bsd/sys/uio.h

   1 /*
   2  * Copyright (c) 2000-2008 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 <sys/cdefs.h>
  68 #include <sys/_types.h>
  69
  70 /*
  71  * [XSI] The ssize_t and size_t types shall be defined as described
  72  * in <sys/types.h>.
  73  */
  74 #ifndef _SIZE_T
  75 #define _SIZE_T
  76 typedef __darwin_size_t         size_t;
  77 #endif
  78
  79 #ifndef _SSIZE_T
  80 #define _SSIZE_T
  81 typedef __darwin_ssize_t        ssize_t;
  82 #endif
  83
  84 /*
  85  * [XSI] Structure whose address is passed as the second parameter to the
  86  * readv() and writev() functions.
  87  */
  88 #ifndef _STRUCT_IOVEC
  89 #define _STRUCT_IOVEC
  90 struct iovec {
  91         void *   iov_base;      /* [XSI] Base address of I/O memory region */
  92         size_t   iov_len;       /* [XSI] Size of region iov_base points to */
  93 };
  94 #endif
  95
  96
  97 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
  98 /*
  99  * IO direction for uio_t.
 100  *      UIO_READ - data moves into iovec(s) associated with uio_t
 101  *      UIO_WRITE - data moves out of iovec(s) associated with uio_t
 102  */
 103 enum uio_rw { UIO_READ, UIO_WRITE };
 104 #endif
 105
 106 #ifdef KERNEL
 107
 108 /*
 109  * XXX This all really wants a uio_internal.h
 110  */
 111
 112 #include <sys/kernel_types.h>
 113
 114
 115 /*
 116  * user / kernel address space type flags.
 117  * WARNING - make sure to check when adding flags!  Be sure new flags
 118  * don't overlap the definitions in uio_internal.h
 119  * NOTES -
 120  *      UIO_USERSPACE is equivalent to UIO_USERSPACE32, but UIO_USERSPACE32
 121  *              is preferred.  UIO_USERSPACE remains for backwards compatibility.
 122  *      UIO_SYSSPACE is equivalent to UIO_SYSSPACE32, but UIO_SYSSPACE
 123  *              is preferred.
 124  */
 125 enum uio_seg {
 126         UIO_USERSPACE           = 0,    /* kernel address is virtual,  to/from user virtual */
 127         UIO_SYSSPACE            = 2,    /* kernel address is virtual,  to/from system virtual */
 128         UIO_USERSPACE32         = 5,    /* kernel address is virtual,  to/from user 32-bit virtual */
 129         UIO_USERSPACE64         = 8,    /* kernel address is virtual,  to/from user 64-bit virtual */
 130         UIO_SYSSPACE32          = 11    /* deprecated */
 131 };
 132
 133 #define UIO_SEG_IS_USER_SPACE( a_uio_seg )  \
 134         ( (a_uio_seg) == UIO_USERSPACE64 || (a_uio_seg) == UIO_USERSPACE32 || \
 135           (a_uio_seg) == UIO_USERSPACE )
 136
 137
 138 __BEGIN_DECLS
 139
 140 /*
 141  * uio_create - create an uio_t.
 142  *      Space is allocated to hold up to a_iovcount number of iovecs.  The uio_t
 143  *      is not fully initialized until all iovecs are added using uio_addiov calls.
 144  *      a_iovcount is the maximum number of iovecs you may add.
 145  */
 146 uio_t uio_create( int a_iovcount,               /* max number of iovecs */
 147                                   off_t a_offset,               /* current offset */
 148                                   int a_spacetype,              /* type of address space */
 149                                   int a_iodirection );  /* read or write flag */
 150
 151 /*
 152  * uio_reset - reset an uio_t.
 153  *      Reset the given uio_t to initial values.  The uio_t is not fully initialized
 154  *      until all iovecs are added using uio_add_ov calls.
 155  *      The a_iovcount value passed in the uio_create is the maximum number of
 156  *      iovecs you may add.
 157  */
 158 void uio_reset( uio_t a_uio,
 159                                 off_t a_offset,                 /* current offset */
 160                                 int a_spacetype,                /* type of address space */
 161                                 int a_iodirection );    /* read or write flag */
 162
 163 /*
 164  * uio_duplicate - allocate a new uio and make a copy of the given uio_t.
