1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2013 Nicira, Inc.
   4 */
   5
   6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7
   8#include <linux/types.h>
   9#include <linux/kernel.h>
  10#include <linux/skbuff.h>
  11#include <linux/netdevice.h>
  12#include <linux/in.h>
  13#include <linux/if_arp.h>
  14#include <linux/init.h>
  15#include <linux/in6.h>
  16#include <linux/inetdevice.h>
  17#include <linux/netfilter_ipv4.h>
  18#include <linux/etherdevice.h>
  19#include <linux/if_ether.h>
  20#include <linux/if_vlan.h>
  21#include <linux/static_key.h>
  22
  23#include <net/ip.h>
  24#include <net/icmp.h>
  25#include <net/protocol.h>
  26#include <net/ip_tunnels.h>
  27#include <net/ip6_tunnel.h>
  28#include <net/ip6_checksum.h>
  29#include <net/arp.h>
  30#include <net/checksum.h>
  31#include <net/dsfield.h>
  32#include <net/inet_ecn.h>
  33#include <net/xfrm.h>
  34#include <net/net_namespace.h>
  35#include <net/netns/generic.h>
  36#include <net/rtnetlink.h>
  37#include <net/dst_metadata.h>
  38#include <net/geneve.h>
  39#include <net/vxlan.h>
  40#include <net/erspan.h>
  41
  42const struct ip_tunnel_encap_ops __rcu *
  43		iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
  44EXPORT_SYMBOL(iptun_encaps);
  45
  46const struct ip6_tnl_encap_ops __rcu *
  47		ip6tun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
  48EXPORT_SYMBOL(ip6tun_encaps);
  49
  50void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
  51		   __be32 src, __be32 dst, __u8 proto,
  52		   __u8 tos, __u8 ttl, __be16 df, bool xnet)
  53{
  54	int pkt_len = skb->len - skb_inner_network_offset(skb);
  55	struct net *net = dev_net(rt->dst.dev);
  56	struct net_device *dev = skb->dev;
  57	struct iphdr *iph;
  58	int err;
  59
  60	skb_scrub_packet(skb, xnet);
  61
  62	skb_clear_hash_if_not_l4(skb);
  63	skb_dst_set(skb, &rt->dst);
  64	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
  65
  66	/* Push down and install the IP header. */
  67	skb_push(skb, sizeof(struct iphdr));
  68	skb_reset_network_header(skb);
  69
  70	iph = ip_hdr(skb);
  71
  72	iph->version	=	4;
  73	iph->ihl	=	sizeof(struct iphdr) >> 2;
  74	iph->frag_off	=	ip_mtu_locked(&rt->dst) ? 0 : df;
  75	iph->protocol	=	proto;
  76	iph->tos	=	tos;
  77	iph->daddr	=	dst;
  78	iph->saddr	=	src;
  79	iph->ttl	=	ttl;
  80	__ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1);
  81
  82	err = ip_local_out(net, sk, skb);
  83
  84	if (dev) {
  85		if (unlikely(net_xmit_eval(err)))
  86			pkt_len = 0;
  87		iptunnel_xmit_stats(dev, pkt_len);
  88	}
  89}
  90EXPORT_SYMBOL_GPL(iptunnel_xmit);
  91
  92int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
  93			   __be16 inner_proto, bool raw_proto, bool xnet)
  94{
  95	if (unlikely(!pskb_may_pull(skb, hdr_len)))
  96		return -ENOMEM;
  97
  98	skb_pull_rcsum(skb, hdr_len);
  99
 100	if (!raw_proto && inner_proto == htons(ETH_P_TEB)) {
 101		struct ethhdr *eh;
 102
 103		if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
 104			return -ENOMEM;
 105
 106		eh = (struct ethhdr *)skb->data;
 107		if (likely(eth_proto_is_802_3(eh->h_proto)))
 108			skb->protocol = eh->h_proto;
 109		else
 110			skb->protocol = htons(ETH_P_802_2);
 111
 112	} else {
 113		skb->protocol = inner_proto;
 114	}
 115
 116	skb_clear_hash_if_not_l4(skb);
 117	__vlan_hwaccel_clear_tag(skb);
 118	skb_set_queue_mapping(skb, 0);
 119	skb_scrub_packet(skb, xnet);
 120
 121	return iptunnel_pull_offloads(skb);
 122}
 123EXPORT_SYMBOL_GPL(__iptunnel_pull_header);
 124
 125struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 126					     gfp_t flags)
 127{
 128	struct metadata_dst *res;
 129	struct ip_tunnel_info *dst, *src;
 130
 131	if (!md || md->type != METADATA_IP_TUNNEL ||
 132	    md->u.tun_info.mode & IP_TUNNEL_INFO_TX)
 133		return NULL;
 134
 135	src = &md->u.tun_info;
 136	res = metadata_dst_alloc(src->options_len, METADATA_IP_TUNNEL, flags);
 137	if (!res)
 138		return NULL;
 139
 140	dst = &res->u.tun_info;
 141	dst->key.tun_id = src->key.tun_id;
 142	if (src->mode & IP_TUNNEL_INFO_IPV6)
 143		memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src,
 144		       sizeof(struct in6_addr));
 145	else
 146		dst->key.u.ipv4.dst = src->key.u.ipv4.src;
 147	dst->key.tun_flags = src->key.tun_flags;
 148	dst->mode = src->mode | IP_TUNNEL_INFO_TX;
 149	ip_tunnel_info_opts_set(dst, ip_tunnel_info_opts(src),
 150				src->options_len, 0);
 151
 152	return res;
 153}
 154EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
 155
 156int iptunnel_handle_offloads(struct sk_buff *skb,
 157			     int gso_type_mask)
 158{
 159	int err;
 160
 161	if (likely(!skb->encapsulation)) {
 162		skb_reset_inner_headers(skb);
 163		skb->encapsulation = 1;
 164	}
 165
 166	if (skb_is_gso(skb)) {
 167		err = skb_header_unclone(skb, GFP_ATOMIC);
 168		if (unlikely(err))
 169			return err;
 170		skb_shinfo(skb)->gso_type |= gso_type_mask;
 171		return 0;
 172	}
 173
 174	if (skb->ip_summed != CHECKSUM_PARTIAL) {
 175		skb->ip_summed = CHECKSUM_NONE;
 176		/* We clear encapsulation here to prevent badly-written
 177		 * drivers potentially deciding to offload an inner checksum
 178		 * if we set CHECKSUM_PARTIAL on the outer header.
