gatel-core 0.1.2

A high-performance, KDL-configured reverse proxy and web server
Documentation 
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
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545

/// Path matching strategies and advanced request matchers.
use std::net::SocketAddr;

use http::Request;

use crate::Body;
use crate::glob::glob_matches;

// ---------------------------------------------------------------------------
// Path matching (existing functionality)
// ---------------------------------------------------------------------------

/// Match a request path against a route pattern.
///
/// Supported patterns:
/// - `"/*"` — matches everything
/// - `"/api/*"` — prefix match (path starts with `/api/`)
/// - `"/exact"` — exact match
/// - `"*.php"` — suffix/extension match
pub fn path_matches(pattern: &str, path: &str) -> bool {
    if pattern == "/*" || pattern == "*" {
        return true;
    }
    // Extension glob: "*.php" matches any path ending with ".php"
    if pattern.starts_with('*') && !pattern.starts_with("**") {
        let suffix = &pattern[1..];
        return path.ends_with(suffix);
    }
    if let Some(prefix) = pattern.strip_suffix("/*") {
        // Prefix match: "/api/*" matches "/api/", "/api/foo", "/api/foo/bar"
        return path == prefix || path.starts_with(&format!("{prefix}/"));
    }
    if let Some(prefix) = pattern.strip_suffix('*') {
        // Glob-like: "/static*" matches "/static", "/staticfiles", etc.
        return path.starts_with(prefix);
    }
    // Exact match
    path == pattern
}

/// Sort patterns by specificity (most specific first).
/// Longer non-wildcard prefixes are more specific.
pub fn pattern_specificity(pattern: &str) -> usize {
    if pattern == "/*" || pattern == "*" {
        return 0;
    }
    if pattern.starts_with('*') {
        // Extension matchers like "*.php" are somewhat specific.
        return pattern.len();
    }
    if let Some(prefix) = pattern.strip_suffix("/*") {
        return prefix.len() + 1;
    }
    if pattern.ends_with('*') {
        return pattern.len();
    }
    // Exact match is most specific
    pattern.len() + 1000
}

// ---------------------------------------------------------------------------
// Advanced request matchers
// ---------------------------------------------------------------------------

/// A composable request matcher that can test various aspects of an incoming
/// HTTP request.  Matchers can be combined with `And`, `Or`, and `Not`.
#[derive(Debug, Clone, serde::Serialize)]
pub enum RequestMatcher {
    /// Match the request path using glob-style patterns.
    Path(String),
    /// Match the HTTP method (e.g. `["GET", "POST"]`).
    Method(Vec<String>),
    /// Match a header value with glob pattern (e.g. `name="X-Custom"`, `pattern="foo*"`).
    Header { name: String, pattern: String },
    /// Match a header value with regex-like glob pattern.
    HeaderRegex { name: String, regex: String },
    /// Match a query parameter.  If `value` is `None`, just check presence.
    Query { key: String, value: Option<String> },
    /// Match client IP against CIDR ranges (e.g. `["192.168.0.0/16", "10.0.0.0/8"]`).
    RemoteIp(Vec<String>),
    /// Match the protocol/scheme (e.g. `"https"`, `"http"`).
    Protocol(String),
    /// Simple expression matcher: `"{method} == GET && {path} ~ /api/*"`.
    Expression(String),
    /// Logical NOT.
    Not(Box<RequestMatcher>),
    /// Logical AND: all must match.
    And(Vec<RequestMatcher>),
    /// Logical OR: at least one must match.
    Or(Vec<RequestMatcher>),
    /// Match the Accept-Language header against a list of language tags.
    /// Uses case-insensitive prefix matching (e.g. "en" matches "en-US").
    Language(Vec<String>),
}

impl RequestMatcher {
    /// Test whether an incoming request matches this matcher.
    pub fn matches(&self, req: &Request<Body>, client_addr: SocketAddr) -> bool {
        match self {
            RequestMatcher::Path(pattern) => {
                let path = req.uri().path();
                path_matches(pattern, path)
            }

            RequestMatcher::Method(methods) => {
                let req_method = req.method().as_str().to_uppercase();
                methods.iter().any(|m| m.to_uppercase() == req_method)
            }

            RequestMatcher::Header { name, pattern } => {
                if let Ok(header_name) = name.parse::<http::header::HeaderName>() {
                    req.headers()
                        .get(&header_name)
                        .and_then(|v| v.to_str().ok())
                        .map(|v| glob_matches(pattern, v))
                        .unwrap_or(false)
                } else {
                    false
                }
            }

