script/dom/processingoptions.rs
1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5use std::str::FromStr;
6
7use cssparser::match_ignore_ascii_case;
8use http::header::HeaderMap;
9use hyper_serde::Serde;
10use mime::Mime;
11use net_traits::fetch::headers::get_decode_and_split_header_name;
12use net_traits::mime_classifier::{MediaType, MimeClassifier};
13use net_traits::policy_container::PolicyContainer;
14use net_traits::request::{
15 CorsSettings, Destination, Initiator, InsecureRequestsPolicy, PreloadId, PreloadKey, Referrer,
16 RequestBuilder, RequestClient, RequestId,
17};
18use net_traits::response::{Response, ResponseBody};
19use net_traits::{
20 CoreResourceMsg, FetchMetadata, NetworkError, ReferrerPolicy, ResourceFetchTiming,
21};
22pub use nom_rfc8288::complete::LinkDataOwned as LinkHeader;
23use nom_rfc8288::complete::link_lenient as parse_link_header;
24use servo_base::id::WebViewId;
25use servo_url::{ImmutableOrigin, ServoUrl};
26use strum::IntoStaticStr;
27
28use crate::dom::bindings::refcounted::Trusted;
29use crate::dom::bindings::reflector::DomGlobal;
30use crate::dom::bindings::root::DomRoot;
31use crate::dom::csp::{GlobalCspReporting, Violation};
32use crate::dom::document::Document;
33use crate::dom::globalscope::GlobalScope;
34use crate::dom::medialist::MediaList;
35use crate::dom::node::NodeTraits;
36use crate::dom::performance::performanceresourcetiming::InitiatorType;
37use crate::dom::types::HTMLLinkElement;
38use crate::fetch::create_a_potential_cors_request;
39use crate::network_listener::{FetchResponseListener, ResourceTimingListener, submit_timing};
40
41trait ValueForKeyInLinkHeader {
42 fn has_key_in_link_header(&self, key: &str) -> bool;
43 fn value_for_key_in_link_header(&self, key: &str) -> Option<&str>;
44}
45
46impl ValueForKeyInLinkHeader for LinkHeader {
47 fn has_key_in_link_header(&self, key: &str) -> bool {
48 self.params.iter().any(|p| p.key == key)
49 }
50 fn value_for_key_in_link_header(&self, key: &str) -> Option<&str> {
51 let param = self.params.iter().find(|p| p.key == key)?;
52 param.val.as_deref()
53 }
54}
55
56#[derive(PartialEq)]
57pub(crate) enum LinkProcessingPhase {
58 Media,
59 PreMedia,
60}
61
62/// <https://html.spec.whatwg.org/multipage/#link-processing-options>
63#[derive(Debug)]
64pub(crate) struct LinkProcessingOptions {
65 /// <https://html.spec.whatwg.org/multipage/#link-options-href>
66 pub(crate) href: String,
67 /// <https://html.spec.whatwg.org/multipage/#link-options-destination>
68 pub(crate) destination: Destination,
69 /// <https://html.spec.whatwg.org/multipage/#link-options-integrity>
70 pub(crate) integrity: String,
71 /// <https://html.spec.whatwg.org/multipage/#link-options-type>
72 pub(crate) link_type: String,
73 /// <https://html.spec.whatwg.org/multipage/#link-options-nonce>
74 pub(crate) cryptographic_nonce_metadata: String,
75 /// <https://html.spec.whatwg.org/multipage/#link-options-crossorigin>
76 pub(crate) cross_origin: Option<CorsSettings>,
77 /// <https://html.spec.whatwg.org/multipage/#link-options-referrer-policy>
78 pub(crate) referrer_policy: ReferrerPolicy,
79 /// <https://html.spec.whatwg.org/multipage/#link-options-policy-container>
80 pub(crate) policy_container: PolicyContainer,
81 /// <https://html.spec.whatwg.org/multipage/#link-options-source-set>
82 pub(crate) source_set: Option<()>,
83 /// <https://html.spec.whatwg.org/multipage/#link-options-base-url>
84 pub(crate) base_url: ServoUrl,
85 /// <https://html.spec.whatwg.org/multipage/#link-options-origin>
86 pub(crate) origin: ImmutableOrigin,
87 pub(crate) insecure_requests_policy: InsecureRequestsPolicy,
88 pub(crate) has_trustworthy_ancestor_origin: bool,
89 pub(crate) referrer: Referrer,
