xref: /linux/fs/nfsd/nfs2acl.c (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
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 
18 /*
19  * NULL call.
20  */
21 static __be32
22 nfsacld_proc_null(struct svc_rqst *rqstp)
23 {
24 	return rpc_success;
25 }
26 
27 /*
28  * Get the Access and/or Default ACL of a file.
29  */
30 static __be32 nfsacld_proc_getacl(struct svc_rqst *rqstp)
31 {
32 	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
33 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
34 	struct posix_acl *acl;
35 	struct inode *inode;
36 	svc_fh *fh;
37 
38 	dprintk("nfsd: GETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
39 
40 	fh = fh_copy(&resp->fh, &argp->fh);
41 	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
42 	if (resp->status != nfs_ok)
43 		goto out;
44 
45 	inode = d_inode(fh->fh_dentry);
46 
47 	if (argp->mask & ~NFS_ACL_MASK) {
48 		resp->status = nfserr_inval;
49 		goto out;
50 	}
51 	resp->mask = argp->mask;
52 
53 	resp->status = fh_getattr(fh, &resp->stat);
54 	if (resp->status != nfs_ok)
55 		goto out;
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 			resp->status = 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 			resp->status = 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 out:
82 	return rpc_success;
83 
84 fail:
85 	posix_acl_release(resp->acl_access);
86 	posix_acl_release(resp->acl_default);
87 	goto out;
88 }
89 
90 /*
91  * Set the Access and/or Default ACL of a file.
92  */
93 static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp)
94 {
95 	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
96 	struct nfsd_attrstat *resp = rqstp->rq_resp;
97 	struct inode *inode;
98 	svc_fh *fh;
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 	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
105 	if (resp->status != nfs_ok)
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 	resp->status = 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 rpc_success;
135 
136 out_drop_lock:
137 	fh_unlock(fh);
138 	fh_drop_write(fh);
139 out_errno:
140 	resp->status = nfserrno(error);
141 	goto out;
142 }
143 
144 /*
145  * Check file attributes
146  */
147 static __be32 nfsacld_proc_getattr(struct svc_rqst *rqstp)
148 {
149 	struct nfsd_fhandle *argp = rqstp->rq_argp;
150 	struct nfsd_attrstat *resp = rqstp->rq_resp;
151 
152 	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
153 
154 	fh_copy(&resp->fh, &argp->fh);
155 	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
156 	if (resp->status != nfs_ok)
157 		goto out;
158 	resp->status = fh_getattr(&resp->fh, &resp->stat);
159 out:
160 	return rpc_success;
161 }
162 
163 /*
164  * Check file access
165  */
166 static __be32 nfsacld_proc_access(struct svc_rqst *rqstp)
167 {
168 	struct nfsd3_accessargs *argp = rqstp->rq_argp;
169 	struct nfsd3_accessres *resp = rqstp->rq_resp;
170 
171 	dprintk("nfsd: ACCESS(2acl)   %s 0x%x\n",
172 			SVCFH_fmt(&argp->fh),
173 			argp->access);
174 
175 	fh_copy(&resp->fh, &argp->fh);
176 	resp->access = argp->access;
177 	resp->status = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
178 	if (resp->status != nfs_ok)
179 		goto out;
180 	resp->status = fh_getattr(&resp->fh, &resp->stat);
181 out:
182 	return rpc_success;
183 }
184 
185 /*
186  * XDR decode functions
187  */
188 
189 static int nfsaclsvc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p)
190 {
191 	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
192 
193 	p = nfs2svc_decode_fh(p, &argp->fh);
194 	if (!p)
195 		return 0;
196 	argp->mask = ntohl(*p); p++;
197 
198 	return xdr_argsize_check(rqstp, p);
199 }
200 
201 
202 static int nfsaclsvc_decode_setaclargs(struct svc_rqst *rqstp, __be32 *p)
203 {
204 	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
205 	struct kvec *head = rqstp->rq_arg.head;
206 	unsigned int base;
207 	int n;
208 
209 	p = nfs2svc_decode_fh(p, &argp->fh);
210 	if (!p)
211 		return 0;
212 	argp->mask = ntohl(*p++);
213 	if (argp->mask & ~NFS_ACL_MASK ||
214 	    !xdr_argsize_check(rqstp, p))
215 		return 0;
216 
217 	base = (char *)p - (char *)head->iov_base;
218 	n = nfsacl_decode(&rqstp->rq_arg, base, NULL,
219 			  (argp->mask & NFS_ACL) ?
