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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)namei.h 8.5 (Berkeley) 1/9/95 34 * $FreeBSD: src/sys/sys/namei.h,v 1.29.2.2 2001/09/30 21:12:54 luigi Exp $ 35 * $DragonFly: src/sys/sys/namei.h,v 1.12 2004/04/08 22:00:40 dillon Exp $ 36 */ 37 38 #ifndef _SYS_NAMEI_H_ 39 #define _SYS_NAMEI_H_ 40 41 #include <sys/queue.h> 42 #include <sys/uio.h> 43 44 #ifdef _KERNEL 45 #ifndef _SYS_THREAD_H_ 46 #include <sys/thread.h> 47 #endif 48 #ifndef _SYS_PROC_H_ 49 #include <sys/proc.h> 50 #endif 51 #endif 52 53 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES) 54 #ifndef _SYS_NCHSTATS_H_ 55 #include <sys/nchstats.h> 56 #endif 57 #endif 58 59 struct componentname { 60 /* 61 * Arguments to lookup. 62 */ 63 u_long cn_nameiop; /* namei operation */ 64 u_long cn_flags; /* flags to namei */ 65 struct thread *cn_td; /* process requesting lookup */ 66 struct ucred *cn_cred; /* credentials */ 67 /* 68 * Shared between lookup and commit routines. 69 */ 70 char *cn_pnbuf; /* pathname buffer */ 71 char *cn_nameptr; /* pointer to looked up name */ 72 long cn_namelen; /* length of looked up component */ 73 long cn_consume; /* chars to consume in lookup() */ 74 int cn_timeout; /* if CNP_CACHETIMEOUT is set, in ticks */ 75 }; 76 77 /* 78 * Encapsulation of namei parameters. 79 */ 80 struct nameidata { 81 /* 82 * Arguments to namei/lookup. 83 */ 84 const char *ni_dirp; /* pathname pointer */ 85 enum uio_seg ni_segflg; /* location of pathname */ 86 /* 87 * Arguments to lookup. 88 */ 89 struct vnode *ni_startdir; /* starting directory */ 90 struct vnode *ni_rootdir; /* logical root directory */ 91 struct vnode *ni_topdir; /* logical top directory */ 92 /* 93 * Results: returned from/manipulated by lookup 94 */ 95 struct vnode *ni_vp; /* vnode of result */ 96 struct vnode *ni_dvp; /* vnode of intermediate directory */ 97 struct namecache *ni_ncp; /* namecache of result */ 98 struct namecache *ni_dncp; /* namecache of intermediate dir */ 99 /* 100 * Shared between namei and lookup/commit routines. 101 */ 102 size_t ni_pathlen; /* remaining chars in path incl \0 */ 103 char *ni_next; /* next location in pathname */ 104 u_long ni_loopcnt; /* count of symlinks encountered */ 105 /* 106 * Lookup parameters: this structure describes the subset of 107 * information from the nameidata structure that is passed 108 * through the VOP interface. 109 */ 110 struct componentname ni_cnd; 111 }; 112 113 #ifdef _KERNEL 114 /* 115 * namei operations 116 */ 117 #define NAMEI_LOOKUP 0 /* perform name lookup only */ 118 #define NAMEI_CREATE 1 /* setup for file creation */ 119 #define NAMEI_DELETE 2 /* setup for file deletion */ 120 #define NAMEI_RENAME 3 /* setup for file renaming */ 121 #define NAMEI_OPMASK 3 /* mask for operation */ 122 /* 123 * namei operational modifier flags, stored in ni_cnd.flags 124 */ 125 #define CNP_LOCKLEAF 0x00000004 /* return target vnode locked */ 126 #define CNP_LOCKPARENT 0x00000008 /* return parent vnode locked */ 127 #define CNP_WANTPARENT 0x00000010 /* return parent vnode unlocked */ 128 #define CNP_NOCACHE 0x00000020 /* name must not be left in cache */ 129 #define CNP_FOLLOW 0x00000040 /* follow symbolic links */ 130 #define CNP_NOOBJ 0x00000080 /* don't create object */ 131 #define CNP_WANTDNCP 0x00400000 /* return target namecache refd */ 132 #define CNP_WANTNCP 0x00800000 /* return target namecache refd */ 133 #define CNP_MODMASK 0x00c000fc /* mask of operational modifiers */ 134 /* 135 * Namei parameter descriptors. 