1 /*
2 * Copyright (c) 2001 The Regents of the University of Michigan.
3 * All rights reserved.
4 *
5 * Kendrick Smith <kmsmith@umich.edu>
6 * Andy Adamson <andros@umich.edu>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <linux/sunrpc/clnt.h>
35 #include <linux/sunrpc/svc_xprt.h>
36 #include <linux/slab.h>
37 #include "nfsd.h"
38 #include "state.h"
39 #include "netns.h"
40 #include "xdr4cb.h"
41
42 #define NFSDDBG_FACILITY NFSDDBG_PROC
43
44 static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
45
46 #define NFSPROC4_CB_NULL 0
47 #define NFSPROC4_CB_COMPOUND 1
48
49 /* Index of predefined Linux callback client operations */
50
51 enum {
52 NFSPROC4_CLNT_CB_NULL = 0,
53 NFSPROC4_CLNT_CB_RECALL,
54 NFSPROC4_CLNT_CB_SEQUENCE,
55 };
56
57 struct nfs4_cb_compound_hdr {
58 /* args */
59 u32 ident; /* minorversion 0 only */
60 u32 nops;
61 __be32 *nops_p;
62 u32 minorversion;
63 /* res */
64 int status;
65 };
66
67 /*
68 * Handle decode buffer overflows out-of-line.
69 */
70 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
71 {
72 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
73 "Remaining buffer length is %tu words.\n",
74 func, xdr->end - xdr->p);
75 }
76
77 static __be32 *xdr_encode_empty_array(__be32 *p)
78 {
79 *p++ = xdr_zero;
80 return p;
81 }
82
83 /*
84 * Encode/decode NFSv4 CB basic data types
85 *
86 * Basic NFSv4 callback data types are defined in section 15 of RFC
87 * 3530: "Network File System (NFS) version 4 Protocol" and section
88 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
89 * 1 Protocol"
90 */
91
92 /*
93 * nfs_cb_opnum4
94 *
95 * enum nfs_cb_opnum4 {
96 * OP_CB_GETATTR = 3,
97 * ...
98 * };
99 */
100 enum nfs_cb_opnum4 {
101 OP_CB_GETATTR = 3,
102 OP_CB_RECALL = 4,
103 OP_CB_LAYOUTRECALL = 5,
104 OP_CB_NOTIFY = 6,
105 OP_CB_PUSH_DELEG = 7,
106 OP_CB_RECALL_ANY = 8,
107 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
108 OP_CB_RECALL_SLOT = 10,
109 OP_CB_SEQUENCE = 11,
110 OP_CB_WANTS_CANCELLED = 12,
111 OP_CB_NOTIFY_LOCK = 13,
112 OP_CB_NOTIFY_DEVICEID = 14,
113 OP_CB_ILLEGAL = 10044
114 };
115
116 static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
117 {
118 __be32 *p;
119
120 p = xdr_reserve_space(xdr, 4);
121 *p = cpu_to_be32(op);
122 }
123
124 /*
125 * nfs_fh4
126 *
127 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
128 */
129 static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
130 {
131 u32 length = fh->fh_size;
132 __be32 *p;
133
134 BUG_ON(length > NFS4_FHSIZE);
135 p = xdr_reserve_space(xdr, 4 + length);
136 xdr_encode_opaque(p, &fh->fh_base, length);
137 }
138
139 /*
140 * stateid4
141 *
142 * struct stateid4 {
143 * uint32_t seqid;
144 * opaque other[12];
145 * };
146 */
147 static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
148 {
149 __be32 *p;
150
151 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
152 *p++ = cpu_to_be32(sid->si_generation);
153 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
154 }
155
156 /*
157 * sessionid4
158 *
159 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
160 */
161 static void encode_sessionid4(struct xdr_stream *xdr,
162 const struct nfsd4_session *session)
163 {
164 __be32 *p;
165
166 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
167 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
168 NFS4_MAX_SESSIONID_LEN);
169 }
170
171 /*
172 * nfsstat4
173 */
174 static const struct {
175 int stat;
176 int errno;
177 } nfs_cb_errtbl[] = {
178 { NFS4_OK, 0 },
179 { NFS4ERR_PERM, -EPERM },
180 { NFS4ERR_NOENT, -ENOENT },
181 { NFS4ERR_IO, -EIO },
182 { NFS4ERR_NXIO, -ENXIO },
183 { NFS4ERR_ACCESS, -EACCES },
184 { NFS4ERR_EXIST, -EEXIST },
185 { NFS4ERR_XDEV, -EXDEV },
186 { NFS4ERR_NOTDIR, -ENOTDIR },
187 { NFS4ERR_ISDIR, -EISDIR },
188 { NFS4ERR_INVAL, -EINVAL },
189 { NFS4ERR_FBIG, -EFBIG },
