This source file includes following definitions.
- proto_ports_offset
- ip_is_fragment
- ipv6_addr_hash
- parse_ip
- parse_ipv6
- flow_dissector
- SEC
1 #include <uapi/linux/bpf.h>
2 #include "bpf_helpers.h"
3 #include <uapi/linux/in.h>
4 #include <uapi/linux/if.h>
5 #include <uapi/linux/if_ether.h>
6 #include <uapi/linux/ip.h>
7 #include <uapi/linux/ipv6.h>
8 #include <uapi/linux/if_tunnel.h>
9 #define IP_MF 0x2000
10 #define IP_OFFSET 0x1FFF
11
12 struct vlan_hdr {
13 __be16 h_vlan_TCI;
14 __be16 h_vlan_encapsulated_proto;
15 };
16
17 struct flow_key_record {
18 __be32 src;
19 __be32 dst;
20 union {
21 __be32 ports;
22 __be16 port16[2];
23 };
24 __u16 thoff;
25 __u8 ip_proto;
26 };
27
28 static inline int proto_ports_offset(__u64 proto)
29 {
30 switch (proto) {
31 case IPPROTO_TCP:
32 case IPPROTO_UDP:
33 case IPPROTO_DCCP:
34 case IPPROTO_ESP:
35 case IPPROTO_SCTP:
36 case IPPROTO_UDPLITE:
37 return 0;
38 case IPPROTO_AH:
39 return 4;
40 default:
41 return 0;
42 }
43 }
44
45 static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
46 {
47 return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
48 & (IP_MF | IP_OFFSET);
49 }
50
51 static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
52 {
53 __u64 w0 = load_word(ctx, off);
54 __u64 w1 = load_word(ctx, off + 4);
55 __u64 w2 = load_word(ctx, off + 8);
56 __u64 w3 = load_word(ctx, off + 12);
57
58 return (__u32)(w0 ^ w1 ^ w2 ^ w3);
59 }
60
61 static inline __u64 parse_ip(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
62 struct flow_key_record *flow)
63 {
64 __u64 verlen;
65
66 if (unlikely(ip_is_fragment(skb, nhoff)))
67 *ip_proto = 0;
68 else
69 *ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
70
71 if (*ip_proto != IPPROTO_GRE) {
72 flow->src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
73 flow->dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
74 }
75
76 verlen = load_byte(skb, nhoff + 0);
77 if (likely(verlen == 0x45))
78 nhoff += 20;
79 else
80 nhoff += (verlen & 0xF) << 2;
81
82 return nhoff;
83 }
84
85 static inline __u64 parse_ipv6(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
86 struct flow_key_record *flow)
87 {
88 *ip_proto = load_byte(skb,
89 nhoff + offsetof(struct ipv6hdr, nexthdr));
90 flow->src = ipv6_addr_hash(skb,
91 nhoff + offsetof(struct ipv6hdr, saddr));
92 flow->dst = ipv6_addr_hash(skb,
93 nhoff + offsetof(struct ipv6hdr, daddr));
94 nhoff += sizeof(struct ipv6hdr);
95
96 return nhoff;
97 }
98
99 static inline bool flow_dissector(struct __sk_buff *skb,
100 struct flow_key_record *flow)
101 {
102 __u64 nhoff = ETH_HLEN;
103 __u64 ip_proto;
104 __u64 proto = load_half(skb, 12);
105 int poff;
106
107 if (proto == ETH_P_8021AD) {
108 proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
109 h_vlan_encapsulated_proto));
110 nhoff += sizeof(struct vlan_hdr);
111 }
112
113 if (proto == ETH_P_8021Q) {
114 proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
115 h_vlan_encapsulated_proto));
116 nhoff += sizeof(struct vlan_hdr);
117 }
118
119 if (likely(proto == ETH_P_IP))
120 nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
121 else if (proto == ETH_P_IPV6)
122 nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
123 else
124 return false;
125
126 switch (ip_proto) {
127 case IPPROTO_GRE: {
128 struct gre_hdr {
129 __be16 flags;
130 __be16 proto;
131 };
132
133 __u64 gre_flags = load_half(skb,
134 nhoff + offsetof(struct gre_hdr, flags));
135 __u64 gre_proto = load_half(skb,
136 nhoff + offsetof(struct gre_hdr, proto));
137
138 if (gre_flags & (GRE_VERSION|GRE_ROUTING))
139 break;
140
141 proto = gre_proto;
142 nhoff += 4;
143 if (gre_flags & GRE_CSUM)
144 nhoff += 4;
145 if (gre_flags & GRE_KEY)
146 nhoff += 4;
147 if (gre_flags & GRE_SEQ)
148 nhoff += 4;
149
150 if (proto == ETH_P_8021Q) {
151 proto = load_half(skb,
152 nhoff + offsetof(struct vlan_hdr,
153 h_vlan_encapsulated_proto));
154 nhoff += sizeof(struct vlan_hdr);
155 }
156
157 if (proto == ETH_P_IP)
158 nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
159 else if (proto == ETH_P_IPV6)
160 nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
161 else
162 return false;
163 break;
164 }
165 case IPPROTO_IPIP:
166 nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
167 break;
168 case IPPROTO_IPV6:
169 nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
170 break;
171 default:
172 break;
173 }
174
175 flow->ip_proto = ip_proto;
176 poff = proto_ports_offset(ip_proto);
177 if (poff >= 0) {
178 nhoff += poff;
179 flow->ports = load_word(skb, nhoff);
180 }
181
182 flow->thoff = (__u16) nhoff;
183
184 return true;
185 }
186
187 struct pair {
188 long packets;
189 long bytes;
190 };
191
192 struct {
193 __uint(type, BPF_MAP_TYPE_HASH);
194 __type(key, __be32);
195 __type(value, struct pair);
196 __uint(max_entries, 1024);
197 } hash_map SEC(".maps");
198
199 SEC("socket2")
200 int bpf_prog2(struct __sk_buff *skb)
201 {
202 struct flow_key_record flow = {};
203 struct pair *value;
204 u32 key;
205
206 if (!flow_dissector(skb, &flow))
207 return 0;
208
209 key = flow.dst;
210 value = bpf_map_lookup_elem(&hash_map, &key);
211 if (value) {
212 __sync_fetch_and_add(&value->packets, 1);
213 __sync_fetch_and_add(&value->bytes, skb->len);
214 } else {
215 struct pair val = {1, skb->len};
216
217 bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
218 }
219 return 0;
220 }
221
222 char _license[] SEC("license") = "GPL";