use std::{ net::IpAddr, sync::Arc, time::{Duration, SystemTime}, }; use bytes::{Bytes, BytesMut}; use futures::{stream::StreamExt, TryFutureExt}; use once_cell::sync::Lazy; use regex::Regex; use reqwest::{ header::{self, HeaderMap, HeaderValue}, Client, Response, }; use rocket::{http::ContentType, response::Redirect, Route}; use tokio::{ fs::{create_dir_all, remove_file, symlink_metadata, File}, io::{AsyncReadExt, AsyncWriteExt}, net::lookup_host, }; use html5gum::{Emitter, EndTag, HtmlString, InfallibleTokenizer, Readable, StartTag, StringReader, Tokenizer}; use crate::{ error::Error, util::{get_reqwest_client_builder, Cached}, CONFIG, }; pub fn routes() -> Vec { match CONFIG.icon_service().as_str() { "internal" => routes![icon_internal], _ => routes![icon_external], } } static CLIENT: Lazy = Lazy::new(|| { // Generate the default headers let mut default_headers = HeaderMap::new(); default_headers.insert(header::USER_AGENT, HeaderValue::from_static("Links (2.22; Linux X86_64; GNU C; text)")); default_headers.insert(header::ACCEPT, HeaderValue::from_static("text/html, text/*;q=0.5, image/*, */*;q=0.1")); default_headers.insert(header::ACCEPT_LANGUAGE, HeaderValue::from_static("en,*;q=0.1")); default_headers.insert(header::CACHE_CONTROL, HeaderValue::from_static("no-cache")); default_headers.insert(header::PRAGMA, HeaderValue::from_static("no-cache")); // Generate the cookie store let cookie_store = Arc::new(Jar::default()); // Reuse the client between requests let client = get_reqwest_client_builder() .cookie_provider(Arc::clone(&cookie_store)) .timeout(Duration::from_secs(CONFIG.icon_download_timeout())) .default_headers(default_headers.clone()); match client.build() { Ok(client) => client, Err(e) => { error!("Possible trust-dns error, trying with trust-dns disabled: '{e}'"); get_reqwest_client_builder() .cookie_provider(cookie_store) .timeout(Duration::from_secs(CONFIG.icon_download_timeout())) .default_headers(default_headers) .trust_dns(false) .build() .expect("Failed to build client") } } }); // Build Regex only once since this takes a lot of time. static ICON_SIZE_REGEX: Lazy = Lazy::new(|| Regex::new(r"(?x)(\d+)\D*(\d+)").unwrap()); // Special HashMap which holds the user defined Regex to speedup matching the regex. static ICON_BLACKLIST_REGEX: Lazy> = Lazy::new(dashmap::DashMap::new); async fn icon_redirect(domain: &str, template: &str) -> Option { if !is_valid_domain(domain) { warn!("Invalid domain: {}", domain); return None; } if is_domain_blacklisted(domain).await { return None; } let url = template.replace("{}", domain); match CONFIG.icon_redirect_code() { 301 => Some(Redirect::moved(url)), // legacy permanent redirect 302 => Some(Redirect::found(url)), // legacy temporary redirect 307 => Some(Redirect::temporary(url)), 308 => Some(Redirect::permanent(url)), _ => { error!("Unexpected redirect code {}", CONFIG.icon_redirect_code()); None } } } #[get("//icon.png")] async fn icon_external(domain: String) -> Option { icon_redirect(&domain, &CONFIG._icon_service_url()).await } #[get("//icon.png")] async fn icon_internal(domain: String) -> Cached<(ContentType, Vec)> { const FALLBACK_ICON: &[u8] = include_bytes!("../static/images/fallback-icon.png"); if !is_valid_domain(&domain) { warn!("Invalid domain: {}", domain); return Cached::ttl( (ContentType::new("image", "png"), FALLBACK_ICON.to_vec()), CONFIG.icon_cache_negttl(), true, ); } match get_icon(&domain).await { Some((icon, icon_type)) => { Cached::ttl((ContentType::new("image", icon_type), icon), CONFIG.icon_cache_ttl(), true) } _ => Cached::ttl((ContentType::new("image", "png"), FALLBACK_ICON.to_vec()), CONFIG.icon_cache_negttl(), true), } } /// Returns if the domain provided is valid or not. /// /// This does some manual checks and makes use of Url to do some basic checking. /// domains can't be larger then 63 characters (not counting multiple subdomains) according to the RFC's, but we limit the total size to 255. fn is_valid_domain(domain: &str) -> bool { const ALLOWED_CHARS: &str = "_-."; // If parsing the domain fails using Url, it will not work with reqwest. if let Err(parse_error) = url::Url::parse(format!