relay_core_lib/proxy/
http_utils.rs

1use crate::capture::loop_detection::LoopDetector;
2use crate::interceptor::HttpBody;
3use crate::proxy::body_codec::process_body;
4use chrono::Utc;
5use cookie::Cookie as CookieCrate;
6use data_encoding::BASE64;
7use http_body_util::{BodyExt, Full};
8use hyper::body::Bytes;
9use hyper::header::{HeaderName, HeaderValue};
10use hyper::{Request, Response, StatusCode};
11use hyper_rustls::HttpsConnector;
12use hyper_util::client::legacy::Client;
13use hyper_util::client::legacy::connect::HttpConnector;
14use relay_core_api::flow::{
15    BodyData, Cookie, Flow, HttpLayer, HttpRequest, HttpResponse, Layer, NetworkInfo,
16    TransportProtocol, WebSocketLayer,
17};
18use relay_core_api::policy::ProxyPolicy;
19use std::net::SocketAddr;
20use url::Url;
21use uuid::Uuid;
22
23pub type HttpsClient = Client<HttpsConnector<HttpConnector>, HttpBody>;
24
25#[derive(Clone, Debug)]
26pub struct RequestMeta {
27    pub method: String,
28    pub url_str: String,
29    pub version: String,
30    pub headers: Vec<(String, String)>,
31    pub query: Vec<(String, String)>,
32    pub cookies: Vec<Cookie>,
33}
34
35pub fn parse_request_meta<B>(req: &Request<B>, is_mitm: bool) -> RequestMeta {
36    let method = req.method().to_string();
37    let mut url_str = req.uri().to_string();
38
39    // Attempt to construct absolute URL if relative
40    if Url::parse(&url_str).is_err()
41        && let Some(host) = req.headers().get("Host").and_then(|v| v.to_str().ok())
42    {
43        let scheme = if is_mitm { "https" } else { "http" };
44        let new_url = format!("{}://{}{}", scheme, host, url_str);
45        if Url::parse(&new_url).is_ok() {
46            url_str = new_url;
47        }
48    }
49
50    let version = format!("{:?}", req.version());
51
52    let headers: Vec<(String, String)> = req
53        .headers()
54        .iter()
55        .map(|(k, v)| (k.to_string(), v.to_str().unwrap_or("").to_string()))
56        .collect();
57
58    let query: Vec<(String, String)> = if let Ok(parsed_url) = Url::parse(&url_str) {
59        parsed_url.query_pairs().into_owned().collect()
60    } else {
61        vec![]
62    };
63
64    let mut cookies = Vec::new();
65    if let Some(cookie_header) = req.headers().get(hyper::header::COOKIE)
66        && let Ok(cookie_str) = cookie_header.to_str()
67    {
68        for c in CookieCrate::split_parse(cookie_str).flatten() {
69            cookies.push(Cookie {
70                name: c.name().to_string(),
71                value: c.value().to_string(),
72                path: None,
73                domain: None,
74                expires: None,
75                http_only: None,
76                secure: None,
77            });
78        }
79    }
80
81    RequestMeta {
82        method,
83        url_str,
84        version,
85        headers,
86        query,
87        cookies,
88    }
89}
90
91pub fn is_hop_by_hop(name: &str) -> bool {
92    name.eq_ignore_ascii_case("connection")
93        || name.eq_ignore_ascii_case("keep-alive")
94        || name.eq_ignore_ascii_case("proxy-authenticate")
95        || name.eq_ignore_ascii_case("proxy-authorization")
96        || name.eq_ignore_ascii_case("te")
97        || name.eq_ignore_ascii_case("trailers")
98        || name.eq_ignore_ascii_case("transfer-encoding")
99        || name.eq_ignore_ascii_case("upgrade")
100}
101
102pub fn create_initial_flow(
103    meta: RequestMeta,
104    req_body: Option<BodyData>,
105    client_addr: SocketAddr,
106    is_mitm: bool,
107    is_websocket: bool,
108) -> Flow {
109    let flow_id = Uuid::new_v4();
110    let start_time = Utc::now();
111
112    let network_info = NetworkInfo {
113        client_ip: client_addr.ip().to_string(),
114        client_port: client_addr.port(),
115        server_ip: "0.0.0.0".to_string(), // Placeholder
116        server_port: 0,                   // Placeholder
117        protocol: TransportProtocol::TCP,
118        tls: is_mitm,
119        tls_version: None,
120        sni: None,
121    };
122
123    let http_request = HttpRequest {
124        method: meta.method,
125        url: Url::parse(&meta.url_str).unwrap_or_else(|_| Url::parse("http://unknown").unwrap()),
126        version: meta.version,
127        headers: meta.headers,