220 			  &argp->acl_access : NULL);
221 	if (n > 0)
222 		n = nfsacl_decode(&rqstp->rq_arg, base + n, NULL,
223 				  (argp->mask & NFS_DFACL) ?
224 				  &argp->acl_default : NULL);
225 	return (n > 0);
226 }
227 
228 static int nfsaclsvc_decode_fhandleargs(struct svc_rqst *rqstp, __be32 *p)
229 {
230 	struct nfsd_fhandle *argp = rqstp->rq_argp;
231 
232 	p = nfs2svc_decode_fh(p, &argp->fh);
233 	if (!p)
234 		return 0;
235 	return xdr_argsize_check(rqstp, p);
236 }
237 
238 static int nfsaclsvc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
239 {
240 	struct nfsd3_accessargs *argp = rqstp->rq_argp;
241 
242 	p = nfs2svc_decode_fh(p, &argp->fh);
243 	if (!p)
244 		return 0;
245 	argp->access = ntohl(*p++);
246 
247 	return xdr_argsize_check(rqstp, p);
248 }
249 
250 /*
251  * XDR encode functions
252  */
253 
254 /* GETACL */
255 static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
256 {
257 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
258 	struct dentry *dentry = resp->fh.fh_dentry;
259 	struct inode *inode;
260 	struct kvec *head = rqstp->rq_res.head;
261 	unsigned int base;
262 	int n;
263 	int w;
264 
265 	*p++ = resp->status;
266 	if (resp->status != nfs_ok)
267 		return xdr_ressize_check(rqstp, p);
268 
269 	/*
270 	 * Since this is version 2, the check for nfserr in
271 	 * nfsd_dispatch actually ensures the following cannot happen.
272 	 * However, it seems fragile to depend on that.
273 	 */
274 	if (dentry == NULL || d_really_is_negative(dentry))
275 		return 0;
276 	inode = d_inode(dentry);
277 
278 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
279 	*p++ = htonl(resp->mask);
280 	if (!xdr_ressize_check(rqstp, p))
281 		return 0;
282 	base = (char *)p - (char *)head->iov_base;
283 
284 	rqstp->rq_res.page_len = w = nfsacl_size(
285 		(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
286 		(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
287 	while (w > 0) {
288 		if (!*(rqstp->rq_next_page++))
289 			return 0;
290 		w -= PAGE_SIZE;
291 	}
292 
293 	n = nfsacl_encode(&rqstp->rq_res, base, inode,
294 			  resp->acl_access,
295 			  resp->mask & NFS_ACL, 0);
296 	if (n > 0)
297 		n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
298 				  resp->acl_default,
299 				  resp->mask & NFS_DFACL,
300 				  NFS_ACL_DEFAULT);
301 	return (n > 0);
302 }
303 
304 static int nfsaclsvc_encode_attrstatres(struct svc_rqst *rqstp, __be32 *p)
305 {
306 	struct nfsd_attrstat *resp = rqstp->rq_resp;
307 
308 	*p++ = resp->status;
309 	if (resp->status != nfs_ok)
310 		goto out;
311 
312 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
313 out:
314 	return xdr_ressize_check(rqstp, p);
315 }
316 
317 /* ACCESS */
318 static int nfsaclsvc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
319 {
320 	struct nfsd3_accessres *resp = rqstp->rq_resp;
321 
322 	*p++ = resp->status;
323 	if (resp->status != nfs_ok)
324 		goto out;
325 
326 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
327 	*p++ = htonl(resp->access);
328 out:
329 	return xdr_ressize_check(rqstp, p);
330 }
331 
332 /*
333  * XDR release functions
