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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/svc_xprt.h>
36#include <linux/slab.h>
37#include "nfsd.h"
38#include "state.h"
39
40#define NFSDDBG_FACILITY NFSDDBG_PROC
41
42static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
43
44#define NFSPROC4_CB_NULL 0
45#define NFSPROC4_CB_COMPOUND 1
46
47/* Index of predefined Linux callback client operations */
48
49enum {
50 NFSPROC4_CLNT_CB_NULL = 0,
51 NFSPROC4_CLNT_CB_RECALL,
52 NFSPROC4_CLNT_CB_SEQUENCE,
53};
54
55#define NFS4_MAXTAGLEN 20
56
57#define NFS4_enc_cb_null_sz 0
58#define NFS4_dec_cb_null_sz 0
59#define cb_compound_enc_hdr_sz 4
60#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
61#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
62#define cb_sequence_enc_sz (sessionid_sz + 4 + \
63 1 /* no referring calls list yet */)
64#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
65
66#define op_enc_sz 1
67#define op_dec_sz 2
68#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
69#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
70#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
71 cb_sequence_enc_sz + \
72 1 + enc_stateid_sz + \
73 enc_nfs4_fh_sz)
74
75#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
76 cb_sequence_dec_sz + \
77 op_dec_sz)
78
79struct nfs4_cb_compound_hdr {
80 /* args */
81 u32 ident; /* minorversion 0 only */
82 u32 nops;
83 __be32 *nops_p;
84 u32 minorversion;
85 /* res */
86 int status;
87};
88
89/*
90 * Handle decode buffer overflows out-of-line.
91 */
92static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
93{
94 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
95 "Remaining buffer length is %tu words.\n",
96 func, xdr->end - xdr->p);
97}
98
99static __be32 *xdr_encode_empty_array(__be32 *p)
100{
101 *p++ = xdr_zero;
102 return p;
103}
104
105/*
106 * Encode/decode NFSv4 CB basic data types
107 *
108 * Basic NFSv4 callback data types are defined in section 15 of RFC
109 * 3530: "Network File System (NFS) version 4 Protocol" and section
110 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
111 * 1 Protocol"
112 */
113
114/*
115 * nfs_cb_opnum4
116 *
117 * enum nfs_cb_opnum4 {
118 * OP_CB_GETATTR = 3,
119 * ...
120 * };
121 */
122enum nfs_cb_opnum4 {
123 OP_CB_GETATTR = 3,
124 OP_CB_RECALL = 4,
125 OP_CB_LAYOUTRECALL = 5,
126 OP_CB_NOTIFY = 6,
127 OP_CB_PUSH_DELEG = 7,
128 OP_CB_RECALL_ANY = 8,
129 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
130 OP_CB_RECALL_SLOT = 10,
131 OP_CB_SEQUENCE = 11,
132 OP_CB_WANTS_CANCELLED = 12,
133 OP_CB_NOTIFY_LOCK = 13,
134 OP_CB_NOTIFY_DEVICEID = 14,
135 OP_CB_ILLEGAL = 10044
136};
137
138static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
139{
140 __be32 *p;
141
142 p = xdr_reserve_space(xdr, 4);
143 *p = cpu_to_be32(op);
144}
145
146/*
147 * nfs_fh4
148 *
149 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
150 */
151static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
152{
153 u32 length = fh->fh_size;
154 __be32 *p;
155
156 BUG_ON(length > NFS4_FHSIZE);
157 p = xdr_reserve_space(xdr, 4 + length);
158 xdr_encode_opaque(p, &fh->fh_base, length);
159}
160
161/*
162 * stateid4
163 *
164 * struct stateid4 {
165 * uint32_t seqid;
166 * opaque other[12];
167 * };
168 */
169static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
170{
171 __be32 *p;
172
173 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
174 *p++ = cpu_to_be32(sid->si_generation);
175 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
176}
177
178/*
179 * sessionid4
180 *
181 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
182 */
183static void encode_sessionid4(struct xdr_stream *xdr,
184 const struct nfsd4_session *session)
185{
186 __be32 *p;
187
188 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
189 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
190 NFS4_MAX_SESSIONID_LEN);
191}
192
193/*
194 * nfsstat4
195 */
196static const struct {
197 int stat;
198 int errno;
199} nfs_cb_errtbl[] = {
200 { NFS4_OK, 0 },
201 { NFS4ERR_PERM, -EPERM },
202 { NFS4ERR_NOENT, -ENOENT },
203 { NFS4ERR_IO, -EIO },
204 { NFS4ERR_NXIO, -ENXIO },
205 { NFS4ERR_ACCESS, -EACCES },
206 { NFS4ERR_EXIST, -EEXIST },
207 { NFS4ERR_XDEV, -EXDEV },
208 { NFS4ERR_NOTDIR, -ENOTDIR },
209 { NFS4ERR_ISDIR, -EISDIR },
210 { NFS4ERR_INVAL, -EINVAL },
211 { NFS4ERR_FBIG, -EFBIG },
212 { NFS4ERR_NOSPC, -ENOSPC },
213 { NFS4ERR_ROFS, -EROFS },
214 { NFS4ERR_MLINK, -EMLINK },
215 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
216 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
217 { NFS4ERR_DQUOT, -EDQUOT },
218 { NFS4ERR_STALE, -ESTALE },
219 { NFS4ERR_BADHANDLE, -EBADHANDLE },
220 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
221 { NFS4ERR_NOTSUPP, -ENOTSUPP },
222 { NFS4ERR_TOOSMALL, -ETOOSMALL },
223 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
224 { NFS4ERR_BADTYPE, -EBADTYPE },
225 { NFS4ERR_LOCKED, -EAGAIN },
226 { NFS4ERR_RESOURCE, -EREMOTEIO },
227 { NFS4ERR_SYMLINK, -ELOOP },
228 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
229 { NFS4ERR_DEADLOCK, -EDEADLK },
230 { -1, -EIO }
231};
232
233/*
234 * If we cannot translate the error, the recovery routines should
235 * handle it.
236 *
237 * Note: remaining NFSv4 error codes have values > 10000, so should
238 * not conflict with native Linux error codes.