("https://{}", domain).as_str()) { debug!("Domain parse error: '{}' - {:?}", domain, parse_error); return false; } else if domain.is_empty() || domain.contains("..") || domain.starts_with('.') || domain.starts_with('-') || domain.ends_with('-') { debug!( "Domain validation error: '{}' is either empty, contains '..', starts with an '.', starts or ends with a '-'", domain ); return false; } else if domain.len() > 255 { debug!("Domain validation error: '{}' exceeds 255 characters", domain); return false; } for c in domain.chars() { if !c.is_alphanumeric() && !ALLOWED_CHARS.contains(c) { debug!("Domain validation error: '{}' contains an invalid character '{}'", domain, c); return false; } } true } /// TODO: This is extracted from IpAddr::is_global, which is unstable: /// https://doc.rust-lang.org/nightly/std/net/enum.IpAddr.html#method.is_global /// Remove once https://github.com/rust-lang/rust/issues/27709 is merged #[allow(clippy::nonminimal_bool)] #[cfg(not(feature = "unstable"))] fn is_global(ip: IpAddr) -> bool { match ip { IpAddr::V4(ip) => { // check if this address is 192.0.0.9 or 192.0.0.10. These addresses are the only two // globally routable addresses in the 192.0.0.0/24 range. if u32::from(ip) == 0xc0000009 || u32::from(ip) == 0xc000000a { return true; } !ip.is_private() && !ip.is_loopback() && !ip.is_link_local() && !ip.is_broadcast() && !ip.is_documentation() && !(ip.octets()[0] == 100 && (ip.octets()[1] & 0b1100_0000 == 0b0100_0000)) && !(ip.octets()[0] == 192 && ip.octets()[1] == 0 && ip.octets()[2] == 0) && !(ip.octets()[0] & 240 == 240 && !ip.is_broadcast()) && !(ip.octets()[0] == 198 && (ip.octets()[1] & 0xfe) == 18) // Make sure the address is not in 0.0.0.0/8 && ip.octets()[0] != 0 } IpAddr::V6(ip) => { if ip.is_multicast() && ip.segments()[0] & 0x000f == 14 { true } else { !ip.is_multicast() && !ip.is_loopback() && !((ip.segments()[0] & 0xffc0) == 0xfe80) && !((ip.segments()[0] & 0xfe00) == 0xfc00) && !ip.is_unspecified() && !((ip.segments()[0] == 0x2001) && (ip.segments()[1] == 0xdb8)) } } } } #[cfg(feature = "unstable")] fn is_global(ip: IpAddr) -> bool { ip.is_global() } /// These are some tests to check that the implementations match /// The IPv4 can be all checked in 5 mins or so and they are correct as of nightly 2020-07-11 /// The IPV6 can't be checked in a reasonable time, so we check about ten billion random ones, so far correct /// Note that the is_global implementation is subject to change as new IP RFCs are created /// /// To run while showing progress output: /// cargo test --features sqlite,unstable -- --nocapture --ignored #[cfg(test)] #[cfg(feature = "unstable")] mod tests { use super::*; #[test] #[ignore] fn test_ipv4_global() { for a in 0..u8::MAX { println!("Iter: {}/255", a); for b in 0..u8::MAX { for c in 0..u8::MAX { for d in 0..u8::MAX { let ip = IpAddr::V4(std::net::Ipv4Addr::new(a, b, c, d)); assert_eq!(ip.is_global(), is_global(ip)) } } } } } #[test] #[ignore] fn test_ipv6_global() { use ring::rand::{SecureRandom, SystemRandom}; let mut v = [0u8; 16]; let rand = SystemRandom::new(); for i in 0..1_000 { println!("Iter: {}/1_000", i); for _ in 0..10_000_000 { rand.fill(&mut v).expect("Error generating random values"); let ip = IpAddr::V6(std::net::Ipv6Addr::new( (v[14] as u16) << 8 | v[15] as u16, (v[12] as u16) << 8 | v[13] as u16, (v[10] as u16) << 8 | v[11] as u16, (v[8] as u16) << 8 | v[9] as u16, (v[6] as u16) << 8 | v[7] as u16, (v[4] as u16) << 8 | v[5] as u16, (v[2] as u16) << 8 | v[3] as u16, (v[0] as u16) << 8 | v[1] as u16, )); assert_eq!