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/* Copyright (C) 2008-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2008.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <signal.h>
#include <sys/socket.h>
#include <sysdep-cancel.h>
#include <sys/syscall.h>
#include <kernel-features.h>
/* Do not use the accept4 syscall on socketcall architectures unless
it was added at the same time as the socketcall support or can be
assumed to be present. */
#if defined __ASSUME_SOCKETCALL \
&& !defined __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL \
&& !defined __ASSUME_ACCEPT4_SYSCALL
# undef __NR_accept4
#endif
#ifdef __NR_accept4
int
accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
{
return SYSCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len, flags);
}
#elif defined __NR_socketcall
# include <socketcall.h>
# ifdef __ASSUME_ACCEPT4_SOCKETCALL
int
accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
{
return SOCKETCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len, flags);
}
# else
static int have_accept4;
int
accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
{
if (__glibc_likely (have_accept4 >= 0))
{
int ret = SOCKETCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len,
flags);
/* The kernel returns -EINVAL for unknown socket operations.
We need to convert that error to an ENOSYS error. */
if (__builtin_expect (ret < 0, 0)
&& have_accept4 == 0
&& errno == EINVAL)
{
/* Try another call, this time with the FLAGS parameter
cleared and an invalid file descriptor. This call will not
cause any harm and it will return immediately. */
ret = SOCKETCALL_CANCEL (invalid, -1);
if (errno == EINVAL)
{
have_accept4 = -1;
__set_errno (ENOSYS);
}
else
{
have_accept4 = 1;
__set_errno (EINVAL);
}
return -1;
}
return ret;
}
__set_errno (ENOSYS);
return -1;
}
# endif /* __ASSUME_ACCEPT4_SOCKETCALL */
#else /* __NR_socketcall */
int
accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
{
__set_errno (ENOSYS);
return -1;
}
stub_warning (accept4)
#endif
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