f74599f7c5
Adds a series of tests to verify the functionality of attaching
BPF programs at LWT hooks.
Also adds a sample which collects a histogram of packet sizes which
pass through an LWT hook.
$ ./lwt_len_hist.sh
Starting netserver with host 'IN(6)ADDR_ANY' port '12865' and family AF_UNSPEC
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.253.2 () port 0 AF_INET : demo
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
87380 16384 16384 10.00 39857.69
1 -> 1 : 0 | |
2 -> 3 : 0 | |
4 -> 7 : 0 | |
8 -> 15 : 0 | |
16 -> 31 : 0 | |
32 -> 63 : 22 | |
64 -> 127 : 98 | |
128 -> 255 : 213 | |
256 -> 511 : 1444251 |******** |
512 -> 1023 : 660610 |*** |
1024 -> 2047 : 535241 |** |
2048 -> 4095 : 19 | |
4096 -> 8191 : 180 | |
8192 -> 16383 : 5578023 |************************************* |
16384 -> 32767 : 632099 |*** |
32768 -> 65535 : 6575 | |
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
254 lines
6.0 KiB
C
254 lines
6.0 KiB
C
/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <stdint.h>
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#include <stddef.h>
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#include <linux/bpf.h>
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#include <linux/ip.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/icmpv6.h>
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#include <linux/if_ether.h>
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#include "bpf_helpers.h"
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#include <string.h>
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# define printk(fmt, ...) \
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({ \
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char ____fmt[] = fmt; \
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bpf_trace_printk(____fmt, sizeof(____fmt), \
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##__VA_ARGS__); \
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})
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#define CB_MAGIC 1234
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/* Test: Pass all packets through */
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SEC("nop")
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int do_nop(struct __sk_buff *skb)
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{
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return BPF_OK;
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}
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/* Test: Verify context information can be accessed */
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SEC("test_ctx")
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int do_test_ctx(struct __sk_buff *skb)
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{
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skb->cb[0] = CB_MAGIC;
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printk("len %d hash %d protocol %d\n", skb->len, skb->hash,
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skb->protocol);
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printk("cb %d ingress_ifindex %d ifindex %d\n", skb->cb[0],
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skb->ingress_ifindex, skb->ifindex);
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return BPF_OK;
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}
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/* Test: Ensure skb->cb[] buffer is cleared */
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SEC("test_cb")
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int do_test_cb(struct __sk_buff *skb)
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{
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printk("cb0: %x cb1: %x cb2: %x\n", skb->cb[0], skb->cb[1],
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skb->cb[2]);
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printk("cb3: %x cb4: %x\n", skb->cb[3], skb->cb[4]);
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return BPF_OK;
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}
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/* Test: Verify skb data can be read */
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SEC("test_data")
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int do_test_data(struct __sk_buff *skb)
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{
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void *data = (void *)(long)skb->data;
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void *data_end = (void *)(long)skb->data_end;
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struct iphdr *iph = data;
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if (data + sizeof(*iph) > data_end) {
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printk("packet truncated\n");
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return BPF_DROP;
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}
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printk("src: %x dst: %x\n", iph->saddr, iph->daddr);
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return BPF_OK;
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}
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#define IP_CSUM_OFF offsetof(struct iphdr, check)
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#define IP_DST_OFF offsetof(struct iphdr, daddr)
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#define IP_SRC_OFF offsetof(struct iphdr, saddr)
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#define IP_PROTO_OFF offsetof(struct iphdr, protocol)
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#define TCP_CSUM_OFF offsetof(struct tcphdr, check)
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#define UDP_CSUM_OFF offsetof(struct udphdr, check)
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#define IS_PSEUDO 0x10
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static inline int rewrite(struct __sk_buff *skb, uint32_t old_ip,
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uint32_t new_ip, int rw_daddr)
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{
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int ret, off = 0, flags = IS_PSEUDO;
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uint8_t proto;
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ret = bpf_skb_load_bytes(skb, IP_PROTO_OFF, &proto, 1);
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if (ret < 0) {
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printk("bpf_l4_csum_replace failed: %d\n", ret);
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return BPF_DROP;
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}
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switch (proto) {
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case IPPROTO_TCP:
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off = TCP_CSUM_OFF;
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break;
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case IPPROTO_UDP:
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off = UDP_CSUM_OFF;
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flags |= BPF_F_MARK_MANGLED_0;
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break;
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case IPPROTO_ICMPV6:
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off = offsetof(struct icmp6hdr, icmp6_cksum);
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break;
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}
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if (off) {
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ret = bpf_l4_csum_replace(skb, off, old_ip, new_ip,
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flags | sizeof(new_ip));
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if (ret < 0) {
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printk("bpf_l4_csum_replace failed: %d\n");
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return BPF_DROP;
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}
