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//
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//
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// Copyright (c) 2026 Vinnie Falco (vinnie.falco@gmail.com)
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// Copyright (c) 2026 Vinnie Falco (vinnie.falco@gmail.com)
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//
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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//
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// Official repository: https://github.com/cppalliance/corosio
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// Official repository: https://github.com/cppalliance/corosio
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//
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//
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#ifndef BOOST_COROSIO_DETAIL_ENDPOINT_CONVERT_HPP
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#ifndef BOOST_COROSIO_DETAIL_ENDPOINT_CONVERT_HPP
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#define BOOST_COROSIO_DETAIL_ENDPOINT_CONVERT_HPP
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#define BOOST_COROSIO_DETAIL_ENDPOINT_CONVERT_HPP
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13   
#include <boost/corosio/endpoint.hpp>
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#include <boost/corosio/endpoint.hpp>
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#include <boost/corosio/detail/platform.hpp>
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#include <boost/corosio/detail/platform.hpp>
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15  
16   
#include <cstring>
16   
#include <cstring>
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17  
18   
#if BOOST_COROSIO_POSIX
18   
#if BOOST_COROSIO_POSIX
19   
#include <sys/socket.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
20   
#include <netinet/in.h>
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#include <arpa/inet.h>
21   
#include <arpa/inet.h>
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#else
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#else
23   
#ifndef WIN32_LEAN_AND_MEAN
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#ifndef WIN32_LEAN_AND_MEAN
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#define WIN32_LEAN_AND_MEAN
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#define WIN32_LEAN_AND_MEAN
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#endif
25   
#endif
26   
#ifndef NOMINMAX
26   
#ifndef NOMINMAX
27   
#define NOMINMAX
27   
#define NOMINMAX
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#endif
28   
#endif
29   
#include <WinSock2.h>
29   
#include <WinSock2.h>
30   
#include <Ws2tcpip.h>
30   
#include <Ws2tcpip.h>
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#endif
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#endif
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32  
33   
namespace boost::corosio::detail {
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namespace boost::corosio::detail {
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34  
35   
/** Convert IPv4 endpoint to sockaddr_in.
35   
/** Convert IPv4 endpoint to sockaddr_in.
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36  
37   
    @param ep The endpoint to convert. Must be IPv4 (is_v4() == true).
37   
    @param ep The endpoint to convert. Must be IPv4 (is_v4() == true).
38   
    @return A sockaddr_in structure with fields in network byte order.
38   
    @return A sockaddr_in structure with fields in network byte order.
39   
*/
39   
*/
40   
inline sockaddr_in
40   
inline sockaddr_in
41   
to_sockaddr_in(endpoint const& ep) noexcept
41   
to_sockaddr_in(endpoint const& ep) noexcept
42   
{
42   
{
43   
    sockaddr_in sa{};
43   
    sockaddr_in sa{};
44   
    sa.sin_family = AF_INET;
44   
    sa.sin_family = AF_INET;
45   
    sa.sin_port   = htons(ep.port());
45   
    sa.sin_port   = htons(ep.port());
46   
    auto bytes    = ep.v4_address().to_bytes();
46   
    auto bytes    = ep.v4_address().to_bytes();
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    std::memcpy(&sa.sin_addr, bytes.data(), 4);
47   
    std::memcpy(&sa.sin_addr, bytes.data(), 4);
48   
    return sa;
48   
    return sa;
49   
}
49   
}
50  
50  
51   
/** Convert IPv6 endpoint to sockaddr_in6.
51   
/** Convert IPv6 endpoint to sockaddr_in6.
52  
52  
53   
    @param ep The endpoint to convert. Must be IPv6 (is_v6() == true).
53   
    @param ep The endpoint to convert. Must be IPv6 (is_v6() == true).
54   
    @return A sockaddr_in6 structure with fields in network byte order.
54   
    @return A sockaddr_in6 structure with fields in network byte order.
55   
*/
55   
*/
56   
inline sockaddr_in6
56   
inline sockaddr_in6
57   
to_sockaddr_in6(endpoint const& ep) noexcept
57   
to_sockaddr_in6(endpoint const& ep) noexcept
58   
{
58   
{
59   
    sockaddr_in6 sa{};
59   
    sockaddr_in6 sa{};
60   
    sa.sin6_family = AF_INET6;
60   
    sa.sin6_family = AF_INET6;
61   
    sa.sin6_port   = htons(ep.port());
61   
    sa.sin6_port   = htons(ep.port());
62   
    auto bytes     = ep.v6_address().to_bytes();
62   
    auto bytes     = ep.v6_address().to_bytes();
63   
    std::memcpy(&sa.sin6_addr, bytes.data(), 16);
63   
    std::memcpy(&sa.sin6_addr, bytes.data(), 16);
64   
    return sa;
64   
    return sa;
65   
}
65   
}
66  
66  
67   
/** Create endpoint from sockaddr_in.
67   
/** Create endpoint from sockaddr_in.
68  
68  
69   
    @param sa The sockaddr_in structure with fields in network byte order.
69   
    @param sa The sockaddr_in structure with fields in network byte order.
70   
    @return An endpoint with address and port extracted from sa.
70   
    @return An endpoint with address and port extracted from sa.
71   
*/
71   
*/
72   
inline endpoint
72   
inline endpoint
73   
from_sockaddr_in(sockaddr_in const& sa) noexcept
73   
from_sockaddr_in(sockaddr_in const& sa) noexcept
74   
{
74   
{
75   
    ipv4_address::bytes_type bytes;
75   
    ipv4_address::bytes_type bytes;
76   
    std::memcpy(bytes.data(), &sa.sin_addr, 4);
76   
    std::memcpy(bytes.data(), &sa.sin_addr, 4);
77   
    return endpoint(ipv4_address(bytes), ntohs(sa.sin_port));
77   
    return endpoint(ipv4_address(bytes), ntohs(sa.sin_port));
78   
}
78   
}
79  
79  
80   
/** Create endpoint from sockaddr_in6.
80   
/** Create endpoint from sockaddr_in6.
81  
81  
82   
    @param sa The sockaddr_in6 structure with fields in network byte order.
82   
    @param sa The sockaddr_in6 structure with fields in network byte order.
83   
    @return An endpoint with address and port extracted from sa.
83   
    @return An endpoint with address and port extracted from sa.
84   
*/
84   
*/
85   
inline endpoint
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inline endpoint
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from_sockaddr_in6(sockaddr_in6 const& sa) noexcept
86   
from_sockaddr_in6(sockaddr_in6 const& sa) noexcept
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{
87   
{
88   
    ipv6_address::bytes_type bytes;
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    ipv6_address::bytes_type bytes;
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    std::memcpy(bytes.data(), &sa.sin6_addr, 16);
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    std::memcpy(bytes.data(), &sa.sin6_addr, 16);
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    return endpoint(ipv6_address(bytes), ntohs(sa.sin6_port));
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    return endpoint(ipv6_address(bytes), ntohs(sa.sin6_port));
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}
91   
}
92  
92  
 
