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 (strlen(info->dirpath) > MNTPATHLEN)
173 return -ENAMETOOLONG;
174
175 if (info->noresvport)
176 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
177
178 mnt_clnt = rpc_create(&args);
179 if (IS_ERR(mnt_clnt))
180 goto out_clnt_err;
181
182 if (info->version == NFS_MNT3_VERSION)
183 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
184 else
185 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
186
187 status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT);
188 rpc_shutdown_client(mnt_clnt);
189
190 if (status < 0)
191 goto out_call_err;
192 if (result.errno != 0)
193 goto out_mnt_err;
194
195 dprintk("NFS: MNT request succeeded\n");
196 status = 0;
197
198 out:
199 return status;
200
201 out_clnt_err:
202 status = PTR_ERR(mnt_clnt);
203 dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
204 goto out;
205
206 out_call_err:
207 dprintk("NFS: MNT request failed, status=%d\n", status);
208 goto out;
209
210 out_mnt_err:
211 dprintk("NFS: MNT server returned result %d\n", result.errno);
212 status = result.errno;
213 goto out;
214 }
215
216 /**
217 * nfs_umount - Notify a server that we have unmounted this export
218 * @info: pointer to umount request arguments
219 *
220 * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
221 * use UDP.
222 */
nfs_umount(const struct nfs_mount_request * info)223 void nfs_umount(const struct nfs_mount_request *info)
224 {
225 static const struct rpc_timeout nfs_umnt_timeout = {
226 .to_initval = 1 * HZ,
227 .to_maxval = 3 * HZ,
228 .to_retries = 2,
229 };
230 struct rpc_create_args args = {
231 .net = info->net,
232 .protocol = IPPROTO_UDP,
233 .address = info->sap,
234 .addrsize = info->salen,
235 .timeout = &nfs_umnt_timeout,
236 .servername = info->hostname,
237 .program = &mnt_program,
238 .version = info->version,
239 .authflavor = RPC_AUTH_UNIX,
240 .flags = RPC_CLNT_CREATE_NOPING,
241 };
242 struct rpc_message msg = {
243 .rpc_argp = info->dirpath,
244 };
245 struct rpc_clnt *clnt;
246 int status;
247
248 if (strlen(info->dirpath) > MNTPATHLEN)
249 return;
250
251 if (info->noresvport)
252 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
253
254 clnt = rpc_create(&args);
255 if (IS_ERR(clnt))
256 goto out_clnt_err;
257
258 dprintk("NFS: sending UMNT request for %s:%s\n",
259 (info->hostname ? info->hostname : "server"), info->dirpath);
260
261 if (info->version == NFS_MNT3_VERSION)
262 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
263 else
264 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
265
266 status = rpc_call_sync(clnt, &msg, 0);
267 rpc_shutdown_client(clnt);
268
269 if (unlikely(status < 0))
270 goto out_call_err;
271
272 return;
273
274 out_clnt_err:
275 dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
276 PTR_ERR(clnt));
277 return;
278
279 out_call_err:
280 dprintk("NFS: UMNT request failed, status=%d\n", status);
281 }
282
283 /*
284 * XDR encode/decode functions for MOUNT
285 */
286
encode_mntdirpath(struct xdr_stream * xdr,const char * pathname)287 static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
288 {
289 const u32 pathname_len = strlen(pathname);
290 __be32 *p;
291
292 p = xdr_reserve_space(xdr, 4 + pathname_len);
293 xdr_encode_opaque(p, pathname, pathname_len);
294 }
295
mnt_xdr_enc_dirpath(struct rpc_rqst * req,struct xdr_stream * xdr,const char * dirpath)296 static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr,
297 const char *dirpath)
298 {
299 encode_mntdirpath(xdr, dirpath);
300 }
301
302 /*
303 * RFC 1094: "A non-zero status indicates some sort of error. In this
304 * case, the status is a UNIX error number." This can be problematic
305 * if the server and client use different errno values for the same
306 * error.
307 *
308 * However, the OpenGroup XNFS spec provides a simple mapping that is
309 * independent of local errno values on the server and the client.
