commit 8e7b504ae09185428a1aad7502e3b25817206250 Author: David Fifield <david@bamsoftware.com> Date: Mon Feb 18 16:37:29 2019 -0700 Minor typo and style fixes. --- webextension/background.js | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/webextension/background.js b/webextension/background.js index da3d118..5aab472 100644 --- a/webextension/background.js +++ b/webextension/background.js @@ -54,8 +54,6 @@ // because that is what enables the native part to match up requests and // responses. -let port = browser.runtime.connectNative("meek.http.helper"); - // Decode a base64-encoded string into an ArrayBuffer. function base64_decode(enc_str) { // First step is to decode the base64. atob returns a byte string; i.e., a @@ -97,7 +95,7 @@ function Mutex() { } } -// Enforces exclusive access for onBeforeSendHeaders listeners. +// Enforces exclusive access to onBeforeSendHeaders listeners. const headersMutex = new Mutex(); async function roundtrip(request) { @@ -136,21 +134,22 @@ async function roundtrip(request) { // TODO: proxy - // We need to use an onBeforeSendHeaders to override certain header fields, - // including Host (passing them to fetch in init.headers does not work). But - // onBeforeSendHeaders is a global setting (applies to all requests) and we - // need to be able to set different headers per request. We make it so that - // any onBeforeSendHeaders listener is only used for a single request, by - // acquiring a lock here and releasing it within the listener itself. The - // lock is acquired and released before any network communication happens; - // i.e., it's fast. + // We need to use a webRequest.onBeforeSendHeaders listener to override + // certain header fields, including Host (passing them to fetch in + // init.headers does not work). But onBeforeSendHeaders is a global setting + // (applies to all requests) and we need to be able to set different headers + // per request. We make it so that any onBeforeSendHeaders listener is only + // used for a single request, by acquiring a lock here and releasing it + // within the listener itself. The lock is acquired and released before any + // network communication happens; i.e., it's fast. let headersUnlock = await headersMutex.lock(); let headersCalled = false; function headersFn(details) { try { - // Sanity assertion: any given listener is called at most once. + // Sanity assertion: per-request listeners are called at most once. if (headersCalled) { - throw new Error("headersFn called more than once"); + console.log("headersFn called more than once"); + return {cancel: true}; } headersCalled = true; @@ -168,18 +167,18 @@ async function roundtrip(request) { return {requestHeaders: browserHeaders.concat(headers)}; } finally { // Now that the listener has been called, remove it and release the - // lock to allow the next request to set different listener. + // lock to allow the next request to set a different listener. browser.webRequest.onBeforeSendHeaders.removeListener(headersFn); headersUnlock(); } - }; + } try { // Set our listener that overrides the headers for this request. // https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/w... browser.webRequest.onBeforeSendHeaders.addListener( headersFn, - {"urls": ["http://*/*", "https://*/*"]}, + {urls: ["http://*/*", "https://*/*"]}, ["blocking", "requestHeaders"] ); @@ -197,7 +196,10 @@ async function roundtrip(request) { } } -port.onMessage.addListener((message) => { +// Connect to our native process. +let port = browser.runtime.connectNative("meek.http.helper"); + +port.onMessage.addListener(message => { switch (message.command) { case "roundtrip": // Do a roundtrip and send the result back to the native process. @@ -221,7 +223,7 @@ port.onMessage.addListener((message) => { } }); -port.onDisconnect.addListener((p) => { +port.onDisconnect.addListener(p => { // https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/r... // "Note that in Google Chrome port.error is not supported: instead, use // runtime.lastError to get the error message."