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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/fs/nfs/callback_xdr.c
4  *
5  * Copyright (C) 2004 Trond Myklebust
6  *
7  * NFSv4 callback encode/decode procedures
8  */
9 #include <linux/kernel.h>
10 #include <linux/sunrpc/svc.h>
11 #include <linux/nfs4.h>
12 #include <linux/nfs_fs.h>
13 #include <linux/ratelimit.h>
14 #include <linux/printk.h>
15 #include <linux/slab.h>
16 #include <linux/sunrpc/bc_xprt.h>
17 #include "nfs4_fs.h"
18 #include "callback.h"
19 #include "internal.h"
20 #include "nfs4session.h"
21 #include "nfs4trace.h"
22 
23 #define CB_OP_TAGLEN_MAXSZ		(512)
24 #define CB_OP_HDR_RES_MAXSZ		(2 * 4) // opcode, status
25 #define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
26 #define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
27 					 CB_OP_GETATTR_BITMAP_MAXSZ + \
28 					 /* change, size, ctime, mtime */\
29 					 (2 + 2 + 3 + 3) * 4)
30 #define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
31 
32 #if defined(CONFIG_NFS_V4_1)
33 #define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
34 #define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
35 #define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
36 					 NFS4_MAX_SESSIONID_LEN + \
37 					 (1 + 3) * 4) // seqid, 3 slotids
38 #define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
39 #define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
40 #define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
41 #endif /* CONFIG_NFS_V4_1 */
42 #ifdef CONFIG_NFS_V4_2
43 #define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
44 #endif /* CONFIG_NFS_V4_2 */
45 
46 #define NFSDBG_FACILITY NFSDBG_CALLBACK
47 
48 /* Internal error code */
49 #define NFS4ERR_RESOURCE_HDR	11050
50 
51 struct callback_op {
52 	__be32 (*process_op)(void *, void *, struct cb_process_state *);
53 	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
54 	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
55 			const void *);
56 	long res_maxsize;
57 };
58 
59 static struct callback_op callback_ops[];
60 
nfs4_callback_null(struct svc_rqst * rqstp)61 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
62 {
63 	return htonl(NFS4_OK);
64 }
65 
nfs4_decode_void(struct svc_rqst * rqstp,__be32 * p)66 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
67 {
68 	return xdr_argsize_check(rqstp, p);
69 }
70 
nfs4_encode_void(struct svc_rqst * rqstp,__be32 * p)71 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
72 {
73 	return xdr_ressize_check(rqstp, p);
74 }
75 
decode_string(struct xdr_stream * xdr,unsigned int * len,const char ** str,size_t maxlen)76 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
77 		const char **str, size_t maxlen)
78 {
79 	ssize_t err;
80 
81 	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
82 	if (err < 0)
83 		return cpu_to_be32(NFS4ERR_RESOURCE);
84 	*len = err;
85 	return 0;
86 }
87 
decode_fh(struct xdr_stream * xdr,struct nfs_fh * fh)88 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
89 {
90 	__be32 *p;
91 
92 	p = xdr_inline_decode(xdr, 4);
93 	if (unlikely(p == NULL))
94 		return htonl(NFS4ERR_RESOURCE);
95 	fh->size = ntohl(*p);
96 	if (fh->size > NFS4_FHSIZE)
97 		return htonl(NFS4ERR_BADHANDLE);
98 	p = xdr_inline_decode(xdr, fh->size);
99 	if (unlikely(p == NULL))
100 		return htonl(NFS4ERR_RESOURCE);
101 	memcpy(&fh->data[0], p, fh->size);
102 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
103 	return 0;
104 }
105 
decode_bitmap(struct xdr_stream * xdr,uint32_t * bitmap)106 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
107 {
108 	__be32 *p;
109 	unsigned int attrlen;
110 
111 	p = xdr_inline_decode(xdr, 4);
112 	if (unlikely(p == NULL))
113 		return htonl(NFS4ERR_RESOURCE);
114 	attrlen = ntohl(*p);
115 	p = xdr_inline_decode(xdr, attrlen << 2);
116 	if (unlikely(p == NULL))
117 		return htonl(NFS4ERR_RESOURCE);
118 	if (likely(attrlen > 0))
119 		bitmap[0] = ntohl(*p++);
120 	if (attrlen > 1)
121 		bitmap[1] = ntohl(*p);
122 	return 0;
123 }
124 
decode_stateid(struct xdr_stream * xdr,nfs4_stateid * stateid)125 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
126 {
127 	__be32 *p;
128 
129 	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
