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#define NFSDBG_FACILITY	NFSDBG_MOUNT
20
21/*
22 * Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4
23 */
24#define MNTPATHLEN		(1024)
25
26/*
27 * XDR data type sizes
28 */
29#define encode_dirpath_sz	(1 + XDR_QUADLEN(MNTPATHLEN))
30#define MNT_status_sz		(1)
31#define MNT_fhs_status_sz	(1)
32#define MNT_fhandle_sz		XDR_QUADLEN(NFS2_FHSIZE)
33#define MNT_fhandle3_sz		(1 + 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_fhandle_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	};
166	struct rpc_clnt		*mnt_clnt;
167	int			status;
168
169	dprintk("NFS: sending MNT request for %s:%s\n",
170		(info->hostname ? info->hostname : "server"),
171			info->dirpath);
172
173	if (strlen(info->dirpath) > MNTPATHLEN)
174		return -ENAMETOOLONG;
175
176	if (info->noresvport)
177		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
178
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	}
208out:
209	return status;
210
211out_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
216out_call_err:
217	dprintk("NFS: MNT request failed, status=%d\n", status);
218	goto out;
219
220out_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 */
233void 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	= 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	};
252	struct rpc_message msg	= {
253		.rpc_argp	= info->dirpath,
254	};
255	struct rpc_clnt *clnt;
256	int status;
257
258	if (strlen(info->dirpath) > MNTPATHLEN)
259		return;
260
261	if (info->noresvport)
262		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
263
264	clnt = rpc_create(&args);
265	if (IS_ERR(clnt))
266		goto out_clnt_err;
267
268	dprintk("NFS: sending UMNT request for %s:%s\n",
269		(info->hostname ? info->hostname : "server"), info->dirpath);
270
271	if (info->version == NFS_MNT3_VERSION)
272		msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
273	else
274		msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
275
276	status = rpc_call_sync(clnt, &msg, 0);
277	rpc_shutdown_client(clnt);
278
279	if (unlikely(status < 0))
280		goto out_call_err;
281
282	return;
283
284out_clnt_err:
285	dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
286			PTR_ERR(clnt));
287	return;
288
289out_call_err:
290	dprintk("NFS: UMNT request failed, status=%d\n", status);
291}
292
293/*
294 * XDR encode/decode functions for MOUNT
295 */
296
297static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
298{
299	const u32 pathname_len = strlen(pathname);
300	__be32 *p;
301
302	p = xdr_reserve_space(xdr, 4 + pathname_len);
303	xdr_encode_opaque(p, pathname, pathname_len);
304}
305
306static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr,
307				const char *dirpath)
308{
309	encode_mntdirpath(xdr, dirpath);
310}
311
312/*
313 * RFC 1094: "A non-zero status indicates some sort of error.  In this
314 * case, the status is a UNIX error number."  This can be problematic
315 * if the server and client use different errno values for the same
316 * error.
317 *
318 * However, the OpenGroup XNFS spec provides a simple mapping that is
319 * independent of local errno values on the server and the client.
320 */
321static int decode_status(struct xdr_stream *xdr, struct mountres *res)
322{
323	unsigned int i;
324	u32 status;
325	__be32 *p;
326
327	p = xdr_inline_decode(xdr, 4);
328	if (unlikely(p == NULL))
329		return -EIO;
330	status = be32_to_cpup(p);
331
332	for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
333		if (mnt_errtbl[i].status == status) {
334			res->errno = mnt_errtbl[i].errno;
335			return 0;
336		}
337	}
338
339	dprintk("NFS: unrecognized MNT status code: %u\n", status);
340	res->errno = -EACCES;
341	return 0;
342}
343
344static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
345{
346	struct nfs_fh *fh = res->fh;
347	__be32 *p;
348
349	p = xdr_inline_decode(xdr, NFS2_FHSIZE);
350	if (unlikely(p == NULL))
351		return -EIO;
352
353	fh->size = NFS2_FHSIZE;
354	memcpy(fh->data, p, NFS2_FHSIZE);
355	return 0;
356}
357
358static int mnt_xdr_dec_mountres(struct rpc_rqst *req,
359				struct xdr_stream *xdr,
360				struct mountres *res)
361{
362	int status;
363
364	status = decode_status(xdr, res);