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/** Convert an IPv4 endpoint to an IPv4-mapped IPv6 sockaddr_in6.
 
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    Produces a `sockaddr_in6` with the `::ffff:` prefix, suitable
 
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    for passing an IPv4 destination to a dual-stack IPv6 socket.
 
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    @param ep The endpoint to convert. Must be IPv4 (is_v4() == true).
 
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    @return A sockaddr_in6 with the IPv4-mapped address.
 
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*/
 
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inline sockaddr_in6
 
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to_v4_mapped_sockaddr_in6(endpoint const& ep) noexcept
 
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{
 
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    sockaddr_in6 sa{};
 
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    sa.sin6_family = AF_INET6;
 
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    sa.sin6_port   = htons(ep.port());
 
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    // ::ffff:0:0/96 prefix
 
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    sa.sin6_addr.s6_addr[10] = 0xff;
 
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    sa.sin6_addr.s6_addr[11] = 0xff;
 
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    auto bytes = ep.v4_address().to_bytes();
 
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    std::memcpy(&sa.sin6_addr.s6_addr[12], bytes.data(), 4);
 
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    return sa;
 
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}
 
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/** Convert endpoint to sockaddr_storage.
 
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    Dispatches to @ref to_sockaddr_in or @ref to_sockaddr_in6
 
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    based on the endpoint's address family.
 
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    @param ep The endpoint to convert.
 
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    @param storage Output parameter filled with the sockaddr.
 
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    @return The length of the filled sockaddr structure.
 
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*/
 
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inline socklen_t
 
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to_sockaddr( endpoint const& ep, sockaddr_storage& storage ) noexcept
 
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{
 
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    std::memset( &storage, 0, sizeof( storage ) );
 
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    if( ep.is_v4() )
 
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    {
 
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        auto sa = to_sockaddr_in( ep );
 
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        std::memcpy( &storage, &sa, sizeof( sa ) );
 
132 + 
        return sizeof( sa );
 
133 + 
    }
 
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    auto sa6 = to_sockaddr_in6( ep );
 
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    std::memcpy( &storage, &sa6, sizeof( sa6 ) );
 
136 + 
    return sizeof( sa6 );
 
137 + 
}
 
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/** Convert endpoint to sockaddr_storage for a specific socket family.
 
