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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 "xdr4cb.h"
42
43#define NFSDDBG_FACILITY NFSDDBG_PROC
44
45static 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
52enum {
53 NFSPROC4_CLNT_CB_NULL = 0,
54 NFSPROC4_CLNT_CB_RECALL,
55 NFSPROC4_CLNT_CB_SEQUENCE,
56};
57
58struct nfs4_cb_compound_hdr {
59 /* args */
60 u32 ident; /* minorversion 0 only */
61 u32 nops;
62 __be32 *nops_p;
63 u32 minorversion;
64 /* res */
65 int status;
66};
67
68/*
69 * Handle decode buffer overflows out-of-line.
70 */
71static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
72{
73 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
74 "Remaining buffer length is %tu words.\n",
75 func, xdr->end - xdr->p);
76}
77
78static __be32 *xdr_encode_empty_array(__be32 *p)
79{
80 *p++ = xdr_zero;
81 return p;
82}
83
84/*
85 * Encode/decode NFSv4 CB basic data types
86 *
87 * Basic NFSv4 callback data types are defined in section 15 of RFC
88 * 3530: "Network File System (NFS) version 4 Protocol" and section
89 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
90 * 1 Protocol"
91 */
92
93/*
94 * nfs_cb_opnum4
95 *
96 * enum nfs_cb_opnum4 {
97 * OP_CB_GETATTR = 3,
98 * ...
99 * };
100 */
101enum nfs_cb_opnum4 {
102 OP_CB_GETATTR = 3,
103 OP_CB_RECALL = 4,
104 OP_CB_LAYOUTRECALL = 5,
105 OP_CB_NOTIFY = 6,
106 OP_CB_PUSH_DELEG = 7,
107 OP_CB_RECALL_ANY = 8,
108 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
109 OP_CB_RECALL_SLOT = 10,
110 OP_CB_SEQUENCE = 11,
111 OP_CB_WANTS_CANCELLED = 12,
112 OP_CB_NOTIFY_LOCK = 13,
113 OP_CB_NOTIFY_DEVICEID = 14,
114 OP_CB_ILLEGAL = 10044
115};
116
117static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
118{
119 __be32 *p;
120
121 p = xdr_reserve_space(xdr, 4);
122 *p = cpu_to_be32(op);
123}
124
125/*
126 * nfs_fh4
127 *
128 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
129 */
130static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
131{
132 u32 length = fh->fh_size;
133 __be32 *p;
134
135 BUG_ON(length > NFS4_FHSIZE);
136 p = xdr_reserve_space(xdr, 4 + length);
137 xdr_encode_opaque(p, &fh->fh_base, length);
138}
139
140/*
141 * stateid4
142 *
143 * struct stateid4 {
144 * uint32_t seqid;
145 * opaque other[12];
146 * };
147 */
148static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
149{
150 __be32 *p;
151
152 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
153 *p++ = cpu_to_be32(sid->si_generation);
154 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
155}
156
157/*
158 * sessionid4
159 *
160 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
161 */
162static void encode_sessionid4(struct xdr_stream *xdr,
163 const struct nfsd4_session *session)
164{
165 __be32 *p;
166
167 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
168 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
169 NFS4_MAX_SESSIONID_LEN);
170}
171
172/*
173 * nfsstat4
174 */
175static const struct {
176 int stat;
177 int errno;
178} nfs_cb_errtbl[] = {
179 { NFS4_OK, 0 },
180 { NFS4ERR_PERM, -EPERM },
181 { NFS4ERR_NOENT, -ENOENT },
182 { NFS4ERR_IO, -EIO },
183 { NFS4ERR_NXIO, -ENXIO },
184 { NFS4ERR_ACCESS, -EACCES },
185 { NFS4ERR_EXIST, -EEXIST },
186 { NFS4ERR_XDEV, -EXDEV },
187 { NFS4ERR_NOTDIR, -ENOTDIR },
188 { NFS4ERR_ISDIR, -EISDIR },
189 { NFS4ERR_INVAL, -EINVAL },
190 { NFS4ERR_FBIG, -EFBIG },
191 { NFS4ERR_NOSPC, -ENOSPC },
192 { NFS4ERR_ROFS, -EROFS },
193 { NFS4ERR_MLINK, -EMLINK },
194 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
195 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
196 { NFS4ERR_DQUOT, -EDQUOT },
197 { NFS4ERR_STALE, -ESTALE },
198 { NFS4ERR_BADHANDLE, -EBADHANDLE },
199 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
200 { NFS4ERR_NOTSUPP, -ENOTSUPP },
201 { NFS4ERR_TOOSMALL, -ETOOSMALL },
202 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
203 { NFS4ERR_BADTYPE, -EBADTYPE },
204 { NFS4ERR_LOCKED, -EAGAIN },
205 { NFS4ERR_RESOURCE, -EREMOTEIO },
206 { NFS4ERR_SYMLINK, -ELOOP },
207 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
208 { NFS4ERR_DEADLOCK, -EDEADLK },
209 { -1, -EIO }
210};
211
212/*
213 * If we cannot translate the error, the recovery routines should
214 * handle it.
215 *
216 * Note: remaining NFSv4 error codes have values > 10000, so should
217 * not conflict with native Linux error codes.
