Merge remote-tracking branch 'remotes/rth/tags/pull-arm-20211021' into staging
[qemu.git] / hw / 9pfs / 9p-posix-acl.c
1 /*
2 * 9p system.posix* xattr callback
3 *
4 * Copyright IBM, Corp. 2010
5 *
6 * Authors:
7 * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
11 *
12 */
13
14 /*
15 * Not so fast! You might want to read the 9p developer docs first:
16 * https://wiki.qemu.org/Documentation/9p
17 */
18
19 #include "qemu/osdep.h"
20 #include "qemu/xattr.h"
21 #include "9p.h"
22 #include "fsdev/file-op-9p.h"
23 #include "9p-xattr.h"
24
25 #define MAP_ACL_ACCESS "user.virtfs.system.posix_acl_access"
26 #define MAP_ACL_DEFAULT "user.virtfs.system.posix_acl_default"
27 #define ACL_ACCESS "system.posix_acl_access"
28 #define ACL_DEFAULT "system.posix_acl_default"
29
30 static ssize_t mp_pacl_getxattr(FsContext *ctx, const char *path,
31 const char *name, void *value, size_t size)
32 {
33 return local_getxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size);
34 }
35
36 static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path,
37 char *name, void *value, size_t osize)
38 {
39 ssize_t len = sizeof(ACL_ACCESS);
40
41 if (!value) {
42 return len;
43 }
44
45 if (osize < len) {
46 errno = ERANGE;
47 return -1;
48 }
49
50 /* len includes the trailing NUL */
51 memcpy(value, ACL_ACCESS, len);
52 return 0;
53 }
54
55 static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name,
56 void *value, size_t size, int flags)
57 {
58 return local_setxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size,
59 flags);
60 }
61
62 static int mp_pacl_removexattr(FsContext *ctx,
63 const char *path, const char *name)
64 {
65 int ret;
66
67 ret = local_removexattr_nofollow(ctx, path, MAP_ACL_ACCESS);
68 if (ret == -1 && errno == ENODATA) {
69 /*
70 * We don't get ENODATA error when trying to remove a
71 * posix acl that is not present. So don't throw the error
72 * even in case of mapped security model
73 */
74 errno = 0;
75 ret = 0;
76 }
77 return ret;
78 }
79
80 static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
81 const char *name, void *value, size_t size)
82 {
83 return local_getxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size);
84 }
85
86 static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
87 char *name, void *value, size_t osize)
88 {
89 ssize_t len = sizeof(ACL_DEFAULT);
90
91 if (!value) {
92 return len;
93 }
94
95 if (osize < len) {
96 errno = ERANGE;
97 return -1;
98 }
99
100 /* len includes the trailing NUL */
101 memcpy(value, ACL_DEFAULT, len);
102 return 0;
103 }
104
105 static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
106 void *value, size_t size, int flags)
107 {
108 return local_setxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size,
109 flags);
110 }
111
112 static int mp_dacl_removexattr(FsContext *ctx,
113 const char *path, const char *name)
114 {
115 int ret;
116
117 ret = local_removexattr_nofollow(ctx, path, MAP_ACL_DEFAULT);
118 if (ret == -1 && errno == ENODATA) {
119 /*
120 * We don't get ENODATA error when trying to remove a
121 * posix acl that is not present. So don't throw the error
122 * even in case of mapped security model
123 */
124 errno = 0;
125 ret = 0;
126 }
127 return ret;
128 }
129
130
131 XattrOperations mapped_pacl_xattr = {
132 .name = "system.posix_acl_access",
133 .getxattr = mp_pacl_getxattr,
134 .setxattr = mp_pacl_setxattr,
135 .listxattr = mp_pacl_listxattr,
136 .removexattr = mp_pacl_removexattr,
137 };
138
139 XattrOperations mapped_dacl_xattr = {
140 .name = "system.posix_acl_default",
141 .getxattr = mp_dacl_getxattr,
142 .setxattr = mp_dacl_setxattr,
143 .listxattr = mp_dacl_listxattr,
144 .removexattr = mp_dacl_removexattr,
145 };
146
147 XattrOperations passthrough_acl_xattr = {
148 .name = "system.posix_acl_",
149 .getxattr = pt_getxattr,
150 .setxattr = pt_setxattr,
151 .listxattr = pt_listxattr,
152 .removexattr = pt_removexattr,
153 };
154
155 XattrOperations none_acl_xattr = {
156 .name = "system.posix_acl_",
157 .getxattr = notsup_getxattr,
158 .setxattr = notsup_setxattr,
159 .listxattr = notsup_listxattr,
160 .removexattr = notsup_removexattr,
161 };