239 */
240static int nfs_cb_stat_to_errno(int status)
241{
242 int i;
243
244 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
245 if (nfs_cb_errtbl[i].stat == status)
246 return nfs_cb_errtbl[i].errno;
247 }
248
249 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
250 return -status;
251}
252
253static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
254 enum nfsstat4 *status)
255{
256 __be32 *p;
257 u32 op;
258
259 p = xdr_inline_decode(xdr, 4 + 4);
260 if (unlikely(p == NULL))
261 goto out_overflow;
262 op = be32_to_cpup(p++);
263 if (unlikely(op != expected))
264 goto out_unexpected;
265 *status = be32_to_cpup(p);
266 return 0;
267out_overflow:
268 print_overflow_msg(__func__, xdr);
269 return -EIO;
270out_unexpected:
271 dprintk("NFSD: Callback server returned operation %d but "
272 "we issued a request for %d\n", op, expected);
273 return -EIO;
274}
275
276/*
277 * CB_COMPOUND4args
278 *
279 * struct CB_COMPOUND4args {
280 * utf8str_cs tag;
281 * uint32_t minorversion;
282 * uint32_t callback_ident;
283 * nfs_cb_argop4 argarray<>;
284 * };
285*/
286static void encode_cb_compound4args(struct xdr_stream *xdr,
287 struct nfs4_cb_compound_hdr *hdr)
288{
289 __be32 * p;
290
291 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
292 p = xdr_encode_empty_array(p); /* empty tag */
293 *p++ = cpu_to_be32(hdr->minorversion);
294 *p++ = cpu_to_be32(hdr->ident);
295
296 hdr->nops_p = p;
297 *p = cpu_to_be32(hdr->nops); /* argarray element count */
298}
299
300/*
301 * Update argarray element count
302 */
303static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
304{
305 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
306 *hdr->nops_p = cpu_to_be32(hdr->nops);
307}
308
309/*
310 * CB_COMPOUND4res
311 *
312 * struct CB_COMPOUND4res {
313 * nfsstat4 status;
314 * utf8str_cs tag;
315 * nfs_cb_resop4 resarray<>;
316 * };
317 */
318static int decode_cb_compound4res(struct xdr_stream *xdr,
319 struct nfs4_cb_compound_hdr *hdr)
320{
321 u32 length;
322 __be32 *p;
323
324 p = xdr_inline_decode(xdr, 4 + 4);
325 if (unlikely(p == NULL))
326 goto out_overflow;
327 hdr->status = be32_to_cpup(p++);
328 /* Ignore the tag */
329 length = be32_to_cpup(p++);
330 p = xdr_inline_decode(xdr, length + 4);
331 if (unlikely(p == NULL))
332 goto out_overflow;
333 hdr->nops = be32_to_cpup(p);
334 return 0;
335out_overflow:
336 print_overflow_msg(__func__, xdr);
337 return -EIO;
338}
339
340/*
341 * CB_RECALL4args
342 *
343 * struct CB_RECALL4args {
344 * stateid4 stateid;
345 * bool truncate;
346 * nfs_fh4 fh;
347 * };
348 */
349static void encode_cb_recall4args(struct xdr_stream *xdr,
350 const struct nfs4_delegation *dp,
351 struct nfs4_cb_compound_hdr *hdr)
352{
353 __be32 *p;
354
355 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
356 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
357
358 p = xdr_reserve_space(xdr, 4);
359 *p++ = xdr_zero; /* truncate */
360
361 encode_nfs_fh4(xdr, &dp->dl_fh);
362
363 hdr->nops++;
364}
365
366/*
367 * CB_SEQUENCE4args
368 *
369 * struct CB_SEQUENCE4args {
370 * sessionid4 csa_sessionid;
371 * sequenceid4 csa_sequenceid;
372 * slotid4 csa_slotid;
373 * slotid4 csa_highest_slotid;
374 * bool csa_cachethis;
375 * referring_call_list4 csa_referring_call_lists<>;
376 * };
377 */
378static void encode_cb_sequence4args(struct xdr_stream *xdr,
379 const struct nfsd4_callback *cb,
380 struct nfs4_cb_compound_hdr *hdr)
381{
382 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
383 __be32 *p;
384
385 if (hdr->minorversion == 0)
386 return;
387
388 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
389 encode_sessionid4(xdr, session);
390
391 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
392 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
393 *p++ = xdr_zero; /* csa_slotid */
394 *p++ = xdr_zero; /* csa_highest_slotid */
395 *p++ = xdr_zero; /* csa_cachethis */
396 xdr_encode_empty_array(p); /* csa_referring_call_lists */
397
398 hdr->nops++;
399}
400
401/*
402 * CB_SEQUENCE4resok
403 *
404 * struct CB_SEQUENCE4resok {
405 * sessionid4 csr_sessionid;
406 * sequenceid4 csr_sequenceid;
407 * slotid4 csr_slotid;
408 * slotid4 csr_highest_slotid;
409 * slotid4 csr_target_highest_slotid;
410 * };
411 *
412 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
413 * case NFS4_OK:
414 * CB_SEQUENCE4resok csr_resok4;
415 * default:
416 * void;
417 * };
418 *
419 * Our current back channel implmentation supports a single backchannel
420 * with a single slot.
421 */
422static int decode_cb_sequence4resok(struct xdr_stream *xdr,
423 struct nfsd4_callback *cb)
424{
425 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
426 struct nfs4_sessionid id;
427 int status;
428 __be32 *p;
429 u32 dummy;
430
431 status = -ESERVERFAULT;
432
433 /*
434 * If the server returns different values for sessionID, slotID or
435 * sequence number, the server is looney tunes.
436 */
437 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
438 if (unlikely(p == NULL))
439 goto out_overflow;
440 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
441 if (memcmp(id.data, session->se_sessionid.data,
442 NFS4_MAX_SESSIONID_LEN) != 0) {
443 dprintk("NFS: %s Invalid session id\n", __func__);
444 goto out;
445 }
446 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
447
448 dummy = be32_to_cpup(p++);
449 if (dummy != session->se_cb_seq_nr) {
450 dprintk("NFS: %s Invalid sequence number\n", __func__);
451 goto out;
452 }
453
454 dummy = be32_to_cpup(p++);
455 if (dummy != 0) {
456 dprintk("NFS: %s Invalid slotid\n", __func__);
457 goto out;
458 }
459
460 /*
461 * FIXME: process highest slotid and target highest slotid
462 */
463 status = 0;
464out:
465 if (status)
466 nfsd4_mark_cb_fault(cb->cb_clp, status);
467 return status;
468out_overflow:
469 print_overflow_msg(__func__, xdr);
470 return -EIO;
471}
472
473static int decode_cb_sequence4res(struct xdr_stream *xdr,
474 struct nfsd4_callback *cb)
475{
476 enum nfsstat4 nfserr;
477 int status;
478
479 if (cb->cb_minorversion == 0)
480 return 0;
481
482 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
483 if (unlikely(status))
484 goto out;
485 if (unlikely(nfserr != NFS4_OK))
486 goto out_default;
487 status = decode_cb_sequence4resok(xdr, cb);
488out:
489 return status;
490out_default:
491 return nfs_cb_stat_to_errno(nfserr);
492}
493
494/*
495 * NFSv4.0 and NFSv4.1 XDR encode functions
496 *
497 * NFSv4.0 callback argument types are defined in section 15 of RFC
498 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
499 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
500 * Protocol".
501 */
502
503/*
504 * NB: Without this zero space reservation, callbacks over krb5p fail
505 */
506static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
507 void *__unused)
508{
509 xdr_reserve_space(xdr, 0);
510}
511
512/*
513 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
514 */
515static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
516 const struct nfsd4_callback *cb)
517{
518 const struct nfs4_delegation *args = cb->cb_op;
519 struct nfs4_cb_compound_hdr hdr = {
520 .ident = cb->cb_clp->cl_cb_ident,
521 .minorversion = cb->cb_minorversion,
522 };
523
524 encode_cb_compound4args(xdr, &hdr);
525 encode_cb_sequence4args(xdr, cb, &hdr);
526 encode_cb_recall4args(xdr, args, &hdr);
527 encode_cb_nops(&hdr);
528}
529
530
531/*
532 * NFSv4.0 and NFSv4.1 XDR decode functions
533 *
534 * NFSv4.0 callback result types are defined in section 15 of RFC
535 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
536 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
537 * Protocol".
538 */
539
540static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
541 void *__unused)
542{
543 return 0;
544}
545
546/*
547 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
548 */
549static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
550 struct xdr_stream *xdr,
551 struct nfsd4_callback *cb)
552{
553 struct nfs4_cb_compound_hdr hdr;
554 enum nfsstat4 nfserr;
555 int status;
556
557 status = decode_cb_compound4res(xdr, &hdr);
558 if (unlikely(status))
559 goto out;
560
561 if (cb != NULL) {
562 status = decode_cb_sequence4res(xdr, cb);
563 if (unlikely(status))
564 goto out;
565 }
566
567 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
568 if (unlikely(status))
569 goto out;
570 if (unlikely(nfserr != NFS4_OK))
571 status = nfs_cb_stat_to_errno(nfserr);
572out:
573 return status;
574}
575
576/*
577 * RPC procedure tables
578 */
579#define PROC(proc, call, argtype, restype) \
580[NFSPROC4_CLNT_##proc] = { \
581 .p_proc = NFSPROC4_CB_##call, \
582 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
583 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
584 .p_arglen = NFS4_enc_##argtype##_sz, \
585 .p_replen = NFS4_dec_##restype##_sz, \
586 .p_statidx = NFSPROC4_CB_##call, \
587 .p_name = #proc, \
588}
589
590static struct rpc_procinfo nfs4_cb_procedures[] = {
591 PROC(CB_NULL, NULL, cb_null, cb_null),
592 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
593};
594
595static struct rpc_version nfs_cb_version4 = {
596/*
597 * Note on the callback rpc program version number: despite language in rfc
598 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
599 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
600 * in practice that appears to be what implementations use. The section
601 * 18.36.3 language is expected to be fixed in an erratum.
