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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/nfs4.h>
35#include <linux/sunrpc/clnt.h>
36#include <linux/sunrpc/xprt.h>
37#include <linux/sunrpc/svc_xprt.h>
38#include <linux/slab.h>
39#include "nfsd.h"
40#include "state.h"
41#include "netns.h"
42#include "trace.h"
43#include "xdr4cb.h"
44#include "xdr4.h"
45
46#define NFSDDBG_FACILITY NFSDDBG_PROC
47
48static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
49
50#define NFSPROC4_CB_NULL 0
51#define NFSPROC4_CB_COMPOUND 1
52
53/* Index of predefined Linux callback client operations */
54
55struct nfs4_cb_compound_hdr {
56 /* args */
57 u32 ident; /* minorversion 0 only */
58 u32 nops;
59 __be32 *nops_p;
60 u32 minorversion;
61 /* res */
62 int status;
63};
64
65static __be32 *xdr_encode_empty_array(__be32 *p)
66{
67 *p++ = xdr_zero;
68 return p;
69}
70
71/*
72 * Encode/decode NFSv4 CB basic data types
73 *
74 * Basic NFSv4 callback data types are defined in section 15 of RFC
75 * 3530: "Network File System (NFS) version 4 Protocol" and section
76 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
77 * 1 Protocol"
78 */
79
80static void encode_uint32(struct xdr_stream *xdr, u32 n)
81{
82 WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
83}
84
85static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
86 size_t len)
87{
88 WARN_ON_ONCE(xdr_stream_encode_uint32_array(xdr, bitmap, len) < 0);
89}
90
91static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
92{
93 __be32 *p;
94
95 p = xdr_reserve_space(xdr, 4);
96 *p = cpu_to_be32(op);
97}
98
99/*
100 * nfs_fh4
101 *
102 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
103 */
104static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
105{
106 u32 length = fh->fh_size;
107 __be32 *p;
108
109 BUG_ON(length > NFS4_FHSIZE);
110 p = xdr_reserve_space(xdr, 4 + length);
111 xdr_encode_opaque(p, &fh->fh_raw, length);
112}
113
114/*
115 * stateid4
116 *
117 * struct stateid4 {
118 * uint32_t seqid;
119 * opaque other[12];
120 * };
121 */
122static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
123{
124 __be32 *p;
125
126 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
127 *p++ = cpu_to_be32(sid->si_generation);
128 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
129}
130
131/*
132 * sessionid4
133 *
134 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
135 */
136static void encode_sessionid4(struct xdr_stream *xdr,
137 const struct nfsd4_session *session)
138{
139 __be32 *p;
140
141 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
142 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
143 NFS4_MAX_SESSIONID_LEN);
144}
145
146/*
147 * nfsstat4
148 */
149static const struct {
150 int stat;
151 int errno;
152} nfs_cb_errtbl[] = {
153 { NFS4_OK, 0 },
154 { NFS4ERR_PERM, -EPERM },
155 { NFS4ERR_NOENT, -ENOENT },
156 { NFS4ERR_IO, -EIO },
157 { NFS4ERR_NXIO, -ENXIO },
158 { NFS4ERR_ACCESS, -EACCES },
159 { NFS4ERR_EXIST, -EEXIST },
160 { NFS4ERR_XDEV, -EXDEV },
161 { NFS4ERR_NOTDIR, -ENOTDIR },
162 { NFS4ERR_ISDIR, -EISDIR },
163 { NFS4ERR_INVAL, -EINVAL },
164 { NFS4ERR_FBIG, -EFBIG },
165 { NFS4ERR_NOSPC, -ENOSPC },
166 { NFS4ERR_ROFS, -EROFS },
167 { NFS4ERR_MLINK, -EMLINK },
168 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
169 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
170 { NFS4ERR_DQUOT, -EDQUOT },
171 { NFS4ERR_STALE, -ESTALE },
172 { NFS4ERR_BADHANDLE, -EBADHANDLE },
173 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
174 { NFS4ERR_NOTSUPP, -ENOTSUPP },
175 { NFS4ERR_TOOSMALL, -ETOOSMALL },
176 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
177 { NFS4ERR_BADTYPE, -EBADTYPE },
178 { NFS4ERR_LOCKED, -EAGAIN },
179 { NFS4ERR_RESOURCE, -EREMOTEIO },
180 { NFS4ERR_SYMLINK, -ELOOP },
181 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
182 { NFS4ERR_DEADLOCK, -EDEADLK },
183 { -1, -EIO }
184};
185
186/*
187 * If we cannot translate the error, the recovery routines should
188 * handle it.
189 *
190 * Note: remaining NFSv4 error codes have values > 10000, so should
191 * not conflict with native Linux error codes.
