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 3403 : xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
99 : {
100 3403 : const struct posix_acl_entry *acl_e;
101 3403 : struct xfs_acl_entry *ace;
102 3403 : int i;
103 :
104 3403 : aclp->acl_cnt = cpu_to_be32(acl->a_count);
105 42396 : for (i = 0; i < acl->a_count; i++) {
106 38993 : ace = &aclp->acl_entry[i];
107 38993 : acl_e = &acl->a_entries[i];
108 :
109 38993 : ace->ae_tag = cpu_to_be32(acl_e->e_tag);
110 38993 : switch (acl_e->e_tag) {
111 25379 : case ACL_USER:
112 25379 : ace->ae_id = cpu_to_be32(
113 : from_kuid(&init_user_ns, acl_e->e_uid));
114 25379 : 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 13604 : default:
120 13604 : ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
121 13604 : break;
122 : }
123 :
124 77986 : ace->ae_perm = cpu_to_be16(acl_e->e_perm);
125 : }
126 3403 : }
127 :
128 : struct posix_acl *
129 1503663 : xfs_get_acl(struct inode *inode, int type, bool rcu)
130 : {
131 1503663 : struct xfs_inode *ip = XFS_I(inode);
132 1503663 : struct xfs_mount *mp = ip->i_mount;
133 1503663 : struct posix_acl *acl = NULL;
134 1503663 : struct xfs_da_args args = {
135 : .dp = ip,
136 : .attr_filter = XFS_ATTR_ROOT,
137 : .valuelen = XFS_ACL_MAX_SIZE(mp),
138 : };
139 1503663 : int error;
140 :
141 1503663 : if (rcu)
142 : return ERR_PTR(-ECHILD);
143 :
144 1503661 : trace_xfs_get_acl(ip);
145 :
146 1503660 : switch (type) {
147 1217711 : case ACL_TYPE_ACCESS:
148 1217711 : args.name = SGI_ACL_FILE;
149 1217711 : break;
150 285949 : case ACL_TYPE_DEFAULT:
151 285949 : args.name = SGI_ACL_DEFAULT;
152 285949 : break;
153 0 : default:
154 0 : BUG();
155 : }
156 1503660 : args.namelen = strlen(args.name);
157 :
158 : /*
159 : * If the attribute doesn't exist make sure we have a negative cache
160 : * entry, for any other error assume it is transient.
161 : */
162 1503660 : error = xfs_attr_get(&args);
163 1503662 : if (!error) {
164 6 : acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
165 : XFS_ACL_MAX_ENTRIES(mp));
166 1503656 : } else if (error != -ENOATTR) {
167 97 : acl = ERR_PTR(error);
168 : }
169 :
170 1503662 : kmem_free(args.value);
171 1503662 : return acl;
172 : }
173 :
174 : int
175 1887916 : __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
176 : {
177 1887916 : struct xfs_inode *ip = XFS_I(inode);
178 1887916 : struct xfs_da_args args = {
179 : .dp = ip,
180 : .attr_filter = XFS_ATTR_ROOT,
181 : };
182 1887916 : int error;
183 :
184 1887916 : switch (type) {
185 1862244 : case ACL_TYPE_ACCESS:
186 1862244 : args.name = SGI_ACL_FILE;
187 1862244 : break;
188 25672 : case ACL_TYPE_DEFAULT:
189 25672 : if (!S_ISDIR(inode->i_mode))
190 0 : return acl ? -EACCES : 0;
191 25672 : args.name = SGI_ACL_DEFAULT;
192 25672 : break;
193 : default:
194 : return -EINVAL;
195 : }
196 1887916 : args.namelen = strlen(args.name);
197 :
198 1887916 : if (acl) {
199 3407 : args.valuelen = XFS_ACL_SIZE(acl->a_count);
200 3407 : args.value = kvzalloc(args.valuelen, GFP_KERNEL);
201 3403 : if (!args.value)
202 : return -ENOMEM;
203 3403 : xfs_acl_to_disk(args.value, acl);
204 : }
205 :
206 1887912 : error = xfs_attr_change(&args);
207 1887918 : kmem_free(args.value);
208 :
209 : /*
210 : * If the attribute didn't exist to start with that's fine.
211 : */
212 1887919 : if (!acl && error == -ENOATTR)
213 : error = 0;
214 3409 : if (!error)
215 1887917 : set_cached_acl(inode, type, acl);
216 : return error;
217 : }
218 :
219 : static int
220 1831195 : xfs_acl_set_mode(
221 : struct inode *inode,
222 : umode_t mode)
223 : {
224 1831195 : struct xfs_inode *ip = XFS_I(inode);
225 1831195 : struct xfs_mount *mp = ip->i_mount;
226 1831195 : struct xfs_trans *tp;
227 1831195 : int error;
228 :
229 1831195 : error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
230 1831192 : if (error)
231 : return error;
232 :
233 1831190 : xfs_ilock(ip, XFS_ILOCK_EXCL);
234 1831195 : xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
235 1831194 : inode->i_mode = mode;
236 1831194 : inode->i_ctime = current_time(inode);
237 1831195 : xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
238 :
239 1831195 : if (xfs_has_wsync(mp))
240 0 : xfs_trans_set_sync(tp);
241 1831195 : return xfs_trans_commit(tp);
242 : }
243 :
244 : int
245 1884537 : xfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
246 : struct posix_acl *acl, int type)
247 : {
248 1884537 : umode_t mode;
249 1884537 : bool set_mode = false;
250 1884537 : int error = 0;
251 1884537 : struct inode *inode = d_inode(dentry);
252 :
253 1884537 : if (!acl)
254 33848 : goto set_acl;
255 :
256 1850689 : error = -E2BIG;
257 1850689 : if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
258 : return error;
259 :
260 1850687 : if (type == ACL_TYPE_ACCESS) {
261 1850673 : error = posix_acl_update_mode(idmap, inode, &mode, &acl);
262 1850715 : if (error)
263 : return error;
264 : set_mode = true;
265 : }
266 :
267 14 : set_acl:
268 : /*
269 : * We set the mode after successfully updating the ACL xattr because the
270 : * xattr update can fail at ENOSPC and we don't want to change the mode
271 : * if the ACL update hasn't been applied.
272 : */
273 1884577 : error = __xfs_set_acl(inode, acl, type);
274 1884461 : if (!error && set_mode && mode != inode->i_mode)
275 1831195 : error = xfs_acl_set_mode(inode, mode);
276 : return error;
277 : }
278 :
279 : /*
280 : * Invalidate any cached ACLs if the user has bypassed the ACL interface.
281 : * We don't validate the content whatsoever so it is caller responsibility to
282 : * provide data in valid format and ensure i_mode is consistent.
283 : */
284 : void
285 83152 : xfs_forget_acl(
286 : struct inode *inode,
287 : const char *name)
288 : {
289 83152 : if (!strcmp(name, SGI_ACL_FILE))
290 2 : forget_cached_acl(inode, ACL_TYPE_ACCESS);
291 83150 : else if (!strcmp(name, SGI_ACL_DEFAULT))
292 0 : forget_cached_acl(inode, ACL_TYPE_DEFAULT);
293 83152 : }
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