xref: /openbmc/linux/fs/nfsd/nfs4callback.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 void nfs4_cb_null(struct rpc_task *task);
57 extern spinlock_t recall_lock;
58 
59 /* Index of predefined Linux callback client operations */
60 
61 enum {
62         NFSPROC4_CLNT_CB_NULL = 0,
63 	NFSPROC4_CLNT_CB_RECALL,
64 };
65 
66 enum nfs_cb_opnum4 {
67 	OP_CB_RECALL            = 4,
68 };
69 
70 #define NFS4_MAXTAGLEN		20
71 
72 #define NFS4_enc_cb_null_sz		0
73 #define NFS4_dec_cb_null_sz		0
74 #define cb_compound_enc_hdr_sz		4
75 #define cb_compound_dec_hdr_sz		(3 + (NFS4_MAXTAGLEN >> 2))
76 #define op_enc_sz			1
77 #define op_dec_sz			2
78 #define enc_nfs4_fh_sz			(1 + (NFS4_FHSIZE >> 2))
79 #define enc_stateid_sz			16
80 #define NFS4_enc_cb_recall_sz		(cb_compound_enc_hdr_sz +       \
81 					1 + enc_stateid_sz +            \
82 					enc_nfs4_fh_sz)
83 
84 #define NFS4_dec_cb_recall_sz		(cb_compound_dec_hdr_sz  +      \
85 					op_dec_sz)
86 
87 /*
88 * Generic encode routines from fs/nfs/nfs4xdr.c
89 */
90 static inline u32 *
91 xdr_writemem(u32 *p, const void *ptr, int nbytes)
92 {
93 	int tmp = XDR_QUADLEN(nbytes);
94 	if (!tmp)
95 		return p;
96 	p[tmp-1] = 0;
97 	memcpy(p, ptr, nbytes);
98 	return p + tmp;
99 }
100 
101 #define WRITE32(n)               *p++ = htonl(n)
102 #define WRITEMEM(ptr,nbytes)     do {                           \
103 	p = xdr_writemem(p, ptr, nbytes);                       \
104 } while (0)
105 #define RESERVE_SPACE(nbytes)   do {                            \
106 	p = xdr_reserve_space(xdr, nbytes);                     \
107 	if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __FUNCTION__); \
108 	BUG_ON(!p);                                             \
109 } while (0)
110 
111 /*
112  * Generic decode routines from fs/nfs/nfs4xdr.c
113  */
114 #define DECODE_TAIL                             \
115 	status = 0;                             \
116 out:                                            \
117 	return status;                          \
118 xdr_error:                                      \
119 	dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
120 	status = -EIO;                          \
121 	goto out
122 
123 #define READ32(x)         (x) = ntohl(*p++)
124 #define READ64(x)         do {                  \
125 	(x) = (u64)ntohl(*p++) << 32;           \
126 	(x) |= ntohl(*p++);                     \
127 } while (0)
128 #define READTIME(x)       do {                  \
129 	p++;                                    \
130 	(x.tv_sec) = ntohl(*p++);               \
131 	(x.tv_nsec) = ntohl(*p++);              \
132 } while (0)
133 #define READ_BUF(nbytes)  do { \
134 	p = xdr_inline_decode(xdr, nbytes); \
135 	if (!p) { \
136 		dprintk("NFSD: %s: reply buffer overflowed in line %d.", \
137 			__FUNCTION__, __LINE__); \
138 		return -EIO; \
139 	} \
140 } while (0)
141 
142 struct nfs4_cb_compound_hdr {
143 	int		status;
144 	u32		ident;
145 	u32		nops;
146 	u32		taglen;
147 	char *		tag;
148 };
149 
150 static struct {
151 int stat;
152 int errno;
153 } nfs_cb_errtbl[] = {
154 	{ NFS4_OK,		0               },
155 	{ NFS4ERR_PERM,		EPERM           },
156 	{ NFS4ERR_NOENT,	ENOENT          },
157 	{ NFS4ERR_IO,		EIO             },
158 	{ NFS4ERR_NXIO,		ENXIO           },
159 	{ NFS4ERR_ACCESS,	EACCES          },
160 	{ NFS4ERR_EXIST,	EEXIST          },
161 	{ NFS4ERR_XDEV,		EXDEV           },
162 	{ NFS4ERR_NOTDIR,	ENOTDIR         },
163 	{ NFS4ERR_ISDIR,	EISDIR          },
164 	{ NFS4ERR_INVAL,	EINVAL          },
165 	{ NFS4ERR_FBIG,		EFBIG           },
166 	{ NFS4ERR_NOSPC,	ENOSPC          },
167 	{ NFS4ERR_ROFS,		EROFS           },
168 	{ NFS4ERR_MLINK,	EMLINK          },
169 	{ NFS4ERR_NAMETOOLONG,	ENAMETOOLONG    },
170 	{ NFS4ERR_NOTEMPTY,	ENOTEMPTY       },
171 	{ NFS4ERR_DQUOT,	EDQUOT          },
172 	{ NFS4ERR_STALE,	ESTALE          },
173 	{ NFS4ERR_BADHANDLE,	EBADHANDLE      },
174 	{ NFS4ERR_BAD_COOKIE,	EBADCOOKIE      },
175 	{ NFS4ERR_NOTSUPP,	ENOTSUPP        },
176 	{ NFS4ERR_TOOSMALL,	ETOOSMALL       },
177 	{ NFS4ERR_SERVERFAULT,	ESERVERFAULT    },
178 	{ NFS4ERR_BADTYPE,	EBADTYPE        },
