[PATCH 03/25] magic: Introduce LABEL_NAK

[Ian Jackson]

Replace ad-hoc comments on the message number of NAK packets with an
explicit #define.  No functional change.

Signed-off-by: Ian Jackson <ijackson at chiark.greenend.org.uk>
---
 magic.h |    1 +
 site.c  |    2 +-
 udp.c   |    3 ++-
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/magic.h b/magic.h
index 5ac1e34..c2503a0c 100644
--- a/magic.h
+++ b/magic.h
@@ -3,6 +3,7 @@
 #ifndef magic_h
 #define magic_h
 
+#define LABEL_NAK  0x00000000
 #define LABEL_MSG0 0x00020200
 #define LABEL_MSG1 0x01010101
 #define LABEL_MSG2 0x02020202
diff --git a/site.c b/site.c
index e96d6f4..b995e52 100644
--- a/site.c
+++ b/site.c
@@ -1285,7 +1285,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 	uint32_t msgtype=ntohl(get_uint32(buf->start+8));
 	if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
 	switch (msgtype) {
-	case 0: /* NAK */
+	case LABEL_NAK:
 	    /* If the source is our current peer then initiate a key setup,
 	       because our peer's forgotten the key */
 	    if (get_uint32(buf->start+4)==st->current.remote_session_id) {
diff --git a/udp.c b/udp.c
index bbf8c64..77be5b1 100644
--- a/udp.c
+++ b/udp.c
@@ -21,6 +21,7 @@
 #include "util.h"
 #include "unaligned.h"
 #include "ipaddr.h"
+#include "magic.h"
 
 static beforepoll_fn udp_beforepoll;
 static afterpoll_fn udp_afterpoll;
@@ -140,7 +141,7 @@ static void udp_afterpoll(void *state, struct pollfd *fds, int nfds)
 		    buffer_init(st->rbuf,0);
 		    buf_append_uint32(st->rbuf,dest);
 		    buf_append_uint32(st->rbuf,source);
-		    buf_append_uint32(st->rbuf,0); /* NAK is msg type 0 */
+		    buf_append_uint32(st->rbuf,LABEL_NAK);
 		    sendto(st->fd, st->rbuf->start, st->rbuf->size, 0,
 			   (struct sockaddr *)&from, sizeof(from));
 		    BUF_FREE(st->rbuf);
-- 
1.7.2.5