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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/init.h>
  28#include <linux/in6.h>
  29#include <linux/inetdevice.h>
  30#include <linux/igmp.h>
  31#include <linux/netfilter_ipv4.h>
  32#include <linux/etherdevice.h>
  33#include <linux/if_ether.h>
  34#include <linux/hash.h>
  35#include <linux/if_tunnel.h>
  36#include <linux/ip6_tunnel.h>
  37
  38#include <net/sock.h>
  39#include <net/ip.h>
  40#include <net/ip_tunnels.h>
  41#include <net/icmp.h>
  42#include <net/protocol.h>
  43#include <net/addrconf.h>
  44#include <net/arp.h>
  45#include <net/checksum.h>
  46#include <net/dsfield.h>
  47#include <net/inet_ecn.h>
  48#include <net/xfrm.h>
  49#include <net/net_namespace.h>
  50#include <net/netns/generic.h>
  51#include <net/rtnetlink.h>
  52
  53#include <net/ipv6.h>
  54#include <net/ip6_fib.h>
  55#include <net/ip6_route.h>
  56#include <net/ip6_tunnel.h>
  57
  58
  59static bool log_ecn_error = true;
  60module_param(log_ecn_error, bool, 0644);
  61MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  62
  63#define HASH_SIZE_SHIFT  5
  64#define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  65
  66static int ip6gre_net_id __read_mostly;
  67struct ip6gre_net {
  68	struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
  69
  70	struct net_device *fb_tunnel_dev;
  71};
  72
  73static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
  74static struct rtnl_link_ops ip6gre_tap_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)
 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 NULL;
 318	if (t || !create)
 319		return t;
 320
 321	if (parms->name[0])
 322		strlcpy(name, parms->name, IFNAMSIZ);
 323	else
 324		strcpy(name, "ip6gre%d");
 325
 326	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 327			   ip6gre_tunnel_setup);
 328	if (!dev)
 329		return NULL;
 330
 331	dev_net_set(dev, net);
 332
 333	nt = netdev_priv(dev);
 334	nt->parms = *parms;
 335	dev->rtnl_link_ops = &ip6gre_link_ops;
 336
 337	nt->dev = dev;
 338	nt->net = dev_net(dev);
 339	ip6gre_tnl_link_config(nt, 1);
 340
 341	if (register_netdevice(dev) < 0)
 342		goto failed_free;
 343
 344	/* Can use a lockless transmit, unless we generate output sequences */
 345	if (!(nt->parms.o_flags & GRE_SEQ))
 346		dev->features |= NETIF_F_LLTX;
 347
 348	dev_hold(dev);
 349	ip6gre_tunnel_link(ign, nt);
 350	return nt;
 351
 352failed_free:
 353	free_netdev(dev);
 354	return NULL;
 355}
 356
 357static void ip6gre_tunnel_uninit(struct net_device *dev)
 358{
 359	struct ip6_tnl *t = netdev_priv(dev);
 360	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
 361
 362	ip6gre_tunnel_unlink(ign, t);
 363	dst_cache_reset(&t->dst_cache);
 364	dev_put(dev);
 365}
 366
 367
 368static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 369		u8 type, u8 code, int offset, __be32 info)
 370{
 371	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 372	__be16 *p = (__be16 *)(skb->data + offset);
 373	int grehlen = offset + 4;
 374	struct ip6_tnl *t;
 375	__be16 flags;
 376
 377	flags = p[0];
 378	if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
 379		if (flags&(GRE_VERSION|GRE_ROUTING))
 380			return;
 381		if (flags&GRE_KEY) {
 382			grehlen += 4;
 383			if (flags&GRE_CSUM)
 384				grehlen += 4;
 385		}
 386	}
 387
 388	/* If only 8 bytes returned, keyed message will be dropped here */
 389	if (!pskb_may_pull(skb, grehlen))
 390		return;
 391	ipv6h = (const struct ipv6hdr *)skb->data;
 392	p = (__be16 *)(skb->data + offset);
 393
 394	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
 395				flags & GRE_KEY ?