136 * 137 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 138 * If the caller of namei sets the flag (for example execve wants to 139 * know the name of the program that is being executed), then it must 140 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 141 * be freed by either the commit routine or the VOP_ABORT routine. 142 * SAVESTART is set only by the callers of namei. It implies SAVENAME 143 * plus the addition of saving the parent directory that contains the 144 * name in ni_startdir. It allows repeated calls to lookup for the 145 * name being sought. The caller is responsible for releasing the 146 * buffer and for vrele'ing ni_startdir. 147 */ 148 #define CNP_NOCROSSMOUNT 0x00000100 /* do not cross mount points */ 149 #define CNP_RDONLY 0x00000200 /* lookup with read-only semantics */ 150 #define CNP_HASBUF 0x00000400 /* has allocated pathname buffer */ 151 #define CNP_SAVENAME 0x00000800 /* save pathname buffer */ 152 #define CNP_SAVESTART 0x00001000 /* save starting directory */ 153 #define CNP_ISDOTDOT 0x00002000 /* current component name is .. */ 154 #define CNP_MAKEENTRY 0x00004000 /* entry will be added to name cache */ 155 #define CNP_ISLASTCN 0x00008000 /* flag last component of pathname */ 156 #define CNP_ISSYMLINK 0x00010000 /* symlink needs interpretation */ 157 #define CNP_ISWHITEOUT 0x00020000 /* found whiteout */ 158 #define CNP_DOWHITEOUT 0x00040000 /* do whiteouts */ 159 #define CNP_WILLBEDIR 0x00080000 /* will be dir, allow trailing / */ 160 #define CNP_ISUNICODE 0x00100000 /* current component name is unicode*/ 161 #define CNP_PDIRUNLOCK 0x00200000 /* fs lookup() unlocked parent dir */ 162 /* (WANTDNCP) 0x00400000 */ 163 /* (WANTNCP) 0x00800000 */ 164 #define CNP_CACHETIMEOUT 0x01000000 /* apply timeout to cache entry */ 165 #define CNP_PARAMASK 0x011fff00 /* mask of parameter descriptors */ 166 167 /* 168 * Initialization of an nameidata structure. 169 */ 170 171 static __inline void 172 _NDINIT(struct nameidata *ndp, u_long op, u_long flags, enum uio_seg segflg, 173 const char *namep, struct thread *td 174 ) { 175 ndp->ni_cnd.cn_nameiop = op; 176 ndp->ni_cnd.cn_flags = flags; 177 ndp->ni_segflg = segflg; 178 ndp->ni_dirp = namep; 179 ndp->ni_cnd.cn_td = td; 180 } 181 182 static __inline void 183 NDINIT(struct nameidata *ndp, u_long op, u_long flags, enum uio_seg segflg, 184 const char *namep, struct thread *td 185 ) { 186 struct proc *p; 187 188 _NDINIT(ndp, op, flags, segflg, namep, td); 189 p = td->td_proc; 190 KKASSERT(p != NULL); 191 ndp->ni_cnd.cn_cred = p->p_ucred; 192 } 193 194 static __inline void 195 NDINIT2(struct nameidata *ndp, u_long op, u_long flags, enum uio_seg segflg, 196 const char *namep, struct thread *td, struct ucred *cr 197 ) { 198 _NDINIT(ndp, op, flags, segflg, namep, td); 199 ndp->ni_cnd.cn_cred = cr; 200 } 201 202 #define NDF_NO_DVP_RELE 0x00000001 203 #define NDF_NO_DVP_UNLOCK 0x00000002 204 #define NDF_NO_DVP_PUT 0x00000003 205 #define NDF_NO_VP_RELE 0x00000004 206 #define NDF_NO_VP_UNLOCK 0x00000008 207 #define NDF_NO_VP_PUT (NDF_NO_VP_RELE|NDF_NO_VP_UNLOCK) 208 #define NDF_NO_STARTDIR_RELE 0x00000010 209 #define NDF_NO_FREE_PNBUF 0x00000020 210 #define NDF_NO_DNCP_RELE 0x00000040 211 #define NDF_NO_NCP_RELE 0x00000080 212 213 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) 214 #define NDF_ONLY_PNBUF_AND_NCPS (~(NDF_NO_FREE_PNBUF|NDF_NO_DNCP_RELE|NDF_NO_NCP_RELE)) 215 216 void NDFREE (struct nameidata *, const uint); 217 218 int namei (struct nameidata *ndp); 219 int lookup (struct nameidata *ndp); 220 int relookup (struct vnode *dvp, struct vnode **vpp, 221 struct componentname *cnp); 222 #endif 223 224 #endif /* !_SYS_NAMEI_H_ */ 225