feat: support ipfs://{dnslink} (#748)

* fix: redirect-based handler vs no redirect on ipfs.io

Disabling redirect does it for all subdomains.
We use gateway.ipfs.io as intermediate step when handling
`ipfs://` in firefox, which resulted in a bizzarre edge case.

This change restores `ipfs://` handler when redirect on ipfs.io is
disabled.

* feat: support ipfs://{dnslink}

This adds support for resolving DNSLink via ipfs:// protocol handler
For now it is just a redirect to proper /ipns/ path, but should improve
UX in the long run.

Closes #534

add-on/src/lib/ipfs-request.js

@@ -7,6 +7,7 @@ log.error = debug('ipfs-companion:request:error')
 
 const LRU = require('lru-cache')
 const IsIpfs = require('is-ipfs')
+const isFQDN = require('is-fqdn')
 const { pathAtHttpGateway } = require('./ipfs-path')
 const redirectOptOutHint = 'x-ipfs-companion-no-redirect'
 const recoverableErrors = new Set([
@@ -74,7 +75,7 @@ function createRequestModifier (getState, dnslinkResolver, ipfsPathValidator, ru
     const fqdn = new URL(request.url).hostname
     const parentFqdn = parentUrl && parentUrl !== 'null' && request.url !== parentUrl ? new URL(parentUrl).hostname : null
     if (state.noRedirectHostnames.some(optout =>
-      fqdn.endsWith(optout) || (parentFqdn && parentFqdn.endsWith(optout)
+      fqdn !== 'gateway.ipfs.io' && (fqdn.endsWith(optout) || (parentFqdn && parentFqdn.endsWith(optout))
       ))) {
       ignore(request.requestId)
     }
@@ -492,13 +493,24 @@ function normalizedRedirectingProtocolRequest (request, pubGwUrl) {
   path = path.replace(/^#dweb:\//i, '/') // dweb:/ipfs/Qm → /ipfs/Qm
   path = path.replace(/^#ipfs:\/\//i, '/ipfs/') // ipfs://Qm → /ipfs/Qm
   path = path.replace(/^#ipns:\/\//i, '/ipns/') // ipns://Qm → /ipns/Qm
-  // console.log(`oldPath: '${oldPath}' new: '${path}'`)
+  // additional fixups of the final path
+  path = fixupDnslinkPath(path) // /ipfs/example.com → /ipns/example.com
   if (oldPath !== path && IsIpfs.path(path)) {
     return { redirectUrl: pathAtHttpGateway(path, pubGwUrl) }
   }
   return null
 }
 
+// idempotent /ipfs/example.com → /ipns/example.com
+function fixupDnslinkPath (path) {
+  if (!(path && path.startsWith('/ipfs/'))) return path
+  const [, root] = path.match(/^\/ipfs\/([^/?#]+)/)
+  if (root && !IsIpfs.cid(root) && isFQDN(root)) {
+    return path.replace(/^\/ipfs\//, '/ipns/')
+  }
+  return path
+}
+
 // SEARCH-HIJACK HANDLERS: UNIVERSAL FALLBACK FOR UNHANDLED PROTOCOLS
 // (Used in Chrome and other browsers that do not provide better alternatives)
 // Background: https://github.com/ipfs-shipyard/ipfs-companion/issues/164#issuecomment-328374052
@@ -521,9 +533,10 @@ function unhandledIpfsPath (requestUrl) {
 }
 
 function normalizedUnhandledIpfsProtocol (request, pubGwUrl) {
-  const path = unhandledIpfsPath(request.url)
+  let path = unhandledIpfsPath(request.url)
+  path = fixupDnslinkPath(path) // /ipfs/example.com → /ipns/example.com
   if (IsIpfs.path(path)) {
-    // replace search query with fake request to the public gateway
+    // replace search query with a request to a public gateway
     // (will be redirected later, if needed)
     return { redirectUrl: pathAtHttpGateway(path, pubGwUrl) }
   }

test/functional/lib/ipfs-request-protocol-handlers.js → test/functional/lib/ipfs-request-protocol-handlers.test.js

