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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/xprt.h>
36#include <linux/sunrpc/svc_xprt.h>
37#include <linux/slab.h>
38#include "nfsd.h"
39#include "state.h"
40#include "netns.h"
41#include "trace.h"
42#include "xdr4cb.h"
43#include "xdr4.h"
44
45#define NFSDDBG_FACILITY NFSDDBG_PROC
46
47static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
48
49#define NFSPROC4_CB_NULL 0
50#define NFSPROC4_CB_COMPOUND 1
51
52/* Index of predefined Linux callback client operations */
53
54struct nfs4_cb_compound_hdr {
55 /* args */
56 u32 ident; /* minorversion 0 only */
57 u32 nops;
58 __be32 *nops_p;
59 u32 minorversion;
60 /* res */
61 int status;
62};
63
64static __be32 *xdr_encode_empty_array(__be32 *p)
65{
66 *p++ = xdr_zero;
67 return p;
68}
69
70/*
71 * Encode/decode NFSv4 CB basic data types
72 *
73 * Basic NFSv4 callback data types are defined in section 15 of RFC
74 * 3530: "Network File System (NFS) version 4 Protocol" and section
75 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
76 * 1 Protocol"
77 */
78
79static void encode_uint32(struct xdr_stream *xdr, u32 n)
80{
81 WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
82}
83
84static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
85 size_t len)
86{
87 WARN_ON_ONCE(xdr_stream_encode_uint32_array(xdr, bitmap, len) < 0);
88}
89
90/*
91 * nfs_cb_opnum4
92 *
93 * enum nfs_cb_opnum4 {
94 * OP_CB_GETATTR = 3,
95 * ...
96 * };
97 */
98enum nfs_cb_opnum4 {
99 OP_CB_GETATTR = 3,
100 OP_CB_RECALL = 4,
101 OP_CB_LAYOUTRECALL = 5,
102 OP_CB_NOTIFY = 6,
103 OP_CB_PUSH_DELEG = 7,
104 OP_CB_RECALL_ANY = 8,
105 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
106 OP_CB_RECALL_SLOT = 10,
107 OP_CB_SEQUENCE = 11,
108 OP_CB_WANTS_CANCELLED = 12,
109 OP_CB_NOTIFY_LOCK = 13,
110 OP_CB_NOTIFY_DEVICEID = 14,
111 OP_CB_OFFLOAD = 15,
112 OP_CB_ILLEGAL = 10044
113};
114
115static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
116{
117 __be32 *p;
118
119 p = xdr_reserve_space(xdr, 4);
120 *p = cpu_to_be32(op);
121}
122
123/*
124 * nfs_fh4
125 *
126 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
127 */
128static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
129{
130 u32 length = fh->fh_size;
131 __be32 *p;
132
133 BUG_ON(length > NFS4_FHSIZE);
134 p = xdr_reserve_space(xdr, 4 + length);
135 xdr_encode_opaque(p, &fh->fh_raw, length);
136}
137
138/*
139 * stateid4
140 *
141 * struct stateid4 {
142 * uint32_t seqid;
143 * opaque other[12];
144 * };
145 */
146static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
147{
148 __be32 *p;
149
150 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
151 *p++ = cpu_to_be32(sid->si_generation);
152 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
153}
154
155/*
156 * sessionid4
157 *
158 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
159 */
160static void encode_sessionid4(struct xdr_stream *xdr,
161 const struct nfsd4_session *session)
162{
163 __be32 *p;
164
165 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
166 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
167 NFS4_MAX_SESSIONID_LEN);
168}
169
170/*
171 * nfsstat4
172 */
173static const struct {
174 int stat;
175 int errno;
176} nfs_cb_errtbl[] = {
177 { NFS4_OK, 0 },
178 { NFS4ERR_PERM, -EPERM },
179 { NFS4ERR_NOENT, -ENOENT },
180 { NFS4ERR_IO, -EIO },
181 { NFS4ERR_NXIO, -ENXIO },
182 { NFS4ERR_ACCESS, -EACCES },
183 { NFS4ERR_EXIST, -EEXIST },
184 { NFS4ERR_XDEV, -EXDEV },
185 { NFS4ERR_NOTDIR, -ENOTDIR },
186 { NFS4ERR_ISDIR, -EISDIR },
187 { NFS4ERR_INVAL, -EINVAL },
188 { NFS4ERR_FBIG, -EFBIG },
189 { NFS4ERR_NOSPC, -ENOSPC },
190 { NFS4ERR_ROFS, -EROFS },
191 { NFS4ERR_MLINK, -EMLINK },
192 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
193 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
194 { NFS4ERR_DQUOT, -EDQUOT },
195 { NFS4ERR_STALE, -ESTALE },
196 { NFS4ERR_BADHANDLE, -EBADHANDLE },
197 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
198 { NFS4ERR_NOTSUPP, -ENOTSUPP },
199 { NFS4ERR_TOOSMALL, -ETOOSMALL },
200 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
201 { NFS4ERR_BADTYPE, -EBADTYPE },
202 { NFS4ERR_LOCKED, -EAGAIN },
203 { NFS4ERR_RESOURCE, -EREMOTEIO },
204 { NFS4ERR_SYMLINK, -ELOOP },
205 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
206 { NFS4ERR_DEADLOCK, -EDEADLK },
207 { -1, -EIO }
208};
209
210/*
211 * If we cannot translate the error, the recovery routines should
212 * handle it.
213 *
214 * Note: remaining NFSv4 error codes have values > 10000, so should
215 * not conflict with native Linux error codes.
216 */
217static int nfs_cb_stat_to_errno(int status)
218{
219 int i;
220
221 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
222 if (nfs_cb_errtbl[i].stat == status)
223 return nfs_cb_errtbl[i].errno;
224 }
225
226 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
227 return -status;
228}
229
230static int decode_cb_op_status(struct xdr_stream *xdr,
231 enum nfs_cb_opnum4 expected, int *status)
232{
233 __be32 *p;
234 u32 op;
235
236 p = xdr_inline_decode(xdr, 4 + 4);
237 if (unlikely(p == NULL))
238 goto out_overflow;
239 op = be32_to_cpup(p++);
240 if (unlikely(op != expected))
241 goto out_unexpected;
242 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
243 return 0;
244out_overflow:
245 return -EIO;
246out_unexpected:
247 dprintk("NFSD: Callback server returned operation %d but "
248 "we issued a request for %d\n", op, expected);
249 return -EIO;
250}
251
252/*
253 * CB_COMPOUND4args
254 *
255 * struct CB_COMPOUND4args {
256 * utf8str_cs tag;
257 * uint32_t minorversion;
258 * uint32_t callback_ident;
259 * nfs_cb_argop4 argarray<>;
260 * };
261*/
262static void encode_cb_compound4args(struct xdr_stream *xdr,
263 struct nfs4_cb_compound_hdr *hdr)
264{
265 __be32 * p;
266
267 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
268 p = xdr_encode_empty_array(p); /* empty tag */
269 *p++ = cpu_to_be32(hdr->minorversion);
270 *p++ = cpu_to_be32(hdr->ident);
271
272 hdr->nops_p = p;
273 *p = cpu_to_be32(hdr->nops); /* argarray element count */
274}
275
276/*
277 * Update argarray element count
278 */
279static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
280{
281 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
282 *hdr->nops_p = cpu_to_be32(hdr->nops);
283}
284
285/*
286 * CB_COMPOUND4res
287 *
288 * struct CB_COMPOUND4res {
289 * nfsstat4 status;
290 * utf8str_cs tag;
291 * nfs_cb_resop4 resarray<>;
292 * };
293 */
294static int decode_cb_compound4res(struct xdr_stream *xdr,
295 struct nfs4_cb_compound_hdr *hdr)
296{
297 u32 length;
298 __be32 *p;
299
300 p = xdr_inline_decode(xdr, 4 + 4);
301 if (unlikely(p == NULL))
302 goto out_overflow;
303 hdr->status = be32_to_cpup(p++);
304 /* Ignore the tag */
305 length = be32_to_cpup(p++);
306 p = xdr_inline_decode(xdr, length + 4);
307 if (unlikely(p == NULL))
308 goto out_overflow;
309 p += XDR_QUADLEN(length);
310 hdr->nops = be32_to_cpup(p);
311 return 0;
312out_overflow:
313 return -EIO;
314}
315
316/*
317 * CB_RECALL4args
318 *
319 * struct CB_RECALL4args {
320 * stateid4 stateid;
321 * bool truncate;
322 * nfs_fh4 fh;
323 * };
324 */
325static void encode_cb_recall4args(struct xdr_stream *xdr,
326 const struct nfs4_delegation *dp,
327 struct nfs4_cb_compound_hdr *hdr)
328{
329 __be32 *p;
330
331 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
332 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
333
334 p = xdr_reserve_space(xdr, 4);
335 *p++ = xdr_zero; /* truncate */
336
337 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
338
339 hdr->nops++;
340}
341
342/*
343 * CB_RECALLANY4args
344 *
345 * struct CB_RECALLANY4args {
346 * uint32_t craa_objects_to_keep;
347 * bitmap4 craa_type_mask;
348 * };
349 */
350static void
351encode_cb_recallany4args(struct xdr_stream *xdr,
352 struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra)
353{
354 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL_ANY);
355 encode_uint32(xdr, ra->ra_keep);
356 encode_bitmap4(xdr, ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval));
357 hdr->nops++;
358}
359
360/*
361 * CB_SEQUENCE4args
362 *
363 * struct CB_SEQUENCE4args {
364 * sessionid4 csa_sessionid;
365 * sequenceid4 csa_sequenceid;
366 * slotid4 csa_slotid;
367 * slotid4 csa_highest_slotid;
368 * bool csa_cachethis;
369 * referring_call_list4 csa_referring_call_lists<>;
370 * };
371 */
372static void encode_cb_sequence4args(struct xdr_stream *xdr,
373 const struct nfsd4_callback *cb,
374 struct nfs4_cb_compound_hdr *hdr)
375{
376 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
377 __be32 *p;
378
379 if (hdr->minorversion == 0)
380 return;
381
382 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
383 encode_sessionid4(xdr, session);
384
385 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
386 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
387 *p++ = xdr_zero; /* csa_slotid */
388 *p++ = xdr_zero; /* csa_highest_slotid */
389 *p++ = xdr_zero; /* csa_cachethis */
390 xdr_encode_empty_array(p); /* csa_referring_call_lists */
391
392 hdr->nops++;
393}
394
395/*
396 * CB_SEQUENCE4resok
397 *
398 * struct CB_SEQUENCE4resok {
399 * sessionid4 csr_sessionid;
400 * sequenceid4 csr_sequenceid;
401 * slotid4 csr_slotid;
402 * slotid4 csr_highest_slotid;
403 * slotid4 csr_target_highest_slotid;
404 * };
405 *
406 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
407 * case NFS4_OK:
408 * CB_SEQUENCE4resok csr_resok4;
409 * default:
410 * void;
411 * };
412 *
413 * Our current back channel implmentation supports a single backchannel
414 * with a single slot.