218 */
219static int nfs_cb_stat_to_errno(int status)
220{
221 int i;
222
223 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
224 if (nfs_cb_errtbl[i].stat == status)
225 return nfs_cb_errtbl[i].errno;
226 }
227
228 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
229 return -status;
230}
231
232static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
233 enum nfsstat4 *status)
234{
235 __be32 *p;
236 u32 op;
237
238 p = xdr_inline_decode(xdr, 4 + 4);
239 if (unlikely(p == NULL))
240 goto out_overflow;
241 op = be32_to_cpup(p++);
242 if (unlikely(op != expected))
243 goto out_unexpected;
244 *status = be32_to_cpup(p);
245 return 0;
246out_overflow:
247 print_overflow_msg(__func__, xdr);
248 return -EIO;
249out_unexpected:
250 dprintk("NFSD: Callback server returned operation %d but "
251 "we issued a request for %d\n", op, expected);
252 return -EIO;
253}
254
255/*
256 * CB_COMPOUND4args
257 *
258 * struct CB_COMPOUND4args {
259 * utf8str_cs tag;
260 * uint32_t minorversion;
261 * uint32_t callback_ident;
262 * nfs_cb_argop4 argarray<>;
263 * };
264*/
265static void encode_cb_compound4args(struct xdr_stream *xdr,
266 struct nfs4_cb_compound_hdr *hdr)
267{
268 __be32 * p;
269
270 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
271 p = xdr_encode_empty_array(p); /* empty tag */
272 *p++ = cpu_to_be32(hdr->minorversion);
273 *p++ = cpu_to_be32(hdr->ident);
274
275 hdr->nops_p = p;
276 *p = cpu_to_be32(hdr->nops); /* argarray element count */
277}
278
279/*
280 * Update argarray element count
281 */
282static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
283{
284 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
285 *hdr->nops_p = cpu_to_be32(hdr->nops);
286}
287
288/*
289 * CB_COMPOUND4res
290 *
291 * struct CB_COMPOUND4res {
292 * nfsstat4 status;
293 * utf8str_cs tag;
294 * nfs_cb_resop4 resarray<>;
295 * };
296 */
297static int decode_cb_compound4res(struct xdr_stream *xdr,
298 struct nfs4_cb_compound_hdr *hdr)
299{
300 u32 length;
301 __be32 *p;
302
303 p = xdr_inline_decode(xdr, 4 + 4);
304 if (unlikely(p == NULL))
305 goto out_overflow;
306 hdr->status = be32_to_cpup(p++);
307 /* Ignore the tag */
308 length = be32_to_cpup(p++);
309 p = xdr_inline_decode(xdr, length + 4);
310 if (unlikely(p == NULL))
311 goto out_overflow;
312 hdr->nops = be32_to_cpup(p);
313 return 0;
314out_overflow:
315 print_overflow_msg(__func__, xdr);
316 return -EIO;
317}
318
319/*
320 * CB_RECALL4args
321 *
322 * struct CB_RECALL4args {
323 * stateid4 stateid;
324 * bool truncate;
325 * nfs_fh4 fh;
326 * };
327 */
328static void encode_cb_recall4args(struct xdr_stream *xdr,
329 const struct nfs4_delegation *dp,
330 struct nfs4_cb_compound_hdr *hdr)
331{
332 __be32 *p;
333
334 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
335 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
336
337 p = xdr_reserve_space(xdr, 4);
338 *p++ = xdr_zero; /* truncate */
339
340 encode_nfs_fh4(xdr, &dp->dl_fh);
341
342 hdr->nops++;
343}
344
345/*
346 * CB_SEQUENCE4args
347 *
348 * struct CB_SEQUENCE4args {
349 * sessionid4 csa_sessionid;
350 * sequenceid4 csa_sequenceid;
351 * slotid4 csa_slotid;
352 * slotid4 csa_highest_slotid;
353 * bool csa_cachethis;
354 * referring_call_list4 csa_referring_call_lists<>;
355 * };
356 */
357static void encode_cb_sequence4args(struct xdr_stream *xdr,
358 const struct nfsd4_callback *cb,
359 struct nfs4_cb_compound_hdr *hdr)
360{
361 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
362 __be32 *p;
363
364 if (hdr->minorversion == 0)
365 return;
366
367 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
368 encode_sessionid4(xdr, session);
369
370 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
371 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
372 *p++ = xdr_zero; /* csa_slotid */
373 *p++ = xdr_zero; /* csa_highest_slotid */
374 *p++ = xdr_zero; /* csa_cachethis */
375 xdr_encode_empty_array(p); /* csa_referring_call_lists */
376
377 hdr->nops++;
378}
379
380/*
381 * CB_SEQUENCE4resok
382 *
383 * struct CB_SEQUENCE4resok {
384 * sessionid4 csr_sessionid;
385 * sequenceid4 csr_sequenceid;
386 * slotid4 csr_slotid;
387 * slotid4 csr_highest_slotid;
388 * slotid4 csr_target_highest_slotid;
389 * };
390 *
391 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
392 * case NFS4_OK:
393 * CB_SEQUENCE4resok csr_resok4;
394 * default:
395 * void;
396 * };
397 *
398 * Our current back channel implmentation supports a single backchannel
399 * with a single slot.
400 */
401static int decode_cb_sequence4resok(struct xdr_stream *xdr,
402 struct nfsd4_callback *cb)
403{
404 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
405 struct nfs4_sessionid id;
406 int status;
407 __be32 *p;
408 u32 dummy;
409
410 status = -ESERVERFAULT;
411
412 /*
413 * If the server returns different values for sessionID, slotID or
414 * sequence number, the server is looney tunes.
415 */
416 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
417 if (unlikely(p == NULL))
418 goto out_overflow;
419 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
420 if (memcmp(id.data, session->se_sessionid.data,
421 NFS4_MAX_SESSIONID_LEN) != 0) {
422 dprintk("NFS: %s Invalid session id\n", __func__);
423 goto out;
424 }
425 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
426
427 dummy = be32_to_cpup(p++);
428 if (dummy != session->se_cb_seq_nr) {
429 dprintk("NFS: %s Invalid sequence number\n", __func__);
430 goto out;
431 }
432
433 dummy = be32_to_cpup(p++);
434 if (dummy != 0) {
435 dprintk("NFS: %s Invalid slotid\n", __func__);
436 goto out;
437 }
438
439 /*
440 * FIXME: process highest slotid and target highest slotid
441 */
442 status = 0;
443out:
444 if (status)
445 nfsd4_mark_cb_fault(cb->cb_clp, status);
446 return status;
447out_overflow:
448 print_overflow_msg(__func__, xdr);
449 return -EIO;
450}
451
452static int decode_cb_sequence4res(struct xdr_stream *xdr,
453 struct nfsd4_callback *cb)
454{
455 enum nfsstat4 nfserr;
456 int status;
457
458 if (cb->cb_minorversion == 0)
459 return 0;
460
461 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
462 if (unlikely(status))
463 goto out;
464 if (unlikely(nfserr != NFS4_OK))
465 goto out_default;
466 status = decode_cb_sequence4resok(xdr, cb);
467out:
468 return status;
469out_default:
470 return nfs_cb_stat_to_errno(nfserr);
471}
472
473/*
474 * NFSv4.0 and NFSv4.1 XDR encode functions
475 *
476 * NFSv4.0 callback argument types are defined in section 15 of RFC
477 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
478 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
479 * Protocol".
480 */
481
482/*
483 * NB: Without this zero space reservation, callbacks over krb5p fail
484 */
485static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
486 void *__unused)
487{
488 xdr_reserve_space(xdr, 0);
489}
490
491/*
492 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
493 */
494static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
495 const struct nfsd4_callback *cb)
496{
497 const struct nfs4_delegation *args = cb->cb_op;
498 struct nfs4_cb_compound_hdr hdr = {
499 .ident = cb->cb_clp->cl_cb_ident,
500 .minorversion = cb->cb_minorversion,
501 };
502
503 encode_cb_compound4args(xdr, &hdr);
504 encode_cb_sequence4args(xdr, cb, &hdr);
505 encode_cb_recall4args(xdr, args, &hdr);
506 encode_cb_nops(&hdr);
507}
508
509
510/*
511 * NFSv4.0 and NFSv4.1 XDR decode functions
512 *
513 * NFSv4.0 callback result types are defined in section 15 of RFC
514 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
515 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
516 * Protocol".
517 */
518
519static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
520 void *__unused)
521{
522 return 0;
523}
524
525/*
526 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
527 */
528static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
529 struct xdr_stream *xdr,
530 struct nfsd4_callback *cb)
531{
532 struct nfs4_cb_compound_hdr hdr;
533 enum nfsstat4 nfserr;
534 int status;
535
536 status = decode_cb_compound4res(xdr, &hdr);
537 if (unlikely(status))
538 goto out;
539
540 if (cb != NULL) {
541 status = decode_cb_sequence4res(xdr, cb);
542 if (unlikely(status))
543 goto out;
544 }
545
546 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
547 if (unlikely(status))
548 goto out;
549 if (unlikely(nfserr != NFS4_OK))
550 status = nfs_cb_stat_to_errno(nfserr);
551out:
552 return status;
553}
554
555/*
556 * RPC procedure tables
557 */
558#define PROC(proc, call, argtype, restype) \
559[NFSPROC4_CLNT_##proc] = { \
560 .p_proc = NFSPROC4_CB_##call, \
561 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
562 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
563 .p_arglen = NFS4_enc_##argtype##_sz, \
564 .p_replen = NFS4_dec_##restype##_sz, \
565 .p_statidx = NFSPROC4_CB_##call, \
566 .p_name = #proc, \
567}
568
569static struct rpc_procinfo nfs4_cb_procedures[] = {
570 PROC(CB_NULL, NULL, cb_null, cb_null),
571 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
572};
573
574static struct rpc_version nfs_cb_version4 = {
575/*
576 * Note on the callback rpc program version number: despite language in rfc
577 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
578 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
579 * in practice that appears to be what implementations use. The section
580 * 18.36.3 language is expected to be fixed in an erratum.
