eCryptfs: allow userspace messaging to be disabled
When the userspace messaging (for the less common case of userspace key
wrap/unwrap via ecryptfsd) is not needed, allow eCryptfs to build with
it removed. This saves on kernel code size and reduces potential attack
surface by removing the /dev/ecryptfs node.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index cfb4b9f..a9df69e 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -172,6 +172,19 @@
#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE 24
#define ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN (18 + 1 + 4 + 1 + 32)
+#ifdef CONFIG_ECRYPT_FS_MESSAGING
+# define ECRYPTFS_VERSIONING_MASK_MESSAGING (ECRYPTFS_VERSIONING_DEVMISC \
+ | ECRYPTFS_VERSIONING_PUBKEY)
+#else
+# define ECRYPTFS_VERSIONING_MASK_MESSAGING 0
+#endif
+
+#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
+ | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \
+ | ECRYPTFS_VERSIONING_XATTR \
+ | ECRYPTFS_VERSIONING_MULTKEY \
+ | ECRYPTFS_VERSIONING_MASK_MESSAGING \
+ | ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION)
struct ecryptfs_key_sig {
struct list_head crypt_stat_list;
char keysig[ECRYPTFS_SIG_SIZE_HEX + 1];
@@ -399,7 +412,9 @@
struct hlist_node euid_chain;
};
+#ifdef CONFIG_ECRYPT_FS_MESSAGING
extern struct mutex ecryptfs_daemon_hash_mux;
+#endif
static inline size_t
ecryptfs_lower_header_size(struct ecryptfs_crypt_stat *crypt_stat)
@@ -604,6 +619,7 @@
ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags);
int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode);
+#ifdef CONFIG_ECRYPT_FS_MESSAGING
int ecryptfs_process_response(struct ecryptfs_daemon *daemon,
struct ecryptfs_message *msg, u32 seq);
int ecryptfs_send_message(char *data, int data_len,
@@ -612,6 +628,24 @@
struct ecryptfs_message **emsg);
int ecryptfs_init_messaging(void);
void ecryptfs_release_messaging(void);
+#else
+static inline int ecryptfs_init_messaging(void)
+{
+ return 0;
+}
+static inline void ecryptfs_release_messaging(void)
+{ }
+static inline int ecryptfs_send_message(char *data, int data_len,
+ struct ecryptfs_msg_ctx **msg_ctx)
+{
+ return -ENOTCONN;
+}
+static inline int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
+ struct ecryptfs_message **emsg)
+{
+ return -ENOMSG;
+}
+#endif
void
ecryptfs_write_header_metadata(char *virt,
@@ -649,12 +683,11 @@
size_t offset_in_page, size_t size,
struct inode *ecryptfs_inode);
struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index);
-int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon);
-int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon);
int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
size_t *length_size);
int ecryptfs_write_packet_length(char *dest, size_t size,
size_t *packet_size_length);
+#ifdef CONFIG_ECRYPT_FS_MESSAGING
int ecryptfs_init_ecryptfs_miscdev(void);
void ecryptfs_destroy_ecryptfs_miscdev(void);
int ecryptfs_send_miscdev(char *data, size_t data_size,
@@ -663,6 +696,9 @@
void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx);
int
ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file);
+int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon);
+int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon);
+#endif
int ecryptfs_init_kthread(void);
void ecryptfs_destroy_kthread(void);
int ecryptfs_privileged_open(struct file **lower_file,
