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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2020 Google LLC.
*/
#include <errno.h>
#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <bpf/bpf_helpers.h>
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, __u32);
} test_result SEC(".maps");
SEC("cgroup_skb/egress")
int load_bytes_relative(struct __sk_buff *skb)
{
struct ethhdr eth;
struct iphdr iph;
__u32 map_key = 0;
__u32 test_passed = 0;
/* MAC header is not set by the time cgroup_skb/egress triggers */
if (bpf_skb_load_bytes_relative(skb, 0, ð, sizeof(eth),
BPF_HDR_START_MAC) != -EFAULT)
goto fail;
if (bpf_skb_load_bytes_relative(skb, 0, &iph, sizeof(iph),
BPF_HDR_START_NET))
goto fail;
if (bpf_skb_load_bytes_relative(skb, 0xffff, &iph, sizeof(iph),
BPF_HDR_START_NET) != -EFAULT)
goto fail;
test_passed = 1;
fail:
bpf_map_update_elem(&test_result, &map_key, &test_passed, BPF_ANY);
return 1;
}
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