1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/lockd/xdr4.c
4 *
5 * XDR support for lockd and the lock client.
6 *
7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
8 * Copyright (C) 1999, Trond Myklebust <trond.myklebust@fys.uio.no>
9 */
10
11#include <linux/types.h>
12#include <linux/sched.h>
13#include <linux/nfs.h>
14
15#include <linux/sunrpc/xdr.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/sunrpc/svc.h>
18#include <linux/sunrpc/stats.h>
19#include <linux/lockd/lockd.h>
20
21#include "svcxdr.h"
22
23static inline s64
24loff_t_to_s64(loff_t offset)
25{
26	s64 res;
27	if (offset > NLM4_OFFSET_MAX)
28		res = NLM4_OFFSET_MAX;
29	else if (offset < -NLM4_OFFSET_MAX)
30		res = -NLM4_OFFSET_MAX;
31	else
32		res = offset;
33	return res;
34}
35
36void nlm4svc_set_file_lock_range(struct file_lock *fl, u64 off, u64 len)
37{
38	s64 end = off + len - 1;
39
40	fl->fl_start = off;
41	if (len == 0 || end < 0)
42		fl->fl_end = OFFSET_MAX;
43	else
44		fl->fl_end = end;
45}
46
47/*
48 * NLM file handles are defined by specification to be a variable-length
49 * XDR opaque no longer than 1024 bytes. However, this implementation
50 * limits their length to the size of an NFSv3 file handle.
51 */
52static bool
53svcxdr_decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
54{
55	__be32 *p;
56	u32 len;
57
58	if (xdr_stream_decode_u32(xdr, &len) < 0)
59		return false;
60	if (len > NFS_MAXFHSIZE)
61		return false;
62
63	p = xdr_inline_decode(xdr, len);
64	if (!p)
65		return false;
66	fh->size = len;
67	memcpy(fh->data, p, len);
68	memset(fh->data + len, 0, sizeof(fh->data) - len);
69
70	return true;
71}
72
73static bool
74svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
75{
76	struct file_lock *fl = &lock->fl;
77
78	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
79		return false;
80	if (!svcxdr_decode_fhandle(xdr, &lock->fh))
81		return false;
82	if (!svcxdr_decode_owner(xdr, &lock->oh))
83		return false;
84	if (xdr_stream_decode_u32(xdr, &lock->svid) < 0)
85		return false;
86	if (xdr_stream_decode_u64(xdr, &lock->lock_start) < 0)
87		return false;
88	if (xdr_stream_decode_u64(xdr, &lock->lock_len) < 0)
89		return false;
90
91	locks_init_lock(fl);
92	fl->c.flc_flags = FL_POSIX;
93	fl->c.flc_type  = F_RDLCK;
94	nlm4svc_set_file_lock_range(fl, lock->lock_start, lock->lock_len);
95	return true;
96}
97
98static bool
99svcxdr_encode_holder(struct xdr_stream *xdr, const struct nlm_lock *lock)
100{
101	const struct file_lock *fl = &lock->fl;
102	s64 start, len;
103
104	/* exclusive */
105	if (xdr_stream_encode_bool(xdr, fl->c.flc_type != F_RDLCK) < 0)
106		return false;
107	if (xdr_stream_encode_u32(xdr, lock->svid) < 0)
108		return false;
109	if (!svcxdr_encode_owner(xdr, &lock->oh))
110		return false;
111	start = loff_t_to_s64(fl->fl_start);
112	if (fl->fl_end == OFFSET_MAX)
113		len = 0;
114	else
115		len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
116	if (xdr_stream_encode_u64(xdr, start) < 0)
117		return false;
118	if (xdr_stream_encode_u64(xdr, len) < 0)
119		return false;
120
121	return true;
122}
123
124static bool
125svcxdr_encode_testrply(struct xdr_stream *xdr, const struct nlm_res *resp)
126{
127	if (!svcxdr_encode_stats(xdr, resp->status))
128		return false;
129	switch (resp->status) {
130	case nlm_lck_denied:
131		if (!svcxdr_encode_holder(xdr, &resp->lock))
132			return false;
133	}
134
135	return true;
136}
137
138
139/*
140 * Decode Call arguments
141 */
142
143bool
144nlm4svc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
145{
146	return true;
147}
148
149bool
150nlm4svc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
151{
152	struct nlm_args *argp = rqstp->rq_argp;
153	u32 exclusive;
154
155	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
156		return false;
157	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
158		return false;
159	if (!svcxdr_decode_lock(xdr, &argp->lock))
160		return false;
161	if (exclusive)
162		argp->lock.fl.c.flc_type = F_WRLCK;
163
164	return true;
165}
166
167bool
168nlm4svc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
169{
170	struct nlm_args *argp = rqstp->rq_argp;
171	u32 exclusive;
172
173	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
174		return false;
175	if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
176		return false;
177	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
178		return false;
