1/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <sys/socket.h>
21
22#include <sysdep-cancel.h>
23#include <sys/syscall.h>
24#include <kernel-features.h>
25
26/* Do not use the sendmmsg syscall on socketcall architectures unless
27 it was added at the same time as the socketcall support or can be
28 assumed to be present. */
29#if defined __ASSUME_SOCKETCALL \
30 && !defined __ASSUME_SENDMMSG_SYSCALL_WITH_SOCKETCALL \
31 && !defined __ASSUME_SENDMMSG_SYSCALL
32# undef __NR_sendmmsg
33#endif
34
35#ifdef __NR_sendmmsg
36int
37__sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
38{
39 return SYSCALL_CANCEL (sendmmsg, fd, vmessages, vlen, flags);
40}
41libc_hidden_def (__sendmmsg)
42weak_alias (__sendmmsg, sendmmsg)
43#elif defined __NR_socketcall
44# include <socketcall.h>
45# ifdef __ASSUME_SENDMMSG_SOCKETCALL
46int
47__sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
48{
49 return SOCKETCALL_CANCEL (sendmmsg, fd, vmessages, vlen, flags);
50}
51# else
52static int have_sendmmsg;
53
54int
55__sendmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags)
56{
57 if (__glibc_likely (have_sendmmsg >= 0))
58 {
59 int ret = SOCKETCALL_CANCEL (sendmmsg, fd, vmessages, vlen, flags);
60 /* The kernel returns -EINVAL for unknown socket operations.
61 We need to convert that error to an ENOSYS error. */
62 if (__builtin_expect (ret < 0, 0)
63 && have_sendmmsg == 0
64 && errno == EINVAL)
65 {
66 /* Try another call, this time with an invalid file
67 descriptor and all other parameters cleared. This call
68 will not cause any harm and it will return
69 immediately. */
70 ret = SOCKETCALL_CANCEL (invalid, -1);
71 if (errno == EINVAL)
72 {
73 have_sendmmsg = -1;
74 __set_errno (ENOSYS);
75 }
76 else
77 {
78 have_sendmmsg = 1;
79 __set_errno (EINVAL);
80 }
81 return -1;
82 }
83 return ret;
84 }
85 __set_errno (ENOSYS);
86 return -1;
87}
88# endif /* __ASSUME_SENDMMSG_SOCKETCALL */
89libc_hidden_def (__sendmmsg)
90weak_alias (__sendmmsg, sendmmsg)
91#else
92# include <socket/sendmmsg.c>
93#endif
94