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
mp_pacl_getxattr(FsContext * ctx,const char * path,const char * name,void * value,size_t size)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
mp_pacl_listxattr(FsContext * ctx,const char * path,char * name,void * value,size_t osize)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
mp_pacl_setxattr(FsContext * ctx,const char * path,const char * name,void * value,size_t size,int flags)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
mp_pacl_removexattr(FsContext * ctx,const char * path,const char * name)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 /*
69 * macOS returns ENOATTR (!=ENODATA on macOS), whereas Linux returns
70 * ENODATA (==ENOATTR on Linux), so checking for ENOATTR is fine
71 */
72 if (ret == -1 && errno == ENOATTR) {
73 /*
74 * We don't get ENODATA error when trying to remove a
75 * posix acl that is not present. So don't throw the error
76 * even in case of mapped security model
77 */
78 errno = 0;
79 ret = 0;
80 }
81 return ret;
82 }
83
mp_dacl_getxattr(FsContext * ctx,const char * path,const char * name,void * value,size_t size)84 static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
85 const char *name, void *value, size_t size)
86 {
87 return local_getxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size);
88 }
89
mp_dacl_listxattr(FsContext * ctx,const char * path,char * name,void * value,size_t osize)90 static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
91 char *name, void *value, size_t osize)
92 {
93 ssize_t len = sizeof(ACL_DEFAULT);
94
95 if (!value) {
96 return len;
97 }
98
99 if (osize < len) {
100 errno = ERANGE;
101 return -1;
102 }
103
104 /* len includes the trailing NUL */
105 memcpy(value, ACL_DEFAULT, len);
106 return 0;
107 }
108
mp_dacl_setxattr(FsContext * ctx,const char * path,const char * name,void * value,size_t size,int flags)109 static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
110 void *value, size_t size, int flags)
111 {
112 return local_setxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size,
113 flags);
114 }
115
mp_dacl_removexattr(FsContext * ctx,const char * path,const char * name)116 static int mp_dacl_removexattr(FsContext *ctx,
117 const char *path, const char *name)
118 {
119 int ret;
120
121 ret = local_removexattr_nofollow(ctx, path, MAP_ACL_DEFAULT);
122 /*
123 * macOS returns ENOATTR (!=ENODATA on macOS), whereas Linux returns
124 * ENODATA (==ENOATTR on Linux), so checking for ENOATTR is fine
125 */
126 if (ret == -1 && errno == ENOATTR) {
127 /*
128 * We don't get ENODATA error when trying to remove a
129 * posix acl that is not present. So don't throw the error
130 * even in case of mapped security model
131 */
132 errno = 0;
133 ret = 0;
134 }
135 return ret;
136 }
137
138
139 XattrOperations mapped_pacl_xattr = {
140 .name = "system.posix_acl_access",
141 .getxattr = mp_pacl_getxattr,
142 .setxattr = mp_pacl_setxattr,
143 .listxattr = mp_pacl_listxattr,
144 .removexattr = mp_pacl_removexattr,
145 };
146
147 XattrOperations mapped_dacl_xattr = {
148 .name = "system.posix_acl_default",
149 .getxattr = mp_dacl_getxattr,
150 .setxattr = mp_dacl_setxattr,
151 .listxattr = mp_dacl_listxattr,
152 .removexattr = mp_dacl_removexattr,
153 };
154
155 XattrOperations passthrough_acl_xattr = {
156 .name = "system.posix_acl_",
157 .getxattr = pt_getxattr,
158 .setxattr = pt_setxattr,
159 .listxattr = pt_listxattr,
160 .removexattr = pt_removexattr,
161 };
162
163 XattrOperations none_acl_xattr = {
164 .name = "system.posix_acl_",
165 .getxattr = notsup_getxattr,
166 .setxattr = notsup_setxattr,
167 .listxattr = notsup_listxattr,
168 .removexattr = notsup_removexattr,
169 };
170