http2: add support for raw header arrays in h2Stream.respond()

Author: pimterry

doc/api/http2.md

@@ -1863,7 +1863,7 @@ changes:
     description: Allow explicitly setting date headers.
 -->
 
-* `headers` {HTTP/2 Headers Object}
+* `headers` {HTTP/2 Headers Object|Array}
 * `options` {Object}
   * `endStream` {boolean} Set to `true` to indicate that the response will not
     include payload data.

lib/internal/http2/core.js

@@ -2541,7 +2541,30 @@ function callStreamClose(stream) {
   stream.close();
 }
 
-function processHeaders(oldHeaders, options) {
+function prepareResponseHeaders(stream, headersParam, options) {
+  let headers;
+  let statusCode;
+
+  if (ArrayIsArray(headersParam)) {
+    ({
+      headers,
+      statusCode,
+    } = prepareResponseHeadersArray(headersParam, options));
+    stream[kRawHeaders] = headers;
+  } else {
+    ({
+      headers,
+      statusCode,
+    } = prepareResponseHeadersObject(headersParam, options));
+    stream[kSentHeaders] = headers;
+  }
+
+  const headersList = buildNgHeaderString(headers, assertValidPseudoHeaderResponse);
+
+  return { headers, headersList, statusCode };
+}
+
+function prepareResponseHeadersObject(oldHeaders, options) {
   assertIsObject(oldHeaders, 'headers');
   const headers = { __proto__: null };
 
@@ -2576,9 +2599,51 @@ function processHeaders(oldHeaders, options) {
   if (neverIndex !== undefined && !ArrayIsArray(neverIndex))
     throw new ERR_INVALID_ARG_VALUE('headers[http2.neverIndex]', neverIndex);
 
-  return headers;
+  return {
+    headers,
+    statusCode: headers[HTTP2_HEADER_STATUS],
+  };
 }
 
+function prepareResponseHeadersArray(headers, options) {
+  let statusCode;
+  let isDateSet = false;
+
+  for (let i = 0; i < headers.length; i += 2) {
+    const header = headers[i].toLowerCase();
+    const value = headers[i + 1];
+
+    if (header === HTTP2_HEADER_STATUS) {
+      statusCode = value | 0;
+    } else if (header === HTTP2_HEADER_DATE) {
+      isDateSet = true;
+    }
+  }
+
+  if (!statusCode) {
+    statusCode = HTTP_STATUS_OK;
+    headers.unshift(HTTP2_HEADER_STATUS, statusCode);
+  }
+
+  if (!isDateSet && (options.sendDate == null || options.sendDate)) {
+    headers.push(HTTP2_HEADER_DATE, utcDate());
+  }
+
+  // This is intentionally stricter than the HTTP/1 implementation, which
+  // allows values between 100 and 999 (inclusive) in order to allow for
+  // backwards compatibility with non-spec compliant code. With HTTP/2,
+  // we have the opportunity to start fresh with stricter spec compliance.
+  // This will have an impact on the compatibility layer for anyone using
+  // non-standard, non-compliant status codes.
+  if (statusCode < 200 || statusCode > 599)
+    throw new ERR_HTTP2_STATUS_INVALID(statusCode);
+
+  const neverIndex = headers[kSensitiveHeaders];
+  if (neverIndex !== undefined && !ArrayIsArray(neverIndex))
+    throw new ERR_INVALID_ARG_VALUE('headers[http2.neverIndex]', neverIndex);
+
+  return { headers, statusCode };
+}
 
 function onFileUnpipe() {
   const stream = this.sink[kOwner];
@@ -2882,7 +2947,7 @@ class ServerHttp2Stream extends Http2Stream {
   }
 
   // Initiate a response on this Http2Stream
-  respond(headers, options) {
+  respond(headersParam, options) {
     if (this.destroyed || this.closed)
       throw new ERR_HTTP2_INVALID_STREAM();
     if (this.headersSent)
@@ -2907,15 +2972,16 @@ class ServerHttp2Stream extends Http2Stream {
       state.flags |= STREAM_FLAGS_HAS_TRAILERS;
     }
 
-    headers = processHeaders(headers, options);
-    const headersList = buildNgHeaderString(headers, assertValidPseudoHeaderResponse);
-    this[kSentHeaders] = headers;
+    const {
+      headers,
+      headersList,
+      statusCode,
+    } = prepareResponseHeaders(this, headersParam, options);
 
     state.flags |= STREAM_FLAGS_HEADERS_SENT;
 
