gems-kernel/source/THIRDPARTY/xnu/bsd/miscfs/devfs/devfsdefs.h
2024-06-03 11:29:39 -05:00

305 lines
10 KiB
C

/*
* Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* Copyright 1997,1998 Julian Elischer. All rights reserved.
* julian@freebsd.org
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* devfsdefs.h
*/
/*
* NOTICE: This file was modified by McAfee Research in 2004 to introduce
* support for mandatory and extensible security protections. This notice
* is included in support of clause 2.2 (b) of the Apple Public License,
* Version 2.0.
*/
/*
* HISTORY
* 8-April-1999 Dieter Siegmund (dieter@apple.com)
* Ported to from FreeBSD 3.1
* Removed unnecessary/unused defines
* Renamed structures/elements to clarify usage in code.
*/
#ifndef __DEVFS_DEVFSDEFS_H__
#define __DEVFS_DEVFSDEFS_H__
#include <sys/appleapiopts.h>
__BEGIN_DECLS
#ifdef __APPLE_API_PRIVATE
#define DEVMAXNAMESIZE 32 /* XXX */
#define DEVMAXPATHSIZE 128 /* XXX */
typedef enum {
DEV_DIR,
DEV_BDEV,
DEV_CDEV,
DEV_SLNK,
#if FDESC
DEV_DEVFD
#endif /* FDESC */
} devfstype_t;
extern int(**devfs_vnodeop_p)(void *); /* our own vector array for dirs */
extern int(**devfs_spec_vnodeop_p)(void *); /* our own vector array for devs */
extern const struct vfsops devfs_vfsops;
typedef struct devnode devnode_t;
typedef struct devdirent devdirent_t;
typedef union devnode_type devnode_type_t;
struct devfs_stats {
int nodes;
int entries;
int mounts;
int stringspace;
};
union devnode_type {
dev_t dev;
struct {
devdirent_t * dirlist;
devdirent_t * * dirlast;
devnode_t * parent;
devdirent_t * myname; /* my entry in .. */
int entrycount;
}Dir;
struct {
char * name;/* must be allocated separately */
size_t namelen;
}Slnk;
};
#define DEV_MAX_VNODE_RETRY 8 /* Max number of retries when we try to
* get a vnode for the devnode */
struct devnode {
devfstype_t dn_type;
/*
* Number of vnodes that point to this devnode. Note, we do not
* add another reference for a lookup which finds an existing
* vnode; a reference is added when a vnode is created and removed
* when a vnode is reclaimed. A devnode will not be freed while
* there are outstanding references. A refcount can be added to
* prevent the free of a devnode in situations where there is not
* guaranteed to be a vnode holding a ref, but it is important to
* make sure that a deferred delete eventually happens if it is
* blocked behind that reference.
*/
os_ref_atomic_t dn_refcount;
u_short dn_mode;
uid_t dn_uid;
gid_t dn_gid;
struct timespec dn_atime;/* time of last access */
struct timespec dn_mtime;/* time of last modification */
struct timespec dn_ctime;/* time file changed */
int(***dn_ops)(void *);/* yuk... pointer to pointer(s) to funcs */
int dn_links;/* how many file links does this node have? */
struct devfsmount * dn_dvm; /* the mount structure for this 'plane' */
struct vnode * dn_vn;/* address of last vnode that represented us */
int dn_len;/* of any associated info (e.g. dir data) */
devdirent_t * dn_linklist;/* circular list of hardlinks to this node */
devnode_t * dn_nextsibling;/* the list of equivalent nodes */
devnode_t * * dn_prevsiblingp;/* backpointer for the above */
devnode_type_t dn_typeinfo;
int dn_change;
int dn_update;
int dn_access;
int dn_lflags;
ino_t dn_ino;
int (*dn_clone)(dev_t dev, int action);/* get minor # */
struct label * dn_label; /* security label */
};
#define DN_DELETE 0x02
#define DN_CREATE 0x04
#define DN_CREATEWAIT 0x08
struct devdirent {
/*-----------------------directory entry fields-------------*/
char de_name[DEVMAXNAMESIZE];
devnode_t * de_dnp; /* the "inode" (devnode) pointer */
devnode_t * de_parent; /* backpointer to the directory itself */
devdirent_t * de_next; /* next object in this directory */
devdirent_t * *de_prevp; /* previous pointer in directory linked list */
devdirent_t * de_nextlink;/* next hardlink to this node */
devdirent_t * *de_prevlinkp;/* previous hardlink pointer for this node */
};
extern devdirent_t * dev_root;
extern struct devfs_stats devfs_stats;
extern lck_mtx_t devfs_mutex;
extern lck_mtx_t devfs_attr_mutex;
/*
* Rules for front nodes:
* Dirs hava a strict 1:1 relationship with their OWN devnode
* Symlinks similarly
* Device Nodes ALWAYS point to the devnode that is linked
* to the Backing node. (with a ref count)
*/
/*
* DEVFS specific per/mount information, used to link a monted fs to a
* particular 'plane' of front nodes.
