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   1/*
   2 *	GRE over IPv6 protocol decoder.
   3 *
   4 *	Authors: Dmitry Kozlov (xeb@mail.ru)
   5 *
   6 *	This program is free software; you can redistribute it and/or
   7 *	modify it under the terms of the GNU General Public License
   8 *	as published by the Free Software Foundation; either version
   9 *	2 of the License, or (at your option) any later version.
  10 *
  11 */
  12
  13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15#include <linux/capability.h>
  16#include <linux/module.h>
  17#include <linux/types.h>
  18#include <linux/kernel.h>
  19#include <linux/slab.h>
  20#include <linux/uaccess.h>
  21#include <linux/skbuff.h>
  22#include <linux/netdevice.h>
  23#include <linux/in.h>
  24#include <linux/tcp.h>
  25#include <linux/udp.h>
  26#include <linux/if_arp.h>
  27#include <linux/mroute.h>
  28#include <linux/init.h>
  29#include <linux/in6.h>
  30#include <linux/inetdevice.h>
  31#include <linux/igmp.h>
  32#include <linux/netfilter_ipv4.h>
  33#include <linux/etherdevice.h>
  34#include <linux/if_ether.h>
  35#include <linux/hash.h>
  36#include <linux/if_tunnel.h>
  37#include <linux/ip6_tunnel.h>
  38
  39#include <net/sock.h>
  40#include <net/ip.h>
  41#include <net/ip_tunnels.h>
  42#include <net/icmp.h>
  43#include <net/protocol.h>
  44#include <net/addrconf.h>
  45#include <net/arp.h>
  46#include <net/checksum.h>
  47#include <net/dsfield.h>
  48#include <net/inet_ecn.h>
  49#include <net/xfrm.h>
  50#include <net/net_namespace.h>
  51#include <net/netns/generic.h>
  52#include <net/rtnetlink.h>
  53
  54#include <net/ipv6.h>
  55#include <net/ip6_fib.h>
  56#include <net/ip6_route.h>
  57#include <net/ip6_tunnel.h>
  58
  59
  60static bool log_ecn_error = true;
  61module_param(log_ecn_error, bool, 0644);
  62MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  63
  64#define HASH_SIZE_SHIFT  5
  65#define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  66
  67static int ip6gre_net_id __read_mostly;
  68struct ip6gre_net {
  69	struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  70
  71	struct net_device *fb_tunnel_dev;
  72};
  73
  74static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  75static int ip6gre_tunnel_init(struct net_device *dev);
  76static void ip6gre_tunnel_setup(struct net_device *dev);
  77static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
  78static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
  79
  80/* Tunnel hash table */
  81
  82/*
  83   4 hash tables:
  84
  85   3: (remote,local)
  86   2: (remote,*)
  87   1: (*,local)
  88   0: (*,*)
  89
  90   We require exact key match i.e. if a key is present in packet
  91   it will match only tunnel with the same key; if it is not present,
  92   it will match only keyless tunnel.
  93
  94   All keysless packets, if not matched configured keyless tunnels
  95   will match fallback tunnel.
  96 */
  97
  98#define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
  99static u32 HASH_ADDR(const struct in6_addr *addr)
 100{
 101	u32 hash = ipv6_addr_hash(addr);
 102
 103	return hash_32(hash, HASH_SIZE_SHIFT);
 104}
 105
 106#define tunnels_r_l	tunnels[3]
 107#define tunnels_r	tunnels[2]
 108#define tunnels_l	tunnels[1]
 109#define tunnels_wc	tunnels[0]
 110
 111/* Given src, dst and key, find appropriate for input tunnel. */
 112
 113static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 114		const struct in6_addr *remote, const struct in6_addr *local,
 115		__be32 key, __be16 gre_proto)
 116{
 117	struct net *net = dev_net(dev);
 118	int link = dev->ifindex;
 119	unsigned int h0 = HASH_ADDR(remote);
 120	unsigned int h1 = HASH_KEY(key);
 121	struct ip6_tnl *t, *cand = NULL;
 122	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 123	int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
 124		       ARPHRD_ETHER : ARPHRD_IP6GRE;
 125	int score, cand_score = 4;
 126
 127	for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 128		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 129		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
 130		    key != t->parms.i_key ||
 131		    !(t->dev->flags & IFF_UP))
 132			continue;
 133
 134		if (t->dev->type != ARPHRD_IP6GRE &&
 135		    t->dev->type != dev_type)
 136			continue;
 137
 138		score = 0;
 139		if (t->parms.link != link)
 140			score |= 1;
 141		if (t->dev->type != dev_type)
 142			score |= 2;
 143		if (score == 0)
 144			return t;
 145
 146		if (score < cand_score) {
 147			cand = t;
 148			cand_score = score;
 149		}
 150	}
 151
 152	for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
 153		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 154		    key != t->parms.i_key ||
 155		    !(t->dev->flags & IFF_UP))
 156			continue;
 157
 158		if (t->dev->type != ARPHRD_IP6GRE &&
 159		    t->dev->type != dev_type)
 160			continue;
 161
 162		score = 0;
 163		if (t->parms.link != link)
 164			score |= 1;
 165		if (t->dev->type != dev_type)
 166			score |= 2;
 167		if (score == 0)
 168			return t;
 169
 170		if (score < cand_score) {
 171			cand = t;
 172			cand_score = score;
 173		}
 174	}
 175
 176	for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
 177		if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
 178			  (!ipv6_addr_equal(local, &t->parms.raddr) ||
 179				 !ipv6_addr_is_multicast(local))) ||
 180		    key != t->parms.i_key ||
 181		    !(t->dev->flags & IFF_UP))
 182			continue;
 183
 184		if (t->dev->type != ARPHRD_IP6GRE &&
 185		    t->dev->type != dev_type)
 186			continue;
 187
 188		score = 0;
 189		if (t->parms.link != link)
 190			score |= 1;
 191		if (t->dev->type != dev_type)
 192			score |= 2;
 193		if (score == 0)
 194			return t;
 195
 196		if (score < cand_score) {
 197			cand = t;
 198			cand_score = score;
 199		}
 200	}
 201
 202	for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
 203		if (t->parms.i_key != key ||
 204		    !(t->dev->flags & IFF_UP))
 205			continue;
 206
 207		if (t->dev->type != ARPHRD_IP6GRE &&
 208		    t->dev->type != dev_type)
 209			continue;
 210
 211		score = 0;
 212		if (t->parms.link != link)
 213			score |= 1;
 214		if (t->dev->type != dev_type)
 215			score |= 2;
 216		if (score == 0)
 217			return t;
 218
 219		if (score < cand_score) {
 220			cand = t;
 221			cand_score = score;
 222		}
 223	}
 224
 225	if (cand != NULL)
