xref: /linux/fs/nfsd/nfs4callback.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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/sunrpc/xdr.h>
42 #include <linux/sunrpc/svc.h>
43 #include <linux/sunrpc/clnt.h>
44 #include <linux/nfsd/nfsd.h>
45 #include <linux/nfsd/state.h>
46 #include <linux/sunrpc/sched.h>
47 #include <linux/nfs4.h>
48 
49 #define NFSDDBG_FACILITY                NFSDDBG_PROC
50 
51 #define NFSPROC4_CB_NULL 0
52 #define NFSPROC4_CB_COMPOUND 1
53 
54 /* declarations */
55 static const struct rpc_call_ops nfs4_cb_null_ops;
56 
57 /* Index of predefined Linux callback client operations */
58 
59 enum {
60         NFSPROC4_CLNT_CB_NULL = 0,
61 	NFSPROC4_CLNT_CB_RECALL,
62 };
63 
64 enum nfs_cb_opnum4 {
65 	OP_CB_RECALL            = 4,
66 };
67 
68 #define NFS4_MAXTAGLEN		20
69 
70 #define NFS4_enc_cb_null_sz		0
71 #define NFS4_dec_cb_null_sz		0
72 #define cb_compound_enc_hdr_sz		4
73 #define cb_compound_dec_hdr_sz		(3 + (NFS4_MAXTAGLEN >> 2))
74 #define op_enc_sz			1
75 #define op_dec_sz			2
76 #define enc_nfs4_fh_sz			(1 + (NFS4_FHSIZE >> 2))
77 #define enc_stateid_sz			16
78 #define NFS4_enc_cb_recall_sz		(cb_compound_enc_hdr_sz +       \
79 					1 + enc_stateid_sz +            \
80 					enc_nfs4_fh_sz)
81 
82 #define NFS4_dec_cb_recall_sz		(cb_compound_dec_hdr_sz  +      \
83 					op_dec_sz)
84 
85 /*
86 * Generic encode routines from fs/nfs/nfs4xdr.c
87 */
88 static inline u32 *
89 xdr_writemem(u32 *p, const void *ptr, int nbytes)
90 {
91 	int tmp = XDR_QUADLEN(nbytes);
92 	if (!tmp)
93 		return p;
94 	p[tmp-1] = 0;
95 	memcpy(p, ptr, nbytes);
96 	return p + tmp;
97 }
98 
99 #define WRITE32(n)               *p++ = htonl(n)
100 #define WRITEMEM(ptr,nbytes)     do {                           \
101 	p = xdr_writemem(p, ptr, nbytes);                       \
102 } while (0)
103 #define RESERVE_SPACE(nbytes)   do {                            \
104 	p = xdr_reserve_space(xdr, nbytes);                     \
105 	if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __FUNCTION__); \
106 	BUG_ON(!p);                                             \
107 } while (0)
108 
109 /*
110  * Generic decode routines from fs/nfs/nfs4xdr.c
111  */
112 #define DECODE_TAIL                             \
113 	status = 0;                             \
114 out:                                            \
115 	return status;                          \
116 xdr_error:                                      \
117 	dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
118 	status = -EIO;                          \
119 	goto out
120 
121 #define READ32(x)         (x) = ntohl(*p++)
122 #define READ64(x)         do {                  \
123 	(x) = (u64)ntohl(*p++) << 32;           \
124 	(x) |= ntohl(*p++);                     \
125 } while (0)
126 #define READTIME(x)       do {                  \
127 	p++;                                    \
128 	(x.tv_sec) = ntohl(*p++);               \
129 	(x.tv_nsec) = ntohl(*p++);              \
130 } while (0)
131 #define READ_BUF(nbytes)  do { \
132 	p = xdr_inline_decode(xdr, nbytes); \
133 	if (!p) { \
134 		dprintk("NFSD: %s: reply buffer overflowed in line %d.", \
135 			__FUNCTION__, __LINE__); \
136 		return -EIO; \
137 	} \
138 } while (0)
139 
140 struct nfs4_cb_compound_hdr {
141 	int		status;
142 	u32		ident;
143 	u32		nops;
144 	u32		taglen;
145 	char *		tag;
146 };
147 
148 static struct {
149 int stat;
150 int errno;
151 } nfs_cb_errtbl[] = {
152 	{ NFS4_OK,		0               },
153 	{ NFS4ERR_PERM,		EPERM           },
154 	{ NFS4ERR_NOENT,	ENOENT          },
155 	{ NFS4ERR_IO,		EIO             },
156 	{ NFS4ERR_NXIO,		ENXIO           },
157 	{ NFS4ERR_ACCESS,	EACCES          },
158 	{ NFS4ERR_EXIST,	EEXIST          },
159 	{ NFS4ERR_XDEV,		EXDEV           },
160 	{ NFS4ERR_NOTDIR,	ENOTDIR         },
161 	{ NFS4ERR_ISDIR,	EISDIR          },
162 	{ NFS4ERR_INVAL,	EINVAL          },
