[PATCH 2/5] ipc: implement mach_port_{set,clear}_protected_payload

[Justus Winter]

* include/mach/mach_port.defs: Add mach_port_{set,clear}_protected_payload.
* ipc/mach_port.c: Implement mach_port_{set,clear}_protected_payload.
* doc/mach.texi (Receive Rights): Document
mach_port_{set,clear}_protected_payload.
---
 doc/mach.texi               | 35 ++++++++++++++++++++++
 include/mach/mach_port.defs | 18 +++++++++++
 ipc/mach_port.c             | 73 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 126 insertions(+)

diff --git a/doc/mach.texi b/doc/mach.texi
index d089224..766cd48 100644
--- a/doc/mach.texi
+++ b/doc/mach.texi
@@ -2715,6 +2715,41 @@ In addition to the normal diagnostic return codes from 
the call's server
 (normally the kernel), the call may return @code{mach_msg} return codes.
 @end deftypefun
 
+@deftypefun kern_return_t mach_port_set_protected_payload (@w{ipc_space_t 
@var{task}}, @w{mach_port_t @var{name}}, @w{unsigned long @var{payload}})
+The function @code{mach_port_set_protected_payload} sets the protected
+payload associated with the right @var{name} to @var{payload}.
+Section @ref{Message Receive} describes how setting a protected
+payload affects the messages delivered to @var{name}.
+
+The function returns @code{KERN_SUCCESS} if the call succeeded,
+@code{KERN_INVALID_TASK} if @var{task} was invalid,
+@code{KERN_INVALID_NAME} if @var{name} did not denote a right and
+@code{KERN_INVALID_RIGHT} if @var{name} denoted a right, but not a
+receive right.
+
+The @code{mach_port_set_protected_payload} call is actually an RPC to
+@var{task}, normally a send right for a task port, but potentially any
+send right.  In addition to the normal diagnostic return codes from
+the call's server (normally the kernel), the call may return
+@code{mach_msg} return codes.
+@end deftypefun
+
+@deftypefun kern_return_t mach_port_clear_protected_payload (@w{ipc_space_t 
@var{task}}, @w{mach_port_t @var{name}}, @w{unsigned long @var{payload}})
+The function @code{mach_port_clear_protected_payload} clears the
+protected payload associated with the right @var{name}.
+
+The function returns @code{KERN_SUCCESS} if the call succeeded,
+@code{KERN_INVALID_TASK} if @var{task} was invalid,
+@code{KERN_INVALID_NAME} if @var{name} did not denote a right and
+@code{KERN_INVALID_RIGHT} if @var{name} denoted a right, but not a
+receive right.
+
+The @code{mach_port_clear_protected_payload} call is actually an RPC
+to @var{task}, normally a send right for a task port, but potentially
+any send right.  In addition to the normal diagnostic return codes
+from the call's server (normally the kernel), the call may return
+@code{mach_msg} return codes.
+@end deftypefun
 
 @node Port Sets
 @subsection Port Sets
diff --git a/include/mach/mach_port.defs b/include/mach/mach_port.defs
index 769d892..c7e8526 100644
--- a/include/mach/mach_port.defs
+++ b/include/mach/mach_port.defs
@@ -349,3 +349,21 @@ skip; /* mach_port_create_act */
 
 #endif /* MIGRATING_THREADS */
 
+/*
+ *     Only valid for receive rights.
+ *     Set the protected payload for this right to the given value.
+ */
+
+routine mach_port_set_protected_payload(
+               task            : ipc_space_t;
+               name            : mach_port_name_t;
+               payload         : natural_t);
+
+/*
+ *     Only valid for receive rights.
+ *     Clear the protected payload for this right.
+ */
+
+routine mach_port_clear_protected_payload(
+               task            : ipc_space_t;
+               name            : mach_port_name_t);
diff --git a/ipc/mach_port.c b/ipc/mach_port.c
index 13572a1..057278b 100644
--- a/ipc/mach_port.c
+++ b/ipc/mach_port.c
@@ -1564,3 +1564,76 @@ mach_port_set_syscall_right(task, name)
 }
 #endif
 #endif /* MIGRATING_THREADS */
+
+/*
+ *     Routine:        mach_port_set_protected_payload [kernel call]
+ *     Purpose:
+ *             Changes a receive right's protected payload.
+ *     Conditions:
+ *             Nothing locked.
+ *     Returns:
+ *             KERN_SUCCESS            Set protected payload.
+ *             KERN_INVALID_TASK       The space is null.
+ *             KERN_INVALID_TASK       The space is dead.
+ *             KERN_INVALID_NAME       The name doesn't denote a right.
+ *             KERN_INVALID_RIGHT      Name doesn't denote receive rights.
+ */
+
+kern_return_t
+mach_port_set_protected_payload(
+       ipc_space_t             space,
+       mach_port_t             name,
+       unsigned long           payload)
+{
+       ipc_port_t port;
+       kern_return_t kr;
+
+       if (space == IS_NULL)
+               return KERN_INVALID_TASK;
+
+       kr = ipc_port_translate_receive(space, name, &port);
+       if (kr != KERN_SUCCESS)
+               return kr;
+       /* port is locked and active */
+
+       ipc_port_set_protected_payload(port, payload);
+
+       ip_unlock(port);
+       return KERN_SUCCESS;
+}
+
+/*
+ *     Routine:        mach_port_clear_protected_payload [kernel call]
+ *     Purpose:
+ *             Clears a receive right's protected payload.
+ *     Conditions:
+ *             Nothing locked.
+ *     Returns:
+ *             KERN_SUCCESS            Clear protected payload.
+ *             KERN_INVALID_TASK       The space is null.
+ *             KERN_INVALID_TASK       The space is dead.
+ *             KERN_INVALID_NAME       The name doesn't denote a right.
+ *             KERN_INVALID_RIGHT      Name doesn't denote receive rights.
+ */
+
+kern_return_t
+mach_port_clear_protected_payload(
+       ipc_space_t             space,
+       mach_port_t             name)
+{
+       ipc_port_t port;
+       kern_return_t kr;
+
+       if (space == IS_NULL)
+               return KERN_INVALID_TASK;
+
+       kr = ipc_port_translate_receive(space, name, &port);
+       if (kr != KERN_SUCCESS)
+               return kr;
+       /* port is locked and active */
+
+       ipc_port_clear_protected_payload(port);
+
+       ip_unlock(port);
+       return KERN_SUCCESS;
+}
-- 
1.8.5.2