xref: /openbmc/qemu/hw/9pfs/9p-xattr.c (revision d341d9f3)
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 "9p.h"
15 #include "fsdev/file-op-9p.h"
16 #include "9p-xattr.h"
17 
18 
19 static XattrOperations *get_xattr_operations(XattrOperations **h,
20                                              const char *name)
21 {
22     XattrOperations *xops;
23     for (xops = *(h)++; xops != NULL; xops = *(h)++) {
24         if (!strncmp(name, xops->name, strlen(xops->name))) {
25             return xops;
26         }
27     }
28     return NULL;
29 }
30 
31 ssize_t v9fs_get_xattr(FsContext *ctx, const char *path,
32                        const char *name, void *value, size_t size)
33 {
34     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
35     if (xops) {
36         return xops->getxattr(ctx, path, name, value, size);
37     }
38     errno = EOPNOTSUPP;
39     return -1;
40 }
41 
42 ssize_t pt_listxattr(FsContext *ctx, const char *path,
43                      char *name, void *value, size_t size)
44 {
45     int name_size = strlen(name) + 1;
46     if (!value) {
47         return name_size;
48     }
49 
50     if (size < name_size) {
51         errno = ERANGE;
52         return -1;
53     }
54 
55     /* no need for strncpy: name_size is strlen(name)+1 */
56     memcpy(value, name, name_size);
57     return name_size;
58 }
59 
60 
61 /*
62  * Get the list and pass to each layer to find out whether
63  * to send the data or not
64  */
65 ssize_t v9fs_list_xattr(FsContext *ctx, const char *path,
66                         void *value, size_t vsize)
67 {
68     ssize_t size = 0;
69     char *buffer;
70     void *ovalue = value;
71     XattrOperations *xops;
72     char *orig_value, *orig_value_start;
73     ssize_t xattr_len, parsed_len = 0, attr_len;
74 
75     /* Get the actual len */
76     buffer = rpath(ctx, path);
77     xattr_len = llistxattr(buffer, value, 0);
78     if (xattr_len <= 0) {
79         g_free(buffer);
80         return xattr_len;
81     }
82 
83     /* Now fetch the xattr and find the actual size */
84     orig_value = g_malloc(xattr_len);
85     xattr_len = llistxattr(buffer, orig_value, xattr_len);
86     g_free(buffer);
87 
88     /* store the orig pointer */
89     orig_value_start = orig_value;
90     while (xattr_len > parsed_len) {
91         xops = get_xattr_operations(ctx->xops, orig_value);
92         if (!xops) {
93             goto next_entry;
94         }
95 
96         if (!value) {
97             size += xops->listxattr(ctx, path, orig_value, value, vsize);
98         } else {
99             size = xops->listxattr(ctx, path, orig_value, value, vsize);
100             if (size < 0) {
101                 goto err_out;
102             }
103             value += size;
104             vsize -= size;
105         }
106 next_entry:
107         /* Got the next entry */
108         attr_len = strlen(orig_value) + 1;
109         parsed_len += attr_len;
110         orig_value += attr_len;
111     }
112     if (value) {
113         size = value - ovalue;
114     }
115 
116 err_out:
117     g_free(orig_value_start);
118     return size;
119 }
120 
121 int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name,
122                    void *value, size_t size, int flags)
123 {
124     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
125     if (xops) {
126         return xops->setxattr(ctx, path, name, value, size, flags);
127     }
128     errno = EOPNOTSUPP;
129     return -1;
130 
131 }
132 
133 int v9fs_remove_xattr(FsContext *ctx,
134                       const char *path, const char *name)
135 {
136     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
137     if (xops) {
138         return xops->removexattr(ctx, path, name);
139     }
140     errno = EOPNOTSUPP;
141     return -1;
142 
143 }
144 
145 XattrOperations *mapped_xattr_ops[] = {
146     &mapped_user_xattr,
147     &mapped_pacl_xattr,
148     &mapped_dacl_xattr,
149     NULL,
150 };
151 
152 XattrOperations *passthrough_xattr_ops[] = {
153     &passthrough_user_xattr,
154     &passthrough_acl_xattr,
155     NULL,
156 };
157 
158 /* for .user none model should be same as passthrough */
159 XattrOperations *none_xattr_ops[] = {
160     &passthrough_user_xattr,
161     &none_acl_xattr,
162     NULL,
163 };
164