[linux-2.6-block.git] / samples / bpf / parse_ldabs.c

/* 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_helpers.h"

#define DEFAULT_PKTGEN_UDP_PORT	9
#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))
		& (IP_MF | IP_OFFSET);
}

SEC("ldabs")
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";
Commit	Line	Data
65d472fb AS	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	*/
96a8eb1e	7	#define KBUILD_MODNAME "foo"
65d472fb AS	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_helpers.h"
	15
	16	#define DEFAULT_PKTGEN_UDP_PORT 9
	17	#define IP_MF 0x2000
	18	#define IP_OFFSET 0x1FFF
	19
	20	static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
	21	{
	22	return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
	23	& (IP_MF \| IP_OFFSET);
	24	}
	25
	26	SEC("ldabs")
	27	int handle_ingress(struct __sk_buff *skb)
	28	{
	29	__u64 troff = ETH_HLEN + sizeof(struct iphdr);
	30
	31	if (load_half(skb, offsetof(struct ethhdr, h_proto)) != ETH_P_IP)
	32	return 0;
	33	if (load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol)) != IPPROTO_UDP \|\|
	34	load_byte(skb, ETH_HLEN) != 0x45)
	35	return 0;
	36	if (ip_is_fragment(skb, ETH_HLEN))
	37	return 0;
	38	if (load_half(skb, troff + offsetof(struct udphdr, dest)) == DEFAULT_PKTGEN_UDP_PORT)
	39	return TC_ACT_SHOT;
	40	return 0;
	41	}
	42	char _license[] SEC("license") = "GPL";