(ip.is_global(), is_global(ip)) } } } } use cached::proc_macro::cached; #[cached(key = "String", convert = r#"{ domain.to_string() }"#, size = 16, time = 60)] #[allow(clippy::unused_async)] // This is needed because cached causes a false-positive here. async fn is_domain_blacklisted(domain: &str) -> bool { if CONFIG.icon_blacklist_non_global_ips() { if let Ok(s) = lookup_host((domain, 0)).await { for addr in s { if !is_global(addr.ip()) { debug!("IP {} for domain '{}' is not a global IP!", addr.ip(), domain); return true; } } } } if let Some(blacklist) = CONFIG.icon_blacklist_regex() { // Use the pre-generate Regex stored in a Lazy HashMap if there's one, else generate it. let is_match = if let Some(regex) = ICON_BLACKLIST_REGEX.get(&blacklist) { regex.is_match(domain) } else { // Clear the current list if the previous key doesn't exists. // To prevent growing of the HashMap after someone has changed it via the admin interface. if ICON_BLACKLIST_REGEX.len() >= 1 { ICON_BLACKLIST_REGEX.clear(); } // Generate the regex to store in too the Lazy Static HashMap. let blacklist_regex = Regex::new(&blacklist).unwrap(); let is_match = blacklist_regex.is_match(domain); ICON_BLACKLIST_REGEX.insert(blacklist.clone(), blacklist_regex); is_match }; if is_match { debug!("Blacklisted domain: {} matched ICON_BLACKLIST_REGEX", domain); return true; } } false } async fn get_icon(domain: &str) -> Option<(Vec, String)> { let path = format!("{}/{}.png", CONFIG.icon_cache_folder(), domain); // Check for expiration of negatively cached copy if icon_is_negcached(&path).await { return None; } if let Some(icon) = get_cached_icon(&path).await { let icon_type = match get_icon_type(&icon) { Some(x) => x, _ => "x-icon", }; return Some((icon, icon_type.to_string())); } if CONFIG.disable_icon_download() { return None; } // Get the icon, or None in case of error match download_icon(domain).await { Ok((icon, icon_type)) => { save_icon(&path, &icon).await; Some((icon.to_vec(), icon_type.unwrap_or("x-icon").to_string())) } Err(e) => { warn!("Unable to download icon: {:?}", e); let miss_indicator = path + ".miss"; save_icon(&miss_indicator, &[]).await; None } } } async fn get_cached_icon(path: &str) -> Option> { // Check for expiration of successfully cached copy if icon_is_expired(path).await { return None; } // Try to read the cached icon, and return it if it exists if let Ok(mut f) = File::open(path).await { let mut buffer = Vec::new(); if f.read_to_end(&mut buffer).await.is_ok() { return Some(buffer); } } None } async fn file_is_expired(path: &str, ttl: u64) -> Result { let meta = symlink_metadata(path).await?; let modified = meta.modified()?; let age = SystemTime::now().duration_since(modified)?; Ok(ttl > 0 && ttl <= age.as_secs()) } async fn icon_is_negcached(path: &str) -> bool { let miss_indicator = path.to_owned() + ".miss"; let expired = file_is_expired(&miss_indicator, CONFIG.icon_cache_negttl()).await; match expired { // No longer negatively cached, drop the marker Ok(true) => { if let Err(e) = remove_file(&miss_indicator).await { error!("Could not remove negative cache indicator for icon {:?}: {:?}", path, e); } false } // The marker hasn't expired yet. Ok(false) => true, // The marker is missing or inaccessible in some way. Err(_) => false, } } async fn icon_is_expired(path: &str) -> bool { let expired = file_is_expired(path, CONFIG.icon_cache_ttl()).await; expired.unwrap_or(true) } struct Icon { priority: u8, href: String, } impl Icon { const fn new(priority: u8, href: String) -> Self { Self { priority, href, } } } fn get_favicons_node( dom: InfallibleTokenizer, FaviconEmitter>, icons: &mut Vec, url: &url::Url, ) { const TAG_LINK: &[u8] = b"link"; const TAG_BASE: &[u8] = b"base"; const TAG_HEAD: &[u8] = b"head"; const ATTR_REL: &[u8] = b"rel"; const ATTR_HREF: &[u8] = b"href"; const ATTR_SIZES: &[u8] = b"sizes"; let mut base_url = url.clone(); let mut icon_tags: Vec = Vec::new(); for token in dom { match token { FaviconToken::StartTag(tag) => { if *tag.name == TAG_LINK && tag.attributes.contains_key(ATTR_REL) && tag.attributes.contains_key(ATTR_HREF) { let rel_value = std::str::from_utf8(tag.attributes.get(ATTR_REL).unwrap()) .unwrap_or_default() .to_ascii_lowercase(); if rel_value.contains("icon") && !rel_value.contains("mask-icon") { icon_tags.push(tag); } } else if *tag.name == TAG_BASE && tag.attributes.contains_key(ATTR_HREF) { let href = std::str::from_utf8(tag.attributes.get(ATTR_HREF).unwrap()).unwrap_or_default(); debug!