192 */
193static int nfs_cb_stat_to_errno(int status)
194{
195 int i;
196
197 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
198 if (nfs_cb_errtbl[i].stat == status)
199 return nfs_cb_errtbl[i].errno;
200 }
201
202 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
203 return -status;
204}
205
206static int decode_cb_op_status(struct xdr_stream *xdr,
207 enum nfs_cb_opnum4 expected, int *status)
208{
209 __be32 *p;
210 u32 op;
211
212 p = xdr_inline_decode(xdr, 4 + 4);
213 if (unlikely(p == NULL))
214 goto out_overflow;
215 op = be32_to_cpup(p++);
216 if (unlikely(op != expected))
217 goto out_unexpected;
218 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
219 return 0;
220out_overflow:
221 return -EIO;
222out_unexpected:
223 dprintk("NFSD: Callback server returned operation %d but "
224 "we issued a request for %d\n", op, expected);
225 return -EIO;
226}
227
228/*
229 * CB_COMPOUND4args
230 *
231 * struct CB_COMPOUND4args {
232 * utf8str_cs tag;
233 * uint32_t minorversion;
234 * uint32_t callback_ident;
235 * nfs_cb_argop4 argarray<>;
236 * };
237*/
238static void encode_cb_compound4args(struct xdr_stream *xdr,
239 struct nfs4_cb_compound_hdr *hdr)
240{
241 __be32 * p;
242
243 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
244 p = xdr_encode_empty_array(p); /* empty tag */
245 *p++ = cpu_to_be32(hdr->minorversion);
246 *p++ = cpu_to_be32(hdr->ident);
247
248 hdr->nops_p = p;
249 *p = cpu_to_be32(hdr->nops); /* argarray element count */
250}
251
252/*
253 * Update argarray element count
254 */
255static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
256{
257 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
258 *hdr->nops_p = cpu_to_be32(hdr->nops);
259}
260
261/*
262 * CB_COMPOUND4res
263 *
264 * struct CB_COMPOUND4res {
265 * nfsstat4 status;
266 * utf8str_cs tag;
267 * nfs_cb_resop4 resarray<>;
268 * };
269 */
270static int decode_cb_compound4res(struct xdr_stream *xdr,
271 struct nfs4_cb_compound_hdr *hdr)
272{
273 u32 length;
274 __be32 *p;
275
276 p = xdr_inline_decode(xdr, 4 + 4);
277 if (unlikely(p == NULL))
278 goto out_overflow;
279 hdr->status = be32_to_cpup(p++);
280 /* Ignore the tag */
281 length = be32_to_cpup(p++);
282 p = xdr_inline_decode(xdr, length + 4);
283 if (unlikely(p == NULL))
284 goto out_overflow;
285 p += XDR_QUADLEN(length);
286 hdr->nops = be32_to_cpup(p);
287 return 0;
288out_overflow:
289 return -EIO;
290}
291
292/*
293 * CB_RECALL4args
294 *
295 * struct CB_RECALL4args {
296 * stateid4 stateid;
297 * bool truncate;
298 * nfs_fh4 fh;
299 * };
300 */
301static void encode_cb_recall4args(struct xdr_stream *xdr,
302 const struct nfs4_delegation *dp,
303 struct nfs4_cb_compound_hdr *hdr)
304{
305 __be32 *p;
306
307 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
308 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
309
310 p = xdr_reserve_space(xdr, 4);
311 *p++ = xdr_zero; /* truncate */
312
313 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
314
315 hdr->nops++;
316}
317
318/*
319 * CB_RECALLANY4args
320 *
321 * struct CB_RECALLANY4args {
322 * uint32_t craa_objects_to_keep;
323 * bitmap4 craa_type_mask;
324 * };
325 */
326static void
327encode_cb_recallany4args(struct xdr_stream *xdr,
328 struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra)
329{
330 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL_ANY);
331 encode_uint32(xdr, ra->ra_keep);
332 encode_bitmap4(xdr, ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval));
333 hdr->nops++;
334}
335
336/*
337 * CB_SEQUENCE4args
338 *
339 * struct CB_SEQUENCE4args {
340 * sessionid4 csa_sessionid;
341 * sequenceid4 csa_sequenceid;
342 * slotid4 csa_slotid;
343 * slotid4 csa_highest_slotid;
344 * bool csa_cachethis;
345 * referring_call_list4 csa_referring_call_lists<>;
346 * };
347 */
348static void encode_cb_sequence4args(struct xdr_stream *xdr,
349 const struct nfsd4_callback *cb,
350 struct nfs4_cb_compound_hdr *hdr)
351{
352 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
353 __be32 *p;
354
355 if (hdr->minorversion == 0)
356 return;
357
358 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
359 encode_sessionid4(xdr, session);
360
361 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
362 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
363 *p++ = xdr_zero; /* csa_slotid */
364 *p++ = xdr_zero; /* csa_highest_slotid */
365 *p++ = xdr_zero; /* csa_cachethis */
366 xdr_encode_empty_array(p); /* csa_referring_call_lists */
367
368 hdr->nops++;
369}
370
371/*
372 * CB_SEQUENCE4resok
373 *
374 * struct CB_SEQUENCE4resok {
375 * sessionid4 csr_sessionid;
376 * sequenceid4 csr_sequenceid;
377 * slotid4 csr_slotid;
378 * slotid4 csr_highest_slotid;
379 * slotid4 csr_target_highest_slotid;
380 * };
381 *
382 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
383 * case NFS4_OK:
384 * CB_SEQUENCE4resok csr_resok4;
385 * default:
386 * void;
387 * };
388 *
389 * Our current back channel implmentation supports a single backchannel
390 * with a single slot.
