1 /* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
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.
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"
18 #define IP_OFFSET 0x1FFF
27 __be16 h_vlan_encapsulated_proto;
30 struct flow_key_record {
40 static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto);
42 static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
44 return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
45 & (IP_MF | IP_OFFSET);
48 static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
50 __u64 w0 = load_word(ctx, off);
51 __u64 w1 = load_word(ctx, off + 4);
52 __u64 w2 = load_word(ctx, off + 8);
53 __u64 w3 = load_word(ctx, off + 12);
55 return (__u32)(w0 ^ w1 ^ w2 ^ w3);
59 struct flow_key_record flow;
63 __uint(type, BPF_MAP_TYPE_ARRAY);
65 __type(value, struct globals);
66 __uint(max_entries, 32);
67 } percpu_map SEC(".maps");
69 /* user poor man's per_cpu until native support is ready */
70 static struct globals *this_cpu_globals(void)
72 u32 key = bpf_get_smp_processor_id();
74 return bpf_map_lookup_elem(&percpu_map, &key);
77 /* some simple stats for user space consumption */
84 __uint(type, BPF_MAP_TYPE_HASH);
85 __type(key, struct flow_key_record);
86 __type(value, struct pair);
87 __uint(max_entries, 1024);
88 } hash_map SEC(".maps");
90 static void update_stats(struct __sk_buff *skb, struct globals *g)
92 struct flow_key_record key = g->flow;
95 value = bpf_map_lookup_elem(&hash_map, &key);
97 __sync_fetch_and_add(&value->packets, 1);
98 __sync_fetch_and_add(&value->bytes, skb->len);
100 struct pair val = {1, skb->len};
102 bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
106 static __always_inline void parse_ip_proto(struct __sk_buff *skb,
107 struct globals *g, __u32 ip_proto)
109 __u32 nhoff = skb->cb[0];
119 __u32 gre_flags = load_half(skb,
120 nhoff + offsetof(struct gre_hdr, flags));
121 __u32 gre_proto = load_half(skb,
122 nhoff + offsetof(struct gre_hdr, proto));
124 if (gre_flags & (GRE_VERSION|GRE_ROUTING))
128 if (gre_flags & GRE_CSUM)
130 if (gre_flags & GRE_KEY)
132 if (gre_flags & GRE_SEQ)
136 parse_eth_proto(skb, gre_proto);
140 parse_eth_proto(skb, ETH_P_IP);
143 parse_eth_proto(skb, ETH_P_IPV6);
147 g->flow.ports = load_word(skb, nhoff);
149 g->flow.ip_proto = ip_proto;
150 update_stats(skb, g);
158 int bpf_func_ip(struct __sk_buff *skb)
160 struct globals *g = this_cpu_globals();
161 __u32 nhoff, verlen, ip_proto;
168 if (unlikely(ip_is_fragment(skb, nhoff)))
171 ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
173 if (ip_proto != IPPROTO_GRE) {
174 g->flow.src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
175 g->flow.dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
178 verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
179 nhoff += (verlen & 0xF) << 2;
182 parse_ip_proto(skb, g, ip_proto);
187 int bpf_func_ipv6(struct __sk_buff *skb)
189 struct globals *g = this_cpu_globals();
190 __u32 nhoff, ip_proto;
197 ip_proto = load_byte(skb,
198 nhoff + offsetof(struct ipv6hdr, nexthdr));
199 g->flow.src = ipv6_addr_hash(skb,
200 nhoff + offsetof(struct ipv6hdr, saddr));
201 g->flow.dst = ipv6_addr_hash(skb,
202 nhoff + offsetof(struct ipv6hdr, daddr));
203 nhoff += sizeof(struct ipv6hdr);
206 parse_ip_proto(skb, g, ip_proto);
211 int bpf_func_vlan(struct __sk_buff *skb)
217 proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
218 h_vlan_encapsulated_proto));
219 nhoff += sizeof(struct vlan_hdr);
222 parse_eth_proto(skb, proto);
228 int bpf_func_mpls(struct __sk_buff *skb)
234 label = load_word(skb, nhoff);
235 nhoff += sizeof(struct mpls_label);
238 if (label & MPLS_LS_S_MASK) {
239 __u8 verlen = load_byte(skb, nhoff);
240 if ((verlen & 0xF0) == 4)
241 parse_eth_proto(skb, ETH_P_IP);
243 parse_eth_proto(skb, ETH_P_IPV6);
245 parse_eth_proto(skb, ETH_P_MPLS_UC);
252 __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
253 __uint(key_size, sizeof(u32));
254 __uint(max_entries, 8);
255 __array(values, u32 (void *));
256 } prog_array_init SEC(".maps") = {
258 [PARSE_VLAN] = (void *)&bpf_func_vlan,
259 [PARSE_IP] = (void *)&bpf_func_ip,
260 [PARSE_IPV6] = (void *)&bpf_func_ipv6,
261 [PARSE_MPLS] = (void *)&bpf_func_mpls,
265 /* Protocol dispatch routine. It tail-calls next BPF program depending
266 * on eth proto. Note, we could have used ...
268 * bpf_tail_call(skb, &prog_array_init, proto);
270 * ... but it would need large prog_array and cannot be optimised given
271 * the map key is not static.
273 static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto)
278 bpf_tail_call(skb, &prog_array_init, PARSE_VLAN);
282 bpf_tail_call(skb, &prog_array_init, PARSE_MPLS);
285 bpf_tail_call(skb, &prog_array_init, PARSE_IP);
288 bpf_tail_call(skb, &prog_array_init, PARSE_IPV6);
294 int main_prog(struct __sk_buff *skb)
296 __u32 nhoff = ETH_HLEN;
297 __u32 proto = load_half(skb, 12);
300 parse_eth_proto(skb, proto);
304 char _license[] SEC("license") = "GPL";