90 // https://html.spec.whatwg.org/multipage/#link-options-environment
91 pub(crate) request_client: RequestClient,
92 // https://html.spec.whatwg.org/multipage/#link-options-document
93 // TODO
94 // https://html.spec.whatwg.org/multipage/#link-options-on-document-ready
95 // TODO
96 // https://html.spec.whatwg.org/multipage/#link-options-fetch-priority
97 // TODO
98}
99
100impl LinkProcessingOptions {
101 /// <https://html.spec.whatwg.org/multipage/#apply-link-options-from-parsed-header-attributes>
102 fn apply_link_options_from_parsed_header(
103 &mut self,
104 link_object: &LinkHeader,
105 rel: &str,
106 ) -> bool {
107 // Step 1. If rel is "preload":
108 if rel == "preload" {
109 // Step 1.1. If attribs["as"] does not exist, then return false.
110 let Some(as_) = link_object.value_for_key_in_link_header("as") else {
111 return false;
112 };
113 // Step 1.2. Let destination be the result of translating attribs["as"].
114 let Some(destination) = Self::translate_a_preload_destination(as_) else {
115 // Step 1.3. If destination is null, then return false.
116 return false;
117 };
118 // Step 1.4. Set options's destination to destination.
119 self.destination = destination;
120 }
121 // Step 2. If attribs["crossorigin"] exists and is an ASCII case-insensitive match for one of the
122 // CORS settings attribute keywords, then set options's crossorigin to the CORS settings attribute
123 // state corresponding to that keyword.
124 if let Some(cross_origin) = link_object.value_for_key_in_link_header("crossorigin") {
125 self.cross_origin = determine_cors_settings_for_token(cross_origin);
126 }
127 // Step 3. If attribs["integrity"] exists, then set options's integrity to attribs["integrity"].
128 if let Some(integrity) = link_object.value_for_key_in_link_header("integrity") {
129 self.integrity = integrity.to_owned();
130 }
131 // Step 4. If attribs["referrerpolicy"] exists and is an ASCII case-insensitive match for
132 // some referrer policy, then set options's referrer policy to that referrer policy.
133 if let Some(referrer_policy) = link_object.value_for_key_in_link_header("referrerpolicy") {
134 self.referrer_policy = ReferrerPolicy::from(referrer_policy);
135 }
136 // Step 5. If attribs["nonce"] exists, then set options's nonce to attribs["nonce"].
137 if let Some(nonce) = link_object.value_for_key_in_link_header("nonce") {
138 self.cryptographic_nonce_metadata = nonce.to_owned();
139 }
140 // Step 6. If attribs["type"] exists, then set options's type to attribs["type"].
141 if let Some(link_type) = link_object.value_for_key_in_link_header("type") {
142 self.link_type = link_type.to_owned();
143 }
144 // Step 7. If attribs["fetchpriority"] exists and is an ASCII case-insensitive match
145 // for a fetch priority attribute keyword, then set options's fetch priority to that
146 // fetch priority attribute keyword.
147 // TODO
148 // Step 8. Return true.
149 true
150 }
151
152 /// <https://html.spec.whatwg.org/multipage/#process-a-link-header>
153 fn process_link_header(self, rel: &str, document: &Document) {
154 if rel == "preload" {
155 // https://html.spec.whatwg.org/multipage/#link-type-preload:process-a-link-header
156 // The process a link header step for this type of link given a link processing options options
157 // is to preload options.
158 if !self.type_matches_destination() {
159 return;
160 }
161 self.preload(document.window().webview_id(), None, document);
162 }
163 }
164
165 /// <https://html.spec.whatwg.org/multipage/#translate-a-preload-destination>
166 pub(crate) fn translate_a_preload_destination(
167 potential_destination: &str,
168 ) -> Option<Destination> {
169 // Step 2. Return the result of translating destination.