163 	{ NFS4ERR_FBIG,		EFBIG           },
164 	{ NFS4ERR_NOSPC,	ENOSPC          },
165 	{ NFS4ERR_ROFS,		EROFS           },
166 	{ NFS4ERR_MLINK,	EMLINK          },
167 	{ NFS4ERR_NAMETOOLONG,	ENAMETOOLONG    },
168 	{ NFS4ERR_NOTEMPTY,	ENOTEMPTY       },
169 	{ NFS4ERR_DQUOT,	EDQUOT          },
170 	{ NFS4ERR_STALE,	ESTALE          },
171 	{ NFS4ERR_BADHANDLE,	EBADHANDLE      },
172 	{ NFS4ERR_BAD_COOKIE,	EBADCOOKIE      },
173 	{ NFS4ERR_NOTSUPP,	ENOTSUPP        },
174 	{ NFS4ERR_TOOSMALL,	ETOOSMALL       },
175 	{ NFS4ERR_SERVERFAULT,	ESERVERFAULT    },
176 	{ NFS4ERR_BADTYPE,	EBADTYPE        },
177 	{ NFS4ERR_LOCKED,	EAGAIN          },
178 	{ NFS4ERR_RESOURCE,	EREMOTEIO       },
179 	{ NFS4ERR_SYMLINK,	ELOOP           },
180 	{ NFS4ERR_OP_ILLEGAL,	EOPNOTSUPP      },
181 	{ NFS4ERR_DEADLOCK,	EDEADLK         },
182 	{ -1,                   EIO             }
183 };
184 
185 static int
186 nfs_cb_stat_to_errno(int stat)
187 {
188 	int i;
189 	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
190 		if (nfs_cb_errtbl[i].stat == stat)
191 			return nfs_cb_errtbl[i].errno;
192 	}
193 	/* If we cannot translate the error, the recovery routines should
194 	* handle it.
195 	* Note: remaining NFSv4 error codes have values > 10000, so should
196 	* not conflict with native Linux error codes.
197 	*/
198 	return stat;
199 }
200 
201 /*
202  * XDR encode
203  */
204 
205 static int
206 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
207 {
208 	u32 * p;
209 
210 	RESERVE_SPACE(16);
211 	WRITE32(0);            /* tag length is always 0 */
212 	WRITE32(NFS4_MINOR_VERSION);
213 	WRITE32(hdr->ident);
214 	WRITE32(hdr->nops);
215 	return 0;
216 }
217 
218 static int
219 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
220 {
221 	u32 *p;
222 	int len = cb_rec->cbr_fhlen;
223 
224 	RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
225 	WRITE32(OP_CB_RECALL);
226 	WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
227 	WRITE32(cb_rec->cbr_trunc);
228 	WRITE32(len);
229 	WRITEMEM(cb_rec->cbr_fhval, len);
230 	return 0;
231 }
232 
233 static int
234 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, u32 *p)
235 {
236 	struct xdr_stream xdrs, *xdr = &xdrs;
237 
238 	xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
239         RESERVE_SPACE(0);
240 	return 0;
241 }
242 
243 static int
244 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, u32 *p, struct nfs4_cb_recall *args)
245 {
246 	struct xdr_stream xdr;
247 	struct nfs4_cb_compound_hdr hdr = {
248 		.ident = args->cbr_ident,
249 		.nops   = 1,
250 	};
251 
252 	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
253 	encode_cb_compound_hdr(&xdr, &hdr);
254 	return (encode_cb_recall(&xdr, args));
255 }
256 
257 
258 static int
259 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
260         u32 *p;
261 
262         READ_BUF(8);
263         READ32(hdr->status);
264         READ32(hdr->taglen);
265         READ_BUF(hdr->taglen + 4);
266         hdr->tag = (char *)p;
267         p += XDR_QUADLEN(hdr->taglen);
268         READ32(hdr->nops);
269         return 0;
270 }
271 
272 static int
273 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
274 {
275 	u32 *p;
276 	u32 op;
277 	int32_t nfserr;
278 
279 	READ_BUF(8);
280 	READ32(op);
281 	if (op != expected) {
282 		dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
283 		         " operation %d but we issued a request for %d\n",
284 		         op, expected);
285 		return -EIO;
286 	}
287 	READ32(nfserr);
288 	if (nfserr != NFS_OK)
289 		return -nfs_cb_stat_to_errno(nfserr);
290 	return 0;
291 }
292 
293 static int
294 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, u32 *p)
295 {
296 	return 0;
297 }
298 
299 static int
300 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, u32 *p)
301 {
302 	struct xdr_stream xdr;
303 	struct nfs4_cb_compound_hdr hdr;
304 	int status;
305 
