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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 "trace.h"
42#include "xdr4cb.h"
43#include "xdr4.h"
44
45#define NFSDDBG_FACILITY NFSDDBG_PROC
46
47static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
48
49#define NFSPROC4_CB_NULL 0
50#define NFSPROC4_CB_COMPOUND 1
51
52/* Index of predefined Linux callback client operations */
53
54struct nfs4_cb_compound_hdr {
55 /* args */
56 u32 ident; /* minorversion 0 only */
57 u32 nops;
58 __be32 *nops_p;
59 u32 minorversion;
60 /* res */
61 int status;
62};
63
64static __be32 *xdr_encode_empty_array(__be32 *p)
65{
66 *p++ = xdr_zero;
67 return p;
68}
69
70/*
71 * Encode/decode NFSv4 CB basic data types
72 *
73 * Basic NFSv4 callback data types are defined in section 15 of RFC
74 * 3530: "Network File System (NFS) version 4 Protocol" and section
75 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
76 * 1 Protocol"
77 */
78
79/*
80 * nfs_cb_opnum4
81 *
82 * enum nfs_cb_opnum4 {
83 * OP_CB_GETATTR = 3,
84 * ...
85 * };
86 */
87enum nfs_cb_opnum4 {
88 OP_CB_GETATTR = 3,
89 OP_CB_RECALL = 4,
90 OP_CB_LAYOUTRECALL = 5,
91 OP_CB_NOTIFY = 6,
92 OP_CB_PUSH_DELEG = 7,
93 OP_CB_RECALL_ANY = 8,
94 OP_CB_RECALLABLE_OBJ_AVAIL = 9,
95 OP_CB_RECALL_SLOT = 10,
96 OP_CB_SEQUENCE = 11,
97 OP_CB_WANTS_CANCELLED = 12,
98 OP_CB_NOTIFY_LOCK = 13,
99 OP_CB_NOTIFY_DEVICEID = 14,
100 OP_CB_OFFLOAD = 15,
101 OP_CB_ILLEGAL = 10044
102};
103
104static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
105{
106 __be32 *p;
107
108 p = xdr_reserve_space(xdr, 4);
109 *p = cpu_to_be32(op);
110}
111
112/*
113 * nfs_fh4
114 *
115 * typedef opaque nfs_fh4<NFS4_FHSIZE>;
116 */
117static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
118{
119 u32 length = fh->fh_size;
120 __be32 *p;
121
122 BUG_ON(length > NFS4_FHSIZE);
123 p = xdr_reserve_space(xdr, 4 + length);
124 xdr_encode_opaque(p, &fh->fh_base, length);
125}
126
127/*
128 * stateid4
129 *
130 * struct stateid4 {
131 * uint32_t seqid;
132 * opaque other[12];
133 * };
134 */
135static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
136{
137 __be32 *p;
138
139 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
140 *p++ = cpu_to_be32(sid->si_generation);
141 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
142}
143
144/*
145 * sessionid4
146 *
147 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
148 */
149static void encode_sessionid4(struct xdr_stream *xdr,
150 const struct nfsd4_session *session)
151{
152 __be32 *p;
153
154 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
155 xdr_encode_opaque_fixed(p, session->se_sessionid.data,
156 NFS4_MAX_SESSIONID_LEN);
157}
158
159/*
160 * nfsstat4
161 */
162static const struct {
163 int stat;
164 int errno;
165} nfs_cb_errtbl[] = {
166 { NFS4_OK, 0 },
167 { NFS4ERR_PERM, -EPERM },
168 { NFS4ERR_NOENT, -ENOENT },
169 { NFS4ERR_IO, -EIO },
170 { NFS4ERR_NXIO, -ENXIO },
171 { NFS4ERR_ACCESS, -EACCES },
172 { NFS4ERR_EXIST, -EEXIST },
173 { NFS4ERR_XDEV, -EXDEV },
174 { NFS4ERR_NOTDIR, -ENOTDIR },
175 { NFS4ERR_ISDIR, -EISDIR },
176 { NFS4ERR_INVAL, -EINVAL },
177 { NFS4ERR_FBIG, -EFBIG },
178 { NFS4ERR_NOSPC, -ENOSPC },
179 { NFS4ERR_ROFS, -EROFS },
180 { NFS4ERR_MLINK, -EMLINK },
181 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
182 { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
183 { NFS4ERR_DQUOT, -EDQUOT },
184 { NFS4ERR_STALE, -ESTALE },
185 { NFS4ERR_BADHANDLE, -EBADHANDLE },
186 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
187 { NFS4ERR_NOTSUPP, -ENOTSUPP },
188 { NFS4ERR_TOOSMALL, -ETOOSMALL },
189 { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
190 { NFS4ERR_BADTYPE, -EBADTYPE },
191 { NFS4ERR_LOCKED, -EAGAIN },
192 { NFS4ERR_RESOURCE, -EREMOTEIO },
193 { NFS4ERR_SYMLINK, -ELOOP },
194 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP },
195 { NFS4ERR_DEADLOCK, -EDEADLK },
196 { -1, -EIO }
197};
198
199/*
200 * If we cannot translate the error, the recovery routines should
201 * handle it.
