1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * In-kernel MOUNT protocol client 4 * 5 * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de> 6 */ 7 8 #include <linux/types.h> 9 #include <linux/socket.h> 10 #include <linux/kernel.h> 11 #include <linux/errno.h> 12 #include <linux/uio.h> 13 #include <linux/net.h> 14 #include <linux/in.h> 15 #include <linux/sunrpc/clnt.h> 16 #include <linux/sunrpc/sched.h> 17 #include <linux/nfs_fs.h> 18 #include "internal.h" 19 20 #define NFSDBG_FACILITY NFSDBG_MOUNT 21 22 /* 23 * Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4 24 */ 25 #define MNTPATHLEN (1024) 26 27 /* 28 * XDR data type sizes 29 */ 30 #define encode_dirpath_sz (1 + XDR_QUADLEN(MNTPATHLEN)) 31 #define MNT_status_sz (1) 32 #define MNT_fhandle_sz XDR_QUADLEN(NFS2_FHSIZE) 33 #define MNT_fhandlev3_sz XDR_QUADLEN(NFS3_FHSIZE) 34 #define MNT_authflav3_sz (1 + NFS_MAX_SECFLAVORS) 35 36 /* 37 * XDR argument and result sizes 38 */ 39 #define MNT_enc_dirpath_sz encode_dirpath_sz 40 #define MNT_dec_mountres_sz (MNT_status_sz + MNT_fhandle_sz) 41 #define MNT_dec_mountres3_sz (MNT_status_sz + MNT_fhandlev3_sz + \ 42 MNT_authflav3_sz) 43 44 /* 45 * Defined by RFC 1094, section A.5 46 */ 47 enum { 48 MOUNTPROC_NULL = 0, 49 MOUNTPROC_MNT = 1, 50 MOUNTPROC_DUMP = 2, 51 MOUNTPROC_UMNT = 3, 52 MOUNTPROC_UMNTALL = 4, 53 MOUNTPROC_EXPORT = 5, 54 }; 55 56 /* 57 * Defined by RFC 1813, section 5.2 58 */ 59 enum { 60 MOUNTPROC3_NULL = 0, 61 MOUNTPROC3_MNT = 1, 62 MOUNTPROC3_DUMP = 2, 63 MOUNTPROC3_UMNT = 3, 64 MOUNTPROC3_UMNTALL = 4, 65 MOUNTPROC3_EXPORT = 5, 66 }; 67 68 static const struct rpc_program mnt_program; 69 70 /* 71 * Defined by OpenGroup XNFS Version 3W, chapter 8 72 */ 73 enum mountstat { 74 MNT_OK = 0, 75 MNT_EPERM = 1, 76 MNT_ENOENT = 2, 77 MNT_EACCES = 13, 78 MNT_EINVAL = 22, 79 }; 80 81 static struct { 82 u32 status; 83 int errno; 84 } mnt_errtbl[] = { 85 { .status = MNT_OK, .errno = 0, }, 86 { .status = MNT_EPERM, .errno = -EPERM, }, 87 { .status = MNT_ENOENT, .errno = -ENOENT, }, 88 { .status = MNT_EACCES, .errno = -EACCES, }, 89 { .status = MNT_EINVAL, .errno = -EINVAL, }, 90 }; 91 92 /* 93 * Defined by RFC 1813, section 5.1.5 94 */ 95 enum mountstat3 { 96 MNT3_OK = 0, /* no error */ 97 MNT3ERR_PERM = 1, /* Not owner */ 98 MNT3ERR_NOENT = 2, /* No such file or directory */ 99 MNT3ERR_IO = 5, /* I/O error */ 100 MNT3ERR_ACCES = 13, /* Permission denied */ 101 MNT3ERR_NOTDIR = 20, /* Not a directory */ 102 MNT3ERR_INVAL = 22, /* Invalid argument */ 103 MNT3ERR_NAMETOOLONG = 63, /* Filename too long */ 104 MNT3ERR_NOTSUPP = 10004, /* Operation not supported */ 105 MNT3ERR_SERVERFAULT = 10006, /* A failure on the server */ 106 }; 107 108 static struct { 109 u32 status; 110 int errno; 111 } mnt3_errtbl[] = { 112 { .status = MNT3_OK, .errno = 0, }, 113 { .status = MNT3ERR_PERM, .errno = -EPERM, }, 114 { .status = MNT3ERR_NOENT, .errno = -ENOENT, }, 115 { .status = MNT3ERR_IO, .errno = -EIO, }, 116 { .status = MNT3ERR_ACCES, .errno = -EACCES, }, 117 { .status = MNT3ERR_NOTDIR, .errno = -ENOTDIR, }, 118 { .status = MNT3ERR_INVAL, .errno = -EINVAL, }, 119 { .status = MNT3ERR_NAMETOOLONG, .errno = -ENAMETOOLONG, }, 120 { .status = MNT3ERR_NOTSUPP, .errno = -ENOTSUPP, }, 121 { .status = MNT3ERR_SERVERFAULT, .errno = -EREMOTEIO, }, 122 }; 123 124 struct mountres { 125 int errno; 126 struct nfs_fh *fh; 127 unsigned int *auth_count; 128 rpc_authflavor_t *auth_flavors; 129 }; 130 131 struct mnt_fhstatus { 132 u32 status; 133 struct nfs_fh *fh; 134 }; 135 136 /** 137 * nfs_mount - Obtain an NFS file handle for the given host and path 