170 Some(match potential_destination {
171 "fetch" => Destination::None,
172 "font" => Destination::Font,
173 "image" => Destination::Image,
174 "script" => Destination::Script,
175 "style" => Destination::Style,
176 "track" => Destination::Track,
177 // Step 1. If destination is not "fetch", "font", "image",
178 // "script", "style", or "track", then return null.
179 _ => return None,
180 })
181 }
182
183 /// <https://html.spec.whatwg.org/multipage/#create-a-link-request>
184 pub(crate) fn create_link_request(self, webview_id: WebViewId) -> Option<RequestBuilder> {
185 // Step 1. Assert: options's href is not the empty string.
186 assert!(!self.href.is_empty());
187
188 // Step 3. Let url be the result of encoding-parsing a URL given options's href, relative to options's base URL.
189 let Ok(url) = ServoUrl::parse_with_base(Some(&self.base_url), &self.href) else {
190 // Step 4. If url is failure, then return null.
191 return None;
192 };
193
194 // Step 5. Let request be the result of creating a potential-CORS request given
195 // url, options's destination, and options's crossorigin.
196 // Step 6. Set request's policy container to options's policy container.
197 // Step 7. Set request's integrity metadata to options's integrity.
198 // Step 8. Set request's cryptographic nonce metadata to options's cryptographic nonce metadata.
199 // Step 9. Set request's referrer policy to options's referrer policy.
200 // Step 10. Set request's client to options's environment.
201 // FIXME: Step 11. Set request's priority to options's fetch priority.
202 let builder = create_a_potential_cors_request(
203 Some(webview_id),
204 url,
205 self.destination,
206 self.cross_origin,
207 None,
208 self.referrer,
209 )
210 .insecure_requests_policy(self.insecure_requests_policy)
211 .has_trustworthy_ancestor_origin(self.has_trustworthy_ancestor_origin)
212 .policy_container(self.policy_container)
213 .client(self.request_client)
214 .initiator(Initiator::Link)
215 .origin(self.origin)
216 .integrity_metadata(self.integrity)
217 .cryptographic_nonce_metadata(self.cryptographic_nonce_metadata)
218 .referrer_policy(self.referrer_policy);
219
220 // Step 12. Return request.
221 Some(builder)
222 }
223
224 /// <https://html.spec.whatwg.org/multipage/#match-preload-type>
225 pub(crate) fn type_matches_destination(&self) -> bool {
226 // Step 1. If type is an empty string, then return true.
227 if self.link_type.is_empty() {
228 return true;
229 }
230 // Step 2. If destination is "fetch", then return true.
231 //
232 // Fetch is handled as an empty string destination in the spec:
233 // https://fetch.spec.whatwg.org/#concept-potential-destination-translate
234 let destination = self.destination;
235 if destination == Destination::None {
236 return true;
237 }
238 // Step 3. Let mimeTypeRecord be the result of parsing type.
239 let Ok(mime_type_record) = Mime::from_str(&self.link_type) else {
240 // Step 4. If mimeTypeRecord is failure, then return false.
241 return false;
242 };
243 // Step 5. If mimeTypeRecord is not supported by the user agent, then return false.
244 //
245 // We currently don't check if we actually support the mime type. Only if we can classify
246 // it according to the spec.
247 let Some(mime_type) = MimeClassifier::get_media_type(&mime_type_record) else {
248 return false;
249 };
250 // Step 6. If any of the following are true:
251 if
252 // destination is "audio" or "video", and mimeTypeRecord is an audio or video MIME type;
253 ((destination == Destination::Audio || destination == Destination::Video) &&
254 mime_type == MediaType::AudioVideo)
255 // destination is a script-like destination and mimeTypeRecord is a JavaScript MIME type;
256 || (destination.is_script_like() && mime_type == MediaType::JavaScript)
257 // destination is "image" and mimeTypeRecord is an image MIME type;
258 || (destination == Destination::Image && mime_type == MediaType::Image)
259 // destination is "font" and mimeTypeRecord is a font MIME type;
260 || (destination == Destination::Font && mime_type == MediaType::Font)
261 // destination is "json" and mimeTypeRecord is a JSON MIME type;
262 || (destination == Destination::Json && mime_type == MediaType::Json)
263 // destination is "style" and mimeTypeRecord's essence is text/css; or
264 || (destination == Destination::Style && mime_type_record == mime::TEXT_CSS)
265 // destination is "track" and mimeTypeRecord's essence is text/vtt,
266 || (destination == Destination::Track && mime_type_record.essence_str() == "text/vtt")
267 {
268 // then return true.
