xref: /xnu-12377.61.12/bsd/sys/uio.h (revision 4d495c6e23c53686cf65f45067f79024cf5dcee8)
1 /*
2  * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Copyright (c) 1982, 1986, 1993, 1994
31  *	The Regents of the University of California.  All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  * 3. All advertising materials mentioning features or use of this software
42  *    must display the following acknowledgement:
43  *	This product includes software developed by the University of
44  *	California, Berkeley and its contributors.
45  * 4. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)uio.h	8.5 (Berkeley) 2/22/94
62  */
63 
64 #ifndef _SYS_UIO_H_
65 #define _SYS_UIO_H_
66 
67 #include <Availability.h>
68 #include <sys/cdefs.h>
69 #include <sys/_types.h>
70 #include <sys/_types/_off_t.h>
71 
72 /*
73  * [XSI] The ssize_t and size_t types shall be defined as described
74  * in <sys/types.h>.
75  */
76 #include <sys/_types/_size_t.h>
77 #include <sys/_types/_ssize_t.h>
78 
79 /*
80  * [XSI] Structure whose address is passed as the second parameter to the
81  * readv(), preadv(), writev() and pwritev() functions.
82  */
83 #include <sys/_types/_iovec_t.h>
84 
85 
86 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
87 /*
88  * IO direction for uio_t.
89  *	UIO_READ - data moves into iovec(s) associated with uio_t
90  *	UIO_WRITE - data moves out of iovec(s) associated with uio_t
91  */
92 enum uio_rw { UIO_READ, UIO_WRITE };
93 #endif
94 
95 #ifdef KERNEL
96 
97 /*
98  * XXX This all really wants a uio_internal.h
99  */
100 
101 #include <sys/kernel_types.h>
102 
103 
104 /*
105  * user / kernel address space type flags.
106  * WARNING - make sure to check when adding flags!  Be sure new flags
107  * don't overlap the definitions in uio_internal.h
108  * NOTES -
109  *	UIO_USERSPACE is equivalent to UIO_USERSPACE32, but UIO_USERSPACE32
110  *		is preferred.  UIO_USERSPACE remains for backwards compatibility.
111  *	UIO_SYSSPACE is equivalent to UIO_SYSSPACE32, but UIO_SYSSPACE
112  *		is preferred.
113  */
114 enum uio_seg {
115 	UIO_USERSPACE           = 0,    /* kernel address is virtual,  to/from user virtual */
116 	UIO_SYSSPACE            = 2,    /* kernel address is virtual,  to/from system virtual */
117 	UIO_USERSPACE32         = 5,    /* kernel address is virtual,  to/from user 32-bit virtual */
118 	UIO_USERSPACE64         = 8,    /* kernel address is virtual,  to/from user 64-bit virtual */
119 	UIO_SYSSPACE32          = 11    /* deprecated */
120 };
121 
122 enum {
123 	UIOF_USERSPACE          = (1 << UIO_USERSPACE),
124 	UIOF_SYSSPACE           = (1 << UIO_SYSSPACE),
125 	UIOF_USERSPACE32        = (1 << UIO_USERSPACE32),
126 	UIOF_USERSPACE64        = (1 << UIO_USERSPACE64),
127 	UIOF_SYSSPACE32         = (1 << UIO_SYSSPACE32),
128 };
129 
130 #define UIO_SEG_IS_USER_SPACE( a_uio_seg )  \
131 	((1 << a_uio_seg) & (UIOF_USERSPACE64 | UIOF_USERSPACE32 | UIOF_USERSPACE))
132 
133 
134 __BEGIN_DECLS
135 
136 /*
137  * uio_create - create an uio_t.
138  *      Space is allocated to hold up to a_iovcount number of iovecs.  The uio_t
139  *	is not fully initialized until all iovecs are added using uio_addiov calls.
140  *	a_iovcount is the maximum number of iovecs you may add.
141  */
142 uio_t uio_create( int a_iovcount,               /* max number of iovecs */
143     off_t a_offset,                                             /* current offset */
144     int a_spacetype,                                            /* type of address space */
145     int a_iodirection );                                /* read or write flag */
146 
147 /*
148  * uio_reset - reset an uio_t.
149  *      Reset the given uio_t to initial values.  The uio_t is not fully initialized
150  *      until all iovecs are added using uio_add_ov calls.
151  *	The a_iovcount value passed in the uio_create is the maximum number of
152  *	iovecs you may add.
153  */
154 void uio_reset( uio_t a_uio,
155     off_t a_offset,                                             /* current offset */
156     int a_spacetype,                                            /* type of address space */
157     int a_iodirection );                                /* read or write flag */
158 
159 /*
160  * uio_duplicate - allocate a new uio and make a copy of the given uio_t.
161  *	may return NULL.