602 */
603 .number = 1,
604 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
605 .procs = nfs4_cb_procedures
606};
607
608static const struct rpc_version *nfs_cb_version[] = {
609 &nfs_cb_version4,
610};
611
612static const struct rpc_program cb_program;
613
614static struct rpc_stat cb_stats = {
615 .program = &cb_program
616};
617
618#define NFS4_CALLBACK 0x40000000
619static const struct rpc_program cb_program = {
620 .name = "nfs4_cb",
621 .number = NFS4_CALLBACK,
622 .nrvers = ARRAY_SIZE(nfs_cb_version),
623 .version = nfs_cb_version,
624 .stats = &cb_stats,
625 .pipe_dir_name = "nfsd4_cb",
626};
627
628static int max_cb_time(void)
629{
630 return max(nfsd4_lease/10, (time_t)1) * HZ;
631}
632
633
634static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
635{
636 struct rpc_timeout timeparms = {
637 .to_initval = max_cb_time(),
638 .to_retries = 0,
639 };
640 struct rpc_create_args args = {
641 .net = &init_net,
642 .address = (struct sockaddr *) &conn->cb_addr,
643 .addrsize = conn->cb_addrlen,
644 .saddress = (struct sockaddr *) &conn->cb_saddr,
645 .timeout = &timeparms,
646 .program = &cb_program,
647 .version = 0,
648 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
649 };
650 struct rpc_clnt *client;
651
652 if (clp->cl_minorversion == 0) {
653 if (!clp->cl_cred.cr_principal &&
654 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
655 return -EINVAL;
656 args.client_name = clp->cl_cred.cr_principal;
657 args.prognumber = conn->cb_prog,
658 args.protocol = XPRT_TRANSPORT_TCP;
659 args.authflavor = clp->cl_cred.cr_flavor;
660 clp->cl_cb_ident = conn->cb_ident;
661 } else {
662 if (!conn->cb_xprt)
663 return -EINVAL;
664 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
665 clp->cl_cb_session = ses;
666 args.bc_xprt = conn->cb_xprt;
667 args.prognumber = clp->cl_cb_session->se_cb_prog;
668 args.protocol = XPRT_TRANSPORT_BC_TCP;
669 args.authflavor = RPC_AUTH_UNIX;
670 }
671 /* Create RPC client */
672 client = rpc_create(&args);
673 if (IS_ERR(client)) {
674 dprintk("NFSD: couldn't create callback client: %ld\n",
675 PTR_ERR(client));
676 return PTR_ERR(client);
677 }
678 clp->cl_cb_client = client;
679 return 0;
680
681}
682
683static void warn_no_callback_path(struct nfs4_client *clp, int reason)
684{
685 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
686 (int)clp->cl_name.len, clp->cl_name.data, reason);
687}
688
689static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
690{
691 clp->cl_cb_state = NFSD4_CB_DOWN;
692 warn_no_callback_path(clp, reason);
693}
694
695static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
696{
697 clp->cl_cb_state = NFSD4_CB_FAULT;
698 warn_no_callback_path(clp, reason);
699}
700
701static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
702{
703 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
704
705 if (task->tk_status)
706 nfsd4_mark_cb_down(clp, task->tk_status);
707 else
708 clp->cl_cb_state = NFSD4_CB_UP;
709}
710
711static const struct rpc_call_ops nfsd4_cb_probe_ops = {
712 /* XXX: release method to ensure we set the cb channel down if
713 * necessary on early failure? */
714 .rpc_call_done = nfsd4_cb_probe_done,
715};
716
717static struct rpc_cred *callback_cred;
718
719int set_callback_cred(void)
720{
721 if (callback_cred)
722 return 0;
723 callback_cred = rpc_lookup_machine_cred("nfs");
724 if (!callback_cred)
725 return -ENOMEM;
726 return 0;
727}
728
729static struct workqueue_struct *callback_wq;
730
731static void run_nfsd4_cb(struct nfsd4_callback *cb)
732{
733 queue_work(callback_wq, &cb->cb_work);
734}
735
736static void do_probe_callback(struct nfs4_client *clp)
737{
738 struct nfsd4_callback *cb = &clp->cl_cb_null;
739
740 cb->cb_op = NULL;
741 cb->cb_clp = clp;
742
743 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
744 cb->cb_msg.rpc_argp = NULL;
745 cb->cb_msg.rpc_resp = NULL;
746 cb->cb_msg.rpc_cred = callback_cred;
747
748 cb->cb_ops = &nfsd4_cb_probe_ops;
749
750 run_nfsd4_cb(cb);
751}
752
753/*
754 * Poke the callback thread to process any updates to the callback
755 * parameters, and send a null probe.
756 */
757void nfsd4_probe_callback(struct nfs4_client *clp)
758{
759 /* XXX: atomicity? Also, should we be using cl_flags? */
760 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
761 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
762 do_probe_callback(clp);
763}
764
765void nfsd4_probe_callback_sync(struct nfs4_client *clp)
766{
767 nfsd4_probe_callback(clp);
768 flush_workqueue(callback_wq);
769}
770
771void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
772{
773 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
774 spin_lock(&clp->cl_lock);
775 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
776 spin_unlock(&clp->cl_lock);
777}
778
779/*
780 * There's currently a single callback channel slot.
781 * If the slot is available, then mark it busy. Otherwise, set the
782 * thread for sleeping on the callback RPC wait queue.
783 */
784static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
785{
786 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
787 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
788 dprintk("%s slot is busy\n", __func__);
789 return false;
790 }
791 return true;
792}
793
794/*
795 * TODO: cb_sequence should support referring call lists, cachethis, multiple
796 * slots, and mark callback channel down on communication errors.
797 */
798static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
799{
800 struct nfsd4_callback *cb = calldata;
801 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
802 struct nfs4_client *clp = dp->dl_stid.sc_client;
803 u32 minorversion = clp->cl_minorversion;
804
805 cb->cb_minorversion = minorversion;
806 if (minorversion) {
807 if (!nfsd41_cb_get_slot(clp, task))
808 return;
809 }
810 spin_lock(&clp->cl_lock);
811 if (list_empty(&cb->cb_per_client)) {
812 /* This is the first call, not a restart */
813 cb->cb_done = false;
814 list_add(&cb->cb_per_client, &clp->cl_callbacks);
815 }
816 spin_unlock(&clp->cl_lock);
817 rpc_call_start(task);
818}
819
820static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
821{
822 struct nfsd4_callback *cb = calldata;
823 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
824 struct nfs4_client *clp = dp->dl_stid.sc_client;
825
826 dprintk("%s: minorversion=%d\n", __func__,
827 clp->cl_minorversion);
828
829 if (clp->cl_minorversion) {
830 /* No need for lock, access serialized in nfsd4_cb_prepare */
831 ++clp->cl_cb_session->se_cb_seq_nr;
832 clear_bit(0, &clp->cl_cb_slot_busy);
833 rpc_wake_up_next(&clp->cl_cb_waitq);
834 dprintk("%s: freed slot, new seqid=%d\n", __func__,
835 clp->cl_cb_session->se_cb_seq_nr);
836
837 /* We're done looking into the sequence information */
838 task->tk_msg.rpc_resp = NULL;
839 }
840}
841
842
843static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
844{
845 struct nfsd4_callback *cb = calldata;
846 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
847 struct nfs4_client *clp = dp->dl_stid.sc_client;
848 struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
849
850 nfsd4_cb_done(task, calldata);
851
852 if (current_rpc_client != task->tk_client) {
853 /* We're shutting down or changing cl_cb_client; leave
854 * it to nfsd4_process_cb_update to restart the call if
855 * necessary. */
856 return;
857 }
858
859 if (cb->cb_done)
860 return;
861 switch (task->tk_status) {
862 case 0:
863 cb->cb_done = true;
864 return;
865 case -EBADHANDLE:
866 case -NFS4ERR_BAD_STATEID:
867 /* Race: client probably got cb_recall
868 * before open reply granting delegation */
869 break;
870 default:
871 /* Network partition? */
872 nfsd4_mark_cb_down(clp, task->tk_status);
873 }
874 if (dp->dl_retries--) {
875 rpc_delay(task, 2*HZ);
876 task->tk_status = 0;
877 rpc_restart_call_prepare(task);
878 return;
879 }
880 nfsd4_mark_cb_down(clp, task->tk_status);
881 cb->cb_done = true;
882}
883
884static void nfsd4_cb_recall_release(void *calldata)
885{
886 struct nfsd4_callback *cb = calldata;
887 struct nfs4_client *clp = cb->cb_clp;
