在C中获取LAN网络上的所有主机？

Question

Is it possible to get all the hosts on a LAN network(using C). I need to get the IP addresses and host names.

Answer 1

As explained in this answer , the to ping all hosts in your subnet and see which respond or access the ARP cache. The first approach is accomplished by creating a raw socket using

int sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP));

However, raw sockets basically give you only the IP header so you need to construct the ICMP echo packet yourself. After you constructed it, then you just send them to every IP in the subnet using sendto() and wait for response. For the second approach I suggest reading something like this .

As for determining the host names, it depends on whether the hosts have DNS or NETBIOS names. If you have a DNS configured on your LAN, you may get away with calling getaddrinfo() on the the addresses that respond. Unfortunately, I do not have any idea how to find out the NETBIOS name of any given IP.