Initial commit

background.js

@@ -0,0 +1,189 @@
+const iconColorAndDesc = {
+    0: { color: "grey",   desc: "Detect Cloudflare" },
+    1: { color: "green",  desc: "This page doesn't seem to use Cloudflare." },
+    2: { color: "orange", desc: "External resources on this page use Cloudflare." },
+    3: { color: "red",    desc: "This page uses Cloudflare!" }
+};
+
+function Counter() {
+    this.counts = new Map();
+    this.setCount = function(key,val) {
+        this.counts.set(key, val);
+    };
+    this.getCount = function(key) {
+        if (!this.counts.has(key)) { return 0; }
+        else { return this.counts.get(key); }
+    };
+    this.incCount = function(key) {
+        if (!this.counts.has(key)) { this.counts.set(key,1); }
+        else { this.counts.set(key, this.counts.get(key)+1); }
+    };
+    this.delCount = function(key) {
+        this.counts.delete(key);
+    };
+}
+
+function mapToObject( map ) {
+    obj = {};
+    map.forEach( function(val,key) { obj[key]=val; } );
+    return obj;
+}
+
+function CFInfo() {
+    this.domainCounter = new Counter();
+    this.result = 0;
+    // maybe more in the future
+}
+
+function CFInfoByTab() {
+    this.info = new Map(); 
+    this.getInfo = function(id) {
+        return this.info.get(id);
+    }
+    this.getOrCreate = function(id) {
+        if (!this.info.has(id)) { this.info.set(id, new CFInfo()); }
+        return this.info.get(id);
+    };
+    this.delInfo = function(id) {
+        this.info.delete(id);
+    };
+}
+
+var cfInfo = new CFInfoByTab();
+
+function onError(e) {
+    console.log(`CF-Detect-Background: ${e}`);
+}
+
+function getDomainFromURL( urltxt ) {
+    try {
+        var url = new URL(urltxt);
+        return url.hostname;
+    } catch(err) {
+        return null;
+    }
+}
+
+function updateStatus( tabId ) {
+    var info = cfInfo.getInfo(tabId);
+    if (info) {
+        if (info.result >= 3) return; // no need for further updates
+        var counts = info.domainCounter.counts;
+        if (counts.size == 0) {
+            info.result = 1;
+            updateIcon( tabId, 1 );
+        } else {
+            chrome.tabs.get(tabId, function(tab) {
+                try {
+                    var domain = getDomainFromURL(tab.url);
+                    if (counts.has(domain)) {
+                        info.result = 3;
+                        updateIcon( tabId, 3 );
+                    } else {
+                        info.result = 2;
+                        updateIcon( tabId, 2 );
+                    }
+                } catch (error) {
+                    onError(error);
+                }
+            });
+        }
+    } else {
+        updateIcon( tabId, 0 );
+    }
+}
+
+function updateIcon( tabId, result ) {
+    var cd = iconColorAndDesc[result];
+    var color = cd.color;
+    var title = cd.desc;
+    chrome.browserAction.setTitle({
+        tabId: tabId,
+        title: title
+    });
+    chrome.browserAction.setIcon({
+        tabId: tabId,
+        path: {
+            16: `icons/cf-${color}-16.png` ,
+            32: `icons/cf-${color}-32.png` ,
+            64: `icons/cf-${color}-64.png`
+        }
+    });
+}
+
+function cfdetect( details ) {
+    var headers = details.responseHeaders;
+    var cf = false;
+    for (var i=0; i<headers.length; i++) {
+        var h = headers[i];
+        var hname = h.name.toLowerCase();
+        if ((hname === "cf-ray") ||
+            (hname === "server" && h.value === "cloudflare-nginx")) {
+            cf = true;
+            break;
+        }
+    }
+    var tabId = details.tabId;
+    if (tabId == -1) return;
+    var info = cfInfo.getOrCreate(tabId);
+    if (cf) {
+        var ctr = info.domainCounter;
+        var domain = getDomainFromURL( details.url );
+        ctr.incCount(domain);
+    }
+    updateStatus(tabId);
+}
+
+function handleBeforeNavigate( details ) {
+    if (details.frameId == 0) {
+        cfInfo.delInfo( details.tabId );
+        updateStatus( details.tabId );
+    }
+}
+
+function handleTabUpdate( tabId, changeInfo, tabInfo ) {
+    if ("url" in changeInfo) {
+        updateStatus( tabId );
+    }
+}
+
+function handleTabClose( tabId, removeInfo ) {
+    cfInfo.delInfo(tabId);
+}
+
+function handleTabReplace( newId, oldId ) {
+    cfInfo.delInfo(oldId);
+}
+
+// triggered by popup script
+function handleConnect(port) {
+    port.onMessage.addListener( function(tabId) {
+        var info = cfInfo.getInfo(tabId);
+        var msg;
+        if (info) {
+            msg = {
+                result: info.result,
+                counts: mapToObject(info.domainCounter.counts)
+            };
+        } else {
+            msg = null;
+        }
+        port.postMessage(msg);
+    });
+}
+
+chrome.webRequest.onHeadersReceived.addListener(
+    cfdetect,
+    { urls: [ "<all_urls>" ] },
+    [ "responseHeaders" ]
+);
+
+chrome.webNavigation.onBeforeNavigate.addListener( handleBeforeNavigate );
+
+chrome.tabs.onUpdated.addListener( handleTabUpdate );
+chrome.tabs.onRemoved.addListener( handleTabClose );
+chrome.tabs.onReplaced.addListener( handleTabReplace );
+
+chrome.runtime.onConnect.addListener( handleConnect );
+
+// vim: set expandtab ts=4 sw=4 :