USDPAA LPM-IPFWD

[zilu]

HI, I have 2 questions about USDPAA-APPS lpm-ipfwd function.

Does somebody  can help me? thank you.

The first: are there some update for usdpaa-apps? 

when we do some test about lpm-ipfwd on T1040 demo board,we found the function ipfwd_del_route is TBD.

that seems it's a uncompleted application. what branch i see is like this:sdk/usdpaa/usdpaa-apps.git - User-Space Data-Path Acceleration Architecture Demo Applications 

Second: also lpm-ipfwd application .if we delete the arp entry,does the ipv4 packet can forward normally?  i think the packet should be drop.But in fact, it can also forward. That's strange.

and if we add arp entry, it's also failed. that's mean once we delete an arp entry, we can never add an entry again!

all those indicate that this usdpaa lpm-ipfwd application all uncomleted.

[yipingwang · Accepted solution]

The function ipfwd_del_route is TBD in SDK 2.0 1703 release, there is no update recently.

static int ipfwd_del_route(const struct app_ctrl_op_info *route_info)
{
        pr_info("ipfwd_del_route: TBD\n");
        return 0;
}

If the frame is to be forwarded, it is checked if ARP entry exists in ARP table for destination IP address. LPM IPFWD
application will not dynamically resolve the ARP. So if sending packets to forward using a regular computer, the user
will have to create static ARP entries. On host computer, ARP table can be updated by sending the ARP request. LPM
IPFWD will respond to external ARP requests.

If ARP entry exists, TTL is decremented in L3 header.

Deleting an ARP Entry
Note: check pid from application print "Message queue to send: /mq_snd_2536"
# lpm_ipfwd_config -P 2536 -H -s 192.168.24.2
Arp Entry Deleted successfully

Adding an ARP Entry
Note: check pid from application print "Message queue to send: /mq_snd_2536"
# lpm_ipfwd_config -P 2536 -G -s 192.168.24.2 -m 02:00:c0:a8:33:fd -r true
ARP Entry Added successfully

[zilu]

Thank you for your reply.

I have known why we can not add ARP entry again if we execute delete an ARP entry.

The count for arp entries(nt->stats->entries) just -- when delete an arp entry, but no ++ when add an arp entry. so the count is overflow.

USDPAA lpm-ipfwd is a good application, but why there are no update for so long time.