1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 2019 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23#include "curl_setup.h"
24#include "socketpair.h"
25
26#if !defined(HAVE_SOCKETPAIR) && !defined(CURL_DISABLE_SOCKETPAIR)
27#ifdef WIN32
28/*
29 * This is a socketpair() implementation for Windows.
30 */
31#include <string.h>
32#include <winsock2.h>
33#include <ws2tcpip.h>
34#include <windows.h>
35#include <io.h>
36#else
37#ifdef HAVE_NETDB_H
38#include <netdb.h>
39#endif
40#ifdef HAVE_NETINET_IN_H
41#include <netinet/in.h> /* IPPROTO_TCP */
42#endif
43#ifdef HAVE_ARPA_INET_H
44#include <arpa/inet.h>
45#endif
46#ifndef INADDR_LOOPBACK
47#define INADDR_LOOPBACK 0x7f000001
48#endif /* !INADDR_LOOPBACK */
49#endif /* !WIN32 */
50
51#include "nonblock.h" /* for curlx_nonblock */
52#include "timeval.h" /* needed before select.h */
53#include "select.h" /* for Curl_poll */
54
55/* The last 3 #include files should be in this order */
56#include "curl_printf.h"
57#include "curl_memory.h"
58#include "memdebug.h"
59
60int Curl_socketpair(int domain, int type, int protocol,
61 curl_socket_t socks[2])
62{
63 union {
64 struct sockaddr_in inaddr;
65 struct sockaddr addr;
66 } a, a2;
67 curl_socket_t listener;
68 curl_socklen_t addrlen = sizeof(a.inaddr);
69 int reuse = 1;
70 struct pollfd pfd[1];
71 (void)domain;
72 (void)type;
73 (void)protocol;
74
75 listener = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
76 if(listener == CURL_SOCKET_BAD)
77 return -1;
78
79 memset(&a, 0, sizeof(a));
80 a.inaddr.sin_family = AF_INET;
81 a.inaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
82 a.inaddr.sin_port = 0;
83
84 socks[0] = socks[1] = CURL_SOCKET_BAD;
85
86 if(setsockopt(listener, SOL_SOCKET, SO_REUSEADDR,
87 (char *)&reuse, (curl_socklen_t)sizeof(reuse)) == -1)
88 goto error;
89 if(bind(listener, &a.addr, sizeof(a.inaddr)) == -1)
90 goto error;
91 if(getsockname(listener, &a.addr, &addrlen) == -1 ||
92 addrlen < (int)sizeof(a.inaddr))
93 goto error;
94 if(listen(listener, 1) == -1)
95 goto error;
96 socks[0] = socket(AF_INET, SOCK_STREAM, 0);
97 if(socks[0] == CURL_SOCKET_BAD)
98 goto error;
99 if(connect(socks[0], &a.addr, sizeof(a.inaddr)) == -1)
100 goto error;
101
102 /* use non-blocking accept to make sure we don't block forever */
103 if(curlx_nonblock(listener, TRUE) < 0)
104 goto error;
105 pfd[0].fd = listener;
106 pfd[0].events = POLLIN;
107 pfd[0].revents = 0;
108 (void)Curl_poll(pfd, 1, 10*1000); /* 10 seconds */
109 socks[1] = accept(listener, NULL, NULL);
110 if(socks[1] == CURL_SOCKET_BAD)
111 goto error;
112
113 /* verify that nothing else connected */
114 addrlen = sizeof(a.inaddr);
115 if(getsockname(socks[0], &a.addr, &addrlen) == -1 ||
116 addrlen < (int)sizeof(a.inaddr))
117 goto error;
118 addrlen = sizeof(a2.inaddr);
119 if(getpeername(socks[1], &a2.addr, &addrlen) == -1 ||
120 addrlen < (int)sizeof(a2.inaddr))
121 goto error;
122 if(a.inaddr.sin_family != a2.inaddr.sin_family ||
123 a.inaddr.sin_addr.s_addr != a2.inaddr.sin_addr.s_addr ||
124 a.inaddr.sin_port != a2.inaddr.sin_port)
125 goto error;
126
127 sclose(listener);
128 return 0;
129
130 error:
131 sclose(listener);
132 sclose(socks[0]);
133 sclose(socks[1]);
134 return -1;
135}
136
137#endif /* ! HAVE_SOCKETPAIR */
138