cregit-Linux how code gets into the kernel

Release 4.7 samples/bpf/parse_simple.c

Directory: samples/bpf
/* 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.
 */
#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 <net/ip.h>
#include "bpf_helpers.h"


#define DEFAULT_PKTGEN_UDP_PORT 9

/* copy of 'struct ethhdr' without __packed */

struct eth_hdr {
	
unsigned char   h_dest[ETH_ALEN];
	
unsigned char   h_source[ETH_ALEN];
	
unsigned short  h_proto;
};

SEC("simple")

int handle_ingress(struct __sk_buff *skb) { void *data = (void *)(long)skb->data; struct eth_hdr *eth = data; struct iphdr *iph = data + sizeof(*eth); struct udphdr *udp = data + sizeof(*eth) + sizeof(*iph); void *data_end = (void *)(long)skb->data_end; /* single length check */ if (data + sizeof(*eth) + sizeof(*iph) + sizeof(*udp) > data_end) return 0; if (eth->h_proto != htons(ETH_P_IP)) return 0; if (iph->protocol != IPPROTO_UDP || iph->ihl != 5) return 0; if (ip_is_fragment(iph)) return 0; if (udp->dest == htons(DEFAULT_PKTGEN_UDP_PORT)) return TC_ACT_SHOT; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
alexei starovoitovalexei starovoitov165100.00%1100.00%
Total165100.00%1100.00%

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

Overall Contributors

PersonTokensPropCommitsCommitProp
alexei starovoitovalexei starovoitov232100.00%1100.00%
Total232100.00%1100.00%
Directory: samples/bpf
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