1/*
2 *  linux/fs/nfsd/nfs4callback.c
3 *
4 *  Copyright (c) 2001 The Regents of the University of Michigan.
5 *  All rights reserved.
6 *
7 *  Kendrick Smith <kmsmith@umich.edu>
8 *  Andy Adamson <andros@umich.edu>
9 *
10 *  Redistribution and use in source and binary forms, with or without
11 *  modification, are permitted provided that the following conditions
12 *  are met:
13 *
14 *  1. Redistributions of source code must retain the above copyright
15 *     notice, this list of conditions and the following disclaimer.
16 *  2. Redistributions in binary form must reproduce the above copyright
17 *     notice, this list of conditions and the following disclaimer in the
18 *     documentation and/or other materials provided with the distribution.
19 *  3. Neither the name of the University nor the names of its
20 *     contributors may be used to endorse or promote products derived
21 *     from this software without specific prior written permission.
22 *
23 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
24 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36#include <linux/module.h>
37#include <linux/list.h>
38#include <linux/inet.h>
39#include <linux/errno.h>
40#include <linux/delay.h>
41#include <linux/sched.h>
42#include <linux/sunrpc/xdr.h>
43#include <linux/sunrpc/svc.h>
44#include <linux/sunrpc/clnt.h>
45#include <linux/nfsd/nfsd.h>
46#include <linux/nfsd/state.h>
47#include <linux/sunrpc/sched.h>
48#include <linux/nfs4.h>
49
50#define NFSDDBG_FACILITY                NFSDDBG_PROC
51
52#define NFSPROC4_CB_NULL 0
53#define NFSPROC4_CB_COMPOUND 1
54
55/* declarations */
56static const struct rpc_call_ops nfs4_cb_null_ops;
57
58/* Index of predefined Linux callback client operations */
59
60enum {
61        NFSPROC4_CLNT_CB_NULL = 0,
62	NFSPROC4_CLNT_CB_RECALL,
63};
64
65enum nfs_cb_opnum4 {
66	OP_CB_RECALL            = 4,
67};
68
69#define NFS4_MAXTAGLEN		20
70
71#define NFS4_enc_cb_null_sz		0
72#define NFS4_dec_cb_null_sz		0
73#define cb_compound_enc_hdr_sz		4
74#define cb_compound_dec_hdr_sz		(3 + (NFS4_MAXTAGLEN >> 2))
75#define op_enc_sz			1
76#define op_dec_sz			2
77#define enc_nfs4_fh_sz			(1 + (NFS4_FHSIZE >> 2))
78#define enc_stateid_sz			16
79#define NFS4_enc_cb_recall_sz		(cb_compound_enc_hdr_sz +       \
80					1 + enc_stateid_sz +            \
81					enc_nfs4_fh_sz)
82
83#define NFS4_dec_cb_recall_sz		(cb_compound_dec_hdr_sz  +      \
84					op_dec_sz)
85
86/*
87* Generic encode routines from fs/nfs/nfs4xdr.c
88*/
89static inline __be32 *
90xdr_writemem(__be32 *p, const void *ptr, int nbytes)
91{
92	int tmp = XDR_QUADLEN(nbytes);
93	if (!tmp)
94		return p;
95	p[tmp-1] = 0;
96	memcpy(p, ptr, nbytes);
97	return p + tmp;
98}
99
100#define WRITE32(n)               *p++ = htonl(n)
101#define WRITEMEM(ptr,nbytes)     do {                           \
102	p = xdr_writemem(p, ptr, nbytes);                       \
103} while (0)
104#define RESERVE_SPACE(nbytes)   do {                            \
105	p = xdr_reserve_space(xdr, nbytes);                     \
106	if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __FUNCTION__); \