391 */
392static int decode_cb_sequence4resok(struct xdr_stream *xdr,
393 struct nfsd4_callback *cb)
394{
395 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
396 int status = -ESERVERFAULT;
397 __be32 *p;
398 u32 dummy;
399
400 /*
401 * If the server returns different values for sessionID, slotID or
402 * sequence number, the server is looney tunes.
403 */
404 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
405 if (unlikely(p == NULL))
406 goto out_overflow;
407
408 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
409 dprintk("NFS: %s Invalid session id\n", __func__);
410 goto out;
411 }
412 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
413
414 dummy = be32_to_cpup(p++);
415 if (dummy != session->se_cb_seq_nr) {
416 dprintk("NFS: %s Invalid sequence number\n", __func__);
417 goto out;
418 }
419
420 dummy = be32_to_cpup(p++);
421 if (dummy != 0) {
422 dprintk("NFS: %s Invalid slotid\n", __func__);
423 goto out;
424 }
425
426 /*
427 * FIXME: process highest slotid and target highest slotid
428 */
429 status = 0;
430out:
431 cb->cb_seq_status = status;
432 return status;
433out_overflow:
434 status = -EIO;
435 goto out;
436}
437
438static int decode_cb_sequence4res(struct xdr_stream *xdr,
439 struct nfsd4_callback *cb)
440{
441 int status;
442
443 if (cb->cb_clp->cl_minorversion == 0)
444 return 0;
445
446 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
447 if (unlikely(status || cb->cb_seq_status))
448 return status;
449
450 return decode_cb_sequence4resok(xdr, cb);
451}
452
453/*
454 * NFSv4.0 and NFSv4.1 XDR encode functions
455 *
456 * NFSv4.0 callback argument types are defined in section 15 of RFC
457 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
458 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
459 * Protocol".
460 */
461
462/*
463 * NB: Without this zero space reservation, callbacks over krb5p fail
464 */
465static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
466 const void *__unused)
467{
468 xdr_reserve_space(xdr, 0);
469}
470
471/*
472 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
473 */
474static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
475 const void *data)
476{
477 const struct nfsd4_callback *cb = data;
478 const struct nfs4_delegation *dp = cb_to_delegation(cb);
479 struct nfs4_cb_compound_hdr hdr = {
480 .ident = cb->cb_clp->cl_cb_ident,
481 .minorversion = cb->cb_clp->cl_minorversion,
482 };
483
484 encode_cb_compound4args(xdr, &hdr);
485 encode_cb_sequence4args(xdr, cb, &hdr);
486 encode_cb_recall4args(xdr, dp, &hdr);
487 encode_cb_nops(&hdr);
488}
489
490/*
491 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
492 */
493static void
494nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
495 struct xdr_stream *xdr, const void *data)
496{
497 const struct nfsd4_callback *cb = data;
498 struct nfsd4_cb_recall_any *ra;
499 struct nfs4_cb_compound_hdr hdr = {
500 .ident = cb->cb_clp->cl_cb_ident,
501 .minorversion = cb->cb_clp->cl_minorversion,
502 };
503
504 ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
505 encode_cb_compound4args(xdr, &hdr);
506 encode_cb_sequence4args(xdr, cb, &hdr);
507 encode_cb_recallany4args(xdr, &hdr, ra);
508 encode_cb_nops(&hdr);
509}
510
511/*
512 * NFSv4.0 and NFSv4.1 XDR decode functions
513 *
514 * NFSv4.0 callback result types are defined in section 15 of RFC
515 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
516 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
517 * Protocol".
