feat: support h2c over unix domain sockets

docs/docs/api/Client.md

@@ -30,6 +30,7 @@ Returns: `Client`
 * **autoSelectFamily**: `boolean` (optional) - Default: depends on local Node version, on Node 18.13.0 and above is `false`. Enables a family autodetection algorithm that loosely implements section 5 of [RFC 8305](https://tools.ietf.org/html/rfc8305#section-5). See [here](https://nodejs.org/api/net.html#socketconnectoptions-connectlistener) for more details. This option is ignored if not supported by the current Node version.
 * **autoSelectFamilyAttemptTimeout**: `number` - Default: depends on local Node version, on Node 18.13.0 and above is `250`. The amount of time in milliseconds to wait for a connection attempt to finish before trying the next address when using the `autoSelectFamily` option. See [here](https://nodejs.org/api/net.html#socketconnectoptions-connectlistener) for more details.
 * **allowH2**: `boolean` - Default: `false`. Enables support for H2 if the server has assigned bigger priority to it through ALPN negotiation.
+* **useH2c**: `boolean` - Default: `false`. Enforces h2c for non-https connections.
 * **maxConcurrentStreams**: `number` - Default: `100`. Dictates the maximum number of concurrent streams for a single H2 session. It can be overridden by a SETTINGS remote frame.
 
 > **Notes about HTTP/2**

lib/core/connect.js

@@ -43,7 +43,7 @@ const SessionCache = class WeakSessionCache {
   }
 }
 
-function buildConnector ({ allowH2, maxCachedSessions, socketPath, timeout, session: customSession, ...opts }) {
+function buildConnector ({ allowH2, useH2c, maxCachedSessions, socketPath, timeout, session: customSession, ...opts }) {
   if (maxCachedSessions != null && (!Number.isInteger(maxCachedSessions) || maxCachedSessions < 0)) {
     throw new InvalidArgumentError('maxCachedSessions must be a positive integer or zero')
   }
@@ -96,6 +96,9 @@ function buildConnector ({ allowH2, maxCachedSessions, socketPath, timeout, sess
         port,
         host: hostname
       })
+      if (useH2c === true) {
+        socket.alpnProtocol = 'h2'
+      }
     }
 
     // Set TCP keep alive options on the socket here instead of in connect() for the case of assigning the socket

lib/dispatcher/client.js

@@ -107,7 +107,8 @@ class Client extends DispatcherBase {
     autoSelectFamilyAttemptTimeout,
     // h2
     maxConcurrentStreams,
-    allowH2
+    allowH2,
+    useH2c
   } = {}) {
     if (keepAlive !== undefined) {
       throw new InvalidArgumentError('unsupported keepAlive, use pipelining=0 instead')
@@ -199,13 +200,18 @@ class Client extends DispatcherBase {
       throw new InvalidArgumentError('maxConcurrentStreams must be a positive integer, greater than 0')
     }
 
+    if (useH2c != null && typeof useH2c !== 'boolean') {
+      throw new InvalidArgumentError('useH2c must be a valid boolean value')
+    }
+
     super()
 
     if (typeof connect !== 'function') {
       connect = buildConnector({
         ...tls,
         maxCachedSessions,
         allowH2,
+        useH2c,
         socketPath,
         timeout: connectTimeout,
         ...(typeof autoSelectFamily === 'boolean' ? { autoSelectFamily, autoSelectFamilyAttemptTimeout } : undefined),

lib/dispatcher/h2c-client.js

@@ -1,16 +1,9 @@
 'use strict'
-const { connect } = require('node:net')
 
-const { kClose, kDestroy } = require('../core/symbols')
 const { InvalidArgumentError } = require('../core/errors')
-const util = require('../core/util')
-
 const Client = require('./client')
-const DispatcherBase = require('./dispatcher-base')
-
-class H2CClient extends DispatcherBase {
-  #client = null
 
+class H2CClient extends Client {
   constructor (origin, clientOpts) {
     if (typeof origin === 'string') {
       origin = new URL(origin)
@@ -23,14 +16,14 @@ class H2CClient extends DispatcherBase {
     }
 
     const { connect, maxConcurrentStreams, pipelining, ...opts } =
-      clientOpts ?? {}
+            clientOpts ?? {}
     let defaultMaxConcurrentStreams = 100
     let defaultPipelining = 100
 
     if (
       maxConcurrentStreams != null &&
-      Number.isInteger(maxConcurrentStreams) &&
-      maxConcurrentStreams > 0
+            Number.isInteger(maxConcurrentStreams) &&
+            maxConcurrentStreams > 0
     ) {
       defaultMaxConcurrentStreams = maxConcurrentStreams
     }
@@ -45,76 +38,14 @@ class H2CClient extends DispatcherBase {
       )
     }
 