334  */
335 static void nfsaclsvc_release_getacl(struct svc_rqst *rqstp)
336 {
337 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
338 
339 	fh_put(&resp->fh);
340 	posix_acl_release(resp->acl_access);
341 	posix_acl_release(resp->acl_default);
342 }
343 
344 static void nfsaclsvc_release_attrstat(struct svc_rqst *rqstp)
345 {
346 	struct nfsd_attrstat *resp = rqstp->rq_resp;
347 
348 	fh_put(&resp->fh);
349 }
350 
351 static void nfsaclsvc_release_access(struct svc_rqst *rqstp)
352 {
353 	struct nfsd3_accessres *resp = rqstp->rq_resp;
354 
355 	fh_put(&resp->fh);
356 }
357 
358 struct nfsd3_voidargs { int dummy; };
359 
360 #define ST 1		/* status*/
361 #define AT 21		/* attributes */
362 #define pAT (1+AT)	/* post attributes - conditional */
363 #define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
364 
365 static const struct svc_procedure nfsd_acl_procedures2[5] = {
366 	[ACLPROC2_NULL] = {
367 		.pc_func = nfsacld_proc_null,
368 		.pc_decode = nfssvc_decode_voidarg,
369 		.pc_encode = nfssvc_encode_voidres,
370 		.pc_argsize = sizeof(struct nfsd_voidargs),
371 		.pc_ressize = sizeof(struct nfsd_voidres),
372 		.pc_cachetype = RC_NOCACHE,
373 		.pc_xdrressize = ST,
374 	},
375 	[ACLPROC2_GETACL] = {
376 		.pc_func = nfsacld_proc_getacl,
377 		.pc_decode = nfsaclsvc_decode_getaclargs,
378 		.pc_encode = nfsaclsvc_encode_getaclres,
379 		.pc_release = nfsaclsvc_release_getacl,
380 		.pc_argsize = sizeof(struct nfsd3_getaclargs),
381 		.pc_ressize = sizeof(struct nfsd3_getaclres),
382 		.pc_cachetype = RC_NOCACHE,
383 		.pc_xdrressize = ST+1+2*(1+ACL),
384 	},
385 	[ACLPROC2_SETACL] = {
386 		.pc_func = nfsacld_proc_setacl,
387 		.pc_decode = nfsaclsvc_decode_setaclargs,
388 		.pc_encode = nfsaclsvc_encode_attrstatres,
389 		.pc_release = nfsaclsvc_release_attrstat,
390 		.pc_argsize = sizeof(struct nfsd3_setaclargs),
391 		.pc_ressize = sizeof(struct nfsd_attrstat),
392 		.pc_cachetype = RC_NOCACHE,
393 		.pc_xdrressize = ST+AT,
394 	},
395 	[ACLPROC2_GETATTR] = {
396 		.pc_func = nfsacld_proc_getattr,
397 		.pc_decode = nfsaclsvc_decode_fhandleargs,
398 		.pc_encode = nfsaclsvc_encode_attrstatres,
399 		.pc_release = nfsaclsvc_release_attrstat,
400 		.pc_argsize = sizeof(struct nfsd_fhandle),
401 		.pc_ressize = sizeof(struct nfsd_attrstat),
402 		.pc_cachetype = RC_NOCACHE,
403 		.pc_xdrressize = ST+AT,
404 	},
405 	[ACLPROC2_ACCESS] = {
406 		.pc_func = nfsacld_proc_access,
407 		.pc_decode = nfsaclsvc_decode_accessargs,
408 		.pc_encode = nfsaclsvc_encode_accessres,
409 		.pc_release = nfsaclsvc_release_access,
410 		.pc_argsize = sizeof(struct nfsd3_accessargs),
411 		.pc_ressize = sizeof(struct nfsd3_accessres),
412 		.pc_cachetype = RC_NOCACHE,
413 		.pc_xdrressize = ST+AT+1,
414 	},
415 };
416 
417 static unsigned int nfsd_acl_count2[ARRAY_SIZE(nfsd_acl_procedures2)];
418 const struct svc_version nfsd_acl_version2 = {
419 	.vs_vers	= 2,
420 	.vs_nproc	= 5,
421 	.vs_proc	= nfsd_acl_procedures2,
422 	.vs_count	= nfsd_acl_count2,
423 	.vs_dispatch	= nfsd_dispatch,
424 	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
425 };
426