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 #define NLMDBG_FACILITY		NLMDBG_XDR
22 
23 static inline loff_t
s64_to_loff_t(__s64 offset)24 s64_to_loff_t(__s64 offset)
25 {
26 	return (loff_t)offset;
27 }
28 
29 
30 static inline s64
loff_t_to_s64(loff_t offset)31 loff_t_to_s64(loff_t offset)
32 {
33 	s64 res;
34 	if (offset > NLM4_OFFSET_MAX)
35 		res = NLM4_OFFSET_MAX;
36 	else if (offset < -NLM4_OFFSET_MAX)
37 		res = -NLM4_OFFSET_MAX;
38 	else
39 		res = offset;
40 	return res;
41 }
42 
43 /*
44  * XDR functions for basic NLM types
45  */
46 static __be32 *
nlm4_decode_cookie(__be32 * p,struct nlm_cookie * c)47 nlm4_decode_cookie(__be32 *p, struct nlm_cookie *c)
48 {
49 	unsigned int	len;
50 
51 	len = ntohl(*p++);
52 
53 	if(len==0)
54 	{
55 		c->len=4;
56 		memset(c->data, 0, 4);	/* hockeypux brain damage */
57 	}
58 	else if(len<=NLM_MAXCOOKIELEN)
59 	{
60 		c->len=len;
61 		memcpy(c->data, p, len);
62 		p+=XDR_QUADLEN(len);
63 	}
64 	else
65 	{
66 		dprintk("lockd: bad cookie size %d (only cookies under "
67 			"%d bytes are supported.)\n",
68 				len, NLM_MAXCOOKIELEN);
69 		return NULL;
70 	}
71 	return p;
72 }
73 
74 static __be32 *
nlm4_encode_cookie(__be32 * p,struct nlm_cookie * c)75 nlm4_encode_cookie(__be32 *p, struct nlm_cookie *c)
76 {
77 	*p++ = htonl(c->len);
78 	memcpy(p, c->data, c->len);
79 	p+=XDR_QUADLEN(c->len);
80 	return p;
81 }
82 
83 static __be32 *
nlm4_decode_fh(__be32 * p,struct nfs_fh * f)84 nlm4_decode_fh(__be32 *p, struct nfs_fh *f)
85 {
86 	memset(f->data, 0, sizeof(f->data));
87 	f->size = ntohl(*p++);
88 	if (f->size > NFS_MAXFHSIZE) {
89 		dprintk("lockd: bad fhandle size %d (should be <=%d)\n",
90 			f->size, NFS_MAXFHSIZE);
91 		return NULL;
92 	}
93       	memcpy(f->data, p, f->size);
94 	return p + XDR_QUADLEN(f->size);
95 }
96 
97 /*
98  * Encode and decode owner handle
99  */
100 static __be32 *
nlm4_decode_oh(__be32 * p,struct xdr_netobj * oh)101 nlm4_decode_oh(__be32 *p, struct xdr_netobj *oh)
102 {
103 	return xdr_decode_netobj(p, oh);
104 }
105 
106 static __be32 *
nlm4_decode_lock(__be32 * p,struct nlm_lock * lock)107 nlm4_decode_lock(__be32 *p, struct nlm_lock *lock)
108 {
109 	struct file_lock	*fl = &lock->fl;
110 	__u64			len, start;
111 	__s64			end;
112 
113 	if (!(p = xdr_decode_string_inplace(p, &lock->caller,
114 					    &lock->len, NLM_MAXSTRLEN))
115 	 || !(p = nlm4_decode_fh(p, &lock->fh))
116 	 || !(p = nlm4_decode_oh(p, &lock->oh)))
117 		return NULL;
118 	lock->svid  = ntohl(*p++);
119 
120 	locks_init_lock(fl);
121 	fl->fl_owner = current->files;
122 	fl->fl_pid   = (pid_t)lock->svid;
123 	fl->fl_flags = FL_POSIX;
124 	fl->fl_type  = F_RDLCK;		/* as good as anything else */
125 	p = xdr_decode_hyper(p, &start);
126 	p = xdr_decode_hyper(p, &len);
127 	end = start + len - 1;
128 
129 	fl->fl_start = s64_to_loff_t(start);
130 
131 	if (len == 0 || end < 0)
132 		fl->fl_end = OFFSET_MAX;
133 	else
134 		fl->fl_end = s64_to_loff_t(end);
135 	return p;
136 }
137 
138 /*
139  * Encode result of a TEST/TEST_MSG call
140  */
141 static __be32 *
nlm4_encode_testres(__be32 * p,struct nlm_res * resp)142 nlm4_encode_testres(__be32 *p, struct nlm_res *resp)
143 {
144 	s64		start, len;
145 
146 	dprintk("xdr: before encode_testres (p %p resp %p)\n", p, resp);
