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(to: &mnt_timeout, proto: info->protocol, timeo, retrans); |
184 | mnt_clnt = rpc_create(args: &args); |
185 | if (IS_ERR(ptr: 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(clnt: mnt_clnt, msg: &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(ptr: 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: &args); |
271 | if (IS_ERR(ptr: 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: &msg, flags: 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, nbytes: 4 + pathname_len); |
309 | xdr_encode_opaque(p, ptr: pathname, len: 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, pathname: 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, nbytes: 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, nbytes: 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, nbytes: 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, nbytes: 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, nbytes: 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, nbytes: 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: 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 | |