190 { NFS4ERR_NOSPC, -ENOSPC },
191 { NFS4ERR_ROFS, -EROFS },
192 { NFS4ERR_MLINK, -EMLINK },
193 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
194 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
195 { NFS4ERR_DQUOT, -EDQUOT },
196 { NFS4ERR_STALE, -ESTALE },
197 { NFS4ERR_BADHANDLE, -EBADHANDLE },
198 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
199 { NFS4ERR_NOTSUPP, -ENOTSUPP },
200 { NFS4ERR_TOOSMALL, -ETOOSMALL },
201 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
202 { NFS4ERR_BADTYPE, -EBADTYPE },
203 { NFS4ERR_LOCKED, -EAGAIN },
204 { NFS4ERR_RESOURCE, -EREMOTEIO },
205 { NFS4ERR_SYMLINK, -ELOOP },
206 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
207 { NFS4ERR_DEADLOCK, -EDEADLK },
208 { -1, -EIO }
209 };
210
211 /*
212 * If we cannot translate the error, the recovery routines should
213 * handle it.
214 *
215 * Note: remaining NFSv4 error codes have values > 10000, so should
216 * not conflict with native Linux error codes.
217 */
218 static int nfs_cb_stat_to_errno(int status)
219 {
220 int i;
221
222 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
223 if (nfs_cb_errtbl[i].stat == status)
224 return nfs_cb_errtbl[i].errno;
225 }
226
227 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
228 return -status;
229 }
230
231 static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
232 enum nfsstat4 *status)
233 {
234 __be32 *p;
235 u32 op;
236
237 p = xdr_inline_decode(xdr, 4 + 4);
238 if (unlikely(p == NULL))
239 goto out_overflow;
240 op = be32_to_cpup(p++);
241 if (unlikely(op != expected))
242 goto out_unexpected;
243 *status = be32_to_cpup(p);
244 return 0;
245 out_overflow:
246 print_overflow_msg(__func__, xdr);
247 return -EIO;
248 out_unexpected:
249 dprintk("NFSD: Callback server returned operation %d but "
250 "we issued a request for %d\n", op, expected);
251 return -EIO;
252 }
253
254 /*
255 * CB_COMPOUND4args
256 *
257 * struct CB_COMPOUND4args {
258 * utf8str_cs tag;
259 * uint32_t minorversion;
260 * uint32_t callback_ident;
261 * nfs_cb_argop4 argarray<>;
262 * };
263 */
264 static void encode_cb_compound4args(struct xdr_stream *xdr,
265 struct nfs4_cb_compound_hdr *hdr)
266 {
267 __be32 * p;
268
269 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
270 p = xdr_encode_empty_array(p); /* empty tag */
271 *p++ = cpu_to_be32(hdr->minorversion);
272 *p++ = cpu_to_be32(hdr->ident);
273
274 hdr->nops_p = p;
275 *p = cpu_to_be32(hdr->nops); /* argarray element count */
276 }
277
278 /*
279 * Update argarray element count
280 */
281 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
282 {
283 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
284 *hdr->nops_p = cpu_to_be32(hdr->nops);
285 }
286
287 /*
288 * CB_COMPOUND4res
289 *
290 * struct CB_COMPOUND4res {
291 * nfsstat4 status;
292 * utf8str_cs tag;
293 * nfs_cb_resop4 resarray<>;
294 * };
295 */
296 static int decode_cb_compound4res(struct xdr_stream *xdr,
297 struct nfs4_cb_compound_hdr *hdr)
298 {
299 u32 length;
300 __be32 *p;
301
302 p = xdr_inline_decode(xdr, 4 + 4);
303 if (unlikely(p == NULL))
304 goto out_overflow;
305 hdr->status = be32_to_cpup(p++);
306 /* Ignore the tag */
307 length = be32_to_cpup(p++);
308 p = xdr_inline_decode(xdr, length + 4);
309 if (unlikely(p == NULL))
310 goto out_overflow;
311 hdr->nops = be32_to_cpup(p);
312 return 0;
313 out_overflow:
314 print_overflow_msg(__func__, xdr);
315 return -EIO;
316 }
317
318 /*
319 * CB_RECALL4args
320 *
321 * struct CB_RECALL4args {
322 * stateid4 stateid;
323 * bool truncate;
324 * nfs_fh4 fh;
325 * };
326 */
327 static void encode_cb_recall4args(struct xdr_stream *xdr,
328 const struct nfs4_delegation *dp,
329 struct nfs4_cb_compound_hdr *hdr)
330 {
331 __be32 *p;
332
333 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
