1 /*
2 * linux/fs/nfsd/nfs4callback.c
3 *
4 * Copyright (c) 2001 The Regents of the University of Michigan.
5 * All rights reserved.
6 *
7 * Kendrick Smith <kmsmith@umich.edu>
8 * Andy Adamson <andros@umich.edu>
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its
20 * contributors may be used to endorse or promote products derived
21 * from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
24 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include <linux/module.h>
37 #include <linux/list.h>
38 #include <linux/inet.h>
39 #include <linux/errno.h>
40 #include <linux/delay.h>
41 #include <linux/sched.h>
42 #include <linux/kthread.h>
43 #include <linux/sunrpc/xdr.h>
44 #include <linux/sunrpc/svc.h>
45 #include <linux/sunrpc/clnt.h>
46 #include <linux/nfsd/nfsd.h>
47 #include <linux/nfsd/state.h>
48 #include <linux/sunrpc/sched.h>
49 #include <linux/nfs4.h>
50
51 #define NFSDDBG_FACILITY NFSDDBG_PROC
52
53 #define NFSPROC4_CB_NULL 0
54 #define NFSPROC4_CB_COMPOUND 1
55
56 /* Index of predefined Linux callback client operations */
57
58 enum {
59 NFSPROC4_CLNT_CB_NULL = 0,
60 NFSPROC4_CLNT_CB_RECALL,
61 };
62
63 enum nfs_cb_opnum4 {
64 OP_CB_RECALL = 4,
65 };
66
67 #define NFS4_MAXTAGLEN 20
68
69 #define NFS4_enc_cb_null_sz 0
70 #define NFS4_dec_cb_null_sz 0
71 #define cb_compound_enc_hdr_sz 4
72 #define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
73 #define op_enc_sz 1
74 #define op_dec_sz 2
75 #define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
76 #define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
77 #define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
78 1 + enc_stateid_sz + \
79 enc_nfs4_fh_sz)
80
81 #define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
82 op_dec_sz)
83
84 /*
85 * Generic encode routines from fs/nfs/nfs4xdr.c
86 */
87 static inline __be32 *
xdr_writemem(__be32 * p,const void * ptr,int nbytes)88 xdr_writemem(__be32 *p, const void *ptr, int nbytes)
89 {
90 int tmp = XDR_QUADLEN(nbytes);
91 if (!tmp)
92 return p;
93 p[tmp-1] = 0;
94 memcpy(p, ptr, nbytes);
95 return p + tmp;
96 }
97
98 #define WRITE32(n) *p++ = htonl(n)
99 #define WRITEMEM(ptr,nbytes) do { \
100 p = xdr_writemem(p, ptr, nbytes); \
101 } while (0)
102 #define RESERVE_SPACE(nbytes) do { \
103 p = xdr_reserve_space(xdr, nbytes); \
104 if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
105 BUG_ON(!p); \
106 } while (0)
107
108 /*
109 * Generic decode routines from fs/nfs/nfs4xdr.c
110 */
111 #define DECODE_TAIL \
112 status = 0; \
113 out: \
114 return status; \
115 xdr_error: \
116 dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
117 status = -EIO; \
118 goto out
119
120 #define READ32(x) (x) = ntohl(*p++)
121 #define READ64(x) do { \
122 (x) = (u64)ntohl(*p++) << 32; \
123 (x) |= ntohl(*p++); \
124 } while (0)
125 #define READTIME(x) do { \
126 p++; \
127 (x.tv_sec) = ntohl(*p++); \
128 (x.tv_nsec) = ntohl(*p++); \
129 } while (0)
130 #define READ_BUF(nbytes) do { \
131 p = xdr_inline_decode(xdr, nbytes); \
132 if (!p) { \
133 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
134 __func__, __LINE__); \
