1 /* 2 * Copyright (c) 2013 Nicira, Inc. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 16 * 02110-1301, USA 17 */ 18 19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #include <linux/types.h> 22 #include <linux/kernel.h> 23 #include <linux/skbuff.h> 24 #include <linux/netdevice.h> 25 #include <linux/in.h> 26 #include <linux/if_arp.h> 27 #include <linux/init.h> 28 #include <linux/in6.h> 29 #include <linux/inetdevice.h> 30 #include <linux/netfilter_ipv4.h> 31 #include <linux/etherdevice.h> 32 #include <linux/if_ether.h> 33 #include <linux/if_vlan.h> 34 #include <linux/static_key.h> 35 36 #include <net/ip.h> 37 #include <net/icmp.h> 38 #include <net/protocol.h> 39 #include <net/ip_tunnels.h> 40 #include <net/ip6_tunnel.h> 41 #include <net/arp.h> 42 #include <net/checksum.h> 43 #include <net/dsfield.h> 44 #include <net/inet_ecn.h> 45 #include <net/xfrm.h> 46 #include <net/net_namespace.h> 47 #include <net/netns/generic.h> 48 #include <net/rtnetlink.h> 49 #include <net/dst_metadata.h> 50 51 const struct ip_tunnel_encap_ops __rcu * 52 iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly; 53 EXPORT_SYMBOL(iptun_encaps); 54 55 const struct ip6_tnl_encap_ops __rcu * 56 ip6tun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly; 57 EXPORT_SYMBOL(ip6tun_encaps); 58 59 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, 60 __be32 src, __be32 dst, __u8 proto, 61 __u8 tos, __u8 ttl, __be16 df, bool xnet) 62 { 63 int pkt_len = skb->len - skb_inner_network_offset(skb); 64 struct net *net = dev_net(rt->dst.dev); 65 struct net_device *dev = skb->dev; 66 int skb_iif = skb->skb_iif; 67 struct iphdr *iph; 68 int err; 69 70 skb_scrub_packet(skb, xnet); 71 72 skb_clear_hash_if_not_l4(skb); 73 skb_dst_set(skb, &rt->dst); 74 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 75 76 if (skb_iif && !(df & htons(IP_DF))) { 77 /* Arrived from an ingress interface, got encapsulated, with 78 * fragmentation of encapulating frames allowed. 79 * If skb is gso, the resulting encapsulated network segments 80 * may exceed dst mtu. 81 * Allow IP Fragmentation of segments. 82 */ 83 IPCB(skb)->flags |= IPSKB_FRAG_SEGS; 84 } 85 86 /* Push down and install the IP header. */ 87 skb_push(skb, sizeof(struct iphdr)); 88 skb_reset_network_header(skb); 89 90 iph = ip_hdr(skb); 91 92 iph->version = 4; 93 iph->ihl = sizeof(struct iphdr) >> 2; 94 iph->frag_off = df; 95 iph->protocol = proto; 96 iph->tos = tos; 97 iph->daddr = dst; 98 iph->saddr = src; 99 iph->ttl = ttl; 100 __ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1); 101 102 err = ip_local_out(net, sk, skb); 103 if (unlikely(net_xmit_eval(err))) 104 pkt_len = 0; 105 iptunnel_xmit_stats(dev, pkt_len); 106 } 107 EXPORT_SYMBOL_GPL(iptunnel_xmit); 108 109 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len, 110 __be16 inner_proto, bool raw_proto, bool xnet) 111 { 112 if (unlikely(!pskb_may_pull(skb, hdr_len))) 113 return -ENOMEM; 114 115 skb_pull_rcsum(skb, hdr_len); 116 117 if (!raw_proto && inner_proto == htons(ETH_P_TEB)) { 118 struct ethhdr *eh; 119 120 if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) 121 return -ENOMEM; 122 123 eh = (struct ethhdr *)skb->data; 124 if (likely(eth_proto_is_802_3(eh->h_proto))) 125 skb->protocol = eh->h_proto; 126 else 127 skb->protocol = htons(ETH_P_802_2); 128 129 } else { 130 skb->protocol = inner_proto; 131 } 132 133 skb_clear_hash_if_not_l4(skb); 134 skb->vlan_tci = 0; 135 skb_set_queue_mapping(skb, 0); 136 skb_scrub_packet(skb, xnet); 137 138 return iptunnel_pull_offloads(skb); 139 } 140 EXPORT_SYMBOL_GPL(__iptunnel_pull_header); 141 142 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md, 143 gfp_t flags) 144 { 145 struct metadata_dst *res; 146 struct ip_tunnel_info *dst, *src; 147 148 if (!md || md->u.tun_info.mode & IP_TUNNEL_INFO_TX) 149 return NULL; 150 151 res = metadata_dst_alloc(0, flags); 152 if (!res) 153 return NULL; 154 155 dst = &res->u.tun_info; 156 src = &md->u.tun_info; 157 dst->key.tun_id = src->key.tun_id; 158 if (src->mode & IP_TUNNEL_INFO_IPV6) 159 memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src, 160 sizeof(struct in6_addr)); 161 else 162 dst->key.u.ipv4.dst = src->key.u.ipv4.src; 163 dst->mode = src->mode | IP_TUNNEL_INFO_TX; 164 165 return res; 166 } 167 EXPORT_SYMBOL_GPL(iptunnel_metadata_reply); 168 169 int iptunnel_handle_offloads(struct sk_buff *skb, 170 int gso_type_mask) 171 { 172 int err; 173 174 if (likely(!skb->encapsulation)) { 175 skb_reset_inner_headers(skb); 176 skb->encapsulation = 1; 177 } 178 179 if (skb_is_gso(skb)) { 180 err = skb_header_unclone(skb, GFP_ATOMIC); 181 if (unlikely(err)) 182 return err; 183 skb_shinfo(skb)->gso_type |= gso_type_mask; 184 return 0; 185 } 186 187 if (skb->ip_summed != CHECKSUM_PARTIAL) { 188 skb->ip_summed = CHECKSUM_NONE; 189 /* We clear encapsulation here to prevent badly-written 190 * drivers potentially deciding to offload an inner checksum 191 * if we set CHECKSUM_PARTIAL on the outer header. 