1/* $NetBSD: nfs_srvsubs.c,v 1.17 2023/03/23 19:52:42 riastradh 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 1.17 2023/03/23 19:52:42 riastradh 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 */ 118int 119nfs_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, int *dirattr_retp, struct vattr *dirattrp, 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 > NFS_MAXPATHLEN - 1) 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 if (dirattr_retp != NULL) { 192 vn_lock(dp, LK_SHARED | LK_RETRY); 193 *dirattr_retp = VOP_GETATTR(dp, dirattrp, ndp->ni_cnd.cn_cred); 194 VOP_UNLOCK(dp); 195 } 196 197 if (pubflag) { 198 /* 199 * Oh joy. For WebNFS, handle those pesky '%' escapes, 200 * and the 'native path' indicator. 201 */ 202 cp = PNBUF_GET(); 203 fromcp = path; 204 tocp = cp; 205 if ((unsigned char)*fromcp >= WEBNFS_SPECCHAR_START) { 206 switch ((unsigned char)*fromcp) { 207 case WEBNFS_NATIVE_CHAR: 208 /* 209 * 'Native' path for us is the same 210 * as a path according to the NFS spec, 211 * just skip the escape char. 212 */ 213 fromcp++; 214 break; 215 /* 216 * More may be added in the future, range 0x80-0xff 217 */ 218 default: 219 error = EIO; 220 vrele(dp); 221 PNBUF_PUT(cp); 222 goto out; 223 } 224 } 225 /* 226 * Translate the '%' escapes, URL-style. 227 */ 228 while (*fromcp != '\0') { 229 if (*fromcp == WEBNFS_ESC_CHAR) { 230 if (fromcp[1] != '\0' && fromcp[2] != '\0') { 231 fromcp++; 232 *tocp++ = HEXSTRTOI(fromcp); 233 fromcp += 2; 234 continue; 235 } else { 236 error = ENOENT; 237 vrele(dp); 238 PNBUF_PUT(cp); 239 goto out; 240 } 241 } else 242 *tocp++ = *fromcp++; 243 } 244 *tocp = '\0'; 245 PNBUF_PUT(path); 246 path = cp; 247 } 248 249 ndp->ni_atdir = NULL; 250 ndp->ni_pathbuf = pathbuf_assimilate(path); 251 if (ndp->ni_pathbuf == NULL) { 252 error = ENOMEM; 253 goto out; 254 } 255 256 if (pubflag) { 257 if (path[0] == '/') 258 dp = rootvnode; 259 } else { 260 cnp->cn_flags |= NOCROSSMOUNT; 261 } 262 263 neverfollow = !pubflag; 264 265 /* 266 * And call lookup() to do the real work 267 * 268 * Note: ndp->ni_pathbuf is left undestroyed on success; 269 * caller must clean it up. 270 */ 271 error = lookup_for_nfsd(ndp, dp, neverfollow); 272 if (error) { 273 goto out; 274 } 275 return 0; 276 277out: 278 if (ndp->ni_pathbuf != NULL) { 279 pathbuf_destroy(ndp->ni_pathbuf); 280 ndp->ni_pathbuf = NULL; 281 } else { 282 PNBUF_PUT(path); 283 } 284 return (error); 285} 286 287/* 288 * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked) 289 * - look up fsid in mount list (if not found ret error) 290 * - get vp and export rights by calling VFS_FHTOVP() 291 * - if cred->cr_uid == 0 or MNT_EXPORTANON set it to credanon 292 * - if not lockflag unlock it with VOP_UNLOCK() 293 */ 294int 295nfsrv_fhtovp(nfsrvfh_t *nsfh, int lockflag, struct vnode **vpp, 296 kauth_cred_t cred, struct nfssvc_sock *slp, struct mbuf *nam, int *rdonlyp, 297 int kerbflag, int pubflag) 298{ 299 struct mount *mp; 300 kauth_cred_t credanon; 301 int error, exflags; 302 struct sockaddr_in *saddr; 303 fhandle_t *fhp; 304 305 fhp = NFSRVFH_FHANDLE(nsfh); 306 *vpp = (struct vnode *)0; 307 308 if (nfs_ispublicfh(nsfh)) { 309 if (!pubflag || !nfs_pub.np_valid) 310 return (ESTALE); 311 fhp = nfs_pub.np_handle; 312 } 313 314 error = netexport_check(&fhp->fh_fsid, nam, &mp, &exflags, &credanon); 315 if (error) { 316 return error; 317 } 318 319 error = VFS_FHTOVP(mp, &fhp->fh_fid, LK_EXCLUSIVE, vpp); 320 if (error) 321 return (error); 322 323 if (!