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endhost_api_client/
client.rs

1// Copyright 2025 Anapaya Systems
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//   http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14//! # Endhost API client
15//!
16//! An [EndhostApiClient] provides the application with the information
17//! necessary to send and receive SCION-packets in the routing domain that is
18//! associated with the endhost API.
19//!
20//! The implementation [CrpcEndhostApiClient] is a concrete implementation
21//! following the current specification of the endhost-API.
22//!
23//! ## Example Usage
24//!
25//! ```no_run
26//! use std::{net::SocketAddr, str::FromStr};
27//!
28//! use endhost_api_client::client::{CrpcEndhostApiClient, EndhostApiClient};
29//! use sciparse::identifier::isd_asn::IsdAsn;
30//!
31//! pub async fn get_all_udp_sockaddrs() -> anyhow::Result<Vec<SocketAddr>> {
32//!     let crpc_client =
33//!         CrpcEndhostApiClient::new(&url::Url::parse("http://10.0.0.1:48080/").unwrap())?;
34//!
35//!     let res = crpc_client
36//!         .list_underlays(IsdAsn::from_str("1-ff00:0:110").unwrap())
37//!         .await?
38//!         .udp_underlay
39//!         .iter()
40//!         .map(|router| router.internal_interface)
41//!         .collect();
42//!
43//!     Ok(res)
44//! }
45//! ```
46use std::{ops::Deref, sync::Arc};
47
48use endhost_api::routes::{
49    ENDHOST_API_V1, LIST_SEGMENTS, LIST_UNDERLAYS, SEGMENTS_SERVICE, UNDERLAY_SERVICE,
50};
51use endhost_api_models::underlays::Underlays;
52use endhost_api_protobuf::v1::{
53    ListSegmentsRequest, ListSegmentsResponse, ListUnderlaysRequest, ListUnderlaysResponse,
54};
55use reqwest_connect_rpc::{
56    client::{CrpcClient, CrpcClientError},
57    token_source::TokenSource,
58};
59use sciparse::{identifier::isd_asn::IsdAsn, rpc::FromRpcError, segment::SegmentsPage};
60
61/// Endhost API client trait.
62///
63/// This allows for a client mock implementation in tests.
64#[async_trait::async_trait]
65pub trait EndhostApiClient: Send + Sync {
66    /// List the available underlays for a given ISD-AS.
67    ///
68    /// # Arguments
69    /// * `isd_as` - The ISD-AS to list the underlays for. For a wildcard ISD AS
70    ///   (`IsdAsn::WILDCARD`), all existing underlays will be returned.
71    ///
72    /// # Returns
73    /// A future that resolves to the list of underlays.
74    async fn list_underlays(&self, isd_as: IsdAsn) -> Result<Underlays, CrpcClientError>;
75    /// List the available segments between a source and destination ISD-AS.
76    ///
77    /// # Arguments
78    /// * `src` - The source ISD-AS.
79    /// * `dst` - The destination ISD-AS.
80    /// * `page_size` - The maximum number of segments to return.
81    /// * `page_token` - The token to use for pagination.
82    async fn list_segments(
83        &self,
84        src: IsdAsn,
85        dst: IsdAsn,
86        page_size: i32,
87        page_token: String,
88    ) -> Result<SegmentsPage, CrpcClientError>;
89}
90
91/// Connect RPC endhost API client.
92pub struct CrpcEndhostApiClient {
93    client: CrpcClient,
94}
95
96impl Deref for CrpcEndhostApiClient {
97    type Target = CrpcClient;
98
99    fn deref(&self) -> &Self::Target {
100        &self.client
101    }
102}
103
104impl CrpcEndhostApiClient {
105    /// Creates a new endhost API client from the given base URL.
106    pub fn new(base_url: &url::Url) -> anyhow::Result<Self> {
107        Ok(CrpcEndhostApiClient {
108            client: CrpcClient::new(base_url)?,
109        })
110    }
111
112    /// Creates a new endhost API client from the given base URL and [`reqwest::Client`].
113    pub fn new_with_client(base_url: &url::Url, client: reqwest::Client) -> anyhow::Result<Self> {
114        Ok(CrpcEndhostApiClient {
115            client: CrpcClient::new_with_client(base_url, client)?,
116        })
117    }
118
119    /// Uses the provided token source for authentication.
120    pub fn use_token_source(&mut self, token_source: Arc<dyn TokenSource>) -> &mut Self {
121        self.client.use_token_source(token_source);
122        self
123    }
124}
125
126#[async_trait::async_trait]
127impl EndhostApiClient for CrpcEndhostApiClient {
128    async fn list_underlays(&self, isd_as: IsdAsn) -> Result<Underlays, CrpcClientError> {
129        self.client
130            .unary_request::<ListUnderlaysRequest, ListUnderlaysResponse>(
131                &format!("{ENDHOST_API_V1}.{UNDERLAY_SERVICE}{LIST_UNDERLAYS}"),
132                &ListUnderlaysRequest {
133                    isd_as: Some(isd_as.into()),
134                },
135            )
136            .await?
137            .try_into()
138            .map_err(|e: url::ParseError| {
139                CrpcClientError::DecodeError {
140                    context: "parsing underlay address as URL".into(),
141                    source: Some(e.into()),
142                    body: None,
143                }
144            })
145            .inspect(|resp| {
146                tracing::debug!(%resp, "Listed underlays");
147            })
148    }
149
150    async fn list_segments(
151        &self,
152        src: IsdAsn,
153        dst: IsdAsn,
154        page_size: i32,
155        page_token: String,
156    ) -> Result<SegmentsPage, CrpcClientError> {
157        self.client
158            .unary_request::<ListSegmentsRequest, ListSegmentsResponse>(
159                &format!("{ENDHOST_API_V1}.{SEGMENTS_SERVICE}{LIST_SEGMENTS}"),
160                &ListSegmentsRequest {
161                    src_isd_as: src.0,
162                    dst_isd_as: dst.0,
163                    page_size,
164                    page_token,
165                },
166            )
167            .await?
168            .try_into()
169            .map_err(|e: FromRpcError| {
170                CrpcClientError::DecodeError {
171                    context: "failed decoding segments".into(),
172                    source: Some(e.into()),
173                    body: None,
174                }
175            })
176            .inspect(|resp: &SegmentsPage| {
177                tracing::debug!(
178                    core=?resp.segments.core_segments.len(),
179                    down=?resp.segments.down_segments.len(),
180                    up=?resp.segments.up_segments.len(),
181                    "Listed segments"
182                );
183            })
184    }
185}