xref: /openbmc/linux/fs/nfs/nfs3acl.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
1 #include <linux/fs.h>
2 #include <linux/nfs.h>
3 #include <linux/nfs3.h>
4 #include <linux/nfs_fs.h>
5 #include <linux/posix_acl_xattr.h>
6 #include <linux/nfsacl.h>
7 
8 #define NFSDBG_FACILITY	NFSDBG_PROC
9 
10 ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
11 {
12 	struct inode *inode = dentry->d_inode;
13 	struct posix_acl *acl;
14 	int pos=0, len=0;
15 
16 #	define output(s) do {						\
17 			if (pos + sizeof(s) <= size) {			\
18 				memcpy(buffer + pos, s, sizeof(s));	\
19 				pos += sizeof(s);			\
20 			}						\
21 			len += sizeof(s);				\
22 		} while(0)
23 
24 	acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
25 	if (IS_ERR(acl))
26 		return PTR_ERR(acl);
27 	if (acl) {
28 		output("system.posix_acl_access");
29 		posix_acl_release(acl);
30 	}
31 
32 	if (S_ISDIR(inode->i_mode)) {
33 		acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
34 		if (IS_ERR(acl))
35 			return PTR_ERR(acl);
36 		if (acl) {
37 			output("system.posix_acl_default");
38 			posix_acl_release(acl);
39 		}
40 	}
41 
42 #	undef output
43 
44 	if (!buffer || len <= size)
45 		return len;
46 	return -ERANGE;
47 }
48 
49 ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
50 		void *buffer, size_t size)
51 {
52 	struct inode *inode = dentry->d_inode;
53 	struct posix_acl *acl;
54 	int type, error = 0;
55 
56 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
57 		type = ACL_TYPE_ACCESS;
58 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
59 		type = ACL_TYPE_DEFAULT;
60 	else
61 		return -EOPNOTSUPP;
62 
63 	acl = nfs3_proc_getacl(inode, type);
64 	if (IS_ERR(acl))
65 		return PTR_ERR(acl);
66 	else if (acl) {
67 		if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
68 			error = -ENODATA;
69 		else
70 			error = posix_acl_to_xattr(acl, buffer, size);
71 		posix_acl_release(acl);
72 	} else
73 		error = -ENODATA;
74 
75 	return error;
76 }
77 
78 int nfs3_setxattr(struct dentry *dentry, const char *name,
79 	     const void *value, size_t size, int flags)
80 {
81 	struct inode *inode = dentry->d_inode;
82 	struct posix_acl *acl;
83 	int type, error;
84 
85 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
86 		type = ACL_TYPE_ACCESS;
87 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
88 		type = ACL_TYPE_DEFAULT;
89 	else
90 		return -EOPNOTSUPP;
91 
92 	acl = posix_acl_from_xattr(value, size);
93 	if (IS_ERR(acl))
94 		return PTR_ERR(acl);
95 	error = nfs3_proc_setacl(inode, type, acl);
96 	posix_acl_release(acl);
97 
98 	return error;
99 }
100 
101 int nfs3_removexattr(struct dentry *dentry, const char *name)
102 {
103 	struct inode *inode = dentry->d_inode;
104 	int type;
105 
106 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
107 		type = ACL_TYPE_ACCESS;
108 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
109 		type = ACL_TYPE_DEFAULT;
110 	else
111 		return -EOPNOTSUPP;
112 
113 	return nfs3_proc_setacl(inode, type, NULL);
114 }
115 
116 static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
117 {
118 	if (!IS_ERR(nfsi->acl_access)) {
119 		posix_acl_release(nfsi->acl_access);
120 		nfsi->acl_access = ERR_PTR(-EAGAIN);
121 	}
122 	if (!IS_ERR(nfsi->acl_default)) {
123 		posix_acl_release(nfsi->acl_default);
124 		nfsi->acl_default = ERR_PTR(-EAGAIN);
125 	}
126 }
127 
128 void nfs3_forget_cached_acls(struct inode *inode)
129 {
130 	dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
131 		inode->i_ino);
132 	spin_lock(&inode->i_lock);
133 	__nfs3_forget_cached_acls(NFS_I(inode));
134 	spin_unlock(&inode->i_lock);
135 }
136 
137 static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
