xref: /openbmc/linux/fs/nfs/nfs3acl.c (revision a09d2831)
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 	acl = nfs3_get_cached_acl(inode, type);
211 	if (acl != ERR_PTR(-EAGAIN))
212 		return acl;
213 	acl = NULL;
214 
215 	/*
216 	 * Only get the access acl when explicitly requested: We don't
217 	 * need it for access decisions, and only some applications use
218 	 * it. Applications which request the access acl first are not
219 	 * penalized from this optimization.
220 	 */
221 	if (type == ACL_TYPE_ACCESS)
222 		args.mask |= NFS_ACLCNT|NFS_ACL;
223 	if (S_ISDIR(inode->i_mode))
224 		args.mask |= NFS_DFACLCNT|NFS_DFACL;
225 	if (args.mask == 0)
226 		return NULL;
227 
228 	dprintk("NFS call getacl\n");
229 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
230 	nfs_fattr_init(&fattr);
231 	status = rpc_call_sync(server->client_acl, &msg, 0);
232 	dprintk("NFS reply getacl: %d\n", status);
233 
234 	/* pages may have been allocated at the xdr layer. */
235 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
236 		__free_page(args.pages[count]);
237 
238 	switch (status) {
239 		case 0:
240 			status = nfs_refresh_inode(inode, &fattr);
241 			break;
242 		case -EPFNOSUPPORT:
243 		case -EPROTONOSUPPORT:
244 			dprintk("NFS_V3_ACL extension not supported; disabling\n");
245 			server->caps &= ~NFS_CAP_ACLS;
246 		case -ENOTSUPP:
247 			status = -EOPNOTSUPP;
248 		default:
249 			goto getout;
250 	}
251 	if ((args.mask & res.mask) != args.mask) {
252 		status = -EIO;
253 		goto getout;
254 	}
255 
256 	if (res.acl_access != NULL) {
257 		if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
258 			posix_acl_release(res.acl_access);
259 			res.acl_access = NULL;
260 		}
261 	}
262 	nfs3_cache_acls(inode,
263 		(res.mask & NFS_ACL)   ? res.acl_access  : ERR_PTR(-EINVAL),
264 		(res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
265 
266 	switch(type) {
267 		case ACL_TYPE_ACCESS:
268 			acl = res.acl_access;
269 			res.acl_access = NULL;
270 			break;
271 
272 		case ACL_TYPE_DEFAULT:
273 			acl = res.acl_default;
274 			res.acl_default = NULL;
275 	}
276 
277 getout:
278 	posix_acl_release(res.acl_access);
279 	posix_acl_release(res.acl_default);
280 
281 	if (status != 0) {
282 		posix_acl_release(acl);
283 		acl = ERR_PTR(status);
284 	}
285 	return acl;
286 }
287 
288 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
289 		  struct posix_acl *dfacl)
290 {
291 	struct nfs_server *server = NFS_SERVER(inode);
292 	struct nfs_fattr fattr;
293 	struct page *pages[NFSACL_MAXPAGES];
294 	struct nfs3_setaclargs args = {
295 		.inode = inode,
296 		.mask = NFS_ACL,
297 		.acl_access = acl,
298 		.pages = pages,
299 	};
300 	struct rpc_message msg = {
301 		.rpc_argp	= &args,
302 		.rpc_resp	= &fattr,
303 	};
304 	int status;
305 
306 	status = -EOPNOTSUPP;
307 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
308 		goto out;
309 
310 	/* We are doing this here, because XDR marshalling can only
311 	   return -ENOMEM. */
312 	status = -ENOSPC;
313 	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
314 		goto out;
315 	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
316 		goto out;
317 	if (S_ISDIR(inode->i_mode)) {
318 		args.mask |= NFS_DFACL;
319 		args.acl_default = dfacl;
320 		args.len = nfsacl_size(acl, dfacl);
321 	} else
322 		args.len = nfsacl_size(acl, NULL);
323 
324 	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
325 		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
326 
327 		status = -ENOMEM;
328 		do {
329 			args.pages[args.npages] = alloc_page(GFP_KERNEL);
330 			if (args.pages[args.npages] == NULL)
331 				goto out_freepages;
332 			args.npages++;
333 		} while (args.npages < npages);
334 	}
335 
336 	dprintk("NFS call setacl\n");
337 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
338 	nfs_fattr_init(&fattr);
339 	status = rpc_call_sync(server->client_acl, &msg, 0);
340 	nfs_access_zap_cache(inode);
341 	nfs_zap_acl_cache(inode);
342 	dprintk("NFS reply setacl: %d\n", status);
343 
344 	switch (status) {
345 		case 0:
346 			status = nfs_refresh_inode(inode, &fattr);
347 			nfs3_cache_acls(inode, acl, dfacl);
348 			break;
349 		case -EPFNOSUPPORT:
350 		case -EPROTONOSUPPORT:
351 			dprintk("NFS_V3_ACL SETACL RPC not supported"
352 					"(will not retry)\n");
353 			server->caps &= ~NFS_CAP_ACLS;
354 		case -ENOTSUPP:
355 			status = -EOPNOTSUPP;
356 	}
357 out_freepages:
358 	while (args.npages != 0) {
359 		args.npages--;
360 		__free_page(args.pages[args.npages]);
361 	}
362 out:
363 	return status;
364 }
365 
366 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
367 {
368 	struct posix_acl *alloc = NULL, *dfacl = NULL;
369 	int status;
370 
371 	if (S_ISDIR(inode->i_mode)) {
372 		switch(type) {
373 			case ACL_TYPE_ACCESS:
374 				alloc = dfacl = nfs3_proc_getacl(inode,
375 						ACL_TYPE_DEFAULT);
376 				if (IS_ERR(alloc))
377 					goto fail;
378 				break;
379 
380 			case ACL_TYPE_DEFAULT:
381 				dfacl = acl;
382 				alloc = acl = nfs3_proc_getacl(inode,
383 						ACL_TYPE_ACCESS);
384 				if (IS_ERR(alloc))
385 					goto fail;
386 				break;
387 
388 			default:
389 				return -EINVAL;
390 		}
391 	} else if (type != ACL_TYPE_ACCESS)
392 			return -EINVAL;
393 
394 	if (acl == NULL) {
395 		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
396 		if (IS_ERR(alloc))
397 			goto fail;
398 	}
399 	status = nfs3_proc_setacls(inode, acl, dfacl);
400 	posix_acl_release(alloc);
401 	return status;
402 
403 fail:
404 	return PTR_ERR(alloc);
405 }
406 
407 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
408 		mode_t mode)
409 {
410 	struct posix_acl *dfacl, *acl;
411 	int error = 0;
412 
413 	dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
414 	if (IS_ERR(dfacl)) {
415 		error = PTR_ERR(dfacl);
416 		return (error == -EOPNOTSUPP) ? 0 : error;
417 	}
418 	if (!dfacl)
419 		return 0;
420 	acl = posix_acl_clone(dfacl, GFP_KERNEL);
421 	error = -ENOMEM;
422 	if (!acl)
423 		goto out_release_dfacl;
424 	error = posix_acl_create_masq(acl, &mode);
425 	if (error < 0)
426 		goto out_release_acl;
427 	error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
428 						      dfacl : NULL);
429 out_release_acl:
430 	posix_acl_release(acl);
431 out_release_dfacl:
432 	posix_acl_release(dfacl);
433 	return error;
434 }
435