138 * @info: pointer to mount request arguments 139 * @timeo: deciseconds the mount waits for a response before it retries 140 * @retrans: number of times the mount retries a request 141 * 142 * Uses timeout parameters specified by caller. On successful return, the 143 * auth_flavs list and auth_flav_len will be populated with the list from the 144 * server or a faked-up list if the server didn't provide one. 145 */ 146 int nfs_mount(struct nfs_mount_request *info, int timeo, int retrans) 147 { 148 struct rpc_timeout mnt_timeout; 149 struct mountres result = { 150 .fh = info->fh, 151 .auth_count = info->auth_flav_len, 152 .auth_flavors = info->auth_flavs, 153 }; 154 struct rpc_message msg = { 155 .rpc_argp = info->dirpath, 156 .rpc_resp = &result, 157 }; 158 struct rpc_create_args args = { 159 .net = info->net, 160 .protocol = info->protocol, 161 .address = (struct sockaddr *)info->sap, 162 .addrsize = info->salen, 163 .timeout = &mnt_timeout, 164 .servername = info->hostname, 165 .program = &mnt_program, 166 .version = info->version, 167 .authflavor = RPC_AUTH_UNIX, 168 .cred = current_cred(), 169 }; 170 struct rpc_clnt *mnt_clnt; 171 int status; 172 173 dprintk("NFS: sending MNT request for %s:%s\n", 174 (info->hostname ? info->hostname : "server"), 175 info->dirpath); 176 177 if (strlen(info->dirpath) > MNTPATHLEN) 178 return -ENAMETOOLONG; 179 180 if (info->noresvport) 181 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; 182 183 nfs_init_timeout_values(&mnt_timeout, info->protocol, timeo, retrans); 184 mnt_clnt = rpc_create(&args); 185 if (IS_ERR(mnt_clnt)) 186 goto out_clnt_err; 187 188 if (info->version == NFS_MNT3_VERSION) 189 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT]; 190 else 191 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT]; 192 193 status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT); 194 rpc_shutdown_client(mnt_clnt); 195 196 if (status < 0) 197 goto out_call_err; 198 if (result.errno != 0) 199 goto out_mnt_err; 200 201 dprintk("NFS: MNT request succeeded\n"); 202 status = 0; 203 204 /* 205 * If the server didn't provide a flavor list, allow the 206 * client to try any flavor. 207 */ 208 if (info->version != NFS_MNT3_VERSION || *info->auth_flav_len == 0) { 209 dprintk("NFS: Faking up auth_flavs list\n"); 210 info->auth_flavs[0] = RPC_AUTH_NULL; 211 *info->auth_flav_len = 1; 212 } 213 out: 214 return status; 215 216 out_clnt_err: 217 status = PTR_ERR(mnt_clnt); 218 dprintk("NFS: failed to create MNT RPC client, status=%d\n", status); 219 goto out; 220 221 out_call_err: 222 dprintk("NFS: MNT request failed, status=%d\n", status); 223 goto out; 224 225 out_mnt_err: 226 dprintk("NFS: MNT server returned result %d\n", result.errno); 227 status = result.errno; 228 goto out; 229 } 230 231 /** 232 * nfs_umount - Notify a server that we have unmounted this export 233 * @info: pointer to umount request arguments 234 * 235 * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always 236 * use UDP. 237 */ 238 void nfs_umount(const struct nfs_mount_request *info) 239 { 240 static const struct rpc_timeout nfs_umnt_timeout = { 241 .to_initval = 1 * HZ, 242 .to_maxval = 3 * HZ, 243 .to_retries = 2, 244 }; 245 struct rpc_create_args args = { 246 .net = info->net, 247 .protocol = IPPROTO_UDP, 248 .address = (struct sockaddr *)info->sap, 249 .addrsize = info->salen, 250 .timeout = &nfs_umnt_timeout, 251 .servername = info->hostname, 252 .program = &mnt_program, 253 .version = info->version, 254 .authflavor = RPC_AUTH_UNIX, 255 .flags = RPC_CLNT_CREATE_NOPING, 256 .cred = current_cred(), 257 }; 258 