415 */
416static int decode_cb_sequence4resok(struct xdr_stream *xdr,
417 struct nfsd4_callback *cb)
418{
419 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
420 int status = -ESERVERFAULT;
421 __be32 *p;
422 u32 dummy;
423
424 /*
425 * If the server returns different values for sessionID, slotID or
426 * sequence number, the server is looney tunes.
427 */
428 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
429 if (unlikely(p == NULL))
430 goto out_overflow;
431
432 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
433 dprintk("NFS: %s Invalid session id\n", __func__);
434 goto out;
435 }
436 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
437
438 dummy = be32_to_cpup(p++);
439 if (dummy != session->se_cb_seq_nr) {
440 dprintk("NFS: %s Invalid sequence number\n", __func__);
441 goto out;
442 }
443
444 dummy = be32_to_cpup(p++);
445 if (dummy != 0) {
446 dprintk("NFS: %s Invalid slotid\n", __func__);
447 goto out;
448 }
449
450 /*
451 * FIXME: process highest slotid and target highest slotid
452 */
453 status = 0;
454out:
455 cb->cb_seq_status = status;
456 return status;
457out_overflow:
458 status = -EIO;
459 goto out;
460}
461
462static int decode_cb_sequence4res(struct xdr_stream *xdr,
463 struct nfsd4_callback *cb)
464{
465 int status;
466
467 if (cb->cb_clp->cl_minorversion == 0)
468 return 0;
469
470 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
471 if (unlikely(status || cb->cb_seq_status))
472 return status;
473
474 return decode_cb_sequence4resok(xdr, cb);
475}
476
477/*
478 * NFSv4.0 and NFSv4.1 XDR encode functions
479 *
480 * NFSv4.0 callback argument types are defined in section 15 of RFC
481 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
482 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
483 * Protocol".
484 */
485
486/*
487 * NB: Without this zero space reservation, callbacks over krb5p fail
488 */
489static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
490 const void *__unused)
491{
492 xdr_reserve_space(xdr, 0);
493}
494
495/*
496 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
497 */
498static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
499 const void *data)
500{
501 const struct nfsd4_callback *cb = data;
502 const struct nfs4_delegation *dp = cb_to_delegation(cb);
503 struct nfs4_cb_compound_hdr hdr = {
504 .ident = cb->cb_clp->cl_cb_ident,
505 .minorversion = cb->cb_clp->cl_minorversion,
506 };
507
508 encode_cb_compound4args(xdr, &hdr);
509 encode_cb_sequence4args(xdr, cb, &hdr);
510 encode_cb_recall4args(xdr, dp, &hdr);
511 encode_cb_nops(&hdr);
512}
513
514/*
515 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
516 */
517static void
518nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
519 struct xdr_stream *xdr, const void *data)
520{
521 const struct nfsd4_callback *cb = data;
522 struct nfsd4_cb_recall_any *ra;
523 struct nfs4_cb_compound_hdr hdr = {
524 .ident = cb->cb_clp->cl_cb_ident,
525 .minorversion = cb->cb_clp->cl_minorversion,
526 };
527
528 ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
529 encode_cb_compound4args(xdr, &hdr);
530 encode_cb_sequence4args(xdr, cb, &hdr);
531 encode_cb_recallany4args(xdr, &hdr, ra);
532 encode_cb_nops(&hdr);
533}
534
535/*
536 * NFSv4.0 and NFSv4.1 XDR decode functions
537 *
538 * NFSv4.0 callback result types are defined in section 15 of RFC
539 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
540 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
541 * Protocol".
542 */
543
544static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
545 void *__unused)
546{
547 return 0;
548}
549
550/*
551 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
552 */
553static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
554 struct xdr_stream *xdr,
555 void *data)
556{
557 struct nfsd4_callback *cb = data;
558 struct nfs4_cb_compound_hdr hdr;
559 int status;
560
561 status = decode_cb_compound4res(xdr, &hdr);
562 if (unlikely(status))
563 return status;
564
565 status = decode_cb_sequence4res(xdr, cb);
566 if (unlikely(status || cb->cb_seq_status))
567 return status;
568
569 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
570}
571
572/*
573 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
574 */
575static int
576nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
577 struct xdr_stream *xdr,
578 void *data)
579{
580 struct nfsd4_callback *cb = data;
581 struct nfs4_cb_compound_hdr hdr;
582 int status;
583
584 status = decode_cb_compound4res(xdr, &hdr);
585 if (unlikely(status))
586 return status;
587 status = decode_cb_sequence4res(xdr, cb);
588 if (unlikely(status || cb->cb_seq_status))
589 return status;
590 status = decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status);
591 return status;
592}
593
594#ifdef CONFIG_NFSD_PNFS
595/*
596 * CB_LAYOUTRECALL4args
597 *
598 * struct layoutrecall_file4 {
599 * nfs_fh4 lor_fh;
600 * offset4 lor_offset;
601 * length4 lor_length;
602 * stateid4 lor_stateid;
603 * };
604 *
605 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
606 * case LAYOUTRECALL4_FILE:
607 * layoutrecall_file4 lor_layout;
608 * case LAYOUTRECALL4_FSID:
609 * fsid4 lor_fsid;
610 * case LAYOUTRECALL4_ALL:
611 * void;
612 * };
613 *
614 * struct CB_LAYOUTRECALL4args {
615 * layouttype4 clora_type;
616 * layoutiomode4 clora_iomode;
617 * bool clora_changed;
618 * layoutrecall4 clora_recall;
619 * };
620 */
621static void encode_cb_layout4args(struct xdr_stream *xdr,
622 const struct nfs4_layout_stateid *ls,
623 struct nfs4_cb_compound_hdr *hdr)
624{
625 __be32 *p;
626
627 BUG_ON(hdr->minorversion == 0);
628
629 p = xdr_reserve_space(xdr, 5 * 4);
630 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
631 *p++ = cpu_to_be32(ls->ls_layout_type);
632 *p++ = cpu_to_be32(IOMODE_ANY);
633 *p++ = cpu_to_be32(1);
634 *p = cpu_to_be32(RETURN_FILE);
635
636 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
637
638 p = xdr_reserve_space(xdr, 2 * 8);
639 p = xdr_encode_hyper(p, 0);
640 xdr_encode_hyper(p, NFS4_MAX_UINT64);
641
642 encode_stateid4(xdr, &ls->ls_recall_sid);
643
644 hdr->nops++;
645}
646
647static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
648 struct xdr_stream *xdr,
649 const void *data)
650{
651 const struct nfsd4_callback *cb = data;
652 const struct nfs4_layout_stateid *ls =
653 container_of(cb, struct nfs4_layout_stateid, ls_recall);
654 struct nfs4_cb_compound_hdr hdr = {
655 .ident = 0,
656 .minorversion = cb->cb_clp->cl_minorversion,
657 };
658
659 encode_cb_compound4args(xdr, &hdr);
660 encode_cb_sequence4args(xdr, cb, &hdr);
661 encode_cb_layout4args(xdr, ls, &hdr);
662 encode_cb_nops(&hdr);
663}
664
665static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
666 struct xdr_stream *xdr,
667 void *data)
668{
669 struct nfsd4_callback *cb = data;
670 struct nfs4_cb_compound_hdr hdr;
671 int status;
672
673 status = decode_cb_compound4res(xdr, &hdr);
674 if (unlikely(status))
675 return status;
676
677 status = decode_cb_sequence4res(xdr, cb);
678 if (unlikely(status || cb->cb_seq_status))
679 return status;
680
681 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
682}
683#endif /* CONFIG_NFSD_PNFS */
684
685static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
686{
687 __be32 *p;