888 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
889
890 if (cb->cb_done) {
891 spin_lock(&clp->cl_lock);
892 list_del(&cb->cb_per_client);
893 spin_unlock(&clp->cl_lock);
894 nfs4_put_delegation(dp);
895 }
896}
897
898static const struct rpc_call_ops nfsd4_cb_recall_ops = {
899 .rpc_call_prepare = nfsd4_cb_prepare,
900 .rpc_call_done = nfsd4_cb_recall_done,
901 .rpc_release = nfsd4_cb_recall_release,
902};
903
904int nfsd4_create_callback_queue(void)
905{
906 callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
907 if (!callback_wq)
908 return -ENOMEM;
909 return 0;
910}
911
912void nfsd4_destroy_callback_queue(void)
913{
914 destroy_workqueue(callback_wq);
915}
916
917/* must be called under the state lock */
918void nfsd4_shutdown_callback(struct nfs4_client *clp)
919{
920 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
921 /*
922 * Note this won't actually result in a null callback;
923 * instead, nfsd4_do_callback_rpc() will detect the killed
924 * client, destroy the rpc client, and stop:
925 */
926 do_probe_callback(clp);
927 flush_workqueue(callback_wq);
928}
929
930static void nfsd4_release_cb(struct nfsd4_callback *cb)
931{
932 if (cb->cb_ops->rpc_release)
933 cb->cb_ops->rpc_release(cb);
934}
935
936/* requires cl_lock: */
937static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
938{
939 struct nfsd4_session *s;
940 struct nfsd4_conn *c;
941
942 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
943 list_for_each_entry(c, &s->se_conns, cn_persession) {
944 if (c->cn_flags & NFS4_CDFC4_BACK)
945 return c;
946 }
947 }
948 return NULL;
949}
950
951static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
952{
953 struct nfs4_cb_conn conn;
954 struct nfs4_client *clp = cb->cb_clp;
955 struct nfsd4_session *ses = NULL;
956 struct nfsd4_conn *c;
957 int err;
958
959 /*
960 * This is either an update, or the client dying; in either case,
961 * kill the old client:
962 */
963 if (clp->cl_cb_client) {
964 rpc_shutdown_client(clp->cl_cb_client);
965 clp->cl_cb_client = NULL;
966 }
967 if (clp->cl_cb_conn.cb_xprt) {
968 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
969 clp->cl_cb_conn.cb_xprt = NULL;
970 }
971 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
972 return;
973 spin_lock(&clp->cl_lock);
974 /*
975 * Only serialized callback code is allowed to clear these
976 * flags; main nfsd code can only set them:
977 */
978 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
979 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
980 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
981 c = __nfsd4_find_backchannel(clp);
982 if (c) {
983 svc_xprt_get(c->cn_xprt);
984 conn.cb_xprt = c->cn_xprt;
985 ses = c->cn_session;
986 }
987 spin_unlock(&clp->cl_lock);
988
989 err = setup_callback_client(clp, &conn, ses);
990 if (err) {
991 nfsd4_mark_cb_down(clp, err);
992 return;
993 }
994 /* Yay, the callback channel's back! Restart any callbacks: */
995 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
996 run_nfsd4_cb(cb);
997}
998
999void nfsd4_do_callback_rpc(struct work_struct *w)
1000{
1001 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
1002 struct nfs4_client *clp = cb->cb_clp;
1003 struct rpc_clnt *clnt;
1004
1005 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1006 nfsd4_process_cb_update(cb);
1007
1008 clnt = clp->cl_cb_client;
1009 if (!clnt) {
1010 /* Callback channel broken, or client killed; give up: */
1011 nfsd4_release_cb(cb);
1012 return;
1013 }
1014 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1015 cb->cb_ops, cb);
1016}
1017
1018void nfsd4_cb_recall(struct nfs4_delegation *dp)
1019{
1020 struct nfsd4_callback *cb = &dp->dl_recall;
1021 struct nfs4_client *clp = dp->dl_stid.sc_client;
1022
1023 dp->dl_retries = 1;
1024 cb->cb_op = dp;
1025 cb->cb_clp = clp;
1026 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
1027 cb->cb_msg.rpc_argp = cb;
1028 cb->cb_msg.rpc_resp = cb;
1029 cb->cb_msg.rpc_cred = callback_cred;
1030
1031 cb->cb_ops = &nfsd4_cb_recall_ops;
1032 dp->dl_retries = 1;
1033
1034 INIT_LIST_HEAD(&cb->cb_per_client);
1035 cb->cb_done = true;
1036
1037 run_nfsd4_cb(&dp->dl_recall);
1038}
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#include "xdr4.h"
43
44#define NFSDDBG_FACILITY NFSDDBG_PROC
45
46static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
47
48#define NFSPROC4_CB_NULL 0
49#define NFSPROC4_CB_COMPOUND 1
50
51/* Index of predefined Linux callback client operations */
52
53struct nfs4_cb_compound_hdr {
54 /* args */
55 u32 ident; /* minorversion 0 only */
56 u32 nops;
57 __be32 *nops_p;
58 u32 minorversion;
59 /* res */
60 int status;
61};
62
63static __be32 *xdr_encode_empty_array(__be32 *p)
64{
65 *p++ = xdr_zero;
66 return p;
67}
68
69/*
70 * Encode/decode NFSv4 CB basic data types
71 *
72 * Basic NFSv4 callback data types are defined in section 15 of RFC
73 * 3530: "Network File System (NFS) version 4 Protocol" and section
74 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
75 * 1 Protocol"
76 */
77
78/*
79 * nfs_cb_opnum4
80 *
81 * enum nfs_cb_opnum4 {
82 * OP_CB_GETATTR = 3,
83 * ...
84 * };
85 */
86enum nfs_cb_opnum4 {
87 OP_CB_GETATTR = 3,
88 OP_CB_RECALL = 4,
89 OP_CB_LAYOUTRECALL = 5,
90 OP_CB_NOTIFY = 6,
91 OP_CB_PUSH_DELEG = 7,
92 OP_CB_RECALL_ANY = 8,
93 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
94 OP_CB_RECALL_SLOT = 10,
95 OP_CB_SEQUENCE = 11,
96 OP_CB_WANTS_CANCELLED = 12,
97 OP_CB_NOTIFY_LOCK = 13,
98 OP_CB_NOTIFY_DEVICEID = 14,
99 OP_CB_OFFLOAD = 15,
100 OP_CB_ILLEGAL = 10044
101};
102
103static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
104{
105 __be32 *p;
106
107 p = xdr_reserve_space(xdr, 4);
108 *p = cpu_to_be32(op);
109}
110
111/*
112 * nfs_fh4
113 *
114 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
115 */
116static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
117{
118 u32 length = fh->fh_size;
119 __be32 *p;
120
121 BUG_ON(length > NFS4_FHSIZE);
122 p = xdr_reserve_space(xdr, 4 + length);
123 xdr_encode_opaque(p, &fh->fh_base, length);
124}
125
126/*
127 * stateid4
128 *
129 * struct stateid4 {
130 * uint32_t seqid;
131 * opaque other[12];
132 * };
133 */
134static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
135{
136 __be32 *p;
137
138 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
139 *p++ = cpu_to_be32(sid->si_generation);
140 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
141}
142
143/*
144 * sessionid4
145 *
146 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
147 */
148static void encode_sessionid4(struct xdr_stream *xdr,
149 const struct nfsd4_session *session)
150{
151 __be32 *p;
152
153 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
154 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
155 NFS4_MAX_SESSIONID_LEN);
156}
157
158/*
159 * nfsstat4
160 */
161static const struct {
162 int stat;
163 int errno;
164} nfs_cb_errtbl[] = {
165 { NFS4_OK, 0 },
166 { NFS4ERR_PERM, -EPERM },
167 { NFS4ERR_NOENT, -ENOENT },
168 { NFS4ERR_IO, -EIO },
169 { NFS4ERR_NXIO, -ENXIO },
170 { NFS4ERR_ACCESS, -EACCES },
171 { NFS4ERR_EXIST, -EEXIST },
172 { NFS4ERR_XDEV, -EXDEV },
173 { NFS4ERR_NOTDIR, -ENOTDIR },
174 { NFS4ERR_ISDIR, -EISDIR },
175 { NFS4ERR_INVAL, -EINVAL },
176 { NFS4ERR_FBIG, -EFBIG },
177 { NFS4ERR_NOSPC, -ENOSPC },
178 { NFS4ERR_ROFS, -EROFS },
179 { NFS4ERR_MLINK, -EMLINK },
180 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
181 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
182 { NFS4ERR_DQUOT, -EDQUOT },
183 { NFS4ERR_STALE, -ESTALE },
184 { NFS4ERR_BADHANDLE, -EBADHANDLE },
185 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
186 { NFS4ERR_NOTSUPP, -ENOTSUPP },
187 { NFS4ERR_TOOSMALL, -ETOOSMALL },
188 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
189 { NFS4ERR_BADTYPE, -EBADTYPE },
190 { NFS4ERR_LOCKED, -EAGAIN },
191 { NFS4ERR_RESOURCE, -EREMOTEIO },
192 { NFS4ERR_SYMLINK, -ELOOP },
193 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
194 { NFS4ERR_DEADLOCK, -EDEADLK },
195 { -1, -EIO }
196};
197
198/*
199 * If we cannot translate the error, the recovery routines should
200 * handle it.
