http: add uniqueHeaders option to request and createServer

PR-URL: https://github.com/nodejs/node/pull/41397
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

4 files changed, 140 insertions, 8 deletions

diff --git a/lib/_http_client.js b/lib/_http_client.js
index a4f7a255a99..41f183aa524 100644
--- a/lib/_http_client.js
+++ b/lib/_http_client.js
@@ -52,7 +52,11 @@ const {
   isLenient,
   prepareError,
 } = require('_http_common');
-const { OutgoingMessage } = require('_http_outgoing');
+const {
+  kUniqueHeaders,
+  parseUniqueHeadersOption,
+  OutgoingMessage
+} = require('_http_outgoing');
 const Agent = require('_http_agent');
 const { Buffer } = require('buffer');
 const { defaultTriggerAsyncIdScope } = require('internal/async_hooks');
@@ -300,6 +304,8 @@ function ClientRequest(input, options, cb) {
                       options.headers);
   }
 
+  this[kUniqueHeaders] = parseUniqueHeadersOption(options.uniqueHeaders);
+
   let optsWithoutSignal = options;
   if (optsWithoutSignal.signal) {
     optsWithoutSignal = ObjectAssign({}, options);
diff --git a/lib/_http_incoming.js b/lib/_http_incoming.js
index 34de1c559c1..f1e6b7f54ff 100644
--- a/lib/_http_incoming.js
+++ b/lib/_http_incoming.js
@@ -33,8 +33,10 @@ const {
 const { Readable, finished } = require('stream');
 
 const kHeaders = Symbol('kHeaders');
+const kHeadersDistinct = Symbol('kHeadersDistinct');
 const kHeadersCount = Symbol('kHeadersCount');
 const kTrailers = Symbol('kTrailers');
+const kTrailersDistinct = Symbol('kTrailersDistinct');
 const kTrailersCount = Symbol('kTrailersCount');
 
 function readStart(socket) {
@@ -123,6 +125,25 @@ ObjectDefineProperty(IncomingMessage.prototype, 'headers', {
   }
 });
 
+ObjectDefineProperty(IncomingMessage.prototype, 'headersDistinct', {
+  get: function() {
+    if (!this[kHeadersDistinct]) {
+      this[kHeadersDistinct] = {};
+
+      const src = this.rawHeaders;
+      const dst = this[kHeadersDistinct];
+
+      for (let n = 0; n < this[kHeadersCount]; n += 2) {
+        this._addHeaderLineDistinct(src[n + 0], src[n + 1], dst);
+      }
+    }
+    return this[kHeadersDistinct];
+  },
+  set: function(val) {
+    this[kHeadersDistinct] = val;
+  }
+});
+
 ObjectDefineProperty(IncomingMessage.prototype, 'trailers', {
   get: function() {
     if (!this[kTrailers]) {
@@ -142,6 +163,25 @@ ObjectDefineProperty(IncomingMessage.prototype, 'trailers', {
   }
 });
 
+ObjectDefineProperty(IncomingMessage.prototype, 'trailersDistinct', {
+  get: function() {
+    if (!this[kTrailersDistinct]) {
+      this[kTrailersDistinct] = {};
+
+      const src = this.rawTrailers;
+      const dst = this[kTrailersDistinct];
+
+      for (let n = 0; n < this[kTrailersCount]; n += 2) {
+        this._addHeaderLineDistinct(src[n + 0], src[n + 1], dst);
+      }
+    }
+    return this[kTrailersDistinct];
+  },
+  set: function(val) {
+    this[kTrailersDistinct] = val;
+  }
+});
+
 IncomingMessage.prototype.setTimeout = function setTimeout(msecs, callback) {
   if (callback)
     this.on('timeout', callback);
@@ -361,6 +401,16 @@ function _addHeaderLine(field, value, dest) {
   }
 }
 
+IncomingMessage.prototype._addHeaderLineDistinct = _addHeaderLineDistinct;
+function _addHeaderLineDistinct(field, value, dest) {
+  field = StringPrototypeToLowerCase(field);
+  if (!dest[field]) {
+    dest[field] = [value];
+  } else {
+    dest[field].push(value);
+  }
+}
+
 
 // Call this instead of resume() if we want to just
 // dump all the data to /dev/null
diff --git a/lib/_http_outgoing.js b/lib/_http_outgoing.js
index 71f6e3e7237..8b2d24bbf69 100644
--- a/lib/_http_outgoing.js
+++ b/lib/_http_outgoing.js
@@ -34,6 +34,7 @@ const {
   ObjectPrototypeHasOwnProperty,
   ObjectSetPrototypeOf,
   RegExpPrototypeTest,
+  SafeSet,
   StringPrototypeToLowerCase,
   Symbol,
 } = primordials;
@@ -82,6 +83,7 @@ let debug = require('internal/util/debuglog').debuglog('http', (fn) => {
 const HIGH_WATER_MARK = getDefaultHighWaterMark();
 
 const kCorked = Symbol('corked');
+const kUniqueHeaders = Symbol('kUniqueHeaders');
 
 const nop = () => {};
 
@@ -502,7 +504,10 @@ function processHeader(self, state, key, value, validate) {
   if (validate)
     validateHeaderName(key);
   if (ArrayIsArray(value)) {
-    if (value.length < 2 || !isCookieField(key)) {
+    if (
+      (value.length < 2 || !isCookieField(key)) &&
+      (!self[kUniqueHeaders] || !self[kUniqueHeaders].has(StringPrototypeToLowerCase(key)))
+    ) {
       // Retain for(;;) loop for performance reasons
       // Refs: https://github.com/nodejs/node/pull/30958
       for (let i = 0; i < value.length; i++)
@@ -571,6 +576,20 @@ const validateHeaderValue = hideStackFrames((name, value) => {
   }
 });
 
