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