clean up marshal/unmarshal

Reference: /n/atom/patch/applied/aanmarshal2
Date: Sat Feb 22 16:32:04 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/aan.c	Sat Feb 22 16:31:24 2014
+++ /sys/src/cmd/aan.c	Sat Feb 22 16:31:25 2014
@@ -37,11 +37,17 @@
 	u32int	acked;		// Number of messages acked
 } Hdr;
 
+typedef struct {
+	uchar	nb[4];
+	uchar	msg[4];
+	uchar	acked[4];
+} Mhdr;
+
 enum{
 	Hdrsz		= 12,
 };
 
-typedef struct t_Buf {
+typedef struct {
 	Hdr	hdr;
 	uchar	buf[Bufsize];
 } Buf;
@@ -73,14 +79,14 @@
 static void		synchronize(void);
 static int 		sendcommand(ulong, ulong);
 static void		showmsg(int, char *, Buf *);
-static int		writen(int, uchar *, int);
+static int		writen(int, void *, int);
 static int		getport(char *);
 static void		dmessage(int, char *, ...);
 static void		timerproc(void *);
 static Endpoints *getendpoints(char *);
 static void		freeendpoints(Endpoints *);
-static void		marshal(Hdr*);
-static void		unmarshal(Hdr*);
+static void		marshal(Hdr*, Mhdr*);
+static void		unmarshal(Hdr*, Mhdr*);
 
 static void
 usage(void)
@@ -106,6 +112,7 @@
 	int i, failed;
 	Buf *b;
 	Channel *timer;
+	Mhdr mhdr;
 	vlong synctime;
 
 	progname = argv[0];
@@ -202,8 +209,8 @@
 			hdr.acked = inmsg;
 			hdr.msg = -1;
 
-			marshal(&hdr);
-			if (writen(netfd, (uchar *)&hdr, Hdrsz) < 0) {
+			marshal(&hdr, &mhdr);
+			if (writen(netfd, &mhdr, Hdrsz) < 0) {
 				dmessage(2, "main; writen failed; %r\n");
 				failed = 1;
 				continue;
@@ -221,8 +228,8 @@
 
 			b->hdr.acked = inmsg;
 
-			marshal(&b->hdr);
-			if (writen(netfd, (uchar *)&b->hdr, Hdrsz) < 0) {
+			marshal(&b->hdr, &mhdr);
+			if (writen(netfd, &mhdr, Hdrsz) < 0) {
 				dmessage(2, "main; writen failed; %r\n");
 				failed = 1;
 			}
@@ -272,6 +279,7 @@
 fromnet(void*)
 {
 	static int lastacked;
+	Mhdr mhdr;
 	Buf *b;
 
 	b = (Buf *)malloc(sizeof(Buf));
@@ -287,7 +295,7 @@
 		}
 
 		// Read the header.
-		if ((len = readn(netfd, &b->hdr, Hdrsz)) <= 0) {
+		if ((len = readn(netfd, &mhdr, Hdrsz)) <= 0) {
 			if (len < 0)
 				dmessage(1, "fromnet; (hdr) network failure; %r\n");
 			else
@@ -296,7 +304,7 @@
 			netfd = -1;
 			continue;
 		}
-		unmarshal(&b->hdr);
+		unmarshal(&b->hdr, &mhdr);
 		dmessage(2, "fromnet: Got message, size %d, nb %d, msg %d\n", len,
 				b->hdr.nb, b->hdr.msg);
 
@@ -399,6 +407,7 @@
 {
 	Channel *tmp;
 	Buf *b;
+	Mhdr mhdr;
 
 	// Ignore network errors here.  If we fail during 
 	// synchronization, the next alarm will pick up 
@@ -406,8 +415,8 @@
 
 	tmp = chancreate(sizeof(Buf *), Nbuf);
 	while ((b = nbrecvp(unacked)) != nil) {
-		marshal(&b->hdr);
-		writen(netfd, (uchar *)&b->hdr, Hdrsz);
+		marshal(&b->hdr, &mhdr);
+		writen(netfd, &mhdr, Hdrsz);
 		writen(netfd, b->buf, b->hdr.nb);
 		sendp(tmp, b);
 	}
@@ -432,10 +441,12 @@
 }
 
 static int
-writen(int fd, uchar *buf, int nb)
+writen(int fd, void *vbuf, int nb)
 {
+	uchar *buf;
 	int len = nb;
 
+	buf = vbuf;
 	while (nb > 0) {
 		int n;
 
@@ -455,29 +466,19 @@
 }
 
 static void
-marshal(Hdr *h)
+marshal(Hdr *h, Mhdr *m)
 {
-	u32int x;
-
-	x = h->nb;
-	putle((uchar*)&h->nb, x, 4);
-	x = h->msg;
-	putle((uchar*)&h->msg, x, 4);
-	x = h->acked;
-	putle((uchar*)&h->acked, x, 4);
+	putle(m->nb, h->nb, 4);
+	putle(m->msg, h->msg, 4);
+	putle(m->acked, h->acked, 4);
 }
 
 static void
-unmarshal(Hdr *h)
+unmarshal(Hdr *h, Mhdr *m)
 {
-	u32int x;
-
-	x = getle((uchar*)&h->nb, 4);
-	h->nb = x;
-	x = getle((uchar*)&h->msg, 4);
-	h->msg = x;
-	x = getle((uchar*)&h->msg, 4);
-	h->msg = x;
+	h->nb = getle(m->nb, 4);
+	h->msg = getle(m->msg, 4);
+	h->acked = getle(m->acked, 4);
 }
 
 static void