 179		 * This should go away when the drivers are all fixed.
 180		 */
 181		skb->encapsulation = 0;
 182	}
 183
 184	return 0;
 185}
 186EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
 187
 188/**
 189 * iptunnel_pmtud_build_icmp() - Build ICMP error message for PMTUD
 190 * @skb:	Original packet with L2 header
 191 * @mtu:	MTU value for ICMP error
 192 *
 193 * Return: length on success, negative error code if message couldn't be built.
 194 */
 195static int iptunnel_pmtud_build_icmp(struct sk_buff *skb, int mtu)
 196{
 197	const struct iphdr *iph = ip_hdr(skb);
 198	struct icmphdr *icmph;
 199	struct iphdr *niph;
 200	struct ethhdr eh;
 201	int len, err;
 202
 203	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
 204		return -EINVAL;
 205
 206	skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
 207	pskb_pull(skb, ETH_HLEN);
 208	skb_reset_network_header(skb);
 209
 210	err = pskb_trim(skb, 576 - sizeof(*niph) - sizeof(*icmph));
 211	if (err)
 212		return err;
 213
 214	len = skb->len + sizeof(*icmph);
 215	err = skb_cow(skb, sizeof(*niph) + sizeof(*icmph) + ETH_HLEN);
 216	if (err)
 217		return err;
 218
 219	icmph = skb_push(skb, sizeof(*icmph));
 220	*icmph = (struct icmphdr) {
 221		.type			= ICMP_DEST_UNREACH,
 222		.code			= ICMP_FRAG_NEEDED,
 223		.checksum		= 0,
 224		.un.frag.__unused	= 0,
 225		.un.frag.mtu		= htons(mtu),
 226	};
 227	icmph->checksum = ip_compute_csum(icmph, len);
 228	skb_reset_transport_header(skb);
 229
 230	niph = skb_push(skb, sizeof(*niph));
 231	*niph = (struct iphdr) {
 232		.ihl			= sizeof(*niph) / 4u,
 233		.version 		= 4,
 234		.tos 			= 0,
 235		.tot_len		= htons(len + sizeof(*niph)),
 236		.id			= 0,
 237		.frag_off		= htons(IP_DF),
 238		.ttl			= iph->ttl,
 239		.protocol		= IPPROTO_ICMP,
 240		.saddr			= iph->daddr,
 241		.daddr			= iph->saddr,
 242	};
 243	ip_send_check(niph);
 244	skb_reset_network_header(skb);
 245
 246	skb->ip_summed = CHECKSUM_NONE;
 247
 248	eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
 249	skb_reset_mac_header(skb);
 250
 251	return skb->len;
 252}
 253
 254/**
 255 * iptunnel_pmtud_check_icmp() - Trigger ICMP reply if needed and allowed
 256 * @skb:	Buffer being sent by encapsulation, L2 headers expected
 257 * @mtu:	Network MTU for path
 258 *
 259 * Return: 0 for no ICMP reply, length if built, negative value on error.
 260 */
 261static int iptunnel_pmtud_check_icmp(struct sk_buff *skb, int mtu)
 262{
 263	const struct icmphdr *icmph = icmp_hdr(skb);
 264	const struct iphdr *iph = ip_hdr(skb);
 265
 266	if (mtu < 576 || iph->frag_off != htons(IP_DF))
 267		return 0;
 268
 269	if (ipv4_is_lbcast(iph->daddr)  || ipv4_is_multicast(iph->daddr) ||
 270	    ipv4_is_zeronet(iph->saddr) || ipv4_is_loopback(iph->saddr)  ||
 271	    ipv4_is_lbcast(iph->saddr)  || ipv4_is_multicast(iph->saddr))
 272		return 0;
 273
 274	if (iph->protocol == IPPROTO_ICMP && icmp_is_err(icmph->type))
 275		return 0;
 276
 277	return iptunnel_pmtud_build_icmp(skb, mtu);
 278}
 279
 280#if IS_ENABLED(CONFIG_IPV6)
 281/**
 282 * iptunnel_pmtud_build_icmpv6() - Build ICMPv6 error message for PMTUD
 283 * @skb:	Original packet with L2 header
 284 * @mtu:	MTU value for ICMPv6 error
 285 *
 286 * Return: length on success, negative error code if message couldn't be built.