518 */
519
520static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
521 void *__unused)
522{
523 return 0;
524}
525
526/*
527 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
528 */
529static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
530 struct xdr_stream *xdr,
531 void *data)
532{
533 struct nfsd4_callback *cb = data;
534 struct nfs4_cb_compound_hdr hdr;
535 int status;
536
537 status = decode_cb_compound4res(xdr, &hdr);
538 if (unlikely(status))
539 return status;
540
541 status = decode_cb_sequence4res(xdr, cb);
542 if (unlikely(status || cb->cb_seq_status))
543 return status;
544
545 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
546}
547
548/*
549 * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
550 */
551static int
552nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
553 struct xdr_stream *xdr,
554 void *data)
555{
556 struct nfsd4_callback *cb = data;
557 struct nfs4_cb_compound_hdr hdr;
558 int status;
559
560 status = decode_cb_compound4res(xdr, &hdr);
561 if (unlikely(status))
562 return status;
563 status = decode_cb_sequence4res(xdr, cb);
564 if (unlikely(status || cb->cb_seq_status))
565 return status;
566 status = decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status);
567 return status;
568}
569
570#ifdef CONFIG_NFSD_PNFS
571/*
572 * CB_LAYOUTRECALL4args
573 *
574 * struct layoutrecall_file4 {
575 * nfs_fh4 lor_fh;
576 * offset4 lor_offset;
577 * length4 lor_length;
578 * stateid4 lor_stateid;
579 * };
580 *
581 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
582 * case LAYOUTRECALL4_FILE:
583 * layoutrecall_file4 lor_layout;
584 * case LAYOUTRECALL4_FSID:
585 * fsid4 lor_fsid;
586 * case LAYOUTRECALL4_ALL:
587 * void;
588 * };
589 *
590 * struct CB_LAYOUTRECALL4args {
591 * layouttype4 clora_type;
592 * layoutiomode4 clora_iomode;
593 * bool clora_changed;
594 * layoutrecall4 clora_recall;
595 * };
596 */
597static void encode_cb_layout4args(struct xdr_stream *xdr,
598 const struct nfs4_layout_stateid *ls,
599 struct nfs4_cb_compound_hdr *hdr)
600{
601 __be32 *p;
602
603 BUG_ON(hdr->minorversion == 0);
604
605 p = xdr_reserve_space(xdr, 5 * 4);
606 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
607 *p++ = cpu_to_be32(ls->ls_layout_type);
608 *p++ = cpu_to_be32(IOMODE_ANY);
609 *p++ = cpu_to_be32(1);
610 *p = cpu_to_be32(RETURN_FILE);
611
612 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
613
614 p = xdr_reserve_space(xdr, 2 * 8);
615 p = xdr_encode_hyper(p, 0);
616 xdr_encode_hyper(p, NFS4_MAX_UINT64);
617
618 encode_stateid4(xdr, &ls->ls_recall_sid);
619
620 hdr->nops++;
621}
622
623static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
624 struct xdr_stream *xdr,
625 const void *data)
626{
627 const struct nfsd4_callback *cb = data;
628 const struct nfs4_layout_stateid *ls =
629 container_of(cb, struct nfs4_layout_stateid, ls_recall);
630 struct nfs4_cb_compound_hdr hdr = {
631 .ident = 0,
632 .minorversion = cb->cb_clp->cl_minorversion,
633 };
634
635 encode_cb_compound4args(xdr, &hdr);
636 encode_cb_sequence4args(xdr, cb, &hdr);
637 encode_cb_layout4args(xdr, ls, &hdr);
638 encode_cb_nops(&hdr);
639}
640
641static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
642 struct xdr_stream *xdr,
643 void *data)
644{
645 struct nfsd4_callback *cb = data;
646 struct nfs4_cb_compound_hdr hdr;
647 int status;
648
649 status = decode_cb_compound4res(xdr, &hdr);
650 if (unlikely(status))
651 return status;
652
653 status = decode_cb_sequence4res(xdr, cb);
654 if (unlikely(status || cb->cb_seq_status))
655 return status;
656
657 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
658}
659#endif /* CONFIG_NFSD_PNFS */
660
661static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
662{
663 __be32 *p;
664
665 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
666 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
667 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
668}
669
670static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
671 struct xdr_stream *xdr,
672 const void *data)
673{
674 const struct nfsd4_callback *cb = data;
675 const struct nfsd4_blocked_lock *nbl =
676 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
677 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
678 struct nfs4_cb_compound_hdr hdr = {
679 .ident = 0,
680 .minorversion = cb->cb_clp->cl_minorversion,
681 };
682
683 __be32 *p;
684
685 BUG_ON(hdr.minorversion == 0);
686
687 encode_cb_compound4args(xdr, &hdr);
688 encode_cb_sequence4args(xdr, cb, &hdr);
689
690 p = xdr_reserve_space(xdr, 4);
691 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
692 encode_nfs_fh4(xdr, &nbl->nbl_fh);
693 encode_stateowner(xdr, &lo->lo_owner);
694 hdr.nops++;
695
696 encode_cb_nops(&hdr);
697}
698
699static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
700 struct xdr_stream *xdr,
701 void *data)
702{
703 struct nfsd4_callback *cb = data;
704 struct nfs4_cb_compound_hdr hdr;
705 int status;
706
707 status = decode_cb_compound4res(xdr, &hdr);
708 if (unlikely(status))
709 return status;
710
711 status = decode_cb_sequence4res(xdr, cb);
712 if (unlikely(status || cb->cb_seq_status))
713 return status;
714
715 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
716}
717
718/*
719 * struct write_response4 {
720 * stateid4 wr_callback_id<1>;
721 * length4 wr_count;
722 * stable_how4 wr_committed;
723 * verifier4 wr_writeverf;
724 * };
725 * union offload_info4 switch (nfsstat4 coa_status) {
726 * case NFS4_OK:
