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#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"
#include <uapi/linux/in.h>
#include <uapi/linux/if.h>
#include <uapi/linux/if_ether.h>
#include <uapi/linux/ip.h>
#include <uapi/linux/ipv6.h>
#include <uapi/linux/if_tunnel.h>
#define IP_MF 0x2000
#define IP_OFFSET 0x1FFF
struct vlan_hdr {
__be16 h_vlan_TCI;
__be16 h_vlan_encapsulated_proto;
};
struct flow_keys {
__be32 src;
__be32 dst;
union {
__be32 ports;
__be16 port16[2];
};
__u16 thoff;
__u8 ip_proto;
};
static inline int proto_ports_offset(__u64 proto)
{
switch (proto) {
case IPPROTO_TCP:
case IPPROTO_UDP:
case IPPROTO_DCCP:
case IPPROTO_ESP:
case IPPROTO_SCTP:
case IPPROTO_UDPLITE:
return 0;
case IPPROTO_AH:
return 4;
default:
return 0;
}
}
static inline int ip_is_fragment(struct sk_buff *ctx, __u64 nhoff)
{
return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
& (IP_MF | IP_OFFSET);
}
static inline __u32 ipv6_addr_hash(struct sk_buff *ctx, __u64 off)
{
__u64 w0 = load_word(ctx, off);
__u64 w1 = load_word(ctx, off + 4);
__u64 w2 = load_word(ctx, off + 8);
__u64 w3 = load_word(ctx, off + 12);
return (__u32)(w0 ^ w1 ^ w2 ^ w3);
}
static inline __u64 parse_ip(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
struct flow_keys *flow)
{
__u64 verlen;
if (unlikely(ip_is_fragment(skb, nhoff)))
*ip_proto = 0;
else
*ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
if (*ip_proto != IPPROTO_GRE) {
flow->src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
flow->dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
}
verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
if (likely(verlen == 0x45))
nhoff += 20;
else
nhoff += (verlen & 0xF) << 2;
return nhoff;
}
static inline __u64 parse_ipv6(struct sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
struct flow_keys *flow)
{
*ip_proto = load_byte(skb,
nhoff + offsetof(struct ipv6hdr, nexthdr));
flow->src = ipv6_addr_hash(skb,
nhoff + offsetof(struct ipv6hdr, saddr));
flow->dst = ipv6_addr_hash(skb,
nhoff + offsetof(struct ipv6hdr, daddr));
nhoff += sizeof(struct ipv6hdr);
return nhoff;
}
static inline bool flow_dissector(struct sk_buff *skb, struct flow_keys *flow)
{
__u64 nhoff = ETH_HLEN;
__u64 ip_proto;
__u64 proto = load_half(skb, 12);
int poff;
if (proto == ETH_P_8021AD) {
proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
h_vlan_encapsulated_proto));
nhoff += sizeof(struct vlan_hdr);
}
if (proto == ETH_P_8021Q) {
proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
h_vlan_encapsulated_proto));
nhoff += sizeof(struct vlan_hdr);
}
if (likely(proto == ETH_P_IP))
nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
else if (proto == ETH_P_IPV6)
nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
else
return false;
switch (ip_proto) {
case IPPROTO_GRE: {
struct gre_hdr {
__be16 flags;
__be16 proto;
};
__u64 gre_flags = load_half(skb,
nhoff + offsetof(struct gre_hdr, flags));
__u64 gre_proto = load_half(skb,
nhoff + offsetof(struct gre_hdr, proto));
if (gre_flags & (GRE_VERSION|GRE_ROUTING))
break;
proto = gre_proto;
nhoff += 4;
if (gre_flags & GRE_CSUM)
nhoff += 4;
if (gre_flags & GRE_KEY)
nhoff += 4;
if (gre_flags & GRE_SEQ)
nhoff += 4;
if (proto == ETH_P_8021Q) {
proto = load_half(skb,
nhoff + offsetof(struct vlan_hdr,
h_vlan_encapsulated_proto));
nhoff += sizeof(struct vlan_hdr);
}
if (proto == ETH_P_IP)
nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
else if (proto == ETH_P_IPV6)
nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
else
return false;
break;
}
case IPPROTO_IPIP:
nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
break;
case IPPROTO_IPV6:
nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
break;
default:
break;
}
flow->ip_proto = ip_proto;
poff = proto_ports_offset(ip_proto);
if (poff >= 0) {
nhoff += poff;
flow->ports = load_word(skb, nhoff);
}
flow->thoff = (__u16) nhoff;
return true;
}
struct bpf_map_def SEC("maps") hash_map = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(__be32),
.value_size = sizeof(long),
.max_entries = 1024,
};
SEC("socket2")
int bpf_prog2(struct sk_buff *skb)
{
struct flow_keys flow;
long *value;
u32 key;
if (!flow_dissector(skb, &flow))
return 0;
key = flow.dst;
value = bpf_map_lookup_elem(&hash_map, &key);
if (value) {
__sync_fetch_and_add(value, 1);
} else {
long val = 1;
bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
}
return 0;
}
char _license[] SEC("license") = "GPL";
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