306 	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
307 	status = decode_cb_compound_hdr(&xdr, &hdr);
308 	if (status)
309 		goto out;
310 	status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
311 out:
312 	return status;
313 }
314 
315 /*
316  * RPC procedure tables
317  */
318 #ifndef MAX
319 # define MAX(a, b)      (((a) > (b))? (a) : (b))
320 #endif
321 
322 #define PROC(proc, call, argtype, restype)                              \
323 [NFSPROC4_CLNT_##proc] = {                                      	\
324         .p_proc   = NFSPROC4_CB_##call,					\
325         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
326         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
327         .p_bufsiz = MAX(NFS4_##argtype##_sz,NFS4_##restype##_sz) << 2,  \
328         .p_statidx = NFSPROC4_CB_##call,				\
329 	.p_name   = #proc,                                              \
330 }
331 
332 static struct rpc_procinfo     nfs4_cb_procedures[] = {
333     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
334     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
335 };
336 
337 static struct rpc_version       nfs_cb_version4 = {
338         .number                 = 1,
339         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
340         .procs                  = nfs4_cb_procedures
341 };
342 
343 static struct rpc_version *	nfs_cb_version[] = {
344 	NULL,
345 	&nfs_cb_version4,
346 };
347 
348 /*
349  * Use the SETCLIENTID credential
350  */
351 static struct rpc_cred *
352 nfsd4_lookupcred(struct nfs4_client *clp, int taskflags)
353 {
354         struct auth_cred acred;
355 	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
356 	struct rpc_cred *ret;
357 
358         get_group_info(clp->cl_cred.cr_group_info);
359         acred.uid = clp->cl_cred.cr_uid;
360         acred.gid = clp->cl_cred.cr_gid;
361         acred.group_info = clp->cl_cred.cr_group_info;
362 
363         dprintk("NFSD:     looking up %s cred\n",
364                 clnt->cl_auth->au_ops->au_name);
365         ret = rpcauth_lookup_credcache(clnt->cl_auth, &acred, taskflags);
366         put_group_info(clp->cl_cred.cr_group_info);
367         return ret;
368 }
369 
370 /*
371  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
372  */
373 void
374 nfsd4_probe_callback(struct nfs4_client *clp)
375 {
376 	struct sockaddr_in	addr;
377 	struct nfs4_callback    *cb = &clp->cl_callback;
378 	struct rpc_timeout	timeparms;
379 	struct rpc_xprt *	xprt;
380 	struct rpc_program *	program = &cb->cb_program;
381 	struct rpc_stat *	stat = &cb->cb_stat;
382 	struct rpc_clnt *	clnt;
383 	struct rpc_message msg = {
384 		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
385 		.rpc_argp       = clp,
386 	};
387 	char                    hostname[32];
388 	int status;
389 
390 	if (atomic_read(&cb->cb_set))
391 		return;
392 
393 	/* Initialize address */
394 	memset(&addr, 0, sizeof(addr));
395 	addr.sin_family = AF_INET;
396 	addr.sin_port = htons(cb->cb_port);
397 	addr.sin_addr.s_addr = htonl(cb->cb_addr);
398 
399 	/* Initialize timeout */
400 	timeparms.to_initval = (NFSD_LEASE_TIME/4) * HZ;
401 	timeparms.to_retries = 0;
402 	timeparms.to_maxval = (NFSD_LEASE_TIME/2) * HZ;
403 	timeparms.to_exponential = 1;
404 
405 	/* Create RPC transport */
406 	xprt = xprt_create_proto(IPPROTO_TCP, &addr, &timeparms);
407 	if (IS_ERR(xprt)) {
408 		dprintk("NFSD: couldn't create callback transport!\n");
409 		goto out_err;
410 	}
411 
412 	/* Initialize rpc_program */
413 	program->name = "nfs4_cb";
414 	program->number = cb->cb_prog;
415 	program->nrvers = ARRAY_SIZE(nfs_cb_version);
416 	program->version = nfs_cb_version;
417 	program->stats = stat;
418 
419 	/* Initialize rpc_stat */
420 	memset(stat, 0, sizeof(struct rpc_stat));
421 	stat->program = program;
422 
423 	/* Create RPC client
424  	 *
425 	 * XXX AUTH_UNIX only - need AUTH_GSS....
