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 if (strcmp(name, "") == 0) 37 return -EINVAL; 38 return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY, 39 name, buffer, size); 40 } 41 42 static int 43 ext4_xattr_security_set(const struct xattr_handler *handler, 44 struct dentry *dentry, const char *name, 45 const void *value, size_t size, int flags) 46 { 47 if (strcmp(name, "") == 0) 48 return -EINVAL; 49 return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY, 50 name, value, size, flags); 51 } 52 53 static int 54 ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array, 55 void *fs_info) 56 { 57 const struct xattr *xattr; 58 handle_t *handle = fs_info; 59 int err = 0; 60 61 for (xattr = xattr_array; xattr->name != NULL; xattr++) { 62 err = ext4_xattr_set_handle(handle, inode, 63 EXT4_XATTR_INDEX_SECURITY, 64 xattr->name, xattr->value, 65 xattr->value_len, 0); 66 if (err < 0) 67 break; 68 } 69 return err; 70 } 71 72 int 73 ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir, 74 const struct qstr *qstr) 75 { 76 return security_inode_init_security(inode, dir, qstr, 77 &ext4_initxattrs, handle); 78 } 79 80 const struct xattr_handler ext4_xattr_security_handler = { 81 .prefix = XATTR_SECURITY_PREFIX, 82 .list = ext4_xattr_security_list, 83 .get = ext4_xattr_security_get, 84 .set = ext4_xattr_security_set, 85 }; 86