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

#![deny(
    missing_docs,
    missing_debug_implementations,
    missing_copy_implementations,
    trivial_casts,
    trivial_numeric_casts,
    unstable_features,
    unused_import_braces,
    unused_qualifications
)]

//! A crate for using hyper as a backend for HTTP(S) git requests with git2-rs.
//!
//! This crate provides one public function, `register`, which will register
//! a custom HTTP transport with hyper for any HTTP(S) requests made by libgit2.
//! At this time the `register` function is unsafe for the same reasons that
//! `git2::transport::register` is also unsafe.
//!
//! > **NOTE**: At this time this crate likely does not support a `git push`
//! >           operation, only clones.

#![doc(html_root_url = "https://docs.rs/git2-hyper/0.1")]
#![deny(missing_docs)]
#![warn(rust_2018_idioms)]
#![cfg_attr(test, deny(warnings))]

use std::error;
use std::io::prelude::*;
use std::io::{self, Cursor};
use std::str::FromStr;
use std::sync::{Arc, Mutex, Once};

use hyper::body::HttpBody;
use hyper::client::HttpConnector;
use hyper::http::header;
use hyper::Body;
use hyper::Request;
use hyper::{Method, Uri};

#[cfg(feature = "native")]
use hyper_tls::HttpsConnector;

#[cfg(feature = "rustls")]
use hyper_rustls::HttpsConnector;

use log::{debug, info};

use git2::transport::{Service, SmartSubtransport, SmartSubtransportStream, Transport};
use git2::Error;

struct HyperTransport {
    handle: Arc<Mutex<hyper::Client<HttpsConnector<HttpConnector>>>>,
    /// The URL of the remote server, e.g. "https://github.com/user/repo"
    ///
    /// This is an empty string until the first action is performed.
    /// If there is an HTTP redirect, this will be updated with the new URL.
    base_url: Arc<Mutex<String>>,
    runtime: Arc<tokio::runtime::Runtime>,
}

struct HyperSubtransport {
    handle: Arc<Mutex<hyper::Client<HttpsConnector<HttpConnector>>>>,
    service: &'static str,
    url_path: &'static str,
    base_url: Arc<Mutex<String>>,
    method: &'static str,
    response: Option<hyper::Response<Body>>,
    sent_request: bool,
    runtime_handle: tokio::runtime::Handle,
}

/// Register the hyper backend for HTTP requests made by libgit2.
///
/// This function takes one parameter, a `handle`, which is used to perform all
/// future HTTP(S) requests. The handle can be previously configured with
/// information such as proxies, SSL information, etc.
///
/// This function is unsafe largely for the same reasons as
/// `git2::transport::register`:
///
/// * The function needs to be synchronized against all other creations of
///   transport (any API calls to libgit2).
/// * The function will leak `handle` as once registered it is not currently
///   possible to unregister the backend.
///
/// This function may be called concurrently, but only the first `handle` will
/// be used. All others will be discarded.
pub unsafe fn register(handle: hyper::Client<HttpsConnector<HttpConnector>>) {
    static INIT: Once = Once::new();

    let handle = Arc::new(Mutex::new(handle));
    let handle2 = handle.clone();
    INIT.call_once(move || {
        git2::transport::register("http", move |remote| factory(remote, handle.clone())).unwrap();
        git2::transport::register("https", move |remote| factory(remote, handle2.clone())).unwrap();
    });
}

fn factory(
    remote: &git2::Remote<'_>,
    handle: Arc<Mutex<hyper::Client<HttpsConnector<HttpConnector>>>>,
) -> Result<Transport, Error> {
    Transport::smart(
        remote,
        true,
        HyperTransport {
            handle,
            base_url: Arc::new(Mutex::new(String::new())),
            runtime: Arc::new(tokio::runtime::Runtime::new().unwrap()),
        },
    )
}