334 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
335
336 p = xdr_reserve_space(xdr, 4);
337 *p++ = xdr_zero; /* truncate */
338
339 encode_nfs_fh4(xdr, &dp->dl_fh);
340
341 hdr->nops++;
342 }
343
344 /*
345 * CB_SEQUENCE4args
346 *
347 * struct CB_SEQUENCE4args {
348 * sessionid4 csa_sessionid;
349 * sequenceid4 csa_sequenceid;
350 * slotid4 csa_slotid;
351 * slotid4 csa_highest_slotid;
352 * bool csa_cachethis;
353 * referring_call_list4 csa_referring_call_lists<>;
354 * };
355 */
356 static void encode_cb_sequence4args(struct xdr_stream *xdr,
357 const struct nfsd4_callback *cb,
358 struct nfs4_cb_compound_hdr *hdr)
359 {
360 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
361 __be32 *p;
362
363 if (hdr->minorversion == 0)
364 return;
365
366 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
367 encode_sessionid4(xdr, session);
368
369 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
370 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
371 *p++ = xdr_zero; /* csa_slotid */
372 *p++ = xdr_zero; /* csa_highest_slotid */
373 *p++ = xdr_zero; /* csa_cachethis */
374 xdr_encode_empty_array(p); /* csa_referring_call_lists */
375
376 hdr->nops++;
377 }
378
379 /*
380 * CB_SEQUENCE4resok
381 *
382 * struct CB_SEQUENCE4resok {
383 * sessionid4 csr_sessionid;
384 * sequenceid4 csr_sequenceid;
385 * slotid4 csr_slotid;
386 * slotid4 csr_highest_slotid;
387 * slotid4 csr_target_highest_slotid;
388 * };
389 *
390 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
391 * case NFS4_OK:
392 * CB_SEQUENCE4resok csr_resok4;
393 * default:
394 * void;
395 * };
396 *
397 * Our current back channel implmentation supports a single backchannel
398 * with a single slot.
399 */
400 static int decode_cb_sequence4resok(struct xdr_stream *xdr,
401 struct nfsd4_callback *cb)
402 {
403 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
404 struct nfs4_sessionid id;
405 int status;
406 __be32 *p;
407 u32 dummy;
408
409 status = -ESERVERFAULT;
410
411 /*
412 * If the server returns different values for sessionID, slotID or
413 * sequence number, the server is looney tunes.
414 */
415 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
416 if (unlikely(p == NULL))
417 goto out_overflow;
418 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
419 if (memcmp(id.data, session->se_sessionid.data,
420 NFS4_MAX_SESSIONID_LEN) != 0) {
421 dprintk("NFS: %s Invalid session id\n", __func__);
422 goto out;
423 }
424 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
425
426 dummy = be32_to_cpup(p++);
427 if (dummy != session->se_cb_seq_nr) {
428 dprintk("NFS: %s Invalid sequence number\n", __func__);
429 goto out;
430 }
431
432 dummy = be32_to_cpup(p++);
433 if (dummy != 0) {
434 dprintk("NFS: %s Invalid slotid\n", __func__);
435 goto out;
436 }
437
438 /*
439 * FIXME: process highest slotid and target highest slotid
440 */
441 status = 0;
442 out:
443 if (status)
444 nfsd4_mark_cb_fault(cb->cb_clp, status);
445 return status;
446 out_overflow:
447 print_overflow_msg(__func__, xdr);
448 return -EIO;
449 }
450
451 static int decode_cb_sequence4res(struct xdr_stream *xdr,
452 struct nfsd4_callback *cb)
453 {
454 enum nfsstat4 nfserr;
455 int status;
456
457 if (cb->cb_minorversion == 0)
458 return 0;
459
460 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
461 if (unlikely(status))
462 goto out;
463 if (unlikely(nfserr != NFS4_OK))
464 goto out_default;
465 status = decode_cb_sequence4resok(xdr, cb);
466 out:
467 return status;
468 out_default:
469 return nfs_cb_stat_to_errno(nfserr);
470 }
471
472 /*
473 * NFSv4.0 and NFSv4.1 XDR encode functions
474 *
475 * NFSv4.0 callback argument types are defined in section 15 of RFC
476 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
477 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
478 * Protocol".
