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, ptr: &len) < 0)
57 return false;
58 if (len != NFS2_FHSIZE)
59 return false;
60
61 p = xdr_inline_decode(xdr, nbytes: len);
62 if (!p)
63 return false;
64 fh->size = NFS2_FHSIZE;
65 memcpy(to: fh->data, from: p, len);
66 memset(s: fh->data + NFS2_FHSIZE, c: 0, n: 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, data: &lock->caller, data_len: &lock->len))
78 return false;
79 if (!svcxdr_decode_fhandle(xdr, fh: &lock->fh))
80 return false;
81 if (!svcxdr_decode_owner(xdr, obj: &lock->oh))
82 return false;
83 if (xdr_stream_decode_u32(xdr, ptr: &lock->svid) < 0)
84 return false;
85 if (xdr_stream_decode_u32(xdr, ptr: &start) < 0)
86 return false;
87 if (xdr_stream_decode_u32(xdr, ptr: &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(offset: start);
95 if (len == 0 || end < 0)
96 fl->fl_end = OFFSET_MAX;
97 else
98 fl->fl_end = s32_to_loff_t(offset: 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, n: fl->c.flc_type != F_RDLCK) < 0)
111 return false;
112 if (xdr_stream_encode_u32(xdr, n: lock->svid) < 0)
113 return false;
114 if (!svcxdr_encode_owner(xdr, obj: &lock->oh))
115 return false;
116 start = loff_t_to_s32(offset: fl->fl_start);
117 if (fl->fl_end == OFFSET_MAX)
118 len = 0;
119 else
120 len = loff_t_to_s32(offset: fl->fl_end - fl->fl_start + 1);
121 if (xdr_stream_encode_u32(xdr, n: start) < 0)
122 return false;
123 if (xdr_stream_encode_u32(xdr, n: 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, status: resp->status))
133 return false;
134 switch (resp->status) {
135 case nlm_lck_denied:
136 if (!svcxdr_encode_holder(xdr, lock: &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, cookie: &argp->cookie))
161 return false;
162 if (xdr_stream_decode_bool(xdr, ptr: &exclusive) < 0)
163 return false;
164 if (!svcxdr_decode_lock(xdr, lock: &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, cookie: &argp->cookie))
179 return false;
180 if (xdr_stream_decode_bool(xdr, ptr: &argp->block) < 0)
181 return false;
182 if (xdr_stream_decode_bool(xdr, ptr: &exclusive) < 0)
183 return false;
184 if (!svcxdr_decode_lock(xdr, lock: &argp->lock))
185 return false;
186 if (exclusive)
187 argp->lock.fl.c.flc_type = F_WRLCK;
188 if (xdr_stream_decode_bool(xdr, ptr: &argp->reclaim) < 0)
189 return false;
190 if (xdr_stream_decode_u32(xdr, ptr: &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, cookie: &argp->cookie))
204 return false;
205 if (xdr_stream_decode_bool(xdr, ptr: &argp->block) < 0)
206 return false;
207 if (xdr_stream_decode_bool(xdr, ptr: &exclusive) < 0)
208 return false;
209 if (!svcxdr_decode_lock(xdr, lock: &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, cookie: &argp->cookie))
223 return false;
224 if (!svcxdr_decode_lock(xdr, lock: &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, cookie: &resp->cookie))
237 return false;
238 if (!svcxdr_decode_stats(xdr, status: &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, ptr: &len) < 0)
252 return false;
253 if (len > SM_MAXSTRLEN)
254 return false;
255 p = xdr_inline_decode(xdr, nbytes: len);
256 if (!p)
257 return false;
258 argp->len = len;
259 argp->mon = (char *)p;
260 if (xdr_stream_decode_u32(xdr, ptr: &argp->state) < 0)
261 return false;
262 p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
263 if (!p)
264 return false;
265 memcpy(to: &argp->priv.data, from: p, len: 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(s: lock, c: 0, n: sizeof(*lock));
277 locks_init_lock(&lock->fl);
278 lock->svid = ~(u32)0;
279
280 if (!svcxdr_decode_cookie(xdr, cookie: &argp->cookie))
281 return false;
282 if (!svcxdr_decode_string(xdr, data: &lock->caller, data_len: &lock->len))
283 return false;
284 if (!svcxdr_decode_fhandle(xdr, fh: &lock->fh))
285 return false;
286 if (!svcxdr_decode_owner(xdr, obj: &lock->oh))
287 return false;
288 /* XXX: Range checks are missing in the original code */
289 if (xdr_stream_decode_u32(xdr, ptr: &argp->fsm_mode) < 0)
290 return false;
291 if (xdr_stream_decode_u32(xdr, ptr: &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, data: &lock->caller, data_len: &lock->len))
304 return false;
305 if (xdr_stream_decode_u32(xdr, ptr: &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, cookie: &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, cookie: &resp->cookie) &&
337 svcxdr_encode_stats(xdr, status: 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, cookie: &resp->cookie))
346 return false;
347 if (!svcxdr_encode_stats(xdr, status: resp->status))
348 return false;
349 /* sequence */
350 if (xdr_stream_encode_u32(xdr, n: 0) < 0)
351 return false;
352
353 return true;
354}
355