688
689 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
690 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
691 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
692}
693
694static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
695 struct xdr_stream *xdr,
696 const void *data)
697{
698 const struct nfsd4_callback *cb = data;
699 const struct nfsd4_blocked_lock *nbl =
700 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
701 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
702 struct nfs4_cb_compound_hdr hdr = {
703 .ident = 0,
704 .minorversion = cb->cb_clp->cl_minorversion,
705 };
706
707 __be32 *p;
708
709 BUG_ON(hdr.minorversion == 0);
710
711 encode_cb_compound4args(xdr, &hdr);
712 encode_cb_sequence4args(xdr, cb, &hdr);
713
714 p = xdr_reserve_space(xdr, 4);
715 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
716 encode_nfs_fh4(xdr, &nbl->nbl_fh);
717 encode_stateowner(xdr, &lo->lo_owner);
718 hdr.nops++;
719
720 encode_cb_nops(&hdr);
721}
722
723static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
724 struct xdr_stream *xdr,
725 void *data)
726{
727 struct nfsd4_callback *cb = data;
728 struct nfs4_cb_compound_hdr hdr;
729 int status;
730
731 status = decode_cb_compound4res(xdr, &hdr);
732 if (unlikely(status))
733 return status;
734
735 status = decode_cb_sequence4res(xdr, cb);
736 if (unlikely(status || cb->cb_seq_status))
737 return status;
738
739 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
740}
741
742/*
743 * struct write_response4 {
744 * stateid4 wr_callback_id<1>;
745 * length4 wr_count;
746 * stable_how4 wr_committed;
747 * verifier4 wr_writeverf;
748 * };
749 * union offload_info4 switch (nfsstat4 coa_status) {
750 * case NFS4_OK:
751 * write_response4 coa_resok4;
752 * default:
753 * length4 coa_bytes_copied;
754 * };
755 * struct CB_OFFLOAD4args {
756 * nfs_fh4 coa_fh;
757 * stateid4 coa_stateid;
758 * offload_info4 coa_offload_info;
759 * };
760 */
761static void encode_offload_info4(struct xdr_stream *xdr,
762 const struct nfsd4_cb_offload *cbo)
763{
764 __be32 *p;
765
766 p = xdr_reserve_space(xdr, 4);
767 *p = cbo->co_nfserr;
768 switch (cbo->co_nfserr) {
769 case nfs_ok:
770 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
771 p = xdr_encode_empty_array(p);
772 p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written);
773 *p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
774 p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data,
775 NFS4_VERIFIER_SIZE);
776 break;
777 default:
778 p = xdr_reserve_space(xdr, 8);
779 /* We always return success if bytes were written */
780 p = xdr_encode_hyper(p, 0);
781 }
782}
783
784static void encode_cb_offload4args(struct xdr_stream *xdr,
785 const struct nfsd4_cb_offload *cbo,
786 struct nfs4_cb_compound_hdr *hdr)
787{
788 __be32 *p;
789
790 p = xdr_reserve_space(xdr, 4);
791 *p = cpu_to_be32(OP_CB_OFFLOAD);
792 encode_nfs_fh4(xdr, &cbo->co_fh);
793 encode_stateid4(xdr, &cbo->co_res.cb_stateid);
794 encode_offload_info4(xdr, cbo);
795
796 hdr->nops++;
797}
798
799static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
800 struct xdr_stream *xdr,
801 const void *data)
802{
803 const struct nfsd4_callback *cb = data;
804 const struct nfsd4_cb_offload *cbo =
805 container_of(cb, struct nfsd4_cb_offload, co_cb);
806 struct nfs4_cb_compound_hdr hdr = {
807 .ident = 0,
808 .minorversion = cb->cb_clp->cl_minorversion,
809 };
810
811 encode_cb_compound4args(xdr, &hdr);
812 encode_cb_sequence4args(xdr, cb, &hdr);
813 encode_cb_offload4args(xdr, cbo, &hdr);
814 encode_cb_nops(&hdr);
815}
816
817static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
818 struct xdr_stream *xdr,
819 void *data)
820{
821 struct nfsd4_callback *cb = data;
822 struct nfs4_cb_compound_hdr hdr;
823 int status;
824
825 status = decode_cb_compound4res(xdr, &hdr);
826 if (unlikely(status))
827 return status;
828
829 status = decode_cb_sequence4res(xdr, cb);
830 if (unlikely(status || cb->cb_seq_status))
831 return status;
832
833 return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
834}
835/*
836 * RPC procedure tables
837 */
838#define PROC(proc, call, argtype, restype) \
839[NFSPROC4_CLNT_##proc] = { \
840 .p_proc = NFSPROC4_CB_##call, \
841 .p_encode = nfs4_xdr_enc_##argtype, \
842 .p_decode = nfs4_xdr_dec_##restype, \
843 .p_arglen = NFS4_enc_##argtype##_sz, \
844 .p_replen = NFS4_dec_##restype##_sz, \
845 .p_statidx = NFSPROC4_CB_##call, \
846 .p_name = #proc, \
847}
848
849static const struct rpc_procinfo nfs4_cb_procedures[] = {
850 PROC(CB_NULL, NULL, cb_null, cb_null),
851 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
852#ifdef CONFIG_NFSD_PNFS
853 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
854#endif
855 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
856 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
857 PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
858};
859
860static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
861static const struct rpc_version nfs_cb_version4 = {
862/*
863 * Note on the callback rpc program version number: despite language in rfc
864 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
865 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
866 * in practice that appears to be what implementations use. The section
867 * 18.36.3 language is expected to be fixed in an erratum.
868 */
869 .number = 1,
870 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
871 .procs = nfs4_cb_procedures,
872 .counts = nfs4_cb_counts,
873};
874
875static const struct rpc_version *nfs_cb_version[2] = {
876 [1] = &nfs_cb_version4,
877};
878
879static const struct rpc_program cb_program;
880
881static struct rpc_stat cb_stats = {
882 .program = &cb_program
883};
884
885#define NFS4_CALLBACK 0x40000000
886static const struct rpc_program cb_program = {
887 .name = "nfs4_cb",
888 .number = NFS4_CALLBACK,
889 .nrvers = ARRAY_SIZE(nfs_cb_version),
890 .version = nfs_cb_version,
891 .stats = &cb_stats,
892 .pipe_dir_name = "nfsd4_cb",
893};
894
895static int max_cb_time(struct net *net)
896{
897 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
898
899 /*
900 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
901 * so we can use 32-bit math on it. Warn if that assumption
902 * ever stops being true.
903 */
904 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
905 return 360 * HZ;
906
907 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
908}
909
910static struct workqueue_struct *callback_wq;
911
912static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
913{
914 return queue_work(callback_wq, &cb->cb_work);
915}
916
917static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
918{
919 atomic_inc(&clp->cl_cb_inflight);
920}
921
922static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
923{
924
925 if (atomic_dec_and_test(&clp->cl_cb_inflight))
926 wake_up_var(&clp->cl_cb_inflight);
927}
928
929static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
930{
931 wait_var_event(&clp->cl_cb_inflight,
932 !atomic_read(&clp->cl_cb_inflight));
933}
934
935static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
936{
937 if (clp->cl_minorversion == 0) {
938 client->cl_principal = clp->cl_cred.cr_targ_princ ?