727 * write_response4 coa_resok4;
728 * default:
729 * length4 coa_bytes_copied;
730 * };
731 * struct CB_OFFLOAD4args {
732 * nfs_fh4 coa_fh;
733 * stateid4 coa_stateid;
734 * offload_info4 coa_offload_info;
735 * };
736 */
737static void encode_offload_info4(struct xdr_stream *xdr,
738 const struct nfsd4_cb_offload *cbo)
739{
740 __be32 *p;
741
742 p = xdr_reserve_space(xdr, 4);
743 *p = cbo->co_nfserr;
744 switch (cbo->co_nfserr) {
745 case nfs_ok:
746 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
747 p = xdr_encode_empty_array(p);
748 p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written);
749 *p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
750 p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data,
751 NFS4_VERIFIER_SIZE);
752 break;
753 default:
754 p = xdr_reserve_space(xdr, 8);
755 /* We always return success if bytes were written */
756 p = xdr_encode_hyper(p, 0);
757 }
758}
759
760static void encode_cb_offload4args(struct xdr_stream *xdr,
761 const struct nfsd4_cb_offload *cbo,
762 struct nfs4_cb_compound_hdr *hdr)
763{
764 __be32 *p;
765
766 p = xdr_reserve_space(xdr, 4);
767 *p = cpu_to_be32(OP_CB_OFFLOAD);
768 encode_nfs_fh4(xdr, &cbo->co_fh);
769 encode_stateid4(xdr, &cbo->co_res.cb_stateid);
770 encode_offload_info4(xdr, cbo);
771
772 hdr->nops++;
773}
774
775static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
776 struct xdr_stream *xdr,
777 const void *data)
778{
779 const struct nfsd4_callback *cb = data;
780 const struct nfsd4_cb_offload *cbo =
781 container_of(cb, struct nfsd4_cb_offload, co_cb);
782 struct nfs4_cb_compound_hdr hdr = {
783 .ident = 0,
784 .minorversion = cb->cb_clp->cl_minorversion,
785 };
786
787 encode_cb_compound4args(xdr, &hdr);
788 encode_cb_sequence4args(xdr, cb, &hdr);
789 encode_cb_offload4args(xdr, cbo, &hdr);
790 encode_cb_nops(&hdr);
791}
792
793static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
794 struct xdr_stream *xdr,
795 void *data)
796{
797 struct nfsd4_callback *cb = data;
798 struct nfs4_cb_compound_hdr hdr;
799 int status;
800
801 status = decode_cb_compound4res(xdr, &hdr);
802 if (unlikely(status))
803 return status;
804
805 status = decode_cb_sequence4res(xdr, cb);
806 if (unlikely(status || cb->cb_seq_status))
807 return status;
808
809 return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
810}
811/*
812 * RPC procedure tables
813 */
814#define PROC(proc, call, argtype, restype) \
815[NFSPROC4_CLNT_##proc] = { \
816 .p_proc = NFSPROC4_CB_##call, \
817 .p_encode = nfs4_xdr_enc_##argtype, \
818 .p_decode = nfs4_xdr_dec_##restype, \
819 .p_arglen = NFS4_enc_##argtype##_sz, \
820 .p_replen = NFS4_dec_##restype##_sz, \
821 .p_statidx = NFSPROC4_CB_##call, \
822 .p_name = #proc, \
823}
824
825static const struct rpc_procinfo nfs4_cb_procedures[] = {
826 PROC(CB_NULL, NULL, cb_null, cb_null),
827 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
828#ifdef CONFIG_NFSD_PNFS
829 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
830#endif
831 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
832 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
833 PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
834};
835
836static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
837static const struct rpc_version nfs_cb_version4 = {
838/*
839 * Note on the callback rpc program version number: despite language in rfc
840 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
841 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
842 * in practice that appears to be what implementations use. The section
843 * 18.36.3 language is expected to be fixed in an erratum.
844 */
845 .number = 1,
846 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
847 .procs = nfs4_cb_procedures,
848 .counts = nfs4_cb_counts,
849};
850
851static const struct rpc_version *nfs_cb_version[2] = {
852 [1] = &nfs_cb_version4,
853};
854
855static const struct rpc_program cb_program;
856
857static struct rpc_stat cb_stats = {
858 .program = &cb_program
859};
860
861#define NFS4_CALLBACK 0x40000000
862static const struct rpc_program cb_program = {
863 .name = "nfs4_cb",
864 .number = NFS4_CALLBACK,
865 .nrvers = ARRAY_SIZE(nfs_cb_version),
866 .version = nfs_cb_version,
867 .stats = &cb_stats,
868 .pipe_dir_name = "nfsd4_cb",
869};
870
871static int max_cb_time(struct net *net)
872{
873 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
874
875 /*
876 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
877 * so we can use 32-bit math on it. Warn if that assumption
878 * ever stops being true.
879 */
880 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
881 return 360 * HZ;
882
883 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
884}
885
886static struct workqueue_struct *callback_wq;
887
888static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
889{
890 return queue_work(callback_wq, &cb->cb_work);
891}
892
893static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
894{
895 atomic_inc(&clp->cl_cb_inflight);
896}
897
898static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
899{
900
901 if (atomic_dec_and_test(&clp->cl_cb_inflight))
902 wake_up_var(&clp->cl_cb_inflight);
903}
904
905static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
906{
907 wait_var_event(&clp->cl_cb_inflight,
908 !atomic_read(&clp->cl_cb_inflight));
909}
910
911static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
912{
913 if (clp->cl_minorversion == 0) {
914 client->cl_principal = clp->cl_cred.cr_targ_princ ?
