Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...
[deliverable/linux.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 enum nfsstat4 *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 = 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 hdr->nops = be32_to_cpup(p);
307 return 0;
308 out_overflow:
309 print_overflow_msg(__func__, xdr);
310 return -EIO;
311 }
312
313 /*
314 * CB_RECALL4args
315 *
316 * struct CB_RECALL4args {
317 * stateid4 stateid;
318 * bool truncate;
319 * nfs_fh4 fh;
320 * };
321 */
322 static void encode_cb_recall4args(struct xdr_stream *xdr,
323 const struct nfs4_delegation *dp,
324 struct nfs4_cb_compound_hdr *hdr)
325 {
326 __be32 *p;
327
328 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
329 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
330
331 p = xdr_reserve_space(xdr, 4);
332 *p++ = xdr_zero; /* truncate */
333
334 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
335
336 hdr->nops++;
337 }
338
339 /*
340 * CB_SEQUENCE4args
341 *
342 * struct CB_SEQUENCE4args {
343 * sessionid4 csa_sessionid;
344 * sequenceid4 csa_sequenceid;
345 * slotid4 csa_slotid;
346 * slotid4 csa_highest_slotid;
347 * bool csa_cachethis;
348 * referring_call_list4 csa_referring_call_lists<>;
349 * };
350 */
351 static void encode_cb_sequence4args(struct xdr_stream *xdr,
352 const struct nfsd4_callback *cb,
353 struct nfs4_cb_compound_hdr *hdr)
354 {
355 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
356 __be32 *p;
357
358 if (hdr->minorversion == 0)
359 return;
360
361 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
362 encode_sessionid4(xdr, session);
363
364 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
365 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
366 *p++ = xdr_zero; /* csa_slotid */
367 *p++ = xdr_zero; /* csa_highest_slotid */
368 *p++ = xdr_zero; /* csa_cachethis */
369 xdr_encode_empty_array(p); /* csa_referring_call_lists */
370
371 hdr->nops++;
372 }
373
374 /*
375 * CB_SEQUENCE4resok
376 *
377 * struct CB_SEQUENCE4resok {
378 * sessionid4 csr_sessionid;
379 * sequenceid4 csr_sequenceid;
380 * slotid4 csr_slotid;
381 * slotid4 csr_highest_slotid;
382 * slotid4 csr_target_highest_slotid;
383 * };
384 *
385 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
386 * case NFS4_OK:
387 * CB_SEQUENCE4resok csr_resok4;
388 * default:
389 * void;
390 * };
391 *
392 * Our current back channel implmentation supports a single backchannel
393 * with a single slot.
394 */
395 static int decode_cb_sequence4resok(struct xdr_stream *xdr,
396 struct nfsd4_callback *cb)
397 {
398 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
399 struct nfs4_sessionid id;
400 int status;
401 __be32 *p;
402 u32 dummy;
403
404 status = -ESERVERFAULT;
405
406 /*
407 * If the server returns different values for sessionID, slotID or
408 * sequence number, the server is looney tunes.
409 */
410 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
411 if (unlikely(p == NULL))
412 goto out_overflow;
413 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
414 if (memcmp(id.data, session->se_sessionid.data,
415 NFS4_MAX_SESSIONID_LEN) != 0) {
416 dprintk("NFS: %s Invalid session id\n", __func__);
417 goto out;
418 }
419 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
420
421 dummy = be32_to_cpup(p++);
422 if (dummy != session->se_cb_seq_nr) {
423 dprintk("NFS: %s Invalid sequence number\n", __func__);
424 goto out;
425 }
426
427 dummy = be32_to_cpup(p++);
428 if (dummy != 0) {
429 dprintk("NFS: %s Invalid slotid\n", __func__);
430 goto out;
431 }
432
433 /*
434 * FIXME: process highest slotid and target highest slotid
435 */
436 status = 0;
437 out:
438 if (status)
439 nfsd4_mark_cb_fault(cb->cb_clp, status);
440 return status;
441 out_overflow:
442 print_overflow_msg(__func__, xdr);
443 return -EIO;
444 }
445
446 static int decode_cb_sequence4res(struct xdr_stream *xdr,
447 struct nfsd4_callback *cb)
448 {
449 enum nfsstat4 nfserr;
450 int status;
451
452 if (cb->cb_minorversion == 0)
453 return 0;
454
455 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
456 if (unlikely(status))
457 goto out;
458 if (unlikely(nfserr != NFS4_OK))
459 goto out_default;
460 status = decode_cb_sequence4resok(xdr, cb);
461 out:
462 return status;
463 out_default:
464 return nfs_cb_stat_to_errno(nfserr);
465 }
466
467 /*
468 * NFSv4.0 and NFSv4.1 XDR encode functions
469 *
470 * NFSv4.0 callback argument types are defined in section 15 of RFC
471 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
472 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
473 * Protocol".
