xref: /openbmc/qemu/hw/9pfs/9p-xattr.c (revision 9c4218e9)
1 /*
2  * 9p  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 "9p.h"
16 #include "fsdev/file-op-9p.h"
17 #include "9p-xattr.h"
18 
19 
20 static XattrOperations *get_xattr_operations(XattrOperations **h,
21                                              const char *name)
22 {
23     XattrOperations *xops;
24     for (xops = *(h)++; xops != NULL; xops = *(h)++) {
25         if (!strncmp(name, xops->name, strlen(xops->name))) {
26             return xops;
27         }
28     }
29     return NULL;
30 }
31 
32 ssize_t v9fs_get_xattr(FsContext *ctx, const char *path,
33                        const char *name, void *value, size_t size)
34 {
35     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
36     if (xops) {
37         return xops->getxattr(ctx, path, name, value, size);
38     }
39     errno = EOPNOTSUPP;
40     return -1;
41 }
42 
43 ssize_t pt_listxattr(FsContext *ctx, const char *path,
44                      char *name, void *value, size_t size)
45 {
46     int name_size = strlen(name) + 1;
47     if (!value) {
48         return name_size;
49     }
50 
51     if (size < name_size) {
52         errno = ERANGE;
53         return -1;
54     }
55 
56     /* no need for strncpy: name_size is strlen(name)+1 */
57     memcpy(value, name, name_size);
58     return name_size;
59 }
60 
61 
62 /*
63  * Get the list and pass to each layer to find out whether
64  * to send the data or not
65  */
66 ssize_t v9fs_list_xattr(FsContext *ctx, const char *path,
67                         void *value, size_t vsize)
68 {
69     ssize_t size = 0;
70     char *buffer;
71     void *ovalue = value;
72     XattrOperations *xops;
73     char *orig_value, *orig_value_start;
74     ssize_t xattr_len, parsed_len = 0, attr_len;
75 
76     /* Get the actual len */
77     buffer = rpath(ctx, path);
78     xattr_len = llistxattr(buffer, value, 0);
79     if (xattr_len <= 0) {
80         g_free(buffer);
81         return xattr_len;
82     }
83 
84     /* Now fetch the xattr and find the actual size */
85     orig_value = g_malloc(xattr_len);
86     xattr_len = llistxattr(buffer, orig_value, xattr_len);
87     g_free(buffer);
88 
89     /* store the orig pointer */
90     orig_value_start = orig_value;
91     while (xattr_len > parsed_len) {
92         xops = get_xattr_operations(ctx->xops, orig_value);
93         if (!xops) {
94             goto next_entry;
95         }
96 
97         if (!value) {
98             size += xops->listxattr(ctx, path, orig_value, value, vsize);
99         } else {
100             size = xops->listxattr(ctx, path, orig_value, value, vsize);
101             if (size < 0) {
102                 goto err_out;
103             }
104             value += size;
105             vsize -= size;
106         }
107 next_entry:
108         /* Got the next entry */
109         attr_len = strlen(orig_value) + 1;
110         parsed_len += attr_len;
111         orig_value += attr_len;
112     }
113     if (value) {
114         size = value - ovalue;
115     }
116 
117 err_out:
118     g_free(orig_value_start);
119     return size;
120 }
121 
122 int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name,
123                    void *value, size_t size, int flags)
124 {
125     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
126     if (xops) {
127         return xops->setxattr(ctx, path, name, value, size, flags);
128     }
129     errno = EOPNOTSUPP;
130     return -1;
131 
132 }
133 
134 int v9fs_remove_xattr(FsContext *ctx,
135                       const char *path, const char *name)
136 {
137     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
138     if (xops) {
139         return xops->removexattr(ctx, path, name);
140     }
141     errno = EOPNOTSUPP;
142     return -1;
143 
144 }
145 
146 XattrOperations *mapped_xattr_ops[] = {
147     &mapped_user_xattr,
148     &mapped_pacl_xattr,
149     &mapped_dacl_xattr,
150     NULL,
151 };
152 
153 XattrOperations *passthrough_xattr_ops[] = {
154     &passthrough_user_xattr,
155     &passthrough_acl_xattr,
156     NULL,
157 };
158 
159 /* for .user none model should be same as passthrough */
160 XattrOperations *none_xattr_ops[] = {
161     &passthrough_user_xattr,
162     &none_acl_xattr,
163     NULL,
164 };
165