915 clp->cl_cred.cr_targ_princ : "nfs";
916
917 return get_cred(rpc_machine_cred());
918 } else {
919 struct cred *kcred;
920
921 kcred = prepare_kernel_cred(&init_task);
922 if (!kcred)
923 return NULL;
924
925 kcred->fsuid = ses->se_cb_sec.uid;
926 kcred->fsgid = ses->se_cb_sec.gid;
927 return kcred;
928 }
929}
930
931static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
932{
933 int maxtime = max_cb_time(clp->net);
934 struct rpc_timeout timeparms = {
935 .to_initval = maxtime,
936 .to_retries = 0,
937 .to_maxval = maxtime,
938 };
939 struct rpc_create_args args = {
940 .net = clp->net,
941 .address = (struct sockaddr *) &conn->cb_addr,
942 .addrsize = conn->cb_addrlen,
943 .saddress = (struct sockaddr *) &conn->cb_saddr,
944 .timeout = &timeparms,
945 .program = &cb_program,
946 .version = 1,
947 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
948 .cred = current_cred(),
949 };
950 struct rpc_clnt *client;
951 const struct cred *cred;
952
953 if (clp->cl_minorversion == 0) {
954 if (!clp->cl_cred.cr_principal &&
955 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
956 trace_nfsd_cb_setup_err(clp, -EINVAL);
957 return -EINVAL;
958 }
959 args.client_name = clp->cl_cred.cr_principal;
960 args.prognumber = conn->cb_prog;
961 args.protocol = XPRT_TRANSPORT_TCP;
962 args.authflavor = clp->cl_cred.cr_flavor;
963 clp->cl_cb_ident = conn->cb_ident;
964 } else {
965 if (!conn->cb_xprt)
966 return -EINVAL;
967 clp->cl_cb_session = ses;
968 args.bc_xprt = conn->cb_xprt;
969 args.prognumber = clp->cl_cb_session->se_cb_prog;
970 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
971 XPRT_TRANSPORT_BC;
972 args.authflavor = ses->se_cb_sec.flavor;
973 }
974 /* Create RPC client */
975 client = rpc_create(&args);
976 if (IS_ERR(client)) {
977 trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
978 return PTR_ERR(client);
979 }
980 cred = get_backchannel_cred(clp, client, ses);
981 if (!cred) {
982 trace_nfsd_cb_setup_err(clp, -ENOMEM);
983 rpc_shutdown_client(client);
984 return -ENOMEM;
985 }
986
987 if (clp->cl_minorversion != 0)
988 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
989 clp->cl_cb_client = client;
990 clp->cl_cb_cred = cred;
991 rcu_read_lock();
992 trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
993 args.authflavor);
994 rcu_read_unlock();
995 return 0;
996}
997
998static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
999{
1000 if (clp->cl_cb_state != newstate) {
1001 clp->cl_cb_state = newstate;
1002 trace_nfsd_cb_state(clp);
1003 }
1004}
1005
1006static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
1007{
1008 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1009 return;
1010 nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
1011}
1012
1013static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
1014{
1015 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
1016 return;
1017 nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
1018}
1019
1020static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
1021{
1022 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1023
1024 if (task->tk_status)
1025 nfsd4_mark_cb_down(clp, task->tk_status);
1026 else
1027 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1028}
1029
1030static void nfsd4_cb_probe_release(void *calldata)
1031{
1032 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
1033
1034 nfsd41_cb_inflight_end(clp);
1035
1036}
1037
1038static const struct rpc_call_ops nfsd4_cb_probe_ops = {
1039 /* XXX: release method to ensure we set the cb channel down if
1040 * necessary on early failure? */
1041 .rpc_call_done = nfsd4_cb_probe_done,
1042 .rpc_release = nfsd4_cb_probe_release,
1043};
1044
1045/*
1046 * Poke the callback thread to process any updates to the callback
1047 * parameters, and send a null probe.
1048 */
1049void nfsd4_probe_callback(struct nfs4_client *clp)
1050{
1051 trace_nfsd_cb_probe(clp);
1052 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1053 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1054 nfsd4_run_cb(&clp->cl_cb_null);
1055}
1056
1057void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1058{
1059 nfsd4_probe_callback(clp);
1060 flush_workqueue(callback_wq);
1061}
1062
1063void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1064{
1065 nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
1066 spin_lock(&clp->cl_lock);
1067 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1068 spin_unlock(&clp->cl_lock);
1069}
1070
1071/*
1072 * There's currently a single callback channel slot.
1073 * If the slot is available, then mark it busy. Otherwise, set the
1074 * thread for sleeping on the callback RPC wait queue.
1075 */
1076static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1077{
1078 struct nfs4_client *clp = cb->cb_clp;
1079
1080 if (!cb->cb_holds_slot &&
1081 test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1082 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1083 /* Race breaker */
1084 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1085 dprintk("%s slot is busy\n", __func__);
1086 return false;
1087 }
1088 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1089 }
1090 cb->cb_holds_slot = true;
1091 return true;
1092}
1093
1094static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1095{
1096 struct nfs4_client *clp = cb->cb_clp;
1097
1098 if (cb->cb_holds_slot) {
1099 cb->cb_holds_slot = false;
1100 clear_bit(0, &clp->cl_cb_slot_busy);
1101 rpc_wake_up_next(&clp->cl_cb_waitq);
1102 }
1103}
1104
1105static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1106{
1107 struct nfs4_client *clp = cb->cb_clp;
1108
1109 nfsd41_cb_release_slot(cb);
1110 if (cb->cb_ops && cb->cb_ops->release)
1111 cb->cb_ops->release(cb);
1112 nfsd41_cb_inflight_end(clp);
1113}
1114
1115/*
1116 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1117 * slots, and mark callback channel down on communication errors.
