1 /* Copyright (c) 2016 Facebook
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 #define KBUILD_MODNAME "foo"
8 #include <uapi/linux/bpf.h>
9 #include <uapi/linux/if_ether.h>
10 #include <uapi/linux/if_packet.h>
11 #include <uapi/linux/ip.h>
12 #include <uapi/linux/ipv6.h>
13 #include <uapi/linux/in.h>
14 #include <uapi/linux/tcp.h>
15 #include <uapi/linux/filter.h>
16 #include <uapi/linux/pkt_cls.h>
18 #include <bpf/bpf_helpers.h>
20 #define _htonl __builtin_bswap32
22 #define PIN_GLOBAL_NS 2
33 /* copy of 'struct ethhdr' without __packed */
35 unsigned char h_dest[ETH_ALEN];
36 unsigned char h_source[ETH_ALEN];
37 unsigned short h_proto;
40 struct bpf_elf_map SEC("maps") tun_iface = {
41 .type = BPF_MAP_TYPE_ARRAY,
42 .size_key = sizeof(int),
43 .size_value = sizeof(int),
44 .pinning = PIN_GLOBAL_NS,
48 static __always_inline bool is_vip_addr(__be16 eth_proto, __be32 daddr)
50 if (eth_proto == htons(ETH_P_IP))
51 return (_htonl(0xffffff00) & daddr) == _htonl(0x0a0a0100);
52 else if (eth_proto == htons(ETH_P_IPV6))
53 return (daddr == _htonl(0x2401face));
58 SEC("l2_to_iptun_ingress_forward")
59 int _l2_to_iptun_ingress_forward(struct __sk_buff *skb)
61 struct bpf_tunnel_key tkey = {};
62 void *data = (void *)(long)skb->data;
63 struct eth_hdr *eth = data;
64 void *data_end = (void *)(long)skb->data_end;
65 int key = 0, *ifindex;
69 if (data + sizeof(*eth) > data_end)
72 ifindex = bpf_map_lookup_elem(&tun_iface, &key);
76 if (eth->h_proto == htons(ETH_P_IP)) {
77 char fmt4[] = "ingress forward to ifindex:%d daddr4:%x\n";
78 struct iphdr *iph = data + sizeof(*eth);
80 if (data + sizeof(*eth) + sizeof(*iph) > data_end)
83 if (iph->protocol != IPPROTO_IPIP)
86 bpf_trace_printk(fmt4, sizeof(fmt4), *ifindex,
88 return bpf_redirect(*ifindex, BPF_F_INGRESS);
89 } else if (eth->h_proto == htons(ETH_P_IPV6)) {
90 char fmt6[] = "ingress forward to ifindex:%d daddr6:%x::%x\n";
91 struct ipv6hdr *ip6h = data + sizeof(*eth);
93 if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
96 if (ip6h->nexthdr != IPPROTO_IPIP &&
97 ip6h->nexthdr != IPPROTO_IPV6)
100 bpf_trace_printk(fmt6, sizeof(fmt6), *ifindex,
101 _htonl(ip6h->daddr.s6_addr32[0]),
102 _htonl(ip6h->daddr.s6_addr32[3]));
103 return bpf_redirect(*ifindex, BPF_F_INGRESS);
109 SEC("l2_to_iptun_ingress_redirect")
110 int _l2_to_iptun_ingress_redirect(struct __sk_buff *skb)
112 struct bpf_tunnel_key tkey = {};
113 void *data = (void *)(long)skb->data;
114 struct eth_hdr *eth = data;
115 void *data_end = (void *)(long)skb->data_end;
116 int key = 0, *ifindex;
120 if (data + sizeof(*eth) > data_end)
123 ifindex = bpf_map_lookup_elem(&tun_iface, &key);
127 if (eth->h_proto == htons(ETH_P_IP)) {
128 char fmt4[] = "e/ingress redirect daddr4:%x to ifindex:%d\n";
129 struct iphdr *iph = data + sizeof(*eth);
130 __be32 daddr = iph->daddr;
132 if (data + sizeof(*eth) + sizeof(*iph) > data_end)
135 if (!is_vip_addr(eth->h_proto, daddr))
138 bpf_trace_printk(fmt4, sizeof(fmt4), _htonl(daddr), *ifindex);
143 tkey.tunnel_id = 10000;
144 tkey.tunnel_ttl = 64;
145 tkey.remote_ipv4 = 0x0a020166; /* 10.2.1.102 */
146 bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), 0);
147 return bpf_redirect(*ifindex, 0);
150 SEC("l2_to_ip6tun_ingress_redirect")
151 int _l2_to_ip6tun_ingress_redirect(struct __sk_buff *skb)
153 struct bpf_tunnel_key tkey = {};
154 void *data = (void *)(long)skb->data;
155 struct eth_hdr *eth = data;
156 void *data_end = (void *)(long)skb->data_end;
157 int key = 0, *ifindex;
159 if (data + sizeof(*eth) > data_end)
162 ifindex = bpf_map_lookup_elem(&tun_iface, &key);
166 if (eth->h_proto == htons(ETH_P_IP)) {
167 char fmt4[] = "e/ingress redirect daddr4:%x to ifindex:%d\n";
168 struct iphdr *iph = data + sizeof(*eth);
170 if (data + sizeof(*eth) + sizeof(*iph) > data_end)
173 if (!is_vip_addr(eth->h_proto, iph->daddr))
176 bpf_trace_printk(fmt4, sizeof(fmt4), _htonl(iph->daddr),
178 } else if (eth->h_proto == htons(ETH_P_IPV6)) {
179 char fmt6[] = "e/ingress redirect daddr6:%x to ifindex:%d\n";
180 struct ipv6hdr *ip6h = data + sizeof(*eth);
182 if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
185 if (!is_vip_addr(eth->h_proto, ip6h->daddr.s6_addr32[0]))
188 bpf_trace_printk(fmt6, sizeof(fmt6),
189 _htonl(ip6h->daddr.s6_addr32[0]), *ifindex);
194 tkey.tunnel_id = 10000;
195 tkey.tunnel_ttl = 64;
196 /* 2401:db02:0:0:0:0:0:66 */
197 tkey.remote_ipv6[0] = _htonl(0x2401db02);
198 tkey.remote_ipv6[1] = 0;
199 tkey.remote_ipv6[2] = 0;
200 tkey.remote_ipv6[3] = _htonl(0x00000066);
201 bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), BPF_F_TUNINFO_IPV6);
202 return bpf_redirect(*ifindex, 0);
205 SEC("drop_non_tun_vip")
206 int _drop_non_tun_vip(struct __sk_buff *skb)
208 struct bpf_tunnel_key tkey = {};
209 void *data = (void *)(long)skb->data;
210 struct eth_hdr *eth = data;
211 void *data_end = (void *)(long)skb->data_end;
213 if (data + sizeof(*eth) > data_end)
216 if (eth->h_proto == htons(ETH_P_IP)) {
217 struct iphdr *iph = data + sizeof(*eth);
219 if (data + sizeof(*eth) + sizeof(*iph) > data_end)
222 if (is_vip_addr(eth->h_proto, iph->daddr))
224 } else if (eth->h_proto == htons(ETH_P_IPV6)) {
225 struct ipv6hdr *ip6h = data + sizeof(*eth);
227 if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
230 if (is_vip_addr(eth->h_proto, ip6h->daddr.s6_addr32[0]))
237 char _license[] SEC("license") = "GPL";