/*
* Handler for the connection "arp" command:
* arp show
* arp show -ip ip_addr
* arp del
* arp del -ip ip_addr
*/
void arpCmd()
{
char *next_tok;
uchar mac_addr[6], ip_addr[4];
next_tok = strtok(NULL, " \n");
if (next_tok == NULL)
{
printf("[arpCmd]:: missing arp action.. type help arp for usage \n");
return;
}
if (!strcmp(next_tok, "show"))
ARPPrintTable();
else if (!strcmp(next_tok, "del"))
{
if ((next_tok = strtok(NULL, " \n")) != NULL)
{
if (!strcmp("-ip", next_tok))
{
next_tok = strtok(NULL, " \n");
Dot2IP(next_tok, ip_addr);
ARPDeleteEntry(ip_addr);
}
} else
ARPReInitTable();
} else if (!strcmp(next_tok, "add"))
{
if ((next_tok = strtok(NULL, " \n")) != NULL)
{
if (!strcmp("-ip", next_tok))
{
next_tok = strtok(NULL, " \n");
Dot2IP(next_tok, ip_addr);
}
} else if ((next_tok = strtok(NULL, " \n")) != NULL)
{
if (!strcmp("-mac", next_tok))
{
next_tok = strtok(NULL, " \n");
Colon2MAC(next_tok, mac_addr);
ARPAddEntry(ip_addr, mac_addr);
}
}
}
}
/*
* ARPProcess: Process a received ARP packet... from remote nodes. If it is
* a reply for a ARP request sent from the local node, use it
* to update the local ARP cache. Flush (dequeue, process, and send) any packets
* that are buffered for ARP processing that match the ARP reply.
* If it a request, send a reply.. no need to record any state here.
*/
void ARPProcess(gpacket_t *pkt)
{
char tmpbuf[MAX_TMPBUF_LEN];
arp_packet_t *apkt = (arp_packet_t *) pkt->data.data;
// check packet is ethernet and addresses of IP type.. otherwise throw away
if ((ntohs(apkt->hw_addr_type) != ETHERNET_PROTOCOL) || (ntohs(apkt->arp_prot) != IP_PROTOCOL))
{
verbose(2, "[ARPProcess]:: unknown hwtype or protocol, dropping ARP packet");
return;
}
verbose(2, "[ARPProcess]:: adding sender of received packet to ARP table");
ARPAddEntry(gNtohl((uchar *)tmpbuf, apkt->src_ip_addr), apkt->src_hw_addr);
// Check it's actually destined to us,if not throw packet
if (COMPARE_IP(apkt->dst_ip_addr, gHtonl((uchar *)tmpbuf, pkt->frame.src_ip_addr)) != 0)
{
verbose(2, "[APRProcess]:: packet has a frame source (after ntohl) %s ...",
IP2Dot(tmpbuf, gNtohl((uchar *)tmpbuf, pkt->frame.src_ip_addr)));
verbose(2, "[APRProcess]:: packet destined for %s, dropping",
IP2Dot(tmpbuf, gNtohl((uchar *)tmpbuf, apkt->dst_ip_addr)));
return;
}
// We have a valid ARP packet, lets process it now.
// If it's a REQUEST, send a reply back
if (ntohs(apkt->arp_opcode) == ARP_REQUEST)
{
apkt->arp_opcode = htons(ARP_REPLY);
COPY_MAC(apkt->src_hw_addr, pkt->frame.src_hw_addr);
COPY_MAC(apkt->dst_hw_addr, pkt->data.header.src);
COPY_IP(apkt->dst_ip_addr, apkt->src_ip_addr);
COPY_IP(apkt->src_ip_addr, gHtonl((uchar *)tmpbuf, pkt->frame.src_ip_addr));
verbose(2, "[ARPProcess]:: packet was ARP REQUEST, sending ARP REPLY packet");
// prepare for sending. Set some parameters that is going to be used
// by the GNET adapter...
pkt->frame.dst_interface = pkt->frame.src_interface;
COPY_MAC(pkt->data.header.dst, pkt->data.header.src);
COPY_MAC(pkt->data.header.src, pkt->frame.src_hw_addr);
COPY_IP(pkt->frame.nxth_ip_addr, gNtohl((uchar *)tmpbuf, apkt->dst_ip_addr));
pkt->frame.arp_valid = TRUE;
pkt->data.header.prot = htons(ARP_PROTOCOL);
ARPSend2Output(pkt);
}
else if (ntohs(apkt->arp_opcode) == ARP_REPLY)
{
// Flush buffer of any packets waiting for the incoming ARP..
verbose(2, "[ARPProcess]:: packet was ARP REPLY... ");
ARPFlushBuffer(gNtohl((uchar *)tmpbuf, apkt->src_ip_addr), apkt->src_hw_addr);
verbose(2, "[ARPProcess]:: flushed the ARP buffer ... ");
}
else
verbose(2, "[ARPProcess]:: unknown ARP type");
return;
}
