sys/kern/vfs_export.c

   1 /*-
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * (c) UNIX System Laboratories, Inc.
   5  * All or some portions of this file are derived from material licensed
   6  * to the University of California by American Telephone and Telegraph
   7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   8  * the permission of UNIX System Laboratories, Inc.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)vfs_subr.c  8.31 (Berkeley) 5/26/95
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/dirent.h>
  42 #include <sys/domain.h>
  43 #include <sys/kernel.h>
  44 #include <sys/lock.h>
  45 #include <sys/malloc.h>
  46 #include <sys/mbuf.h>
  47 #include <sys/mount.h>
  48 #include <sys/mutex.h>
  49 #include <sys/refcount.h>
  50 #include <sys/socket.h>
  51 #include <sys/systm.h>
  52 #include <sys/vnode.h>
  53
  54 #include <net/radix.h>
  55
  56 static MALLOC_DEFINE(M_NETADDR, "export_host", "Export host address structure");
  57
  58 static void     vfs_free_addrlist(struct netexport *nep);
  59 static int      vfs_free_netcred(struct radix_node *rn, void *w);
  60 static int      vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
  61                     struct export_args *argp);
  62 static struct netcred *vfs_export_lookup(struct mount *, struct sockaddr *);
  63
  64 /*
  65  * Network address lookup element
  66  */
  67 struct netcred {
  68         struct  radix_node netc_rnodes[2];
  69         int     netc_exflags;
  70         struct  ucred netc_anon;
  71 };
  72
  73 /*
  74  * Network export information
  75  */
  76 struct netexport {
  77         struct  netcred ne_defexported;               /* Default export */
  78         struct  radix_node_head *ne_rtable[AF_MAX+1]; /* Individual exports */
  79 };
  80
  81 /*
  82  * Build hash lists of net addresses and hang them off the mount point.
  83  * Called by ufs_mount() to set up the lists of export addresses.
  84  */
  85 static int
  86 vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
  87     struct export_args *argp)
  88 {
  89         register struct netcred *np;
  90         register struct radix_node_head *rnh;
  91         register int i;
  92         struct radix_node *rn;
  93         struct sockaddr *saddr, *smask = 0;
  94         struct domain *dom;
  95         int error;
  96
  97         /*
  98          * XXX: This routine converts from a `struct xucred'
  99          * (argp->ex_anon) to a `struct ucred' (np->netc_anon).  This
 100          * operation is questionable; for example, what should be done
 101          * with fields like cr_uidinfo and cr_prison?  Currently, this
 102          * routine does not touch them (leaves them as NULL).
 103          */
 104         if (argp->ex_anon.cr_version != XUCRED_VERSION) {
 105                 vfs_mount_error(mp, "ex_anon.cr_version: %d != %d",
 106                     argp->ex_anon.cr_version, XUCRED_VERSION);
 107                 return (EINVAL);
 108         }
 109
 110         if (argp->ex_addrlen == 0) {
 111                 if (mp->mnt_flag & MNT_DEFEXPORTED) {
 112                         vfs_mount_error(mp,
 113                             "MNT_DEFEXPORTED already set for mount %p", mp);
 114                         return (EPERM);
 115                 }
 116                 np = &nep->ne_defexported;
 117                 np->netc_exflags = argp->ex_flags;
 118                 bzero(&np->netc_anon, sizeof(np->netc_anon));
 119                 np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
 120                 np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
 121                 bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
 122                     sizeof(np->netc_anon.cr_groups));
 123                 refcount_init(&np->netc_anon.cr_ref, 1);
 124                 MNT_ILOCK(mp);
 125                 mp->mnt_flag |= MNT_DEFEXPORTED;
 126                 MNT_IUNLOCK(mp);
 127                 return (0);
 128         }
 129
 130 #if MSIZE <= 256
 131         if (argp->ex_addrlen > MLEN) {
 132                 vfs_mount_error(mp, "ex_addrlen %d is greater than %d",
 133                     argp->ex_addrlen, MLEN);
 134                 return (EINVAL);
 135         }
 136 #endif
 137