128        cookies: meta.cookies,
129        query: meta.query,
130        body: req_body,
131    };
132
133    let mut flow = if is_websocket {
134        Flow {
135            id: flow_id,
136            start_time,
137            end_time: None,
138            network: network_info,
139            layer: Layer::WebSocket(WebSocketLayer {
140                handshake_request: http_request,
141                handshake_response: HttpResponse {
142                    status: 0,
143                    status_text: "".to_string(),
144                    version: "".to_string(),
145                    headers: vec![],
146                    cookies: vec![],
147                    body: None,
148                    timing: relay_core_api::flow::ResponseTiming {
149                        time_to_first_byte: None,
150                        time_to_last_byte: None,
151                        connect_time_ms: None,
152                        ssl_time_ms: None,
153                    },
154                },
155                messages: vec![],
156                closed: false,
157            }),
158            tags: vec!["websocket".to_string()],
159            meta: std::collections::HashMap::new(),
160        }
161    } else {
162        Flow {
163            id: flow_id,
164            start_time,
165            end_time: None,
166            network: network_info,
167            layer: Layer::Http(HttpLayer {
168                request: http_request,
169                response: None,
170                error: None,
171            }),
172            tags: vec!["proxy".to_string()],
173            meta: std::collections::HashMap::new(),
174        }
175    };
176
177    if is_mitm {
178        flow.tags.push("mitm".to_string());
179    }
180
181    flow
182}
183
184pub fn create_error_response(status: StatusCode, message: impl Into<Bytes>) -> Response<HttpBody> {
185    Response::builder()
186        .status(status)
187        .body(Full::new(message.into()).map_err(|e| e.into()).boxed())
188        .unwrap_or_else(|_| {
189            Response::new(
190                Full::new(Bytes::from("Internal Error"))
191                    .map_err(|e| e.into())
192                    .boxed(),
193            )
194        })
195}
196
197pub fn mock_to_response(mock: HttpResponse) -> Response<HttpBody> {
198    let mut builder =
199        Response::builder().status(StatusCode::from_u16(mock.status).unwrap_or(StatusCode::OK));
200
201    for (k, v) in mock.headers {
202        if let (Ok(name), Ok(val)) = (
203            HeaderName::from_bytes(k.as_bytes()),
204            HeaderValue::from_str(&v),
205        ) {
206            builder = builder.header(name, val);
207        }
208    }
209
210    let body = if let Some(b) = mock.body {
211        Bytes::from(b.content)
212    } else {
213        Bytes::new()
214    };
215
216    builder
217        .body(Full::new(body).map_err(|e| e.into()).boxed())
218        .unwrap_or_else(|_| {
219            create_error_response(
220                StatusCode::INTERNAL_SERVER_ERROR,
221                "Failed to build mock response",
222            )
223        })
224}
225
226#[allow(clippy::result_large_err)]
227pub fn build_forward_request(
228    flow: &mut Flow,
229    body: HttpBody,
230    target_addr: Option<SocketAddr>,
231    policy: &ProxyPolicy,
232    loop_detector: &LoopDetector,
233) -> Result<Request<HttpBody>, Response<HttpBody>> {
234    let current_req = if let Layer::Http(http) = &flow.layer {
235        &http.request
236    } else {
237        return Err(create_error_response(
238            StatusCode::INTERNAL_SERVER_ERROR,
239            "Invalid Flow Layer State",
240        ));
241    };
242
243    let mut forward_req_builder = Request::builder().method(current_req.method.as_str());
244
245    // Determine upstream URI
246    let mut target_url = current_req.url.clone();
247
248    // Transparent Proxy Routing Logic
249    if policy.transparent_enabled
250        && let Some(addr) = target_addr
251    {
252        flow.tags.push("transparent".to_string());
253
254        // Update Flow Network Info
255        flow.network.server_ip = addr.ip().to_string();
256        flow.network.server_port = addr.port();
257
258        // Loop Detection