192 * This should go away when the drivers are all fixed. 193 */ 194 skb->encapsulation = 0; 195 } 196 197 return 0; 198 } 199 EXPORT_SYMBOL_GPL(iptunnel_handle_offloads); 200 201 /* Often modified stats are per cpu, other are shared (netdev->stats) */ 202 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev, 203 struct rtnl_link_stats64 *tot) 204 { 205 int i; 206 207 netdev_stats_to_stats64(tot, &dev->stats); 208 209 for_each_possible_cpu(i) { 210 const struct pcpu_sw_netstats *tstats = 211 per_cpu_ptr(dev->tstats, i); 212 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 213 unsigned int start; 214 215 do { 216 start = u64_stats_fetch_begin_irq(&tstats->syncp); 217 rx_packets = tstats->rx_packets; 218 tx_packets = tstats->tx_packets; 219 rx_bytes = tstats->rx_bytes; 220 tx_bytes = tstats->tx_bytes; 221 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start)); 222 223 tot->rx_packets += rx_packets; 224 tot->tx_packets += tx_packets; 225 tot->rx_bytes += rx_bytes; 226 tot->tx_bytes += tx_bytes; 227 } 228 229 return tot; 230 } 231 EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64); 232 233 static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = { 234 [LWTUNNEL_IP_ID] = { .type = NLA_U64 }, 235 [LWTUNNEL_IP_DST] = { .type = NLA_U32 }, 236 [LWTUNNEL_IP_SRC] = { .type = NLA_U32 }, 237 [LWTUNNEL_IP_TTL] = { .type = NLA_U8 }, 238 [LWTUNNEL_IP_TOS] = { .type = NLA_U8 }, 239 [LWTUNNEL_IP_FLAGS] = { .type = NLA_U16 }, 240 }; 241 242 static int ip_tun_build_state(struct net_device *dev, struct nlattr *attr, 243 unsigned int family, const void *cfg, 244 struct lwtunnel_state **ts) 245 { 246 struct ip_tunnel_info *tun_info; 247 struct lwtunnel_state *new_state; 248 struct nlattr *tb[LWTUNNEL_IP_MAX + 1]; 249 int err; 250 251 err = nla_parse_nested(tb, LWTUNNEL_IP_MAX, attr, ip_tun_policy); 252 if (err < 0) 253 return err; 254 255 new_state = lwtunnel_state_alloc(sizeof(*tun_info)); 256 if (!new_state) 257 return -ENOMEM; 258 259 new_state->type = LWTUNNEL_ENCAP_IP; 260 261 tun_info = lwt_tun_info(new_state); 262 263 if (tb[LWTUNNEL_IP_ID]) 264 tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]); 265 266 if (tb[LWTUNNEL_IP_DST]) 267 tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]); 268 269 if (tb[LWTUNNEL_IP_SRC]) 270 tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]); 271 272 if (tb[LWTUNNEL_IP_TTL]) 273 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]); 274 275 if (tb[LWTUNNEL_IP_TOS]) 276 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]); 277 278 if (tb[LWTUNNEL_IP_FLAGS]) 279 tun_info->key.tun_flags = nla_get_be16(tb[LWTUNNEL_IP_FLAGS]); 280 281 tun_info->mode = IP_TUNNEL_INFO_TX; 282 tun_info->options_len = 0; 283 284 *ts = new_state; 285 286 return 0; 287 } 288 289 static int ip_tun_fill_encap_info(struct sk_buff *skb, 290 struct lwtunnel_state *lwtstate) 291 { 292 struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate); 293 294 if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id, 295 LWTUNNEL_IP_PAD) || 296 nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) || 297 nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) || 298 nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) || 299 nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) || 300 nla_put_be16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags)) 301 return -ENOMEM; 302 303 return 0; 304 } 305 306 static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate) 307 { 308 return nla_total_size_64bit(8) /* LWTUNNEL_IP_ID */ 309 + nla_total_size(4) /* LWTUNNEL_IP_DST */ 310 + nla_total_size(4) /* LWTUNNEL_IP_SRC */ 311 + nla_total_size(1) /* LWTUNNEL_IP_TOS */ 312 + nla_total_size(1) /* LWTUNNEL_IP_TTL */ 313 + nla_total_size(2); /* LWTUNNEL_IP_FLAGS */ 314 } 315 316 static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b) 317 { 318 return memcmp(lwt_tun_info(a), lwt_tun_info(b), 319 sizeof(struct ip_tunnel_info)); 320 } 321 322 static const struct lwtunnel_encap_ops ip_tun_lwt_ops = { 323 .build_state = ip_tun_build_state, 324 .fill_encap = ip_tun_fill_encap_info, 325 .get_encap_size = ip_tun_encap_nlsize, 326 .cmp_encap = ip_tun_cmp_encap, 327 }; 328 329 static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = { 330 [LWTUNNEL_IP6_ID] = { .type = NLA_U64 }, 331 [LWTUNNEL_IP6_DST] = { .len = sizeof(struct in6_addr) }, 332 [LWTUNNEL_IP6_SRC] = { .len = sizeof(struct in6_addr) }, 333 [LWTUNNEL_IP6_HOPLIMIT] = { .type = NLA_U8 }, 334 [LWTUNNEL_IP6_TC] = { .type = NLA_U8 }, 335 [LWTUNNEL_IP6_FLAGS] = { .type = NLA_U16 }, 336 }; 337 338 static int ip6_tun_build_state(struct net_device *dev, struct nlattr *attr, 339 unsigned int family, const void *cfg, 340 struct lwtunnel_state **ts) 341 { 342 struct ip_tunnel_info *tun_info; 343 struct lwtunnel_state *new_state; 344 struct nlattr *tb[LWTUNNEL_IP6_MAX + 1]; 345 int err; 346 347 err = nla_parse_nested(tb, LWTUNNEL_IP6_MAX, attr, ip6_tun_policy); 348 if (err < 0) 349 return err; 350 351 new_state = lwtunnel_state_alloc(sizeof(*tun_info)); 352 if (!new_state) 353 return -ENOMEM; 354 355 new_state->type = LWTUNNEL_ENCAP_IP6; 356 357 tun_info = lwt_tun_info(new_state); 358 359 if (tb[LWTUNNEL_IP6_ID]) 360 tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]); 361 362 if (tb[LWTUNNEL_IP6_DST]) 363 tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]); 364 365 if (tb[LWTUNNEL_IP6_SRC]) 366 tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]); 367 368 if (tb[LWTUNNEL_IP6_HOPLIMIT]) 369 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]); 370 371 if (tb[LWTUNNEL_IP6_TC]) 372 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]); 373 374 if (tb[LWTUNNEL_IP6_FLAGS]) 375 tun_info->key.tun_flags = nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]); 376 377 tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6; 378 tun_info->options_len = 0; 379 380 *ts = new_state; 381 382 return 0; 383 } 384 385 static int ip6_tun_fill_encap_info(struct sk_buff *skb, 386 struct lwtunnel_state *lwtstate) 387 { 388 struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate); 389 390 if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id, 391 LWTUNNEL_IP6_PAD) || 392 nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) || 393 nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) || 394 nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) || 395 nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) || 396 nla_put_be16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags)) 397 return -ENOMEM; 398 399 return 0; 400 } 401 402 static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate) 403 { 404 return nla_total_size_64bit(8) /* LWTUNNEL_IP6_ID */ 405 + nla_total_size(16) /* LWTUNNEL_IP6_DST */ 406 + nla_total_size(16) /* LWTUNNEL_IP6_SRC */ 407 + nla_total_size(1) /* LWTUNNEL_IP6_HOPLIMIT */ 408 + nla_total_size(1) /* LWTUNNEL_IP6_TC */ 409 + nla_total_size(2); /* LWTUNNEL_IP6_FLAGS */ 410 } 411 412 static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = { 413 .build_state = ip6_tun_build_state, 414 .fill_encap = ip6_tun_fill_encap_info, 415 .get_encap_size = ip6_tun_encap_nlsize, 416 .cmp_encap = ip_tun_cmp_encap, 417 }; 418 419 void __init ip_tunnel_core_init(void) 420 { 421 /* If you land here, make sure whether increasing ip_tunnel_info's 422 * options_len is a reasonable choice with its usage in front ends 423 * (f.e., it's part of flow keys, etc). 424 */ 425 BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255); 426 427 lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP); 428 lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6); 429 } 430 431 struct static_key ip_tunnel_metadata_cnt = STATIC_KEY_INIT_FALSE; 432 EXPORT_SYMBOL(ip_tunnel_metadata_cnt); 433 434 void ip_tunnel_need_metadata(void) 435 { 436 static_key_slow_inc(&ip_tunnel_metadata_cnt); 437 } 438 EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata); 439 440 void ip_tunnel_unneed_metadata(void) 441 { 442 static_key_slow_dec(&ip_tunnel_metadata_cnt); 443 } 444 EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata); 445