 287 */
 288static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu)
 289{
 290	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 291	struct icmp6hdr *icmp6h;
 292	struct ipv6hdr *nip6h;
 293	struct ethhdr eh;
 294	int len, err;
 295	__wsum csum;
 296
 297	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
 298		return -EINVAL;
 299
 300	skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
 301	pskb_pull(skb, ETH_HLEN);
 302	skb_reset_network_header(skb);
 303
 304	err = pskb_trim(skb, IPV6_MIN_MTU - sizeof(*nip6h) - sizeof(*icmp6h));
 305	if (err)
 306		return err;
 307
 308	len = skb->len + sizeof(*icmp6h);
 309	err = skb_cow(skb, sizeof(*nip6h) + sizeof(*icmp6h) + ETH_HLEN);
 310	if (err)
 311		return err;
 312
 313	icmp6h = skb_push(skb, sizeof(*icmp6h));
 314	*icmp6h = (struct icmp6hdr) {
 315		.icmp6_type		= ICMPV6_PKT_TOOBIG,
 316		.icmp6_code		= 0,
 317		.icmp6_cksum		= 0,
 318		.icmp6_mtu		= htonl(mtu),
 319	};
 320	skb_reset_transport_header(skb);
 321
 322	nip6h = skb_push(skb, sizeof(*nip6h));
 323	*nip6h = (struct ipv6hdr) {
 324		.priority		= 0,
 325		.version		= 6,
 326		.flow_lbl		= { 0 },
 327		.payload_len		= htons(len),
 328		.nexthdr		= IPPROTO_ICMPV6,
 329		.hop_limit		= ip6h->hop_limit,
 330		.saddr			= ip6h->daddr,
 331		.daddr			= ip6h->saddr,
 332	};
 333	skb_reset_network_header(skb);
 334
 335	csum = csum_partial(icmp6h, len, 0);
 336	icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len,
 337					      IPPROTO_ICMPV6, csum);
 338
 339	skb->ip_summed = CHECKSUM_NONE;
 340
 341	eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
 342	skb_reset_mac_header(skb);
 343
 344	return skb->len;
 345}
 346
 347/**
 348 * iptunnel_pmtud_check_icmpv6() - Trigger ICMPv6 reply if needed and allowed
 349 * @skb:	Buffer being sent by encapsulation, L2 headers expected
 350 * @mtu:	Network MTU for path
 351 *
 352 * Return: 0 for no ICMPv6 reply, length if built, negative value on error.
 353 */
 354static int iptunnel_pmtud_check_icmpv6(struct sk_buff *skb, int mtu)
 355{
 356	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 357	int stype = ipv6_addr_type(&ip6h->saddr);
 358	u8 proto = ip6h->nexthdr;
 359	__be16 frag_off;
 360	int offset;
 361
 362	if (mtu < IPV6_MIN_MTU)
 363		return 0;
 364
 365	if (stype == IPV6_ADDR_ANY || stype == IPV6_ADDR_MULTICAST ||
 366	    stype == IPV6_ADDR_LOOPBACK)
 367		return 0;
 368
 369	offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto,
 370				  &frag_off);
 371	if (offset < 0 || (frag_off & htons(~0x7)))
 372		return 0;
 373
 374	if (proto == IPPROTO_ICMPV6) {
 375		struct icmp6hdr *icmp6h;
 376
 377		if (!pskb_may_pull(skb, skb_network_header(skb) +
 378					offset + 1 - skb->data))
 379			return 0;
 380
 381		icmp6h = (struct icmp6hdr *)(skb_network_header(skb) + offset);
 382		if (icmpv6_is_err(icmp6h->icmp6_type) ||
 383		    icmp6h->icmp6_type == NDISC_REDIRECT)
 384			return 0;
 385	}
 386
 387	return iptunnel_pmtud_build_icmpv6(skb, mtu);
 388}
 389#endif /* IS_ENABLED(CONFIG_IPV6) */
 390
 391/**
 392 * skb_tunnel_check_pmtu() - Check, update PMTU and trigger ICMP reply as needed
 393 * @skb:	Buffer being sent by encapsulation, L2 headers expected
 394 * @encap_dst:	Destination for tunnel encapsulation (outer IP)
 395 * @headroom:	Encapsulation header size, bytes
 396 * @reply:	Build matching ICMP or ICMPv6 message as a result
 397 *
 398 * L2 tunnel implementations that can carry IP and can be directly bridged
 399 * (currently UDP tunnels) can't always rely on IP forwarding paths to handle
 400 * PMTU discovery. In the bridged case, ICMP or ICMPv6 messages need to be built
 401 * based on payload and sent back by the encapsulation itself.
 402 *
 403 * For routable interfaces, we just need to update the PMTU for the destination.
