bsd/miscfs/devfs/devfs_vfsops.c

   1 /*
   2  * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*-
  29  * Copyright 1997,1998 Julian Elischer.  All rights reserved.
  30  * julian@freebsd.org
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions are
  34  * met:
  35  *  1. Redistributions of source code must retain the above copyright
  36  *     notice, this list of conditions and the following disclaimer.
  37  *  2. Redistributions in binary form must reproduce the above copyright notice,
  38  *     this list of conditions and the following disclaimer in the documentation
  39  *     and/or other materials provided with the distribution.
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
  42  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  43  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  44  * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
  45  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  47  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  48  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * devfs_vfsops.c
  54  *
  55  */
  56 /*
  57  * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
  58  * support for mandatory and extensible security protections.  This notice
  59  * is included in support of clause 2.2 (b) of the Apple Public License,
  60  * Version 2.0.
  61  */
  62 /*
  63  * HISTORY
  64  *  Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
  65  *  - modified devfs_statfs() to use devfs_stats to calculate the
  66  *    amount of memory used by devfs
  67  */
  68
  69
  70 #include <sys/param.h>
  71 #include <sys/systm.h>
  72 #include <sys/kernel.h>
  73 #include <sys/vnode_internal.h>
  74 #include <sys/proc.h>
  75 #include <sys/kauth.h>
  76 #include <sys/mount_internal.h>
  77 #include <sys/malloc.h>
  78
  79 #include <libkern/OSAtomic.h>
  80
  81 #if CONFIG_MACF
  82 #include <security/mac_framework.h>
  83 #endif
  84
  85 #include "devfs.h"
  86 #include "devfsdefs.h"
  87
  88 static int devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, vfs_context_t ctx);
  89 static int devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t ctx);
  90
  91 static struct vfstable * devfs_vfsp = 0;
  92 extern int setup_kmem;
  93 __private_extern__ void devfs_setup_kmem(void);
  94
  95
  96 /*-
  97  * Called from the generic VFS startups.
  98  * This is the second stage of DEVFS initialisation.
  99  * The probed devices have already been loaded and the
 100  * basic structure of the DEVFS created.
 101  * We take the oportunity to mount the hidden DEVFS layer, so that
 102  * devices from devfs get sync'd.
 103  */
 104 static int
 105 devfs_init(struct vfsconf *vfsp)
 106 {
 107     devfs_vfsp = (struct vfstable *)vfsp; /* remember this for devfs_kernel_mount below */
 108
 109     if (devfs_sinit())
 110         return (ENOTSUP);
 111     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
 112                     UID_ROOT, GID_WHEEL, 0622, "console");
 113     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
 114                     UID_ROOT, GID_WHEEL, 0666, "tty");
 115     if (setup_kmem) {
 116         devfs_setup_kmem();
 117     }
 118     devfs_make_node(makedev(3, 2), DEVFS_CHAR,
 119                     UID_ROOT, GID_WHEEL, 0666, "null");
 120     devfs_make_node(makedev(3, 3), DEVFS_CHAR,
 121                     UID_ROOT, GID_WHEEL, 0666, "zero");
 122     devfs_make_node(makedev(6, 0), DEVFS_CHAR,
 123                     UID_ROOT, GID_WHEEL, 0600, "klog");
 124     return 0;
 125 }
 126
 127 __private_extern__ void
 128 devfs_setup_kmem(void)
 129 {
 130         devfs_make_node(makedev(3, 0), DEVFS_CHAR,
 131                     UID_ROOT, GID_KMEM, 0640, "mem");
 132         devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 133                     UID_ROOT, GID_KMEM, 0640, "kmem");
 134 }
 135
 136
 137 /*-
 138  *  mp   - pointer to 'mount' structure
 139  *  path - addr in user space of mount point (ie /usr or whatever)
 140  *  data - addr in user space of mount params including the
 141  *         name of the block special file to treat as a filesystem.
 142  *         (NOT USED)
 143  *  ndp  - namei data pointer (NOT USED)
 144  *  p    - proc pointer
 145  * devfs is special in that it doesn't require any device to be mounted..
 146  * It makes up its data as it goes along.
 147  * it must be mounted during single user.. until it is, only std{in/out/err}
 148  * and the root filesystem are available.
 149  */
 150 /*proto*/
 151 int
 152 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t ctx)
 153 {
 154         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 155         int error;
 156
 157         /*-
 158          *  If they just want to update, we don't need to do anything.
 159          */
 160         if (mp->mnt_flag & MNT_UPDATE)
 161         {
 162                 return 0;
 163         }
 164
 165         /* Advisory locking should be handled at the VFS layer */
 166         vfs_setlocklocal(mp);
 167
 168         /*-
 169          *  Well, it's not an update, it's a real mount request.
 170          *  Time to get dirty.
 171          * HERE we should check to see if we are already mounted here.