 226		return cand;
 227
 228	dev = ign->fb_tunnel_dev;
 229	if (dev->flags & IFF_UP)
 230		return netdev_priv(dev);
 231
 232	return NULL;
 233}
 234
 235static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
 236		const struct __ip6_tnl_parm *p)
 237{
 238	const struct in6_addr *remote = &p->raddr;
 239	const struct in6_addr *local = &p->laddr;
 240	unsigned int h = HASH_KEY(p->i_key);
 241	int prio = 0;
 242
 243	if (!ipv6_addr_any(local))
 244		prio |= 1;
 245	if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
 246		prio |= 2;
 247		h ^= HASH_ADDR(remote);
 248	}
 249
 250	return &ign->tunnels[prio][h];
 251}
 252
 253static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
 254		const struct ip6_tnl *t)
 255{
 256	return __ip6gre_bucket(ign, &t->parms);
 257}
 258
 259static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
 260{
 261	struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
 262
 263	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 264	rcu_assign_pointer(*tp, t);
 265}
 266
 267static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
 268{
 269	struct ip6_tnl __rcu **tp;
 270	struct ip6_tnl *iter;
 271
 272	for (tp = ip6gre_bucket(ign, t);
 273	     (iter = rtnl_dereference(*tp)) != NULL;
 274	     tp = &iter->next) {
 275		if (t == iter) {
 276			rcu_assign_pointer(*tp, t->next);
 277			break;
 278		}
 279	}
 280}
 281
 282static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
 283					   const struct __ip6_tnl_parm *parms,
 284					   int type)
 285{
 286	const struct in6_addr *remote = &parms->raddr;
 287	const struct in6_addr *local = &parms->laddr;
 288	__be32 key = parms->i_key;
 289	int link = parms->link;
 290	struct ip6_tnl *t;
 291	struct ip6_tnl __rcu **tp;
 292	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 293
 294	for (tp = __ip6gre_bucket(ign, parms);
 295	     (t = rtnl_dereference(*tp)) != NULL;
 296	     tp = &t->next)
 297		if (ipv6_addr_equal(local, &t->parms.laddr) &&
 298		    ipv6_addr_equal(remote, &t->parms.raddr) &&
 299		    key == t->parms.i_key &&
 300		    link == t->parms.link &&
 301		    type == t->dev->type)
 302			break;
 303
 304	return t;
 305}
 306
 307static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
 308		const struct __ip6_tnl_parm *parms, int create)
 309{
 310	struct ip6_tnl *t, *nt;
 311	struct net_device *dev;
 312	char name[IFNAMSIZ];
 313	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 314
 315	t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
 316	if (t || !create)
 317		return t;
 318
 319	if (parms->name[0])
 320		strlcpy(name, parms->name, IFNAMSIZ);
 321	else
 322		strcpy(name, "ip6gre%d");
 323
 324	dev = alloc_netdev(sizeof(*t), name, ip6gre_tunnel_setup);
 325	if (!dev)
 326		return NULL;
 327
 328	dev_net_set(dev, net);
 329
 330	nt = netdev_priv(dev);
 331	nt->parms = *parms;
 332	dev->rtnl_link_ops = &ip6gre_link_ops;
 333
 334	nt->dev = dev;
 335	nt->net = dev_net(dev);
 336	ip6gre_tnl_link_config(nt, 1);
 337
 338	if (register_netdevice(dev) < 0)
 339		goto failed_free;
 340
 341	/* Can use a lockless transmit, unless we generate output sequences */
 342	if (!(nt->parms.o_flags & GRE_SEQ))
 343		dev->features |= NETIF_F_LLTX;
 344
 345	dev_hold(dev);
 346	ip6gre_tunnel_link(ign, nt);
 347	return nt;
 348
 349failed_free:
 350	free_netdev(dev);
 351	return NULL;
 352}
 353
 354static void ip6gre_tunnel_uninit(struct net_device *dev)
 355{
 356	struct net *net = dev_net(dev);
 357	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 358
 359	ip6gre_tunnel_unlink(ign, netdev_priv(dev));
 360	dev_put(dev);
 361}
 362
 363
 364static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 365		u8 type, u8 code, int offset, __be32 info)
 366{
 367	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 368	__be16 *p = (__be16 *)(skb->data + offset);
 369	int grehlen = offset + 4;
 370	struct ip6_tnl *t;
 371	__be16 flags;
 372
 373	flags = p[0];
 374	if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 375		if (flags&(GRE_VERSION|GRE_ROUTING))
 376			return;
 377		if (flags&GRE_KEY) {
 378			grehlen += 4;
 379			if (flags&GRE_CSUM)
 380				grehlen += 4;
 381		}
 382	}
 383
 384	/* If only 8 bytes returned, keyed message will be dropped here */
 385	if (!pskb_may_pull(skb, grehlen))
 386		return;
 387	ipv6h = (const struct ipv6hdr *)skb->data;
 388	p = (__be16 *)(skb->data + offset);
 389
 390	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 391				flags & GRE_KEY ?
 392				*(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 393				p[1]);
 394	if (t == NULL)
 395		return;
 396
 397	switch (type) {
 398		__u32 teli;
 399		struct ipv6_tlv_tnl_enc_lim *tel;
 400		__u32 mtu;
 401	case ICMPV6_DEST_UNREACH:
 402		net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 403				     t->parms.name);
 404		break;
 405	case ICMPV6_TIME_EXCEED:
 406		if (code == ICMPV6_EXC_HOPLIMIT) {
 407			net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 408					     t->parms.name);
 409		}
 410		break;
 411	case ICMPV6_PARAMPROB:
 412		teli = 0;
 413		if (code == ICMPV6_HDR_FIELD)
 414			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 415
 416		if (teli && teli == info - 2) {
 417			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 418			if (tel->encap_limit == 0) {
 419				net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 420						     t->parms.name);
 421			}
 422		} else {
 423			net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 424					     t->parms.name);
 425		}
 426		break;
 427	case ICMPV6_PKT_TOOBIG:
 428		mtu = info - offset;
 429		if (mtu < IPV6_MIN_MTU)
 430			mtu = IPV6_MIN_MTU;
 431		t->dev->mtu = mtu;
 432		break;
 433	}
 434
 435	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 436		t->err_count++;
 437	else
 438		t->err_count = 1;
 439	t->err_time = jiffies;
 440}
 441
 442static int ip6gre_rcv(struct sk_buff *skb)
 443{
 444	const struct ipv6hdr *ipv6h;
 445	u8     *h;
 446	__be16    flags;
 447	__sum16   csum = 0;
 448	__be32 key = 0;
 449	u32    seqno = 0;
 450	struct ip6_tnl *tunnel;
 451	int    offset = 4;
 452	__be16 gre_proto;
 453	int err;
 454
 455	if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 456		goto drop;
 457
 458	ipv6h = ipv6_hdr(skb);
 459	h = skb->data;
 460	flags = *(__be16 *)h;
 461
 462	if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 463		/* - Version must be 0.
