1 #include <uapi/linux/bpf.h>
2 #include <uapi/linux/in.h>
3 #include <uapi/linux/if.h>
4 #include <uapi/linux/if_ether.h>
5 #include <uapi/linux/ip.h>
6 #include <uapi/linux/ipv6.h>
7 #include <uapi/linux/if_tunnel.h>
8 #include <bpf/bpf_helpers.h>
9 #include "bpf_legacy.h"
10 #define IP_MF 0x2000
11 #define IP_OFFSET 0x1FFF
12
13 struct vlan_hdr {
14 __be16 h_vlan_TCI;
15 __be16 h_vlan_encapsulated_proto;
16 };
17
18 struct flow_key_record {
19 __be32 src;
20 __be32 dst;
21 union {
22 __be32 ports;
23 __be16 port16[2];
24 };
25 __u16 thoff;
26 __u8 ip_proto;
27 };
28
29 static inline int proto_ports_offset(__u64 proto)
30 {
31 switch (proto) {
32 case IPPROTO_TCP:
33 case IPPROTO_UDP:
34 case IPPROTO_DCCP:
35 case IPPROTO_ESP:
36 case IPPROTO_SCTP:
37 case IPPROTO_UDPLITE:
38 return 0;
39 case IPPROTO_AH:
40 return 4;
41 default:
42 return 0;
43 }
44 }
45
46 static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
47 {
48 return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
49 & (IP_MF | IP_OFFSET);
50 }
51
52 static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
53 {
54 __u64 w0 = load_word(ctx, off);
55 __u64 w1 = load_word(ctx, off + 4);
56 __u64 w2 = load_word(ctx, off + 8);
57 __u64 w3 = load_word(ctx, off + 12);
58
59 return (__u32)(w0 ^ w1 ^ w2 ^ w3);
60 }
61
62 static inline __u64 parse_ip(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
63 struct flow_key_record *flow)
64 {
65 __u64 verlen;
66
67 if (unlikely(ip_is_fragment(skb, nhoff)))
68 *ip_proto = 0;
69 else
70 *ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
71
72 if (*ip_proto != IPPROTO_GRE) {
73 flow->src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
74 flow->dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
75 }
76
77 verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
78 if (likely(verlen == 0x45))
79 nhoff += 20;
80 else
81 nhoff += (verlen & 0xF) << 2;
82
83 return nhoff;
84 }
85
86 static inline __u64 parse_ipv6(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
87 struct flow_key_record *flow)
88 {
89 *ip_proto = load_byte(skb,
90 nhoff + offsetof(struct ipv6hdr, nexthdr));
91 flow->src = ipv6_addr_hash(skb,
92 nhoff + offsetof(struct ipv6hdr, saddr));
93 flow->dst = ipv6_addr_hash(skb,
94 nhoff + offsetof(struct ipv6hdr, daddr));
95 nhoff += sizeof(struct ipv6hdr);
96
97 return nhoff;
98 }
99
100 static inline bool flow_dissector(struct __sk_buff *skb,
101 struct flow_key_record *flow)
102 {
103 __u64 nhoff = ETH_HLEN;
104 __u64 ip_proto;
105 __u64 proto = load_half(skb, 12);
106 int poff;
107
108 if (proto == ETH_P_8021AD) {
109 proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
110 h_vlan_encapsulated_proto));
111 nhoff += sizeof(struct vlan_hdr);
112 }
113
114 if (proto == ETH_P_8021Q) {
115 proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
116 h_vlan_encapsulated_proto));
117 nhoff += sizeof(struct vlan_hdr);
118 }
119
120 if (likely(proto == ETH_P_IP))
121 nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
122 else if (proto == ETH_P_IPV6)
123 nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
124 else
125 return false;
126
127 switch (ip_proto) {
128 case IPPROTO_GRE: {
129 struct gre_hdr {
130 __be16 flags;
131 __be16 proto;
132 };
133
134 __u64 gre_flags = load_half(skb,
135 nhoff + offsetof(struct gre_hdr, flags));
136 __u64 gre_proto = load_half(skb,
137 nhoff + offsetof(struct gre_hdr, proto));
138
139 if (gre_flags & (GRE_VERSION|GRE_ROUTING))
140 break;
141
142 proto = gre_proto;
143 nhoff += 4;
144 if (gre_flags & GRE_CSUM)
145 nhoff += 4;
146 if (gre_flags & GRE_KEY)
147 nhoff += 4;
148 if (gre_flags & GRE_SEQ)
149 nhoff += 4;
150
151 if (proto == ETH_P_8021Q) {
152 proto = load_half(skb,
153 nhoff + offsetof(struct vlan_hdr,
154 h_vlan_encapsulated_proto));
155 nhoff += sizeof(struct vlan_hdr);
156 }
157
158 if (proto == ETH_P_IP)
159 nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
160 else if (proto == ETH_P_IPV6)
161 nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
162 else
163 return false;
164 break;
165 }
166 case IPPROTO_IPIP:
167 nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
168 break;
169 case IPPROTO_IPV6:
170 nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
171 break;
172 default:
173 break;
174 }
175
176 flow->ip_proto = ip_proto;
177 poff = proto_ports_offset(ip_proto);
178 if (poff >= 0) {
179 nhoff += poff;
180 flow->ports = load_word(skb, nhoff);
181 }
182
183 flow->thoff = (__u16) nhoff;
184
185 return true;
186 }
187
188 struct pair {
189 long packets;
190 long bytes;
191 };
192
193 struct {
194 __uint(type, BPF_MAP_TYPE_HASH);
195 __type(key, __be32);
196 __type(value, struct pair);
197 __uint(max_entries, 1024);
198 } hash_map SEC(".maps");
199
200 SEC("socket2")
201 int bpf_prog2(struct __sk_buff *skb)
202 {
203 struct flow_key_record flow = {};
204 struct pair *value;
205 u32 key;
206
207 if (!flow_dissector(skb, &flow))
208 return 0;
209
210 key = flow.dst;
211 value = bpf_map_lookup_elem(&hash_map, &key);
212 if (value) {
213 __sync_fetch_and_add(&value->packets, 1);
214 __sync_fetch_and_add(&value->bytes, skb->len);
215 } else {
216 struct pair val = {1, skb->len};
217
218 bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
219 }
220 return 0;
221 }
222
223 char _license[] SEC("license") = "GPL";
224
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