259        if loop_detector.would_loop(addr) {
260            if let Layer::Http(http) = &mut flow.layer {
261                http.error = Some("Loop Detected".to_string());
262            }
263            return Err(create_error_response(
264                StatusCode::LOOP_DETECTED,
265                "Loop Detected",
266            ));
267        }
268
269        // Rewrite URI to use target IP
270        if target_url.set_ip_host(addr.ip()).is_ok() {
271            target_url.set_port(Some(addr.port())).ok();
272        }
273
274        // Update scheme if MITM
275        if flow.network.tls && target_url.scheme() == "http" {
276            target_url.set_scheme("https").ok();
277        }
278    }
279
280    forward_req_builder = forward_req_builder.uri(target_url.as_str());
281
282    for (k, v) in &current_req.headers {
283        // Filter out hop-by-hop headers to allow connection pooling
284        if is_hop_by_hop(k) {
285            continue;
286        }
287
288        if let (Ok(name), Ok(val)) = (
289            HeaderName::from_bytes(k.as_bytes()),
290            HeaderValue::from_str(v),
291        ) {
292            forward_req_builder = forward_req_builder.header(name, val);
293        }
294    }
295
296    match forward_req_builder.body(body) {
297        Ok(req) => Ok(req),
298        Err(e) => Err(create_error_response(
299            StatusCode::INTERNAL_SERVER_ERROR,
300            format!("Failed to build forward request: {}", e),
301        )),
302    }
303}
304
305pub fn update_flow_with_response_headers(
306    flow: &mut Flow,
307    status: StatusCode,
308    version: hyper::Version,
309    headers: &hyper::HeaderMap,
310) {
311    let mut response_cookies = Vec::new();
312    for (k, v) in headers.iter() {
313        if k == hyper::header::SET_COOKIE
314            && let Ok(v_str) = v.to_str()
315            && let Ok(c) = CookieCrate::parse(v_str)
316        {
317            response_cookies.push(Cookie {
318                name: c.name().to_string(),
319                value: c.value().to_string(),
320                path: c.path().map(|s| s.to_string()),
321                domain: c.domain().map(|s| s.to_string()),
322                expires: c.expires().map(|e| format!("{:?}", e)),
323                http_only: c.http_only(),
324                secure: c.secure(),
325            });
326        }
327    }
328
329    let resp_headers_vec: Vec<(String, String)> = headers
330        .iter()
331        .map(|(k, v)| (k.to_string(), v.to_str().unwrap_or("").to_string()))
332        .collect();
333
334    let http_response = HttpResponse {
335        status: status.as_u16(),
336        status_text: status.to_string(),
337        version: format!("{:?}", version),
338        headers: resp_headers_vec,
339        cookies: response_cookies,
340        body: None,
341        timing: relay_core_api::flow::ResponseTiming {
342            time_to_first_byte: None,
343            time_to_last_byte: None,
344            connect_time_ms: None,
345            ssl_time_ms: None,
346        },
347    };
348
349    match &mut flow.layer {
350        Layer::Http(http) => {
351            http.response = Some(http_response);
352        }
353        Layer::WebSocket(ws) => {
354            ws.handshake_response = http_response;
355        }
356        _ => {}
357    }
358}
359
360pub fn update_flow_with_response_body(flow: &mut Flow, body_bytes: Bytes) {
361    let headers = match &flow.layer {
362        Layer::Http(http) => http
363            .response
364            .as_ref()
365            .map(|r| r.headers.clone())
366            .unwrap_or_default(),
367        Layer::WebSocket(ws) => ws.handshake_response.headers.clone(),
368        _ => Vec::new(),
369    };
370
371    let (resp_encoding, resp_content) = process_body(&body_bytes, &headers);
372
373    let body_data = BodyData {
374        encoding: resp_encoding,
375        content: resp_content,
376        size: body_bytes.len() as u64,
377    };
378
379    match &mut flow.layer {
380        Layer::Http(http) => {
381            if let Some(resp) = &mut http.response {
382                resp.body = Some(body_data);
383            }
384        }
385        Layer::WebSocket(ws) => {
386            ws.handshake_response.body = Some(body_data);
