//------------------------------------------------------------------------
// rarp_in - handle RARP packet coming in from Ethernet network
//------------------------------------------------------------------------
int
rarp_in(struct epacket *packet, int dev)
{
int ps;
int pid;
int ret;
struct arppak *apacptr;
struct etblk *etptr;
apacptr = (struct arppak *)packet->ep_data;
ret = SYSERR;
if (net2hs(apacptr->ar_op) == AR_RRLY) {
etptr = (struct etblk *)devtab[dev].iobuf;
if (memcmp(apacptr->ar_tha, etptr->etpaddr, EPADLEN) == 0) {
memmove(Net.myaddr, apacptr->ar_tpa, IPLEN);
netnum(Net.mynet, Net.myaddr);
ps = disable();
Net.mavalid = TRUE;
pid = Arp.rarppid;
if (!isbadpid(pid)) {
Arp.rarppid = BADPID;
send(pid, OK);
}
restore(ps);
}
ret = OK;
}
freebuf(packet);
return ret;
}
/*------------------------------------------------------------------------
* netmask - set the default mask for the given net
*------------------------------------------------------------------------
*/
IPaddr
netmask(IPaddr net)
{
IPaddr netpart;
int i;
if (net == 0)
return net;
/* check for net match (for subnets) */
netpart = netnum(net);
for (i=0; i<Net.nif; ++i)
if (nif[i].ni_svalid && nif[i].ni_ivalid &&
nif[i].ni_net == netpart)
return nif[i].ni_mask;
if (IP_CLASSA(net)) return hl2net(0xff000000);
if (IP_CLASSB(net)) return hl2net(0xffff0000);
if (IP_CLASSC(net)) return hl2net(0xffffff00);
return ~0;
}
