[apple/xnu.git] / bsd / sys / namei.h

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This 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 OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1985, 1989, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS 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.
 *
 *	@(#)namei.h	8.4 (Berkeley) 8/20/94
 */

#ifndef _SYS_NAMEI_H_
#define	_SYS_NAMEI_H_

#include <sys/queue.h>
#include <sys/uio.h>

/*
 * Lookup parameters: this structure describes the subset of
 * information from the nameidata structure that is passed
 * through the VOP interface.
 */
struct componentname {
	/*
	 * Arguments to lookup.
	 */
	u_long	cn_nameiop;	/* namei operation */
	u_long	cn_flags;	/* flags to namei */
	struct	proc *cn_proc;	/* process requesting lookup */
	struct	ucred *cn_cred;	/* credentials */
	/*
	 * Shared between lookup and commit routines.
	 */
	char	*cn_pnbuf;	/* pathname buffer */
	long	cn_pnlen;	/* length of allocated buffer */
	char	*cn_nameptr;	/* pointer to looked up name */
	long	cn_namelen;	/* length of looked up component */
	u_long	cn_hash;	/* hash value of looked up name */
	long	cn_consume;	/* chars to consume in lookup() */
};

/*
 * Encapsulation of namei parameters.
 */
struct nameidata {
	/*
	 * Arguments to namei/lookup.
	 */
	caddr_t	ni_dirp;		/* pathname pointer */
	enum	uio_seg ni_segflg;	/* location of pathname */
     /* u_long	ni_nameiop;		   namei operation */
     /* u_long	ni_flags;		   flags to namei */
     /* struct	proc *ni_proc;		   process requesting lookup */
	/*
	 * Arguments to lookup.
	 */
     /* struct	ucred *ni_cred;		   credentials */
	struct	vnode *ni_startdir;	/* starting directory */
	struct	vnode *ni_rootdir;	/* logical root directory */
	/*
	 * Results: returned from/manipulated by lookup
	 */
	struct	vnode *ni_vp;		/* vnode of result */
	struct	vnode *ni_dvp;		/* vnode of intermediate directory */
	/*
	 * Shared between namei and lookup/commit routines.
	 */
	u_int	ni_pathlen;		/* remaining chars in path */
	char	*ni_next;		/* next location in pathname */
	u_long	ni_loopcnt;		/* count of symlinks encountered */
	struct componentname ni_cnd;
};

#ifdef KERNEL
/*
 * namei operations
 */
#define	LOOKUP		0	/* perform name lookup only */
#define	CREATE		1	/* setup for file creation */
#define	DELETE		2	/* setup for file deletion */
#define	RENAME		3	/* setup for file renaming */
#define	OPMASK		3	/* mask for operation */
/*
 * namei operational modifier flags, stored in ni_cnd.flags
 */
#define	LOCKLEAF	0x0004	/* lock inode on return */
#define	LOCKPARENT	0x0008	/* want parent vnode returned locked */
#define	WANTPARENT	0x0010	/* want parent vnode returned unlocked */
#define	NOCACHE		0x0020	/* name must not be left in cache */
#define	FOLLOW		0x0040	/* follow symbolic links */
#define	NOFOLLOW	0x0000	/* do not follow symbolic links (pseudo) */
#define	MODMASK		0x00fc	/* mask of operational modifiers */
/*
 * Namei parameter descriptors.
 *
 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
 * If the caller of namei sets the flag (for example execve wants to
 * know the name of the program that is being executed), then it must
 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
 * be freed by either the commit routine or the VOP_ABORT routine.
 * SAVESTART is set only by the callers of namei. It implies SAVENAME
 * plus the addition of saving the parent directory that contains the
 * name in ni_startdir. It allows repeated calls to lookup for the
 * name being sought. The caller is responsible for releasing the
 * buffer and for vrele'ing ni_startdir.
 */
#define	NOCROSSMOUNT	0x000100 /* do not cross mount points */
#define	RDONLY		0x000200 /* lookup with read-only semantics */
#define	HASBUF		0x000400 /* has allocated pathname buffer */
#define	SAVENAME	0x000800 /* save pathanme buffer */
#define	SAVESTART	0x001000 /* save starting directory */
#define	ISDOTDOT	0x002000 /* current component name is .. */
#define	MAKEENTRY	0x004000 /* entry is to be added to name cache */
#define	ISLASTCN	0x008000 /* this is last component of pathname */
#define	ISSYMLINK	0x010000 /* symlink needs interpretation */
#define	ISWHITEOUT	0x020000 /* found whiteout */
#define	DOWHITEOUT	0x040000 /* do whiteouts */
#define	NODELETEBUSY	0x800000 /* do not delete busy files (HFS semantic) */
#define	PARAMASK	0x0fff00 /* mask of parameter descriptors */
/*
 * Initialization of an nameidata structure.
 */
#define NDINIT(ndp, op, flags, segflg, namep, p) { \
	(ndp)->ni_cnd.cn_nameiop = op; \
	(ndp)->ni_cnd.cn_flags = flags; \
	(ndp)->ni_segflg = segflg; \
	(ndp)->ni_dirp = namep; \
	(ndp)->ni_cnd.cn_proc = p; \
}
#endif /* KERNEL */

