1#include <linux/fs.h>
2#include <linux/gfp.h>
3#include <linux/nfs.h>
4#include <linux/nfs3.h>
5#include <linux/nfs_fs.h>
6#include <linux/posix_acl_xattr.h>
7#include <linux/nfsacl.h>
8
9#include "internal.h"
10#include "nfs3_fs.h"
11
12#define NFSDBG_FACILITY	NFSDBG_PROC
13
14struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
15{
16	struct nfs_server *server = NFS_SERVER(inode);
17	struct page *pages[NFSACL_MAXPAGES] = { };
18	struct nfs3_getaclargs args = {
19		.fh = NFS_FH(inode),
20		/* The xdr layer may allocate pages here. */
21		.pages = pages,
22	};
23	struct nfs3_getaclres res = {
24		NULL,
25	};
26	struct rpc_message msg = {
27		.rpc_argp	= &args,
28		.rpc_resp	= &res,
29	};
30	int status, count;
31
32	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
33		return ERR_PTR(-EOPNOTSUPP);
34
35	status = nfs_revalidate_inode(server, inode);
36	if (status < 0)
37		return ERR_PTR(status);
38
39	/*
40	 * Only get the access acl when explicitly requested: We don't
41	 * need it for access decisions, and only some applications use
42	 * it. Applications which request the access acl first are not
43	 * penalized from this optimization.
44	 */
45	if (type == ACL_TYPE_ACCESS)
46		args.mask |= NFS_ACLCNT|NFS_ACL;
47	if (S_ISDIR(inode->i_mode))
48		args.mask |= NFS_DFACLCNT|NFS_DFACL;
49	if (args.mask == 0)
50		return NULL;
51
52	dprintk("NFS call getacl\n");
53	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
54	res.fattr = nfs_alloc_fattr();
55	if (res.fattr == NULL)
56		return ERR_PTR(-ENOMEM);
57
58	status = rpc_call_sync(server->client_acl, &msg, 0);
59	dprintk("NFS reply getacl: %d\n", status);
60
61	/* pages may have been allocated at the xdr layer. */
62	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
63		__free_page(args.pages[count]);
64
65	switch (status) {
66		case 0:
67			status = nfs_refresh_inode(inode, res.fattr);
68			break;
69		case -EPFNOSUPPORT:
70		case -EPROTONOSUPPORT:
71			dprintk("NFS_V3_ACL extension not supported; disabling\n");
72			server->caps &= ~NFS_CAP_ACLS;
73		case -ENOTSUPP:
74			status = -EOPNOTSUPP;
75		default:
76			goto getout;
77	}
78	if ((args.mask & res.mask) != args.mask) {
79		status = -EIO;
80		goto getout;
81	}
82
83	if (res.acl_access != NULL) {
84		if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
85		    res.acl_access->a_count == 0) {
86			posix_acl_release(res.acl_access);
87			res.acl_access = NULL;
88		}
89	}
90
91	if (res.mask & NFS_ACL)
92		set_cached_acl(inode, ACL_TYPE_ACCESS, res.acl_access);
93	else
94		forget_cached_acl(inode, ACL_TYPE_ACCESS);
95
96	if (res.mask & NFS_DFACL)
97		set_cached_acl(inode, ACL_TYPE_DEFAULT, res.acl_default);
98	else
99		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
100
101	nfs_free_fattr(res.fattr);
102	if (type == ACL_TYPE_ACCESS) {
103		posix_acl_release(res.acl_default);
104		return res.acl_access;
105	} else {
106		posix_acl_release(res.acl_access);
107		return res.acl_default;
108	}
109
110getout:
111	posix_acl_release(res.acl_access);
112	posix_acl_release(res.acl_default);
113	nfs_free_fattr(res.fattr);
114	return ERR_PTR(status);
115}
116
117static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
118		struct posix_acl *dfacl)
119{
120	struct nfs_server *server = NFS_SERVER(inode);
121	struct nfs_fattr *fattr;
122	struct page *pages[NFSACL_MAXPAGES];
123	struct nfs3_setaclargs args = {
124		.inode = inode,
125		.mask = NFS_ACL,
126		.acl_access = acl,
127		.pages = pages,
128	};
129	struct rpc_message msg = {
130		.rpc_argp	= &args,
131		.rpc_resp	= &fattr,
132	};
133	int status = 0;
134
135	if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
136		goto out;
137
138	status = -EOPNOTSUPP;
139	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
140		goto out;
141
142	/* We are doing this here because XDR marshalling does not
143	 * return any results, it BUGs. */
