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[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / fs / nfsd / nfs4callback.c
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 "xdr4cb.h"
42
43 #define NFSDDBG_FACILITY NFSDDBG_PROC
44
45 static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
46
47 #define NFSPROC4_CB_NULL 0
48 #define NFSPROC4_CB_COMPOUND 1
49
50 /* Index of predefined Linux callback client operations */
51
52 struct nfs4_cb_compound_hdr {
53 /* args */
54 u32 ident; /* minorversion 0 only */
55 u32 nops;
56 __be32 *nops_p;
57 u32 minorversion;
58 /* res */
59 int status;
60 };
61
62 /*
63 * Handle decode buffer overflows out-of-line.
64 */
65 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
66 {
67 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
68 "Remaining buffer length is %tu words.\n",
69 func, xdr->end - xdr->p);
70 }
71
72 static __be32 *xdr_encode_empty_array(__be32 *p)
73 {
74 *p++ = xdr_zero;
75 return p;
76 }
77
78 /*
79 * Encode/decode NFSv4 CB basic data types
80 *
81 * Basic NFSv4 callback data types are defined in section 15 of RFC
82 * 3530: "Network File System (NFS) version 4 Protocol" and section
83 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
84 * 1 Protocol"
85 */
86
87 /*
88 * nfs_cb_opnum4
89 *
90 * enum nfs_cb_opnum4 {
91 * OP_CB_GETATTR = 3,
92 * ...
93 * };
94 */
95 enum nfs_cb_opnum4 {
96 OP_CB_GETATTR = 3,
97 OP_CB_RECALL = 4,
98 OP_CB_LAYOUTRECALL = 5,
99 OP_CB_NOTIFY = 6,
100 OP_CB_PUSH_DELEG = 7,
101 OP_CB_RECALL_ANY = 8,
102 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
103 OP_CB_RECALL_SLOT = 10,
104 OP_CB_SEQUENCE = 11,
105 OP_CB_WANTS_CANCELLED = 12,
106 OP_CB_NOTIFY_LOCK = 13,
107 OP_CB_NOTIFY_DEVICEID = 14,
108 OP_CB_ILLEGAL = 10044
109 };
110
111 static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
112 {
113 __be32 *p;
114
115 p = xdr_reserve_space(xdr, 4);
116 *p = cpu_to_be32(op);
117 }
118
119 /*
120 * nfs_fh4
121 *
122 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
123 */
124 static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
125 {
126 u32 length = fh->fh_size;
127 __be32 *p;
128
129 BUG_ON(length > NFS4_FHSIZE);
130 p = xdr_reserve_space(xdr, 4 + length);
131 xdr_encode_opaque(p, &fh->fh_base, length);
132 }
133
134 /*
135 * stateid4
136 *
137 * struct stateid4 {
138 * uint32_t seqid;
139 * opaque other[12];
140 * };
141 */
142 static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
143 {
144 __be32 *p;
145
146 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
147 *p++ = cpu_to_be32(sid->si_generation);
148 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
149 }
150
151 /*
152 * sessionid4
153 *
154 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
155 */
156 static void encode_sessionid4(struct xdr_stream *xdr,
157 const struct nfsd4_session *session)
158 {
159 __be32 *p;
160
161 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
162 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
163 NFS4_MAX_SESSIONID_LEN);
164 }
165
166 /*
167 * nfsstat4
168 */
169 static const struct {
170 int stat;
171 int errno;
172 } nfs_cb_errtbl[] = {
173 { NFS4_OK, 0 },
174 { NFS4ERR_PERM, -EPERM },
175 { NFS4ERR_NOENT, -ENOENT },
176 { NFS4ERR_IO, -EIO },
177 { NFS4ERR_NXIO, -ENXIO },
178 { NFS4ERR_ACCESS, -EACCES },
179 { NFS4ERR_EXIST, -EEXIST },
180 { NFS4ERR_XDEV, -EXDEV },
181 { NFS4ERR_NOTDIR, -ENOTDIR },
182 { NFS4ERR_ISDIR, -EISDIR },
183 { NFS4ERR_INVAL, -EINVAL },
184 { NFS4ERR_FBIG, -EFBIG },
185 { NFS4ERR_NOSPC, -ENOSPC },
186 { NFS4ERR_ROFS, -EROFS },
187 { NFS4ERR_MLINK, -EMLINK },
188 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
189 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
190 { NFS4ERR_DQUOT, -EDQUOT },
191 { NFS4ERR_STALE, -ESTALE },
192 { NFS4ERR_BADHANDLE, -EBADHANDLE },
193 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
194 { NFS4ERR_NOTSUPP, -ENOTSUPP },
195 { NFS4ERR_TOOSMALL, -ETOOSMALL },
196 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
197 { NFS4ERR_BADTYPE, -EBADTYPE },
198 { NFS4ERR_LOCKED, -EAGAIN },
199 { NFS4ERR_RESOURCE, -EREMOTEIO },
200 { NFS4ERR_SYMLINK, -ELOOP },
201 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
202 { NFS4ERR_DEADLOCK, -EDEADLK },
203 { -1, -EIO }
204 };
205
206 /*
207 * If we cannot translate the error, the recovery routines should
208 * handle it.