("Found base href: {href}"); base_url = match base_url.join(href) { Ok(inner_url) => inner_url, _ => url.clone(), }; } } FaviconToken::EndTag(tag) => { if *tag.name == TAG_HEAD { break; } } } } for icon_tag in icon_tags { if let Some(icon_href) = icon_tag.attributes.get(ATTR_HREF) { if let Ok(full_href) = base_url.join(std::str::from_utf8(icon_href).unwrap_or_default()) { let sizes = if let Some(v) = icon_tag.attributes.get(ATTR_SIZES) { std::str::from_utf8(v).unwrap_or_default() } else { "" }; let priority = get_icon_priority(full_href.as_str(), sizes); icons.push(Icon::new(priority, full_href.to_string())); } }; } } struct IconUrlResult { iconlist: Vec, referer: String, } /// Returns a IconUrlResult which holds a Vector IconList and a string which holds the referer. /// There will always two items within the iconlist which holds http(s)://domain.tld/favicon.ico. /// This does not mean that that location does exists, but it is the default location browser use. /// /// # Argument /// * `domain` - A string which holds the domain with extension. /// /// # Example /// ``` /// let icon_result = get_icon_url("github.com").await?; /// let icon_result = get_icon_url("vaultwarden.discourse.group").await?; /// ``` async fn get_icon_url(domain: &str) -> Result { // Default URL with secure and insecure schemes let ssldomain = format!("https://{domain}"); let httpdomain = format!("http://{domain}"); // First check the domain as given during the request for both HTTPS and HTTP. let resp = match get_page(&ssldomain).or_else(|_| get_page(&httpdomain)).await { Ok(c) => Ok(c), Err(e) => { let mut sub_resp = Err(e); // When the domain is not an IP, and has more then one dot, remove all subdomains. let is_ip = domain.parse::(); if is_ip.is_err() && domain.matches('.').count() > 1 { let mut domain_parts = domain.split('.'); let base_domain = format!( "{base}.{tld}", tld = domain_parts.next_back().unwrap(), base = domain_parts.next_back().unwrap() ); if is_valid_domain(&base_domain) { let sslbase = format!("https://{base_domain}"); let httpbase = format!("http://{base_domain}"); debug!("[get_icon_url]: Trying without subdomains '{base_domain}'"); sub_resp = get_page(&sslbase).or_else(|_| get_page(&httpbase)).await; } // When the domain is not an IP, and has less then 2 dots, try to add www. infront of it. } else if is_ip.is_err() && domain.matches('.').count() < 2 { let www_domain = format!("www.{domain}"); if is_valid_domain(&www_domain) { let sslwww = format!("https://{www_domain}"); let httpwww = format!("http://{www_domain}"); debug!("[get_icon_url]: Trying with www. prefix '{www_domain}'"); sub_resp = get_page(&sslwww).or_else(|_| get_page(&httpwww)).await; } } sub_resp } }; // Create the iconlist let mut iconlist: Vec = Vec::new(); let mut referer = String::from(""); if let Ok(content) = resp { // Extract the URL from the respose in case redirects occured (like @ gitlab.com) let url = content.url().clone(); // Set the referer to be used on the final request, some sites check this. // Mostly used to prevent direct linking and other security resons. referer = url.to_string(); // Add the fallback favicon.ico and apple-touch-icon.png to the list with the domain the content responded from. iconlist.push(Icon::new(35, String::from(url.join("/favicon.ico").unwrap()))); iconlist.push(Icon::new(40, String::from(url.join("/apple-touch-icon.png").unwrap()))); // 384KB should be more than enough for the HTML, though as we only really need the HTML header. let limited_reader = stream_to_bytes_limit(content, 384 * 1024).await?.to_vec(); let dom = Tokenizer::new_with_emitter(limited_reader.to_reader(), FaviconEmitter::default()).infallible(); get_favicons_node(dom, &mut iconlist, &url); } else { // Add the default favicon.ico to the list with just the given domain iconlist.push(Icon::new(35, format!