bsd/miscfs/devfs/devfsdefs.h

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, 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 /*
  29  * Copyright 1997,1998 Julian Elischer.  All rights reserved.
  30  * julian@freebsd.org
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions are
  34  * met:
  35  *  1. Redistributions of source code must retain the above copyright
  36  *     notice, this list of conditions and the following disclaimer.
  37  *  2. Redistributions in binary form must reproduce the above copyright notice,
  38  *     this list of conditions and the following disclaimer in the documentation
  39  *     and/or other materials provided with the distribution.
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
  42  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  43  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  44  * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
  45  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  47  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  48  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * devfsdefs.h
  54  */
  55 /*
  56  * NOTICE: This file was modified by McAfee Research in 2004 to introduce
  57  * support for mandatory and extensible security protections.  This notice
  58  * is included in support of clause 2.2 (b) of the Apple Public License,
  59  * Version 2.0.
  60  */
  61
  62 /*
  63  * HISTORY
  64  *  8-April-1999 Dieter Siegmund (dieter@apple.com)
  65  *      Ported to from FreeBSD 3.1
  66  *      Removed unnecessary/unused defines
  67  *      Renamed structures/elements to clarify usage in code.
  68  */
  69
  70 #ifndef __DEVFS_DEVFSDEFS_H__
  71 #define __DEVFS_DEVFSDEFS_H__
  72
  73 #include  <sys/appleapiopts.h>
  74
  75 __BEGIN_DECLS
  76 #ifdef __APPLE_API_PRIVATE
  77 #define DEVMAXNAMESIZE  32              /* XXX */
  78 #define DEVMAXPATHSIZE  128             /* XXX */
  79
  80 typedef enum {
  81         DEV_DIR,
  82         DEV_BDEV,
  83         DEV_CDEV,
  84         DEV_SLNK,
  85 #if FDESC
  86         DEV_DEVFD
  87 #endif /* FDESC */
  88 } devfstype_t;
  89
  90 extern int(**devfs_vnodeop_p)(void *);  /* our own vector array for dirs */
  91 extern int(**devfs_spec_vnodeop_p)(void *);  /* our own vector array for devs */
  92 extern const struct vfsops devfs_vfsops;
  93
  94 typedef struct devnode          devnode_t;
  95 typedef struct devdirent        devdirent_t;
  96 typedef union devnode_type      devnode_type_t;
  97
  98 struct devfs_stats {
  99         int                 nodes;
 100         int                 entries;
 101         int                 mounts;
 102         int                 stringspace;
 103 };
 104
 105 union devnode_type {
 106         dev_t               dev;
 107         struct {
 108                 devdirent_t *   dirlist;
 109                 devdirent_t * * dirlast;
 110                 devnode_t *     parent;
 111                 devdirent_t *   myname; /* my entry in .. */
 112                 int             entrycount;
 113         }Dir;
 114         struct {
 115                 char *          name;/* must be allocated separately */
 116                 int             namelen;
 117         }Slnk;
 118 };
 119
 120 #define DEV_MAX_VNODE_RETRY  8          /* Max number of retries when we try to
 121                                          *  get a vnode for the devnode */
 122 struct devnode {
 123         devfstype_t         dn_type;
 124         /*
 125          * Number of vnodes that point to this devnode.  Note, we do not
 126          * add another reference for a lookup which finds an existing
 127          * vnode; a reference is added when a vnode is created and removed
 128          * when a vnode is reclaimed.  A devnode will not be freed while
 129          * there are outstanding references.  A refcount can be added to
 130          * prevent the free of a devnode in situations where there is not
 131          * guaranteed to be a vnode holding a ref, but it is important to
 132          * make sure that a deferred delete eventually happens if it is
 133          * blocked behind that reference.
 134          */
 135         os_ref_atomic_t     dn_refcount;
 136         u_short             dn_mode;
 137         uid_t               dn_uid;
 138         gid_t               dn_gid;
 139         struct timespec     dn_atime;/* time of last access */
 140         struct timespec     dn_mtime;/* time of last modification */
 141         struct timespec     dn_ctime;/* time file changed */
 142         int(***dn_ops)(void *);/* yuk... pointer to pointer(s) to funcs */
 143         int                 dn_links;/* how many file links does this node have? */
 144         struct devfsmount * dn_dvm; /* the mount structure for this 'plane' */
 145         struct vnode *      dn_vn;/* address of last vnode that represented us */
 146         int                 dn_len;/* of any associated info (e.g. dir data) */
 147         devdirent_t *       dn_linklist;/* circular list of hardlinks to this node */
 148         devnode_t *         dn_nextsibling;/* the list of equivalent nodes */
 149         devnode_t * *       dn_prevsiblingp;/* backpointer for the above */
 150         devnode_type_t      dn_typeinfo;
 151         int                 dn_change;
 152         int                 dn_update;
 153         int                 dn_access;
 154         int                 dn_lflags;
 155         ino_t               dn_ino;
 156         int                 (*dn_clone)(dev_t dev, int action);/* get minor # */
 157         struct label *      dn_label;   /* security label */
 158 };
 159
 160 #define DN_DELETE               0x02
 161 #define DN_CREATE               0x04
 162 #define DN_CREATEWAIT           0x08
 163
 164
 165 struct devdirent {
 166         /*-----------------------directory entry fields-------------*/
 167         char                de_name[DEVMAXNAMESIZE];
 168         devnode_t *         de_dnp;     /* the "inode" (devnode) pointer */
 169         devnode_t *         de_parent;  /* backpointer to the directory itself */
 170         devdirent_t *       de_next;    /* next object in this directory */
 171         devdirent_t *       *de_prevp;  /* previous pointer in directory linked list */
 172         devdirent_t *       de_nextlink;/* next hardlink to this node */
 173         devdirent_t *       *de_prevlinkp;/* previous hardlink pointer for this node */
 174 };
 175
 176 extern devdirent_t *            dev_root;
 177 extern struct devfs_stats       devfs_stats;
 178 extern lck_mtx_t                devfs_mutex;
 179 extern lck_mtx_t                devfs_attr_mutex;
 180
 181 /*
 182  * Rules for front nodes:
 183  * Dirs hava a strict 1:1 relationship with their OWN devnode
 184  * Symlinks similarly
 185  * Device Nodes ALWAYS point to the devnode that is linked
 186  * to the Backing node. (with a ref count)
 187  */
 188
 189 /*
 190  * DEVFS specific per/mount information, used to link a monted fs to a
 191  * particular 'plane' of front nodes.
