Commit | Line | Data |
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f0c8bd16 AG |
1 | /* |
2 | * fs/generic_acl.c | |
3 | * | |
4 | * (C) 2005 Andreas Gruenbacher <agruen@suse.de> | |
5 | * | |
6 | * This file is released under the GPL. | |
7 | */ | |
8 | ||
9 | #include <linux/sched.h> | |
10 | #include <linux/fs.h> | |
11 | #include <linux/generic_acl.h> | |
12 | ||
13 | /** | |
14 | * generic_acl_list - Generic xattr_handler->list() operation | |
15 | * @ops: Filesystem specific getacl and setacl callbacks | |
16 | */ | |
17 | size_t | |
18 | generic_acl_list(struct inode *inode, struct generic_acl_operations *ops, | |
19 | int type, char *list, size_t list_size) | |
20 | { | |
21 | struct posix_acl *acl; | |
22 | const char *name; | |
23 | size_t size; | |
24 | ||
25 | acl = ops->getacl(inode, type); | |
26 | if (!acl) | |
27 | return 0; | |
28 | posix_acl_release(acl); | |
29 | ||
30 | switch(type) { | |
31 | case ACL_TYPE_ACCESS: | |
32 | name = POSIX_ACL_XATTR_ACCESS; | |
33 | break; | |
34 | ||
35 | case ACL_TYPE_DEFAULT: | |
36 | name = POSIX_ACL_XATTR_DEFAULT; | |
37 | break; | |
38 | ||
39 | default: | |
40 | return 0; | |
41 | } | |
42 | size = strlen(name) + 1; | |
43 | if (list && size <= list_size) | |
44 | memcpy(list, name, size); | |
45 | return size; | |
46 | } | |
47 | ||
48 | /** | |
49 | * generic_acl_get - Generic xattr_handler->get() operation | |
50 | * @ops: Filesystem specific getacl and setacl callbacks | |
51 | */ | |
52 | int | |
53 | generic_acl_get(struct inode *inode, struct generic_acl_operations *ops, | |
54 | int type, void *buffer, size_t size) | |
55 | { | |
56 | struct posix_acl *acl; | |
57 | int error; | |
58 | ||
59 | acl = ops->getacl(inode, type); | |
60 | if (!acl) | |
61 | return -ENODATA; | |
62 | error = posix_acl_to_xattr(acl, buffer, size); | |
63 | posix_acl_release(acl); | |
64 | ||
65 | return error; | |
66 | } | |
67 | ||
68 | /** | |
69 | * generic_acl_set - Generic xattr_handler->set() operation | |
70 | * @ops: Filesystem specific getacl and setacl callbacks | |
71 | */ | |
72 | int | |
73 | generic_acl_set(struct inode *inode, struct generic_acl_operations *ops, | |
74 | int type, const void *value, size_t size) | |
75 | { | |
76 | struct posix_acl *acl = NULL; | |
77 | int error; | |
78 | ||
79 | if (S_ISLNK(inode->i_mode)) | |
80 | return -EOPNOTSUPP; | |
3bd858ab | 81 | if (!is_owner_or_cap(inode)) |
f0c8bd16 AG |
82 | return -EPERM; |
83 | if (value) { | |
84 | acl = posix_acl_from_xattr(value, size); | |
85 | if (IS_ERR(acl)) | |
86 | return PTR_ERR(acl); | |
87 | } | |
88 | if (acl) { | |
89 | mode_t mode; | |
90 | ||
91 | error = posix_acl_valid(acl); | |
92 | if (error) | |
93 | goto failed; | |
94 | switch(type) { | |
95 | case ACL_TYPE_ACCESS: | |
96 | mode = inode->i_mode; | |
97 | error = posix_acl_equiv_mode(acl, &mode); | |
98 | if (error < 0) | |
99 | goto failed; | |
100 | inode->i_mode = mode; | |
101 | if (error == 0) { | |
102 | posix_acl_release(acl); | |
103 | acl = NULL; | |
104 | } | |
105 | break; | |
106 | ||
107 | case ACL_TYPE_DEFAULT: | |
108 | if (!S_ISDIR(inode->i_mode)) { | |
109 | error = -EINVAL; | |
110 | goto failed; | |
111 | } | |
112 | break; | |
113 | } | |
114 | } | |
115 | ops->setacl(inode, type, acl); | |
116 | error = 0; | |
117 | failed: | |
118 | posix_acl_release(acl); | |
119 | return error; | |
120 | } | |
121 | ||
122 | /** | |
123 | * generic_acl_init - Take care of acl inheritance at @inode create time | |
124 | * @ops: Filesystem specific getacl and setacl callbacks | |
125 | * | |
126 | * Files created inside a directory with a default ACL inherit the | |
127 | * directory's default ACL. | |
128 | */ | |
129 | int | |
130 | generic_acl_init(struct inode *inode, struct inode *dir, | |
131 | struct generic_acl_operations *ops) | |
132 | { | |
133 | struct posix_acl *acl = NULL; | |
134 | mode_t mode = inode->i_mode; | |
135 | int error; | |
136 | ||
137 | inode->i_mode = mode & ~current->fs->umask; | |
138 | if (!S_ISLNK(inode->i_mode)) | |
139 | acl = ops->getacl(dir, ACL_TYPE_DEFAULT); | |
140 | if (acl) { | |
141 | struct posix_acl *clone; | |
142 | ||
143 | if (S_ISDIR(inode->i_mode)) { | |
144 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
145 | error = -ENOMEM; | |
146 | if (!clone) | |
147 | goto cleanup; | |
148 | ops->setacl(inode, ACL_TYPE_DEFAULT, clone); | |
149 | posix_acl_release(clone); | |
150 | } | |
151 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
152 | error = -ENOMEM; | |
153 | if (!clone) | |
154 | goto cleanup; | |
155 | error = posix_acl_create_masq(clone, &mode); | |
156 | if (error >= 0) { | |
157 | inode->i_mode = mode; | |
158 | if (error > 0) | |
159 | ops->setacl(inode, ACL_TYPE_ACCESS, clone); | |
160 | } | |
161 | posix_acl_release(clone); | |
162 | } | |
163 | error = 0; | |
164 | ||
165 | cleanup: | |
166 | posix_acl_release(acl); | |
167 | return error; | |
168 | } | |
169 | ||
170 | /** | |
171 | * generic_acl_chmod - change the access acl of @inode upon chmod() | |
172 | * @ops: FIlesystem specific getacl and setacl callbacks | |
173 | * | |
174 | * A chmod also changes the permissions of the owner, group/mask, and | |
175 | * other ACL entries. | |
176 | */ | |
177 | int | |
178 | generic_acl_chmod(struct inode *inode, struct generic_acl_operations *ops) | |
179 | { | |
180 | struct posix_acl *acl, *clone; | |
181 | int error = 0; | |
182 | ||
183 | if (S_ISLNK(inode->i_mode)) | |
184 | return -EOPNOTSUPP; | |
185 | acl = ops->getacl(inode, ACL_TYPE_ACCESS); | |
186 | if (acl) { | |
187 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
188 | posix_acl_release(acl); | |
189 | if (!clone) | |
190 | return -ENOMEM; | |
191 | error = posix_acl_chmod_masq(clone, inode->i_mode); | |
192 | if (!error) | |
193 | ops->setacl(inode, ACL_TYPE_ACCESS, clone); | |
194 | posix_acl_release(clone); | |
195 | } | |
196 | return error; | |
197 | } |