107	BUG_ON(!p);                                             \
108} while (0)
109
110/*
111 * Generic decode routines from fs/nfs/nfs4xdr.c
112 */
113#define DECODE_TAIL                             \
114	status = 0;                             \
115out:                                            \
116	return status;                          \
117xdr_error:                                      \
118	dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
119	status = -EIO;                          \
120	goto out
121
122#define READ32(x)         (x) = ntohl(*p++)
123#define READ64(x)         do {                  \
124	(x) = (u64)ntohl(*p++) << 32;           \
125	(x) |= ntohl(*p++);                     \
126} while (0)
127#define READTIME(x)       do {                  \
128	p++;                                    \
129	(x.tv_sec) = ntohl(*p++);               \
130	(x.tv_nsec) = ntohl(*p++);              \
131} while (0)
132#define READ_BUF(nbytes)  do { \
133	p = xdr_inline_decode(xdr, nbytes); \
134	if (!p) { \
135		dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
136			__FUNCTION__, __LINE__); \
137		return -EIO; \
138	} \
139} while (0)
140
141struct nfs4_cb_compound_hdr {
142	int		status;
143	u32		ident;
144	u32		nops;
145	u32		taglen;
146	char *		tag;
147};
148
149static struct {
150int stat;
151int errno;
152} nfs_cb_errtbl[] = {
153	{ NFS4_OK,		0               },
154	{ NFS4ERR_PERM,		EPERM           },
155	{ NFS4ERR_NOENT,	ENOENT          },
156	{ NFS4ERR_IO,		EIO             },
157	{ NFS4ERR_NXIO,		ENXIO           },
158	{ NFS4ERR_ACCESS,	EACCES          },
159	{ NFS4ERR_EXIST,	EEXIST          },
160	{ NFS4ERR_XDEV,		EXDEV           },
161	{ NFS4ERR_NOTDIR,	ENOTDIR         },
162	{ NFS4ERR_ISDIR,	EISDIR          },
163	{ NFS4ERR_INVAL,	EINVAL          },
164	{ NFS4ERR_FBIG,		EFBIG           },
165	{ NFS4ERR_NOSPC,	ENOSPC          },
166	{ NFS4ERR_ROFS,		EROFS           },
167	{ NFS4ERR_MLINK,	EMLINK          },
168	{ NFS4ERR_NAMETOOLONG,	ENAMETOOLONG    },
169	{ NFS4ERR_NOTEMPTY,	ENOTEMPTY       },
170	{ NFS4ERR_DQUOT,	EDQUOT          },
171	{ NFS4ERR_STALE,	ESTALE          },
172	{ NFS4ERR_BADHANDLE,	EBADHANDLE      },
173	{ NFS4ERR_BAD_COOKIE,	EBADCOOKIE      },
174	{ NFS4ERR_NOTSUPP,	ENOTSUPP        },
175	{ NFS4ERR_TOOSMALL,	ETOOSMALL       },
176	{ NFS4ERR_SERVERFAULT,	ESERVERFAULT    },
177	{ NFS4ERR_BADTYPE,	EBADTYPE        },
178	{ NFS4ERR_LOCKED,	EAGAIN          },
179	{ NFS4ERR_RESOURCE,	EREMOTEIO       },
180	{ NFS4ERR_SYMLINK,	ELOOP           },
181	{ NFS4ERR_OP_ILLEGAL,	EOPNOTSUPP      },
182	{ NFS4ERR_DEADLOCK,	EDEADLK         },
183	{ -1,                   EIO             }
184};
185
186static int
187nfs_cb_stat_to_errno(int stat)
188{
189	int i;
190	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
191		if (nfs_cb_errtbl[i].stat == stat)
192			return nfs_cb_errtbl[i].errno;
193	}
194	/* If we cannot translate the error, the recovery routines should
195	* handle it.
196	* Note: remaining NFSv4 error codes have values > 10000, so should
197	* not conflict with native Linux error codes.