 464		   - We do not support routing headers.
 465		 */
 466		if (flags&(GRE_VERSION|GRE_ROUTING))
 467			goto drop;
 468
 469		if (flags&GRE_CSUM) {
 470			switch (skb->ip_summed) {
 471			case CHECKSUM_COMPLETE:
 472				csum = csum_fold(skb->csum);
 473				if (!csum)
 474					break;
 475				/* fall through */
 476			case CHECKSUM_NONE:
 477				skb->csum = 0;
 478				csum = __skb_checksum_complete(skb);
 479				skb->ip_summed = CHECKSUM_COMPLETE;
 480			}
 481			offset += 4;
 482		}
 483		if (flags&GRE_KEY) {
 484			key = *(__be32 *)(h + offset);
 485			offset += 4;
 486		}
 487		if (flags&GRE_SEQ) {
 488			seqno = ntohl(*(__be32 *)(h + offset));
 489			offset += 4;
 490		}
 491	}
 492
 493	gre_proto = *(__be16 *)(h + 2);
 494
 495	tunnel = ip6gre_tunnel_lookup(skb->dev,
 496					  &ipv6h->saddr, &ipv6h->daddr, key,
 497					  gre_proto);
 498	if (tunnel) {
 499		struct pcpu_sw_netstats *tstats;
 500
 501		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 502			goto drop;
 503
 504		if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 505			tunnel->dev->stats.rx_dropped++;
 506			goto drop;
 507		}
 508
 509		skb->protocol = gre_proto;
 510		/* WCCP version 1 and 2 protocol decoding.
 511		 * - Change protocol to IP
 512		 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 513		 */
 514		if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 515			skb->protocol = htons(ETH_P_IP);
 516			if ((*(h + offset) & 0xF0) != 0x40)
 517				offset += 4;
 518		}
 519
 520		skb->mac_header = skb->network_header;
 521		__pskb_pull(skb, offset);
 522		skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 523
 524		if (((flags&GRE_CSUM) && csum) ||
 525		    (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 526			tunnel->dev->stats.rx_crc_errors++;
 527			tunnel->dev->stats.rx_errors++;
 528			goto drop;
 529		}
 530		if (tunnel->parms.i_flags&GRE_SEQ) {
 531			if (!(flags&GRE_SEQ) ||
 532			    (tunnel->i_seqno &&
 533					(s32)(seqno - tunnel->i_seqno) < 0)) {
 534				tunnel->dev->stats.rx_fifo_errors++;
 535				tunnel->dev->stats.rx_errors++;
 536				goto drop;
 537			}
 538			tunnel->i_seqno = seqno + 1;
 539		}
 540
 541		/* Warning: All skb pointers will be invalidated! */
 542		if (tunnel->dev->type == ARPHRD_ETHER) {
 543			if (!pskb_may_pull(skb, ETH_HLEN)) {
 544				tunnel->dev->stats.rx_length_errors++;
 545				tunnel->dev->stats.rx_errors++;
 546				goto drop;
 547			}
 548
 549			ipv6h = ipv6_hdr(skb);
 550			skb->protocol = eth_type_trans(skb, tunnel->dev);
 551			skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 552		}
 553
 554		__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 555
 556		skb_reset_network_header(skb);
 557
 558		err = IP6_ECN_decapsulate(ipv6h, skb);
 559		if (unlikely(err)) {
 560			if (log_ecn_error)
 561				net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 562						     &ipv6h->saddr,
 563						     ipv6_get_dsfield(ipv6h));
 564			if (err > 1) {
 565				++tunnel->dev->stats.rx_frame_errors;
 566				++tunnel->dev->stats.rx_errors;
 567				goto drop;
 568			}
 569		}
 570
 571		tstats = this_cpu_ptr(tunnel->dev->tstats);
 572		u64_stats_update_begin(&tstats->syncp);
 573		tstats->rx_packets++;
 574		tstats->rx_bytes += skb->len;
 575		u64_stats_update_end(&tstats->syncp);
 576
 577		netif_rx(skb);
 578
 579		return 0;
 580	}
 581	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 582
 583drop:
 584	kfree_skb(skb);
 585	return 0;
 586}
 587
 588struct ipv6_tel_txoption {
 589	struct ipv6_txoptions ops;
 590	__u8 dst_opt[8];
 591};
 592
 593static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 594{
 595	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 596
 597	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 598	opt->dst_opt[3] = 1;
 599	opt->dst_opt[4] = encap_limit;
 600	opt->dst_opt[5] = IPV6_TLV_PADN;
 601	opt->dst_opt[6] = 1;
 602
 603	opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 604	opt->ops.opt_nflen = 8;
 605}
 606
 607static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 608			 struct net_device *dev,
 609			 __u8 dsfield,
 610			 struct flowi6 *fl6,
 611			 int encap_limit,
 612			 __u32 *pmtu)
 613{
 614	struct net *net = dev_net(dev);
 615	struct ip6_tnl *tunnel = netdev_priv(dev);
 616	struct net_device *tdev;    /* Device to other host */
 617	struct ipv6hdr  *ipv6h;     /* Our new IP header */
 618	unsigned int max_headroom = 0; /* The extra header space needed */
 619	int    gre_hlen;
 620	struct ipv6_tel_txoption opt;
 621	int    mtu;
 622	struct dst_entry *dst = NULL, *ndst = NULL;
 623	struct net_device_stats *stats = &tunnel->dev->stats;
 624	int err = -1;
 625	u8 proto;
 626	struct sk_buff *new_skb;
 627
 628	if (dev->type == ARPHRD_ETHER)
 629		IPCB(skb)->flags = 0;
 630
 631	if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 632		gre_hlen = 0;
 633		ipv6h = (struct ipv6hdr *)skb->data;
 634		fl6->daddr = ipv6h->daddr;
 635	} else {
 636		gre_hlen = tunnel->hlen;
 637		fl6->daddr = tunnel->parms.raddr;
 638	}
 639
 640	if (!fl6->flowi6_mark)
 641		dst = ip6_tnl_dst_check(tunnel);
 642
 643	if (!dst) {
 644		ndst = ip6_route_output(net, NULL, fl6);
 645
 646		if (ndst->error)
 647			goto tx_err_link_failure;
 648		ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 649		if (IS_ERR(ndst)) {
 650			err = PTR_ERR(ndst);
 651			ndst = NULL;
 652			goto tx_err_link_failure;
 653		}
 654		dst = ndst;
 655	}
 656
 657	tdev = dst->dev;
 658
 659	if (tdev == dev) {
 660		stats->collisions++;
 661		net_warn_ratelimited("%s: Local routing loop detected!\n",
 662				     tunnel->parms.name);
 663		goto tx_err_dst_release;
 664	}
 665
 666	mtu = dst_mtu(dst) - sizeof(*ipv6h);
 667	if (encap_limit >= 0) {
 668		max_headroom += 8;
 669		mtu -= 8;
 670	}
