Optional support for redirect triggered by dnslink

- implements #44
- disabled by default
- still work in progress, performance is poor due to the lack
  of any dns cache

lib/api.js

@@ -3,7 +3,8 @@
 const prefs = require('sdk/simple-prefs').prefs
 
 const notifications = require('sdk/notifications')
-const Request = require('sdk/request').Request
+const {Request} = require('sdk/request')
+const {XMLHttpRequest} = require('sdk/net/xhr')
 const URL = require('sdk/url').URL
 
 function apiUrl (path) {
@@ -47,7 +48,22 @@ function getSwarmPeers (callback) {
   query('swarm/peers?stream-channels=true', callback)
 }
 
+function isDnslinkPresent (fqdn) {
+  let xhr = new XMLHttpRequest()
+  xhr.overrideMimeType('application/json')
+  xhr.open('GET', apiUrl('dns/' + fqdn), false)
+  xhr.send(null)
+  if (xhr.status === 200) {
+    let json = JSON.parse(xhr.responseText)
+    return !!json.Path
+  } else {
+    return false
+  }
+}
+
+exports.apiUrl = apiUrl
 exports.query = query
 exports.pin = pin
 exports.getVersion = getVersion
 exports.getSwarmPeers = getSwarmPeers
+exports.isDnslinkPresent = isDnslinkPresent

lib/dns.js

@@ -0,0 +1,17 @@
+'use strict'
+
+const prefs = require('sdk/simple-prefs').prefs
+// const URL = require('sdk/url').URL
+const api = require('./api.js')
+
+function isIpfsEnabled (fqdn) {
+  if (fqdn === '127.0.0.1' || fqdn === prefs.customGatewayHost) { // TODO: be smarter?
+    return false
+  }
+  // TODO: add cache
+  let ipfsSupport = api.isDnslinkPresent(fqdn)
+  // console.log('dns.isIpfsEnabled(' + fqdn + ')=' + ipfsSupport)
+  return ipfsSupport
+}
+
+exports.isIpfsEnabled = isIpfsEnabled

lib/redirects.js

@@ -1,25 +1,37 @@
 'use strict'
 
+const prefs = require('sdk/simple-prefs').prefs
 const gw = require('./gateways')
+const dns = require('./dns')
 
 const {Cc, Ci} = require('chrome')
 
 const ioservice = Cc['@mozilla.org/network/io-service;1'].getService(Ci.nsIIOService)
 const observice = Cc['@mozilla.org/observer-service;1'].getService(Ci.nsIObserverService)
 
+function redirectFor (uri) {
+  let redirectUri = null
+  if (gw.redirectEnabled) {
+    let uriSpec = uri.spec
+    if (uriSpec.match(gw.publicHosts) && uriSpec.match(gw.IPFS_RESOURCE)) {
+      // redirect IPFS paths from known public gateways
+      redirectUri = ioservice.newURI(uriSpec.replace(gw.publicHosts, gw.customUri.spec), null, null)
+    } else if (prefs.dns && dns.isIpfsEnabled(uri.host)) {
+      // redirect sites with dnslink record in DNS
+      redirectUri = ioservice.newURI(gw.customUri.spec + 'ipns/' + uri.host + uri.path + uri.ref, null, null)
+    }
+  }
+  // if (redirectUri) console.log('redirectFor(' + uri.spec + ')=' + redirectUri.spec)
+  return redirectUri
+}
+
 const ipfsRequestObserver = {
   observe: function (subject, topic, data) { // eslint-disable-line no-unused-vars
     if (topic === 'http-on-modify-request') {
       let channel = subject.QueryInterface(Ci.nsIHttpChannel)
-      let httpUrl = channel.URI.spec
-      if (httpUrl.match(gw.publicHosts) && httpUrl.match(gw.IPFS_RESOURCE)) {
-        channel.setRequestHeader('x-ipfs-firefox-addon', 'true', false)
-        if (gw.redirectEnabled) {
-          // console.info('Detected HTTP request to the public gateway: ' + channel.URI.spec)
-          let uri = ioservice.newURI(httpUrl.replace(gw.publicHosts, gw.customUri.spec), null, null)
-          // console.info('Redirecting to custom gateway: ' + uri.spec)
-          channel.redirectTo(uri)
-        }
+      let redirect = redirectFor(channel.URI)
+      if (redirect) {
+        channel.redirectTo(redirect)
       }
     }
   },

locale/en-US.properties

@@ -23,6 +23,9 @@ automatic_up_notification_text=Redirection of IPFS requests is enabled
 automatic_down_notification_title=IPFS is Down
 automatic_down_notification_text=Redirection of IPFS requests is disabled
 
+dns_title=Enable DNS Lookup
+dns_description=(EXPERIMENTAL) Check if domain contains DNS TXT record with dnslink to IPFS path and redirect to it
+
 linkify_title=Extended IPFS Link Support
 linkify_description=(EXPERIMENTAL) Rewrite links to /ip(f|n)s/* paths on every page to point to IPFS gateway. Make plaintext IPFS links clickable.
 

locale/pl-PL.properties

@@ -23,6 +23,9 @@ automatic_up_notification_text=Włączono przekierowanie
 automatic_down_notification_title=IPFS jest niedostępne
 automatic_down_notification_text=Wyłączono przekierowanie
 
+dns_title=Odpytywanie DNS
+dns_description=(EKSPERYMENT) Sprawdza, czy domena posiada wpis TXT w DNS z dnslink do zasobu IPFS i przekierowuje jeśli jest obecny
+
 linkify_title=Rozszerzone wsparcie linków IPFS
 linkify_description=(EKSPERYMENT) Przepisuje linki do zasobów /ip(f|n)s/* na każdej stronie tak, aby wskazywały na Bramę. Dodatkowo sprawia, że czysto-tekstowe adresy IPFS są klikalne.
 

package.json

@@ -50,6 +50,12 @@
       "type": "integer",
       "value": 5001
     },
+    {
+      "name": "dns",
+      "title": "Enable DNS Lookup",
+      "type": "bool",
+      "value": false
+    },
     {
       "name": "linkify",
       "title": "Extended IPFS Link Support",