Refactor Referrer-Policy header

- Change the variable to always-headers so it can be extended in the future
- New function build-headers that assists combining complex logic headers
  together with less mess
- Also apply headers to the proxy

info.rkt

@@ -1,3 +1,3 @@
 #lang info
 
-(define build-deps '("rackunit-lib" "web-server-lib" "http-easy-lib" "html-parsing" "html-writing" "json-pointer" "ini-lib"))
+(define build-deps '("rackunit-lib" "web-server-lib" "http-easy-lib" "html-parsing" "html-writing" "json-pointer" "ini-lib" "memo"))

src/application-globals.rkt

@@ -9,6 +9,8 @@
          "url-utils.rkt")
 
 (provide
+ ; headers to always send on all http responses
+ always-headers
  ; timeout durations for http-easy requests
  timeouts
  ; generates a consistent footer
@@ -22,6 +24,8 @@
   (require rackunit
            html-writing))
 
+(define always-headers
+  (list (header #"Referrer-Policy" #"same-origin"))) ; header to not send referers to fandom
 (define timeouts (easy:make-timeout-config #:lease 5 #:connect 5))
 
 (define (application-footer source-url #:license [license-in #f])
@@ -48,8 +52,8 @@
                 ,(if source-url
                      `(div (p "This page displays proxied content from "
                               (a (@ (href ,source-url) (rel "noreferrer")) ,source-url)
-                              ,(format ". Text content is available under the ~a license, " (license-text license))
-                              (a (@ (href ,(license-url license))) "see license info.")
+                              ,(format ". Text content is available under the ~a license, " (license^-text license))
+                              (a (@ (href ,(license^-url license))) "see license info.")
                               " Media files may have different copying restrictions.")
                            (p ,(format "Fandom is a trademark of Fandom, Inc. ~a is not affiliated with Fandom." (config-get 'application_name))))
                      `(div (p "Text content on wikis run by Fandom is available under the Creative Commons Attribution-Share Alike License 3.0 (Unported), "
@@ -63,7 +67,8 @@
          #:wikiname wikiname
          #:title title
          #:body-class [body-class-in #f]
-         #:license [license #f])
+         #:siteinfo [siteinfo-in #f])
+  (define siteinfo (or siteinfo-in siteinfo-default))
   (define body-class (if (not body-class-in)
                          "skin-fandomdesktop"
                          body-class-in))
@@ -82,7 +87,10 @@
   `(html
     (head
      (meta (@ (name "viewport") (content "width=device-width, initial-scale=1")))
-     (title ,(format "~a | ~a" title (config-get 'application_name)))
+     (title ,(format "~a | ~a+~a"
+                     title
+                     (regexp-replace #rx" ?Wiki$" (siteinfo^-sitename siteinfo) "")
+                     (config-get 'application_name)))
      ,@(map (λ (url)
               `(link (@ (rel "stylesheet") (type "text/css") (href ,url))))
             (required-styles (format "https://~a.fandom.com" wikiname)))
@@ -101,7 +109,7 @@
                           (div (@ (id "content") #;(class "page-content"))
                                (div (@ (id "mw-content-text"))
                                     ,content))
-                          ,(application-footer source-url #:license license)))))))
+                          ,(application-footer source-url #:license (siteinfo^-license siteinfo))))))))
 (module+ test
   (define page
     (parameterize ([(config-parameter 'strict_proxy) "true"])

src/data.rkt

@@ -1,33 +1,36 @@
 #lang racket/base
-(require (prefix-in easy: net/http-easy)
+(require racket/list
+         (prefix-in easy: net/http-easy)
+         memo
          "url-utils.rkt"
          "xexpr-utils.rkt")
 
 (provide
- (struct-out license)
- license-default
- license-auto)
+ (struct-out siteinfo^)
+ (struct-out license^)
+ siteinfo-fetch
+ siteinfo-default
+ license-default)
 
-(struct license (text url) #:transparent)
-(define license-default (license "CC-BY-SA" "https://www.fandom.com/licensing"))
-(define license-hash (make-hash))
-(define (license-fetch wikiname)
+(struct siteinfo^ (sitename basepage license) #:transparent)
+(struct license^ (text url) #:transparent)
+
+(define license-default (license^ "CC-BY-SA" "https://www.fandom.com/licensing"))
+(define siteinfo-default (siteinfo^ "Test Wiki" "Main_Page" license-default))
+
+(define/memoize (siteinfo-fetch wikiname) #:hash hash
   (define dest-url
     (format "https://~a.fandom.com/api.php?~a"
             wikiname
             (params->query '(("action" . "query")
                              ("meta" . "siteinfo")
-                             ("siprop" . "rightsinfo")
+                             ("siprop" . "general|rightsinfo")
                              ("format" . "json")
                              ("formatversion" . "2")))))
   (log-outgoing dest-url)
   (define res (easy:get dest-url))
   (define data (easy:response-json res))
-  (license (jp "/query/rightsinfo/text" data)
-           (jp "/query/rightsinfo/url" data)))
-(define (license-auto wikiname)
-  (if (hash-has-key? license-hash wikiname)
-      (hash-ref license-hash wikiname)
-      (let ([result (license-fetch wikiname)])
-        (hash-set! license-hash wikiname result)
-        result)))
+  (siteinfo^ (jp "/query/general/sitename" data)
+             (second (regexp-match #rx"/wiki/(.*)" (jp "/query/general/base" data)))
+             (license^ (jp "/query/rightsinfo/text" data)
+                       (jp "/query/rightsinfo/url" data))))