 671	if (mtu < IPV6_MIN_MTU)
 672		mtu = IPV6_MIN_MTU;
 673	if (skb_dst(skb))
 674		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 675	if (skb->len > mtu) {
 676		*pmtu = mtu;
 677		err = -EMSGSIZE;
 678		goto tx_err_dst_release;
 679	}
 680
 681	if (tunnel->err_count > 0) {
 682		if (time_before(jiffies,
 683				tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 684			tunnel->err_count--;
 685
 686			dst_link_failure(skb);
 687		} else
 688			tunnel->err_count = 0;
 689	}
 690
 691	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 692
 693	max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 694
 695	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 696	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 697		new_skb = skb_realloc_headroom(skb, max_headroom);
 698		if (max_headroom > dev->needed_headroom)
 699			dev->needed_headroom = max_headroom;
 700		if (!new_skb)
 701			goto tx_err_dst_release;
 702
 703		if (skb->sk)
 704			skb_set_owner_w(new_skb, skb->sk);
 705		consume_skb(skb);
 706		skb = new_skb;
 707	}
 708
 709	if (fl6->flowi6_mark) {
 710		skb_dst_set(skb, dst);
 711		ndst = NULL;
 712	} else {
 713		skb_dst_set_noref(skb, dst);
 714	}
 715
 716	proto = NEXTHDR_GRE;
 717	if (encap_limit >= 0) {
 718		init_tel_txopt(&opt, encap_limit);
 719		ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 720	}
 721
 722	if (likely(!skb->encapsulation)) {
 723		skb_reset_inner_headers(skb);
 724		skb->encapsulation = 1;
 725	}
 726
 727	skb_push(skb, gre_hlen);
 728	skb_reset_network_header(skb);
 729	skb_set_transport_header(skb, sizeof(*ipv6h));
 730
 731	/*
 732	 *	Push down and install the IP header.
 733	 */
 734	ipv6h = ipv6_hdr(skb);
 735	ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
 736	ipv6h->hop_limit = tunnel->parms.hop_limit;
 737	ipv6h->nexthdr = proto;
 738	ipv6h->saddr = fl6->saddr;
 739	ipv6h->daddr = fl6->daddr;
 740
 741	((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 742	((__be16 *)(ipv6h + 1))[1] = (dev->type == ARPHRD_ETHER) ?
 743				   htons(ETH_P_TEB) : skb->protocol;
 744
 745	if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 746		__be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 747
 748		if (tunnel->parms.o_flags&GRE_SEQ) {
 749			++tunnel->o_seqno;
 750			*ptr = htonl(tunnel->o_seqno);
 751			ptr--;
 752		}
 753		if (tunnel->parms.o_flags&GRE_KEY) {
 754			*ptr = tunnel->parms.o_key;
 755			ptr--;
 756		}
 757		if (tunnel->parms.o_flags&GRE_CSUM) {
 758			*ptr = 0;
 759			*(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 760				skb->len - sizeof(struct ipv6hdr));
 761		}
 762	}
 763
 764	ip6tunnel_xmit(skb, dev);
 765	if (ndst)
 766		ip6_tnl_dst_store(tunnel, ndst);
 767	return 0;
 768tx_err_link_failure:
 769	stats->tx_carrier_errors++;
 770	dst_link_failure(skb);
 771tx_err_dst_release:
 772	dst_release(ndst);
 773	return err;
 774}
 775
 776static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 777{
 778	struct ip6_tnl *t = netdev_priv(dev);
 779	const struct iphdr  *iph = ip_hdr(skb);
 780	int encap_limit = -1;
 781	struct flowi6 fl6;
 782	__u8 dsfield;
 783	__u32 mtu;
 784	int err;
 785
 786	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 787		encap_limit = t->parms.encap_limit;
 788
 789	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 790	fl6.flowi6_proto = IPPROTO_IPIP;
 791
 792	dsfield = ipv4_get_dsfield(iph);
 793
 794	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 795		fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 796					  & IPV6_TCLASS_MASK;
 797	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 798		fl6.flowi6_mark = skb->mark;
 799
 800	err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 801	if (err != 0) {
 802		/* XXX: send ICMP error even if DF is not set. */
 803		if (err == -EMSGSIZE)
 804			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 805				  htonl(mtu));
 806		return -1;
 807	}
 808
 809	return 0;
 810}
 811
 812static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 813{
 814	struct ip6_tnl *t = netdev_priv(dev);
 815	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 816	int encap_limit = -1;
 817	__u16 offset;
 818	struct flowi6 fl6;
 819	__u8 dsfield;
 820	__u32 mtu;
 821	int err;
 822
 823	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 824		return -1;
 825
 826	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 827	if (offset > 0) {
 828		struct ipv6_tlv_tnl_enc_lim *tel;
 829		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 830		if (tel->encap_limit == 0) {
 831			icmpv6_send(skb, ICMPV6_PARAMPROB,
 832				    ICMPV6_HDR_FIELD, offset + 2);
 833			return -1;
 834		}
 835		encap_limit = tel->encap_limit - 1;
 836	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 837		encap_limit = t->parms.encap_limit;
 838
 839	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 840	fl6.flowi6_proto = IPPROTO_IPV6;
 841
 842	dsfield = ipv6_get_dsfield(ipv6h);
 843	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 844		fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 845	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 846		fl6.flowlabel |= ip6_flowlabel(ipv6h);
 847	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 848		fl6.flowi6_mark = skb->mark;
 849
 850	err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 851	if (err != 0) {
 852		if (err == -EMSGSIZE)
 853			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 854		return -1;
 855	}
 856
 857	return 0;
 858}
 859
 860/**
 861 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 862 *   @t: the outgoing tunnel device
 863 *   @hdr: IPv6 header from the incoming packet
 864 *
 865 * Description:
 866 *   Avoid trivial tunneling loop by checking that tunnel exit-point
 867 *   doesn't match source of incoming packet.
