xref: /openbmc/linux/fs/nfs/nfs3acl.c (revision 367b8112)
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 #include "internal.h"
9 
10 #define NFSDBG_FACILITY	NFSDBG_PROC
11 
12 ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
13 {
14 	struct inode *inode = dentry->d_inode;
15 	struct posix_acl *acl;
16 	int pos=0, len=0;
17 
18 #	define output(s) do {						\
19 			if (pos + sizeof(s) <= size) {			\
20 				memcpy(buffer + pos, s, sizeof(s));	\
21 				pos += sizeof(s);			\
22 			}						\
23 			len += sizeof(s);				\
24 		} while(0)
25 
26 	acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
27 	if (IS_ERR(acl))
28 		return PTR_ERR(acl);
29 	if (acl) {
30 		output("system.posix_acl_access");
31 		posix_acl_release(acl);
32 	}
33 
34 	if (S_ISDIR(inode->i_mode)) {
35 		acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
36 		if (IS_ERR(acl))
37 			return PTR_ERR(acl);
38 		if (acl) {
39 			output("system.posix_acl_default");
40 			posix_acl_release(acl);
41 		}
42 	}
43 
44 #	undef output
45 
46 	if (!buffer || len <= size)
47 		return len;
48 	return -ERANGE;
49 }
50 
51 ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
52 		void *buffer, size_t size)
53 {
54 	struct inode *inode = dentry->d_inode;
55 	struct posix_acl *acl;
56 	int type, error = 0;
57 
58 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
59 		type = ACL_TYPE_ACCESS;
60 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
61 		type = ACL_TYPE_DEFAULT;
62 	else
63 		return -EOPNOTSUPP;
64 
65 	acl = nfs3_proc_getacl(inode, type);
66 	if (IS_ERR(acl))
67 		return PTR_ERR(acl);
68 	else if (acl) {
69 		if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
70 			error = -ENODATA;
71 		else
72 			error = posix_acl_to_xattr(acl, buffer, size);
73 		posix_acl_release(acl);
74 	} else
75 		error = -ENODATA;
76 
77 	return error;
78 }
79 
80 int nfs3_setxattr(struct dentry *dentry, const char *name,
81 	     const void *value, size_t size, int flags)
82 {
83 	struct inode *inode = dentry->d_inode;
84 	struct posix_acl *acl;
85 	int type, error;
86 
87 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
88 		type = ACL_TYPE_ACCESS;
89 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
90 		type = ACL_TYPE_DEFAULT;
91 	else
92 		return -EOPNOTSUPP;
93 
94 	acl = posix_acl_from_xattr(value, size);
95 	if (IS_ERR(acl))
96 		return PTR_ERR(acl);
97 	error = nfs3_proc_setacl(inode, type, acl);
98 	posix_acl_release(acl);
99 
100 	return error;
101 }
102 
103 int nfs3_removexattr(struct dentry *dentry, const char *name)
104 {
105 	struct inode *inode = dentry->d_inode;
106 	int type;
107 
108 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
109 		type = ACL_TYPE_ACCESS;
110 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
111 		type = ACL_TYPE_DEFAULT;
112 	else
113 		return -EOPNOTSUPP;
114 
115 	return nfs3_proc_setacl(inode, type, NULL);
116 }
117 
118 static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
119 {
120 	if (!IS_ERR(nfsi->acl_access)) {
121 		posix_acl_release(nfsi->acl_access);
122 		nfsi->acl_access = ERR_PTR(-EAGAIN);
123 	}
124 	if (!IS_ERR(nfsi->acl_default)) {
125 		posix_acl_release(nfsi->acl_default);
126 		nfsi->acl_default = ERR_PTR(-EAGAIN);
127 	}
128 }
129 
130 void nfs3_forget_cached_acls(struct inode *inode)
131 {
132 	dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
133 		inode->i_ino);
134 	spin_lock(&inode->i_lock);
135 	__nfs3_forget_cached_acls(NFS_I(inode));
136 	spin_unlock(&inode->i_lock);
137 }
138 
139 static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
140 {
141 	struct nfs_inode *nfsi = NFS_I(inode);
142 	struct posix_acl *acl = ERR_PTR(-EINVAL);
143 
144 	spin_lock(&inode->i_lock);
145 	switch(type) {
146 		case ACL_TYPE_ACCESS:
147 			acl = nfsi->acl_access;