130 	if (unlikely(p == NULL))
131 		return htonl(NFS4ERR_RESOURCE);
132 	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
133 	return 0;
134 }
135 
decode_delegation_stateid(struct xdr_stream * xdr,nfs4_stateid * stateid)136 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
137 {
138 	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
139 	return decode_stateid(xdr, stateid);
140 }
141 
decode_compound_hdr_arg(struct xdr_stream * xdr,struct cb_compound_hdr_arg * hdr)142 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
143 {
144 	__be32 *p;
145 	__be32 status;
146 
147 	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
148 	if (unlikely(status != 0))
149 		return status;
150 	p = xdr_inline_decode(xdr, 12);
151 	if (unlikely(p == NULL))
152 		return htonl(NFS4ERR_RESOURCE);
153 	hdr->minorversion = ntohl(*p++);
154 	/* Check for minor version support */
155 	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
156 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
157 	} else {
158 		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
159 			"illegal minor version %u!\n",
160 			__func__, hdr->minorversion);
161 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
162 	}
163 	hdr->nops = ntohl(*p);
164 	return 0;
165 }
166 
decode_op_hdr(struct xdr_stream * xdr,unsigned int * op)167 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
168 {
169 	__be32 *p;
170 	p = xdr_inline_decode(xdr, 4);
171 	if (unlikely(p == NULL))
172 		return htonl(NFS4ERR_RESOURCE_HDR);
173 	*op = ntohl(*p);
174 	return 0;
175 }
176 
decode_getattr_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * argp)177 static __be32 decode_getattr_args(struct svc_rqst *rqstp,
178 		struct xdr_stream *xdr, void *argp)
179 {
180 	struct cb_getattrargs *args = argp;
181 	__be32 status;
182 
183 	status = decode_fh(xdr, &args->fh);
184 	if (unlikely(status != 0))
185 		return status;
186 	return decode_bitmap(xdr, args->bitmap);
187 }
188 
decode_recall_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * argp)189 static __be32 decode_recall_args(struct svc_rqst *rqstp,
190 		struct xdr_stream *xdr, void *argp)
191 {
192 	struct cb_recallargs *args = argp;
193 	__be32 *p;
194 	__be32 status;
195 
196 	status = decode_delegation_stateid(xdr, &args->stateid);
197 	if (unlikely(status != 0))
198 		return status;
199 	p = xdr_inline_decode(xdr, 4);
200 	if (unlikely(p == NULL))
201 		return htonl(NFS4ERR_RESOURCE);
202 	args->truncate = ntohl(*p);
203 	return decode_fh(xdr, &args->fh);
204 }
205 
206 #if defined(CONFIG_NFS_V4_1)
decode_layout_stateid(struct xdr_stream * xdr,nfs4_stateid * stateid)207 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
208 {
209 	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
210 	return decode_stateid(xdr, stateid);
211 }
212 
decode_layoutrecall_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * argp)213 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
214 				       struct xdr_stream *xdr, void *argp)
215 {
216 	struct cb_layoutrecallargs *args = argp;
217 	__be32 *p;
218 	__be32 status = 0;
219 	uint32_t iomode;
220 
221 	p = xdr_inline_decode(xdr, 4 * sizeof(uint32_t));
222 	if (unlikely(p == NULL))
223 		return htonl(NFS4ERR_BADXDR);
224 
225 	args->cbl_layout_type = ntohl(*p++);
226 	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
227 	 * as it is unusable and ignored with the other types.
228 	 */
229 	iomode = ntohl(*p++);
230 	args->cbl_layoutchanged = ntohl(*p++);
231 	args->cbl_recall_type = ntohl(*p++);
232 
233 	if (args->cbl_recall_type == RETURN_FILE) {
234 		args->cbl_range.iomode = iomode;
235 		status = decode_fh(xdr, &args->cbl_fh);
236 		if (unlikely(status != 0))
237 			return status;
238 
239 		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
240 		if (unlikely(p == NULL))
241 			return htonl(NFS4ERR_BADXDR);
242 		p = xdr_decode_hyper(p, &args->cbl_range.offset);
243 		p = xdr_decode_hyper(p, &args->cbl_range.length);
244 		return decode_layout_stateid(xdr, &args->cbl_stateid);
245 	} else if (args->cbl_recall_type == RETURN_FSID) {
246 		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
247 		if (unlikely(p == NULL))
248 			return htonl(NFS4ERR_BADXDR);