+function parseUniqueHeadersOption(headers) {
+  if (!ArrayIsArray(headers)) {
+    return null;
+  }
+
+  const unique = new SafeSet();
+  const l = headers.length;
+  for (let i = 0; i < l; i++) {
+    unique.add(StringPrototypeToLowerCase(headers[i]));
+  }
+
+  return unique;
+}
+
 OutgoingMessage.prototype.setHeader = function setHeader(name, value) {
   if (this._header) {
     throw new ERR_HTTP_HEADERS_SENT('set');
@@ -586,6 +605,36 @@ OutgoingMessage.prototype.setHeader = function setHeader(name, value) {
   return this;
 };
 
+OutgoingMessage.prototype.appendHeader = function appendHeader(name, value) {
+  if (this._header) {
+    throw new ERR_HTTP_HEADERS_SENT('append');
+  }
+  validateHeaderName(name);
+  validateHeaderValue(name, value);
+
+  const field = StringPrototypeToLowerCase(name);
+  const headers = this[kOutHeaders];
+  if (headers === null || !headers[field]) {
+    return this.setHeader(name, value);
+  }
+
+  // Prepare the field for appending, if required
+  if (!ArrayIsArray(headers[field][1])) {
+    headers[field][1] = [headers[field][1]];
+  }
+
+  const existingValues = headers[field][1];
+  if (ArrayIsArray(value)) {
+    for (let i = 0, length = value.length; i < length; i++) {
+      existingValues.push(value[i]);
+    }
+  } else {
+    existingValues.push(value);
+  }
+
+  return this;
+};
+
 
 OutgoingMessage.prototype.getHeader = function getHeader(name) {
   validateString(name, 'name');
@@ -797,7 +846,6 @@ function connectionCorkNT(conn) {
   conn.uncork();
 }
 
-
 OutgoingMessage.prototype.addTrailers = function addTrailers(headers) {
   this._trailer = '';
   const keys = ObjectKeys(headers);
@@ -817,11 +865,31 @@ OutgoingMessage.prototype.addTrailers = function addTrailers(headers) {
     if (typeof field !== 'string' || !field || !checkIsHttpToken(field)) {
       throw new ERR_INVALID_HTTP_TOKEN('Trailer name', field);
     }
-    if (checkInvalidHeaderChar(value)) {
-      debug('Trailer "%s" contains invalid characters', field);
-      throw new ERR_INVALID_CHAR('trailer content', field);
+
+    // Check if the field must be sent several times
+    const isArrayValue = ArrayIsArray(value);
+    if (
+      isArrayValue && value.length > 1 &&
+      (!this[kUniqueHeaders] || !this[kUniqueHeaders].has(StringPrototypeToLowerCase(field)))
+    ) {
+      for (let j = 0, l = value.length; j < l; j++) {
+        if (checkInvalidHeaderChar(value[j])) {
+          debug('Trailer "%s"[%d] contains invalid characters', field, j);
+          throw new ERR_INVALID_CHAR('trailer content', field);
+        }
+        this._trailer += field + ': ' + value[j] + '\r\n';
+      }
+    } else {
+      if (isArrayValue) {
+        value = ArrayPrototypeJoin(value, '; ');
+      }
+
+      if (checkInvalidHeaderChar(value)) {
+        debug('Trailer "%s" contains invalid characters', field);
+        throw new ERR_INVALID_CHAR('trailer content', field);
+      }
+      this._trailer += field + ': ' + value + '\r\n';
     }
-    this._trailer += field + ': ' + value + '\r\n';
   }
 };
 
@@ -997,6 +1065,8 @@ function(err, event) {
 };
 
 module.exports = {
+  kUniqueHeaders,
+  parseUniqueHeadersOption,
   validateHeaderName,
   validateHeaderValue,
   OutgoingMessage
diff --git a/lib/_http_server.js b/lib/_http_server.js
index c8dc22929bf..615ee4c670c 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -47,7 +47,11 @@ const {
   prepareError,
 } = require('_http_common');
 const { ConnectionsList } = internalBinding('http_parser');
-const { OutgoingMessage } = require('_http_outgoing');
+const {
+  kUniqueHeaders,
+  parseUniqueHeadersOption,
+  OutgoingMessage
+} = require('_http_outgoing');
 const {
   kOutHeaders,
   kNeedDrain,
@@ -450,6 +454,7 @@ function Server(options, requestListener) {
   this.maxHeadersCount = null;
   this.maxRequestsPerSocket = 0;
   setupConnectionsTracking(this);
+  this[kUniqueHeaders] = parseUniqueHeadersOption(options.uniqueHeaders);
 }
 ObjectSetPrototypeOf(Server.prototype, net.Server.prototype);
 ObjectSetPrototypeOf(Server, net.Server);
@@ -916,6 +921,7 @@ function parserOnIncoming(server, socket, state, req, keepAlive) {
                                                socket, state);
 
   res.shouldKeepAlive = keepAlive;
+  res[kUniqueHeaders] = server[kUniqueHeaders];
   DTRACE_HTTP_SERVER_REQUEST(req, socket);
 
   if (onRequestStartChannel.hasSubscribers) {