479 */
480
481 /*
482 * NB: Without this zero space reservation, callbacks over krb5p fail
483 */
484 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
485 void *__unused)
486 {
487 xdr_reserve_space(xdr, 0);
488 }
489
490 /*
491 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
492 */
493 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
494 const struct nfsd4_callback *cb)
495 {
496 const struct nfs4_delegation *args = cb->cb_op;
497 struct nfs4_cb_compound_hdr hdr = {
498 .ident = cb->cb_clp->cl_cb_ident,
499 .minorversion = cb->cb_minorversion,
500 };
501
502 encode_cb_compound4args(xdr, &hdr);
503 encode_cb_sequence4args(xdr, cb, &hdr);
504 encode_cb_recall4args(xdr, args, &hdr);
505 encode_cb_nops(&hdr);
506 }
507
508
509 /*
510 * NFSv4.0 and NFSv4.1 XDR decode functions
511 *
512 * NFSv4.0 callback result types are defined in section 15 of RFC
513 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
514 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
515 * Protocol".
516 */
517
518 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
519 void *__unused)
520 {
521 return 0;
522 }
523
524 /*
525 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
526 */
527 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
528 struct xdr_stream *xdr,
529 struct nfsd4_callback *cb)
530 {
531 struct nfs4_cb_compound_hdr hdr;
532 enum nfsstat4 nfserr;
533 int status;
534
535 status = decode_cb_compound4res(xdr, &hdr);
536 if (unlikely(status))
537 goto out;
538
539 if (cb != NULL) {
540 status = decode_cb_sequence4res(xdr, cb);
541 if (unlikely(status))
542 goto out;
543 }
544
545 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
546 if (unlikely(status))
547 goto out;
548 if (unlikely(nfserr != NFS4_OK))
549 status = nfs_cb_stat_to_errno(nfserr);
550 out:
551 return status;
552 }
553
554 /*
555 * RPC procedure tables
556 */
557 #define PROC(proc, call, argtype, restype) \
558 [NFSPROC4_CLNT_##proc] = { \
559 .p_proc = NFSPROC4_CB_##call, \
560 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
561 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
562 .p_arglen = NFS4_enc_##argtype##_sz, \
563 .p_replen = NFS4_dec_##restype##_sz, \
564 .p_statidx = NFSPROC4_CB_##call, \
565 .p_name = #proc, \
566 }
567
568 static struct rpc_procinfo nfs4_cb_procedures[] = {
569 PROC(CB_NULL, NULL, cb_null, cb_null),
570 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
571 };
572
573 static struct rpc_version nfs_cb_version4 = {
574 /*
575 * Note on the callback rpc program version number: despite language in rfc
576 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
577 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
578 * in practice that appears to be what implementations use. The section
579 * 18.36.3 language is expected to be fixed in an erratum.
