1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/lockd/xdr.c
4 *
5 * XDR support for lockd and the lock client.
6 *
7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
8 */
9
10#include <linux/types.h>
11#include <linux/sched.h>
12#include <linux/nfs.h>
13
14#include <linux/sunrpc/xdr.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/sunrpc/svc.h>
17#include <linux/sunrpc/stats.h>
18#include <linux/lockd/lockd.h>
19
20#include <uapi/linux/nfs2.h>
21
22#include "svcxdr.h"
23
24
25static inline loff_t
26s32_to_loff_t(__s32 offset)
27{
28	return (loff_t)offset;
29}
30
31static inline __s32
32loff_t_to_s32(loff_t offset)
33{
34	__s32 res;
35	if (offset >= NLM_OFFSET_MAX)
36		res = NLM_OFFSET_MAX;
37	else if (offset <= -NLM_OFFSET_MAX)
38		res = -NLM_OFFSET_MAX;
39	else
40		res = offset;
41	return res;
42}
43
44/*
45 * NLM file handles are defined by specification to be a variable-length
46 * XDR opaque no longer than 1024 bytes. However, this implementation
47 * constrains their length to exactly the length of an NFSv2 file
48 * handle.
49 */
50static bool
51svcxdr_decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
52{
53	__be32 *p;
54	u32 len;
55
56	if (xdr_stream_decode_u32(xdr, &len) < 0)
57		return false;
58	if (len != NFS2_FHSIZE)
59		return false;
60
61	p = xdr_inline_decode(xdr, len);
62	if (!p)
63		return false;
64	fh->size = NFS2_FHSIZE;
65	memcpy(fh->data, p, len);
66	memset(fh->data + NFS2_FHSIZE, 0, sizeof(fh->data) - NFS2_FHSIZE);
67
68	return true;
69}
70
71static bool
72svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
73{
74	struct file_lock *fl = &lock->fl;
75	s32 start, len, end;
76
77	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
78		return false;
79	if (!svcxdr_decode_fhandle(xdr, &lock->fh))
80		return false;
81	if (!svcxdr_decode_owner(xdr, &lock->oh))
82		return false;
83	if (xdr_stream_decode_u32(xdr, &lock->svid) < 0)
84		return false;
85	if (xdr_stream_decode_u32(xdr, &start) < 0)
86		return false;
87	if (xdr_stream_decode_u32(xdr, &len) < 0)
88		return false;
89
90	locks_init_lock(fl);
91	fl->c.flc_flags = FL_POSIX;
92	fl->c.flc_type  = F_RDLCK;
93	end = start + len - 1;
94	fl->fl_start = s32_to_loff_t(start);
95	if (len == 0 || end < 0)
96		fl->fl_end = OFFSET_MAX;
97	else
98		fl->fl_end = s32_to_loff_t(end);
99
100	return true;
101}
102
103static bool
104svcxdr_encode_holder(struct xdr_stream *xdr, const struct nlm_lock *lock)
105{
106	const struct file_lock *fl = &lock->fl;
107	s32 start, len;
108
109	/* exclusive */
110	if (xdr_stream_encode_bool(xdr, fl->c.flc_type != F_RDLCK) < 0)
111		return false;
112	if (xdr_stream_encode_u32(xdr, lock->svid) < 0)
113		return false;
114	if (!svcxdr_encode_owner(xdr, &lock->oh))
115		return false;
116	start = loff_t_to_s32(fl->fl_start);
117	if (fl->fl_end == OFFSET_MAX)
118		len = 0;
119	else
120		len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
121	if (xdr_stream_encode_u32(xdr, start) < 0)
122		return false;
123	if (xdr_stream_encode_u32(xdr, len) < 0)
124		return false;
125
126	return true;
127}
128
129static bool
130svcxdr_encode_testrply(struct xdr_stream *xdr, const struct nlm_res *resp)
131{
132	if (!svcxdr_encode_stats(xdr, resp->status))
133		return false;
134	switch (resp->status) {
135	case nlm_lck_denied:
136		if (!svcxdr_encode_holder(xdr, &resp->lock))
137			return false;
138	}
139
140	return true;
141}
142
143
144/*
145 * Decode Call arguments
146 */
147
148bool
149nlmsvc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
150{
151	return true;
152}
153
154bool
155nlmsvc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
156{
157	struct nlm_args *argp = rqstp->rq_argp;
158	u32 exclusive;
159
160	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
161		return false;
162	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
163		return false;
164	if (!svcxdr_decode_lock(xdr, &argp->lock))
165		return false;
166	if (exclusive)
167		argp->lock.fl.c.flc_type = F_WRLCK;
168
169	return true;
170}
171
172bool
173nlmsvc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
174{
175	struct nlm_args *argp = rqstp->rq_argp;
176	u32 exclusive;
177
178	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
179		return false;
180	if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
181		return false;
182	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
183		return false;