135 return -EIO; \
136 } \
137 } while (0)
138
139 struct nfs4_cb_compound_hdr {
140 int status;
141 u32 ident;
142 u32 nops;
143 u32 taglen;
144 char * tag;
145 };
146
147 static struct {
148 int stat;
149 int errno;
150 } nfs_cb_errtbl[] = {
151 { NFS4_OK, 0 },
152 { NFS4ERR_PERM, EPERM },
153 { NFS4ERR_NOENT, ENOENT },
154 { NFS4ERR_IO, EIO },
155 { NFS4ERR_NXIO, ENXIO },
156 { NFS4ERR_ACCESS, EACCES },
157 { NFS4ERR_EXIST, EEXIST },
158 { NFS4ERR_XDEV, EXDEV },
159 { NFS4ERR_NOTDIR, ENOTDIR },
160 { NFS4ERR_ISDIR, EISDIR },
161 { NFS4ERR_INVAL, EINVAL },
162 { NFS4ERR_FBIG, EFBIG },
163 { NFS4ERR_NOSPC, ENOSPC },
164 { NFS4ERR_ROFS, EROFS },
165 { NFS4ERR_MLINK, EMLINK },
166 { NFS4ERR_NAMETOOLONG, ENAMETOOLONG },
167 { NFS4ERR_NOTEMPTY, ENOTEMPTY },
168 { NFS4ERR_DQUOT, EDQUOT },
169 { NFS4ERR_STALE, ESTALE },
170 { NFS4ERR_BADHANDLE, EBADHANDLE },
171 { NFS4ERR_BAD_COOKIE, EBADCOOKIE },
172 { NFS4ERR_NOTSUPP, ENOTSUPP },
173 { NFS4ERR_TOOSMALL, ETOOSMALL },
174 { NFS4ERR_SERVERFAULT, ESERVERFAULT },
175 { NFS4ERR_BADTYPE, EBADTYPE },
176 { NFS4ERR_LOCKED, EAGAIN },
177 { NFS4ERR_RESOURCE, EREMOTEIO },
178 { NFS4ERR_SYMLINK, ELOOP },
179 { NFS4ERR_OP_ILLEGAL, EOPNOTSUPP },
180 { NFS4ERR_DEADLOCK, EDEADLK },
181 { -1, EIO }
182 };
183
184 static int
nfs_cb_stat_to_errno(int stat)185 nfs_cb_stat_to_errno(int stat)
186 {
187 int i;
188 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
189 if (nfs_cb_errtbl[i].stat == stat)
190 return nfs_cb_errtbl[i].errno;
191 }
192 /* If we cannot translate the error, the recovery routines should
193 * handle it.
194 * Note: remaining NFSv4 error codes have values > 10000, so should
195 * not conflict with native Linux error codes.
196 */
197 return stat;
198 }
199
200 /*
201 * XDR encode
202 */
203
204 static int
encode_cb_compound_hdr(struct xdr_stream * xdr,struct nfs4_cb_compound_hdr * hdr)205 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
206 {
207 __be32 * p;
208
209 RESERVE_SPACE(16);
210 WRITE32(0); /* tag length is always 0 */
211 WRITE32(NFS4_MINOR_VERSION);
212 WRITE32(hdr->ident);
213 WRITE32(hdr->nops);
214 return 0;
215 }
216
217 static int
encode_cb_recall(struct xdr_stream * xdr,struct nfs4_cb_recall * cb_rec)218 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
219 {
220 __be32 *p;
221 int len = cb_rec->cbr_fhlen;
222
223 RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
224 WRITE32(OP_CB_RECALL);
225 WRITE32(cb_rec->cbr_stateid.si_generation);
226 WRITEMEM(&cb_rec->cbr_stateid.si_opaque, sizeof(stateid_opaque_t));
227 WRITE32(cb_rec->cbr_trunc);
228 WRITE32(len);
229 WRITEMEM(cb_rec->cbr_fhval, len);
230 return 0;
231 }
232
233 static int
nfs4_xdr_enc_cb_null(struct rpc_rqst * req,__be32 * p)234 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
235 {
236 struct xdr_stream xdrs, *xdr = &xdrs;
237
238 xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
239 RESERVE_SPACE(0);
240 return 0;
241 }
242
243 static int
nfs4_xdr_enc_cb_recall(struct rpc_rqst * req,__be32 * p,struct nfs4_cb_recall * args)244 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
245 {
246 struct xdr_stream xdr;