/*
 * This structure describes the elements in the cache of recent
 * names looked up by namei. NCHNAMLEN is sized to make structure
 * size a power of two to optimize malloc's. Minimum reasonable
 * size is 15.
 */

#define	NCHNAMLEN	31	/* maximum name segment length we bother with */

struct	namecache {
	LIST_ENTRY(namecache) nc_hash;	/* hash chain */
	TAILQ_ENTRY(namecache) nc_lru;	/* LRU chain */
	struct	vnode *nc_dvp;		/* vnode of parent of name */
	u_long	nc_dvpid;		/* capability number of nc_dvp */
	struct	vnode *nc_vp;		/* vnode the name refers to */
	u_long	nc_vpid;		/* capability number of nc_vp */
	char	nc_nlen;		/* length of name */
	char	nc_name[NCHNAMLEN];	/* segment name */
};

#ifdef KERNEL
extern u_long	nextvnodeid;
int	namei __P((struct nameidata *ndp));
int	lookup __P((struct nameidata *ndp));
int	relookup __P((struct vnode *dvp, struct vnode **vpp,
		struct componentname *cnp));

/* namecache function prototypes */
int	cache_lookup __P((struct vnode *dvp, struct vnode **vpp,
		struct componentname *cnp));
void	cache_enter __P((struct vnode *dvp, struct vnode *vpp,
		struct componentname *cnp));
void	cache_purge __P((struct vnode *vp));
void    cache_purgevfs __P((struct mount *mp));
#endif /* KERNEL */

