1 /*
2 * In-kernel MOUNT protocol client
3 *
4 * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
5 */
6
7 #include <linux/types.h>
8 #include <linux/socket.h>
9 #include <linux/kernel.h>
10 #include <linux/errno.h>
11 #include <linux/uio.h>
12 #include <linux/net.h>
13 #include <linux/in.h>
14 #include <linux/sunrpc/clnt.h>
15 #include <linux/sunrpc/sched.h>
16 #include <linux/nfs_fs.h>
17 #include "internal.h"
18
19 #ifdef NFS_DEBUG
20 # define NFSDBG_FACILITY NFSDBG_MOUNT
21 #endif
22
23 /*
24 * Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4
25 */
26 #define MNTPATHLEN (1024)
27
28 /*
29 * XDR data type sizes
30 */
31 #define encode_dirpath_sz (1 + XDR_QUADLEN(MNTPATHLEN))
32 #define MNT_status_sz (1)
33 #define MNT_fhs_status_sz (1)
34 #define MNT_fhandle_sz XDR_QUADLEN(NFS2_FHSIZE)
35 #define MNT_fhandle3_sz (1 + XDR_QUADLEN(NFS3_FHSIZE))
36 #define MNT_authflav3_sz (1 + NFS_MAX_SECFLAVORS)
37
38 /*
39 * XDR argument and result sizes
40 */
41 #define MNT_enc_dirpath_sz encode_dirpath_sz
42 #define MNT_dec_mountres_sz (MNT_status_sz + MNT_fhandle_sz)
43 #define MNT_dec_mountres3_sz (MNT_status_sz + MNT_fhandle_sz + \
44 MNT_authflav3_sz)
45
46 /*
47 * Defined by RFC 1094, section A.5
48 */
49 enum {
50 MOUNTPROC_NULL = 0,
51 MOUNTPROC_MNT = 1,
52 MOUNTPROC_DUMP = 2,
53 MOUNTPROC_UMNT = 3,
54 MOUNTPROC_UMNTALL = 4,
55 MOUNTPROC_EXPORT = 5,
56 };
57
58 /*
59 * Defined by RFC 1813, section 5.2
60 */
61 enum {
62 MOUNTPROC3_NULL = 0,
63 MOUNTPROC3_MNT = 1,
64 MOUNTPROC3_DUMP = 2,
65 MOUNTPROC3_UMNT = 3,
66 MOUNTPROC3_UMNTALL = 4,
67 MOUNTPROC3_EXPORT = 5,
68 };
69
70 static const struct rpc_program mnt_program;
71
72 /*
73 * Defined by OpenGroup XNFS Version 3W, chapter 8
74 */
75 enum mountstat {
76 MNT_OK = 0,
77 MNT_EPERM = 1,
78 MNT_ENOENT = 2,
79 MNT_EACCES = 13,
80 MNT_EINVAL = 22,
81 };
82
83 static struct {
84 u32 status;
85 int errno;
86 } mnt_errtbl[] = {
87 { .status = MNT_OK, .errno = 0, },
88 { .status = MNT_EPERM, .errno = -EPERM, },
89 { .status = MNT_ENOENT, .errno = -ENOENT, },
90 { .status = MNT_EACCES, .errno = -EACCES, },
91 { .status = MNT_EINVAL, .errno = -EINVAL, },
92 };
93
94 /*
95 * Defined by RFC 1813, section 5.1.5
96 */
97 enum mountstat3 {
98 MNT3_OK = 0, /* no error */
99 MNT3ERR_PERM = 1, /* Not owner */
100 MNT3ERR_NOENT = 2, /* No such file or directory */
101 MNT3ERR_IO = 5, /* I/O error */
102 MNT3ERR_ACCES = 13, /* Permission denied */
103 MNT3ERR_NOTDIR = 20, /* Not a directory */
104 MNT3ERR_INVAL = 22, /* Invalid argument */
105 MNT3ERR_NAMETOOLONG = 63, /* Filename too long */
106 MNT3ERR_NOTSUPP = 10004, /* Operation not supported */
107 MNT3ERR_SERVERFAULT = 10006, /* A failure on the server */
108 };
109
110 static struct {
111 u32 status;
112 int errno;
113 } mnt3_errtbl[] = {
114 { .status = MNT3_OK, .errno = 0, },
115 { .status = MNT3ERR_PERM, .errno = -EPERM, },
116 { .status = MNT3ERR_NOENT, .errno = -ENOENT, },
117 { .status = MNT3ERR_IO, .errno = -EIO, },
118 { .status = MNT3ERR_ACCES, .errno = -EACCES, },
119 { .status = MNT3ERR_NOTDIR, .errno = -ENOTDIR, },
120 { .status = MNT3ERR_INVAL, .errno = -EINVAL, },
121 { .status = MNT3ERR_NAMETOOLONG, .errno = -ENAMETOOLONG, },
122 { .status = MNT3ERR_NOTSUPP, .errno = -ENOTSUPP, },
123 { .status = MNT3ERR_SERVERFAULT, .errno = -EREMOTEIO, },
124 };
125
126 struct mountres {
127 int errno;
128 struct nfs_fh *fh;
129 unsigned int *auth_count;
130 rpc_authflavor_t *auth_flavors;
131 };
132
133 struct mnt_fhstatus {
134 u32 status;
135 struct nfs_fh *fh;
136 };
137
138 /**
139 * nfs_mount - Obtain an NFS file handle for the given host and path
140 * @info: pointer to mount request arguments
141 *
142 * Uses default timeout parameters specified by underlying transport.