src/page-category.rkt

@@ -35,14 +35,14 @@
          #:members-data members-data
          #:page page
          #:body-class [body-class #f]
-         #:license [license #f])
+         #:siteinfo [siteinfo #f])
   (define members (jp "/query/categorymembers" members-data))
   (generate-wiki-page
    #:source-url source-url
    #:wikiname wikiname
    #:title title
    #:body-class body-class
-   #:license license
+   #:siteinfo siteinfo
    `(div
      ,(update-tree-wiki page wikiname)
      (hr)
@@ -89,7 +89,7 @@
                 (log-outgoing dest-url)
                 (define dest-res (easy:get dest-url #:timeouts timeouts))
                 (easy:response-json dest-res)]
-     [license (license-auto wikiname)])
+     [siteinfo (siteinfo-fetch wikiname)])
 
     (define title (preprocess-html-wiki (jp "/parse/title" page-data prefixed-category)))
     (define page-html (preprocess-html-wiki (jp "/parse/text" page-data "")))
@@ -105,7 +105,7 @@
                   #:members-data members-data
                   #:page page
                   #:body-class body-class
-                  #:license license))
+                  #:siteinfo siteinfo))
 
     (when (config-true? 'debug)
       ; used for its side effects
@@ -113,6 +113,7 @@
       (xexp->html body))
     (response/output
      #:code 200
+     #:headers (build-headers always-headers)
      (λ (out)
        (write-html body out))))))
 (module+ test

src/page-home.rkt

@@ -4,6 +4,7 @@
          html-writing
          web-server/http
          "application-globals.rkt"
+         "url-utils.rkt"
          "xexpr-utils.rkt"
          "config.rkt")
 
@@ -81,6 +82,7 @@
 (define (page-home req)
   (response/output
    #:code 200
+   #:headers (build-headers always-headers)
    (λ (out)
      (write-html body out))))
 

src/page-proxy.rkt

@@ -8,6 +8,7 @@
          net/url
          web-server/http
          (only-in web-server/dispatchers/dispatch next-dispatcher)
+         "application-globals.rkt"
          "url-utils.rkt"
          "xexpr-utils.rkt")
 
@@ -26,6 +27,7 @@
               (response/output
                #:code (easy:response-status-code dest-r)
                #:mime-type (easy:response-headers-ref dest-r 'content-type)
+               #:headers (build-headers always-headers)
                (λ (out)
                  (copy-port (easy:response-output dest-r) out)
                  (easy:response-close! dest-r))))))

src/page-redirect-wiki-home.rkt

@@ -2,6 +2,7 @@
 (require net/url
          web-server/http
          "application-globals.rkt"
+         "data.rkt"
          "url-utils.rkt"
          "xexpr-utils.rkt")
 
@@ -11,5 +12,6 @@
 (define (redirect-wiki-home req)
   (response-handler
    (define wikiname (path/param-path (car (url-path (request-uri req)))))
-   (define dest (format "/~a/wiki/Main_Page" wikiname))
+   (define siteinfo (siteinfo-fetch wikiname))
+   (define dest (format "/~a/wiki/~a" wikiname (or (siteinfo^-basepage siteinfo) "Main_Page")))
    (generate-redirect dest)))

src/page-search.rkt

@@ -25,13 +25,13 @@
   (define search-json-data
     '#hasheq((batchcomplete . #t) (query . #hasheq((search . (#hasheq((ns . 0) (pageid . 219) (size . 1482) (snippet . "") (timestamp . "2022-08-21T08:54:23Z") (title . "Gacha Capsule") (wordcount . 214)) #hasheq((ns . 0) (pageid . 201) (size . 1198) (snippet . "") (timestamp . "2022-07-11T17:52:47Z") (title . "Badges") (wordcount . 181)))))))))
 
