Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Copyright (c) 2008, Christoph Hellwig
4 : * All Rights Reserved.
5 : */
6 : #include "xfs.h"
7 : #include "xfs_shared.h"
8 : #include "xfs_format.h"
9 : #include "xfs_log_format.h"
10 : #include "xfs_trans_resv.h"
11 : #include "xfs_mount.h"
12 : #include "xfs_inode.h"
13 : #include "xfs_da_format.h"
14 : #include "xfs_da_btree.h"
15 : #include "xfs_attr.h"
16 : #include "xfs_trace.h"
17 : #include "xfs_error.h"
18 : #include "xfs_acl.h"
19 : #include "xfs_trans.h"
20 : #include "xfs_xattr.h"
21 :
22 : #include <linux/posix_acl_xattr.h>
23 :
24 : /*
25 : * Locking scheme:
26 : * - all ACL updates are protected by inode->i_mutex, which is taken before
27 : * calling into this file.
28 : */
29 :
30 : STATIC struct posix_acl *
31 6 : xfs_acl_from_disk(
32 : struct xfs_mount *mp,
33 : const struct xfs_acl *aclp,
34 : int len,
35 : int max_entries)
36 : {
37 6 : struct posix_acl_entry *acl_e;
38 6 : struct posix_acl *acl;
39 6 : const struct xfs_acl_entry *ace;
40 6 : unsigned int count, i;
41 :
42 6 : if (len < sizeof(*aclp)) {
43 0 : XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
44 : len);
45 0 : return ERR_PTR(-EFSCORRUPTED);
46 : }
47 :
48 6 : count = be32_to_cpu(aclp->acl_cnt);
49 6 : if (count > max_entries || XFS_ACL_SIZE(count) != len) {
50 0 : XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
51 : len);
52 0 : return ERR_PTR(-EFSCORRUPTED);
53 : }
54 :
55 6 : acl = posix_acl_alloc(count, GFP_KERNEL);
56 6 : if (!acl)
57 : return ERR_PTR(-ENOMEM);
58 :
59 40 : for (i = 0; i < count; i++) {
60 34 : acl_e = &acl->a_entries[i];
61 34 : ace = &aclp->acl_entry[i];
62 :
63 : /*
64 : * The tag is 32 bits on disk and 16 bits in core.
65 : *
66 : * Because every access to it goes through the core
67 : * format first this is not a problem.
68 : */
69 34 : acl_e->e_tag = be32_to_cpu(ace->ae_tag);
70 34 : acl_e->e_perm = be16_to_cpu(ace->ae_perm);
71 :
72 34 : switch (acl_e->e_tag) {
73 6 : case ACL_USER:
74 12 : acl_e->e_uid = make_kuid(&init_user_ns,
75 6 : be32_to_cpu(ace->ae_id));
76 6 : break;
77 4 : case ACL_GROUP:
78 8 : acl_e->e_gid = make_kgid(&init_user_ns,
79 4 : be32_to_cpu(ace->ae_id));
80 4 : break;
81 : case ACL_USER_OBJ:
82 : case ACL_GROUP_OBJ:
83 : case ACL_MASK:
84 : case ACL_OTHER:
85 : break;
86 0 : default:
87 0 : goto fail;
88 : }
89 : }
90 : return acl;
91 :
92 : fail:
93 0 : posix_acl_release(acl);
94 0 : return ERR_PTR(-EINVAL);
95 : }
96 :
97 : STATIC void
98 3467 : xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
99 : {
100 3467 : const struct posix_acl_entry *acl_e;
101 3467 : struct xfs_acl_entry *ace;
102 3467 : int i;
103 :
104 3467 : aclp->acl_cnt = cpu_to_be32(acl->a_count);
105 42780 : for (i = 0; i < acl->a_count; i++) {
106 39313 : ace = &aclp->acl_entry[i];
107 39313 : acl_e = &acl->a_entries[i];
108 :
109 39313 : ace->ae_tag = cpu_to_be32(acl_e->e_tag);
110 39313 : switch (acl_e->e_tag) {
111 25443 : case ACL_USER:
112 25443 : ace->ae_id = cpu_to_be32(
113 : from_kuid(&init_user_ns, acl_e->e_uid));
114 25443 : break;
115 10 : case ACL_GROUP:
116 10 : ace->ae_id = cpu_to_be32(
117 : from_kgid(&init_user_ns, acl_e->e_gid));
118 10 : break;
119 13860 : default:
120 13860 : ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
121 13860 : break;
122 : }
123 :
124 78626 : ace->ae_perm = cpu_to_be16(acl_e->e_perm);
125 : }
126 3467 : }
127 :
128 : struct posix_acl *
129 12304016 : xfs_get_acl(struct inode *inode, int type, bool rcu)
130 : {
131 12304016 : struct xfs_inode *ip = XFS_I(inode);
132 12304016 : struct xfs_mount *mp = ip->i_mount;
133 12304016 : struct posix_acl *acl = NULL;
134 12304016 : struct xfs_da_args args = {
135 : .dp = ip,
136 : .attr_filter = XFS_ATTR_ROOT,
137 : .valuelen = XFS_ACL_MAX_SIZE(mp),
138 12304016 : .owner = ip->i_ino,
139 : };
140 12304016 : int error;
141 :
142 12304016 : if (rcu)
143 : return ERR_PTR(-ECHILD);
144 :
145 12303919 : trace_xfs_get_acl(ip);
146 :
147 12303921 : switch (type) {
148 5991474 : case ACL_TYPE_ACCESS:
149 5991474 : args.name = SGI_ACL_FILE;
150 5991474 : break;
151 6312447 : case ACL_TYPE_DEFAULT:
152 6312447 : args.name = SGI_ACL_DEFAULT;
153 6312447 : break;
154 0 : default:
155 0 : BUG();
156 : }
157 12303921 : args.namelen = strlen(args.name);
158 :
159 : /*
160 : * If the attribute doesn't exist make sure we have a negative cache
161 : * entry, for any other error assume it is transient.
