addrinfo.hpp

Go to the documentation of this file.

#ifndef UPnPsdk_INCLUDE_ADDRINFO_HPP
#define UPnPsdk_INCLUDE_ADDRINFO_HPP
// Copyright (C) 2023+ GPL 3 and higher by Ingo Höft, <Ingo@Hoeft-online.de>
// Redistribution only with this Copyright remark. Last modified: 2025-06-11
#include <UPnPsdk/sockaddr.hpp>
 
namespace UPnPsdk {
 
// This is a stripped version. It is only as snapshot to get information about
// a netaddress. There is no need to copy the object. The last full featured
// version with copy constructor, copy asignment operator, compare operator,
// additional getter and its unit tests can be found at Github commit
// e2ffc0c46a2d8f15390f2816e1a18782e500fd09
class UPnPsdk_VIS CAddrinfo {
  public:
    //  -----------------------------------------------------------------------
    CAddrinfo(
        std::string_view a_node,
        std::string_view a_service,
        const int a_flags = 0,
        const int a_socktype = SOCK_STREAM);
 
 
    // -------------------------------------------------------------------
    CAddrinfo(
        std::string_view a_node,
        const int a_flags = 0,
        const int a_socktype = SOCK_STREAM);
 
    // Destructor
    virtual ~CAddrinfo();
 
    // Copy constructor
    // We cannot use the default copy constructor because there is also
    // allocated memory for the addrinfo structure to copy. We get segfaults
    // and program aborts. This class is not usable for copying the object.
    CAddrinfo(const CAddrinfo&) = delete;
 
    // Copy assignment operator
    // Same as with the copy constructor.
    CAddrinfo& operator=(CAddrinfo) = delete;
 
 
    // REF:_<a_href="https://stackoverflow.com/a/8782794/5014688">Overloading_member_access_operators_->,_.*</a>
    const ::addrinfo* operator->() const noexcept;
 
 
    bool get_first();
 
 
    bool get_next() noexcept;
 
 
    void sockaddr( //
        SSockaddr& a_saddr);
 
    const std::string& what() const;
 
  private:
    // Cache the hints that are given with the constructor by the user, so we
    // can always get identical address information from the operating system.
    DISABLE_MSVC_WARN_4251
    const std::string m_node;
    const std::string m_service;
    ENABLE_MSVC_WARN
    addrinfo m_hints{};
 
    // Pointer to the address information returned from systemcall
    // ::getaddrinfo(). This pointer must be freed. That is done with the
    // destructor. It is initialized to point to the hints so there is never a
    // dangling pointer that may segfault. Pointing to the hints means there is
    // no information available, e.g.
    // if (m_res == &m_hints) { // do nothing }
    ::addrinfo* m_res{&m_hints};
    // This points to the current used address info. If more than one address
    // info is available it is modified with CAddrinfo::get_next() or
    // CAddrinfo::find().
    ::addrinfo* m_res_current{&m_hints};
 
    // Storage for a message in case of an error, that can be called afterwards.
    SUPPRESS_MSVC_WARN_4251_NEXT_LINE
    std::string m_error_msg{"Success."};
 
    // Private method to free allocated memory for address information.
    void free_addrinfo() noexcept;
};
 
} // namespace UPnPsdk
 
#endif // UPnPsdk_INCLUDE_ADDRINFO_HPP