usr/src/uts/common/sys/pathconf.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  *
  22  *      Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
  23  *      Use is subject to license terms.
  24  */
  25
  26 #ifndef _SYS_PATHCONF_H
  27 #define _SYS_PATHCONF_H
  28
  29 #pragma ident   "%Z%%M% %I%     %E% SMI"
  30
  31 /*      pathconf.h 1.9 89/06/26 SMI     */
  32
  33 #include <sys/unistd.h>
  34 #include <sys/types.h>
  35
  36 #ifdef  __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /*
  41  * POSIX pathconf information
  42  *
  43  * static pathconf kludge notes:
  44  *      For NFSv2 servers, we've added a vop (vop_cntl) to dig out pathconf
  45  *      information.  The mount program asked for the information from
  46  *      a remote mountd daemon.  If it gets it, it passes the info
  47  *      down in a new args field.  The info is passed in the struct below
  48  *      in nfsargs.pathconf.  There's a new NFS mount flag so that you know
  49  *      this is happening.  NFS stores the information locally; when a
  50  *      pathconf request is made, the request is intercepted at the client
  51  *      and the information is retrieved from the struct passed down by
  52  *      mount. It's a kludge that will go away as soon
  53  *      as we can ask the nfs protocol these sorts of questions (NFSr3).
  54  *      All code is noted by "static pathconf kludge" comments and is
  55  *      restricted to nfs code in the kernel.
  56  */
  57
  58 #define _BITS           (8 * sizeof (short))
  59 #define _PC_N           ((_PC_LAST + _BITS - 1) / _BITS)
  60 #define _PC_ISSET(n, a) (a[(n) / _BITS] & (1 << ((n) % _BITS)))
  61 #define _PC_SET(n, a)   (a[(n) / _BITS] |= (1 << ((n) % _BITS)))
  62 #define _PC_ERROR       0
  63
  64 struct  pathcnf {
  65         /*
  66          * pathconf() information
  67          */
  68         int             pc_link_max;    /* max links allowed */
  69         short           pc_max_canon;   /* max line len for a tty */
  70         short           pc_max_input;   /* input a tty can eat all once */
  71         short           pc_name_max;    /* max file name length (dir entry) */
  72         short           pc_path_max;    /* path name len (/x/y/z/...) */
  73         short           pc_pipe_buf;    /* size of a pipe (bytes) */
  74         uchar_t         pc_vdisable;    /* safe char to turn off c_cc[i] */
  75         char            pc_xxx;         /* alignment padding; cc_t == char */
  76         short           pc_mask[_PC_N]; /* see below */
  77 #ifdef  _KERNEL
  78         short           pc_refcnt;      /* number of mounts that use this */
  79         struct pathcnf  *pc_next;       /* linked list */
  80 #endif
  81 };
  82
  83 #ifdef _SYSCALL32
  84 struct  pathcnf32 {
  85         /*
  86          * pathconf() information
  87          */
  88         int32_t         pc_link_max;    /* max links allowed */
  89         int16_t         pc_max_canon;   /* max line len for a tty */
  90         int16_t         pc_max_input;   /* input a tty can eat all once */
  91         int16_t         pc_name_max;    /* max file name length (dir entry) */
  92         int16_t         pc_path_max;    /* path name len (/x/y/z/...) */
  93         int16_t         pc_pipe_buf;    /* size of a pipe (bytes) */
  94         uint8_t         pc_vdisable;    /* safe char to turn off c_cc[i] */
  95         int8_t          pc_xxx;         /* alignment padding; cc_t == char */
  96         int16_t         pc_mask[_PC_N]; /* see below */
  97 #ifdef  _KERNEL
  98         int16_t         pc_refcnt;      /* number of mounts that use this */
  99         caddr32_t       pc_next;        /* linked list */
 100 #endif
 101 };
 102 #endif /* _SYSCALL32 */
 103
 104 /*
 105  * pc_mask is used to encode either
 106  *      a) boolean values (for chown_restricted and no_trunc)
 107  *      b) errno on/off (for link, canon, input, name, path, and pipe)
 108  * The _PC_XXX values are defined in unistd.h; they start at 1 and go up
 109  * sequentially.
 110  * _PC_ERROR is used as the first bit to indicate total failure
 111  * (all info invalid).
 112  * To check for an error something like
 113  *      _PC_ISSET(_PC_PATHMAX, foo.pc_mask) != 0
 114  * is used.
 115  */
 116
 117 /*
 118  * The size of the non-kernel part of the struct.
 119  */
 120 #ifdef  _KERNEL
 121 #define PCSIZ           (int)(&(((struct pathcnf *)0)->pc_refcnt))
 122 #define PCCMP(p1, p2)   bcmp((char *)p1, (char *)p2, PCSIZ)
 123 #endif
 124
 125 #ifdef  __cplusplus
 126 }
 127 #endif
 128
 129 #endif  /* _SYS_PATHCONF_H */