src/net_util.h

// Copyright (c) 2011 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.

#ifndef NET_BASE_NET_UTIL_H_
#define NET_BASE_NET_UTIL_H_
#pragma once

#if defined(OS_WIN)
#include <windows.h>
#include <ws2tcpip.h>
#elif defined(OS_POSIX)
#include <sys/socket.h>
#endif

#include <list>
#include <string>
#include <set>
#include <vector>

#include <cstdint>

namespace net {

// IPAddressNumber is used to represent an IP address's numeric value as an
// array of bytes, from most significant to least significant. This is the
// network byte ordering.
//
// IPv4 addresses will have length 4, whereas IPv6 address will have length 16.
typedef std::vector<unsigned char> IPAddressNumber;
typedef std::vector<IPAddressNumber> IPAddressList;

// Parses an IP address literal (either IPv4 or IPv6) to its numeric value.
// Returns true on success and fills |ip_number| with the numeric value.
bool ParseIPLiteralToNumber(const std::string& ip_literal,
                            IPAddressNumber* ip_number);

// Parses an IP block specifier from CIDR notation to an
// (IP address, prefix length) pair. Returns true on success and fills
// |*ip_number| with the numeric value of the IP address and sets
// |*prefix_length_in_bits| with the length of the prefix.
//
// CIDR notation literals can use either IPv4 or IPv6 literals. Some examples:
//
//    10.10.3.1/20
//    a:b:c::/46
//    ::1/128
bool ParseCIDRBlock(const std::string& cidr_literal,
                    IPAddressNumber* ip_number,
                    size_t* prefix_length_in_bits);

// Compares an IP address to see if it falls within the specified IP block.
// Returns true if it does, false otherwise.
//
// The IP block is given by (|ip_prefix|, |prefix_length_in_bits|) -- any
// IP address whose |prefix_length_in_bits| most significant bits match
// |ip_prefix| will be matched.
//
// In cases when an IPv4 address is being compared to an IPv6 address prefix
// and vice versa, the IPv4 addresses will be converted to IPv4-mapped
// (IPv6) addresses.
bool IPNumberMatchesPrefix(const IPAddressNumber& ip_number,
                           const IPAddressNumber& ip_prefix,
                           size_t prefix_length_in_bits);

}  // namespace net

#endif  // NET_BASE_NET_UTIL_H_