xref: /openbmc/linux/fs/nfsd/nfs2acl.c (revision 11a163f2)
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 static int nfsaclsvc_decode_voidarg(struct svc_rqst *rqstp, __be32 *p)
189 {
190 	return 1;
191 }
192 
193 static int nfsaclsvc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p)
194 {
195 	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
196 
197 	p = nfs2svc_decode_fh(p, &argp->fh);
198 	if (!p)
199 		return 0;
200 	argp->mask = ntohl(*p); p++;
201 
202 	return xdr_argsize_check(rqstp, p);
203 }
204 
205 
206 static int nfsaclsvc_decode_setaclargs(struct svc_rqst *rqstp, __be32 *p)
207 {
208 	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
209 	struct kvec *head = rqstp->rq_arg.head;
210 	unsigned int base;
211 	int n;
212 
213 	p = nfs2svc_decode_fh(p, &argp->fh);
214 	if (!p)
215 		return 0;
216 	argp->mask = ntohl(*p++);
217 	if (argp->mask & ~NFS_ACL_MASK ||
218 	    !xdr_argsize_check(rqstp, p))
219 		return 0;
220 
221 	base = (char *)p - (char *)head->iov_base;
222 	n = nfsacl_decode(&rqstp->rq_arg, base, NULL,
223 			  (argp->mask & NFS_ACL) ?
224 			  &argp->acl_access : NULL);
225 	if (n > 0)
226 		n = nfsacl_decode(&rqstp->rq_arg, base + n, NULL,
227 				  (argp->mask & NFS_DFACL) ?
228 				  &argp->acl_default : NULL);
229 	return (n > 0);
230 }
231 
232 static int nfsaclsvc_decode_fhandleargs(struct svc_rqst *rqstp, __be32 *p)
233 {
234 	struct nfsd_fhandle *argp = rqstp->rq_argp;
235 
236 	p = nfs2svc_decode_fh(p, &argp->fh);
237 	if (!p)
238 		return 0;
239 	return xdr_argsize_check(rqstp, p);
240 }
241 
242 static int nfsaclsvc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
243 {
244 	struct nfsd3_accessargs *argp = rqstp->rq_argp;
245 
246 	p = nfs2svc_decode_fh(p, &argp->fh);
247 	if (!p)
248 		return 0;
249 	argp->access = ntohl(*p++);
250 
251 	return xdr_argsize_check(rqstp, p);
252 }
253 
254 /*
255  * XDR encode functions
256  */
257 
258 /*
259  * There must be an encoding function for void results so svc_process
260  * will work properly.
261  */
262 static int nfsaclsvc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
263 {
264 	return xdr_ressize_check(rqstp, p);
265 }
266 
267 /* GETACL */
268 static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
269 {
270 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
271 	struct dentry *dentry = resp->fh.fh_dentry;
272 	struct inode *inode;
273 	struct kvec *head = rqstp->rq_res.head;
274 	unsigned int base;
275 	int n;
276 	int w;
277 
278 	*p++ = resp->status;
279 	if (resp->status != nfs_ok)
280 		return xdr_ressize_check(rqstp, p);
281 
282 	/*
283 	 * Since this is version 2, the check for nfserr in
284 	 * nfsd_dispatch actually ensures the following cannot happen.
285 	 * However, it seems fragile to depend on that.
286 	 */
287 	if (dentry == NULL || d_really_is_negative(dentry))
288 		return 0;
289 	inode = d_inode(dentry);
290 
291 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
292 	*p++ = htonl(resp->mask);
293 	if (!xdr_ressize_check(rqstp, p))
294 		return 0;
295 	base = (char *)p - (char *)head->iov_base;
296 
297 	rqstp->rq_res.page_len = w = nfsacl_size(
298 		(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
299 		(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
300 	while (w > 0) {
301 		if (!*(rqstp->rq_next_page++))
302 			return 0;
303 		w -= PAGE_SIZE;
304 	}
305 
306 	n = nfsacl_encode(&rqstp->rq_res, base, inode,
307 			  resp->acl_access,
308 			  resp->mask & NFS_ACL, 0);
309 	if (n > 0)
310 		n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
311 				  resp->acl_default,
312 				  resp->mask & NFS_DFACL,
313 				  NFS_ACL_DEFAULT);
314 	return (n > 0);
315 }
316 
317 static int nfsaclsvc_encode_attrstatres(struct svc_rqst *rqstp, __be32 *p)
318 {