269 return true;
270 }
271 // Step 7. Return false.
272 false
273 }
274
275 /// <https://html.spec.whatwg.org/multipage/#preload>
276 pub(crate) fn preload(
277 self,
278 webview_id: WebViewId,
279 link: Option<Trusted<HTMLLinkElement>>,
280 document: &Document,
281 ) {
282 // Step 1. If options's type doesn't match options's destination, then return.
283 //
284 // Handled by callers, since we need to check the previous destination type
285 assert!(self.type_matches_destination());
286 // Step 2. If options's destination is "image" and options's source set is not null,
287 // then set options's href to the result of selecting an image source from options's source set.
288 // TODO
289 // Step 3. Let request be the result of creating a link request given options.
290 let Some(request) = self.create_link_request(webview_id) else {
291 // Step 4. If request is null, then return.
292 return;
293 };
294 let preload_id = PreloadId::default();
295 let request = request.preload_id(preload_id.clone());
296 // Step 5. Let unsafeEndTime be 0.
297 // TODO
298 // Step 6. Let entry be a new preload entry whose integrity metadata is options's integrity.
299 //
300 // This is performed in `CoreResourceManager::fetch`
301 // Step 7. Let key be the result of creating a preload key given request.
302 let key = PreloadKey::new(&request);
303 // Step 8. If options's document is "pending", then set request's initiator type to "early hint".
304 // TODO
305 // Step 9. Let controller be null.
306 // Step 10. Let reportTiming given a Document document be to report timing for controller
307 // given document's relevant global object.
308 let url = request.url.url();
309 let fetch_context = LinkFetchContext {
310 url,
311 link,
312 document: Trusted::new(document),
313 global: Trusted::new(&document.global()),
314 type_: LinkFetchContextType::Preload(key.clone()),
315 response_body: vec![],
316 };
317 document.insert_preloaded_resource(key, preload_id);
318 // Step 11. Set controller to the result of fetching request, with processResponseConsumeBody
319 // set to the following steps given a response response and null, failure, or a byte sequence bodyBytes:
320 document.fetch_background(request, fetch_context);
321 }
322}
323
324pub(crate) fn determine_cors_settings_for_token(token: &str) -> Option<CorsSettings> {
325 match_ignore_ascii_case! { token,
326 "anonymous" => Some(CorsSettings::Anonymous),
327 "use-credentials" => Some(CorsSettings::UseCredentials),
328 _ => None,
329 }
330}
331
332/// <https://html.spec.whatwg.org/multipage/#extract-links-from-headers>
333pub(crate) fn extract_links_from_headers(headers: &Option<Serde<HeaderMap>>) -> Vec<LinkHeader> {
334 // Step 1. Let links be a new list.
335 let mut links = Vec::new();
336 let Some(headers) = headers else {
337 return links;
338 };
339 // Step 2. Let rawLinkHeaders be the result of getting, decoding, and splitting `Link` from headers.
340 let Some(raw_link_headers) = get_decode_and_split_header_name("Link", headers) else {
341 return links;
342 };
343 // Step 3. For each linkHeader of rawLinkHeaders:
344 for link_header in raw_link_headers {
345 // Step 3.1. Let linkObject be the result of parsing linkHeader. [WEBLINK]
346 let Ok(parsed_link_header) = parse_link_header(&link_header) else {
347 continue;
348 };
349 for link_object in parsed_link_header {
350 let Some(link_object) = link_object else {
351 // Step 3.2. If linkObject["target_uri"] does not exist, then continue.