249 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
250 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
251 	} else if (args->cbl_recall_type != RETURN_ALL)
252 		return htonl(NFS4ERR_BADXDR);
253 	return 0;
254 }
255 
256 static
decode_devicenotify_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * argp)257 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
258 				struct xdr_stream *xdr,
259 				void *argp)
260 {
261 	struct cb_devicenotifyargs *args = argp;
262 	uint32_t tmp, n, i;
263 	__be32 *p;
264 	__be32 status = 0;
265 
266 	/* Num of device notifications */
267 	p = xdr_inline_decode(xdr, sizeof(uint32_t));
268 	if (unlikely(p == NULL)) {
269 		status = htonl(NFS4ERR_BADXDR);
270 		goto out;
271 	}
272 	n = ntohl(*p++);
273 	if (n == 0)
274 		goto out;
275 
276 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
277 	if (!args->devs) {
278 		status = htonl(NFS4ERR_DELAY);
279 		goto out;
280 	}
281 
282 	/* Decode each dev notification */
283 	for (i = 0; i < n; i++) {
284 		struct cb_devicenotifyitem *dev = &args->devs[i];
285 
286 		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
287 				      NFS4_DEVICEID4_SIZE);
288 		if (unlikely(p == NULL)) {
289 			status = htonl(NFS4ERR_BADXDR);
290 			goto err;
291 		}
292 
293 		tmp = ntohl(*p++);	/* bitmap size */
294 		if (tmp != 1) {
295 			status = htonl(NFS4ERR_INVAL);
296 			goto err;
297 		}
298 		dev->cbd_notify_type = ntohl(*p++);
299 		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
300 		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
301 			status = htonl(NFS4ERR_INVAL);
302 			goto err;
303 		}
304 
305 		tmp = ntohl(*p++);	/* opaque size */
306 		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
307 		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
308 		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
309 		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
310 			status = htonl(NFS4ERR_INVAL);
311 			goto err;
312 		}
313 		dev->cbd_layout_type = ntohl(*p++);
314 		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
315 		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
316 
317 		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
318 			p = xdr_inline_decode(xdr, sizeof(uint32_t));
319 			if (unlikely(p == NULL)) {
320 				status = htonl(NFS4ERR_BADXDR);
321 				goto err;
322 			}
323 			dev->cbd_immediate = ntohl(*p++);
324 		} else {
325 			dev->cbd_immediate = 0;
326 		}
327 
328 		dprintk("%s: type %d layout 0x%x immediate %d\n",
329 			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
330 			dev->cbd_immediate);
331 	}
332 	args->ndevs = n;
333 	dprintk("%s: ndevs %d\n", __func__, args->ndevs);
334 	return 0;
335 err:
336 	kfree(args->devs);
337 out:
338 	args->devs = NULL;
339 	args->ndevs = 0;
340 	dprintk("%s: status %d ndevs %d\n",
341 		__func__, ntohl(status), args->ndevs);
342 	return status;
343 }
344 
decode_sessionid(struct xdr_stream * xdr,struct nfs4_sessionid * sid)345 static __be32 decode_sessionid(struct xdr_stream *xdr,
346 				 struct nfs4_sessionid *sid)
347 {
348 	__be32 *p;
349 
350 	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
351 	if (unlikely(p == NULL))
352 		return htonl(NFS4ERR_RESOURCE);
353 
354 	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
355 	return 0;
356 }
357 
decode_rc_list(struct xdr_stream * xdr,struct referring_call_list * rc_list)358 static __be32 decode_rc_list(struct xdr_stream *xdr,
359 			       struct referring_call_list *rc_list)
360 {
361 	__be32 *p;
362 	int i;
363 	__be32 status;
364 
365 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
366 	if (status)
367 		goto out;
368 
369 	status = htonl(NFS4ERR_RESOURCE);
370 	p = xdr_inline_decode(xdr, sizeof(uint32_t));
371 	if (unlikely(p == NULL))
372 		goto out;
373 
374 	rc_list->rcl_nrefcalls = ntohl(*p++);
375 	if (rc_list->rcl_nrefcalls) {
376 		p = xdr_inline_decode(xdr,
377 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
378 		if (unlikely(p == NULL))
379 			goto out;
380 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
381 						sizeof(*rc_list->rcl_refcalls),
382 						GFP_KERNEL);
383 		if (unlikely(rc_list->rcl_refcalls == NULL))
384 			goto out;
