blob: 64bf1c775fea634ade26e6bcae42af1d3ff717d8 [file] [log] [blame]
// Copyright (c) 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "quiche/quic/core/internet_checksum.h"
#include <stdint.h>
#include <string.h>
#include "absl/strings/string_view.h"
#include "absl/types/span.h"
namespace quic {
void InternetChecksum::Update(const char* data, size_t size) {
const char* current;
for (current = data; current + 1 < data + size; current += 2) {
uint16_t v;
memcpy(&v, current, sizeof(v));
accumulator_ += v;
}
if (current < data + size) {
accumulator_ += *reinterpret_cast<const unsigned char*>(current);
}
}
void InternetChecksum::Update(const uint8_t* data, size_t size) {
Update(reinterpret_cast<const char*>(data), size);
}
void InternetChecksum::Update(absl::string_view data) {
Update(data.data(), data.size());
}
void InternetChecksum::Update(absl::Span<const uint8_t> data) {
Update(reinterpret_cast<const char*>(data.data()), data.size());
}
uint16_t InternetChecksum::Value() const {
uint32_t total = accumulator_;
while (total & 0xffff0000u) {
total = (total >> 16u) + (total & 0xffffu);
}
return ~static_cast<uint16_t>(total);
}
} // namespace quic