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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 | /* Copyright (c) 2016 Facebook * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ #define KBUILD_MODNAME "foo" #include <uapi/linux/bpf.h> #include <uapi/linux/if_ether.h> #include <uapi/linux/if_packet.h> #include <uapi/linux/ip.h> #include <uapi/linux/ipv6.h> #include <uapi/linux/in.h> #include <uapi/linux/tcp.h> #include <uapi/linux/filter.h> #include <uapi/linux/pkt_cls.h> #include <net/ipv6.h> #include <bpf/bpf_helpers.h> #define _htonl __builtin_bswap32 #define PIN_GLOBAL_NS 2 struct bpf_elf_map { __u32 type; __u32 size_key; __u32 size_value; __u32 max_elem; __u32 flags; __u32 id; __u32 pinning; }; /* copy of 'struct ethhdr' without __packed */ struct eth_hdr { unsigned char h_dest[ETH_ALEN]; unsigned char h_source[ETH_ALEN]; unsigned short h_proto; }; struct bpf_elf_map SEC("maps") tun_iface = { .type = BPF_MAP_TYPE_ARRAY, .size_key = sizeof(int), .size_value = sizeof(int), .pinning = PIN_GLOBAL_NS, .max_elem = 1, }; static __always_inline bool is_vip_addr(__be16 eth_proto, __be32 daddr) { if (eth_proto == htons(ETH_P_IP)) return (_htonl(0xffffff00) & daddr) == _htonl(0x0a0a0100); else if (eth_proto == htons(ETH_P_IPV6)) return (daddr == _htonl(0x2401face)); return false; } SEC("l2_to_iptun_ingress_forward") int _l2_to_iptun_ingress_forward(struct __sk_buff *skb) { struct bpf_tunnel_key tkey = {}; void *data = (void *)(long)skb->data; struct eth_hdr *eth = data; void *data_end = (void *)(long)skb->data_end; int key = 0, *ifindex; int ret; if (data + sizeof(*eth) > data_end) return TC_ACT_OK; ifindex = bpf_map_lookup_elem(&tun_iface, &key); if (!ifindex) return TC_ACT_OK; if (eth->h_proto == htons(ETH_P_IP)) { char fmt4[] = "ingress forward to ifindex:%d daddr4:%x\n"; struct iphdr *iph = data + sizeof(*eth); if (data + sizeof(*eth) + sizeof(*iph) > data_end) return TC_ACT_OK; if (iph->protocol != IPPROTO_IPIP) return TC_ACT_OK; bpf_trace_printk(fmt4, sizeof(fmt4), *ifindex, _htonl(iph->daddr)); return bpf_redirect(*ifindex, BPF_F_INGRESS); } else if (eth->h_proto == htons(ETH_P_IPV6)) { char fmt6[] = "ingress forward to ifindex:%d daddr6:%x::%x\n"; struct ipv6hdr *ip6h = data + sizeof(*eth); if (data + sizeof(*eth) + sizeof(*ip6h) > data_end) return TC_ACT_OK; if (ip6h->nexthdr != IPPROTO_IPIP && ip6h->nexthdr != IPPROTO_IPV6) return TC_ACT_OK; bpf_trace_printk(fmt6, sizeof(fmt6), *ifindex, _htonl(ip6h->daddr.s6_addr32[0]), _htonl(ip6h->daddr.s6_addr32[3])); return bpf_redirect(*ifindex, BPF_F_INGRESS); } return TC_ACT_OK; } SEC("l2_to_iptun_ingress_redirect") int _l2_to_iptun_ingress_redirect(struct __sk_buff *skb) { struct bpf_tunnel_key tkey = {}; void *data = (void *)(long)skb->data; struct eth_hdr *eth = data; void *data_end = (void *)(long)skb->data_end; int key = 0, *ifindex; int ret; if (data + sizeof(*eth) > data_end) return TC_ACT_OK; ifindex = bpf_map_lookup_elem(&tun_iface, &key); if (!ifindex) return TC_ACT_OK; if (eth->h_proto == htons(ETH_P_IP)) { char fmt4[] = "e/ingress redirect daddr4:%x to ifindex:%d\n"; struct iphdr *iph = data + sizeof(*eth); __be32 daddr = iph->daddr; if (data + sizeof(*eth) + sizeof(*iph) > data_end) return TC_ACT_OK; if (!is_vip_addr(eth->h_proto, daddr)) return TC_ACT_OK; bpf_trace_printk(fmt4, sizeof(fmt4), _htonl(daddr), *ifindex); } else { return TC_ACT_OK; } tkey.tunnel_id = 10000; tkey.tunnel_ttl = 64; tkey.remote_ipv4 = 0x0a020166; /* 10.2.1.102 */ bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), 0); return bpf_redirect(*ifindex, 0); } SEC("l2_to_ip6tun_ingress_redirect") int _l2_to_ip6tun_ingress_redirect(struct __sk_buff *skb) { struct bpf_tunnel_key tkey = {}; void *data = (void *)(long)skb->data; struct eth_hdr *eth = data; void *data_end = (void *)(long)skb->data_end; int key = 0, *ifindex; if (data + sizeof(*eth) > data_end) return TC_ACT_OK; ifindex = bpf_map_lookup_elem(&tun_iface, &key); if (!ifindex) return TC_ACT_OK; if (eth->h_proto == htons(ETH_P_IP)) { char fmt4[] = "e/ingress redirect daddr4:%x to ifindex:%d\n"; struct iphdr *iph = data + sizeof(*eth); if (data + sizeof(*eth) + sizeof(*iph) > data_end) return TC_ACT_OK; if (!is_vip_addr(eth->h_proto, iph->daddr)) return TC_ACT_OK; bpf_trace_printk(fmt4, sizeof(fmt4), _htonl(iph->daddr), *ifindex); } else if (eth->h_proto == htons(ETH_P_IPV6)) { char fmt6[] = "e/ingress redirect daddr6:%x to ifindex:%d\n"; struct ipv6hdr *ip6h = data + sizeof(*eth); if (data + sizeof(*eth) + sizeof(*ip6h) > data_end) return TC_ACT_OK; if (!is_vip_addr(eth->h_proto, ip6h->daddr.s6_addr32[0])) return TC_ACT_OK; bpf_trace_printk(fmt6, sizeof(fmt6), _htonl(ip6h->daddr.s6_addr32[0]), *ifindex); } else { return TC_ACT_OK; } tkey.tunnel_id = 10000; tkey.tunnel_ttl = 64; /* 2401:db02:0:0:0:0:0:66 */ tkey.remote_ipv6[0] = _htonl(0x2401db02); tkey.remote_ipv6[1] = 0; tkey.remote_ipv6[2] = 0; tkey.remote_ipv6[3] = _htonl(0x00000066); bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), BPF_F_TUNINFO_IPV6); return bpf_redirect(*ifindex, 0); } SEC("drop_non_tun_vip") int _drop_non_tun_vip(struct __sk_buff *skb) { struct bpf_tunnel_key tkey = {}; void *data = (void *)(long)skb->data; struct eth_hdr *eth = data; void *data_end = (void *)(long)skb->data_end; if (data + sizeof(*eth) > data_end) return TC_ACT_OK; if (eth->h_proto == htons(ETH_P_IP)) { struct iphdr *iph = data + sizeof(*eth); if (data + sizeof(*eth) + sizeof(*iph) > data_end) return TC_ACT_OK; if (is_vip_addr(eth->h_proto, iph->daddr)) return TC_ACT_SHOT; } else if (eth->h_proto == htons(ETH_P_IPV6)) { struct ipv6hdr *ip6h = data + sizeof(*eth); if (data + sizeof(*eth) + sizeof(*ip6h) > data_end) return TC_ACT_OK; if (is_vip_addr(eth->h_proto, ip6h->daddr.s6_addr32[0])) return TC_ACT_SHOT; } return TC_ACT_OK; } char _license[] SEC("license") = "GPL"; |