 404 *
 405 * Return: 0 if ICMP error not needed, length if built, negative value on error
 406 */
 407int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
 408			  int headroom, bool reply)
 409{
 410	u32 mtu = dst_mtu(encap_dst) - headroom;
 411
 412	if ((skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) ||
 413	    (!skb_is_gso(skb) && (skb->len - skb_mac_header_len(skb)) <= mtu))
 414		return 0;
 415
 416	skb_dst_update_pmtu_no_confirm(skb, mtu);
 417
 418	if (!reply || skb->pkt_type == PACKET_HOST)
 419		return 0;
 420
 421	if (skb->protocol == htons(ETH_P_IP))
 422		return iptunnel_pmtud_check_icmp(skb, mtu);
 423
 424#if IS_ENABLED(CONFIG_IPV6)
 425	if (skb->protocol == htons(ETH_P_IPV6))
 426		return iptunnel_pmtud_check_icmpv6(skb, mtu);
 427#endif
 428	return 0;
 429}
 430EXPORT_SYMBOL(skb_tunnel_check_pmtu);
 431
 432static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
 433	[LWTUNNEL_IP_UNSPEC]	= { .strict_start_type = LWTUNNEL_IP_OPTS },
 434	[LWTUNNEL_IP_ID]	= { .type = NLA_U64 },
 435	[LWTUNNEL_IP_DST]	= { .type = NLA_U32 },
 436	[LWTUNNEL_IP_SRC]	= { .type = NLA_U32 },
 437	[LWTUNNEL_IP_TTL]	= { .type = NLA_U8 },
 438	[LWTUNNEL_IP_TOS]	= { .type = NLA_U8 },
 439	[LWTUNNEL_IP_FLAGS]	= { .type = NLA_U16 },
 440	[LWTUNNEL_IP_OPTS]	= { .type = NLA_NESTED },
 441};
 442
 443static const struct nla_policy ip_opts_policy[LWTUNNEL_IP_OPTS_MAX + 1] = {
 444	[LWTUNNEL_IP_OPTS_GENEVE]	= { .type = NLA_NESTED },
 445	[LWTUNNEL_IP_OPTS_VXLAN]	= { .type = NLA_NESTED },
 446	[LWTUNNEL_IP_OPTS_ERSPAN]	= { .type = NLA_NESTED },
 447};
 448
 449static const struct nla_policy
 450geneve_opt_policy[LWTUNNEL_IP_OPT_GENEVE_MAX + 1] = {
 451	[LWTUNNEL_IP_OPT_GENEVE_CLASS]	= { .type = NLA_U16 },
 452	[LWTUNNEL_IP_OPT_GENEVE_TYPE]	= { .type = NLA_U8 },
 453	[LWTUNNEL_IP_OPT_GENEVE_DATA]	= { .type = NLA_BINARY, .len = 128 },
 454};
 455
 456static const struct nla_policy
 457vxlan_opt_policy[LWTUNNEL_IP_OPT_VXLAN_MAX + 1] = {
 458	[LWTUNNEL_IP_OPT_VXLAN_GBP]	= { .type = NLA_U32 },
 459};
 460
 461static const struct nla_policy
 462erspan_opt_policy[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1] = {
 463	[LWTUNNEL_IP_OPT_ERSPAN_VER]	= { .type = NLA_U8 },
 464	[LWTUNNEL_IP_OPT_ERSPAN_INDEX]	= { .type = NLA_U32 },
 465	[LWTUNNEL_IP_OPT_ERSPAN_DIR]	= { .type = NLA_U8 },
 466	[LWTUNNEL_IP_OPT_ERSPAN_HWID]	= { .type = NLA_U8 },
 467};
 468
 469static int ip_tun_parse_opts_geneve(struct nlattr *attr,
 470				    struct ip_tunnel_info *info, int opts_len,
 471				    struct netlink_ext_ack *extack)
 472{
 473	struct nlattr *tb[LWTUNNEL_IP_OPT_GENEVE_MAX + 1];
 474	int data_len, err;
 475
 476	err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_GENEVE_MAX, attr,
 477			       geneve_opt_policy, extack);
 478	if (err)
 479		return err;
 480
 481	if (!tb[LWTUNNEL_IP_OPT_GENEVE_CLASS] ||
 482	    !tb[LWTUNNEL_IP_OPT_GENEVE_TYPE] ||
 483	    !tb[LWTUNNEL_IP_OPT_GENEVE_DATA])
 484		return -EINVAL;
 485
 486	attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA];
 487	data_len = nla_len(attr);
 488	if (data_len % 4)
 489		return -EINVAL;
 490
 491	if (info) {
 492		struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;
 493
 494		memcpy(opt->opt_data, nla_data(attr), data_len);
 495		opt->length = data_len / 4;
 496		attr = tb[LWTUNNEL_IP_OPT_GENEVE_CLASS];
 497		opt->opt_class = nla_get_be16(attr);
 498		attr = tb[LWTUNNEL_IP_OPT_GENEVE_TYPE];
 499		opt->type = nla_get_u8(attr);
 500		info->key.tun_flags |= TUNNEL_GENEVE_OPT;
 501	}
 502
 503	return sizeof(struct geneve_opt) + data_len;
 504}
 505
 506static int ip_tun_parse_opts_vxlan(struct nlattr *attr,
 507				   struct ip_tunnel_info *info, int opts_len,
 508				   struct netlink_ext_ack *extack)
 509{
 510	struct nlattr *tb[LWTUNNEL_IP_OPT_VXLAN_MAX + 1];
 511	int err;
 512
 513	err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_VXLAN_MAX, attr,
 514			       vxlan_opt_policy, extack);
 515	if (err)
 516		return err;
 517
 518	if (!tb[LWTUNNEL_IP_OPT_VXLAN_GBP])
 519		return -EINVAL;
 520
 521	if (info) {
 522		struct vxlan_metadata *md =
 523			ip_tunnel_info_opts(info) + opts_len;
 524
 525		attr = tb[LWTUNNEL_IP_OPT_VXLAN_GBP];
 526		md->gbp = nla_get_u32(attr);
 527		md->gbp &= VXLAN_GBP_MASK;
 528		info->key.tun_flags |= TUNNEL_VXLAN_OPT;
 529	}
 530
 531	return sizeof(struct vxlan_metadata);
 532}
 533
 534static int ip_tun_parse_opts_erspan(struct nlattr *attr,