581 */
582 .number = 1,
583 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
584 .procs = nfs4_cb_procedures
585};
586
587static const struct rpc_version *nfs_cb_version[] = {
588 &nfs_cb_version4,
589};
590
591static const struct rpc_program cb_program;
592
593static struct rpc_stat cb_stats = {
594 .program = &cb_program
595};
596
597#define NFS4_CALLBACK 0x40000000
598static const struct rpc_program cb_program = {
599 .name = "nfs4_cb",
600 .number = NFS4_CALLBACK,
601 .nrvers = ARRAY_SIZE(nfs_cb_version),
602 .version = nfs_cb_version,
603 .stats = &cb_stats,
604 .pipe_dir_name = "nfsd4_cb",
605};
606
607static int max_cb_time(struct net *net)
608{
609 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
610 return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
611}
612
613static struct rpc_cred *callback_cred;
614
615int set_callback_cred(void)
616{
617 if (callback_cred)
618 return 0;
619 callback_cred = rpc_lookup_machine_cred("nfs");
620 if (!callback_cred)
621 return -ENOMEM;
622 return 0;
623}
624
625static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
626{
627 if (clp->cl_minorversion == 0) {
628 return get_rpccred(callback_cred);
629 } else {
630 struct rpc_auth *auth = client->cl_auth;
631 struct auth_cred acred = {};
632
633 acred.uid = ses->se_cb_sec.uid;
634 acred.gid = ses->se_cb_sec.gid;
635 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
636 }
637}
638
639static struct rpc_clnt *create_backchannel_client(struct rpc_create_args *args)
640{
641 struct rpc_xprt *xprt;
642
643 if (args->protocol != XPRT_TRANSPORT_BC_TCP)
644 return rpc_create(args);
645
646 xprt = args->bc_xprt->xpt_bc_xprt;
647 if (xprt) {
648 xprt_get(xprt);
649 return rpc_create_xprt(args, xprt);
650 }
651
652 return rpc_create(args);
653}
654
655static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
656{
657 int maxtime = max_cb_time(clp->net);
658 struct rpc_timeout timeparms = {
659 .to_initval = maxtime,
660 .to_retries = 0,
661 .to_maxval = maxtime,
662 };
663 struct rpc_create_args args = {
664 .net = clp->net,
665 .address = (struct sockaddr *) &conn->cb_addr,
666 .addrsize = conn->cb_addrlen,
667 .saddress = (struct sockaddr *) &conn->cb_saddr,
668 .timeout = &timeparms,
669 .program = &cb_program,
670 .version = 0,
671 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
672 };
673 struct rpc_clnt *client;
674 struct rpc_cred *cred;
675
676 if (clp->cl_minorversion == 0) {
677 if (!clp->cl_cred.cr_principal &&
678 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
679 return -EINVAL;
680 args.client_name = clp->cl_cred.cr_principal;
681 args.prognumber = conn->cb_prog,
682 args.protocol = XPRT_TRANSPORT_TCP;
683 args.authflavor = clp->cl_cred.cr_flavor;
684 clp->cl_cb_ident = conn->cb_ident;
685 } else {
686 if (!conn->cb_xprt)
687 return -EINVAL;
688 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
689 clp->cl_cb_session = ses;
690 args.bc_xprt = conn->cb_xprt;
691 args.prognumber = clp->cl_cb_session->se_cb_prog;
692 args.protocol = XPRT_TRANSPORT_BC_TCP;
693 args.authflavor = ses->se_cb_sec.flavor;
694 }
695 /* Create RPC client */
696 client = create_backchannel_client(&args);
697 if (IS_ERR(client)) {
698 dprintk("NFSD: couldn't create callback client: %ld\n",
699 PTR_ERR(client));
700 return PTR_ERR(client);
701 }
702 cred = get_backchannel_cred(clp, client, ses);
703 if (IS_ERR(cred)) {
704 rpc_shutdown_client(client);
705 return PTR_ERR(cred);
706 }
707 clp->cl_cb_client = client;
708 clp->cl_cb_cred = cred;
709 return 0;
710}
711
712static void warn_no_callback_path(struct nfs4_client *clp, int reason)
713{
714 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
715 (int)clp->cl_name.len, clp->cl_name.data, reason);
716}
717
718static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
719{
720 clp->cl_cb_state = NFSD4_CB_DOWN;
721 warn_no_callback_path(clp, reason);
722}
723
724static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
725{
726 clp->cl_cb_state = NFSD4_CB_FAULT;
727 warn_no_callback_path(clp, reason);
728}
729
730static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
731{
732 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
733
734 if (task->tk_status)
735 nfsd4_mark_cb_down(clp, task->tk_status);
736 else
737 clp->cl_cb_state = NFSD4_CB_UP;
738}
739
740static const struct rpc_call_ops nfsd4_cb_probe_ops = {
741 /* XXX: release method to ensure we set the cb channel down if
742 * necessary on early failure? */
743 .rpc_call_done = nfsd4_cb_probe_done,
744};
745
746static struct workqueue_struct *callback_wq;
747
748static void run_nfsd4_cb(struct nfsd4_callback *cb)
749{
750 queue_work(callback_wq, &cb->cb_work);
751}
752
753static void do_probe_callback(struct nfs4_client *clp)
754{
755 struct nfsd4_callback *cb = &clp->cl_cb_null;
756
757 cb->cb_op = NULL;
758 cb->cb_clp = clp;
759
760 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
761 cb->cb_msg.rpc_argp = NULL;
762 cb->cb_msg.rpc_resp = NULL;
763
764 cb->cb_ops = &nfsd4_cb_probe_ops;
765
766 run_nfsd4_cb(cb);
767}
768
769/*
770 * Poke the callback thread to process any updates to the callback
771 * parameters, and send a null probe.
772 */
773void nfsd4_probe_callback(struct nfs4_client *clp)
774{
775 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
776 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
777 do_probe_callback(clp);
778}
779
780void nfsd4_probe_callback_sync(struct nfs4_client *clp)
781{
782 nfsd4_probe_callback(clp);
783 flush_workqueue(callback_wq);
784}
785
786void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
787{
788 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
789 spin_lock(&clp->cl_lock);
790 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
791 spin_unlock(&clp->cl_lock);
792}
793
794/*
795 * There's currently a single callback channel slot.
796 * If the slot is available, then mark it busy. Otherwise, set the
797 * thread for sleeping on the callback RPC wait queue.
798 */
799static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
800{
801 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
802 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
803 dprintk("%s slot is busy\n", __func__);
804 return false;
805 }
806 return true;
807}
808
809/*
810 * TODO: cb_sequence should support referring call lists, cachethis, multiple
811 * slots, and mark callback channel down on communication errors.
