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mac-seqno: add a lifetime to sequence numbers in history

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This commit is contained in:
Simon Duquennoy 2016-06-23 18:28:18 +02:00
parent a8989f9f1c
commit 54957e4e03
1 changed files with 16 additions and 1 deletions
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17
core/net/mac/mac-sequence.c
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@ -51,9 +51,16 @@
struct seqno {
linkaddr_t sender;
clock_time_t timestamp;
uint8_t seqno;
};
#ifdef NETSTACK_CONF_MAC_SEQNO_MAX_AGE
#define SEQNO_MAX_AGE NETSTACK_CONF_MAC_SEQNO_MAX_AGE
#else /* NETSTACK_CONF_MAC_SEQNO_MAX_AGE */
#define SEQNO_MAX_AGE (20 * CLOCK_SECOND)
#endif /* NETSTACK_CONF_MAC_SEQNO_MAX_AGE */
#ifdef NETSTACK_CONF_MAC_SEQNO_HISTORY
#define MAX_SEQNOS NETSTACK_CONF_MAC_SEQNO_HISTORY
#else /* NETSTACK_CONF_MAC_SEQNO_HISTORY */
@ -66,6 +73,7 @@ int
mac_sequence_is_duplicate(void)
{
int i;
clock_time_t now = clock_time();
/*
* Check for duplicate packet by comparing the sequence number of the incoming
@ -75,8 +83,14 @@ mac_sequence_is_duplicate(void)
if(linkaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_SENDER),
&received_seqnos[i].sender)) {
if(packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO) == received_seqnos[i].seqno) {
/* Duplicate packet. */
#if SEQNO_MAX_AGE > 0
if(now - received_seqnos[i].timestamp <= SEQNO_MAX_AGE) {
/* Duplicate packet. */
return 1;
}
#else /* SEQNO_MAX_AGE > 0 */
return 1;
#endif /* SEQNO_MAX_AGE > 0 */
}
break;
}
@ -103,6 +117,7 @@ mac_sequence_register_seqno(void)
memcpy(&received_seqnos[j], &received_seqnos[j - 1], sizeof(struct seqno));
}
received_seqnos[0].seqno = packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO);
received_seqnos[0].timestamp = clock_time();
linkaddr_copy(&received_seqnos[0].sender,
packetbuf_addr(PACKETBUF_ADDR_SENDER));
}