     // Close the writable side if the endStream option is set or status
     // is one of known codes with no payload, or it's a head request
-    const statusCode = headers[HTTP2_HEADER_STATUS] | 0;
     if (!!options.endStream ||
         statusCode === HTTP_STATUS_NO_CONTENT ||
         statusCode === HTTP_STATUS_RESET_CONTENT ||
@@ -2945,7 +3011,7 @@ class ServerHttp2Stream extends Http2Stream {
   // regular file, here the fd is passed directly. If the underlying
   // mechanism is not able to read from the fd, then the stream will be
   // reset with an error code.
-  respondWithFD(fd, headers, options) {
+  respondWithFD(fd, headersParam, options) {
     if (this.destroyed || this.closed)
       throw new ERR_HTTP2_INVALID_STREAM();
     if (this.headersSent)
@@ -2982,8 +3048,11 @@ class ServerHttp2Stream extends Http2Stream {
     this[kUpdateTimer]();
     this.ownsFd = false;
 
-    headers = processHeaders(headers, options);
-    const statusCode = headers[HTTP2_HEADER_STATUS] |= 0;
+    const {
+      headers,
+      statusCode,
+    } = prepareResponseHeadersObject(headersParam, options);
+
     // Payload/DATA frames are not permitted in these cases
     if (statusCode === HTTP_STATUS_NO_CONTENT ||
         statusCode === HTTP_STATUS_RESET_CONTENT ||
@@ -3011,7 +3080,7 @@ class ServerHttp2Stream extends Http2Stream {
   // giving the user an opportunity to verify the details and set additional
   // headers. If statCheck returns false, the operation is aborted and no
   // file details are sent.
-  respondWithFile(path, headers, options) {
+  respondWithFile(path, headersParam, options) {
     if (this.destroyed || this.closed)
       throw new ERR_HTTP2_INVALID_STREAM();
     if (this.headersSent)
@@ -3042,8 +3111,11 @@ class ServerHttp2Stream extends Http2Stream {
     this[kUpdateTimer]();
     this.ownsFd = true;
 
-    headers = processHeaders(headers, options);
-    const statusCode = headers[HTTP2_HEADER_STATUS] |= 0;
+    const {
+      headers,
+      statusCode,
+    } = prepareResponseHeadersObject(headersParam, options);
+
     // Payload/DATA frames are not permitted in these cases
     if (statusCode === HTTP_STATUS_NO_CONTENT ||
         statusCode === HTTP_STATUS_RESET_CONTENT ||

lib/internal/http2/util.js

@@ -690,7 +690,6 @@ function prepareRequestHeadersArray(headers, session) {
   const headersList = buildNgHeaderString(
     rawHeaders,
     assertValidPseudoHeader,
-    headers[kSensitiveHeaders],
   );
 
   return {
@@ -755,14 +754,14 @@ const kNoHeaderFlags = StringFromCharCode(NGHTTP2_NV_FLAG_NONE);
  * @returns {[string, number]}
  */
 function buildNgHeaderString(arrayOrMap,
-                             assertValuePseudoHeader = assertValidPseudoHeader,
-                             sensitiveHeaders = arrayOrMap[kSensitiveHeaders]) {
+                             assertValuePseudoHeader = assertValidPseudoHeader) {
   let headers = '';
   let pseudoHeaders = '';
   let count = 0;
 
   const singles = new SafeSet();
-  const neverIndex = (sensitiveHeaders || emptyArray).map((v) => v.toLowerCase());
+  const sensitiveHeaders = arrayOrMap[kSensitiveHeaders] || emptyArray;
+  const neverIndex = sensitiveHeaders.map((v) => v.toLowerCase());
 
   function processHeader(key, value) {
     key = key.toLowerCase();

test/parallel/test-http2-raw-headers.js

@@ -8,19 +8,23 @@ const http2 = require('http2');
 
 {
   const server = http2.createServer();
-  server.on('stream', common.mustCall((stream, headers, flags, rawHeaders) => {
+  server.on('stream', common.mustCall((stream, _headers, _flags, rawHeaders) => {
     assert.deepStrictEqual(rawHeaders, [
       ':path', '/foobar',
       ':scheme', 'http',
       ':authority', `localhost:${server.address().port}`,
       ':method', 'GET',
       'a', 'b',
-      'x-foo', 'bar',
-      'a', 'c',
+      'x-foo', 'bar', // Lowercased as required for HTTP/2
+      'a', 'c', // Duplicate header order preserved
+    ]);
+    stream.respond([
+      ':status', '200',
+      'x', '1',
+      'x-FOO', 'bar',
+      'x', '2',
+      'DATE', '0000'
     ]);
-    stream.respond({
-      ':status': 200
-    });
     stream.end();
   }));
 
@@ -49,8 +53,14 @@ const http2 = require('http2');
       'x-FOO': 'bar',
     });
 
-    req.on('response', common.mustCall((headers) => {
-      assert.strictEqual(headers[':status'], 200);
+    req.on('response', common.mustCall((_headers, _flags, rawHeaders) => {
+      assert.deepStrictEqual(rawHeaders, [
+        ':status', '200',
+        'x', '1',
+        'x-foo', 'bar', // Lowercased as required for HTTP/2
+        'x', '2', // Duplicate header order preserved
+        'date', '0000' // Server doesn't automatically set its own value
+      ]);
       client.close();
       server.close();
     }));