 535				    struct ip_tunnel_info *info, int opts_len,
 536				    struct netlink_ext_ack *extack)
 537{
 538	struct nlattr *tb[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1];
 539	int err;
 540	u8 ver;
 541
 542	err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_ERSPAN_MAX, attr,
 543			       erspan_opt_policy, extack);
 544	if (err)
 545		return err;
 546
 547	if (!tb[LWTUNNEL_IP_OPT_ERSPAN_VER])
 548		return -EINVAL;
 549
 550	ver = nla_get_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_VER]);
 551	if (ver == 1) {
 552		if (!tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX])
 553			return -EINVAL;
 554	} else if (ver == 2) {
 555		if (!tb[LWTUNNEL_IP_OPT_ERSPAN_DIR] ||
 556		    !tb[LWTUNNEL_IP_OPT_ERSPAN_HWID])
 557			return -EINVAL;
 558	} else {
 559		return -EINVAL;
 560	}
 561
 562	if (info) {
 563		struct erspan_metadata *md =
 564			ip_tunnel_info_opts(info) + opts_len;
 565
 566		md->version = ver;
 567		if (ver == 1) {
 568			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX];
 569			md->u.index = nla_get_be32(attr);
 570		} else {
 571			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_DIR];
 572			md->u.md2.dir = nla_get_u8(attr);
 573			attr = tb[LWTUNNEL_IP_OPT_ERSPAN_HWID];
 574			set_hwid(&md->u.md2, nla_get_u8(attr));
 575		}
 576
 577		info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
 578	}
 579
 580	return sizeof(struct erspan_metadata);
 581}
 582
 583static int ip_tun_parse_opts(struct nlattr *attr, struct ip_tunnel_info *info,
 584			     struct netlink_ext_ack *extack)
 585{
 586	int err, rem, opt_len, opts_len = 0;
 587	struct nlattr *nla;
 588	__be16 type = 0;
 589
 590	if (!attr)
 591		return 0;
 592
 593	err = nla_validate(nla_data(attr), nla_len(attr), LWTUNNEL_IP_OPTS_MAX,
 594			   ip_opts_policy, extack);
 595	if (err)
 596		return err;
 597
 598	nla_for_each_attr(nla, nla_data(attr), nla_len(attr), rem) {
 599		switch (nla_type(nla)) {
 600		case LWTUNNEL_IP_OPTS_GENEVE:
 601			if (type && type != TUNNEL_GENEVE_OPT)
 602				return -EINVAL;
 603			opt_len = ip_tun_parse_opts_geneve(nla, info, opts_len,
 604							   extack);
 605			if (opt_len < 0)
 606				return opt_len;
 607			opts_len += opt_len;
 608			if (opts_len > IP_TUNNEL_OPTS_MAX)
 609				return -EINVAL;
 610			type = TUNNEL_GENEVE_OPT;
 611			break;
 612		case LWTUNNEL_IP_OPTS_VXLAN:
 613			if (type)
 614				return -EINVAL;
 615			opt_len = ip_tun_parse_opts_vxlan(nla, info, opts_len,
 616							  extack);
 617			if (opt_len < 0)
 618				return opt_len;
 619			opts_len += opt_len;
 620			type = TUNNEL_VXLAN_OPT;
 621			break;
 622		case LWTUNNEL_IP_OPTS_ERSPAN:
 623			if (type)
 624				return -EINVAL;
 625			opt_len = ip_tun_parse_opts_erspan(nla, info, opts_len,
 626							   extack);
 627			if (opt_len < 0)
 628				return opt_len;
 629			opts_len += opt_len;
 630			type = TUNNEL_ERSPAN_OPT;
 631			break;
 632		default:
 633			return -EINVAL;
 634		}
 635	}
 636
 637	return opts_len;
 638}
 639
 640static int ip_tun_get_optlen(struct nlattr *attr,
 641			     struct netlink_ext_ack *extack)
 642{
 643	return ip_tun_parse_opts(attr, NULL, extack);
 644}
 645
 646static int ip_tun_set_opts(struct nlattr *attr, struct ip_tunnel_info *info,
 647			   struct netlink_ext_ack *extack)
 648{
 649	return ip_tun_parse_opts(attr, info, extack);
 650}
 651
 652static int ip_tun_build_state(struct net *net, struct nlattr *attr,
 653			      unsigned int family, const void *cfg,
 654			      struct lwtunnel_state **ts,
 655			      struct netlink_ext_ack *extack)
 656{
 657	struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
 658	struct lwtunnel_state *new_state;
 659	struct ip_tunnel_info *tun_info;
 660	int err, opt_len;
 661
 662	err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP_MAX, attr,
 663					  ip_tun_policy, extack);
 664	if (err < 0)
 665		return err;
 666
 667	opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP_OPTS], extack);
 668	if (opt_len < 0)
 669		return opt_len;
 670
 671	new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
 672	if (!new_state)
 673		return -ENOMEM;
 674
 675	new_state->type = LWTUNNEL_ENCAP_IP;
 676
 677	tun_info = lwt_tun_info(new_state);
 678
 679	err = ip_tun_set_opts(tb[LWTUNNEL_IP_OPTS], tun_info, extack);
 680	if (err < 0) {
 681		lwtstate_free(new_state);
 682		return err;
 683	}
 684
 685#ifdef CONFIG_DST_CACHE
