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 #include <security/mac.h>
  76
  77 __BEGIN_DECLS
  78 #ifdef __APPLE_API_PRIVATE
  79 #define DEVMAXNAMESIZE  32              /* XXX */
  80 #define DEVMAXPATHSIZE  128             /* XXX */
  81
  82 typedef enum {
  83     DEV_DIR,
  84     DEV_BDEV,
  85     DEV_CDEV,
  86     DEV_SLNK,
  87 #if FDESC
  88     DEV_DEVFD
  89 #endif /* FDESC */
  90 } devfstype_t;
  91
  92 extern int (**devfs_vnodeop_p)(void *); /* our own vector array for dirs */
  93 extern int (**devfs_spec_vnodeop_p)(void *); /* our own vector array for devs */
  94 extern struct vfsops devfs_vfsops;
  95
  96 typedef struct devnode          devnode_t;
  97 typedef struct devdirent        devdirent_t;
  98 typedef union devnode_type      devnode_type_t;
  99
 100 struct devfs_stats {
 101     int                 nodes;
 102     int                 entries;
 103     int                 mounts;
 104     int                 stringspace;
 105 };
 106
 107 union devnode_type {
 108     dev_t               dev;
 109     struct {
 110         devdirent_t *   dirlist;
 111         devdirent_t * * dirlast;
 112         devnode_t *     parent;
 113         devdirent_t *   myname;         /* my entry in .. */
 114         int             entrycount;
 115     }Dir;
 116     struct {
 117         char *          name;   /* must be allocated separately */
 118         int             namelen;
 119     }Slnk;
 120 };
 121
 122 #define DEV_MAX_VNODE_RETRY  8          /* Max number of retries when we try to
 123                                            get a vnode for the devnode */
 124 struct devnode
 125 {
 126     devfstype_t         dn_type;
 127     /*
 128      * Number of vnodes that point to this devnode.  Note, we do not
 129      * add another reference for a lookup which finds an existing
 130      * vnode; a reference is added when a vnode is created and removed
 131      * when a vnode is reclaimed.  A devnode will not be freed while
 132      * there are outstanding references.  A refcount can be added to
 133      * prevent the free of a devnode in situations where there is not
 134      * guaranteed to be a vnode holding a ref, but it is important to
 135          * make sure that a deferred delete eventually happens if it is
 136          * blocked behind that reference.
 137      */
 138     int                 dn_refcount;
 139     u_short             dn_mode;
 140     uid_t               dn_uid;
 141     gid_t               dn_gid;
 142     struct timespec     dn_atime;/* time of last access */
 143     struct timespec     dn_mtime;/* time of last modification */
 144     struct timespec     dn_ctime;/* time file changed */
 145     int (***dn_ops)(void *);/* yuk... pointer to pointer(s) to funcs */
 146     int                 dn_links;/* how many file links does this node have? */
 147     struct devfsmount * dn_dvm; /* the mount structure for this 'plane' */
 148     struct vnode *      dn_vn;  /* address of last vnode that represented us */
 149     int                 dn_len;   /* of any associated info (e.g. dir data) */
 150     devdirent_t *       dn_linklist;/* circular list of hardlinks to this node */
 151     devnode_t *         dn_nextsibling; /* the list of equivalent nodes */
 152     devnode_t * *       dn_prevsiblingp;/* backpointer for the above */
 153     devnode_type_t      dn_typeinfo;
 154     int                 dn_change;
 155     int                 dn_update;
 156     int                 dn_access;
 157     int                 dn_lflags;
 158     ino_t               dn_ino;
 159     int                 (*dn_clone)(dev_t dev, int action); /* get minor # */
 160     struct label *      dn_label;       /* security label */
 161 };
 162
 163 #define DN_DELETE               0x02
 164 #define DN_CREATE               0x04
 165 #define DN_CREATEWAIT           0x08
 166
 167
 168 struct devdirent
 169 {
 170     /*-----------------------directory entry fields-------------*/
 171     char                de_name[DEVMAXNAMESIZE];
 172     devnode_t *         de_dnp;         /* the "inode" (devnode) pointer */
 173     devnode_t *         de_parent;      /* backpointer to the directory itself */
 174     devdirent_t *       de_next;        /* next object in this directory */
 175     devdirent_t *       *de_prevp;      /* previous pointer in directory linked list */
 176     devdirent_t *       de_nextlink;    /* next hardlink to this node */
 177     devdirent_t *       *de_prevlinkp;  /* previous hardlink pointer for this node */
 178 };
 179
 180 extern devdirent_t *            dev_root;
 181 extern struct devfs_stats       devfs_stats;
 182 extern lck_mtx_t                devfs_mutex;
 183 extern lck_mtx_t                devfs_attr_mutex;
 184
 185 /*
 186  * Rules for front nodes:
 187  * Dirs hava a strict 1:1 relationship with their OWN devnode
 188  * Symlinks similarly
 189  * Device Nodes ALWAYS point to the devnode that is linked
 190  * to the Backing node. (with a ref count)
 191  */
 192
 193 /*
 194  * DEVFS specific per/mount information, used to link a monted fs to a
 195  * particular 'plane' of front nodes.