 138         i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
 139         np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO);
 140         saddr = (struct sockaddr *) (np + 1);
 141         if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen)))
 142                 goto out;
 143         if (saddr->sa_family == AF_UNSPEC || saddr->sa_family > AF_MAX) {
 144                 error = EINVAL;
 145                 vfs_mount_error(mp, "Invalid saddr->sa_family: %d");
 146                 goto out;
 147         }
 148         if (saddr->sa_len > argp->ex_addrlen)
 149                 saddr->sa_len = argp->ex_addrlen;
 150         if (argp->ex_masklen) {
 151                 smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
 152                 error = copyin(argp->ex_mask, smask, argp->ex_masklen);
 153                 if (error)
 154                         goto out;
 155                 if (smask->sa_len > argp->ex_masklen)
 156                         smask->sa_len = argp->ex_masklen;
 157         }
 158         i = saddr->sa_family;
 159         if ((rnh = nep->ne_rtable[i]) == NULL) {
 160                 /*
 161                  * Seems silly to initialize every AF when most are not used,
 162                  * do so on demand here
 163                  */
 164                 for (dom = domains; dom; dom = dom->dom_next) {
 165                         KASSERT(((i == AF_INET) || (i == AF_INET6)),
 166                             ("unexpected protocol in vfs_hang_addrlist"));
 167                         if (dom->dom_family == i && dom->dom_rtattach) {
 168                                 /*
 169                                  * XXX MRT
 170                                  * The INET and INET6 domains know the
 171                                  * offset already. We don't need to send it
 172                                  * So we just use it as a flag to say that
 173                                  * we are or are not setting up a real routing
 174                                  * table. Only IP and IPV6 need have this
 175                                  * be 0 so all other protocols can stay the
 176                                  * same (ABI compatible).
 177                                  */
 178                                 dom->dom_rtattach(
 179                                     (void **) &nep->ne_rtable[i], 0);
 180                                 break;
 181                         }
 182                 }
 183                 if ((rnh = nep->ne_rtable[i]) == NULL) {
 184                         error = ENOBUFS;
 185                         vfs_mount_error(mp, "%s %s %d",
 186                             "Unable to initialize radix node head ",
 187                             "for address family", i);
 188                         goto out;
 189                 }
 190         }
 191         RADIX_NODE_HEAD_LOCK(rnh);
 192         rn = (*rnh->rnh_addaddr)(saddr, smask, rnh, np->netc_rnodes);
 193         RADIX_NODE_HEAD_UNLOCK(rnh);
 194         if (rn == NULL || np != (struct netcred *)rn) { /* already exists */
 195                 error = EPERM;
 196                 vfs_mount_error(mp, "Invalid radix node head, rn: %p %p",
 197                     rn, np);
 198                 goto out;
 199         }
 200         np->netc_exflags = argp->ex_flags;
 201         bzero(&np->netc_anon, sizeof(np->netc_anon));
 202         np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
 203         np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
 204         bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
 205             sizeof(np->netc_anon.cr_groups));
 206         refcount_init(&np->netc_anon.cr_ref, 1);
 207         return (0);
 208 out:
 209         free(np, M_NETADDR);
 210         return (error);
 211 }
 212
 213 /* Helper for vfs_free_addrlist. */
 214 /* ARGSUSED */
 215 static int
 216 vfs_free_netcred(struct radix_node *rn, void *w)
 217 {
 218         register struct radix_node_head *rnh = (struct radix_node_head *) w;
 219
 220         (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
 221         free(rn, M_NETADDR);
 222         return (0);
 223 }
 224
 225 /*
 226  * Free the net address hash lists that are hanging off the mount points.