-    super()
-
-    this.#client = new Client(origin, {
+    super(origin, {
       ...opts,
-      connect: this.#buildConnector(connect),
       maxConcurrentStreams: defaultMaxConcurrentStreams,
       pipelining: defaultPipelining,
-      allowH2: true
+      allowH2: true,
+      useH2c: true
     })
   }
-
-  #buildConnector (connectOpts) {
-    return (opts, callback) => {
-      const timeout = connectOpts?.connectOpts ?? 10e3
-      const { hostname, port, pathname } = opts
-      const socket = connect({
-        ...opts,
-        host: hostname,
-        port,
-        pathname
-      })
-
-      // Set TCP keep alive options on the socket here instead of in connect() for the case of assigning the socket
-      if (opts.keepAlive == null || opts.keepAlive) {
-        const keepAliveInitialDelay =
-          opts.keepAliveInitialDelay == null ? 60e3 : opts.keepAliveInitialDelay
-        socket.setKeepAlive(true, keepAliveInitialDelay)
-      }
-
-      socket.alpnProtocol = 'h2'
-
-      const clearConnectTimeout = util.setupConnectTimeout(
-        new WeakRef(socket),
-        { timeout, hostname, port }
-      )
-
-      socket
-        .setNoDelay(true)
-        .once('connect', function () {
-          queueMicrotask(clearConnectTimeout)
-          if (callback) {
-            const cb = callback
-            callback = null
-            cb(null, this)
-          }
-        })
-        .on('error', function (err) {
-          queueMicrotask(clearConnectTimeout)
-          if (callback) {
-            const cb = callback
-            callback = null
-            cb(err)
-          }
-        })
-
-      return socket
-    }
-  }
-
-  dispatch (opts, handler) {
-    return this.#client.dispatch(opts, handler)
-  }
-
-  [kClose] () {
-    return this.#client.close()
-  }
-
-  [kDestroy] () {
-    return this.#client.destroy()
-  }
 }
 
 module.exports = H2CClient

test/h2c-client.js

@@ -7,7 +7,7 @@ const { test } = require('node:test')
 const { tspl } = require('@matteo.collina/tspl')
 const pem = require('@metcoder95/https-pem')
 
-const { H2CClient } = require('..')
+const { H2CClient, Client } = require('..')
 
 test('Should throw if no h2c origin', async t => {
   const planner = tspl(t, { plan: 1 })
@@ -103,3 +103,54 @@ test('Should reject request if not h2c supported', async t => {
     'SocketError: other side closed'
   )
 })
+
+test('Connect to h2c server over a unix domain socket', { skip: process.platform === 'win32' }, async t => {
+  const planner = tspl(t, { plan: 6 })
+  const { mkdtemp, rm } = require('node:fs/promises')
+  const { join } = require('node:path')
+  const { tmpdir } = require('node:os')
+
+  const tmpDir = await mkdtemp(join(tmpdir(), 'h2c-client-'))
+  const socketPath = join(tmpDir, 'server.sock')
+  const authority = 'localhost'
+
+  const server = createServer((req, res) => {
+    planner.equal(req.headers[':authority'], authority)
+    planner.equal(req.headers[':method'], 'GET')
+    planner.equal(req.headers[':path'], '/')
+    planner.equal(req.headers[':scheme'], 'http')
+    res.writeHead(200)
+    res.end('Hello, world!')
+  })
+
+  server.listen(socketPath)
+  await once(server, 'listening')
+  const client = new H2CClient(`http://${authority}/`, {
+    socketPath
+  })
+
+  const response = await client.request({ path: '/', method: 'GET' })
+  planner.equal(response.statusCode, 200)
+  planner.equal(await response.body.text(), 'Hello, world!')
+
+  t.after(async () => {
+    await rm(tmpDir, { recursive: true })
+    client.close()
+    server.close()
+  })
+})
+
+test('Should throw if bad useH2c has been passed', async t => {
+  t = tspl(t, { plan: 1 })
+
+  t.throws(() => {
+    // eslint-disable-next-line
+    new Client('https://localhost:1000', {
+      useH2c: 'true'
+    })
+  }, {
+    message: 'useH2c must be a valid boolean value'
+  })
+
+  await t.completed
+})