474 */
475
476 /*
477 * NB: Without this zero space reservation, callbacks over krb5p fail
478 */
479 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
480 void *__unused)
481 {
482 xdr_reserve_space(xdr, 0);
483 }
484
485 /*
486 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
487 */
488 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
489 const struct nfsd4_callback *cb)
490 {
491 const struct nfs4_delegation *dp = cb_to_delegation(cb);
492 struct nfs4_cb_compound_hdr hdr = {
493 .ident = cb->cb_clp->cl_cb_ident,
494 .minorversion = cb->cb_minorversion,
495 };
496
497 encode_cb_compound4args(xdr, &hdr);
498 encode_cb_sequence4args(xdr, cb, &hdr);
499 encode_cb_recall4args(xdr, dp, &hdr);
500 encode_cb_nops(&hdr);
501 }
502
503
504 /*
505 * NFSv4.0 and NFSv4.1 XDR decode functions
506 *
507 * NFSv4.0 callback result types are defined in section 15 of RFC
508 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
509 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
510 * Protocol".
511 */
512
513 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
514 void *__unused)
515 {
516 return 0;
517 }
518
519 /*
520 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
521 */
522 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
523 struct xdr_stream *xdr,
524 struct nfsd4_callback *cb)
525 {
526 struct nfs4_cb_compound_hdr hdr;
527 enum nfsstat4 nfserr;
528 int status;
529
530 status = decode_cb_compound4res(xdr, &hdr);
531 if (unlikely(status))
532 goto out;
533
534 if (cb != NULL) {
535 status = decode_cb_sequence4res(xdr, cb);
536 if (unlikely(status))
537 goto out;
538 }
539
540 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
541 if (unlikely(status))
542 goto out;
543 if (unlikely(nfserr != NFS4_OK))
544 status = nfs_cb_stat_to_errno(nfserr);
545 out:
546 return status;
547 }
548
549 #ifdef CONFIG_NFSD_PNFS
550 /*
551 * CB_LAYOUTRECALL4args
552 *
553 * struct layoutrecall_file4 {
554 * nfs_fh4 lor_fh;
555 * offset4 lor_offset;
556 * length4 lor_length;
557 * stateid4 lor_stateid;
558 * };
559 *
560 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
561 * case LAYOUTRECALL4_FILE:
562 * layoutrecall_file4 lor_layout;
563 * case LAYOUTRECALL4_FSID:
564 * fsid4 lor_fsid;
565 * case LAYOUTRECALL4_ALL:
566 * void;
567 * };
568 *
569 * struct CB_LAYOUTRECALL4args {
570 * layouttype4 clora_type;
571 * layoutiomode4 clora_iomode;
572 * bool clora_changed;
573 * layoutrecall4 clora_recall;
574 * };
575 */
576 static void encode_cb_layout4args(struct xdr_stream *xdr,
577 const struct nfs4_layout_stateid *ls,
578 struct nfs4_cb_compound_hdr *hdr)
579 {
580 __be32 *p;
581
582 BUG_ON(hdr->minorversion == 0);
583
584 p = xdr_reserve_space(xdr, 5 * 4);
