1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
3 * This file is open source software, licensed to you under the terms
4 * of the Apache License, Version 2.0 (the "License"). See the NOTICE file
5 * distributed with this work for additional information regarding copyright
6 * ownership. You may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
20 * Copyright (C) 2014 Cloudius Systems, Ltd.
23 * Ceph - scalable distributed file system
25 * Copyright (C) 2015 XSky <haomai@xsky.com>
27 * Author: Haomai Wang <haomaiwang@gmail.com>
29 * This is free software; you can redistribute it and/or
30 * modify it under the terms of the GNU Lesser General Public
31 * License version 2.1, as published by the Free Software
32 * Foundation. See file COPYING.
36 #include <arpa/inet.h>
38 #include "IPChecksum.h"
40 void checksummer::sum(const char* data, size_t len) {
43 csum += uint8_t(*data++);
46 auto p64 = reinterpret_cast<const uint64_t*>(data);
48 csum += ntohq(*p64++);
51 auto p16 = reinterpret_cast<const uint16_t*>(p64);
53 csum += ntohs(*p16++);
56 auto p8 = reinterpret_cast<const uint8_t*>(p16);
64 uint16_t checksummer::get() const {
65 __int128 csum1 = (csum & 0xffffffffffffffff) + (csum >> 64);
66 uint64_t csum = (csum1 & 0xffffffffffffffff) + (csum1 >> 64);
67 csum = (csum & 0xffff) + ((csum >> 16) & 0xffff) + ((csum >> 32) & 0xffff) + (csum >> 48);
68 csum = (csum & 0xffff) + (csum >> 16);
69 csum = (csum & 0xffff) + (csum >> 16);
73 void checksummer::sum(const Packet& p) {
74 for (auto&& f : p.fragments()) {
79 uint16_t ip_checksum(const void* data, size_t len) {
81 cksum.sum(reinterpret_cast<const char*>(data), len);