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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 <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.
35 * It tail-calls next BPF program depending on eth proto
36 * Note, we could have used:
37 * bpf_tail_call(skb, &jmp_table, proto);
38 * but it would need large prog_array
39 */
40static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto)
41{
42 switch (proto) {
43 case ETH_P_8021Q:
44 case ETH_P_8021AD:
45 bpf_tail_call(skb, &jmp_table, PARSE_VLAN);
46 break;
47 case ETH_P_MPLS_UC:
48 case ETH_P_MPLS_MC:
49 bpf_tail_call(skb, &jmp_table, PARSE_MPLS);
50 break;
51 case ETH_P_IP:
52 bpf_tail_call(skb, &jmp_table, PARSE_IP);
53 break;
54 case ETH_P_IPV6:
55 bpf_tail_call(skb, &jmp_table, PARSE_IPV6);
56 break;
57 }
58}
59
60struct vlan_hdr {
61 __be16 h_vlan_TCI;
62 __be16 h_vlan_encapsulated_proto;
63};
64
65struct flow_key_record {
66 __be32 src;
67 __be32 dst;
68 union {
69 __be32 ports;
70 __be16 port16[2];
71 };
72 __u32 ip_proto;
73};
74
75static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
76{
77 return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
78 & (IP_MF | IP_OFFSET);
79}
80
81static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
82{
83 __u64 w0 = load_word(ctx, off);
84 __u64 w1 = load_word(ctx, off + 4);
85 __u64 w2 = load_word(ctx, off + 8);
86 __u64 w3 = load_word(ctx, off + 12);
87
88 return (__u32)(w0 ^ w1 ^ w2 ^ w3);
89}
90
91struct globals {
92 struct flow_key_record flow;
93};
94
95struct {
96 __uint(type, BPF_MAP_TYPE_ARRAY);
97 __type(key, __u32);
98 __type(value, struct globals);
99 __uint(max_entries, 32);
100} percpu_map SEC(".maps");
101
102/* user poor man's per_cpu until native support is ready */
103static struct globals *this_cpu_globals(void)
104{
105 u32 key = bpf_get_smp_processor_id();
106
107 return bpf_map_lookup_elem(&percpu_map, &key);
108}
109
110/* some simple stats for user space consumption */
111struct pair {
112 __u64 packets;
113 __u64 bytes;
114};
115
116struct {
117 __uint(type, BPF_MAP_TYPE_HASH);
118 __type(key, struct flow_key_record);
119 __type(value, struct pair);
120 __uint(max_entries, 1024);
121} hash_map SEC(".maps");
122
123static void update_stats(struct __sk_buff *skb, struct globals *g)
124{
125 struct flow_key_record key = g->flow;
126 struct pair *value;
127
128 value = bpf_map_lookup_elem(&hash_map, &key);
129 if (value) {
130 __sync_fetch_and_add(&value->packets, 1);
131 __sync_fetch_and_add(&value->bytes, skb->len);
132 } else {
133 struct pair val = {1, skb->len};
134
135 bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
136 }
137}
138
139static __always_inline void parse_ip_proto(struct __sk_buff *skb,
140 struct globals *g, __u32 ip_proto)
141{
142 __u32 nhoff = skb->cb[0];
143 int poff;
144
145 switch (ip_proto) {
146 case IPPROTO_GRE: {
147 struct gre_hdr {
148 __be16 flags;
149 __be16 proto;
150 };
151
152 __u32 gre_flags = load_half(skb,
153 nhoff + offsetof(struct gre_hdr, flags));
154 __u32 gre_proto = load_half(skb,
155 nhoff + offsetof(struct gre_hdr, proto));
156
157 if (gre_flags & (GRE_VERSION|GRE_ROUTING))
158 break;
159
160 nhoff += 4;
161 if (gre_flags & GRE_CSUM)