387        }
388        _ => {}
389    }
390}
391
392pub fn update_flow_with_response(
393    flow: &mut Flow,
394    status: StatusCode,
395    version: hyper::Version,
396    headers: &hyper::HeaderMap,
397    body_bytes: Bytes,
398) {
399    update_flow_with_response_headers(flow, status, version, headers);
400    update_flow_with_response_body(flow, body_bytes);
401}
402
403pub fn build_client_response_from_flow(
404    flow: &Flow,
405    default_version: hyper::Version,
406    strict_mode: bool,
407) -> Result<Response<Full<Bytes>>, String> {
408    if let Layer::Http(http) = &flow.layer {
409        if let Some(response) = &http.response {
410            let status = match StatusCode::from_u16(response.status) {
411                Ok(s) => s,
412                Err(_) => {
413                    if strict_mode {
414                        return Err(format!("Invalid status code: {}", response.status));
415                    }
416                    StatusCode::OK
417                }
418            };
419
420            let mut builder = Response::builder().status(status).version(default_version); // TODO: Parse version from flow string if needed
421
422            for (k, v) in &response.headers {
423                // Filter out transport-level headers that might conflict with the new body
424                if k.eq_ignore_ascii_case("content-length")
425                    || k.eq_ignore_ascii_case("transfer-encoding")
426                    || k.eq_ignore_ascii_case("connection")
427                {
428                    continue;
429                }
430
431                if let (Ok(name), Ok(val)) = (
432                    HeaderName::from_bytes(k.as_bytes()),
433                    HeaderValue::from_str(v),
434                ) {
435                    builder = builder.header(name, val);
436                } else if strict_mode {
437                    return Err(format!("Invalid header: {}: {}", k, v));
438                }
439            }
440
441            let body_bytes = if let Some(b) = &response.body {
442                if b.encoding == "base64" {
443                    match BASE64.decode(b.content.as_bytes()) {
444                        Ok(bytes) => Bytes::from(bytes),
445                        Err(_e) => {
446                            // Fallback
447                            Bytes::from(b.content.clone())
448                        }
449                    }
450                } else {
451                    Bytes::from(b.content.clone())
452                }
453            } else {
454                Bytes::new()
455            };
456
457            builder
458                .body(Full::new(body_bytes))
459                .map_err(|e| format!("Failed to build response: {}", e))
460        } else {
461            Err("No response in flow".to_string())
462        }
463    } else {
464        Err("Not HTTP layer".to_string())
465    }
466}
467
468#[cfg(test)]
469mod tests {
470    use super::{build_client_response_from_flow, parse_request_meta};
471    use chrono::Utc;
472    use http_body_util::BodyExt;
473    use hyper::{Request, StatusCode, Version};
474    use relay_core_api::flow::{
475        Flow, HttpLayer, HttpRequest, HttpResponse, Layer, NetworkInfo, ResponseTiming,
476        TransportProtocol,
477    };
478    use std::collections::HashMap;
479    use url::Url;
480    use uuid::Uuid;
481
482    fn sample_flow_with_response(status: u16) -> Flow {
483        Flow {
484            id: Uuid::new_v4(),
485            start_time: Utc::now(),
486            end_time: None,
487            network: NetworkInfo {
488                client_ip: "127.0.0.1".to_string(),
489                client_port: 12345,
490                server_ip: "1.1.1.1".to_string(),
491                server_port: 80,
492                protocol: TransportProtocol::TCP,
493                tls: false,
494                tls_version: None,
495                sni: None,
496            },
497            layer: Layer::Http(HttpLayer {
498                request: HttpRequest {
499                    method: "GET".to_string(),
500                    url: Url::parse("http://example.com/a").expect("url"),
501                    version: "HTTP/1.1".to_string(),
