Chris@16: /*
Chris@101:  *          Copyright Andrey Semashev 2007 - 2015.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  *    (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  *          http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  */
Chris@16: /*!
Chris@16:  * \file   syslog_backend.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   08.01.2008
Chris@16:  *
Chris@16:  * The header contains implementation of a Syslog sink backend along with its setup facilities.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_SINKS_SYSLOG_BACKEND_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_SINKS_SYSLOG_BACKEND_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #ifndef BOOST_LOG_WITHOUT_SYSLOG
Chris@16: 
Chris@16: #include <string>
Chris@16: #include <boost/log/detail/asio_fwd.hpp>
Chris@16: #include <boost/log/detail/light_function.hpp>
Chris@16: #include <boost/log/detail/parameter_tools.hpp>
Chris@16: #include <boost/log/sinks/basic_sink_backend.hpp>
Chris@16: #include <boost/log/sinks/syslog_constants.hpp>
Chris@16: #include <boost/log/sinks/attribute_mapping.hpp>
Chris@16: #include <boost/log/attributes/attribute_value_set.hpp>
Chris@16: #include <boost/log/keywords/facility.hpp>
Chris@16: #include <boost/log/keywords/use_impl.hpp>
Chris@16: #include <boost/log/keywords/ident.hpp>
Chris@16: #include <boost/log/keywords/ip_version.hpp>
Chris@16: #include <boost/log/detail/header.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace sinks {
Chris@16: 
Chris@16: //! Supported IP protocol versions
Chris@16: enum ip_versions
Chris@16: {
Chris@16:     v4,
Chris@16:     v6
Chris@16: };
Chris@16: 
Chris@16: namespace syslog {
Chris@16: 
Chris@16:     //! The enumeration defined the possible implementation types for the syslog backend
Chris@16:     enum impl_types
Chris@16:     {
Chris@16: #ifdef BOOST_LOG_USE_NATIVE_SYSLOG
Chris@16:         native = 0                  //!< Use native syslog API
Chris@16: #ifndef BOOST_LOG_NO_ASIO
Chris@16:         ,
Chris@16: #endif
Chris@16: #endif
Chris@16: #ifndef BOOST_LOG_NO_ASIO
Chris@16:         udp_socket_based = 1        //!< Use UDP sockets, according to RFC3164
Chris@16: #endif
Chris@16:     };
Chris@16: 
Chris@16:     /*!
Chris@16:      * \brief Straightforward severity level mapping
Chris@16:      *
Chris@16:      * This type of mapping assumes that attribute with a particular name always
Chris@16:      * provides values that map directly onto the Syslog levels. The mapping
Chris@16:      * simply returns the extracted attribute value converted to the Syslog severity level.
Chris@16:      */
Chris@16:     template< typename AttributeValueT = int >
Chris@16:     class direct_severity_mapping :
Chris@16:         public basic_direct_mapping< level, AttributeValueT >
Chris@16:     {
Chris@16:         //! Base type
Chris@16:         typedef basic_direct_mapping< level, AttributeValueT > base_type;
Chris@16: 
Chris@16:     public:
Chris@16:         /*!
Chris@16:          * Constructor
Chris@16:          *
Chris@16:          * \param name Attribute name
Chris@16:          */
Chris@16:         explicit direct_severity_mapping(attribute_name const& name) :
Chris@16:             base_type(name, info)
Chris@16:         {
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     /*!
Chris@16:      * \brief Customizable severity level mapping
Chris@16:      *
Chris@16:      * The class allows to setup a custom mapping between an attribute and Syslog severity levels.
Chris@16:      * The mapping should be initialized similarly to the standard \c map container, by using
Chris@16:      * indexing operator and assignment.
Chris@16:      */
Chris@16:     template< typename AttributeValueT = int >
Chris@16:     class custom_severity_mapping :
Chris@16:         public basic_custom_mapping< level, AttributeValueT >
Chris@16:     {
Chris@16:         //! Base type
Chris@16:         typedef basic_custom_mapping< level, AttributeValueT > base_type;
Chris@16: 
Chris@16:     public:
Chris@16:         /*!
