xref: /linux/fs/nfsd/nfs4callback.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/config.h>
37 #include <linux/module.h>
38 #include <linux/list.h>
39 #include <linux/inet.h>
40 #include <linux/errno.h>
41 #include <linux/delay.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 */
56 static const struct rpc_call_ops nfs4_cb_null_ops;
57 
58 /* Index of predefined Linux callback client operations */
59 
60 enum {
61         NFSPROC4_CLNT_CB_NULL = 0,
62 	NFSPROC4_CLNT_CB_RECALL,
63 };
64 
65 enum 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 */
89 static inline u32 *
90 xdr_writemem(u32 *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;                             \
115 out:                                            \
116 	return status;                          \
117 xdr_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.", \
136 			__FUNCTION__, __LINE__); \
137 		return -EIO; \
138 	} \
139 } while (0)
140 
141 struct nfs4_cb_compound_hdr {
142 	int		status;
143 	u32		ident;
144 	u32		nops;
145 	u32		taglen;
146 	char *		tag;
147 };
148 
149 static struct {
150 int stat;
151 int 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 
186 static int
187 nfs_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 
206 static int
207 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
208 {
209 	u32 * 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 
219 static int
220 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
221 {
222 	u32 *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 
234 static int
235 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, u32 *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 
244 static int
245 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, u32 *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 
259 static int
260 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
261         u32 *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 
273 static int
274 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
275 {
276 	u32 *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 
294 static int
295 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, u32 *p)
296 {
297 	return 0;
298 }
299 
300 static int
301 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, u32 *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);
312 out:
313 	return status;
314 }
315 
316 /*
317  * RPC procedure tables
318  */
319 #ifndef MAX
320 # define MAX(a, b)      (((a) > (b))? (a) : (b))
321 #endif
322 
323 #define PROC(proc, call, argtype, restype)                              \
324 [NFSPROC4_CLNT_##proc] = {                                      	\
325         .p_proc   = NFSPROC4_CB_##call,					\
326         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
327         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
328         .p_bufsiz = MAX(NFS4_##argtype##_sz,NFS4_##restype##_sz) << 2,  \
329         .p_statidx = NFSPROC4_CB_##call,				\
330 	.p_name   = #proc,                                              \
331 }
332 
333 static struct rpc_procinfo     nfs4_cb_procedures[] = {
334     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
335     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
336 };
337 
338 static struct rpc_version       nfs_cb_version4 = {
339         .number                 = 1,
340         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
341         .procs                  = nfs4_cb_procedures
342 };
343 
344 static struct rpc_version *	nfs_cb_version[] = {
345 	NULL,
346 	&nfs_cb_version4,
347 };
348 
349 /*
350  * Use the SETCLIENTID credential
351  */
352 static struct rpc_cred *
353 nfsd4_lookupcred(struct nfs4_client *clp, int taskflags)
354 {
355         struct auth_cred acred;
356 	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
357 	struct rpc_cred *ret;
358 
359         get_group_info(clp->cl_cred.cr_group_info);
360         acred.uid = clp->cl_cred.cr_uid;
361         acred.gid = clp->cl_cred.cr_gid;
362         acred.group_info = clp->cl_cred.cr_group_info;
363 
364         dprintk("NFSD:     looking up %s cred\n",
365                 clnt->cl_auth->au_ops->au_name);
366         ret = rpcauth_lookup_credcache(clnt->cl_auth, &acred, taskflags);
367         put_group_info(clp->cl_cred.cr_group_info);
368         return ret;
369 }
370 
371 /*
372  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
373  */
374 void
375 nfsd4_probe_callback(struct nfs4_client *clp)
376 {
377 	struct sockaddr_in	addr;
378 	struct nfs4_callback    *cb = &clp->cl_callback;
379 	struct rpc_timeout	timeparms;
380 	struct rpc_xprt *	xprt;
381 	struct rpc_program *	program = &cb->cb_program;
382 	struct rpc_stat *	stat = &cb->cb_stat;
383 	struct rpc_clnt *	clnt;
384 	struct rpc_message msg = {
385 		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
386 		.rpc_argp       = clp,
387 	};
388 	char                    hostname[32];
389 	int status;
390 
391 	if (atomic_read(&cb->cb_set))
392 		return;
393 
394 	/* Initialize address */
395 	memset(&addr, 0, sizeof(addr));
396 	addr.sin_family = AF_INET;
397 	addr.sin_port = htons(cb->cb_port);
398 	addr.sin_addr.s_addr = htonl(cb->cb_addr);
399 
400 	/* Initialize timeout */
401 	timeparms.to_initval = (NFSD_LEASE_TIME/4) * HZ;
402 	timeparms.to_retries = 0;
403 	timeparms.to_maxval = (NFSD_LEASE_TIME/2) * HZ;
404 	timeparms.to_exponential = 1;
405 
406 	/* Create RPC transport */
407 	xprt = xprt_create_proto(IPPROTO_TCP, &addr, &timeparms);
408 	if (IS_ERR(xprt)) {
409 		dprintk("NFSD: couldn't create callback transport!\n");
410 		goto out_err;
411 	}
412 
413 	/* Initialize rpc_program */
414 	program->name = "nfs4_cb";
415 	program->number = cb->cb_prog;
416 	program->nrvers = ARRAY_SIZE(nfs_cb_version);
417 	program->version = nfs_cb_version;
418 	program->stats = stat;
419 
420 	/* Initialize rpc_stat */
421 	memset(stat, 0, sizeof(struct rpc_stat));
422 	stat->program = program;
423 
424 	/* Create RPC client
425  	 *
426 	 * XXX AUTH_UNIX only - need AUTH_GSS....