179 	{ NFS4ERR_LOCKED,	EAGAIN          },
180 	{ NFS4ERR_RESOURCE,	EREMOTEIO       },
181 	{ NFS4ERR_SYMLINK,	ELOOP           },
182 	{ NFS4ERR_OP_ILLEGAL,	EOPNOTSUPP      },
183 	{ NFS4ERR_DEADLOCK,	EDEADLK         },
184 	{ -1,                   EIO             }
185 };
186 
187 static int
188 nfs_cb_stat_to_errno(int stat)
189 {
190 	int i;
191 	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
192 		if (nfs_cb_errtbl[i].stat == stat)
193 			return nfs_cb_errtbl[i].errno;
194 	}
195 	/* If we cannot translate the error, the recovery routines should
196 	* handle it.
197 	* Note: remaining NFSv4 error codes have values > 10000, so should
198 	* not conflict with native Linux error codes.
199 	*/
200 	return stat;
201 }
202 
203 /*
204  * XDR encode
205  */
206 
207 static int
208 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
209 {
210 	u32 * p;
211 
212 	RESERVE_SPACE(16);
213 	WRITE32(0);            /* tag length is always 0 */
214 	WRITE32(NFS4_MINOR_VERSION);
215 	WRITE32(hdr->ident);
216 	WRITE32(hdr->nops);
217 	return 0;
218 }
219 
220 static int
221 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
222 {
223 	u32 *p;
224 	int len = cb_rec->cbr_fhlen;
225 
226 	RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
227 	WRITE32(OP_CB_RECALL);
228 	WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
229 	WRITE32(cb_rec->cbr_trunc);
230 	WRITE32(len);
231 	WRITEMEM(cb_rec->cbr_fhval, len);
232 	return 0;
233 }
234 
235 static int
236 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, u32 *p)
237 {
238 	struct xdr_stream xdrs, *xdr = &xdrs;
239 
240 	xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
241         RESERVE_SPACE(0);
242 	return 0;
243 }
244 
245 static int
246 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, u32 *p, struct nfs4_cb_recall *args)
247 {
248 	struct xdr_stream xdr;
249 	struct nfs4_cb_compound_hdr hdr = {
250 		.ident = args->cbr_ident,
251 		.nops   = 1,
252 	};
253 
254 	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
255 	encode_cb_compound_hdr(&xdr, &hdr);
256 	return (encode_cb_recall(&xdr, args));
257 }
258 
259 
260 static int
261 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
262         u32 *p;
263 
264         READ_BUF(8);
265         READ32(hdr->status);
266         READ32(hdr->taglen);
267         READ_BUF(hdr->taglen + 4);
268         hdr->tag = (char *)p;
269         p += XDR_QUADLEN(hdr->taglen);
270         READ32(hdr->nops);
271         return 0;
272 }
273 
274 static int
275 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
276 {
277 	u32 *p;
278 	u32 op;
279 	int32_t nfserr;
280 
281 	READ_BUF(8);
282 	READ32(op);
283 	if (op != expected) {
284 		dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
285 		         " operation %d but we issued a request for %d\n",
286 		         op, expected);
287 		return -EIO;
288 	}
289 	READ32(nfserr);
290 	if (nfserr != NFS_OK)
291 		return -nfs_cb_stat_to_errno(nfserr);
292 	return 0;
293 }
294 
295 static int
296 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, u32 *p)
297 {
298 	return 0;
299 }
300 
301 static int
302 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, u32 *p)
303 {
304 	struct xdr_stream xdr;
305 	struct nfs4_cb_compound_hdr hdr;
306 	int status;
307 
308 	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
309 	status = decode_cb_compound_hdr(&xdr, &hdr);
310 	if (status)
311 		goto out;
312 	status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
313 out:
314 	return status;
315 }
316 
317 /*
318  * RPC procedure tables
319  */
320 #ifndef MAX
321 # define MAX(a, b)      (((a) > (b))? (a) : (b))
322 #endif
323 
324 #define PROC(proc, call, argtype, restype)                              \
325 [NFSPROC4_CLNT_##proc] = {                                      	\
326         .p_proc   = NFSPROC4_CB_##call,					\
327         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
328         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
329         .p_bufsiz = MAX(NFS4_##argtype##_sz,NFS4_##restype##_sz) << 2,  \
330 }
331 