162  */
163 uio_t uio_duplicate( uio_t a_uio );
164 
165 /*
166  * uio_restore - restore a uio to the state it was in the provided snapshot.
167  *      returns 0 if it was successful else non zero.
168  */
169 int uio_restore(uio_t uio, uio_t snapshot_uio);
170 
171 /*
172  * uio_free - free a uio_t allocated via uio_create.
173  */
174 void uio_free( uio_t a_uio );
175 
176 /*
177  * uio_addiov - add an iovec to the given uio_t.  You may call this up to
178  *      the a_iovcount number that was passed to uio_create.
179  *	returns 0 if add was successful else non zero.
180  */
181 int uio_addiov( uio_t a_uio, user_addr_t a_baseaddr, user_size_t a_length );
182 
183 /*
184  * uio_getiov - get iovec data associated with the given uio_t.  Use
185  *  a_index to iterate over each iovec (0 to (uio_iovcnt(uio_t) - 1)).
186  *  a_baseaddr_p and a_length_p may be NULL.
187  *      returns -1 when a_index is out of range or invalid uio_t.
188  *	returns 0 when data is returned.
189  */
190 int uio_getiov( uio_t a_uio,
191     int a_index,
192     user_addr_t * a_baseaddr_p,
193     user_size_t * a_length_p );
194 
195 /*
196  * uio_update - update the given uio_t for a_count of completed IO.
197  *	This call adjusts decrements the current iovec length and residual IO,
198  *	and increments the current iovec base address and offset value.
199  */
200 void uio_update( uio_t a_uio, user_size_t a_count );
201 
202 /*
203  * uio_resid - return the residual IO value for the given uio_t
204  */
205 user_ssize_t uio_resid( uio_t a_uio );
206 
207 /*
208  * uio_setresid - set the residual IO value for the given uio_t
209  */
210 void uio_setresid( uio_t a_uio, user_ssize_t a_value );
211 
212 /*
213  * uio_iovcnt - return count of active iovecs for the given uio_t
214  */
215 int uio_iovcnt( uio_t a_uio );
216 
217 /*
218  * uio_offset - return the current offset value for the given uio_t
219  */
220 off_t uio_offset( uio_t a_uio );
221 
222 /*
223  * uio_setoffset - set the current offset value for the given uio_t
224  */
225 void uio_setoffset( uio_t a_uio, off_t a_offset );
226 
227 /*
228  * uio_rw - return the read / write flag for the given uio_t
229  */
230 int uio_rw( uio_t a_uio );
231 
232 /*
233  * uio_setrw - set the read / write flag for the given uio_t
234  */
235 void uio_setrw( uio_t a_uio, int a_value );
236 
237 /*
238  * uio_isuserspace - return non zero value if the address space
239  * flag is for a user address space (could be 32 or 64 bit).
240  */
241 int uio_isuserspace( uio_t a_uio );
242 
243 /*
244  * uio_curriovbase - return the base address of the current iovec associated
245  *	with the given uio_t.  May return 0.
246  */
247 user_addr_t uio_curriovbase( uio_t a_uio );
248 
249 /*
250  * uio_curriovlen - return the length value of the current iovec associated
251  *	with the given uio_t.
252  */
253 user_size_t uio_curriovlen( uio_t a_uio );
254 
255 /*
256  * Limits
257  */
258 #define UIO_MAXIOV      1024            /* max 1K of iov's */
259 #define UIO_SMALLIOV    8               /* 8 on stack, else malloc */
260 
261 extern int uiomove(const char *__sized_by(n) cp, int n, struct uio *uio);
262 extern int uiomove64(const __uint64_t cp, int n, struct uio *uio);
263 __END_DECLS
264 
265 #endif /* KERNEL */
266 
267 #ifndef KERNEL
268 
269 __BEGIN_DECLS
270 ssize_t readv(int, const struct iovec *, int) __DARWIN_ALIAS_C(readv);
271 ssize_t writev(int, const struct iovec *, int) __DARWIN_ALIAS_C(writev);
272 
273 #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)) || defined(_DARWIN_C_SOURCE)
274 
275 ssize_t preadv(int, const struct iovec *, int, off_t) __DARWIN_NOCANCEL(preadv) __API_AVAILABLE(macos(10.16), ios(14.0), watchos(7.0), tvos(14.0));
276 ssize_t pwritev(int, const struct iovec *, int, off_t) __DARWIN_NOCANCEL(pwritev) __API_AVAILABLE(macos(10.16), ios(14.0), watchos(7.0), tvos(14.0));
277 
278 #endif /* #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)) || defined(_DARWIN_C_SOURCE) */
279 
280 __END_DECLS
281 
282 #endif /* !KERNEL */
283 
284 #endif /* !_SYS_UIO_H_ */
285