 196  */
 197 struct devfsmount
 198 {
 199     struct mount *      mount;  /* vfs mount struct for this fs */
 200     devdirent_t *       plane_root;/* the root of this 'plane'  */
 201 };
 202
 203 /*
 204  * Prototypes for DEVFS virtual filesystem operations
 205  */
 206 #include <sys/lock.h>
 207 #include <miscfs/devfs/devfs_proto.h>
 208 #include <libkern/OSAtomic.h>           /* required for OSAddAtomic() */
 209
 210 //#define HIDDEN_MOUNTPOINT     1
 211
 212 /* misc */
 213 #define M_DEVFSNAME     M_DEVFS
 214 #define M_DEVFSNODE     M_DEVFS
 215 #define M_DEVFSMNT      M_DEVFS
 216
 217 #define VTODN(vp)       ((devnode_t *)(vp)->v_data)
 218
 219 #define DEVFS_LOCK()    lck_mtx_lock(&devfs_mutex)
 220 #define DEVFS_UNLOCK()  lck_mtx_unlock(&devfs_mutex)
 221
 222 #define DEVFS_ATTR_LOCK_SPIN()  lck_mtx_lock_spin(&devfs_attr_mutex);
 223 #define DEVFS_ATTR_UNLOCK()     lck_mtx_unlock(&devfs_attr_mutex);
 224
 225 /*
 226  * XXX all the (SInt32 *) casts below assume sizeof(int) == sizeof(long)
 227  */
 228 static __inline__ void
 229 DEVFS_INCR_ENTRIES(void)
 230 {
 231     OSAddAtomic(1, &devfs_stats.entries);
 232 }
 233
 234 static __inline__ void
 235 DEVFS_DECR_ENTRIES(void)
 236 {
 237     OSAddAtomic(-1, &devfs_stats.entries);
 238 }
 239
 240 static __inline__ void
 241 DEVFS_INCR_NODES(void)
 242 {
 243     OSAddAtomic(1, &devfs_stats.nodes);
 244 }
 245
 246 static __inline__ void
 247 DEVFS_DECR_NODES(void)
 248 {
 249     OSAddAtomic(-1, &devfs_stats.nodes);
 250 }
 251
 252 static __inline__ void
 253 DEVFS_INCR_MOUNTS(void)
 254 {
 255     OSAddAtomic(1, &devfs_stats.mounts);
 256 }
 257
 258 static __inline__ void
 259 DEVFS_DECR_MOUNTS(void)
 260 {
 261     OSAddAtomic(-1, &devfs_stats.mounts);
 262 }
 263
 264 static __inline__ void
 265 DEVFS_INCR_STRINGSPACE(int space)
 266 {
 267     OSAddAtomic(space, &devfs_stats.stringspace);
 268 }
 269
 270 static __inline__ void
 271 DEVFS_DECR_STRINGSPACE(int space)
 272 {
 273     OSAddAtomic(-space, &devfs_stats.stringspace);
 274 }
 275
 276 /*
 277  * Access, change, and modify times are protected by a separate lock,
 278  * which allows tty times to be updated (no more than once per second)
 279  * in the I/O path without too much fear of contention.
 280  *
 281  * For getattr, update times to current time if the last update was recent;
 282  * preserve  legacy behavior that frequent stats can yield sub-second resolutions.
 283  * If the last time is old, however, we know that the event that triggered
 284  * the need for an update was no more than 1s after the last update.  In that case,
 285  * use (last update + 1s) as the time, avoiding the illusion that last update happened
 286  * much later than it really did.
 287  */
 288 #define DEVFS_LAZY_UPDATE_SECONDS       1
 289
 290 #define DEVFS_UPDATE_CHANGE             0x1
 291 #define DEVFS_UPDATE_MOD                0x2
 292 #define DEVFS_UPDATE_ACCESS             0x4
 293
 294 static __inline__ void
 295 dn_copy_times(devnode_t * target, devnode_t * source)
 296 {
 297     DEVFS_ATTR_LOCK_SPIN();
 298     target->dn_atime = source->dn_atime;
 299     target->dn_mtime = source->dn_mtime;
 300     target->dn_ctime = source->dn_ctime;
 301     DEVFS_ATTR_UNLOCK();
 302     return;
 303 }
 304
 305 #ifdef BSD_KERNEL_PRIVATE
 306 int     devfs_make_symlink(devnode_t *dir_p, char *name, int mode, char *target, devdirent_t **newent);
 307 #endif /* BSD_KERNEL_PRIVATE */
 308
 309 #endif /* __APPLE_API_PRIVATE */
 310
 311 __END_DECLS
 312
 313 #endif /* __DEVFS_DEVFSDEFS_H__ */