812 */
813static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
814{
815 struct nfsd4_callback *cb = calldata;
816 struct nfs4_client *clp = cb->cb_clp;
817 u32 minorversion = clp->cl_minorversion;
818
819 cb->cb_minorversion = minorversion;
820 if (minorversion) {
821 if (!nfsd41_cb_get_slot(clp, task))
822 return;
823 }
824 spin_lock(&clp->cl_lock);
825 if (list_empty(&cb->cb_per_client)) {
826 /* This is the first call, not a restart */
827 cb->cb_done = false;
828 list_add(&cb->cb_per_client, &clp->cl_callbacks);
829 }
830 spin_unlock(&clp->cl_lock);
831 rpc_call_start(task);
832}
833
834static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
835{
836 struct nfsd4_callback *cb = calldata;
837 struct nfs4_client *clp = cb->cb_clp;
838
839 dprintk("%s: minorversion=%d\n", __func__,
840 clp->cl_minorversion);
841
842 if (clp->cl_minorversion) {
843 /* No need for lock, access serialized in nfsd4_cb_prepare */
844 ++clp->cl_cb_session->se_cb_seq_nr;
845 clear_bit(0, &clp->cl_cb_slot_busy);
846 rpc_wake_up_next(&clp->cl_cb_waitq);
847 dprintk("%s: freed slot, new seqid=%d\n", __func__,
848 clp->cl_cb_session->se_cb_seq_nr);
849
850 /* We're done looking into the sequence information */
851 task->tk_msg.rpc_resp = NULL;
852 }
853}
854
855
856static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
857{
858 struct nfsd4_callback *cb = calldata;
859 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
860 struct nfs4_client *clp = cb->cb_clp;
861 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
862
863 nfsd4_cb_done(task, calldata);
864
865 if (current_rpc_client != task->tk_client) {
866 /* We're shutting down or changing cl_cb_client; leave
867 * it to nfsd4_process_cb_update to restart the call if
868 * necessary. */
869 return;
870 }
871
872 if (cb->cb_done)
873 return;
874 switch (task->tk_status) {
875 case 0:
876 cb->cb_done = true;
877 return;
878 case -EBADHANDLE:
879 case -NFS4ERR_BAD_STATEID:
880 /* Race: client probably got cb_recall
881 * before open reply granting delegation */
882 break;
883 default:
884 /* Network partition? */
885 nfsd4_mark_cb_down(clp, task->tk_status);
886 }
887 if (dp->dl_retries--) {
888 rpc_delay(task, 2*HZ);
889 task->tk_status = 0;
890 rpc_restart_call_prepare(task);
891 return;
892 }
893 nfsd4_mark_cb_down(clp, task->tk_status);
894 cb->cb_done = true;
895}
896
897static void nfsd4_cb_recall_release(void *calldata)
898{
899 struct nfsd4_callback *cb = calldata;
900 struct nfs4_client *clp = cb->cb_clp;
901 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
902
903 if (cb->cb_done) {
904 spin_lock(&clp->cl_lock);
905 list_del(&cb->cb_per_client);
906 spin_unlock(&clp->cl_lock);
907 nfs4_put_delegation(dp);
908 }
909}
910
911static const struct rpc_call_ops nfsd4_cb_recall_ops = {
912 .rpc_call_prepare = nfsd4_cb_prepare,
913 .rpc_call_done = nfsd4_cb_recall_done,
914 .rpc_release = nfsd4_cb_recall_release,
915};
916
917int nfsd4_create_callback_queue(void)
918{
919 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
920 if (!callback_wq)
921 return -ENOMEM;
922 return 0;
923}
924
925void nfsd4_destroy_callback_queue(void)
926{
927 destroy_workqueue(callback_wq);
928}
929
930/* must be called under the state lock */
931void nfsd4_shutdown_callback(struct nfs4_client *clp)
932{
933 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
934 /*
935 * Note this won't actually result in a null callback;
936 * instead, nfsd4_do_callback_rpc() will detect the killed
937 * client, destroy the rpc client, and stop:
938 */
939 do_probe_callback(clp);
940 flush_workqueue(callback_wq);
941}
942
943static void nfsd4_release_cb(struct nfsd4_callback *cb)
944{
945 if (cb->cb_ops->rpc_release)
946 cb->cb_ops->rpc_release(cb);
947}
948
949/* requires cl_lock: */
950static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
951{
952 struct nfsd4_session *s;
953 struct nfsd4_conn *c;
954
955 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
956 list_for_each_entry(c, &s->se_conns, cn_persession) {
957 if (c->cn_flags & NFS4_CDFC4_BACK)
958 return c;
959 }
960 }
961 return NULL;
962}
963
964static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
965{
966 struct nfs4_cb_conn conn;
967 struct nfs4_client *clp = cb->cb_clp;
968 struct nfsd4_session *ses = NULL;
969 struct nfsd4_conn *c;
970 int err;
971
972 /*
973 * This is either an update, or the client dying; in either case,
974 * kill the old client:
975 */
976 if (clp->cl_cb_client) {
977 rpc_shutdown_client(clp->cl_cb_client);
978 clp->cl_cb_client = NULL;
979 put_rpccred(clp->cl_cb_cred);
980 clp->cl_cb_cred = NULL;
981 }
982 if (clp->cl_cb_conn.cb_xprt) {
983 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
984 clp->cl_cb_conn.cb_xprt = NULL;
985 }
986 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
987 return;
988 spin_lock(&clp->cl_lock);
989 /*
990 * Only serialized callback code is allowed to clear these
991 * flags; main nfsd code can only set them:
992 */
993 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
994 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
995 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
996 c = __nfsd4_find_backchannel(clp);
997 if (c) {
998 svc_xprt_get(c->cn_xprt);
999 conn.cb_xprt = c->cn_xprt;
1000 ses = c->cn_session;
1001 }
1002 spin_unlock(&clp->cl_lock);
1003
1004 err = setup_callback_client(clp, &conn, ses);
1005 if (err) {
1006 nfsd4_mark_cb_down(clp, err);
1007 return;
1008 }
1009 /* Yay, the callback channel's back! Restart any callbacks: */
1010 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
1011 run_nfsd4_cb(cb);
1012}
1013
1014static void nfsd4_do_callback_rpc(struct work_struct *w)
1015{
1016 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
1017 struct nfs4_client *clp = cb->cb_clp;
1018 struct rpc_clnt *clnt;
1019
1020 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1021 nfsd4_process_cb_update(cb);
1022
1023 clnt = clp->cl_cb_client;
1024 if (!clnt) {
1025 /* Callback channel broken, or client killed; give up: */
1026 nfsd4_release_cb(cb);
1027 return;
1028 }
1029 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1030 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1031 cb->cb_ops, cb);
1032}
1033
1034void nfsd4_init_callback(struct nfsd4_callback *cb)
1035{
1036 INIT_WORK(&cb->cb_work, nfsd4_do_callback_rpc);
1037}
1038
1039void nfsd4_cb_recall(struct nfs4_delegation *dp)
1040{
1041 struct nfsd4_callback *cb = &dp->dl_recall;
1042 struct nfs4_client *clp = dp->dl_stid.sc_client;
1043
1044 dp->dl_retries = 1;
1045 cb->cb_op = dp;
1046 cb->cb_clp = clp;
1047 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
1048 cb->cb_msg.rpc_argp = cb;
1049 cb->cb_msg.rpc_resp = cb;
1050
1051 cb->cb_ops = &nfsd4_cb_recall_ops;
1052
1053 INIT_LIST_HEAD(&cb->cb_per_client);
1054 cb->cb_done = true;
1055
1056 run_nfsd4_cb(&dp->dl_recall);
1057}
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
42#define NFSPROC4_CB_NULL 0
43#define NFSPROC4_CB_COMPOUND 1
44
45/* Index of predefined Linux callback client operations */
46
47enum {
48 NFSPROC4_CLNT_CB_NULL = 0,
49 NFSPROC4_CLNT_CB_RECALL,
50 NFSPROC4_CLNT_CB_SEQUENCE,
51};
52
53#define NFS4_MAXTAGLEN 20
54
55#define NFS4_enc_cb_null_sz 0
56#define NFS4_dec_cb_null_sz 0
57#define cb_compound_enc_hdr_sz 4
58#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
59#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
60#define cb_sequence_enc_sz (sessionid_sz + 4 + \
61 1 /* no referring calls list yet */)
62#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
63
64#define op_enc_sz 1
65#define op_dec_sz 2
66#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
67#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
68#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
69 cb_sequence_enc_sz + \
70 1 + enc_stateid_sz + \
71 enc_nfs4_fh_sz)
72
73#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
74 cb_sequence_dec_sz + \
75 op_dec_sz)
76
77struct nfs4_cb_compound_hdr {
78 /* args */
79 u32 ident; /* minorversion 0 only */
80 u32 nops;
81 __be32 *nops_p;
82 u32 minorversion;
83 /* res */
84 int status;
85};
86
87/*
88 * Handle decode buffer overflows out-of-line.