 686	err = dst_cache_init(&tun_info->dst_cache, GFP_KERNEL);
 687	if (err) {
 688		lwtstate_free(new_state);
 689		return err;
 690	}
 691#endif
 692
 693	if (tb[LWTUNNEL_IP_ID])
 694		tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]);
 695
 696	if (tb[LWTUNNEL_IP_DST])
 697		tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]);
 698
 699	if (tb[LWTUNNEL_IP_SRC])
 700		tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]);
 701
 702	if (tb[LWTUNNEL_IP_TTL])
 703		tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]);
 704
 705	if (tb[LWTUNNEL_IP_TOS])
 706		tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]);
 707
 708	if (tb[LWTUNNEL_IP_FLAGS])
 709		tun_info->key.tun_flags |=
 710				(nla_get_be16(tb[LWTUNNEL_IP_FLAGS]) &
 711				 ~TUNNEL_OPTIONS_PRESENT);
 712
 713	tun_info->mode = IP_TUNNEL_INFO_TX;
 714	tun_info->options_len = opt_len;
 715
 716	*ts = new_state;
 717
 718	return 0;
 719}
 720
 721static void ip_tun_destroy_state(struct lwtunnel_state *lwtstate)
 722{
 723#ifdef CONFIG_DST_CACHE
 724	struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
 725
 726	dst_cache_destroy(&tun_info->dst_cache);
 727#endif
 728}
 729
 730static int ip_tun_fill_encap_opts_geneve(struct sk_buff *skb,
 731					 struct ip_tunnel_info *tun_info)
 732{
 733	struct geneve_opt *opt;
 734	struct nlattr *nest;
 735	int offset = 0;
 736
 737	nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_GENEVE);
 738	if (!nest)
 739		return -ENOMEM;
 740
 741	while (tun_info->options_len > offset) {
 742		opt = ip_tunnel_info_opts(tun_info) + offset;
 743		if (nla_put_be16(skb, LWTUNNEL_IP_OPT_GENEVE_CLASS,
 744				 opt->opt_class) ||
 745		    nla_put_u8(skb, LWTUNNEL_IP_OPT_GENEVE_TYPE, opt->type) ||
 746		    nla_put(skb, LWTUNNEL_IP_OPT_GENEVE_DATA, opt->length * 4,
 747			    opt->opt_data)) {
 748			nla_nest_cancel(skb, nest);
 749			return -ENOMEM;
 750		}
 751		offset += sizeof(*opt) + opt->length * 4;
 752	}
 753
 754	nla_nest_end(skb, nest);
 755	return 0;
 756}
 757
 758static int ip_tun_fill_encap_opts_vxlan(struct sk_buff *skb,
 759					struct ip_tunnel_info *tun_info)
 760{
 761	struct vxlan_metadata *md;
 762	struct nlattr *nest;
 763
 764	nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_VXLAN);
 765	if (!nest)
 766		return -ENOMEM;
 767
 768	md = ip_tunnel_info_opts(tun_info);
 769	if (nla_put_u32(skb, LWTUNNEL_IP_OPT_VXLAN_GBP, md->gbp)) {
 770		nla_nest_cancel(skb, nest);
 771		return -ENOMEM;
 772	}
 773
 774	nla_nest_end(skb, nest);
 775	return 0;
 776}
 777
 778static int ip_tun_fill_encap_opts_erspan(struct sk_buff *skb,
 779					 struct ip_tunnel_info *tun_info)
 780{
 781	struct erspan_metadata *md;
 782	struct nlattr *nest;
 783
 784	nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_ERSPAN);
 785	if (!nest)
 786		return -ENOMEM;
 787
 788	md = ip_tunnel_info_opts(tun_info);
 789	if (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_VER, md->version))
 790		goto err;
 791
 792	if (md->version == 1 &&
 793	    nla_put_be32(skb, LWTUNNEL_IP_OPT_ERSPAN_INDEX, md->u.index))
 794		goto err;
 795
 796	if (md->version == 2 &&
 797	    (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_DIR, md->u.md2.dir) ||
 798	     nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_HWID,
 799			get_hwid(&md->u.md2))))
 800		goto err;
 801
 802	nla_nest_end(skb, nest);
 803	return 0;
 804err:
 805	nla_nest_cancel(skb, nest);
 806	return -ENOMEM;
 807}
 808
 809static int ip_tun_fill_encap_opts(struct sk_buff *skb, int type,
 810				  struct ip_tunnel_info *tun_info)
 811{
 812	struct nlattr *nest;
 813	int err = 0;
 814
 815	if (!(tun_info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))
 816		return 0;
 817
 818	nest = nla_nest_start_noflag(skb, type);
 819	if (!nest)
 820		return -ENOMEM;
 821
 822	if (tun_info->key.tun_flags & TUNNEL_GENEVE_OPT)
 823		err = ip_tun_fill_encap_opts_geneve(skb, tun_info);
 824	else if (tun_info->key.tun_flags & TUNNEL_VXLAN_OPT)
 825		err = ip_tun_fill_encap_opts_vxlan(skb, tun_info);
 826	else if (tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)
 827		err = ip_tun_fill_encap_opts_erspan(skb, tun_info);
 828
 829	if (err) {
 830		nla_nest_cancel(skb, nest);
 831		return err;
 832	}
 833
 834	nla_nest_end(skb, nest);
 835	return 0;
 836}
 837
 838static int ip_tun_fill_encap_info(struct sk_buff *skb,
 839				  struct lwtunnel_state *lwtstate)
 840{