198	*/
199	return stat;
200}
201
202/*
203 * XDR encode
204 */
205
206static int
207encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
208{
209	__be32 * p;
210
211	RESERVE_SPACE(16);
212	WRITE32(0);            /* tag length is always 0 */
213	WRITE32(NFS4_MINOR_VERSION);
214	WRITE32(hdr->ident);
215	WRITE32(hdr->nops);
216	return 0;
217}
218
219static int
220encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
221{
222	__be32 *p;
223	int len = cb_rec->cbr_fhlen;
224
225	RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
226	WRITE32(OP_CB_RECALL);
227	WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
228	WRITE32(cb_rec->cbr_trunc);
229	WRITE32(len);
230	WRITEMEM(cb_rec->cbr_fhval, len);
231	return 0;
232}
233
234static int
235nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
236{
237	struct xdr_stream xdrs, *xdr = &xdrs;
238
239	xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
240        RESERVE_SPACE(0);
241	return 0;
242}
243
244static int
245nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
246{
247	struct xdr_stream xdr;
248	struct nfs4_cb_compound_hdr hdr = {
249		.ident = args->cbr_ident,
250		.nops   = 1,
251	};
252
253	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
254	encode_cb_compound_hdr(&xdr, &hdr);
255	return (encode_cb_recall(&xdr, args));
256}
257
258
259static int
260decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
261        __be32 *p;
262
263        READ_BUF(8);
264        READ32(hdr->status);
265        READ32(hdr->taglen);
266        READ_BUF(hdr->taglen + 4);
267        hdr->tag = (char *)p;
268        p += XDR_QUADLEN(hdr->taglen);
269        READ32(hdr->nops);
270        return 0;
271}
272
273static int
274decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
275{
276	__be32 *p;
277	u32 op;
278	int32_t nfserr;
279
280	READ_BUF(8);
281	READ32(op);
282	if (op != expected) {
283		dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
284		         " operation %d but we issued a request for %d\n",
285		         op, expected);
286		return -EIO;
287	}
288	READ32(nfserr);
289	if (nfserr != NFS_OK)
290		return -nfs_cb_stat_to_errno(nfserr);
291	return 0;
292}
293
294static int
295nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
296{
297	return 0;
298}
299
300static int
301nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
302{
303	struct xdr_stream xdr;
304	struct nfs4_cb_compound_hdr hdr;
305	int status;
306
307	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
308	status = decode_cb_compound_hdr(&xdr, &hdr);
309	if (status)
310		goto out;
311	status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
312out:
313	return status;
314}
315
316/*
317 * RPC procedure tables
318 */
319#define PROC(proc, call, argtype, restype)                              \
320[NFSPROC4_CLNT_##proc] = {                                      	\
321        .p_proc   = NFSPROC4_CB_##call,					\
322        .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
323        .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
324        .p_arglen = NFS4_##argtype##_sz,                                \
325        .p_replen = NFS4_##restype##_sz,                                \
326        .p_statidx = NFSPROC4_CB_##call,				\
327	.p_name   = #proc,                                              \
328}
329
330static struct rpc_procinfo     nfs4_cb_procedures[] = {
331    PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
332    PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
333};
334
335static struct rpc_version       nfs_cb_version4 = {
336        .number                 = 1,
337        .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
338        .procs                  = nfs4_cb_procedures
339};
340
341static struct rpc_version *	nfs_cb_version[] = {
342	NULL,
343	&nfs_cb_version4,
344};
345
346/*
347 * Use the SETCLIENTID credential
348 */
349static struct rpc_cred *
350nfsd4_lookupcred(struct nfs4_client *clp, int taskflags)
351{
352        struct auth_cred acred;
353	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
354	struct rpc_cred *ret;
355
356        get_group_info(clp->cl_cred.cr_group_info);
357        acred.uid = clp->cl_cred.cr_uid;
358        acred.gid = clp->cl_cred.cr_gid;
359        acred.group_info = clp->cl_cred.cr_group_info;
360
361        dprintk("NFSD:     looking up %s cred\n",
362                clnt->cl_auth->au_ops->au_name);
363        ret = rpcauth_lookup_credcache(clnt->cl_auth, &acred, taskflags);
364        put_group_info(clp->cl_cred.cr_group_info);
365        return ret;
366}
367
368/*
369 * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
370 */
371void
372nfsd4_probe_callback(struct nfs4_client *clp)
373{
374	struct sockaddr_in	addr;