332 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 struct rpc_version              nfs_cb_version4 = {
338         .number                 = 1,
339         .nrprocs                = sizeof(nfs4_cb_procedures)/sizeof(nfs4_cb_procedures[0]),
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 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 	dprintk("NFSD: probe_callback. cb_parsed %d cb_set %d\n",
391 			cb->cb_parsed, atomic_read(&cb->cb_set));
392 	if (!cb->cb_parsed || atomic_read(&cb->cb_set))
393 		return;
394 
395 	/* Initialize address */
396 	memset(&addr, 0, sizeof(addr));
397 	addr.sin_family = AF_INET;
398 	addr.sin_port = htons(cb->cb_port);
399 	addr.sin_addr.s_addr = htonl(cb->cb_addr);
400 
401 	/* Initialize timeout */
402 	timeparms.to_initval = (NFSD_LEASE_TIME/4) * HZ;
403 	timeparms.to_retries = 0;
404 	timeparms.to_maxval = (NFSD_LEASE_TIME/2) * HZ;
405 	timeparms.to_exponential = 1;
406 
407 	/* Create RPC transport */
408 	if (!(xprt = xprt_create_proto(IPPROTO_TCP, &addr, &timeparms))) {
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 = sizeof(nfs_cb_version)/sizeof(nfs_cb_version[0]);
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 	if (!(clnt = rpc_create_client(xprt, hostname, program, 1, RPC_AUTH_UNIX))) {
430 		dprintk("NFSD: couldn't create callback client\n");
431 		goto out_xprt;
432 	}
433 	clnt->cl_intr = 0;
434 	clnt->cl_softrtry = 1;
435 	clnt->cl_chatty = 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 	/* the task holds a reference to the nfs4_client struct */
445 	cb->cb_client = clnt;
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, 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 out_clnt:
464 	rpc_shutdown_client(clnt);
465 	goto out_err;
466 out_xprt:
467 	xprt_destroy(xprt);
468 out_err:
469 	dprintk("NFSD: warning: no callback path to client %.*s\n",
470 		(int)clp->cl_name.len, clp->cl_name.data);
471 	cb->cb_client = NULL;
472 }
473 
474 static void
475 nfs4_cb_null(struct rpc_task *task)
476 {
477 	struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
478 	struct nfs4_callback *cb = &clp->cl_callback;
479 	u32 addr = htonl(cb->cb_addr);
480 
481 	dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
482 
483 	if (task->tk_status < 0) {
484 		dprintk("NFSD: callback establishment to client %.*s failed\n",
485 			(int)clp->cl_name.len, clp->cl_name.data);
486 		goto out;
487 	}
488 	atomic_set(&cb->cb_set, 1);
489 	dprintk("NFSD: callback set to client %u.%u.%u.%u\n", NIPQUAD(addr));
490 out:
491 	put_nfs4_client(clp);
492 }
493 
494 /*
495  * called with dp->dl_count inc'ed.
496  * nfs4_lock_state() may or may not have been called.
497  */
498 void
499 nfsd4_cb_recall(struct nfs4_delegation *dp)
500 {
501 	struct nfs4_client *clp = dp->dl_client;
502 	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
503 	struct nfs4_cb_recall *cbr = &dp->dl_recall;
504 	struct rpc_message msg = {
505 		.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
506 		.rpc_argp = cbr,
507 	};
508 	int retries = 1;
509 	int status = 0;
510 
511 	if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
512 		return;
513 
514 	msg.rpc_cred = nfsd4_lookupcred(clp, 0);
515 	if (IS_ERR(msg.rpc_cred))
516 		goto out;
517 
518 	cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
519 	cbr->cbr_dp = dp;
520 
521 	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
522 	while (retries--) {
523 		switch (status) {
524 			case -EIO:
525 				/* Network partition? */
526 			case -EBADHANDLE:
527 			case -NFS4ERR_BAD_STATEID:
528 				/* Race: client probably got cb_recall
529 				 * before open reply granting delegation */
530 				break;
531 			default:
532 				goto out_put_cred;
533 		}
534 		ssleep(2);
535 		status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
536 	}
537 out_put_cred:
538 	put_rpccred(msg.rpc_cred);
539 out:
540 	if (status == -EIO)
541 		atomic_set(&clp->cl_callback.cb_set, 0);
542 	/* Success or failure, now we're either waiting for lease expiration
543 	 * or deleg_return. */
544 	dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
545 	nfs4_put_delegation(dp);
546 	return;
547 }
548