1118 */
1119static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1120{
1121 struct nfsd4_callback *cb = calldata;
1122 struct nfs4_client *clp = cb->cb_clp;
1123 u32 minorversion = clp->cl_minorversion;
1124
1125 /*
1126 * cb_seq_status is only set in decode_cb_sequence4res,
1127 * and so will remain 1 if an rpc level failure occurs.
1128 */
1129 cb->cb_seq_status = 1;
1130 cb->cb_status = 0;
1131 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1132 return;
1133 rpc_call_start(task);
1134}
1135
1136static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1137{
1138 struct nfs4_client *clp = cb->cb_clp;
1139 struct nfsd4_session *session = clp->cl_cb_session;
1140 bool ret = true;
1141
1142 if (!clp->cl_minorversion) {
1143 /*
1144 * If the backchannel connection was shut down while this
1145 * task was queued, we need to resubmit it after setting up
1146 * a new backchannel connection.
1147 *
1148 * Note that if we lost our callback connection permanently
1149 * the submission code will error out, so we don't need to
1150 * handle that case here.
1151 */
1152 if (RPC_SIGNALLED(task))
1153 goto need_restart;
1154
1155 return true;
1156 }
1157
1158 if (!cb->cb_holds_slot)
1159 goto need_restart;
1160
1161 switch (cb->cb_seq_status) {
1162 case 0:
1163 /*
1164 * No need for lock, access serialized in nfsd4_cb_prepare
1165 *
1166 * RFC5661 20.9.3
1167 * If CB_SEQUENCE returns an error, then the state of the slot
1168 * (sequence ID, cached reply) MUST NOT change.
1169 */
1170 ++session->se_cb_seq_nr;
1171 break;
1172 case -ESERVERFAULT:
1173 ++session->se_cb_seq_nr;
1174 fallthrough;
1175 case 1:
1176 case -NFS4ERR_BADSESSION:
1177 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1178 ret = false;
1179 break;
1180 case -NFS4ERR_DELAY:
1181 if (!rpc_restart_call(task))
1182 goto out;
1183
1184 rpc_delay(task, 2 * HZ);
1185 return false;
1186 case -NFS4ERR_BADSLOT:
1187 goto retry_nowait;
1188 case -NFS4ERR_SEQ_MISORDERED:
1189 if (session->se_cb_seq_nr != 1) {
1190 session->se_cb_seq_nr = 1;
1191 goto retry_nowait;
1192 }
1193 break;
1194 default:
1195 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1196 dprintk("%s: unprocessed error %d\n", __func__,
1197 cb->cb_seq_status);
1198 }
1199
1200 nfsd41_cb_release_slot(cb);
1201 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1202 clp->cl_cb_session->se_cb_seq_nr);
1203
1204 if (RPC_SIGNALLED(task))
1205 goto need_restart;
1206out:
1207 return ret;
1208retry_nowait:
1209 if (rpc_restart_call_prepare(task))
1210 ret = false;
1211 goto out;
1212need_restart:
1213 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1214 task->tk_status = 0;
1215 cb->cb_need_restart = true;
1216 }
1217 return false;
1218}
1219
1220static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1221{
1222 struct nfsd4_callback *cb = calldata;
1223 struct nfs4_client *clp = cb->cb_clp;
1224
1225 if (!nfsd4_cb_sequence_done(task, cb))
1226 return;
1227
1228 if (cb->cb_status) {
1229 WARN_ON_ONCE(task->tk_status);
1230 task->tk_status = cb->cb_status;
1231 }
1232
1233 switch (cb->cb_ops->done(cb, task)) {
1234 case 0:
1235 task->tk_status = 0;
1236 rpc_restart_call_prepare(task);
1237 return;
1238 case 1:
1239 switch (task->tk_status) {
1240 case -EIO:
1241 case -ETIMEDOUT:
1242 case -EACCES:
1243 nfsd4_mark_cb_down(clp, task->tk_status);
1244 }
1245 break;
1246 default:
1247 BUG();
1248 }
1249}
1250
1251static void nfsd4_cb_release(void *calldata)
1252{
1253 struct nfsd4_callback *cb = calldata;
1254
1255 if (cb->cb_need_restart)
1256 nfsd4_queue_cb(cb);
1257 else
1258 nfsd41_destroy_cb(cb);
1259
1260}
1261
1262static const struct rpc_call_ops nfsd4_cb_ops = {
1263 .rpc_call_prepare = nfsd4_cb_prepare,
1264 .rpc_call_done = nfsd4_cb_done,
1265 .rpc_release = nfsd4_cb_release,
1266};
1267
1268int nfsd4_create_callback_queue(void)
1269{
1270 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1271 if (!callback_wq)
1272 return -ENOMEM;
1273 return 0;
1274}
1275
1276void nfsd4_destroy_callback_queue(void)
1277{
1278 destroy_workqueue(callback_wq);
1279}
1280
1281/* must be called under the state lock */
1282void nfsd4_shutdown_callback(struct nfs4_client *clp)
1283{
1284 if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
1285 trace_nfsd_cb_shutdown(clp);
1286
1287 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1288 /*
1289 * Note this won't actually result in a null callback;