 396				*(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 397				p[1]);
 398	if (!t)
 399		return;
 400
 401	switch (type) {
 402		__u32 teli;
 403		struct ipv6_tlv_tnl_enc_lim *tel;
 404		__u32 mtu;
 405	case ICMPV6_DEST_UNREACH:
 406		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 407				    t->parms.name);
 408		break;
 409	case ICMPV6_TIME_EXCEED:
 410		if (code == ICMPV6_EXC_HOPLIMIT) {
 411			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 412					    t->parms.name);
 413		}
 414		break;
 415	case ICMPV6_PARAMPROB:
 416		teli = 0;
 417		if (code == ICMPV6_HDR_FIELD)
 418			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 419
 420		if (teli && teli == be32_to_cpu(info) - 2) {
 421			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 422			if (tel->encap_limit == 0) {
 423				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 424						    t->parms.name);
 425			}
 426		} else {
 427			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 428					    t->parms.name);
 429		}
 430		break;
 431	case ICMPV6_PKT_TOOBIG:
 432		mtu = be32_to_cpu(info) - offset;
 433		if (mtu < IPV6_MIN_MTU)
 434			mtu = IPV6_MIN_MTU;
 435		t->dev->mtu = mtu;
 436		break;
 437	}
 438
 439	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
 440		t->err_count++;
 441	else
 442		t->err_count = 1;
 443	t->err_time = jiffies;
 444}
 445
 446static int ip6gre_rcv(struct sk_buff *skb)
 447{
 448	const struct ipv6hdr *ipv6h;
 449	u8     *h;
 450	__be16    flags;
 451	__sum16   csum = 0;
 452	__be32 key = 0;
 453	u32    seqno = 0;
 454	struct ip6_tnl *tunnel;
 455	int    offset = 4;
 456	__be16 gre_proto;
 457	int err;
 458
 459	if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
 460		goto drop;
 461
 462	ipv6h = ipv6_hdr(skb);
 463	h = skb->data;
 464	flags = *(__be16 *)h;
 465
 466	if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
 467		/* - Version must be 0.
 468		   - We do not support routing headers.
 469		 */
 470		if (flags&(GRE_VERSION|GRE_ROUTING))
 471			goto drop;
 472
 473		if (flags&GRE_CSUM) {
 474			csum = skb_checksum_simple_validate(skb);
 475			offset += 4;
 476		}
 477		if (flags&GRE_KEY) {
 478			key = *(__be32 *)(h + offset);
 479			offset += 4;
 480		}
 481		if (flags&GRE_SEQ) {
 482			seqno = ntohl(*(__be32 *)(h + offset));
 483			offset += 4;
 484		}
 485	}
 486
 487	gre_proto = *(__be16 *)(h + 2);
 488
 489	tunnel = ip6gre_tunnel_lookup(skb->dev,
 490					  &ipv6h->saddr, &ipv6h->daddr, key,
 491					  gre_proto);
 492	if (tunnel) {
 493		struct pcpu_sw_netstats *tstats;
 494
 495		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 496			goto drop;
 497
 498		if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
 499			tunnel->dev->stats.rx_dropped++;
 500			goto drop;
 501		}
 502
 503		skb->protocol = gre_proto;
 504		/* WCCP version 1 and 2 protocol decoding.
