1/*-
2 * Copyright (c) 1985, 1989, 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	@(#)namei.h	8.5 (Berkeley) 1/9/95
30 * $FreeBSD$
31 */
32
33#ifndef _SYS_NAMEI_H_
34#define	_SYS_NAMEI_H_
35
36#include <sys/caprights.h>
37#include <sys/filedesc.h>
38#include <sys/queue.h>
39#include <sys/uio.h>
40
41struct componentname {
42	/*
43	 * Arguments to lookup.
44	 */
45	u_long	cn_nameiop;	/* namei operation */
46	u_int64_t cn_flags;	/* flags to namei */
47	struct	thread *cn_thread;/* thread requesting lookup */
48	struct	ucred *cn_cred;	/* credentials */
49	int	cn_lkflags;	/* Lock flags LK_EXCLUSIVE or LK_SHARED */
50	/*
51	 * Shared between lookup and commit routines.
52	 */
53	char	*cn_pnbuf;	/* pathname buffer */
54	char	*cn_nameptr;	/* pointer to looked up name */
55	long	cn_namelen;	/* length of looked up component */
56	long	cn_consume;	/* chars to consume in lookup() */
57};
58
59/*
60 * Encapsulation of namei parameters.
61 */
62struct nameidata {
63	/*
64	 * Arguments to namei/lookup.
65	 */
66	const	char *ni_dirp;		/* pathname pointer */
67	enum	uio_seg ni_segflg;	/* location of pathname */
68	cap_rights_t ni_rightsneeded;	/* rights required to look up vnode */
69	/*
70	 * Arguments to lookup.
71	 */
72	struct  vnode *ni_startdir;	/* starting directory */
73	struct	vnode *ni_rootdir;	/* logical root directory */
74	struct	vnode *ni_topdir;	/* logical top directory */
75	int	ni_dirfd;		/* starting directory for *at functions */
76	int	ni_strictrelative;	/* relative lookup only; no '..' */
77	/*
78	 * Results: returned from namei
79	 */
80	struct filecaps ni_filecaps;	/* rights the *at base has */
81	/*
82	 * Results: returned from/manipulated by lookup
83	 */
84	struct	vnode *ni_vp;		/* vnode of result */
85	struct	vnode *ni_dvp;		/* vnode of intermediate directory */
86	/*
87	 * Shared between namei and lookup/commit routines.
88	 */
89	size_t	ni_pathlen;		/* remaining chars in path */
90	char	*ni_next;		/* next location in pathname */
91	u_int	ni_loopcnt;		/* count of symlinks encountered */
92	/*
93	 * Lookup parameters: this structure describes the subset of
94	 * information from the nameidata structure that is passed
95	 * through the VOP interface.
96	 */
97	struct componentname ni_cnd;
98};
99
100#ifdef _KERNEL
101/*
102 * namei operations
103 */
104#define	LOOKUP		0	/* perform name lookup only */
105#define	CREATE		1	/* setup for file creation */
106#define	DELETE		2	/* setup for file deletion */
107#define	RENAME		3	/* setup for file renaming */
108#define	OPMASK		3	/* mask for operation */
109/*
110 * namei operational modifier flags, stored in ni_cnd.flags
111 */
112#define	LOCKLEAF	0x0004	/* lock vnode on return */
113#define	LOCKPARENT	0x0008	/* want parent vnode returned locked */
114#define	WANTPARENT	0x0010	/* want parent vnode returned unlocked */
115#define	NOCACHE		0x0020	/* name must not be left in cache */
116#define	FOLLOW		0x0040	/* follow symbolic links */
117#define	LOCKSHARED	0x0100	/* Shared lock leaf */
118#define	NOFOLLOW	0x0000	/* do not follow symbolic links (pseudo) */
119#define	MODMASK		0x01fc	/* mask of operational modifiers */
120/*
121 * Namei parameter descriptors.
122 *
123 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
124 * If the caller of namei sets the flag (for example execve wants to
125 * know the name of the program that is being executed), then it must
126 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
127 * be freed by either the commit routine or the VOP_ABORT routine.
