change the imsg header fields a bit to prepare for upcoming changes.

add a flag field, use u_int32_t for pid_t and extend type to 32 bits
for padding.
ok pyr@

src/usr.sbin/ntpd/imsg.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg.c,v 1.13 2009/06/06 18:14:25 pyr Exp $	*/
+/*	$OpenBSD: imsg.c,v 1.14 2009/06/06 22:11:25 eric Exp $	*/
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -125,7 +125,7 @@ imsg_get(struct imsgbuf *ibuf, struct imsg *imsg)
 }
 
 int
-imsg_compose(struct imsgbuf *ibuf, u_int16_t type, u_int32_t peerid,
+imsg_compose(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
     pid_t pid, int fd, void *data, u_int16_t datalen)
 {
 	struct buf	*wbuf;
@@ -144,7 +144,7 @@ imsg_compose(struct imsgbuf *ibuf, u_int16_t type, u_int32_t peerid,
 }
 
 int
-imsg_composev(struct imsgbuf *ibuf, u_int16_t type, u_int32_t peerid,
+imsg_composev(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
     pid_t pid, int fd, const struct iovec *iov, int iovcnt)
 {
 	struct buf	*wbuf;
@@ -169,7 +169,7 @@ imsg_composev(struct imsgbuf *ibuf, u_int16_t type, u_int32_t peerid,
 
 /* ARGSUSED */
 struct buf *
-imsg_create(struct imsgbuf *ibuf, u_int16_t type, u_int32_t peerid,
+imsg_create(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
     pid_t pid, u_int16_t datalen)
 {
 	struct buf	*wbuf;
@@ -182,6 +182,7 @@ imsg_create(struct imsgbuf *ibuf, u_int16_t type, u_int32_t peerid,
 	}
 
 	hdr.type = type;
+	hdr.flags = 0;
 	hdr.peerid = peerid;
 	if ((hdr.pid = pid) == 0)
 		hdr.pid = ibuf->pid;

src/usr.sbin/ntpd/imsg.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg.h,v 1.1 2009/06/06 18:14:25 pyr Exp $	*/
+/*	$OpenBSD: imsg.h,v 1.2 2009/06/06 22:11:25 eric Exp $	*/
 
 /*
  * Copyright (c) 2006, 2007 Pierre-Yves Ritschard <pyr@openbsd.org>
@@ -60,10 +60,11 @@ struct imsgbuf {
 };
 
 struct imsg_hdr {
-	u_int16_t	 type;
+	u_int32_t	 type;
 	u_int16_t	 len;
+	u_int16_t	 flags;
 	u_int32_t	 peerid;
-	pid_t		 pid;
+	u_int32_t	 pid;
 };
 
 struct imsg {
@@ -91,11 +92,11 @@ int		 msgbuf_write(struct msgbuf *);
 void	 imsg_init(struct imsgbuf *, int);
 ssize_t	 imsg_read(struct imsgbuf *);
 ssize_t	 imsg_get(struct imsgbuf *, struct imsg *);
-int	 imsg_compose(struct imsgbuf *, u_int16_t, u_int32_t, pid_t,
+int	 imsg_compose(struct imsgbuf *, u_int32_t, u_int32_t, pid_t,
 	    int, void *, u_int16_t);
-int	 imsg_composev(struct imsgbuf *, u_int16_t, u_int32_t,  pid_t,
+int	 imsg_composev(struct imsgbuf *, u_int32_t, u_int32_t,  pid_t,
 	    int, const struct iovec *, int);
-struct buf *imsg_create(struct imsgbuf *, u_int16_t, u_int32_t, pid_t,
+struct buf *imsg_create(struct imsgbuf *, u_int32_t, u_int32_t, pid_t,
 	    u_int16_t);
 int	 imsg_add(struct buf *, void *, u_int16_t);
 void	 imsg_close(struct imsgbuf *, struct buf *);