385 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
386 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
387 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
388 		}
389 	}
390 	status = 0;
391 
392 out:
393 	return status;
394 }
395 
decode_cb_sequence_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * argp)396 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
397 					struct xdr_stream *xdr,
398 					void *argp)
399 {
400 	struct cb_sequenceargs *args = argp;
401 	__be32 *p;
402 	int i;
403 	__be32 status;
404 
405 	status = decode_sessionid(xdr, &args->csa_sessionid);
406 	if (status)
407 		return status;
408 
409 	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
410 	if (unlikely(p == NULL))
411 		return htonl(NFS4ERR_RESOURCE);
412 
413 	args->csa_addr = svc_addr(rqstp);
414 	args->csa_sequenceid = ntohl(*p++);
415 	args->csa_slotid = ntohl(*p++);
416 	args->csa_highestslotid = ntohl(*p++);
417 	args->csa_cachethis = ntohl(*p++);
418 	args->csa_nrclists = ntohl(*p++);
419 	args->csa_rclists = NULL;
420 	if (args->csa_nrclists) {
421 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
422 						  sizeof(*args->csa_rclists),
423 						  GFP_KERNEL);
424 		if (unlikely(args->csa_rclists == NULL))
425 			return htonl(NFS4ERR_RESOURCE);
426 
427 		for (i = 0; i < args->csa_nrclists; i++) {
428 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
429 			if (status) {
430 				args->csa_nrclists = i;
431 				goto out_free;
432 			}
433 		}
434 	}
435 	return 0;
436 
437 out_free:
438 	for (i = 0; i < args->csa_nrclists; i++)
439 		kfree(args->csa_rclists[i].rcl_refcalls);
440 	kfree(args->csa_rclists);
441 	return status;
442 }
443 
decode_recallany_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * argp)444 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
445 				      struct xdr_stream *xdr,
446 				      void *argp)
447 {
448 	struct cb_recallanyargs *args = argp;
449 	uint32_t bitmap[2];
450 	__be32 *p, status;
451 
452 	p = xdr_inline_decode(xdr, 4);
453 	if (unlikely(p == NULL))
454 		return htonl(NFS4ERR_BADXDR);
455 	args->craa_objs_to_keep = ntohl(*p++);
456 	status = decode_bitmap(xdr, bitmap);
457 	if (unlikely(status))
458 		return status;
459 	args->craa_type_mask = bitmap[0];
460 
461 	return 0;
462 }
463 
decode_recallslot_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * argp)464 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
465 					struct xdr_stream *xdr,
466 					void *argp)
467 {
468 	struct cb_recallslotargs *args = argp;
469 	__be32 *p;
470 
471 	p = xdr_inline_decode(xdr, 4);
472 	if (unlikely(p == NULL))
473 		return htonl(NFS4ERR_BADXDR);
474 	args->crsa_target_highest_slotid = ntohl(*p++);
475 	return 0;
476 }
477 
decode_lockowner(struct xdr_stream * xdr,struct cb_notify_lock_args * args)478 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
479 {
480 	__be32		*p;
481 	unsigned int	len;
482 
483 	p = xdr_inline_decode(xdr, 12);
484 	if (unlikely(p == NULL))
485 		return htonl(NFS4ERR_BADXDR);
486 
487 	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
488 	len = be32_to_cpu(*p);
489 
490 	p = xdr_inline_decode(xdr, len);
491 	if (unlikely(p == NULL))
492 		return htonl(NFS4ERR_BADXDR);
493 
494 	/* Only try to decode if the length is right */
495 	if (len == 20) {
496 		p += 2;	/* skip "lock id:" */
497 		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
498 		xdr_decode_hyper(p, &args->cbnl_owner.id);
499 		args->cbnl_valid = true;
500 	} else {
501 		args->cbnl_owner.s_dev = 0;
502 		args->cbnl_owner.id = 0;
503 		args->cbnl_valid = false;
504 	}
505 	return 0;
506 }
507 
decode_notify_lock_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * argp)508 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
509 		struct xdr_stream *xdr, void *argp)
510 {
511 	struct cb_notify_lock_args *args = argp;
512 	__be32 status;
513 
514 	status = decode_fh(xdr, &args->cbnl_fh);
515 	if (unlikely(status != 0))
516 		return status;
517 	return decode_lockowner(xdr, args);
518 }
519 
520 #endif /* CONFIG_NFS_V4_1 */
521 #ifdef CONFIG_NFS_V4_2
decode_write_response(struct xdr_stream * xdr,struct cb_offloadargs * args)522 static __be32 decode_write_response(struct xdr_stream *xdr,