 841	struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
 842
 843	if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id,
 844			 LWTUNNEL_IP_PAD) ||
 845	    nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) ||
 846	    nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) ||
 847	    nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) ||
 848	    nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) ||
 849	    nla_put_be16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags) ||
 850	    ip_tun_fill_encap_opts(skb, LWTUNNEL_IP_OPTS, tun_info))
 851		return -ENOMEM;
 852
 853	return 0;
 854}
 855
 856static int ip_tun_opts_nlsize(struct ip_tunnel_info *info)
 857{
 858	int opt_len;
 859
 860	if (!(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))
 861		return 0;
 862
 863	opt_len = nla_total_size(0);		/* LWTUNNEL_IP_OPTS */
 864	if (info->key.tun_flags & TUNNEL_GENEVE_OPT) {
 865		struct geneve_opt *opt;
 866		int offset = 0;
 867
 868		opt_len += nla_total_size(0);	/* LWTUNNEL_IP_OPTS_GENEVE */
 869		while (info->options_len > offset) {
 870			opt = ip_tunnel_info_opts(info) + offset;
 871			opt_len += nla_total_size(2)	/* OPT_GENEVE_CLASS */
 872				   + nla_total_size(1)	/* OPT_GENEVE_TYPE */
 873				   + nla_total_size(opt->length * 4);
 874							/* OPT_GENEVE_DATA */
 875			offset += sizeof(*opt) + opt->length * 4;
 876		}
 877	} else if (info->key.tun_flags & TUNNEL_VXLAN_OPT) {
 878		opt_len += nla_total_size(0)	/* LWTUNNEL_IP_OPTS_VXLAN */
 879			   + nla_total_size(4);	/* OPT_VXLAN_GBP */
 880	} else if (info->key.tun_flags & TUNNEL_ERSPAN_OPT) {
 881		struct erspan_metadata *md = ip_tunnel_info_opts(info);
 882
 883		opt_len += nla_total_size(0)	/* LWTUNNEL_IP_OPTS_ERSPAN */
 884			   + nla_total_size(1)	/* OPT_ERSPAN_VER */
 885			   + (md->version == 1 ? nla_total_size(4)
 886						/* OPT_ERSPAN_INDEX (v1) */
 887					       : nla_total_size(1) +
 888						 nla_total_size(1));
 889						/* OPT_ERSPAN_DIR + HWID (v2) */
 890	}
 891
 892	return opt_len;
 893}
 894
 895static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
 896{
 897	return nla_total_size_64bit(8)	/* LWTUNNEL_IP_ID */
 898		+ nla_total_size(4)	/* LWTUNNEL_IP_DST */
 899		+ nla_total_size(4)	/* LWTUNNEL_IP_SRC */
 900		+ nla_total_size(1)	/* LWTUNNEL_IP_TOS */
 901		+ nla_total_size(1)	/* LWTUNNEL_IP_TTL */
 902		+ nla_total_size(2)	/* LWTUNNEL_IP_FLAGS */
 903		+ ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
 904					/* LWTUNNEL_IP_OPTS */
 905}
 906
 907static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
 908{
 909	struct ip_tunnel_info *info_a = lwt_tun_info(a);
 910	struct ip_tunnel_info *info_b = lwt_tun_info(b);
 911
 912	return memcmp(info_a, info_b, sizeof(info_a->key)) ||
 913	       info_a->mode != info_b->mode ||
 914	       info_a->options_len != info_b->options_len ||
 915	       memcmp(ip_tunnel_info_opts(info_a),
 916		      ip_tunnel_info_opts(info_b), info_a->options_len);
 917}
 918
 919static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
 920	.build_state = ip_tun_build_state,
 921	.destroy_state = ip_tun_destroy_state,
 922	.fill_encap = ip_tun_fill_encap_info,
 923	.get_encap_size = ip_tun_encap_nlsize,
 924	.cmp_encap = ip_tun_cmp_encap,
 925	.owner = THIS_MODULE,
 926};
 927
 928static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
 929	[LWTUNNEL_IP6_UNSPEC]	= { .strict_start_type = LWTUNNEL_IP6_OPTS },
 930	[LWTUNNEL_IP6_ID]		= { .type = NLA_U64 },
 931	[LWTUNNEL_IP6_DST]		= { .len = sizeof(struct in6_addr) },
 932	[LWTUNNEL_IP6_SRC]		= { .len = sizeof(struct in6_addr) },
 933	[LWTUNNEL_IP6_HOPLIMIT]		= { .type = NLA_U8 },
 934	[LWTUNNEL_IP6_TC]		= { .type = NLA_U8 },
 935	[LWTUNNEL_IP6_FLAGS]		= { .type = NLA_U16 },
 936	[LWTUNNEL_IP6_OPTS]		= { .type = NLA_NESTED },
 937};
 938
 939static int ip6_tun_build_state(struct net *net, struct nlattr *attr,
 940			       unsigned int family, const void *cfg,
 941			       struct lwtunnel_state **ts,
 942			       struct netlink_ext_ack *extack)
 943{
 944	struct nlattr *tb[LWTUNNEL_IP6_MAX + 1];
 945	struct lwtunnel_state *new_state;
 946	struct ip_tunnel_info *tun_info;
 947	int err, opt_len;
 948
 949	err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP6_MAX, attr,
 950					  ip6_tun_policy, extack);
 951	if (err < 0)
 952		return err;
 953
 954	opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP6_OPTS], extack);