impl SmartSubtransport for HyperTransport {
    fn action(
        &self,
        url: &str,
        action: Service,
    ) -> Result<Box<dyn SmartSubtransportStream>, Error> {
        let mut base_url = self.base_url.lock().unwrap();
        if base_url.len() == 0 {
            *base_url = url.to_string();
        }
        let (service, path, method) = match action {
            Service::UploadPackLs => ("upload-pack", "/info/refs?service=git-upload-pack", "GET"),
            Service::UploadPack => ("upload-pack", "/git-upload-pack", "POST"),
            Service::ReceivePackLs => {
                ("receive-pack", "/info/refs?service=git-receive-pack", "GET")
            }
            Service::ReceivePack => ("receive-pack", "/git-receive-pack", "POST"),
        };
        info!("action {} {}", service, path);
        Ok(Box::new(HyperSubtransport {
            handle: self.handle.clone(),
            service,
            url_path: path,
            base_url: self.base_url.clone(),
            method,
            response: None,
            sent_request: false,
            runtime_handle: self.runtime.handle().clone(),
        }))
    }

    fn close(&self) -> Result<(), Error> {
        Ok(())
    }
}

impl HyperSubtransport {
    fn err<E: Into<Box<dyn error::Error + Send + Sync>>>(&self, err: E) -> io::Error {
        io::Error::new(io::ErrorKind::Other, err)
    }

    fn execute(&mut self, data: &[u8]) -> io::Result<()> {
        if self.sent_request {
            return Err(self.err("already sent HTTP request"));
        }

        let agent = format!("git/1.0 (git2-hyper {})", env!("CARGO_PKG_VERSION"));

        // Parse our input URL to figure out the host
        let url = format!("{}{}", self.base_url.lock().unwrap(), self.url_path);
        let parsed = Uri::from_str(&url).map_err(|_| self.err("invalid url, failed to parse"))?;
        let host = match parsed.host() {
            Some(host) => host,
            None => return Err(self.err("invalid url, did not have a host")),
        };

        // Prep the request
        debug!("request to {}", url);
        let client = self.handle.lock().unwrap();

        let method =
            Method::from_bytes(self.method.as_bytes()).map_err(|_| self.err("invalid method"))?;
        let request = Request::builder()
            .method(method)
            .uri(&url)
            .header(header::USER_AGENT, agent)
            .header(header::HOST, host)
            .header(header::EXPECT, "");

        let request = if data.is_empty() {
            request.header(header::ACCEPT, "*/*")
        } else {
            request
                .header(
                    header::ACCEPT,
                    format!("application/x-git-{}-result", self.service),
                )
                .header(
                    header::CONTENT_TYPE,
                    format!("application/x-git-{}-request", self.service),
                )
        };

        let request = request
            .body(Body::from(Vec::from(data)))
            .map_err(|_| self.err("invalid body"))?;

        let res = self
            .runtime_handle
            .block_on(client.request(request))
            .unwrap();
        let headers = res.headers();

        let content_type = headers
            .get(header::CONTENT_TYPE)
            .map(|v| v.to_str().unwrap());

        let code = res.status();
        if code.as_u16() != 200 {
            return Err(self.err(
                &format!(
                    "failed to receive HTTP 200 response: \
                     got {}",
                    code
                )[..],
            ));
        }

        // Check returned headers
        let expected = match self.method {
            "GET" => format!("application/x-git-{}-advertisement", self.service),
            _ => format!("application/x-git-{}-result", self.service),
        };

        if let Some(content_type) = content_type {
            if content_type != expected {
                return Err(self.err(
                    &format!(
                        "expected a Content-Type header \
                         with `{}` but found `{}`",
                        expected, content_type
                    )[..],
                ));
            }
        } else {
            return Err(self.err(
                &format!(
                    "expected a Content-Type header \
                         with `{}` but didn't find one",
                    expected
                )[..],
            ));
        }

        // preserve response body for reading afterwards
        self.response = Some(res);

        Ok(())
    }
}

impl Read for HyperSubtransport {
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        if self.response.is_none() {
            self.execute(&[])?;
        }

        let data = self.response.as_mut().unwrap().body_mut().data();

        let body = match self.runtime_handle.block_on(data) {
            Some(b) => b,
            None => return Err(self.err("empty response body")),
        };

        let bytes = match body {
            Ok(b) => b,
            Err(_) => return Err(self.err("invalid response body")),
        };

        let mut reader = Cursor::new(bytes);
        reader.read(buf)
    }
}

impl Write for HyperSubtransport {
    fn write(&mut self, data: &[u8]) -> io::Result<usize> {
        if self.response.is_none() {
            self.execute(data)?;
        }
        Ok(data.len())
    }
    fn flush(&mut self) -> io::Result<()> {
        Ok(())
    }
}