xref: /openbmc/qemu/hw/9pfs/9p-posix-acl.c (revision 9dea2df8)
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 #include "qemu/osdep.h"
15 #include "qemu/xattr.h"
16 #include "9p.h"
17 #include "fsdev/file-op-9p.h"
18 #include "9p-xattr.h"
19 
20 #define MAP_ACL_ACCESS "user.virtfs.system.posix_acl_access"
21 #define MAP_ACL_DEFAULT "user.virtfs.system.posix_acl_default"
22 #define ACL_ACCESS "system.posix_acl_access"
23 #define ACL_DEFAULT "system.posix_acl_default"
24 
25 static ssize_t mp_pacl_getxattr(FsContext *ctx, const char *path,
26                                 const char *name, void *value, size_t size)
27 {
28     return local_getxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size);
29 }
30 
31 static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path,
32                                  char *name, void *value, size_t osize)
33 {
34     ssize_t len = sizeof(ACL_ACCESS);
35 
36     if (!value) {
37         return len;
38     }
39 
40     if (osize < len) {
41         errno = ERANGE;
42         return -1;
43     }
44 
45     /* len includes the trailing NUL */
46     memcpy(value, ACL_ACCESS, len);
47     return 0;
48 }
49 
50 static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name,
51                             void *value, size_t size, int flags)
52 {
53     return local_setxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size,
54                                    flags);
55 }
56 
57 static int mp_pacl_removexattr(FsContext *ctx,
58                                const char *path, const char *name)
59 {
60     int ret;
61 
62     ret = local_removexattr_nofollow(ctx, path, MAP_ACL_ACCESS);
63     if (ret == -1 && errno == ENODATA) {
64         /*
65          * We don't get ENODATA error when trying to remove a
66          * posix acl that is not present. So don't throw the error
67          * even in case of mapped security model
68          */
69         errno = 0;
70         ret = 0;
71     }
72     return ret;
73 }
74 
75 static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
76                                 const char *name, void *value, size_t size)
77 {
78     return local_getxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size);
79 }
80 
81 static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
82                                  char *name, void *value, size_t osize)
83 {
84     ssize_t len = sizeof(ACL_DEFAULT);
85 
86     if (!value) {
87         return len;
88     }
89 
90     if (osize < len) {
91         errno = ERANGE;
92         return -1;
93     }
94 
95     /* len includes the trailing NUL */
96     memcpy(value, ACL_DEFAULT, len);
97     return 0;
98 }
99 
100 static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
101                             void *value, size_t size, int flags)
102 {
103     return local_setxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size,
104                                    flags);
105 }
106 
107 static int mp_dacl_removexattr(FsContext *ctx,
108                                const char *path, const char *name)
109 {
110     int ret;
111 
112     ret = local_removexattr_nofollow(ctx, path, MAP_ACL_DEFAULT);
113     if (ret == -1 && errno == ENODATA) {
114         /*
115          * We don't get ENODATA error when trying to remove a
116          * posix acl that is not present. So don't throw the error
117          * even in case of mapped security model
118          */
119         errno = 0;
120         ret = 0;
121     }
122     return ret;
123 }
124 
125 
126 XattrOperations mapped_pacl_xattr = {
127     .name = "system.posix_acl_access",
128     .getxattr = mp_pacl_getxattr,
129     .setxattr = mp_pacl_setxattr,
130     .listxattr = mp_pacl_listxattr,
131     .removexattr = mp_pacl_removexattr,
132 };
133 
134 XattrOperations mapped_dacl_xattr = {
135     .name = "system.posix_acl_default",
136     .getxattr = mp_dacl_getxattr,
137     .setxattr = mp_dacl_setxattr,
138     .listxattr = mp_dacl_listxattr,
139     .removexattr = mp_dacl_removexattr,
140 };
141 
142 XattrOperations passthrough_acl_xattr = {
143     .name = "system.posix_acl_",
144     .getxattr = pt_getxattr,
145     .setxattr = pt_setxattr,
146     .listxattr = pt_listxattr,
147     .removexattr = pt_removexattr,
148 };
149 
150 XattrOperations none_acl_xattr = {
151     .name = "system.posix_acl_",
152     .getxattr = notsup_getxattr,
153     .setxattr = notsup_setxattr,
154     .listxattr = notsup_listxattr,
155     .removexattr = notsup_removexattr,
156 };
157