 227  */
 228 static void
 229 vfs_free_addrlist(struct netexport *nep)
 230 {
 231         register int i;
 232         register struct radix_node_head *rnh;
 233
 234         for (i = 0; i <= AF_MAX; i++)
 235                 if ((rnh = nep->ne_rtable[i])) {
 236                         RADIX_NODE_HEAD_LOCK(rnh);
 237                         (*rnh->rnh_walktree) (rnh, vfs_free_netcred, rnh);
 238                         RADIX_NODE_HEAD_DESTROY(rnh);
 239                         free(rnh, M_RTABLE);
 240                         nep->ne_rtable[i] = NULL;       /* not SMP safe XXX */
 241                 }
 242 }
 243
 244 /*
 245  * High level function to manipulate export options on a mount point
 246  * and the passed in netexport.
 247  * Struct export_args *argp is the variable used to twiddle options,
 248  * the structure is described in sys/mount.h
 249  */
 250 int
 251 vfs_export(struct mount *mp, struct export_args *argp)
 252 {
 253         struct netexport *nep;
 254         int error;
 255
 256         nep = mp->mnt_export;
 257         error = 0;
 258         lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL);
 259         if (argp->ex_flags & MNT_DELEXPORT) {
 260                 if (nep == NULL) {
 261                         error = ENOENT;
 262                         goto out;
 263                 }
 264                 if (mp->mnt_flag & MNT_EXPUBLIC) {
 265                         vfs_setpublicfs(NULL, NULL, NULL);
 266                         MNT_ILOCK(mp);
 267                         mp->mnt_flag &= ~MNT_EXPUBLIC;
 268                         MNT_IUNLOCK(mp);
 269                 }
 270                 vfs_free_addrlist(nep);
 271                 mp->mnt_export = NULL;
 272                 free(nep, M_MOUNT);
 273                 nep = NULL;
 274                 MNT_ILOCK(mp);
 275                 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
 276                 MNT_IUNLOCK(mp);
 277         }
 278         if (argp->ex_flags & MNT_EXPORTED) {
 279                 if (nep == NULL) {
 280                         nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO);
 281                         mp->mnt_export = nep;
 282                 }
 283                 if (argp->ex_flags & MNT_EXPUBLIC) {
 284                         if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
 285                                 goto out;
 286                         MNT_ILOCK(mp);
 287                         mp->mnt_flag |= MNT_EXPUBLIC;
 288                         MNT_IUNLOCK(mp);
 289                 }
 290                 if ((error = vfs_hang_addrlist(mp, nep, argp)))
 291                         goto out;
 292                 MNT_ILOCK(mp);
 293                 mp->mnt_flag |= MNT_EXPORTED;
 294                 MNT_IUNLOCK(mp);
 295         }
 296
 297 out:
 298         lockmgr(&mp->mnt_explock, LK_RELEASE, NULL);
 299         /*
 300          * Once we have executed the vfs_export() command, we do
 301          * not want to keep the "export" option around in the
 302          * options list, since that will cause subsequent MNT_UPDATE
 303          * calls to fail.  The export information is saved in
 304          * mp->mnt_export, so we can safely delete the "export" mount option
 305          * here.
 306          */
 307         vfs_deleteopt(mp->mnt_optnew, "export");
 308         vfs_deleteopt(mp->mnt_opt, "export");
 309         return (error);
 310 }
 311
 312 /*
 313  * Set the publicly exported filesystem (WebNFS). Currently, only
 314  * one public filesystem is possible in the spec (RFC 2054 and 2055)
 315  */
 316 int
 317 vfs_setpublicfs(struct mount *mp, struct netexport *nep,
 318     struct export_args *argp)
 319 {
 320         int error;
 321         struct vnode *rvp;
 322         char *cp;
 323
 324         /*
 325          * mp == NULL -> invalidate the current info, the FS is
 326          * no longer exported. May be called from either vfs_export
 327          * or unmount, so check if it hasn't already been done.
