eBPFPacketFilter

#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/in.h>

SEC("filter")
int filter_packets(struct __sk_buff *skb) {
    void *data = (void *)(long)skb->data;
    void *data_end = (void *)(long)skb->data_end;
    struct ethhdr *eth = data;
    struct iphdr *ip = data + sizeof(*eth);

    if (data + sizeof(*eth) + sizeof(*ip) > data_end)
        return 0;

    if (eth->h_proto == htons(ETH_P_IP) && ip->protocol == IPPROTO_TCP) {
        // Implement your filtering logic here
        // Example: Drop packets from a specific IP address
        if (ip->saddr == inet_addr("192.168.1.1"))
            return TC_ACT_SHOT;
    }

    return TC_ACT_OK;
}

char _license[] SEC("license") = "GPL";