201 *
202 * Note: remaining NFSv4 error codes have values > 10000, so should
203 * not conflict with native Linux error codes.
204 */
205static int nfs_cb_stat_to_errno(int status)
206{
207 int i;
208
209 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
210 if (nfs_cb_errtbl[i].stat == status)
211 return nfs_cb_errtbl[i].errno;
212 }
213
214 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
215 return -status;
216}
217
218static int decode_cb_op_status(struct xdr_stream *xdr,
219 enum nfs_cb_opnum4 expected, int *status)
220{
221 __be32 *p;
222 u32 op;
223
224 p = xdr_inline_decode(xdr, 4 + 4);
225 if (unlikely(p == NULL))
226 goto out_overflow;
227 op = be32_to_cpup(p++);
228 if (unlikely(op != expected))
229 goto out_unexpected;
230 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
231 return 0;
232out_overflow:
233 return -EIO;
234out_unexpected:
235 dprintk("NFSD: Callback server returned operation %d but "
236 "we issued a request for %d\n", op, expected);
237 return -EIO;
238}
239
240/*
241 * CB_COMPOUND4args
242 *
243 * struct CB_COMPOUND4args {
244 * utf8str_cs tag;
245 * uint32_t minorversion;
246 * uint32_t callback_ident;
247 * nfs_cb_argop4 argarray<>;
248 * };
249*/
250static void encode_cb_compound4args(struct xdr_stream *xdr,
251 struct nfs4_cb_compound_hdr *hdr)
252{
253 __be32 * p;
254
255 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
256 p = xdr_encode_empty_array(p); /* empty tag */
257 *p++ = cpu_to_be32(hdr->minorversion);
258 *p++ = cpu_to_be32(hdr->ident);
259
260 hdr->nops_p = p;
261 *p = cpu_to_be32(hdr->nops); /* argarray element count */
262}
263
264/*
265 * Update argarray element count
266 */
267static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
268{
269 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
270 *hdr->nops_p = cpu_to_be32(hdr->nops);
271}
272
273/*
274 * CB_COMPOUND4res
275 *
276 * struct CB_COMPOUND4res {
277 * nfsstat4 status;
278 * utf8str_cs tag;
279 * nfs_cb_resop4 resarray<>;
280 * };
281 */
282static int decode_cb_compound4res(struct xdr_stream *xdr,
283 struct nfs4_cb_compound_hdr *hdr)
284{
285 u32 length;
286 __be32 *p;
287
288 p = xdr_inline_decode(xdr, 4 + 4);
289 if (unlikely(p == NULL))
290 goto out_overflow;
291 hdr->status = be32_to_cpup(p++);
292 /* Ignore the tag */
293 length = be32_to_cpup(p++);
294 p = xdr_inline_decode(xdr, length + 4);
295 if (unlikely(p == NULL))
296 goto out_overflow;
297 p += XDR_QUADLEN(length);
298 hdr->nops = be32_to_cpup(p);
299 return 0;
300out_overflow:
301 return -EIO;
302}
303
304/*
305 * CB_RECALL4args
306 *
307 * struct CB_RECALL4args {
308 * stateid4 stateid;
309 * bool truncate;
310 * nfs_fh4 fh;
311 * };
312 */
313static void encode_cb_recall4args(struct xdr_stream *xdr,
314 const struct nfs4_delegation *dp,
315 struct nfs4_cb_compound_hdr *hdr)
316{
317 __be32 *p;
318
319 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
320 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
321
322 p = xdr_reserve_space(xdr, 4);
323 *p++ = xdr_zero; /* truncate */
324
325 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
326
327 hdr->nops++;
328}
329
330/*
331 * CB_SEQUENCE4args
332 *
333 * struct CB_SEQUENCE4args {
334 * sessionid4 csa_sessionid;
335 * sequenceid4 csa_sequenceid;
336 * slotid4 csa_slotid;
337 * slotid4 csa_highest_slotid;
338 * bool csa_cachethis;
339 * referring_call_list4 csa_referring_call_lists<>;
340 * };
341 */
342static void encode_cb_sequence4args(struct xdr_stream *xdr,
343 const struct nfsd4_callback *cb,
344 struct nfs4_cb_compound_hdr *hdr)
345{
346 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
347 __be32 *p;
348
349 if (hdr->minorversion == 0)
350 return;
351
352 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
353 encode_sessionid4(xdr, session);
354
355 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
356 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
357 *p++ = xdr_zero; /* csa_slotid */
358 *p++ = xdr_zero; /* csa_highest_slotid */
359 *p++ = xdr_zero; /* csa_cachethis */
360 xdr_encode_empty_array(p); /* csa_referring_call_lists */
361
362 hdr->nops++;
363}
364
365/*
366 * CB_SEQUENCE4resok
367 *
368 * struct CB_SEQUENCE4resok {
369 * sessionid4 csr_sessionid;
370 * sequenceid4 csr_sequenceid;
371 * slotid4 csr_slotid;
372 * slotid4 csr_highest_slotid;
373 * slotid4 csr_target_highest_slotid;
374 * };
375 *
376 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
377 * case NFS4_OK:
378 * CB_SEQUENCE4resok csr_resok4;
379 * default:
380 * void;
381 * };
382 *
383 * Our current back channel implmentation supports a single backchannel
384 * with a single slot.
385 */
386static int decode_cb_sequence4resok(struct xdr_stream *xdr,
387 struct nfsd4_callback *cb)
388{
389 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
390 int status = -ESERVERFAULT;
391 __be32 *p;
392 u32 dummy;
393
394 /*
395 * If the server returns different values for sessionID, slotID or
396 * sequence number, the server is looney tunes.
397 */
398 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
399 if (unlikely(p == NULL))
400 goto out_overflow;
401
402 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
403 dprintk("NFS: %s Invalid session id\n", __func__);
404 goto out;
405 }
406 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
407
408 dummy = be32_to_cpup(p++);
409 if (dummy != session->se_cb_seq_nr) {
410 dprintk("NFS: %s Invalid sequence number\n", __func__);
411 goto out;
412 }
413
414 dummy = be32_to_cpup(p++);
415 if (dummy != 0) {
416 dprintk("NFS: %s Invalid slotid\n", __func__);
417 goto out;
418 }
419
420 /*
421 * FIXME: process highest slotid and target highest slotid
422 */
423 status = 0;
424out:
425 cb->cb_seq_status = status;
426 return status;
427out_overflow:
428 status = -EIO;
429 goto out;
430}
431
432static int decode_cb_sequence4res(struct xdr_stream *xdr,
433 struct nfsd4_callback *cb)
434{
435 int status;
436
437 if (cb->cb_clp->cl_minorversion == 0)
438 return 0;
439
440 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
441 if (unlikely(status || cb->cb_seq_status))
442 return status;
443
444 return decode_cb_sequence4resok(xdr, cb);
445}
446
447/*
448 * NFSv4.0 and NFSv4.1 XDR encode functions
449 *
450 * NFSv4.0 callback argument types are defined in section 15 of RFC
451 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
452 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
453 * Protocol".
