blob: c6f65f90a0973afe711c033f75e04beb5f33416d [file] [log] [blame]
/* Copyright (c) 2016 Facebook
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
#define KBUILD_MODNAME "foo"
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/in.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <uapi/linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "bpf_legacy.h"
#define IP_MF 0x2000
#define IP_OFFSET 0x1FFF
static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
int handle_ingress(struct __sk_buff *skb)
__u64 troff = ETH_HLEN + sizeof(struct iphdr);
if (load_half(skb, offsetof(struct ethhdr, h_proto)) != ETH_P_IP)
return 0;
if (load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol)) != IPPROTO_UDP ||
load_byte(skb, ETH_HLEN) != 0x45)
return 0;
if (ip_is_fragment(skb, ETH_HLEN))
return 0;
if (load_half(skb, troff + offsetof(struct udphdr, dest)) == DEFAULT_PKTGEN_UDP_PORT)
return TC_ACT_SHOT;
return 0;
char _license[] SEC("license") = "GPL";