xref: /openbmc/linux/fs/nfsd/nfs2acl.c (revision f9a82c48)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Process version 2 NFSACL requests.
4  *
5  * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
6  */
7 
8 #include "nfsd.h"
9 /* FIXME: nfsacl.h is a broken header */
10 #include <linux/nfsacl.h>
11 #include <linux/gfp.h>
12 #include "cache.h"
13 #include "xdr3.h"
14 #include "vfs.h"
15 
16 #define NFSDDBG_FACILITY		NFSDDBG_PROC
17 #define RETURN_STATUS(st)	{ resp->status = (st); return (st); }
18 
19 /*
20  * NULL call.
21  */
22 static __be32
23 nfsacld_proc_null(struct svc_rqst *rqstp)
24 {
25 	return nfs_ok;
26 }
27 
28 /*
29  * Get the Access and/or Default ACL of a file.
30  */
31 static __be32 nfsacld_proc_getacl(struct svc_rqst *rqstp)
32 {
33 	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
34 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
35 	struct posix_acl *acl;
36 	struct inode *inode;
37 	svc_fh *fh;
38 	__be32 nfserr = 0;
39 
40 	dprintk("nfsd: GETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
41 
42 	fh = fh_copy(&resp->fh, &argp->fh);
43 	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
44 	if (nfserr)
45 		RETURN_STATUS(nfserr);
46 
47 	inode = d_inode(fh->fh_dentry);
48 
49 	if (argp->mask & ~NFS_ACL_MASK)
50 		RETURN_STATUS(nfserr_inval);
51 	resp->mask = argp->mask;
52 
53 	nfserr = fh_getattr(fh, &resp->stat);
54 	if (nfserr)
55 		RETURN_STATUS(nfserr);
56 
57 	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
58 		acl = get_acl(inode, ACL_TYPE_ACCESS);
59 		if (acl == NULL) {
60 			/* Solaris returns the inode's minimum ACL. */
61 			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
62 		}
63 		if (IS_ERR(acl)) {
64 			nfserr = nfserrno(PTR_ERR(acl));
65 			goto fail;
66 		}
67 		resp->acl_access = acl;
68 	}
69 	if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) {
70 		/* Check how Solaris handles requests for the Default ACL
71 		   of a non-directory! */
72 		acl = get_acl(inode, ACL_TYPE_DEFAULT);
73 		if (IS_ERR(acl)) {
74 			nfserr = nfserrno(PTR_ERR(acl));
75 			goto fail;
76 		}
77 		resp->acl_default = acl;
78 	}
79 
80 	/* resp->acl_{access,default} are released in nfssvc_release_getacl. */
81 	RETURN_STATUS(0);
82 
83 fail:
84 	posix_acl_release(resp->acl_access);
85 	posix_acl_release(resp->acl_default);
86 	RETURN_STATUS(nfserr);
87 }
88 
89 /*
90  * Set the Access and/or Default ACL of a file.
91  */
92 static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp)
93 {
94 	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
95 	struct nfsd_attrstat *resp = rqstp->rq_resp;
96 	struct inode *inode;
97 	svc_fh *fh;
98 	__be32 nfserr = 0;
99 	int error;
100 
101 	dprintk("nfsd: SETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
102 
103 	fh = fh_copy(&resp->fh, &argp->fh);
104 	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
105 	if (nfserr)
106 		goto out;
107 
108 	inode = d_inode(fh->fh_dentry);
109 
110 	error = fh_want_write(fh);
111 	if (error)
112 		goto out_errno;
113 
114 	fh_lock(fh);
115 
116 	error = set_posix_acl(inode, ACL_TYPE_ACCESS, argp->acl_access);
117 	if (error)
118 		goto out_drop_lock;
119 	error = set_posix_acl(inode, ACL_TYPE_DEFAULT, argp->acl_default);
120 	if (error)
121 		goto out_drop_lock;
122 
123 	fh_unlock(fh);
124 
125 	fh_drop_write(fh);
126 
127 	nfserr = fh_getattr(fh, &resp->stat);
128 
129 out:
130 	/* argp->acl_{access,default} may have been allocated in
131 	   nfssvc_decode_setaclargs. */
132 	posix_acl_release(argp->acl_access);
133 	posix_acl_release(argp->acl_default);
134 	return nfserr;
135 out_drop_lock:
136 	fh_unlock(fh);
137 	fh_drop_write(fh);
138 out_errno:
139 	nfserr = nfserrno(error);
140 	goto out;
141 }
142 
143 /*
144  * Check file attributes
145  */
146 static __be32 nfsacld_proc_getattr(struct svc_rqst *rqstp)
147 {
148 	struct nfsd_fhandle *argp = rqstp->rq_argp;
149 	struct nfsd_attrstat *resp = rqstp->rq_resp;
150 	__be32 nfserr;
151 	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
152 
153 	fh_copy(&resp->fh, &argp->fh);
154 	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
155 	if (nfserr)
156 		return nfserr;
157 	nfserr = fh_getattr(&resp->fh, &resp->stat);
158 	return nfserr;
159 }
160 
161 /*
162  * Check file access
163  */
164 static __be32 nfsacld_proc_access(struct svc_rqst *rqstp)
165 {
166 	struct nfsd3_accessargs *argp = rqstp->rq_argp;
167 	struct nfsd3_accessres *resp = rqstp->rq_resp;
168 	__be32 nfserr;
169 
170 	dprintk("nfsd: ACCESS(2acl)   %s 0x%x\n",
171 			SVCFH_fmt(&argp->fh),
172 			argp->access);
173 
174 	fh_copy(&resp->fh, &argp->fh);
175 	resp->access = argp->access;
176 	nfserr = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
177 	if (nfserr)
178 		return nfserr;
179 	nfserr = fh_getattr(&resp->fh, &resp->stat);
180 	return nfserr;
181 }
182 
183 /*
184  * XDR decode functions
185  */
186 static int nfsaclsvc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p)
187 {
188 	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
189 
190 	p = nfs2svc_decode_fh(p, &argp->fh);
191 	if (!p)
192 		return 0;
193 	argp->mask = ntohl(*p); p++;
194 
195 	return xdr_argsize_check(rqstp, p);
196 }
197 
198 
199 static int nfsaclsvc_decode_setaclargs(struct svc_rqst *rqstp, __be32 *p)
200 {
201 	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
202 	struct kvec *head = rqstp->rq_arg.head;
203 	unsigned int base;
204 	int n;
205 
206 	p = nfs2svc_decode_fh(p, &argp->fh);
207 	if (!p)
208 		return 0;
209 	argp->mask = ntohl(*p++);
210 	if (argp->mask & ~NFS_ACL_MASK ||
211 	    !xdr_argsize_check(rqstp, p))
212 		return 0;
213 
214 	base = (char *)p - (char *)head->iov_base;
215 	n = nfsacl_decode(&rqstp->rq_arg, base, NULL,
216 			  (argp->mask & NFS_ACL) ?
217 			  &argp->acl_access : NULL);
218 	if (n > 0)
219 		n = nfsacl_decode(&rqstp->rq_arg, base + n, NULL,
220 				  (argp->mask & NFS_DFACL) ?
221 				  &argp->acl_default : NULL);
222 	return (n > 0);
223 }
224 
225 static int nfsaclsvc_decode_fhandleargs(struct svc_rqst *rqstp, __be32 *p)
226 {
227 	struct nfsd_fhandle *argp = rqstp->rq_argp;
228 
229 	p = nfs2svc_decode_fh(p, &argp->fh);
230 	if (!p)
231 		return 0;
232 	return xdr_argsize_check(rqstp, p);
233 }
234 
235 static int nfsaclsvc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
236 {
237 	struct nfsd3_accessargs *argp = rqstp->rq_argp;
238 
239 	p = nfs2svc_decode_fh(p, &argp->fh);
240 	if (!p)
241 		return 0;
242 	argp->access = ntohl(*p++);
243 
244 	return xdr_argsize_check(rqstp, p);
245 }
246 
247 /*
248  * XDR encode functions
249  */
250 
251 /*
252  * There must be an encoding function for void results so svc_process
253  * will work properly.
254  */
255 static int nfsaclsvc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
256 {
257 	return xdr_ressize_check(rqstp, p);
258 }
259 
260 /* GETACL */
261 static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
262 {
263 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
264 	struct dentry *dentry = resp->fh.fh_dentry;
265 	struct inode *inode;
266 	struct kvec *head = rqstp->rq_res.head;
267 	unsigned int base;
268 	int n;
269 	int w;
270 
271 	/*
272 	 * Since this is version 2, the check for nfserr in
273 	 * nfsd_dispatch actually ensures the following cannot happen.
274 	 * However, it seems fragile to depend on that.
