Skip to main content

commonware_p2p/authenticated/discovery/
config.rs

1use crate::Ingress;
2use commonware_cryptography::Signer;
3use commonware_runtime::Quota;
4use commonware_utils::{NZUsize, NZU32};
5use std::{
6    net::SocketAddr,
7    num::{NonZeroU32, NonZeroUsize},
8    time::Duration,
9};
10
11/// Known peer and its accompanying ingress address that will be dialed on startup.
12pub type Bootstrapper<P> = (P, Ingress);
13
14/// Configuration for the peer-to-peer instance.
15///
16/// # Warning
17/// It is recommended to synchronize this configuration across peers in the network (with the
18/// exception of `crypto`, `listen`, `bootstrappers`, `allow_private_ips`, `mailbox_size`, and
19/// `send_batch_size`).
20/// If this is not synchronized, connections could be unnecessarily dropped, messages could be parsed incorrectly,
21/// and/or peers will rate limit each other during normal operation.
22#[derive(Clone)]
23pub struct Config<C: Signer> {
24    /// Cryptographic primitives.
25    pub crypto: C,
26
27    /// Prefix for all signed messages to avoid replay attacks.
28    pub namespace: Vec<u8>,
29
30    /// Address to listen on.
31    pub listen: SocketAddr,
32
33    /// Dialable ingress address of the peer.
34    pub dialable: Ingress,
35
36    /// Peers dialed on startup.
37    pub bootstrappers: Vec<Bootstrapper<C::PublicKey>>,
38
39    /// Whether or not to allow DNS-based ingress addresses.
40    ///
41    /// When dialing a DNS-based address, the hostname is resolved and a random IP
42    /// is selected from the results (shuffled for each dial attempt).
43    pub allow_dns: bool,
44
45    /// Whether or not to allow connections with private IP addresses.
46    pub allow_private_ips: bool,
47
48    /// Maximum size allowed for messages over any connection.
49    ///
50    /// The actual size of the network message will be higher due to overhead from the protocol;
51    /// this may include additional metadata, data from the codec, and/or cryptographic signatures.
52    pub max_message_size: u32,
53
54    /// Message backlog allowed for internal actors.
55    ///
56    /// When there are more messages in the mailbox than this value, any actor
57    /// sending a message will be blocked until the mailbox is processed.
58    pub mailbox_size: usize,
59
60    /// Maximum number of already-queued outbound messages to combine into one connection write.
61    ///
62    /// Set this to `1` to disable batching.
63    pub send_batch_size: NonZeroUsize,
64
65    /// Time into the future that a timestamp can be and still be considered valid.
66    pub synchrony_bound: Duration,
67
68    /// Duration after which a handshake message is considered stale.
69    pub max_handshake_age: Duration,
70
71    /// Timeout for the handshake process.
72    ///
73    /// This is often set to some value less than the connection read timeout to prevent
74    /// unauthenticated peers from holding open connection.
75    pub handshake_timeout: Duration,
76
77    /// Minimum time between connection reservations for a single peer.
78    pub peer_connection_cooldown: Duration,
79
80    /// Maximum number of concurrent handshake attempts allowed.
81    pub max_concurrent_handshakes: NonZeroU32,
82
83    /// Quota for handshake attempts originating from a single IP address.
84    ///
85    /// To cap the number of handshakes concurrently attempted for a single
86    /// IP, set this to [Config::handshake_timeout].
87    pub allowed_handshake_rate_per_ip: Quota,
88
89    /// Quota for handshake attempts originating from a single IP subnet.
90    pub allowed_handshake_rate_per_subnet: Quota,
91
92    /// Average frequency at which we make a single dial attempt across all peers.
93    pub dial_frequency: Duration,
94
95    /// Times that dialing a given peer should fail before asking for updated peer information for
96    /// that peer.
97    pub dial_fail_limit: usize,
98
99    /// Number of peer sets to track.
100    ///
101    /// We will attempt to maintain connections to peers stored
102    /// across all peer sets, not just the most recent. This allows
103    /// us to continue serving requests to peers that have recently
104    /// been evicted and/or to communicate with peers in a future
105    /// set (if we, for example, are trying to do a reshare of a threshold
106    /// key).
107    pub tracked_peer_sets: NonZeroUsize,
108
109    /// Maximum number of peers to track in a single peer set.
110    ///
111    /// This is used to limit the size of the bit vec messages, which will take one bit per peer in
112    /// the set. This number can be set to a reasonably high value that we never expect to reach.
113    pub max_peer_set_size: u64,
114
115    /// Frequency we gossip about known peers.
116    ///
117    /// If there is no other network activity, this message is used as a ping
118    /// and should be sent more often than the read_timeout.
119    ///
120    /// This also determines the rate limit for incoming BitVec and Peers messages
121    /// (one per half this frequency to account for jitter).
122    pub gossip_bit_vec_frequency: Duration,
123
124    /// Maximum number of peers we will send or consider valid when receiving in a single message.
125    ///
126    /// This is used to prevent malicious peers from sending us a large number of peers at one time (each
127    /// of which requires a signature verification).
