xref: /xnu-8019.80.24/bsd/sys/uio.h (revision a325d9c4a84054e40bbe985afedcb50ab80993ea)
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 #define UIO_SEG_IS_USER_SPACE( a_uio_seg )  \
123 	( (a_uio_seg) == UIO_USERSPACE64 || (a_uio_seg) == UIO_USERSPACE32 || \
124 	  (a_uio_seg) == UIO_USERSPACE )
125 
126 
127 __BEGIN_DECLS
128 
129 /*
130  * uio_create - create an uio_t.
131  *      Space is allocated to hold up to a_iovcount number of iovecs.  The uio_t
132  *	is not fully initialized until all iovecs are added using uio_addiov calls.
133  *	a_iovcount is the maximum number of iovecs you may add.
134  */
135 uio_t uio_create( int a_iovcount,               /* max number of iovecs */
136     off_t a_offset,                                             /* current offset */
137     int a_spacetype,                                            /* type of address space */
138     int a_iodirection );                                /* read or write flag */
139 
140 /*
141  * uio_reset - reset an uio_t.
142  *      Reset the given uio_t to initial values.  The uio_t is not fully initialized
143  *      until all iovecs are added using uio_add_ov calls.
144  *	The a_iovcount value passed in the uio_create is the maximum number of
145  *	iovecs you may add.
146  */
147 void uio_reset( uio_t a_uio,
148     off_t a_offset,                                             /* current offset */
149     int a_spacetype,                                            /* type of address space */
150     int a_iodirection );                                /* read or write flag */
151 
152 /*
153  * uio_duplicate - allocate a new uio and make a copy of the given uio_t.
154  *	may return NULL.
155  */
156 uio_t uio_duplicate( uio_t a_uio );
157 
158 
159 /*
160  * uio_free - free a uio_t allocated via uio_create.
161  */
162 void uio_free( uio_t a_uio );
163 
164 /*
165  * uio_addiov - add an iovec to the given uio_t.  You may call this up to
166  *      the a_iovcount number that was passed to uio_create.
167  *	returns 0 if add was successful else non zero.
168  */
169 int uio_addiov( uio_t a_uio, user_addr_t a_baseaddr, user_size_t a_length );
170 
171 /*
172  * uio_getiov - get iovec data associated with the given uio_t.  Use
173  *  a_index to iterate over each iovec (0 to (uio_iovcnt(uio_t) - 1)).
174  *  a_baseaddr_p and a_length_p may be NULL.
175  *      returns -1 when a_index is out of range or invalid uio_t.
176  *	returns 0 when data is returned.
177  */
178 int uio_getiov( uio_t a_uio,
179     int a_index,
180     user_addr_t * a_baseaddr_p,
181     user_size_t * a_length_p );
182 
183 /*
184  * uio_update - update the given uio_t for a_count of completed IO.
185  *	This call adjusts decrements the current iovec length and residual IO,
186  *	and increments the current iovec base address and offset value.
187  */
188 void uio_update( uio_t a_uio, user_size_t a_count );
189 
190 /*
191  * uio_resid - return the residual IO value for the given uio_t
192  */
193 user_ssize_t uio_resid( uio_t a_uio );
194 
195 /*
196  * uio_setresid - set the residual IO value for the given uio_t
197  */
198 void uio_setresid( uio_t a_uio, user_ssize_t a_value );
199 
200 /*
201  * uio_iovcnt - return count of active iovecs for the given uio_t
202  */
203 int uio_iovcnt( uio_t a_uio );
204 
205 /*
206  * uio_offset - return the current offset value for the given uio_t
207  */
208 off_t uio_offset( uio_t a_uio );
209 
210 /*
211  * uio_setoffset - set the current offset value for the given uio_t
212  */
213 void uio_setoffset( uio_t a_uio, off_t a_offset );
214 
215 /*
216  * uio_rw - return the read / write flag for the given uio_t
217  */
218 int uio_rw( uio_t a_uio );
219 
220 /*
221  * uio_setrw - set the read / write flag for the given uio_t
222  */
223 void uio_setrw( uio_t a_uio, int a_value );
224 
225 /*
226  * uio_isuserspace - return non zero value if the address space
227  * flag is for a user address space (could be 32 or 64 bit).
228  */
229 int uio_isuserspace( uio_t a_uio );
230 
231 /*
232  * uio_curriovbase - return the base address of the current iovec associated
233  *	with the given uio_t.  May return 0.
234  */
235 user_addr_t uio_curriovbase( uio_t a_uio );
236 
237 /*
238  * uio_curriovlen - return the length value of the current iovec associated
239  *	with the given uio_t.
240  */
241 user_size_t uio_curriovlen( uio_t a_uio );
242 
243 /*
244  * Limits
245  */
246 #define UIO_MAXIOV      1024            /* max 1K of iov's */
247 #define UIO_SMALLIOV    8               /* 8 on stack, else malloc */
248 
249 extern int uiomove(const char * cp, int n, struct uio *uio);
250 extern int uiomove64(const __uint64_t cp, int n, struct uio *uio);
251 __END_DECLS
252 
253 #endif /* KERNEL */
254 
255 #ifndef KERNEL
256 
257 __BEGIN_DECLS
258 ssize_t readv(int, const struct iovec *, int) __DARWIN_ALIAS_C(readv);
259 ssize_t writev(int, const struct iovec *, int) __DARWIN_ALIAS_C(writev);
260 
261 #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)) || defined(_DARWIN_C_SOURCE)
262 
263 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));
264 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));
265 
266 #endif /* #if (!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)) || defined(_DARWIN_C_SOURCE) */
267 
268 __END_DECLS
269 
270 #endif /* !KERNEL */
271 
272 #endif /* !_SYS_UIO_H_ */
273