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Construct the X-MAC header on the stack instead of directly in the packet header, because the packet header may be misaligned. A bit of cleanup in the code too.

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This commit is contained in:
adamdunkels 2009-02-15 22:05:06 +00:00
parent bed1b4cc4f
commit aaa8c9d2c9
1 changed files with 17 additions and 12 deletions
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29
core/net/mac/xmac.c
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@ -28,7 +28,7 @@
*
* This file is part of the Contiki operating system.
*
* $Id: xmac.c,v 1.23 2009/02/14 20:35:03 adamdunkels Exp $
* $Id: xmac.c,v 1.24 2009/02/15 22:05:06 adamdunkels Exp $
*/
/**
@ -52,6 +52,8 @@
#include "contiki-conf.h"
#include <string.h>
#if CHAMELEON
#include "net/chameleon/packattr.h"
#endif
@ -107,7 +109,7 @@ struct xmac_hdr {
/* The time before sending an announcement within one announcement
cycle. */
#define ANNOUNCEMENT_TIME (rand() % (ANNOUNCEMENT_PERIOD))
#define ANNOUNCEMENT_TIME (random_rand() % (ANNOUNCEMENT_PERIOD))
#define DEFAULT_STROBE_WAIT_TIME (7 * DEFAULT_ON_TIME / 8)
@ -343,7 +345,7 @@ send_packet(void)
rtimer_clock_t t0;
rtimer_clock_t t;
int strobes;
struct xmac_hdr *hdr;
struct xmac_hdr hdr;
int got_ack = 0;
struct {
struct xmac_hdr hdr;
@ -383,15 +385,20 @@ send_packet(void)
off();
rimebuf_hdralloc(sizeof(struct xmac_hdr));
hdr = rimebuf_hdrptr();
hdr->type = TYPE_DATA;
rimeaddr_copy(&hdr->sender, &rimeaddr_node_addr);
rimeaddr_copy(&hdr->receiver, rimebuf_addr(RIMEBUF_ADDR_RECEIVER));
if(rimeaddr_cmp(&hdr->receiver, &rimeaddr_null)) {
/* Create the X-MAC header for the data packet. We cannot do this
in-place in the packet buffer, because we cannot be sure of the
alignment of the header in the packet buffer. */
hdr.type = TYPE_DATA;
rimeaddr_copy(&hdr.sender, &rimeaddr_node_addr);
rimeaddr_copy(&hdr.receiver, rimebuf_addr(RIMEBUF_ADDR_RECEIVER));
if(rimeaddr_cmp(&hdr.receiver, &rimeaddr_null)) {
is_broadcast = 1;
}
/* Copy the X-MAC header to the header portion of the packet
buffer. */
rimebuf_hdralloc(sizeof(struct xmac_hdr));
memcpy(rimebuf_hdrptr(), &hdr, sizeof(struct xmac_hdr));
rimebuf_compact();
t0 = RTIMER_NOW();
@ -642,8 +649,6 @@ static void
send_announcement(void *ptr)
{
struct xmac_hdr *hdr;
struct announcement_msg *adata;
struct announcement *a;
int announcement_len;
/* Set up the probe header. */