128    pub peer_gossip_max_count: usize,
129
130    /// Duration after which a blocked peer is allowed to reconnect.
131    pub block_duration: Duration,
132}
133
134impl<C: Signer> Config<C> {
135    /// Generates a configuration with reasonable defaults for usage in production.
136    pub fn recommended(
137        crypto: C,
138        namespace: &[u8],
139        listen: SocketAddr,
140        dialable: impl Into<Ingress>,
141        bootstrappers: Vec<Bootstrapper<C::PublicKey>>,
142        max_message_size: u32,
143    ) -> Self {
144        Self {
145            crypto,
146            namespace: namespace.to_vec(),
147            listen,
148            dialable: dialable.into(),
149            bootstrappers,
150            allow_dns: true,
151
152            allow_private_ips: false,
153            max_message_size,
154            mailbox_size: 1_000,
155            send_batch_size: NZUsize!(8),
156            synchrony_bound: Duration::from_secs(5),
157            max_handshake_age: Duration::from_secs(10),
158            handshake_timeout: Duration::from_secs(5),
159            peer_connection_cooldown: Duration::from_secs(60),
160            max_concurrent_handshakes: NZU32!(512),
161            allowed_handshake_rate_per_ip: Quota::with_period(Duration::from_secs(5)).unwrap(), // 1 concurrent handshake per IP
162            allowed_handshake_rate_per_subnet: Quota::per_second(NZU32!(64)),
163            dial_frequency: Duration::from_secs(1),
164            dial_fail_limit: 2,
165            tracked_peer_sets: NZUsize!(4),
166            max_peer_set_size: 1 << 16, // 2^16
167            gossip_bit_vec_frequency: Duration::from_secs(50),
168            peer_gossip_max_count: 32,
169            block_duration: Duration::from_hours(4),
170        }
171    }
172
173    /// Generates a configuration that minimizes peer discovery latency. This
174    /// can be useful when running local demos.
175    ///
176    /// # Warning
177    ///
178    /// It is not recommended to use this configuration in production.
179    pub fn local(
180        crypto: C,
181        namespace: &[u8],
182        listen: SocketAddr,
183        dialable: impl Into<Ingress>,
184        bootstrappers: Vec<Bootstrapper<C::PublicKey>>,
185        max_message_size: u32,
186    ) -> Self {
187        Self {
188            crypto,
189            namespace: namespace.to_vec(),
190            listen,
191            dialable: dialable.into(),
192            bootstrappers,
193            allow_dns: true,
194
195            allow_private_ips: true,
196            max_message_size,
197            mailbox_size: 1_000,
198            send_batch_size: NZUsize!(8),
199            synchrony_bound: Duration::from_secs(5),
200            max_handshake_age: Duration::from_secs(10),
201            handshake_timeout: Duration::from_secs(5),
202            peer_connection_cooldown: Duration::from_secs(1),
203            max_concurrent_handshakes: NZU32!(1_024),
204            allowed_handshake_rate_per_ip: Quota::per_second(NZU32!(16)), // 80 concurrent handshakes per IP
205            allowed_handshake_rate_per_subnet: Quota::per_second(NZU32!(128)),
206            dial_frequency: Duration::from_millis(500),
207            dial_fail_limit: 1,
208            tracked_peer_sets: NZUsize!(4),
209            max_peer_set_size: 1 << 16, // 2^16
210            gossip_bit_vec_frequency: Duration::from_secs(5),
211            peer_gossip_max_count: 32,
212            block_duration: Duration::from_hours(1),
213        }
214    }
215
216    #[cfg(test)]
217    pub fn test(
218        crypto: C,
219        listen: SocketAddr,
220        bootstrappers: Vec<Bootstrapper<C::PublicKey>>,
221        max_message_size: u32,
222    ) -> Self {
223        Self {
224            crypto,
225            namespace: b"test_namespace".to_vec(),
226            listen,
227            dialable: listen.into(),
228            bootstrappers,
229            allow_dns: true,
230
231            allow_private_ips: true,
232            max_message_size,
233            mailbox_size: 1_000,
234            send_batch_size: NZUsize!(8),
235            synchrony_bound: Duration::from_secs(5),
236            max_handshake_age: Duration::from_secs(10),
237            handshake_timeout: Duration::from_secs(5),
238            peer_connection_cooldown: Duration::from_millis(250),
239            max_concurrent_handshakes: NZU32!(1_024),
240            allowed_handshake_rate_per_ip: Quota::per_second(NZU32!(128)), // 640 concurrent handshakes per IP
241            allowed_handshake_rate_per_subnet: Quota::per_second(NZU32!(256)),
242            dial_frequency: Duration::from_millis(200),
243            dial_fail_limit: 1,
244            tracked_peer_sets: NZUsize!(4),
245            max_peer_set_size: 1 << 8, // 2^8
246            gossip_bit_vec_frequency: Duration::from_secs(1),
247            peer_gossip_max_count: 32,
248            block_duration: Duration::from_mins(1),
249        }
250    }
251}