Divorce the kernel binary ABI version number from the message

format version number. (userland programs should not need to be
recompiled when the netgraph kernel internal ABI is changed.

Also fix modules that don;t handle the fact that a caller may not supply
a return message pointer. (benign at the moment because the calling code
checks, but that will change)

1 files changed, 7 insertions, 2 deletions

diff --git a/sys/netgraph/ng_message.h b/sys/netgraph/ng_message.h
index 3eb6096..993768d 100644
--- a/sys/netgraph/ng_message.h
+++ b/sys/netgraph/ng_message.h
@@ -54,7 +54,7 @@
 /* A netgraph message */
 struct ng_mesg {
 	struct	ng_msghdr {
-		u_char		version;		/* must == NG_VERSION */
+		u_char		version;		/*  == NGM_VERSION */
 		u_char		spare;			/* pad to 2 bytes */
 		u_int16_t	arglen;			/* length of data */
 		u_int32_t	flags;			/* message status */
@@ -66,6 +66,7 @@ struct ng_mesg {
 	char	data[0];		/* placeholder for actual data */
 };
 
+
 /* Keep this in sync with the above structure definition */
 #define NG_GENERIC_NG_MESG_INFO(dtype)	{			\
 	{							\
@@ -82,7 +83,11 @@ struct ng_mesg {
 	}							\
 }
 
-/* Negraph type binary compatibility field */
+/*
+ * Netgraph message header compatibility field
+ * Interfaces within the kernel are defined by a different 
+ * value (see NG_ABI_VERSION in netgraph.g)
+ */
 #define NG_VERSION	4
 
 /* Flags field flags */