580 */
581 .number = 1,
582 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
583 .procs = nfs4_cb_procedures
584 };
585
586 static const struct rpc_version *nfs_cb_version[] = {
587 &nfs_cb_version4,
588 };
589
590 static const struct rpc_program cb_program;
591
592 static struct rpc_stat cb_stats = {
593 .program = &cb_program
594 };
595
596 #define NFS4_CALLBACK 0x40000000
597 static const struct rpc_program cb_program = {
598 .name = "nfs4_cb",
599 .number = NFS4_CALLBACK,
600 .nrvers = ARRAY_SIZE(nfs_cb_version),
601 .version = nfs_cb_version,
602 .stats = &cb_stats,
603 .pipe_dir_name = "nfsd4_cb",
604 };
605
606 static int max_cb_time(struct net *net)
607 {
608 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
609 return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
610 }
611
612 static struct rpc_cred *callback_cred;
613
614 int set_callback_cred(void)
615 {
616 if (callback_cred)
617 return 0;
618 callback_cred = rpc_lookup_machine_cred("nfs");
619 if (!callback_cred)
620 return -ENOMEM;
621 return 0;
622 }
623
624 static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
625 {
626 if (clp->cl_minorversion == 0) {
627 return get_rpccred(callback_cred);
628 } else {
629 struct rpc_auth *auth = client->cl_auth;
630 struct auth_cred acred = {};
631
632 acred.uid = ses->se_cb_sec.uid;
633 acred.gid = ses->se_cb_sec.gid;
634 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
635 }
636 }
637
638 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
639 {
640 int maxtime = max_cb_time(clp->net);
641 struct rpc_timeout timeparms = {
642 .to_initval = maxtime,
643 .to_retries = 0,
644 .to_maxval = maxtime,
645 };
646 struct rpc_create_args args = {
647 .net = clp->net,
648 .address = (struct sockaddr *) &conn->cb_addr,
649 .addrsize = conn->cb_addrlen,
650 .saddress = (struct sockaddr *) &conn->cb_saddr,
651 .timeout = &timeparms,
652 .program = &cb_program,
653 .version = 0,
654 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
655 };
656 struct rpc_clnt *client;
657 struct rpc_cred *cred;
658
659 if (clp->cl_minorversion == 0) {
660 if (!clp->cl_cred.cr_principal &&
661 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
662 return -EINVAL;
663 args.client_name = clp->cl_cred.cr_principal;
664 args.prognumber = conn->cb_prog,
665 args.protocol = XPRT_TRANSPORT_TCP;
666 args.authflavor = clp->cl_cred.cr_flavor;
667 clp->cl_cb_ident = conn->cb_ident;
668 } else {
669 if (!conn->cb_xprt)
670 return -EINVAL;
671 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
672 clp->cl_cb_session = ses;
673 args.bc_xprt = conn->cb_xprt;
674 args.prognumber = clp->cl_cb_session->se_cb_prog;
675 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
676 XPRT_TRANSPORT_BC;
677 args.authflavor = ses->se_cb_sec.flavor;
678 }
679 /* Create RPC client */
680 client = rpc_create(&args);
681 if (IS_ERR(client)) {
682 dprintk("NFSD: couldn't create callback client: %ld\n",
683 PTR_ERR(client));
684 return PTR_ERR(client);
685 }
686 cred = get_backchannel_cred(clp, client, ses);
687 if (IS_ERR(cred)) {
688 rpc_shutdown_client(client);
689 return PTR_ERR(cred);
690 }
691 clp->cl_cb_client = client;
692 clp->cl_cb_cred = cred;
693 return 0;
694 }
695
696 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
697 {
698 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
699 (int)clp->cl_name.len, clp->cl_name.data, reason);
700 }
701
702 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
703 {
704 clp->cl_cb_state = NFSD4_CB_DOWN;
705 warn_no_callback_path(clp, reason);
706 }
707
708 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
709 {
710 clp->cl_cb_state = NFSD4_CB_FAULT;
711 warn_no_callback_path(clp, reason);
712 }
713
714 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
715 {
716 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
717
718 if (task->tk_status)
719 nfsd4_mark_cb_down(clp, task->tk_status);
720 else
721 clp->cl_cb_state = NFSD4_CB_UP;
722 }
723
724 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
725 /* XXX: release method to ensure we set the cb channel down if
726 * necessary on early failure? */
727 .rpc_call_done = nfsd4_cb_probe_done,
728 };
729
730 static struct workqueue_struct *callback_wq;
731
732 static void run_nfsd4_cb(struct nfsd4_callback *cb)
733 {
734 queue_work(callback_wq, &cb->cb_work);
735 }
736
737 static void do_probe_callback(struct nfs4_client *clp)
738 {
739 struct nfsd4_callback *cb = &clp->cl_cb_null;
740
741 cb->cb_op = NULL;
742 cb->cb_clp = clp;
743
744 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
745 cb->cb_msg.rpc_argp = NULL;
746 cb->cb_msg.rpc_resp = NULL;
747
748 cb->cb_ops = &nfsd4_cb_probe_ops;
749
750 run_nfsd4_cb(cb);
751 }
752
753 /*
754 * Poke the callback thread to process any updates to the callback
755 * parameters, and send a null probe.
