49 lines
1003 B
C
49 lines
1003 B
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2020 Google LLC.
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*/
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#include <errno.h>
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#include <linux/bpf.h>
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#include <linux/if_ether.h>
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#include <linux/ip.h>
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#include <bpf/bpf_helpers.h>
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__uint(max_entries, 1);
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__type(key, __u32);
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__type(value, __u32);
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} test_result SEC(".maps");
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SEC("cgroup_skb/egress")
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int load_bytes_relative(struct __sk_buff *skb)
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{
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struct ethhdr eth;
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struct iphdr iph;
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__u32 map_key = 0;
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__u32 test_passed = 0;
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/* MAC header is not set by the time cgroup_skb/egress triggers */
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if (bpf_skb_load_bytes_relative(skb, 0, ð, sizeof(eth),
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BPF_HDR_START_MAC) != -EFAULT)
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goto fail;
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if (bpf_skb_load_bytes_relative(skb, 0, &iph, sizeof(iph),
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BPF_HDR_START_NET))
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goto fail;
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if (bpf_skb_load_bytes_relative(skb, 0xffff, &iph, sizeof(iph),
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BPF_HDR_START_NET) != -EFAULT)
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goto fail;
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test_passed = 1;
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fail:
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bpf_map_update_elem(&test_result, &map_key, &test_passed, BPF_ANY);
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return 1;
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}
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