1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
#include <uapi/linux/bpf.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>
#include <bpf/bpf_helpers.h>
#include "bpf_legacy.h"
#define IP_MF 0x2000
#define IP_OFFSET 0x1FFF
struct vlan_hdr {
__be16 h_vlan_TCI;
__be16 h_vlan_encapsulated_proto;
};
struct flow_key_record {
__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_key_record *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_key_record *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_key_record *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 pair {
long packets;
long bytes;
};
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, __be32);
__type(value, struct pair);
__uint(max_entries, 1024);
} hash_map SEC(".maps");
SEC("socket2")
int bpf_prog2(struct __sk_buff *skb)
{
struct flow_key_record flow = {};
struct pair *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->packets, 1);
__sync_fetch_and_add(&value->bytes, skb->len);
} else {
struct pair val = {1, skb->len};
bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
}
return 0;
}
char _license[] SEC("license") = "GPL";
|