209 *
210 * Note: remaining NFSv4 error codes have values > 10000, so should
211 * not conflict with native Linux error codes.
212 */
213 static int nfs_cb_stat_to_errno(int status)
214 {
215 int i;
216
217 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
218 if (nfs_cb_errtbl[i].stat == status)
219 return nfs_cb_errtbl[i].errno;
220 }
221
222 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
223 return -status;
224 }
225
226 static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
227 int *status)
228 {
229 __be32 *p;
230 u32 op;
231
232 p = xdr_inline_decode(xdr, 4 + 4);
233 if (unlikely(p == NULL))
234 goto out_overflow;
235 op = be32_to_cpup(p++);
236 if (unlikely(op != expected))
237 goto out_unexpected;
238 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
239 return 0;
240 out_overflow:
241 print_overflow_msg(__func__, xdr);
242 return -EIO;
243 out_unexpected:
244 dprintk("NFSD: Callback server returned operation %d but "
245 "we issued a request for %d\n", op, expected);
246 return -EIO;
247 }
248
249 /*
250 * CB_COMPOUND4args
251 *
252 * struct CB_COMPOUND4args {
253 * utf8str_cs tag;
254 * uint32_t minorversion;
255 * uint32_t callback_ident;
256 * nfs_cb_argop4 argarray<>;
257 * };
258 */
259 static void encode_cb_compound4args(struct xdr_stream *xdr,
260 struct nfs4_cb_compound_hdr *hdr)
261 {
262 __be32 * p;
263
264 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
265 p = xdr_encode_empty_array(p); /* empty tag */
266 *p++ = cpu_to_be32(hdr->minorversion);
267 *p++ = cpu_to_be32(hdr->ident);
268
269 hdr->nops_p = p;
270 *p = cpu_to_be32(hdr->nops); /* argarray element count */
271 }
272
273 /*
274 * Update argarray element count
275 */
276 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
277 {
278 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
279 *hdr->nops_p = cpu_to_be32(hdr->nops);
280 }
281
282 /*
283 * CB_COMPOUND4res
284 *
285 * struct CB_COMPOUND4res {
286 * nfsstat4 status;
287 * utf8str_cs tag;
288 * nfs_cb_resop4 resarray<>;
289 * };
290 */
291 static int decode_cb_compound4res(struct xdr_stream *xdr,
292 struct nfs4_cb_compound_hdr *hdr)
293 {
294 u32 length;
295 __be32 *p;
296
297 p = xdr_inline_decode(xdr, 4 + 4);
298 if (unlikely(p == NULL))
299 goto out_overflow;
300 hdr->status = be32_to_cpup(p++);
301 /* Ignore the tag */
302 length = be32_to_cpup(p++);
303 p = xdr_inline_decode(xdr, length + 4);
304 if (unlikely(p == NULL))
305 goto out_overflow;
306 p += XDR_QUADLEN(length);
307 hdr->nops = be32_to_cpup(p);
308 return 0;
309 out_overflow:
310 print_overflow_msg(__func__, xdr);
311 return -EIO;
312 }
313
314 /*
315 * CB_RECALL4args
316 *
317 * struct CB_RECALL4args {
318 * stateid4 stateid;
319 * bool truncate;
320 * nfs_fh4 fh;
321 * };
322 */
323 static void encode_cb_recall4args(struct xdr_stream *xdr,
324 const struct nfs4_delegation *dp,
325 struct nfs4_cb_compound_hdr *hdr)
326 {
327 __be32 *p;
328
329 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
330 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
331
332 p = xdr_reserve_space(xdr, 4);
333 *p++ = xdr_zero; /* truncate */
334
335 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
336
337 hdr->nops++;
338 }
339
340 /*
341 * CB_SEQUENCE4args
342 *
343 * struct CB_SEQUENCE4args {