 505		 * - Change protocol to IPv6
 506		 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 507		 */
 508		if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
 509			skb->protocol = htons(ETH_P_IPV6);
 510			if ((*(h + offset) & 0xF0) != 0x40)
 511				offset += 4;
 512		}
 513
 514		skb->mac_header = skb->network_header;
 515		__pskb_pull(skb, offset);
 516		skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
 517
 518		if (((flags&GRE_CSUM) && csum) ||
 519		    (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
 520			tunnel->dev->stats.rx_crc_errors++;
 521			tunnel->dev->stats.rx_errors++;
 522			goto drop;
 523		}
 524		if (tunnel->parms.i_flags&GRE_SEQ) {
 525			if (!(flags&GRE_SEQ) ||
 526			    (tunnel->i_seqno &&
 527					(s32)(seqno - tunnel->i_seqno) < 0)) {
 528				tunnel->dev->stats.rx_fifo_errors++;
 529				tunnel->dev->stats.rx_errors++;
 530				goto drop;
 531			}
 532			tunnel->i_seqno = seqno + 1;
 533		}
 534
 535		/* Warning: All skb pointers will be invalidated! */
 536		if (tunnel->dev->type == ARPHRD_ETHER) {
 537			if (!pskb_may_pull(skb, ETH_HLEN)) {
 538				tunnel->dev->stats.rx_length_errors++;
 539				tunnel->dev->stats.rx_errors++;
 540				goto drop;
 541			}
 542
 543			ipv6h = ipv6_hdr(skb);
 544			skb->protocol = eth_type_trans(skb, tunnel->dev);
 545			skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 546		}
 547
 548		__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 549
 550		skb_reset_network_header(skb);
 551
 552		err = IP6_ECN_decapsulate(ipv6h, skb);
 553		if (unlikely(err)) {
 554			if (log_ecn_error)
 555				net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 556						     &ipv6h->saddr,
 557						     ipv6_get_dsfield(ipv6h));
 558			if (err > 1) {
 559				++tunnel->dev->stats.rx_frame_errors;
 560				++tunnel->dev->stats.rx_errors;
 561				goto drop;
 562			}
 563		}
 564
 565		tstats = this_cpu_ptr(tunnel->dev->tstats);
 566		u64_stats_update_begin(&tstats->syncp);
 567		tstats->rx_packets++;
 568		tstats->rx_bytes += skb->len;
 569		u64_stats_update_end(&tstats->syncp);
 570
 571		netif_rx(skb);
 572
 573		return 0;
 574	}
 575	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 576
 577drop:
 578	kfree_skb(skb);
 579	return 0;
 580}
 581
 582struct ipv6_tel_txoption {
 583	struct ipv6_txoptions ops;
 584	__u8 dst_opt[8];
 585};
 586
 587static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 588{
 589	memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 590
 591	opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 592	opt->dst_opt[3] = 1;
 593	opt->dst_opt[4] = encap_limit;
 594	opt->dst_opt[5] = IPV6_TLV_PADN;
 595	opt->dst_opt[6] = 1;
 596
 597	opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 598	opt->ops.opt_nflen = 8;
 599}
 600
 601static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 602			 struct net_device *dev,
 603			 __u8 dsfield,
 604			 struct flowi6 *fl6,
 605			 int encap_limit,
 606			 __u32 *pmtu)
 607{
 608	struct ip6_tnl *tunnel = netdev_priv(dev);
 609	struct net *net = tunnel->net;
 610	struct net_device *tdev;    /* Device to other host */
 611	struct ipv6hdr  *ipv6h;     /* Our new IP header */
 612	unsigned int max_headroom = 0; /* The extra header space needed */
 613	int    gre_hlen;
 614	struct ipv6_tel_txoption opt;
 615	int    mtu;
 616	struct dst_entry *dst = NULL, *ndst = NULL;
 617	struct net_device_stats *stats = &tunnel->dev->stats;
 618	int err = -1;
 619	u8 proto;
 620	struct sk_buff *new_skb;
 621	__be16 protocol;
 622
 623	if (dev->type == ARPHRD_ETHER)
 624		IPCB(skb)->flags = 0;
 625
 626	if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
 627		gre_hlen = 0;
 628		ipv6h = (struct ipv6hdr *)skb->data;
 629		fl6->daddr = ipv6h->daddr;
 630	} else {
 631		gre_hlen = tunnel->hlen;
 632		fl6->daddr = tunnel->parms.raddr;
 633	}
 634
 635	if (!fl6->flowi6_mark)
 636		dst = dst_cache_get(&tunnel->dst_cache);
 637
 638	if (!dst) {
 639		dst = ip6_route_output(net, NULL, fl6);
 640
 641		if (dst->error)
 642			goto tx_err_link_failure;
 643		dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
 644		if (IS_ERR(dst)) {
 645			err = PTR_ERR(dst);
 646			dst = NULL;
 647			goto tx_err_link_failure;
 648		}
 649		ndst = dst;
 650	}
 651
 652	tdev = dst->dev;
 653
 654	if (tdev == dev) {
 655		stats->collisions++;
 656		net_warn_ratelimited("%s: Local routing loop detected!\n",
 657				     tunnel->parms.name);