89 */
90static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
91{
92 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
93 "Remaining buffer length is %tu words.\n",
94 func, xdr->end - xdr->p);
95}
96
97static __be32 *xdr_encode_empty_array(__be32 *p)
98{
99 *p++ = xdr_zero;
100 return p;
101}
102
103/*
104 * Encode/decode NFSv4 CB basic data types
105 *
106 * Basic NFSv4 callback data types are defined in section 15 of RFC
107 * 3530: "Network File System (NFS) version 4 Protocol" and section
108 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
109 * 1 Protocol"
110 */
111
112/*
113 * nfs_cb_opnum4
114 *
115 * enum nfs_cb_opnum4 {
116 * OP_CB_GETATTR = 3,
117 * ...
118 * };
119 */
120enum nfs_cb_opnum4 {
121 OP_CB_GETATTR = 3,
122 OP_CB_RECALL = 4,
123 OP_CB_LAYOUTRECALL = 5,
124 OP_CB_NOTIFY = 6,
125 OP_CB_PUSH_DELEG = 7,
126 OP_CB_RECALL_ANY = 8,
127 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
128 OP_CB_RECALL_SLOT = 10,
129 OP_CB_SEQUENCE = 11,
130 OP_CB_WANTS_CANCELLED = 12,
131 OP_CB_NOTIFY_LOCK = 13,
132 OP_CB_NOTIFY_DEVICEID = 14,
133 OP_CB_ILLEGAL = 10044
134};
135
136static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
137{
138 __be32 *p;
139
140 p = xdr_reserve_space(xdr, 4);
141 *p = cpu_to_be32(op);
142}
143
144/*
145 * nfs_fh4
146 *
147 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
148 */
149static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
150{
151 u32 length = fh->fh_size;
152 __be32 *p;
153
154 BUG_ON(length > NFS4_FHSIZE);
155 p = xdr_reserve_space(xdr, 4 + length);
156 xdr_encode_opaque(p, &fh->fh_base, length);
157}
158
159/*
160 * stateid4
161 *
162 * struct stateid4 {
163 * uint32_t seqid;
164 * opaque other[12];
165 * };
166 */
167static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
168{
169 __be32 *p;
170
171 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
172 *p++ = cpu_to_be32(sid->si_generation);
173 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
174}
175
176/*
177 * sessionid4
178 *
179 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
180 */
181static void encode_sessionid4(struct xdr_stream *xdr,
182 const struct nfsd4_session *session)
183{
184 __be32 *p;
185
186 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
187 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
188 NFS4_MAX_SESSIONID_LEN);
189}
190
191/*
192 * nfsstat4
193 */
194static const struct {
195 int stat;
196 int errno;
197} nfs_cb_errtbl[] = {
198 { NFS4_OK, 0 },
199 { NFS4ERR_PERM, -EPERM },
200 { NFS4ERR_NOENT, -ENOENT },
201 { NFS4ERR_IO, -EIO },
202 { NFS4ERR_NXIO, -ENXIO },
203 { NFS4ERR_ACCESS, -EACCES },
204 { NFS4ERR_EXIST, -EEXIST },
205 { NFS4ERR_XDEV, -EXDEV },
206 { NFS4ERR_NOTDIR, -ENOTDIR },
207 { NFS4ERR_ISDIR, -EISDIR },
208 { NFS4ERR_INVAL, -EINVAL },
209 { NFS4ERR_FBIG, -EFBIG },
210 { NFS4ERR_NOSPC, -ENOSPC },
211 { NFS4ERR_ROFS, -EROFS },
212 { NFS4ERR_MLINK, -EMLINK },
213 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
214 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
215 { NFS4ERR_DQUOT, -EDQUOT },
216 { NFS4ERR_STALE, -ESTALE },
217 { NFS4ERR_BADHANDLE, -EBADHANDLE },
218 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
219 { NFS4ERR_NOTSUPP, -ENOTSUPP },
220 { NFS4ERR_TOOSMALL, -ETOOSMALL },
221 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
222 { NFS4ERR_BADTYPE, -EBADTYPE },
223 { NFS4ERR_LOCKED, -EAGAIN },
224 { NFS4ERR_RESOURCE, -EREMOTEIO },
225 { NFS4ERR_SYMLINK, -ELOOP },
226 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
227 { NFS4ERR_DEADLOCK, -EDEADLK },
228 { -1, -EIO }
229};
230
231/*
232 * If we cannot translate the error, the recovery routines should
233 * handle it.
234 *
235 * Note: remaining NFSv4 error codes have values > 10000, so should
236 * not conflict with native Linux error codes.