454 */
455
456/*
457 * NB: Without this zero space reservation, callbacks over krb5p fail
458 */
459static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
460 const void *__unused)
461{
462 xdr_reserve_space(xdr, 0);
463}
464
465/*
466 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
467 */
468static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
469 const void *data)
470{
471 const struct nfsd4_callback *cb = data;
472 const struct nfs4_delegation *dp = cb_to_delegation(cb);
473 struct nfs4_cb_compound_hdr hdr = {
474 .ident = cb->cb_clp->cl_cb_ident,
475 .minorversion = cb->cb_clp->cl_minorversion,
476 };
477
478 encode_cb_compound4args(xdr, &hdr);
479 encode_cb_sequence4args(xdr, cb, &hdr);
480 encode_cb_recall4args(xdr, dp, &hdr);
481 encode_cb_nops(&hdr);
482}
483
484
485/*
486 * NFSv4.0 and NFSv4.1 XDR decode functions
487 *
488 * NFSv4.0 callback result types are defined in section 15 of RFC
489 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
490 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
491 * Protocol".
492 */
493
494static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
495 void *__unused)
496{
497 return 0;
498}
499
500/*
501 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
502 */
503static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
504 struct xdr_stream *xdr,
505 void *data)
506{
507 struct nfsd4_callback *cb = data;
508 struct nfs4_cb_compound_hdr hdr;
509 int status;
510
511 status = decode_cb_compound4res(xdr, &hdr);
512 if (unlikely(status))
513 return status;
514
515 status = decode_cb_sequence4res(xdr, cb);
516 if (unlikely(status || cb->cb_seq_status))
517 return status;
518
519 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
520}
521
522#ifdef CONFIG_NFSD_PNFS
523/*
524 * CB_LAYOUTRECALL4args
525 *
526 * struct layoutrecall_file4 {
527 * nfs_fh4 lor_fh;
528 * offset4 lor_offset;
529 * length4 lor_length;
530 * stateid4 lor_stateid;
531 * };
532 *
533 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
534 * case LAYOUTRECALL4_FILE:
535 * layoutrecall_file4 lor_layout;
536 * case LAYOUTRECALL4_FSID:
537 * fsid4 lor_fsid;
538 * case LAYOUTRECALL4_ALL:
539 * void;
540 * };
541 *
542 * struct CB_LAYOUTRECALL4args {
543 * layouttype4 clora_type;
544 * layoutiomode4 clora_iomode;
545 * bool clora_changed;
546 * layoutrecall4 clora_recall;
547 * };
548 */
549static void encode_cb_layout4args(struct xdr_stream *xdr,
550 const struct nfs4_layout_stateid *ls,
551 struct nfs4_cb_compound_hdr *hdr)
552{
553 __be32 *p;
554
555 BUG_ON(hdr->minorversion == 0);
556
557 p = xdr_reserve_space(xdr, 5 * 4);
558 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
559 *p++ = cpu_to_be32(ls->ls_layout_type);
560 *p++ = cpu_to_be32(IOMODE_ANY);
561 *p++ = cpu_to_be32(1);
562 *p = cpu_to_be32(RETURN_FILE);
563
564 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
565
566 p = xdr_reserve_space(xdr, 2 * 8);
567 p = xdr_encode_hyper(p, 0);
568 xdr_encode_hyper(p, NFS4_MAX_UINT64);
569
570 encode_stateid4(xdr, &ls->ls_recall_sid);
571
572 hdr->nops++;
573}
574
575static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
576 struct xdr_stream *xdr,
577 const void *data)
578{
579 const struct nfsd4_callback *cb = data;
580 const struct nfs4_layout_stateid *ls =
581 container_of(cb, struct nfs4_layout_stateid, ls_recall);
582 struct nfs4_cb_compound_hdr hdr = {
583 .ident = 0,
584 .minorversion = cb->cb_clp->cl_minorversion,
585 };
586
587 encode_cb_compound4args(xdr, &hdr);
588 encode_cb_sequence4args(xdr, cb, &hdr);
589 encode_cb_layout4args(xdr, ls, &hdr);
590 encode_cb_nops(&hdr);
591}
592
593static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
594 struct xdr_stream *xdr,
595 void *data)
596{
597 struct nfsd4_callback *cb = data;
598 struct nfs4_cb_compound_hdr hdr;
599 int status;
600
601 status = decode_cb_compound4res(xdr, &hdr);
602 if (unlikely(status))
603 return status;
604
605 status = decode_cb_sequence4res(xdr, cb);
606 if (unlikely(status || cb->cb_seq_status))
607 return status;
608
609 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
610}
611#endif /* CONFIG_NFSD_PNFS */
612
613static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
614{
615 __be32 *p;
616
617 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
618 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
619 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
620}
621
622static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
623 struct xdr_stream *xdr,
624 const void *data)
625{
626 const struct nfsd4_callback *cb = data;
627 const struct nfsd4_blocked_lock *nbl =
628 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
629 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
630 struct nfs4_cb_compound_hdr hdr = {
631 .ident = 0,
632 .minorversion = cb->cb_clp->cl_minorversion,
633 };
634
635 __be32 *p;
636
637 BUG_ON(hdr.minorversion == 0);
638
639 encode_cb_compound4args(xdr, &hdr);
640 encode_cb_sequence4args(xdr, cb, &hdr);
641
642 p = xdr_reserve_space(xdr, 4);
643 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
644 encode_nfs_fh4(xdr, &nbl->nbl_fh);
645 encode_stateowner(xdr, &lo->lo_owner);
646 hdr.nops++;
647
648 encode_cb_nops(&hdr);
649}
650
651static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
652 struct xdr_stream *xdr,
653 void *data)
654{
655 struct nfsd4_callback *cb = data;
656 struct nfs4_cb_compound_hdr hdr;
657 int status;
658
659 status = decode_cb_compound4res(xdr, &hdr);
660 if (unlikely(status))
661 return status;
662
663 status = decode_cb_sequence4res(xdr, cb);
664 if (unlikely(status || cb->cb_seq_status))
665 return status;
666
667 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
668}
669
670/*
671 * struct write_response4 {
672 * stateid4 wr_callback_id<1>;
673 * length4 wr_count;
674 * stable_how4 wr_committed;
675 * verifier4 wr_writeverf;
676 * };
677 * union offload_info4 switch (nfsstat4 coa_status) {
678 * case NFS4_OK:
679 * write_response4 coa_resok4;
680 * default:
681 * length4 coa_bytes_copied;
682 * };
683 * struct CB_OFFLOAD4args {
684 * nfs_fh4 coa_fh;
685 * stateid4 coa_stateid;
686 * offload_info4 coa_offload_info;
687 * };
688 */
689static void encode_offload_info4(struct xdr_stream *xdr,
690 __be32 nfserr,
691 const struct nfsd4_copy *cp)
692{
693 __be32 *p;
694
695 p = xdr_reserve_space(xdr, 4);
696 *p++ = nfserr;
697 if (!nfserr) {
698 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
699 p = xdr_encode_empty_array(p);
700 p = xdr_encode_hyper(p, cp->cp_res.wr_bytes_written);
701 *p++ = cpu_to_be32(cp->cp_res.wr_stable_how);
702 p = xdr_encode_opaque_fixed(p, cp->cp_res.wr_verifier.data,
703 NFS4_VERIFIER_SIZE);
704 } else {
705 p = xdr_reserve_space(xdr, 8);
706 /* We always return success if bytes were written */
707 p = xdr_encode_hyper(p, 0);
708 }
709}
710
711static void encode_cb_offload4args(struct xdr_stream *xdr,
712 __be32 nfserr,
713 const struct knfsd_fh *fh,
714 const struct nfsd4_copy *cp,
715 struct nfs4_cb_compound_hdr *hdr)
716{
717 __be32 *p;
718
719 p = xdr_reserve_space(xdr, 4);
720 *p++ = cpu_to_be32(OP_CB_OFFLOAD);
721 encode_nfs_fh4(xdr, fh);
722 encode_stateid4(xdr, &cp->cp_res.cb_stateid);
723 encode_offload_info4(xdr, nfserr, cp);
724
725 hdr->nops++;
726}
727
728static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
729 struct xdr_stream *xdr,
730 const void *data)
731{
732 const struct nfsd4_callback *cb = data;
733 const struct nfsd4_copy *cp =
734 container_of(cb, struct nfsd4_copy, cp_cb);
735 struct nfs4_cb_compound_hdr hdr = {
736 .ident = 0,
737 .minorversion = cb->cb_clp->cl_minorversion,
738 };
739
740 encode_cb_compound4args(xdr, &hdr);
741 encode_cb_sequence4args(xdr, cb, &hdr);
742 encode_cb_offload4args(xdr, cp->nfserr, &cp->fh, cp, &hdr);
743 encode_cb_nops(&hdr);
744}
745
746static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
747 struct xdr_stream *xdr,
748 void *data)
749{
750 struct nfsd4_callback *cb = data;
751 struct nfs4_cb_compound_hdr hdr;
752 int status;
753
754 status = decode_cb_compound4res(xdr, &hdr);
755 if (unlikely(status))
756 return status;
757
758 status = decode_cb_sequence4res(xdr, cb);
759 if (unlikely(status || cb->cb_seq_status))
760 return status;
761
762 return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
763}
764/*
765 * RPC procedure tables
766 */
767#define PROC(proc, call, argtype, restype) \
768[NFSPROC4_CLNT_##proc] = { \
769 .p_proc = NFSPROC4_CB_##call, \
770 .p_encode = nfs4_xdr_enc_##argtype, \
771 .p_decode = nfs4_xdr_dec_##restype, \
772 .p_arglen = NFS4_enc_##argtype##_sz, \
773 .p_replen = NFS4_dec_##restype##_sz, \
774 .p_statidx = NFSPROC4_CB_##call, \
775 .p_name = #proc, \
776}
777
778static const struct rpc_procinfo nfs4_cb_procedures[] = {
779 PROC(CB_NULL, NULL, cb_null, cb_null),
780 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
781#ifdef CONFIG_NFSD_PNFS
782 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
783#endif
784 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
785 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
786};
787
788static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
789static const struct rpc_version nfs_cb_version4 = {
790/*
791 * Note on the callback rpc program version number: despite language in rfc
792 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
793 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
794 * in practice that appears to be what implementations use. The section
795 * 18.36.3 language is expected to be fixed in an erratum.
