nfs_srvsubs.c revision 1.4
1 /* $NetBSD: nfs_srvsubs.c,v 1.4 2009/09/27 17:19:07 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 1.4 2009/09/27 17:19:07 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; 124 struct iovec aiov; 125 struct uio auio; 126 struct vnode *dp; 127 int error, rdonly, linklen; 128 struct componentname *cnp = &ndp->ni_cnd; 129 130 *retdirp = NULL; 131 132 if ((len + 1) > MAXPATHLEN) 133 return (ENAMETOOLONG); 134 if (len == 0) 135 return (EACCES); 136 cnp->cn_pnbuf = PNBUF_GET(); 137 138 /* 139 * Copy the name from the mbuf list to ndp->ni_pnbuf 140 * and set the various ndp fields appropriately. 141 */ 142 fromcp = *dposp; 143 tocp = cnp->cn_pnbuf; 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 = cnp->cn_pnbuf; 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(cnp->cn_pnbuf); 241 cnp->cn_pnbuf = cp; 242 } 243 244 ndp->ni_pathlen = (tocp - cnp->cn_pnbuf) + 1; 245 ndp->ni_segflg = UIO_SYSSPACE; 246 ndp->ni_rootdir = rootvnode; 247 ndp->ni_erootdir = NULL; 248 249 if (pubflag) { 250 ndp->ni_loopcnt = 0; 251 if (cnp->cn_pnbuf[0] == '/') 252 dp = rootvnode; 253 } else { 254 cnp->cn_flags |= NOCROSSMOUNT; 255 } 256 257 VREF(dp); 258 vn_lock(dp, LK_EXCLUSIVE | LK_RETRY); 259 260 for (;;) { 261 cnp->cn_nameptr = cnp->cn_pnbuf; 262 ndp->ni_startdir = dp; 263 264 /* 265 * And call lookup() to do the real work 266 */ 267 error = lookup_for_nfsd(ndp); 268 if (error) { 269 if (ndp->ni_dvp) { 270 vput(ndp->ni_dvp); 271 } 272 PNBUF_PUT(cnp->cn_pnbuf); 273 return (error); 274 } 275 276 /* 277 * Check for encountering a symbolic link 278 */ 279 if ((cnp->cn_flags & ISSYMLINK) == 0) { 280 if ((cnp->cn_flags & LOCKPARENT) == 0 && ndp->ni_dvp) { 281 if (ndp->ni_dvp == ndp->ni_vp) { 282 vrele(ndp->ni_dvp); 283 } else { 284 vput(ndp->ni_dvp); 285 } 286 } 287 if (cnp->cn_flags & (SAVENAME | SAVESTART)) { 288 cnp->cn_flags |= HASBUF; 289 } else { 290 PNBUF_PUT(cnp->cn_pnbuf); 291 #if defined(DIAGNOSTIC) 292 cnp->cn_pnbuf = NULL; 293 #endif /* defined(DIAGNOSTIC) */ 294 } 295 return (0); 296 } else { 297 if (!pubflag) { 298 error = EINVAL; 299 break; 300 } 301 if (ndp->ni_loopcnt++ >= MAXSYMLINKS) { 302 error = ELOOP; 303 break; 304 } 305 if (ndp->ni_vp->v_mount->mnt_flag & MNT_SYMPERM) { 306 error = VOP_ACCESS(ndp->ni_vp, VEXEC, cnp->cn_cred); 307 if (error != 0) 308 break; 309 } 310 if (ndp->ni_pathlen > 1) 311 cp = PNBUF_GET(); 312 else 313 cp = cnp->cn_pnbuf; 314 aiov.iov_base = cp; 315 aiov.iov_len = MAXPATHLEN; 316 auio.uio_iov = &aiov; 317 auio.uio_iovcnt = 1; 318 auio.uio_offset = 0; 319 auio.uio_rw = UIO_READ; 320 auio.uio_resid = MAXPATHLEN; 321 UIO_SETUP_SYSSPACE(&auio); 322 error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred); 323 if (error) { 324 badlink: 325 if (ndp->ni_pathlen > 1) 326 PNBUF_PUT(cp); 327 break; 328 } 329 linklen = MAXPATHLEN - auio.uio_resid; 330 if (linklen == 0) { 331 error = ENOENT; 332 goto badlink; 333 } 334 if (linklen + ndp->ni_pathlen >= MAXPATHLEN) { 335 error = ENAMETOOLONG; 336 goto badlink; 337 } 338 if (ndp->ni_pathlen > 1) { 339 memcpy(cp + linklen, ndp->ni_next, ndp->ni_pathlen); 340 PNBUF_PUT(cnp->cn_pnbuf); 341 cnp->cn_pnbuf = cp; 342 } else 343 cnp->cn_pnbuf[linklen] = '\0'; 344 ndp->ni_pathlen += linklen; 345 vput(ndp->ni_vp); 346 dp = ndp->ni_dvp; 347 348 /* 349 * Check if root directory should replace current directory. 