/*
 * Stats on usefulness of namei caches.
 */
struct	nchstats {
	long	ncs_goodhits;		/* hits that we can really use */
	long	ncs_neghits;		/* negative hits that we can use */
	long	ncs_badhits;		/* hits we must drop */
	long	ncs_falsehits;		/* hits with id mismatch */
	long	ncs_miss;		/* misses */
	long	ncs_long;		/* long names that ignore cache */
	long	ncs_pass2;		/* names found with passes == 2 */
	long	ncs_2passes;		/* number of times we attempt it */
};
#endif /* !_SYS_NAMEI_H_ */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
	23	/*
	24	* Copyright (c) 1985, 1989, 1991, 1993
	25	* The Regents of the University of California. All rights reserved.
	26	*
	27	* Redistribution and use in source and binary forms, with or without
	28	* modification, are permitted provided that the following conditions
	29	* are met:
	30	* 1. Redistributions of source code must retain the above copyright
	31	* notice, this list of conditions and the following disclaimer.
	32	* 2. Redistributions in binary form must reproduce the above copyright
	33	* notice, this list of conditions and the following disclaimer in the
	34	* documentation and/or other materials provided with the distribution.
	35	* 3. All advertising materials mentioning features or use of this software
	36	* must display the following acknowledgement:
	37	* This product includes software developed by the University of
	38	* California, Berkeley and its contributors.
	39	* 4. Neither the name of the University nor the names of its contributors
	40	* may be used to endorse or promote products derived from this software
	41	* without specific prior written permission.
	42	*
	43	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	44	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	45	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	46	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	47	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	48	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	49	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	50	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	51	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	52	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	53	* SUCH DAMAGE.
	54	*
	55	* @(#)namei.h 8.4 (Berkeley) 8/20/94
	56	*/
	57
	58	#ifndef _SYS_NAMEI_H_
	59	#define _SYS_NAMEI_H_
	60
	61	#include <sys/queue.h>
	62	#include <sys/uio.h>
	63
	64	/*
65	* Lookup parameters: this structure describes the subset of
66	* information from the nameidata structure that is passed
67	* through the VOP interface.
68	*/
69	struct componentname {
70	/*
71	* Arguments to lookup.
72	*/
73	u_long cn_nameiop; /* namei operation */
74	u_long cn_flags; /* flags to namei */
75	struct proc cn_proc; / process requesting lookup */
76	struct ucred cn_cred; / credentials */
77	/*
78	* Shared between lookup and commit routines.
79	*/
80	char cn_pnbuf; / pathname buffer */
81	long cn_pnlen; /* length of allocated buffer */
82	char cn_nameptr; / pointer to looked up name */
83	long cn_namelen; /* length of looked up component */
84	u_long cn_hash; /* hash value of looked up name */
85	long cn_consume; /* chars to consume in lookup() */
86	};
87
88	/*
89	* Encapsulation of namei parameters.
90	*/
91	struct nameidata {
92	/*
93	* Arguments to namei/lookup.
94	*/
95	caddr_t ni_dirp; /* pathname pointer */
96	enum uio_seg ni_segflg; /* location of pathname */
97	/* u_long ni_nameiop; namei operation */
98	/* u_long ni_flags; flags to namei */
99	/* struct proc ni_proc; process requesting lookup /
100	/*
101	* Arguments to lookup.
102	*/
103	/* struct ucred ni_cred; credentials /
104	struct vnode ni_startdir; / starting directory */
105	struct vnode ni_rootdir; / logical root directory */
106	/*
107	* Results: returned from/manipulated by lookup
108	*/
109	struct vnode ni_vp; / vnode of result */
110	struct vnode ni_dvp; / vnode of intermediate directory */
111	/*
112	* Shared between namei and lookup/commit routines.
113	*/
114	u_int ni_pathlen; /* remaining chars in path */
115	char ni_next; / next location in pathname */
116	u_long ni_loopcnt; /* count of symlinks encountered */
117	struct componentname ni_cnd;
118	};
119
120	#ifdef KERNEL
121	/*
122	* namei operations
123	*/
124	#define LOOKUP 0 /* perform name lookup only */
125	#define CREATE 1 /* setup for file creation */
126	#define DELETE 2 /* setup for file deletion */