            RequestMatcher::HeaderRegex { name, regex } => {
                if let Ok(header_name) = name.parse::<http::header::HeaderName>() {
                    req.headers()
                        .get(&header_name)
                        .and_then(|v| v.to_str().ok())
                        .map(|v| glob_matches(regex, v))
                        .unwrap_or(false)
                } else {
                    false
                }
            }

            RequestMatcher::Query { key, value } => {
                let query_str = req.uri().query().unwrap_or("");
                match_query_param(query_str, key, value.as_deref())
            }

            RequestMatcher::RemoteIp(cidrs) => {
                let client_ip = client_addr.ip();
                cidrs.iter().any(|cidr| match_cidr(cidr, &client_ip))
            }

            RequestMatcher::Protocol(proto) => {
                let scheme = req.uri().scheme_str().unwrap_or("http");
                scheme.eq_ignore_ascii_case(proto)
            }

            RequestMatcher::Expression(expr) => eval_expression(expr, req, client_addr),

            RequestMatcher::Not(inner) => !inner.matches(req, client_addr),

            RequestMatcher::And(matchers) => matchers.iter().all(|m| m.matches(req, client_addr)),

            RequestMatcher::Or(matchers) => matchers.iter().any(|m| m.matches(req, client_addr)),

            RequestMatcher::Language(langs) => {
                // Parse Accept-Language header value and check for prefix matches.
                // E.g. "en-US,en;q=0.9,fr;q=0.8" → ["en-US", "en", "fr"]
                let header_value = req
                    .headers()
                    .get(http::header::ACCEPT_LANGUAGE)
                    .and_then(|v| v.to_str().ok())
                    .unwrap_or("");
                // Extract the language tags (strip quality values).
                let accepted: Vec<&str> = header_value
                    .split(',')
                    .map(|part| part.split(';').next().unwrap_or("").trim())
                    .filter(|s| !s.is_empty())
                    .collect();
                langs.iter().any(|configured| {
                    accepted.iter().any(|accepted_lang| {
                        // Prefix match: "en" matches "en-US" or "en"
                        let c = configured.to_lowercase();
                        let a = accepted_lang.to_lowercase();
                        a == c || a.starts_with(&format!("{c}-"))
                    })
                })
            }
        }
    }
}

// ---------------------------------------------------------------------------
// Glob matching
// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------
// Query parameter matching
// ---------------------------------------------------------------------------

/// Check if a query string contains a parameter with the given key
/// (and optionally value).
fn match_query_param(query: &str, key: &str, value: Option<&str>) -> bool {
    for pair in query.split('&') {
        if pair.is_empty() {
            continue;
        }
        let (k, v) = if let Some(eq_pos) = pair.find('=') {
            (&pair[..eq_pos], Some(&pair[eq_pos + 1..]))
        } else {
            (pair, None)
        };
        if k == key {
            match value {
                None => return true, // just check presence
                Some(expected) => {
                    if v == Some(expected) {
                        return true;
                    }
                }
            }
        }
    }
    false
}

// ---------------------------------------------------------------------------
// CIDR matching
// ---------------------------------------------------------------------------

/// Public re-export of CIDR matching used by the router condition evaluator.
pub fn match_cidr_pub(cidr: &str, ip: &std::net::IpAddr) -> bool {
    match_cidr(cidr, ip)
}

/// Match an IP address against a CIDR range.
///
/// Supports:
/// - Exact IP: `"192.168.1.1"`
/// - CIDR notation: `"192.168.0.0/16"`, `"10.0.0.0/8"`
/// - IPv6: `"::1"`, `"fd00::/8"`
fn match_cidr(cidr: &str, ip: &std::net::IpAddr) -> bool {
    if let Some(slash_pos) = cidr.find('/') {
        let network_str = &cidr[..slash_pos];
        let prefix_str = &cidr[slash_pos + 1..];

        let network: std::net::IpAddr = match network_str.parse() {
            Ok(addr) => addr,
            Err(_) => return false,
        };
        let prefix_len: u32 = match prefix_str.parse() {
            Ok(p) => p,
            Err(_) => return false,
        };

        match (network, ip) {
            (std::net::IpAddr::V4(net), std::net::IpAddr::V4(addr)) => {
                if prefix_len > 32 {
                    return false;
                }
                if prefix_len == 0 {
                    return true;
                }
                let mask = u32::MAX << (32 - prefix_len);
                (u32::from(*addr) & mask) == (u32::from(net) & mask)
            }
            (std::net::IpAddr::V6(net), std::net::IpAddr::V6(addr)) => {
                if prefix_len > 128 {
                    return false;
                }
                if prefix_len == 0 {
                    return true;
                }
                let net_bits = u128::from(net);
                let addr_bits = u128::from(*addr);
                let mask = u128::MAX << (128 - prefix_len);
                (addr_bits & mask) == (net_bits & mask)
            }
            _ => false, // v4/v6 mismatch
        }
    } else {
        // Exact IP match.
        match cidr.parse::<std::net::IpAddr>() {
            Ok(expected) => *ip == expected,
            Err(_) => false,
        }
    }
}