247 struct nfs4_cb_compound_hdr hdr = {
248 .ident = args->cbr_ident,
249 .nops = 1,
250 };
251
252 xdr_init_encode(&xdr, &req->rq_snd_buf, p);
253 encode_cb_compound_hdr(&xdr, &hdr);
254 return (encode_cb_recall(&xdr, args));
255 }
256
257
258 static int
decode_cb_compound_hdr(struct xdr_stream * xdr,struct nfs4_cb_compound_hdr * hdr)259 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
260 __be32 *p;
261
262 READ_BUF(8);
263 READ32(hdr->status);
264 READ32(hdr->taglen);
265 READ_BUF(hdr->taglen + 4);
266 hdr->tag = (char *)p;
267 p += XDR_QUADLEN(hdr->taglen);
268 READ32(hdr->nops);
269 return 0;
270 }
271
272 static int
decode_cb_op_hdr(struct xdr_stream * xdr,enum nfs_opnum4 expected)273 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
274 {
275 __be32 *p;
276 u32 op;
277 int32_t nfserr;
278
279 READ_BUF(8);
280 READ32(op);
281 if (op != expected) {
282 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
283 " operation %d but we issued a request for %d\n",
284 op, expected);
285 return -EIO;
286 }
287 READ32(nfserr);
288 if (nfserr != NFS_OK)
289 return -nfs_cb_stat_to_errno(nfserr);
290 return 0;
291 }
292
293 static int
nfs4_xdr_dec_cb_null(struct rpc_rqst * req,__be32 * p)294 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
295 {
296 return 0;
297 }
298
299 static int
nfs4_xdr_dec_cb_recall(struct rpc_rqst * rqstp,__be32 * p)300 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
301 {
302 struct xdr_stream xdr;
303 struct nfs4_cb_compound_hdr hdr;
304 int status;
305
306 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
307 status = decode_cb_compound_hdr(&xdr, &hdr);
308 if (status)
309 goto out;
310 status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
311 out:
312 return status;
313 }
314
315 /*
316 * RPC procedure tables
317 */
318 #define PROC(proc, call, argtype, restype) \
319 [NFSPROC4_CLNT_##proc] = { \
320 .p_proc = NFSPROC4_CB_##call, \
321 .p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \
322 .p_decode = (kxdrproc_t) nfs4_xdr_##restype, \
323 .p_arglen = NFS4_##argtype##_sz, \
324 .p_replen = NFS4_##restype##_sz, \
325 .p_statidx = NFSPROC4_CB_##call, \
326 .p_name = #proc, \
327 }
328
329 static struct rpc_procinfo nfs4_cb_procedures[] = {
330 PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null),
331 PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall),
332 };
333
334 static struct rpc_version nfs_cb_version4 = {
335 .number = 1,
336 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
337 .procs = nfs4_cb_procedures
338 };
339
340 static struct rpc_version * nfs_cb_version[] = {
341 NULL,
342 &nfs_cb_version4,
343 };
344
345 static struct rpc_program cb_program;
346
347 static struct rpc_stat cb_stats = {
348 .program = &cb_program
349 };
350
351 #define NFS4_CALLBACK 0x40000000
352 static struct rpc_program cb_program = {
353 .name = "nfs4_cb",
354 .number = NFS4_CALLBACK,
355 .nrvers = ARRAY_SIZE(nfs_cb_version),
356 .version = nfs_cb_version,
357 .stats = &cb_stats,
358 .pipe_dir_name = "/nfsd4_cb",
359 };
360
361 /* Reference counting, callback cleanup, etc., all look racy as heck.