344 * sessionid4 csa_sessionid;
345 * sequenceid4 csa_sequenceid;
346 * slotid4 csa_slotid;
347 * slotid4 csa_highest_slotid;
348 * bool csa_cachethis;
349 * referring_call_list4 csa_referring_call_lists<>;
350 * };
351 */
352 static void encode_cb_sequence4args(struct xdr_stream *xdr,
353 const struct nfsd4_callback *cb,
354 struct nfs4_cb_compound_hdr *hdr)
355 {
356 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
357 __be32 *p;
358
359 if (hdr->minorversion == 0)
360 return;
361
362 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
363 encode_sessionid4(xdr, session);
364
365 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
366 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
367 *p++ = xdr_zero; /* csa_slotid */
368 *p++ = xdr_zero; /* csa_highest_slotid */
369 *p++ = xdr_zero; /* csa_cachethis */
370 xdr_encode_empty_array(p); /* csa_referring_call_lists */
371
372 hdr->nops++;
373 }
374
375 /*
376 * CB_SEQUENCE4resok
377 *
378 * struct CB_SEQUENCE4resok {
379 * sessionid4 csr_sessionid;
380 * sequenceid4 csr_sequenceid;
381 * slotid4 csr_slotid;
382 * slotid4 csr_highest_slotid;
383 * slotid4 csr_target_highest_slotid;
384 * };
385 *
386 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
387 * case NFS4_OK:
388 * CB_SEQUENCE4resok csr_resok4;
389 * default:
390 * void;
391 * };
392 *
393 * Our current back channel implmentation supports a single backchannel
394 * with a single slot.
395 */
396 static int decode_cb_sequence4resok(struct xdr_stream *xdr,
397 struct nfsd4_callback *cb)
398 {
399 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
400 int status = -ESERVERFAULT;
401 __be32 *p;
402 u32 dummy;
403
404 /*
405 * If the server returns different values for sessionID, slotID or
406 * sequence number, the server is looney tunes.
407 */
408 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
409 if (unlikely(p == NULL))
410 goto out_overflow;
411
412 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
413 dprintk("NFS: %s Invalid session id\n", __func__);
414 goto out;
415 }
416 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
417
418 dummy = be32_to_cpup(p++);
419 if (dummy != session->se_cb_seq_nr) {
420 dprintk("NFS: %s Invalid sequence number\n", __func__);
421 goto out;
422 }
423
424 dummy = be32_to_cpup(p++);
425 if (dummy != 0) {
426 dprintk("NFS: %s Invalid slotid\n", __func__);
427 goto out;
428 }
429
430 /*
431 * FIXME: process highest slotid and target highest slotid
432 */
433 status = 0;
434 out:
435 cb->cb_seq_status = status;
436 return status;
437 out_overflow:
438 print_overflow_msg(__func__, xdr);
439 status = -EIO;
440 goto out;
441 }
442
443 static int decode_cb_sequence4res(struct xdr_stream *xdr,
444 struct nfsd4_callback *cb)
445 {
446 int status;
447
448 if (cb->cb_clp->cl_minorversion == 0)
449 return 0;
450
451 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
452 if (unlikely(status || cb->cb_seq_status))
453 return status;
454
455 return decode_cb_sequence4resok(xdr, cb);
456 }
457
458 /*
459 * NFSv4.0 and NFSv4.1 XDR encode functions
460 *
461 * NFSv4.0 callback argument types are defined in section 15 of RFC
462 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
463 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
464 * Protocol".
