PERFORCE change 163941 for review

[Marko Zec]

http://perforce.freebsd.org/chv.cgi?CH=163941

Change 163941 by zec at zec_amdx4 on 2009/06/09 23:05:04

	A still nonfunctional hack aiming at preventing inbound
	path of the network stack being called directly from the
	outbound path via netgraph.

Affected files ...

.. //depot/projects/vimage-commit2/src/sys/netgraph/netgraph.h#25 edit
.. //depot/projects/vimage-commit2/src/sys/netgraph/ng_base.c#33 edit
.. //depot/projects/vimage-commit2/src/sys/netgraph/ng_eiface.c#23 edit
.. //depot/projects/vimage-commit2/src/sys/sys/proc.h#18 edit

Differences ...

==== //depot/projects/vimage-commit2/src/sys/netgraph/netgraph.h#25 (text+ko) ====

@@ -130,6 +130,8 @@
 #define HK_FORCE_WRITER		0x0004	/* Incoming data queued as a writer */
 #define HK_DEAD			0x0008	/* This is the dead hook.. don't free */
 #define HK_HI_STACK		0x0010	/* Hook has hi stack usage */
+#define HK_TO_INBOUND		0x0020	/* Hook calls into the inbound path
+					   of the network stack.  */
 
 /*
  * Public Methods for hook
@@ -150,6 +152,8 @@
 #define _NG_HOOK_FORCE_WRITER(hook)				\
 		do { hook->hk_flags |= HK_FORCE_WRITER; } while (0)
 #define _NG_HOOK_FORCE_QUEUE(hook) do { hook->hk_flags |= HK_QUEUE; } while (0)
+#define _NG_HOOK_SET_TO_INBOUND(hook)				\
+		do { hook->hk_flags |= HK_TO_INBOUND; } while (0)
 #define _NG_HOOK_HI_STACK(hook) do { hook->hk_flags |= HK_HI_STACK; } while (0)
 
 /* Some shortcuts */
@@ -176,8 +180,11 @@
 static __inline node_p	_ng_hook_node(hook_p hook, char * file, int line);
 static __inline hook_p	_ng_hook_peer(hook_p hook, char * file, int line);
 static __inline void	_ng_hook_force_writer(hook_p hook, char * file,
-					int line);
-static __inline void	_ng_hook_force_queue(hook_p hook, char * file, int line);
+				int line);
+static __inline void	_ng_hook_force_queue(hook_p hook, char * file,
+				int line);
+static __inline void	_ng_hook_set_to_inbound(hook_p hook, char * file,
+				int line);
 
 static __inline void
 _chkhook(hook_p hook, char *file, int line)
@@ -282,6 +289,13 @@
 }
 
 static __inline void
+_ng_hook_set_to_inbound(hook_p hook, char * file, int line)
+{
+	_chkhook(hook, file, line);
+	_NG_HOOK_SET_TO_INBOUND(hook);
+}
+
+static __inline void
 _ng_hook_hi_stack(hook_p hook, char * file, int line)
 {
 	_chkhook(hook, file, line);
@@ -302,6 +316,7 @@
 #define NG_HOOK_PEER(hook)		_ng_hook_peer(hook, _NN_)
 #define NG_HOOK_FORCE_WRITER(hook)	_ng_hook_force_writer(hook, _NN_)
 #define NG_HOOK_FORCE_QUEUE(hook)	_ng_hook_force_queue(hook, _NN_)
+#define NG_HOOK_SET_TO_INBOUND(hook)	_ng_hook_set_to_inbound(hook, _NN_)
 #define NG_HOOK_HI_STACK(hook)		_ng_hook_hi_stack(hook, _NN_)
 
 #else	/* NETGRAPH_DEBUG */ /*----------------------------------------------*/
@@ -319,6 +334,7 @@
 #define NG_HOOK_PEER(hook)		_NG_HOOK_PEER(hook)
 #define NG_HOOK_FORCE_WRITER(hook)	_NG_HOOK_FORCE_WRITER(hook)
 #define NG_HOOK_FORCE_QUEUE(hook)	_NG_HOOK_FORCE_QUEUE(hook)
+#define NG_HOOK_SET_TO_INBOUND(hook)	_NG_HOOK_SET_TO_INBOUND(hook)
 #define NG_HOOK_HI_STACK(hook)		_NG_HOOK_HI_STACK(hook)
 
 #endif	/* NETGRAPH_DEBUG */ /*----------------------------------------------*/

==== //depot/projects/vimage-commit2/src/sys/netgraph/ng_base.c#33 (text+ko) ====

@@ -2213,11 +2213,16 @@
 	}
 
 	/*
-	 * If sender or receiver requests queued delivery or stack usage
+	 * If sender or receiver requests queued delivery, or call graph
+	 * loops back from outbound to inbound path, or stack usage
 	 * level is dangerous - enqueue message.
 	 */
 	if ((flags & NG_QUEUE) || (hook && (hook->hk_flags & HK_QUEUE))) {
 		queue = 1;
+	} else if (hook && (hook->hk_flags & HK_TO_INBOUND) /* &&
+	    (curthread->td_flags & TDF_NG_OUTBOUND) */) {
+printf("ng queuing: td_flags = %X\n", curthread->td_flags);
+		queue = 1;
 	} else {
 		queue = 0;
 #ifdef GET_STACK_USAGE

==== //depot/projects/vimage-commit2/src/sys/netgraph/ng_eiface.c#23 (text+ko) ====

@@ -95,6 +95,7 @@
 static ng_rcvmsg_t	ng_eiface_rcvmsg;
 static ng_shutdown_t	ng_eiface_rmnode;
 static ng_newhook_t	ng_eiface_newhook;
+static ng_connect_t	ng_eiface_connect;
 static ng_rcvdata_t	ng_eiface_rcvdata;
 static ng_disconnect_t	ng_eiface_disconnect;
 
@@ -107,6 +108,7 @@
 	.rcvmsg =	ng_eiface_rcvmsg,
 	.shutdown =	ng_eiface_rmnode,
 	.newhook =	ng_eiface_newhook,
+	.connect =	ng_eiface_connect,
 	.rcvdata =	ng_eiface_rcvdata,
 	.disconnect =	ng_eiface_disconnect,
 	.cmdlist =	ng_eiface_cmdlist
@@ -421,6 +423,19 @@
 }
 
 /*
+ * Mark a hook as leading to inbound path of the network stack, so
+ * that framework can queue calls to us that arrived from the outbound
+ * path.
+ */
+static int
+ng_eiface_connect(hook_p hook)
+{
+
+        NG_HOOK_SET_TO_INBOUND(hook);
+	return (0);
+}
+
+/*
  * Receive a control message
  */
 static int

==== //depot/projects/vimage-commit2/src/sys/sys/proc.h#18 (text+ko) ====

@@ -319,7 +319,7 @@
 #define	TDF_BOUNDARY	0x00000400 /* Thread suspended at user boundary */
 #define	TDF_ASTPENDING	0x00000800 /* Thread has some asynchronous events. */
 #define	TDF_TIMOFAIL	0x00001000 /* Timeout from sleep after we were awake. */
-#define	TDF_UNUSED2000	0x00002000 /* --available-- */
+#define	TDF_NG_OUTBOUND	0x00002000 /* Thread called into ng from ntw stack. */
 #define	TDF_UPIBLOCKED	0x00004000 /* Thread blocked on user PI mutex. */
 #define	TDF_NEEDSUSPCHK	0x00008000 /* Thread may need to suspend. */
 #define	TDF_NEEDRESCHED	0x00010000 /* Thread needs to yield. */