1 // Networking implementation details -*- C++ -*-
2 
3 // Copyright (C) 2015-2019 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file experimental/bits/net.h
26  *  This is an internal header file, included by other library headers.
27  *  Do not attempt to use it directly. @headername{experimental/networking}
28  */
29 
30 #ifndef _GLIBCXX_EXPERIMENTAL_NET_H
31 #define _GLIBCXX_EXPERIMENTAL_NET_H 1
32 
33 #pragma GCC system_header
34 
35 #if __cplusplus >= 201402L
36 
37 #include <type_traits>
38 #include <system_error>
39 #include <experimental/netfwd>
40 
_GLIBCXX_VISIBILITY(default)41 namespace std _GLIBCXX_VISIBILITY(default)
42 {
43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 namespace experimental
45 {
46 namespace net
47 {
48 inline namespace v1
49 {
50 
51   /**
52    * @ingroup networking
53    * @{
54    */
55 
56   template<typename _CompletionToken, typename _Signature, typename>
57     class async_result;
58 
59   // A type denoted by DEDUCED in the TS.
60   template<typename _CompletionToken, typename _Signature>
61     using __deduced_t = typename
62       async_result<decay_t<_CompletionToken>, _Signature, void>::return_type;
63 
64   // Trait to check for construction from const/non-const lvalue/rvalue.
65   template<typename _Tp>
66     using __is_value_constructible = typename __and_<
67       is_copy_constructible<_Tp>, is_move_constructible<_Tp>,
68       is_constructible<_Tp, _Tp&>, is_constructible<_Tp, const _Tp&&>
69       >::type;
70 
71     struct __throw_on_error
72     {
73       explicit
74       __throw_on_error(const char* __msg) : _M_msg(__msg) { }
75 
76       ~__throw_on_error() noexcept(false)
77       {
78 	if (_M_ec)
79 	  _GLIBCXX_THROW_OR_ABORT(system_error(_M_ec, _M_msg));
80       }
81 
82       __throw_on_error(const __throw_on_error&) = delete;
83       __throw_on_error& operator=(const __throw_on_error&) = delete;
84 
85       operator error_code&() noexcept { return _M_ec; }
86 
87       const char* _M_msg;
88       error_code _M_ec;
89     };
90 
91   // Base class for types meeting IntegerSocketOption requirements.
92   template<typename _Tp>
93     struct __sockopt_base
94     {
95       __sockopt_base() = default;
96 
97       explicit __sockopt_base(int __val) : _M_value(__val) { }
98 
99       int value() const noexcept { return _M_value; }
100 
101       template<typename _Protocol>
102 	void*
103 	data(const _Protocol&) noexcept
104 	{ return std::addressof(_M_value); }
105 
106       template<typename _Protocol>
107 	const void*
108 	data(const _Protocol&) const noexcept
109 	{ return std::addressof(_M_value); }
110 
111       template<typename _Protocol>
112 	size_t
113 	size(const _Protocol&) const noexcept
114 	{ return sizeof(_M_value); }
115 
116       template<typename _Protocol>
117 	void
118 	resize(const _Protocol&, size_t __s)
119 	{
120 	  if (__s != sizeof(_M_value))
121 	    __throw_length_error("invalid value for socket option resize");
122 	}
123 
124     protected:
125       _Tp _M_value { };
126     };
127 
128   // Base class for types meeting BooleanSocketOption requirements.
129   template<>
130     struct __sockopt_base<bool> : __sockopt_base<int>
131     {
132       __sockopt_base() = default;
133 
134       explicit __sockopt_base(bool __val) : __sockopt_base<int>(__val) { }
135 
136       bool value() const noexcept { return __sockopt_base<int>::_M_value; }
137       explicit operator bool() const noexcept { return value(); }
138       bool operator!() const noexcept { return !value(); }
139     };
140 
141   template<typename _Derived, typename _Tp = int>
142     struct __sockopt_crtp : __sockopt_base<_Tp>
143     {
144       using __sockopt_base<_Tp>::__sockopt_base;
145 
146       _Derived&
147       operator=(_Tp __value)
148       {
149 	__sockopt_base<_Tp>::_M_value = __value;
150 	return static_cast<_Derived&>(*this);
151       }
152 
153       template<typename _Protocol>
154 	int
155 	level(const _Protocol&) const noexcept
156 	{ return _Derived::_S_level; }
157 
158       template<typename _Protocol>
159 	int
160 	name(const _Protocol&) const noexcept
161 	{ return _Derived::_S_name; }
162     };
163 
164   /// @}
165 
166 } // namespace v1
167 } // namespace net
168 } // namespace experimental
169 _GLIBCXX_END_NAMESPACE_VERSION
170 } // namespace std
171 
172 #endif // C++14
173 
174 #endif // _GLIBCXX_EXPERIMENTAL_NET_H
175