("{ssldomain}/favicon.ico"))); iconlist.push(Icon::new(40, format!("{ssldomain}/apple-touch-icon.png"))); iconlist.push(Icon::new(35, format!("{httpdomain}/favicon.ico"))); iconlist.push(Icon::new(40, format!("{httpdomain}/apple-touch-icon.png"))); } // Sort the iconlist by priority iconlist.sort_by_key(|x| x.priority); // There always is an icon in the list, so no need to check if it exists, and just return the first one Ok(IconUrlResult { iconlist, referer, }) } async fn get_page(url: &str) -> Result { get_page_with_referer(url, "").await } async fn get_page_with_referer(url: &str, referer: &str) -> Result { if is_domain_blacklisted(url::Url::parse(url).unwrap().host_str().unwrap_or_default()).await { warn!("Favicon '{}' resolves to a blacklisted domain or IP!", url); } let mut client = CLIENT.get(url); if !referer.is_empty() { client = client.header("Referer", referer) } match client.send().await { Ok(c) => c.error_for_status().map_err(Into::into), Err(e) => err_silent!(format!("{}", e)), } } /// Returns a Integer with the priority of the type of the icon which to prefer. /// The lower the number the better. /// /// # Arguments /// * `href` - A string which holds the href value or relative path. /// * `sizes` - The size of the icon if available as a x value like 32x32. /// /// # Example /// ``` /// priority1 = get_icon_priority("http://example.com/path/to/a/favicon.png", "32x32"); /// priority2 = get_icon_priority("https://example.com/path/to/a/favicon.ico", ""); /// ``` fn get_icon_priority(href: &str, sizes: &str) -> u8 { // Check if there is a dimension set let (width, height) = parse_sizes(sizes); // Check if there is a size given if width != 0 && height != 0 { // Only allow square dimensions if width == height { // Change priority by given size if width == 32 { 1 } else if width == 64 { 2 } else if (24..=192).contains(&width) { 3 } else if width == 16 { 4 } else { 5 } // There are dimensions available, but the image is not a square } else { 200 } } else { // Change priority by file extension if href.ends_with(".png") { 10 } else if href.ends_with(".jpg") || href.ends_with(".jpeg") { 20 } else { 30 } } } /// Returns a Tuple with the width and hight as a seperate value extracted from the sizes attribute /// It will return 0 for both values if no match has been found. /// /// # Arguments /// * `sizes` - The size of the icon if available as a x value like 32x32. /// /// # Example /// ``` /// let (width, height) = parse_sizes("64x64"); // (64, 64) /// let (width, height) = parse_sizes("x128x128"); // (128, 128) /// let (width, height) = parse_sizes("32"); // (0, 0) /// ``` fn parse_sizes(sizes: &str) -> (u16, u16) { let mut width: u16 = 0; let mut height: u16 = 0; if !sizes.is_empty() { match ICON_SIZE_REGEX.captures(sizes.trim()) { None => {} Some(dimensions) => { if dimensions.len() >= 3 { width = dimensions[1].parse::().unwrap_or_default(); height = dimensions[2].parse::().unwrap_or_default(); } } } } (width, height) } async fn download_icon(domain: &str) -> Result<(Bytes, Option<&str>), Error> { if is_domain_blacklisted(domain).await { err_silent!