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 #define PFS_AUTODRAIN 0x0040 /* sbuf_print can sleep to drain */ 82 83 /* 84 * Data structures 85 */ 86 struct pfs_info; 87 struct pfs_node; 88 89 /* 90 * Init / uninit callback 91 */ 92 #define PFS_INIT_ARGS \ 93 struct pfs_info *pi, struct vfsconf *vfc 94 #define PFS_INIT_ARGNAMES \ 95 pi, vfc 96 #define PFS_INIT_PROTO(name) \ 97 int name(PFS_INIT_ARGS); 98 typedef int (*pfs_init_t)(PFS_INIT_ARGS); 99 100 /* 101 * Filler callback 102 * Called with proc held but unlocked 103 */ 104 #define PFS_FILL_ARGS \ 105 struct thread *td, struct proc *p, struct pfs_node *pn, \ 106 struct sbuf *sb, struct uio *uio 107 #define PFS_FILL_ARGNAMES \ 108 td, p, pn, sb, uio 109 #define PFS_FILL_PROTO(name) \ 110 int name(PFS_FILL_ARGS); 111 typedef int (*pfs_fill_t)(PFS_FILL_ARGS); 112 113 /* 114 * Attribute callback 115 * Called with proc locked 116 */ 117 struct vattr; 118 #define PFS_ATTR_ARGS \ 119 struct thread *td, struct proc *p, struct pfs_node *pn, \ 120 struct vattr *vap 121 #define PFS_ATTR_ARGNAMES \ 122 td, p, pn, vap 123 #define PFS_ATTR_PROTO(name) \ 124 int name(PFS_ATTR_ARGS); 125 typedef int (*pfs_attr_t)(PFS_ATTR_ARGS); 126 127 /* 128 * Visibility callback 129 * Called with proc locked 130 */ 131 #define PFS_VIS_ARGS \ 132 struct thread *td, struct proc *p, struct pfs_node *pn 133 #define PFS_VIS_ARGNAMES \ 134 td, p, pn 135 #define PFS_VIS_PROTO(name) \ 136 int name(PFS_VIS_ARGS); 137 typedef int (*pfs_vis_t)(PFS_VIS_ARGS); 138 139 /* 140 * Ioctl callback 141 * Called with proc locked 142 */ 143 #define PFS_IOCTL_ARGS \ 144 struct thread *td, struct proc *p, struct pfs_node *pn, \ 145 unsigned long cmd, void *data 146 #define PFS_IOCTL_ARGNAMES \ 147 td, p, pn, cmd, data 148 #define PFS_IOCTL_PROTO(name) \ 149 int name(PFS_IOCTL_ARGS); 150 typedef int (*pfs_ioctl_t)(PFS_IOCTL_ARGS); 151 152 /* 153 * Getextattr callback 154 * Called with proc locked 155 */ 156 #define PFS_GETEXTATTR_ARGS \ 157 struct thread *td, struct proc *p, struct pfs_node *pn, \ 158 int attrnamespace, const char *name, struct uio *uio, \ 159 size_t *size, struct ucred *cred 160 #define PFS_GETEXTATTR_ARGNAMES \ 161 td, p, pn, attrnamespace, name, uio, size, cred 162 #define PFS_GETEXTATTR_PROTO(name) \ 163 int name(PFS_GETEXTATTR_ARGS); 164 struct ucred; 165 typedef int (*pfs_getextattr_t)(PFS_GETEXTATTR_ARGS); 166 167 /* 168 * Last-close callback 169 * Called with proc locked 170 */ 171 #define PFS_CLOSE_ARGS \ 172 struct thread *td, struct proc *p, struct pfs_node *pn 173 #define PFS_CLOSE_ARGNAMES \ 174 td, p, pn 175 #define PFS_CLOSE_PROTO(name) \ 176 int name(PFS_CLOSE_ARGS); 177 typedef int (*pfs_close_t)(PFS_CLOSE_ARGS); 178 179 /* 180 * Destroy callback 181 */ 182 #define PFS_DESTROY_ARGS \ 183 struct pfs_node *pn 184 #define PFS_DESTROY_ARGNAMES \ 185 pn 186 #define PFS_DESTROY_PROTO(name) \ 187 int name(PFS_DESTROY_ARGS); 188 typedef int (*pfs_destroy_t)(PFS_DESTROY_ARGS); 189 190 /* 191 * pfs_info: describes a pseudofs instance 192 * 193 * The pi_mutex is only used to avoid using the global subr_unit lock 194 * for unrhdr. The rest of struct pfs_info is only modified during 195 * vfs_init() and vfs_uninit() of the consumer filesystem. 