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1/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 */
7#include <uapi/linux/bpf.h>
8#include "bpf_helpers.h"
9#include <uapi/linux/in.h>
10#include <uapi/linux/if.h>
11#include <uapi/linux/if_ether.h>
12#include <uapi/linux/ip.h>
13#include <uapi/linux/ipv6.h>
14#include <uapi/linux/if_tunnel.h>
15#include <uapi/linux/mpls.h>
16#define IP_MF 0x2000
17#define IP_OFFSET 0x1FFF
18
19#define PROG(F) SEC("socket/"__stringify(F)) int bpf_func_##F
20
21struct bpf_map_def SEC("maps") jmp_table = {
22 .type = BPF_MAP_TYPE_PROG_ARRAY,
23 .key_size = sizeof(u32),
24 .value_size = sizeof(u32),
25 .max_entries = 8,
26};
27
28#define PARSE_VLAN 1
29#define PARSE_MPLS 2
30#define PARSE_IP 3
31#define PARSE_IPV6 4
32
33/* protocol dispatch routine.
34 * It tail-calls next BPF program depending on eth proto
35 * Note, we could have used:
36 * bpf_tail_call(skb, &jmp_table, proto);
37 * but it would need large prog_array
38 */
39static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto)
40{
41 switch (proto) {
42 case ETH_P_8021Q:
43 case ETH_P_8021AD:
44 bpf_tail_call(skb, &jmp_table, PARSE_VLAN);
45 break;
46 case ETH_P_MPLS_UC:
47 case ETH_P_MPLS_MC:
48 bpf_tail_call(skb, &jmp_table, PARSE_MPLS);
49 break;
50 case ETH_P_IP:
51 bpf_tail_call(skb, &jmp_table, PARSE_IP);
52 break;
53 case ETH_P_IPV6:
54 bpf_tail_call(skb, &jmp_table, PARSE_IPV6);
55 break;
56 }
57}
58
59struct vlan_hdr {
60 __be16 h_vlan_TCI;
61 __be16 h_vlan_encapsulated_proto;
62};
63
64struct flow_keys {
65 __be32 src;
66 __be32 dst;
67 union {
68 __be32 ports;
69 __be16 port16[2];
70 };
71 __u32 ip_proto;
72};
73
74static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
75{
76 return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
77 & (IP_MF | IP_OFFSET);
78}
79
80static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
81{
82 __u64 w0 = load_word(ctx, off);
83 __u64 w1 = load_word(ctx, off + 4);
84 __u64 w2 = load_word(ctx, off + 8);
85 __u64 w3 = load_word(ctx, off + 12);
86
87 return (__u32)(w0 ^ w1 ^ w2 ^ w3);
88}
89
90struct globals {
91 struct flow_keys flow;
92};
93
94struct bpf_map_def SEC("maps") percpu_map = {
95 .type = BPF_MAP_TYPE_ARRAY,
96 .key_size = sizeof(__u32),
97 .value_size = sizeof(struct globals),
98 .max_entries = 32,
99};
100
101/* user poor man's per_cpu until native support is ready */
102static struct globals *this_cpu_globals(void)
103{
104 u32 key = bpf_get_smp_processor_id();
105
106 return bpf_map_lookup_elem(&percpu_map, &key);
107}
108
109/* some simple stats for user space consumption */
110struct pair {
111 __u64 packets;
112 __u64 bytes;
113};
114
115struct bpf_map_def SEC("maps") hash_map = {
116 .type = BPF_MAP_TYPE_HASH,
117 .key_size = sizeof(struct flow_keys),
118 .value_size = sizeof(struct pair),
119 .max_entries = 1024,
120};
121
122static void update_stats(struct __sk_buff *skb, struct globals *g)
123{
124 struct flow_keys key = g->flow;
125 struct pair *value;
126
127 value = bpf_map_lookup_elem(&hash_map, &key);
128 if (value) {
129 __sync_fetch_and_add(&value->packets, 1);
130 __sync_fetch_and_add(&value->bytes, skb->len);
131 } else {
132 struct pair val = {1, skb->len};
133
134 bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
135 }
136}
137
138static __always_inline void parse_ip_proto(struct __sk_buff *skb,
139 struct globals *g, __u32 ip_proto)
140{
141 __u32 nhoff = skb->cb[0];
142 int poff;
143
144 switch (ip_proto) {
145 case IPPROTO_GRE: {
146 struct gre_hdr {
147 __be16 flags;
148 __be16 proto;
149 };
150
151 __u32 gre_flags = load_half(skb,
152 nhoff + offsetof(struct gre_hdr, flags));
153 __u32 gre_proto = load_half(skb,
154 nhoff + offsetof(struct gre_hdr, proto));
155
156 if (gre_flags & (GRE_VERSION|GRE_ROUTING))
157 break;
