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, 36 insertions, 22 deletions

diff --git a/sys/dev/musycc/musycc.c b/sys/dev/musycc/musycc.c
index c8f35ff..85ec6e0 100644
--- a/sys/dev/musycc/musycc.c
+++ b/sys/dev/musycc/musycc.c
@@ -265,7 +265,7 @@ static  ng_rcvdata_t musycc_rcvdata;
 static  ng_disconnect_t musycc_disconnect;
 
 static struct ng_type ngtypestruct = {
-	NG_VERSION,
+	NG_ABI_VERSION,
 	NG_NODETYPE,
 	NULL, 
 	musycc_constructor,
@@ -926,56 +926,70 @@ barf:
 	return;
 }
 
+/*
+ * Handle status and config enquiries.
+ * Respond with a synchronous response.
+ * [JRE] -this would be easier to read with the usual 'switch' structure-
+ */
 static int
-musycc_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr, struct ng_mesg **resp, hook_p lasthook)
+musycc_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
+					struct ng_mesg **rptr, hook_p lasthook)
 {
 	struct softc *sc;
+	struct ng_mesg *resp = NULL;
 	char *s, *r;
+	int error = 0;
 
 	sc = node->private;
+	if (rptr)
+		*rptr = NULL; /* default answer in case of errors */
 
 	if (msg->header.typecookie != NGM_GENERIC_COOKIE)
 		goto out;
 
 	if (msg->header.cmd == NGM_TEXT_STATUS) {
-		NG_MKRESPONSE(*resp, msg, 
+		NG_MKRESPONSE(resp, msg, 
 		    sizeof(struct ng_mesg) + NG_TEXTRESPONSE, M_NOWAIT);
-		if (*resp == NULL) {
-			FREE(msg, M_NETGRAPH);
-			return (ENOMEM);
+		if (resp == NULL) {
+			error = ENOMEM;
+			goto out;
 		}
-		s = (char *)(*resp)->data;
+		s = (char *)resp->data;
 		status_8370(sc, s);
-		(*resp)->header.arglen = strlen(s) + 1;
+		resp->header.arglen = strlen(s) + 1;
 		FREE(msg, M_NETGRAPH);
-		return (0);
-        }
-	if (msg->header.cmd == NGM_TEXT_CONFIG) {
+		
+	} else if (msg->header.cmd == NGM_TEXT_CONFIG) {
 		if (msg->header.arglen) {
 			s = (char *)msg->data;
 		} else {
 			s = NULL;
 		}
 		
-		NG_MKRESPONSE(*resp, msg, 
+		NG_MKRESPONSE(resp, msg, 
 		    sizeof(struct ng_mesg) + NG_TEXTRESPONSE, M_NOWAIT);
-		if (*resp == NULL) {
-			FREE(msg, M_NETGRAPH);
-			return (ENOMEM);
+		if (resp == NULL) {
+			error = ENOMEM;
+			goto out;
 		}
-		r = (char *)(*resp)->data;
+		r = (char *)resp->data;
 		*r = '\0';
 		musycc_config(node, s, r);
-		(*resp)->header.arglen = strlen(r) + 1;
+		resp->header.arglen = strlen(r) + 1;
 		FREE(msg, M_NETGRAPH);
-		return (0);
-        }
+	} else {
+		error = EINVAL;
+	}
 
 out:
-	if (resp)
-		*resp = NULL;
+	/* Take care of synchronous response, if any */
+	if (rptr)
+		*rptr = resp;
+	else if (resp)
+		FREE(resp, M_NETGRAPH); /* eventually 'send' the response */
+
 	FREE(msg, M_NETGRAPH);
-	return (EINVAL);
+	return (error);
 }
 
 static int