Backed out 2 changesets (bug 1822495) for causing a very high failure rate in Bug 1775997. CLOSED TREE

Backed out changeset c2121c4069d9 (bug 1822495)
Backed out changeset 356e59590921 (bug 1822495)

Author: ncsoregi

browser/components/doh/DoHHeuristics.sys.mjs

@@ -188,47 +188,15 @@ async function dnsListLookup(domainList) {
 }
 
 // TODO: Confirm the expected behavior when filtering is on
-export async function globalCanary() {
-  // Check that a commonly used domain resolves before and after
-  // checking the global canary.
-  // If this check fails, the globalCanary isn't to be trusted, as it's
-  // an indication it might have failed due to DNS being unavailable.
-  async function preconditionCheck(domain) {
-    let { addresses, err } = await dnsLookup(domain);
-    if (err === NXDOMAIN_ERR || !addresses.length) {
-      return false;
-    }
-    return true;
-  }
-
-  let preCheckSuccess = await preconditionCheck("example.com.");
-  if (!preCheckSuccess) {
-    return "enable_doh";
-  }
-
-  // Actual global canary check
+async function globalCanary() {
   let { addresses, err } = await dnsLookup(GLOBAL_CANARY);
 
-  let postCheckSuccess = await preconditionCheck("example.org.");
-  if (!postCheckSuccess) {
-    return "enable_doh";
-  }
-
-  function isLocal(addr) {
-    // hostnameIsLocalIPAddress does not return true for loopback addresses
-    // so we specifically handle these.
-    if (addr == "127.0.0.1" || addr == "::1" || addr == "0.0.0.0") {
-      return true;
-    }
-    return Services.io.hostnameIsLocalIPAddress(
-      Services.io.newURI(`http://${addr}`)
-    );
-  }
-
   if (
     err === NXDOMAIN_ERR ||
     !addresses.length ||
-    addresses.every(addr => isLocal(addr))
+    addresses.every(addr =>
+      Services.io.hostnameIsLocalIPAddress(Services.io.newURI(`http://${addr}`))
+    )
   ) {
     return "disable_doh";
   }

browser/components/doh/test/unit/test_heuristics.js

@@ -78,109 +78,3 @@ add_task(async function test_parentalControls() {
     "By default, parental controls should be disabled and doh should be enabled"
   );
 });
-
-add_task(async function test_canary() {
-  let DoHHeuristics = ChromeUtils.importESModule(
-    "resource:///modules/DoHHeuristics.sys.mjs"
-  );
-  const override = Cc["@mozilla.org/network/native-dns-override;1"].getService(
-    Ci.nsINativeDNSResolverOverride
-  );
-
-  function setCanary(ip, pre, post) {
-    override.clearOverrides();
-    override.addIPOverride("use-application-dns.net.", ip);
-
-    if (!pre) {
-      pre = "1.2.3.4";
-    }
-    if (!post) {
-      post = "1.2.3.4";
-    }
-
-    override.addIPOverride("example.com.", pre);
-    override.addIPOverride("example.org.", post);
-  }
-
-  setCanary("1.2.3.4");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "enable_doh",
-    "Canary should not be triggered"
-  );
-
-  setCanary("0.0.0.0");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "disable_doh",
-    "Canary should be triggered"
-  );
-  setCanary("127.0.0.1");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "disable_doh",
-    "Canary should be triggered"
-  );
-  setCanary("::1");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "disable_doh",
-    "Canary should be triggered"
-  );
-  setCanary("192.168.1.1");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "disable_doh",
-    "Canary should be triggered"
-  );
-  setCanary("10.1.1.1");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "disable_doh",
-    "Canary should be triggered"
-  );
-  setCanary("N/A");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "disable_doh",
-    "Canary should be triggered"
-  );
-
-  Services.io.offline = true;
-  setCanary("N/A");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "enable_doh",
-    "Canary should not be triggered when offline"
-  );
-
-  Services.io.offline = false;
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "disable_doh",
-    "Canary should be triggered when online"
-  );
-
-  setCanary("N/A", "N/A", "1.2.3.4");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "enable_doh",
-    "Canary should not be triggered when precondition fails"
-  );
-
-  setCanary("N/A", "1.2.3.4", "N/A");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "enable_doh",
-    "Canary should not be triggered when postcondition fails"
-  );
-
-  setCanary("N/A", "N/A", "N/A");
-  Assert.equal(
-    await DoHHeuristics.globalCanary(),
-    "enable_doh",
-    "Canary should not be triggered when pre&postcondition fails"
-  );
-
-  override.clearOverrides();
-});