HttpHeaderValidationUtil.java — netty Source File

Source Code

/*
 * Copyright 2022 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.http;

import io.netty.util.AsciiString;

import static io.netty.util.AsciiString.contentEqualsIgnoreCase;

/**
 * Functions used to perform various validations of HTTP header names and values.
 */
public final class HttpHeaderValidationUtil {
    private HttpHeaderValidationUtil() {
    }

    /**
     * Check if a header name is "connection related".
     * <p>
     * The <a href="https://datatracker.ietf.org/doc/html/rfc9110#section-7.6.1">RFC9110</a> only specify an incomplete
     * list of the following headers:
     *
     * <ul>
     *     <li><tt>Connection</tt></li>
     *     <li><tt>Proxy-Connection</tt></li>
     *     <li><tt>Keep-Alive</tt></li>
     *     <li><tt>TE</tt></li>
     *     <li><tt>Transfer-Encoding</tt></li>
     *     <li><tt>Upgrade</tt></li>
     * </ul>
     *
     * @param name the name of the header to check. The check is case-insensitive.
     * @param ignoreTeHeader {@code true} if the <tt>TE</tt> header should be ignored by this check.
     * This is relevant for HTTP/2 header validation, where the <tt>TE</tt> header has special rules.
     * @return {@code true} if the given header name is one of the specified connection-related headers.
     */
    @SuppressWarnings("deprecation") // We need to check for deprecated headers as well.
    public static boolean isConnectionHeader(CharSequence name, boolean ignoreTeHeader) {
        // These are the known standard and non-standard connection related headers:
        // - upgrade (7 chars)
        // - connection (10 chars)
        // - keep-alive (10 chars)
        // - proxy-connection (16 chars)
        // - transfer-encoding (17 chars)
        //
        // See https://datatracker.ietf.org/doc/html/rfc9113#section-8.2.2
        // and https://datatracker.ietf.org/doc/html/rfc9110#section-7.6.1
        // for the list of connection related headers.
// ... (122 more lines)