143 */
nfs_mount(struct nfs_mount_request * info)144 int nfs_mount(struct nfs_mount_request *info)
145 {
146 struct mountres result = {
147 .fh = info->fh,
148 .auth_count = info->auth_flav_len,
149 .auth_flavors = info->auth_flavs,
150 };
151 struct rpc_message msg = {
152 .rpc_argp = info->dirpath,
153 .rpc_resp = &result,
154 };
155 struct rpc_create_args args = {
156 .net = info->net,
157 .protocol = info->protocol,
158 .address = info->sap,
159 .addrsize = info->salen,
160 .servername = info->hostname,
161 .program = &mnt_program,
162 .version = info->version,
163 .authflavor = RPC_AUTH_UNIX,
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 (info->noresvport)
173 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
174
175 mnt_clnt = rpc_create(&args);
176 if (IS_ERR(mnt_clnt))
177 goto out_clnt_err;
178
179 if (info->version == NFS_MNT3_VERSION)
180 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
181 else
182 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
183
184 status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT);
185 rpc_shutdown_client(mnt_clnt);
186
187 if (status < 0)
188 goto out_call_err;
189 if (result.errno != 0)
190 goto out_mnt_err;
191
192 dprintk("NFS: MNT request succeeded\n");
193 status = 0;
194
195 out:
196 return status;
197
198 out_clnt_err:
199 status = PTR_ERR(mnt_clnt);
200 dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
201 goto out;
202
203 out_call_err:
204 dprintk("NFS: MNT request failed, status=%d\n", status);
205 goto out;
206
207 out_mnt_err:
208 dprintk("NFS: MNT server returned result %d\n", result.errno);
209 status = result.errno;
210 goto out;
211 }
212
213 /**
214 * nfs_umount - Notify a server that we have unmounted this export
215 * @info: pointer to umount request arguments
216 *
217 * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
218 * use UDP.
219 */
nfs_umount(const struct nfs_mount_request * info)220 void nfs_umount(const struct nfs_mount_request *info)
221 {
222 static const struct rpc_timeout nfs_umnt_timeout = {
223 .to_initval = 1 * HZ,
224 .to_maxval = 3 * HZ,
225 .to_retries = 2,
226 };
227 struct rpc_create_args args = {
228 .net = info->net,
229 .protocol = IPPROTO_UDP,
230 .address = info->sap,
231 .addrsize = info->salen,
232 .timeout = &nfs_umnt_timeout,
233 .servername = info->hostname,
234 .program = &mnt_program,
235 .version = info->version,
236 .authflavor = RPC_AUTH_UNIX,
237 .flags = RPC_CLNT_CREATE_NOPING,
238 };
239 struct rpc_message msg = {
240 .rpc_argp = info->dirpath,
241 };
242 struct rpc_clnt *clnt;
243 int status;
244
245 if (info->noresvport)
246 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
247
248 clnt = rpc_create(&args);
249 if (IS_ERR(clnt))
250 goto out_clnt_err;
251
252 dprintk("NFS: sending UMNT request for %s:%s\n",
253 (info->hostname ? info->hostname : "server"), info->dirpath);
254
255 if (info->version == NFS_MNT3_VERSION)
256 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
257 else
258 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
259
260 status = rpc_call_sync(clnt, &msg, 0);
261 rpc_shutdown_client(clnt);
262
263 if (unlikely(status < 0))
264 goto out_call_err;
265
266 return;
267
268 out_clnt_err:
269 dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
270 PTR_ERR(clnt));
271 return;
272
273 out_call_err:
274 dprintk("NFS: UMNT request failed, status=%d\n", status);
275 }
276
277 /*
278 * XDR encode/decode functions for MOUNT
279 */
280
encode_mntdirpath(struct xdr_stream * xdr,const char * pathname)281 static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
282 {
283 const u32 pathname_len = strlen(pathname);
284 __be32 *p;
285
286 BUG_ON(pathname_len > MNTPATHLEN);
287 p = xdr_reserve_space(xdr, 4 + pathname_len);
288 xdr_encode_opaque(p, pathname, pathname_len);
289 }
290
mnt_xdr_enc_dirpath(struct rpc_rqst * req,struct xdr_stream * xdr,const char * dirpath)291 static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr,
292 const char *dirpath)
293 {
294 encode_mntdirpath(xdr, dirpath);
295 }
296
297 /*
298 * RFC 1094: "A non-zero status indicates some sort of error. In this
299 * case, the status is a UNIX error number." This can be problematic
300 * if the server and client use different errno values for the same
301 * error.
