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 /** 132 * nfs_mount - Obtain an NFS file handle for the given host and path 133 * @info: pointer to mount request arguments 134 * @timeo: deciseconds the mount waits for a response before it retries 135 * @retrans: number of times the mount retries a request 136 * 137 * Uses timeout parameters specified by caller. On successful return, the 138 * auth_flavs list and auth_flav_len will be populated with the list from the 139 * server or a faked-up list if the server didn't provide one. 140 */ 141 int nfs_mount(struct nfs_mount_request *info, int timeo, int retrans) 142 { 143 struct rpc_timeout mnt_timeout; 144 struct mountres result = { 145 .fh = info->fh, 146 .auth_count = info->auth_flav_len, 147 .auth_flavors = info->auth_flavs, 148 }; 149 struct rpc_message msg = { 150 .rpc_argp = info->dirpath, 151 .rpc_resp = &result, 152 }; 153 struct rpc_create_args args = { 154 .net = info->net, 155 .protocol = info->protocol, 156 .address = (struct sockaddr *)info->sap, 157 .addrsize = info->salen, 158 .timeout = &mnt_timeout, 159 .servername = info->hostname, 160 .program = &mnt_program, 161 .version = info->version, 162 .authflavor = RPC_AUTH_UNIX, 163 .cred = current_cred(), 164 }; 165 struct rpc_clnt *mnt_clnt; 166 int status; 167 168 dprintk("NFS: sending MNT request for %s:%s\n", 169 (info->hostname ? info->hostname : "server"), 170 info->dirpath); 171 172 if (strlen(info->dirpath) > MNTPATHLEN) 173 return -ENAMETOOLONG; 174 175 if (info->noresvport) 176 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; 177 178 nfs_init_timeout_values(&mnt_timeout, info->protocol, timeo, retrans); 179 mnt_clnt = rpc_create(&args); 180 if (IS_ERR(mnt_clnt)) 181 goto out_clnt_err; 182 183 if (info->version == NFS_MNT3_VERSION) 184 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT]; 185 else 186 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT]; 187 188 status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT); 189 rpc_shutdown_client(mnt_clnt); 190 191 if (status < 0) 192 goto out_call_err; 193 if (result.errno != 0) 194 goto out_mnt_err; 195 196 dprintk("NFS: MNT request succeeded\n"); 197 status = 0; 198 199 /* 200 * If the server didn't provide a flavor list, allow the 201 * client to try any flavor. 202 */ 203 if (info->version != NFS_MNT3_VERSION || *info->auth_flav_len == 0) { 204 dprintk("NFS: Faking up auth_flavs list\n"); 205 info->auth_flavs[0] = RPC_AUTH_NULL; 206 *info->auth_flav_len = 1; 207 } 208 out: 209 return status; 210 211 out_clnt_err: 212 status = PTR_ERR(mnt_clnt); 213 dprintk("NFS: failed to create MNT RPC client, status=%d\n", status); 214 goto out; 215 216 out_call_err: 217 dprintk("NFS: MNT request failed, status=%d\n", status); 218 goto out; 219 220 out_mnt_err: 221 dprintk("NFS: MNT server returned result %d\n", result.errno); 222 status = result.errno; 223 goto out; 224 } 225 226 /** 227 * nfs_umount - Notify a server that we have unmounted this export 228 * @info: pointer to umount request arguments 229 * 230 * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always 231 * use UDP. 232 */ 233 void nfs_umount(const struct nfs_mount_request *info) 234 { 235 static const struct rpc_timeout nfs_umnt_timeout = { 236 .to_initval = 1 * HZ, 237 .to_maxval = 3 * HZ, 238 .to_retries = 2, 239 }; 240 struct rpc_create_args args = { 241 .net = info->net, 242 .protocol = IPPROTO_UDP, 243 .address = (struct sockaddr *)info->sap, 244 .addrsize = info->salen, 245 .timeout = &nfs_umnt_timeout, 246 .servername = info->hostname, 247 .program = &mnt_program, 248 .version = info->version, 249 .authflavor = RPC_AUTH_UNIX, 250 .flags = RPC_CLNT_CREATE_NOPING, 251 .cred = current_cred(), 252 }; 253 struct rpc_message msg = { 254 .rpc_argp = info->dirpath, 255 }; 256 struct rpc_clnt *clnt; 257 int status; 258 259 if (strlen(info->dirpath) > MNTPATHLEN) 260 return; 261 262 if (info->noresvport) 263 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; 264 265 clnt = rpc_create(&args); 266 if (IS_ERR(clnt)) 267 goto out_clnt_err; 268 269 dprintk("NFS: sending UMNT request for %s:%s\n", 270 (info->hostname ? info->hostname : "server"), info->dirpath); 271 272 if (info->version == NFS_MNT3_VERSION) 273 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT]; 274 else 275 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT]; 276 277 status = rpc_call_sync(clnt, &msg, 0); 278 rpc_shutdown_client(clnt); 279 280 if (unlikely(status < 0)) 281 goto out_call_err; 282 283 return; 284 285 out_clnt_err: 286 dprintk("NFS: failed to create UMNT RPC client, status=%ld\n", 287 PTR_ERR(clnt)); 288 return; 289 290 out_call_err: 291 dprintk("NFS: UMNT request failed, status=%d\n", status); 292 } 293 294 /* 295 * XDR encode/decode functions for MOUNT 296 */ 297 298 static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname) 299 { 300 const u32 pathname_len = strlen(pathname); 301 __be32 *p; 302 303 p = xdr_reserve_space(xdr, 4 + pathname_len); 304 xdr_encode_opaque(p, pathname, pathname_len); 305 } 306 307 static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr, 308 const void *dirpath) 309 { 310 encode_mntdirpath(xdr, dirpath); 311 } 312 313 /* 314 * RFC 1094: "A non-zero status indicates some sort of error. In this 315 * case, the status is a UNIX error number." This can be problematic 316 * if the server and client use different errno values for the same 317 * error. 318 * 319 * However, the OpenGroup XNFS spec provides a simple mapping that is 320 * independent of local errno values on the server and the client. 321 */ 322 static int decode_status(struct xdr_stream *xdr, struct mountres *res) 323 { 324 unsigned int i; 325 u32 status; 326 __be32 *p; 327 328 p = xdr_inline_decode(xdr, 4); 329 if (unlikely(p == NULL)) 330 return -EIO; 331 status = be32_to_cpup(p); 332 333 for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) { 334 if (mnt_errtbl[i].status == status) { 335 res->errno = mnt_errtbl[i].errno; 336 return 0; 337 } 338 } 339 340 dprintk("NFS: unrecognized MNT status code: %u\n", status); 341 res->errno = -EACCES; 342 return 0; 343 } 344 345 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res) 346 { 347 struct nfs_fh *fh = res->fh; 348 __be32 *p; 349 350 p = xdr_inline_decode(xdr, NFS2_FHSIZE); 351 if (unlikely(p == NULL)) 352 return -EIO; 353 354 fh->size = NFS2_FHSIZE; 355 memcpy(fh->data, p, NFS2_FHSIZE); 356 return 0; 357 } 358 359 static int mnt_xdr_dec_mountres(struct rpc_rqst *req, 360 struct xdr_stream *xdr, 361 void *data) 362 { 363 struct mountres *res = data; 364 int status; 365 366 status = decode_status(xdr, res); 367 if (unlikely(status != 0 || res->errno != 0)) 368 return status; 369 return decode_fhandle(xdr, res); 370 } 371 372 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res) 373 { 374 unsigned int i; 375 u32 status; 376 __be32 *p; 377 378 p = xdr_inline_decode(xdr, 4); 379 if (unlikely(p == NULL)) 380 return -EIO; 381 status = be32_to_cpup(p); 382 383 for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) { 384 if (mnt3_errtbl[i].status == status) { 385 res->errno = mnt3_errtbl[i].errno; 386 return 0; 387 } 388 } 389 390 dprintk("NFS: unrecognized MNT3 status code: %u\n", status); 391 res->errno = -EACCES; 392 return 0; 393 } 394 395 