("Domain is blacklisted", domain) } let icon_result = get_icon_url(domain).await?; let mut buffer = Bytes::new(); let mut icon_type: Option<&str> = None; use data_url::DataUrl; for icon in icon_result.iconlist.iter().take(5) { if icon.href.starts_with("data:image") { let datauri = DataUrl::process(&icon.href).unwrap(); // Check if we are able to decode the data uri let mut body = BytesMut::new(); match datauri.decode::<_, ()>(|bytes| { body.extend_from_slice(bytes); Ok(()) }) { Ok(_) => { // Also check if the size is atleast 67 bytes, which seems to be the smallest png i could create if body.len() >= 67 { // Check if the icon type is allowed, else try an icon from the list. icon_type = get_icon_type(&body); if icon_type.is_none() { debug!("Icon from {} data:image uri, is not a valid image type", domain); continue; } info!("Extracted icon from data:image uri for {}", domain); buffer = body.freeze(); break; } } _ => debug!("Extracted icon from data:image uri is invalid"), }; } else { match get_page_with_referer(&icon.href, &icon_result.referer).await { Ok(res) => { buffer = stream_to_bytes_limit(res, 5120 * 1024).await?; // 5120KB/5MB for each icon max (Same as icons.bitwarden.net) // Check if the icon type is allowed, else try an icon from the list. icon_type = get_icon_type(&buffer); if icon_type.is_none() { buffer.clear(); debug!("Icon from {}, is not a valid image type", icon.href); continue; } info!("Downloaded icon from {}", icon.href); break; } Err(e) => debug!("{:?}", e), }; } } if buffer.is_empty() { err_silent!("Empty response or unable find a valid icon", domain); } Ok((buffer, icon_type)) } async fn save_icon(path: &str, icon: &[u8]) { match File::create(path).await { Ok(mut f) => { f.write_all(icon).await.expect("Error writing icon file"); } Err(ref e) if e.kind() == std::io::ErrorKind::NotFound => { create_dir_all(&CONFIG.icon_cache_folder()).await.expect("Error creating icon cache folder"); } Err(e) => { warn!("Unable to save icon: {:?}", e); } } } fn get_icon_type(bytes: &[u8]) -> Option<&'static str> { match bytes { [137, 80, 78, 71, ..] => Some("png"), [0, 0, 1, 0, ..] => Some("x-icon"), [82, 73, 70, 70, ..] => Some("webp"), [255, 216, 255, ..] => Some("jpeg"), [71, 73, 70, 56, ..] => Some("gif"), [66, 77, ..] => Some("bmp"), _ => None, } } /// Minimize the amount of bytes to be parsed from a reqwest result. /// This prevents very long parsing and memory usage. async fn stream_to_bytes_limit(res: Response, max_size: usize) -> Result { let mut stream = res.bytes_stream().take(max_size); let mut buf = BytesMut::new(); let mut size = 0; while let Some(chunk) = stream.next().await { let chunk = &chunk?; size += chunk.len(); buf.extend(chunk); if size >= max_size { break; } } Ok(buf.freeze()) } /// This is an implementation of the default Cookie Jar from Reqwest and reqwest_cookie_store build by pfernie. /// The default cookie jar used by Reqwest keeps all the cookies based upon the Max-Age or Expires which could be a long time. /// That could be used for tracking, to prevent this we force the lifespan of the cookies to always be max two minutes. /// A Cookie Jar is needed because some sites force a redirect with cookies to verify if a request uses cookies or not. use cookie_store::CookieStore; #[derive(Default)] pub struct Jar(std::sync::RwLock); impl reqwest::cookie::CookieStore for Jar { fn set_cookies(&self, cookie_headers: &mut dyn Iterator, url: &url::Url) { use cookie::{Cookie as RawCookie, ParseError as RawCookieParseError}; use time::Duration; let mut cookie_store = self.0.write().unwrap(); let cookies = cookie_headers.filter_map(|val| { std::str::from_utf8(val.as_bytes()) .map_err(RawCookieParseError::from) .and_then(RawCookie::parse) .map(|mut c| { c.set_expires(None); c.set_max_age(Some(Duration::minutes(2))); c.into_owned() }) .ok() }); cookie_store.store_response_cookies(cookies, url); } fn cookies(&self, url: &url::Url) -> Option { let cookie_store = self.0.read().unwrap(); let s = cookie_store .get_request_values(url) .map(|(name, value)| format!