| // Copyright (c) PLUMgrid, Inc. |
| // Licensed under the Apache License, Version 2.0 (the "License") |
| |
| #include <bcc/proto.h> |
| |
| struct ipkey { |
| u32 client_ip; |
| }; |
| |
| BPF_TABLE("hash", struct ipkey, int, learned_ips, 1024); |
| |
| // trivial action |
| int pass(struct __sk_buff *skb) { |
| return 1; |
| } |
| |
| // Process each wan packet, and determine if the packet is in the IP |
| // table or not. Learned IPs are rate-limited and unclassified are not. |
| // returns: > 0 when an IP is known |
| // = 0 when an IP is not known, or non-IP traffic |
| int classify_wan(struct __sk_buff *skb) { |
| BEGIN(ethernet); |
| PROTO(ethernet) { |
| switch (ethernet->type) { |
| case 0x0800: goto ip; |
| } |
| goto EOP; |
| } |
| PROTO(ip) { |
| u32 dip = ip->dst; |
| struct ipkey key = {.client_ip=dip}; |
| int *val = learned_ips.lookup(&key); |
| if (val) |
| return *val; |
| goto EOP; |
| } |
| EOP: |
| return 0; |
| } |
| |
| // Process each neighbor packet, and store the source IP in the learned table. |
| // Mark the inserted entry with a non-zero value to be used by the classify_wan |
| // lookup. |
| int classify_neighbor(struct __sk_buff *skb) { |
| BEGIN(ethernet); |
| PROTO(ethernet) { |
| switch (ethernet->type) { |
| case 0x0800: goto ip; |
| } |
| goto EOP; |
| } |
| PROTO(ip) { |
| u32 sip = ip->src; |
| struct ipkey key = {.client_ip=sip}; |
| int val = 1; |
| learned_ips.update(&key, &val); |
| goto EOP; |
| } |
| EOP: |
| return 1; |
| } |