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//
1   
//
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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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9  
10   
#ifndef BOOST_COROSIO_DETAIL_ENDPOINT_CONVERT_HPP
10   
#ifndef BOOST_COROSIO_DETAIL_ENDPOINT_CONVERT_HPP
11   
#define BOOST_COROSIO_DETAIL_ENDPOINT_CONVERT_HPP
11   
#define BOOST_COROSIO_DETAIL_ENDPOINT_CONVERT_HPP
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12  
13   
#include <boost/corosio/endpoint.hpp>
13   
#include <boost/corosio/endpoint.hpp>
14   
#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>
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>
31   
#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   
}
49   
}
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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).
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    @return A sockaddr_in6 structure with fields in network byte order.
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    @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.
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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.
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    @return An endpoint with address and port extracted from sa.
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*/
71   
*/
72   
inline endpoint
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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
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   
}
92  
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   
*/
100   
*/
101   
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{};
104   
    sockaddr_in6 sa{};
105   
    sa.sin6_family = AF_INET6;
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    sa.sin6_family = AF_INET6;
106   
    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();
110   
    auto bytes = ep.v4_address().to_bytes();
111   
    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.
116  
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.
118   
    based on the endpoint's address family.
119  
119  
120   
    @param ep The endpoint to convert.
120   
    @param ep The endpoint to convert.
121   
    @param storage Output parameter filled with the sockaddr.
121   
    @param storage Output parameter filled with the sockaddr.
122   
    @return The length of the filled sockaddr structure.
122   
    @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   
*/
150   
*/
151   
inline socklen_t
151   
inline socklen_t
152   
to_sockaddr(
152   
to_sockaddr(
153   
    endpoint const& ep,
153   
    endpoint const& ep,
154   
    int socket_family,
154   
    int socket_family,
155   
    sockaddr_storage& storage) noexcept
155   
    sockaddr_storage& storage) noexcept
156   
{
156   
{
157   
    // IPv4 endpoint on IPv6 socket: use IPv4-mapped address
157   
    // IPv4 endpoint on IPv6 socket: use IPv4-mapped address
158   
    if (ep.is_v4() && socket_family == AF_INET6)
158   
    if (ep.is_v4() && socket_family == AF_INET6)
159   
    {
159   
    {
160   
        std::memset(&storage, 0, sizeof(storage));
160   
        std::memset(&storage, 0, sizeof(storage));
161   
        auto sa6 = to_v4_mapped_sockaddr_in6(ep);
161   
        auto sa6 = to_v4_mapped_sockaddr_in6(ep);
162   
        std::memcpy(&storage, &sa6, sizeof(sa6));
162   
        std::memcpy(&storage, &sa6, sizeof(sa6));
163   
        return sizeof(sa6);
163   
        return sizeof(sa6);
164   
    }
164   
    }
165   
    return to_sockaddr(ep, storage);
165   
    return to_sockaddr(ep, storage);
166   
}
166   
}
167  
167  
168   
/** Create endpoint from sockaddr_storage.
168   
/** Create endpoint from sockaddr_storage.
169  
169  
170   
    Dispatches on `ss_family` to reconstruct the appropriate
170   
    Dispatches on `ss_family` to reconstruct the appropriate
171   
    IPv4 or IPv6 endpoint.
171   
    IPv4 or IPv6 endpoint.
172  
172  
173   
    @param storage The sockaddr_storage with fields in network byte order.
173   
    @param storage The sockaddr_storage with fields in network byte order.
174   
    @return An endpoint with address and port extracted from storage.
174   
    @return An endpoint with address and port extracted from storage.
175   
*/
175   
*/
176   
inline endpoint
176   
inline endpoint
177   
from_sockaddr( sockaddr_storage const& storage ) noexcept
177   
from_sockaddr( sockaddr_storage const& storage ) noexcept
178   
{
178   
{
179   
    if( storage.ss_family == AF_INET )
179   
    if( storage.ss_family == AF_INET )
180   
    {
180   
    {
181   
        sockaddr_in sa;
181   
        sockaddr_in sa;
182   
        std::memcpy( &sa, &storage, sizeof( sa ) );
182   
        std::memcpy( &sa, &storage, sizeof( sa ) );
183   
        return from_sockaddr_in( sa );
183   
        return from_sockaddr_in( sa );
184   
    }
184   
    }
185   
    if( storage.ss_family == AF_INET6 )
185   
    if( storage.ss_family == AF_INET6 )
186   
    {
186   
    {
187   
        sockaddr_in6 sa6;
187   
        sockaddr_in6 sa6;
188   
        std::memcpy( &sa6, &storage, sizeof( sa6 ) );
188   
        std::memcpy( &sa6, &storage, sizeof( sa6 ) );
189   
        return from_sockaddr_in6( sa6 );
189   
        return from_sockaddr_in6( sa6 );
190   
    }
190   
    }
191   
    return endpoint{};
191   
    return endpoint{};
192   
}
192   
}
193  
193  
194   
/** Return the native address family for an endpoint.
194   
/** Return the native address family for an endpoint.
195  
195  
196   
    @param ep The endpoint to query.
196   
    @param ep The endpoint to query.
197   
    @return `AF_INET` for IPv4, `AF_INET6` for IPv6.
197   
    @return `AF_INET` for IPv4, `AF_INET6` for IPv6.
198   
*/
198   
*/
199   
inline int
199   
inline int
200   
endpoint_family( endpoint const& ep ) noexcept
200   
endpoint_family( endpoint const& ep ) noexcept
201   
{
201   
{
202   
    return ep.is_v6() ? AF_INET6 : AF_INET;
202   
    return ep.is_v6() ? AF_INET6 : AF_INET;
203   
}
203   
}
204  
204  
205   
/** Return the address family of a socket descriptor.
205   
/** Return the address family of a socket descriptor.
206  
206  
207   
    @param fd The socket file descriptor.
207   
    @param fd The socket file descriptor.
208   
    @return AF_INET, AF_INET6, or AF_UNSPEC on failure.
208   
    @return AF_INET, AF_INET6, or AF_UNSPEC on failure.
209   
*/
209   
*/
210   
inline int
210   
inline int
211   
socket_family(
211   
socket_family(
212   
#if BOOST_COROSIO_POSIX
212   
#if BOOST_COROSIO_POSIX
213   
    int fd
213   
    int fd
214   
#else
214   
#else
215   
    std::uintptr_t fd
215   
    std::uintptr_t fd
216   
#endif
216   
#endif
217   
    ) noexcept
217   
    ) noexcept
218   
{
218   
{
219   
    sockaddr_storage storage{};
219   
    sockaddr_storage storage{};
220   
    socklen_t len = sizeof(storage);
220   
    socklen_t len = sizeof(storage);
221   
    if (getsockname(
221   
    if (getsockname(
222   
#if BOOST_COROSIO_POSIX
222   
#if BOOST_COROSIO_POSIX
223   
            fd,
223   
            fd,
224   
#else
224   
#else
225   
            static_cast<SOCKET>(fd),
225   
            static_cast<SOCKET>(fd),
226   
#endif
226   
#endif
227   
            reinterpret_cast<sockaddr*>(&storage), &len) != 0)
227   
            reinterpret_cast<sockaddr*>(&storage), &len) != 0)
228   
        return AF_UNSPEC;
228   
        return AF_UNSPEC;
229   
    return storage.ss_family;
229   
    return storage.ss_family;
230   
}
230   
}
231  
231  
232   
} // namespace boost::corosio::detail
232   
} // namespace boost::corosio::detail
233  
233  
234   
#endif
234   
#endif