158
159 nhoff += 4;
160 if (gre_flags & GRE_CSUM)
161 nhoff += 4;
162 if (gre_flags & GRE_KEY)
163 nhoff += 4;
164 if (gre_flags & GRE_SEQ)
165 nhoff += 4;
166
167 skb->cb[0] = nhoff;
168 parse_eth_proto(skb, gre_proto);
169 break;
170 }
171 case IPPROTO_IPIP:
172 parse_eth_proto(skb, ETH_P_IP);
173 break;
174 case IPPROTO_IPV6:
175 parse_eth_proto(skb, ETH_P_IPV6);
176 break;
177 case IPPROTO_TCP:
178 case IPPROTO_UDP:
179 g->flow.ports = load_word(skb, nhoff);
180 case IPPROTO_ICMP:
181 g->flow.ip_proto = ip_proto;
182 update_stats(skb, g);
183 break;
184 default:
185 break;
186 }
187}
188
189PROG(PARSE_IP)(struct __sk_buff *skb)
190{
191 struct globals *g = this_cpu_globals();
192 __u32 nhoff, verlen, ip_proto;
193
194 if (!g)
195 return 0;
196
197 nhoff = skb->cb[0];
198
199 if (unlikely(ip_is_fragment(skb, nhoff)))
200 return 0;
201
202 ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
203
204 if (ip_proto != IPPROTO_GRE) {
205 g->flow.src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
206 g->flow.dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
207 }
208
209 verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
210 nhoff += (verlen & 0xF) << 2;
211
212 skb->cb[0] = nhoff;
213 parse_ip_proto(skb, g, ip_proto);
214 return 0;
215}
216
217PROG(PARSE_IPV6)(struct __sk_buff *skb)
218{
219 struct globals *g = this_cpu_globals();
220 __u32 nhoff, ip_proto;
221
222 if (!g)
223 return 0;
224
225 nhoff = skb->cb[0];
226
227 ip_proto = load_byte(skb,
228 nhoff + offsetof(struct ipv6hdr, nexthdr));
229 g->flow.src = ipv6_addr_hash(skb,
230 nhoff + offsetof(struct ipv6hdr, saddr));
231 g->flow.dst = ipv6_addr_hash(skb,
232 nhoff + offsetof(struct ipv6hdr, daddr));
233 nhoff += sizeof(struct ipv6hdr);
234
235 skb->cb[0] = nhoff;
236 parse_ip_proto(skb, g, ip_proto);
237 return 0;
238}
239
240PROG(PARSE_VLAN)(struct __sk_buff *skb)
241{
242 __u32 nhoff, proto;
243
244 nhoff = skb->cb[0];
245
246 proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
247 h_vlan_encapsulated_proto));
248 nhoff += sizeof(struct vlan_hdr);
249 skb->cb[0] = nhoff;
250
251 parse_eth_proto(skb, proto);
252
253 return 0;
254}
255
256PROG(PARSE_MPLS)(struct __sk_buff *skb)
257{
258 __u32 nhoff, label;
259
260 nhoff = skb->cb[0];
261
262 label = load_word(skb, nhoff);
263 nhoff += sizeof(struct mpls_label);
264 skb->cb[0] = nhoff;
265
266 if (label & MPLS_LS_S_MASK) {
267 __u8 verlen = load_byte(skb, nhoff);
268 if ((verlen & 0xF0) == 4)
269 parse_eth_proto(skb, ETH_P_IP);
270 else
271 parse_eth_proto(skb, ETH_P_IPV6);
272 } else {
273 parse_eth_proto(skb, ETH_P_MPLS_UC);
274 }
275
276 return 0;
277}
278
279SEC("socket/0")
280int main_prog(struct __sk_buff *skb)
281{
282 __u32 nhoff = ETH_HLEN;
283 __u32 proto = load_half(skb, 12);
284
285 skb->cb[0] = nhoff;
286 parse_eth_proto(skb, proto);
287 return 0;
288}
289
290char _license[] SEC("license") = "GPL";
1/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 */
7#include <uapi/linux/bpf.h>
8#include <uapi/linux/in.h>
9#include <uapi/linux/if.h>
10#include <uapi/linux/if_ether.h>
11#include <uapi/linux/ip.h>
12#include <uapi/linux/ipv6.h>
13#include <uapi/linux/if_tunnel.h>
14#include <uapi/linux/mpls.h>
15#include <bpf/bpf_helpers.h>
16#include "bpf_legacy.h"
17#define IP_MF 0x2000
18#define IP_OFFSET 0x1FFF
19
20#define PROG(F) SEC("socket/"__stringify(F)) int bpf_func_##F
21
22struct {
23 __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
24 __uint(key_size, sizeof(u32));
25 __uint(value_size, sizeof(u32));
26 __uint(max_entries, 8);
27} jmp_table SEC(".maps");
28
29#define PARSE_VLAN 1
30#define PARSE_MPLS 2
31#define PARSE_IP 3
32#define PARSE_IPV6 4
33
34/* Protocol dispatch routine. It tail-calls next BPF program depending
35 * on eth proto. Note, we could have used ...