365	if (unlikely(status != 0 || res->errno != 0))
366		return status;
367	return decode_fhandle(xdr, res);
368}
369
370static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
371{
372	unsigned int i;
373	u32 status;
374	__be32 *p;
375
376	p = xdr_inline_decode(xdr, 4);
377	if (unlikely(p == NULL))
378		return -EIO;
379	status = be32_to_cpup(p);
380
381	for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
382		if (mnt3_errtbl[i].status == status) {
383			res->errno = mnt3_errtbl[i].errno;
384			return 0;
385		}
386	}
387
388	dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
389	res->errno = -EACCES;
390	return 0;
391}
392
393static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
394{
395	struct nfs_fh *fh = res->fh;
396	u32 size;
397	__be32 *p;
398
399	p = xdr_inline_decode(xdr, 4);
400	if (unlikely(p == NULL))
401		return -EIO;
402
403	size = be32_to_cpup(p);
404	if (size > NFS3_FHSIZE || size == 0)
405		return -EIO;
406
407	p = xdr_inline_decode(xdr, size);
408	if (unlikely(p == NULL))
409		return -EIO;
410
411	fh->size = size;
412	memcpy(fh->data, p, size);
413	return 0;
414}
415
416static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
417{
418	rpc_authflavor_t *flavors = res->auth_flavors;
419	unsigned int *count = res->auth_count;
420	u32 entries, i;
421	__be32 *p;
422
423	if (*count == 0)
424		return 0;
425
426	p = xdr_inline_decode(xdr, 4);
427	if (unlikely(p == NULL))
428		return -EIO;
429	entries = be32_to_cpup(p);
430	dprintk("NFS: received %u auth flavors\n", entries);
431	if (entries > NFS_MAX_SECFLAVORS)
432		entries = NFS_MAX_SECFLAVORS;
433
434	p = xdr_inline_decode(xdr, 4 * entries);
435	if (unlikely(p == NULL))
436		return -EIO;
437
438	if (entries > *count)
439		entries = *count;
440
441	for (i = 0; i < entries; i++) {
442		flavors[i] = be32_to_cpup(p++);
443		dprintk("NFS:   auth flavor[%u]: %d\n", i, flavors[i]);
444	}
445	*count = i;
446
447	return 0;
448}
449
450static int mnt_xdr_dec_mountres3(struct rpc_rqst *req,
451				 struct xdr_stream *xdr,
452				 struct mountres *res)
453{
454	int status;
455
456	status = decode_fhs_status(xdr, res);
457	if (unlikely(status != 0 || res->errno != 0))
458		return status;
459	status = decode_fhandle3(xdr, res);
460	if (unlikely(status != 0)) {
461		res->errno = -EBADHANDLE;
462		return 0;
463	}
464	return decode_auth_flavors(xdr, res);
465}
466
467static struct rpc_procinfo mnt_procedures[] = {
468	[MOUNTPROC_MNT] = {
469		.p_proc		= MOUNTPROC_MNT,
470		.p_encode	= (kxdreproc_t)mnt_xdr_enc_dirpath,
471		.p_decode	= (kxdrdproc_t)mnt_xdr_dec_mountres,
472		.p_arglen	= MNT_enc_dirpath_sz,
473		.p_replen	= MNT_dec_mountres_sz,
474		.p_statidx	= MOUNTPROC_MNT,
475		.p_name		= "MOUNT",
476	},
477	[MOUNTPROC_UMNT] = {
478		.p_proc		= MOUNTPROC_UMNT,
479		.p_encode	= (kxdreproc_t)mnt_xdr_enc_dirpath,
480		.p_arglen	= MNT_enc_dirpath_sz,
481		.p_statidx	= MOUNTPROC_UMNT,
482		.p_name		= "UMOUNT",
483	},
484};
485
486static struct rpc_procinfo mnt3_procedures[] = {
487	[MOUNTPROC3_MNT] = {
488		.p_proc		= MOUNTPROC3_MNT,
489		.p_encode	= (kxdreproc_t)mnt_xdr_enc_dirpath,
490		.p_decode	= (kxdrdproc_t)mnt_xdr_dec_mountres3,
491		.p_arglen	= MNT_enc_dirpath_sz,
492		.p_replen	= MNT_dec_mountres3_sz,
493		.p_statidx	= MOUNTPROC3_MNT,
494		.p_name		= "MOUNT",
495	},
496	[MOUNTPROC3_UMNT] = {
497		.p_proc		= MOUNTPROC3_UMNT,
498		.p_encode	= (kxdreproc_t)mnt_xdr_enc_dirpath,
499		.p_arglen	= MNT_enc_dirpath_sz,
500		.p_statidx	= MOUNTPROC3_UMNT,
501		.p_name		= "UMOUNT",
502	},
503};
504
505
506static const struct rpc_version mnt_version1 = {
507	.number		= 1,
508	.nrprocs	= ARRAY_SIZE(mnt_procedures),
509	.procs		= mnt_procedures,
510};
511
512static const struct rpc_version mnt_version3 = {
513	.number		= 3,
514	.nrprocs	= ARRAY_SIZE(mnt3_procedures),
515	.procs		= mnt3_procedures,
516};
517
518static const struct rpc_version *mnt_version[] = {
519	NULL,
520	&mnt_version1,
521	NULL,
522	&mnt_version3,
523};
524
525static struct rpc_stat mnt_stats;
526
527static const struct rpc_program mnt_program = {
528	.name		= "mount",
529	.number		= NFS_MNT_PROGRAM,
530	.nrvers		= ARRAY_SIZE(mnt_version),
531	.version	= mnt_version,
532	.stats		= &mnt_stats,
533};
534