From 54957e4e03e6cef3a6f99d7562306b6981c2e69e Mon Sep 17 00:00:00 2001 From: Simon Duquennoy Date: Thu, 23 Jun 2016 18:28:18 +0200 Subject: [PATCH] mac-seqno: add a lifetime to sequence numbers in history --- core/net/mac/mac-sequence.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/core/net/mac/mac-sequence.c b/core/net/mac/mac-sequence.c index 40ac3c28a..ccbbb2114 100644 --- a/core/net/mac/mac-sequence.c +++ b/core/net/mac/mac-sequence.c @@ -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)); }