| 1 | /* $NetBSD: nfs_srvsubs.c,v 1.14 2012/11/05 19:06:27 dholland Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1989, 1993 |
| 5 | * The Regents of the University of California. All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to Berkeley by |
| 8 | * Rick Macklem at The University of Guelph. |
| 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 | * 3. 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 | * @(#)nfs_subs.c 8.8 (Berkeley) 5/22/95 |
| 35 | */ |
| 36 | |
| 37 | /* |
| 38 | * Copyright 2000 Wasabi Systems, Inc. |
| 39 | * All rights reserved. |
| 40 | * |
| 41 | * Written by Frank van der Linden for Wasabi Systems, Inc. |
| 42 | * |
| 43 | * Redistribution and use in source and binary forms, with or without |
| 44 | * modification, are permitted provided that the following conditions |
| 45 | * are met: |
| 46 | * 1. Redistributions of source code must retain the above copyright |
| 47 | * notice, this list of conditions and the following disclaimer. |
| 48 | * 2. Redistributions in binary form must reproduce the above copyright |
| 49 | * notice, this list of conditions and the following disclaimer in the |
| 50 | * documentation and/or other materials provided with the distribution. |
| 51 | * 3. All advertising materials mentioning features or use of this software |
| 52 | * must display the following acknowledgement: |
| 53 | * This product includes software developed for the NetBSD Project by |
| 54 | * Wasabi Systems, Inc. |
| 55 | * 4. The name of Wasabi Systems, Inc. may not be used to endorse |
| 56 | * or promote products derived from this software without specific prior |
| 57 | * written permission. |
| 58 | * |
| 59 | * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND |
| 60 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 61 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 62 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC |
| 63 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 64 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 65 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 66 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 67 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 68 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 69 | * POSSIBILITY OF SUCH DAMAGE. |
| 70 | */ |
| 71 | |
| 72 | #include <sys/cdefs.h> |
| 73 | __KERNEL_RCSID(0, "$NetBSD: nfs_srvsubs.c,v 1.14 2012/11/05 19:06:27 dholland Exp $" ); |
| 74 | |
| 75 | #include <sys/param.h> |
| 76 | #include <sys/proc.h> |
| 77 | #include <sys/systm.h> |
| 78 | #include <sys/kernel.h> |
| 79 | #include <sys/kmem.h> |
| 80 | #include <sys/mount.h> |
| 81 | #include <sys/vnode.h> |
| 82 | #include <sys/namei.h> |
| 83 | #include <sys/mbuf.h> |
| 84 | #include <sys/socket.h> |
| 85 | #include <sys/stat.h> |
| 86 | #include <sys/filedesc.h> |
| 87 | #include <sys/time.h> |
| 88 | #include <sys/dirent.h> |
| 89 | #include <sys/once.h> |
| 90 | #include <sys/kauth.h> |
| 91 | #include <sys/atomic.h> |
| 92 | |
| 93 | #include <uvm/uvm_extern.h> |
| 94 | |
| 95 | #include <nfs/rpcv2.h> |
| 96 | #include <nfs/nfsproto.h> |
| 97 | #include <nfs/nfsnode.h> |
| 98 | #include <nfs/nfs.h> |
| 99 | #include <nfs/xdr_subs.h> |
| 100 | #include <nfs/nfsm_subs.h> |
| 101 | #include <nfs/nfsmount.h> |