523 					struct cb_offloadargs *args)
524 {
525 	__be32 *p;
526 
527 	/* skip the always zero field */
528 	p = xdr_inline_decode(xdr, 4);
529 	if (unlikely(!p))
530 		goto out;
531 	p++;
532 
533 	/* decode count, stable_how, verifier */
534 	p = xdr_inline_decode(xdr, 8 + 4);
535 	if (unlikely(!p))
536 		goto out;
537 	p = xdr_decode_hyper(p, &args->wr_count);
538 	args->wr_writeverf.committed = be32_to_cpup(p);
539 	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
540 	if (likely(p)) {
541 		memcpy(&args->wr_writeverf.verifier.data[0], p,
542 			NFS4_VERIFIER_SIZE);
543 		return 0;
544 	}
545 out:
546 	return htonl(NFS4ERR_RESOURCE);
547 }
548 
decode_offload_args(struct svc_rqst * rqstp,struct xdr_stream * xdr,void * data)549 static __be32 decode_offload_args(struct svc_rqst *rqstp,
550 					struct xdr_stream *xdr,
551 					void *data)
552 {
553 	struct cb_offloadargs *args = data;
554 	__be32 *p;
555 	__be32 status;
556 
557 	/* decode fh */
558 	status = decode_fh(xdr, &args->coa_fh);
559 	if (unlikely(status != 0))
560 		return status;
561 
562 	/* decode stateid */
563 	status = decode_stateid(xdr, &args->coa_stateid);
564 	if (unlikely(status != 0))
565 		return status;
566 
567 	/* decode status */
568 	p = xdr_inline_decode(xdr, 4);
569 	if (unlikely(!p))
570 		goto out;
571 	args->error = ntohl(*p++);
572 	if (!args->error) {
573 		status = decode_write_response(xdr, args);
574 		if (unlikely(status != 0))
575 			return status;
576 	} else {
577 		p = xdr_inline_decode(xdr, 8);
578 		if (unlikely(!p))
579 			goto out;
580 		p = xdr_decode_hyper(p, &args->wr_count);
581 	}
582 	return 0;
583 out:
584 	return htonl(NFS4ERR_RESOURCE);
585 }
586 #endif /* CONFIG_NFS_V4_2 */
encode_string(struct xdr_stream * xdr,unsigned int len,const char * str)587 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
588 {
589 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
590 		return cpu_to_be32(NFS4ERR_RESOURCE);
591 	return 0;
592 }
593 
encode_attr_bitmap(struct xdr_stream * xdr,const uint32_t * bitmap,size_t sz)594 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
595 {
596 	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
597 		return cpu_to_be32(NFS4ERR_RESOURCE);
598 	return 0;
599 }
600 
encode_attr_change(struct xdr_stream * xdr,const uint32_t * bitmap,uint64_t change)601 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
602 {
603 	__be32 *p;
604 
605 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
606 		return 0;
607 	p = xdr_reserve_space(xdr, 8);
608 	if (unlikely(!p))
609 		return htonl(NFS4ERR_RESOURCE);
610 	p = xdr_encode_hyper(p, change);
611 	return 0;
612 }
613 
encode_attr_size(struct xdr_stream * xdr,const uint32_t * bitmap,uint64_t size)614 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
615 {
616 	__be32 *p;
617 
618 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
619 		return 0;
620 	p = xdr_reserve_space(xdr, 8);
621 	if (unlikely(!p))
622 		return htonl(NFS4ERR_RESOURCE);
623 	p = xdr_encode_hyper(p, size);
624 	return 0;
625 }
626 
encode_attr_time(struct xdr_stream * xdr,const struct timespec64 * time)627 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
628 {
629 	__be32 *p;
630 
631 	p = xdr_reserve_space(xdr, 12);
632 	if (unlikely(!p))
633 		return htonl(NFS4ERR_RESOURCE);
634 	p = xdr_encode_hyper(p, time->tv_sec);
635 	*p = htonl(time->tv_nsec);
636 	return 0;
637 }
638 
encode_attr_ctime(struct xdr_stream * xdr,const uint32_t * bitmap,const struct timespec64 * time)639 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
640 {
641 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
642 		return 0;
643 	return encode_attr_time(xdr,time);
644 }
645 
encode_attr_mtime(struct xdr_stream * xdr,const uint32_t * bitmap,const struct timespec64 * time)646 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
647 {
648 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
649 		return 0;
650 	return encode_attr_time(xdr,time);
651 }
652 
encode_compound_hdr_res(struct xdr_stream * xdr,struct cb_compound_hdr_res * hdr)653 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
654 {
655 	__be32 status;
656 
657 	hdr->status = xdr_reserve_space(xdr, 4);
658 	if (unlikely(hdr->status == NULL))