// ---------------------------------------------------------------------------
// Simple expression evaluation
// ---------------------------------------------------------------------------

/// Evaluate a simple expression against a request.
///
/// Supported tokens:
/// - `{method}` — HTTP method
/// - `{path}` — request path
/// - `{host}` — Host header
/// - `{remote_ip}` — client IP
///
/// Operators:
/// - `==` — exact equality
/// - `!=` — inequality
/// - `~` — glob match
///
/// Combinators:
/// - `&&` — logical AND
/// - `||` — logical OR
fn eval_expression(expr: &str, req: &Request<Body>, client_addr: SocketAddr) -> bool {
    // Split by "||" first (lowest precedence), then "&&".
    let or_parts: Vec<&str> = expr.split("||").collect();
    for or_part in &or_parts {
        let and_parts: Vec<&str> = or_part.split("&&").collect();
        let all_match = and_parts
            .iter()
            .all(|part| eval_single_condition(part.trim(), req, client_addr));
        if all_match {
            return true;
        }
    }
    false
}

fn eval_single_condition(cond: &str, req: &Request<Body>, client_addr: SocketAddr) -> bool {
    // Try to parse: "{var} op value"
    let (var, op, value) = if let Some(pos) = cond.find("!=") {
        let var = cond[..pos].trim();
        let value = cond[pos + 2..].trim();
        (var, "!=", value)
    } else if let Some(pos) = cond.find("==") {
        let var = cond[..pos].trim();
        let value = cond[pos + 2..].trim();
        (var, "==", value)
    } else if let Some(pos) = cond.find('~') {
        let var = cond[..pos].trim();
        let value = cond[pos + 1..].trim();
        (var, "~", value)
    } else {
        // Cannot parse; treat as false.
        return false;
    };

    let resolved = resolve_variable(var, req, client_addr);

    match op {
        "==" => resolved == value,
        "!=" => resolved != value,
        "~" => glob_matches(value, &resolved),
        _ => false,
    }
}

fn resolve_variable(var: &str, req: &Request<Body>, client_addr: SocketAddr) -> String {
    match var.trim_matches(|c| c == '{' || c == '}') {
        "method" => req.method().to_string(),
        "path" => req.uri().path().to_string(),
        "host" => req
            .headers()
            .get(http::header::HOST)
            .and_then(|v| v.to_str().ok())
            .unwrap_or("")
            .to_string(),
        "remote_ip" => client_addr.ip().to_string(),
        "scheme" | "protocol" => req.uri().scheme_str().unwrap_or("http").to_string(),
        "query" => req.uri().query().unwrap_or("").to_string(),
        _ => String::new(),
    }
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_wildcard() {
        assert!(path_matches("/*", "/anything"));
        assert!(path_matches("/*", "/"));
        assert!(path_matches("*", "/foo"));
    }

    #[test]
    fn test_prefix() {
        assert!(path_matches("/api/*", "/api/users"));
        assert!(path_matches("/api/*", "/api/"));
        assert!(path_matches("/api/*", "/api"));
        assert!(!path_matches("/api/*", "/apifoo"));
        assert!(!path_matches("/api/*", "/other"));
    }

    #[test]
    fn test_exact() {
        assert!(path_matches("/health", "/health"));
        assert!(!path_matches("/health", "/health/check"));
    }

    #[test]
    fn test_extension_match() {
        assert!(path_matches("*.php", "/index.php"));
        assert!(path_matches("*.php", "/app/page.php"));
        assert!(!path_matches("*.php", "/index.html"));
    }

    #[test]
    fn test_specificity_ordering() {
        assert!(pattern_specificity("/api/*") > pattern_specificity("/*"));
        assert!(pattern_specificity("/api/v1/*") > pattern_specificity("/api/*"));
        assert!(pattern_specificity("/exact") > pattern_specificity("/api/v1/*"));
    }

    #[test]
    fn test_glob_matches_star() {
        assert!(glob_matches("foo*", "foobar"));
        assert!(glob_matches("foo*", "foo"));
        assert!(!glob_matches("foo*", "baz"));
        assert!(glob_matches("*bar", "foobar"));
        assert!(!glob_matches("foo*", "foo/bar"));
    }