756 */
757 void nfsd4_probe_callback(struct nfs4_client *clp)
758 {
759 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
760 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
761 do_probe_callback(clp);
762 }
763
764 void nfsd4_probe_callback_sync(struct nfs4_client *clp)
765 {
766 nfsd4_probe_callback(clp);
767 flush_workqueue(callback_wq);
768 }
769
770 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
771 {
772 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
773 spin_lock(&clp->cl_lock);
774 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
775 spin_unlock(&clp->cl_lock);
776 }
777
778 /*
779 * There's currently a single callback channel slot.
780 * If the slot is available, then mark it busy. Otherwise, set the
781 * thread for sleeping on the callback RPC wait queue.
782 */
783 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
784 {
785 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
786 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
787 /* Race breaker */
788 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
789 dprintk("%s slot is busy\n", __func__);
790 return false;
791 }
792 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
793 }
794 return true;
795 }
796
797 /*
798 * TODO: cb_sequence should support referring call lists, cachethis, multiple
799 * slots, and mark callback channel down on communication errors.
800 */
801 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
802 {
803 struct nfsd4_callback *cb = calldata;
804 struct nfs4_client *clp = cb->cb_clp;
805 u32 minorversion = clp->cl_minorversion;
806
807 cb->cb_minorversion = minorversion;
808 if (minorversion) {
809 if (!nfsd41_cb_get_slot(clp, task))
810 return;
811 }
812 spin_lock(&clp->cl_lock);
813 if (list_empty(&cb->cb_per_client)) {
814 /* This is the first call, not a restart */
815 cb->cb_done = false;
816 list_add(&cb->cb_per_client, &clp->cl_callbacks);
817 }
818 spin_unlock(&clp->cl_lock);
819 rpc_call_start(task);
820 }
821
822 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
823 {
824 struct nfsd4_callback *cb = calldata;
825 struct nfs4_client *clp = cb->cb_clp;
826
827 dprintk("%s: minorversion=%d\n", __func__,
828 clp->cl_minorversion);
829
830 if (clp->cl_minorversion) {
831 /* No need for lock, access serialized in nfsd4_cb_prepare */
832 ++clp->cl_cb_session->se_cb_seq_nr;
833 clear_bit(0, &clp->cl_cb_slot_busy);
834 rpc_wake_up_next(&clp->cl_cb_waitq);
835 dprintk("%s: freed slot, new seqid=%d\n", __func__,
836 clp->cl_cb_session->se_cb_seq_nr);
837
838 /* We're done looking into the sequence information */
839 task->tk_msg.rpc_resp = NULL;
840 }
841 }
842
843
844 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
845 {
846 struct nfsd4_callback *cb = calldata;
847 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
848 struct nfs4_client *clp = cb->cb_clp;
849 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
850
851 nfsd4_cb_done(task, calldata);
852
853 if (current_rpc_client != task->tk_client) {
854 /* We're shutting down or changing cl_cb_client; leave
855 * it to nfsd4_process_cb_update to restart the call if
856 * necessary. */
857 return;
858 }
859
860 if (cb->cb_done)
861 return;
862 switch (task->tk_status) {
863 case 0:
864 cb->cb_done = true;
865 return;
866 case -EBADHANDLE:
867 case -NFS4ERR_BAD_STATEID:
868 /* Race: client probably got cb_recall
869 * before open reply granting delegation */
870 break;
871 default:
872 /* Network partition? */
873 nfsd4_mark_cb_down(clp, task->tk_status);
874 }
875 if (dp->dl_retries--) {
876 rpc_delay(task, 2*HZ);
877 task->tk_status = 0;
878 rpc_restart_call_prepare(task);
879 return;
880 }
881 nfsd4_mark_cb_down(clp, task->tk_status);
882 cb->cb_done = true;
883 }
884
885 static void nfsd4_cb_recall_release(void *calldata)
886 {
887 struct nfsd4_callback *cb = calldata;
888 struct nfs4_client *clp = cb->cb_clp;
889 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
890
891 if (cb->cb_done) {
892 spin_lock(&clp->cl_lock);
893 list_del(&cb->cb_per_client);
894 spin_unlock(&clp->cl_lock);
895 nfs4_put_delegation(dp);
896 }
897 }
898
899 static const struct rpc_call_ops nfsd4_cb_recall_ops = {
