tor_hsclient/
lib.rs

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1#![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg))]
2#![doc = include_str!("../README.md")]
3// @@ begin lint list maintained by maint/add_warning @@
4#![allow(renamed_and_removed_lints)] // @@REMOVE_WHEN(ci_arti_stable)
5#![allow(unknown_lints)] // @@REMOVE_WHEN(ci_arti_nightly)
6#![warn(missing_docs)]
7#![warn(noop_method_call)]
8#![warn(unreachable_pub)]
9#![warn(clippy::all)]
10#![deny(clippy::await_holding_lock)]
11#![deny(clippy::cargo_common_metadata)]
12#![deny(clippy::cast_lossless)]
13#![deny(clippy::checked_conversions)]
14#![warn(clippy::cognitive_complexity)]
15#![deny(clippy::debug_assert_with_mut_call)]
16#![deny(clippy::exhaustive_enums)]
17#![deny(clippy::exhaustive_structs)]
18#![deny(clippy::expl_impl_clone_on_copy)]
19#![deny(clippy::fallible_impl_from)]
20#![deny(clippy::implicit_clone)]
21#![deny(clippy::large_stack_arrays)]
22#![warn(clippy::manual_ok_or)]
23#![deny(clippy::missing_docs_in_private_items)]
24#![warn(clippy::needless_borrow)]
25#![warn(clippy::needless_pass_by_value)]
26#![warn(clippy::option_option)]
27#![deny(clippy::print_stderr)]
28#![deny(clippy::print_stdout)]
29#![warn(clippy::rc_buffer)]
30#![deny(clippy::ref_option_ref)]
31#![warn(clippy::semicolon_if_nothing_returned)]
32#![warn(clippy::trait_duplication_in_bounds)]
33#![deny(clippy::unchecked_duration_subtraction)]
34#![deny(clippy::unnecessary_wraps)]
35#![warn(clippy::unseparated_literal_suffix)]
36#![deny(clippy::unwrap_used)]
37#![deny(clippy::mod_module_files)]
38#![allow(clippy::let_unit_value)] // This can reasonably be done for explicitness
39#![allow(clippy::uninlined_format_args)]
40#![allow(clippy::significant_drop_in_scrutinee)] // arti/-/merge_requests/588/#note_2812945
41#![allow(clippy::result_large_err)] // temporary workaround for arti#587
42#![allow(clippy::needless_raw_string_hashes)] // complained-about code is fine, often best
43#![allow(clippy::needless_lifetimes)] // See arti#1765
44#![allow(mismatched_lifetime_syntaxes)] // temporary workaround for arti#2060
45//! <!-- @@ end lint list maintained by maint/add_warning @@ -->
46
47mod connect;
48mod err;
49mod isol_map;
50mod keys;
51mod pow;
52mod proto_oneshot;
53mod relay_info;
54mod state;
55
56use std::future::Future;
57use std::sync::{Arc, Mutex, MutexGuard};
58
59use futures::StreamExt as _;
60use futures::stream::BoxStream;
61use futures::task::SpawnExt as _;
62
63use educe::Educe;
64use tracing::debug;
65
66use tor_circmgr::ClientOnionServiceDataTunnel;
67use tor_circmgr::hspool::HsCircPool;
68use tor_circmgr::isolation::StreamIsolation;
69use tor_error::{Bug, internal};
70use tor_hscrypto::pk::HsId;
71use tor_netdir::NetDir;
72use tor_rtcompat::Runtime;
73
74pub use err::FailedAttemptError;
75pub use err::{ConnError, DescriptorError, DescriptorErrorDetail, StartupError};
76pub use keys::{HsClientDescEncKeypairSpecifier, HsClientSecretKeys, HsClientSecretKeysBuilder};
77pub use relay_info::InvalidTarget;
78pub use state::HsClientConnectorConfig;
79
80use err::{IntroPtIndex, RendPtIdentityForError, rend_pt_identity_for_error};
81use state::{Config, MockableConnectorData, Services};
82
83/// An object that negotiates connections with onion services
84///
85/// This can be used by multiple requests on behalf of different clients,
86/// with potentially different HS service discovery keys (`KS_hsc_*`)
87/// and potentially different circuit isolation.
88///
89/// The principal entrypoint is
90/// [`get_or_launch_tunnel()`](HsClientConnector::get_or_launch_tunnel).
91///
92/// This object is handle-like: it is fairly cheap to clone,
93///  and contains `Arc`s internally.
94#[derive(Educe)]
95#[educe(Clone)]
96pub struct HsClientConnector<R: Runtime, D: state::MockableConnectorData = connect::Data> {
97    /// The runtime
98    runtime: R,
99    /// A [`HsCircPool`] that we use to build circuits to HsDirs, introduction
100    /// points, and rendezvous points.
101    circpool: Arc<HsCircPool<R>>,
102    /// Information we are remembering about different onion services.
103    services: Arc<Mutex<state::Services<D>>>,
104    /// For mocking in tests of `state.rs`
105    mock_for_state: D::MockGlobalState,
106}
107
108impl<R: Runtime> HsClientConnector<R, connect::Data> {
109    /// Create a new `HsClientConnector`
110    ///
111    /// `housekeeping_prompt` should yield "occasionally",
112    /// perhaps every few hours or maybe daily.
113    ///
114    /// In Arti we arrange for this to happen when we have a new consensus.
115    ///
116    /// Housekeeping events shouldn't arrive while we're dormant,
117    /// since the housekeeping might involve processing that ought to be deferred.
118    // This ^ is why we don't have a separate "launch background tasks" method.