659 		return htonl(NFS4ERR_RESOURCE);
660 	status = encode_string(xdr, hdr->taglen, hdr->tag);
661 	if (unlikely(status != 0))
662 		return status;
663 	hdr->nops = xdr_reserve_space(xdr, 4);
664 	if (unlikely(hdr->nops == NULL))
665 		return htonl(NFS4ERR_RESOURCE);
666 	return 0;
667 }
668 
encode_op_hdr(struct xdr_stream * xdr,uint32_t op,__be32 res)669 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
670 {
671 	__be32 *p;
672 
673 	p = xdr_reserve_space(xdr, 8);
674 	if (unlikely(p == NULL))
675 		return htonl(NFS4ERR_RESOURCE_HDR);
676 	*p++ = htonl(op);
677 	*p = res;
678 	return 0;
679 }
680 
encode_getattr_res(struct svc_rqst * rqstp,struct xdr_stream * xdr,const void * resp)681 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
682 		const void *resp)
683 {
684 	const struct cb_getattrres *res = resp;
685 	__be32 *savep = NULL;
686 	__be32 status = res->status;
687 
688 	if (unlikely(status != 0))
689 		goto out;
690 	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
691 	if (unlikely(status != 0))
692 		goto out;
693 	status = cpu_to_be32(NFS4ERR_RESOURCE);
694 	savep = xdr_reserve_space(xdr, sizeof(*savep));
695 	if (unlikely(!savep))
696 		goto out;
697 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
698 	if (unlikely(status != 0))
699 		goto out;
700 	status = encode_attr_size(xdr, res->bitmap, res->size);
701 	if (unlikely(status != 0))
702 		goto out;
703 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
704 	if (unlikely(status != 0))
705 		goto out;
706 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
707 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
708 out:
709 	return status;
710 }
711 
712 #if defined(CONFIG_NFS_V4_1)
713 
encode_sessionid(struct xdr_stream * xdr,const struct nfs4_sessionid * sid)714 static __be32 encode_sessionid(struct xdr_stream *xdr,
715 				 const struct nfs4_sessionid *sid)
716 {
717 	__be32 *p;
718 
719 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
720 	if (unlikely(p == NULL))
721 		return htonl(NFS4ERR_RESOURCE);
722 
723 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
724 	return 0;
725 }
726 
encode_cb_sequence_res(struct svc_rqst * rqstp,struct xdr_stream * xdr,const void * resp)727 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
728 				       struct xdr_stream *xdr,
729 				       const void *resp)
730 {
731 	const struct cb_sequenceres *res = resp;
732 	__be32 *p;
733 	__be32 status = res->csr_status;
734 
735 	if (unlikely(status != 0))
736 		return status;
737 
738 	status = encode_sessionid(xdr, &res->csr_sessionid);
739 	if (status)
740 		return status;
741 
742 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
743 	if (unlikely(p == NULL))
744 		return htonl(NFS4ERR_RESOURCE);
745 
746 	*p++ = htonl(res->csr_sequenceid);
747 	*p++ = htonl(res->csr_slotid);
748 	*p++ = htonl(res->csr_highestslotid);
749 	*p++ = htonl(res->csr_target_highestslotid);
750 	return 0;
751 }
752 
753 static __be32
preprocess_nfs41_op(int nop,unsigned int op_nr,struct callback_op ** op)754 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
755 {
756 	if (op_nr == OP_CB_SEQUENCE) {
757 		if (nop != 0)
758 			return htonl(NFS4ERR_SEQUENCE_POS);
759 	} else {
760 		if (nop == 0)
761 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
762 	}
763 
764 	switch (op_nr) {
765 	case OP_CB_GETATTR:
766 	case OP_CB_RECALL:
767 	case OP_CB_SEQUENCE:
768 	case OP_CB_RECALL_ANY:
769 	case OP_CB_RECALL_SLOT:
770 	case OP_CB_LAYOUTRECALL:
771 	case OP_CB_NOTIFY_DEVICEID:
772 	case OP_CB_NOTIFY_LOCK:
773 		*op = &callback_ops[op_nr];
774 		break;
775 
776 	case OP_CB_NOTIFY:
777 	case OP_CB_PUSH_DELEG:
778 	case OP_CB_RECALLABLE_OBJ_AVAIL:
779 	case OP_CB_WANTS_CANCELLED:
780 		return htonl(NFS4ERR_NOTSUPP);
781 
782 	default:
783 		return htonl(NFS4ERR_OP_ILLEGAL);
784 	}
785 
786 	return htonl(NFS_OK);
787 }
788 
nfs4_callback_free_slot(struct nfs4_session * session,struct nfs4_slot * slot)789 static void nfs4_callback_free_slot(struct nfs4_session *session,
790 		struct nfs4_slot *slot)
791 {
792 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
793 
794 	spin_lock(&tbl->slot_tbl_lock);
795 	/*
796 	 * Let the state manager know callback processing done.
