1 /* Copyright (C) 1996-2015 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18 #if !defined _SYS_UIO_H && !defined _FCNTL_H
19 # error "Never include <bits/uio.h> directly; use <sys/uio.h> instead."
20 #endif
21
22 #ifndef _BITS_UIO_H
23 #define _BITS_UIO_H 1
24
25 #include <sys/types.h>
26
27
28 /* We should normally use the Linux kernel header file to define this
29 type and macros but this calls for trouble because of the header
30 includes other kernel headers. */
31
32 /* Size of object which can be written atomically.
33
34 This macro has different values in different kernel versions. The
35 latest versions of the kernel use 1024 and this is good choice. Since
36 the C library implementation of readv/writev is able to emulate the
37 functionality even if the currently running kernel does not support
38 this large value the readv/writev call will not fail because of this. */
39 #define UIO_MAXIOV 1024
40
41
42 /* Structure for scatter/gather I/O. */
43 struct iovec
44 {
45 void *iov_base; /* Pointer to data. */
46 size_t iov_len; /* Length of data. */
47 };
48
49 #endif
50
51
52 #ifdef __USE_GNU
53 # if defined _SYS_UIO_H && !defined _BITS_UIO_H_FOR_SYS_UIO_H
54 # define _BITS_UIO_H_FOR_SYS_UIO_H 1
55
56 __BEGIN_DECLS
57
58 /* Read from another process' address space. */
59 extern ssize_t process_vm_readv (pid_t __pid, const struct iovec *__lvec,
60 unsigned long int __liovcnt,
61 const struct iovec *__rvec,
62 unsigned long int __riovcnt,
63 unsigned long int __flags)
64 __THROW;
65
66 /* Write to another process' address space. */
67 extern ssize_t process_vm_writev (pid_t __pid, const struct iovec *__lvec,
68 unsigned long int __liovcnt,
69 const struct iovec *__rvec,
70 unsigned long int __riovcnt,
71 unsigned long int __flags)
72 __THROW;
73
74 __END_DECLS
75
76 # endif
77 #endif
78