 658		goto tx_err_dst_release;
 659	}
 660
 661	mtu = dst_mtu(dst) - sizeof(*ipv6h);
 662	if (encap_limit >= 0) {
 663		max_headroom += 8;
 664		mtu -= 8;
 665	}
 666	if (mtu < IPV6_MIN_MTU)
 667		mtu = IPV6_MIN_MTU;
 668	if (skb_dst(skb))
 669		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 670	if (skb->len > mtu) {
 671		*pmtu = mtu;
 672		err = -EMSGSIZE;
 673		goto tx_err_dst_release;
 674	}
 675
 676	if (tunnel->err_count > 0) {
 677		if (time_before(jiffies,
 678				tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
 679			tunnel->err_count--;
 680
 681			dst_link_failure(skb);
 682		} else
 683			tunnel->err_count = 0;
 684	}
 685
 686	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 687
 688	max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 689
 690	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 691	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 692		new_skb = skb_realloc_headroom(skb, max_headroom);
 693		if (max_headroom > dev->needed_headroom)
 694			dev->needed_headroom = max_headroom;
 695		if (!new_skb)
 696			goto tx_err_dst_release;
 697
 698		if (skb->sk)
 699			skb_set_owner_w(new_skb, skb->sk);
 700		consume_skb(skb);
 701		skb = new_skb;
 702	}
 703
 704	if (!fl6->flowi6_mark && ndst)
 705		dst_cache_set_ip6(&tunnel->dst_cache, ndst, &fl6->saddr);
 706	skb_dst_set(skb, dst);
 707
 708	proto = NEXTHDR_GRE;
 709	if (encap_limit >= 0) {
 710		init_tel_txopt(&opt, encap_limit);
 711		ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 712	}
 713
 714	if (likely(!skb->encapsulation)) {
 715		skb_reset_inner_headers(skb);
 716		skb->encapsulation = 1;
 717	}
 718
 719	skb_push(skb, gre_hlen);
 720	skb_reset_network_header(skb);
 721	skb_set_transport_header(skb, sizeof(*ipv6h));
 722
 723	/*
 724	 *	Push down and install the IP header.
 725	 */
 726	ipv6h = ipv6_hdr(skb);
 727	ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
 728		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
 729	ipv6h->hop_limit = tunnel->parms.hop_limit;
 730	ipv6h->nexthdr = proto;
 731	ipv6h->saddr = fl6->saddr;
 732	ipv6h->daddr = fl6->daddr;
 733
 734	((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
 735	protocol = (dev->type == ARPHRD_ETHER) ?
 736		    htons(ETH_P_TEB) : skb->protocol;
 737	((__be16 *)(ipv6h + 1))[1] = protocol;
 738
 739	if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
 740		__be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
 741
 742		if (tunnel->parms.o_flags&GRE_SEQ) {
 743			++tunnel->o_seqno;
 744			*ptr = htonl(tunnel->o_seqno);
 745			ptr--;
 746		}
 747		if (tunnel->parms.o_flags&GRE_KEY) {
 748			*ptr = tunnel->parms.o_key;
 749			ptr--;
 750		}
 751		if (tunnel->parms.o_flags&GRE_CSUM) {
 752			*ptr = 0;
 753			*(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
 754				skb->len - sizeof(struct ipv6hdr));
 755		}
 756	}
 757
 758	skb_set_inner_protocol(skb, protocol);
 759
 760	ip6tunnel_xmit(NULL, skb, dev);
 761	return 0;
 762tx_err_link_failure:
 763	stats->tx_carrier_errors++;
 764	dst_link_failure(skb);
 765tx_err_dst_release:
 766	dst_release(dst);
 767	return err;
 768}
 769
 770static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 771{
 772	struct ip6_tnl *t = netdev_priv(dev);
 773	const struct iphdr  *iph = ip_hdr(skb);
 774	int encap_limit = -1;
 775	struct flowi6 fl6;
 776	__u8 dsfield;
 777	__u32 mtu;
 778	int err;
 779
 780	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 781
 782	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 783		encap_limit = t->parms.encap_limit;
 784
 785	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 786	fl6.flowi6_proto = IPPROTO_GRE;
 787
 788	dsfield = ipv4_get_dsfield(iph);
 789
 790	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 791		fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 792					  & IPV6_TCLASS_MASK;
 793	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 794		fl6.flowi6_mark = skb->mark;
 795
 796	err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 797	if (err != 0) {
 798		/* XXX: send ICMP error even if DF is not set. */
 799		if (err == -EMSGSIZE)
 800			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 801				  htonl(mtu));
 802		return -1;
 803	}
 804
 805	return 0;
 806}
 807
 808static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 809{
 810	struct ip6_tnl *t = netdev_priv(dev);
 811	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 812	int encap_limit = -1;