-(define (generate-results-page dest-url wikiname query data #:license [license #f])
+(define (generate-results-page dest-url wikiname query data #:siteinfo [siteinfo #f])
   (define search-results (jp "/query/search" data))
   (generate-wiki-page
    #:source-url dest-url
    #:wikiname wikiname
    #:title "Search Results"
-   #:license license
+   #:siteinfo siteinfo
    `(div (@ (class "mw-parser-output"))
          (p ,(format "~a results found for " (length search-results))
             (strong ,query))
@@ -70,17 +70,18 @@
    (thread-let
     ([dest-res (log-outgoing dest-url)
                (easy:get dest-url #:timeouts timeouts)]
-     [license (license-auto wikiname)])
+     [siteinfo (siteinfo-fetch wikiname)])
 
     (define data (easy:response-json dest-res))
 
-    (define body (generate-results-page dest-url wikiname query data #:license license))
+    (define body (generate-results-page dest-url wikiname query data #:siteinfo siteinfo))
     (when (config-true? 'debug)
       ; used for its side effects
       ; convert to string with error checking, error will be raised if xexp is invalid
       (xexp->html body))
     (response/output
      #:code 200
+     #:headers (build-headers always-headers)
      (λ (out)
        (write-html body out))))))
 (module+ test

src/page-wiki.rkt

@@ -152,15 +152,17 @@
                        (λ (v) (dict-update v 'rel (λ (s)
                                                     (list (string-append (car s) " noreferrer")))
                                            '(""))))
-                ; proxy images from inline styles
-                (curry attribute-maybe-update 'style
+                ; proxy images from inline styles, if strict_proxy is set
+                (curry u
+                       (λ (v) (config-true? 'strict_proxy))
+                       (λ (v) (attribute-maybe-update 'style
                          (λ (style)
                            (regexp-replace #rx"url\\(['\"]?(.*?)['\"]?\\)" style
                                            (λ (whole url)
                                              (string-append
                                               "url("
                                               (u-proxy-url url)
-                                            ")")))))
+                                              ")")))) v)))
                 ; and also their links, if strict_proxy is set
                 (curry u
                        (λ (v)
@@ -168,8 +170,10 @@
                               (eq? element-type 'a)
                               (has-class? "image-thumbnail" v)))
                        (λ (v) (attribute-maybe-update 'href u-proxy-url v)))
-                ; proxy images from src attributes
-                (curry attribute-maybe-update 'src u-proxy-url)
+                ; proxy images from src attributes, if strict_proxy is set
+                (curry u
+                       (λ (v) (config-true? 'strict_proxy))
+                       (λ (v) (attribute-maybe-update 'src u-proxy-url v)))
                 ; don't lazyload images
                 (curry u
                        (λ (v) (dict-has-key? v 'data-src))
@@ -248,7 +252,7 @@
                                          ("format" . "json")))))
               (log-outgoing dest-url)
               (easy:get dest-url #:timeouts timeouts)]
-    [license (license-auto wikiname)])
+    [siteinfo (siteinfo-fetch wikiname)])
 
    (cond
      [(eq? 200 (easy:response-status-code dest-res))
@@ -271,13 +275,15 @@
                 #:wikiname wikiname
                 #:title title
                 #:body-class body-class
-                #:license license))
+                #:siteinfo siteinfo))
              (define redirect-msg ((query-selector (attribute-selector 'class "redirectMsg") body)))
-             (define headers (if redirect-msg
+             (define headers
+               (build-headers
+                always-headers
+                (when redirect-msg
                     (let* ([dest (get-attribute 'href (bits->attributes ((query-selector (λ (t a c) (eq? t 'a)) redirect-msg))))]
                            [value (bytes-append #"0;url=" (string->bytes/utf-8 dest))])
-                                   (list (header #"Refresh" value)))
-                                 (list)))
+                      (header #"Refresh" value)))))
              (when (config-true? 'debug)
                ; used for its side effects
                ; convert to string with error checking, error will be raised if xexp is invalid

src/url-utils.rkt

@@ -2,6 +2,8 @@
 (require racket/string
          "config.rkt"
          "pure-utils.rkt")
+(require/typed web-server/http/request-structs
+               [#:opaque Header header?])
 
 (provide
  ; regex to match wiki names
@@ -13,7 +15,9 @@
  ; check whether a url is on a domain controlled by fandom
  is-fandom-url?
   ; prints "out: <url>"
- log-outgoing)
+ log-outgoing
+ ; pass in a header, headers, or something useless. they'll all combine into a list
+ build-headers)
 
 (module+ test
   (require "typed-rackunit.rkt"))
@@ -81,3 +85,16 @@
 (define (log-outgoing url-string)
   (when (config-true? 'log_outgoing)
     (printf "out: ~a~n" url-string)))
+
+(: build-headers ((U Header (Listof Header) False Void) * -> (Listof Header)))
+(define (build-headers . fs)
+  (apply
+   append
+   (map (λ ([f : (U Header (Listof Header) False Void)])
+         (cond
+           [(not f) null]
+           [(void? f) null]
+           [(null? f) null]
+           [(header? f) (list f)]
+           [(pair? f) f]))
+       fs)))