boost库之dns解析模块源码

// // dns.hpp // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 1998-2008 Andreas Haberstroh (andreas at ibusy dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #ifndef BOOST_NET_DNS_HPP #define BOOST_NET_DNS_HPP #include <boost/asio/detail/push_options.hpp> #include <vector> #include <string> #include <boost/asio.hpp> #include <boost/net/network_array.hpp> #include <boost/net/rfc1035_414.hpp> using namespace std; using namespace boost; using namespace boost::algorithm; namespace boost { namespace net { namespace dns { // quick forward declarations class message; class request_base_t; class resource_base_t; //! Shared Resource Base Pointer typedef shared_ptr<resource_base_t> shared_resource_base_t; //! A list of resource records typedef std::vector<shared_resource_base_t> rr_list_t; //! A shared list of resource records typedef shared_ptr<rr_list_t> shared_rr_list_t; //! Shared Request Base Pointer typedef shared_ptr<request_base_t> shared_request_base_t; //! Class identification for resource records. Included is the QCLASS that is in the 0xF0 range. typedef enum { class_none = 0x00, //!< No class definition class_in, //!< Internet class. Default class class_cs, //!< CSNET class, obsolete, used for examples. class_ch, //!< CHAOS class class_hs, //!< Hesiod [Dyer 87] class_all = 0xff //!< Query all classes } class_t; //! Type identification for resource records. Included are the QTYPE's that are in the 0xF0 range typedef enum { type_none = 0x00, //!< No type definition. type_a = 0x01, //!< Address type type_ns = 0x02, //!< Name Server type type_cname = 0x05, //!< Canonical name type type_soa = 0x06, //!< Start of Authority type type_ptr = 0x0c, //!< Pointer type type_hinfo = 0x0d, //!< Host Information type type_mx = 0x0f, //!< Mail Exchanger type type_txt = 0x10, //!< Text type type_a6 = 0x1c, //!< Address (IP6) type type_srv = 0x21, //!< Service type type_ax = 0x68, //!< AX type zengfh 2012.4.15 type_cnamex= 0x69, //!< CNAMEX type zengfh 2012.4.15 type_tsig = 0xfa, //!< tsig type zengfh 2011.12.29 type_axfr = 0xfc, //!< Zone transfer type type_all = 0xff //!< Query all types } type_t; /*! Basic definition of a DNS request. Shared by Questions and all the different resource record types */ class request_base_t { protected: /// Domain name of the resource record string rr_domain; /// Resource record type uint16_t rr_type; /// Resource record class uint16_t rr_class; public: /// Default constructor request_base_t() : rr_type(type_none), rr_class(class_none) {} /*! Copy contructor \param o request_base_t to copy */ request_base_t(const request_base_t & o) : rr_domain(o.rr_domain), rr_type(o.rr_type), rr_class(o.rr_class) { } /*! Constructs a request_base_t \param t Resource type to create object for \param c Resource class to create object for */ request_base_t(const type_t t, const class_t c=class_in) : rr_type(t), rr_class(c) { } /*! Constructs a request_base_t \param d Domain name to create object for \param t Resource type to create object for \param c Resource class to create object for */ request_base_t(const string & d, const type_t t, const class_t c=class_in) : rr_domain(d), rr_type(t), rr_class(c) {} /*! Constructor that creates the request_base_t from a network buffer \param buffer Memory buffer to read from \param offset_map DNS label compression map for label/offset values */ request_base_t(dns_buffer_t& buffer, rfc1035_414_t& offset_map) { decode(buffer, offset_map); } /// Virtual Destructor virtual ~request_base_t() { } /*! Sets the domain name \param s Domain name to assign to the request_base_t \return current domain name */ const string& domain(const string& s) { return domain(s.c_str()); } /*! Sets the domain name \param s Domain name to assign to the request_base_t. \return current domain name */ const string& domain(const char* s) { rr_domain = s; return rr_domain; } /*! Gets the domain name \return current domain name */ const string& domain() const { return rr_domain; } /*! Sets the resource record type \param t resource type to assign to the request_base_t. \return Current type */ const type_t rtype(const type_t t) { rr_type = t; return (type_t)rr_type; } /*! Gets the resource record type \return Current type */ const type_t rtype() const { return (type_t)rr_type; } /*! Sets the resource record class \param c resource class to assign to the request_base_t. \return current class */ const class_t rclass(const class_t c) { rr_class = c; return (class_t)rr_class; } /*! Gets the resource record class \return current class */ const class_t rclass() const { return (class_t)rr_class; } /// Friend to tie to the containers in the message class. friend class message; protected: /*! Encodes the request_base_t into a memory buffer \param buffer Buffer to encode the request into \param offset_map DNS label compression map for label/offset values */ void encode(dns_buffer_t& buffer, rfc1035_414_t& offset_map) { offset_map.write_label(rr_domain, buffer);