1 /* 2 * FUSE: Filesystem in Userspace 3 * Copyright (C) 2001-2016 Miklos Szeredi <miklos@szeredi.hu> 4 * 5 * This program can be distributed under the terms of the GNU GPL. 6 * See the file COPYING. 7 */ 8 9 #include "fuse_i.h" 10 11 #include <linux/xattr.h> 12 #include <linux/posix_acl_xattr.h> 13 14 int fuse_setxattr(struct inode *inode, const char *name, const void *value, 15 size_t size, int flags) 16 { 17 struct fuse_mount *fm = get_fuse_mount(inode); 18 FUSE_ARGS(args); 19 struct fuse_setxattr_in inarg; 20 int err; 21 22 if (fm->fc->no_setxattr) 23 return -EOPNOTSUPP; 24 25 memset(&inarg, 0, sizeof(inarg)); 26 inarg.size = size; 27 inarg.flags = flags; 28 args.opcode = FUSE_SETXATTR; 29 args.nodeid = get_node_id(inode); 30 args.in_numargs = 3; 31 args.in_args[0].size = sizeof(inarg); 32 args.in_args[0].value = &inarg; 33 args.in_args[1].size = strlen(name) + 1; 34 args.in_args[1].value = name; 35 args.in_args[2].size = size; 36 args.in_args[2].value = value; 37 err = fuse_simple_request(fm, &args); 38 if (err == -ENOSYS) { 39 fm->fc->no_setxattr = 1; 40 err = -EOPNOTSUPP; 41 } 42 if (!err) { 43 fuse_invalidate_attr(inode); 44 fuse_update_ctime(inode); 45 } 46 return err; 47 } 48 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(ssize_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 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 } 106 107 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(ssize_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 } 153 154 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 = 1; 166 args.in_args[0].size = strlen(name) + 1; 167 args.in_args[0].value = name; 168 err = fuse_simple_request(fm, &args); 169 if (err == -ENOSYS) { 170 fm->fc->no_removexattr = 1; 171 err = -EOPNOTSUPP; 172 } 173 if (!err) { 174 fuse_invalidate_attr(inode); 175 fuse_update_ctime(inode); 176 } 177 return err; 178 } 179 180 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 } 189 190 static int fuse_xattr_set(const struct xattr_handler *handler, 191 struct user_namespace *mnt_userns, 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); 203 } 204 205 static bool no_xattr_list(struct dentry *dentry) 206 { 207 return false; 208 } 209 210 static int no_xattr_get(const struct xattr_handler *handler, 211 struct dentry *dentry, struct inode *inode, 212 const char *name, void *value, size_t size) 213 { 214 return -EOPNOTSUPP; 215 } 216 217 static int no_xattr_set(const struct xattr_handler *handler, 218 struct user_namespace *mnt_userns, 219 struct dentry *dentry, struct inode *nodee, 220 const char *name, const void *value, 221 size_t size, int flags) 222 { 223 return -EOPNOTSUPP; 224 } 225 226 static const struct xattr_handler fuse_xattr_handler = { 227 .prefix = "", 228 .get = fuse_xattr_get, 229 .set = fuse_xattr_set, 230 }; 231 232 const struct xattr_handler *fuse_xattr_handlers[] = { 233 &fuse_xattr_handler, 234 NULL 235 }; 236 237 const struct xattr_handler *fuse_acl_xattr_handlers[] = { 238 &posix_acl_access_xattr_handler, 239 &posix_acl_default_xattr_handler, 240 &fuse_xattr_handler, 241 NULL 242 }; 243 244 static const struct xattr_handler fuse_no_acl_access_xattr_handler = { 245 .name = XATTR_NAME_POSIX_ACL_ACCESS, 246 .flags = ACL_TYPE_ACCESS, 247 .list = no_xattr_list, 248 .get = no_xattr_get, 249 .set = no_xattr_set, 250 }; 251 252 static const struct xattr_handler fuse_no_acl_default_xattr_handler = { 253 .name = XATTR_NAME_POSIX_ACL_DEFAULT, 254 .flags = ACL_TYPE_ACCESS, 255 .list = no_xattr_list, 256 .get = no_xattr_get, 257 .set = no_xattr_set, 258 }; 259 260 const struct xattr_handler *fuse_no_acl_xattr_handlers[] = { 261 &fuse_no_acl_access_xattr_handler, 262 &fuse_no_acl_default_xattr_handler, 263 &fuse_xattr_handler, 264 NULL 265 }; 266