* Keep track of last known seqno. Send last known seqno in RREQs.

* If we have rebooted, bump seqno (gleaned from RREQs).

* Reworked filtering of RREQs.

* Use last known seqno check before responding to RREQ that we have a
  route for. Never graft onto an existing but old route.
This commit is contained in:
bg- 2007-05-07 11:51:20 +00:00
parent cce656e23d
commit b9a3721076

View File

@ -28,7 +28,7 @@
*
* This file is part of the Contiki operating system.
*
* $Id: uaodv.c,v 1.12 2007/04/30 15:26:09 bg- Exp $
* $Id: uaodv.c,v 1.13 2007/05/07 11:51:20 bg- Exp $
*/
/**
@ -46,6 +46,9 @@
#include "net/uaodv-def.h"
#include "net/uaodv-rt.h"
#define NDEBUG
#include "lib/assert.h"
#ifdef CC2420_RADIO
#include "dev/cc2420.h"
#endif
@ -69,6 +72,34 @@ static struct uip_udp_conn *bcastconn, *unicastconn;
#define SCMP32(a, b) exit(1)
#endif /* __GNUC__ */
#define NDELETED 4
/*
* Save known seqno:s in network byte order.
*/
static
struct {
uip_ipaddr_t orig;
u32_t seqno;
} lseq[NDELETED];
static CC_INLINE void
save_latest_seqno(const uip_ipaddr_t *originator, const u32_t *seqno)
{
unsigned n = (originator->u8[2] + originator->u8[3]) % NDELETED;
uip_ipaddr_copy(&lseq[n].orig, originator);
lseq[n].seqno = *seqno;
}
static CC_INLINE u32_t
latest_seqno(const uip_ipaddr_t *originator)
{
unsigned n = (originator->u8[2] + originator->u8[3]) % NDELETED;
if(uip_ipaddr_cmp(&lseq[n].orig, originator))
return lseq[n].seqno;
return 0;
}
/*
* When possible, keep state across reboots.
*/
@ -101,7 +132,7 @@ fwc_add(const uip_ipaddr_t *orig, const u32_t *id)
fwcache[n].orig = *orig;
}
#if 0
#ifdef NDEBUG
#define PRINTF(...) do {} while (0)
#define print_debug(...) do{}while(0)
#else
@ -150,12 +181,15 @@ send_rreq(uip_ipaddr_t *addr)
print_debug("send RREQ for %d.%d.%d.%d\n", uip_ipaddr_to_quad(addr));
rm->type = UAODV_RREQ_TYPE;
rm->flags = UAODV_RREQ_UNKSEQNO;
rm->dest_seqno = latest_seqno(addr);
if(rm->dest_seqno == 0)
rm->flags = UAODV_RREQ_UNKSEQNO;
else
rm->flags = 0;
rm->reserved = 0;
rm->hop_count = 0;
rm->rreq_id = htonl(rreq_id++);
uip_ipaddr_copy(&rm->dest_addr, addr);
rm->dest_seqno = 0; /* UNKSEQNO */
uip_gethostaddr(&rm->orig_addr);
rreq_seqno++; /* Always */
rm->orig_seqno = htonl(rreq_seqno);
@ -176,7 +210,7 @@ send_rrep(uip_ipaddr_t *dest, uip_ipaddr_t *nexthop, uip_ipaddr_t *orig,
rm->reserved = 0;
rm->hop_count = hop_count;
uip_ipaddr_copy(&rm->orig_addr, orig);
rm->dest_seqno = htonl(*seqno);
rm->dest_seqno = *seqno;
uip_ipaddr_copy(&rm->dest_addr, dest);
rm->lifetime = HTONL(MY_ROUTE_TIMEOUT);
sendto(nexthop, rm, sizeof(struct uaodv_msg_rrep));
@ -215,26 +249,27 @@ handle_incoming_rreq(void)
rm->hop_count,
uip_ipaddr_to_quad(&rm->dest_addr), ntohl(rm->dest_seqno));
if(uip_ipaddr_cmp(&rm->orig_addr, &uip_hostaddr)) {
return; /* RREQ looped back! */
}
#ifdef CC2420_RADIO
if(cc2420_last_rssi <= -38 || cc2420_last_correlation < 100) {
print_debug("RREQ drop %d %d\n", cc2420_last_rssi,cc2420_last_correlation);
return;
}
{
int ret = cc2420_check_remote(uip_udp_sender()->u16[1]);
if(cc2420_check_remote(uip_udp_sender()->u16[1]) == REMOTE_YES) {
print_debug("RREQ drop is remote\n");
return;
}
if(ret == REMOTE_YES) {
