diff options
Diffstat (limited to 'src/lib/asiolink/io_address.h')
| -rw-r--r-- | src/lib/asiolink/io_address.h | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/src/lib/asiolink/io_address.h b/src/lib/asiolink/io_address.h new file mode 100644 index 0000000..fb1d67b --- /dev/null +++ b/src/lib/asiolink/io_address.h @@ -0,0 +1,318 @@ +// Copyright (C) 2010-2020 Internet Systems Consortium, Inc. ("ISC") +// +// This Source Code Form is subject to the terms of the Mozilla Public +// License, v. 2.0. If a copy of the MPL was not distributed with this +// file, You can obtain one at http://mozilla.org/MPL/2.0/. + +#ifndef IO_ADDRESS_H +#define IO_ADDRESS_H 1 + +// IMPORTANT NOTE: only very few ASIO headers files can be included in +// this file. In particular, asio.hpp should never be included here. +// See the description of the namespace below. +#include <unistd.h> // for some network system calls +#include <stdint.h> // for uint32_t +#include <boost/asio/ip/address.hpp> + +#include <functional> +#include <string> +#include <vector> + +#include <exceptions/exceptions.h> + +namespace isc { +namespace asiolink { + + /// Defines length of IPv6 address (in binary format). + static constexpr size_t V6ADDRESS_LEN = 16; + + /// Defines length of IPv4 address (in binary format). + static constexpr size_t V4ADDRESS_LEN = 4; + + /// @brief Maximum size of an IPv4 address represented as a text string. 12 + /// digits plus 3 full stops (dots). + static constexpr size_t V4ADDRESS_TEXT_MAX_LEN = 15u; + + /// @brief Maximum size of an IPv6 address represented as a text string. 32 + /// hexadecimal characters written in 8 groups of four, plus 7 colon + /// separators. + static constexpr size_t V6ADDRESS_TEXT_MAX_LEN = 39u; + +/// \brief The \c IOAddress class represents an IP addresses (version +/// agnostic) +/// +/// This class is a wrapper for the ASIO \c ip::address class. +class IOAddress { +public: + /// + /// \name Constructors and Destructor + /// + /// This class is copyable. We use default versions of copy constructor + /// and the assignment operator. + /// We use the default destructor. + //@{ + /// \brief Constructor from string. + /// + /// This constructor converts a textual representation of IPv4 and IPv6 + /// addresses into an IOAddress object. + /// If \c address_str is not a valid representation of any type of + /// address, an exception of class \c IOError will be thrown. + /// This constructor allocates memory for the object, and if that fails + /// a corresponding standard exception will be thrown. + /// + /// \param address_str Textual representation of address. + IOAddress(const std::string& address_str); + + /// \brief Constructor from an ASIO \c ip::address object. + /// + /// This constructor is intended to be used within the wrapper + /// implementation; user applications of the wrapper API won't use it. + /// + /// This constructor never throws an exception. + /// + /// \param asio_address The ASIO \c ip::address to be converted. + IOAddress(const boost::asio::ip::address& asio_address); + //@} + + /// @brief Constructor for ip::address_v4 object. + /// + /// This constructor is intended to be used when constructing + /// IPv4 address out of uint32_t type. Passed value must be in + /// network byte order + /// + /// @param v4address IPv4 address represented by uint32_t + IOAddress(uint32_t v4address); + + /// \brief Convert the address to a string. + /// + /// This method is basically expected to be exception free, but + /// generating the string will involve resource allocation, + /// and if it fails the corresponding standard exception will be thrown. + /// + /// \return A string representation of the address. + std::string toText() const; + + /// \brief Returns the address family + /// + /// \return AF_INET for IPv4 or AF_INET6 for IPv6. + short getFamily() const; + + /// \brief Convenience function to check for an IPv4 address + /// + /// \return true if the address is a V4 address + bool isV4() const { + return (asio_address_.is_v4()); + } + + /// \brief Convenience function to check if it is an IPv4 zero address. + /// + /// \return true if the address is the zero IPv4 address. + bool isV4Zero() const { + return (equals(IPV4_ZERO_ADDRESS())); + } + + /// \brief Convenience function to check if it is an IPv4 broadcast + /// address. + /// + /// \return true if the address is the broadcast IPv4 address. + bool isV4Bcast() const { + return (equals(IPV4_BCAST_ADDRESS())); + } + + /// \brief Convenience function to check for an IPv6 address + /// + /// \return true if the address is a V6 address + bool isV6() const { + return (asio_address_.is_v6()); + } + + /// \brief Convenience function to check if it is an IPv4 zero address. + /// + /// \return true if the address is the zero IPv4 address. + bool isV6Zero() const { + return (equals(IPV6_ZERO_ADDRESS())); + } + + /// \brief checks whether and address is IPv6 and is link-local + /// + /// \return true if the address is IPv6 link-local, false otherwise + bool isV6LinkLocal() const; + + /// \brief checks whether and address is IPv6 and is multicast + /// + /// \return true if the address is IPv6 multicast, false otherwise + bool isV6Multicast() const; + + /// \brief Creates an address from over wire data. + /// + /// \param family AF_INET for IPv4 or AF_INET6 for IPv6. + /// \param data pointer to first char of data + /// + /// \return Created IOAddress object + static IOAddress fromBytes(short family, const uint8_t* data); + + /// \brief