/**
* Format and send a ICMP packet.
* \note: src and dest are on network order.
*/
static int icmp_send (struct _pkt *pkt, DWORD src, DWORD dest, int length)
{
in_Header *ip = &pkt->ip;
ICMP_PKT *icmp = &pkt->icmp;
icmp->unused.checksum = 0;
icmp->unused.checksum = ~CHECKSUM (icmp, length);
return IP4_OUTPUT (ip, src, dest, ICMP_PROTO, 0, 0, 0, length, NULL);
}
static int ping_gateway (DWORD host, void *eth)
{
struct ping_pkt *pkt;
struct icmp_echo *icmp;
struct in_Header *ip;
int len;
pkt = (struct ping_pkt*) _eth_formatpacket (eth, IP4_TYPE);
ip = &pkt->in;
icmp = &pkt->icmp;
len = sizeof (*icmp);
icmp_id = (WORD) set_timeout (0); /* "random" id */
icmp->type = ICMP_ECHO;
icmp->code = 0;
icmp->index = 1;
icmp->identifier = icmp_id;
icmp->sequence = icmp_seq++;
icmp->checksum = 0;
icmp->checksum = ~CHECKSUM (icmp, len);
return IP4_OUTPUT (ip, 0, intel(host), ICMP_PROTO, 1,
(BYTE)_default_tos, 0, len, NULL);
}