196 */ 197 struct pfs_info { 198 char pi_name[PFS_FSNAMELEN]; 199 pfs_init_t pi_init; 200 pfs_init_t pi_uninit; 201 202 /* members below this line are initialized at run time */ 203 struct pfs_node *pi_root; 204 struct mtx pi_mutex; 205 struct unrhdr *pi_unrhdr; 206 }; 207 208 /* 209 * pfs_node: describes a node (file or directory) within a pseudofs 210 * 211 * - Fields marked (o) are protected by the node's own mutex. 212 * - Fields marked (p) are protected by the node's parent's mutex. 213 * - Remaining fields are not protected by any lock and are assumed to be 214 * immutable once the node has been created. 215 * 216 * To prevent deadlocks, if a node's mutex is to be held at the same time 217 * as its parent's (e.g. when adding or removing nodes to a directory), 218 * the parent's mutex must always be acquired first. Unfortunately, this 219 * is not enforcable by WITNESS. 220 */ 221 struct pfs_node { 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_last_node; /* (o) */ 241 struct pfs_node *pn_next; /* (p) */ 242 char pn_name[]; /* Keep it last */ 243 }; 244 245 /* 246 * VFS interface 247 */ 248 int pfs_mount (struct pfs_info *pi, struct mount *mp); 249 int pfs_cmount (struct mntarg *ma, void *data, uint64_t flags); 250 int pfs_unmount (struct mount *mp, int mntflags); 251 int pfs_root (struct mount *mp, int flags, 252 struct vnode **vpp); 253 int pfs_statfs (struct mount *mp, struct statfs *sbp); 254 int pfs_init (struct pfs_info *pi, struct vfsconf *vfc); 255 int pfs_uninit (struct pfs_info *pi, struct vfsconf *vfc); 256 257 /* 258 * Directory structure construction and manipulation 259 */ 260 struct pfs_node *pfs_create_dir (struct pfs_node *parent, const char *name, 261 pfs_attr_t attr, pfs_vis_t vis, 262 pfs_destroy_t destroy, int flags); 263 struct pfs_node *pfs_create_file(struct pfs_node *parent, const char *name, 264 pfs_fill_t fill, pfs_attr_t attr, 265 pfs_vis_t vis, pfs_destroy_t destroy, 266 int flags); 267 struct pfs_node *pfs_create_link(struct pfs_node *parent, const char *name, 268 pfs_fill_t fill, pfs_attr_t attr, 269 pfs_vis_t vis, pfs_destroy_t destroy, 270 int flags); 271 struct pfs_node *pfs_find_node (struct pfs_node *parent, const char *name); 272 void pfs_purge (struct pfs_node *pn); 273 int pfs_destroy (struct pfs_node *pn); 274 275 /* 276 * Now for some initialization magic... 277 */ 278 #define PSEUDOFS(name, version, flags) \ 279 \ 280 static struct pfs_info name##_info = { \ 281 #name, \ 282 name##_init, \ 283 name##_uninit, \ 284 }; \ 285 \ 286 static int \ 287 _##name##_mount(struct mount *mp) { \ 288 return (pfs_mount(&name##_info, mp)); \ 289 } \ 290 \ 291 static int \ 292 _##name##_init(struct vfsconf *vfc) { \ 293 return (pfs_init(&name##_info, vfc)); \ 294 } \ 295 \ 296 static int \ 297 _##name##_uninit(struct vfsconf *vfc) { \ 298 return (pfs_uninit(&name##_info, vfc)); \ 299 } \ 300 \ 301 static struct vfsops name##_vfsops = { \ 302 .vfs_cmount = pfs_cmount, \ 303 .vfs_init = _##name##_init, \ 304 .vfs_mount = _##name##_mount, \ 305 .vfs_root = pfs_root, \ 306 .vfs_statfs = pfs_statfs, \ 307 .vfs_uninit = _##name##_uninit, \ 308 .vfs_unmount = pfs_unmount, \ 309 }; \ 310 VFS_SET(name##_vfsops, name, VFCF_SYNTHETIC | flags); \ 311 MODULE_VERSION(name, version); \ 312 MODULE_DEPEND(name, pseudofs, 1, 1, 1); 313 314 #endif 315