struct udpiphdr *udp_read(void)
{
int len;
char *ptr;
struct ether_header *eptr;
for ( ; ; ) {
// 从分组捕获设备获取下一个分组
ptr = next_pcap(&len);
switch (datalink) {
case DLT_NULL: // loopback header = 4 bytes
return(udp_check(ptr + 4, len - 4));
case DLT_EN10MB:
eptr = (struct ether_header *) ptr;
if (ntohs(eptr->ether_type) != ETHERTYPE_IP) {
err_quit("Ethernet type %x not IP", ntohs(eptr->ether_type));
}
return(udp_check(ptr + 14, len - 14));
case DLT_SLIP: // SLIP header = 24 bytes
return(udp_check(ptr + 24, len - 24));
case DLT_PPP: // PPP header = 24 bytes
return(udp_check(ptr + 24, len - 24));
default:
err_quit("unsupported datalink (%d)", datalink);
}
}
}
void capture_packet(pcap_t *pd)
{
int len;
char *ptr = NULL;
for(;;)
{
ptr = next_pcap(&len, pd);
if(ptr == NULL)
{
log_print(LOG_TYPE_ERROR,"ptr is NULL!\n");
exit(1);
}
if (len < (ETHER_LEN + IP_LEN + UDP_LEN)) {
log_print(LOG_TYPE_ERROR, "packet is too small\n");
continue;
}
insert_packet(ptr, len);
}
}
void tcp_read(void)
{
int len;
char *ptr;
struct ether_header *eptr;
for ( ; ; )
{
ptr = next_pcap(&len);
switch (datalink)
{
case DLT_NULL: /* loopback header = 4 bytes */
printf("case 1 packet\n");
return ;
//(check(ptr + 4, len - 4));
case DLT_EN10MB:
eptr = (struct ether_header *) ptr;
if (ntohs(eptr->ether_type) != ETHERTYPE_IP)
printf("Ethernet type %x not IP", ntohs(eptr->ether_type));
printf("\n\ncase 2 packet IPHEADER\n");
check(ptr + 14, len - 14);
return ;
// (check(ptr + 14, len - 14));
case DLT_SLIP: /* SLIP header = 24 bytes */
printf("case 3 packet\n");
return ;
//(check(ptr + 24, len - 24));
case DLT_PPP: /* PPP header = 24 bytes */
printf("case 4 packet\n");
return ;
//(check(ptr + 24, len - 24));
default:
printf("unsupported datalink (%d)", datalink);
}
}
}