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
s32_to_loff_t(__s32 offset)26 s32_to_loff_t(__s32 offset)
27 {
28 return (loff_t)offset;
29 }
30
31 static inline __s32
loff_t_to_s32(loff_t offset)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
svcxdr_decode_fhandle(struct xdr_stream * xdr,struct nfs_fh * fh)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
svcxdr_decode_lock(struct xdr_stream * xdr,struct nlm_lock * lock)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->fl_flags = FL_POSIX;
92 fl->fl_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
svcxdr_encode_holder(struct xdr_stream * xdr,const struct nlm_lock * lock)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->fl_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
svcxdr_encode_testrply(struct xdr_stream * xdr,const struct nlm_res * resp)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 int
nlmsvc_decode_void(struct svc_rqst * rqstp,__be32 * p)149 nlmsvc_decode_void(struct svc_rqst *rqstp, __be32 *p)
150 {
151 return 1;
152 }
153
154 int
nlmsvc_decode_testargs(struct svc_rqst * rqstp,__be32 * p)155 nlmsvc_decode_testargs(struct svc_rqst *rqstp, __be32 *p)
156 {
157 struct xdr_stream *xdr = &rqstp->rq_arg_stream;
158 struct nlm_args *argp = rqstp->rq_argp;
159 u32 exclusive;
160
161 if (!svcxdr_decode_cookie(xdr, &argp->cookie))
162 return 0;
163 if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
164 return 0;
165 if (!svcxdr_decode_lock(xdr, &argp->lock))
166 return 0;
167 if (exclusive)
168 argp->lock.fl.fl_type = F_WRLCK;
169
170 return 1;
171 }
172
173 int
nlmsvc_decode_lockargs(struct svc_rqst * rqstp,__be32 * p)174 nlmsvc_decode_lockargs(struct svc_rqst *rqstp, __be32 *p)
175 {
176 struct xdr_stream *xdr = &rqstp->rq_arg_stream;
177 struct nlm_args *argp = rqstp->rq_argp;
178 u32 exclusive;
179
180 if (!svcxdr_decode_cookie(xdr, &argp->cookie))
181 return 0;
182 if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
183 return 0;
184 if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
185 return 0;
186 if (!svcxdr_decode_lock(xdr, &argp->lock))
187 return 0;
188 if (exclusive)
189 argp->lock.fl.fl_type = F_WRLCK;
190 if (xdr_stream_decode_bool(xdr, &argp->reclaim) < 0)
191 return 0;
192 if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
193 return 0;
194 argp->monitor = 1; /* monitor client by default */
195
196 return 1;
197 }
198
199 int
nlmsvc_decode_cancargs(struct svc_rqst * rqstp,__be32 * p)200 nlmsvc_decode_cancargs(struct svc_rqst *rqstp, __be32 *p)
201 {
202 struct xdr_stream *xdr = &rqstp->rq_arg_stream;
203 struct nlm_args *argp = rqstp->rq_argp;
204 u32 exclusive;
205
206 if (!svcxdr_decode_cookie(xdr, &argp->cookie))
207 return 0;
208 if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
209 return 0;
210 if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
211 return 0;
212 if (!svcxdr_decode_lock(xdr, &argp->lock))
213 return 0;
214 if (exclusive)
215 argp->lock.fl.fl_type = F_WRLCK;
216
217 return 1;
218 }
219
220 int
nlmsvc_decode_unlockargs(struct svc_rqst * rqstp,__be32 * p)221 nlmsvc_decode_unlockargs(struct svc_rqst *rqstp, __be32 *p)
222 {
223 struct xdr_stream *xdr = &rqstp->rq_arg_stream;
224 struct nlm_args *argp = rqstp->rq_argp;
225
226 if (!svcxdr_decode_cookie(xdr, &argp->cookie))
227 return 0;
228 if (!svcxdr_decode_lock(xdr, &argp->lock))
229 return 0;
230 argp->lock.fl.fl_type = F_UNLCK;
231
232 return 1;
233 }
234
235 int
nlmsvc_decode_res(struct svc_rqst * rqstp,__be32 * p)236 nlmsvc_decode_res(struct svc_rqst *rqstp, __be32 *p)
237 {
238 struct xdr_stream *xdr = &rqstp->rq_arg_stream;