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}
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ret = bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
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if (ret < 0) {
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printk("bpf_l3_csum_replace failed: %d\n", ret);
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return BPF_DROP;
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}
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if (rw_daddr)
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ret = bpf_skb_store_bytes(skb, IP_DST_OFF, &new_ip, sizeof(new_ip), 0);
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else
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ret = bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
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if (ret < 0) {
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printk("bpf_skb_store_bytes() failed: %d\n", ret);
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return BPF_DROP;
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}
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return BPF_OK;
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}
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/* Test: Verify skb data can be modified */
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SEC("test_rewrite")
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int do_test_rewrite(struct __sk_buff *skb)
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{
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uint32_t old_ip, new_ip = 0x3fea8c0;
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int ret;
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ret = bpf_skb_load_bytes(skb, IP_DST_OFF, &old_ip, 4);
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if (ret < 0) {
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printk("bpf_skb_load_bytes failed: %d\n", ret);
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return BPF_DROP;
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}
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if (old_ip == 0x2fea8c0) {
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printk("out: rewriting from %x to %x\n", old_ip, new_ip);
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return rewrite(skb, old_ip, new_ip, 1);
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}
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return BPF_OK;
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}
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static inline int __do_push_ll_and_redirect(struct __sk_buff *skb)
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{
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uint64_t smac = SRC_MAC, dmac = DST_MAC;
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int ret, ifindex = DST_IFINDEX;
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struct ethhdr ehdr;
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ret = bpf_skb_change_head(skb, 14, 0);
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if (ret < 0) {
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printk("skb_change_head() failed: %d\n", ret);
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}
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ehdr.h_proto = __constant_htons(ETH_P_IP);
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memcpy(&ehdr.h_source, &smac, 6);
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memcpy(&ehdr.h_dest, &dmac, 6);
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ret = bpf_skb_store_bytes(skb, 0, &ehdr, sizeof(ehdr), 0);
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if (ret < 0) {
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printk("skb_store_bytes() failed: %d\n", ret);
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return BPF_DROP;
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}
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return bpf_redirect(ifindex, 0);
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}
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SEC("push_ll_and_redirect_silent")
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int do_push_ll_and_redirect_silent(struct __sk_buff *skb)
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{
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return __do_push_ll_and_redirect(skb);
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}
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SEC("push_ll_and_redirect")
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int do_push_ll_and_redirect(struct __sk_buff *skb)
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{
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int ret, ifindex = DST_IFINDEX;
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ret = __do_push_ll_and_redirect(skb);
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if (ret >= 0)
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printk("redirected to %d\n", ifindex);
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return ret;
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}
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static inline void __fill_garbage(struct __sk_buff *skb)
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{
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uint64_t f = 0xFFFFFFFFFFFFFFFF;
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bpf_skb_store_bytes(skb, 0, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 8, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 16, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 24, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 32, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 40, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 48, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 56, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 64, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 72, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 80, &f, sizeof(f), 0);
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bpf_skb_store_bytes(skb, 88, &f, sizeof(f), 0);
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}
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SEC("fill_garbage")
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int do_fill_garbage(struct __sk_buff *skb)
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{
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__fill_garbage(skb);
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printk("Set initial 96 bytes of header to FF\n");
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return BPF_OK;
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}
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SEC("fill_garbage_and_redirect")
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int do_fill_garbage_and_redirect(struct __sk_buff *skb)
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{
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int ifindex = DST_IFINDEX;
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__fill_garbage(skb);
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printk("redirected to %d\n", ifindex);
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return bpf_redirect(ifindex, 0);
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}
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/* Drop all packets */
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SEC("drop_all")
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int do_drop_all(struct __sk_buff *skb)
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{
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printk("dropping with: %d\n", BPF_DROP);
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return BPF_DROP;
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}
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char _license[] SEC("license") = "GPL";
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