projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 65d472fb AS |
1 | /* Copyright (c) 2016 Facebook |
| 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 | */ | |
| 96a8eb1e | 7 | #define KBUILD_MODNAME "foo" |
| 65d472fb AS |
8 | #include <linux/ip.h> |
| 9 | #include <linux/ipv6.h> | |
| 10 | #include <linux/in.h> | |
| 11 | #include <linux/tcp.h> | |
| 12 | #include <linux/udp.h> | |
| 13 | #include <uapi/linux/bpf.h> | |
| 14 | #include <net/ip.h> | |
| 7cf245a3 | 15 | #include <bpf/bpf_helpers.h> |
| 65d472fb AS |
16 | |
| 17 | #define DEFAULT_PKTGEN_UDP_PORT 9 | |
| 18 | ||
| 19 | /* copy of 'struct ethhdr' without __packed */ | |
| 20 | struct eth_hdr { | |
| 21 | unsigned char h_dest[ETH_ALEN]; | |
| 22 | unsigned char h_source[ETH_ALEN]; | |
| 23 | unsigned short h_proto; | |
| 24 | }; | |
| 25 | ||
| 26 | SEC("simple") | |
| 27 | int handle_ingress(struct __sk_buff *skb) | |
| 28 | { | |
| 29 | void *data = (void *)(long)skb->data; | |
| 30 | struct eth_hdr *eth = data; | |
| 31 | struct iphdr *iph = data + sizeof(*eth); | |
| 32 | struct udphdr *udp = data + sizeof(*eth) + sizeof(*iph); | |
| 33 | void *data_end = (void *)(long)skb->data_end; | |
| 34 | ||
| 35 | /* single length check */ | |
| 36 | if (data + sizeof(*eth) + sizeof(*iph) + sizeof(*udp) > data_end) | |
| 37 | return 0; | |
| 38 | ||
| 39 | if (eth->h_proto != htons(ETH_P_IP)) | |
| 40 | return 0; | |
| 41 | if (iph->protocol != IPPROTO_UDP || iph->ihl != 5) | |
| 42 | return 0; | |
| 43 | if (ip_is_fragment(iph)) | |
| 44 | return 0; | |
| 45 | if (udp->dest == htons(DEFAULT_PKTGEN_UDP_PORT)) | |
| 46 | return TC_ACT_SHOT; | |
| 47 | return 0; | |
| 48 | } | |
| 49 | char _license[] SEC("license") = "GPL"; |