 192  */
 193 struct devfsmount {
 194         struct mount *      mount;/* vfs mount struct for this fs       */
 195         devdirent_t *       plane_root;/* the root of this 'plane'      */
 196 };
 197
 198 /*
 199  * Prototypes for DEVFS virtual filesystem operations
 200  */
 201 #include <sys/lock.h>
 202 #include <miscfs/devfs/devfs_proto.h>
 203 #include <libkern/OSAtomic.h>           /* required for OSAddAtomic() */
 204
 205 //#define HIDDEN_MOUNTPOINT     1
 206
 207 /* misc */
 208 #define M_DEVFSNAME     M_DEVFS
 209 #define M_DEVFSNODE     M_DEVFS
 210 #define M_DEVFSMNT      M_DEVFS
 211
 212 #define VTODN(vp)       ((devnode_t *)(vp)->v_data)
 213
 214 #define DEVFS_LOCK()    lck_mtx_lock(&devfs_mutex)
 215 #define DEVFS_UNLOCK()  lck_mtx_unlock(&devfs_mutex)
 216
 217 #define DEVFS_ATTR_LOCK_SPIN()  lck_mtx_lock_spin(&devfs_attr_mutex);
 218 #define DEVFS_ATTR_UNLOCK()     lck_mtx_unlock(&devfs_attr_mutex);
 219
 220 /*
 221  * XXX all the (SInt32 *) casts below assume sizeof(int) == sizeof(long)
 222  */
 223 static __inline__ void
 224 DEVFS_INCR_ENTRIES(void)
 225 {
 226         OSAddAtomic(1, &devfs_stats.entries);
 227 }
 228
 229 static __inline__ void
 230 DEVFS_DECR_ENTRIES(void)
 231 {
 232         OSAddAtomic(-1, &devfs_stats.entries);
 233 }
 234
 235 static __inline__ void
 236 DEVFS_INCR_NODES(void)
 237 {
 238         OSAddAtomic(1, &devfs_stats.nodes);
 239 }
 240
 241 static __inline__ void
 242 DEVFS_DECR_NODES(void)
 243 {
 244         OSAddAtomic(-1, &devfs_stats.nodes);
 245 }
 246
 247 static __inline__ void
 248 DEVFS_INCR_MOUNTS(void)
 249 {
 250         OSAddAtomic(1, &devfs_stats.mounts);
 251 }
 252
 253 static __inline__ void
 254 DEVFS_DECR_MOUNTS(void)
 255 {
 256         OSAddAtomic(-1, &devfs_stats.mounts);
 257 }
 258
 259 static __inline__ void
 260 DEVFS_INCR_STRINGSPACE(int space)
 261 {
 262         OSAddAtomic(space, &devfs_stats.stringspace);
 263 }
 264
 265 static __inline__ void
 266 DEVFS_DECR_STRINGSPACE(int space)
 267 {
 268         OSAddAtomic(-space, &devfs_stats.stringspace);
 269 }
 270
 271 /*
 272  * Access, change, and modify times are protected by a separate lock,
 273  * which allows tty times to be updated (no more than once per second)
 274  * in the I/O path without too much fear of contention.
 275  *
 276  * For getattr, update times to current time if the last update was recent;
 277  * preserve  legacy behavior that frequent stats can yield sub-second resolutions.
 278  * If the last time is old, however, we know that the event that triggered
 279  * the need for an update was no more than 1s after the last update.  In that case,
 280  * use (last update + 1s) as the time, avoiding the illusion that last update happened
 281  * much later than it really did.
 282  */
 283 #define DEVFS_LAZY_UPDATE_SECONDS       1
 284
 285 #define DEVFS_UPDATE_CHANGE             0x1
 286 #define DEVFS_UPDATE_MOD                0x2
 287 #define DEVFS_UPDATE_ACCESS             0x4
 288
 289 static __inline__ void
 290 dn_copy_times(devnode_t * target, devnode_t * source)
 291 {
 292         DEVFS_ATTR_LOCK_SPIN();
 293         target->dn_atime = source->dn_atime;
 294         target->dn_mtime = source->dn_mtime;
 295         target->dn_ctime = source->dn_ctime;
 296         DEVFS_ATTR_UNLOCK();
 297         return;
 298 }
 299
 300 #ifdef BSD_KERNEL_PRIVATE
 301 int     devfs_make_symlink(devnode_t *dir_p, char *name, int mode, char *target, devdirent_t **newent);
 302 #endif /* BSD_KERNEL_PRIVATE */
 303
 304 #endif /* __APPLE_API_PRIVATE */
 305
 306 __END_DECLS
 307
 308 #endif /* __DEVFS_DEVFSDEFS_H__ */