302 *
303 * However, the OpenGroup XNFS spec provides a simple mapping that is
304 * independent of local errno values on the server and the client.
305 */
decode_status(struct xdr_stream * xdr,struct mountres * res)306 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
307 {
308 unsigned int i;
309 u32 status;
310 __be32 *p;
311
312 p = xdr_inline_decode(xdr, 4);
313 if (unlikely(p == NULL))
314 return -EIO;
315 status = be32_to_cpup(p);
316
317 for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
318 if (mnt_errtbl[i].status == status) {
319 res->errno = mnt_errtbl[i].errno;
320 return 0;
321 }
322 }
323
324 dprintk("NFS: unrecognized MNT status code: %u\n", status);
325 res->errno = -EACCES;
326 return 0;
327 }
328
decode_fhandle(struct xdr_stream * xdr,struct mountres * res)329 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
330 {
331 struct nfs_fh *fh = res->fh;
332 __be32 *p;
333
334 p = xdr_inline_decode(xdr, NFS2_FHSIZE);
335 if (unlikely(p == NULL))
336 return -EIO;
337
338 fh->size = NFS2_FHSIZE;
339 memcpy(fh->data, p, NFS2_FHSIZE);
340 return 0;
341 }
342
mnt_xdr_dec_mountres(struct rpc_rqst * req,struct xdr_stream * xdr,struct mountres * res)343 static int mnt_xdr_dec_mountres(struct rpc_rqst *req,
344 struct xdr_stream *xdr,
345 struct mountres *res)
346 {
347 int status;
348
349 status = decode_status(xdr, res);
350 if (unlikely(status != 0 || res->errno != 0))
351 return status;
352 return decode_fhandle(xdr, res);
353 }
354
decode_fhs_status(struct xdr_stream * xdr,struct mountres * res)355 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
356 {
357 unsigned int i;
358 u32 status;
359 __be32 *p;
360
361 p = xdr_inline_decode(xdr, 4);
362 if (unlikely(p == NULL))
363 return -EIO;
364 status = be32_to_cpup(p);
365
366 for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
367 if (mnt3_errtbl[i].status == status) {
368 res->errno = mnt3_errtbl[i].errno;
369 return 0;
370 }
371 }
372
373 dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
374 res->errno = -EACCES;
375 return 0;
376 }
377
decode_fhandle3(struct xdr_stream * xdr,struct mountres * res)378 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
379 {
380 struct nfs_fh *fh = res->fh;
381 u32 size;
382 __be32 *p;
383
384 p = xdr_inline_decode(xdr, 4);
385 if (unlikely(p == NULL))
386 return -EIO;
387
388 size = be32_to_cpup(p);
389 if (size > NFS3_FHSIZE || size == 0)
390 return -EIO;
391
392 p = xdr_inline_decode(xdr, size);
393 if (unlikely(p == NULL))
394 return -EIO;
395
396 fh->size = size;
397 memcpy(fh->data, p, size);
398 return 0;
399 }
400
decode_auth_flavors(struct xdr_stream * xdr,struct mountres * res)401 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
402 {
403 rpc_authflavor_t *flavors = res->auth_flavors;
404 unsigned int *count = res->auth_count;
405 u32 entries, i;
406 __be32 *p;
407
408 if (*count == 0)
409 return 0;
410