237 */
238static int nfs_cb_stat_to_errno(int status)
239{
240 int i;
241
242 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
243 if (nfs_cb_errtbl[i].stat == status)
244 return nfs_cb_errtbl[i].errno;
245 }
246
247 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
248 return -status;
249}
250
251static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
252 enum nfsstat4 *status)
253{
254 __be32 *p;
255 u32 op;
256
257 p = xdr_inline_decode(xdr, 4 + 4);
258 if (unlikely(p == NULL))
259 goto out_overflow;
260 op = be32_to_cpup(p++);
261 if (unlikely(op != expected))
262 goto out_unexpected;
263 *status = be32_to_cpup(p);
264 return 0;
265out_overflow:
266 print_overflow_msg(__func__, xdr);
267 return -EIO;
268out_unexpected:
269 dprintk("NFSD: Callback server returned operation %d but "
270 "we issued a request for %d\n", op, expected);
271 return -EIO;
272}
273
274/*
275 * CB_COMPOUND4args
276 *
277 * struct CB_COMPOUND4args {
278 * utf8str_cs tag;
279 * uint32_t minorversion;
280 * uint32_t callback_ident;
281 * nfs_cb_argop4 argarray<>;
282 * };
283*/
284static void encode_cb_compound4args(struct xdr_stream *xdr,
285 struct nfs4_cb_compound_hdr *hdr)
286{
287 __be32 * p;
288
289 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
290 p = xdr_encode_empty_array(p); /* empty tag */
291 *p++ = cpu_to_be32(hdr->minorversion);
292 *p++ = cpu_to_be32(hdr->ident);
293
294 hdr->nops_p = p;
295 *p = cpu_to_be32(hdr->nops); /* argarray element count */
296}
297
298/*
299 * Update argarray element count
300 */
301static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
302{
303 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
304 *hdr->nops_p = cpu_to_be32(hdr->nops);
305}
306
307/*
308 * CB_COMPOUND4res
309 *
310 * struct CB_COMPOUND4res {
311 * nfsstat4 status;
312 * utf8str_cs tag;
313 * nfs_cb_resop4 resarray<>;
314 * };
315 */
316static int decode_cb_compound4res(struct xdr_stream *xdr,
317 struct nfs4_cb_compound_hdr *hdr)
318{
319 u32 length;
320 __be32 *p;
321
322 p = xdr_inline_decode(xdr, 4 + 4);
323 if (unlikely(p == NULL))
324 goto out_overflow;
325 hdr->status = be32_to_cpup(p++);
326 /* Ignore the tag */
327 length = be32_to_cpup(p++);
328 p = xdr_inline_decode(xdr, length + 4);
329 if (unlikely(p == NULL))
330 goto out_overflow;
331 hdr->nops = be32_to_cpup(p);
332 return 0;
333out_overflow:
334 print_overflow_msg(__func__, xdr);
335 return -EIO;
336}
337
338/*
339 * CB_RECALL4args
340 *
341 * struct CB_RECALL4args {
342 * stateid4 stateid;
343 * bool truncate;
344 * nfs_fh4 fh;
345 * };
346 */
347static void encode_cb_recall4args(struct xdr_stream *xdr,
348 const struct nfs4_delegation *dp,
349 struct nfs4_cb_compound_hdr *hdr)
350{
351 __be32 *p;
352
353 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
354 encode_stateid4(xdr, &dp->dl_stateid);
355
356 p = xdr_reserve_space(xdr, 4);
357 *p++ = xdr_zero; /* truncate */
358
359 encode_nfs_fh4(xdr, &dp->dl_fh);
360
361 hdr->nops++;
362}
363
364/*
365 * CB_SEQUENCE4args
366 *
367 * struct CB_SEQUENCE4args {
368 * sessionid4 csa_sessionid;
369 * sequenceid4 csa_sequenceid;
370 * slotid4 csa_slotid;
371 * slotid4 csa_highest_slotid;
372 * bool csa_cachethis;
373 * referring_call_list4 csa_referring_call_lists<>;
374 * };
375 */
376static void encode_cb_sequence4args(struct xdr_stream *xdr,
377 const struct nfsd4_callback *cb,
378 struct nfs4_cb_compound_hdr *hdr)
379{
380 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
381 __be32 *p;
382
383 if (hdr->minorversion == 0)
384 return;
385
386 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
387 encode_sessionid4(xdr, session);
388
389 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
390 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
391 *p++ = xdr_zero; /* csa_slotid */
392 *p++ = xdr_zero; /* csa_highest_slotid */
393 *p++ = xdr_zero; /* csa_cachethis */
394 xdr_encode_empty_array(p); /* csa_referring_call_lists */
395
396 hdr->nops++;
397}
398
399/*
400 * CB_SEQUENCE4resok
401 *
402 * struct CB_SEQUENCE4resok {
403 * sessionid4 csr_sessionid;
404 * sequenceid4 csr_sequenceid;
405 * slotid4 csr_slotid;
406 * slotid4 csr_highest_slotid;
407 * slotid4 csr_target_highest_slotid;
408 * };
409 *
410 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
411 * case NFS4_OK:
412 * CB_SEQUENCE4resok csr_resok4;
413 * default:
414 * void;
415 * };
416 *
417 * Our current back channel implmentation supports a single backchannel
418 * with a single slot.
419 */
420static int decode_cb_sequence4resok(struct xdr_stream *xdr,
421 struct nfsd4_callback *cb)
422{
423 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
424 struct nfs4_sessionid id;
425 int status;
426 __be32 *p;
427 u32 dummy;
428
429 status = -ESERVERFAULT;
430
431 /*
432 * If the server returns different values for sessionID, slotID or
433 * sequence number, the server is looney tunes.
434 */
435 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
436 if (unlikely(p == NULL))
437 goto out_overflow;
438 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
439 if (memcmp(id.data, session->se_sessionid.data,
440 NFS4_MAX_SESSIONID_LEN) != 0) {
441 dprintk("NFS: %s Invalid session id\n", __func__);
442 goto out;
443 }
444 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
445
446 dummy = be32_to_cpup(p++);
447 if (dummy != session->se_cb_seq_nr) {
448 dprintk("NFS: %s Invalid sequence number\n", __func__);
449 goto out;
450 }
451
452 dummy = be32_to_cpup(p++);
453 if (dummy != 0) {
454 dprintk("NFS: %s Invalid slotid\n", __func__);
455 goto out;
456 }
457
458 /*
459 * FIXME: process highest slotid and target highest slotid
460 */
461 status = 0;
462out:
463 return status;
464out_overflow:
465 print_overflow_msg(__func__, xdr);
466 return -EIO;
467}
468
469static int decode_cb_sequence4res(struct xdr_stream *xdr,
470 struct nfsd4_callback *cb)
471{
472 enum nfsstat4 nfserr;
473 int status;
474
475 if (cb->cb_minorversion == 0)
476 return 0;
477
478 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
479 if (unlikely(status))
480 goto out;
481 if (unlikely(nfserr != NFS4_OK))
482 goto out_default;
483 status = decode_cb_sequence4resok(xdr, cb);
484out:
485 return status;
486out_default:
487 return nfs_cb_stat_to_errno(nfserr);
488}
489
490/*
491 * NFSv4.0 and NFSv4.1 XDR encode functions
492 *
493 * NFSv4.0 callback argument types are defined in section 15 of RFC
494 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
495 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
496 * Protocol".
497 */
498
499/*
500 * NB: Without this zero space reservation, callbacks over krb5p fail
501 */
502static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
503 void *__unused)
504{
505 xdr_reserve_space(xdr, 0);
506}
507
508/*
509 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
510 */
511static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
512 const struct nfsd4_callback *cb)
513{
514 const struct nfs4_delegation *args = cb->cb_op;
515 struct nfs4_cb_compound_hdr hdr = {
516 .ident = cb->cb_clp->cl_cb_ident,
517 .minorversion = cb->cb_minorversion,
518 };
519
520 encode_cb_compound4args(xdr, &hdr);
521 encode_cb_sequence4args(xdr, cb, &hdr);
522 encode_cb_recall4args(xdr, args, &hdr);
523 encode_cb_nops(&hdr);
524}
525
526
527/*
528 * NFSv4.0 and NFSv4.1 XDR decode functions
529 *
530 * NFSv4.0 callback result types are defined in section 15 of RFC
531 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
532 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
533 * Protocol".
