/* Compatibility version of recvmsg.
Copyright (C) 2010-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
. */
#include
#include
#include
#include
#if __WORDSIZE == 64
# if SHLIB_COMPAT (libc, GLIBC_2_12, GLIBC_2_24)
/* Do not use the recvmmsg 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_RECVMMSG_SYSCALL_WITH_SOCKETCALL \
&& !defined __ASSUME_RECVMMSG_SYSCALL
# undef __NR_recvmmsg
# endif
int
__old_recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen,
int flags, struct timespec *tmo)
{
# ifdef __NR_recvmmsg
return SYSCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo);
# elif defined __NR_socketcall
# ifdef __ASSUME_RECVMMSG_SOCKETCALL
return SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo);
# else
static int have_recvmmsg;
if (__glibc_likely (have_recvmmsg >= 0))
{
int ret = SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags,
tmo);
/* 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_recvmmsg == 0
&& errno == EINVAL)
{
/* Try another call, this time with an invalid file
descriptor and all other parameters cleared. This call
will not cause any harm and it will return
immediately. */
ret = SOCKETCALL_CANCEL (invalid, -1);
if (errno == EINVAL)
{
have_recvmmsg = -1;
__set_errno (ENOSYS);
}
else
{
have_recvmmsg = 1;
__set_errno (EINVAL);
}
return -1;
}
return ret;
}
__set_errno (ENOSYS);
return -1;
# endif /* __ASSUME_RECVMMSG_SOCKETCALL */
# else
__set_errno (ENOSYS);
return -1;
# endif
}
compat_symbol (libc, __old_recvmmsg, recvmmsg, GLIBC_2_12);
# endif /* SHLIB_COMPAT (libc, GLIBC_2_12, GLIBC_2_24) */
#endif /* __WORDSIZE == 64 */