939 clp->cl_cred.cr_targ_princ : "nfs";
940
941 return get_cred(rpc_machine_cred());
942 } else {
943 struct cred *kcred;
944
945 kcred = prepare_kernel_cred(&init_task);
946 if (!kcred)
947 return NULL;
948
949 kcred->uid = ses->se_cb_sec.uid;
950 kcred->gid = ses->se_cb_sec.gid;
951 return kcred;
952 }
953}
954
955static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
956{
957 int maxtime = max_cb_time(clp->net);
958 struct rpc_timeout timeparms = {
959 .to_initval = maxtime,
960 .to_retries = 0,
961 .to_maxval = maxtime,
962 };
963 struct rpc_create_args args = {
964 .net = clp->net,
965 .address = (struct sockaddr *) &conn->cb_addr,
966 .addrsize = conn->cb_addrlen,
967 .saddress = (struct sockaddr *) &conn->cb_saddr,
968 .timeout = &timeparms,
969 .program = &cb_program,
970 .version = 1,
971 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
972 .cred = current_cred(),
973 };
974 struct rpc_clnt *client;
975 const struct cred *cred;
976
977 if (clp->cl_minorversion == 0) {
978 if (!clp->cl_cred.cr_principal &&
979 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
980 trace_nfsd_cb_setup_err(clp, -EINVAL);
981 return -EINVAL;
982 }
983 args.client_name = clp->cl_cred.cr_principal;
984 args.prognumber = conn->cb_prog;
985 args.protocol = XPRT_TRANSPORT_TCP;
986 args.authflavor = clp->cl_cred.cr_flavor;
987 clp->cl_cb_ident = conn->cb_ident;
988 } else {
989 if (!conn->cb_xprt)
990 return -EINVAL;
991 clp->cl_cb_session = ses;
992 args.bc_xprt = conn->cb_xprt;
993 args.prognumber = clp->cl_cb_session->se_cb_prog;
994 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
995 XPRT_TRANSPORT_BC;
996 args.authflavor = ses->se_cb_sec.flavor;
997 }
998 /* Create RPC client */
999 client = rpc_create(&args);
1000 if (IS_ERR(client)) {
1001 trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
1002 return PTR_ERR(client);
1003 }
1004 cred = get_backchannel_cred(clp, client, ses);
1005 if (!cred) {
1006 trace_nfsd_cb_setup_err(clp, -ENOMEM);
1007 rpc_shutdown_client(client);
1008 return -ENOMEM;
1009 }
1010
1011 if (clp->cl_minorversion != 0)
1012 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
1013 clp->cl_cb_client = client;
1014 clp->cl_cb_cred = cred;
1015 rcu_read_lock();
1016 trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
1017 args.authflavor);
1018 rcu_read_unlock();
1019 return 0;
1020}
1021
1022static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
1023{
1024 if (clp->cl_cb_state != newstate) {
1025 clp->cl_cb_state = newstate;
1026 trace_nfsd_cb_state(clp);
1027 }
1028}
1029
1030static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
1031{
1032 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1033 return;
1034 nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
1035}
1036
1037static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
1038{
1039 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1040 return;
1041 nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
1042}
1043
1044static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
1045{
1046 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1047
1048 if (task->tk_status)
1049 nfsd4_mark_cb_down(clp, task->tk_status);
1050 else
1051 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1052}
1053
1054static void nfsd4_cb_probe_release(void *calldata)
1055{
1056 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1057
1058 nfsd41_cb_inflight_end(clp);
1059
1060}
1061
1062static const struct rpc_call_ops nfsd4_cb_probe_ops = {
1063 /* XXX: release method to ensure we set the cb channel down if
1064 * necessary on early failure? */
1065 .rpc_call_done = nfsd4_cb_probe_done,
1066 .rpc_release = nfsd4_cb_probe_release,
1067};
1068
1069/*
1070 * Poke the callback thread to process any updates to the callback
1071 * parameters, and send a null probe.
1072 */
1073void nfsd4_probe_callback(struct nfs4_client *clp)
1074{
1075 trace_nfsd_cb_probe(clp);
1076 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1077 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1078 nfsd4_run_cb(&clp->cl_cb_null);
1079}
1080
1081void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1082{
1083 nfsd4_probe_callback(clp);
1084 flush_workqueue(callback_wq);
1085}
1086
1087void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1088{
1089 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1090 spin_lock(&clp->cl_lock);
1091 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1092 spin_unlock(&clp->cl_lock);
1093}
1094
1095/*
1096 * There's currently a single callback channel slot.
1097 * If the slot is available, then mark it busy. Otherwise, set the
1098 * thread for sleeping on the callback RPC wait queue.
1099 */
1100static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1101{
1102 struct nfs4_client *clp = cb->cb_clp;
1103
1104 if (!cb->cb_holds_slot &&
1105 test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1106 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1107 /* Race breaker */
1108 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1109 dprintk("%s slot is busy\n", __func__);
1110 return false;
1111 }
1112 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1113 }
1114 cb->cb_holds_slot = true;
1115 return true;
1116}
1117
1118static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1119{
1120 struct nfs4_client *clp = cb->cb_clp;
1121
1122 if (cb->cb_holds_slot) {
1123 cb->cb_holds_slot = false;
1124 clear_bit(0, &clp->cl_cb_slot_busy);
1125 rpc_wake_up_next(&clp->cl_cb_waitq);
1126 }
1127}
1128
1129static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1130{
1131 struct nfs4_client *clp = cb->cb_clp;
1132
1133 nfsd41_cb_release_slot(cb);
1134 if (cb->cb_ops && cb->cb_ops->release)
1135 cb->cb_ops->release(cb);
1136 nfsd41_cb_inflight_end(clp);
1137}
1138
1139/*
1140 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1141 * slots, and mark callback channel down on communication errors.
1142 */
1143static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1144{
1145 struct nfsd4_callback *cb = calldata;
1146 struct nfs4_client *clp = cb->cb_clp;
1147 u32 minorversion = clp->cl_minorversion;
1148
1149 /*
1150 * cb_seq_status is only set in decode_cb_sequence4res,
1151 * and so will remain 1 if an rpc level failure occurs.
1152 */
1153 cb->cb_seq_status = 1;
1154 cb->cb_status = 0;
1155 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1156 return;
1157 rpc_call_start(task);
1158}
1159
1160static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1161{
1162 struct nfs4_client *clp = cb->cb_clp;
1163 struct nfsd4_session *session = clp->cl_cb_session;
1164 bool ret = true;
1165
1166 if (!clp->cl_minorversion) {
1167 /*
1168 * If the backchannel connection was shut down while this
1169 * task was queued, we need to resubmit it after setting up
1170 * a new backchannel connection.
1171 *
1172 * Note that if we lost our callback connection permanently
1173 * the submission code will error out, so we don't need to
1174 * handle that case here.
1175 */
1176 if (RPC_SIGNALLED(task))
1177 goto need_restart;
1178
1179 return true;
1180 }
1181
1182 if (!cb->cb_holds_slot)
1183 goto need_restart;
1184
1185 switch (cb->cb_seq_status) {
1186 case 0:
1187 /*
1188 * No need for lock, access serialized in nfsd4_cb_prepare
1189 *
1190 * RFC5661 20.9.3
1191 * If CB_SEQUENCE returns an error, then the state of the slot
1192 * (sequence ID, cached reply) MUST NOT change.