(exflags & (MNT_EXNORESPORT|MNT_EXPUBLIC))) { 324 saddr = mtod(nam, struct sockaddr_in *); 325 if ((saddr->sin_family == AF_INET) && 326 ntohs(saddr->sin_port) >= IPPORT_RESERVED) { 327 vput(*vpp); 328 return (NFSERR_AUTHERR | AUTH_TOOWEAK); 329 } 330 if ((saddr->sin_family == AF_INET6) && 331 ntohs(saddr->sin_port) >= IPV6PORT_RESERVED) { 332 vput(*vpp); 333 return (NFSERR_AUTHERR | AUTH_TOOWEAK); 334 } 335 } 336 /* 337 * Check/setup credentials. 338 */ 339 if (exflags & MNT_EXKERB) { 340 if (!kerbflag) { 341 vput(*vpp); 342 return (NFSERR_AUTHERR | AUTH_TOOWEAK); 343 } 344 } else if (kerbflag) { 345 vput(*vpp); 346 return (NFSERR_AUTHERR | AUTH_TOOWEAK); 347 } else if (kauth_cred_geteuid(cred) == 0 || /* NFS maproot, see below */ 348 (exflags & MNT_EXPORTANON)) { 349 /* 350 * This is used by the NFS maproot option. While we can change 351 * the secmodel on our own host, we can't change it on the 352 * clients. As means of least surprise, we're doing the 353 * traditional thing here. 354 * Should look into adding a "mapprivileged" or similar where 355 * the users can be explicitly specified... 356 * [elad, yamt 2008-03-05] 357 */ 358 kauth_cred_clone(credanon, cred); 359 } 360 if (exflags & MNT_EXRDONLY) 361 *rdonlyp = 1; 362 else 363 *rdonlyp = 0; 364 if (!lockflag) 365 VOP_UNLOCK(*vpp); 366 return (0); 367} 368 369/* 370 * WebNFS: check if a filehandle is a public filehandle. For v3, this 371 * means a length of 0, for v2 it means all zeroes. 372 */ 373int 374nfs_ispublicfh(const nfsrvfh_t *nsfh) 375{ 376 const char *cp = (const void *)(NFSRVFH_DATA(nsfh)); 377 int i; 378 379 if (NFSRVFH_SIZE(nsfh) == 0) { 380 return true; 381 } 382 if (NFSRVFH_SIZE(nsfh) != NFSX_V2FH) { 383 return false; 384 } 385 for (i = 0; i < NFSX_V2FH; i++) 386 if (*cp++ != 0) 387 return false; 388 return true; 389} 390 391int 392nfsrv_composefh(struct vnode *vp, nfsrvfh_t *nsfh, bool v3) 393{ 394 int error; 395 size_t fhsize; 396 397 fhsize = NFSD_MAXFHSIZE; 398 error = vfs_composefh(vp, (void *)NFSRVFH_DATA(nsfh), &fhsize); 399 if (NFSX_FHTOOBIG_P(fhsize, v3)) { 400 error = EOPNOTSUPP; 401 } 402 if (error != 0) { 403 return error; 404 } 405 if (!v3 && fhsize < NFSX_V2FH) { 406 memset((char *)NFSRVFH_DATA(nsfh) + fhsize, 0, 407 NFSX_V2FH - fhsize); 408 fhsize = NFSX_V2FH; 409 } 410 if ((fhsize % NFSX_UNSIGNED) != 0) { 411 return EOPNOTSUPP; 412 } 413 nsfh->nsfh_size = fhsize; 414 return 0; 415} 416 417int 418nfsrv_comparefh(const nfsrvfh_t *fh1, const nfsrvfh_t *fh2) 419{ 420 421 if (NFSRVFH_SIZE(fh1) != NFSRVFH_SIZE(fh2)) { 422 return NFSRVFH_SIZE(fh2) - NFSRVFH_SIZE(fh1); 423 } 424 return memcmp(NFSRVFH_DATA(fh1), NFSRVFH_DATA(fh2), NFSRVFH_SIZE(fh1)); 425} 426 427void 428nfsrv_copyfh(nfsrvfh_t *fh1, const nfsrvfh_t *fh2) 429{ 430 size_t size; 431 432 fh1->nsfh_size = size = NFSRVFH_SIZE(fh2); 433 memcpy(NFSRVFH_DATA(fh1), NFSRVFH_DATA(fh2), size); 434} 435