465 */
466
467 /*
468 * NB: Without this zero space reservation, callbacks over krb5p fail
469 */
470 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
471 const void *__unused)
472 {
473 xdr_reserve_space(xdr, 0);
474 }
475
476 /*
477 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
478 */
479 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
480 const void *data)
481 {
482 const struct nfsd4_callback *cb = data;
483 const struct nfs4_delegation *dp = cb_to_delegation(cb);
484 struct nfs4_cb_compound_hdr hdr = {
485 .ident = cb->cb_clp->cl_cb_ident,
486 .minorversion = cb->cb_clp->cl_minorversion,
487 };
488
489 encode_cb_compound4args(xdr, &hdr);
490 encode_cb_sequence4args(xdr, cb, &hdr);
491 encode_cb_recall4args(xdr, dp, &hdr);
492 encode_cb_nops(&hdr);
493 }
494
495
496 /*
497 * NFSv4.0 and NFSv4.1 XDR decode functions
498 *
499 * NFSv4.0 callback result types are defined in section 15 of RFC
500 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
501 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
502 * Protocol".
503 */
504
505 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
506 void *__unused)
507 {
508 return 0;
509 }
510
511 /*
512 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
513 */
514 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
515 struct xdr_stream *xdr,
516 void *data)
517 {
518 struct nfsd4_callback *cb = data;
519 struct nfs4_cb_compound_hdr hdr;
520 int status;
521
522 status = decode_cb_compound4res(xdr, &hdr);
523 if (unlikely(status))
524 return status;
525
526 if (cb != NULL) {
527 status = decode_cb_sequence4res(xdr, cb);
528 if (unlikely(status || cb->cb_seq_status))
529 return status;
530 }
531
532 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
533 }
534
535 #ifdef CONFIG_NFSD_PNFS
536 /*
537 * CB_LAYOUTRECALL4args
538 *
539 * struct layoutrecall_file4 {
540 * nfs_fh4 lor_fh;
541 * offset4 lor_offset;
542 * length4 lor_length;
543 * stateid4 lor_stateid;
544 * };
545 *
546 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
547 * case LAYOUTRECALL4_FILE:
548 * layoutrecall_file4 lor_layout;
549 * case LAYOUTRECALL4_FSID:
550 * fsid4 lor_fsid;
551 * case LAYOUTRECALL4_ALL:
552 * void;
553 * };
554 *
555 * struct CB_LAYOUTRECALL4args {
556 * layouttype4 clora_type;
557 * layoutiomode4 clora_iomode;
558 * bool clora_changed;
559 * layoutrecall4 clora_recall;
560 * };
561 */
562 static void encode_cb_layout4args(struct xdr_stream *xdr,
563 const struct nfs4_layout_stateid *ls,
564 struct nfs4_cb_compound_hdr *hdr)
565 {
566 __be32 *p;
567
568 BUG_ON(hdr->minorversion == 0);
569
570 p = xdr_reserve_space(xdr, 5 * 4);
571 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
572 *p++ = cpu_to_be32(ls->ls_layout_type);
573 *p++ = cpu_to_be32(IOMODE_ANY);
574 *p++ = cpu_to_be32(1);
575 *p = cpu_to_be32(RETURN_FILE);
576
577 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
578
579 p = xdr_reserve_space(xdr, 2 * 8);
580 p = xdr_encode_hyper(p, 0);
581 xdr_encode_hyper(p, NFS4_MAX_UINT64);
582
583 encode_stateid4(xdr, &ls->ls_recall_sid);
584
585 hdr->nops++;
586 }
587
588 static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
589 struct xdr_stream *xdr,
590 const void *data)
591 {
592 const struct nfsd4_callback *cb = data;
593 const struct nfs4_layout_stateid *ls =
594 container_of(cb, struct nfs4_layout_stateid, ls_recall);
595 struct nfs4_cb_compound_hdr hdr = {
596 .ident = 0,
597 .minorversion = cb->cb_clp->cl_minorversion,
598 };
599
600 encode_cb_compound4args(xdr, &hdr);
601 encode_cb_sequence4args(xdr, cb, &hdr);
602 encode_cb_layout4args(xdr, ls, &hdr);
603 encode_cb_nops(&hdr);
604 }
605
606 static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
607 struct xdr_stream *xdr,
608 void *data)
609 {
610 struct nfsd4_callback *cb = data;
611 struct nfs4_cb_compound_hdr hdr;
612 int status;
613
614 status = decode_cb_compound4res(xdr, &hdr);
615 if (unlikely(status))
616 return status;
617
618 if (cb) {
619 status = decode_cb_sequence4res(xdr, cb);
620 if (unlikely(status || cb->cb_seq_status))
621 return status;
622 }
623 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
624 }
625 #endif /* CONFIG_NFSD_PNFS */
626
627 static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
628 {
629 __be32 *p;
630
631 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
632 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