1193 */
1194 ++session->se_cb_seq_nr;
1195 break;
1196 case -ESERVERFAULT:
1197 ++session->se_cb_seq_nr;
1198 fallthrough;
1199 case 1:
1200 case -NFS4ERR_BADSESSION:
1201 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1202 ret = false;
1203 break;
1204 case -NFS4ERR_DELAY:
1205 if (!rpc_restart_call(task))
1206 goto out;
1207
1208 rpc_delay(task, 2 * HZ);
1209 return false;
1210 case -NFS4ERR_BADSLOT:
1211 goto retry_nowait;
1212 case -NFS4ERR_SEQ_MISORDERED:
1213 if (session->se_cb_seq_nr != 1) {
1214 session->se_cb_seq_nr = 1;
1215 goto retry_nowait;
1216 }
1217 break;
1218 default:
1219 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1220 dprintk("%s: unprocessed error %d\n", __func__,
1221 cb->cb_seq_status);
1222 }
1223
1224 nfsd41_cb_release_slot(cb);
1225 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1226 clp->cl_cb_session->se_cb_seq_nr);
1227
1228 if (RPC_SIGNALLED(task))
1229 goto need_restart;
1230out:
1231 return ret;
1232retry_nowait:
1233 if (rpc_restart_call_prepare(task))
1234 ret = false;
1235 goto out;
1236need_restart:
1237 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1238 task->tk_status = 0;
1239 cb->cb_need_restart = true;
1240 }
1241 return false;
1242}
1243
1244static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1245{
1246 struct nfsd4_callback *cb = calldata;
1247 struct nfs4_client *clp = cb->cb_clp;
1248
1249 if (!nfsd4_cb_sequence_done(task, cb))
1250 return;
1251
1252 if (cb->cb_status) {
1253 WARN_ON_ONCE(task->tk_status);
1254 task->tk_status = cb->cb_status;
1255 }
1256
1257 switch (cb->cb_ops->done(cb, task)) {
1258 case 0:
1259 task->tk_status = 0;
1260 rpc_restart_call_prepare(task);
1261 return;
1262 case 1:
1263 switch (task->tk_status) {
1264 case -EIO:
1265 case -ETIMEDOUT:
1266 case -EACCES:
1267 nfsd4_mark_cb_down(clp, task->tk_status);
1268 }
1269 break;
1270 default:
1271 BUG();
1272 }
1273}
1274
1275static void nfsd4_cb_release(void *calldata)
1276{
1277 struct nfsd4_callback *cb = calldata;
1278
1279 if (cb->cb_need_restart)
1280 nfsd4_queue_cb(cb);
1281 else
1282 nfsd41_destroy_cb(cb);
1283
1284}
1285
1286static const struct rpc_call_ops nfsd4_cb_ops = {
1287 .rpc_call_prepare = nfsd4_cb_prepare,
1288 .rpc_call_done = nfsd4_cb_done,
1289 .rpc_release = nfsd4_cb_release,
1290};
1291
1292int nfsd4_create_callback_queue(void)
1293{
1294 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1295 if (!callback_wq)
1296 return -ENOMEM;
1297 return 0;
1298}
1299
1300void nfsd4_destroy_callback_queue(void)
1301{
1302 destroy_workqueue(callback_wq);
1303}
1304
1305/* must be called under the state lock */
1306void nfsd4_shutdown_callback(struct nfs4_client *clp)
1307{
1308 if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
1309 trace_nfsd_cb_shutdown(clp);
1310
1311 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1312 /*
1313 * Note this won't actually result in a null callback;
1314 * instead, nfsd4_run_cb_null() will detect the killed
1315 * client, destroy the rpc client, and stop:
1316 */
1317 nfsd4_run_cb(&clp->cl_cb_null);
1318 flush_workqueue(callback_wq);
1319 nfsd41_cb_inflight_wait_complete(clp);
1320}
1321
1322/* requires cl_lock: */
1323static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1324{
1325 struct nfsd4_session *s;
1326 struct nfsd4_conn *c;
1327
1328 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1329 list_for_each_entry(c, &s->se_conns, cn_persession) {
1330 if (c->cn_flags & NFS4_CDFC4_BACK)
1331 return c;
1332 }
1333 }
1334 return NULL;
1335}
1336
1337/*
1338 * Note there isn't a lot of locking in this code; instead we depend on
1339 * the fact that it is run from the callback_wq, which won't run two
1340 * work items at once. So, for example, callback_wq handles all access
1341 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1342 */
1343static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1344{
1345 struct nfs4_cb_conn conn;
1346 struct nfs4_client *clp = cb->cb_clp;
1347 struct nfsd4_session *ses = NULL;
1348 struct nfsd4_conn *c;
1349 int err;
1350
1351 /*
1352 * This is either an update, or the client dying; in either case,
1353 * kill the old client:
1354 */
1355 if (clp->cl_cb_client) {
1356 rpc_shutdown_client(clp->cl_cb_client);
1357 clp->cl_cb_client = NULL;
1358 put_cred(clp->cl_cb_cred);
1359 clp->cl_cb_cred = NULL;
1360 }
1361 if (clp->cl_cb_conn.cb_xprt) {
1362 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1363 clp->cl_cb_conn.cb_xprt = NULL;
1364 }
1365 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1366 return;
1367 spin_lock(&clp->cl_lock);
1368 /*
1369 * Only serialized callback code is allowed to clear these
1370 * flags; main nfsd code can only set them:
1371 */
1372 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1373 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1374 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1375 c = __nfsd4_find_backchannel(clp);
1376 if (c) {
1377 svc_xprt_get(c->cn_xprt);
1378 conn.cb_xprt = c->cn_xprt;
1379 ses = c->cn_session;
1380 }
1381 spin_unlock(&clp->cl_lock);
1382
1383 err = setup_callback_client(clp, &conn, ses);
1384 if (err) {
1385 nfsd4_mark_cb_down(clp, err);
1386 if (c)
1387 svc_xprt_put(c->cn_xprt);
1388 return;
1389 }
1390}
1391
1392static void
1393nfsd4_run_cb_work(struct work_struct *work)
1394{
1395 struct nfsd4_callback *cb =
1396 container_of(work, struct nfsd4_callback, cb_work);
1397 struct nfs4_client *clp = cb->cb_clp;
1398 struct rpc_clnt *clnt;
1399 int flags;
1400
1401 if (cb->cb_need_restart) {
1402 cb->cb_need_restart = false;
1403 } else {
1404 if (cb->cb_ops && cb->cb_ops->prepare)
1405 cb->cb_ops->prepare(cb);
1406 }
1407
1408 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1409 nfsd4_process_cb_update(cb);
1410
1411 clnt = clp->cl_cb_client;
1412 if (!clnt) {
1413 /* Callback channel broken, or client killed; give up: */
1414 nfsd41_destroy_cb(cb);
1415 return;
1416 }
1417
1418 /*
1419 * Don't send probe messages for 4.1 or later.
1420 */
1421 if (!cb->cb_ops && clp->cl_minorversion) {
1422 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1423 nfsd41_destroy_cb(cb);
1424 return;
1425 }
1426
1427 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1428 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1429 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1430 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1431}
1432
1433void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1434 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1435{
1436 cb->cb_clp = clp;
1437 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1438 cb->cb_msg.rpc_argp = cb;
1439 cb->cb_msg.rpc_resp = cb;
1440 cb->cb_ops = ops;
1441 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1442 cb->cb_seq_status = 1;
1443 cb->cb_status = 0;
1444 cb->cb_need_restart = false;
1445 cb->cb_holds_slot = false;
1446}
1447
1448/**
1449 * nfsd4_run_cb - queue up a callback job to run
1450 * @cb: callback to queue
1451 *
1452 * Kick off a callback to do its thing. Returns false if it was already
1453 * on a queue, true otherwise.
1454 */
1455bool nfsd4_run_cb(struct nfsd4_callback *cb)
1456{
1457 struct nfs4_client *clp = cb->cb_clp;
1458 bool queued;
1459
1460 nfsd41_cb_inflight_begin(clp);
1461 queued = nfsd4_queue_cb(cb);
1462 if (!queued)
1463 nfsd41_cb_inflight_end(clp);
1464 return queued;
1465}
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
40#define NFSDDBG_FACILITY NFSDDBG_PROC
41
42static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
43
44#define NFSPROC4_CB_NULL 0
45#define NFSPROC4_CB_COMPOUND 1
46
47/* Index of predefined Linux callback client operations */
48
49enum {
50 NFSPROC4_CLNT_CB_NULL = 0,
51 NFSPROC4_CLNT_CB_RECALL,
52 NFSPROC4_CLNT_CB_SEQUENCE,
53};
54
55#define NFS4_MAXTAGLEN 20
56
57#define NFS4_enc_cb_null_sz 0
58#define NFS4_dec_cb_null_sz 0
59#define cb_compound_enc_hdr_sz 4
60#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
61#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
62#define cb_sequence_enc_sz (sessionid_sz + 4 + \
63 1 /* no referring calls list yet */)
64#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
65
66#define op_enc_sz 1
67#define op_dec_sz 2
68#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
69#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
70#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
71 cb_sequence_enc_sz + \
72 1 + enc_stateid_sz + \
73 enc_nfs4_fh_sz)
74
75#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
76 cb_sequence_dec_sz + \
77 op_dec_sz)
78
79struct nfs4_cb_compound_hdr {
80 /* args */
81 u32 ident; /* minorversion 0 only */
82 u32 nops;
83 __be32 *nops_p;
84 u32 minorversion;
85 /* res */
86 int status;
87};
88
89/*
90 * Handle decode buffer overflows out-of-line.
91 */
92static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
93{
94 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
95 "Remaining buffer length is %tu words.\n",
96 func, xdr->end - xdr->p);
97}
98
99static __be32 *xdr_encode_empty_array(__be32 *p)
100{
101 *p++ = xdr_zero;
102 return p;
103}
104
105/*
106 * Encode/decode NFSv4 CB basic data types
107 *
108 * Basic NFSv4 callback data types are defined in section 15 of RFC
109 * 3530: "Network File System (NFS) version 4 Protocol" and section
110 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
111 * 1 Protocol"
112 */
113
114/*
115 * nfs_cb_opnum4
116 *
117 * enum nfs_cb_opnum4 {
118 * OP_CB_GETATTR = 3,
119 * ...
