xref: /openbmc/qemu/hw/9pfs/9p-xattr-user.c (revision d341d9f3)
1 /*
2  * 9p user. 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 <sys/types.h>
15 #include "9p.h"
16 #include "fsdev/file-op-9p.h"
17 #include "9p-xattr.h"
18 
19 
20 static ssize_t mp_user_getxattr(FsContext *ctx, const char *path,
21                                 const char *name, void *value, size_t size)
22 {
23     char *buffer;
24     ssize_t ret;
25 
26     if (strncmp(name, "user.virtfs.", 12) == 0) {
27         /*
28          * Don't allow fetch of user.virtfs namesapce
29          * in case of mapped security
30          */
31         errno = ENOATTR;
32         return -1;
33     }
34     buffer = rpath(ctx, path);
35     ret = lgetxattr(buffer, name, value, size);
36     g_free(buffer);
37     return ret;
38 }
39 
40 static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,
41                                  char *name, void *value, size_t size)
42 {
43     int name_size = strlen(name) + 1;
44     if (strncmp(name, "user.virtfs.", 12) == 0) {
45 
46         /*  check if it is a mapped posix acl */
47         if (strncmp(name, "user.virtfs.system.posix_acl_", 29) == 0) {
48             /* adjust the name and size */
49             name += 12;
50             name_size -= 12;
51         } else {
52             /*
53              * Don't allow fetch of user.virtfs namesapce
54              * in case of mapped security
55              */
56             return 0;
57         }
58     }
59     if (!value) {
60         return name_size;
61     }
62 
63     if (size < name_size) {
64         errno = ERANGE;
65         return -1;
66     }
67 
68     /* name_size includes the trailing NUL. */
69     memcpy(value, name, name_size);
70     return name_size;
71 }
72 
73 static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name,
74                             void *value, size_t size, int flags)
75 {
76     char *buffer;
77     int ret;
78 
79     if (strncmp(name, "user.virtfs.", 12) == 0) {
80         /*
81          * Don't allow fetch of user.virtfs namesapce
82          * in case of mapped security
83          */
84         errno = EACCES;
85         return -1;
86     }
87     buffer = rpath(ctx, path);
88     ret = lsetxattr(buffer, name, value, size, flags);
89     g_free(buffer);
90     return ret;
91 }
92 
93 static int mp_user_removexattr(FsContext *ctx,
94                                const char *path, const char *name)
95 {
96     char *buffer;
97     int ret;
98 
99     if (strncmp(name, "user.virtfs.", 12) == 0) {
100         /*
101          * Don't allow fetch of user.virtfs namesapce
102          * in case of mapped security
103          */
104         errno = EACCES;
105         return -1;
106     }
107     buffer = rpath(ctx, path);
108     ret = lremovexattr(buffer, name);
109     g_free(buffer);
110     return ret;
111 }
112 
113 XattrOperations mapped_user_xattr = {
114     .name = "user.",
115     .getxattr = mp_user_getxattr,
116     .setxattr = mp_user_setxattr,
117     .listxattr = mp_user_listxattr,
118     .removexattr = mp_user_removexattr,
119 };
120 
121 XattrOperations passthrough_user_xattr = {
122     .name = "user.",
123     .getxattr = pt_getxattr,
124     .setxattr = pt_setxattr,
125     .listxattr = pt_listxattr,
126     .removexattr = pt_removexattr,
127 };
128