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    When the socket is AF_INET6 and the endpoint is IPv4, the address
 
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    is converted to an IPv4-mapped IPv6 address (`::ffff:x.x.x.x`) so
 
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    dual-stack sockets can connect to IPv4 destinations.
 
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    @param ep The endpoint to convert.
 
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    @param socket_family The address family of the socket (AF_INET or
 
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        AF_INET6).
 
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    @param storage Output parameter filled with the sockaddr.
 
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    @return The length of the filled sockaddr structure.
 
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*/
 
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inline socklen_t
 
152 + 
to_sockaddr(
 
153 + 
    endpoint const& ep,
 
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    int socket_family,
 
155 + 
    sockaddr_storage& storage) noexcept
 
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{
 
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    // IPv4 endpoint on IPv6 socket: use IPv4-mapped address
 
158 + 
    if (ep.is_v4() && socket_family == AF_INET6)
 
159 + 
    {
 
160 + 
        std::memset(&storage, 0, sizeof(storage));
 
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        auto sa6 = to_v4_mapped_sockaddr_in6(ep);
 
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        std::memcpy(&storage, &sa6, sizeof(sa6));
 
163 + 
        return sizeof(sa6);
 
164 + 
    }
 
165 + 
    return to_sockaddr(ep, storage);
 
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}
 
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/** Create endpoint from sockaddr_storage.
 
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170 + 
    Dispatches on `ss_family` to reconstruct the appropriate
 
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    IPv4 or IPv6 endpoint.
 
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173 + 
    @param storage The sockaddr_storage with fields in network byte order.
 
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    @return An endpoint with address and port extracted from storage.
 
175 + 
*/
 
176 + 
inline endpoint
 
177 + 
from_sockaddr( sockaddr_storage const& storage ) noexcept
 
178 + 
{
 
179 + 
    if( storage.ss_family == AF_INET )
 
180 + 
    {
 
181 + 
        sockaddr_in sa;
 
182 + 
        std::memcpy( &sa, &storage, sizeof( sa ) );
 
183 + 
        return from_sockaddr_in( sa );
 
184 + 
    }
 
185 + 
    if( storage.ss_family == AF_INET6 )
 
186 + 
    {
 
187 + 
        sockaddr_in6 sa6;
 
188 + 
        std::memcpy( &sa6, &storage, sizeof( sa6 ) );
 
189 + 
        return from_sockaddr_in6( sa6 );
 
190 + 
    }
 
191 + 
    return endpoint{};
 
192 + 
}
 
193 +
 
194 + 
/** Return the native address family for an endpoint.
 
195 +
 
196 + 
    @param ep The endpoint to query.
 
197 + 
    @return `AF_INET` for IPv4, `AF_INET6` for IPv6.
 
198 + 
*/
 
199 + 
inline int
 
200 + 
endpoint_family( endpoint const& ep ) noexcept
 
201 + 
{
 
202 + 
    return ep.is_v6() ? AF_INET6 : AF_INET;
 
203 + 
}
 
204 +
 
205 + 
/** Return the address family of a socket descriptor.
 
206 +
 
207 + 
    @param fd The socket file descriptor.
 
208 + 
    @return AF_INET, AF_INET6, or AF_UNSPEC on failure.
 
209 + 
*/
 
210 + 
inline int
 
211 + 
socket_family(
 
212 + 
#if BOOST_COROSIO_POSIX
 
213 + 
    int fd
 
214 + 
#else
 
215 + 
    std::uintptr_t fd
 
216 + 
#endif
 
217 + 
    ) noexcept
 
218 + 
{
 
219 + 
    sockaddr_storage storage{};
 
220 + 
    socklen_t len = sizeof(storage);
 
221 + 
    if (getsockname(
 
222 + 
#if BOOST_COROSIO_POSIX
 
223 + 
            fd,
 
224 + 
#else
 
225 + 
            static_cast<SOCKET>(fd),
 
226 + 
#endif
 
227 + 
            reinterpret_cast<sockaddr*>(&storage), &len) != 0)
 
228 + 
        return AF_UNSPEC;
 
229 + 
    return storage.ss_family;
 
230 + 
}
 
231 +
93   
} // namespace boost::corosio::detail
232   
} // namespace boost::corosio::detail
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95   
#endif
234   
#endif