147 	if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
148 		return NULL;
149 	*p++ = resp->status;
150 
151 	if (resp->status == nlm_lck_denied) {
152 		struct file_lock	*fl = &resp->lock.fl;
153 
154 		*p++ = (fl->fl_type == F_RDLCK)? xdr_zero : xdr_one;
155 		*p++ = htonl(resp->lock.svid);
156 
157 		/* Encode owner handle. */
158 		if (!(p = xdr_encode_netobj(p, &resp->lock.oh)))
159 			return NULL;
160 
161 		start = loff_t_to_s64(fl->fl_start);
162 		if (fl->fl_end == OFFSET_MAX)
163 			len = 0;
164 		else
165 			len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
166 
167 		p = xdr_encode_hyper(p, start);
168 		p = xdr_encode_hyper(p, len);
169 		dprintk("xdr: encode_testres (status %u pid %d type %d start %Ld end %Ld)\n",
170 			resp->status, (int)resp->lock.svid, fl->fl_type,
171 			(long long)fl->fl_start,  (long long)fl->fl_end);
172 	}
173 
174 	dprintk("xdr: after encode_testres (p %p resp %p)\n", p, resp);
175 	return p;
176 }
177 
178 
179 /*
180  * First, the server side XDR functions
181  */
182 int
nlm4svc_decode_testargs(struct svc_rqst * rqstp,__be32 * p)183 nlm4svc_decode_testargs(struct svc_rqst *rqstp, __be32 *p)
184 {
185 	struct nlm_args *argp = rqstp->rq_argp;
186 	u32	exclusive;
187 
188 	if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
189 		return 0;
190 
191 	exclusive = ntohl(*p++);
192 	if (!(p = nlm4_decode_lock(p, &argp->lock)))
193 		return 0;
194 	if (exclusive)
195 		argp->lock.fl.fl_type = F_WRLCK;
196 
197 	return xdr_argsize_check(rqstp, p);
198 }
199 
200 int
nlm4svc_encode_testres(struct svc_rqst * rqstp,__be32 * p)201 nlm4svc_encode_testres(struct svc_rqst *rqstp, __be32 *p)
202 {
203 	struct nlm_res *resp = rqstp->rq_resp;
204 
205 	if (!(p = nlm4_encode_testres(p, resp)))
206 		return 0;
207 	return xdr_ressize_check(rqstp, p);
208 }
209 
210 int
nlm4svc_decode_lockargs(struct svc_rqst * rqstp,__be32 * p)211 nlm4svc_decode_lockargs(struct svc_rqst *rqstp, __be32 *p)
212 {
213 	struct nlm_args *argp = rqstp->rq_argp;
214 	u32	exclusive;
215 
216 	if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
217 		return 0;
218 	argp->block  = ntohl(*p++);
219 	exclusive    = ntohl(*p++);
220 	if (!(p = nlm4_decode_lock(p, &argp->lock)))
221 		return 0;
222 	if (exclusive)
223 		argp->lock.fl.fl_type = F_WRLCK;
224 	argp->reclaim = ntohl(*p++);
225 	argp->state   = ntohl(*p++);
226 	argp->monitor = 1;		/* monitor client by default */
227 
228 	return xdr_argsize_check(rqstp, p);
229 }
230 
231 int
nlm4svc_decode_cancargs(struct svc_rqst * rqstp,__be32 * p)232 nlm4svc_decode_cancargs(struct svc_rqst *rqstp, __be32 *p)
233 {
234 	struct nlm_args *argp = rqstp->rq_argp;
235 	u32	exclusive;
236 
237 	if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
238 		return 0;
239 	argp->block = ntohl(*p++);
240 	exclusive = ntohl(*p++);
241 	if (!(p = nlm4_decode_lock(p, &argp->lock)))
242 		return 0;
243 	if (exclusive)
244 		argp->lock.fl.fl_type = F_WRLCK;
245 	return xdr_argsize_check(rqstp, p);
246 }
247 
248 int
nlm4svc_decode_unlockargs(struct svc_rqst * rqstp,__be32 * p)249 nlm4svc_decode_unlockargs(struct svc_rqst *rqstp, __be32 *p)
250 {
251 	struct nlm_args *argp = rqstp->rq_argp;
252 
