curl/lib/socketpair.c
Daniel Stenberg 0a51355556
Revert "Revert "socketpair: fix potential hangs""
This reverts commit 3e70c3430a.

Thus brings back the change from #7144 as was originally landed in
c769d1eab4

Closes #7144 (again)
2021-06-05 12:58:13 +02:00

138 lines
3.9 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 2019 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#include "socketpair.h"
#if !defined(HAVE_SOCKETPAIR) && !defined(CURL_DISABLE_SOCKETPAIR)
#ifdef WIN32
/*
* This is a socketpair() implementation for Windows.
*/
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <windows.h>
#include <io.h>
#else
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h> /* IPPROTO_TCP */
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifndef INADDR_LOOPBACK
#define INADDR_LOOPBACK 0x7f000001
#endif /* !INADDR_LOOPBACK */
#endif /* !WIN32 */
#include "nonblock.h" /* for curlx_nonblock */
#include "timeval.h" /* needed before select.h */
#include "select.h" /* for Curl_poll */
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
int Curl_socketpair(int domain, int type, int protocol,
curl_socket_t socks[2])
{
union {
struct sockaddr_in inaddr;
struct sockaddr addr;
} a, a2;
curl_socket_t listener;
curl_socklen_t addrlen = sizeof(a.inaddr);
int reuse = 1;
struct pollfd pfd[1];
(void)domain;
(void)type;
(void)protocol;
listener = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if(listener == CURL_SOCKET_BAD)
return -1;
memset(&a, 0, sizeof(a));
a.inaddr.sin_family = AF_INET;
a.inaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
a.inaddr.sin_port = 0;
socks[0] = socks[1] = CURL_SOCKET_BAD;
if(setsockopt(listener, SOL_SOCKET, SO_REUSEADDR,
(char *)&reuse, (curl_socklen_t)sizeof(reuse)) == -1)
goto error;
if(bind(listener, &a.addr, sizeof(a.inaddr)) == -1)
goto error;
if(getsockname(listener, &a.addr, &addrlen) == -1 ||
addrlen < (int)sizeof(a.inaddr))
goto error;
if(listen(listener, 1) == -1)
goto error;
socks[0] = socket(AF_INET, SOCK_STREAM, 0);
if(socks[0] == CURL_SOCKET_BAD)
goto error;
if(connect(socks[0], &a.addr, sizeof(a.inaddr)) == -1)
goto error;
/* use non-blocking accept to make sure we don't block forever */
if(curlx_nonblock(listener, TRUE) < 0)
goto error;
pfd[0].fd = listener;
pfd[0].events = POLLIN;
pfd[0].revents = 0;
(void)Curl_poll(pfd, 1, 10*1000); /* 10 seconds */
socks[1] = accept(listener, NULL, NULL);
if(socks[1] == CURL_SOCKET_BAD)
goto error;
/* verify that nothing else connected */
addrlen = sizeof(a.inaddr);
if(getsockname(socks[0], &a.addr, &addrlen) == -1 ||
addrlen < (int)sizeof(a.inaddr))
goto error;
addrlen = sizeof(a2.inaddr);
if(getpeername(socks[1], &a2.addr, &addrlen) == -1 ||
addrlen < (int)sizeof(a2.inaddr))
goto error;
if(a.inaddr.sin_family != a2.inaddr.sin_family ||
a.inaddr.sin_addr.s_addr != a2.inaddr.sin_addr.s_addr ||
a.inaddr.sin_port != a2.inaddr.sin_port)
goto error;
sclose(listener);
return 0;
error:
sclose(listener);
sclose(socks[0]);
sclose(socks[1]);
return -1;
}
#endif /* ! HAVE_SOCKETPAIR */