310 */
decode_status(struct xdr_stream * xdr,struct mountres * res)311 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
312 {
313 unsigned int i;
314 u32 status;
315 __be32 *p;
316
317 p = xdr_inline_decode(xdr, 4);
318 if (unlikely(p == NULL))
319 return -EIO;
320 status = be32_to_cpup(p);
321
322 for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
323 if (mnt_errtbl[i].status == status) {
324 res->errno = mnt_errtbl[i].errno;
325 return 0;
326 }
327 }
328
329 dprintk("NFS: unrecognized MNT status code: %u\n", status);
330 res->errno = -EACCES;
331 return 0;
332 }
333
decode_fhandle(struct xdr_stream * xdr,struct mountres * res)334 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
335 {
336 struct nfs_fh *fh = res->fh;
337 __be32 *p;
338
339 p = xdr_inline_decode(xdr, NFS2_FHSIZE);
340 if (unlikely(p == NULL))
341 return -EIO;
342
343 fh->size = NFS2_FHSIZE;
344 memcpy(fh->data, p, NFS2_FHSIZE);
345 return 0;
346 }
347
mnt_xdr_dec_mountres(struct rpc_rqst * req,struct xdr_stream * xdr,struct mountres * res)348 static int mnt_xdr_dec_mountres(struct rpc_rqst *req,
349 struct xdr_stream *xdr,
350 struct mountres *res)
351 {
352 int status;
353
354 status = decode_status(xdr, res);
355 if (unlikely(status != 0 || res->errno != 0))
356 return status;
357 return decode_fhandle(xdr, res);
358 }
359
decode_fhs_status(struct xdr_stream * xdr,struct mountres * res)360 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
361 {
362 unsigned int i;
363 u32 status;
364 __be32 *p;
365
366 p = xdr_inline_decode(xdr, 4);
367 if (unlikely(p == NULL))
368 return -EIO;
369 status = be32_to_cpup(p);
370
371 for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
372 if (mnt3_errtbl[i].status == status) {
373 res->errno = mnt3_errtbl[i].errno;
374 return 0;
375 }
376 }
377
378 dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
379 res->errno = -EACCES;
380 return 0;
381 }
382
decode_fhandle3(struct xdr_stream * xdr,struct mountres * res)383 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
384 {
385 struct nfs_fh *fh = res->fh;
386 u32 size;
387 __be32 *p;
388
389 p = xdr_inline_decode(xdr, 4);
390 if (unlikely(p == NULL))
391 return -EIO;
392
393 size = be32_to_cpup(p);
394 if (size > NFS3_FHSIZE || size == 0)
395 return -EIO;
396
397 p = xdr_inline_decode(xdr, size);
398 if (unlikely(p == NULL))
399 return -EIO;
400
401 fh->size = size;
402 memcpy(fh->data, p, size);
403 return 0;
404 }
405
decode_auth_flavors(struct xdr_stream * xdr,struct mountres * res)406 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
407 {
408 rpc_authflavor_t *flavors = res->auth_flavors;
409 unsigned int *count = res->auth_count;
410 u32 entries, i;
411 __be32 *p;
412
413 if (*count == 0)
414 return 0;
415
416 p = xdr_inline_decode(xdr, 4);
417 if (unlikely(p == NULL))
418 return -EIO;
419 entries = be32_to_cpup(p);
420 dprintk("NFS: received %u auth flavors\n", entries);
421 if (entries > NFS_MAX_SECFLAVORS)
422 entries = NFS_MAX_SECFLAVORS;
423
424 p = xdr_inline_decode(xdr, 4 * entries);
425 if (unlikely(p == NULL))
426 return -EIO;
427
428 if (entries > *count)
429 entries = *count;
430
431 for (i = 0; i < entries; i++) {
432 flavors[i] = be32_to_cpup(p++);
433 dprintk("NFS: auth flavor[%u]: %d\n", i, flavors[i]);
434 }
435 *count = i;
436
437 return 0;
438 }
439
mnt_xdr_dec_mountres3(struct rpc_rqst * req,struct xdr_stream * xdr,struct mountres * res)440 static int mnt_xdr_dec_mountres3(struct rpc_rqst *req,
441 struct xdr_stream *xdr,
442 struct mountres *res)
443 {
444 int status;
445
446 status = decode_fhs_status(xdr, res);
447 if (unlikely(status != 0 || res->errno != 0))
448 return status;
449 status = decode_fhandle3(xdr, res);
450 if (unlikely(status != 0)) {
451 res->errno = -EBADHANDLE;
452 return 0;
453 }
454 return decode_auth_flavors(xdr, res);
455 }
456
457 static struct rpc_procinfo mnt_procedures[] = {
458 [MOUNTPROC_MNT] = {
459 .p_proc = MOUNTPROC_MNT,
460 .p_encode = (kxdreproc_t)mnt_xdr_enc_dirpath,
461 .p_decode = (kxdrdproc_t)mnt_xdr_dec_mountres,
462 .p_arglen = MNT_enc_dirpath_sz,
463 .p_replen = MNT_dec_mountres_sz,
464 .p_statidx = MOUNTPROC_MNT,
465 .p_name = "MOUNT",
466 },
467 [MOUNTPROC_UMNT] = {
468 .p_proc = MOUNTPROC_UMNT,
469 .p_encode = (kxdreproc_t)mnt_xdr_enc_dirpath,
470 .p_arglen = MNT_enc_dirpath_sz,
471 .p_statidx = MOUNTPROC_UMNT,
472 .p_name = "UMOUNT",
473 },
474 };
475
476 static struct rpc_procinfo mnt3_procedures[] = {
477 [MOUNTPROC3_MNT] = {
478 .p_proc = MOUNTPROC3_MNT,
479 .p_encode = (kxdreproc_t)mnt_xdr_enc_dirpath,
480 .p_decode = (kxdrdproc_t)mnt_xdr_dec_mountres3,
481 .p_arglen = MNT_enc_dirpath_sz,
482 .p_replen = MNT_dec_mountres3_sz,
483 .p_statidx = MOUNTPROC3_MNT,
484 .p_name = "MOUNT",
485 },
486 [MOUNTPROC3_UMNT] = {
487 .p_proc = MOUNTPROC3_UMNT,
488 .p_encode = (kxdreproc_t)mnt_xdr_enc_dirpath,
489 .p_arglen = MNT_enc_dirpath_sz,
490 .p_statidx = MOUNTPROC3_UMNT,
491 .p_name = "UMOUNT",
492 },
493 };
494
495
496 static const struct rpc_version mnt_version1 = {
497 .number = 1,
498 .nrprocs = ARRAY_SIZE(mnt_procedures),
499 .procs = mnt_procedures,
500 };
501
502 static const struct rpc_version mnt_version3 = {
503 .number = 3,
504 .nrprocs = ARRAY_SIZE(mnt3_procedures),
505 .procs = mnt3_procedures,
506 };
507
508 static const struct rpc_version *mnt_version[] = {
509 NULL,
510 &mnt_version1,
511 NULL,
512 &mnt_version3,
513 };
514
515 static struct rpc_stat mnt_stats;
516
517 static const struct rpc_program mnt_program = {
518 .name = "mount",
519 .number = NFS_MNT_PROGRAM,
520 .nrvers = ARRAY_SIZE(mnt_version),
521 .version = mnt_version,
522 .stats = &mnt_stats,
523 };
524