 868 *
 869 * Return:
 870 *   1 if conflict,
 871 *   0 else
 872 **/
 873
 874static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 875	const struct ipv6hdr *hdr)
 876{
 877	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 878}
 879
 880static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 881{
 882	struct ip6_tnl *t = netdev_priv(dev);
 883	int encap_limit = -1;
 884	struct flowi6 fl6;
 885	__u32 mtu;
 886	int err;
 887
 888	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 889		encap_limit = t->parms.encap_limit;
 890
 891	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 892	fl6.flowi6_proto = skb->protocol;
 893
 894	err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 895
 896	return err;
 897}
 898
 899static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 900	struct net_device *dev)
 901{
 902	struct ip6_tnl *t = netdev_priv(dev);
 903	struct net_device_stats *stats = &t->dev->stats;
 904	int ret;
 905
 906	if (!ip6_tnl_xmit_ctl(t))
 907		goto tx_err;
 908
 909	switch (skb->protocol) {
 910	case htons(ETH_P_IP):
 911		ret = ip6gre_xmit_ipv4(skb, dev);
 912		break;
 913	case htons(ETH_P_IPV6):
 914		ret = ip6gre_xmit_ipv6(skb, dev);
 915		break;
 916	default:
 917		ret = ip6gre_xmit_other(skb, dev);
 918		break;
 919	}
 920
 921	if (ret < 0)
 922		goto tx_err;
 923
 924	return NETDEV_TX_OK;
 925
 926tx_err:
 927	stats->tx_errors++;
 928	stats->tx_dropped++;
 929	kfree_skb(skb);
 930	return NETDEV_TX_OK;
 931}
 932
 933static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 934{
 935	struct net_device *dev = t->dev;
 936	struct __ip6_tnl_parm *p = &t->parms;
 937	struct flowi6 *fl6 = &t->fl.u.ip6;
 938	int addend = sizeof(struct ipv6hdr) + 4;
 939
 940	if (dev->type != ARPHRD_ETHER) {
 941		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 942		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 943	}
 944
 945	/* Set up flowi template */
 946	fl6->saddr = p->laddr;
 947	fl6->daddr = p->raddr;
 948	fl6->flowi6_oif = p->link;
 949	fl6->flowlabel = 0;
 950
 951	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 952		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 953	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 954		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 955
 956	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 957	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 958
 959	if (p->flags&IP6_TNL_F_CAP_XMIT &&
 960			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 961		dev->flags |= IFF_POINTOPOINT;
 962	else
 963		dev->flags &= ~IFF_POINTOPOINT;
 964
 965	dev->iflink = p->link;
 966
 967	/* Precalculate GRE options length */
 968	if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 969		if (t->parms.o_flags&GRE_CSUM)
 970			addend += 4;
 971		if (t->parms.o_flags&GRE_KEY)
 972			addend += 4;
 973		if (t->parms.o_flags&GRE_SEQ)
 974			addend += 4;
 975	}
 976	t->hlen = addend;
 977
 978	if (p->flags & IP6_TNL_F_CAP_XMIT) {
 979		int strict = (ipv6_addr_type(&p->raddr) &
 980			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 981
 982		struct rt6_info *rt = rt6_lookup(dev_net(dev),
 983						 &p->raddr, &p->laddr,
 984						 p->link, strict);
 985
 986		if (rt == NULL)
 987			return;
 988
 989		if (rt->dst.dev) {
 990			dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 991
 992			if (set_mtu) {
 993				dev->mtu = rt->dst.dev->mtu - addend;
 994				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 995					dev->mtu -= 8;
 996
 997				if (dev->mtu < IPV6_MIN_MTU)
 998					dev->mtu = IPV6_MIN_MTU;
 999			}
1000		}
1001		ip6_rt_put(rt);
1002	}
1003}
1004
1005static int ip6gre_tnl_change(struct ip6_tnl *t,
1006	const struct __ip6_tnl_parm *p, int set_mtu)
1007{
1008	t->parms.laddr = p->laddr;
1009	t->parms.raddr = p->raddr;
1010	t->parms.flags = p->flags;
1011	t->parms.hop_limit = p->hop_limit;
1012	t->parms.encap_limit = p->encap_limit;
1013	t->parms.flowinfo = p->flowinfo;
1014	t->parms.link = p->link;
1015	t->parms.proto = p->proto;
1016	t->parms.i_key = p->i_key;
1017	t->parms.o_key = p->o_key;
1018	t->parms.i_flags = p->i_flags;
1019	t->parms.o_flags = p->o_flags;
1020	ip6_tnl_dst_reset(t);
1021	ip6gre_tnl_link_config(t, set_mtu);
1022	return 0;
1023}
1024
1025static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1026	const struct ip6_tnl_parm2 *u)
1027{
1028	p->laddr = u->laddr;
1029	p->raddr = u->raddr;
1030	p->flags = u->flags;
1031	p->hop_limit = u->hop_limit;
1032	p->encap_limit = u->encap_limit;
1033	p->flowinfo = u->flowinfo;
1034	p->link = u->link;
1035	p->i_key = u->i_key;
1036	p->o_key = u->o_key;
1037	p->i_flags = u->i_flags;
1038	p->o_flags = u->o_flags;
1039	memcpy(p->name, u->name, sizeof(u->name));
1040}
1041
1042static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1043	const struct __ip6_tnl_parm *p)
1044{
1045	u->proto = IPPROTO_GRE;
1046	u->laddr = p->laddr;
1047	u->raddr = p->raddr;
1048	u->flags = p->flags;
1049	u->hop_limit = p->hop_limit;
1050	u->encap_limit = p->encap_limit;
1051	u->flowinfo = p->flowinfo;
1052	u->link = p->link;
1053	u->i_key = p->i_key;
1054	u->o_key = p->o_key;
1055	u->i_flags = p->i_flags;
1056	u->o_flags = p->o_flags;
1057	memcpy(u->name, p->name, sizeof(u->name));
1058}
1059
1060static int ip6gre_tunnel_ioctl(struct net_device *dev,
1061	struct ifreq *ifr, int cmd)
1062{
1063	int err = 0;
1064	struct ip6_tnl_parm2 p;
1065	struct __ip6_tnl_parm p1;
1066	struct ip6_tnl *t;
1067	struct net *net = dev_net(dev);
1068	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1069
1070	switch (cmd) {
1071	case SIOCGETTUNNEL:
1072		t = NULL;
1073		if (dev == ign->fb_tunnel_dev) {
1074			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1075				err = -EFAULT;
1076				break;
1077			}
1078			ip6gre_tnl_parm_from_user(&p1, &p);
1079			t = ip6gre_tunnel_locate(net, &p1, 0);
1080		}
1081		if (t == NULL)
1082			t = netdev_priv(dev);
1083		memset(&p, 0, sizeof(p));
