1 /* 2 * linux/fs/ext4/xattr_security.c 3 * Handler for storing security labels as extended attributes. 4 */ 5 6 #include <linux/string.h> 7 #include <linux/fs.h> 8 #include <linux/security.h> 9 #include <linux/slab.h> 10 #include "ext4_jbd2.h" 11 #include "ext4.h" 12 #include "xattr.h" 13 14 static size_t 15 ext4_xattr_security_list(const struct xattr_handler *handler, 16 struct dentry *dentry, char *list, size_t list_size, 17 const char *name, size_t name_len) 18 { 19 const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1; 20 const size_t total_len = prefix_len + name_len + 1; 21 22 23 if (list && total_len <= list_size) { 24 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len); 25 memcpy(list+prefix_len, name, name_len); 26 list[prefix_len + name_len] = '\0'; 27 } 28 return total_len; 29 } 30 31 static int 32 ext4_xattr_security_get(const struct xattr_handler *handler, 33 struct dentry *dentry, const char *name, 34 void *buffer, size_t size) 35 { 36 return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY, 37 name, buffer, size); 38 } 39 40 static int 41 ext4_xattr_security_set(const struct xattr_handler *handler, 42 struct dentry *dentry, const char *name, 43 const void *value, size_t size, int flags) 44 { 45 return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY, 46 name, value, size, flags); 47 } 48 49 static int 50 ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array, 51 void *fs_info) 52 { 53 const struct xattr *xattr; 54 handle_t *handle = fs_info; 55 int err = 0; 56 57 for (xattr = xattr_array; xattr->name != NULL; xattr++) { 58 err = ext4_xattr_set_handle(handle, inode, 59 EXT4_XATTR_INDEX_SECURITY, 60 xattr->name, xattr->value, 61 xattr->value_len, 0); 62 if (err < 0) 63 break; 64 } 65 return err; 66 } 67 68 int 69 ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir, 70 const struct qstr *qstr) 71 { 72 return security_inode_init_security(inode, dir, qstr, 73 &ext4_initxattrs, handle); 74 } 75 76 const struct xattr_handler ext4_xattr_security_handler = { 77 .prefix = XATTR_SECURITY_PREFIX, 78 .list = ext4_xattr_security_list, 79 .get = ext4_xattr_security_get, 80 .set = ext4_xattr_security_set, 81 }; 82