502                    headers: vec![],
503                    cookies: vec![],
504                    query: vec![],
505                    body: None,
506                },
507                response: Some(HttpResponse {
508                    status,
509                    status_text: "X".to_string(),
510                    version: "HTTP/2.0".to_string(),
511                    headers: vec![
512                        ("X-Test".to_string(), "1".to_string()),
513                        ("content-length".to_string(), "999".to_string()),
514                        ("connection".to_string(), "keep-alive".to_string()),
515                    ],
516                    cookies: vec![],
517                    body: None,
518                    timing: ResponseTiming {
519                        time_to_first_byte: None,
520                        time_to_last_byte: None,
521                        connect_time_ms: None,
522                        ssl_time_ms: None,
523                    },
524                }),
525                error: None,
526            }),
527            tags: vec![],
528            meta: HashMap::new(),
529        }
530    }
531
532    #[test]
533    fn test_parse_request_meta_relative_uri_uses_host_http() {
534        let req = Request::builder()
535            .uri("/api/v1?q=1")
536            .header("Host", "example.com:8080")
537            .body(())
538            .expect("request");
539        let meta = parse_request_meta(&req, false);
540        assert_eq!(meta.url_str, "http://example.com:8080/api/v1?q=1");
541        assert_eq!(meta.query, vec![("q".to_string(), "1".to_string())]);
542    }
543
544    #[test]
545    fn test_parse_request_meta_relative_uri_uses_host_https_in_mitm() {
546        let req = Request::builder()
547            .uri("/secure")
548            .header("Host", "secure.example.com")
549            .body(())
550            .expect("request");
551        let meta = parse_request_meta(&req, true);
552        assert_eq!(meta.url_str, "https://secure.example.com/secure");
553    }
554
555    #[test]
556    fn test_build_client_response_from_flow_uses_default_version_currently() {
557        let flow = sample_flow_with_response(201);
558        let resp = build_client_response_from_flow(&flow, Version::HTTP_11, true)
559            .expect("response should build");
560        assert_eq!(resp.version(), Version::HTTP_11);
561        assert_eq!(resp.status(), StatusCode::CREATED);
562        assert_eq!(
563            resp.headers().get("x-test").and_then(|v| v.to_str().ok()),
564            Some("1")
565        );
566        assert!(
567            resp.headers().get("content-length").is_none(),
568            "content-length should be stripped from forwarded mock response"
569        );
570        assert!(resp.headers().get("connection").is_none());
571    }
572
573    #[test]
574    fn test_build_client_response_from_flow_invalid_status_strict_fails() {
575        let flow = sample_flow_with_response(1000);
576        let err = build_client_response_from_flow(&flow, Version::HTTP_11, true)
577            .expect_err("strict mode should reject invalid status");
578        assert!(err.contains("Invalid status code"));
579    }
580
581    #[tokio::test]
582    async fn test_build_client_response_from_flow_invalid_status_non_strict_fallback_ok() {
583        let mut flow = sample_flow_with_response(1000);
584        if let Layer::Http(http) = &mut flow.layer {
585            if let Some(res) = &mut http.response {
586                res.body = Some(relay_core_api::flow::BodyData {
587                    encoding: "utf-8".to_string(),
588                    content: "hello".to_string(),
589                    size: 5,
590                });
591            }
592        }
593
594        let resp = build_client_response_from_flow(&flow, Version::HTTP_11, false)
595            .expect("non-strict should fallback");
596        assert_eq!(resp.status(), StatusCode::OK);
597        let body = resp
598            .into_body()
599            .collect()
600            .await
601            .expect("collect body")
602            .to_bytes();
603        assert_eq!(body.as_ref(), b"hello");
604    }
605}
relay_core_lib/proxy/http_utils.rs

relay_core_lib/proxy/
http_utils.rs