1084		ip6gre_tnl_parm_to_user(&p, &t->parms);
1085		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1086			err = -EFAULT;
1087		break;
1088
1089	case SIOCADDTUNNEL:
1090	case SIOCCHGTUNNEL:
1091		err = -EPERM;
1092		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1093			goto done;
1094
1095		err = -EFAULT;
1096		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1097			goto done;
1098
1099		err = -EINVAL;
1100		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1101			goto done;
1102
1103		if (!(p.i_flags&GRE_KEY))
1104			p.i_key = 0;
1105		if (!(p.o_flags&GRE_KEY))
1106			p.o_key = 0;
1107
1108		ip6gre_tnl_parm_from_user(&p1, &p);
1109		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1110
1111		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1112			if (t != NULL) {
1113				if (t->dev != dev) {
1114					err = -EEXIST;
1115					break;
1116				}
1117			} else {
1118				t = netdev_priv(dev);
1119
1120				ip6gre_tunnel_unlink(ign, t);
1121				synchronize_net();
1122				ip6gre_tnl_change(t, &p1, 1);
1123				ip6gre_tunnel_link(ign, t);
1124				netdev_state_change(dev);
1125			}
1126		}
1127
1128		if (t) {
1129			err = 0;
1130
1131			memset(&p, 0, sizeof(p));
1132			ip6gre_tnl_parm_to_user(&p, &t->parms);
1133			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1134				err = -EFAULT;
1135		} else
1136			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1137		break;
1138
1139	case SIOCDELTUNNEL:
1140		err = -EPERM;
1141		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1142			goto done;
1143
1144		if (dev == ign->fb_tunnel_dev) {
1145			err = -EFAULT;
1146			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1147				goto done;
1148			err = -ENOENT;
1149			ip6gre_tnl_parm_from_user(&p1, &p);
1150			t = ip6gre_tunnel_locate(net, &p1, 0);
1151			if (t == NULL)
1152				goto done;
1153			err = -EPERM;
1154			if (t == netdev_priv(ign->fb_tunnel_dev))
1155				goto done;
1156			dev = t->dev;
1157		}
1158		unregister_netdevice(dev);
1159		err = 0;
1160		break;
1161
1162	default:
1163		err = -EINVAL;
1164	}
1165
1166done:
1167	return err;
1168}
1169
1170static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1171{
1172	if (new_mtu < 68 ||
1173	    new_mtu > 0xFFF8 - dev->hard_header_len)
1174		return -EINVAL;
1175	dev->mtu = new_mtu;
1176	return 0;
1177}
1178
1179static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1180			unsigned short type,
1181			const void *daddr, const void *saddr, unsigned int len)
1182{
1183	struct ip6_tnl *t = netdev_priv(dev);
1184	struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1185	__be16 *p = (__be16 *)(ipv6h+1);
1186
1187	ip6_flow_hdr(ipv6h, 0, t->fl.u.ip6.flowlabel);
1188	ipv6h->hop_limit = t->parms.hop_limit;
1189	ipv6h->nexthdr = NEXTHDR_GRE;
1190	ipv6h->saddr = t->parms.laddr;
1191	ipv6h->daddr = t->parms.raddr;
1192
1193	p[0]		= t->parms.o_flags;
1194	p[1]		= htons(type);
1195
1196	/*
1197	 *	Set the source hardware address.
1198	 */
1199
1200	if (saddr)
1201		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1202	if (daddr)
1203		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1204	if (!ipv6_addr_any(&ipv6h->daddr))
1205		return t->hlen;
1206
1207	return -t->hlen;
1208}
1209
1210static const struct header_ops ip6gre_header_ops = {
1211	.create	= ip6gre_header,
1212};
1213
1214static const struct net_device_ops ip6gre_netdev_ops = {
1215	.ndo_init		= ip6gre_tunnel_init,
1216	.ndo_uninit		= ip6gre_tunnel_uninit,
1217	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1218	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1219	.ndo_change_mtu		= ip6gre_tunnel_change_mtu,
1220	.ndo_get_stats64	= ip_tunnel_get_stats64,
1221};
1222
1223static void ip6gre_dev_free(struct net_device *dev)
1224{
1225	free_percpu(dev->tstats);
1226	free_netdev(dev);
1227}
1228
1229static void ip6gre_tunnel_setup(struct net_device *dev)
1230{
1231	struct ip6_tnl *t;
1232
1233	dev->netdev_ops = &ip6gre_netdev_ops;
1234	dev->destructor = ip6gre_dev_free;
1235
1236	dev->type = ARPHRD_IP6GRE;
1237	dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1238	dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1239	t = netdev_priv(dev);
1240	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1241		dev->mtu -= 8;
1242	dev->flags |= IFF_NOARP;
1243	dev->iflink = 0;
1244	dev->addr_len = sizeof(struct in6_addr);
1245	dev->features |= NETIF_F_NETNS_LOCAL;
1246	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1247}
1248
1249static int ip6gre_tunnel_init(struct net_device *dev)
1250{
1251	struct ip6_tnl *tunnel;
1252	int i;
1253
1254	tunnel = netdev_priv(dev);
1255
1256	tunnel->dev = dev;
1257	tunnel->net = dev_net(dev);
1258	strcpy(tunnel->parms.name, dev->name);
1259
1260	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1261	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1262
1263	if (ipv6_addr_any(&tunnel->parms.raddr))
1264		dev->header_ops = &ip6gre_header_ops;
1265
1266	dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
1267	if (!dev->tstats)
1268		return -ENOMEM;
1269
1270	for_each_possible_cpu(i) {
1271		struct pcpu_sw_netstats *ip6gre_tunnel_stats;
1272		ip6gre_tunnel_stats = per_cpu_ptr(dev->tstats, i);
1273		u64_stats_init(&ip6gre_tunnel_stats->syncp);
1274	}
1275
1276
1277	return 0;
1278}
1279
1280static void ip6gre_fb_tunnel_init(struct net_device *dev)
1281{
1282	struct ip6_tnl *tunnel = netdev_priv(dev);
1283
1284	tunnel->dev = dev;
1285	tunnel->net = dev_net(dev);
1286	strcpy(tunnel->parms.name, dev->name);
1287
1288	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1289
1290	dev_hold(dev);
1291}
1292
1293
1294static struct inet6_protocol ip6gre_protocol __read_mostly = {
1295	.handler     = ip6gre_rcv,
1296	.err_handler = ip6gre_err,
1297	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1298};
1299
1300static void ip6gre_destroy_tunnels(struct ip6gre_net *ign,
1301	struct list_head *head)
1302{