202 *
203 * Note: remaining NFSv4 error codes have values > 10000, so should
204 * not conflict with native Linux error codes.
205 */
206static int nfs_cb_stat_to_errno(int status)
207{
208 int i;
209
210 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
211 if (nfs_cb_errtbl[i].stat == status)
212 return nfs_cb_errtbl[i].errno;
213 }
214
215 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
216 return -status;
217}
218
219static int decode_cb_op_status(struct xdr_stream *xdr,
220 enum nfs_cb_opnum4 expected, int *status)
221{
222 __be32 *p;
223 u32 op;
224
225 p = xdr_inline_decode(xdr, 4 + 4);
226 if (unlikely(p == NULL))
227 goto out_overflow;
228 op = be32_to_cpup(p++);
229 if (unlikely(op != expected))
230 goto out_unexpected;
231 *status = nfs_cb_stat_to_errno(be32_to_cpup(p));
232 return 0;
233out_overflow:
234 return -EIO;
235out_unexpected:
236 dprintk("NFSD: Callback server returned operation %d but "
237 "we issued a request for %d\n", op, expected);
238 return -EIO;
239}
240
241/*
242 * CB_COMPOUND4args
243 *
244 * struct CB_COMPOUND4args {
245 * utf8str_cs tag;
246 * uint32_t minorversion;
247 * uint32_t callback_ident;
248 * nfs_cb_argop4 argarray<>;
249 * };
250*/
251static void encode_cb_compound4args(struct xdr_stream *xdr,
252 struct nfs4_cb_compound_hdr *hdr)
253{
254 __be32 * p;
255
256 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
257 p = xdr_encode_empty_array(p); /* empty tag */
258 *p++ = cpu_to_be32(hdr->minorversion);
259 *p++ = cpu_to_be32(hdr->ident);
260
261 hdr->nops_p = p;
262 *p = cpu_to_be32(hdr->nops); /* argarray element count */
263}
264
265/*
266 * Update argarray element count
267 */
268static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
269{
270 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
271 *hdr->nops_p = cpu_to_be32(hdr->nops);
272}
273
274/*
275 * CB_COMPOUND4res
276 *
277 * struct CB_COMPOUND4res {
278 * nfsstat4 status;
279 * utf8str_cs tag;
280 * nfs_cb_resop4 resarray<>;
281 * };
282 */
283static int decode_cb_compound4res(struct xdr_stream *xdr,
284 struct nfs4_cb_compound_hdr *hdr)
285{
286 u32 length;
287 __be32 *p;
288
289 p = xdr_inline_decode(xdr, 4 + 4);
290 if (unlikely(p == NULL))
291 goto out_overflow;
292 hdr->status = be32_to_cpup(p++);
293 /* Ignore the tag */
294 length = be32_to_cpup(p++);
295 p = xdr_inline_decode(xdr, length + 4);
296 if (unlikely(p == NULL))
297 goto out_overflow;
298 p += XDR_QUADLEN(length);
299 hdr->nops = be32_to_cpup(p);
300 return 0;
301out_overflow:
302 return -EIO;
303}
304
305/*
306 * CB_RECALL4args
307 *
308 * struct CB_RECALL4args {
309 * stateid4 stateid;
310 * bool truncate;
311 * nfs_fh4 fh;
312 * };
313 */
314static void encode_cb_recall4args(struct xdr_stream *xdr,
315 const struct nfs4_delegation *dp,
316 struct nfs4_cb_compound_hdr *hdr)
317{
318 __be32 *p;
319
320 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
321 encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
322
323 p = xdr_reserve_space(xdr, 4);
324 *p++ = xdr_zero; /* truncate */
325
326 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
327
328 hdr->nops++;
329}
330
331/*
332 * CB_SEQUENCE4args
333 *
334 * struct CB_SEQUENCE4args {
335 * sessionid4 csa_sessionid;
336 * sequenceid4 csa_sequenceid;
337 * slotid4 csa_slotid;
338 * slotid4 csa_highest_slotid;
339 * bool csa_cachethis;
340 * referring_call_list4 csa_referring_call_lists<>;
341 * };
342 */
343static void encode_cb_sequence4args(struct xdr_stream *xdr,
344 const struct nfsd4_callback *cb,
345 struct nfs4_cb_compound_hdr *hdr)
346{
347 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
348 __be32 *p;
349
350 if (hdr->minorversion == 0)
351 return;
352
353 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
354 encode_sessionid4(xdr, session);
355
356 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
357 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
358 *p++ = xdr_zero; /* csa_slotid */
359 *p++ = xdr_zero; /* csa_highest_slotid */
360 *p++ = xdr_zero; /* csa_cachethis */
361 xdr_encode_empty_array(p); /* csa_referring_call_lists */
362
363 hdr->nops++;
364}
365
366/*
367 * CB_SEQUENCE4resok
368 *
369 * struct CB_SEQUENCE4resok {
370 * sessionid4 csr_sessionid;
371 * sequenceid4 csr_sequenceid;
372 * slotid4 csr_slotid;
373 * slotid4 csr_highest_slotid;
374 * slotid4 csr_target_highest_slotid;
375 * };
376 *
377 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
378 * case NFS4_OK:
379 * CB_SEQUENCE4resok csr_resok4;
380 * default:
381 * void;
382 * };
383 *
384 * Our current back channel implmentation supports a single backchannel
385 * with a single slot.