struct rpc_message msg = { 259 .rpc_argp = info->dirpath, 260 }; 261 struct rpc_clnt *clnt; 262 int status; 263 264 if (strlen(info->dirpath) > MNTPATHLEN) 265 return; 266 267 if (info->noresvport) 268 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; 269 270 clnt = rpc_create(&args); 271 if (IS_ERR(clnt)) 272 goto out_clnt_err; 273 274 dprintk("NFS: sending UMNT request for %s:%s\n", 275 (info->hostname ? info->hostname : "server"), info->dirpath); 276 277 if (info->version == NFS_MNT3_VERSION) 278 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT]; 279 else 280 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT]; 281 282 status = rpc_call_sync(clnt, &msg, 0); 283 rpc_shutdown_client(clnt); 284 285 if (unlikely(status < 0)) 286 goto out_call_err; 287 288 return; 289 290 out_clnt_err: 291 dprintk("NFS: failed to create UMNT RPC client, status=%ld\n", 292 PTR_ERR(clnt)); 293 return; 294 295 out_call_err: 296 dprintk("NFS: UMNT request failed, status=%d\n", status); 297 } 298 299 /* 300 * XDR encode/decode functions for MOUNT 301 */ 302 303 static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname) 304 { 305 const u32 pathname_len = strlen(pathname); 306 __be32 *p; 307 308 p = xdr_reserve_space(xdr, 4 + pathname_len); 309 xdr_encode_opaque(p, pathname, pathname_len); 310 } 311 312 static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr, 313 const void *dirpath) 314 { 315 encode_mntdirpath(xdr, dirpath); 316 } 317 318 /* 319 * RFC 1094: "A non-zero status indicates some sort of error. In this 320 * case, the status is a UNIX error number." This can be problematic 321 * if the server and client use different errno values for the same 322 * error. 323 * 324 * However, the OpenGroup XNFS spec provides a simple mapping that is 325 * independent of local errno values on the server and the client. 326 */ 327 static int decode_status(struct xdr_stream *xdr, struct mountres *res) 328 { 329 unsigned int i; 330 u32 status; 331 __be32 *p; 332 333 p = xdr_inline_decode(xdr, 4); 334 if (unlikely(p == NULL)) 335 return -EIO; 336 status = be32_to_cpup(p); 337 338 for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) { 339 if (mnt_errtbl[i].status == status) { 340 res->errno = mnt_errtbl[i].errno; 341 return 0; 342 } 343 } 344 345 dprintk("NFS: unrecognized MNT status code: %u\n", status); 346 res->errno = -EACCES; 347 return 0; 348 } 349 350 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res) 351 { 352 struct nfs_fh *fh = res->fh; 353 __be32 *p; 354 355 p = xdr_inline_decode(xdr, NFS2_FHSIZE); 356 if (unlikely(p == NULL)) 357 return -EIO; 358 359 fh->size = NFS2_FHSIZE; 360 memcpy(fh->data, p, NFS2_FHSIZE); 361 return 0; 362 } 363 364 static int mnt_xdr_dec_mountres(struct rpc_rqst *req, 365 struct xdr_stream *xdr, 366 void *data) 367 { 368 struct mountres *res = data; 369 int status; 370 371 status = decode_status(xdr, res); 372 if (unlikely(status != 0 || res->errno != 0)) 373 return status; 374 return decode_fhandle(xdr, res); 375 } 376 377 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res) 378 { 379 unsigned int i; 380 u32 status; 381 __be32 *p; 382 383 p = xdr_inline_decode(xdr, 4); 384 if (unlikely(p == NULL)) 385 return -EIO; 386 status = be32_to_cpup(p); 387 388 for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) { 389 if (mnt3_errtbl[i].status == status) { 390 res->errno = mnt3_errtbl[i].errno; 391 return 0; 392 } 393 } 394 395 dprintk("NFS: unrecognized MNT3 status code: %u\n", status); 396 res->errno = -EACCES; 397 return 0; 398 } 399 400 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res) 