253 	if (!(p = nlm4_decode_cookie(p, &argp->cookie))
254 	 || !(p = nlm4_decode_lock(p, &argp->lock)))
255 		return 0;
256 	argp->lock.fl.fl_type = F_UNLCK;
257 	return xdr_argsize_check(rqstp, p);
258 }
259 
260 int
nlm4svc_decode_shareargs(struct svc_rqst * rqstp,__be32 * p)261 nlm4svc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p)
262 {
263 	struct nlm_args *argp = rqstp->rq_argp;
264 	struct nlm_lock	*lock = &argp->lock;
265 
266 	memset(lock, 0, sizeof(*lock));
267 	locks_init_lock(&lock->fl);
268 	lock->svid = ~(u32) 0;
269 	lock->fl.fl_pid = (pid_t)lock->svid;
270 
271 	if (!(p = nlm4_decode_cookie(p, &argp->cookie))
272 	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
273 					    &lock->len, NLM_MAXSTRLEN))
274 	 || !(p = nlm4_decode_fh(p, &lock->fh))
275 	 || !(p = nlm4_decode_oh(p, &lock->oh)))
276 		return 0;
277 	argp->fsm_mode = ntohl(*p++);
278 	argp->fsm_access = ntohl(*p++);
279 	return xdr_argsize_check(rqstp, p);
280 }
281 
282 int
nlm4svc_encode_shareres(struct svc_rqst * rqstp,__be32 * p)283 nlm4svc_encode_shareres(struct svc_rqst *rqstp, __be32 *p)
284 {
285 	struct nlm_res *resp = rqstp->rq_resp;
286 
287 	if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
288 		return 0;
289 	*p++ = resp->status;
290 	*p++ = xdr_zero;		/* sequence argument */
291 	return xdr_ressize_check(rqstp, p);
292 }
293 
294 int
nlm4svc_encode_res(struct svc_rqst * rqstp,__be32 * p)295 nlm4svc_encode_res(struct svc_rqst *rqstp, __be32 *p)
296 {
297 	struct nlm_res *resp = rqstp->rq_resp;
298 
299 	if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
300 		return 0;
301 	*p++ = resp->status;
302 	return xdr_ressize_check(rqstp, p);
303 }
304 
305 int
nlm4svc_decode_notify(struct svc_rqst * rqstp,__be32 * p)306 nlm4svc_decode_notify(struct svc_rqst *rqstp, __be32 *p)
307 {
308 	struct nlm_args *argp = rqstp->rq_argp;
309 	struct nlm_lock	*lock = &argp->lock;
310 
311 	if (!(p = xdr_decode_string_inplace(p, &lock->caller,
312 					    &lock->len, NLM_MAXSTRLEN)))
313 		return 0;
314 	argp->state = ntohl(*p++);
315 	return xdr_argsize_check(rqstp, p);
316 }
317 
318 int
nlm4svc_decode_reboot(struct svc_rqst * rqstp,__be32 * p)319 nlm4svc_decode_reboot(struct svc_rqst *rqstp, __be32 *p)
320 {
321 	struct nlm_reboot *argp = rqstp->rq_argp;
322 
323 	if (!(p = xdr_decode_string_inplace(p, &argp->mon, &argp->len, SM_MAXSTRLEN)))
324 		return 0;
325 	argp->state = ntohl(*p++);
326 	memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
327 	p += XDR_QUADLEN(SM_PRIV_SIZE);
328 	return xdr_argsize_check(rqstp, p);
329 }
330 
331 int
nlm4svc_decode_res(struct svc_rqst * rqstp,__be32 * p)332 nlm4svc_decode_res(struct svc_rqst *rqstp, __be32 *p)
333 {
334 	struct nlm_res *resp = rqstp->rq_argp;
335 
336 	if (!(p = nlm4_decode_cookie(p, &resp->cookie)))
337 		return 0;
338 	resp->status = *p++;
339 	return xdr_argsize_check(rqstp, p);
340 }
341 
342 int
nlm4svc_decode_void(struct svc_rqst * rqstp,__be32 * p)343 nlm4svc_decode_void(struct svc_rqst *rqstp, __be32 *p)
344 {
345 	return xdr_argsize_check(rqstp, p);
346 }
347 
348 int
nlm4svc_encode_void(struct svc_rqst * rqstp,__be32 * p)349 nlm4svc_encode_void(struct svc_rqst *rqstp, __be32 *p)
350 {
351 	return xdr_ressize_check(rqstp, p);
352 }
353