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_conn *fc = get_fuse_conn(inode); 18 FUSE_ARGS(args); 19 struct fuse_setxattr_in inarg; 20 int err; 21 22 if (fc->no_setxattr) 23 return -EOPNOTSUPP; 24 25 memset(&inarg, 0, sizeof(inarg)); 26 inarg.size = size; 27 inarg.flags = flags; 28 args.in.h.opcode = FUSE_SETXATTR; 29 args.in.h.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(fc, &args); 38 if (err == -ENOSYS) { 39 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_conn *fc = get_fuse_conn(inode); 53 FUSE_ARGS(args); 54 struct fuse_getxattr_in inarg; 55 struct fuse_getxattr_out outarg; 56 ssize_t ret; 57 58 if (fc->no_getxattr) 59 return -EOPNOTSUPP; 60 61 memset(&inarg, 0, sizeof(inarg)); 62 inarg.size = size; 63 args.in.h.opcode = FUSE_GETXATTR; 64 args.in.h.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 = 1; 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(fc, &args); 81 if (!ret && !size) 82 ret = min_t(ssize_t, outarg.size, XATTR_SIZE_MAX); 83 if (ret == -ENOSYS) { 84 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_conn *fc = get_fuse_conn(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_allow_current_process(fc)) 117 return -EACCES; 118 119 if (fc->no_listxattr) 120 return -EOPNOTSUPP; 121 122 memset(&inarg, 0, sizeof(inarg)); 123 inarg.size = size; 124 args.in.h.opcode = FUSE_LISTXATTR; 125 args.in.h.nodeid = get_node_id(inode); 126 args.in.numargs = 1; 127 args.in.args[0].size = sizeof(inarg); 128 args.in.args[0].value = &inarg; 129 /* This is really two different operations rolled into one */ 130 args.out.numargs = 1; 131 if (size) { 132 args.out.argvar = 1; 133 args.out.args[0].size = size; 134 args.out.args[0].value = list; 135 } else { 136 args.out.args[0].size = sizeof(outarg); 137 args.out.args[0].value = &outarg; 138 } 139 ret = fuse_simple_request(fc, &args); 140 if (!ret && !size) 141 ret = min_t(ssize_t, outarg.size, XATTR_LIST_MAX); 142 if (ret > 0 && size) 143 ret = fuse_verify_xattr_list(list, ret); 144 if (ret == -ENOSYS) { 145 fc->no_listxattr = 1; 146 ret = -EOPNOTSUPP; 147 } 148 return ret; 149 } 150 151 int fuse_removexattr(struct inode *inode, const char *name) 152 { 153 struct fuse_conn *fc = get_fuse_conn(inode); 154 FUSE_ARGS(args); 155 int err; 156 157 if (fc->no_removexattr) 158 return -EOPNOTSUPP; 159 160 args.in.h.opcode = FUSE_REMOVEXATTR; 161 args.in.h.nodeid = get_node_id(inode); 162 args.in.numargs = 1; 163 args.in.args[0].size = strlen(name) + 1; 164 args.in.args[0].value = name; 165 err = fuse_simple_request(fc, &args); 166 if (err == -ENOSYS) { 167 fc->no_removexattr = 1; 168 err = -EOPNOTSUPP; 169 } 170 if (!err) { 171 fuse_invalidate_attr(inode); 172 fuse_update_ctime(inode); 173 } 174 return err; 175 } 176 177 static int fuse_xattr_get(const struct xattr_handler *handler, 178 struct dentry *dentry, struct inode *inode, 179 const char *name, void *value, size_t size) 180 { 181 return fuse_getxattr(inode, name, value, size); 182 } 183 184 static int fuse_xattr_set(const struct xattr_handler *handler, 185 struct dentry *dentry, struct inode *inode, 186 const char *name, const void *value, size_t size, 187 int flags) 188 { 189 if (!value) 190 return fuse_removexattr(inode, name); 191 192 return fuse_setxattr(inode, name, value, size, flags); 193 } 194 195 static bool no_xattr_list(struct dentry *dentry) 196 { 197 return false; 198 } 199 200 static int no_xattr_get(const struct xattr_handler *handler, 201 struct dentry *dentry, struct inode *inode, 202 const char *name, void *value, size_t size) 203 { 204 return -EOPNOTSUPP; 205 } 206 207 static int no_xattr_set(const struct xattr_handler *handler, 208 struct dentry *dentry, struct inode *nodee, 209 const char *name, const void *value, 210 size_t size, int flags) 211 { 212 return -EOPNOTSUPP; 213 } 214 215 static const struct xattr_handler fuse_xattr_handler = { 216 .prefix = "", 217 .get = fuse_xattr_get, 218 .set = fuse_xattr_set, 219 }; 220 221 const struct xattr_handler *fuse_xattr_handlers[] = { 222 &fuse_xattr_handler, 223 NULL 224 }; 225 226 const struct xattr_handler *fuse_acl_xattr_handlers[] = { 227 &posix_acl_access_xattr_handler, 228 &posix_acl_default_xattr_handler, 229 &fuse_xattr_handler, 230 NULL 231 }; 232 233 static const struct xattr_handler fuse_no_acl_access_xattr_handler = { 234 .name = XATTR_NAME_POSIX_ACL_ACCESS, 235 .flags = ACL_TYPE_ACCESS, 236 .list = no_xattr_list, 237 .get = no_xattr_get, 238 .set = no_xattr_set, 239 }; 240 241 static const struct xattr_handler fuse_no_acl_default_xattr_handler = { 242 .name = XATTR_NAME_POSIX_ACL_DEFAULT, 243 .flags = ACL_TYPE_ACCESS, 244 .list = no_xattr_list, 245 .get = no_xattr_get, 246 .set = no_xattr_set, 247 }; 248 249 const struct xattr_handler *fuse_no_acl_xattr_handlers[] = { 250 &fuse_no_acl_access_xattr_handler, 251 &fuse_no_acl_default_xattr_handler, 252 &fuse_xattr_handler, 253 NULL 254 }; 255