1 /*- 2 * Copyright (c) 2001 Dag-Erling Coïdan Smørgrav 3 * 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 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #ifndef _PSEUDOFS_H_INCLUDED 32 #define _PSEUDOFS_H_INCLUDED 33 34 #include <sys/jail.h> 35 36 /* 37 * Opaque structures 38 */ 39 struct mntarg; 40 struct mount; 41 struct nameidata; 42 struct proc; 43 struct sbuf; 44 struct statfs; 45 struct thread; 46 struct uio; 47 struct vfsconf; 48 struct vnode; 49 50 /* 51 * Limits and constants 52 */ 53 #define PFS_NAMELEN 24 54 #define PFS_FSNAMELEN 16 /* equal to MFSNAMELEN */ 55 #define PFS_DELEN (8 + PFS_NAMELEN) 56 57 typedef enum { 58 pfstype_none = 0, 59 pfstype_root, 60 pfstype_dir, 61 pfstype_this, 62 pfstype_parent, 63 pfstype_file, 64 pfstype_symlink, 65 pfstype_procdir 66 } pfs_type_t; 67 68 /* 69 * Flags 70 */ 71 #define PFS_RD 0x0001 /* readable */ 72 #define PFS_WR 0x0002 /* writeable */ 73 #define PFS_RDWR (PFS_RD|PFS_WR) 74 #define PFS_RAWRD 0x0004 /* raw reader */ 75 #define PFS_RAWWR 0x0008 /* raw writer */ 76 #define PFS_RAW (PFS_RAWRD|PFS_RAWWR) 77 #define PFS_PROCDEP 0x0010 /* process-dependent */ 78 79 /* 80 * Data structures 81 */ 82 struct pfs_info; 83 struct pfs_node; 84 struct pfs_bitmap; 85 86 /* 87 * Init / uninit callback 88 */ 89 #define PFS_INIT_ARGS \ 90 struct pfs_info *pi, struct vfsconf *vfc 91 #define PFS_INIT_ARGNAMES \ 92 pi, vfc 93 #define PFS_INIT_PROTO(name) \ 94 int name(PFS_INIT_ARGS); 95 typedef int (*pfs_init_t)(PFS_INIT_ARGS); 96 97 /* 98 * Filler callback 99 * Called with proc held but unlocked 100 */ 101 #define PFS_FILL_ARGS \ 102 struct thread *td, struct proc *p, struct pfs_node *pn, \ 103 struct sbuf *sb, struct uio *uio 104 #define PFS_FILL_ARGNAMES \ 105 td, p, pn, sb, uio 106 #define PFS_FILL_PROTO(name) \ 107 int name(PFS_FILL_ARGS); 108 typedef int (*pfs_fill_t)(PFS_FILL_ARGS); 109 110 /* 111 * Attribute callback 112 * Called with proc locked 113 */ 114 struct vattr; 115 #define PFS_ATTR_ARGS \ 116 struct thread *td, struct proc *p, struct pfs_node *pn, \ 117 struct vattr *vap 118 #define PFS_ATTR_ARGNAMES \ 119 td, p, pn, vap 120 #define PFS_ATTR_PROTO(name) \ 121 int name(PFS_ATTR_ARGS); 122 typedef int (*pfs_attr_t)(PFS_ATTR_ARGS); 123 124 struct pfs_bitmap; /* opaque */ 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 for 193 * unrhdr. The rest of struct pfs_info is only modified while Giant is 194 * held (during vfs_init() and vfs_uninit()). 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, jflag) \ 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 if (jflag && !prison_allow(curthread->td_ucred, jflag)) \ 287 return (EPERM); \ 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 | (jflag ? VFCF_JAIL : 0)); \ 311 MODULE_VERSION(name, version); \ 312 MODULE_DEPEND(name, pseudofs, 1, 1, 1); 313 314 #endif 315