    #[test]
    fn test_glob_matches_double_star() {
        assert!(glob_matches("**", "anything/at/all"));
        assert!(glob_matches("/api/**", "/api/v1/users"));
        assert!(glob_matches("foo/**/bar", "foo/a/b/c/bar"));
    }

    #[test]
    fn test_glob_matches_question() {
        assert!(glob_matches("fo?", "foo"));
        assert!(glob_matches("fo?", "fob"));
        assert!(!glob_matches("fo?", "fooo"));
    }

    #[test]
    fn test_query_param() {
        assert!(match_query_param("a=1&b=2", "a", Some("1")));
        assert!(match_query_param("a=1&b=2", "b", None));
        assert!(!match_query_param("a=1&b=2", "c", None));
        assert!(!match_query_param("a=1", "a", Some("2")));
    }

    #[test]
    fn test_cidr_match_v4() {
        let ip: std::net::IpAddr = "192.168.1.100".parse().unwrap();
        assert!(match_cidr("192.168.0.0/16", &ip));
        assert!(match_cidr("192.168.1.0/24", &ip));
        assert!(!match_cidr("10.0.0.0/8", &ip));
        assert!(match_cidr("192.168.1.100", &ip));
    }

    #[test]
    fn test_cidr_match_v6() {
        let ip: std::net::IpAddr = "::1".parse().unwrap();
        assert!(match_cidr("::1", &ip));
        assert!(match_cidr("::0/0", &ip));
    }

    #[test]
    fn test_request_matcher_method() {
        let req = http::Request::builder()
            .method("GET")
            .uri("/test")
            .body(crate::empty_body())
            .unwrap();
        let addr: SocketAddr = "127.0.0.1:1234".parse().unwrap();

        let matcher = RequestMatcher::Method(vec!["GET".into(), "POST".into()]);
        assert!(matcher.matches(&req, addr));

        let matcher = RequestMatcher::Method(vec!["POST".into()]);
        assert!(!matcher.matches(&req, addr));
    }

    #[test]
    fn test_request_matcher_query() {
        let req = http::Request::builder()
            .uri("/test?foo=bar&baz=1")
            .body(crate::empty_body())
            .unwrap();
        let addr: SocketAddr = "127.0.0.1:1234".parse().unwrap();

        let matcher = RequestMatcher::Query {
            key: "foo".into(),
            value: Some("bar".into()),
        };
        assert!(matcher.matches(&req, addr));

        let matcher = RequestMatcher::Query {
            key: "baz".into(),
            value: None,
        };
        assert!(matcher.matches(&req, addr));

        let matcher = RequestMatcher::Query {
            key: "missing".into(),
            value: None,
        };
        assert!(!matcher.matches(&req, addr));
    }

    #[test]
    fn test_request_matcher_not() {
        let req = http::Request::builder()
            .method("GET")
            .uri("/test")
            .body(crate::empty_body())
            .unwrap();
        let addr: SocketAddr = "127.0.0.1:1234".parse().unwrap();

        let matcher = RequestMatcher::Not(Box::new(RequestMatcher::Method(vec!["POST".into()])));
        assert!(matcher.matches(&req, addr));
    }

    #[test]
    fn test_request_matcher_and_or() {
        let req = http::Request::builder()
            .method("GET")
            .uri("/api/test?debug=1")
            .body(crate::empty_body())
            .unwrap();
        let addr: SocketAddr = "127.0.0.1:1234".parse().unwrap();

        let matcher = RequestMatcher::And(vec![
            RequestMatcher::Method(vec!["GET".into()]),
            RequestMatcher::Path("/api/*".into()),
        ]);
        assert!(matcher.matches(&req, addr));

        let matcher = RequestMatcher::Or(vec![
            RequestMatcher::Method(vec!["POST".into()]),
            RequestMatcher::Path("/api/*".into()),
        ]);
        assert!(matcher.matches(&req, addr));
    }

    #[test]
    fn test_request_matcher_remote_ip() {
        let req = http::Request::builder()
            .uri("/test")
            .body(crate::empty_body())
            .unwrap();
        let addr: SocketAddr = "192.168.1.50:1234".parse().unwrap();

        let matcher = RequestMatcher::RemoteIp(vec!["192.168.0.0/16".into()]);
        assert!(matcher.matches(&req, addr));

        let matcher = RequestMatcher::RemoteIp(vec!["10.0.0.0/8".into()]);
        assert!(!matcher.matches(&req, addr));
    }
}