Chris@16:          * Constructor
Chris@16:          *
Chris@16:          * \param name Attribute name
Chris@16:          */
Chris@16:         explicit custom_severity_mapping(attribute_name const& name) :
Chris@16:             base_type(name, info)
Chris@16:         {
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16: } // namespace syslog
Chris@16: 
Chris@16: /*!
Chris@16:  * \brief An implementation of a syslog sink backend
Chris@16:  *
Chris@16:  * The backend provides support for the syslog protocol, defined in RFC3164.
Chris@16:  * The backend sends log records to a remote host via UDP. The host name can
Chris@16:  * be specified by calling the \c set_target_address method. By default log
Chris@16:  * records will be sent to localhost:514. The local address can be specified
Chris@16:  * as well, by calling the \c set_local_address method. By default syslog
Chris@16:  * packets will be sent from any local address available.
Chris@16:  *
Chris@16:  * It is safe to create several sink backends with the same local addresses -
Chris@16:  * the backends within the process will share the same socket. The same applies
Chris@16:  * to different processes that use the syslog backends to send records from
Chris@16:  * the same socket. However, it is not guaranteed to work if some third party
Chris@16:  * facility is using the socket.
Chris@16:  *
Chris@16:  * On systems with native syslog implementation it may be preferable to utilize
Chris@16:  * the POSIX syslog API instead of direct socket management in order to bypass
Chris@16:  * possible security limitations that may be in action. To do so one has to pass
Chris@16:  * the <tt>use_impl = native</tt> to the backend constructor. Note, however,
Chris@16:  * that in that case you will only have one chance to specify syslog facility and
Chris@16:  * process identification string - on the first native syslog backend construction.
Chris@16:  * Other native syslog backends will ignore these parameters.
Chris@16:  * Obviously, the \c set_local_address and \c set_target_address
Chris@16:  * methods have no effect for native backends. Using <tt>use_impl = native</tt>
Chris@16:  * on platforms with no native support for POSIX syslog API will have no effect.
Chris@16:  */
Chris@16: class syslog_backend :
Chris@16:     public basic_formatted_sink_backend< char >
Chris@16: {
Chris@16:     //! Base type
Chris@16:     typedef basic_formatted_sink_backend< char > base_type;
Chris@16:     //! Implementation type
Chris@16:     struct implementation;
Chris@16: 
Chris@16: public:
Chris@16:     //! Character type
Chris@16:     typedef base_type::char_type char_type;
Chris@16:     //! String type that is used to pass message test
Chris@16:     typedef base_type::string_type string_type;
Chris@16: 
Chris@16:     //! Syslog severity level mapper type
Chris@16:     typedef boost::log::aux::light_function< syslog::level (record_view const&) > severity_mapper_type;
Chris@16: 
Chris@16: private:
Chris@16:     //! Pointer to the implementation
Chris@16:     implementation* m_pImpl;
Chris@16: 
Chris@16: public:
Chris@16:     /*!
Chris@16:      * Constructor. Creates a UDP socket-based backend with <tt>syslog::user</tt> facility code.
Chris@16:      * IPv4 protocol will be used.
Chris@16:      */
Chris@16:     BOOST_LOG_API syslog_backend();
Chris@16:     /*!
Chris@16:      * Constructor. Creates a sink backend with the specified named parameters.
Chris@16:      * The following named parameters are supported:
Chris@16:      *
Chris@16:      * \li \c facility - Specifies the facility code. If not specified, <tt>syslog::user</tt> will be used.
Chris@16:      * \li \c use_impl - Specifies the backend implementation. Can be one of:
Chris@16:      *                   \li \c native - Use the native syslog API, if available. If no native API
Chris@16:      *                                   is available, it is equivalent to \c udp_socket_based.
Chris@16:      *                   \li \c udp_socket_based - Use the UDP socket-based implementation, conforming to
Chris@16:      *                                             RFC3164 protocol specification. This is the default.
Chris@16:      * \li \c ip_version - Specifies IP protocol version to use, in case if socket-based implementation
Chris@16:      *                     is used. Can be either \c v4 (the default one) or \c v6.
Chris@16:      * \li \c ident - Process identification string. This parameter is only supported by native syslog implementation.