386 */
387static int decode_cb_sequence4resok(struct xdr_stream *xdr,
388 struct nfsd4_callback *cb)
389{
390 struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
391 int status = -ESERVERFAULT;
392 __be32 *p;
393 u32 dummy;
394
395 /*
396 * If the server returns different values for sessionID, slotID or
397 * sequence number, the server is looney tunes.
398 */
399 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
400 if (unlikely(p == NULL))
401 goto out_overflow;
402
403 if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
404 dprintk("NFS: %s Invalid session id\n", __func__);
405 goto out;
406 }
407 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
408
409 dummy = be32_to_cpup(p++);
410 if (dummy != session->se_cb_seq_nr) {
411 dprintk("NFS: %s Invalid sequence number\n", __func__);
412 goto out;
413 }
414
415 dummy = be32_to_cpup(p++);
416 if (dummy != 0) {
417 dprintk("NFS: %s Invalid slotid\n", __func__);
418 goto out;
419 }
420
421 /*
422 * FIXME: process highest slotid and target highest slotid
423 */
424 status = 0;
425out:
426 cb->cb_seq_status = status;
427 return status;
428out_overflow:
429 status = -EIO;
430 goto out;
431}
432
433static int decode_cb_sequence4res(struct xdr_stream *xdr,
434 struct nfsd4_callback *cb)
435{
436 int status;
437
438 if (cb->cb_clp->cl_minorversion == 0)
439 return 0;
440
441 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
442 if (unlikely(status || cb->cb_seq_status))
443 return status;
444
445 return decode_cb_sequence4resok(xdr, cb);
446}
447
448/*
449 * NFSv4.0 and NFSv4.1 XDR encode functions
450 *
451 * NFSv4.0 callback argument types are defined in section 15 of RFC
452 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
453 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
454 * Protocol".
455 */
456
457/*
458 * NB: Without this zero space reservation, callbacks over krb5p fail
459 */
460static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
461 const void *__unused)
462{
463 xdr_reserve_space(xdr, 0);
464}
465
466/*
467 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
468 */
469static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
470 const void *data)
471{
472 const struct nfsd4_callback *cb = data;
473 const struct nfs4_delegation *dp = cb_to_delegation(cb);
474 struct nfs4_cb_compound_hdr hdr = {
475 .ident = cb->cb_clp->cl_cb_ident,
476 .minorversion = cb->cb_clp->cl_minorversion,
477 };
478
479 encode_cb_compound4args(xdr, &hdr);
480 encode_cb_sequence4args(xdr, cb, &hdr);
481 encode_cb_recall4args(xdr, dp, &hdr);
482 encode_cb_nops(&hdr);
483}
484
485
486/*
487 * NFSv4.0 and NFSv4.1 XDR decode functions
488 *
489 * NFSv4.0 callback result types are defined in section 15 of RFC
490 * 3530: "Network File System (NFS) version 4 Protocol" and section 20
491 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
492 * Protocol".
493 */
494
495static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
496 void *__unused)
497{
498 return 0;
499}
500
501/*
502 * 20.2. Operation 4: CB_RECALL - Recall a Delegation
503 */
504static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
505 struct xdr_stream *xdr,
506 void *data)
507{
508 struct nfsd4_callback *cb = data;
509 struct nfs4_cb_compound_hdr hdr;
510 int status;
511
512 status = decode_cb_compound4res(xdr, &hdr);
513 if (unlikely(status))
514 return status;
515
516 status = decode_cb_sequence4res(xdr, cb);
517 if (unlikely(status || cb->cb_seq_status))
518 return status;
519
520 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
521}
522
523#ifdef CONFIG_NFSD_PNFS
524/*
525 * CB_LAYOUTRECALL4args
526 *
527 * struct layoutrecall_file4 {
528 * nfs_fh4 lor_fh;
529 * offset4 lor_offset;
530 * length4 lor_length;
531 * stateid4 lor_stateid;
532 * };
533 *
534 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
535 * case LAYOUTRECALL4_FILE:
536 * layoutrecall_file4 lor_layout;
537 * case LAYOUTRECALL4_FSID:
538 * fsid4 lor_fsid;
539 * case LAYOUTRECALL4_ALL:
540 * void;
541 * };
542 *
543 * struct CB_LAYOUTRECALL4args {
544 * layouttype4 clora_type;
545 * layoutiomode4 clora_iomode;
546 * bool clora_changed;
547 * layoutrecall4 clora_recall;
548 * };
549 */
550static void encode_cb_layout4args(struct xdr_stream *xdr,
551 const struct nfs4_layout_stateid *ls,
552 struct nfs4_cb_compound_hdr *hdr)
553{
554 __be32 *p;
555
556 BUG_ON(hdr->minorversion == 0);
557
558 p = xdr_reserve_space(xdr, 5 * 4);