534 */
535
536static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
537 void *__unused)
538{
539 return 0;
540}
541
542/*
543 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
544 */
545static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
546 struct xdr_stream *xdr,
547 struct nfsd4_callback *cb)
548{
549 struct nfs4_cb_compound_hdr hdr;
550 enum nfsstat4 nfserr;
551 int status;
552
553 status = decode_cb_compound4res(xdr, &hdr);
554 if (unlikely(status))
555 goto out;
556
557 if (cb != NULL) {
558 status = decode_cb_sequence4res(xdr, cb);
559 if (unlikely(status))
560 goto out;
561 }
562
563 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
564 if (unlikely(status))
565 goto out;
566 if (unlikely(nfserr != NFS4_OK))
567 status = nfs_cb_stat_to_errno(nfserr);
568out:
569 return status;
570}
571
572/*
573 * RPC procedure tables
574 */
575#define PROC(proc, call, argtype, restype) \
576[NFSPROC4_CLNT_##proc] = { \
577 .p_proc = NFSPROC4_CB_##call, \
578 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
579 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
580 .p_arglen = NFS4_enc_##argtype##_sz, \
581 .p_replen = NFS4_dec_##restype##_sz, \
582 .p_statidx = NFSPROC4_CB_##call, \
583 .p_name = #proc, \
584}
585
586static struct rpc_procinfo nfs4_cb_procedures[] = {
587 PROC(CB_NULL, NULL, cb_null, cb_null),
588 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
589};
590
591static struct rpc_version nfs_cb_version4 = {
592/*
593 * Note on the callback rpc program version number: despite language in rfc
594 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
595 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
596 * in practice that appears to be what implementations use. The section
597 * 18.36.3 language is expected to be fixed in an erratum.
598 */
599 .number = 1,
600 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
601 .procs = nfs4_cb_procedures
602};
603
604static struct rpc_version *nfs_cb_version[] = {
605 &nfs_cb_version4,
606};
607
608static struct rpc_program cb_program;
609
610static struct rpc_stat cb_stats = {
611 .program = &cb_program
612};
613
614#define NFS4_CALLBACK 0x40000000
615static struct rpc_program cb_program = {
616 .name = "nfs4_cb",
617 .number = NFS4_CALLBACK,
618 .nrvers = ARRAY_SIZE(nfs_cb_version),
619 .version = nfs_cb_version,
620 .stats = &cb_stats,
621 .pipe_dir_name = "/nfsd4_cb",
622};
623
624static int max_cb_time(void)
625{
626 return max(nfsd4_lease/10, (time_t)1) * HZ;
627}
628
629
630static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
631{
632 struct rpc_timeout timeparms = {
633 .to_initval = max_cb_time(),
634 .to_retries = 0,
635 };
636 struct rpc_create_args args = {
637 .net = &init_net,
638 .address = (struct sockaddr *) &conn->cb_addr,
639 .addrsize = conn->cb_addrlen,
640 .saddress = (struct sockaddr *) &conn->cb_saddr,
641 .timeout = &timeparms,
642 .program = &cb_program,
643 .version = 0,
644 .authflavor = clp->cl_flavor,
645 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
646 };
647 struct rpc_clnt *client;
648
649 if (clp->cl_minorversion == 0) {
650 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
651 return -EINVAL;
652 args.client_name = clp->cl_principal;
653 args.prognumber = conn->cb_prog,
654 args.protocol = XPRT_TRANSPORT_TCP;
655 clp->cl_cb_ident = conn->cb_ident;
656 } else {
657 if (!conn->cb_xprt)
658 return -EINVAL;
659 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
660 clp->cl_cb_session = ses;
661 args.bc_xprt = conn->cb_xprt;
662 args.prognumber = clp->cl_cb_session->se_cb_prog;
663 args.protocol = XPRT_TRANSPORT_BC_TCP;
664 }
665 /* Create RPC client */
666 client = rpc_create(&args);
667 if (IS_ERR(client)) {
668 dprintk("NFSD: couldn't create callback client: %ld\n",
669 PTR_ERR(client));
670 return PTR_ERR(client);
671 }
672 clp->cl_cb_client = client;
673 return 0;
674
675}
676
677static void warn_no_callback_path(struct nfs4_client *clp, int reason)
678{
679 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
680 (int)clp->cl_name.len, clp->cl_name.data, reason);
681}
682
683static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
684{
685 clp->cl_cb_state = NFSD4_CB_DOWN;
686 warn_no_callback_path(clp, reason);
687}
688
689static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
690{
691 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
692
693 if (task->tk_status)
694 nfsd4_mark_cb_down(clp, task->tk_status);
695 else
696 clp->cl_cb_state = NFSD4_CB_UP;
697}
698
699static const struct rpc_call_ops nfsd4_cb_probe_ops = {
700 /* XXX: release method to ensure we set the cb channel down if
701 * necessary on early failure? */
702 .rpc_call_done = nfsd4_cb_probe_done,
703};
704
705static struct rpc_cred *callback_cred;
706
707int set_callback_cred(void)
708{
709 if (callback_cred)
710 return 0;
711 callback_cred = rpc_lookup_machine_cred();
712 if (!callback_cred)
713 return -ENOMEM;
714 return 0;
715}
716
717static struct workqueue_struct *callback_wq;
718
719static void run_nfsd4_cb(struct nfsd4_callback *cb)
720{
721 queue_work(callback_wq, &cb->cb_work);
722}
723
724static void do_probe_callback(struct nfs4_client *clp)
725{
726 struct nfsd4_callback *cb = &clp->cl_cb_null;
727
728 cb->cb_op = NULL;
729 cb->cb_clp = clp;
730
731 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
732 cb->cb_msg.rpc_argp = NULL;
733 cb->cb_msg.rpc_resp = NULL;
734 cb->cb_msg.rpc_cred = callback_cred;
735
736 cb->cb_ops = &nfsd4_cb_probe_ops;
737
738 run_nfsd4_cb(cb);
739}
740
741/*
742 * Poke the callback thread to process any updates to the callback
743 * parameters, and send a null probe.
744 */
745void nfsd4_probe_callback(struct nfs4_client *clp)
746{
747 /* XXX: atomicity? Also, should we be using cl_cb_flags? */
748 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
749 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
750 do_probe_callback(clp);
751}
752
753void nfsd4_probe_callback_sync(struct nfs4_client *clp)
754{
755 nfsd4_probe_callback(clp);
756 flush_workqueue(callback_wq);
757}
758
759void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
760{
761 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
762 spin_lock(&clp->cl_lock);
763 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
764 spin_unlock(&clp->cl_lock);
765}
766
767/*
768 * There's currently a single callback channel slot.
769 * If the slot is available, then mark it busy. Otherwise, set the
770 * thread for sleeping on the callback RPC wait queue.
771 */
772static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
773{
774 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
775 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
776 dprintk("%s slot is busy\n", __func__);
777 return false;
778 }
779 return true;
780}
781
782/*
783 * TODO: cb_sequence should support referring call lists, cachethis, multiple
784 * slots, and mark callback channel down on communication errors.