319 	struct nfsd_attrstat *resp = rqstp->rq_resp;
320 
321 	*p++ = resp->status;
322 	if (resp->status != nfs_ok)
323 		goto out;
324 
325 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
326 out:
327 	return xdr_ressize_check(rqstp, p);
328 }
329 
330 /* ACCESS */
331 static int nfsaclsvc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
332 {
333 	struct nfsd3_accessres *resp = rqstp->rq_resp;
334 
335 	*p++ = resp->status;
336 	if (resp->status != nfs_ok)
337 		goto out;
338 
339 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
340 	*p++ = htonl(resp->access);
341 out:
342 	return xdr_ressize_check(rqstp, p);
343 }
344 
345 /*
346  * XDR release functions
347  */
348 static void nfsaclsvc_release_getacl(struct svc_rqst *rqstp)
349 {
350 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
351 
352 	fh_put(&resp->fh);
353 	posix_acl_release(resp->acl_access);
354 	posix_acl_release(resp->acl_default);
355 }
356 
357 static void nfsaclsvc_release_attrstat(struct svc_rqst *rqstp)
358 {
359 	struct nfsd_attrstat *resp = rqstp->rq_resp;
360 
361 	fh_put(&resp->fh);
362 }
363 
364 static void nfsaclsvc_release_access(struct svc_rqst *rqstp)
365 {
366 	struct nfsd3_accessres *resp = rqstp->rq_resp;
367 
368 	fh_put(&resp->fh);
369 }
370 
371 struct nfsd3_voidargs { int dummy; };
372 
373 #define ST 1		/* status*/
374 #define AT 21		/* attributes */
375 #define pAT (1+AT)	/* post attributes - conditional */
376 #define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
377 
378 static const struct svc_procedure nfsd_acl_procedures2[5] = {
379 	[ACLPROC2_NULL] = {
380 		.pc_func = nfsacld_proc_null,
381 		.pc_decode = nfsaclsvc_decode_voidarg,
382 		.pc_encode = nfsaclsvc_encode_voidres,
383 		.pc_argsize = sizeof(struct nfsd3_voidargs),
384 		.pc_ressize = sizeof(struct nfsd3_voidargs),
385 		.pc_cachetype = RC_NOCACHE,
386 		.pc_xdrressize = ST,
387 	},
388 	[ACLPROC2_GETACL] = {
389 		.pc_func = nfsacld_proc_getacl,
390 		.pc_decode = nfsaclsvc_decode_getaclargs,
391 		.pc_encode = nfsaclsvc_encode_getaclres,
392 		.pc_release = nfsaclsvc_release_getacl,
393 		.pc_argsize = sizeof(struct nfsd3_getaclargs),
394 		.pc_ressize = sizeof(struct nfsd3_getaclres),
395 		.pc_cachetype = RC_NOCACHE,
396 		.pc_xdrressize = ST+1+2*(1+ACL),
397 	},
398 	[ACLPROC2_SETACL] = {
399 		.pc_func = nfsacld_proc_setacl,
400 		.pc_decode = nfsaclsvc_decode_setaclargs,
401 		.pc_encode = nfsaclsvc_encode_attrstatres,
402 		.pc_release = nfsaclsvc_release_attrstat,
403 		.pc_argsize = sizeof(struct nfsd3_setaclargs),
404 		.pc_ressize = sizeof(struct nfsd_attrstat),
405 		.pc_cachetype = RC_NOCACHE,
406 		.pc_xdrressize = ST+AT,
407 	},
408 	[ACLPROC2_GETATTR] = {
409 		.pc_func = nfsacld_proc_getattr,
410 		.pc_decode = nfsaclsvc_decode_fhandleargs,
411 		.pc_encode = nfsaclsvc_encode_attrstatres,
412 		.pc_release = nfsaclsvc_release_attrstat,
413 		.pc_argsize = sizeof(struct nfsd_fhandle),
414 		.pc_ressize = sizeof(struct nfsd_attrstat),
415 		.pc_cachetype = RC_NOCACHE,
416 		.pc_xdrressize = ST+AT,
417 	},
418 	[ACLPROC2_ACCESS] = {
419 		.pc_func = nfsacld_proc_access,
420 		.pc_decode = nfsaclsvc_decode_accessargs,
421 		.pc_encode = nfsaclsvc_encode_accessres,
422 		.pc_release = nfsaclsvc_release_access,
423 		.pc_argsize = sizeof(struct nfsd3_accessargs),
424 		.pc_ressize = sizeof(struct nfsd3_accessres),
425 		.pc_cachetype = RC_NOCACHE,
426 		.pc_xdrressize = ST+AT+1,
427 	},
428 };
429 
430 static unsigned int nfsd_acl_count2[ARRAY_SIZE(nfsd_acl_procedures2)];
431 const struct svc_version nfsd_acl_version2 = {
432 	.vs_vers	= 2,
433 	.vs_nproc	= 5,
434 	.vs_proc	= nfsd_acl_procedures2,
435 	.vs_count	= nfsd_acl_count2,
436 	.vs_dispatch	= nfsd_dispatch,
437 	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
438 };
439