120 * };
121 */
122enum nfs_cb_opnum4 {
123 OP_CB_GETATTR = 3,
124 OP_CB_RECALL = 4,
125 OP_CB_LAYOUTRECALL = 5,
126 OP_CB_NOTIFY = 6,
127 OP_CB_PUSH_DELEG = 7,
128 OP_CB_RECALL_ANY = 8,
129 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
130 OP_CB_RECALL_SLOT = 10,
131 OP_CB_SEQUENCE = 11,
132 OP_CB_WANTS_CANCELLED = 12,
133 OP_CB_NOTIFY_LOCK = 13,
134 OP_CB_NOTIFY_DEVICEID = 14,
135 OP_CB_ILLEGAL = 10044
136};
137
138static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
139{
140 __be32 *p;
141
142 p = xdr_reserve_space(xdr, 4);
143 *p = cpu_to_be32(op);
144}
145
146/*
147 * nfs_fh4
148 *
149 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
150 */
151static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
152{
153 u32 length = fh->fh_size;
154 __be32 *p;
155
156 BUG_ON(length > NFS4_FHSIZE);
157 p = xdr_reserve_space(xdr, 4 + length);
158 xdr_encode_opaque(p, &fh->fh_base, length);
159}
160
161/*
162 * stateid4
163 *
164 * struct stateid4 {
165 * uint32_t seqid;
166 * opaque other[12];
167 * };
168 */
169static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
170{
171 __be32 *p;
172
173 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
174 *p++ = cpu_to_be32(sid->si_generation);
175 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
176}
177
178/*
179 * sessionid4
180 *
181 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
182 */
183static void encode_sessionid4(struct xdr_stream *xdr,
184 const struct nfsd4_session *session)
185{
186 __be32 *p;
187
188 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
189 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
190 NFS4_MAX_SESSIONID_LEN);
191}
192
193/*
194 * nfsstat4
195 */
196static const struct {
197 int stat;
198 int errno;
199} nfs_cb_errtbl[] = {
200 { NFS4_OK, 0 },
201 { NFS4ERR_PERM, -EPERM },
202 { NFS4ERR_NOENT, -ENOENT },
203 { NFS4ERR_IO, -EIO },
204 { NFS4ERR_NXIO, -ENXIO },
205 { NFS4ERR_ACCESS, -EACCES },
206 { NFS4ERR_EXIST, -EEXIST },
207 { NFS4ERR_XDEV, -EXDEV },
208 { NFS4ERR_NOTDIR, -ENOTDIR },
209 { NFS4ERR_ISDIR, -EISDIR },
210 { NFS4ERR_INVAL, -EINVAL },
211 { NFS4ERR_FBIG, -EFBIG },
212 { NFS4ERR_NOSPC, -ENOSPC },
213 { NFS4ERR_ROFS, -EROFS },
214 { NFS4ERR_MLINK, -EMLINK },
215 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
216 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
217 { NFS4ERR_DQUOT, -EDQUOT },
218 { NFS4ERR_STALE, -ESTALE },
219 { NFS4ERR_BADHANDLE, -EBADHANDLE },
220 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
221 { NFS4ERR_NOTSUPP, -ENOTSUPP },
222 { NFS4ERR_TOOSMALL, -ETOOSMALL },
223 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
224 { NFS4ERR_BADTYPE, -EBADTYPE },
225 { NFS4ERR_LOCKED, -EAGAIN },
226 { NFS4ERR_RESOURCE, -EREMOTEIO },
227 { NFS4ERR_SYMLINK, -ELOOP },
228 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
229 { NFS4ERR_DEADLOCK, -EDEADLK },
230 { -1, -EIO }
231};
232
233/*
234 * If we cannot translate the error, the recovery routines should
235 * handle it.
236 *
237 * Note: remaining NFSv4 error codes have values > 10000, so should
238 * not conflict with native Linux error codes.
239 */
240static int nfs_cb_stat_to_errno(int status)
241{
242 int i;
243
244 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
245 if (nfs_cb_errtbl[i].stat == status)
246 return nfs_cb_errtbl[i].errno;
247 }
248
249 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
250 return -status;
251}
252
253static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
254 enum nfsstat4 *status)
255{
256 __be32 *p;
257 u32 op;
258
259 p = xdr_inline_decode(xdr, 4 + 4);
260 if (unlikely(p == NULL))
261 goto out_overflow;
262 op = be32_to_cpup(p++);
263 if (unlikely(op != expected))
264 goto out_unexpected;
265 *status = be32_to_cpup(p);
266 return 0;
267out_overflow:
268 print_overflow_msg(__func__, xdr);
269 return -EIO;
270out_unexpected:
271 dprintk("NFSD: Callback server returned operation %d but "
272 "we issued a request for %d\n", op, expected);
273 return -EIO;
274}
275
276/*
277 * CB_COMPOUND4args
278 *
279 * struct CB_COMPOUND4args {
280 * utf8str_cs tag;
281 * uint32_t minorversion;
282 * uint32_t callback_ident;
283 * nfs_cb_argop4 argarray<>;
284 * };
285*/
286static void encode_cb_compound4args(struct xdr_stream *xdr,
287 struct nfs4_cb_compound_hdr *hdr)
288{
289 __be32 * p;
290
291 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
292 p = xdr_encode_empty_array(p); /* empty tag */
293 *p++ = cpu_to_be32(hdr->minorversion);
294 *p++ = cpu_to_be32(hdr->ident);
295
296 hdr->nops_p = p;
297 *p = cpu_to_be32(hdr->nops); /* argarray element count */
298}
299
300/*
301 * Update argarray element count
302 */
303static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
304{
305 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
306 *hdr->nops_p = cpu_to_be32(hdr->nops);
307}
308
309/*
310 * CB_COMPOUND4res
311 *
312 * struct CB_COMPOUND4res {
313 * nfsstat4 status;
314 * utf8str_cs tag;
315 * nfs_cb_resop4 resarray<>;
316 * };
317 */
318static int decode_cb_compound4res(struct xdr_stream *xdr,
319 struct nfs4_cb_compound_hdr *hdr)
320{
321 u32 length;
322 __be32 *p;
323
324 p = xdr_inline_decode(xdr, 4 + 4);
325 if (unlikely(p == NULL))
326 goto out_overflow;
327 hdr->status = be32_to_cpup(p++);
328 /* Ignore the tag */
329 length = be32_to_cpup(p++);
330 p = xdr_inline_decode(xdr, length + 4);
331 if (unlikely(p == NULL))
332 goto out_overflow;
333 hdr->nops = be32_to_cpup(p);
334 return 0;
335out_overflow:
336 print_overflow_msg(__func__, xdr);
337 return -EIO;
338}
339
340/*
341 * CB_RECALL4args
342 *
343 * struct CB_RECALL4args {
344 * stateid4 stateid;
345 * bool truncate;
346 * nfs_fh4 fh;
347 * };
348 */
349static void encode_cb_recall4args(struct xdr_stream *xdr,
350 const struct nfs4_delegation *dp,
351 struct nfs4_cb_compound_hdr *hdr)
352{
353 __be32 *p;
354
355 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
356 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
357
358 p = xdr_reserve_space(xdr, 4);
359 *p++ = xdr_zero; /* truncate */
360
361 encode_nfs_fh4(xdr, &dp->dl_fh);
362
363 hdr->nops++;
364}
365
366/*
367 * CB_SEQUENCE4args
368 *
369 * struct CB_SEQUENCE4args {
370 * sessionid4 csa_sessionid;
371 * sequenceid4 csa_sequenceid;
372 * slotid4 csa_slotid;
373 * slotid4 csa_highest_slotid;
374 * bool csa_cachethis;
375 * referring_call_list4 csa_referring_call_lists<>;
376 * };
377 */
378static void encode_cb_sequence4args(struct xdr_stream *xdr,
379 const struct nfsd4_callback *cb,
380 struct nfs4_cb_compound_hdr *hdr)
381{
382 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
383 __be32 *p;
384
385 if (hdr->minorversion == 0)
386 return;
387
388 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
389 encode_sessionid4(xdr, session);
390
391 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
392 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
393 *p++ = xdr_zero; /* csa_slotid */
394 *p++ = xdr_zero; /* csa_highest_slotid */
395 *p++ = xdr_zero; /* csa_cachethis */
396 xdr_encode_empty_array(p); /* csa_referring_call_lists */
397
398 hdr->nops++;
399}
400
401/*
402 * CB_SEQUENCE4resok
403 *
404 * struct CB_SEQUENCE4resok {
405 * sessionid4 csr_sessionid;
406 * sequenceid4 csr_sequenceid;
407 * slotid4 csr_slotid;
408 * slotid4 csr_highest_slotid;
409 * slotid4 csr_target_highest_slotid;
410 * };
411 *
412 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
413 * case NFS4_OK:
414 * CB_SEQUENCE4resok csr_resok4;
415 * default:
416 * void;
417 * };
418 *
419 * Our current back channel implmentation supports a single backchannel
420 * with a single slot.