585 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
586 *p++ = cpu_to_be32(ls->ls_layout_type);
587 *p++ = cpu_to_be32(IOMODE_ANY);
588 *p++ = cpu_to_be32(1);
589 *p = cpu_to_be32(RETURN_FILE);
590
591 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
592
593 p = xdr_reserve_space(xdr, 2 * 8);
594 p = xdr_encode_hyper(p, 0);
595 xdr_encode_hyper(p, NFS4_MAX_UINT64);
596
597 encode_stateid4(xdr, &ls->ls_recall_sid);
598
599 hdr->nops++;
600 }
601
602 static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
603 struct xdr_stream *xdr,
604 const struct nfsd4_callback *cb)
605 {
606 const struct nfs4_layout_stateid *ls =
607 container_of(cb, struct nfs4_layout_stateid, ls_recall);
608 struct nfs4_cb_compound_hdr hdr = {
609 .ident = 0,
610 .minorversion = cb->cb_minorversion,
611 };
612
613 encode_cb_compound4args(xdr, &hdr);
614 encode_cb_sequence4args(xdr, cb, &hdr);
615 encode_cb_layout4args(xdr, ls, &hdr);
616 encode_cb_nops(&hdr);
617 }
618
619 static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
620 struct xdr_stream *xdr,
621 struct nfsd4_callback *cb)
622 {
623 struct nfs4_cb_compound_hdr hdr;
624 enum nfsstat4 nfserr;
625 int status;
626
627 status = decode_cb_compound4res(xdr, &hdr);
628 if (unlikely(status))
629 goto out;
630 if (cb) {
631 status = decode_cb_sequence4res(xdr, cb);
632 if (unlikely(status))
633 goto out;
634 }
635 status = decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &nfserr);
636 if (unlikely(status))
637 goto out;
638 if (unlikely(nfserr != NFS4_OK))
639 status = nfs_cb_stat_to_errno(nfserr);
640 out:
641 return status;
642 }
643 #endif /* CONFIG_NFSD_PNFS */
644
645 /*
646 * RPC procedure tables
647 */
648 #define PROC(proc, call, argtype, restype) \
649 [NFSPROC4_CLNT_##proc] = { \
650 .p_proc = NFSPROC4_CB_##call, \
651 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
652 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
653 .p_arglen = NFS4_enc_##argtype##_sz, \
654 .p_replen = NFS4_dec_##restype##_sz, \
655 .p_statidx = NFSPROC4_CB_##call, \
656 .p_name = #proc, \
657 }
658
659 static struct rpc_procinfo nfs4_cb_procedures[] = {
660 PROC(CB_NULL, NULL, cb_null, cb_null),
661 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
662 #ifdef CONFIG_NFSD_PNFS
663 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
664 #endif
665 };
666
667 static struct rpc_version nfs_cb_version4 = {
668 /*
669 * Note on the callback rpc program version number: despite language in rfc
670 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
671 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
672 * in practice that appears to be what implementations use. The section
673 * 18.36.3 language is expected to be fixed in an erratum.