119    // It is fine for this background task to be launched pre-bootstrap, since it willp
120    // do nothing until it gets events.
121    pub fn new(
122        runtime: R,
123        circpool: Arc<HsCircPool<R>>,
124        config: &impl HsClientConnectorConfig,
125        housekeeping_prompt: BoxStream<'static, ()>,
126    ) -> Result<Self, StartupError> {
127        let config = Config {
128            retry: config.as_ref().clone(),
129        };
130        let connector = HsClientConnector {
131            runtime,
132            circpool,
133            services: Arc::new(Mutex::new(Services::new(config))),
134            mock_for_state: (),
135        };
136        connector.spawn_housekeeping_task(housekeeping_prompt)?;
137        Ok(connector)
138    }
139
140    /// Connect to a hidden service
141    ///
142    /// On success, this function will return an open
143    /// rendezvous circuit with an authenticated connection to the onion service
144    /// whose identity is `hs_id`.  If such a circuit already exists, and its isolation
145    /// is compatible with `isolation`, that circuit may be returned; otherwise,
146    /// a new circuit will be created.
147    ///
148    /// Once a circuit is returned, the caller can use it to open new streams to the
149    /// onion service. To do so, call [`ClientOnionServiceDataTunnel::begin_stream`] on it.
150    ///
151    /// Each HS connection request must provide the appropriate
152    /// service discovery keys to use -
153    /// or [`default`](HsClientSecretKeys::default)
154    /// if the hidden service is not running in restricted discovery mode.
155    //
156    // This returns an explicit `impl Future` so that we can write the `Send` bound.
157    // Without this, it is possible for `Services::get_or_launch_connection`
158    // to not return a `Send` future.
159    // https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/1034#note_2881718
160    pub fn get_or_launch_tunnel<'r>(
161        &'r self,
162        netdir: &'r Arc<NetDir>,
163        hs_id: HsId,
164        secret_keys: HsClientSecretKeys,
165        isolation: StreamIsolation,
166    ) -> impl Future<Output = Result<Arc<ClientOnionServiceDataTunnel>, ConnError>> + Send + Sync + 'r
167    {
168        // As in tor-circmgr,  we take `StreamIsolation`, to ensure that callers in
169        // arti-client pass us the final overall isolation,
170        // including the per-TorClient isolation.
171        // But internally we need a Box<dyn Isolation> since we need .join().
172        let isolation = Box::new(isolation);
173        Services::get_or_launch_connection(self, netdir, hs_id, isolation, secret_keys)
174    }
175}
176
177impl<R: Runtime, D: MockableConnectorData> HsClientConnector<R, D> {
178    /// Lock the `Services` table and return the guard
179    ///
180    /// Convenience method
181    fn services(&self) -> Result<MutexGuard<Services<D>>, Bug> {
182        self.services
183            .lock()
184            .map_err(|_| internal!("HS connector poisoned"))
185    }
186
187    /// Spawn a task which watches `prompt` and calls [`Services::run_housekeeping`]
188    fn spawn_housekeeping_task(
189        &self,
190        mut prompt: BoxStream<'static, ()>,
191    ) -> Result<(), StartupError> {
192        self.runtime
193            .spawn({
194                let connector = self.clone();
195                let runtime = self.runtime.clone();
196                async move {
197                    while let Some(()) = prompt.next().await {
198                        let Ok(mut services) = connector.services() else {
199                            break;
200                        };
201
202                        // (Currently) this is "expire old data".
203                        services.run_housekeeping(runtime.now());
204                    }
205                    debug!("HS connector housekeeping task exiting (EOF on prompt stream)");
206                }
207            })
208            .map_err(|cause| StartupError::Spawn {
209                spawning: "housekeeping task",
210                cause: cause.into(),
211            })
212    }
213}
214
215/// Return a list of the protocols [supported](tor_protover::doc_supported) by this crate,
216/// running as a hidden service client.
217pub fn supported_hsclient_protocols() -> tor_protover::Protocols {
218    use tor_protover::named::*;
219    // WARNING: REMOVING ELEMENTS FROM THIS LIST CAN BE DANGEROUS!
220    // SEE [`tor_protover::doc_changing`]
221    [
222        HSINTRO_V3,
223        // Technically, there is nothing for a client to do to support HSINTRO_RATELIM.
224        // See torspec#319
225        HSINTRO_RATELIM,
226        HSREND_V3,
227        HSDIR_V3,
228    ]
229    .into_iter()
230    .collect()
231}
232
233#[cfg(test)]
234mod test {
235    // @@ begin test lint list maintained by maint/add_warning @@
236    #![allow(clippy::bool_assert_comparison)]
237    #![allow(clippy::clone_on_copy)]
238    #![allow(clippy::dbg_macro)]
239    #![allow(clippy::mixed_attributes_style)]
240    #![allow(clippy::print_stderr)]
241    #![allow(clippy::print_stdout)]
242    #![allow(clippy::single_char_pattern)]
243    #![allow(clippy::unwrap_used)]
244    #![allow(clippy::unchecked_duration_subtraction)]
245    #![allow(clippy::useless_vec)]
246    #![allow(clippy::needless_pass_by_value)]
247    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
248
249    use super::*;
250
251    #[test]
252    fn protocols() {
253        let pr = supported_hsclient_protocols();
254        let expected = "HSIntro=4-5 HSRend=2 HSDir=2".parse().unwrap();
255        assert_eq!(pr, expected);
256    }
257}
tor_hsclient/lib.rs

tor_hsclient/
lib.rs
