cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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parse_ldabs.c (1230B)

      1/* Copyright (c) 2016 Facebook
      2 *
      3 * This program is free software; you can redistribute it and/or
      4 * modify it under the terms of version 2 of the GNU General Public
      5 * License as published by the Free Software Foundation.
      6 */
      7#define KBUILD_MODNAME "foo"
      8#include <linux/ip.h>
      9#include <linux/ipv6.h>
     10#include <linux/in.h>
     11#include <linux/tcp.h>
     12#include <linux/udp.h>
     13#include <uapi/linux/bpf.h>
     14#include <bpf/bpf_helpers.h>
     15#include "bpf_legacy.h"
     16
     17#define DEFAULT_PKTGEN_UDP_PORT	9
     18#define IP_MF			0x2000
     19#define IP_OFFSET		0x1FFF
     20
     21static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
     22{
     23	return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
     24		& (IP_MF | IP_OFFSET);
     25}
     26
     27SEC("ldabs")
     28int handle_ingress(struct __sk_buff *skb)
     29{
     30	__u64 troff = ETH_HLEN + sizeof(struct iphdr);
     31
     32	if (load_half(skb, offsetof(struct ethhdr, h_proto)) != ETH_P_IP)
     33		return 0;
     34	if (load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol)) != IPPROTO_UDP ||
     35	    load_byte(skb, ETH_HLEN) != 0x45)
     36		return 0;
     37	if (ip_is_fragment(skb, ETH_HLEN))
     38		return 0;
     39	if (load_half(skb, troff + offsetof(struct udphdr, dest)) == DEFAULT_PKTGEN_UDP_PORT)
     40		return TC_ACT_SHOT;
     41	return 0;
     42}
     43char _license[] SEC("license") = "GPL";