350 */ 351 if (cnp->cn_pnbuf[0] == '/') { 352 vput(dp); 353 dp = ndp->ni_rootdir; 354 VREF(dp); 355 vn_lock(dp, LK_EXCLUSIVE | LK_RETRY); 356 } 357 } 358 } 359 vput(ndp->ni_dvp); 360 vput(ndp->ni_vp); 361 ndp->ni_vp = NULL; 362 out: 363 PNBUF_PUT(cnp->cn_pnbuf); 364 return (error); 365 } 366 367 /* 368 * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked) 369 * - look up fsid in mount list (if not found ret error) 370 * - get vp and export rights by calling VFS_FHTOVP() 371 * - if cred->cr_uid == 0 or MNT_EXPORTANON set it to credanon 372 * - if not lockflag unlock it with VOP_UNLOCK() 373 */ 374 int 375 nfsrv_fhtovp(nfsrvfh_t *nsfh, int lockflag, struct vnode **vpp, 376 kauth_cred_t cred, struct nfssvc_sock *slp, struct mbuf *nam, int *rdonlyp, 377 int kerbflag, int pubflag) 378 { 379 struct mount *mp; 380 kauth_cred_t credanon; 381 int error, exflags; 382 struct sockaddr_in *saddr; 383 fhandle_t *fhp; 384 385 fhp = NFSRVFH_FHANDLE(nsfh); 386 *vpp = (struct vnode *)0; 387 388 if (nfs_ispublicfh(nsfh)) { 389 if (!pubflag || !nfs_pub.np_valid) 390 return (ESTALE); 391 fhp = nfs_pub.np_handle; 392 } 393 394 error = netexport_check(&fhp->fh_fsid, nam, &mp, &exflags, &credanon); 395 if (error) { 396 return error; 397 } 398 399 error = VFS_FHTOVP(mp, &fhp->fh_fid, vpp); 400 if (error) 401 return (error); 402 403 if (!(exflags & (MNT_EXNORESPORT|MNT_EXPUBLIC))) { 404 saddr = mtod(nam, struct sockaddr_in *); 405 if ((saddr->sin_family == AF_INET) && 406 ntohs(saddr->sin_port) >= IPPORT_RESERVED) { 407 vput(*vpp); 408 return (NFSERR_AUTHERR | AUTH_TOOWEAK); 409 } 410 if ((saddr->sin_family == AF_INET6) && 411 ntohs(saddr->sin_port) >= IPV6PORT_RESERVED) { 412 vput(*vpp); 413 return (NFSERR_AUTHERR | AUTH_TOOWEAK); 414 } 415 } 416 /* 417 * Check/setup credentials. 418 */ 419 if (exflags & MNT_EXKERB) { 420 if (!kerbflag) { 421 vput(*vpp); 422 return (NFSERR_AUTHERR | AUTH_TOOWEAK); 423 } 424 } else if (kerbflag) { 425 vput(*vpp); 426 return (NFSERR_AUTHERR | AUTH_TOOWEAK); 427 } else if (kauth_cred_geteuid(cred) == 0 || /* NFS maproot, see below */ 428 (exflags & MNT_EXPORTANON)) { 429 /* 430 * This is used by the NFS maproot option. While we can change 431 * the secmodel on our own host, we can't change it on the 432 * clients. As means of least surprise, we're doing the 433 * traditional thing here. 434 * Should look into adding a "mapprivileged" or similar where 435 * the users can be explicitly specified... 436 * [elad, yamt 2008-03-05] 437 */ 438 kauth_cred_clone(credanon, cred); 439 } 440 if (exflags & MNT_EXRDONLY) 441 *rdonlyp = 1; 442 else 443 *rdonlyp = 0; 444 if (!lockflag) 445 VOP_UNLOCK(*vpp, 0); 446 return (0); 447 } 448 449 /* 450 * WebNFS: check if a filehandle is a public filehandle. For v3, this 451 * means a length of 0, for v2 it means all zeroes. 452 */ 453 int 454 nfs_ispublicfh(const nfsrvfh_t *nsfh) 455 { 456 const char *cp = (const void *)(NFSRVFH_DATA(nsfh)); 457 int i; 458 459 if (NFSRVFH_SIZE(nsfh) == 0) { 460 return true; 461 } 462 if (NFSRVFH_SIZE(nsfh) != NFSX_V2FH) { 463 return false; 464 } 465 for (i = 0; i < NFSX_V2FH; i++) 466 if (*cp++ != 0) 467 return false; 468 return true; 469 } 470 471 int 472 nfsrv_composefh(struct vnode *vp, nfsrvfh_t *nsfh, bool v3) 473 { 474 int error; 475 size_t fhsize; 476 477 fhsize = NFSD_MAXFHSIZE; 478 error = vfs_composefh(vp, (void *)NFSRVFH_DATA(nsfh), &fhsize); 479 if (NFSX_FHTOOBIG_P(fhsize, v3)) { 480 error = EOPNOTSUPP; 481 } 482 if (error != 0) { 483 return error; 484 } 485 if (!v3 && fhsize < NFSX_V2FH) { 486 memset((char *)NFSRVFH_DATA(nsfh) + fhsize, 0, 487 NFSX_V2FH - fhsize); 488 fhsize = NFSX_V2FH; 489 } 490 if ((fhsize % NFSX_UNSIGNED) != 0) { 491 return EOPNOTSUPP; 492 } 493 nsfh->nsfh_size = fhsize; 494 return 0; 495 } 496 497 int 498 nfsrv_comparefh(const nfsrvfh_t *fh1, const nfsrvfh_t *fh2) 499 { 500 501 if (NFSRVFH_SIZE(fh1) != NFSRVFH_SIZE(fh2)) { 502 return NFSRVFH_SIZE(fh2) - NFSRVFH_SIZE(fh1); 503 } 504 return memcmp(NFSRVFH_DATA(fh1), NFSRVFH_DATA(fh2), NFSRVFH_SIZE(fh1)); 505 } 506 507 void 508 nfsrv_copyfh(nfsrvfh_t *fh1, const nfsrvfh_t *fh2) 509 { 510 size_t size; 511 512 fh1->nsfh_size = size = NFSRVFH_SIZE(fh2); 513 memcpy(NFSRVFH_DATA(fh1), NFSRVFH_DATA(fh2), size); 514 } 515
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