 172          */
 173
 174         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 175                M_DEVFSMNT, M_WAITOK);
 176         if (devfs_mp_p == NULL)
 177                 return (ENOMEM);
 178         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 179         devfs_mp_p->mount = mp;
 180
 181         /*-
 182          *  Fill out some fields
 183          */
 184         mp->mnt_data = (qaddr_t)devfs_mp_p;
 185         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 186         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 187         mp->mnt_flag |= MNT_LOCAL;
 188
 189         DEVFS_LOCK();
 190         error = dev_dup_plane(devfs_mp_p);
 191         DEVFS_UNLOCK();
 192
 193         if (error) {
 194                 mp->mnt_data = (qaddr_t)0;
 195                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 196                 return (error);
 197         } else
 198                 DEVFS_INCR_MOUNTS();
 199
 200         /*-
 201          *  Copy in the name of the directory the filesystem
 202          *  is to be mounted on.
 203          *  And we clear the remainder of the character strings
 204          *  to be tidy.
 205          */
 206
 207         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 208         bcopy("devfs",mp->mnt_vfsstat.f_mntfromname, 5);
 209         (void)devfs_statfs(mp, &mp->mnt_vfsstat, ctx);
 210
 211         return 0;
 212 }
 213
 214
 215 static int
 216 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t ctx)
 217 {
 218         return 0;
 219 }
 220
 221 /*-
 222  *  Unmount the filesystem described by mp.
 223  */
 224 static int
 225 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t ctx)
 226 {
 227         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 228         int flags = 0;
 229         int force = 0;
 230         int error;
 231
 232         if (mntflags & MNT_FORCE) {
 233                 flags |= FORCECLOSE;
 234                 force = 1;
 235         }
 236         error = vflush(mp, NULLVP, flags);
 237         if (error && !force)
 238                 return error;
 239
 240         DEVFS_LOCK();
 241         devfs_free_plane(devfs_mp_p);
 242         DEVFS_UNLOCK();
 243
 244         DEVFS_DECR_MOUNTS();
 245
 246         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 247         mp->mnt_data = (qaddr_t)0;
 248         mp->mnt_flag &= ~MNT_LOCAL;
 249
 250         return 0;
 251 }
 252
 253 /* return the address of the root vnode  in *vpp */
 254 static int
 255 devfs_root(struct mount *mp, struct vnode **vpp, __unused vfs_context_t ctx)
 256 {
 257         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 258         int error;
 259
 260         DEVFS_LOCK();
 261         /* last parameter to devfs_dntovn() is ignored */
 262         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, NULL);
 263         DEVFS_UNLOCK();
 264
 265         return error;
 266 }
 267
 268 static int
 269 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t ctx)
 270 {
 271         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 272
 273         /*-
 274          *  Fill in the stat block.
 275          */
 276         //sbp->f_type   = mp->mnt_vfsstat.f_type;
 277         sbp->f_flags  = 0;              /* XXX */
 278         sbp->f_bsize  = 512;
 279         sbp->f_iosize = 512;
 280         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 281                          + devfs_stats.nodes * sizeof(devnode_t)
 282                          + devfs_stats.entries * sizeof(devdirent_t)
 283                          + devfs_stats.stringspace
 284                          ) / sbp->f_bsize;
 285         sbp->f_bfree  = 0;
 286         sbp->f_bavail = 0;
 287         sbp->f_files  = devfs_stats.nodes;
 288         sbp->f_ffree  = 0;
 289         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 290         sbp->f_fsid.val[1] = vfs_typenum(mp);
 291
 292         return 0;
 293 }
 294
 295 static int
 296 devfs_vfs_getattr(__unused mount_t mp, struct vfs_attr *fsap, __unused vfs_context_t ctx)
 297 {
 298         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 299         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 300         VFSATTR_RETURN(fsap, f_bsize, 512);
 301         VFSATTR_RETURN(fsap, f_iosize, 512);
 302         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 303                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 304                          + devfs_stats.nodes * sizeof(devnode_t)
 305                          + devfs_stats.entries * sizeof(devdirent_t)
 306                          + devfs_stats.stringspace
 307                          ) / fsap->f_bsize;
 308                 fsap->f_bused = fsap->f_blocks;
 309                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 310                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 311         }
 312         VFSATTR_RETURN(fsap, f_bfree, 0);
 313         VFSATTR_RETURN(fsap, f_bavail, 0);
 314         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 315         VFSATTR_RETURN(fsap, f_ffree, 0);
 316         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 317
 318         return 0;
 319 }
 320
 321 static int
 322 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t ctx)
 323 {
 324     return (0);
 325 }
 326
 327
 328 static int
 329 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t ctx)
 330 {
 331         return ENOTSUP;
 332 }
 333
 334 /*************************************************************
 335  * The concept of exporting a kernel generated devfs is stupid
 336  * So don't handle filehandles
 337  */
 338
 339 static int
 340 devfs_fhtovp (__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t ctx)
 341 {
 342         return (EINVAL);
 343 }
 344
 345
 346 static int
 347 devfs_vptofh (__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t ctx)
 348 {
 349         return (EINVAL);
 350 }
 351
 352 static int
 353 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 354              __unused size_t *oldlenp, __unused user_addr_t newp,
 355              __unused size_t newlen, __unused vfs_context_t ctx)
 356 {
 357     return (ENOTSUP);
 358 }
 359
 360 #include <sys/namei.h>
 361
 362 /*
 363  * Function: devfs_kernel_mount
 364  * Purpose:
 365  *   Mount devfs at the given mount point from within the kernel.