36 *
37 * bpf_tail_call(skb, &jmp_table, proto);
38 *
39 * ... but it would need large prog_array and cannot be optimised given
40 * the map key is not static.
41 */
42static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto)
43{
44 switch (proto) {
45 case ETH_P_8021Q:
46 case ETH_P_8021AD:
47 bpf_tail_call(skb, &jmp_table, PARSE_VLAN);
48 break;
49 case ETH_P_MPLS_UC:
50 case ETH_P_MPLS_MC:
51 bpf_tail_call(skb, &jmp_table, PARSE_MPLS);
52 break;
53 case ETH_P_IP:
54 bpf_tail_call(skb, &jmp_table, PARSE_IP);
55 break;
56 case ETH_P_IPV6:
57 bpf_tail_call(skb, &jmp_table, PARSE_IPV6);
58 break;
59 }
60}
61
62struct vlan_hdr {
63 __be16 h_vlan_TCI;
64 __be16 h_vlan_encapsulated_proto;
65};
66
67struct flow_key_record {
68 __be32 src;
69 __be32 dst;
70 union {
71 __be32 ports;
72 __be16 port16[2];
73 };
74 __u32 ip_proto;
75};
76
77static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
78{
79 return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
80 & (IP_MF | IP_OFFSET);
81}
82
83static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
84{
85 __u64 w0 = load_word(ctx, off);
86 __u64 w1 = load_word(ctx, off + 4);
87 __u64 w2 = load_word(ctx, off + 8);
88 __u64 w3 = load_word(ctx, off + 12);
89
90 return (__u32)(w0 ^ w1 ^ w2 ^ w3);
91}
92
93struct globals {
94 struct flow_key_record flow;
95};
96
97struct {
98 __uint(type, BPF_MAP_TYPE_ARRAY);
99 __type(key, __u32);
100 __type(value, struct globals);
101 __uint(max_entries, 32);
102} percpu_map SEC(".maps");
103
104/* user poor man's per_cpu until native support is ready */
105static struct globals *this_cpu_globals(void)
106{
107 u32 key = bpf_get_smp_processor_id();
108
109 return bpf_map_lookup_elem(&percpu_map, &key);
110}
111
112/* some simple stats for user space consumption */
113struct pair {
114 __u64 packets;
115 __u64 bytes;
116};
117
118struct {
119 __uint(type, BPF_MAP_TYPE_HASH);
120 __type(key, struct flow_key_record);
121 __type(value, struct pair);
122 __uint(max_entries, 1024);
123} hash_map SEC(".maps");
124
125static void update_stats(struct __sk_buff *skb, struct globals *g)
126{
127 struct flow_key_record key = g->flow;
128 struct pair *value;
129
130 value = bpf_map_lookup_elem(&hash_map, &key);
131 if (value) {
132 __sync_fetch_and_add(&value->packets, 1);
133 __sync_fetch_and_add(&value->bytes, skb->len);
134 } else {
135 struct pair val = {1, skb->len};
136
137 bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
138 }
139}
140
141static __always_inline void parse_ip_proto(struct __sk_buff *skb,
142 struct globals *g, __u32 ip_proto)
143{
144 __u32 nhoff = skb->cb[0];
145 int poff;
146
147 switch (ip_proto) {
148 case IPPROTO_GRE: {
149 struct gre_hdr {
150 __be16 flags;
151 __be16 proto;
152 };
153
154 __u32 gre_flags = load_half(skb,
155 nhoff + offsetof(struct gre_hdr, flags));
156 __u32 gre_proto = load_half(skb,
157 nhoff + offsetof(struct gre_hdr, proto));
158