559 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
560 *p++ = cpu_to_be32(ls->ls_layout_type);
561 *p++ = cpu_to_be32(IOMODE_ANY);
562 *p++ = cpu_to_be32(1);
563 *p = cpu_to_be32(RETURN_FILE);
564
565 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
566
567 p = xdr_reserve_space(xdr, 2 * 8);
568 p = xdr_encode_hyper(p, 0);
569 xdr_encode_hyper(p, NFS4_MAX_UINT64);
570
571 encode_stateid4(xdr, &ls->ls_recall_sid);
572
573 hdr->nops++;
574}
575
576static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
577 struct xdr_stream *xdr,
578 const void *data)
579{
580 const struct nfsd4_callback *cb = data;
581 const struct nfs4_layout_stateid *ls =
582 container_of(cb, struct nfs4_layout_stateid, ls_recall);
583 struct nfs4_cb_compound_hdr hdr = {
584 .ident = 0,
585 .minorversion = cb->cb_clp->cl_minorversion,
586 };
587
588 encode_cb_compound4args(xdr, &hdr);
589 encode_cb_sequence4args(xdr, cb, &hdr);
590 encode_cb_layout4args(xdr, ls, &hdr);
591 encode_cb_nops(&hdr);
592}
593
594static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
595 struct xdr_stream *xdr,
596 void *data)
597{
598 struct nfsd4_callback *cb = data;
599 struct nfs4_cb_compound_hdr hdr;
600 int status;
601
602 status = decode_cb_compound4res(xdr, &hdr);
603 if (unlikely(status))
604 return status;
605
606 status = decode_cb_sequence4res(xdr, cb);
607 if (unlikely(status || cb->cb_seq_status))
608 return status;
609
610 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
611}
612#endif /* CONFIG_NFSD_PNFS */
613
614static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
615{
616 __be32 *p;
617
618 p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
619 p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
620 xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
621}
622
623static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
624 struct xdr_stream *xdr,
625 const void *data)
626{
627 const struct nfsd4_callback *cb = data;
628 const struct nfsd4_blocked_lock *nbl =
629 container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
630 struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
631 struct nfs4_cb_compound_hdr hdr = {
632 .ident = 0,
633 .minorversion = cb->cb_clp->cl_minorversion,
634 };
635
636 __be32 *p;
637
638 BUG_ON(hdr.minorversion == 0);
639
640 encode_cb_compound4args(xdr, &hdr);
641 encode_cb_sequence4args(xdr, cb, &hdr);
642
643 p = xdr_reserve_space(xdr, 4);
644 *p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
645 encode_nfs_fh4(xdr, &nbl->nbl_fh);
646 encode_stateowner(xdr, &lo->lo_owner);
647 hdr.nops++;
648
649 encode_cb_nops(&hdr);
650}
651
652static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
653 struct xdr_stream *xdr,
654 void *data)
655{
656 struct nfsd4_callback *cb = data;
657 struct nfs4_cb_compound_hdr hdr;
658 int status;
659
660 status = decode_cb_compound4res(xdr, &hdr);
661 if (unlikely(status))
662 return status;
663
664 status = decode_cb_sequence4res(xdr, cb);
665 if (unlikely(status || cb->cb_seq_status))
666 return status;
667
668 return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
669}
670
671/*
672 * struct write_response4 {
673 * stateid4 wr_callback_id<1>;
674 * length4 wr_count;
675 * stable_how4 wr_committed;
676 * verifier4 wr_writeverf;
677 * };
678 * union offload_info4 switch (nfsstat4 coa_status) {
679 * case NFS4_OK:
680 * write_response4 coa_resok4;
681 * default:
682 * length4 coa_bytes_copied;
683 * };
684 * struct CB_OFFLOAD4args {
685 * nfs_fh4 coa_fh;
686 * stateid4 coa_stateid;
687 * offload_info4 coa_offload_info;
688 * };
689 */
690static void encode_offload_info4(struct xdr_stream *xdr,
691 __be32 nfserr,
692 const struct nfsd4_copy *cp)
693{
694 __be32 *p;
695
696 p = xdr_reserve_space(xdr, 4);
697 *p++ = nfserr;
698 if (!nfserr) {
699 p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
700 p = xdr_encode_empty_array(p);
701 p = xdr_encode_hyper(p, cp->cp_res.wr_bytes_written);
702 *p++ = cpu_to_be32(cp->cp_res.wr_stable_how);
703 p = xdr_encode_opaque_fixed(p, cp->cp_res.wr_verifier.data,
704 NFS4_VERIFIER_SIZE);
705 } else {
706 p = xdr_reserve_space(xdr, 8);
707 /* We always return success if bytes were written */
708 p = xdr_encode_hyper(p, 0);
709 }
710}
711
712static void encode_cb_offload4args(struct xdr_stream *xdr,
713 __be32 nfserr,
714 const struct knfsd_fh *fh,
715 const struct nfsd4_copy *cp,
716 struct nfs4_cb_compound_hdr *hdr)