633 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
634 }
635
636 static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
637 struct xdr_stream *xdr,
638 const void *data)
639 {
640 const struct nfsd4_callback *cb = data;
641 const struct nfsd4_blocked_lock *nbl =
642 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
643 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
644 struct nfs4_cb_compound_hdr hdr = {
645 .ident = 0,
646 .minorversion = cb->cb_clp->cl_minorversion,
647 };
648
649 __be32 *p;
650
651 BUG_ON(hdr.minorversion == 0);
652
653 encode_cb_compound4args(xdr, &hdr);
654 encode_cb_sequence4args(xdr, cb, &hdr);
655
656 p = xdr_reserve_space(xdr, 4);
657 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
658 encode_nfs_fh4(xdr, &nbl->nbl_fh);
659 encode_stateowner(xdr, &lo->lo_owner);
660 hdr.nops++;
661
662 encode_cb_nops(&hdr);
663 }
664
665 static int nfs4_xdr_dec_cb_notify_lock(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 if (cb) {
678 status = decode_cb_sequence4res(xdr, cb);
679 if (unlikely(status || cb->cb_seq_status))
680 return status;
681 }
682 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
683 }
684
685 /*
686 * RPC procedure tables
687 */
688 #define PROC(proc, call, argtype, restype) \
689 [NFSPROC4_CLNT_##proc] = { \
690 .p_proc = NFSPROC4_CB_##call, \
691 .p_encode = nfs4_xdr_enc_##argtype, \
692 .p_decode = nfs4_xdr_dec_##restype, \
693 .p_arglen = NFS4_enc_##argtype##_sz, \
694 .p_replen = NFS4_dec_##restype##_sz, \
695 .p_statidx = NFSPROC4_CB_##call, \
696 .p_name = #proc, \
697 }
698
699 static const struct rpc_procinfo nfs4_cb_procedures[] = {
700 PROC(CB_NULL, NULL, cb_null, cb_null),
701 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
702 #ifdef CONFIG_NFSD_PNFS
703 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
704 #endif
705 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
706 };
707
708 static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
709 static const struct rpc_version nfs_cb_version4 = {
710 /*
711 * Note on the callback rpc program version number: despite language in rfc
712 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
713 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
714 * in practice that appears to be what implementations use. The section
715 * 18.36.3 language is expected to be fixed in an erratum.
716 */
717 .number = 1,
718 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
719 .procs = nfs4_cb_procedures,
720 .counts = nfs4_cb_counts,
721 };
722
723 static const struct rpc_version *nfs_cb_version[2] = {
724 [1] = &nfs_cb_version4,
725 };
726
727 static const struct rpc_program cb_program;
728
729 static struct rpc_stat cb_stats = {
730 .program = &cb_program
731 };
732
733 #define NFS4_CALLBACK 0x40000000
734 static const struct rpc_program cb_program = {
735 .name = "nfs4_cb",
736 .number = NFS4_CALLBACK,
737 .nrvers = ARRAY_SIZE(nfs_cb_version),
738 .version = nfs_cb_version,
739 .stats = &cb_stats,
740 .pipe_dir_name = "nfsd4_cb",
741 };
742
743 static int max_cb_time(struct net *net)
744 {
745 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
746 return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
747 }
748
749 static struct rpc_cred *callback_cred;
750
751 int set_callback_cred(void)
752 {
753 if (callback_cred)
754 return 0;
755 callback_cred = rpc_lookup_machine_cred("nfs");
756 if (!callback_cred)
757 return -ENOMEM;
758 return 0;
759 }
760
761 void cleanup_callback_cred(void)
762 {
763 if (callback_cred) {
764 put_rpccred(callback_cred);
765 callback_cred = NULL;
766 }
767 }
768
769 static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
770 {
771 if (clp->cl_minorversion == 0) {
772 return get_rpccred(callback_cred);
773 } else {
774 struct rpc_auth *auth = client->cl_auth;
775 struct auth_cred acred = {};
776
777 acred.uid = ses->se_cb_sec.uid;
778 acred.gid = ses->se_cb_sec.gid;
779 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
780 }
781 }
782
783 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
784 {
785 int maxtime = max_cb_time(clp->net);
786 struct rpc_timeout timeparms = {
787 .to_initval = maxtime,
788 .to_retries = 0,
789 .to_maxval = maxtime,
790 };
791 struct rpc_create_args args = {
792 .net = clp->net,
793 .address = (struct sockaddr *) &conn->cb_addr,
794 .addrsize = conn->cb_addrlen,
