ipc: add protected payload

Add a field ip_protected_payload and a flag ip_has_protected_payload
to struct ipc_port.

Clear the protected payload when a receive port is moved from one ipc
space to another.  This is done to retain the old behavior of
mach_msg, so that a port name is sent in the msgh_local_port field.
If the new owner of that receive right wishes to use the protected
payload mechanism, it has to be explicitly set again.

* ipc/ipc_port.h (struct ipc_port): Add field ip_protected_payload.
(ipc_port_set_protected_payload): Add function declaration.
(ipc_port_clear_protected_payload): Likewise.
(ipc_port_flag_protected_payload): Add accessor for the protected
payload flag.
(ipc_port_flag_protected_payload_set): Likewise.
(ipc_port_flag_protected_payload_clear): Likewise.
* ipc/ipc_port.c (ipc_port_init): Initialize protected payload.
(ipc_port_print): Print protected_payload.
(ipc_port_set_protected_payload): New function.
(ipc_port_clear_protected_payload): Likewise.
(ipc_port_destroy): Clear the payload when moving a receive port.
* ipc/ipc_right.c (ipc_right_copyin): Likewise.
(ipc_right_copyout): Likewise.
* ipc/ipc_object.c (ipc_object_copyin_from_kernel): Likewise.
* ipc/ipc_object.h (IO_BITS_PROTECTED_PAYLOAD): New bitmask.
(IO_BITS_OTYPE): Adjust accordingly.

1 files changed, 3 insertions, 1 deletions

diff --git a/ipc/ipc_object.h b/ipc/ipc_object.h
index adf5bca4..b83bb5a6 100644
--- a/ipc/ipc_object.h
+++ b/ipc/ipc_object.h
@@ -57,7 +57,9 @@ typedef struct ipc_object {
 #define	IO_VALID(io)		(((io) != IO_NULL) && ((io) != IO_DEAD))
 
 #define	IO_BITS_KOTYPE		0x0000ffff	/* used by the object */
-#define IO_BITS_OTYPE		0x7fff0000 	/* determines a cache */
+#define IO_BITS_OTYPE		0x3fff0000 	/* determines a cache */
+/* The following masks are used to store attributes of ipc ports.  */
+#define	IO_BITS_PROTECTED_PAYLOAD	0x40000000	/* pp set? */
 #define	IO_BITS_ACTIVE		0x80000000U	/* is object alive? */
 
 #define	io_active(io)		((int)(io)->io_bits < 0)	/* hack */