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//
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//
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// Copyright (c) 2026 Vinnie Falco (vinnie.falco@gmail.com)
2   
// 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
4   
// 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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10   
#ifndef BOOST_COROSIO_NATIVE_DETAIL_ENDPOINT_CONVERT_HPP
10   
#ifndef BOOST_COROSIO_NATIVE_DETAIL_ENDPOINT_CONVERT_HPP
11   
#define BOOST_COROSIO_NATIVE_DETAIL_ENDPOINT_CONVERT_HPP
11   
#define BOOST_COROSIO_NATIVE_DETAIL_ENDPOINT_CONVERT_HPP
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12  
13   
#include <boost/corosio/endpoint.hpp>
13   
#include <boost/corosio/endpoint.hpp>
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#include <boost/corosio/detail/platform.hpp>
14   
#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>
19   
#include <sys/socket.h>
20   
#include <netinet/in.h>
20   
#include <netinet/in.h>
21   
#include <arpa/inet.h>
21   
#include <arpa/inet.h>
22   
#else
22   
#else
23   
#ifndef WIN32_LEAN_AND_MEAN
23   
#ifndef WIN32_LEAN_AND_MEAN
24   
#define WIN32_LEAN_AND_MEAN
24   
#define WIN32_LEAN_AND_MEAN
25   
#endif
25   
#endif
26   
#ifndef NOMINMAX
26   
#ifndef NOMINMAX
27   
#define NOMINMAX
27   
#define NOMINMAX
28   
#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.
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/** 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   
{
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    sockaddr_in sa{};
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    sockaddr_in sa{};
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    sa.sin_family = AF_INET;
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    sa.sin_family = AF_INET;
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    sa.sin_port   = htons(ep.port());
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    sa.sin_port   = htons(ep.port());
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    auto bytes    = ep.v4_address().to_bytes();
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    auto bytes    = ep.v4_address().to_bytes();
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    std::memcpy(&sa.sin_addr, bytes.data(), 4);
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    std::memcpy(&sa.sin_addr, bytes.data(), 4);
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    return sa;
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    return sa;
49   
}
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}
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50  
51   
/** Convert IPv6 endpoint to sockaddr_in6.
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/** 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).
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    @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   
}
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66  
67   
/** Create endpoint from sockaddr_in.
67   
/** Create endpoint from sockaddr_in.
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68  
69   
    @param sa The sockaddr_in structure with fields in network byte order.
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    @param sa The sockaddr_in structure with fields in network byte order.
70   
    @return An endpoint with address and port extracted from sa.
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    @return An endpoint with address and port extracted from sa.
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*/
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*/
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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);
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    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   
}
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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
85   
inline endpoint
86   
from_sockaddr_in6(sockaddr_in6 const& sa) noexcept
86   
from_sockaddr_in6(sockaddr_in6 const& sa) noexcept
87   
{
87   
{
88   
    ipv6_address::bytes_type bytes;
88   
    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);
90   
    return endpoint(ipv6_address(bytes), ntohs(sa.sin6_port));
90   
    return endpoint(ipv6_address(bytes), ntohs(sa.sin6_port));
91   
}
91   
}
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92  
93   
/** Convert an IPv4 endpoint to an IPv4-mapped IPv6 sockaddr_in6.
93   
/** Convert an IPv4 endpoint to an IPv4-mapped IPv6 sockaddr_in6.
94  
94  
95   
    Produces a `sockaddr_in6` with the `::ffff:` prefix, suitable
95   
    Produces a `sockaddr_in6` with the `::ffff:` prefix, suitable
96   
    for passing an IPv4 destination to a dual-stack IPv6 socket.
96   
    for passing an IPv4 destination to a dual-stack IPv6 socket.
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98   
    @param ep The endpoint to convert. Must be IPv4 (is_v4() == true).
98   
    @param ep The endpoint to convert. Must be IPv4 (is_v4() == true).
99   
    @return A sockaddr_in6 with the IPv4-mapped address.
99   
    @return A sockaddr_in6 with the IPv4-mapped address.
100   
*/
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*/
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inline sockaddr_in6
101   
inline sockaddr_in6
102   
to_v4_mapped_sockaddr_in6(endpoint const& ep) noexcept
102   
to_v4_mapped_sockaddr_in6(endpoint const& ep) noexcept
103   
{
103   
{
104   
    sockaddr_in6 sa{};
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    sockaddr_in6 sa{};
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    sa.sin6_family = AF_INET6;
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    sa.sin6_family = AF_INET6;
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    sa.sin6_port   = htons(ep.port());
106   
    sa.sin6_port   = htons(ep.port());
107   
    // ::ffff:0:0/96 prefix
107   
    // ::ffff:0:0/96 prefix
108   
    sa.sin6_addr.s6_addr[10] = 0xff;
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    sa.sin6_addr.s6_addr[10] = 0xff;
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    sa.sin6_addr.s6_addr[11] = 0xff;
109   
    sa.sin6_addr.s6_addr[11] = 0xff;
110   
    auto bytes               = ep.v4_address().to_bytes();
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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);
111   
    std::memcpy(&sa.sin6_addr.s6_addr[12], bytes.data(), 4);
112   
    return sa;
112   
    return sa;
113   
}
113   
}
114  
114  
115   
/** Convert endpoint to sockaddr_storage.