797 	 * A single slot, so highest used slotid is either 0 or -1
798 	 */
799 	nfs4_free_slot(tbl, slot);
800 	spin_unlock(&tbl->slot_tbl_lock);
801 }
802 
nfs4_cb_free_slot(struct cb_process_state * cps)803 static void nfs4_cb_free_slot(struct cb_process_state *cps)
804 {
805 	if (cps->slot) {
806 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
807 		cps->slot = NULL;
808 	}
809 }
810 
811 #else /* CONFIG_NFS_V4_1 */
812 
813 static __be32
preprocess_nfs41_op(int nop,unsigned int op_nr,struct callback_op ** op)814 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
815 {
816 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
817 }
818 
nfs4_cb_free_slot(struct cb_process_state * cps)819 static void nfs4_cb_free_slot(struct cb_process_state *cps)
820 {
821 }
822 #endif /* CONFIG_NFS_V4_1 */
823 
824 #ifdef CONFIG_NFS_V4_2
825 static __be32
preprocess_nfs42_op(int nop,unsigned int op_nr,struct callback_op ** op)826 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
827 {
828 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
829 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
830 		return status;
831 
832 	if (op_nr == OP_CB_OFFLOAD) {
833 		*op = &callback_ops[op_nr];
834 		return htonl(NFS_OK);
835 	} else
836 		return htonl(NFS4ERR_NOTSUPP);
837 	return htonl(NFS4ERR_OP_ILLEGAL);
838 }
839 #else /* CONFIG_NFS_V4_2 */
840 static __be32
preprocess_nfs42_op(int nop,unsigned int op_nr,struct callback_op ** op)841 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
842 {
843 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
844 }
845 #endif /* CONFIG_NFS_V4_2 */
846 
847 static __be32
preprocess_nfs4_op(unsigned int op_nr,struct callback_op ** op)848 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
849 {
850 	switch (op_nr) {
851 	case OP_CB_GETATTR:
852 	case OP_CB_RECALL:
853 		*op = &callback_ops[op_nr];
854 		break;
855 	default:
856 		return htonl(NFS4ERR_OP_ILLEGAL);
857 	}
858 
859 	return htonl(NFS_OK);
860 }
861 
process_op(int nop,struct svc_rqst * rqstp,struct xdr_stream * xdr_in,void * argp,struct xdr_stream * xdr_out,void * resp,struct cb_process_state * cps)862 static __be32 process_op(int nop, struct svc_rqst *rqstp,
863 		struct xdr_stream *xdr_in, void *argp,
864 		struct xdr_stream *xdr_out, void *resp,
865 		struct cb_process_state *cps)
866 {
867 	struct callback_op *op = &callback_ops[0];
868 	unsigned int op_nr;
869 	__be32 status;
870 	long maxlen;
871 	__be32 res;
872 
873 	status = decode_op_hdr(xdr_in, &op_nr);
874 	if (unlikely(status))
875 		return status;
876 
877 	switch (cps->minorversion) {
878 	case 0:
879 		status = preprocess_nfs4_op(op_nr, &op);
880 		break;
881 	case 1:
882 		status = preprocess_nfs41_op(nop, op_nr, &op);
883 		break;
884 	case 2:
885 		status = preprocess_nfs42_op(nop, op_nr, &op);
886 		break;
887 	default:
888 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
889 	}
890 
891 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
892 		op_nr = OP_CB_ILLEGAL;
893 	if (status)
894 		goto encode_hdr;
895 
896 	if (cps->drc_status) {
897 		status = cps->drc_status;
898 		goto encode_hdr;
899 	}
900 
901 	maxlen = xdr_out->end - xdr_out->p;
902 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
903 		status = op->decode_args(rqstp, xdr_in, argp);
904 		if (likely(status == 0))
905 			status = op->process_op(argp, resp, cps);
906 	} else
907 		status = htonl(NFS4ERR_RESOURCE);
908 
909 encode_hdr:
910 	res = encode_op_hdr(xdr_out, op_nr, status);
911 	if (unlikely(res))
912 		return res;
913 	if (op->encode_res != NULL && status == 0)
914 		status = op->encode_res(rqstp, xdr_out, resp);
915 	return status;
916 }
917 
918 /*
919  * Decode, process and encode a COMPOUND
920  */
nfs4_callback_compound(struct svc_rqst * rqstp)921 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
922 {
923 	struct cb_compound_hdr_arg hdr_arg = { 0 };
924 	struct cb_compound_hdr_res hdr_res = { NULL };
925 	struct xdr_stream xdr_in, xdr_out;
926 	__be32 *p, status;
927 	struct cb_process_state cps = {
928 		.drc_status = 0,
929 		.clp = NULL,
930 		.net = SVC_NET(rqstp),
931 	};
932 	unsigned int nops = 0;
933 
934 	xdr_init_decode(&xdr_in, &rqstp->rq_arg,
935 			rqstp->rq_arg.head[0].iov_base, NULL);
936 
937 	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
938 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p, NULL);
939 
940 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
941 	if (status == htonl(NFS4ERR_RESOURCE))
942 		return rpc_garbage_args;
943 
944 	if (hdr_arg.minorversion == 0) {
945 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
946 		if (!cps.clp) {
947 			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
948 			goto out_invalidcred;
949 		}
950 		if (!check_gss_callback_principal(cps.clp, rqstp)) {
951 			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
952 			nfs_put_client(cps.clp);
953 			goto out_invalidcred;
954 		}
955 	}
956 
957 	cps.minorversion = hdr_arg.minorversion;
958 	hdr_res.taglen = hdr_arg.taglen;
959 	hdr_res.tag = hdr_arg.tag;
960 	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) {
961 		if (cps.clp)
962 			nfs_put_client(cps.clp);
963 		return rpc_system_err;
964 	}
965 	while (status == 0 && nops != hdr_arg.nops) {
966 		status = process_op(nops, rqstp, &xdr_in,
967 				    rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
968 				    &cps);
969 		nops++;
970 	}
971 
972 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
973 	* resource error in cb_compound status without returning op */
974 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
975 		status = htonl(NFS4ERR_RESOURCE);
976 		nops--;
977 	}
978 
979 	*hdr_res.status = status;
980 	*hdr_res.nops = htonl(nops);
981 	nfs4_cb_free_slot(&cps);
982 	nfs_put_client(cps.clp);
983 	return rpc_success;
984 
985 out_invalidcred:
986 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
987 	return svc_return_autherr(rqstp, rpc_autherr_badcred);
988 }
989 
990 /*
991  * Define NFS4 callback COMPOUND ops.