Return address as set of bytes + /// + /// \return Contents of the address as a set of bytes in network-byte + /// order. + std::vector<uint8_t> toBytes() const; + + /// \brief Compare addresses for equality + /// + /// \param other Address to compare against. + /// + /// \return true if addresses are equal, false if not. + bool equals(const IOAddress& other) const { + return (asio_address_ == other.asio_address_); + } + + /// \brief Compare addresses for equality + /// + /// \param other Address to compare against. + /// + /// \return true if addresses are equal, false if not. + bool operator==(const IOAddress& other) const { + return equals(other); + } + + /// \brief Compare addresses for inequality + /// + /// \param other Address to compare against. + /// + /// \return false if addresses are equal, true if not. + bool nequals(const IOAddress& other) const { + return (!equals(other)); + } + + /// \brief Checks if one address is smaller than the other + /// + /// \param other Address to compare against. + bool operator<(const IOAddress& other) const { + return (asio_address_ < other.asio_address_); + } + + /// \brief Checks if one address is smaller or equal than the other + /// + /// \param other Address to compare against. + bool operator<=(const IOAddress& other) const { + return (asio_address_ <= other.asio_address_); + } + + /// \brief Compare addresses for inequality + /// + /// \param other Address to compare against. + /// + /// \return false if addresses are equal, true if not. + bool operator!=(const IOAddress& other) const { + return (nequals(other)); + } + + /// @brief Subtracts one address from another (a - b) + /// + /// Treats addresses as integers and subtracts them. For example: + /// @code + /// 192.0.2.5 - 192.0.2.0 = 0.0.0.5 + /// fe80::abcd - fe80:: = ::abcd + /// @endcode + /// + /// It is possible to subtract greater from lesser address, e.g. + /// 192.168.56.10 - 192.168.67.20, but please do understand that + /// the address space is a finite field in mathematical sense, so + /// you may end up with a result that is greater then any of the + /// addresses you specified. Also, subtraction is not commutative, + /// so a - b != b - a. + /// + /// This operation is essential for calculating the number of + /// leases in a pool, where we need to calculate (max - min). + /// @throw BadValue if addresses are of different family + /// @param a address to be subtracted from + /// @param b address to be subtracted + /// @return IOAddress object that represents the difference + static IOAddress subtract(const IOAddress& a, const IOAddress& b); + + /// @brief Returns an address increased by one + /// + /// This method works for both IPv4 and IPv6 addresses. For example, + /// increase 192.0.2.255 will become 192.0.3.0. + /// + /// Address space is a finite field in the mathematical sense, so keep + /// in mind that the address space "loops". 255.255.255.255 increased + /// by one gives 0.0.0.0. The same is true for maximum value of IPv6 + /// (all 1's) looping to ::. + /// + /// @todo Determine if we have a use-case for increasing the address + /// by more than one. Increase by one is used in AllocEngine. This method + /// could take extra parameter that specifies the value by which the + /// address should be increased. + /// + /// @param addr address to be increased + /// @return address increased by one + static IOAddress + increase(const IOAddress& addr); + + /// \brief Converts IPv4 address to uint32_t + /// + /// Will throw BadValue exception if that is not IPv4 + /// address. + /// + /// \return uint32_t that represents IPv4 address in + /// network byte order + uint32_t toUint32() const; + + /// @name Methods returning @c IOAddress objects encapsulating typical addresses. + /// + //@{ + /// @brief Returns an address set to all zeros. + static const IOAddress& IPV4_ZERO_ADDRESS() { + static IOAddress address(0); + return (address); + } + + /// @brief Returns a "255.255.255.255" broadcast address. + static const IOAddress& IPV4_BCAST_ADDRESS() { + static IOAddress address(0xFFFFFFFF); + return (address); + } + + /// @brief Returns an IPv6 zero address. + static const IOAddress& IPV6_ZERO_ADDRESS() { + static IOAddress address("::"); + return (address); + } + + //@} + +private: + boost::asio::ip::address asio_address_; +}; + +/// \brief Insert the IOAddress as a string into stream. +/// +/// This method converts the \c address into a string and inserts it +/// into the output stream \c os. +/// +/// This function overloads the global operator<< to behave as described +/// in ostream::operator<< but applied to \c IOAddress objects. +/// +/// \param os A \c std::ostream object on which the insertion operation is +/// performed. +/// \param address The \c IOAddress object output by the operation. +/// \return A reference to the same \c std::ostream object referenced by +/// parameter \c os after the insertion operation. +std::ostream& +operator<<(std::ostream& os, const IOAddress& address); + +/// \brief Hash the IOAddress. +/// +/// This method allows boost multi-index hashed indexes on IOAddresses. +/// It follows the requirement with equality: if two addresses are equal +/// their hashes are equal, if two addresses are not equal their hashes +/// are almost surely not equal. +/// +/// \param address A \c IOAddress to hash. +/// \return The hash of the IOAddress. +size_t hash_value(const IOAddress& address); + +} // namespace asiolink +} // namespace isc +#endif // IO_ADDRESS_H |