1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2001 Dag-Erling Coïdan Smørgrav 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33 #ifndef _PSEUDOFS_H_INCLUDED 34 #define _PSEUDOFS_H_INCLUDED 35 36 #include <sys/jail.h> 37 38 /* 39 * Opaque structures 40 */ 41 struct mntarg; 42 struct mount; 43 struct nameidata; 44 struct proc; 45 struct sbuf; 46 struct statfs; 47 struct thread; 48 struct uio; 49 struct vfsconf; 50 struct vnode; 51 52 /* 53 * Limits and constants 54 */ 55 #define PFS_NAMELEN 128 56 #define PFS_FSNAMELEN 16 /* equal to MFSNAMELEN */ 57 #define PFS_DELEN (offsetof(struct dirent, d_name) + PFS_NAMELEN) 58 59 typedef enum { 60 pfstype_none = 0, 61 pfstype_root, 62 pfstype_dir, 63 pfstype_this, 64 pfstype_parent, 65 pfstype_file, 66 pfstype_symlink, 67 pfstype_procdir 68 } pfs_type_t; 69 70 /* 71 * Flags 72 */ 73 #define PFS_RD 0x0001 /* readable */ 74 #define PFS_WR 0x0002 /* writeable */ 75 #define PFS_RDWR (PFS_RD|PFS_WR) 76 #define PFS_RAWRD 0x0004 /* raw reader */ 77 #define PFS_RAWWR 0x0008 /* raw writer */ 78 #define PFS_RAW (PFS_RAWRD|PFS_RAWWR) 79 #define PFS_PROCDEP 0x0010 /* process-dependent */ 80 #define PFS_NOWAIT 0x0020 /* allow malloc to fail */ 81 82 /* 83 * Data structures 84 */ 85 struct pfs_info; 86 struct pfs_node; 87 88 /* 89 * Init / uninit callback 90 */ 91 #define PFS_INIT_ARGS \ 92 struct pfs_info *pi, struct vfsconf *vfc 93 #define PFS_INIT_ARGNAMES \ 94 pi, vfc 95 #define PFS_INIT_PROTO(name) \ 96 int name(PFS_INIT_ARGS); 97 typedef int (*pfs_init_t)(PFS_INIT_ARGS); 98 99 /* 100 * Filler callback 101 * Called with proc held but unlocked 102 */ 103 #define PFS_FILL_ARGS \ 104 struct thread *td, struct proc *p, struct pfs_node *pn, \ 105 struct sbuf *sb, struct uio *uio 106 #define PFS_FILL_ARGNAMES \ 107 td, p, pn, sb, uio 108 #define PFS_FILL_PROTO(name) \ 109 int name(PFS_FILL_ARGS); 110 typedef int (*pfs_fill_t)(PFS_FILL_ARGS); 111 112 /* 113 * Attribute callback 114 * Called with proc locked 115 */ 116 struct vattr; 117 #define PFS_ATTR_ARGS \ 118 struct thread *td, struct proc *p, struct pfs_node *pn, \ 119 struct vattr *vap 120 #define PFS_ATTR_ARGNAMES \ 121 td, p, pn, vap 122 #define PFS_ATTR_PROTO(name) \ 123 int name(PFS_ATTR_ARGS); 124 typedef int (*pfs_attr_t)(PFS_ATTR_ARGS); 125 126 /* 127 * Visibility callback 128 * Called with proc locked 129 */ 130 #define PFS_VIS_ARGS \ 131 struct thread *td, struct proc *p, struct pfs_node *pn 132 #define PFS_VIS_ARGNAMES \ 133 td, p, pn 134 #define PFS_VIS_PROTO(name) \ 135 int name(PFS_VIS_ARGS); 136 typedef int (*pfs_vis_t)(PFS_VIS_ARGS); 137 138 /* 139 * Ioctl callback 140 * Called with proc locked 141 */ 142 #define PFS_IOCTL_ARGS \ 143 struct thread *td, struct proc *p, struct pfs_node *pn, \ 144 unsigned long cmd, void *data 145 #define PFS_IOCTL_ARGNAMES \ 146 td, p, pn, cmd, data 147 #define PFS_IOCTL_PROTO(name) \ 148 int name(PFS_IOCTL_ARGS); 149 typedef int (*pfs_ioctl_t)(PFS_IOCTL_ARGS); 150 151 /* 152 * Getextattr callback 153 * Called with proc locked 154 */ 155 #define PFS_GETEXTATTR_ARGS \ 156 struct thread *td, struct proc *p, struct pfs_node *pn, \ 157 int attrnamespace, const char *name, struct uio *uio, \ 158 size_t *size, struct ucred *cred 159 #define PFS_GETEXTATTR_ARGNAMES \ 160 td, p, pn, attrnamespace, name, uio, size, cred 161 #define PFS_GETEXTATTR_PROTO(name) \ 162 int name(PFS_GETEXTATTR_ARGS); 163 struct ucred; 164 typedef int (*pfs_getextattr_t)(PFS_GETEXTATTR_ARGS); 165 166 /* 167 * Last-close callback 168 * Called with proc locked 169 */ 170 #define PFS_CLOSE_ARGS \ 171 struct thread *td, struct proc *p, struct pfs_node *pn 172 #define PFS_CLOSE_ARGNAMES \ 173 td, p, pn 174 #define PFS_CLOSE_PROTO(name) \ 175 int name(PFS_CLOSE_ARGS); 176 typedef int (*pfs_close_t)(PFS_CLOSE_ARGS); 177 178 /* 179 * Destroy callback 180 */ 181 #define PFS_DESTROY_ARGS \ 182 struct pfs_node *pn 183 #define PFS_DESTROY_ARGNAMES \ 184 pn 185 #define PFS_DESTROY_PROTO(name) \ 186 int name(PFS_DESTROY_ARGS); 187 typedef int (*pfs_destroy_t)(PFS_DESTROY_ARGS); 188 189 /* 190 * pfs_info: describes a pseudofs instance 191 * 192 * The pi_mutex is only used to avoid using the global subr_unit lock 193 * for unrhdr. The rest of struct pfs_info is only modified during 194 * vfs_init() and vfs_uninit() of the consumer filesystem. 