print_debug("RREQ drop is remote\n");
return;
} else if (ret == REMOTE_NO) {
/* Is neigbour, accept it. */
} else if(cc2420_last_rssi <= -38 || cc2420_last_correlation < 100) {
print_debug("RREQ drop %d %d\n",
cc2420_last_rssi,cc2420_last_correlation);
return;
}
}
#endif
/* Have we seen this RREQ before? */
if(uip_ipaddr_cmp(&rm->orig_addr, &uip_hostaddr)
|| fwc_lookup(&rm->orig_addr, &rm->rreq_id)) {
print_debug("Not fwd rreq\n");
return;
}
fwc_add(&rm->orig_addr, &rm->rreq_id);
/* New reverse route? */
rt = uaodv_rt_lookup(&rm->orig_addr);
if(rt == NULL
@ -246,21 +281,51 @@ handle_incoming_rreq(void)
rm->hop_count, ntohl(rm->orig_seqno));
}
/* Check if it is for our address or an existing route. */
if(uip_ipaddr_cmp(&rm->dest_addr, &uip_hostaddr)
|| (fw = uaodv_rt_lookup(&rm->dest_addr)) != NULL) {
print_debug("RREQ for known address\n");
/* Send an RREP back to the source of the RREQ. */
/* Check if it is for our address or a fresh route. */
if(uip_ipaddr_cmp(&rm->dest_addr, &uip_hostaddr)) {
fw = NULL;
} else {
fw = uaodv_rt_lookup(&rm->dest_addr);
if(!(rm->flags & UAODV_RREQ_UNKSEQNO)
&& fw != NULL
&& SCMP32(ntohl(rm->dest_seqno), fw->seqno) >= 0) {
fw = NULL;
}
}
if (fw != NULL) {
u32_t net_seqno;
print_debug("RREQ for known route\n");
uip_ipaddr_copy(&dest_addr, &rm->dest_addr);
uip_ipaddr_copy(&orig_addr, &rm->orig_addr);
if(fw != NULL) /* Existing route. */
send_rrep(&dest_addr, &rt->nexthop, &orig_addr,
&fw->seqno, fw->hop_count + 1);
else {
rreq_seqno++; /* XXX Not really always. */
send_rrep(&dest_addr, &rt->nexthop, &orig_addr, &rreq_seqno, 0);
net_seqno = htonl(fw->seqno);
send_rrep(&dest_addr, &rt->nexthop, &orig_addr, &net_seqno,
fw->hop_count + 1);
} else if(uip_ipaddr_cmp(&rm->dest_addr, &uip_hostaddr)) {
u32_t net_seqno;
print_debug("RREQ for our address\n");
uip_ipaddr_copy(&dest_addr, &rm->dest_addr);
uip_ipaddr_copy(&orig_addr, &rm->orig_addr);
if(!(rm->flags & UAODV_RREQ_UNKSEQNO)
&& SCMP32(rreq_seqno, ntohl(rm->dest_seqno)) < 0) {
print_debug("New rreq_seqno\n"); /* We must have rebooted. */
rreq_seqno = ntohl(rm->dest_seqno) + 1;
} else {
rreq_seqno++;
}
net_seqno = htonl(rreq_seqno);
send_rrep(&dest_addr, &rt->nexthop, &orig_addr, &net_seqno, 0);
} else {
/* Have we seen this RREQ before? */
if(fwc_lookup(&rm->orig_addr, &rm->rreq_id)) {
print_debug("RREQ cached, not fwd\n");
return;
}
fwc_add(&rm->orig_addr, &rm->rreq_id);
print_debug("RREQ fwd\n");
rm->hop_count++;
uip_udp_packet_send(bcastconn, rm, sizeof(struct uaodv_msg_rreq));
@ -342,6 +407,7 @@ handle_incoming_rerr(void)
if(rt != NULL
&& uip_ipaddr_cmp(&rt->nexthop, uip_udp_sender())
&& SCMP32(rt->seqno, ntohl(rm->unreach[0].seqno)) <= 0) {
save_latest_seqno(&rm->unreach[0].addr, &rm->unreach[0].seqno);
uaodv_rt_remove(rt);
print_debug("RERR rebroadcast\n");
uip_udp_packet_send(bcastconn, rm, sizeof(struct uaodv_msg_rerr));
@ -382,6 +448,8 @@ static u32_t bad_seqno; /* In network byte order! */
void
uaodv_bad_route(struct uaodv_rt_entry *rt)
{
u32_t net_seqno = htonl(rt->seqno);
save_latest_seqno(&rt->dest, &net_seqno);
uip_ipaddr_copy(&bad_dest, &rt->dest);
bad_seqno = htonl(rt->seqno);
command = COMMAND_SEND_RERR;