411 p = xdr_inline_decode(xdr, 4);
412 if (unlikely(p == NULL))
413 return -EIO;
414 entries = be32_to_cpup(p);
415 dprintk("NFS: received %u auth flavors\n", entries);
416 if (entries > NFS_MAX_SECFLAVORS)
417 entries = NFS_MAX_SECFLAVORS;
418
419 p = xdr_inline_decode(xdr, 4 * entries);
420 if (unlikely(p == NULL))
421 return -EIO;
422
423 if (entries > *count)
424 entries = *count;
425
426 for (i = 0; i < entries; i++) {
427 flavors[i] = be32_to_cpup(p++);
428 dprintk("NFS: auth flavor[%u]: %d\n", i, flavors[i]);
429 }
430 *count = i;
431
432 return 0;
433 }
434
mnt_xdr_dec_mountres3(struct rpc_rqst * req,struct xdr_stream * xdr,struct mountres * res)435 static int mnt_xdr_dec_mountres3(struct rpc_rqst *req,
436 struct xdr_stream *xdr,
437 struct mountres *res)
438 {
439 int status;
440
441 status = decode_fhs_status(xdr, res);
442 if (unlikely(status != 0 || res->errno != 0))
443 return status;
444 status = decode_fhandle3(xdr, res);
445 if (unlikely(status != 0)) {
446 res->errno = -EBADHANDLE;
447 return 0;
448 }
449 return decode_auth_flavors(xdr, res);
450 }
451
452 static struct rpc_procinfo mnt_procedures[] = {
453 [MOUNTPROC_MNT] = {
454 .p_proc = MOUNTPROC_MNT,
455 .p_encode = (kxdreproc_t)mnt_xdr_enc_dirpath,
456 .p_decode = (kxdrdproc_t)mnt_xdr_dec_mountres,
457 .p_arglen = MNT_enc_dirpath_sz,
458 .p_replen = MNT_dec_mountres_sz,
459 .p_statidx = MOUNTPROC_MNT,
460 .p_name = "MOUNT",
461 },
462 [MOUNTPROC_UMNT] = {
463 .p_proc = MOUNTPROC_UMNT,
464 .p_encode = (kxdreproc_t)mnt_xdr_enc_dirpath,
465 .p_arglen = MNT_enc_dirpath_sz,
466 .p_statidx = MOUNTPROC_UMNT,
467 .p_name = "UMOUNT",
468 },
469 };
470
471 static struct rpc_procinfo mnt3_procedures[] = {
472 [MOUNTPROC3_MNT] = {
473 .p_proc = MOUNTPROC3_MNT,
474 .p_encode = (kxdreproc_t)mnt_xdr_enc_dirpath,
475 .p_decode = (kxdrdproc_t)mnt_xdr_dec_mountres3,
476 .p_arglen = MNT_enc_dirpath_sz,
477 .p_replen = MNT_dec_mountres3_sz,
478 .p_statidx = MOUNTPROC3_MNT,
479 .p_name = "MOUNT",
480 },
481 [MOUNTPROC3_UMNT] = {
482 .p_proc = MOUNTPROC3_UMNT,
483 .p_encode = (kxdreproc_t)mnt_xdr_enc_dirpath,
484 .p_arglen = MNT_enc_dirpath_sz,
485 .p_statidx = MOUNTPROC3_UMNT,
486 .p_name = "UMOUNT",
487 },
488 };
489
490
491 static const struct rpc_version mnt_version1 = {
492 .number = 1,
493 .nrprocs = ARRAY_SIZE(mnt_procedures),
494 .procs = mnt_procedures,
495 };
496
497 static const struct rpc_version mnt_version3 = {
498 .number = 3,
499 .nrprocs = ARRAY_SIZE(mnt3_procedures),
500 .procs = mnt3_procedures,
501 };
502
503 static const struct rpc_version *mnt_version[] = {
504 NULL,
505 &mnt_version1,
506 NULL,
507 &mnt_version3,
508 };
509
510 static struct rpc_stat mnt_stats;
511
512 static const struct rpc_program mnt_program = {
513 .name = "mount",
514 .number = NFS_MNT_PROGRAM,
515 .nrvers = ARRAY_SIZE(mnt_version),
516 .version = mnt_version,
517 .stats = &mnt_stats,
518 };
519