Chris@16:      */
Chris@16: #ifndef BOOST_LOG_DOXYGEN_PASS
Chris@16:     BOOST_LOG_PARAMETRIZED_CONSTRUCTORS_CALL(syslog_backend, construct)
Chris@16: #else
Chris@16:     template< typename... ArgsT >
Chris@16:     explicit syslog_backend(ArgsT... const& args);
Chris@16: #endif
Chris@16: 
Chris@16:     /*!
Chris@16:      * Destructor
Chris@16:      */
Chris@16:     BOOST_LOG_API ~syslog_backend();
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method installs the function object that maps application severity levels to syslog levels
Chris@16:      */
Chris@16:     BOOST_LOG_API void set_severity_mapper(severity_mapper_type const& mapper);
Chris@16: 
Chris@16: #if !defined(BOOST_LOG_NO_ASIO)
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method sets the local host name which log records will be sent from. The host name
Chris@16:      * is resolved to obtain the final IP address.
Chris@16:      *
Chris@16:      * \note Does not have effect if the backend was constructed to use native syslog API
Chris@16:      *
Chris@16:      * \param addr The local address
Chris@16:      * \param port The local port number
Chris@16:      */
Chris@16:     BOOST_LOG_API void set_local_address(std::string const& addr, unsigned short port = 514);
Chris@16:     /*!
Chris@16:      * The method sets the local address which log records will be sent from.
Chris@16:      *
Chris@16:      * \note Does not have effect if the backend was constructed to use native syslog API
Chris@16:      *
Chris@16:      * \param addr The local address
Chris@16:      * \param port The local port number
Chris@16:      */
Chris@16:     BOOST_LOG_API void set_local_address(boost::asio::ip::address const& addr, unsigned short port = 514);
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method sets the remote host name where log records will be sent to. The host name
Chris@16:      * is resolved to obtain the final IP address.
Chris@16:      *
Chris@16:      * \note Does not have effect if the backend was constructed to use native syslog API
Chris@16:      *
Chris@16:      * \param addr The remote host address
Chris@16:      * \param port The port number on the remote host
Chris@16:      */
Chris@16:     BOOST_LOG_API void set_target_address(std::string const& addr, unsigned short port = 514);
Chris@16:     /*!
Chris@16:      * The method sets the address of the remote host where log records will be sent to.
Chris@16:      *
Chris@16:      * \note Does not have effect if the backend was constructed to use native syslog API
Chris@16:      *
Chris@16:      * \param addr The remote host address
Chris@16:      * \param port The port number on the remote host
Chris@16:      */
Chris@16:     BOOST_LOG_API void set_target_address(boost::asio::ip::address const& addr, unsigned short port = 514);
Chris@16: 
Chris@16: #endif // !defined(BOOST_LOG_NO_ASIO)
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method passes the formatted message to the syslog API or sends to a syslog server
Chris@16:      */
Chris@16:     BOOST_LOG_API void consume(record_view const& rec, string_type const& formatted_message);
Chris@16: 
Chris@16: private:
Chris@16: #ifndef BOOST_LOG_DOXYGEN_PASS
Chris@16:     //! The method creates the backend implementation
Chris@16:     template< typename ArgsT >
Chris@16:     void construct(ArgsT const& args)
Chris@16:     {
Chris@16:         construct(
Chris@16:             args[keywords::facility | syslog::user],
Chris@16: #if !defined(BOOST_LOG_NO_ASIO)
Chris@16:             args[keywords::use_impl | syslog::udp_socket_based],
Chris@16: #else
Chris@16:             args[keywords::use_impl | syslog::native],
Chris@16: #endif
Chris@16:             args[keywords::ip_version | v4],
Chris@16:             args[keywords::ident | std::string()]);
Chris@16:     }
Chris@16:     BOOST_LOG_API void construct(
Chris@16:         syslog::facility facility, syslog::impl_types use_impl, ip_versions ip_version, std::string const& ident);
Chris@16: #endif // BOOST_LOG_DOXYGEN_PASS
Chris@16: };
Chris@16: 
Chris@16: } // namespace sinks
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/log/detail/footer.hpp>
Chris@16: 
Chris@16: #endif // BOOST_LOG_WITHOUT_SYSLOG
Chris@16: 
Chris@16: #endif // BOOST_LOG_SINKS_SYSLOG_BACKEND_HPP_INCLUDED_