional(self, allowed_ip: Option<IpNet>) -> Self {
+        if let Some(allowed_ip) = allowed_ip {
+            self.allowed_ip(allowed_ip)
+        } else {
+            self
+        }
+    }
+
+    pub fn allowed_ip(mut self, allowed_ip: IpNet) -> Self {
+        let mut allowed_ips = self.allowed_ips.take().unwrap_or_default();
+        allowed_ips.push(allowed_ip);
+        self.allowed_ips = Some(allowed_ips);
+        self
+    }
+
+    pub fn allowed_ips_optional(self, allowed_ips: Option<Vec<IpNet>>) -> Self {
+        if let Some(allowed_ips) = allowed_ips {
+            self.allowed_ips(allowed_ips)
+        } else {
+            self
+        }
+    }
+
+    pub fn allowed_ips(mut self, allowed_ips: Vec<IpNet>) -> Self {
+        self.allowed_ips = Some(allowed_ips);
+        self
+    }
+
+    pub(super) fn into_wireguard(self) -> WgPeer {
+        let mut nlas = Vec::new();
+        nlas.push(WgPeerAttrs::PublicKey(self.public_key.into_array()));
+        nlas.extend(
+            self.preshared_key
+                .map(|key| WgPeerAttrs::PresharedKey(key.into_array())),
+        );
+        nlas.extend(self.endpoint.map(WgPeerAttrs::Endpoint));
+        nlas.extend(self.keepalive.map(WgPeerAttrs::PersistentKeepalive));
+        nlas.extend(self.allowed_ips.map(|allowed_ips| {
+            WgPeerAttrs::AllowedIps(allowed_ips.into_iter().map(ipnet_to_wg).collect())
+        }));
+        nlas.push(WgPeerAttrs::Flags(WGPEER_F_REPLACE_ALLOWEDIPS));
+        WgPeer(nlas)
+    }
+}
+
+#[derive(Debug)]
+pub struct DeviceDescriptor {
+    pub(super) addresses: Vec<IpNet>,
+    pub(super) private_key: Option<Key>,
+    pub(super) listen_port: Option<u16>,
+    pub(super) fwmark: Option<u32>,
+    pub(super) peers: Option<Vec<PeerDescriptor>>,
+}
+
+impl Default for DeviceDescriptor {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl DeviceDescriptor {
+    pub fn new() -> Self {
+        Self {
+            addresses: Vec::default(),
+            private_key: None,
+            listen_port: None,
+            fwmark: None,
+            peers: None,
+        }
+    }
+
+    pub fn address(mut self, address: IpNet) -> Self {
+        self.addresses.push(address);
+        self
+    }
+
+    pub fn addresses(mut self, addresses: impl IntoIterator<Item = IpNet>) -> Self {
+        self.addresses.extend(addresses);
+        self
+    }
+
+    pub fn private_key(mut self, key: Key) -> Self {
+        self.private_key = Some(key);
+        self
+    }
+
+    pub fn listen_port(mut self, port: u16) -> Self {
+        self.listen_port = Some(port);
+        self
+    }
+
+    pub fn listen_port_optional(mut self, port: Option<u16>) -> Self {
+        self.listen_port = port;
+        self
+    }
+
+    pub fn fwmark(mut self, fwmark: u32) -> Self {
+        self.fwmark = Some(fwmark);
+        self
+    }
+
+    pub fn peer(mut self, peer: PeerDescriptor) -> Self {
+        let mut p = self.peers.take().unwrap_or_default();
+        p.push(peer);
+        self.peers = Some(p);
+        self
+    }
+
+    pub fn peers(mut self, peers: impl IntoIterator<Item = PeerDescriptor>) -> Self {
+        let mut p = self.peers.take().unwrap_or_default();
+        p.extend(peers);
+        self.peers = Some(p);
+        self
+    }
+
+    pub(super) fn into_wireguard(self, device_name: String) -> Wireguard {
+        let mut nlas = Vec::new();
+        nlas.push(WgDeviceAttrs::IfName(device_name));
+        nlas.extend(
+            self.private_key
+                .map(|key| WgDeviceAttrs::PrivateKey(key.into_array())),
+        );
+        nlas.extend(self.listen_port.map(WgDeviceAttrs::ListenPort));
+        nlas.extend(self.fwmark.map(WgDeviceAttrs::Fwmark));
+        nlas.extend(self.peers.map(|peers| {
+            WgDeviceAttrs::Peers(
+                peers
+                    .into_iter()
+                    .map(PeerDescriptor::into_wireguard)
+                    .collect(),
+            )
+        }));
+        nlas.push(WgDeviceAttrs::Flags(WGDEVICE_F_REPLACE_PEERS));
+
+        Wireguard {
+            cmd: WireguardCmd::SetDevice,
+            nlas,
+        }
+    }
+}
+
+fn ipnet_to_wg(net: IpNet) -> WgAllowedIp {
+    let mut nlas = Vec::default();
+    nlas.push(WgAllowedIpAttrs::Cidr(net.prefix_len()));
+    nlas.push(WgAllowedIpAttrs::IpAddr(net.addr()));
+    match net.addr() {
+        IpAddr::V4(_) => nlas.push(WgAllowedIpAttrs::Family(AF_INET)),
+        IpAddr::V6(_) => nlas.push(WgAllowedIpAttrs::Family(AF_INET6)),
+    }
+    WgAllowedIp(nlas)
+}