148 			break;
149 
150 		case ACL_TYPE_DEFAULT:
151 			acl = nfsi->acl_default;
152 			break;
153 
154 		default:
155 			goto out;
156 	}
157 	if (IS_ERR(acl))
158 		acl = ERR_PTR(-EAGAIN);
159 	else
160 		acl = posix_acl_dup(acl);
161 out:
162 	spin_unlock(&inode->i_lock);
163 	dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
164 		inode->i_ino, type, acl);
165 	return acl;
166 }
167 
168 static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
169 		    struct posix_acl *dfacl)
170 {
171 	struct nfs_inode *nfsi = NFS_I(inode);
172 
173 	dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
174 		inode->i_ino, acl, dfacl);
175 	spin_lock(&inode->i_lock);
176 	__nfs3_forget_cached_acls(NFS_I(inode));
177 	if (!IS_ERR(acl))
178 		nfsi->acl_access = posix_acl_dup(acl);
179 	if (!IS_ERR(dfacl))
180 		nfsi->acl_default = posix_acl_dup(dfacl);
181 	spin_unlock(&inode->i_lock);
182 }
183 
184 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
185 {
186 	struct nfs_server *server = NFS_SERVER(inode);
187 	struct nfs_fattr fattr;
188 	struct page *pages[NFSACL_MAXPAGES] = { };
189 	struct nfs3_getaclargs args = {
190 		.fh = NFS_FH(inode),
191 		/* The xdr layer may allocate pages here. */
192 		.pages = pages,
193 	};
194 	struct nfs3_getaclres res = {
195 		.fattr =	&fattr,
196 	};
197 	struct rpc_message msg = {
198 		.rpc_argp	= &args,
199 		.rpc_resp	= &res,
200 	};
201 	struct posix_acl *acl;
202 	int status, count;
203 
204 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
205 		return ERR_PTR(-EOPNOTSUPP);
206 
207 	status = nfs_revalidate_inode(server, inode);
208 	if (status < 0)
209 		return ERR_PTR(status);
210 	if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_ACL)
211 		nfs_zap_acl_cache(inode);
212 	acl = nfs3_get_cached_acl(inode, type);
213 	if (acl != ERR_PTR(-EAGAIN))
214 		return acl;
215 	acl = NULL;
216 
217 	/*
218 	 * Only get the access acl when explicitly requested: We don't
219 	 * need it for access decisions, and only some applications use
220 	 * it. Applications which request the access acl first are not
221 	 * penalized from this optimization.
222 	 */
223 	if (type == ACL_TYPE_ACCESS)
224 		args.mask |= NFS_ACLCNT|NFS_ACL;
225 	if (S_ISDIR(inode->i_mode))
226 		args.mask |= NFS_DFACLCNT|NFS_DFACL;
227 	if (args.mask == 0)
228 		return NULL;
229 
230 	dprintk("NFS call getacl\n");
231 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
232 	nfs_fattr_init(&fattr);
233 	status = rpc_call_sync(server->client_acl, &msg, 0);
234 	dprintk("NFS reply getacl: %d\n", status);
235 
236 	/* pages may have been allocated at the xdr layer. */
237 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
238 		__free_page(args.pages[count]);
239 
240 	switch (status) {
241 		case 0:
242 			status = nfs_refresh_inode(inode, &fattr);
243 			break;
244 		case -EPFNOSUPPORT:
245 		case -EPROTONOSUPPORT:
246 			dprintk("NFS_V3_ACL extension not supported; disabling\n");
247 			server->caps &= ~NFS_CAP_ACLS;
248 		case -ENOTSUPP:
249 			status = -EOPNOTSUPP;
250 		default:
251 			goto getout;
252 	}
253 	if ((args.mask & res.mask) != args.mask) {
254 		status = -EIO;
255 		goto getout;
256 	}
257 
258 	if (res.acl_access != NULL) {
259 		if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
260 			posix_acl_release(res.acl_access);
261 			res.acl_access = NULL;
262 		}
263 	}
264 	nfs3_cache_acls(inode,
265 		(res.mask & NFS_ACL)   ? res.acl_access  : ERR_PTR(-EINVAL),
266 		(res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
267 
268 	switch(type) {
269 		case ACL_TYPE_ACCESS:
270 			acl = res.acl_access;
271 			res.acl_access = NULL;
272 			break;
273 
274 		case ACL_TYPE_DEFAULT:
275 			acl = res.acl_default;
276 			res.acl_default = NULL;
277 	}
278 
279 getout:
