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