1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * FUSE: Filesystem in Userspace
4 * Copyright (C) 2001-2016 Miklos Szeredi <miklos@szeredi.hu>
5 */
6
7 #include "fuse_i.h"
8
9 #include <linux/xattr.h>
10 #include <linux/posix_acl_xattr.h>
11
fuse_setxattr(struct inode * inode,const char * name,const void * value,size_t size,int flags,unsigned int extra_flags)12 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
13 size_t size, int flags, unsigned int extra_flags)
14 {
15 struct fuse_mount *fm = get_fuse_mount(inode);
16 FUSE_ARGS(args);
17 struct fuse_setxattr_in inarg;
18 int err;
19
20 if (fm->fc->no_setxattr)
21 return -EOPNOTSUPP;
22
23 memset(&inarg, 0, sizeof(inarg));
24 inarg.size = size;
25 inarg.flags = flags;
26 inarg.setxattr_flags = extra_flags;
27
28 args.opcode = FUSE_SETXATTR;
29 args.nodeid = get_node_id(inode);
30 args.in_numargs = 3;
31 args.in_args[0].size = fm->fc->setxattr_ext ?
32 sizeof(inarg) : FUSE_COMPAT_SETXATTR_IN_SIZE;
33 args.in_args[0].value = &inarg;
34 args.in_args[1].size = strlen(name) + 1;
35 args.in_args[1].value = name;
36 args.in_args[2].size = size;
37 args.in_args[2].value = value;
38 err = fuse_simple_request(fm, &args);
39 if (err == -ENOSYS) {
40 fm->fc->no_setxattr = 1;
41 err = -EOPNOTSUPP;
42 }
43 if (!err)
44 fuse_update_ctime(inode);
45
46 return err;
47 }
48
fuse_getxattr(struct inode * inode,const char * name,void * value,size_t size)49 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
50 size_t size)
51 {
52 struct fuse_mount *fm = get_fuse_mount(inode);
53 FUSE_ARGS(args);
54 struct fuse_getxattr_in inarg;
55 struct fuse_getxattr_out outarg;
56 ssize_t ret;
57
58 if (fm->fc->no_getxattr)
59 return -EOPNOTSUPP;
60
61 memset(&inarg, 0, sizeof(inarg));
62 inarg.size = size;
63 args.opcode = FUSE_GETXATTR;
64 args.nodeid = get_node_id(inode);
65 args.in_numargs = 2;
66 args.in_args[0].size = sizeof(inarg);
67 args.in_args[0].value = &inarg;
68 args.in_args[1].size = strlen(name) + 1;
69 args.in_args[1].value = name;
70 /* This is really two different operations rolled into one */
71 args.out_numargs = 1;
72 if (size) {
73 args.out_argvar = true;
74 args.out_args[0].size = size;
75 args.out_args[0].value = value;
76 } else {
77 args.out_args[0].size = sizeof(outarg);
78 args.out_args[0].value = &outarg;
79 }
80 ret = fuse_simple_request(fm, &args);
81 if (!ret && !size)
82 ret = min_t(size_t, outarg.size, XATTR_SIZE_MAX);
83 if (ret == -ENOSYS) {
84 fm->fc->no_getxattr = 1;
85 ret = -EOPNOTSUPP;
86 }
87 return ret;
88 }
89
fuse_verify_xattr_list(char * list,size_t size)90 static int fuse_verify_xattr_list(char *list, size_t size)
91 {
92 size_t origsize = size;
93
94 while (size) {
95 size_t thislen = strnlen(list, size);
96
97 if (!thislen || thislen == size)
98 return -EIO;
99
100 size -= thislen + 1;
101 list += thislen + 1;
102 }
103
104 return origsize;
105 }
106
fuse_listxattr(struct dentry * entry,char * list,size_t size)107 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
108 {
109 struct inode *inode = d_inode(entry);
110 struct fuse_mount *fm = get_fuse_mount(inode);
111 FUSE_ARGS(args);
112 struct fuse_getxattr_in inarg;
113 struct fuse_getxattr_out outarg;
114 ssize_t ret;
115
116 if (fuse_is_bad(inode))
117 return -EIO;
118
119 if (!fuse_allow_current_process(fm->fc))
120 return -EACCES;
121
122 if (fm->fc->no_listxattr)
123 return -EOPNOTSUPP;
124
125 memset(&inarg, 0, sizeof(inarg));
126 inarg.size = size;
127 args.opcode = FUSE_LISTXATTR;
128 args.nodeid = get_node_id(inode);
129 args.in_numargs = 1;
130 args.in_args[0].size = sizeof(inarg);
131 args.in_args[0].value = &inarg;
132 /* This is really two different operations rolled into one */
133 args.out_numargs = 1;
134 if (size) {
135 args.out_argvar = true;
136 args.out_args[0].size = size;
137 args.out_args[0].value = list;
138 } else {
139 args.out_args[0].size = sizeof(outarg);
140 args.out_args[0].value = &outarg;
141 }
142 ret = fuse_simple_request(fm, &args);
143 if (!ret && !size)
144 ret = min_t(size_t, outarg.size, XATTR_LIST_MAX);
145 if (ret > 0 && size)
146 ret = fuse_verify_xattr_list(list, ret);
147 if (ret == -ENOSYS) {
148 fm->fc->no_listxattr = 1;
149 ret = -EOPNOTSUPP;
150 }
151 return ret;
152 }
153
fuse_removexattr(struct inode * inode,const char * name)154 int fuse_removexattr(struct inode *inode, const char *name)
155 {
156 struct fuse_mount *fm = get_fuse_mount(inode);
157 FUSE_ARGS(args);
158 int err;
159
160 if (fm->fc->no_removexattr)
161 return -EOPNOTSUPP;
162
163 args.opcode = FUSE_REMOVEXATTR;
164 args.nodeid = get_node_id(inode);
165 args.in_numargs = 2;
166 fuse_set_zero_arg0(&args);
167 args.in_args[1].size = strlen(name) + 1;
168 args.in_args[1].value = name;
169 err = fuse_simple_request(fm, &args);
170 if (err == -ENOSYS) {
171 fm->fc->no_removexattr = 1;
172 err = -EOPNOTSUPP;
173 }
174 if (!err)
175 fuse_update_ctime(inode);
176
177 return err;
178 }
179
fuse_xattr_get(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,void * value,size_t size)180 static int fuse_xattr_get(const struct xattr_handler *handler,
181 struct dentry *dentry, struct inode *inode,
182 const char *name, void *value, size_t size)
183 {
184 if (fuse_is_bad(inode))
185 return -EIO;
186
187 return fuse_getxattr(inode, name, value, size);
188 }
189
fuse_xattr_set(const struct xattr_handler * handler,const struct mnt_idmap * idmap,struct dentry * dentry,struct inode * inode,const char * name,const void * value,size_t size,int flags)190 static int fuse_xattr_set(const struct xattr_handler *handler,
191 const struct mnt_idmap *idmap,
192 struct dentry *dentry, struct inode *inode,
193 const char *name, const void *value, size_t size,
194 int flags)
195 {
196 if (fuse_is_bad(inode))
197 return -EIO;
198
199 if (!value)
200 return fuse_removexattr(inode, name);
201
202 return fuse_setxattr(inode, name, value, size, flags, 0);
203 }
204
205 static const struct xattr_handler fuse_xattr_handler = {
206 .prefix = "",
207 .get = fuse_xattr_get,
208 .set = fuse_xattr_set,
209 };
210
211 const struct xattr_handler * const fuse_xattr_handlers[] = {
212 &fuse_xattr_handler,
213 NULL
214 };
215