xref: /illumos-kvm-cmd/hw/virtio-9p-xattr.c (revision 68396ea9)
1 /*
2  * Virtio 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 "virtio.h"
15 #include "virtio-9p.h"
16 #include "file-op-9p.h"
17 #include "virtio-9p-xattr.h"
18 
19 
get_xattr_operations(XattrOperations ** h,const char * name)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 
v9fs_get_xattr(FsContext * ctx,const char * path,const char * name,void * value,size_t size)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 
pt_listxattr(FsContext * ctx,const char * path,char * name,void * value,size_t size)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     strncpy(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  */
v9fs_list_xattr(FsContext * ctx,const char * path,void * value,size_t vsize)65 ssize_t v9fs_list_xattr(FsContext *ctx, const char *path,
66                         void *value, size_t vsize)
67 {
68     ssize_t size = 0;
69     void *ovalue = value;
70     XattrOperations *xops;
71     char *orig_value, *orig_value_start;
72     ssize_t xattr_len, parsed_len = 0, attr_len;
73 
74     /* Get the actual len */
75     xattr_len = llistxattr(rpath(ctx, path), value, 0);
76     if (xattr_len <= 0) {
77         return xattr_len;
78     }
79 
80     /* Now fetch the xattr and find the actual size */
81     orig_value = qemu_malloc(xattr_len);
82     xattr_len = llistxattr(rpath(ctx, path), orig_value, xattr_len);
83 
84     /* store the orig pointer */
85     orig_value_start = orig_value;
86     while (xattr_len > parsed_len) {
87         xops = get_xattr_operations(ctx->xops, orig_value);
88         if (!xops) {
89             goto next_entry;
90         }
91 
92         if (!value) {
93             size += xops->listxattr(ctx, path, orig_value, value, vsize);
94         } else {
95             size = xops->listxattr(ctx, path, orig_value, value, vsize);
96             if (size < 0) {
97                 goto err_out;
98             }
99             value += size;
100             vsize -= size;
101         }
102 next_entry:
103         /* Got the next entry */
104         attr_len = strlen(orig_value) + 1;
105         parsed_len += attr_len;
106         orig_value += attr_len;
107     }
108     if (value) {
109         size = value - ovalue;
110     }
111 
112 err_out:
113     qemu_free(orig_value_start);
114     return size;
115 }
116 
v9fs_set_xattr(FsContext * ctx,const char * path,const char * name,void * value,size_t size,int flags)117 int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name,
118                    void *value, size_t size, int flags)
119 {
120     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
121     if (xops) {
122         return xops->setxattr(ctx, path, name, value, size, flags);
123     }
124     errno = -EOPNOTSUPP;
125     return -1;
126 
127 }
128 
v9fs_remove_xattr(FsContext * ctx,const char * path,const char * name)129 int v9fs_remove_xattr(FsContext *ctx,
130                       const char *path, const char *name)
131 {
132     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
133     if (xops) {
134         return xops->removexattr(ctx, path, name);
135     }
136     errno = -EOPNOTSUPP;
137     return -1;
138 
139 }
140 
141 XattrOperations *mapped_xattr_ops[] = {
142     &mapped_user_xattr,
143     &mapped_pacl_xattr,
144     &mapped_dacl_xattr,
145     NULL,
146 };
147 
148 XattrOperations *passthrough_xattr_ops[] = {
149     &passthrough_user_xattr,
150     &passthrough_acl_xattr,
151     NULL,
152 };
153 
154 /* for .user none model should be same as passthrough */
155 XattrOperations *none_xattr_ops[] = {
156     &passthrough_user_xattr,
157     &none_acl_xattr,
158     NULL,
159 };
160