1303	int prio;
1304
1305	for (prio = 0; prio < 4; prio++) {
1306		int h;
1307		for (h = 0; h < HASH_SIZE; h++) {
1308			struct ip6_tnl *t;
1309
1310			t = rtnl_dereference(ign->tunnels[prio][h]);
1311
1312			while (t != NULL) {
1313				unregister_netdevice_queue(t->dev, head);
1314				t = rtnl_dereference(t->next);
1315			}
1316		}
1317	}
1318}
1319
1320static int __net_init ip6gre_init_net(struct net *net)
1321{
1322	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1323	int err;
1324
1325	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1326					   ip6gre_tunnel_setup);
1327	if (!ign->fb_tunnel_dev) {
1328		err = -ENOMEM;
1329		goto err_alloc_dev;
1330	}
1331	dev_net_set(ign->fb_tunnel_dev, net);
1332
1333	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1334	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1335
1336	err = register_netdev(ign->fb_tunnel_dev);
1337	if (err)
1338		goto err_reg_dev;
1339
1340	rcu_assign_pointer(ign->tunnels_wc[0],
1341			   netdev_priv(ign->fb_tunnel_dev));
1342	return 0;
1343
1344err_reg_dev:
1345	ip6gre_dev_free(ign->fb_tunnel_dev);
1346err_alloc_dev:
1347	return err;
1348}
1349
1350static void __net_exit ip6gre_exit_net(struct net *net)
1351{
1352	struct ip6gre_net *ign;
1353	LIST_HEAD(list);
1354
1355	ign = net_generic(net, ip6gre_net_id);
1356	rtnl_lock();
1357	ip6gre_destroy_tunnels(ign, &list);
1358	unregister_netdevice_many(&list);
1359	rtnl_unlock();
1360}
1361
1362static struct pernet_operations ip6gre_net_ops = {
1363	.init = ip6gre_init_net,
1364	.exit = ip6gre_exit_net,
1365	.id   = &ip6gre_net_id,
1366	.size = sizeof(struct ip6gre_net),
1367};
1368
1369static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1370{
1371	__be16 flags;
1372
1373	if (!data)
1374		return 0;
1375
1376	flags = 0;
1377	if (data[IFLA_GRE_IFLAGS])
1378		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1379	if (data[IFLA_GRE_OFLAGS])
1380		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1381	if (flags & (GRE_VERSION|GRE_ROUTING))
1382		return -EINVAL;
1383
1384	return 0;
1385}
1386
1387static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1388{
1389	struct in6_addr daddr;
1390
1391	if (tb[IFLA_ADDRESS]) {
1392		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1393			return -EINVAL;
1394		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1395			return -EADDRNOTAVAIL;
1396	}
1397
1398	if (!data)
1399		goto out;
1400
1401	if (data[IFLA_GRE_REMOTE]) {
1402		nla_memcpy(&daddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1403		if (ipv6_addr_any(&daddr))
1404			return -EINVAL;
1405	}
1406
1407out:
1408	return ip6gre_tunnel_validate(tb, data);
1409}
1410
1411
1412static void ip6gre_netlink_parms(struct nlattr *data[],
1413				struct __ip6_tnl_parm *parms)
1414{
1415	memset(parms, 0, sizeof(*parms));
1416
1417	if (!data)
1418		return;
1419
1420	if (data[IFLA_GRE_LINK])
1421		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1422
1423	if (data[IFLA_GRE_IFLAGS])
1424		parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1425
1426	if (data[IFLA_GRE_OFLAGS])
1427		parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1428
1429	if (data[IFLA_GRE_IKEY])
1430		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1431
1432	if (data[IFLA_GRE_OKEY])
1433		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1434
1435	if (data[IFLA_GRE_LOCAL])
1436		nla_memcpy(&parms->laddr, data[IFLA_GRE_LOCAL], sizeof(struct in6_addr));
1437
1438	if (data[IFLA_GRE_REMOTE])
1439		nla_memcpy(&parms->raddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1440
1441	if (data[IFLA_GRE_TTL])
1442		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1443
1444	if (data[IFLA_GRE_ENCAP_LIMIT])
1445		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1446
1447	if (data[IFLA_GRE_FLOWINFO])
1448		parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1449
1450	if (data[IFLA_GRE_FLAGS])
1451		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1452}
1453
1454static int ip6gre_tap_init(struct net_device *dev)
1455{
1456	struct ip6_tnl *tunnel;
1457
1458	tunnel = netdev_priv(dev);
1459
1460	tunnel->dev = dev;
1461	tunnel->net = dev_net(dev);
1462	strcpy(tunnel->parms.name, dev->name);
1463
1464	ip6gre_tnl_link_config(tunnel, 1);
1465
1466	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1467	if (!dev->tstats)
1468		return -ENOMEM;
1469
1470	return 0;
1471}
1472
1473static const struct net_device_ops ip6gre_tap_netdev_ops = {
1474	.ndo_init = ip6gre_tap_init,
1475	.ndo_uninit = ip6gre_tunnel_uninit,
1476	.ndo_start_xmit = ip6gre_tunnel_xmit,
1477	.ndo_set_mac_address = eth_mac_addr,
1478	.ndo_validate_addr = eth_validate_addr,
1479	.ndo_change_mtu = ip6gre_tunnel_change_mtu,
1480	.ndo_get_stats64 = ip_tunnel_get_stats64,
1481};
1482
1483static void ip6gre_tap_setup(struct net_device *dev)
1484{
1485
1486	ether_setup(dev);
1487
1488	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1489	dev->destructor = ip6gre_dev_free;
1490
1491	dev->iflink = 0;
1492	dev->features |= NETIF_F_NETNS_LOCAL;
1493}
1494
1495static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1496	struct nlattr *tb[], struct nlattr *data[])
1497{
1498	struct ip6_tnl *nt;
1499	struct net *net = dev_net(dev);
1500	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1501	int err;
1502
1503	nt = netdev_priv(dev);
1504	ip6gre_netlink_parms(data, &nt->parms);
1505
1506	if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1507		return -EEXIST;
1508
1509	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1510		eth_hw_addr_random(dev);
1511
1512	nt->dev = dev;
1513	nt->net = dev_net(dev);
1514	ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1515
1516	/* Can use a lockless transmit, unless we generate output sequences */
1517	if (!(nt->parms.o_flags & GRE_SEQ))
1518		dev->features |= NETIF_F_LLTX;
1519
1520	err = register_netdevice(dev);
1521	if (err)
1522		goto out;
1523
1524	dev_hold(dev);
