void Arp::receive(Packet_ptr pckt) {
PRINT("<ARP handler> got %i bytes of data\n", pckt->size());
header* hdr = reinterpret_cast<header*>(pckt->layer_begin());
/// cache entry
this->cache(hdr->sipaddr, hdr->shwaddr);
/// always try to ship waiting packets when someone talks
auto waiting = waiting_packets_.find(hdr->sipaddr);
if (waiting != waiting_packets_.end()) {
PRINT("<Arp> Had a packet waiting for this IP. Sending\n");
transmit(std::move(waiting->second.pckt), hdr->sipaddr);
waiting_packets_.erase(waiting);
}
switch(hdr->opcode) {
case H_request: {
// Stat increment requests received
requests_rx_++;
PRINT("<Arp> %s is looking for %s\n",
hdr->sipaddr.str().c_str(),
hdr->dipaddr.str().c_str());
if (hdr->dipaddr == inet_.ip_addr()) {
// The packet is for us. Respond.
arp_respond(hdr, inet_.ip_addr());
} else if (proxy_ and proxy_(hdr->dipaddr)){
// The packet is for an IP to which we know a route
arp_respond(hdr, hdr->dipaddr);
} else {
// Drop
PRINT("\t NO MATCH for My IP (%s). DROP!\n",
inet_.ip_addr().str().c_str());
}
break;
}
case H_reply: {
// Stat increment replies received
replies_rx_++;
PRINT("\t ARP REPLY: %s belongs to %s (waiting: %u)\n",
hdr->sipaddr.str().c_str(), hdr->shwaddr.str().c_str(), waiting_packets_.size());
break;
}
default:
PRINT("\t UNKNOWN OPCODE\n");
break;
} //< switch(hdr->opcode)
}
void arp_handle(struct sr_instance* sr, uint8_t * packet, unsigned int length, char* interface) {
if(!arp_valid(packet, length)) {
fprintf(stderr, "ARP packet does not match the recognized format.\n");
return;
}
struct sr_if *sr_interface = sr_get_interface(sr, interface);
if(sr_interface == 0) {
fprintf(stderr, "Failed to retrieve interface %s.\n", interface);
return;
}
struct sr_arphdr *arp_hdr = (struct sr_arphdr *)(packet + sizeof(struct sr_ethernet_hdr));
if(ntohs(arp_hdr->ar_op) == ARP_REQUEST) {
if(arp_hdr->ar_tip == sr_interface->ip)
arp_respond(sr, packet, sr_interface);
else printf("Received ARP packet destined for %d\n", arp_hdr->ar_tip);
}
else if(ntohs(arp_hdr->ar_op) == ARP_REPLY) {
struct sr_arp_record *record = cache_add_record(sr, packet);
if(record == NULL) {
fprintf(stderr, "Received ARP response that does not match any outstanding ARP requests.\n");
return;
}
cache_send_outstanding(sr, record);
}
else {
fprintf(stderr, "ARP packet opcode must be of type request or reply.\n");
}
}
void arp_layer_receive( struct sk_buff *comer_skb ){
assert(comer_skb->pkgsize = 14 + 28);
struct arphdr *arphdr = (void *)(comer_skb->ethhdr + 1);
comer_skb->arphdr = arphdr;
////////////Entry here !!
///////////network byte order to host order, only performed on arp header
BYTE_ENDIAN_FLIP2(arphdr->hardware);
BYTE_ENDIAN_FLIP2(arphdr->protocol);
BYTE_ENDIAN_FLIP2(arphdr->operation);
BYTE_ENDIAN_FLIP4(arphdr->myip);
BYTE_ENDIAN_FLIP4(arphdr->yourip);
//////////done
//u8 *mac = arphdr->mymac;
//oprintf("arp layer receive: operation=%u, from mac(%x %x %x %x %x %x)", arphdr->operation, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
if(arphdr->operation == 1){ /* it's an inquiry */
arp_respond(comer_skb);
}
else if(arphdr->operation == 2){ /* it's a REPLY */
arp_act(comer_skb);
}
else spin("unknown operation");
//oprintf(" ARP layer exit\n");
}
void Arp::bottom(Packet_ptr pckt) {
debug2("<ARP handler> got %i bytes of data\n", pckt->size());
header* hdr = reinterpret_cast<header*>(pckt->buffer());
debug2("Have valid cache? %s\n", is_valid_cached(hdr->sipaddr) ? "YES" : "NO");
cache(hdr->sipaddr, hdr->shwaddr);
switch(hdr->opcode) {
case H_request: {
// Stat increment requests received
requests_rx_++;
debug2("\t ARP REQUEST: ");
debug2("%s is looking for %s\n",
hdr->sipaddr.str().c_str(),
hdr->dipaddr.str().c_str());
if (hdr->dipaddr == inet_.ip_addr()) {
arp_respond(hdr);
} else {
debug2("\t NO MATCH for My IP (%s). DROP!\n",
inet_.ip_addr().str().c_str());
}
break;
}
case H_reply: {
// Stat increment replies received
replies_rx_++;
debug2("\t ARP REPLY: %s belongs to %s (waiting: %u)\n",
hdr->sipaddr.str().c_str(), hdr->shwaddr.str().c_str(), waiting_packets_.size());
auto waiting = waiting_packets_.find(hdr->sipaddr);
if (waiting != waiting_packets_.end()) {
debug("Had a packet waiting for this IP. Sending\n");
transmit(std::move(waiting->second));
waiting_packets_.erase(waiting);
}
break;
}
default:
debug2("\t UNKNOWN OPCODE\n");
break;
} //< switch(hdr->opcode)
}