162 : */
163 12303921 : error = xfs_attr_get(&args);
164 12303962 : if (!error) {
165 6 : acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
166 : XFS_ACL_MAX_ENTRIES(mp));
167 12303956 : } else if (error != -ENOATTR) {
168 164 : acl = ERR_PTR(error);
169 : }
170 :
171 12303962 : kmem_free(args.value);
172 12303962 : return acl;
173 : }
174 :
175 : int
176 1886938 : __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
177 : {
178 1886938 : struct xfs_inode *ip = XFS_I(inode);
179 1886938 : struct xfs_da_args args = {
180 : .dp = ip,
181 : .attr_filter = XFS_ATTR_ROOT,
182 1886938 : .owner = ip->i_ino,
183 : };
184 1886938 : int error;
185 :
186 1886938 : switch (type) {
187 1860893 : case ACL_TYPE_ACCESS:
188 1860893 : args.name = SGI_ACL_FILE;
189 1860893 : break;
190 26045 : case ACL_TYPE_DEFAULT:
191 26045 : if (!S_ISDIR(inode->i_mode))
192 0 : return acl ? -EACCES : 0;
193 26045 : args.name = SGI_ACL_DEFAULT;
194 26045 : break;
195 : default:
196 : return -EINVAL;
197 : }
198 1886938 : args.namelen = strlen(args.name);
199 :
200 1886938 : if (acl) {
201 4393 : args.valuelen = XFS_ACL_SIZE(acl->a_count);
202 4393 : args.value = kvzalloc(args.valuelen, GFP_KERNEL);
203 3467 : if (!args.value)
204 : return -ENOMEM;
205 3467 : xfs_acl_to_disk(args.value, acl);
206 : }
207 :
208 1886012 : error = xfs_attr_change(&args);
209 1888760 : kmem_free(args.value);
210 :
211 : /*
212 : * If the attribute didn't exist to start with that's fine.
213 : */
214 1888609 : if (!acl && error == -ENOATTR)
215 : error = 0;
216 3473 : if (!error)
217 1888607 : set_cached_acl(inode, type, acl);
218 : return error;
219 : }
220 :
221 : static int
222 1831459 : xfs_acl_set_mode(
223 : struct inode *inode,
224 : umode_t mode)
225 : {
226 1831459 : struct xfs_inode *ip = XFS_I(inode);
227 1831459 : struct xfs_mount *mp = ip->i_mount;
228 1831459 : struct xfs_trans *tp;
229 1831459 : int error;
230 :
231 1831459 : error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
232 1831572 : if (error)
233 : return error;
234 :
235 1831573 : xfs_ilock(ip, XFS_ILOCK_EXCL);
236 1831571 : xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
237 1831571 : inode->i_mode = mode;
238 1831571 : inode->i_ctime = current_time(inode);
239 1831541 : xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
240 :
241 1831567 : if (xfs_has_wsync(mp))
242 0 : xfs_trans_set_sync(tp);
243 1831567 : return xfs_trans_commit(tp);
244 : }
245 :
246 : int
247 1883354 : xfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
248 : struct posix_acl *acl, int type)
249 : {
250 1883354 : umode_t mode;
251 1883354 : bool set_mode = false;
252 1883354 : int error = 0;
253 1883354 : struct inode *inode = d_inode(dentry);
254 :
255 1883354 : if (!acl)
256 34541 : goto set_acl;
257 :
258 1848813 : error = -E2BIG;
259 1848813 : if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
260 : return error;
261 :
262 1848811 : if (type == ACL_TYPE_ACCESS) {
263 1848797 : error = posix_acl_update_mode(idmap, inode, &mode, &acl);
264 1848593 : if (error)
265 : return error;
266 : set_mode = true;
267 : }
268 :
269 14 : set_acl:
270 : /*
271 : * We set the mode after successfully updating the ACL xattr because the
272 : * xattr update can fail at ENOSPC and we don't want to change the mode
273 : * if the ACL update hasn't been applied.
274 : */
275 1883148 : error = __xfs_set_acl(inode, acl, type);
276 1885317 : if (!error && set_mode && mode != inode->i_mode)
277 1831459 : error = xfs_acl_set_mode(inode, mode);
278 : return error;
279 : }
280 :
281 : /*
282 : * Invalidate any cached ACLs if the user has bypassed the ACL interface.
283 : * We don't validate the content whatsoever so it is caller responsibility to
284 : * provide data in valid format and ensure i_mode is consistent.
285 : */
286 : void
287 324607 : xfs_forget_acl(
288 : struct inode *inode,
289 : const char *name)
290 : {
291 324607 : if (!strcmp(name, SGI_ACL_FILE))
292 119410 : forget_cached_acl(inode, ACL_TYPE_ACCESS);
293 205197 : else if (!strcmp(name, SGI_ACL_DEFAULT))
294 119408 : forget_cached_acl(inode, ACL_TYPE_DEFAULT);
295 324605 : }
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