717{
718 __be32 *p;
719
720 p = xdr_reserve_space(xdr, 4);
721 *p++ = cpu_to_be32(OP_CB_OFFLOAD);
722 encode_nfs_fh4(xdr, fh);
723 encode_stateid4(xdr, &cp->cp_res.cb_stateid);
724 encode_offload_info4(xdr, nfserr, cp);
725
726 hdr->nops++;
727}
728
729static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
730 struct xdr_stream *xdr,
731 const void *data)
732{
733 const struct nfsd4_callback *cb = data;
734 const struct nfsd4_copy *cp =
735 container_of(cb, struct nfsd4_copy, cp_cb);
736 struct nfs4_cb_compound_hdr hdr = {
737 .ident = 0,
738 .minorversion = cb->cb_clp->cl_minorversion,
739 };
740
741 encode_cb_compound4args(xdr, &hdr);
742 encode_cb_sequence4args(xdr, cb, &hdr);
743 encode_cb_offload4args(xdr, cp->nfserr, &cp->fh, cp, &hdr);
744 encode_cb_nops(&hdr);
745}
746
747static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
748 struct xdr_stream *xdr,
749 void *data)
750{
751 struct nfsd4_callback *cb = data;
752 struct nfs4_cb_compound_hdr hdr;
753 int status;
754
755 status = decode_cb_compound4res(xdr, &hdr);
756 if (unlikely(status))
757 return status;
758
759 status = decode_cb_sequence4res(xdr, cb);
760 if (unlikely(status || cb->cb_seq_status))
761 return status;
762
763 return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
764}
765/*
766 * RPC procedure tables
767 */
768#define PROC(proc, call, argtype, restype) \
769[NFSPROC4_CLNT_##proc] = { \
770 .p_proc = NFSPROC4_CB_##call, \
771 .p_encode = nfs4_xdr_enc_##argtype, \
772 .p_decode = nfs4_xdr_dec_##restype, \
773 .p_arglen = NFS4_enc_##argtype##_sz, \
774 .p_replen = NFS4_dec_##restype##_sz, \
775 .p_statidx = NFSPROC4_CB_##call, \
776 .p_name = #proc, \
777}
778
779static const struct rpc_procinfo nfs4_cb_procedures[] = {
780 PROC(CB_NULL, NULL, cb_null, cb_null),
781 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
782#ifdef CONFIG_NFSD_PNFS
783 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
784#endif
785 PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
786 PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
787};
788
789static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
790static const struct rpc_version nfs_cb_version4 = {
791/*
792 * Note on the callback rpc program version number: despite language in rfc
793 * 5661 section 18.36.3 requiring servers to use 4 in this field, the
794 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
795 * in practice that appears to be what implementations use. The section
796 * 18.36.3 language is expected to be fixed in an erratum.
797 */
798 .number = 1,
799 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
800 .procs = nfs4_cb_procedures,
801 .counts = nfs4_cb_counts,
802};
803
804static const struct rpc_version *nfs_cb_version[2] = {
805 [1] = &nfs_cb_version4,
806};
807
808static const struct rpc_program cb_program;
809
810static struct rpc_stat cb_stats = {
811 .program = &cb_program
812};
813
814#define NFS4_CALLBACK 0x40000000
815static const struct rpc_program cb_program = {
816 .name = "nfs4_cb",
817 .number = NFS4_CALLBACK,
818 .nrvers = ARRAY_SIZE(nfs_cb_version),
819 .version = nfs_cb_version,
820 .stats = &cb_stats,
821 .pipe_dir_name = "nfsd4_cb",
822};
823
824static int max_cb_time(struct net *net)
825{
826 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
827
828 /*
829 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
830 * so we can use 32-bit math on it. Warn if that assumption
831 * ever stops being true.
832 */
833 if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
834 return 360 * HZ;
835
836 return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
837}
838
839static struct workqueue_struct *callback_wq;
840
841static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
842{
843 return queue_work(callback_wq, &cb->cb_work);
844}
845
846static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
847{
848 atomic_inc(&clp->cl_cb_inflight);
849}
850
851static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
852{
853
854 if (atomic_dec_and_test(&clp->cl_cb_inflight))
855 wake_up_var(&clp->cl_cb_inflight);
856}
857
858static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
859{
860 wait_var_event(&clp->cl_cb_inflight,
861 !atomic_read(&clp->cl_cb_inflight));
862}
863
864static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
865{
866 if (clp->cl_minorversion == 0) {
867 client->cl_principal = clp->cl_cred.cr_targ_princ ?