144	status = -ENOSPC;
145	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
146		goto out;
147	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
148		goto out;
149	if (S_ISDIR(inode->i_mode)) {
150		args.mask |= NFS_DFACL;
151		args.acl_default = dfacl;
152		args.len = nfsacl_size(acl, dfacl);
153	} else
154		args.len = nfsacl_size(acl, NULL);
155
156	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
157		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
158
159		status = -ENOMEM;
160		do {
161			args.pages[args.npages] = alloc_page(GFP_KERNEL);
162			if (args.pages[args.npages] == NULL)
163				goto out_freepages;
164			args.npages++;
165		} while (args.npages < npages);
166	}
167
168	dprintk("NFS call setacl\n");
169	status = -ENOMEM;
170	fattr = nfs_alloc_fattr();
171	if (fattr == NULL)
172		goto out_freepages;
173
174	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
175	msg.rpc_resp = fattr;
176	status = rpc_call_sync(server->client_acl, &msg, 0);
177	nfs_access_zap_cache(inode);
178	nfs_zap_acl_cache(inode);
179	dprintk("NFS reply setacl: %d\n", status);
180
181	switch (status) {
182		case 0:
183			status = nfs_refresh_inode(inode, fattr);
184			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
185			set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
186			break;
187		case -EPFNOSUPPORT:
188		case -EPROTONOSUPPORT:
189			dprintk("NFS_V3_ACL SETACL RPC not supported"
190					"(will not retry)\n");
191			server->caps &= ~NFS_CAP_ACLS;
192		case -ENOTSUPP:
193			status = -EOPNOTSUPP;
194	}
195	nfs_free_fattr(fattr);
196out_freepages:
197	while (args.npages != 0) {
198		args.npages--;
199		__free_page(args.pages[args.npages]);
200	}
201out:
202	return status;
203}
204
205int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
206		struct posix_acl *dfacl)
207{
208	int ret;
209	ret = __nfs3_proc_setacls(inode, acl, dfacl);
210	return (ret == -EOPNOTSUPP) ? 0 : ret;
211
212}
213
214int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
215{
216	struct posix_acl *alloc = NULL, *dfacl = NULL;
217	int status;
218
219	if (S_ISDIR(inode->i_mode)) {
220		switch(type) {
221		case ACL_TYPE_ACCESS:
222			alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
223			if (IS_ERR(alloc))
224				goto fail;
225			break;
226
227		case ACL_TYPE_DEFAULT:
228			dfacl = acl;
229			alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
230			if (IS_ERR(alloc))
231				goto fail;
232			break;
233		}
234	}
235
236	if (acl == NULL) {
237		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
238		if (IS_ERR(alloc))
239			goto fail;
240	}
241	status = __nfs3_proc_setacls(inode, acl, dfacl);
242	posix_acl_release(alloc);
243	return status;
244
245fail:
246	return PTR_ERR(alloc);
247}
248
249const struct xattr_handler *nfs3_xattr_handlers[] = {
250	&posix_acl_access_xattr_handler,
251	&posix_acl_default_xattr_handler,
252	NULL,
253};
254
255static int
256nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
257		size_t size, ssize_t *result)
258{
259	struct posix_acl *acl;
260	char *p = data + *result;
261
262	acl = get_acl(inode, type);
263	if (IS_ERR_OR_NULL(acl))
264		return 0;
265
266	posix_acl_release(acl);
267
268	*result += strlen(name);
269	*result += 1;
270	if (!size)
271		return 0;
272	if (*result > size)
273		return -ERANGE;
274
275	strcpy(p, name);
276	return 0;
277}
278
279ssize_t
280nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
281{
282	struct inode *inode = d_inode(dentry);
283	ssize_t result = 0;
284	int error;
285
286	error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
287			POSIX_ACL_XATTR_ACCESS, data, size, &result);
288	if (error)
289		return error;
290
291	error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
292			POSIX_ACL_XATTR_DEFAULT, data, size, &result);
293	if (error)
294		return error;
295	return result;
296}
297