128 * SAVESTART is set only by the callers of namei. It implies SAVENAME
129 * plus the addition of saving the parent directory that contains the
130 * name in ni_startdir. It allows repeated calls to lookup for the
131 * name being sought. The caller is responsible for releasing the
132 * buffer and for vrele'ing ni_startdir.
133 */
134#define	RDONLY		0x00000200 /* lookup with read-only semantics */
135#define	HASBUF		0x00000400 /* has allocated pathname buffer */
136#define	SAVENAME	0x00000800 /* save pathname buffer */
137#define	SAVESTART	0x00001000 /* save starting directory */
138#define	ISDOTDOT	0x00002000 /* current component name is .. */
139#define	MAKEENTRY	0x00004000 /* entry is to be added to name cache */
140#define	ISLASTCN	0x00008000 /* this is last component of pathname */
141#define	ISSYMLINK	0x00010000 /* symlink needs interpretation */
142#define	ISWHITEOUT	0x00020000 /* found whiteout */
143#define	DOWHITEOUT	0x00040000 /* do whiteouts */
144#define	WILLBEDIR	0x00080000 /* new files will be dirs; allow trailing / */
145#define	ISUNICODE	0x00100000 /* current component name is unicode*/
146#define	ISOPEN		0x00200000 /* caller is opening; return a real vnode. */
147#define	NOCROSSMOUNT	0x00400000 /* do not cross mount points */
148#define	NOMACCHECK	0x00800000 /* do not perform MAC checks */
149#define	AUDITVNODE1	0x04000000 /* audit the looked up vnode information */
150#define	AUDITVNODE2	0x08000000 /* audit the looked up vnode information */
151#define	TRAILINGSLASH	0x10000000 /* path ended in a slash */
152#define	NOCAPCHECK	0x20000000 /* do not perform capability checks */
153#define	PARAMASK	0x3ffffe00 /* mask of parameter descriptors */
154
155/*
156 * Initialization of a nameidata structure.
157 */
158#define	NDINIT(ndp, op, flags, segflg, namep, td)			\
159	NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, 0, td)
160#define	NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td)		\
161	NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, 0, td)
162#define	NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \
163	NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td)
164#define	NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td)		\
165	NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, 0, td)
166
167void NDINIT_ALL(struct nameidata *ndp, u_long op, u_long flags,
168    enum uio_seg segflg, const char *namep, int dirfd, struct vnode *startdir,
169    cap_rights_t *rightsp, struct thread *td);
170
171#define NDF_NO_DVP_RELE		0x00000001
172#define NDF_NO_DVP_UNLOCK	0x00000002
173#define NDF_NO_DVP_PUT		0x00000003
174#define NDF_NO_VP_RELE		0x00000004
175#define NDF_NO_VP_UNLOCK	0x00000008
176#define NDF_NO_VP_PUT		0x0000000c
177#define NDF_NO_STARTDIR_RELE	0x00000010
178#define NDF_NO_FREE_PNBUF	0x00000020
179#define NDF_ONLY_PNBUF		(~NDF_NO_FREE_PNBUF)
180
181void NDFREE(struct nameidata *, const u_int);
182
183int	namei(struct nameidata *ndp);
184int	lookup(struct nameidata *ndp);
185int	relookup(struct vnode *dvp, struct vnode **vpp,
186	    struct componentname *cnp);
187#endif
188
189/*
190 * Stats on usefulness of namei caches.
191 */
192struct nchstats {
193	long	ncs_goodhits;		/* hits that we can really use */
194	long	ncs_neghits;		/* negative hits that we can use */
195	long	ncs_badhits;		/* hits we must drop */
196	long	ncs_falsehits;		/* hits with id mismatch */
197	long	ncs_miss;		/* misses */
198	long	ncs_long;		/* long names that ignore cache */
199	long	ncs_pass2;		/* names found with passes == 2 */
200	long	ncs_2passes;		/* number of times we attempt it */
201};
202
203extern struct nchstats nchstats;
204
205#endif /* !_SYS_NAMEI_H_ */
206