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 */ 47enum { 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 */ 59enum { 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 68static const struct rpc_program mnt_program; 69 70/* 71 * Defined by OpenGroup XNFS Version 3W, chapter 8 72 */ 73enum mountstat { 74 MNT_OK = 0, 75 MNT_EPERM = 1, 76 MNT_ENOENT = 2, 77 MNT_EACCES = 13, 78 MNT_EINVAL = 22, 79}; 80 81static 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 */ 95enum 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 108static 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 124struct mountres { 125 int errno; 126 struct nfs_fh *fh; 127 unsigned int *auth_count; 128 rpc_authflavor_t *auth_flavors; 129}; 130 131struct 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 * 140 * Uses default timeout parameters specified by underlying transport. On 141 * successful return, the auth_flavs list and auth_flav_len will be populated 142 * with the list from the server or a faked-up list if the server didn't 143 * provide one. 144 */ 145int nfs_mount(struct nfs_mount_request *info) 146{ 147 struct mountres result = { 148 .fh = info->fh, 149 .auth_count = info->auth_flav_len, 150 .auth_flavors = info->auth_flavs, 151 }; 152 struct rpc_message msg = { 153 .rpc_argp = info->dirpath, 154 .rpc_resp = &result, 155 }; 156 struct rpc_create_args args = { 157 .net = info->net, 158 .protocol = info->protocol, 159 .address = info->sap, 160 .addrsize = info->salen, 161 .servername = info->hostname, 162 .program = &mnt_program, 163 .version = info->version, 164 .authflavor = RPC_AUTH_UNIX, 165 .cred = current_cred(), 166 }; 167 struct rpc_clnt *mnt_clnt; 168 int status; 169 170 dprintk("NFS: sending MNT request for %s:%s\n", 171 (info->hostname ? info->hostname : "server"), 172 info->dirpath); 173 174 if (strlen(info->dirpath) > MNTPATHLEN) 175 return -ENAMETOOLONG; 176 177 if (info->noresvport) 178 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; 179 180 mnt_clnt = rpc_create(&args); 181 if (IS_ERR(mnt_clnt)) 182 goto out_clnt_err; 183 184 if (info->version == NFS_MNT3_VERSION) 185 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT]; 186 else 187 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT]; 188 189 status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT); 190 rpc_shutdown_client(mnt_clnt); 191 192 if (status < 0) 193 goto out_call_err; 194 if (result.errno != 0) 195 goto out_mnt_err; 196 197 dprintk("NFS: MNT request succeeded\n"); 198 status = 0; 199 200 /* 201 * If the server didn't provide a flavor list, allow the 202 * client to try any flavor. 203 */ 204 if (info->version != NFS_MNT3_VERSION || *info->auth_flav_len == 0) { 205 dprintk("NFS: Faking up auth_flavs list\n"); 206 info->auth_flavs[0] = RPC_AUTH_NULL; 207 *info->auth_flav_len = 1; 208 } 209out: 210 return status; 211 212out_clnt_err: 213 status = PTR_ERR(mnt_clnt); 214 dprintk("NFS: failed to create MNT RPC client, status=%d\n", status); 215 goto out; 216 217out_call_err: 218 dprintk("NFS: MNT request failed, status=%d\n", status); 219 goto out; 220 221out_mnt_err: 222 dprintk("NFS: MNT server returned result %d\n", result.errno); 223 status = result.errno; 224 goto out; 225} 226 227/** 228 * nfs_umount - Notify a server that we have unmounted this export 229 * @info: pointer to umount request arguments 230 * 231 * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always 232 * use UDP. 233 */ 234void nfs_umount(const struct nfs_mount_request *info) 235{ 236 static const struct rpc_timeout nfs_umnt_timeout = { 237 .to_initval = 1 * HZ, 238 .to_maxval = 3 * HZ, 239 .to_retries = 2, 240 }; 241 struct rpc_create_args args = { 242 .net = info->net, 243 .protocol = IPPROTO_UDP, 244 .address = info->sap, 245 .addrsize = info->salen, 246 .timeout = &nfs_umnt_timeout, 247 .servername = info->hostname, 248 .program = &mnt_program, 249 .version = info->version, 250 .authflavor = RPC_AUTH_UNIX, 251 .flags = RPC_CLNT_CREATE_NOPING, 252 .cred = current_cred(), 253 }; 254 struct rpc_message msg = { 255 .rpc_argp = info->dirpath, 256 }; 257 struct rpc_clnt *clnt; 258 int status; 259 260 if (strlen(info->dirpath) > MNTPATHLEN) 261 return; 262 263 if (info->noresvport) 264 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; 265 266 clnt = rpc_create(&args); 267 if (IS_ERR(clnt)) 268 goto out_clnt_err; 269 270 dprintk("NFS: sending UMNT request for %s:%s\n", 271 (info->hostname ? info->hostname : "server"), info->dirpath); 272 273 if (info->version == NFS_MNT3_VERSION) 274 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT]; 275 else 276 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT]; 277 278 status = rpc_call_sync(clnt, &msg, 0); 279 rpc_shutdown_client(clnt); 280 281 if (unlikely(status < 0)) 282 goto out_call_err; 283 284 return; 285 286out_clnt_err: 287 dprintk("NFS: failed to create UMNT RPC client, status=%ld\n", 288 PTR_ERR(clnt)); 289 return; 290 291out_call_err: 292 dprintk("NFS: UMNT request failed, status=%d\n", status); 293} 294 295/* 296 * XDR encode/decode functions for MOUNT 297 */ 298 299static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname) 300{ 301 const u32 pathname_len = strlen(pathname); 302 __be32 *p; 303 304 p = xdr_reserve_space(xdr, 4 + pathname_len); 305 xdr_encode_opaque(p, pathname, pathname_len); 306} 307 308static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr, 309 const void *dirpath) 310{ 311 encode_mntdirpath(xdr, dirpath); 312} 313 314/* 315 * RFC 1094: "A non-zero status indicates some sort of error. In this 316 * case, the status is a UNIX error number." This can be problematic 317 * if the server and client use different errno values for the same 318 * error. 319 * 320 * However, the OpenGroup XNFS spec provides a simple mapping that is 321 * independent of local errno values on the server and the client. 322 */ 323static int decode_status(struct xdr_stream *xdr, struct mountres *res) 324{ 325 unsigned int i; 326 u32 status; 327 __be32 *p; 328 329 p = xdr_inline_decode(xdr, 4); 330 if (unlikely(p == NULL)) 331 return -EIO; 332 status = be32_to_cpup(p); 333 334 for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) { 335 if (mnt_errtbl[i].status == status) { 336 res->errno = mnt_errtbl[i].errno; 337 return 0; 338 } 339 } 340 341 dprintk("NFS: unrecognized MNT status code: %u\n", status); 342 res->errno = -EACCES; 343 return 0; 344} 345 346static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res) 347{ 348 struct nfs_fh *fh = res->fh; 349 __be32 *p; 350 351 p = xdr_inline_decode(xdr, NFS2_FHSIZE); 352 if (unlikely(p == NULL)) 353 return -EIO; 354 355 fh->size = NFS2_FHSIZE; 356 memcpy(fh->data, p, NFS2_FHSIZE); 357 return 0; 358} 359 360static int mnt_xdr_dec_mountres(struct rpc_rqst *req, 361 struct xdr_stream *xdr, 362 void *data) 363{ 364 struct mountres *res = data; 365 int status; 366 367 status = decode_status(xdr, res); 368 if (unlikely(status != 0 || res->errno != 0)) 369 return status; 370 return decode_fhandle(xdr, res); 371} 372 373static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res) 374{ 375 unsigned int i; 376 u32 status; 377 __be32 *p; 378 379 p = xdr_inline_decode(xdr, 4); 380 if (unlikely(p == NULL)) 381 return -EIO; 382 status = be32_to_cpup(p); 383 384 for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) { 385 if (mnt3_errtbl[i].status == status) { 386 res->errno = mnt3_errtbl[i].errno; 387 return 0; 388 } 389 } 390 391 dprintk("NFS: unrecognized MNT3 status code: %u\n", status); 392 res->errno = -EACCES; 393 return 0; 394} 395 396static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res) 397{ 398 struct nfs_fh *fh = res->fh; 399 u32 size; 400 __be32 *p; 401 402 p = xdr_inline_decode(xdr, 4); 403 if (unlikely(p == NULL)) 404 return -EIO; 405 406 size = be32_to_cpup(p); 407 if (size > NFS3_FHSIZE || size == 0) 408 return -EIO; 409 410 p = xdr_inline_decode(xdr, size); 411 if (unlikely(p == NULL)) 412 return -EIO; 413 414 fh->size = size; 415 memcpy(fh->data, p, size); 416 return 0; 417} 418 419static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res) 420{ 421 rpc_authflavor_t *flavors = res->auth_flavors; 422 unsigned int *count = res->auth_count; 423 u32 entries, i; 424 __be32 *p; 425 426 if (*count == 0) 427 return 0; 428 429 p = xdr_inline_decode(xdr, 4); 430 if (unlikely(p == NULL)) 431 return -EIO; 432 entries = be32_to_cpup(p); 433 dprintk("NFS: received %u auth flavors\n", entries); 434 if (entries > NFS_MAX_SECFLAVORS) 435 entries = NFS_MAX_SECFLAVORS; 436 437 p = xdr_inline_decode(xdr, 4 * entries); 438 if (unlikely(p == NULL)) 439 return -EIO; 440 441 if (entries > *count) 442 entries = *count; 443 444 for (i = 0; i < entries; i++) { 445 flavors[i] = be32_to_cpup(p++); 446 dprintk("NFS: auth flavor[%u]: %d\n", i, flavors[i]); 447 } 448 *count = i; 449 450 return 0; 451} 452 453static int mnt_xdr_dec_mountres3(struct rpc_rqst *req, 454 struct xdr_stream *xdr, 455 void *data) 456{ 457 struct mountres *res = data; 458 int status; 459 460 status = decode_fhs_status(xdr, res); 461 if (unlikely(status != 0 || res->errno != 0)) 462 return status; 463 status = decode_fhandle3(xdr, res); 464 if (unlikely(status != 0)) { 465 res->errno = -EBADHANDLE; 466 return 0; 467 } 468 return decode_auth_flavors(xdr, res); 469} 470 471static const struct rpc_procinfo mnt_procedures[] = { 472 [MOUNTPROC_MNT] = { 473 .p_proc = MOUNTPROC_MNT, 474 .p_encode = mnt_xdr_enc_dirpath, 475 .p_decode = mnt_xdr_dec_mountres, 476 .p_arglen = MNT_enc_dirpath_sz, 477 .p_replen = MNT_dec_mountres_sz, 478 .p_statidx = MOUNTPROC_MNT, 479 .p_name = "MOUNT", 480 }, 481 [MOUNTPROC_UMNT] = { 482 .p_proc = MOUNTPROC_UMNT, 483 .p_encode = mnt_xdr_enc_dirpath, 484 .p_arglen = MNT_enc_dirpath_sz, 485 .p_statidx = MOUNTPROC_UMNT, 486 .p_name = "UMOUNT", 487 }, 488}; 489 490static const struct rpc_procinfo mnt3_procedures[] = { 491 [MOUNTPROC3_MNT] = { 492 .p_proc = MOUNTPROC3_MNT, 493 .p_encode = mnt_xdr_enc_dirpath, 494 .p_decode = mnt_xdr_dec_mountres3, 495 .p_arglen = MNT_enc_dirpath_sz, 496 .p_replen = MNT_dec_mountres3_sz, 497 .p_statidx = MOUNTPROC3_MNT, 498 .p_name = "MOUNT", 499 }, 500 [MOUNTPROC3_UMNT] = { 501 .p_proc = MOUNTPROC3_UMNT, 502 .p_encode = mnt_xdr_enc_dirpath, 503 .p_arglen = MNT_enc_dirpath_sz, 504 .p_statidx = MOUNTPROC3_UMNT, 505 .p_name = "UMOUNT", 506 }, 507}; 508 509static unsigned int mnt_counts[ARRAY_SIZE(mnt_procedures)]; 510static const struct rpc_version mnt_version1 = { 511 .number = 1, 512 .nrprocs = ARRAY_SIZE(mnt_procedures), 513 .procs = mnt_procedures, 514 .counts = mnt_counts, 515}; 516 517static unsigned int mnt3_counts[ARRAY_SIZE(mnt3_procedures)]; 518static const struct rpc_version mnt_version3 = { 519 .number = 3, 520 .nrprocs = ARRAY_SIZE(mnt3_procedures), 521 .procs = mnt3_procedures, 522 .counts = mnt3_counts, 523}; 524 525static const struct rpc_version *mnt_version[] = { 526 NULL, 527 &mnt_version1, 528 NULL, 529 &mnt_version3, 530}; 531 532static struct rpc_stat mnt_stats; 533 534static const struct rpc_program mnt_program = { 535 .name = "mount", 536 .number = NFS_MNT_PROGRAM, 537 .nrvers = ARRAY_SIZE(mnt_version), 538 .version = mnt_version, 539 .stats = &mnt_stats, 540}; 541