992  */
993 static struct callback_op callback_ops[] = {
994 	[0] = {
995 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
996 	},
997 	[OP_CB_GETATTR] = {
998 		.process_op = nfs4_callback_getattr,
999 		.decode_args = decode_getattr_args,
1000 		.encode_res = encode_getattr_res,
1001 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1002 	},
1003 	[OP_CB_RECALL] = {
1004 		.process_op = nfs4_callback_recall,
1005 		.decode_args = decode_recall_args,
1006 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1007 	},
1008 #if defined(CONFIG_NFS_V4_1)
1009 	[OP_CB_LAYOUTRECALL] = {
1010 		.process_op = nfs4_callback_layoutrecall,
1011 		.decode_args = decode_layoutrecall_args,
1012 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1013 	},
1014 	[OP_CB_NOTIFY_DEVICEID] = {
1015 		.process_op = nfs4_callback_devicenotify,
1016 		.decode_args = decode_devicenotify_args,
1017 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1018 	},
1019 	[OP_CB_SEQUENCE] = {
1020 		.process_op = nfs4_callback_sequence,
1021 		.decode_args = decode_cb_sequence_args,
1022 		.encode_res = encode_cb_sequence_res,
1023 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1024 	},
1025 	[OP_CB_RECALL_ANY] = {
1026 		.process_op = nfs4_callback_recallany,
1027 		.decode_args = decode_recallany_args,
1028 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1029 	},
1030 	[OP_CB_RECALL_SLOT] = {
1031 		.process_op = nfs4_callback_recallslot,
1032 		.decode_args = decode_recallslot_args,
1033 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1034 	},
1035 	[OP_CB_NOTIFY_LOCK] = {
1036 		.process_op = nfs4_callback_notify_lock,
1037 		.decode_args = decode_notify_lock_args,
1038 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1039 	},
1040 #endif /* CONFIG_NFS_V4_1 */
1041 #ifdef CONFIG_NFS_V4_2
1042 	[OP_CB_OFFLOAD] = {
1043 		.process_op = nfs4_callback_offload,
1044 		.decode_args = decode_offload_args,
1045 		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1046 	},
1047 #endif /* CONFIG_NFS_V4_2 */
1048 };
1049 
1050 /*
1051  * Define NFS4 callback procedures
1052  */
1053 static const struct svc_procedure nfs4_callback_procedures1[] = {
1054 	[CB_NULL] = {
1055 		.pc_func = nfs4_callback_null,
1056 		.pc_decode = nfs4_decode_void,
1057 		.pc_encode = nfs4_encode_void,
1058 		.pc_xdrressize = 1,
1059 	},
1060 	[CB_COMPOUND] = {
1061 		.pc_func = nfs4_callback_compound,
1062 		.pc_encode = nfs4_encode_void,
1063 		.pc_argsize = 256,
1064 		.pc_ressize = 256,
1065 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1066 	}
1067 };
1068 
1069 static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1070 const struct svc_version nfs4_callback_version1 = {
1071 	.vs_vers = 1,
1072 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1073 	.vs_proc = nfs4_callback_procedures1,
1074 	.vs_count = nfs4_callback_count1,
1075 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1076 	.vs_dispatch = NULL,
1077 	.vs_hidden = true,
1078 	.vs_need_cong_ctrl = true,
1079 };
1080 
1081 static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1082 const struct svc_version nfs4_callback_version4 = {
1083 	.vs_vers = 4,
1084 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1085 	.vs_proc = nfs4_callback_procedures1,
1086 	.vs_count = nfs4_callback_count4,
1087 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1088 	.vs_dispatch = NULL,
1089 	.vs_hidden = true,
1090 	.vs_need_cong_ctrl = true,
1091 };
1092