796 */
797 .number = 1,
798 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
799 .procs = nfs4_cb_procedures,
800 .counts = nfs4_cb_counts,
801};
802
803static const struct rpc_version *nfs_cb_version[2] = {
804 [1] = &nfs_cb_version4,
805};
806
807static const struct rpc_program cb_program;
808
809static struct rpc_stat cb_stats = {
810 .program = &cb_program
811};
812
813#define NFS4_CALLBACK 0x40000000
814static const struct rpc_program cb_program = {
815 .name = "nfs4_cb",
816 .number = NFS4_CALLBACK,
817 .nrvers = ARRAY_SIZE(nfs_cb_version),
818 .version = nfs_cb_version,
819 .stats = &cb_stats,
820 .pipe_dir_name = "nfsd4_cb",
821};
822
823static int max_cb_time(struct net *net)
824{
825 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
826 return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
827}
828
829static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
830{
831 if (clp->cl_minorversion == 0) {
832 client->cl_principal = clp->cl_cred.cr_targ_princ ?
833 clp->cl_cred.cr_targ_princ : "nfs";
834
835 return get_cred(rpc_machine_cred());
836 } else {
837 struct cred *kcred;
838
839 kcred = prepare_kernel_cred(NULL);
840 if (!kcred)
841 return NULL;
842
843 kcred->uid = ses->se_cb_sec.uid;
844 kcred->gid = ses->se_cb_sec.gid;
845 return kcred;
846 }
847}
848
849static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
850{
851 int maxtime = max_cb_time(clp->net);
852 struct rpc_timeout timeparms = {
853 .to_initval = maxtime,
854 .to_retries = 0,
855 .to_maxval = maxtime,
856 };
857 struct rpc_create_args args = {
858 .net = clp->net,
859 .address = (struct sockaddr *) &conn->cb_addr,
860 .addrsize = conn->cb_addrlen,
861 .saddress = (struct sockaddr *) &conn->cb_saddr,
862 .timeout = &timeparms,
863 .program = &cb_program,
864 .version = 1,
865 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
866 .cred = current_cred(),
867 };
868 struct rpc_clnt *client;
869 const struct cred *cred;
870
871 if (clp->cl_minorversion == 0) {
872 if (!clp->cl_cred.cr_principal &&
873 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
874 return -EINVAL;
875 args.client_name = clp->cl_cred.cr_principal;
876 args.prognumber = conn->cb_prog;
877 args.protocol = XPRT_TRANSPORT_TCP;
878 args.authflavor = clp->cl_cred.cr_flavor;
879 clp->cl_cb_ident = conn->cb_ident;
880 } else {
881 if (!conn->cb_xprt)
882 return -EINVAL;
883 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
884 clp->cl_cb_session = ses;
885 args.bc_xprt = conn->cb_xprt;
886 args.prognumber = clp->cl_cb_session->se_cb_prog;
887 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
888 XPRT_TRANSPORT_BC;
889 args.authflavor = ses->se_cb_sec.flavor;
890 }
891 /* Create RPC client */
892 client = rpc_create(&args);
893 if (IS_ERR(client)) {
894 dprintk("NFSD: couldn't create callback client: %ld\n",
895 PTR_ERR(client));
896 return PTR_ERR(client);
897 }
898 cred = get_backchannel_cred(clp, client, ses);
899 if (!cred) {
900 rpc_shutdown_client(client);
901 return -ENOMEM;
902 }
903 clp->cl_cb_client = client;
904 clp->cl_cb_cred = cred;
905 return 0;
906}
907
908static void warn_no_callback_path(struct nfs4_client *clp, int reason)
909{
910 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
911 (int)clp->cl_name.len, clp->cl_name.data, reason);
912}
913
914static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
915{
916 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
917 return;
918 clp->cl_cb_state = NFSD4_CB_DOWN;
919 warn_no_callback_path(clp, reason);
920}
921
922static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
923{
924 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
925 return;
926 clp->cl_cb_state = NFSD4_CB_FAULT;
927 warn_no_callback_path(clp, reason);
928}
929
930static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
931{
932 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
933
934 if (task->tk_status)
935 nfsd4_mark_cb_down(clp, task->tk_status);
936 else
937 clp->cl_cb_state = NFSD4_CB_UP;
938}
939
940static const struct rpc_call_ops nfsd4_cb_probe_ops = {
941 /* XXX: release method to ensure we set the cb channel down if
942 * necessary on early failure? */
943 .rpc_call_done = nfsd4_cb_probe_done,
944};
945
946static struct workqueue_struct *callback_wq;
947
948/*
949 * Poke the callback thread to process any updates to the callback
950 * parameters, and send a null probe.
951 */
952void nfsd4_probe_callback(struct nfs4_client *clp)
953{
954 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
955 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
956 nfsd4_run_cb(&clp->cl_cb_null);
957}
958
959void nfsd4_probe_callback_sync(struct nfs4_client *clp)
960{
961 nfsd4_probe_callback(clp);
962 flush_workqueue(callback_wq);
963}
964
965void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
966{
967 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
968 spin_lock(&clp->cl_lock);
969 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
970 spin_unlock(&clp->cl_lock);
971}
972
973/*
974 * There's currently a single callback channel slot.
975 * If the slot is available, then mark it busy. Otherwise, set the
976 * thread for sleeping on the callback RPC wait queue.
977 */
978static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
979{
980 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
981 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
982 /* Race breaker */
983 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
984 dprintk("%s slot is busy\n", __func__);
985 return false;
986 }
987 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
988 }
989 return true;
990}
991
992/*
993 * TODO: cb_sequence should support referring call lists, cachethis, multiple
994 * slots, and mark callback channel down on communication errors.
995 */
996static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
997{
998 struct nfsd4_callback *cb = calldata;
999 struct nfs4_client *clp = cb->cb_clp;
1000 u32 minorversion = clp->cl_minorversion;
1001
1002 /*
1003 * cb_seq_status is only set in decode_cb_sequence4res,
1004 * and so will remain 1 if an rpc level failure occurs.
1005 */
1006 cb->cb_seq_status = 1;
1007 cb->cb_status = 0;
1008 if (minorversion) {
1009 if (!cb->cb_holds_slot && !nfsd41_cb_get_slot(clp, task))
1010 return;
1011 cb->cb_holds_slot = true;
1012 }
1013 rpc_call_start(task);
1014}
1015
1016static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1017{
1018 struct nfs4_client *clp = cb->cb_clp;
1019 struct nfsd4_session *session = clp->cl_cb_session;
1020 bool ret = true;
1021
1022 if (!clp->cl_minorversion) {
1023 /*
1024 * If the backchannel connection was shut down while this
1025 * task was queued, we need to resubmit it after setting up
1026 * a new backchannel connection.
