static int icmp_recv(struct netbuf *pkt)
{
struct icmp_header *icmphdr;
icmphdr = (struct icmp_header *)pkt->top;
/* 正式にはコンソールドライバタスクに依頼する必要があるが，とりあえず */
puts("ICMP received: ");
putxval(pkt->option.common.ipaddr.addr, 8); puts(" ");
putxval(icmphdr->type, 2); puts(" ");
putxval(icmphdr->code, 2); puts(" ");
putxval(ntoh2(icmphdr->checksum), 4); puts("\n");
switch (icmphdr->type) {
case ICMP_TYPE_REPLY:
break;
case ICMP_TYPE_REQUEST:
icmp_sendpkt(pkt->option.common.ipaddr.addr,
ICMP_TYPE_REPLY, icmphdr->code,
ntoh2(icmphdr->param.id),
ntoh2(icmphdr->param.sequence_number),
pkt->size - sizeof(struct icmp_header),
(char *)icmphdr + sizeof(*icmphdr));
break;
}
return 0;
}
static int arp_recv(struct netbuf *pkt)
{
struct addrset *addr;
struct arp_header *arphdr;
uint32 ipaddr;
uint32 ipaddr_n;
arphdr = (struct arp_header *)pkt->top;
if (ntoh2(arphdr->hardware) != ARP_HARDWARE_ETHER)
return 0;
if (ntoh2(arphdr->protocol) != ETHERNET_TYPE_IP)
return 0;
switch (ntoh2(arphdr->operation)) {
case ARP_OPERATION_REPLY:
case ARP_OPERATION_REQUEST:
memcpy(&ipaddr_n, arphdr->sender_ipaddr, IPADDR_SIZE);
ipaddr = ntoh4(ipaddr_n);
addr = arp_setaddr(ipaddr, arphdr->sender_macaddr);
arp_flush(-1);
if (ntoh2(arphdr->operation) == ARP_OPERATION_REPLY)
break;
ipaddr_n = hton4(my_ipaddr);
if (memcmp(arphdr->target_ipaddr, &ipaddr_n, IPADDR_SIZE))
break;
/* ARP reply を返送 */
arp_sendpkt(ARP_OPERATION_REPLY, addr->macaddr, addr->ipaddr);
break;
default:
break;
}
return 0;
}
static MyEventType NetGenFunc(EventGenRec *gen, MyEvent *event)
{
int result;
short type, size;
netint2 data[2];
result = MyRead(sock, netBuf + netBufSize, netBufGoal - netBufSize);
if (result < 0) {
lostConn = 1;
return E_lostConn;
}
netBufSize += result;
if (netBufSize < netBufGoal)
return E_none;
memcpy(data, netBuf, sizeof(data));
type = ntoh2(data[0]);
size = ntoh2(data[1]);
if (size >= sizeof(netBuf))
fatal("Received an invalid packet (too large), possibly an attempt\n"
" to exploit a vulnerability in versions before 0.52 !");
netBufGoal = size;
if (netBufSize < netBufGoal)
return E_none;
netBufSize = 0;
netBufGoal = HEADER_SIZE;
event->u.net.type = type;
event->u.net.size = size - HEADER_SIZE;
event->u.net.data = netBuf + HEADER_SIZE;
if (type == NP_endConn) {
gotEndConn = 1;
return E_lostConn;
}
else if (type == NP_byeBye) {
lostConn = 1;
return E_lostConn;
}
return E_net;
}