 955	if (opt_len < 0)
 956		return opt_len;
 957
 958	new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
 959	if (!new_state)
 960		return -ENOMEM;
 961
 962	new_state->type = LWTUNNEL_ENCAP_IP6;
 963
 964	tun_info = lwt_tun_info(new_state);
 965
 966	err = ip_tun_set_opts(tb[LWTUNNEL_IP6_OPTS], tun_info, extack);
 967	if (err < 0) {
 968		lwtstate_free(new_state);
 969		return err;
 970	}
 971
 972	if (tb[LWTUNNEL_IP6_ID])
 973		tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]);
 974
 975	if (tb[LWTUNNEL_IP6_DST])
 976		tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]);
 977
 978	if (tb[LWTUNNEL_IP6_SRC])
 979		tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]);
 980
 981	if (tb[LWTUNNEL_IP6_HOPLIMIT])
 982		tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]);
 983
 984	if (tb[LWTUNNEL_IP6_TC])
 985		tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
 986
 987	if (tb[LWTUNNEL_IP6_FLAGS])
 988		tun_info->key.tun_flags |=
 989				(nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]) &
 990				 ~TUNNEL_OPTIONS_PRESENT);
 991
 992	tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6;
 993	tun_info->options_len = opt_len;
 994
 995	*ts = new_state;
 996
 997	return 0;
 998}
 999
1000static int ip6_tun_fill_encap_info(struct sk_buff *skb,
1001				   struct lwtunnel_state *lwtstate)
1002{
1003	struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
1004
1005	if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id,
1006			 LWTUNNEL_IP6_PAD) ||
1007	    nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) ||
1008	    nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) ||
1009	    nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) ||
1010	    nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) ||
1011	    nla_put_be16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags) ||
1012	    ip_tun_fill_encap_opts(skb, LWTUNNEL_IP6_OPTS, tun_info))
1013		return -ENOMEM;
1014
1015	return 0;
1016}
1017
1018static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
1019{
1020	return nla_total_size_64bit(8)	/* LWTUNNEL_IP6_ID */
1021		+ nla_total_size(16)	/* LWTUNNEL_IP6_DST */
1022		+ nla_total_size(16)	/* LWTUNNEL_IP6_SRC */
1023		+ nla_total_size(1)	/* LWTUNNEL_IP6_HOPLIMIT */
1024		+ nla_total_size(1)	/* LWTUNNEL_IP6_TC */
1025		+ nla_total_size(2)	/* LWTUNNEL_IP6_FLAGS */
1026		+ ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
1027					/* LWTUNNEL_IP6_OPTS */
1028}
1029
1030static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
1031	.build_state = ip6_tun_build_state,
1032	.fill_encap = ip6_tun_fill_encap_info,
1033	.get_encap_size = ip6_tun_encap_nlsize,
1034	.cmp_encap = ip_tun_cmp_encap,
1035	.owner = THIS_MODULE,
1036};
1037
1038void __init ip_tunnel_core_init(void)
1039{
1040	/* If you land here, make sure whether increasing ip_tunnel_info's
1041	 * options_len is a reasonable choice with its usage in front ends
1042	 * (f.e., it's part of flow keys, etc).
1043	 */
1044	BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255);
1045
1046	lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
1047	lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
1048}
1049
1050DEFINE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
1051EXPORT_SYMBOL(ip_tunnel_metadata_cnt);
1052
1053void ip_tunnel_need_metadata(void)
1054{
1055	static_branch_inc(&ip_tunnel_metadata_cnt);
1056}
1057EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata);
1058
1059void ip_tunnel_unneed_metadata(void)
1060{
1061	static_branch_dec(&ip_tunnel_metadata_cnt);
1062}
1063EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);
1064
1065/* Returns either the correct skb->protocol value, or 0 if invalid. */
1066__be16 ip_tunnel_parse_protocol(const struct sk_buff *skb)
1067{
1068	if (skb_network_header(skb) >= skb->head &&
1069	    (skb_network_header(skb) + sizeof(struct iphdr)) <= skb_tail_pointer(skb) &&
1070	    ip_hdr(skb)->version == 4)
1071		return htons(ETH_P_IP);
1072	if (skb_network_header(skb) >= skb->head &&
1073	    (skb_network_header(skb) + sizeof(struct ipv6hdr)) <= skb_tail_pointer(skb) &&
1074	    ipv6_hdr(skb)->version == 6)
1075		return htons(ETH_P_IPV6);
1076	return 0;
1077}
1078EXPORT_SYMBOL(ip_tunnel_parse_protocol);
1079
1080const struct header_ops ip_tunnel_header_ops = { .parse_protocol = ip_tunnel_parse_protocol };
1081EXPORT_SYMBOL(ip_tunnel_header_ops);