674 */
675 .number = 1,
676 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
677 .procs = nfs4_cb_procedures
678 };
679
680 static const struct rpc_version *nfs_cb_version[] = {
681 &nfs_cb_version4,
682 };
683
684 static const struct rpc_program cb_program;
685
686 static struct rpc_stat cb_stats = {
687 .program = &cb_program
688 };
689
690 #define NFS4_CALLBACK 0x40000000
691 static const struct rpc_program cb_program = {
692 .name = "nfs4_cb",
693 .number = NFS4_CALLBACK,
694 .nrvers = ARRAY_SIZE(nfs_cb_version),
695 .version = nfs_cb_version,
696 .stats = &cb_stats,
697 .pipe_dir_name = "nfsd4_cb",
698 };
699
700 static int max_cb_time(struct net *net)
701 {
702 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
703 return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
704 }
705
706 static struct rpc_cred *callback_cred;
707
708 int set_callback_cred(void)
709 {
710 if (callback_cred)
711 return 0;
712 callback_cred = rpc_lookup_machine_cred("nfs");
713 if (!callback_cred)
714 return -ENOMEM;
715 return 0;
716 }
717
718 static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
719 {
720 if (clp->cl_minorversion == 0) {
721 return get_rpccred(callback_cred);
722 } else {
723 struct rpc_auth *auth = client->cl_auth;
724 struct auth_cred acred = {};
725
726 acred.uid = ses->se_cb_sec.uid;
727 acred.gid = ses->se_cb_sec.gid;
728 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
729 }
730 }
731
732 static struct rpc_clnt *create_backchannel_client(struct rpc_create_args *args)
733 {
734 struct rpc_xprt *xprt;
735
736 if (args->protocol != XPRT_TRANSPORT_BC_TCP)
737 return rpc_create(args);
738
739 xprt = args->bc_xprt->xpt_bc_xprt;
740 if (xprt) {
741 xprt_get(xprt);
742 return rpc_create_xprt(args, xprt);
743 }
744
745 return rpc_create(args);
746 }
747
748 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
749 {
750 int maxtime = max_cb_time(clp->net);
751 struct rpc_timeout timeparms = {
752 .to_initval = maxtime,
753 .to_retries = 0,
754 .to_maxval = maxtime,
755 };
756 struct rpc_create_args args = {
757 .net = clp->net,
758 .address = (struct sockaddr *) &conn->cb_addr,
759 .addrsize = conn->cb_addrlen,
760 .saddress = (struct sockaddr *) &conn->cb_saddr,
761 .timeout = &timeparms,
762 .program = &cb_program,
763 .version = 0,
764 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
765 };
766 struct rpc_clnt *client;
767 struct rpc_cred *cred;
768
769 if (clp->cl_minorversion == 0) {
770 if (!clp->cl_cred.cr_principal &&
771 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
772 return -EINVAL;
773 args.client_name = clp->cl_cred.cr_principal;
774 args.prognumber = conn->cb_prog;
775 args.protocol = XPRT_TRANSPORT_TCP;
776 args.authflavor = clp->cl_cred.cr_flavor;
777 clp->cl_cb_ident = conn->cb_ident;
778 } else {
779 if (!conn->cb_xprt)
780 return -EINVAL;
781 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
782 clp->cl_cb_session = ses;
783 args.bc_xprt = conn->cb_xprt;
784 args.prognumber = clp->cl_cb_session->se_cb_prog;
785 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
786 XPRT_TRANSPORT_BC;
787 args.authflavor = ses->se_cb_sec.flavor;
788 }
789 /* Create RPC client */
790 client = create_backchannel_client(&args);
791 if (IS_ERR(client)) {
792 dprintk("NFSD: couldn't create callback client: %ld\n",
793 PTR_ERR(client));
794 return PTR_ERR(client);
795 }
796 cred = get_backchannel_cred(clp, client, ses);
797 if (IS_ERR(cred)) {
798 rpc_shutdown_client(client);
799 return PTR_ERR(cred);
800 }
801 clp->cl_cb_client = client;
802 clp->cl_cb_cred = cred;
803 return 0;
804 }
805
806 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
807 {
808 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
809 (int)clp->cl_name.len, clp->cl_name.data, reason);
810 }
811
812 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
813 {
814 clp->cl_cb_state = NFSD4_CB_DOWN;
815 warn_no_callback_path(clp, reason);
816 }
817
818 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
819 {
820 clp->cl_cb_state = NFSD4_CB_FAULT;
821 warn_no_callback_path(clp, reason);
822 }
823
824 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
825 {
826 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
827
828 if (task->tk_status)
829 nfsd4_mark_cb_down(clp, task->tk_status);
830 else
831 clp->cl_cb_state = NFSD4_CB_UP;
832 }
833
834 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
835 /* XXX: release method to ensure we set the cb channel down if
836 * necessary on early failure? */
837 .rpc_call_done = nfsd4_cb_probe_done,
838 };
839
840 static struct workqueue_struct *callback_wq;
841
842 /*
843 * Poke the callback thread to process any updates to the callback
844 * parameters, and send a null probe.