*/
struct devfsmount {
struct mount * mount;/* vfs mount struct for this fs */
devdirent_t * plane_root;/* the root of this 'plane' */
};
/*
* Prototypes for DEVFS virtual filesystem operations
*/
#include <sys/lock.h>
#include <miscfs/devfs/devfs_proto.h>
#include <libkern/OSAtomic.h> /* required for OSAddAtomic() */
//#define HIDDEN_MOUNTPOINT 1
/* misc */
#define VTODN(vp) ((devnode_t *)(vp)->v_data)
#define DEVFS_LOCK() lck_mtx_lock(&devfs_mutex)
#define DEVFS_UNLOCK() lck_mtx_unlock(&devfs_mutex)
#define DEVFS_ATTR_LOCK_SPIN() lck_mtx_lock_spin(&devfs_attr_mutex);
#define DEVFS_ATTR_UNLOCK() lck_mtx_unlock(&devfs_attr_mutex);
/*
* XXX all the (SInt32 *) casts below assume sizeof(int) == sizeof(long)
*/
static __inline__ void
DEVFS_INCR_ENTRIES(void)
{
OSAddAtomic(1, &devfs_stats.entries);
}
static __inline__ void
DEVFS_DECR_ENTRIES(void)
{
OSAddAtomic(-1, &devfs_stats.entries);
}
static __inline__ void
DEVFS_INCR_NODES(void)
{
OSAddAtomic(1, &devfs_stats.nodes);
}
static __inline__ void
DEVFS_DECR_NODES(void)
{
OSAddAtomic(-1, &devfs_stats.nodes);
}
static __inline__ void
DEVFS_INCR_MOUNTS(void)
{
OSAddAtomic(1, &devfs_stats.mounts);
}
static __inline__ void
DEVFS_DECR_MOUNTS(void)
{
OSAddAtomic(-1, &devfs_stats.mounts);
}
static __inline__ void
DEVFS_INCR_STRINGSPACE(int space)
{
OSAddAtomic(space, &devfs_stats.stringspace);
}
static __inline__ void
DEVFS_DECR_STRINGSPACE(int space)
{
OSAddAtomic(-space, &devfs_stats.stringspace);
}
/*
* Access, change, and modify times are protected by a separate lock,
* which allows tty times to be updated (no more than once per second)
* in the I/O path without too much fear of contention.
*
* For getattr, update times to current time if the last update was recent;
* preserve legacy behavior that frequent stats can yield sub-second resolutions.
* If the last time is old, however, we know that the event that triggered
* the need for an update was no more than 1s after the last update. In that case,
* use (last update + 1s) as the time, avoiding the illusion that last update happened
* much later than it really did.
*/
#define DEVFS_LAZY_UPDATE_SECONDS 1
#define DEVFS_UPDATE_CHANGE 0x1
#define DEVFS_UPDATE_MOD 0x2
#define DEVFS_UPDATE_ACCESS 0x4
static __inline__ void
dn_copy_times(devnode_t * target, devnode_t * source)
{
DEVFS_ATTR_LOCK_SPIN();
target->dn_atime = source->dn_atime;
target->dn_mtime = source->dn_mtime;
target->dn_ctime = source->dn_ctime;
DEVFS_ATTR_UNLOCK();
return;
}
#ifdef BSD_KERNEL_PRIVATE
int devfs_make_symlink(devnode_t *dir_p, char *name, mode_t mode, char *target, devdirent_t **newent);
#endif /* BSD_KERNEL_PRIVATE */
#endif /* __APPLE_API_PRIVATE */
__END_DECLS
#endif /* __DEVFS_DEVFSDEFS_H__ */