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(struct dentry *dentry, char *list, size_t list_size, 16 const char *name, size_t name_len, int type) 17 { 18 const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1; 19 const size_t total_len = prefix_len + name_len + 1; 20 21 22 if (list && total_len <= list_size) { 23 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len); 24 memcpy(list+prefix_len, name, name_len); 25 list[prefix_len + name_len] = '\0'; 26 } 27 return total_len; 28 } 29 30 static int 31 ext4_xattr_security_get(struct dentry *dentry, const char *name, 32 void *buffer, size_t size, int type) 33 { 34 if (strcmp(name, "") == 0) 35 return -EINVAL; 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(struct dentry *dentry, const char *name, 42 const void *value, size_t size, int flags, int type) 43 { 44 if (strcmp(name, "") == 0) 45 return -EINVAL; 46 return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY, 47 name, value, size, flags); 48 } 49 50 static int 51 ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array, 52 void *fs_info) 53 { 54 const struct xattr *xattr; 55 handle_t *handle = fs_info; 56 int err = 0; 57 58 for (xattr = xattr_array; xattr->name != NULL; xattr++) { 59 err = ext4_xattr_set_handle(handle, inode, 60 EXT4_XATTR_INDEX_SECURITY, 61 xattr->name, xattr->value, 62 xattr->value_len, 0); 63 if (err < 0) 64 break; 65 } 66 return err; 67 } 68 69 int 70 ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir, 71 const struct qstr *qstr) 72 { 73 return security_inode_init_security(inode, dir, qstr, 74 &ext4_initxattrs, handle); 75 } 76 77 const struct xattr_handler ext4_xattr_security_handler = { 78 .prefix = XATTR_SECURITY_PREFIX, 79 .list = ext4_xattr_security_list, 80 .get = ext4_xattr_security_get, 81 .set = ext4_xattr_security_set, 82 }; 83