1027 *
1028 * Note that if we lost our callback connection permanently
1029 * the submission code will error out, so we don't need to
1030 * handle that case here.
1031 */
1032 if (RPC_SIGNALLED(task))
1033 goto need_restart;
1034
1035 return true;
1036 }
1037
1038 if (!cb->cb_holds_slot)
1039 goto need_restart;
1040
1041 switch (cb->cb_seq_status) {
1042 case 0:
1043 /*
1044 * No need for lock, access serialized in nfsd4_cb_prepare
1045 *
1046 * RFC5661 20.9.3
1047 * If CB_SEQUENCE returns an error, then the state of the slot
1048 * (sequence ID, cached reply) MUST NOT change.
1049 */
1050 ++session->se_cb_seq_nr;
1051 break;
1052 case -ESERVERFAULT:
1053 ++session->se_cb_seq_nr;
1054 /* Fall through */
1055 case 1:
1056 case -NFS4ERR_BADSESSION:
1057 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1058 ret = false;
1059 break;
1060 case -NFS4ERR_DELAY:
1061 if (!rpc_restart_call(task))
1062 goto out;
1063
1064 rpc_delay(task, 2 * HZ);
1065 return false;
1066 case -NFS4ERR_BADSLOT:
1067 goto retry_nowait;
1068 case -NFS4ERR_SEQ_MISORDERED:
1069 if (session->se_cb_seq_nr != 1) {
1070 session->se_cb_seq_nr = 1;
1071 goto retry_nowait;
1072 }
1073 break;
1074 default:
1075 dprintk("%s: unprocessed error %d\n", __func__,
1076 cb->cb_seq_status);
1077 }
1078
1079 cb->cb_holds_slot = false;
1080 clear_bit(0, &clp->cl_cb_slot_busy);
1081 rpc_wake_up_next(&clp->cl_cb_waitq);
1082 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1083 clp->cl_cb_session->se_cb_seq_nr);
1084
1085 if (RPC_SIGNALLED(task))
1086 goto need_restart;
1087out:
1088 return ret;
1089retry_nowait:
1090 if (rpc_restart_call_prepare(task))
1091 ret = false;
1092 goto out;
1093need_restart:
1094 task->tk_status = 0;
1095 cb->cb_need_restart = true;
1096 return false;
1097}
1098
1099static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1100{
1101 struct nfsd4_callback *cb = calldata;
1102 struct nfs4_client *clp = cb->cb_clp;
1103
1104 dprintk("%s: minorversion=%d\n", __func__,
1105 clp->cl_minorversion);
1106
1107 if (!nfsd4_cb_sequence_done(task, cb))
1108 return;
1109
1110 if (cb->cb_status) {
1111 WARN_ON_ONCE(task->tk_status);
1112 task->tk_status = cb->cb_status;
1113 }
1114
1115 switch (cb->cb_ops->done(cb, task)) {
1116 case 0:
1117 task->tk_status = 0;
1118 rpc_restart_call_prepare(task);
1119 return;
1120 case 1:
1121 switch (task->tk_status) {
1122 case -EIO:
1123 case -ETIMEDOUT:
1124 nfsd4_mark_cb_down(clp, task->tk_status);
1125 }
1126 break;
1127 default:
1128 BUG();
1129 }
1130}
1131
1132static void nfsd4_cb_release(void *calldata)
1133{
1134 struct nfsd4_callback *cb = calldata;
1135
1136 if (cb->cb_need_restart)
1137 nfsd4_run_cb(cb);
1138 else
1139 cb->cb_ops->release(cb);
1140
1141}
1142
1143static const struct rpc_call_ops nfsd4_cb_ops = {
1144 .rpc_call_prepare = nfsd4_cb_prepare,
1145 .rpc_call_done = nfsd4_cb_done,
1146 .rpc_release = nfsd4_cb_release,
1147};
1148
1149int nfsd4_create_callback_queue(void)
1150{
1151 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1152 if (!callback_wq)
1153 return -ENOMEM;
1154 return 0;
1155}
1156
1157void nfsd4_destroy_callback_queue(void)
1158{
1159 destroy_workqueue(callback_wq);
1160}
1161
1162/* must be called under the state lock */
1163void nfsd4_shutdown_callback(struct nfs4_client *clp)
1164{
1165 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1166 /*
1167 * Note this won't actually result in a null callback;
1168 * instead, nfsd4_run_cb_null() will detect the killed
1169 * client, destroy the rpc client, and stop:
1170 */
1171 nfsd4_run_cb(&clp->cl_cb_null);
1172 flush_workqueue(callback_wq);
1173}
1174
1175/* requires cl_lock: */
1176static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1177{
1178 struct nfsd4_session *s;
1179 struct nfsd4_conn *c;
1180
1181 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1182 list_for_each_entry(c, &s->se_conns, cn_persession) {
1183 if (c->cn_flags & NFS4_CDFC4_BACK)
1184 return c;
1185 }
1186 }
1187 return NULL;
1188}
1189
1190static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1191{
1192 struct nfs4_cb_conn conn;
1193 struct nfs4_client *clp = cb->cb_clp;
1194 struct nfsd4_session *ses = NULL;
1195 struct nfsd4_conn *c;
1196 int err;
1197
1198 /*
1199 * This is either an update, or the client dying; in either case,
1200 * kill the old client:
1201 */
1202 if (clp->cl_cb_client) {
1203 rpc_shutdown_client(clp->cl_cb_client);
1204 clp->cl_cb_client = NULL;
1205 put_cred(clp->cl_cb_cred);
1206 clp->cl_cb_cred = NULL;
1207 }
1208 if (clp->cl_cb_conn.cb_xprt) {
1209 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1210 clp->cl_cb_conn.cb_xprt = NULL;
1211 }
1212 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1213 return;
1214 spin_lock(&clp->cl_lock);
1215 /*
1216 * Only serialized callback code is allowed to clear these
1217 * flags; main nfsd code can only set them:
1218 */
1219 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1220 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1221 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1222 c = __nfsd4_find_backchannel(clp);
1223 if (c) {
1224 svc_xprt_get(c->cn_xprt);
1225 conn.cb_xprt = c->cn_xprt;
1226 ses = c->cn_session;
1227 }
1228 spin_unlock(&clp->cl_lock);
1229
1230 err = setup_callback_client(clp, &conn, ses);
1231 if (err) {
1232 nfsd4_mark_cb_down(clp, err);
1233 return;
1234 }
1235}
1236
1237static void
1238nfsd4_run_cb_work(struct work_struct *work)
1239{
1240 struct nfsd4_callback *cb =
1241 container_of(work, struct nfsd4_callback, cb_work);
1242 struct nfs4_client *clp = cb->cb_clp;
1243 struct rpc_clnt *clnt;
1244
1245 if (cb->cb_need_restart) {
1246 cb->cb_need_restart = false;
1247 } else {
1248 if (cb->cb_ops && cb->cb_ops->prepare)
1249 cb->cb_ops->prepare(cb);
1250 }
1251
1252 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1253 nfsd4_process_cb_update(cb);
1254
1255 clnt = clp->cl_cb_client;
1256 if (!clnt) {
1257 /* Callback channel broken, or client killed; give up: */
1258 if (cb->cb_ops && cb->cb_ops->release)
1259 cb->cb_ops->release(cb);
1260 return;
1261 }
1262
1263 /*
1264 * Don't send probe messages for 4.1 or later.
1265 */
1266 if (!cb->cb_ops && clp->cl_minorversion) {
1267 clp->cl_cb_state = NFSD4_CB_UP;
1268 return;
1269 }
1270
1271 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1272 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
1273 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1274}
1275
1276void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1277 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1278{
1279 cb->cb_clp = clp;
1280 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1281 cb->cb_msg.rpc_argp = cb;
1282 cb->cb_msg.rpc_resp = cb;
1283 cb->cb_ops = ops;
1284 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1285 cb->cb_seq_status = 1;
1286 cb->cb_status = 0;
1287 cb->cb_need_restart = false;
1288 cb->cb_holds_slot = false;
1289}
1290
1291void nfsd4_run_cb(struct nfsd4_callback *cb)
1292{
1293 queue_work(callback_wq, &cb->cb_work);
1294}