115   
/** Convert endpoint to sockaddr_storage.
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116  
117   
    Dispatches to @ref to_sockaddr_in or @ref to_sockaddr_in6
117   
    Dispatches to @ref to_sockaddr_in or @ref to_sockaddr_in6
118   
    based on the endpoint's address family.
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    based on the endpoint's address family.
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120   
    @param ep The endpoint to convert.
120   
    @param ep The endpoint to convert.
121   
    @param storage Output parameter filled with the sockaddr.
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    @param storage Output parameter filled with the sockaddr.
122   
    @return The length of the filled sockaddr structure.
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    @return The length of the filled sockaddr structure.
123   
*/
123   
*/
124   
inline socklen_t
124   
inline socklen_t
125   
to_sockaddr(endpoint const& ep, sockaddr_storage& storage) noexcept
125   
to_sockaddr(endpoint const& ep, sockaddr_storage& storage) noexcept
126   
{
126   
{
127   
    std::memset(&storage, 0, sizeof(storage));
127   
    std::memset(&storage, 0, sizeof(storage));
128   
    if (ep.is_v4())
128   
    if (ep.is_v4())
129   
    {
129   
    {
130   
        auto sa = to_sockaddr_in(ep);
130   
        auto sa = to_sockaddr_in(ep);
131   
        std::memcpy(&storage, &sa, sizeof(sa));
131   
        std::memcpy(&storage, &sa, sizeof(sa));
132   
        return sizeof(sa);
132   
        return sizeof(sa);
133   
    }
133   
    }
134   
    auto sa6 = to_sockaddr_in6(ep);
134   
    auto sa6 = to_sockaddr_in6(ep);
135   
    std::memcpy(&storage, &sa6, sizeof(sa6));
135   
    std::memcpy(&storage, &sa6, sizeof(sa6));
136   
    return sizeof(sa6);
136   
    return sizeof(sa6);
137   
}
137   
}
138  
138  
139   
/** Convert endpoint to sockaddr_storage for a specific socket family.
139   
/** Convert endpoint to sockaddr_storage for a specific socket family.
140  
140  
141   
    When the socket is AF_INET6 and the endpoint is IPv4, the address
141   
    When the socket is AF_INET6 and the endpoint is IPv4, the address
142   
    is converted to an IPv4-mapped IPv6 address (`::ffff:x.x.x.x`) so
142   
    is converted to an IPv4-mapped IPv6 address (`::ffff:x.x.x.x`) so
143   
    dual-stack sockets can connect to IPv4 destinations.
143   
    dual-stack sockets can connect to IPv4 destinations.
144  
144  
145   
    @param ep The endpoint to convert.
145   
    @param ep The endpoint to convert.
146   
    @param socket_family The address family of the socket (AF_INET or
146   
    @param socket_family The address family of the socket (AF_INET or
147   
        AF_INET6).
147   
        AF_INET6).
148   
    @param storage Output parameter filled with the sockaddr.
148   
    @param storage Output parameter filled with the sockaddr.
149   
    @return The length of the filled sockaddr structure.
149   
    @return The length of the filled sockaddr structure.
150   
*/
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*/
151   
inline socklen_t
151   
inline socklen_t
152   
to_sockaddr(
152   
to_sockaddr(
153   
    endpoint const& ep, int socket_family, sockaddr_storage& storage) noexcept
153   
    endpoint const& ep, int socket_family, sockaddr_storage& storage) noexcept
154   
{
154   
{
155   
    // IPv4 endpoint on IPv6 socket: use IPv4-mapped address
155   
    // IPv4 endpoint on IPv6 socket: use IPv4-mapped address
156   
    if (ep.is_v4() && socket_family == AF_INET6)
156   
    if (ep.is_v4() && socket_family == AF_INET6)
157   
    {
157   
    {
158   
        std::memset(&storage, 0, sizeof(storage));
158   
        std::memset(&storage, 0, sizeof(storage));
159   
        auto sa6 = to_v4_mapped_sockaddr_in6(ep);
159   
        auto sa6 = to_v4_mapped_sockaddr_in6(ep);
160   
        std::memcpy(&storage, &sa6, sizeof(sa6));
160   
        std::memcpy(&storage, &sa6, sizeof(sa6));
161   
        return sizeof(sa6);
161   
        return sizeof(sa6);
162   
    }
162   
    }
163   
    return to_sockaddr(ep, storage);
163   
    return to_sockaddr(ep, storage);
164   
}
164   
}
165  
165  
166   
/** Create endpoint from sockaddr_storage.
