wireguard-control 1.6.1

High level bindings to the WireGuard embeddable C library
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
use crate::{
    device::AllowedIp, Backend, Device, DeviceUpdate, InterfaceName, Key, PeerConfig,
    PeerConfigBuilder, PeerInfo, PeerStats,
};
use netlink_packet_core::{
    NetlinkMessage, NetlinkPayload, NLM_F_ACK, NLM_F_CREATE, NLM_F_DUMP, NLM_F_EXCL, NLM_F_REQUEST,
};
use netlink_packet_generic::GenlMessage;
use netlink_packet_route::{
    constants::*,
    link::{
        self,
        nlas::{Info, InfoKind},
    },
    LinkMessage, RtnlMessage,
};
use netlink_packet_utils::traits::Emitable;
use netlink_packet_wireguard::{
    self,
    constants::{WGDEVICE_F_REPLACE_PEERS, WGPEER_F_REMOVE_ME, WGPEER_F_REPLACE_ALLOWEDIPS},
    nlas::{WgAllowedIp, WgAllowedIpAttrs, WgDeviceAttrs, WgPeer, WgPeerAttrs},
    Wireguard, WireguardCmd,
};
use netlink_request::{max_genl_payload_length, netlink_request_genl, netlink_request_rtnl};

use std::{convert::TryFrom, io};

macro_rules! get_nla_value {
    ($nlas:expr, $e:ident, $v:ident) => {
        $nlas.iter().find_map(|attr| match attr {
            $e::$v(value) => Some(value),
            _ => None,
        })
    };
}

impl TryFrom<WgAllowedIp> for AllowedIp {
    type Error = io::Error;

    fn try_from(attrs: WgAllowedIp) -> Result<Self, Self::Error> {
        let address = *get_nla_value!(attrs, WgAllowedIpAttrs, IpAddr)
            .ok_or_else(|| io::ErrorKind::NotFound)?;
        let cidr = *get_nla_value!(attrs, WgAllowedIpAttrs, Cidr)
            .ok_or_else(|| io::ErrorKind::NotFound)?;
        Ok(AllowedIp { address, cidr })
    }
}

impl AllowedIp {
    fn to_nla(&self) -> WgAllowedIp {
        WgAllowedIp(vec![
            WgAllowedIpAttrs::Family(if self.address.is_ipv4() {
                AF_INET
            } else {
                AF_INET6
            }),
            WgAllowedIpAttrs::IpAddr(self.address),
            WgAllowedIpAttrs::Cidr(self.cidr),
        ])
    }
}

impl PeerConfigBuilder {
    fn to_nla(&self) -> WgPeer {
        let mut attrs = vec![WgPeerAttrs::PublicKey(self.public_key.0)];
        let mut flags = 0u32;
        if let Some(endpoint) = self.endpoint {
            attrs.push(WgPeerAttrs::Endpoint(endpoint));
        }
        if let Some(ref key) = self.preshared_key {
            attrs.push(WgPeerAttrs::PresharedKey(key.0));
        }
        if let Some(i) = self.persistent_keepalive_interval {
            attrs.push(WgPeerAttrs::PersistentKeepalive(i));
        }
        let allowed_ips: Vec<_> = self.allowed_ips.iter().map(AllowedIp::to_nla).collect();
        attrs.push(WgPeerAttrs::AllowedIps(allowed_ips));
        if self.remove_me {
            flags |= WGPEER_F_REMOVE_ME;
        }
        if self.replace_allowed_ips {
            flags |= WGPEER_F_REPLACE_ALLOWEDIPS;
        }
        if flags != 0 {
            attrs.push(WgPeerAttrs::Flags(flags));
        }
        WgPeer(attrs)
    }
}

impl TryFrom<WgPeer> for PeerInfo {
    type Error = io::Error;

