RE: [lwip-users] arp reply, no ping

[Charles-Christophe Thomart]

Thanks Chris, this helped me solve one of my problems.

I am using lwIP/ppp on home phones, and had a problem with packets not 
redirected to the ppp stack. The reason was that netif->flags was not set 
with NETIF_FLAG_UP.
For what I see in lwip/ppp code, the netif_set_up function is never called 
(my version is CVS, two weeks old).

I suggest the following change:
===== ppp/ppp.c line 996 =====
/*
 * sifup - Config the interface up and enable IP packets to pass.
 */
int sifup(int pd)
{
    PPPControl *pc = &pppControl[pd];
    int st = 1;

    if (pd < 0 || pd >= NUM_PPP || !pc->openFlag) {
        st = 0;
        PPPDEBUG((LOG_WARNING, "sifup[%d]: bad parms\n", pd));
    } else {
  netif_remove(&pc->netif);
  if (netif_add(&pc->netif, &pc->addrs.our_ipaddr, &pc->addrs.netmask, 
&pc->addrs.his_ipaddr, (void *)pd, pppifNetifInit, ip_input)) {
          pc->if_up = 1;
          pc->errCode = PPPERR_NONE;

+      netif_set_up(&pc->netif);

   PPPDEBUG((LOG_DEBUG, "sifup: unit %d: linkStatusCB=%lx errCode=%d\n", 
pd, pc->linkStatusCB, pc->errCode));
   if(pc->linkStatusCB)
    pc->linkStatusCB(pc->linkStatusCtx, pc->errCode, &pc->addrs);
  } else {
         st = 0;
         PPPDEBUG((LOG_ERR, "sifup[%d]: netif_add failed\n", pd));
  }
    }

    return st;
}
==========

There is no need for error checking since it is just a flag to set.
I do not see a better place to put it since the netif structure is not given 
to the user callback function. PPP could just want to create interface and 
let user set it up, but then the comment of this function seems wrong to me.
Please correct me if you think I did not get the catch.

Cheers,
Charles-Christophe

> I found and fixed the problem that I earlier reported.>
> After setting my ethernet interface as the default interface with 
> netif_set_default(ethif), I apparently needed to bring it up with 
> >netif_set_up(ethif). This was not done in the 
> contrib/ports/unix/minimal/main.c code. Is this code outdated?

> Cheers,
> Chris