352 continue;
353 };
354 // Step 3.3. Append linkObject to links.
355 links.push(link_object.to_owned());
356 }
357 }
358 // Step 4. Return links.
359 links
360}
361
362/// <https://html.spec.whatwg.org/multipage/#process-link-headers>
363pub(crate) fn process_link_headers(
364 link_headers: &[LinkHeader],
365 document: &Document,
366 phase: LinkProcessingPhase,
367) {
368 let global = document.owner_global();
369 // Step 1. Let links be the result of extracting links from response's header list.
370 //
371 // Already performed once when parsing headers by caller
372 // Step 2. For each linkObject in links:
373 for link_object in link_headers {
374 // Step 2.1. Let rel be linkObject["relation_type"].
375 let Some(rel) = link_object.value_for_key_in_link_header("rel") else {
376 continue;
377 };
378 // Step 2.2. Let attribs be linkObject["target_attributes"].
379 //
380 // Not applicable, that's in `link_object.params`
381 // Step 2.3. Let expectedPhase be "media" if either "srcset", "imagesrcset",
382 // or "media" exist in attribs; otherwise "pre-media".
383 let expected_phase = if link_object.has_key_in_link_header("srcset") ||
384 link_object.has_key_in_link_header("imagesrcset") ||
385 link_object.has_key_in_link_header("media")
386 {
387 LinkProcessingPhase::Media
388 } else {
389 LinkProcessingPhase::PreMedia
390 };
391 // Step 2.4. If expectedPhase is not phase, then continue.
392 if expected_phase != phase {
393 continue;
394 }
395 // Step 2.5. If attribs["media"] exists and attribs["media"] does not match the environment, then continue.
396 if let Some(media) = link_object.value_for_key_in_link_header("media") {
397 if !MediaList::matches_environment(document, media) {
398 continue;
399 }
400 }
401 // Step 2.6. Let options be a new link processing options with
402 let mut options = LinkProcessingOptions {
403 href: link_object.url.clone(),
404 destination: Destination::None,
405 integrity: String::new(),
406 link_type: String::new(),
407 cryptographic_nonce_metadata: String::new(),
408 cross_origin: None,
409 referrer_policy: ReferrerPolicy::EmptyString,
410 policy_container: document.policy_container().to_owned(),
411 source_set: None,
412 origin: document.origin().immutable().to_owned(),
413 base_url: document.base_url(),
414 insecure_requests_policy: document.insecure_requests_policy(),
415 has_trustworthy_ancestor_origin: document.has_trustworthy_ancestor_or_current_origin(),
416 request_client: global.request_client(),
417 referrer: global.get_referrer(),
418 };
419 // Step 2.7. Apply link options from parsed header attributes to options given attribs and rel.
420 // If that returned false, then return.
421 if !options.apply_link_options_from_parsed_header(link_object, rel) {
422 return;
423 }
424 // Step 2.8. If attribs["imagesrcset"] exists and attribs["imagesizes"] exists,
425 // then set options's source set to the result of creating a source set given
426 // linkObject["target_uri"], attribs["imagesrcset"], attribs["imagesizes"], and null.
427 // TODO
428 // Step 2.9. Run the process a link header steps for rel given options.
429 options.process_link_header(rel, document);
430 }
431}
432
433#[derive(Clone, IntoStaticStr)]
434#[strum(serialize_all = "lowercase")]
435pub(crate) enum LinkFetchContextType {
436 Prefetch,
437 Preload(PreloadKey),
438}
439
440impl From<LinkFetchContextType> for InitiatorType {
441 fn from(other: LinkFetchContextType) -> Self {
442 let name: &'static str = other.into();
443 InitiatorType::LocalName(name.to_owned())
444 }
445}
446
447pub(crate) struct LinkFetchContext {
448 /// The `<link>` element (if any) that caused this fetch
449 pub(crate) link: Option<Trusted<HTMLLinkElement>>,
450
451 pub(crate) global: Trusted<GlobalScope>,
452 pub(crate) document: Trusted<Document>,
453
454 /// The url being prefetched
455 pub(crate) url: ServoUrl,
456
457 /// The type of fetching we perform, used when report timings.