1290 * instead, nfsd4_run_cb_null() will detect the killed
1291 * client, destroy the rpc client, and stop:
1292 */
1293 nfsd4_run_cb(&clp->cl_cb_null);
1294 flush_workqueue(callback_wq);
1295 nfsd41_cb_inflight_wait_complete(clp);
1296}
1297
1298/* requires cl_lock: */
1299static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1300{
1301 struct nfsd4_session *s;
1302 struct nfsd4_conn *c;
1303
1304 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1305 list_for_each_entry(c, &s->se_conns, cn_persession) {
1306 if (c->cn_flags & NFS4_CDFC4_BACK)
1307 return c;
1308 }
1309 }
1310 return NULL;
1311}
1312
1313/*
1314 * Note there isn't a lot of locking in this code; instead we depend on
1315 * the fact that it is run from the callback_wq, which won't run two
1316 * work items at once. So, for example, callback_wq handles all access
1317 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1318 */
1319static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1320{
1321 struct nfs4_cb_conn conn;
1322 struct nfs4_client *clp = cb->cb_clp;
1323 struct nfsd4_session *ses = NULL;
1324 struct nfsd4_conn *c;
1325 int err;
1326
1327 /*
1328 * This is either an update, or the client dying; in either case,
1329 * kill the old client:
1330 */
1331 if (clp->cl_cb_client) {
1332 rpc_shutdown_client(clp->cl_cb_client);
1333 clp->cl_cb_client = NULL;
1334 put_cred(clp->cl_cb_cred);
1335 clp->cl_cb_cred = NULL;
1336 }
1337 if (clp->cl_cb_conn.cb_xprt) {
1338 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1339 clp->cl_cb_conn.cb_xprt = NULL;
1340 }
1341 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1342 return;
1343 spin_lock(&clp->cl_lock);
1344 /*
1345 * Only serialized callback code is allowed to clear these
1346 * flags; main nfsd code can only set them:
1347 */
1348 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1349 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1350 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1351 c = __nfsd4_find_backchannel(clp);
1352 if (c) {
1353 svc_xprt_get(c->cn_xprt);
1354 conn.cb_xprt = c->cn_xprt;
1355 ses = c->cn_session;
1356 }
1357 spin_unlock(&clp->cl_lock);
1358
1359 err = setup_callback_client(clp, &conn, ses);
1360 if (err) {
1361 nfsd4_mark_cb_down(clp, err);
1362 if (c)
1363 svc_xprt_put(c->cn_xprt);
1364 return;
1365 }
1366}
1367
1368static void
1369nfsd4_run_cb_work(struct work_struct *work)
1370{
1371 struct nfsd4_callback *cb =
1372 container_of(work, struct nfsd4_callback, cb_work);
1373 struct nfs4_client *clp = cb->cb_clp;
1374 struct rpc_clnt *clnt;
1375 int flags;
1376
1377 if (cb->cb_need_restart) {
1378 cb->cb_need_restart = false;
1379 } else {
1380 if (cb->cb_ops && cb->cb_ops->prepare)
1381 cb->cb_ops->prepare(cb);
1382 }
1383
1384 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1385 nfsd4_process_cb_update(cb);
1386
1387 clnt = clp->cl_cb_client;
1388 if (!clnt) {
1389 /* Callback channel broken, or client killed; give up: */
1390 nfsd41_destroy_cb(cb);
1391 return;
1392 }
1393
1394 /*
1395 * Don't send probe messages for 4.1 or later.
1396 */
1397 if (!cb->cb_ops && clp->cl_minorversion) {
1398 nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
1399 nfsd41_destroy_cb(cb);
1400 return;
1401 }
1402
1403 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1404 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1405 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1406 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1407}
1408
1409void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1410 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1411{
1412 cb->cb_clp = clp;
1413 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1414 cb->cb_msg.rpc_argp = cb;
1415 cb->cb_msg.rpc_resp = cb;
1416 cb->cb_ops = ops;
1417 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1418 cb->cb_seq_status = 1;
1419 cb->cb_status = 0;
1420 cb->cb_need_restart = false;
1421 cb->cb_holds_slot = false;
1422}
1423
1424/**
1425 * nfsd4_run_cb - queue up a callback job to run
1426 * @cb: callback to queue
1427 *
1428 * Kick off a callback to do its thing. Returns false if it was already
1429 * on a queue, true otherwise.
1430 */
1431bool nfsd4_run_cb(struct nfsd4_callback *cb)
1432{
1433 struct nfs4_client *clp = cb->cb_clp;
1434 bool queued;
1435
1436 nfsd41_cb_inflight_begin(clp);
1437 queued = nfsd4_queue_cb(cb);
1438 if (!queued)
1439 nfsd41_cb_inflight_end(clp);
1440 return queued;
1441}