421 */
422static int decode_cb_sequence4resok(struct xdr_stream *xdr,
423 struct nfsd4_callback *cb)
424{
425 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
426 struct nfs4_sessionid id;
427 int status;
428 __be32 *p;
429 u32 dummy;
430
431 status = -ESERVERFAULT;
432
433 /*
434 * If the server returns different values for sessionID, slotID or
435 * sequence number, the server is looney tunes.
436 */
437 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
438 if (unlikely(p == NULL))
439 goto out_overflow;
440 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
441 if (memcmp(id.data, session->se_sessionid.data,
442 NFS4_MAX_SESSIONID_LEN) != 0) {
443 dprintk("NFS: %s Invalid session id\n", __func__);
444 goto out;
445 }
446 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
447
448 dummy = be32_to_cpup(p++);
449 if (dummy != session->se_cb_seq_nr) {
450 dprintk("NFS: %s Invalid sequence number\n", __func__);
451 goto out;
452 }
453
454 dummy = be32_to_cpup(p++);
455 if (dummy != 0) {
456 dprintk("NFS: %s Invalid slotid\n", __func__);
457 goto out;
458 }
459
460 /*
461 * FIXME: process highest slotid and target highest slotid
462 */
463 status = 0;
464out:
465 if (status)
466 nfsd4_mark_cb_fault(cb->cb_clp, status);
467 return status;
468out_overflow:
469 print_overflow_msg(__func__, xdr);
470 return -EIO;
471}
472
473static int decode_cb_sequence4res(struct xdr_stream *xdr,
474 struct nfsd4_callback *cb)
475{
476 enum nfsstat4 nfserr;
477 int status;
478
479 if (cb->cb_minorversion == 0)
480 return 0;
481
482 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
483 if (unlikely(status))
484 goto out;
485 if (unlikely(nfserr != NFS4_OK))
486 goto out_default;
487 status = decode_cb_sequence4resok(xdr, cb);
488out:
489 return status;
490out_default:
491 return nfs_cb_stat_to_errno(nfserr);
492}
493
494/*
495 * NFSv4.0 and NFSv4.1 XDR encode functions
496 *
497 * NFSv4.0 callback argument types are defined in section 15 of RFC
498 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
499 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
500 * Protocol".
501 */
502
503/*
504 * NB: Without this zero space reservation, callbacks over krb5p fail
505 */
506static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
507 void *__unused)
508{
509 xdr_reserve_space(xdr, 0);
510}
511
512/*
513 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
514 */
515static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
516 const struct nfsd4_callback *cb)
517{
518 const struct nfs4_delegation *args = cb->cb_op;
519 struct nfs4_cb_compound_hdr hdr = {
520 .ident = cb->cb_clp->cl_cb_ident,
521 .minorversion = cb->cb_minorversion,
522 };
523
524 encode_cb_compound4args(xdr, &hdr);
525 encode_cb_sequence4args(xdr, cb, &hdr);
526 encode_cb_recall4args(xdr, args, &hdr);
527 encode_cb_nops(&hdr);
528}
529
530
531/*
532 * NFSv4.0 and NFSv4.1 XDR decode functions
533 *
534 * NFSv4.0 callback result types are defined in section 15 of RFC
535 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
536 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
537 * Protocol".
538 */
539
540static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
541 void *__unused)
542{
543 return 0;
544}
545
546/*
547 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
548 */
549static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
550 struct xdr_stream *xdr,
551 struct nfsd4_callback *cb)
552{
553 struct nfs4_cb_compound_hdr hdr;
554 enum nfsstat4 nfserr;
555 int status;
556
557 status = decode_cb_compound4res(xdr, &hdr);
558 if (unlikely(status))
559 goto out;
560
561 if (cb != NULL) {
562 status = decode_cb_sequence4res(xdr, cb);
563 if (unlikely(status))
564 goto out;
565 }
566
567 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
568 if (unlikely(status))
569 goto out;
570 if (unlikely(nfserr != NFS4_OK))
571 status = nfs_cb_stat_to_errno(nfserr);
572out:
573 return status;
574}
575
576/*
577 * RPC procedure tables
578 */
579#define PROC(proc, call, argtype, restype) \
580[NFSPROC4_CLNT_##proc] = { \
581 .p_proc = NFSPROC4_CB_##call, \
582 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
583 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
584 .p_arglen = NFS4_enc_##argtype##_sz, \
585 .p_replen = NFS4_dec_##restype##_sz, \
586 .p_statidx = NFSPROC4_CB_##call, \
587 .p_name = #proc, \
588}
589
590static struct rpc_procinfo nfs4_cb_procedures[] = {
591 PROC(CB_NULL, NULL, cb_null, cb_null),
592 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
593};
594
595static struct rpc_version nfs_cb_version4 = {
596/*
597 * Note on the callback rpc program version number: despite language in rfc
598 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
599 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
600 * in practice that appears to be what implementations use. The section
601 * 18.36.3 language is expected to be fixed in an erratum.
602 */
603 .number = 1,
604 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
605 .procs = nfs4_cb_procedures
606};
607
608static const struct rpc_version *nfs_cb_version[] = {
609 &nfs_cb_version4,
610};
611
612static const struct rpc_program cb_program;
613
614static struct rpc_stat cb_stats = {
615 .program = &cb_program
616};
617
618#define NFS4_CALLBACK 0x40000000
619static const struct rpc_program cb_program = {
620 .name = "nfs4_cb",
621 .number = NFS4_CALLBACK,
622 .nrvers = ARRAY_SIZE(nfs_cb_version),
623 .version = nfs_cb_version,
624 .stats = &cb_stats,
625 .pipe_dir_name = "nfsd4_cb",
626};
627
628static int max_cb_time(void)
629{
630 return max(nfsd4_lease/10, (time_t)1) * HZ;
631}
632
633
634static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
635{
636 struct rpc_timeout timeparms = {
637 .to_initval = max_cb_time(),
638 .to_retries = 0,
639 };
640 struct rpc_create_args args = {
641 .net = &init_net,
642 .address = (struct sockaddr *) &conn->cb_addr,
643 .addrsize = conn->cb_addrlen,
644 .saddress = (struct sockaddr *) &conn->cb_saddr,
645 .timeout = &timeparms,
646 .program = &cb_program,
647 .version = 0,
648 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
649 };
650 struct rpc_clnt *client;
651
652 if (clp->cl_minorversion == 0) {
653 if (!clp->cl_cred.cr_principal &&
654 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
655 return -EINVAL;
656 args.client_name = clp->cl_cred.cr_principal;
657 args.prognumber = conn->cb_prog,
658 args.protocol = XPRT_TRANSPORT_TCP;
659 args.authflavor = clp->cl_cred.cr_flavor;
660 clp->cl_cb_ident = conn->cb_ident;
661 } else {
662 if (!conn->cb_xprt)
663 return -EINVAL;
664 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
665 clp->cl_cb_session = ses;
666 args.bc_xprt = conn->cb_xprt;
667 args.prognumber = clp->cl_cb_session->se_cb_prog;
668 args.protocol = XPRT_TRANSPORT_BC_TCP;
669 args.authflavor = RPC_AUTH_UNIX;
670 }
671 /* Create RPC client */
672 client = rpc_create(&args);
673 if (IS_ERR(client)) {
674 dprintk("NFSD: couldn't create callback client: %ld\n",
675 PTR_ERR(client));
676 return PTR_ERR(client);
677 }
678 clp->cl_cb_client = client;
679 return 0;
680
681}
682
683static void warn_no_callback_path(struct nfs4_client *clp, int reason)
684{
685 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
686 (int)clp->cl_name.len, clp->cl_name.data, reason);
687}
688
689static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
690{
691 clp->cl_cb_state = NFSD4_CB_DOWN;
692 warn_no_callback_path(clp, reason);
693}
694
695static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
696{
697 clp->cl_cb_state = NFSD4_CB_FAULT;
698 warn_no_callback_path(clp, reason);
699}
700
701static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
702{
703 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
704
705 if (task->tk_status)
706 nfsd4_mark_cb_down(clp, task->tk_status);
707 else
708 clp->cl_cb_state = NFSD4_CB_UP;
709}
710
711static const struct rpc_call_ops nfsd4_cb_probe_ops = {
712 /* XXX: release method to ensure we set the cb channel down if
713 * necessary on early failure? */
714 .rpc_call_done = nfsd4_cb_probe_done,
715};
716
717static struct rpc_cred *callback_cred;
718
719int set_callback_cred(void)
720{
721 if (callback_cred)
722 return 0;
723 callback_cred = rpc_lookup_machine_cred("nfs");
724 if (!callback_cred)
725 return -ENOMEM;
726 return 0;
727}
728
729static struct workqueue_struct *callback_wq;
730
731static void run_nfsd4_cb(struct nfsd4_callback *cb)
732{
733 queue_work(callback_wq, &cb->cb_work);
734}
735
736static void do_probe_callback(struct nfs4_client *clp)
737{
738 struct nfsd4_callback *cb = &clp->cl_cb_null;
739
740 cb->cb_op = NULL;
741 cb->cb_clp = clp;
742
743 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
744 cb->cb_msg.rpc_argp = NULL;
745 cb->cb_msg.rpc_resp = NULL;
746 cb->cb_msg.rpc_cred = callback_cred;
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 */
757void nfsd4_probe_callback(struct nfs4_client *clp)
758{
759 /* XXX: atomicity? Also, should we be using cl_flags? */
760 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
761 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
762 do_probe_callback(clp);
763}
764
765void nfsd4_probe_callback_sync(struct nfs4_client *clp)
766{
767 nfsd4_probe_callback(clp);
768 flush_workqueue(callback_wq);
769}
770
771void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
772{
773 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
774 spin_lock(&clp->cl_lock);
775 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
776 spin_unlock(&clp->cl_lock);
777}
778
779/*
780 * There's currently a single callback channel slot.