179	if (!svcxdr_decode_lock(xdr, &argp->lock))
180		return false;
181	if (exclusive)
182		argp->lock.fl.c.flc_type = F_WRLCK;
183	if (xdr_stream_decode_bool(xdr, &argp->reclaim) < 0)
184		return false;
185	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
186		return false;
187	argp->monitor = 1;		/* monitor client by default */
188
189	return true;
190}
191
192bool
193nlm4svc_decode_cancargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
194{
195	struct nlm_args *argp = rqstp->rq_argp;
196	u32 exclusive;
197
198	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
199		return false;
200	if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
201		return false;
202	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
203		return false;
204	if (!svcxdr_decode_lock(xdr, &argp->lock))
205		return false;
206	if (exclusive)
207		argp->lock.fl.c.flc_type = F_WRLCK;
208
209	return true;
210}
211
212bool
213nlm4svc_decode_unlockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
214{
215	struct nlm_args *argp = rqstp->rq_argp;
216
217	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
218		return false;
219	if (!svcxdr_decode_lock(xdr, &argp->lock))
220		return false;
221	argp->lock.fl.c.flc_type = F_UNLCK;
222
223	return true;
224}
225
226bool
227nlm4svc_decode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
228{
229	struct nlm_res *resp = rqstp->rq_argp;
230
231	if (!svcxdr_decode_cookie(xdr, &resp->cookie))
232		return false;
233	if (!svcxdr_decode_stats(xdr, &resp->status))
234		return false;
235
236	return true;
237}
238
239bool
240nlm4svc_decode_reboot(struct svc_rqst *rqstp, struct xdr_stream *xdr)
241{
242	struct nlm_reboot *argp = rqstp->rq_argp;
243	__be32 *p;
244	u32 len;
245
246	if (xdr_stream_decode_u32(xdr, &len) < 0)
247		return false;
248	if (len > SM_MAXSTRLEN)
249		return false;
250	p = xdr_inline_decode(xdr, len);
251	if (!p)
252		return false;
253	argp->len = len;
254	argp->mon = (char *)p;
255	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
256		return false;
257	p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
258	if (!p)
259		return false;
260	memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
261
262	return true;
263}
264
265bool
266nlm4svc_decode_shareargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
267{
268	struct nlm_args *argp = rqstp->rq_argp;
269	struct nlm_lock	*lock = &argp->lock;
270
271	memset(lock, 0, sizeof(*lock));
272	locks_init_lock(&lock->fl);
273	lock->svid = ~(u32)0;
274
275	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
276		return false;
277	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
278		return false;
279	if (!svcxdr_decode_fhandle(xdr, &lock->fh))
280		return false;
281	if (!svcxdr_decode_owner(xdr, &lock->oh))
282		return false;
283	/* XXX: Range checks are missing in the original code */
284	if (xdr_stream_decode_u32(xdr, &argp->fsm_mode) < 0)
285		return false;
286	if (xdr_stream_decode_u32(xdr, &argp->fsm_access) < 0)
287		return false;
288
289	return true;
290}
291
292bool
293nlm4svc_decode_notify(struct svc_rqst *rqstp, struct xdr_stream *xdr)
294{
295	struct nlm_args *argp = rqstp->rq_argp;
296	struct nlm_lock	*lock = &argp->lock;
297
298	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
299		return false;
300	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
301		return false;
302
303	return true;
304}
305
306
307/*
308 * Encode Reply results
309 */
310
311bool
312nlm4svc_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
313{
314	return true;
315}
316
317bool
318nlm4svc_encode_testres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
319{
320	struct nlm_res *resp = rqstp->rq_resp;
321
322	return svcxdr_encode_cookie(xdr, &resp->cookie) &&
323		svcxdr_encode_testrply(xdr, resp);
324}
325
326bool
327nlm4svc_encode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
328{
329	struct nlm_res *resp = rqstp->rq_resp;
330
331	return svcxdr_encode_cookie(xdr, &resp->cookie) &&
332		svcxdr_encode_stats(xdr, resp->status);
333}
334
335bool
336nlm4svc_encode_shareres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
337{
338	struct nlm_res *resp = rqstp->rq_resp;
339
340	if (!svcxdr_encode_cookie(xdr, &resp->cookie))
341		return false;
342	if (!svcxdr_encode_stats(xdr, resp->status))
343		return false;
344	/* sequence */
345	if (xdr_stream_encode_u32(xdr, 0) < 0)
346		return false;
347
348	return true;
349}
350