900 .rpc_call_prepare = nfsd4_cb_prepare,
901 .rpc_call_done = nfsd4_cb_recall_done,
902 .rpc_release = nfsd4_cb_recall_release,
903 };
904
905 int nfsd4_create_callback_queue(void)
906 {
907 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
908 if (!callback_wq)
909 return -ENOMEM;
910 return 0;
911 }
912
913 void nfsd4_destroy_callback_queue(void)
914 {
915 destroy_workqueue(callback_wq);
916 }
917
918 /* must be called under the state lock */
919 void nfsd4_shutdown_callback(struct nfs4_client *clp)
920 {
921 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
922 /*
923 * Note this won't actually result in a null callback;
924 * instead, nfsd4_do_callback_rpc() will detect the killed
925 * client, destroy the rpc client, and stop:
926 */
927 do_probe_callback(clp);
928 flush_workqueue(callback_wq);
929 }
930
931 static void nfsd4_release_cb(struct nfsd4_callback *cb)
932 {
933 if (cb->cb_ops->rpc_release)
934 cb->cb_ops->rpc_release(cb);
935 }
936
937 /* requires cl_lock: */
938 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
939 {
940 struct nfsd4_session *s;
941 struct nfsd4_conn *c;
942
943 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
944 list_for_each_entry(c, &s->se_conns, cn_persession) {
945 if (c->cn_flags & NFS4_CDFC4_BACK)
946 return c;
947 }
948 }
949 return NULL;
950 }
951
952 static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
953 {
954 struct nfs4_cb_conn conn;
955 struct nfs4_client *clp = cb->cb_clp;
956 struct nfsd4_session *ses = NULL;
957 struct nfsd4_conn *c;
958 int err;
959
960 /*
961 * This is either an update, or the client dying; in either case,
962 * kill the old client:
963 */
964 if (clp->cl_cb_client) {
965 rpc_shutdown_client(clp->cl_cb_client);
966 clp->cl_cb_client = NULL;
967 put_rpccred(clp->cl_cb_cred);
968 clp->cl_cb_cred = NULL;
969 }
970 if (clp->cl_cb_conn.cb_xprt) {
971 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
972 clp->cl_cb_conn.cb_xprt = NULL;
973 }
974 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
975 return;
976 spin_lock(&clp->cl_lock);
977 /*
978 * Only serialized callback code is allowed to clear these
979 * flags; main nfsd code can only set them:
980 */
981 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
982 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
983 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
984 c = __nfsd4_find_backchannel(clp);
985 if (c) {
986 svc_xprt_get(c->cn_xprt);
987 conn.cb_xprt = c->cn_xprt;
988 ses = c->cn_session;
989 }
990 spin_unlock(&clp->cl_lock);
991
992 err = setup_callback_client(clp, &conn, ses);
993 if (err) {
994 nfsd4_mark_cb_down(clp, err);
995 return;
996 }
997 /* Yay, the callback channel's back! Restart any callbacks: */
998 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
999 run_nfsd4_cb(cb);
1000 }
1001
1002 static void nfsd4_do_callback_rpc(struct work_struct *w)
1003 {
1004 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
1005 struct nfs4_client *clp = cb->cb_clp;
1006 struct rpc_clnt *clnt;
1007
1008 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1009 nfsd4_process_cb_update(cb);
1010
1011 clnt = clp->cl_cb_client;
1012 if (!clnt) {
1013 /* Callback channel broken, or client killed; give up: */
1014 nfsd4_release_cb(cb);
1015 return;
1016 }
1017 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1018 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1019 cb->cb_ops, cb);
1020 }
1021
1022 void nfsd4_init_callback(struct nfsd4_callback *cb)
1023 {
1024 INIT_WORK(&cb->cb_work, nfsd4_do_callback_rpc);
1025 }
1026
1027 void nfsd4_cb_recall(struct nfs4_delegation *dp)
1028 {
1029 struct nfsd4_callback *cb = &dp->dl_recall;
1030 struct nfs4_client *clp = dp->dl_stid.sc_client;
1031
1032 dp->dl_retries = 1;
1033 cb->cb_op = dp;
1034 cb->cb_clp = clp;
1035 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
1036 cb->cb_msg.rpc_argp = cb;
1037 cb->cb_msg.rpc_resp = cb;
1038
1039 cb->cb_ops = &nfsd4_cb_recall_ops;
1040
1041 INIT_LIST_HEAD(&cb->cb_per_client);
1042 cb->cb_done = true;
1043
1044 run_nfsd4_cb(&dp->dl_recall);
1045 }
1046
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