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
25 static inline loff_t
26 s32_to_loff_t(__s32 offset)
27 {
28 return (loff_t)offset;
29 }
30
31 static inline __s32
32 loff_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 */
50 static bool
51 svcxdr_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
71 static bool
72 svcxdr_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
103 static bool
104 svcxdr_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
129 static bool
130 svcxdr_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
148 bool
149 nlmsvc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
150 {
151 return true;
152 }
153
154 bool
155 nlmsvc_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
172 bool
173 nlmsvc_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
197 bool
198 nlmsvc_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
217 bool
218 nlmsvc_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
231 bool
232 nlmsvc_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
244 bool
245 nlmsvc_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
270 bool
271 nlmsvc_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
297 bool
298 nlmsvc_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
316 bool
317 nlmsvc_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
318 {
319 return true;
320 }
321
322 bool
323 nlmsvc_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
331 bool
332 nlmsvc_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
340 bool
341 nlmsvc_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
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