 366  */
 367 int
 368 devfs_kernel_mount(char * mntname)
 369 {
 370         struct mount *mp;
 371         int error;
 372         struct nameidata nd;
 373         struct vnode  * vp;
 374         vfs_context_t ctx = vfs_context_kernel();
 375
 376         if (devfs_vfsp == NULL) {
 377             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 378             return (EINVAL);
 379         }
 380
 381         /*
 382          * Get vnode to be covered
 383          */
 384         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
 385             CAST_USER_ADDR_T(mntname), ctx);
 386         if ((error = namei(&nd))) {
 387             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 388                    mntname, error);
 389             return (error);
 390         }
 391         nameidone(&nd);
 392         vp = nd.ni_vp;
 393
 394         if ((error = VNOP_FSYNC(vp, MNT_WAIT, ctx))) {
 395             printf("devfs_kernel_mount: vnop_fsync failed: %d\n", error);
 396             vnode_put(vp);
 397             return (error);
 398         }
 399         if ((error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
 400             printf("devfs_kernel_mount: buf_invalidateblks failed: %d\n", error);
 401             vnode_put(vp);
 402             return (error);
 403         }
 404         if (vnode_isdir(vp) == 0) {
 405             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 406             vnode_put(vp);
 407             return (ENOTDIR);
 408         }
 409         if ((vnode_mountedhere(vp))) {
 410             vnode_put(vp);
 411             return (EBUSY);
 412         }
 413
 414         /*
 415          * Allocate and initialize the filesystem.
 416          */
 417         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 418                 M_MOUNT, M_WAITOK);
 419         bzero((char *)mp, (u_long)sizeof(struct mount));
 420
 421         /* Initialize the default IO constraints */
 422         mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 423         mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 424         mp->mnt_ioflags = 0;
 425         mp->mnt_realrootvp = NULLVP;
 426         mp->mnt_authcache_ttl = CACHED_LOOKUP_RIGHT_TTL;
 427
 428         mount_lock_init(mp);
 429         TAILQ_INIT(&mp->mnt_vnodelist);
 430         TAILQ_INIT(&mp->mnt_workerqueue);
 431         TAILQ_INIT(&mp->mnt_newvnodes);
 432
 433         (void)vfs_busy(mp, LK_NOWAIT);
 434         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 435         mp->mnt_vtable = devfs_vfsp;
 436         devfs_vfsp->vfc_refcount++;
 437         devfs_vfsp->vfc_threadsafe = TRUE;
 438         devfs_vfsp->vfc_64bitready = TRUE;
 439         mp->mnt_flag = 0;
 440         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 441         strlcpy(mp->mnt_vfsstat.f_fstypename, devfs_vfsp->vfc_name, MFSTYPENAMELEN);
 442         vp->v_mountedhere = mp;
 443         mp->mnt_vnodecovered = vp;
 444         mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
 445         (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
 446 #if CONFIG_MACF
 447         mac_mount_label_init(mp);
 448         mac_mount_label_associate(ctx, mp);
 449 #endif
 450
 451         error = devfs_mount(mp, NULL, USER_ADDR_NULL, ctx);
 452
 453         if (error) {
 454             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 455             mp->mnt_vtable->vfc_refcount--;
 456
 457             vfs_unbusy(mp);
 458
 459             mount_lock_destroy(mp);
 460 #if CONFIG_MACF
 461             mac_mount_label_destroy(mp);
 462 #endif
 463             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 464             vnode_put(vp);
 465             return (error);
 466         }
 467         vnode_ref(vp);
 468         vnode_put(vp);
 469         vfs_unbusy(mp);
 470         mount_list_add(mp);
 471         return (0);
 472 }
 473
 474 struct vfsops devfs_vfsops = {
 475         devfs_mount,
 476         devfs_start,
 477         devfs_unmount,
 478         devfs_root,
 479         NULL,                           /* quotactl */
 480         devfs_vfs_getattr,
 481         devfs_sync,
 482         devfs_vget,
 483         devfs_fhtovp,
 484         devfs_vptofh,
 485         devfs_init,
 486         devfs_sysctl,
 487         NULL,
 488         {NULL}
 489 };