868 clp->cl_cred.cr_targ_princ : "nfs";
869
870 return get_cred(rpc_machine_cred());
871 } else {
872 struct cred *kcred;
873
874 kcred = prepare_kernel_cred(NULL);
875 if (!kcred)
876 return NULL;
877
878 kcred->uid = ses->se_cb_sec.uid;
879 kcred->gid = ses->se_cb_sec.gid;
880 return kcred;
881 }
882}
883
884static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
885{
886 int maxtime = max_cb_time(clp->net);
887 struct rpc_timeout timeparms = {
888 .to_initval = maxtime,
889 .to_retries = 0,
890 .to_maxval = maxtime,
891 };
892 struct rpc_create_args args = {
893 .net = clp->net,
894 .address = (struct sockaddr *) &conn->cb_addr,
895 .addrsize = conn->cb_addrlen,
896 .saddress = (struct sockaddr *) &conn->cb_saddr,
897 .timeout = &timeparms,
898 .program = &cb_program,
899 .version = 1,
900 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
901 .cred = current_cred(),
902 };
903 struct rpc_clnt *client;
904 const struct cred *cred;
905
906 if (clp->cl_minorversion == 0) {
907 if (!clp->cl_cred.cr_principal &&
908 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
909 trace_nfsd_cb_setup_err(clp, -EINVAL);
910 return -EINVAL;
911 }
912 args.client_name = clp->cl_cred.cr_principal;
913 args.prognumber = conn->cb_prog;
914 args.protocol = XPRT_TRANSPORT_TCP;
915 args.authflavor = clp->cl_cred.cr_flavor;
916 clp->cl_cb_ident = conn->cb_ident;
917 } else {
918 if (!conn->cb_xprt) {
919 trace_nfsd_cb_setup_err(clp, -EINVAL);
920 return -EINVAL;
921 }
922 clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
923 clp->cl_cb_session = ses;
924 args.bc_xprt = conn->cb_xprt;
925 args.prognumber = clp->cl_cb_session->se_cb_prog;
926 args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
927 XPRT_TRANSPORT_BC;
928 args.authflavor = ses->se_cb_sec.flavor;
929 }
930 /* Create RPC client */
931 client = rpc_create(&args);
932 if (IS_ERR(client)) {
933 trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
934 return PTR_ERR(client);
935 }
936 cred = get_backchannel_cred(clp, client, ses);
937 if (!cred) {
938 trace_nfsd_cb_setup_err(clp, -ENOMEM);
939 rpc_shutdown_client(client);
940 return -ENOMEM;
941 }
942 clp->cl_cb_client = client;
943 clp->cl_cb_cred = cred;
944 trace_nfsd_cb_setup(clp);
945 return 0;
946}
947
948static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
949{
950 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
951 return;
952 clp->cl_cb_state = NFSD4_CB_DOWN;
953 trace_nfsd_cb_state(clp);
954}
955
956static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
957{
958 if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
959 return;
960 clp->cl_cb_state = NFSD4_CB_FAULT;
961 trace_nfsd_cb_state(clp);
962}
963
964static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
965{
966 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
967
968 trace_nfsd_cb_done(clp, task->tk_status);
969 if (task->tk_status)
970 nfsd4_mark_cb_down(clp, task->tk_status);
971 else {
972 clp->cl_cb_state = NFSD4_CB_UP;
973 trace_nfsd_cb_state(clp);
974 }
975}
976
977static void nfsd4_cb_probe_release(void *calldata)
978{
979 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
980
981 nfsd41_cb_inflight_end(clp);
982
983}
984
985static const struct rpc_call_ops nfsd4_cb_probe_ops = {
986 /* XXX: release method to ensure we set the cb channel down if
987 * necessary on early failure? */
988 .rpc_call_done = nfsd4_cb_probe_done,
989 .rpc_release = nfsd4_cb_probe_release,
990};
991
992/*
993 * Poke the callback thread to process any updates to the callback
994 * parameters, and send a null probe.
995 */
996void nfsd4_probe_callback(struct nfs4_client *clp)
997{
998 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
999 trace_nfsd_cb_state(clp);
1000 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1001 nfsd4_run_cb(&clp->cl_cb_null);
1002}
1003
1004void nfsd4_probe_callback_sync(struct nfs4_client *clp)
1005{
1006 nfsd4_probe_callback(clp);
1007 flush_workqueue(callback_wq);
1008}
1009
1010void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
1011{
1012 clp->cl_cb_state = NFSD4_CB_UNKNOWN;
1013 spin_lock(&clp->cl_lock);
1014 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
1015 spin_unlock(&clp->cl_lock);
1016 trace_nfsd_cb_state(clp);
1017}
1018
1019/*
1020 * There's currently a single callback channel slot.
1021 * If the slot is available, then mark it busy. Otherwise, set the
1022 * thread for sleeping on the callback RPC wait queue.
1023 */
1024static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
1025{
1026 struct nfs4_client *clp = cb->cb_clp;
1027
1028 if (!cb->cb_holds_slot &&
1029 test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1030 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
1031 /* Race breaker */
1032 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
1033 dprintk("%s slot is busy\n", __func__);
1034 return false;
1035 }
1036 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
1037 }
1038 cb->cb_holds_slot = true;
1039 return true;
1040}
1041
1042static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
1043{
1044 struct nfs4_client *clp = cb->cb_clp;
1045
1046 if (cb->cb_holds_slot) {
1047 cb->cb_holds_slot = false;
1048 clear_bit(0, &clp->cl_cb_slot_busy);
1049 rpc_wake_up_next(&clp->cl_cb_waitq);
1050 }
1051}
1052
1053static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
1054{
1055 struct nfs4_client *clp = cb->cb_clp;
1056
1057 nfsd41_cb_release_slot(cb);
1058 if (cb->cb_ops && cb->cb_ops->release)
1059 cb->cb_ops->release(cb);
1060 nfsd41_cb_inflight_end(clp);
1061}
1062
1063/*
1064 * TODO: cb_sequence should support referring call lists, cachethis, multiple
1065 * slots, and mark callback channel down on communication errors.