458 pub(crate) type_: LinkFetchContextType,
459
460 pub(crate) response_body: Vec<u8>,
461}
462
463impl FetchResponseListener for LinkFetchContext {
464 fn process_request_body(&mut self, _: RequestId) {}
465
466 fn process_response(
467 &mut self,
468 _: &mut js::context::JSContext,
469 _: RequestId,
470 fetch_metadata: Result<FetchMetadata, NetworkError>,
471 ) {
472 _ = fetch_metadata;
473 }
474
475 fn process_response_chunk(
476 &mut self,
477 _: &mut js::context::JSContext,
478 _: RequestId,
479 mut chunk: Vec<u8>,
480 ) {
481 if matches!(self.type_, LinkFetchContextType::Preload(..)) {
482 self.response_body.append(&mut chunk);
483 }
484 }
485
486 /// Step 7 of <https://html.spec.whatwg.org/multipage/#link-type-prefetch:fetch-and-process-the-linked-resource-2>
487 /// and step 3.1 of <https://html.spec.whatwg.org/multipage/#link-type-preload:fetch-and-process-the-linked-resource-2>
488 fn process_response_eof(
489 mut self,
490 cx: &mut js::context::JSContext,
491 _: RequestId,
492 response_result: Result<(), NetworkError>,
493 timing: ResourceFetchTiming,
494 ) {
495 // Steps for https://html.spec.whatwg.org/multipage/#preload
496 if let LinkFetchContextType::Preload(key) = &self.type_ {
497 let response = if response_result.is_ok() {
498 // Step 11.1. If bodyBytes is a byte sequence, then set response's body to bodyBytes as a body.
499 let response = Response::new(self.url.clone(), timing.clone());
500 *response.body.lock() = ResponseBody::Done(std::mem::take(&mut self.response_body));
501 response
502 } else {
503 // Step 11.2. Otherwise, set response to a network error.
504 Response::network_error(NetworkError::ResourceLoadError("Failed to preload".into()))
505 };
506 // Step 11.5. If entry's on response available is null, then set entry's response to response;
507 // otherwise call entry's on response available given response.
508 // Step 12. Let commit be the following steps given a Document document:
509 // Step 12.1. If entry's response is not null, then call reportTiming given document.
510 // Step 12.2. Set document's map of preloaded resources[key] to entry.
511 // Step 13. If options's document is null, then set options's on document ready to commit. Otherwise, call commit with options's document.
512 let document = self.document.root();
513 let document_preloaded_resources = document.preloaded_resources();
514 let Some(preload_id) = document_preloaded_resources.get(key) else {
515 unreachable!(
516 "Must only be able to lookup preloaded resources if they already exist in document"
517 );
518 };
519 let _ = self.global.root().core_resource_thread().send(
520 CoreResourceMsg::StorePreloadedResponse(preload_id.clone(), response),
521 );
522 }
523
524 submit_timing(cx, &self, &response_result, &timing);
525
526 // Step 11.6. If processResponse is given, then call processResponse with response.
527 //
528 // Part of Preload
529 //
530 // Step 6. Let processPrefetchResponse be the following steps given a response response and null, failure, or a byte sequence bytesOrNull:
531 //
532 // Part of Prefetch
533 if let Some(link) = self.link.as_ref() {
534 link.root().fire_event_after_response(cx, response_result);
535 }
536 }
537
538 fn process_csp_violations(&mut self, _request_id: RequestId, violations: Vec<Violation>) {
539 let global = &self.resource_timing_global();
540 global.report_csp_violations(violations, None, None);
541 }
542}
543
544impl ResourceTimingListener for LinkFetchContext {
545 fn resource_timing_information(&self) -> (InitiatorType, ServoUrl) {
546 (self.type_.clone().into(), self.url.clone())
547 }
548
549 fn resource_timing_global(&self) -> DomRoot<GlobalScope> {
550 self.global.root()
551 }
552}