162 nhoff += 4;
163 if (gre_flags & GRE_KEY)
164 nhoff += 4;
165 if (gre_flags & GRE_SEQ)
166 nhoff += 4;
167
168 skb->cb[0] = nhoff;
169 parse_eth_proto(skb, gre_proto);
170 break;
171 }
172 case IPPROTO_IPIP:
173 parse_eth_proto(skb, ETH_P_IP);
174 break;
175 case IPPROTO_IPV6:
176 parse_eth_proto(skb, ETH_P_IPV6);
177 break;
178 case IPPROTO_TCP:
179 case IPPROTO_UDP:
180 g->flow.ports = load_word(skb, nhoff);
181 case IPPROTO_ICMP:
182 g->flow.ip_proto = ip_proto;
183 update_stats(skb, g);
184 break;
185 default:
186 break;
187 }
188}
189
190PROG(PARSE_IP)(struct __sk_buff *skb)
191{
192 struct globals *g = this_cpu_globals();
193 __u32 nhoff, verlen, ip_proto;
194
195 if (!g)
196 return 0;
197
198 nhoff = skb->cb[0];
199
200 if (unlikely(ip_is_fragment(skb, nhoff)))
201 return 0;
202
203 ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
204
205 if (ip_proto != IPPROTO_GRE) {
206 g->flow.src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
207 g->flow.dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
208 }
209
210 verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
211 nhoff += (verlen & 0xF) << 2;
212
213 skb->cb[0] = nhoff;
214 parse_ip_proto(skb, g, ip_proto);
215 return 0;
216}
217
218PROG(PARSE_IPV6)(struct __sk_buff *skb)
219{
220 struct globals *g = this_cpu_globals();
221 __u32 nhoff, ip_proto;
222
223 if (!g)
224 return 0;
225
226 nhoff = skb->cb[0];
227
228 ip_proto = load_byte(skb,
229 nhoff + offsetof(struct ipv6hdr, nexthdr));
230 g->flow.src = ipv6_addr_hash(skb,
231 nhoff + offsetof(struct ipv6hdr, saddr));
232 g->flow.dst = ipv6_addr_hash(skb,
233 nhoff + offsetof(struct ipv6hdr, daddr));
234 nhoff += sizeof(struct ipv6hdr);
235
236 skb->cb[0] = nhoff;
237 parse_ip_proto(skb, g, ip_proto);
238 return 0;
239}
240
241PROG(PARSE_VLAN)(struct __sk_buff *skb)
242{
243 __u32 nhoff, proto;
244
245 nhoff = skb->cb[0];
246
247 proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
248 h_vlan_encapsulated_proto));
249 nhoff += sizeof(struct vlan_hdr);
250 skb->cb[0] = nhoff;
251
252 parse_eth_proto(skb, proto);
253
254 return 0;
255}
256
257PROG(PARSE_MPLS)(struct __sk_buff *skb)
258{
259 __u32 nhoff, label;
260
261 nhoff = skb->cb[0];
262
263 label = load_word(skb, nhoff);
264 nhoff += sizeof(struct mpls_label);
265 skb->cb[0] = nhoff;
266
267 if (label & MPLS_LS_S_MASK) {
268 __u8 verlen = load_byte(skb, nhoff);
269 if ((verlen & 0xF0) == 4)
270 parse_eth_proto(skb, ETH_P_IP);
271 else
272 parse_eth_proto(skb, ETH_P_IPV6);
273 } else {
274 parse_eth_proto(skb, ETH_P_MPLS_UC);
275 }
276
277 return 0;
278}
279
280SEC("socket/0")
281int main_prog(struct __sk_buff *skb)
282{
283 __u32 nhoff = ETH_HLEN;
284 __u32 proto = load_half(skb, 12);
285
286 skb->cb[0] = nhoff;
287 parse_eth_proto(skb, proto);
288 return 0;
289}
290
291char _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 "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_key_record {
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_key_record 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_key_record),
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_key_record 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";