1066 */
1067static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
1068{
1069 struct nfsd4_callback *cb = calldata;
1070 struct nfs4_client *clp = cb->cb_clp;
1071 u32 minorversion = clp->cl_minorversion;
1072
1073 /*
1074 * cb_seq_status is only set in decode_cb_sequence4res,
1075 * and so will remain 1 if an rpc level failure occurs.
1076 */
1077 cb->cb_seq_status = 1;
1078 cb->cb_status = 0;
1079 if (minorversion && !nfsd41_cb_get_slot(cb, task))
1080 return;
1081 rpc_call_start(task);
1082}
1083
1084static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
1085{
1086 struct nfs4_client *clp = cb->cb_clp;
1087 struct nfsd4_session *session = clp->cl_cb_session;
1088 bool ret = true;
1089
1090 if (!clp->cl_minorversion) {
1091 /*
1092 * If the backchannel connection was shut down while this
1093 * task was queued, we need to resubmit it after setting up
1094 * a new backchannel connection.
1095 *
1096 * Note that if we lost our callback connection permanently
1097 * the submission code will error out, so we don't need to
1098 * handle that case here.
1099 */
1100 if (RPC_SIGNALLED(task))
1101 goto need_restart;
1102
1103 return true;
1104 }
1105
1106 if (!cb->cb_holds_slot)
1107 goto need_restart;
1108
1109 switch (cb->cb_seq_status) {
1110 case 0:
1111 /*
1112 * No need for lock, access serialized in nfsd4_cb_prepare
1113 *
1114 * RFC5661 20.9.3
1115 * If CB_SEQUENCE returns an error, then the state of the slot
1116 * (sequence ID, cached reply) MUST NOT change.
1117 */
1118 ++session->se_cb_seq_nr;
1119 break;
1120 case -ESERVERFAULT:
1121 ++session->se_cb_seq_nr;
1122 fallthrough;
1123 case 1:
1124 case -NFS4ERR_BADSESSION:
1125 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1126 ret = false;
1127 break;
1128 case -NFS4ERR_DELAY:
1129 if (!rpc_restart_call(task))
1130 goto out;
1131
1132 rpc_delay(task, 2 * HZ);
1133 return false;
1134 case -NFS4ERR_BADSLOT:
1135 goto retry_nowait;
1136 case -NFS4ERR_SEQ_MISORDERED:
1137 if (session->se_cb_seq_nr != 1) {
1138 session->se_cb_seq_nr = 1;
1139 goto retry_nowait;
1140 }
1141 break;
1142 default:
1143 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
1144 dprintk("%s: unprocessed error %d\n", __func__,
1145 cb->cb_seq_status);
1146 }
1147
1148 nfsd41_cb_release_slot(cb);
1149 dprintk("%s: freed slot, new seqid=%d\n", __func__,
1150 clp->cl_cb_session->se_cb_seq_nr);
1151
1152 if (RPC_SIGNALLED(task))
1153 goto need_restart;
1154out:
1155 return ret;
1156retry_nowait:
1157 if (rpc_restart_call_prepare(task))
1158 ret = false;
1159 goto out;
1160need_restart:
1161 if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
1162 task->tk_status = 0;
1163 cb->cb_need_restart = true;
1164 }
1165 return false;
1166}
1167
1168static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
1169{
1170 struct nfsd4_callback *cb = calldata;
1171 struct nfs4_client *clp = cb->cb_clp;
1172
1173 trace_nfsd_cb_done(clp, task->tk_status);
1174
1175 if (!nfsd4_cb_sequence_done(task, cb))
1176 return;
1177
1178 if (cb->cb_status) {
1179 WARN_ON_ONCE(task->tk_status);
1180 task->tk_status = cb->cb_status;
1181 }
1182
1183 switch (cb->cb_ops->done(cb, task)) {
1184 case 0:
1185 task->tk_status = 0;
1186 rpc_restart_call_prepare(task);
1187 return;
1188 case 1:
1189 switch (task->tk_status) {
1190 case -EIO:
1191 case -ETIMEDOUT:
1192 nfsd4_mark_cb_down(clp, task->tk_status);
1193 }
1194 break;
1195 default:
1196 BUG();
1197 }
1198}
1199
1200static void nfsd4_cb_release(void *calldata)
1201{
1202 struct nfsd4_callback *cb = calldata;
1203
1204 if (cb->cb_need_restart)
1205 nfsd4_queue_cb(cb);
1206 else
1207 nfsd41_destroy_cb(cb);
1208
1209}
1210
1211static const struct rpc_call_ops nfsd4_cb_ops = {
1212 .rpc_call_prepare = nfsd4_cb_prepare,
1213 .rpc_call_done = nfsd4_cb_done,
1214 .rpc_release = nfsd4_cb_release,
1215};
1216
1217int nfsd4_create_callback_queue(void)
1218{
1219 callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
1220 if (!callback_wq)
1221 return -ENOMEM;
1222 return 0;
1223}
1224
1225void nfsd4_destroy_callback_queue(void)
1226{
1227 destroy_workqueue(callback_wq);
1228}
1229
1230/* must be called under the state lock */
1231void nfsd4_shutdown_callback(struct nfs4_client *clp)
1232{
1233 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
1234 /*
