cregit-Linux how code gets into the kernel

Release 4.7 samples/bpf/parse_ldabs.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 "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); }

Contributors

PersonTokensPropCommitsCommitProp
alexei starovoitovalexei starovoitov37100.00%1100.00%
Total37100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
alexei starovoitovalexei starovoitov109100.00%1100.00%
Total109100.00%1100.00%

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

Overall Contributors

PersonTokensPropCommitsCommitProp
alexei starovoitovalexei starovoitov194100.00%1100.00%
Total194100.00%1100.00%
Directory: samples/bpf
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