138 {
139 	struct nfs_inode *nfsi = NFS_I(inode);
140 	struct posix_acl *acl = ERR_PTR(-EINVAL);
141 
142 	spin_lock(&inode->i_lock);
143 	switch(type) {
144 		case ACL_TYPE_ACCESS:
145 			acl = nfsi->acl_access;
146 			break;
147 
148 		case ACL_TYPE_DEFAULT:
149 			acl = nfsi->acl_default;
150 			break;
151 
152 		default:
153 			goto out;
154 	}
155 	if (IS_ERR(acl))
156 		acl = ERR_PTR(-EAGAIN);
157 	else
158 		acl = posix_acl_dup(acl);
159 out:
160 	spin_unlock(&inode->i_lock);
161 	dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
162 		inode->i_ino, type, acl);
163 	return acl;
164 }
165 
166 static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
167 		    struct posix_acl *dfacl)
168 {
169 	struct nfs_inode *nfsi = NFS_I(inode);
170 
171 	dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
172 		inode->i_ino, acl, dfacl);
173 	spin_lock(&inode->i_lock);
174 	__nfs3_forget_cached_acls(NFS_I(inode));
175 	nfsi->acl_access = posix_acl_dup(acl);
176 	nfsi->acl_default = posix_acl_dup(dfacl);
177 	spin_unlock(&inode->i_lock);
178 }
179 
180 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
181 {
182 	struct nfs_server *server = NFS_SERVER(inode);
183 	struct nfs_fattr fattr;
184 	struct page *pages[NFSACL_MAXPAGES] = { };
185 	struct nfs3_getaclargs args = {
186 		.fh = NFS_FH(inode),
187 		/* The xdr layer may allocate pages here. */
188 		.pages = pages,
189 	};
190 	struct nfs3_getaclres res = {
191 		.fattr =	&fattr,
192 	};
193 	struct posix_acl *acl;
194 	int status, count;
195 
196 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
197 		return ERR_PTR(-EOPNOTSUPP);
198 
199 	status = nfs_revalidate_inode(server, inode);
200 	if (status < 0)
201 		return ERR_PTR(status);
202 	acl = nfs3_get_cached_acl(inode, type);
203 	if (acl != ERR_PTR(-EAGAIN))
204 		return acl;
205 	acl = NULL;
206 
207 	/*
208 	 * Only get the access acl when explicitly requested: We don't
209 	 * need it for access decisions, and only some applications use
210 	 * it. Applications which request the access acl first are not
211 	 * penalized from this optimization.
212 	 */
213 	if (type == ACL_TYPE_ACCESS)
214 		args.mask |= NFS_ACLCNT|NFS_ACL;
215 	if (S_ISDIR(inode->i_mode))
216 		args.mask |= NFS_DFACLCNT|NFS_DFACL;
217 	if (args.mask == 0)
218 		return NULL;
219 
220 	dprintk("NFS call getacl\n");
221 	status = rpc_call(server->client_acl, ACLPROC3_GETACL,
222 			  &args, &res, 0);
223 	dprintk("NFS reply getacl: %d\n", status);
224 
225 	/* pages may have been allocated at the xdr layer. */
226 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
227 		__free_page(args.pages[count]);
228 
229 	switch (status) {
230 		case 0:
231 			status = nfs_refresh_inode(inode, &fattr);
232 			break;
233 		case -EPFNOSUPPORT:
234 		case -EPROTONOSUPPORT:
235 			dprintk("NFS_V3_ACL extension not supported; disabling\n");
236 			server->caps &= ~NFS_CAP_ACLS;
237 		case -ENOTSUPP:
238 			status = -EOPNOTSUPP;
239 		default:
240 			goto getout;
241 	}
242 	if ((args.mask & res.mask) != args.mask) {
243 		status = -EIO;
244 		goto getout;
245 	}
246 
247 	if (res.acl_access != NULL) {
248 		if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
249 			posix_acl_release(res.acl_access);
250 			res.acl_access = NULL;
251 		}
252 	}
253 	nfs3_cache_acls(inode, res.acl_access, res.acl_default);
254 
255 	switch(type) {
256 		case ACL_TYPE_ACCESS:
257 			acl = res.acl_access;
258 			res.acl_access = NULL;
259 			break;
260 
261 		case ACL_TYPE_DEFAULT:
262 			acl = res.acl_default;
263 			res.acl_default = NULL;
264 	}
265 
266 getout:
267 	posix_acl_release(res.acl_access);
268 	posix_acl_release(res.acl_default);