795 .saddress = (struct sockaddr *) &conn->cb_saddr,
796 .timeout = &timeparms,
797 .program = &cb_program,
798 .version = 1,
799 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
800 };
801 struct rpc_clnt *client;
802 struct rpc_cred *cred;
803
804 if (clp->cl_minorversion == 0) {
805 if (!clp->cl_cred.cr_principal &&
806 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
807 return -EINVAL;
808 args.client_name = clp->cl_cred.cr_principal;
809 args.prognumber = conn->cb_prog;
810 args.protocol = XPRT_TRANSPORT_TCP;
811 args.authflavor = clp->cl_cred.cr_flavor;
812 clp->cl_cb_ident = conn->cb_ident;
813 } else {
814 if (!conn->cb_xprt)
815 return -EINVAL;
816 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
817 clp->cl_cb_session = ses;
818 args.bc_xprt = conn->cb_xprt;
819 args.prognumber = clp->cl_cb_session->se_cb_prog;
820 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
821 XPRT_TRANSPORT_BC;
822 args.authflavor = ses->se_cb_sec.flavor;
823 }
824 /* Create RPC client */
825 client = rpc_create(&args);
826 if (IS_ERR(client)) {
827 dprintk("NFSD: couldn't create callback client: %ld\n",
828 PTR_ERR(client));
829 return PTR_ERR(client);
830 }
831 cred = get_backchannel_cred(clp, client, ses);
832 if (IS_ERR(cred)) {
833 rpc_shutdown_client(client);
834 return PTR_ERR(cred);
835 }
836 clp->cl_cb_client = client;
837 clp->cl_cb_cred = cred;
838 return 0;
839 }
840
841 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
842 {
843 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
844 (int)clp->cl_name.len, clp->cl_name.data, reason);
845 }
846
847 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
848 {
849 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
850 return;
851 clp->cl_cb_state = NFSD4_CB_DOWN;
852 warn_no_callback_path(clp, reason);
853 }
854
855 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
856 {
857 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
858 return;
859 clp->cl_cb_state = NFSD4_CB_FAULT;
860 warn_no_callback_path(clp, reason);
861 }
862
863 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
864 {
865 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
866
867 if (task->tk_status)
868 nfsd4_mark_cb_down(clp, task->tk_status);
869 else
870 clp->cl_cb_state = NFSD4_CB_UP;
871 }
872
873 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
874 /* XXX: release method to ensure we set the cb channel down if
875 * necessary on early failure? */
876 .rpc_call_done = nfsd4_cb_probe_done,
877 };
878
879 static struct workqueue_struct *callback_wq;
880
881 /*
882 * Poke the callback thread to process any updates to the callback
883 * parameters, and send a null probe.
884 */
885 void nfsd4_probe_callback(struct nfs4_client *clp)
886 {
887 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
888 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
889 nfsd4_run_cb(&clp->cl_cb_null);
890 }
891
892 void nfsd4_probe_callback_sync(struct nfs4_client *clp)
893 {
894 nfsd4_probe_callback(clp);
895 flush_workqueue(callback_wq);
896 }
897
898 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
899 {
900 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
901 spin_lock(&clp->cl_lock);
902 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
903 spin_unlock(&clp->cl_lock);
904 }
905
906 /*
907 * There's currently a single callback channel slot.
908 * If the slot is available, then mark it busy. Otherwise, set the
909 * thread for sleeping on the callback RPC wait queue.
910 */
911 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
912 {
913 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
914 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
915 /* Race breaker */
916 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
917 dprintk("%s slot is busy\n", __func__);
918 return false;
919 }
920 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
921 }
922 return true;
923 }
924
925 /*
926 * TODO: cb_sequence should support referring call lists, cachethis, multiple
927 * slots, and mark callback channel down on communication errors.
928 */
929 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
930 {
931 struct nfsd4_callback *cb = calldata;
932 struct nfs4_client *clp = cb->cb_clp;
933 u32 minorversion = clp->cl_minorversion;
934
935 /*
936 * cb_seq_status is only set in decode_cb_sequence4res,
937 * and so will remain 1 if an rpc level failure occurs.
