net: introduce skb_flow_dissect() (0744dd00) · Commits · 戴 / test

include/net/flow_keys.h

0 → 100644

+15 −0

Original line number	Diff line number	Diff line
		#ifndef _NET_FLOW_KEYS_H
		#define _NET_FLOW_KEYS_H

		struct flow_keys {
		__be32 src;
		__be32 dst;
		union {
		__be32 ports;
		__be16 port16[2];
		};
		u8 ip_proto;
		};

		extern bool skb_flow_dissect(const struct sk_buff skb, struct flow_keys flow);
		#endif

net/core/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -3,7 +3,7 @@
		#

		obj-y := sock.o request_sock.o skbuff.o iovec.o datagram.o stream.o scm.o \
		gen_stats.o gen_estimator.o net_namespace.o secure_seq.o
		gen_stats.o gen_estimator.o net_namespace.o secure_seq.o flow_dissector.o

		obj-$(CONFIG_SYSCTL) += sysctl_net_core.o

net/core/flow_dissector.c

0 → 100644

+134 −0

Original line number	Diff line number	Diff line
		#include <linux/skbuff.h>
		#include <linux/ip.h>
		#include <linux/ipv6.h>
		#include <linux/if_vlan.h>
		#include <net/ip.h>
		#include <linux/if_tunnel.h>
		#include <linux/if_pppox.h>
		#include <linux/ppp_defs.h>
		#include <net/flow_keys.h>


		bool skb_flow_dissect(const struct sk_buff skb, struct flow_keys flow)
		{
		int poff, nhoff = skb_network_offset(skb);
		u8 ip_proto;
		__be16 proto = skb->protocol;

		memset(flow, 0, sizeof(*flow));

		again:
		switch (proto) {
		case __constant_htons(ETH_P_IP): {
		const struct iphdr *iph;
		struct iphdr _iph;
		ip:
		iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
		if (!iph)
		return false;

		if (ip_is_fragment(iph))
		ip_proto = 0;
		else
		ip_proto = iph->protocol;
		flow->src = iph->saddr;
		flow->dst = iph->daddr;
		nhoff += iph->ihl * 4;
		break;
		}
		case __constant_htons(ETH_P_IPV6): {
		const struct ipv6hdr *iph;
		struct ipv6hdr _iph;
		ipv6:
		iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
		if (!iph)
		return false;

		ip_proto = iph->nexthdr;
		flow->src = iph->saddr.s6_addr32[3];
		flow->dst = iph->daddr.s6_addr32[3];
		nhoff += sizeof(struct ipv6hdr);
		break;
		}
		case __constant_htons(ETH_P_8021Q): {
		const struct vlan_hdr *vlan;
		struct vlan_hdr _vlan;

		vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan);
		if (!vlan)
		return false;

		proto = vlan->h_vlan_encapsulated_proto;
		nhoff += sizeof(*vlan);
		goto again;
		}
		case __constant_htons(ETH_P_PPP_SES): {
		struct {
		struct pppoe_hdr hdr;
		__be16 proto;
		} *hdr, _hdr;
		hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
		if (!hdr)
		return false;
		proto = hdr->proto;
		nhoff += PPPOE_SES_HLEN;
		switch (proto) {
		case __constant_htons(PPP_IP):
		goto ip;
		case __constant_htons(PPP_IPV6):
		goto ipv6;
		default:
		return false;
		}
		}
		default:
		return false;
		}

		switch (ip_proto) {
		case IPPROTO_GRE: {
		struct gre_hdr {
		__be16 flags;
		__be16 proto;
		} *hdr, _hdr;

		hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
		if (!hdr)
		return false;
		/*
		* Only look inside GRE if version zero and no
		* routing
		*/
		if (!(hdr->flags & (GRE_VERSION\|GRE_ROUTING))) {
		proto = hdr->proto;
		nhoff += 4;
		if (hdr->flags & GRE_CSUM)
		nhoff += 4;
		if (hdr->flags & GRE_KEY)
		nhoff += 4;
		if (hdr->flags & GRE_SEQ)
		nhoff += 4;
		goto again;
		}
		break;
		}
		case IPPROTO_IPIP:
		goto again;
		default:
		break;
		}

		flow->ip_proto = ip_proto;
		poff = proto_ports_offset(ip_proto);
		if (poff >= 0) {
		__be32 *ports, _ports;

		nhoff += poff;
		ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports);
		if (ports)
		flow->ports = *ports;
		}

		return true;
		}
		EXPORT_SYMBOL(skb_flow_dissect);

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