195 */ 196 struct pfs_info { 197 char pi_name[PFS_FSNAMELEN]; 198 pfs_init_t pi_init; 199 pfs_init_t pi_uninit; 200 201 /* members below this line are initialized at run time */ 202 struct pfs_node *pi_root; 203 struct mtx pi_mutex; 204 struct unrhdr *pi_unrhdr; 205 }; 206 207 /* 208 * pfs_node: describes a node (file or directory) within a pseudofs 209 * 210 * - Fields marked (o) are protected by the node's own mutex. 211 * - Fields marked (p) are protected by the node's parent's mutex. 212 * - Remaining fields are not protected by any lock and are assumed to be 213 * immutable once the node has been created. 214 * 215 * To prevent deadlocks, if a node's mutex is to be held at the same time 216 * as its parent's (e.g. when adding or removing nodes to a directory), 217 * the parent's mutex must always be acquired first. Unfortunately, this 218 * is not enforcable by WITNESS. 219 */ 220 struct pfs_node { 221 char pn_name[PFS_NAMELEN]; 222 pfs_type_t pn_type; 223 int pn_flags; 224 struct mtx pn_mutex; 225 void *pn_data; /* (o) */ 226 227 pfs_fill_t pn_fill; 228 pfs_ioctl_t pn_ioctl; 229 pfs_close_t pn_close; 230 pfs_attr_t pn_attr; 231 pfs_vis_t pn_vis; 232 pfs_getextattr_t pn_getextattr; 233 pfs_destroy_t pn_destroy; 234 235 struct pfs_info *pn_info; 236 u_int32_t pn_fileno; /* (o) */ 237 238 struct pfs_node *pn_parent; /* (o) */ 239 struct pfs_node *pn_nodes; /* (o) */ 240 struct pfs_node *pn_next; /* (p) */ 241 }; 242 243 /* 244 * VFS interface 245 */ 246 int pfs_mount (struct pfs_info *pi, struct mount *mp); 247 int pfs_cmount (struct mntarg *ma, void *data, uint64_t flags); 248 int pfs_unmount (struct mount *mp, int mntflags); 249 int pfs_root (struct mount *mp, int flags, 250 struct vnode **vpp); 251 int pfs_statfs (struct mount *mp, struct statfs *sbp); 252 int pfs_init (struct pfs_info *pi, struct vfsconf *vfc); 253 int pfs_uninit (struct pfs_info *pi, struct vfsconf *vfc); 254 255 /* 256 * Directory structure construction and manipulation 257 */ 258 struct pfs_node *pfs_create_dir (struct pfs_node *parent, const char *name, 259 pfs_attr_t attr, pfs_vis_t vis, 260 pfs_destroy_t destroy, int flags); 261 struct pfs_node *pfs_create_file(struct pfs_node *parent, const char *name, 262 pfs_fill_t fill, pfs_attr_t attr, 263 pfs_vis_t vis, pfs_destroy_t destroy, 264 int flags); 265 struct pfs_node *pfs_create_link(struct pfs_node *parent, const char *name, 266 pfs_fill_t fill, pfs_attr_t attr, 267 pfs_vis_t vis, pfs_destroy_t destroy, 268 int flags); 269 struct pfs_node *pfs_find_node (struct pfs_node *parent, const char *name); 270 void pfs_purge (struct pfs_node *pn); 271 int pfs_destroy (struct pfs_node *pn); 272 273 /* 274 * Now for some initialization magic... 275 */ 276 #define PSEUDOFS(name, version, flags) \ 277 \ 278 static struct pfs_info name##_info = { \ 279 #name, \ 280 name##_init, \ 281 name##_uninit, \ 282 }; \ 283 \ 284 static int \ 285 _##name##_mount(struct mount *mp) { \ 286 return (pfs_mount(&name##_info, mp)); \ 287 } \ 288 \ 289 static int \ 290 _##name##_init(struct vfsconf *vfc) { \ 291 return (pfs_init(&name##_info, vfc)); \ 292 } \ 293 \ 294 static int \ 295 _##name##_uninit(struct vfsconf *vfc) { \ 296 return (pfs_uninit(&name##_info, vfc)); \ 297 } \ 298 \ 299 static struct vfsops name##_vfsops = { \ 300 .vfs_cmount = pfs_cmount, \ 301 .vfs_init = _##name##_init, \ 302 .vfs_mount = _##name##_mount, \ 303 .vfs_root = pfs_root, \ 304 .vfs_statfs = pfs_statfs, \ 305 .vfs_uninit = _##name##_uninit, \ 306 .vfs_unmount = pfs_unmount, \ 307 }; \ 308 VFS_SET(name##_vfsops, name, VFCF_SYNTHETIC | flags); \ 309 MODULE_VERSION(name, version); \ 310 MODULE_DEPEND(name, pseudofs, 1, 1, 1); 311 312 #endif 313