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res) 396 { 397 struct nfs_fh *fh = res->fh; 398 u32 size; 399 __be32 *p; 400 401 p = xdr_inline_decode(xdr, 4); 402 if (unlikely(p == NULL)) 403 return -EIO; 404 405 size = be32_to_cpup(p); 406 if (size > NFS3_FHSIZE || size == 0) 407 return -EIO; 408 409 p = xdr_inline_decode(xdr, size); 410 if (unlikely(p == NULL)) 411 return -EIO; 412 413 fh->size = size; 414 memcpy(fh->data, p, size); 415 return 0; 416 } 417 418 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res) 419 { 420 rpc_authflavor_t *flavors = res->auth_flavors; 421 unsigned int *count = res->auth_count; 422 u32 entries, i; 423 __be32 *p; 424 425 if (*count == 0) 426 return 0; 427 428 p = xdr_inline_decode(xdr, 4); 429 if (unlikely(p == NULL)) 430 return -EIO; 431 entries = be32_to_cpup(p); 432 dprintk("NFS: received %u auth flavors\n", entries); 433 if (entries > NFS_MAX_SECFLAVORS) 434 entries = NFS_MAX_SECFLAVORS; 435 436 p = xdr_inline_decode(xdr, 4 * entries); 437 if (unlikely(p == NULL)) 438 return -EIO; 439 440 if (entries > *count) 441 entries = *count; 442 443 for (i = 0; i < entries; i++) { 444 flavors[i] = be32_to_cpup(p++); 445 dprintk("NFS: auth flavor[%u]: %d\n", i, flavors[i]); 446 } 447 *count = i; 448 449 return 0; 450 } 451 452 static int mnt_xdr_dec_mountres3(struct rpc_rqst *req, 453 struct xdr_stream *xdr, 454 void *data) 455 { 456 struct mountres *res = data; 457 int status; 458 459 status = decode_fhs_status(xdr, res); 460 if (unlikely(status != 0 || res->errno != 0)) 461 return status; 462 status = decode_fhandle3(xdr, res); 463 if (unlikely(status != 0)) { 464 res->errno = -EBADHANDLE; 465 return 0; 466 } 467 return decode_auth_flavors(xdr, res); 468 } 469 470 static const struct rpc_procinfo mnt_procedures[] = { 471 [MOUNTPROC_MNT] = { 472 .p_proc = MOUNTPROC_MNT, 473 .p_encode = mnt_xdr_enc_dirpath, 474 .p_decode = mnt_xdr_dec_mountres, 475 .p_arglen = MNT_enc_dirpath_sz, 476 .p_replen = MNT_dec_mountres_sz, 477 .p_statidx = MOUNTPROC_MNT, 478 .p_name = "MOUNT", 479 }, 480 [MOUNTPROC_UMNT] = { 481 .p_proc = MOUNTPROC_UMNT, 482 .p_encode = mnt_xdr_enc_dirpath, 483 .p_arglen = MNT_enc_dirpath_sz, 484 .p_statidx = MOUNTPROC_UMNT, 485 .p_name = "UMOUNT", 486 }, 487 }; 488 489 static const struct rpc_procinfo mnt3_procedures[] = { 490 [MOUNTPROC3_MNT] = { 491 .p_proc = MOUNTPROC3_MNT, 492 .p_encode = mnt_xdr_enc_dirpath, 493 .p_decode = mnt_xdr_dec_mountres3, 494 .p_arglen = MNT_enc_dirpath_sz, 495 .p_replen = MNT_dec_mountres3_sz, 496 .p_statidx = MOUNTPROC3_MNT, 497 .p_name = "MOUNT", 498 }, 499 [MOUNTPROC3_UMNT] = { 500 .p_proc = MOUNTPROC3_UMNT, 501 .p_encode = mnt_xdr_enc_dirpath, 502 .p_arglen = MNT_enc_dirpath_sz, 503 .p_statidx = MOUNTPROC3_UMNT, 504 .p_name = "UMOUNT", 505 }, 506 }; 507 508 static unsigned int mnt_counts[ARRAY_SIZE(mnt_procedures)]; 509 static const struct rpc_version mnt_version1 = { 510 .number = 1, 511 .nrprocs = ARRAY_SIZE(mnt_procedures), 512 .procs = mnt_procedures, 513 .counts = mnt_counts, 514 }; 515 516 static unsigned int mnt3_counts[ARRAY_SIZE(mnt3_procedures)]; 517 static const struct rpc_version mnt_version3 = { 518 .number = 3, 519 .nrprocs = ARRAY_SIZE(mnt3_procedures), 520 .procs = mnt3_procedures, 521 .counts = mnt3_counts, 522 }; 523 524 static const struct rpc_version *mnt_version[] = { 525 NULL, 526 &mnt_version1, 527 NULL, 528 &mnt_version3, 529 }; 530 531 static struct rpc_stat mnt_stats; 532 533 static const struct rpc_program mnt_program = { 534 .name = "mount", 535 .number = NFS_MNT_PROGRAM, 536 .nrvers = ARRAY_SIZE(mnt_version), 537 .version = mnt_version, 538 .stats = &mnt_stats, 539 }; 540