159 if (gre_flags & (GRE_VERSION|GRE_ROUTING))
160 break;
161
162 nhoff += 4;
163 if (gre_flags & GRE_CSUM)
164 nhoff += 4;
165 if (gre_flags & GRE_KEY)
166 nhoff += 4;
167 if (gre_flags & GRE_SEQ)
168 nhoff += 4;
169
170 skb->cb[0] = nhoff;
171 parse_eth_proto(skb, gre_proto);
172 break;
173 }
174 case IPPROTO_IPIP:
175 parse_eth_proto(skb, ETH_P_IP);
176 break;
177 case IPPROTO_IPV6:
178 parse_eth_proto(skb, ETH_P_IPV6);
179 break;
180 case IPPROTO_TCP:
181 case IPPROTO_UDP:
182 g->flow.ports = load_word(skb, nhoff);
183 case IPPROTO_ICMP:
184 g->flow.ip_proto = ip_proto;
185 update_stats(skb, g);
186 break;
187 default:
188 break;
189 }
190}
191
192PROG(PARSE_IP)(struct __sk_buff *skb)
193{
194 struct globals *g = this_cpu_globals();
195 __u32 nhoff, verlen, ip_proto;
196
197 if (!g)
198 return 0;
199
200 nhoff = skb->cb[0];
201
202 if (unlikely(ip_is_fragment(skb, nhoff)))
203 return 0;
204
205 ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
206
207 if (ip_proto != IPPROTO_GRE) {
208 g->flow.src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
209 g->flow.dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
210 }
211
212 verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
213 nhoff += (verlen & 0xF) << 2;
214
215 skb->cb[0] = nhoff;
216 parse_ip_proto(skb, g, ip_proto);
217 return 0;
218}
219
220PROG(PARSE_IPV6)(struct __sk_buff *skb)
221{
222 struct globals *g = this_cpu_globals();
223 __u32 nhoff, ip_proto;
224
225 if (!g)
226 return 0;
227
228 nhoff = skb->cb[0];
229
230 ip_proto = load_byte(skb,
231 nhoff + offsetof(struct ipv6hdr, nexthdr));
232 g->flow.src = ipv6_addr_hash(skb,
233 nhoff + offsetof(struct ipv6hdr, saddr));
234 g->flow.dst = ipv6_addr_hash(skb,
235 nhoff + offsetof(struct ipv6hdr, daddr));
236 nhoff += sizeof(struct ipv6hdr);
237
238 skb->cb[0] = nhoff;
239 parse_ip_proto(skb, g, ip_proto);
240 return 0;
241}
242
243PROG(PARSE_VLAN)(struct __sk_buff *skb)
244{
245 __u32 nhoff, proto;
246
247 nhoff = skb->cb[0];
248
249 proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
250 h_vlan_encapsulated_proto));
251 nhoff += sizeof(struct vlan_hdr);
252 skb->cb[0] = nhoff;
253
254 parse_eth_proto(skb, proto);
255
256 return 0;
257}
258
259PROG(PARSE_MPLS)(struct __sk_buff *skb)
260{
261 __u32 nhoff, label;
262
263 nhoff = skb->cb[0];
264
265 label = load_word(skb, nhoff);
266 nhoff += sizeof(struct mpls_label);
267 skb->cb[0] = nhoff;
268
269 if (label & MPLS_LS_S_MASK) {
270 __u8 verlen = load_byte(skb, nhoff);
271 if ((verlen & 0xF0) == 4)
272 parse_eth_proto(skb, ETH_P_IP);
273 else
274 parse_eth_proto(skb, ETH_P_IPV6);
275 } else {
276 parse_eth_proto(skb, ETH_P_MPLS_UC);
277 }
278
279 return 0;
280}
281
282SEC("socket/0")
283int main_prog(struct __sk_buff *skb)
284{
285 __u32 nhoff = ETH_HLEN;
286 __u32 proto = load_half(skb, 12);
287
288 skb->cb[0] = nhoff;
289 parse_eth_proto(skb, proto);
290 return 0;
291}
292
293char _license[] SEC("license") = "GPL";