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Linux kernel mirror (for testing)
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2008 Christoph Hellwig.
4 * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
5 */
6
7#include "xfs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_da_format.h"
12#include "xfs_trans_resv.h"
13#include "xfs_mount.h"
14#include "xfs_inode.h"
15#include "xfs_attr.h"
16#include "xfs_acl.h"
17#include "xfs_da_btree.h"
18
19#include <linux/posix_acl_xattr.h>
20
21
22static int
23xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
24 struct inode *inode, const char *name, void *value, size_t size)
25{
26 struct xfs_da_args args = {
27 .dp = XFS_I(inode),
28 .attr_filter = handler->flags,
29 .name = name,
30 .namelen = strlen(name),
31 .value = value,
32 .valuelen = size,
33 };
34 int error;
35
36 error = xfs_attr_get(&args);
37 if (error)
38 return error;
39 return args.valuelen;
40}
41
42static int
43xfs_xattr_set(const struct xattr_handler *handler,
44 struct user_namespace *mnt_userns, struct dentry *unused,
45 struct inode *inode, const char *name, const void *value,
46 size_t size, int flags)
47{
48 struct xfs_da_args args = {
49 .dp = XFS_I(inode),
50 .attr_filter = handler->flags,
51 .attr_flags = flags,
52 .name = name,
53 .namelen = strlen(name),
54 .value = (void *)value,
55 .valuelen = size,
56 };
57 int error;
58
59 error = xfs_attr_set(&args);
60 if (!error && (handler->flags & XFS_ATTR_ROOT))
61 xfs_forget_acl(inode, name);
62 return error;
63}
64
65static const struct xattr_handler xfs_xattr_user_handler = {
66 .prefix = XATTR_USER_PREFIX,
67 .flags = 0, /* no flags implies user namespace */
68 .get = xfs_xattr_get,
69 .set = xfs_xattr_set,
70};
71
72static const struct xattr_handler xfs_xattr_trusted_handler = {
73 .prefix = XATTR_TRUSTED_PREFIX,
74 .flags = XFS_ATTR_ROOT,
75 .get = xfs_xattr_get,
76 .set = xfs_xattr_set,
77};
78
79static const struct xattr_handler xfs_xattr_security_handler = {
80 .prefix = XATTR_SECURITY_PREFIX,
81 .flags = XFS_ATTR_SECURE,
82 .get = xfs_xattr_get,
83 .set = xfs_xattr_set,
84};
85
86const struct xattr_handler *xfs_xattr_handlers[] = {
87 &xfs_xattr_user_handler,
88 &xfs_xattr_trusted_handler,
89 &xfs_xattr_security_handler,
90#ifdef CONFIG_XFS_POSIX_ACL
91 &posix_acl_access_xattr_handler,
92 &posix_acl_default_xattr_handler,
93#endif
94 NULL
95};
96
97static void
98__xfs_xattr_put_listent(
99 struct xfs_attr_list_context *context,
100 char *prefix,
101 int prefix_len,
102 unsigned char *name,
103 int namelen)
104{
105 char *offset;
106 int arraytop;
107
108 if (context->count < 0 || context->seen_enough)
109 return;
110
111 if (!context->buffer)
112 goto compute_size;
113
114 arraytop = context->count + prefix_len + namelen + 1;
115 if (arraytop > context->firstu) {
116 context->count = -1; /* insufficient space */
117 context->seen_enough = 1;
118 return;
119 }
120 offset = context->buffer + context->count;
121 strncpy(offset, prefix, prefix_len);
122 offset += prefix_len;
123 strncpy(offset, (char *)name, namelen); /* real name */
124 offset += namelen;
125 *offset = '\0';
126
127compute_size:
128 context->count += prefix_len + namelen + 1;
129 return;
130}
131
132static void
133xfs_xattr_put_listent(
134 struct xfs_attr_list_context *context,
135 int flags,
136 unsigned char *name,
137 int namelen,
138 int valuelen)
139{
140 char *prefix;
141 int prefix_len;
142
143 ASSERT(context->count >= 0);
144
145 if (flags & XFS_ATTR_ROOT) {
146#ifdef CONFIG_XFS_POSIX_ACL
147 if (namelen == SGI_ACL_FILE_SIZE &&
148 strncmp(name, SGI_ACL_FILE,
149 SGI_ACL_FILE_SIZE) == 0) {
150 __xfs_xattr_put_listent(
151 context, XATTR_SYSTEM_PREFIX,
152 XATTR_SYSTEM_PREFIX_LEN,
153 XATTR_POSIX_ACL_ACCESS,
154 strlen(XATTR_POSIX_ACL_ACCESS));
155 } else if (namelen == SGI_ACL_DEFAULT_SIZE &&
156 strncmp(name, SGI_ACL_DEFAULT,
157 SGI_ACL_DEFAULT_SIZE) == 0) {
158 __xfs_xattr_put_listent(
159 context, XATTR_SYSTEM_PREFIX,
160 XATTR_SYSTEM_PREFIX_LEN,
161 XATTR_POSIX_ACL_DEFAULT,
162 strlen(XATTR_POSIX_ACL_DEFAULT));
163 }
164#endif
165
166 /*
167 * Only show root namespace entries if we are actually allowed to
168 * see them.
169 */
170 if (!capable(CAP_SYS_ADMIN))
171 return;
172
173 prefix = XATTR_TRUSTED_PREFIX;
174 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
175 } else if (flags & XFS_ATTR_SECURE) {
176 prefix = XATTR_SECURITY_PREFIX;
177 prefix_len = XATTR_SECURITY_PREFIX_LEN;
178 } else {
179 prefix = XATTR_USER_PREFIX;
180 prefix_len = XATTR_USER_PREFIX_LEN;
181 }
182
183 __xfs_xattr_put_listent(context, prefix, prefix_len, name,
184 namelen);
185 return;
186}
187
188ssize_t
189xfs_vn_listxattr(
190 struct dentry *dentry,
191 char *data,
192 size_t size)
193{
194 struct xfs_attr_list_context context;
195 struct inode *inode = d_inode(dentry);
196 int error;
197
198 /*
199 * First read the regular on-disk attributes.
200 */
201 memset(&context, 0, sizeof(context));
202 context.dp = XFS_I(inode);
203 context.resynch = 1;
204 context.buffer = size ? data : NULL;
205 context.bufsize = size;
206 context.firstu = context.bufsize;
207 context.put_listent = xfs_xattr_put_listent;
208
209 error = xfs_attr_list(&context);
210 if (error)
211 return error;
212 if (context.count < 0)
213 return -ERANGE;
214
215 return context.count;
216}