 165  *      may return NULL.
 166  */
 167 uio_t uio_duplicate( uio_t a_uio );
 168
 169
 170 /*
 171  * uio_free - free a uio_t allocated via uio_create.
 172  */
 173 void uio_free( uio_t a_uio );
 174
 175 /*
 176  * uio_addiov - add an iovec to the given uio_t.  You may call this up to
 177  *      the a_iovcount number that was passed to uio_create.
 178  *      returns 0 if add was successful else non zero.
 179  */
 180 int uio_addiov( uio_t a_uio, user_addr_t a_baseaddr, user_size_t a_length );
 181
 182 /*
 183  * uio_getiov - get iovec data associated with the given uio_t.  Use
 184  *  a_index to iterate over each iovec (0 to (uio_iovcnt(uio_t) - 1)).
 185  *  a_baseaddr_p and a_length_p may be NULL.
 186  *      returns -1 when a_index is out of range or invalid uio_t.
 187  *      returns 0 when data is returned.
 188  */
 189 int uio_getiov( uio_t a_uio,
 190                  int a_index,
 191                  user_addr_t * a_baseaddr_p,
 192                  user_size_t * a_length_p );
 193
 194 /*
 195  * uio_update - update the given uio_t for a_count of completed IO.
 196  *      This call adjusts decrements the current iovec length and residual IO,
 197  *      and increments the current iovec base address and offset value.
 198  */
 199 void uio_update( uio_t a_uio, user_size_t a_count );
 200
 201 /*
 202  * uio_resid - return the residual IO value for the given uio_t
 203  */
 204 user_ssize_t uio_resid( uio_t a_uio );
 205
 206 /*
 207  * uio_setresid - set the residual IO value for the given uio_t
 208  */
 209 void uio_setresid( uio_t a_uio, user_ssize_t a_value );
 210
 211 /*
 212  * uio_iovcnt - return count of active iovecs for the given uio_t
 213  */
 214 int uio_iovcnt( uio_t a_uio );
 215
 216 /*
 217  * uio_offset - return the current offset value for the given uio_t
 218  */
 219 off_t uio_offset( uio_t a_uio );
 220
 221 /*
 222  * uio_setoffset - set the current offset value for the given uio_t
 223  */
 224 void uio_setoffset( uio_t a_uio, off_t a_offset );
 225
 226 /*
 227  * uio_rw - return the read / write flag for the given uio_t
 228  */
 229 int uio_rw( uio_t a_uio );
 230
 231 /*
 232  * uio_setrw - set the read / write flag for the given uio_t
 233  */
 234 void uio_setrw( uio_t a_uio, int a_value );
 235
 236 /*
 237  * uio_isuserspace - return non zero value if the address space
 238  * flag is for a user address space (could be 32 or 64 bit).
 239  */
 240 int uio_isuserspace( uio_t a_uio );
 241
 242 /*
 243  * uio_curriovbase - return the base address of the current iovec associated
 244  *      with the given uio_t.  May return 0.
 245  */
 246 user_addr_t uio_curriovbase( uio_t a_uio );
 247
 248 /*
 249  * uio_curriovlen - return the length value of the current iovec associated
 250  *      with the given uio_t.
 251  */
 252 user_size_t uio_curriovlen( uio_t a_uio );
 253
 254 /*
 255  * Limits
 256  */
 257 #define UIO_MAXIOV      1024            /* max 1K of iov's */
 258 #define UIO_SMALLIOV    8               /* 8 on stack, else malloc */
 259
 260 extern int uiomove(const char * cp, int n, struct uio *uio);
 261 extern int uiomove64(const __uint64_t cp, int n, struct uio *uio);
 262 __END_DECLS
 263
 264 #endif /* KERNEL */
 265
 266 #ifndef KERNEL
 267
 268 __BEGIN_DECLS
 269 ssize_t readv(int, const struct iovec *, int) __DARWIN_ALIAS_C(readv);
 270 ssize_t writev(int, const struct iovec *, int) __DARWIN_ALIAS_C(writev);
 271 __END_DECLS
 272 #endif /* !KERNEL */
 273
 274 #endif /* !_SYS_UIO_H_ */