1525	ip6gre_tunnel_link(ign, nt);
1526
1527out:
1528	return err;
1529}
1530
1531static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1532			    struct nlattr *data[])
1533{
1534	struct ip6_tnl *t, *nt;
1535	struct net *net = dev_net(dev);
1536	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1537	struct __ip6_tnl_parm p;
1538
1539	if (dev == ign->fb_tunnel_dev)
1540		return -EINVAL;
1541
1542	nt = netdev_priv(dev);
1543	ip6gre_netlink_parms(data, &p);
1544
1545	t = ip6gre_tunnel_locate(net, &p, 0);
1546
1547	if (t) {
1548		if (t->dev != dev)
1549			return -EEXIST;
1550	} else {
1551		t = nt;
1552
1553		ip6gre_tunnel_unlink(ign, t);
1554		ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1555		ip6gre_tunnel_link(ign, t);
1556		netdev_state_change(dev);
1557	}
1558
1559	return 0;
1560}
1561
1562static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1563{
1564	struct net *net = dev_net(dev);
1565	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1566
1567	if (dev != ign->fb_tunnel_dev)
1568		unregister_netdevice_queue(dev, head);
1569}
1570
1571static size_t ip6gre_get_size(const struct net_device *dev)
1572{
1573	return
1574		/* IFLA_GRE_LINK */
1575		nla_total_size(4) +
1576		/* IFLA_GRE_IFLAGS */
1577		nla_total_size(2) +
1578		/* IFLA_GRE_OFLAGS */
1579		nla_total_size(2) +
1580		/* IFLA_GRE_IKEY */
1581		nla_total_size(4) +
1582		/* IFLA_GRE_OKEY */
1583		nla_total_size(4) +
1584		/* IFLA_GRE_LOCAL */
1585		nla_total_size(sizeof(struct in6_addr)) +
1586		/* IFLA_GRE_REMOTE */
1587		nla_total_size(sizeof(struct in6_addr)) +
1588		/* IFLA_GRE_TTL */
1589		nla_total_size(1) +
1590		/* IFLA_GRE_TOS */
1591		nla_total_size(1) +
1592		/* IFLA_GRE_ENCAP_LIMIT */
1593		nla_total_size(1) +
1594		/* IFLA_GRE_FLOWINFO */
1595		nla_total_size(4) +
1596		/* IFLA_GRE_FLAGS */
1597		nla_total_size(4) +
1598		0;
1599}
1600
1601static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1602{
1603	struct ip6_tnl *t = netdev_priv(dev);
1604	struct __ip6_tnl_parm *p = &t->parms;
1605
1606	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1607	    nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1608	    nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1609	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1610	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1611	    nla_put(skb, IFLA_GRE_LOCAL, sizeof(struct in6_addr), &p->laddr) ||
1612	    nla_put(skb, IFLA_GRE_REMOTE, sizeof(struct in6_addr), &p->raddr) ||
1613	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1614	    /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1615	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1616	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1617	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1618		goto nla_put_failure;
1619	return 0;
1620
1621nla_put_failure:
1622	return -EMSGSIZE;
1623}
1624
1625static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1626	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
1627	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1628	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1629	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1630	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1631	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1632	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1633	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
1634	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1635	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1636	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1637};
1638
1639static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1640	.kind		= "ip6gre",
1641	.maxtype	= IFLA_GRE_MAX,
1642	.policy		= ip6gre_policy,
1643	.priv_size	= sizeof(struct ip6_tnl),
1644	.setup		= ip6gre_tunnel_setup,
1645	.validate	= ip6gre_tunnel_validate,
1646	.newlink	= ip6gre_newlink,
1647	.changelink	= ip6gre_changelink,
1648	.dellink	= ip6gre_dellink,
1649	.get_size	= ip6gre_get_size,
1650	.fill_info	= ip6gre_fill_info,
1651};
1652
1653static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1654	.kind		= "ip6gretap",
1655	.maxtype	= IFLA_GRE_MAX,
1656	.policy		= ip6gre_policy,
1657	.priv_size	= sizeof(struct ip6_tnl),
1658	.setup		= ip6gre_tap_setup,
1659	.validate	= ip6gre_tap_validate,
1660	.newlink	= ip6gre_newlink,
1661	.changelink	= ip6gre_changelink,
1662	.get_size	= ip6gre_get_size,
1663	.fill_info	= ip6gre_fill_info,
1664};
1665
1666/*
1667 *	And now the modules code and kernel interface.
1668 */
1669
1670static int __init ip6gre_init(void)
1671{
1672	int err;
1673
1674	pr_info("GRE over IPv6 tunneling driver\n");
1675
1676	err = register_pernet_device(&ip6gre_net_ops);
1677	if (err < 0)
1678		return err;
1679
1680	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1681	if (err < 0) {
1682		pr_info("%s: can't add protocol\n", __func__);
1683		goto add_proto_failed;
1684	}
1685
1686	err = rtnl_link_register(&ip6gre_link_ops);
1687	if (err < 0)
1688		goto rtnl_link_failed;
1689
1690	err = rtnl_link_register(&ip6gre_tap_ops);
1691	if (err < 0)
1692		goto tap_ops_failed;
1693
1694out:
1695	return err;
1696
1697tap_ops_failed:
1698	rtnl_link_unregister(&ip6gre_link_ops);
1699rtnl_link_failed:
1700	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1701add_proto_failed:
1702	unregister_pernet_device(&ip6gre_net_ops);
1703	goto out;
1704}
1705
1706static void __exit ip6gre_fini(void)
1707{
1708	rtnl_link_unregister(&ip6gre_tap_ops);
1709	rtnl_link_unregister(&ip6gre_link_ops);
1710	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1711	unregister_pernet_device(&ip6gre_net_ops);
1712}
1713
1714module_init(ip6gre_init);
1715module_exit(ip6gre_fini);
1716MODULE_LICENSE("GPL");
1717MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1718MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1719MODULE_ALIAS_RTNL_LINK("ip6gre");
1720MODULE_ALIAS_NETDEV("ip6gre0");