64 lines
1.3 KiB
C
64 lines
1.3 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include <stdint.h>
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#include <stdbool.h>
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#include <linux/bpf.h>
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#include <linux/stddef.h>
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#include <linux/pkt_cls.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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volatile const __u32 IFINDEX_SRC;
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volatile const __u32 IFINDEX_DST;
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static const __u8 src_mac[] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55};
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static const __u8 dst_mac[] = {0x00, 0x22, 0x33, 0x44, 0x55, 0x66};
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SEC("tc")
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int tc_chk(struct __sk_buff *skb)
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{
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return TC_ACT_SHOT;
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}
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SEC("tc")
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int tc_dst(struct __sk_buff *skb)
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{
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return bpf_redirect_peer(IFINDEX_SRC, 0);
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}
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SEC("tc")
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int tc_src(struct __sk_buff *skb)
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{
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return bpf_redirect_peer(IFINDEX_DST, 0);
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}
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SEC("tc")
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int tc_dst_l3(struct __sk_buff *skb)
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{
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return bpf_redirect(IFINDEX_SRC, 0);
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}
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SEC("tc")
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int tc_src_l3(struct __sk_buff *skb)
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{
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__u16 proto = skb->protocol;
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if (bpf_skb_change_head(skb, ETH_HLEN, 0) != 0)
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return TC_ACT_SHOT;
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if (bpf_skb_store_bytes(skb, 0, &src_mac, ETH_ALEN, 0) != 0)
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return TC_ACT_SHOT;
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if (bpf_skb_store_bytes(skb, ETH_ALEN, &dst_mac, ETH_ALEN, 0) != 0)
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return TC_ACT_SHOT;
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if (bpf_skb_store_bytes(skb, ETH_ALEN + ETH_ALEN, &proto, sizeof(__u16), 0) != 0)
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return TC_ACT_SHOT;
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return bpf_redirect_peer(IFINDEX_DST, 0);
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}
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char __license[] SEC("license") = "GPL";
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