275 	 */
276 	if (dentry == NULL || d_really_is_negative(dentry))
277 		return 0;
278 	inode = d_inode(dentry);
279 
280 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
281 	*p++ = htonl(resp->mask);
282 	if (!xdr_ressize_check(rqstp, p))
283 		return 0;
284 	base = (char *)p - (char *)head->iov_base;
285 
286 	rqstp->rq_res.page_len = w = nfsacl_size(
287 		(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
288 		(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
289 	while (w > 0) {
290 		if (!*(rqstp->rq_next_page++))
291 			return 0;
292 		w -= PAGE_SIZE;
293 	}
294 
295 	n = nfsacl_encode(&rqstp->rq_res, base, inode,
296 			  resp->acl_access,
297 			  resp->mask & NFS_ACL, 0);
298 	if (n > 0)
299 		n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
300 				  resp->acl_default,
301 				  resp->mask & NFS_DFACL,
302 				  NFS_ACL_DEFAULT);
303 	return (n > 0);
304 }
305 
306 static int nfsaclsvc_encode_attrstatres(struct svc_rqst *rqstp, __be32 *p)
307 {
308 	struct nfsd_attrstat *resp = rqstp->rq_resp;
309 
310 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
311 	return xdr_ressize_check(rqstp, p);
312 }
313 
314 /* ACCESS */
315 static int nfsaclsvc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
316 {
317 	struct nfsd3_accessres *resp = rqstp->rq_resp;
318 
319 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
320 	*p++ = htonl(resp->access);
321 	return xdr_ressize_check(rqstp, p);
322 }
323 
324 /*
325  * XDR release functions
326  */
327 static void nfsaclsvc_release_getacl(struct svc_rqst *rqstp)
328 {
329 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
330 
331 	fh_put(&resp->fh);
332 	posix_acl_release(resp->acl_access);
333 	posix_acl_release(resp->acl_default);
334 }
335 
336 static void nfsaclsvc_release_attrstat(struct svc_rqst *rqstp)
337 {
338 	struct nfsd_attrstat *resp = rqstp->rq_resp;
339 
340 	fh_put(&resp->fh);
341 }
342 
343 static void nfsaclsvc_release_access(struct svc_rqst *rqstp)
344 {
345 	struct nfsd3_accessres *resp = rqstp->rq_resp;
346 
347 	fh_put(&resp->fh);
348 }
349 
350 #define nfsaclsvc_decode_voidargs	NULL
351 #define nfsaclsvc_release_void		NULL
352 #define nfsd3_fhandleargs	nfsd_fhandle
353 #define nfsd3_attrstatres	nfsd_attrstat
354 #define nfsd3_voidres		nfsd3_voidargs
355 struct nfsd3_voidargs { int dummy; };
356 
357 #define PROC(name, argt, rest, relt, cache, respsize)			\
358 {									\
359 	.pc_func	= nfsacld_proc_##name,				\
360 	.pc_decode	= nfsaclsvc_decode_##argt##args,		\
361 	.pc_encode	= nfsaclsvc_encode_##rest##res,			\
362 	.pc_release	= nfsaclsvc_release_##relt,	\
363 	.pc_argsize	= sizeof(struct nfsd3_##argt##args),		\
364 	.pc_ressize	= sizeof(struct nfsd3_##rest##res),		\
365 	.pc_cachetype	= cache,					\
366 	.pc_xdrressize	= respsize,					\
367 }
368 
369 #define ST 1		/* status*/
370 #define AT 21		/* attributes */
371 #define pAT (1+AT)	/* post attributes - conditional */
372 #define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
373 
374 static const struct svc_procedure nfsd_acl_procedures2[] = {
375   PROC(null,	void,		void,		void,	  RC_NOCACHE, ST),
376   PROC(getacl,	getacl,		getacl,		getacl,	  RC_NOCACHE, ST+1+2*(1+ACL)),
377   PROC(setacl,	setacl,		attrstat,	attrstat, RC_NOCACHE, ST+AT),
378   PROC(getattr, fhandle,	attrstat,	attrstat, RC_NOCACHE, ST+AT),
379   PROC(access,	access,		access,		access,   RC_NOCACHE, ST+AT+1),
380 };
381 
382 static unsigned int nfsd_acl_count2[ARRAY_SIZE(nfsd_acl_procedures2)];
383 const struct svc_version nfsd_acl_version2 = {
384 	.vs_vers	= 2,
385 	.vs_nproc	= 5,
386 	.vs_proc	= nfsd_acl_procedures2,
387 	.vs_count	= nfsd_acl_count2,
388 	.vs_dispatch	= nfsd_dispatch,
389 	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
390 };
391