diff --git a/src/view.rs b/src/view.rs
new file mode 100644
index 0000000..2858811
--- /dev/null
+++ b/src/view.rs
@@ -0,0 +1,130 @@
+use std::{net::SocketAddr, time::SystemTime};
+
+use ipnet::IpNet;
+use netlink_packet_wireguard::{
+    nlas::{WgAllowedIp, WgAllowedIpAttrs, WgDeviceAttrs, WgPeer, WgPeerAttrs},
+    Wireguard,
+};
+
+use super::{Error, Key, Result};
+
+#[derive(Debug, Clone)]
+pub struct DeviceView {
+    pub name: String,
+    pub ifindex: u32,
+    pub private_key: Option<Key>,
+    pub public_key: Option<Key>,
+    pub listen_port: u16,
+    pub fwmark: u32,
+    pub peers: Vec<PeerView>,
+}
+
+#[derive(Debug, Clone)]
+pub struct PeerView {
+    pub public_key: Key,
+    pub preshared_key: Option<Key>,
+    pub endpoint: Option<SocketAddr>,
+    pub persistent_keepalive: Option<u16>,
+    pub last_handshake: SystemTime,
+    pub rx_bytes: u64,
+    pub tx_bytes: u64,
+    pub allowed_ips: Vec<IpNet>,
+}
+
+pub(super) fn device_view_from_payload(wg: Wireguard) -> Result<DeviceView> {
+    let mut if_index = None;
+    let mut if_name = None;
+    let mut private_key = None;
+    let mut public_key = None;
+    let mut listen_port = None;
+    let mut fwmark = None;
+    let mut peers = None;
+
+    for nla in wg.nlas {
+        match nla {
+            WgDeviceAttrs::IfIndex(v) => if_index = Some(v),
+            WgDeviceAttrs::IfName(v) => if_name = Some(v),
+            WgDeviceAttrs::PrivateKey(v) => private_key = Some(Key::from(v)),
+            WgDeviceAttrs::PublicKey(v) => public_key = Some(Key::from(v)),
+            WgDeviceAttrs::ListenPort(v) => listen_port = Some(v),
+            WgDeviceAttrs::Fwmark(v) => fwmark = Some(v),
+            WgDeviceAttrs::Peers(v) => peers = Some(peers_from_wg_peers(v)?),
+            _ => {}
+        }
+    }
+
+    Ok(DeviceView {
+        name: if_name.ok_or_else(|| Error::message("missing if_name"))?,
+        ifindex: if_index.ok_or_else(|| Error::message("missing if_index"))?,
+        private_key,
+        public_key,
+        listen_port: listen_port.ok_or_else(|| Error::message("missing listen_port"))?,
+        fwmark: fwmark.ok_or_else(|| Error::message("missing fwmark"))?,
+        peers: peers.unwrap_or_default(),
+    })
+}
+
+fn peers_from_wg_peers(wg_peers: Vec<WgPeer>) -> Result<Vec<PeerView>> {
+    let mut peers = Vec::with_capacity(wg_peers.len());
+    for wg_peer in wg_peers {
+        peers.push(peer_from_wg_peer(wg_peer)?);
+    }
+    Ok(peers)
+}
+
+fn peer_from_wg_peer(wg_peer: WgPeer) -> Result<PeerView> {
+    let mut public_key = None;
+    let mut preshared_key = None;
+    let mut endpoint = None;
+    let mut persistent_keepalive = None;
+    let mut last_handshake = None;
+    let mut rx_bytes = None;
+    let mut tx_bytes = None;
+    let mut allowed_ips = Vec::default();
+
+    for attr in wg_peer.iter() {
+        match attr {
+            WgPeerAttrs::PublicKey(v) => public_key = Some(Key::from(v)),
+            WgPeerAttrs::PresharedKey(v) => preshared_key = Some(Key::from(v)),
+            WgPeerAttrs::Endpoint(v) => endpoint = Some(*v),
+            WgPeerAttrs::PersistentKeepalive(v) => persistent_keepalive = Some(*v),
+            WgPeerAttrs::LastHandshake(v) => last_handshake = Some(*v),
+            WgPeerAttrs::RxBytes(v) => rx_bytes = Some(*v),
+            WgPeerAttrs::TxBytes(v) => tx_bytes = Some(*v),
+            WgPeerAttrs::AllowedIps(v) => {
+                for ip in v {
+                    allowed_ips.push(ipnet_from_wg(ip)?);
+                }
+            }
+            _ => {}
+        }
+    }
+
+    Ok(PeerView {
+        public_key: public_key.ok_or_else(|| Error::message("missing public_key"))?,
+        preshared_key,
+        endpoint,
+        persistent_keepalive,
+        last_handshake: last_handshake.ok_or_else(|| Error::message("missing last_handshake"))?,
+        rx_bytes: rx_bytes.ok_or_else(|| Error::message("missing rx_bytes"))?,
+        tx_bytes: tx_bytes.ok_or_else(|| Error::message("missing tx_bytes"))?,
+        allowed_ips,
+    })
+}
+
+fn ipnet_from_wg(wg: &WgAllowedIp) -> Result<IpNet> {
+    let mut ip = None;
+    let mut prefix = None;
+    for attr in wg.iter() {
+        match attr {
+            WgAllowedIpAttrs::IpAddr(v) => ip = Some(*v),
+            WgAllowedIpAttrs::Cidr(v) => prefix = Some(*v),
+            _ => {}
+        }
+    }
+    Ok(IpNet::new(
+        ip.ok_or_else(|| Error::message("missing ip"))?,
+        prefix.ok_or_else(|| Error::message("missing prefix"))?,
+    )
+    .map_err(|e| Error::with_message(e, "invalid ipnet"))?)
+}