269 
270 	if (status != 0) {
271 		posix_acl_release(acl);
272 		acl = ERR_PTR(status);
273 	}
274 	return acl;
275 }
276 
277 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
278 		  struct posix_acl *dfacl)
279 {
280 	struct nfs_server *server = NFS_SERVER(inode);
281 	struct nfs_fattr fattr;
282 	struct page *pages[NFSACL_MAXPAGES] = { };
283 	struct nfs3_setaclargs args = {
284 		.inode = inode,
285 		.mask = NFS_ACL,
286 		.acl_access = acl,
287 		.pages = pages,
288 	};
289 	int status, count;
290 
291 	status = -EOPNOTSUPP;
292 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
293 		goto out;
294 
295 	/* We are doing this here, because XDR marshalling can only
296 	   return -ENOMEM. */
297 	status = -ENOSPC;
298 	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
299 		goto out;
300 	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
301 		goto out;
302 	if (S_ISDIR(inode->i_mode)) {
303 		args.mask |= NFS_DFACL;
304 		args.acl_default = dfacl;
305 	}
306 
307 	dprintk("NFS call setacl\n");
308 	nfs_begin_data_update(inode);
309 	status = rpc_call(server->client_acl, ACLPROC3_SETACL,
310 			  &args, &fattr, 0);
311 	spin_lock(&inode->i_lock);
312 	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS;
313 	spin_unlock(&inode->i_lock);
314 	nfs_end_data_update(inode);
315 	dprintk("NFS reply setacl: %d\n", status);
316 
317 	/* pages may have been allocated at the xdr layer. */
318 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
319 		__free_page(args.pages[count]);
320 
321 	switch (status) {
322 		case 0:
323 			status = nfs_refresh_inode(inode, &fattr);
324 			break;
325 		case -EPFNOSUPPORT:
326 		case -EPROTONOSUPPORT:
327 			dprintk("NFS_V3_ACL SETACL RPC not supported"
328 					"(will not retry)\n");
329 			server->caps &= ~NFS_CAP_ACLS;
330 		case -ENOTSUPP:
331 			status = -EOPNOTSUPP;
332 	}
333 out:
334 	return status;
335 }
336 
337 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
338 {
339 	struct posix_acl *alloc = NULL, *dfacl = NULL;
340 	int status;
341 
342 	if (S_ISDIR(inode->i_mode)) {
343 		switch(type) {
344 			case ACL_TYPE_ACCESS:
345 				alloc = dfacl = nfs3_proc_getacl(inode,
346 						ACL_TYPE_DEFAULT);
347 				if (IS_ERR(alloc))
348 					goto fail;
349 				break;
350 
351 			case ACL_TYPE_DEFAULT:
352 				dfacl = acl;
353 				alloc = acl = nfs3_proc_getacl(inode,
354 						ACL_TYPE_ACCESS);
355 				if (IS_ERR(alloc))
356 					goto fail;
357 				break;
358 
359 			default:
360 				return -EINVAL;
361 		}
362 	} else if (type != ACL_TYPE_ACCESS)
363 			return -EINVAL;
364 
365 	if (acl == NULL) {
366 		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
367 		if (IS_ERR(alloc))
368 			goto fail;
369 	}
370 	status = nfs3_proc_setacls(inode, acl, dfacl);
371 	posix_acl_release(alloc);
372 	return status;
373 
374 fail:
375 	return PTR_ERR(alloc);
376 }
377 
378 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
379 		mode_t mode)
380 {
381 	struct posix_acl *dfacl, *acl;
382 	int error = 0;
383 
384 	dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
385 	if (IS_ERR(dfacl)) {
386 		error = PTR_ERR(dfacl);
387 		return (error == -EOPNOTSUPP) ? 0 : error;
388 	}
389 	if (!dfacl)
390 		return 0;
391 	acl = posix_acl_clone(dfacl, GFP_KERNEL);
392 	error = -ENOMEM;
393 	if (!acl)
394 		goto out_release_dfacl;
395 	error = posix_acl_create_masq(acl, &mode);
396 	if (error < 0)
397 		goto out_release_acl;
398 	error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
399 						      dfacl : NULL);
400 out_release_acl:
401 	posix_acl_release(acl);
402 out_release_dfacl:
403 	posix_acl_release(dfacl);
404 	return error;
405 }
406