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a3f74617 MKL |
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" |
a3f74617 MKL |
8 | #include <uapi/linux/if_ether.h> |
9 | #include <uapi/linux/in6.h> | |
10 | #include <uapi/linux/ipv6.h> | |
11 | #include <uapi/linux/pkt_cls.h> | |
12 | #include <uapi/linux/bpf.h> | |
13 | #include "bpf_helpers.h" | |
14 | ||
15 | /* copy of 'struct ethhdr' without __packed */ | |
16 | struct eth_hdr { | |
17 | unsigned char h_dest[ETH_ALEN]; | |
18 | unsigned char h_source[ETH_ALEN]; | |
19 | unsigned short h_proto; | |
20 | }; | |
21 | ||
22 | #define PIN_GLOBAL_NS 2 | |
23 | struct bpf_elf_map { | |
24 | __u32 type; | |
25 | __u32 size_key; | |
26 | __u32 size_value; | |
27 | __u32 max_elem; | |
28 | __u32 flags; | |
29 | __u32 id; | |
30 | __u32 pinning; | |
31 | }; | |
32 | ||
33 | struct bpf_elf_map SEC("maps") test_cgrp2_array_pin = { | |
34 | .type = BPF_MAP_TYPE_CGROUP_ARRAY, | |
35 | .size_key = sizeof(uint32_t), | |
36 | .size_value = sizeof(uint32_t), | |
37 | .pinning = PIN_GLOBAL_NS, | |
38 | .max_elem = 1, | |
39 | }; | |
40 | ||
41 | SEC("filter") | |
42 | int handle_egress(struct __sk_buff *skb) | |
43 | { | |
44 | void *data = (void *)(long)skb->data; | |
45 | struct eth_hdr *eth = data; | |
46 | struct ipv6hdr *ip6h = data + sizeof(*eth); | |
47 | void *data_end = (void *)(long)skb->data_end; | |
48 | char dont_care_msg[] = "dont care %04x %d\n"; | |
49 | char pass_msg[] = "pass\n"; | |
50 | char reject_msg[] = "reject\n"; | |
51 | ||
52 | /* single length check */ | |
53 | if (data + sizeof(*eth) + sizeof(*ip6h) > data_end) | |
54 | return TC_ACT_OK; | |
55 | ||
56 | if (eth->h_proto != htons(ETH_P_IPV6) || | |
57 | ip6h->nexthdr != IPPROTO_ICMPV6) { | |
58 | bpf_trace_printk(dont_care_msg, sizeof(dont_care_msg), | |
59 | eth->h_proto, ip6h->nexthdr); | |
60 | return TC_ACT_OK; | |
747ea55e | 61 | } else if (bpf_skb_under_cgroup(skb, &test_cgrp2_array_pin, 0) != 1) { |
a3f74617 MKL |
62 | bpf_trace_printk(pass_msg, sizeof(pass_msg)); |
63 | return TC_ACT_OK; | |
64 | } else { | |
65 | bpf_trace_printk(reject_msg, sizeof(reject_msg)); | |
66 | return TC_ACT_SHOT; | |
67 | } | |
68 | } | |
69 | ||
70 | char _license[] SEC("license") = "GPL"; |