| 102 | #include <nfs/nfsrtt.h> |
| 103 | #include <nfs/nfs_var.h> |
| 104 | |
| 105 | #include <miscfs/specfs/specdev.h> |
| 106 | |
| 107 | #include <netinet/in.h> |
| 108 | |
| 109 | /* |
| 110 | * Set up nameidata for a lookup() call and do it. |
| 111 | * |
| 112 | * If pubflag is set, this call is done for a lookup operation on the |
| 113 | * public filehandle. In that case we allow crossing mountpoints and |
| 114 | * absolute pathnames. However, the caller is expected to check that |
| 115 | * the lookup result is within the public fs, and deny access if |
| 116 | * it is not. |
| 117 | */ |
| 118 | int |
| 119 | nfs_namei(struct nameidata *ndp, nfsrvfh_t *nsfh, uint32_t len, struct nfssvc_sock *slp, struct mbuf *nam, struct mbuf **mdp, char **dposp, struct vnode **retdirp, struct lwp *l, int kerbflag, int pubflag) |
| 120 | { |
| 121 | int i, rem; |
| 122 | struct mbuf *md; |
| 123 | char *fromcp, *tocp, *cp, *path; |
| 124 | struct vnode *dp; |
| 125 | int error, rdonly; |
| 126 | int neverfollow; |
| 127 | struct componentname *cnp = &ndp->ni_cnd; |
| 128 | |
| 129 | *retdirp = NULL; |
| 130 | ndp->ni_pathbuf = NULL; |
| 131 | |
| 132 | if ((len + 1) > NFS_MAXPATHLEN) |
| 133 | return (ENAMETOOLONG); |
| 134 | if (len == 0) |
| 135 | return (EACCES); |
| 136 | |
| 137 | /* |
| 138 | * Copy the name from the mbuf list to ndp->ni_pathbuf |
| 139 | * and set the various ndp fields appropriately. |
| 140 | */ |
| 141 | path = PNBUF_GET(); |
| 142 | fromcp = *dposp; |
| 143 | tocp = path; |
| 144 | md = *mdp; |
| 145 | rem = mtod(md, char *) + md->m_len - fromcp; |
| 146 | for (i = 0; i < len; i++) { |
| 147 | while (rem == 0) { |
| 148 | md = md->m_next; |
| 149 | if (md == NULL) { |
| 150 | error = EBADRPC; |
| 151 | goto out; |
| 152 | } |
| 153 | fromcp = mtod(md, void *); |
| 154 | rem = md->m_len; |
| 155 | } |
| 156 | if (*fromcp == '\0' || (!pubflag && *fromcp == '/')) { |
| 157 | error = EACCES; |
| 158 | goto out; |
| 159 | } |
| 160 | *tocp++ = *fromcp++; |
| 161 | rem--; |
| 162 | } |
| 163 | *tocp = '\0'; |
| 164 | *mdp = md; |
| 165 | *dposp = fromcp; |
| 166 | len = nfsm_rndup(len)-len; |
| 167 | if (len > 0) { |
| 168 | if (rem >= len) |
| 169 | *dposp += len; |
| 170 | else if ((error = nfs_adv(mdp, dposp, len, rem)) != 0) |
| 171 | goto out; |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * Extract and set starting directory. |
| 176 | */ |
| 177 | error = nfsrv_fhtovp(nsfh, false, &dp, ndp->ni_cnd.cn_cred, slp, |
| 178 | nam, &rdonly, kerbflag, pubflag); |
| 179 | if (error) |
| 180 | goto out; |
| 181 | if (dp->v_type != VDIR) { |
| 182 | vrele(dp); |
| 183 | error = ENOTDIR; |
| 184 | goto out; |
| 185 | } |
| 186 | |
| 187 | if (rdonly) |
| 188 | cnp->cn_flags |= RDONLY; |
| 189 | |
| 190 | *retdirp = dp; |
| 191 | |
| 192 | if (pubflag) { |
| 193 | /* |
| 194 | * Oh joy. For WebNFS, handle those pesky '%' escapes, |
| 195 | * and the 'native path' indicator. |
| 196 | */ |
| 197 | cp = PNBUF_GET(); |
| 198 | fromcp = path; |
| 199 | tocp = cp; |
| 200 | if ((unsigned char)*fromcp >= WEBNFS_SPECCHAR_START) { |
| 201 | switch ((unsigned char)*fromcp) { |
| 202 | case WEBNFS_NATIVE_CHAR: |
| 203 | /* |
| 204 | * 'Native' path for us is the same |
| 205 | * as a path according to the NFS spec, |
| 206 | * just skip the escape char. |