781 * If the slot is available, then mark it busy. Otherwise, set the
782 * thread for sleeping on the callback RPC wait queue.
783 */
784static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
785{
786 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
787 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
788 dprintk("%s slot is busy\n", __func__);
789 return false;
790 }
791 return true;
792}
793
794/*
795 * TODO: cb_sequence should support referring call lists, cachethis, multiple
796 * slots, and mark callback channel down on communication errors.
797 */
798static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
799{
800 struct nfsd4_callback *cb = calldata;
801 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
802 struct nfs4_client *clp = dp->dl_stid.sc_client;
803 u32 minorversion = clp->cl_minorversion;
804
805 cb->cb_minorversion = minorversion;
806 if (minorversion) {
807 if (!nfsd41_cb_get_slot(clp, task))
808 return;
809 }
810 spin_lock(&clp->cl_lock);
811 if (list_empty(&cb->cb_per_client)) {
812 /* This is the first call, not a restart */
813 cb->cb_done = false;
814 list_add(&cb->cb_per_client, &clp->cl_callbacks);
815 }
816 spin_unlock(&clp->cl_lock);
817 rpc_call_start(task);
818}
819
820static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
821{
822 struct nfsd4_callback *cb = calldata;
823 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
824 struct nfs4_client *clp = dp->dl_stid.sc_client;
825
826 dprintk("%s: minorversion=%d\n", __func__,
827 clp->cl_minorversion);
828
829 if (clp->cl_minorversion) {
830 /* No need for lock, access serialized in nfsd4_cb_prepare */
831 ++clp->cl_cb_session->se_cb_seq_nr;
832 clear_bit(0, &clp->cl_cb_slot_busy);
833 rpc_wake_up_next(&clp->cl_cb_waitq);
834 dprintk("%s: freed slot, new seqid=%d\n", __func__,
835 clp->cl_cb_session->se_cb_seq_nr);
836
837 /* We're done looking into the sequence information */
838 task->tk_msg.rpc_resp = NULL;
839 }
840}
841
842
843static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
844{
845 struct nfsd4_callback *cb = calldata;
846 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
847 struct nfs4_client *clp = dp->dl_stid.sc_client;
848 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
849
850 nfsd4_cb_done(task, calldata);
851
852 if (current_rpc_client != task->tk_client) {
853 /* We're shutting down or changing cl_cb_client; leave
854 * it to nfsd4_process_cb_update to restart the call if
855 * necessary. */
856 return;
857 }
858
859 if (cb->cb_done)
860 return;
861 switch (task->tk_status) {
862 case 0:
863 cb->cb_done = true;
864 return;
865 case -EBADHANDLE:
866 case -NFS4ERR_BAD_STATEID:
867 /* Race: client probably got cb_recall
868 * before open reply granting delegation */
869 break;
870 default:
871 /* Network partition? */
872 nfsd4_mark_cb_down(clp, task->tk_status);
873 }
874 if (dp->dl_retries--) {
875 rpc_delay(task, 2*HZ);
876 task->tk_status = 0;
877 rpc_restart_call_prepare(task);
878 return;
879 }
880 nfsd4_mark_cb_down(clp, task->tk_status);
881 cb->cb_done = true;
882}
883
884static void nfsd4_cb_recall_release(void *calldata)
885{
886 struct nfsd4_callback *cb = calldata;
887 struct nfs4_client *clp = cb->cb_clp;
888 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
889
890 if (cb->cb_done) {
891 spin_lock(&clp->cl_lock);
892 list_del(&cb->cb_per_client);
893 spin_unlock(&clp->cl_lock);
894 nfs4_put_delegation(dp);
895 }
896}
897
898static const struct rpc_call_ops nfsd4_cb_recall_ops = {
899 .rpc_call_prepare = nfsd4_cb_prepare,
900 .rpc_call_done = nfsd4_cb_recall_done,
901 .rpc_release = nfsd4_cb_recall_release,
902};
903
904int nfsd4_create_callback_queue(void)
905{
906 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
907 if (!callback_wq)
908 return -ENOMEM;
909 return 0;
910}
911
912void nfsd4_destroy_callback_queue(void)
913{
914 destroy_workqueue(callback_wq);
915}
916
917/* must be called under the state lock */
918void nfsd4_shutdown_callback(struct nfs4_client *clp)
919{
920 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
921 /*
922 * Note this won't actually result in a null callback;
923 * instead, nfsd4_do_callback_rpc() will detect the killed
924 * client, destroy the rpc client, and stop:
925 */
926 do_probe_callback(clp);
927 flush_workqueue(callback_wq);
928}
929
930static void nfsd4_release_cb(struct nfsd4_callback *cb)
931{
932 if (cb->cb_ops->rpc_release)
933 cb->cb_ops->rpc_release(cb);
934}
935
936/* requires cl_lock: */
937static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
938{
939 struct nfsd4_session *s;
940 struct nfsd4_conn *c;
941
942 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
943 list_for_each_entry(c, &s->se_conns, cn_persession) {
944 if (c->cn_flags & NFS4_CDFC4_BACK)
945 return c;
946 }
947 }
948 return NULL;
949}
950
951static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
952{
953 struct nfs4_cb_conn conn;
954 struct nfs4_client *clp = cb->cb_clp;
955 struct nfsd4_session *ses = NULL;
956 struct nfsd4_conn *c;
957 int err;
958
959 /*
960 * This is either an update, or the client dying; in either case,
961 * kill the old client:
962 */
963 if (clp->cl_cb_client) {
964 rpc_shutdown_client(clp->cl_cb_client);
965 clp->cl_cb_client = NULL;
966 }
967 if (clp->cl_cb_conn.cb_xprt) {
968 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
969 clp->cl_cb_conn.cb_xprt = NULL;
970 }
971 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
972 return;
973 spin_lock(&clp->cl_lock);
974 /*
975 * Only serialized callback code is allowed to clear these
976 * flags; main nfsd code can only set them:
977 */
978 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
979 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
980 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
981 c = __nfsd4_find_backchannel(clp);
982 if (c) {
983 svc_xprt_get(c->cn_xprt);
984 conn.cb_xprt = c->cn_xprt;
985 ses = c->cn_session;
986 }
987 spin_unlock(&clp->cl_lock);
988
989 err = setup_callback_client(clp, &conn, ses);
990 if (err) {
991 nfsd4_mark_cb_down(clp, err);
992 return;
993 }
994 /* Yay, the callback channel's back! Restart any callbacks: */
995 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
996 run_nfsd4_cb(cb);
997}
998
999void nfsd4_do_callback_rpc(struct work_struct *w)
1000{
1001 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
1002 struct nfs4_client *clp = cb->cb_clp;
1003 struct rpc_clnt *clnt;
1004
1005 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1006 nfsd4_process_cb_update(cb);
1007
1008 clnt = clp->cl_cb_client;
1009 if (!clnt) {
1010 /* Callback channel broken, or client killed; give up: */
1011 nfsd4_release_cb(cb);
1012 return;
1013 }
1014 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1015 cb->cb_ops, cb);
1016}
1017
1018void nfsd4_cb_recall(struct nfs4_delegation *dp)
1019{
1020 struct nfsd4_callback *cb = &dp->dl_recall;
1021 struct nfs4_client *clp = dp->dl_stid.sc_client;
1022
1023 dp->dl_retries = 1;
1024 cb->cb_op = dp;
1025 cb->cb_clp = clp;
1026 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
1027 cb->cb_msg.rpc_argp = cb;
1028 cb->cb_msg.rpc_resp = cb;
1029 cb->cb_msg.rpc_cred = callback_cred;
1030
1031 cb->cb_ops = &nfsd4_cb_recall_ops;
1032 dp->dl_retries = 1;
1033
1034 INIT_LIST_HEAD(&cb->cb_per_client);
1035 cb->cb_done = true;
1036
1037 run_nfsd4_cb(&dp->dl_recall);
1038}