    fn try_from(attrs: WgPeer) -> Result<Self, Self::Error> {
        let public_key = get_nla_value!(attrs, WgPeerAttrs, PublicKey)
            .map(|key| Key(*key))
            .ok_or(io::ErrorKind::NotFound)?;
        let preshared_key = get_nla_value!(attrs, WgPeerAttrs, PresharedKey).map(|key| Key(*key));
        let endpoint = get_nla_value!(attrs, WgPeerAttrs, Endpoint).cloned();
        let persistent_keepalive_interval =
            get_nla_value!(attrs, WgPeerAttrs, PersistentKeepalive).cloned();
        let allowed_ips = get_nla_value!(attrs, WgPeerAttrs, AllowedIps)
            .cloned()
            .unwrap_or_default()
            .into_iter()
            .map(AllowedIp::try_from)
            .collect::<Result<Vec<_>, _>>()?;
        let last_handshake_time = get_nla_value!(attrs, WgPeerAttrs, LastHandshake).cloned();
        let rx_bytes = get_nla_value!(attrs, WgPeerAttrs, RxBytes)
            .cloned()
            .unwrap_or_default();
        let tx_bytes = get_nla_value!(attrs, WgPeerAttrs, TxBytes)
            .cloned()
            .unwrap_or_default();
        Ok(PeerInfo {
            config: PeerConfig {
                public_key,
                preshared_key,
                endpoint,
                persistent_keepalive_interval,
                allowed_ips,
                __cant_construct_me: (),
            },
            stats: PeerStats {
                last_handshake_time,
                rx_bytes,
                tx_bytes,
            },
        })
    }
}

impl<'a> TryFrom<&'a [WgDeviceAttrs]> for Device {
    type Error = io::Error;

    fn try_from(nlas: &'a [WgDeviceAttrs]) -> Result<Self, Self::Error> {
        let name = get_nla_value!(nlas, WgDeviceAttrs, IfName)
            .ok_or_else(|| io::ErrorKind::NotFound)?
            .parse()?;
        let public_key = get_nla_value!(nlas, WgDeviceAttrs, PublicKey).map(|key| Key(*key));
        let private_key = get_nla_value!(nlas, WgDeviceAttrs, PrivateKey).map(|key| Key(*key));
        let listen_port = get_nla_value!(nlas, WgDeviceAttrs, ListenPort).cloned();
        let fwmark = get_nla_value!(nlas, WgDeviceAttrs, Fwmark).cloned();
        let peers = nlas
            .iter()
            .filter_map(|nla| match nla {
                WgDeviceAttrs::Peers(peers) => Some(peers.clone()),
                _ => None,
            })
            .flatten()
            .map(PeerInfo::try_from)
            .collect::<Result<Vec<_>, _>>()?;
        Ok(Device {
            name,
            public_key,
            private_key,
            listen_port,
            fwmark,
            peers,
            linked_name: None,
            backend: Backend::Kernel,
            __cant_construct_me: (),
        })
    }
}

pub fn enumerate() -> Result<Vec<InterfaceName>, io::Error> {
    let link_responses = netlink_request_rtnl(
        RtnlMessage::GetLink(LinkMessage::default()),
        Some(NLM_F_DUMP | NLM_F_REQUEST),
    )?;
    let links = link_responses
        .into_iter()
        // Filter out non-link messages
        .filter_map(|response| match response {
            NetlinkMessage {
                payload: NetlinkPayload::InnerMessage(RtnlMessage::NewLink(link)),
                ..
            } => Some(link),
            _ => None,
        })
        .filter(|link| {
            for nla in link.nlas.iter() {
                if let link::nlas::Nla::Info(infos) = nla {
                    return infos.iter().any(|info| info == &Info::Kind(InfoKind::Wireguard))
                }
            }
            false
        })
        .filter_map(|link| link.nlas.iter().find_map(|nla| match nla {
            link::nlas::Nla::IfName(name) => Some(name.clone()),
            _ => None,
        }))
        .filter_map(|name| name.parse().ok())
        .collect::<Vec<_>>();

    Ok(links)
}

fn add_del(iface: &InterfaceName, add: bool) -> io::Result<()> {
    let mut message = LinkMessage::default();
    message
        .nlas
        .push(link::nlas::Nla::IfName(iface.as_str_lossy().to_string()));
    message.nlas.push(link::nlas::Nla::Info(vec![Info::Kind(
        link::nlas::InfoKind::Wireguard,
    )]));
    let extra_flags = if add { NLM_F_CREATE | NLM_F_EXCL } else { 0 };
    let rtnl_message = if add {
        RtnlMessage::NewLink(message)
    } else {
        RtnlMessage::DelLink(message)
    };
    match netlink_request_rtnl(rtnl_message, Some(NLM_F_REQUEST | NLM_F_ACK | extra_flags)) {
        Err(e) if e.kind() != io::ErrorKind::AlreadyExists => Err(e),
        _ => Ok(()),
    }
}

pub fn apply(builder: &DeviceUpdate, iface: &InterfaceName) -> io::Result<()> {
    add_del(iface, true)?;
    let mut payload = ApplyPayload::new(iface);
    if let Some(Key(k)) = builder.private_key {
        payload.push(WgDeviceAttrs::PrivateKey(k))?;
    }
    if let Some(f) = builder.fwmark {
        payload.push(WgDeviceAttrs::Fwmark(f))?;
    }
    if let Some(f) = builder.listen_port {
        payload.push(WgDeviceAttrs::ListenPort(f))?;
    }
    if builder.replace_peers {
        payload.push(WgDeviceAttrs::Flags(WGDEVICE_F_REPLACE_PEERS))?;
    }