785 */
786static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
787{
788 struct nfsd4_callback *cb = calldata;
789 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
790 struct nfs4_client *clp = dp->dl_client;
791 u32 minorversion = clp->cl_minorversion;
792
793 cb->cb_minorversion = minorversion;
794 if (minorversion) {
795 if (!nfsd41_cb_get_slot(clp, task))
796 return;
797 }
798 spin_lock(&clp->cl_lock);
799 if (list_empty(&cb->cb_per_client)) {
800 /* This is the first call, not a restart */
801 cb->cb_done = false;
802 list_add(&cb->cb_per_client, &clp->cl_callbacks);
803 }
804 spin_unlock(&clp->cl_lock);
805 rpc_call_start(task);
806}
807
808static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
809{
810 struct nfsd4_callback *cb = calldata;
811 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
812 struct nfs4_client *clp = dp->dl_client;
813
814 dprintk("%s: minorversion=%d\n", __func__,
815 clp->cl_minorversion);
816
817 if (clp->cl_minorversion) {
818 /* No need for lock, access serialized in nfsd4_cb_prepare */
819 ++clp->cl_cb_session->se_cb_seq_nr;
820 clear_bit(0, &clp->cl_cb_slot_busy);
821 rpc_wake_up_next(&clp->cl_cb_waitq);
822 dprintk("%s: freed slot, new seqid=%d\n", __func__,
823 clp->cl_cb_session->se_cb_seq_nr);
824
825 /* We're done looking into the sequence information */
826 task->tk_msg.rpc_resp = NULL;
827 }
828}
829
830
831static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
832{
833 struct nfsd4_callback *cb = calldata;
834 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
835 struct nfs4_client *clp = dp->dl_client;
836 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
837
838 nfsd4_cb_done(task, calldata);
839
840 if (current_rpc_client != task->tk_client) {
841 /* We're shutting down or changing cl_cb_client; leave
842 * it to nfsd4_process_cb_update to restart the call if
843 * necessary. */
844 return;
845 }
846
847 if (cb->cb_done)
848 return;
849 switch (task->tk_status) {
850 case 0:
851 cb->cb_done = true;
852 return;
853 case -EBADHANDLE:
854 case -NFS4ERR_BAD_STATEID:
855 /* Race: client probably got cb_recall
856 * before open reply granting delegation */
857 break;
858 default:
859 /* Network partition? */
860 nfsd4_mark_cb_down(clp, task->tk_status);
861 }
862 if (dp->dl_retries--) {
863 rpc_delay(task, 2*HZ);
864 task->tk_status = 0;
865 rpc_restart_call_prepare(task);
866 return;
867 }
868 nfsd4_mark_cb_down(clp, task->tk_status);
869 cb->cb_done = true;
870}
871
872static void nfsd4_cb_recall_release(void *calldata)
873{
874 struct nfsd4_callback *cb = calldata;
875 struct nfs4_client *clp = cb->cb_clp;
876 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
877
878 if (cb->cb_done) {
879 spin_lock(&clp->cl_lock);
880 list_del(&cb->cb_per_client);
881 spin_unlock(&clp->cl_lock);
882 nfs4_put_delegation(dp);
883 }
884}
885
886static const struct rpc_call_ops nfsd4_cb_recall_ops = {
887 .rpc_call_prepare = nfsd4_cb_prepare,
888 .rpc_call_done = nfsd4_cb_recall_done,
889 .rpc_release = nfsd4_cb_recall_release,
890};
891
892int nfsd4_create_callback_queue(void)
893{
894 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
895 if (!callback_wq)
896 return -ENOMEM;
897 return 0;
898}
899
900void nfsd4_destroy_callback_queue(void)
901{
902 destroy_workqueue(callback_wq);
903}
904
905/* must be called under the state lock */
906void nfsd4_shutdown_callback(struct nfs4_client *clp)
907{
908 set_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags);
909 /*
910 * Note this won't actually result in a null callback;
911 * instead, nfsd4_do_callback_rpc() will detect the killed
912 * client, destroy the rpc client, and stop:
913 */
914 do_probe_callback(clp);
915 flush_workqueue(callback_wq);
916}
917
918static void nfsd4_release_cb(struct nfsd4_callback *cb)
919{
920 if (cb->cb_ops->rpc_release)
921 cb->cb_ops->rpc_release(cb);
922}
923
924/* requires cl_lock: */
925static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
926{
927 struct nfsd4_session *s;
928 struct nfsd4_conn *c;
929
930 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
931 list_for_each_entry(c, &s->se_conns, cn_persession) {
932 if (c->cn_flags & NFS4_CDFC4_BACK)
933 return c;
934 }
935 }
936 return NULL;
937}
938
939static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
940{
941 struct nfs4_cb_conn conn;
942 struct nfs4_client *clp = cb->cb_clp;
943 struct nfsd4_session *ses = NULL;
944 struct nfsd4_conn *c;
945 int err;
946
947 /*
948 * This is either an update, or the client dying; in either case,
949 * kill the old client:
950 */
951 if (clp->cl_cb_client) {
952 rpc_shutdown_client(clp->cl_cb_client);
953 clp->cl_cb_client = NULL;
954 }
955 if (clp->cl_cb_conn.cb_xprt) {
956 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
957 clp->cl_cb_conn.cb_xprt = NULL;
958 }
959 if (test_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags))
960 return;
961 spin_lock(&clp->cl_lock);
962 /*
963 * Only serialized callback code is allowed to clear these
964 * flags; main nfsd code can only set them:
965 */
966 BUG_ON(!clp->cl_cb_flags);
967 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags);
968 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
969 c = __nfsd4_find_backchannel(clp);
970 if (c) {
971 svc_xprt_get(c->cn_xprt);
972 conn.cb_xprt = c->cn_xprt;
973 ses = c->cn_session;
974 }
975 spin_unlock(&clp->cl_lock);
976
977 err = setup_callback_client(clp, &conn, ses);
978 if (err) {
979 warn_no_callback_path(clp, err);
980 return;
981 }
982 /* Yay, the callback channel's back! Restart any callbacks: */
983 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
984 run_nfsd4_cb(cb);
985}
986
987void nfsd4_do_callback_rpc(struct work_struct *w)
988{
989 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
990 struct nfs4_client *clp = cb->cb_clp;
991 struct rpc_clnt *clnt;
992
993 if (clp->cl_cb_flags)
994 nfsd4_process_cb_update(cb);
995
996 clnt = clp->cl_cb_client;
997 if (!clnt) {
998 /* Callback channel broken, or client killed; give up: */
999 nfsd4_release_cb(cb);
1000 return;
1001 }
1002 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1003 cb->cb_ops, cb);
1004}
1005
1006void nfsd4_cb_recall(struct nfs4_delegation *dp)
1007{
1008 struct nfsd4_callback *cb = &dp->dl_recall;
1009 struct nfs4_client *clp = dp->dl_client;
1010
1011 dp->dl_retries = 1;
1012 cb->cb_op = dp;
1013 cb->cb_clp = clp;
1014 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
1015 cb->cb_msg.rpc_argp = cb;
1016 cb->cb_msg.rpc_resp = cb;
1017 cb->cb_msg.rpc_cred = callback_cred;
1018
1019 cb->cb_ops = &nfsd4_cb_recall_ops;
1020 dp->dl_retries = 1;
1021
1022 INIT_LIST_HEAD(&cb->cb_per_client);
1023 cb->cb_done = true;
1024
1025 run_nfsd4_cb(&dp->dl_recall);
1026}