427 	 */
428 	sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(addr.sin_addr.s_addr));
429 	clnt = rpc_new_client(xprt, hostname, program, 1, RPC_AUTH_UNIX);
430 	if (IS_ERR(clnt)) {
431 		dprintk("NFSD: couldn't create callback client\n");
432 		goto out_err;
433 	}
434 	clnt->cl_intr = 0;
435 	clnt->cl_softrtry = 1;
436 
437 	/* Kick rpciod, put the call on the wire. */
438 
439 	if (rpciod_up() != 0) {
440 		dprintk("nfsd: couldn't start rpciod for callbacks!\n");
441 		goto out_clnt;
442 	}
443 
444 	cb->cb_client = clnt;
445 
446 	/* the task holds a reference to the nfs4_client struct */
447 	atomic_inc(&clp->cl_count);
448 
449 	msg.rpc_cred = nfsd4_lookupcred(clp,0);
450 	if (IS_ERR(msg.rpc_cred))
451 		goto out_rpciod;
452 	status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, &nfs4_cb_null_ops, NULL);
453 	put_rpccred(msg.rpc_cred);
454 
455 	if (status != 0) {
456 		dprintk("NFSD: asynchronous NFSPROC4_CB_NULL failed!\n");
457 		goto out_rpciod;
458 	}
459 	return;
460 
461 out_rpciod:
462 	atomic_dec(&clp->cl_count);
463 	rpciod_down();
464 	cb->cb_client = NULL;
465 out_clnt:
466 	rpc_shutdown_client(clnt);
467 out_err:
468 	dprintk("NFSD: warning: no callback path to client %.*s\n",
469 		(int)clp->cl_name.len, clp->cl_name.data);
470 }
471 
472 static void
473 nfs4_cb_null(struct rpc_task *task, void *dummy)
474 {
475 	struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
476 	struct nfs4_callback *cb = &clp->cl_callback;
477 	u32 addr = htonl(cb->cb_addr);
478 
479 	dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
480 
481 	if (task->tk_status < 0) {
482 		dprintk("NFSD: callback establishment to client %.*s failed\n",
483 			(int)clp->cl_name.len, clp->cl_name.data);
484 		goto out;
485 	}
486 	atomic_set(&cb->cb_set, 1);
487 	dprintk("NFSD: callback set to client %u.%u.%u.%u\n", NIPQUAD(addr));
488 out:
489 	put_nfs4_client(clp);
490 }
491 
492 static const struct rpc_call_ops nfs4_cb_null_ops = {
493 	.rpc_call_done = nfs4_cb_null,
494 };
495 
496 /*
497  * called with dp->dl_count inc'ed.
498  * nfs4_lock_state() may or may not have been called.
499  */
500 void
501 nfsd4_cb_recall(struct nfs4_delegation *dp)
502 {
503 	struct nfs4_client *clp = dp->dl_client;
504 	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
505 	struct nfs4_cb_recall *cbr = &dp->dl_recall;
506 	struct rpc_message msg = {
507 		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
508 		.rpc_argp = cbr,
509 	};
510 	int retries = 1;
511 	int status = 0;
512 
513 	if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
514 		return;
515 
516 	msg.rpc_cred = nfsd4_lookupcred(clp, 0);
517 	if (IS_ERR(msg.rpc_cred))
518 		goto out;
519 
520 	cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
521 	cbr->cbr_dp = dp;
522 
523 	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
524 	while (retries--) {
525 		switch (status) {
526 			case -EIO:
527 				/* Network partition? */
528 			case -EBADHANDLE:
529 			case -NFS4ERR_BAD_STATEID:
530 				/* Race: client probably got cb_recall
531 				 * before open reply granting delegation */
532 				break;
533 			default:
534 				goto out_put_cred;
535 		}
536 		ssleep(2);
537 		status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
538 	}
539 out_put_cred:
540 	put_rpccred(msg.rpc_cred);
541 out:
542 	if (status == -EIO)
543 		atomic_set(&clp->cl_callback.cb_set, 0);
544 	/* Success or failure, now we're either waiting for lease expiration
545 	 * or deleg_return. */
546 	dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
547 	nfs4_put_delegation(dp);
548 	return;
549 }
550