Eric Lee / smarc-fsl-linux-kernel

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samples/bpf/tcbpf1_kern.c 2.56 KB
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96a8eb1ee   Daniel Borkmann   bpf: fix samples ... 
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  #define KBUILD_MODNAME "foo"
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  #include <uapi/linux/bpf.h>
  #include <uapi/linux/if_ether.h>
  #include <uapi/linux/if_packet.h>
  #include <uapi/linux/ip.h>
  #include <uapi/linux/in.h>
  #include <uapi/linux/tcp.h>
a166151cb   Alexei Starovoitov   bpf: fix bpf help... 
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  #include <uapi/linux/filter.h>
27b29f630   Alexei Starovoitov   bpf: add bpf_redi... 
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  #include <uapi/linux/pkt_cls.h>
7cf245a37   Toke Høiland-Jørgensen   samples/bpf: Use ... 
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  #include <bpf/bpf_helpers.h>
36b5d4711   Andrii Nakryiko   selftests/bpf: sa... 
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  #include "bpf_legacy.h"
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  /* compiler workaround */
  #define _htonl __builtin_bswap32
  
  static inline void set_dst_mac(struct __sk_buff *skb, char *mac)
  {
  	bpf_skb_store_bytes(skb, 0, mac, ETH_ALEN, 1);
  }
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  #define IP_CSUM_OFF (ETH_HLEN + offsetof(struct iphdr, check))
  #define TOS_OFF (ETH_HLEN + offsetof(struct iphdr, tos))
  
  static inline void set_ip_tos(struct __sk_buff *skb, __u8 new_tos)
  {
3431205e0   Alexei Starovoitov   bpf: make program... 
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  	__u8 old_tos = load_byte(skb, TOS_OFF);
91bc4822c   Alexei Starovoitov   tc: bpf: add chec... 
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  	bpf_l3_csum_replace(skb, IP_CSUM_OFF, htons(old_tos), htons(new_tos), 2);
  	bpf_skb_store_bytes(skb, TOS_OFF, &new_tos, sizeof(new_tos), 0);
  }
  
  #define TCP_CSUM_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, check))
  #define IP_SRC_OFF (ETH_HLEN + offsetof(struct iphdr, saddr))
  
  #define IS_PSEUDO 0x10
  
  static inline void set_tcp_ip_src(struct __sk_buff *skb, __u32 new_ip)
  {
3431205e0   Alexei Starovoitov   bpf: make program... 
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  	__u32 old_ip = _htonl(load_word(skb, IP_SRC_OFF));
91bc4822c   Alexei Starovoitov   tc: bpf: add chec... 
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  	bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_ip, new_ip, IS_PSEUDO | sizeof(new_ip));
  	bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
  	bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
  }
  
  #define TCP_DPORT_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, dest))
  static inline void set_tcp_dest_port(struct __sk_buff *skb, __u16 new_port)
  {
3431205e0   Alexei Starovoitov   bpf: make program... 
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  	__u16 old_port = htons(load_half(skb, TCP_DPORT_OFF));
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  	bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_port, new_port, sizeof(new_port));
  	bpf_skb_store_bytes(skb, TCP_DPORT_OFF, &new_port, sizeof(new_port), 0);
  }
  
  SEC("classifier")
  int bpf_prog1(struct __sk_buff *skb)
  {
3431205e0   Alexei Starovoitov   bpf: make program... 
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  	__u8 proto = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
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  	long *value;
  
  	if (proto == IPPROTO_TCP) {
  		set_ip_tos(skb, 8);
  		set_tcp_ip_src(skb, 0xA010101);
  		set_tcp_dest_port(skb, 5001);
  	}
  
  	return 0;
  }
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  SEC("redirect_xmit")
  int _redirect_xmit(struct __sk_buff *skb)
  {
  	return bpf_redirect(skb->ifindex + 1, 0);
  }
  SEC("redirect_recv")
  int _redirect_recv(struct __sk_buff *skb)
  {
  	return bpf_redirect(skb->ifindex + 1, 1);
  }
  SEC("clone_redirect_xmit")
  int _clone_redirect_xmit(struct __sk_buff *skb)
  {
  	bpf_clone_redirect(skb, skb->ifindex + 1, 0);
  	return TC_ACT_SHOT;
  }
  SEC("clone_redirect_recv")
  int _clone_redirect_recv(struct __sk_buff *skb)
  {
  	bpf_clone_redirect(skb, skb->ifindex + 1, 1);
  	return TC_ACT_SHOT;
  }
91bc4822c   Alexei Starovoitov   tc: bpf: add chec... 
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  char _license[] SEC("license") = "GPL";