    builder
        .peers
        .iter()
        .map(|peer| payload.push_peer(peer.to_nla()))
        .collect::<Result<Vec<_>, _>>()?;

    for message in payload.finish() {
        netlink_request_genl(message, Some(NLM_F_REQUEST | NLM_F_ACK))?;
    }
    Ok(())
}

struct ApplyPayload {
    iface: String,
    nlas: Vec<WgDeviceAttrs>,
    current_buffer_len: usize,
    queue: Vec<GenlMessage<Wireguard>>,
}

impl ApplyPayload {
    fn new(iface: &InterfaceName) -> Self {
        let iface_str = iface.as_str_lossy().to_string();
        let nlas = vec![WgDeviceAttrs::IfName(iface_str.clone())];
        let current_buffer_len = nlas.as_slice().buffer_len();
        Self {
            iface: iface_str,
            nlas,
            queue: vec![],
            current_buffer_len,
        }
    }

    fn flush_nlas(&mut self) {
        // // cleanup: clear out any empty peer lists.
        self.nlas
            .retain(|nla| !matches!(nla, WgDeviceAttrs::Peers(peers) if peers.is_empty()));

        let name = WgDeviceAttrs::IfName(self.iface.clone());
        let template = vec![name];

        if !self.nlas.is_empty() && self.nlas != template {
            self.current_buffer_len = template.as_slice().buffer_len();
            let message = GenlMessage::from_payload(Wireguard {
                cmd: WireguardCmd::SetDevice,
                nlas: std::mem::replace(&mut self.nlas, template),
            });
            self.queue.push(message);
        }
    }

    /// Push a device attribute which will be optimally packed into 1 or more netlink messages
    pub fn push(&mut self, nla: WgDeviceAttrs) -> io::Result<()> {
        let max_payload_len = max_genl_payload_length();

        let nla_buffer_len = nla.buffer_len();
        if (self.current_buffer_len + nla_buffer_len) > max_payload_len {
            self.flush_nlas();
        }

        // If the NLA *still* doesn't fit...
        if (self.current_buffer_len + nla_buffer_len) > max_payload_len {
            return Err(io::Error::new(
                io::ErrorKind::InvalidInput,
                format!("encoded NLA ({nla_buffer_len} bytes) is too large: {nla:?}"),
            ));
        }
        self.nlas.push(nla);
        self.current_buffer_len += nla_buffer_len;
        Ok(())
    }

    /// A helper function to assist in breaking up large peer lists across multiple netlink messages
    pub fn push_peer(&mut self, peer: WgPeer) -> io::Result<()> {
        const EMPTY_PEERS: WgDeviceAttrs = WgDeviceAttrs::Peers(vec![]);
        let max_payload_len = max_genl_payload_length();
        let mut needs_peer_nla = !self
            .nlas
            .iter()
            .any(|nla| matches!(nla, WgDeviceAttrs::Peers(_)));
        let peer_buffer_len = peer.buffer_len();
        let mut additional_buffer_len = peer_buffer_len;
        if needs_peer_nla {
            additional_buffer_len += EMPTY_PEERS.buffer_len();
        }
        if (self.current_buffer_len + additional_buffer_len) > max_payload_len {
            self.flush_nlas();
            needs_peer_nla = true;
        }

        if needs_peer_nla {
            self.push(EMPTY_PEERS)?;
        }

        // If the peer *still* doesn't fit...
        if (self.current_buffer_len + peer_buffer_len) > max_payload_len {
            return Err(io::Error::new(
                io::ErrorKind::InvalidInput,
                format!("encoded peer ({peer_buffer_len} bytes) is too large: {peer:?}"),
            ));
        }

        let peers_nla = self
            .nlas
            .iter_mut()
            .find_map(|nla| match nla {
                WgDeviceAttrs::Peers(peers) => Some(peers),
                _ => None,
            })
            .expect("WgDeviceAttrs::Peers missing from NLAs when it should exist.");

        peers_nla.push(peer);
        self.current_buffer_len += peer_buffer_len;