375	struct nfs4_callback    *cb = &clp->cl_callback;
376	struct rpc_timeout	timeparms = {
377		.to_initval	= (NFSD_LEASE_TIME/4) * HZ,
378		.to_retries	= 5,
379		.to_maxval	= (NFSD_LEASE_TIME/2) * HZ,
380		.to_exponential	= 1,
381	};
382	struct rpc_program *	program = &cb->cb_program;
383	struct rpc_create_args args = {
384		.protocol	= IPPROTO_TCP,
385		.address	= (struct sockaddr *)&addr,
386		.addrsize	= sizeof(addr),
387		.timeout	= &timeparms,
388		.program	= program,
389		.version	= nfs_cb_version[1]->number,
390		.authflavor	= RPC_AUTH_UNIX,
391		.flags		= (RPC_CLNT_CREATE_NOPING),
392	};
393	struct rpc_message msg = {
394		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
395		.rpc_argp       = clp,
396	};
397	char clientname[16];
398	int status;
399
400	if (atomic_read(&cb->cb_set))
401		return;
402
403	/* Initialize address */
404	memset(&addr, 0, sizeof(addr));
405	addr.sin_family = AF_INET;
406	addr.sin_port = htons(cb->cb_port);
407	addr.sin_addr.s_addr = htonl(cb->cb_addr);
408
409	/* Initialize rpc_program */
410	program->name = "nfs4_cb";
411	program->number = cb->cb_prog;
412	program->nrvers = ARRAY_SIZE(nfs_cb_version);
413	program->version = nfs_cb_version;
414	program->stats = &cb->cb_stat;
415
416	/* Initialize rpc_stat */
417	memset(program->stats, 0, sizeof(cb->cb_stat));
418	program->stats->program = program;
419
420	/* Just here to make some printk's more useful: */
421	snprintf(clientname, sizeof(clientname),
422		"%u.%u.%u.%u", NIPQUAD(addr.sin_addr));
423	args.servername = clientname;
424
425	/* Create RPC client */
426	cb->cb_client = rpc_create(&args);
427	if (IS_ERR(cb->cb_client)) {
428		dprintk("NFSD: couldn't create callback client\n");
429		goto out_err;
430	}
431
432	/* Kick rpciod, put the call on the wire. */
433	if (rpciod_up() != 0)
434		goto out_clnt;
435
436	/* the task holds a reference to the nfs4_client struct */
437	atomic_inc(&clp->cl_count);
438
439	msg.rpc_cred = nfsd4_lookupcred(clp,0);
440	if (IS_ERR(msg.rpc_cred))
441		goto out_rpciod;
442	status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_ASYNC, &nfs4_cb_null_ops, NULL);
443	put_rpccred(msg.rpc_cred);
444
445	if (status != 0) {
446		dprintk("NFSD: asynchronous NFSPROC4_CB_NULL failed!\n");
447		goto out_rpciod;
448	}
449	return;
450
451out_rpciod:
452	atomic_dec(&clp->cl_count);
453	rpciod_down();
454out_clnt:
455	rpc_shutdown_client(cb->cb_client);
456out_err:
457	cb->cb_client = NULL;
458	dprintk("NFSD: warning: no callback path to client %.*s\n",
459		(int)clp->cl_name.len, clp->cl_name.data);
460}
461
462static void
463nfs4_cb_null(struct rpc_task *task, void *dummy)
464{
465	struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
466	struct nfs4_callback *cb = &clp->cl_callback;
467	__be32 addr = htonl(cb->cb_addr);
468
469	dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
470
471	if (task->tk_status < 0) {
472		dprintk("NFSD: callback establishment to client %.*s failed\n",
473			(int)clp->cl_name.len, clp->cl_name.data);
474		goto out;
475	}
476	atomic_set(&cb->cb_set, 1);
477	dprintk("NFSD: callback set to client %u.%u.%u.%u\n", NIPQUAD(addr));
478out:
479	put_nfs4_client(clp);
480}
481
482static const struct rpc_call_ops nfs4_cb_null_ops = {
483	.rpc_call_done = nfs4_cb_null,
484};
485
486/*
487 * called with dp->dl_count inc'ed.
488 * nfs4_lock_state() may or may not have been called.
489 */
490void
491nfsd4_cb_recall(struct nfs4_delegation *dp)
492{
493	struct nfs4_client *clp = dp->dl_client;
494	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
495	struct nfs4_cb_recall *cbr = &dp->dl_recall;
496	struct rpc_message msg = {
497		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
498		.rpc_argp = cbr,
499	};
500	int retries = 1;
501	int status = 0;
502
503	if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
504		return;
505
506	msg.rpc_cred = nfsd4_lookupcred(clp, 0);
507	if (IS_ERR(msg.rpc_cred))
508		goto out;
509
510	cbr->cbr_trunc = 0;
511	cbr->cbr_dp = dp;
512
513	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
514	while (retries--) {
515		switch (status) {
516			case -EIO:
517				/* Network partition? */
518			case -EBADHANDLE:
519			case -NFS4ERR_BAD_STATEID:
520				/* Race: client probably got cb_recall
521				 * before open reply granting delegation */
522				break;
523			default:
524				goto out_put_cred;
525		}
526		ssleep(2);
527		status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
528	}
529out_put_cred:
530	put_rpccred(msg.rpc_cred);
531out:
532	if (status == -EIO)
533		atomic_set(&clp->cl_callback.cb_set, 0);
534	/* Success or failure, now we're either waiting for lease expiration
535	 * or deleg_return. */
536	dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
537	nfs4_put_delegation(dp);
538	return;
539}
540