166   
/** Create endpoint from sockaddr_storage.
167  
167  
168   
    Dispatches on `ss_family` to reconstruct the appropriate
168   
    Dispatches on `ss_family` to reconstruct the appropriate
169   
    IPv4 or IPv6 endpoint.
169   
    IPv4 or IPv6 endpoint.
170  
170  
171   
    @param storage The sockaddr_storage with fields in network byte order.
171   
    @param storage The sockaddr_storage with fields in network byte order.
172   
    @return An endpoint with address and port extracted from storage.
172   
    @return An endpoint with address and port extracted from storage.
173   
*/
173   
*/
174   
inline endpoint
174   
inline endpoint
175   
from_sockaddr(sockaddr_storage const& storage) noexcept
175   
from_sockaddr(sockaddr_storage const& storage) noexcept
176   
{
176   
{
177   
    if (storage.ss_family == AF_INET)
177   
    if (storage.ss_family == AF_INET)
178   
    {
178   
    {
179   
        sockaddr_in sa;
179   
        sockaddr_in sa;
180   
        std::memcpy(&sa, &storage, sizeof(sa));
180   
        std::memcpy(&sa, &storage, sizeof(sa));
181   
        return from_sockaddr_in(sa);
181   
        return from_sockaddr_in(sa);
182   
    }
182   
    }
183   
    if (storage.ss_family == AF_INET6)
183   
    if (storage.ss_family == AF_INET6)
184   
    {
184   
    {
185   
        sockaddr_in6 sa6;
185   
        sockaddr_in6 sa6;
186   
        std::memcpy(&sa6, &storage, sizeof(sa6));
186   
        std::memcpy(&sa6, &storage, sizeof(sa6));
187   
        return from_sockaddr_in6(sa6);
187   
        return from_sockaddr_in6(sa6);
188   
    }
188   
    }
189   
    return endpoint{};
189   
    return endpoint{};
190   
}
190   
}
191  
191  
192   
/** Return the native address family for an endpoint.
192   
/** Return the native address family for an endpoint.
193  
193  
194   
    @param ep The endpoint to query.
194   
    @param ep The endpoint to query.
195   
    @return `AF_INET` for IPv4, `AF_INET6` for IPv6.
195   
    @return `AF_INET` for IPv4, `AF_INET6` for IPv6.
196   
*/
196   
*/
197   
inline int
197   
inline int
198   
endpoint_family(endpoint const& ep) noexcept
198   
endpoint_family(endpoint const& ep) noexcept
199   
{
199   
{
200   
    return ep.is_v6() ? AF_INET6 : AF_INET;
200   
    return ep.is_v6() ? AF_INET6 : AF_INET;
201   
}
201   
}
202  
202  
203   
/** Return the address family of a socket descriptor.
203   
/** Return the address family of a socket descriptor.
204  
204  
205   
    @param fd The socket file descriptor.
205   
    @param fd The socket file descriptor.
206   
    @return AF_INET, AF_INET6, or AF_UNSPEC on failure.
206   
    @return AF_INET, AF_INET6, or AF_UNSPEC on failure.
207   
*/
207   
*/
208   
inline int
208   
inline int
209   
socket_family(
209   
socket_family(
210   
#if BOOST_COROSIO_POSIX
210   
#if BOOST_COROSIO_POSIX
211   
    int fd
211   
    int fd
212   
#else
212   
#else
213   
    std::uintptr_t fd
213   
    std::uintptr_t fd
214   
#endif
214   
#endif
215   
    ) noexcept
215   
    ) noexcept
216   
{
216   
{
217   
    sockaddr_storage storage{};
217   
    sockaddr_storage storage{};
218   
    socklen_t len = sizeof(storage);
218   
    socklen_t len = sizeof(storage);
219   
    if (getsockname(
219   
    if (getsockname(
220   
#if BOOST_COROSIO_POSIX
220   
#if BOOST_COROSIO_POSIX
221   
            fd,
221   
            fd,
222   
#else
222   
#else
223   
            static_cast<SOCKET>(fd),
223   
            static_cast<SOCKET>(fd),
224   
#endif
224   
#endif
225   
            reinterpret_cast<sockaddr*>(&storage), &len) != 0)
225   
            reinterpret_cast<sockaddr*>(&storage), &len) != 0)
226   
        return AF_UNSPEC;
226   
        return AF_UNSPEC;
227   
    return storage.ss_family;
227   
    return storage.ss_family;
228   
}
228   
}
229  
229  
230   
} // namespace boost::corosio::detail
230   
} // namespace boost::corosio::detail
231  
231  
232   
#endif
232   
#endif