938 */
939 cb->cb_seq_status = 1;
940 cb->cb_status = 0;
941 if (minorversion) {
942 if (!nfsd41_cb_get_slot(clp, task))
943 return;
944 }
945 rpc_call_start(task);
946 }
947
948 static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
949 {
950 struct nfs4_client *clp = cb->cb_clp;
951 struct nfsd4_session *session = clp->cl_cb_session;
952 bool ret = true;
953
954 if (!clp->cl_minorversion) {
955 /*
956 * If the backchannel connection was shut down while this
957 * task was queued, we need to resubmit it after setting up
958 * a new backchannel connection.
959 *
960 * Note that if we lost our callback connection permanently
961 * the submission code will error out, so we don't need to
962 * handle that case here.
963 */
964 if (task->tk_flags & RPC_TASK_KILLED)
965 goto need_restart;
966
967 return true;
968 }
969
970 switch (cb->cb_seq_status) {
971 case 0:
972 /*
973 * No need for lock, access serialized in nfsd4_cb_prepare
974 *
975 * RFC5661 20.9.3
976 * If CB_SEQUENCE returns an error, then the state of the slot
977 * (sequence ID, cached reply) MUST NOT change.
978 */
979 ++session->se_cb_seq_nr;
980 break;
981 case -ESERVERFAULT:
982 ++session->se_cb_seq_nr;
983 case 1:
984 case -NFS4ERR_BADSESSION:
985 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
986 ret = false;
987 break;
988 case -NFS4ERR_DELAY:
989 if (!rpc_restart_call(task))
990 goto out;
991
992 rpc_delay(task, 2 * HZ);
993 return false;
994 case -NFS4ERR_BADSLOT:
995 goto retry_nowait;
996 case -NFS4ERR_SEQ_MISORDERED:
997 if (session->se_cb_seq_nr != 1) {
998 session->se_cb_seq_nr = 1;
999 goto retry_nowait;
1000 }
1001 break;
1002 default:
1003 dprintk("%s: unprocessed error %d\n", __func__,
1004 cb->cb_seq_status);
1005 }
1006
1007 clear_bit(0, &clp->cl_cb_slot_busy);
1008 rpc_wake_up_next(&clp->cl_cb_waitq);
1009 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1010 clp->cl_cb_session->se_cb_seq_nr);
1011
1012 if (task->tk_flags & RPC_TASK_KILLED)
1013 goto need_restart;
1014 out:
1015 return ret;
1016 retry_nowait:
1017 if (rpc_restart_call_prepare(task))
1018 ret = false;
1019 goto out;
1020 need_restart:
1021 task->tk_status = 0;
1022 cb->cb_need_restart = true;
1023 return false;
1024 }
1025
1026 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1027 {
1028 struct nfsd4_callback *cb = calldata;
1029 struct nfs4_client *clp = cb->cb_clp;
1030
1031 dprintk("%s: minorversion=%d\n", __func__,
1032 clp->cl_minorversion);
1033
1034 if (!nfsd4_cb_sequence_done(task, cb))
1035 return;
1036
1037 if (cb->cb_status) {
1038 WARN_ON_ONCE(task->tk_status);
1039 task->tk_status = cb->cb_status;
1040 }
1041
1042 switch (cb->cb_ops->done(cb, task)) {
1043 case 0:
1044 task->tk_status = 0;
1045 rpc_restart_call_prepare(task);
1046 return;
1047 case 1:
1048 break;
1049 case -1:
1050 /* Network partition? */
1051 nfsd4_mark_cb_down(clp, task->tk_status);
1052 break;
1053 default:
1054 BUG();
1055 }
1056 }
1057
1058 static void nfsd4_cb_release(void *calldata)
1059 {
1060 struct nfsd4_callback *cb = calldata;
1061
1062 if (cb->cb_need_restart)
1063 nfsd4_run_cb(cb);
1064 else
1065 cb->cb_ops->release(cb);
1066
1067 }
1068
1069 static const struct rpc_call_ops nfsd4_cb_ops = {
1070 .rpc_call_prepare = nfsd4_cb_prepare,
1071 .rpc_call_done = nfsd4_cb_done,
1072 .rpc_release = nfsd4_cb_release,
1073 };
1074
1075 int nfsd4_create_callback_queue(void)
1076 {
1077 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1078 if (!callback_wq)
1079 return -ENOMEM;
1080 return 0;
1081 }
1082
1083 void nfsd4_destroy_callback_queue(void)
1084 {
1085 destroy_workqueue(callback_wq);
1086 }
1087
1088 /* must be called under the state lock */
1089 void nfsd4_shutdown_callback(struct nfs4_client *clp)