184	if (!svcxdr_decode_lock(xdr, &argp->lock))
185		return false;
186	if (exclusive)
187		argp->lock.fl.c.flc_type = F_WRLCK;
188	if (xdr_stream_decode_bool(xdr, &argp->reclaim) < 0)
189		return false;
190	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
191		return false;
192	argp->monitor = 1;		/* monitor client by default */
193
194	return true;
195}
196
197bool
198nlmsvc_decode_cancargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
199{
200	struct nlm_args *argp = rqstp->rq_argp;
201	u32 exclusive;
202
203	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
204		return false;
205	if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
206		return false;
207	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
208		return false;
209	if (!svcxdr_decode_lock(xdr, &argp->lock))
210		return false;
211	if (exclusive)
212		argp->lock.fl.c.flc_type = F_WRLCK;
213
214	return true;
215}
216
217bool
218nlmsvc_decode_unlockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
219{
220	struct nlm_args *argp = rqstp->rq_argp;
221
222	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
223		return false;
224	if (!svcxdr_decode_lock(xdr, &argp->lock))
225		return false;
226	argp->lock.fl.c.flc_type = F_UNLCK;
227
228	return true;
229}
230
231bool
232nlmsvc_decode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
233{
234	struct nlm_res *resp = rqstp->rq_argp;
235
236	if (!svcxdr_decode_cookie(xdr, &resp->cookie))
237		return false;
238	if (!svcxdr_decode_stats(xdr, &resp->status))
239		return false;
240
241	return true;
242}
243
244bool
245nlmsvc_decode_reboot(struct svc_rqst *rqstp, struct xdr_stream *xdr)
246{
247	struct nlm_reboot *argp = rqstp->rq_argp;
248	__be32 *p;
249	u32 len;
250
251	if (xdr_stream_decode_u32(xdr, &len) < 0)
252		return false;
253	if (len > SM_MAXSTRLEN)
254		return false;
255	p = xdr_inline_decode(xdr, len);
256	if (!p)
257		return false;
258	argp->len = len;
259	argp->mon = (char *)p;
260	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
261		return false;
262	p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
263	if (!p)
264		return false;
265	memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
266
267	return true;
268}
269
270bool
271nlmsvc_decode_shareargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
272{
273	struct nlm_args *argp = rqstp->rq_argp;
274	struct nlm_lock	*lock = &argp->lock;
275
276	memset(lock, 0, sizeof(*lock));
277	locks_init_lock(&lock->fl);
278	lock->svid = ~(u32)0;
279
280	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
281		return false;
282	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
283		return false;
284	if (!svcxdr_decode_fhandle(xdr, &lock->fh))
285		return false;
286	if (!svcxdr_decode_owner(xdr, &lock->oh))
287		return false;
288	/* XXX: Range checks are missing in the original code */
289	if (xdr_stream_decode_u32(xdr, &argp->fsm_mode) < 0)
290		return false;
291	if (xdr_stream_decode_u32(xdr, &argp->fsm_access) < 0)
292		return false;
293
294	return true;
295}
296
297bool
298nlmsvc_decode_notify(struct svc_rqst *rqstp, struct xdr_stream *xdr)
299{
300	struct nlm_args *argp = rqstp->rq_argp;
301	struct nlm_lock	*lock = &argp->lock;
302
303	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
304		return false;
305	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
306		return false;
307
308	return true;
309}
310
311
312/*
313 * Encode Reply results
314 */
315
316bool
317nlmsvc_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
318{
319	return true;
320}
321
322bool
323nlmsvc_encode_testres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
324{
325	struct nlm_res *resp = rqstp->rq_resp;
326
327	return svcxdr_encode_cookie(xdr, &resp->cookie) &&
328		svcxdr_encode_testrply(xdr, resp);
329}
330
331bool
332nlmsvc_encode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
333{
334	struct nlm_res *resp = rqstp->rq_resp;
335
336	return svcxdr_encode_cookie(xdr, &resp->cookie) &&
337		svcxdr_encode_stats(xdr, resp->status);
338}
339
340bool
341nlmsvc_encode_shareres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
342{
343	struct nlm_res *resp = rqstp->rq_resp;
344
345	if (!svcxdr_encode_cookie(xdr, &resp->cookie))
346		return false;
347	if (!svcxdr_encode_stats(xdr, resp->status))
348		return false;
349	/* sequence */
350	if (xdr_stream_encode_u32(xdr, 0) < 0)
351		return false;
352
353	return true;
354}
355