| 207 | */ |
| 208 | fromcp++; |
| 209 | break; |
| 210 | /* |
| 211 | * More may be added in the future, range 0x80-0xff |
| 212 | */ |
| 213 | default: |
| 214 | error = EIO; |
| 215 | vrele(dp); |
| 216 | PNBUF_PUT(cp); |
| 217 | goto out; |
| 218 | } |
| 219 | } |
| 220 | /* |
| 221 | * Translate the '%' escapes, URL-style. |
| 222 | */ |
| 223 | while (*fromcp != '\0') { |
| 224 | if (*fromcp == WEBNFS_ESC_CHAR) { |
| 225 | if (fromcp[1] != '\0' && fromcp[2] != '\0') { |
| 226 | fromcp++; |
| 227 | *tocp++ = HEXSTRTOI(fromcp); |
| 228 | fromcp += 2; |
| 229 | continue; |
| 230 | } else { |
| 231 | error = ENOENT; |
| 232 | vrele(dp); |
| 233 | PNBUF_PUT(cp); |
| 234 | goto out; |
| 235 | } |
| 236 | } else |
| 237 | *tocp++ = *fromcp++; |
| 238 | } |
| 239 | *tocp = '\0'; |
| 240 | PNBUF_PUT(path); |
| 241 | path = cp; |
| 242 | } |
| 243 | |
| 244 | ndp->ni_atdir = NULL; |
| 245 | ndp->ni_pathbuf = pathbuf_assimilate(path); |
| 246 | if (ndp->ni_pathbuf == NULL) { |
| 247 | error = ENOMEM; |
| 248 | goto out; |
| 249 | } |
| 250 | |
| 251 | if (pubflag) { |
| 252 | if (path[0] == '/') |
| 253 | dp = rootvnode; |
| 254 | } else { |
| 255 | cnp->cn_flags |= NOCROSSMOUNT; |
| 256 | } |
| 257 | |
| 258 | neverfollow = !pubflag; |
| 259 | |
| 260 | /* |
| 261 | * And call lookup() to do the real work |
| 262 | * |
| 263 | * Note: ndp->ni_pathbuf is left undestroyed on success; |
| 264 | * caller must clean it up. |
| 265 | */ |
| 266 | error = lookup_for_nfsd(ndp, dp, neverfollow); |
| 267 | if (error) { |
| 268 | goto out; |
| 269 | } |
| 270 | return 0; |
| 271 | |
| 272 | out: |
| 273 | if (ndp->ni_pathbuf != NULL) { |
| 274 | pathbuf_destroy(ndp->ni_pathbuf); |
| 275 | ndp->ni_pathbuf = NULL; |
| 276 | } else { |
| 277 | PNBUF_PUT(path); |
| 278 | } |
| 279 | return (error); |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked) |
| 284 | * - look up fsid in mount list (if not found ret error) |
| 285 | * - get vp and export rights by calling VFS_FHTOVP() |
| 286 | * - if cred->cr_uid == 0 or MNT_EXPORTANON set it to credanon |
| 287 | * - if not lockflag unlock it with VOP_UNLOCK() |
| 288 | */ |
| 289 | int |
| 290 | nfsrv_fhtovp(nfsrvfh_t *nsfh, int lockflag, struct vnode **vpp, |
| 291 | kauth_cred_t cred, struct nfssvc_sock *slp, struct mbuf *nam, int *rdonlyp, |
| 292 | int kerbflag, int pubflag) |
| 293 | { |
| 294 | struct mount *mp; |
| 295 | kauth_cred_t credanon; |
| 296 | int error, exflags; |
| 297 | struct sockaddr_in *saddr; |
| 298 | fhandle_t *fhp; |
| 299 | |
| 300 | fhp = NFSRVFH_FHANDLE(nsfh); |
| 301 | *vpp = (struct vnode *)0; |
| 302 | |
| 303 | if (nfs_ispublicfh(nsfh)) { |
| 304 | if (!pubflag || !nfs_pub.np_valid) |
| 305 | return (ESTALE); |
| 306 | fhp = nfs_pub.np_handle; |
| 307 | } |
| 308 | |
| 309 | error = netexport_check(&fhp->fh_fsid, nam, &mp, &exflags, &credanon); |
| 310 | if (error) { |
| 311 | return error; |
| 312 | } |
| 313 | |
| 314 | error = VFS_FHTOVP(mp, &fhp->fh_fid, vpp); |
| 315 | if (error) |
| 316 | return (error); |
| 317 | |
| 318 | if (!(exflags & (MNT_EXNORESPORT|MNT_EXPUBLIC))) { |
| 319 | saddr = mtod(nam, struct sockaddr_in *); |
| 320 | if ((saddr->sin_family == AF_INET) && |
| 321 | ntohs(saddr->sin_port) >= IPPORT_RESERVED) { |
| 322 | vput(*vpp); |
| 323 | return (NFSERR_AUTHERR | AUTH_TOOWEAK); |
