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