27b29f6305
Existing bpf_clone_redirect() helper clones skb before redirecting it to RX or TX of destination netdev. Introduce bpf_redirect() helper that does that without cloning. Benchmarked with two hosts using 10G ixgbe NICs. One host is doing line rate pktgen. Another host is configured as: $ tc qdisc add dev $dev ingress $ tc filter add dev $dev root pref 10 u32 match u32 0 0 flowid 1:2 \ action bpf run object-file tcbpf1_kern.o section clone_redirect_xmit drop so it receives the packet on $dev and immediately xmits it on $dev + 1 The section 'clone_redirect_xmit' in tcbpf1_kern.o file has the program that does bpf_clone_redirect() and performance is 2.0 Mpps $ tc filter add dev $dev root pref 10 u32 match u32 0 0 flowid 1:2 \ action bpf run object-file tcbpf1_kern.o section redirect_xmit drop which is using bpf_redirect() - 2.4 Mpps and using cls_bpf with integrated actions as: $ tc filter add dev $dev root pref 10 \ bpf run object-file tcbpf1_kern.o section redirect_xmit integ_act classid 1 performance is 2.5 Mpps To summarize: u32+act_bpf using clone_redirect - 2.0 Mpps u32+act_bpf using redirect - 2.4 Mpps cls_bpf using redirect - 2.5 Mpps For comparison linux bridge in this setup is doing 2.1 Mpps and ixgbe rx + drop in ip_rcv - 7.8 Mpps Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
89 lines
2.5 KiB
C
89 lines
2.5 KiB
C
#include <uapi/linux/bpf.h>
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#include <uapi/linux/if_ether.h>
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#include <uapi/linux/if_packet.h>
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#include <uapi/linux/ip.h>
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#include <uapi/linux/in.h>
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#include <uapi/linux/tcp.h>
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#include <uapi/linux/filter.h>
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#include <uapi/linux/pkt_cls.h>
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#include "bpf_helpers.h"
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/* compiler workaround */
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#define _htonl __builtin_bswap32
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static inline void set_dst_mac(struct __sk_buff *skb, char *mac)
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{
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bpf_skb_store_bytes(skb, 0, mac, ETH_ALEN, 1);
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}
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#define IP_CSUM_OFF (ETH_HLEN + offsetof(struct iphdr, check))
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#define TOS_OFF (ETH_HLEN + offsetof(struct iphdr, tos))
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static inline void set_ip_tos(struct __sk_buff *skb, __u8 new_tos)
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{
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__u8 old_tos = load_byte(skb, TOS_OFF);
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bpf_l3_csum_replace(skb, IP_CSUM_OFF, htons(old_tos), htons(new_tos), 2);
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bpf_skb_store_bytes(skb, TOS_OFF, &new_tos, sizeof(new_tos), 0);
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}
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#define TCP_CSUM_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, check))
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#define IP_SRC_OFF (ETH_HLEN + offsetof(struct iphdr, saddr))
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#define IS_PSEUDO 0x10
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static inline void set_tcp_ip_src(struct __sk_buff *skb, __u32 new_ip)
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{
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__u32 old_ip = _htonl(load_word(skb, IP_SRC_OFF));
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bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_ip, new_ip, IS_PSEUDO | sizeof(new_ip));
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bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
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bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
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}
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#define TCP_DPORT_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, dest))
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static inline void set_tcp_dest_port(struct __sk_buff *skb, __u16 new_port)
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{
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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));
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bpf_skb_store_bytes(skb, TCP_DPORT_OFF, &new_port, sizeof(new_port), 0);
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}
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SEC("classifier")
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int bpf_prog1(struct __sk_buff *skb)
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{
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__u8 proto = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
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long *value;
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if (proto == IPPROTO_TCP) {
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set_ip_tos(skb, 8);
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set_tcp_ip_src(skb, 0xA010101);
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set_tcp_dest_port(skb, 5001);
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}
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return 0;
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}
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SEC("redirect_xmit")
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int _redirect_xmit(struct __sk_buff *skb)
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{
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return bpf_redirect(skb->ifindex + 1, 0);
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}
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SEC("redirect_recv")
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int _redirect_recv(struct __sk_buff *skb)
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{
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return bpf_redirect(skb->ifindex + 1, 1);
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}
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SEC("clone_redirect_xmit")
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int _clone_redirect_xmit(struct __sk_buff *skb)
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{
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bpf_clone_redirect(skb, skb->ifindex + 1, 0);
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return TC_ACT_SHOT;
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}
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SEC("clone_redirect_recv")
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int _clone_redirect_recv(struct __sk_buff *skb)
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{
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bpf_clone_redirect(skb, skb->ifindex + 1, 1);
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return TC_ACT_SHOT;
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}
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char _license[] SEC("license") = "GPL";
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