Re: [lwip-users] Etharp drops packets for unlisted arp entries

[Leon Woestenberg]

Tom,

Tom C. Barker wrote:

> To confirm, I have 0.7.2. And my observation of my request being dropped 
>  
Your code fragment does not match the 0.7.2 source code from CVS. Please 
re-check.

> /* i is available, create ARP entry */
> arp_table[i].state = ETHARP_STATE_PENDING;
> ip_addr_set(&arp_table[i].ipaddr, ipaddr);
> /* queried address was already in ARP table */
> } else {
> #if ARP_QUEUEING
>   etharp_enqueue(i, q);
> #endif
> }
>  
There is no "} else {" in 0.7.2 (which has etharp.c 1.49.2.4).

This could explain the wrong behaviour you are experiencing. Please see 
that you are
using 0.7.2 or let me know if you think I am wrong in this.

For completeness, I have copied a snippet of code (from 0.7.2) below.

Regards,

Leon.



 /* queried address not yet in ARP table? */
 if (i == ARP_TABLE_SIZE) {
   LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE, ("etharp_query: IP address not 
found in ARP table\n"));
   /* find an available (unused or old) entry */
   i = find_arp_entry();
   /* bail out if no ARP entries are available */
   if (i == ERR_MEM) {
     LWIP_DEBUGF(ETHARP_DEBUG | 2, ("etharp_query: no more ARP entries 
available. Should seldom occur.\n"));
     return ERR_MEM;
   }
   /* i is available, create ARP entry */
   arp_table[i].state = ETHARP_STATE_PENDING;
   ip_addr_set(&arp_table[i].ipaddr, ipaddr);
 }
 /* { i is now valid } */
#if ARP_QUEUEING /* queue packet (even on a stable entry, see above) */
 etharp_enqueue(i, q);
#endif