        Ok(())
    }

    pub fn finish(mut self) -> Vec<GenlMessage<Wireguard>> {
        self.flush_nlas();
        self.queue
    }
}

pub fn get_by_name(name: &InterfaceName) -> Result<Device, io::Error> {
    let genlmsg: GenlMessage<Wireguard> = GenlMessage::from_payload(Wireguard {
        cmd: WireguardCmd::GetDevice,
        nlas: vec![WgDeviceAttrs::IfName(name.as_str_lossy().to_string())],
    });
    let responses = netlink_request_genl(genlmsg, Some(NLM_F_REQUEST | NLM_F_DUMP | NLM_F_ACK))?;
    log::debug!(
        "get_by_name: got {} response message(s) from netlink request",
        responses.len()
    );

    let nlas = responses.into_iter().try_fold(vec![], |mut nlas, nlmsg| {
        let mut message = match nlmsg {
            NetlinkMessage {
                payload: NetlinkPayload::InnerMessage(message),
                ..
            } => message,
            _ => {
                return Err(io::Error::new(
                    io::ErrorKind::InvalidData,
                    format!("unexpected netlink payload: {nlmsg:?}"),
                ))
            },
        };
        nlas.append(&mut message.payload.nlas);
        Ok(nlas)
    })?;
    let device = Device::try_from(&nlas[..])?;
    log::debug!(
        "get_by_name: parsed wireguard device {} with {} peer(s)",
        device.name,
        device.peers.len(),
    );
    Ok(device)
}

pub fn delete_interface(iface: &InterfaceName) -> io::Result<()> {
    add_del(iface, false)
}

#[cfg(test)]
mod tests {
    use super::*;
    use netlink_packet_wireguard::nlas::WgAllowedIp;
    use netlink_request::max_netlink_buffer_length;
    use std::str::FromStr;

    #[test]
    fn test_simple_payload() {
        let mut payload = ApplyPayload::new(&InterfaceName::from_str("wg0").unwrap());
        payload.push(WgDeviceAttrs::PrivateKey([1u8; 32])).unwrap();
        payload.push(WgDeviceAttrs::Fwmark(111)).unwrap();
        payload.push(WgDeviceAttrs::ListenPort(12345)).unwrap();
        payload
            .push(WgDeviceAttrs::Flags(WGDEVICE_F_REPLACE_PEERS))
            .unwrap();
        payload
            .push_peer(WgPeer(vec![
                WgPeerAttrs::PublicKey([2u8; 32]),
                WgPeerAttrs::PersistentKeepalive(25),
                WgPeerAttrs::Endpoint("1.1.1.1:51820".parse().unwrap()),
                WgPeerAttrs::Flags(WGPEER_F_REPLACE_ALLOWEDIPS),
                WgPeerAttrs::AllowedIps(vec![WgAllowedIp(vec![
                    WgAllowedIpAttrs::Family(AF_INET),
                    WgAllowedIpAttrs::IpAddr([10, 1, 1, 1].into()),
                    WgAllowedIpAttrs::Cidr(24),
                ])]),
            ]))
            .unwrap();
        assert_eq!(payload.finish().len(), 1);
    }

    #[test]
    fn test_massive_payload() {
        let mut payload = ApplyPayload::new(&InterfaceName::from_str("wg0").unwrap());
        payload.push(WgDeviceAttrs::PrivateKey([1u8; 32])).unwrap();
        payload.push(WgDeviceAttrs::Fwmark(111)).unwrap();
        payload.push(WgDeviceAttrs::ListenPort(12345)).unwrap();
        payload
            .push(WgDeviceAttrs::Flags(WGDEVICE_F_REPLACE_PEERS))
            .unwrap();

        for i in 0..10_000 {
            payload
                .push_peer(WgPeer(vec![
                    WgPeerAttrs::PublicKey([2u8; 32]),
                    WgPeerAttrs::PersistentKeepalive(25),
                    WgPeerAttrs::Endpoint("1.1.1.1:51820".parse().unwrap()),
                    WgPeerAttrs::Flags(WGPEER_F_REPLACE_ALLOWEDIPS),
                    WgPeerAttrs::AllowedIps(vec![WgAllowedIp(vec![
                        WgAllowedIpAttrs::Family(AF_INET),
                        WgAllowedIpAttrs::IpAddr([10, 1, 1, 1].into()),
                        WgAllowedIpAttrs::Cidr(24),
                    ])]),
                    WgPeerAttrs::Unspec(vec![1u8; (i % 256) as usize]),
                ]))
                .unwrap();
        }

        let messages = payload.finish();
        println!("generated {} messages", messages.len());
        assert!(messages.len() > 1);
        let max_buffer_len = max_netlink_buffer_length();
        for message in messages {
            assert!(NetlinkMessage::from(message).buffer_len() <= max_buffer_len);
        }
    }
}