@@ -1,6 +1,5 @@
 'use strict'
 const { describe, it, before, beforeEach, after } = require('mocha')
-// const sinon = require('sinon')
 const { expect } = require('chai')
 const { URL } = require('url')
 const browser = require('sinon-chrome')
@@ -30,6 +29,7 @@ describe('modifyRequest.onBeforeRequest:', function () {
       ipfsNodeType: 'external',
       peerCount: 1,
       redirect: true,
+      dnslinkPolicy: false, // dnslink test suite is in ipfs-request-dnslink.test.js
       catchUnhandledProtocols: true,
       gwURLString: 'http://127.0.0.1:8080',
       pubGwURLString: 'https://ipfs.io'
@@ -66,14 +66,18 @@ describe('modifyRequest.onBeforeRequest:', function () {
           const request = url2request('https://gateway.ipfs.io/ipfs/QmXQY7mKr28B964Uj4ouq3fPgkNLqzaKiajTA7surAiQuD#ipfs%3A%2F%2FQmbWqxBEKC3P8tqsKc98xmWNzrzDtRLMiMPL8wBuTGsMnR%3FargTest%23hashTest')
           expect(modifyRequest.onBeforeRequest(request).redirectUrl).to.equal('https://ipfs.io/ipfs/QmbWqxBEKC3P8tqsKc98xmWNzrzDtRLMiMPL8wBuTGsMnR?argTest#hashTest')
         })
-        it('should not be normalized if ipns:/{foo}', function () {
+        it('should not be normalized if ipns:/{fqdn}', function () {
           const request = url2request('https://gateway.ipfs.io/ipfs/QmXQY7mKr28B964Uj4ouq3fPgkNLqzaKiajTA7surAiQuD#ipns%3A%2Fipfs.io%3FargTest%23hashTest')
           expect(modifyRequest.onBeforeRequest(request)).to.equal(undefined)
         })
-        it('should be normalized if ipns://{foo}', function () {
+        it('should be normalized if ipns://{fqdn}', function () {
           const request = url2request('https://gateway.ipfs.io/ipfs/QmXQY7mKr28B964Uj4ouq3fPgkNLqzaKiajTA7surAiQuD#ipns%3A%2F%2Fipfs.io%3FargTest%23hashTest')
           expect(modifyRequest.onBeforeRequest(request).redirectUrl).to.equal('https://ipfs.io/ipns/ipfs.io?argTest#hashTest')
         })
+        it('should be normalized if ipfs://{fqdn}', function () {
+          const request = url2request('https://gateway.ipfs.io/ipfs/QmXQY7mKr28B964Uj4ouq3fPgkNLqzaKiajTA7surAiQuD#ipfs%3A%2F%2Fipfs.io%3FargTest%23hashTest')
+          expect(modifyRequest.onBeforeRequest(request).redirectUrl).to.equal('https://ipfs.io/ipns/ipfs.io?argTest#hashTest')
+        })
         it('should be normalized if dweb:/ipfs/{CID}', function () {
           const request = url2request('https://gateway.ipfs.io/ipfs/QmXQY7mKr28B964Uj4ouq3fPgkNLqzaKiajTA7surAiQuD#dweb%3A%2Fipfs/QmbWqxBEKC3P8tqsKc98xmWNzrzDtRLMiMPL8wBuTGsMnR%3FargTest%23hashTest')
           expect(modifyRequest.onBeforeRequest(request).redirectUrl).to.equal('https://ipfs.io/ipfs/QmbWqxBEKC3P8tqsKc98xmWNzrzDtRLMiMPL8wBuTGsMnR?argTest#hashTest')
@@ -151,6 +155,10 @@ describe('modifyRequest.onBeforeRequest:', function () {
           const request = url2request('https://duckduckgo.com/?q=ipns%3A%2F%2Fipns.io%2Findex.html%3Farg%3Dfoo%26bar%3Dbuzz%23hashTest')
           expect(modifyRequest.onBeforeRequest(request).redirectUrl).to.equal('https://ipfs.io/ipns/ipns.io/index.html?arg=foo&bar=buzz#hashTest')
         })
+        it('should be normalized if ipfs://{fqdn}', function () {
+          const request = url2request('https://duckduckgo.com/?q=ipfs%3A%2F%2Fipns.io%2Findex.html%3Farg%3Dfoo%26bar%3Dbuzz%23hashTest')
+          expect(modifyRequest.onBeforeRequest(request).redirectUrl).to.equal('https://ipfs.io/ipns/ipns.io/index.html?arg=foo&bar=buzz#hashTest')
+        })
         it('should be normalized if dweb:/ipfs/{CID}', function () {
           const request = url2request('https://duckduckgo.com/?q=dweb%3A%2Fipfs%2FQmbWqxBEKC3P8tqsKc98xmWNzrzDtRLMiMPL8wBuTGsMnR%3Farg%3Dfoo%26bar%3Dbuzz%23hash&ia=software')
           expect(modifyRequest.onBeforeRequest(request).redirectUrl).to.equal('https://ipfs.io/ipfs/QmbWqxBEKC3P8tqsKc98xmWNzrzDtRLMiMPL8wBuTGsMnR?arg=foo&bar=buzz#hash')