239 struct nlm_res *resp = rqstp->rq_argp;
240
241 if (!svcxdr_decode_cookie(xdr, &resp->cookie))
242 return 0;
243 if (!svcxdr_decode_stats(xdr, &resp->status))
244 return 0;
245
246 return 1;
247 }
248
249 int
nlmsvc_decode_reboot(struct svc_rqst * rqstp,__be32 * p)250 nlmsvc_decode_reboot(struct svc_rqst *rqstp, __be32 *p)
251 {
252 struct xdr_stream *xdr = &rqstp->rq_arg_stream;
253 struct nlm_reboot *argp = rqstp->rq_argp;
254 u32 len;
255
256 if (xdr_stream_decode_u32(xdr, &len) < 0)
257 return 0;
258 if (len > SM_MAXSTRLEN)
259 return 0;
260 p = xdr_inline_decode(xdr, len);
261 if (!p)
262 return 0;
263 argp->len = len;
264 argp->mon = (char *)p;
265 if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
266 return 0;
267 p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
268 if (!p)
269 return 0;
270 memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
271
272 return 1;
273 }
274
275 int
nlmsvc_decode_shareargs(struct svc_rqst * rqstp,__be32 * p)276 nlmsvc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p)
277 {
278 struct xdr_stream *xdr = &rqstp->rq_arg_stream;
279 struct nlm_args *argp = rqstp->rq_argp;
280 struct nlm_lock *lock = &argp->lock;
281
282 memset(lock, 0, sizeof(*lock));
283 locks_init_lock(&lock->fl);
284 lock->svid = ~(u32)0;
285
286 if (!svcxdr_decode_cookie(xdr, &argp->cookie))
287 return 0;
288 if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
289 return 0;
290 if (!svcxdr_decode_fhandle(xdr, &lock->fh))
291 return 0;
292 if (!svcxdr_decode_owner(xdr, &lock->oh))
293 return 0;
294 /* XXX: Range checks are missing in the original code */
295 if (xdr_stream_decode_u32(xdr, &argp->fsm_mode) < 0)
296 return 0;
297 if (xdr_stream_decode_u32(xdr, &argp->fsm_access) < 0)
298 return 0;
299
300 return 1;
301 }
302
303 int
nlmsvc_decode_notify(struct svc_rqst * rqstp,__be32 * p)304 nlmsvc_decode_notify(struct svc_rqst *rqstp, __be32 *p)
305 {
306 struct xdr_stream *xdr = &rqstp->rq_arg_stream;
307 struct nlm_args *argp = rqstp->rq_argp;
308 struct nlm_lock *lock = &argp->lock;
309
310 if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
311 return 0;
312 if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
313 return 0;
314
315 return 1;
316 }
317
318
319 /*
320 * Encode Reply results
321 */
322
323 int
nlmsvc_encode_void(struct svc_rqst * rqstp,__be32 * p)324 nlmsvc_encode_void(struct svc_rqst *rqstp, __be32 *p)
325 {
326 return 1;
327 }
328
329 int
nlmsvc_encode_testres(struct svc_rqst * rqstp,__be32 * p)330 nlmsvc_encode_testres(struct svc_rqst *rqstp, __be32 *p)
331 {
332 struct xdr_stream *xdr = &rqstp->rq_res_stream;
333 struct nlm_res *resp = rqstp->rq_resp;
334
335 return svcxdr_encode_cookie(xdr, &resp->cookie) &&
336 svcxdr_encode_testrply(xdr, resp);
337 }
338
339 int
nlmsvc_encode_res(struct svc_rqst * rqstp,__be32 * p)340 nlmsvc_encode_res(struct svc_rqst *rqstp, __be32 *p)
341 {
342 struct xdr_stream *xdr = &rqstp->rq_res_stream;
343 struct nlm_res *resp = rqstp->rq_resp;
344
345 return svcxdr_encode_cookie(xdr, &resp->cookie) &&
346 svcxdr_encode_stats(xdr, resp->status);
347 }
348
349 int
nlmsvc_encode_shareres(struct svc_rqst * rqstp,__be32 * p)350 nlmsvc_encode_shareres(struct svc_rqst *rqstp, __be32 *p)
351 {
352 struct xdr_stream *xdr = &rqstp->rq_res_stream;
353 struct nlm_res *resp = rqstp->rq_resp;
354
355 if (!svcxdr_encode_cookie(xdr, &resp->cookie))
356 return 0;
357 if (!svcxdr_encode_stats(xdr, resp->status))
358 return 0;
359 /* sequence */
360 if (xdr_stream_encode_u32(xdr, 0) < 0)
361 return 0;
362
363 return 1;
364 }
365