401 { 402 struct nfs_fh *fh = res->fh; 403 u32 size; 404 __be32 *p; 405 406 p = xdr_inline_decode(xdr, 4); 407 if (unlikely(p == NULL)) 408 return -EIO; 409 410 size = be32_to_cpup(p); 411 if (size > NFS3_FHSIZE || size == 0) 412 return -EIO; 413 414 p = xdr_inline_decode(xdr, size); 415 if (unlikely(p == NULL)) 416 return -EIO; 417 418 fh->size = size; 419 memcpy(fh->data, p, size); 420 return 0; 421 } 422 423 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res) 424 { 425 rpc_authflavor_t *flavors = res->auth_flavors; 426 unsigned int *count = res->auth_count; 427 u32 entries, i; 428 __be32 *p; 429 430 if (*count == 0) 431 return 0; 432 433 p = xdr_inline_decode(xdr, 4); 434 if (unlikely(p == NULL)) 435 return -EIO; 436 entries = be32_to_cpup(p); 437 dprintk("NFS: received %u auth flavors\n", entries); 438 if (entries > NFS_MAX_SECFLAVORS) 439 entries = NFS_MAX_SECFLAVORS; 440 441 p = xdr_inline_decode(xdr, 4 * entries); 442 if (unlikely(p == NULL)) 443 return -EIO; 444 445 if (entries > *count) 446 entries = *count; 447 448 for (i = 0; i < entries; i++) { 449 flavors[i] = be32_to_cpup(p++); 450 dprintk("NFS: auth flavor[%u]: %d\n", i, flavors[i]); 451 } 452 *count = i; 453 454 return 0; 455 } 456 457 static int mnt_xdr_dec_mountres3(struct rpc_rqst *req, 458 struct xdr_stream *xdr, 459 void *data) 460 { 461 struct mountres *res = data; 462 int status; 463 464 status = decode_fhs_status(xdr, res); 465 if (unlikely(status != 0 || res->errno != 0)) 466 return status; 467 status = decode_fhandle3(xdr, res); 468 if (unlikely(status != 0)) { 469 res->errno = -EBADHANDLE; 470 return 0; 471 } 472 return decode_auth_flavors(xdr, res); 473 } 474 475 static const struct rpc_procinfo mnt_procedures[] = { 476 [MOUNTPROC_MNT] = { 477 .p_proc = MOUNTPROC_MNT, 478 .p_encode = mnt_xdr_enc_dirpath, 479 .p_decode = mnt_xdr_dec_mountres, 480 .p_arglen = MNT_enc_dirpath_sz, 481 .p_replen = MNT_dec_mountres_sz, 482 .p_statidx = MOUNTPROC_MNT, 483 .p_name = "MOUNT", 484 }, 485 [MOUNTPROC_UMNT] = { 486 .p_proc = MOUNTPROC_UMNT, 487 .p_encode = mnt_xdr_enc_dirpath, 488 .p_arglen = MNT_enc_dirpath_sz, 489 .p_statidx = MOUNTPROC_UMNT, 490 .p_name = "UMOUNT", 491 }, 492 }; 493 494 static const struct rpc_procinfo mnt3_procedures[] = { 495 [MOUNTPROC3_MNT] = { 496 .p_proc = MOUNTPROC3_MNT, 497 .p_encode = mnt_xdr_enc_dirpath, 498 .p_decode = mnt_xdr_dec_mountres3, 499 .p_arglen = MNT_enc_dirpath_sz, 500 .p_replen = MNT_dec_mountres3_sz, 501 .p_statidx = MOUNTPROC3_MNT, 502 .p_name = "MOUNT", 503 }, 504 [MOUNTPROC3_UMNT] = { 505 .p_proc = MOUNTPROC3_UMNT, 506 .p_encode = mnt_xdr_enc_dirpath, 507 .p_arglen = MNT_enc_dirpath_sz, 508 .p_statidx = MOUNTPROC3_UMNT, 509 .p_name = "UMOUNT", 510 }, 511 }; 512 513 static unsigned int mnt_counts[ARRAY_SIZE(mnt_procedures)]; 514 static const struct rpc_version mnt_version1 = { 515 .number = 1, 516 .nrprocs = ARRAY_SIZE(mnt_procedures), 517 .procs = mnt_procedures, 518 .counts = mnt_counts, 519 }; 520 521 static unsigned int mnt3_counts[ARRAY_SIZE(mnt3_procedures)]; 522 static const struct rpc_version mnt_version3 = { 523 .number = 3, 524 .nrprocs = ARRAY_SIZE(mnt3_procedures), 525 .procs = mnt3_procedures, 526 .counts = mnt3_counts, 527 }; 528 529 static const struct rpc_version *mnt_version[] = { 530 NULL, 531 &mnt_version1, 532 NULL, 533 &mnt_version3, 534 }; 535 536 static struct rpc_stat mnt_stats; 537 538 static const struct rpc_program mnt_program = { 539 .name = "mount", 540 .number = NFS_MNT_PROGRAM, 541 .nrvers = ARRAY_SIZE(mnt_version), 542 .version = mnt_version, 543 .stats = &mnt_stats, 544 }; 545