362 * And why is cb_set an atomic? */
363
do_probe_callback(void * data)364 static int do_probe_callback(void *data)
365 {
366 struct nfs4_client *clp = data;
367 struct sockaddr_in addr;
368 struct nfs4_callback *cb = &clp->cl_callback;
369 struct rpc_timeout timeparms = {
370 .to_initval = (NFSD_LEASE_TIME/4) * HZ,
371 .to_retries = 5,
372 .to_maxval = (NFSD_LEASE_TIME/2) * HZ,
373 .to_exponential = 1,
374 };
375 struct rpc_create_args args = {
376 .protocol = IPPROTO_TCP,
377 .address = (struct sockaddr *)&addr,
378 .addrsize = sizeof(addr),
379 .timeout = &timeparms,
380 .program = &cb_program,
381 .prognumber = cb->cb_prog,
382 .version = nfs_cb_version[1]->number,
383 .authflavor = clp->cl_flavor,
384 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
385 .client_name = clp->cl_principal,
386 };
387 struct rpc_message msg = {
388 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
389 .rpc_argp = clp,
390 };
391 struct rpc_clnt *client;
392 int status;
393
394 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) {
395 status = nfserr_cb_path_down;
396 goto out_err;
397 }
398
399 /* Initialize address */
400 memset(&addr, 0, sizeof(addr));
401 addr.sin_family = AF_INET;
402 addr.sin_port = htons(cb->cb_port);
403 addr.sin_addr.s_addr = htonl(cb->cb_addr);
404
405 /* Create RPC client */
406 client = rpc_create(&args);
407 if (IS_ERR(client)) {
408 dprintk("NFSD: couldn't create callback client\n");
409 status = PTR_ERR(client);
410 goto out_err;
411 }
412
413 status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);
414
415 if (status)
416 goto out_release_client;
417
418 cb->cb_client = client;
419 atomic_set(&cb->cb_set, 1);
420 put_nfs4_client(clp);
421 return 0;
422 out_release_client:
423 rpc_shutdown_client(client);
424 out_err:
425 dprintk("NFSD: warning: no callback path to client %.*s\n",
426 (int)clp->cl_name.len, clp->cl_name.data);
427 put_nfs4_client(clp);
428 return status;
429 }
430
431 /*
432 * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
433 */
434 void
nfsd4_probe_callback(struct nfs4_client * clp)435 nfsd4_probe_callback(struct nfs4_client *clp)
436 {
437 struct task_struct *t;
438
439 BUG_ON(atomic_read(&clp->cl_callback.cb_set));
440
441 /* the task holds a reference to the nfs4_client struct */
442 atomic_inc(&clp->cl_count);
443
444 t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
445
446 if (IS_ERR(t))
447 atomic_dec(&clp->cl_count);
448
449 return;
450 }
451
452 /*
453 * called with dp->dl_count inc'ed.
454 * nfs4_lock_state() may or may not have been called.
455 */
456 void
nfsd4_cb_recall(struct nfs4_delegation * dp)457 nfsd4_cb_recall(struct nfs4_delegation *dp)
458 {
459 struct nfs4_client *clp = dp->dl_client;
460 struct rpc_clnt *clnt = clp->cl_callback.cb_client;
461 struct nfs4_cb_recall *cbr = &dp->dl_recall;
462 struct rpc_message msg = {
463 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
464 .rpc_argp = cbr,
465 };
466 int retries = 1;
467 int status = 0;
468
469 cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
470 cbr->cbr_dp = dp;
471
472 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
473 while (retries--) {
474 switch (status) {
475 case -EIO:
476 /* Network partition? */
477 atomic_set(&clp->cl_callback.cb_set, 0);
478 case -EBADHANDLE:
479 case -NFS4ERR_BAD_STATEID:
480 /* Race: client probably got cb_recall
481 * before open reply granting delegation */
482 break;
483 default:
484 goto out_put_cred;
485 }
486 ssleep(2);
487 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
488 }
489 out_put_cred:
490 /*
491 * Success or failure, now we're either waiting for lease expiration
492 * or deleg_return.
493 */
494 put_nfs4_client(clp);
495 nfs4_put_delegation(dp);
496 return;
497 }
498