 328          */
 329         if (mp == NULL) {
 330                 if (nfs_pub.np_valid) {
 331                         nfs_pub.np_valid = 0;
 332                         if (nfs_pub.np_index != NULL) {
 333                                 FREE(nfs_pub.np_index, M_TEMP);
 334                                 nfs_pub.np_index = NULL;
 335                         }
 336                 }
 337                 return (0);
 338         }
 339
 340         /*
 341          * Only one allowed at a time.
 342          */
 343         if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
 344                 return (EBUSY);
 345
 346         /*
 347          * Get real filehandle for root of exported FS.
 348          */
 349         bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
 350         nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
 351
 352         if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp, curthread /* XXX */)))
 353                 return (error);
 354
 355         if ((error = VOP_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
 356                 return (error);
 357
 358         vput(rvp);
 359
 360         /*
 361          * If an indexfile was specified, pull it in.
 362          */
 363         if (argp->ex_indexfile != NULL) {
 364                 MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
 365                     M_WAITOK);
 366                 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
 367                     MAXNAMLEN, (size_t *)0);
 368                 if (!error) {
 369                         /*
 370                          * Check for illegal filenames.
 371                          */
 372                         for (cp = nfs_pub.np_index; *cp; cp++) {
 373                                 if (*cp == '/') {
 374                                         error = EINVAL;
 375                                         break;
 376                                 }
 377                         }
 378                 }
 379                 if (error) {
 380                         FREE(nfs_pub.np_index, M_TEMP);
 381                         return (error);
 382                 }
 383         }
 384
 385         nfs_pub.np_mount = mp;
 386         nfs_pub.np_valid = 1;
 387         return (0);
 388 }
 389
 390 /*
 391  * Used by the filesystems to determine if a given network address
 392  * (passed in 'nam') is present in thier exports list, returns a pointer
 393  * to struct netcred so that the filesystem can examine it for
 394  * access rights (read/write/etc).
 395  */
 396 static struct netcred *
 397 vfs_export_lookup(struct mount *mp, struct sockaddr *nam)
 398 {
 399         struct netexport *nep;
 400         register struct netcred *np;
 401         register struct radix_node_head *rnh;
 402         struct sockaddr *saddr;
 403
 404         nep = mp->mnt_export;
 405         if (nep == NULL)
 406                 return (NULL);
 407         np = NULL;
 408         if (mp->mnt_flag & MNT_EXPORTED) {
 409                 /*
 410                  * Lookup in the export list first.
 411                  */
 412                 if (nam != NULL) {
 413                         saddr = nam;
 414                         rnh = nep->ne_rtable[saddr->sa_family];
 415                         if (rnh != NULL) {
 416                                 RADIX_NODE_HEAD_LOCK(rnh);
 417                                 np = (struct netcred *)
 418                                     (*rnh->rnh_matchaddr)(saddr, rnh);
 419                                 RADIX_NODE_HEAD_UNLOCK(rnh);
 420                                 if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
 421                                         np = NULL;
 422                         }
 423                 }
 424                 /*
 425                  * If no address match, use the default if it exists.
 426                  */
 427                 if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
 428                         np = &nep->ne_defexported;
 429         }
 430         return (np);
 431 }
 432
 433 /*
 434  * XXX: This comment comes from the deprecated ufs_check_export()
 435  * XXX: and may not entirely apply, but lacking something better:
 436  * This is the generic part of fhtovp called after the underlying
 437  * filesystem has validated the file handle.
 438  *
 439  * Verify that a host should have access to a filesystem.
 440  */
 441
 442 int
 443 vfs_stdcheckexp(struct mount *mp, struct sockaddr *nam, int *extflagsp,
 444     struct ucred **credanonp)
 445 {
 446         struct netcred *np;
 447
 448         lockmgr(&mp->mnt_explock, LK_SHARED, NULL);
 449         np = vfs_export_lookup(mp, nam);
 450         lockmgr(&mp->mnt_explock, LK_RELEASE, NULL);
 451         if (np == NULL)
 452                 return (EACCES);
 453         *extflagsp = np->netc_exflags;
 454         *credanonp = &np->netc_anon;
 455         return (0);
 456 }
 457