1235 * Note this won't actually result in a null callback;
1236 * instead, nfsd4_run_cb_null() will detect the killed
1237 * client, destroy the rpc client, and stop:
1238 */
1239 nfsd4_run_cb(&clp->cl_cb_null);
1240 flush_workqueue(callback_wq);
1241 nfsd41_cb_inflight_wait_complete(clp);
1242}
1243
1244/* requires cl_lock: */
1245static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
1246{
1247 struct nfsd4_session *s;
1248 struct nfsd4_conn *c;
1249
1250 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
1251 list_for_each_entry(c, &s->se_conns, cn_persession) {
1252 if (c->cn_flags & NFS4_CDFC4_BACK)
1253 return c;
1254 }
1255 }
1256 return NULL;
1257}
1258
1259/*
1260 * Note there isn't a lot of locking in this code; instead we depend on
1261 * the fact that it is run from the callback_wq, which won't run two
1262 * work items at once. So, for example, callback_wq handles all access
1263 * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
1264 */
1265static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
1266{
1267 struct nfs4_cb_conn conn;
1268 struct nfs4_client *clp = cb->cb_clp;
1269 struct nfsd4_session *ses = NULL;
1270 struct nfsd4_conn *c;
1271 int err;
1272
1273 /*
1274 * This is either an update, or the client dying; in either case,
1275 * kill the old client:
1276 */
1277 if (clp->cl_cb_client) {
1278 trace_nfsd_cb_shutdown(clp);
1279 rpc_shutdown_client(clp->cl_cb_client);
1280 clp->cl_cb_client = NULL;
1281 put_cred(clp->cl_cb_cred);
1282 clp->cl_cb_cred = NULL;
1283 }
1284 if (clp->cl_cb_conn.cb_xprt) {
1285 svc_xprt_put(clp->cl_cb_conn.cb_xprt);
1286 clp->cl_cb_conn.cb_xprt = NULL;
1287 }
1288 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
1289 return;
1290 spin_lock(&clp->cl_lock);
1291 /*
1292 * Only serialized callback code is allowed to clear these
1293 * flags; main nfsd code can only set them:
1294 */
1295 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
1296 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
1297 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
1298 c = __nfsd4_find_backchannel(clp);
1299 if (c) {
1300 svc_xprt_get(c->cn_xprt);
1301 conn.cb_xprt = c->cn_xprt;
1302 ses = c->cn_session;
1303 }
1304 spin_unlock(&clp->cl_lock);
1305
1306 err = setup_callback_client(clp, &conn, ses);
1307 if (err) {
1308 nfsd4_mark_cb_down(clp, err);
1309 if (c)
1310 svc_xprt_put(c->cn_xprt);
1311 return;
1312 }
1313}
1314
1315static void
1316nfsd4_run_cb_work(struct work_struct *work)
1317{
1318 struct nfsd4_callback *cb =
1319 container_of(work, struct nfsd4_callback, cb_work);
1320 struct nfs4_client *clp = cb->cb_clp;
1321 struct rpc_clnt *clnt;
1322 int flags;
1323
1324 trace_nfsd_cb_work(clp, cb->cb_msg.rpc_proc->p_name);
1325
1326 if (cb->cb_need_restart) {
1327 cb->cb_need_restart = false;
1328 } else {
1329 if (cb->cb_ops && cb->cb_ops->prepare)
1330 cb->cb_ops->prepare(cb);
1331 }
1332
1333 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
1334 nfsd4_process_cb_update(cb);
1335
1336 clnt = clp->cl_cb_client;
1337 if (!clnt) {
1338 /* Callback channel broken, or client killed; give up: */
1339 nfsd41_destroy_cb(cb);
1340 return;
1341 }
1342
1343 /*
1344 * Don't send probe messages for 4.1 or later.
1345 */
1346 if (!cb->cb_ops && clp->cl_minorversion) {
1347 clp->cl_cb_state = NFSD4_CB_UP;
1348 nfsd41_destroy_cb(cb);
1349 return;
1350 }
1351
1352 cb->cb_msg.rpc_cred = clp->cl_cb_cred;
1353 flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
1354 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
1355 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
1356}
1357
1358void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
1359 const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
1360{
1361 cb->cb_clp = clp;
1362 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
1363 cb->cb_msg.rpc_argp = cb;
1364 cb->cb_msg.rpc_resp = cb;
1365 cb->cb_ops = ops;
1366 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
1367 cb->cb_seq_status = 1;
1368 cb->cb_status = 0;
1369 cb->cb_need_restart = false;
1370 cb->cb_holds_slot = false;
1371}
1372
1373void nfsd4_run_cb(struct nfsd4_callback *cb)
1374{
1375 struct nfs4_client *clp = cb->cb_clp;
1376
1377 nfsd41_cb_inflight_begin(clp);
1378 if (!nfsd4_queue_cb(cb))
1379 nfsd41_cb_inflight_end(clp);
1380}