280 	posix_acl_release(res.acl_access);
281 	posix_acl_release(res.acl_default);
282 
283 	if (status != 0) {
284 		posix_acl_release(acl);
285 		acl = ERR_PTR(status);
286 	}
287 	return acl;
288 }
289 
290 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
291 		  struct posix_acl *dfacl)
292 {
293 	struct nfs_server *server = NFS_SERVER(inode);
294 	struct nfs_fattr fattr;
295 	struct page *pages[NFSACL_MAXPAGES] = { };
296 	struct nfs3_setaclargs args = {
297 		.inode = inode,
298 		.mask = NFS_ACL,
299 		.acl_access = acl,
300 		.pages = pages,
301 	};
302 	struct rpc_message msg = {
303 		.rpc_argp	= &args,
304 		.rpc_resp	= &fattr,
305 	};
306 	int status, count;
307 
308 	status = -EOPNOTSUPP;
309 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
310 		goto out;
311 
312 	/* We are doing this here, because XDR marshalling can only
313 	   return -ENOMEM. */
314 	status = -ENOSPC;
315 	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
316 		goto out;
317 	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
318 		goto out;
319 	if (S_ISDIR(inode->i_mode)) {
320 		args.mask |= NFS_DFACL;
321 		args.acl_default = dfacl;
322 	}
323 
324 	dprintk("NFS call setacl\n");
325 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
326 	nfs_fattr_init(&fattr);
327 	status = rpc_call_sync(server->client_acl, &msg, 0);
328 	nfs_access_zap_cache(inode);
329 	nfs_zap_acl_cache(inode);
330 	dprintk("NFS reply setacl: %d\n", status);
331 
332 	/* pages may have been allocated at the xdr layer. */
333 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
334 		__free_page(args.pages[count]);
335 
336 	switch (status) {
337 		case 0:
338 			status = nfs_refresh_inode(inode, &fattr);
339 			nfs3_cache_acls(inode, acl, dfacl);
340 			break;
341 		case -EPFNOSUPPORT:
342 		case -EPROTONOSUPPORT:
343 			dprintk("NFS_V3_ACL SETACL RPC not supported"
344 					"(will not retry)\n");
345 			server->caps &= ~NFS_CAP_ACLS;
346 		case -ENOTSUPP:
347 			status = -EOPNOTSUPP;
348 	}
349 out:
350 	return status;
351 }
352 
353 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
354 {
355 	struct posix_acl *alloc = NULL, *dfacl = NULL;
356 	int status;
357 
358 	if (S_ISDIR(inode->i_mode)) {
359 		switch(type) {
360 			case ACL_TYPE_ACCESS:
361 				alloc = dfacl = nfs3_proc_getacl(inode,
362 						ACL_TYPE_DEFAULT);
363 				if (IS_ERR(alloc))
364 					goto fail;
365 				break;
366 
367 			case ACL_TYPE_DEFAULT:
368 				dfacl = acl;
369 				alloc = acl = nfs3_proc_getacl(inode,
370 						ACL_TYPE_ACCESS);
371 				if (IS_ERR(alloc))
372 					goto fail;
373 				break;
374 
375 			default:
376 				return -EINVAL;
377 		}
378 	} else if (type != ACL_TYPE_ACCESS)
379 			return -EINVAL;
380 
381 	if (acl == NULL) {
382 		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
383 		if (IS_ERR(alloc))
384 			goto fail;
385 	}
386 	status = nfs3_proc_setacls(inode, acl, dfacl);
387 	posix_acl_release(alloc);
388 	return status;
389 
390 fail:
391 	return PTR_ERR(alloc);
392 }
393 
394 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
395 		mode_t mode)
396 {
397 	struct posix_acl *dfacl, *acl;
398 	int error = 0;
399 
400 	dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
401 	if (IS_ERR(dfacl)) {
402 		error = PTR_ERR(dfacl);
403 		return (error == -EOPNOTSUPP) ? 0 : error;
404 	}
405 	if (!dfacl)
406 		return 0;
407 	acl = posix_acl_clone(dfacl, GFP_KERNEL);
408 	error = -ENOMEM;
409 	if (!acl)
410 		goto out_release_dfacl;
411 	error = posix_acl_create_masq(acl, &mode);
412 	if (error < 0)
413 		goto out_release_acl;
414 	error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
415 						      dfacl : NULL);
416 out_release_acl:
417 	posix_acl_release(acl);
418 out_release_dfacl:
419 	posix_acl_release(dfacl);
420 	return error;
421 }
422