| 324 | } |
| 325 | if ((saddr->sin_family == AF_INET6) && |
| 326 | ntohs(saddr->sin_port) >= IPV6PORT_RESERVED) { |
| 327 | vput(*vpp); |
| 328 | return (NFSERR_AUTHERR | AUTH_TOOWEAK); |
| 329 | } |
| 330 | } |
| 331 | /* |
| 332 | * Check/setup credentials. |
| 333 | */ |
| 334 | if (exflags & MNT_EXKERB) { |
| 335 | if (!kerbflag) { |
| 336 | vput(*vpp); |
| 337 | return (NFSERR_AUTHERR | AUTH_TOOWEAK); |
| 338 | } |
| 339 | } else if (kerbflag) { |
| 340 | vput(*vpp); |
| 341 | return (NFSERR_AUTHERR | AUTH_TOOWEAK); |
| 342 | } else if (kauth_cred_geteuid(cred) == 0 || /* NFS maproot, see below */ |
| 343 | (exflags & MNT_EXPORTANON)) { |
| 344 | /* |
| 345 | * This is used by the NFS maproot option. While we can change |
| 346 | * the secmodel on our own host, we can't change it on the |
| 347 | * clients. As means of least surprise, we're doing the |
| 348 | * traditional thing here. |
| 349 | * Should look into adding a "mapprivileged" or similar where |
| 350 | * the users can be explicitly specified... |
| 351 | * [elad, yamt 2008-03-05] |
| 352 | */ |
| 353 | kauth_cred_clone(credanon, cred); |
| 354 | } |
| 355 | if (exflags & MNT_EXRDONLY) |
| 356 | *rdonlyp = 1; |
| 357 | else |
| 358 | *rdonlyp = 0; |
| 359 | if (!lockflag) |
| 360 | VOP_UNLOCK(*vpp); |
| 361 | return (0); |
| 362 | } |
| 363 | |
| 364 | /* |
| 365 | * WebNFS: check if a filehandle is a public filehandle. For v3, this |
| 366 | * means a length of 0, for v2 it means all zeroes. |
| 367 | */ |
| 368 | int |
| 369 | nfs_ispublicfh(const nfsrvfh_t *nsfh) |
| 370 | { |
| 371 | const char *cp = (const void *)(NFSRVFH_DATA(nsfh)); |
| 372 | int i; |
| 373 | |
| 374 | if (NFSRVFH_SIZE(nsfh) == 0) { |
| 375 | return true; |
| 376 | } |
| 377 | if (NFSRVFH_SIZE(nsfh) != NFSX_V2FH) { |
| 378 | return false; |
| 379 | } |
| 380 | for (i = 0; i < NFSX_V2FH; i++) |
| 381 | if (*cp++ != 0) |
| 382 | return false; |
| 383 | return true; |
| 384 | } |
| 385 | |
| 386 | int |
| 387 | nfsrv_composefh(struct vnode *vp, nfsrvfh_t *nsfh, bool v3) |
| 388 | { |
| 389 | int error; |
| 390 | size_t fhsize; |
| 391 | |
| 392 | fhsize = NFSD_MAXFHSIZE; |
| 393 | error = vfs_composefh(vp, (void *)NFSRVFH_DATA(nsfh), &fhsize); |
| 394 | if (NFSX_FHTOOBIG_P(fhsize, v3)) { |
| 395 | error = EOPNOTSUPP; |
| 396 | } |
| 397 | if (error != 0) { |
| 398 | return error; |
| 399 | } |
| 400 | if (!v3 && fhsize < NFSX_V2FH) { |
| 401 | memset((char *)NFSRVFH_DATA(nsfh) + fhsize, 0, |
| 402 | NFSX_V2FH - fhsize); |
| 403 | fhsize = NFSX_V2FH; |
| 404 | } |
| 405 | if ((fhsize % NFSX_UNSIGNED) != 0) { |
| 406 | return EOPNOTSUPP; |
| 407 | } |
| 408 | nsfh->nsfh_size = fhsize; |
| 409 | return 0; |
| 410 | } |
| 411 | |
| 412 | int |
| 413 | nfsrv_comparefh(const nfsrvfh_t *fh1, const nfsrvfh_t *fh2) |
| 414 | { |
| 415 | |
| 416 | if (NFSRVFH_SIZE(fh1) != NFSRVFH_SIZE(fh2)) { |
| 417 | return NFSRVFH_SIZE(fh2) - NFSRVFH_SIZE(fh1); |
| 418 | } |
| 419 | return memcmp(NFSRVFH_DATA(fh1), NFSRVFH_DATA(fh2), NFSRVFH_SIZE(fh1)); |
| 420 | } |
| 421 | |
| 422 | void |
| 423 | nfsrv_copyfh(nfsrvfh_t *fh1, const nfsrvfh_t *fh2) |
| 424 | { |
| 425 | size_t size; |
| 426 | |
| 427 | fh1->nsfh_size = size = NFSRVFH_SIZE(fh2); |
| 428 | memcpy(NFSRVFH_DATA(fh1), NFSRVFH_DATA(fh2), size); |
| 429 | } |
| 430 | |