845 */
846 void nfsd4_probe_callback(struct nfs4_client *clp)
847 {
848 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
849 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
850 nfsd4_run_cb(&clp->cl_cb_null);
851 }
852
853 void nfsd4_probe_callback_sync(struct nfs4_client *clp)
854 {
855 nfsd4_probe_callback(clp);
856 flush_workqueue(callback_wq);
857 }
858
859 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
860 {
861 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
862 spin_lock(&clp->cl_lock);
863 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
864 spin_unlock(&clp->cl_lock);
865 }
866
867 /*
868 * There's currently a single callback channel slot.
869 * If the slot is available, then mark it busy. Otherwise, set the
870 * thread for sleeping on the callback RPC wait queue.
871 */
872 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
873 {
874 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
875 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
876 /* Race breaker */
877 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
878 dprintk("%s slot is busy\n", __func__);
879 return false;
880 }
881 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
882 }
883 return true;
884 }
885
886 /*
887 * TODO: cb_sequence should support referring call lists, cachethis, multiple
888 * slots, and mark callback channel down on communication errors.
889 */
890 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
891 {
892 struct nfsd4_callback *cb = calldata;
893 struct nfs4_client *clp = cb->cb_clp;
894 u32 minorversion = clp->cl_minorversion;
895
896 cb->cb_minorversion = minorversion;
897 if (minorversion) {
898 if (!nfsd41_cb_get_slot(clp, task))
899 return;
900 }
901 spin_lock(&clp->cl_lock);
902 if (list_empty(&cb->cb_per_client)) {
903 /* This is the first call, not a restart */
904 cb->cb_done = false;
905 list_add(&cb->cb_per_client, &clp->cl_callbacks);
906 }
907 spin_unlock(&clp->cl_lock);
908 rpc_call_start(task);
909 }
910
911 static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
912 {
913 struct nfsd4_callback *cb = calldata;
914 struct nfs4_client *clp = cb->cb_clp;
915
916 dprintk("%s: minorversion=%d\n", __func__,
917 clp->cl_minorversion);
918
919 if (clp->cl_minorversion) {
920 /* No need for lock, access serialized in nfsd4_cb_prepare */
921 ++clp->cl_cb_session->se_cb_seq_nr;
922 clear_bit(0, &clp->cl_cb_slot_busy);
923 rpc_wake_up_next(&clp->cl_cb_waitq);
924 dprintk("%s: freed slot, new seqid=%d\n", __func__,
925 clp->cl_cb_session->se_cb_seq_nr);
926 }
927
928 if (clp->cl_cb_client != task->tk_client) {
929 /* We're shutting down or changing cl_cb_client; leave
930 * it to nfsd4_process_cb_update to restart the call if
931 * necessary. */
932 return;
933 }
934
935 if (cb->cb_done)
936 return;
937
938 switch (cb->cb_ops->done(cb, task)) {
939 case 0:
940 task->tk_status = 0;
941 rpc_restart_call_prepare(task);
942 return;
943 case 1:
944 break;
945 case -1:
946 /* Network partition? */
947 nfsd4_mark_cb_down(clp, task->tk_status);
948 break;
949 default:
950 BUG();
951 }
952 cb->cb_done = true;
953 }
954
955 static void nfsd4_cb_release(void *calldata)
956 {
957 struct nfsd4_callback *cb = calldata;
958 struct nfs4_client *clp = cb->cb_clp;
959
960 if (cb->cb_done) {
961 spin_lock(&clp->cl_lock);
962 list_del(&cb->cb_per_client);
963 spin_unlock(&clp->cl_lock);
964
965 cb->cb_ops->release(cb);
966 }
967 }
968
969 static const struct rpc_call_ops nfsd4_cb_ops = {
970 .rpc_call_prepare = nfsd4_cb_prepare,
971 .rpc_call_done = nfsd4_cb_done,
972 .rpc_release = nfsd4_cb_release,
973 };
974
975 int nfsd4_create_callback_queue(void)
976 {
977 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
978 if (!callback_wq)
979 return -ENOMEM;
980 return 0;
981 }
982
983 void nfsd4_destroy_callback_queue(void)