("{}={}", name, value)) .collect::>() .join("; "); if s.is_empty() { return None; } header::HeaderValue::from_maybe_shared(Bytes::from(s)).ok() } } /// Custom FaviconEmitter for the html5gum parser. /// The FaviconEmitter is using an almost 1:1 copy of the DefaultEmitter with some small changes. /// This prevents emitting tags like comments, doctype and also strings between the tags. /// Therefor parsing the HTML content is faster. use std::collections::{BTreeSet, VecDeque}; #[derive(Debug)] enum FaviconToken { StartTag(StartTag), EndTag(EndTag), } #[derive(Default, Debug)] struct FaviconEmitter { current_token: Option, last_start_tag: HtmlString, current_attribute: Option<(HtmlString, HtmlString)>, seen_attributes: BTreeSet, emitted_tokens: VecDeque, } impl FaviconEmitter { fn emit_token(&mut self, token: FaviconToken) { self.emitted_tokens.push_front(token); } fn flush_current_attribute(&mut self) { if let Some((k, v)) = self.current_attribute.take() { match self.current_token { Some(FaviconToken::StartTag(ref mut tag)) => { tag.attributes.entry(k).and_modify(|_| {}).or_insert(v); } Some(FaviconToken::EndTag(_)) => { self.seen_attributes.insert(k); } _ => { debug_assert!(false); } } } } } impl Emitter for FaviconEmitter { type Token = FaviconToken; fn set_last_start_tag(&mut self, last_start_tag: Option<&[u8]>) { self.last_start_tag.clear(); self.last_start_tag.extend(last_start_tag.unwrap_or_default()); } fn pop_token(&mut self) -> Option { self.emitted_tokens.pop_back() } fn init_start_tag(&mut self) { self.current_token = Some(FaviconToken::StartTag(StartTag::default())); } fn init_end_tag(&mut self) { self.current_token = Some(FaviconToken::EndTag(EndTag::default())); self.seen_attributes.clear(); } fn emit_current_tag(&mut self) -> Option { self.flush_current_attribute(); let mut token = self.current_token.take().unwrap(); let mut emit = false; match token { FaviconToken::EndTag(ref mut tag) => { // Always clean seen attributes self.seen_attributes.clear(); // Only trigger an emit for the tag. // This is matched, and will break the for-loop. if *tag.name == b"head" { emit = true; } } FaviconToken::StartTag(ref mut tag) => { // Only trriger an emit for and tags. // These are the only tags we want to parse. if *tag.name == b"link" || *tag.name == b"base" { self.set_last_start_tag(Some(&tag.name)); emit = true; } else { self.set_last_start_tag(None); } } } // Only emit the tags we want to parse. if emit { self.emit_token(token); } None } fn push_tag_name(&mut self, s: &[u8]) { match self.current_token { Some( FaviconToken::StartTag(StartTag { ref mut name, .. }) | FaviconToken::EndTag(EndTag { ref mut name, .. }), ) => { name.extend(s); } _ => debug_assert!(false), } } fn init_attribute(&mut self) { self.flush_current_attribute(); self.current_attribute = Some(Default::default()); } fn push_attribute_name(&mut self, s: &[u8]) { self.current_attribute.as_mut().unwrap().0.extend(s); } fn push_attribute_value(&mut self, s: &[u8]) { self.current_attribute.as_mut().unwrap().1.extend(s); } fn current_is_appropriate_end_tag_token(&mut self) -> bool { match self.current_token { Some(FaviconToken::EndTag(ref tag)) => !self.last_start_tag.is_empty() && self.last_start_tag == tag.name, _ => false, } } // We do not want and need these parts of the HTML document // These will be skipped and ignored during the tokenization and iteration. fn emit_current_comment(&mut self) {} fn emit_current_doctype(&mut self) {} fn emit_eof(&mut self) {} fn emit_error(&mut self, _: html5gum::Error) {} fn emit_string(&mut self, _: &[u8]) {} fn init_comment(&mut self) {} fn init_doctype(&mut self) {} fn push_comment(&mut self, _: &[u8]) {} fn push_doctype_name(&mut self, _: &[u8]) {} fn push_doctype_public_identifier(&mut self, _: &[u8]) {} fn push_doctype_system_identifier(&mut self, _: &[u8]) {} fn set_doctype_public_identifier(&mut self, _: &[u8]) {} fn set_doctype_system_identifier(&mut self, _: &[u8]) {} fn set_force_quirks(&mut self) {} fn set_self_closing(&mut self) {} }