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Diffstat (limited to 'sys/sys/namei.h')
| -rw-r--r-- | sys/sys/namei.h | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/sys/sys/namei.h b/sys/sys/namei.h new file mode 100644 index 0000000..975dfa9 --- /dev/null +++ b/sys/sys/namei.h @@ -0,0 +1,279 @@ +/* $OpenBSD: namei.h,v 1.45 2020/03/19 13:55:20 anton Exp $ */ +/* $NetBSD: namei.h,v 1.11 1996/02/09 18:25:20 christos Exp $ */ + +/* + * 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. 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/tree.h> +#include <sys/uio.h> + +struct unveil; + +/* + * Encapsulation of namei parameters. + */ +struct nameidata { + /* + * Arguments to namei/lookup. + */ + const char *ni_dirp; /* pathname pointer */ + int ni_dirfd; /* dirfd from *at() functions */ + 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 */ + uint64_t ni_pledge; /* expected pledge for namei */ + u_char ni_unveil; /* required unveil flags for namei */ + /* + * 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. + */ + size_t ni_pathlen; /* remaining chars in path */ + char *ni_next; /* next location in pathname */ + u_long ni_loopcnt; /* count of symlinks encountered */ + struct unveil *ni_unveil_match; /* last matching unveil component */ + struct vnode **ni_tvp; /* traversed vnodes */ + size_t ni_tvpend; /* end of traversed vnode list */ + size_t ni_tvpsize; /* size of traversed vnode list */ + int ni_unveil_eacces; /* indicates unveil flag mismatch */ + + /* + * Lookup parameters: this structure describes the subset of + * information from the nameidat satructure 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 */ + char *cn_rpbuf; /* realpath buffer */ + size_t cn_rpi; /* realpath index */ + char *cn_nameptr; /* pointer to looked up name */ + long cn_namelen; /* length of looked up component */ + long cn_consume; /* chars to consume in lookup() */ + } 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 REALPATH 0x020000 /* save pathname buffer for realpath */ +#define REQUIREDIR 0x080000 /* must be a directory */ +#define STRIPSLASHES 0x100000 /* strip trailing slashes */ +#define PDIRUNLOCK 0x200000 /* vfs_lookup() unlocked parent dir */ +#define BYPASSUNVEIL 0x400000 /* bypass pledgepath check */ +#define KERNELPATH 0x800000 /* access file as kernel, not process */ + +/* + * Initialization of an nameidata structure. + */ +void ndinitat(struct nameidata *ndp, u_long op, u_long flags, + enum uio_seg segflg, int dirfd, const char *namep, struct proc *p); + +#define NDINITAT(ndp, op, flags, segflg, dirfd, namep, p) \ + ndinitat(ndp, op, flags, segflg, dirfd, namep, p) + +#define NDINIT(ndp, op, flags, segflp, namep, p) \ + ndinitat(ndp, op, flags, segflp, AT_FDCWD, namep, p) + +/* Defined for users of NDINIT(). */ +#define AT_FDCWD -100 +#endif + +/* + * This structure describes the elements in the cache of recent + * names looked up by namei. + */ + +#define NAMECACHE_MAXLEN 31 /* maximum name segment length we bother with */ + +struct namecache { + TAILQ_ENTRY(namecache) nc_lru; /* Regular Entry LRU chain */ + TAILQ_ENTRY(namecache) nc_neg; /* Negative Entry LRU chain */ + RBT_ENTRY(namecache) n_rbcache; /* Namecache rb tree from vnode */ + TAILQ_ENTRY(namecache) nc_me; /* ncp's referring to me */ + 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[NAMECACHE_MAXLEN]; /* segment name */ +}; + +#ifdef _KERNEL +struct namecache_rb_cache; + +int namei(struct nameidata *ndp); +int vfs_lookup(struct nameidata *ndp); +int vfs_relookup(struct vnode *dvp, struct vnode **vpp, + struct componentname *cnp); +void cache_tree_init(struct namecache_rb_cache *); +void cache_purge(struct vnode *); +int cache_lookup(struct vnode *, struct vnode **, struct componentname *); +void cache_enter(struct vnode *, struct vnode *, struct componentname *); +int cache_revlookup(struct vnode *, struct vnode **, char **, char *); +void nchinit(void); +struct mount; +void cache_purgevfs(struct mount *); + +int unveil_add(struct proc *, struct nameidata *, const char *); +void unveil_removevnode(struct vnode *); +void unveil_free_traversed_vnodes(struct nameidata *); +ssize_t unveil_find_cover(struct vnode *, struct proc *); +struct unveil *unveil_lookup(struct vnode *, struct process *, ssize_t *); +void unveil_start_relative(struct proc *, struct nameidata *, struct vnode *); +void unveil_check_component(struct proc *, struct nameidata *, struct vnode *); +int unveil_check_final(struct proc *, struct nameidata *); + +extern struct pool namei_pool; + +#endif + +/* + * Stats on usefulness of namei caches. + */ +struct nchstats { + u_int64_t ncs_goodhits; /* hits that we can really use */ + u_int64_t ncs_neghits; /* negative hits that we can use */ + u_int64_t ncs_badhits; /* hits we must drop */ + u_int64_t ncs_falsehits; /* hits with id mismatch */ + u_int64_t ncs_miss; /* misses */ + u_int64_t ncs_long; /* long names that ignore cache */ + u_int64_t ncs_pass2; /* names found with passes == 2 */ + u_int64_t ncs_2passes; /* number of times we attempt it */ + u_int64_t ncs_revhits; /* reverse-cache hits */ + u_int64_t ncs_revmiss; /* reverse-cache misses */ + u_int64_t ncs_dothits; /* hits on '.' lookups */ + u_int64_t ncs_dotdothits; /* hits on '..' lookups */ +}; + +/* These sysctl names are only really used by sysctl(8) */ +#define KERN_NCHSTATS_GOODHITS 1 +#define KERN_NCHSTATS_NEGHITS 2 +#define KERN_NCHSTATS_BADHITS 3 +#define KERN_NCHSTATS_FALSEHITS 4 +#define KERN_NCHSTATS_MISS 5 +#define KERN_NCHSTATS_LONG 6 +#define KERN_NCHSTATS_PASS2 7 +#define KERN_NCHSTATS_2PASSES 8 +#define KERN_NCHSTATS_REVHITS 9 +#define KERN_NCHSTATS_REVMISS 10 +#define KERN_NCHSTATS_DOTHITS 11 +#define KERN_NCHSTATS_DOTDOTHITS 12 +#define KERN_NCHSTATS_MAXID 13 + +#define CTL_KERN_NCHSTATS_NAMES { \ + { 0, 0 }, \ + { "good_hits", CTLTYPE_QUAD }, \ + { "negative_hits", CTLTYPE_QUAD }, \ + { "bad_hits", CTLTYPE_QUAD }, \ + { "false_hits", CTLTYPE_QUAD }, \ + { "misses", CTLTYPE_QUAD }, \ + { "long_names", CTLTYPE_QUAD }, \ + { "pass2", CTLTYPE_QUAD }, \ + { "2passes", CTLTYPE_QUAD }, \ + { "ncs_revhits", CTLTYPE_QUAD }, \ + { "ncs_revmiss", CTLTYPE_QUAD }, \ + { "ncs_dothits", CTLTYPE_QUAD }, \ + { "nch_dotdothits", CTLTYPE_QUAD }, \ +} + +/* Unveil flags for namei */ +#define UNVEIL_READ 0x01 +#define UNVEIL_WRITE 0x02 +#define UNVEIL_CREATE 0x04 +#define UNVEIL_EXEC 0x08 +#define UNVEIL_USERSET 0x0F +#define UNVEIL_INSPECT 0x80 + +#endif /* !_SYS_NAMEI_H_ */ |