984 {
985 destroy_workqueue(callback_wq);
986 }
987
988 /* must be called under the state lock */
989 void nfsd4_shutdown_callback(struct nfs4_client *clp)
990 {
991 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
992 /*
993 * Note this won't actually result in a null callback;
994 * instead, nfsd4_run_cb_null() will detect the killed
995 * client, destroy the rpc client, and stop:
996 */
997 nfsd4_run_cb(&clp->cl_cb_null);
998 flush_workqueue(callback_wq);
999 }
1000
1001 /* requires cl_lock: */
1002 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1003 {
1004 struct nfsd4_session *s;
1005 struct nfsd4_conn *c;
1006
1007 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1008 list_for_each_entry(c, &s->se_conns, cn_persession) {
1009 if (c->cn_flags & NFS4_CDFC4_BACK)
1010 return c;
1011 }
1012 }
1013 return NULL;
1014 }
1015
1016 static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1017 {
1018 struct nfs4_cb_conn conn;
1019 struct nfs4_client *clp = cb->cb_clp;
1020 struct nfsd4_session *ses = NULL;
1021 struct nfsd4_conn *c;
1022 int err;
1023
1024 /*
1025 * This is either an update, or the client dying; in either case,
1026 * kill the old client:
1027 */
1028 if (clp->cl_cb_client) {
1029 rpc_shutdown_client(clp->cl_cb_client);
1030 clp->cl_cb_client = NULL;
1031 put_rpccred(clp->cl_cb_cred);
1032 clp->cl_cb_cred = NULL;
1033 }
1034 if (clp->cl_cb_conn.cb_xprt) {
1035 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1036 clp->cl_cb_conn.cb_xprt = NULL;
1037 }
1038 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1039 return;
1040 spin_lock(&clp->cl_lock);
1041 /*
1042 * Only serialized callback code is allowed to clear these
1043 * flags; main nfsd code can only set them:
1044 */
1045 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1046 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1047 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1048 c = __nfsd4_find_backchannel(clp);
1049 if (c) {
1050 svc_xprt_get(c->cn_xprt);
1051 conn.cb_xprt = c->cn_xprt;
1052 ses = c->cn_session;
1053 }
1054 spin_unlock(&clp->cl_lock);
1055
1056 err = setup_callback_client(clp, &conn, ses);
1057 if (err) {
1058 nfsd4_mark_cb_down(clp, err);
1059 return;
1060 }
1061 /* Yay, the callback channel's back! Restart any callbacks: */
1062 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
1063 queue_work(callback_wq, &cb->cb_work);
1064 }
1065
1066 static void
1067 nfsd4_run_cb_work(struct work_struct *work)
1068 {
1069 struct nfsd4_callback *cb =
1070 container_of(work, struct nfsd4_callback, cb_work);
1071 struct nfs4_client *clp = cb->cb_clp;
1072 struct rpc_clnt *clnt;
1073
1074 if (cb->cb_ops && cb->cb_ops->prepare)
1075 cb->cb_ops->prepare(cb);
1076
1077 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1078 nfsd4_process_cb_update(cb);
1079
1080 clnt = clp->cl_cb_client;
1081 if (!clnt) {
1082 /* Callback channel broken, or client killed; give up: */
1083 if (cb->cb_ops && cb->cb_ops->release)
1084 cb->cb_ops->release(cb);
1085 return;
1086 }
1087 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1088 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1089 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1090 }
1091
1092 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1093 struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1094 {
1095 cb->cb_clp = clp;
1096 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1097 cb->cb_msg.rpc_argp = cb;
1098 cb->cb_msg.rpc_resp = cb;
1099 cb->cb_ops = ops;
1100 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1101 INIT_LIST_HEAD(&cb->cb_per_client);
1102 cb->cb_done = true;
1103 }
1104
1105 void nfsd4_run_cb(struct nfsd4_callback *cb)
1106 {
1107 queue_work(callback_wq, &cb->cb_work);
1108 }
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