Senior LevelLinux Commands & SysAdmin
What is XDP (eXpress Data Path) and how does it execute packet filtering at the network driver layer?
❓ Interview Prompt: Explain XDP (eXpress Data Path), in-driver eBPF packet processing, bypassing OS socket buffers (sk_buff), and 40Gbps DDoS mitigation.
XDP (eXpress Data Path) is a high-performance bare-metal packet processing framework built into the Linux kernel network stack:
Driver-Level Speed:
XDP executes eBPF programs directly inside the network interface card (NIC) driver before the kernel allocates OS socket buffers ('sk_buff')!
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Allows dropping malicious DDoS packet floods at wire speed (40+ Million Packets Per Second per core) with minimal CPU usage!
Code Implementation Example
c
// XDP eBPF Kernel Program dropping UDP port 53 DNS flood attacks
SEC("xdp")
int xdp_drop_dns(struct xdp_md *ctx) {
void *data = (void *)(long)ctx->data;
void *data_end = (void *)(long)ctx->data_end;
// Parse packet headers...
if (is_dns_flood) {
return XDP_DROP; // Drop packet instantly in network driver!
}
return XDP_PASS;
}💡In-driver XDP eBPF C program dropping malicious network packets at wire speed.
🎯 Interview Key Takeaway
Use XDP eBPF programs at the network driver layer to drop high-volume DDoS packet floods before allocating OS socket buffers.
#XDP#eBPF#Packet Filtering#DDoS Defense#Senior
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