diff options
| -rw-r--r-- | include/net/flow_keys.h | 15 | ||||
| -rw-r--r-- | net/core/Makefile | 2 | ||||
| -rw-r--r-- | net/core/flow_dissector.c | 134 |
3 files changed, 150 insertions, 1 deletions
diff --git a/include/net/flow_keys.h b/include/net/flow_keys.h new file mode 100644 index 000000000000..e4cb28526563 --- /dev/null +++ b/include/net/flow_keys.h @@ -0,0 +1,15 @@ +#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 diff --git a/net/core/Makefile b/net/core/Makefile index 3606d40aae62..c4ecc864020f 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -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 diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c new file mode 100644 index 000000000000..f0516d9280c3 --- /dev/null +++ b/net/core/flow_dissector.c @@ -0,0 +1,134 @@ +#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); |