426 	 */
427 	sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(addr.sin_addr.s_addr));
428 	clnt = rpc_new_client(xprt, hostname, program, 1, RPC_AUTH_UNIX);
429 	if (IS_ERR(clnt)) {
430 		dprintk("NFSD: couldn't create callback client\n");
431 		goto out_err;
432 	}
433 	clnt->cl_intr = 0;
434 	clnt->cl_softrtry = 1;
435 
436 	/* Kick rpciod, put the call on the wire. */
437 
438 	if (rpciod_up() != 0) {
439 		dprintk("nfsd: couldn't start rpciod for callbacks!\n");
440 		goto out_clnt;
441 	}
442 
443 	cb->cb_client = clnt;
444 
445 	/* the task holds a reference to the nfs4_client struct */
446 	atomic_inc(&clp->cl_count);
447 
448 	msg.rpc_cred = nfsd4_lookupcred(clp,0);
449 	if (IS_ERR(msg.rpc_cred))
450 		goto out_rpciod;
451 	status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, &nfs4_cb_null_ops, NULL);
452 	put_rpccred(msg.rpc_cred);
453 
454 	if (status != 0) {
455 		dprintk("NFSD: asynchronous NFSPROC4_CB_NULL failed!\n");
456 		goto out_rpciod;
457 	}
458 	return;
459 
460 out_rpciod:
461 	atomic_dec(&clp->cl_count);
462 	rpciod_down();
463 	cb->cb_client = NULL;
464 out_clnt:
465 	rpc_shutdown_client(clnt);
466 out_err:
467 	dprintk("NFSD: warning: no callback path to client %.*s\n",
468 		(int)clp->cl_name.len, clp->cl_name.data);
469 }
470 
471 static void
472 nfs4_cb_null(struct rpc_task *task, void *dummy)
473 {
474 	struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
475 	struct nfs4_callback *cb = &clp->cl_callback;
476 	u32 addr = htonl(cb->cb_addr);
477 
478 	dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
479 
480 	if (task->tk_status < 0) {
481 		dprintk("NFSD: callback establishment to client %.*s failed\n",
482 			(int)clp->cl_name.len, clp->cl_name.data);
483 		goto out;
484 	}
485 	atomic_set(&cb->cb_set, 1);
486 	dprintk("NFSD: callback set to client %u.%u.%u.%u\n", NIPQUAD(addr));
487 out:
488 	put_nfs4_client(clp);
489 }
490 
491 static const struct rpc_call_ops nfs4_cb_null_ops = {
492 	.rpc_call_done = nfs4_cb_null,
493 };
494 
495 /*
496  * called with dp->dl_count inc'ed.
497  * nfs4_lock_state() may or may not have been called.
498  */
499 void
500 nfsd4_cb_recall(struct nfs4_delegation *dp)
501 {
502 	struct nfs4_client *clp = dp->dl_client;
503 	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
504 	struct nfs4_cb_recall *cbr = &dp->dl_recall;
505 	struct rpc_message msg = {
506 		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
507 		.rpc_argp = cbr,
508 	};
509 	int retries = 1;
510 	int status = 0;
511 
512 	if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
513 		return;
514 
515 	msg.rpc_cred = nfsd4_lookupcred(clp, 0);
516 	if (IS_ERR(msg.rpc_cred))
517 		goto out;
518 
519 	cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
520 	cbr->cbr_dp = dp;
521 
522 	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
523 	while (retries--) {
524 		switch (status) {
525 			case -EIO:
526 				/* Network partition? */
527 			case -EBADHANDLE:
528 			case -NFS4ERR_BAD_STATEID:
529 				/* Race: client probably got cb_recall
530 				 * before open reply granting delegation */
531 				break;
532 			default:
533 				goto out_put_cred;
534 		}
535 		ssleep(2);
536 		status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
537 	}
538 out_put_cred:
539 	put_rpccred(msg.rpc_cred);
540 out:
541 	if (status == -EIO)
542 		atomic_set(&clp->cl_callback.cb_set, 0);
543 	/* Success or failure, now we're either waiting for lease expiration
544 	 * or deleg_return. */
545 	dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
546 	nfs4_put_delegation(dp);
547 	return;
548 }
549