1090 {
1091 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1092 /*
1093 * Note this won't actually result in a null callback;
1094 * instead, nfsd4_run_cb_null() will detect the killed
1095 * client, destroy the rpc client, and stop:
1096 */
1097 nfsd4_run_cb(&clp->cl_cb_null);
1098 flush_workqueue(callback_wq);
1099 }
1100
1101 /* requires cl_lock: */
1102 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1103 {
1104 struct nfsd4_session *s;
1105 struct nfsd4_conn *c;
1106
1107 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1108 list_for_each_entry(c, &s->se_conns, cn_persession) {
1109 if (c->cn_flags & NFS4_CDFC4_BACK)
1110 return c;
1111 }
1112 }
1113 return NULL;
1114 }
1115
1116 static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1117 {
1118 struct nfs4_cb_conn conn;
1119 struct nfs4_client *clp = cb->cb_clp;
1120 struct nfsd4_session *ses = NULL;
1121 struct nfsd4_conn *c;
1122 int err;
1123
1124 /*
1125 * This is either an update, or the client dying; in either case,
1126 * kill the old client:
1127 */
1128 if (clp->cl_cb_client) {
1129 rpc_shutdown_client(clp->cl_cb_client);
1130 clp->cl_cb_client = NULL;
1131 put_rpccred(clp->cl_cb_cred);
1132 clp->cl_cb_cred = NULL;
1133 }
1134 if (clp->cl_cb_conn.cb_xprt) {
1135 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1136 clp->cl_cb_conn.cb_xprt = NULL;
1137 }
1138 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1139 return;
1140 spin_lock(&clp->cl_lock);
1141 /*
1142 * Only serialized callback code is allowed to clear these
1143 * flags; main nfsd code can only set them:
1144 */
1145 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1146 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1147 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1148 c = __nfsd4_find_backchannel(clp);
1149 if (c) {
1150 svc_xprt_get(c->cn_xprt);
1151 conn.cb_xprt = c->cn_xprt;
1152 ses = c->cn_session;
1153 }
1154 spin_unlock(&clp->cl_lock);
1155
1156 err = setup_callback_client(clp, &conn, ses);
1157 if (err) {
1158 nfsd4_mark_cb_down(clp, err);
1159 return;
1160 }
1161 }
1162
1163 static void
1164 nfsd4_run_cb_work(struct work_struct *work)
1165 {
1166 struct nfsd4_callback *cb =
1167 container_of(work, struct nfsd4_callback, cb_work);
1168 struct nfs4_client *clp = cb->cb_clp;
1169 struct rpc_clnt *clnt;
1170
1171 if (cb->cb_need_restart) {
1172 cb->cb_need_restart = false;
1173 } else {
1174 if (cb->cb_ops && cb->cb_ops->prepare)
1175 cb->cb_ops->prepare(cb);
1176 }
1177
1178 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1179 nfsd4_process_cb_update(cb);
1180
1181 clnt = clp->cl_cb_client;
1182 if (!clnt) {
1183 /* Callback channel broken, or client killed; give up: */
1184 if (cb->cb_ops && cb->cb_ops->release)
1185 cb->cb_ops->release(cb);
1186 return;
1187 }
1188
1189 /*
1190 * Don't send probe messages for 4.1 or later.
1191 */
1192 if (!cb->cb_ops && clp->cl_minorversion) {
1193 clp->cl_cb_state = NFSD4_CB_UP;
1194 return;
1195 }
1196
1197 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1198 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1199 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1200 }
1201
1202 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1203 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1204 {
1205 cb->cb_clp = clp;
1206 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1207 cb->cb_msg.rpc_argp = cb;
1208 cb->cb_msg.rpc_resp = cb;
1209 cb->cb_ops = ops;
1210 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1211 cb->cb_seq_status = 1;
1212 cb->cb_status = 0;
1213 cb->cb_need_restart = false;
1214 }
1215
1216 void nfsd4_run_cb(struct nfsd4_callback *cb)
1217 {
1218 queue_work(callback_wq, &cb->cb_work);
1219 }