127	#define RENAME 3 /* setup for file renaming */
128	#define OPMASK 3 /* mask for operation */
129	/*
130	* namei operational modifier flags, stored in ni_cnd.flags
131	*/
132	#define LOCKLEAF 0x0004 /* lock inode on return */
133	#define LOCKPARENT 0x0008 /* want parent vnode returned locked */
134	#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
135	#define NOCACHE 0x0020 /* name must not be left in cache */
136	#define FOLLOW 0x0040 /* follow symbolic links */
137	#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
138	#define MODMASK 0x00fc /* mask of operational modifiers */
139	/*
140	* Namei parameter descriptors.
141	*
142	* SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
143	* If the caller of namei sets the flag (for example execve wants to
144	* know the name of the program that is being executed), then it must
145	* free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
146	* be freed by either the commit routine or the VOP_ABORT routine.
147	* SAVESTART is set only by the callers of namei. It implies SAVENAME
148	* plus the addition of saving the parent directory that contains the
149	* name in ni_startdir. It allows repeated calls to lookup for the
150	* name being sought. The caller is responsible for releasing the
151	* buffer and for vrele'ing ni_startdir.
152	*/
153	#define NOCROSSMOUNT 0x000100 /* do not cross mount points */
154	#define RDONLY 0x000200 /* lookup with read-only semantics */
155	#define HASBUF 0x000400 /* has allocated pathname buffer */
156	#define SAVENAME 0x000800 /* save pathanme buffer */
157	#define SAVESTART 0x001000 /* save starting directory */
158	#define ISDOTDOT 0x002000 /* current component name is .. */
159	#define MAKEENTRY 0x004000 /* entry is to be added to name cache */
160	#define ISLASTCN 0x008000 /* this is last component of pathname */
161	#define ISSYMLINK 0x010000 /* symlink needs interpretation */
162	#define ISWHITEOUT 0x020000 /* found whiteout */
163	#define DOWHITEOUT 0x040000 /* do whiteouts */
164	#define NODELETEBUSY 0x800000 /* do not delete busy files (HFS semantic) */
165	#define PARAMASK 0x0fff00 /* mask of parameter descriptors */
166	/*
167	* Initialization of an nameidata structure.
168	*/
169	#define NDINIT(ndp, op, flags, segflg, namep, p) { \
170	(ndp)->ni_cnd.cn_nameiop = op; \
171	(ndp)->ni_cnd.cn_flags = flags; \
172	(ndp)->ni_segflg = segflg; \
173	(ndp)->ni_dirp = namep; \
174	(ndp)->ni_cnd.cn_proc = p; \
175	}
176	#endif /* KERNEL */
177
178	/*
179	* This structure describes the elements in the cache of recent
180	* names looked up by namei. NCHNAMLEN is sized to make structure
181	* size a power of two to optimize malloc's. Minimum reasonable
182	* size is 15.
183	*/
184
185	#define NCHNAMLEN 31 /* maximum name segment length we bother with */
186
187	struct namecache {
188	LIST_ENTRY(namecache) nc_hash; /* hash chain */
189	TAILQ_ENTRY(namecache) nc_lru; /* LRU chain */
190	struct vnode nc_dvp; / vnode of parent of name */
191	u_long nc_dvpid; /* capability number of nc_dvp */
192	struct vnode nc_vp; / vnode the name refers to */
193	u_long nc_vpid; /* capability number of nc_vp */
194	char nc_nlen; /* length of name */
195	char nc_name[NCHNAMLEN]; /* segment name */
196	};
197
198	#ifdef KERNEL
199	extern u_long nextvnodeid;
200	int namei __P((struct nameidata *ndp));
201	int lookup __P((struct nameidata *ndp));
202	int relookup __P((struct vnode dvp, struct vnode *vpp,
203	struct componentname *cnp));
204
205	/* namecache function prototypes */
206	int cache_lookup __P((struct vnode dvp, struct vnode *vpp,
207	struct componentname *cnp));
208	void cache_enter __P((struct vnode dvp, struct vnode vpp,
209	struct componentname *cnp));
210	void cache_purge __P((struct vnode *vp));
211	void cache_purgevfs __P((struct mount *mp));
212	#endif /* KERNEL */
213
214	/*
215	* Stats on usefulness of namei caches.
216	*/
217	struct nchstats {
218	long ncs_goodhits; /* hits that we can really use */
219	long ncs_neghits; /* negative hits that we can use */
220	long ncs_badhits; /* hits we must drop */
221	long ncs_falsehits; /* hits with id mismatch */
222	long ncs_miss; /* misses */
223	long ncs_long; /* long names that ignore cache */
224	long ncs_pass2; /* names found with passes == 2 */
225	long ncs_2passes; /* number of times we attempt it */
226	};
227	#endif /* !_SYS_NAMEI_H_ */