 813	__u16 offset;
 814	struct flowi6 fl6;
 815	__u8 dsfield;
 816	__u32 mtu;
 817	int err;
 818
 819	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
 820		return -1;
 821
 822	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 823	if (offset > 0) {
 824		struct ipv6_tlv_tnl_enc_lim *tel;
 825		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 826		if (tel->encap_limit == 0) {
 827			icmpv6_send(skb, ICMPV6_PARAMPROB,
 828				    ICMPV6_HDR_FIELD, offset + 2);
 829			return -1;
 830		}
 831		encap_limit = tel->encap_limit - 1;
 832	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 833		encap_limit = t->parms.encap_limit;
 834
 835	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 836	fl6.flowi6_proto = IPPROTO_GRE;
 837
 838	dsfield = ipv6_get_dsfield(ipv6h);
 839	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
 840		fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
 841	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 842		fl6.flowlabel |= ip6_flowlabel(ipv6h);
 843	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 844		fl6.flowi6_mark = skb->mark;
 845
 846	err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
 847	if (err != 0) {
 848		if (err == -EMSGSIZE)
 849			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 850		return -1;
 851	}
 852
 853	return 0;
 854}
 855
 856/**
 857 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 858 *   @t: the outgoing tunnel device
 859 *   @hdr: IPv6 header from the incoming packet
 860 *
 861 * Description:
 862 *   Avoid trivial tunneling loop by checking that tunnel exit-point
 863 *   doesn't match source of incoming packet.
 864 *
 865 * Return:
 866 *   1 if conflict,
 867 *   0 else
 868 **/
 869
 870static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
 871	const struct ipv6hdr *hdr)
 872{
 873	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 874}
 875
 876static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
 877{
 878	struct ip6_tnl *t = netdev_priv(dev);
 879	int encap_limit = -1;
 880	struct flowi6 fl6;
 881	__u32 mtu;
 882	int err;
 883
 884	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 885		encap_limit = t->parms.encap_limit;
 886
 887	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 888	fl6.flowi6_proto = skb->protocol;
 889
 890	err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
 891
 892	return err;
 893}
 894
 895static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 896	struct net_device *dev)
 897{
 898	struct ip6_tnl *t = netdev_priv(dev);
 899	struct net_device_stats *stats = &t->dev->stats;
 900	int ret;
 901
 902	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
 903		goto tx_err;
 904
 905	switch (skb->protocol) {
 906	case htons(ETH_P_IP):
 907		ret = ip6gre_xmit_ipv4(skb, dev);
 908		break;
 909	case htons(ETH_P_IPV6):
 910		ret = ip6gre_xmit_ipv6(skb, dev);
 911		break;
 912	default:
 913		ret = ip6gre_xmit_other(skb, dev);
 914		break;
 915	}
 916
 917	if (ret < 0)
 918		goto tx_err;
 919
 920	return NETDEV_TX_OK;
 921
 922tx_err:
 923	stats->tx_errors++;
 924	stats->tx_dropped++;
 925	kfree_skb(skb);
 926	return NETDEV_TX_OK;
 927}
 928
 929static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 930{
 931	struct net_device *dev = t->dev;
 932	struct __ip6_tnl_parm *p = &t->parms;
 933	struct flowi6 *fl6 = &t->fl.u.ip6;
 934	int addend = sizeof(struct ipv6hdr) + 4;
 935
 936	if (dev->type != ARPHRD_ETHER) {
 937		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
 938		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 939	}
 940
 941	/* Set up flowi template */
 942	fl6->saddr = p->laddr;
 943	fl6->daddr = p->raddr;
 944	fl6->flowi6_oif = p->link;
 945	fl6->flowlabel = 0;
 946
 947	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 948		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
 949	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
 950		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
 951
 952	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
 953	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 954
 955	if (p->flags&IP6_TNL_F_CAP_XMIT &&
 956			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
 957		dev->flags |= IFF_POINTOPOINT;
 958	else
 959		dev->flags &= ~IFF_POINTOPOINT;
 960
 961	/* Precalculate GRE options length */
 962	if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
 963		if (t->parms.o_flags&GRE_CSUM)
 964			addend += 4;
 965		if (t->parms.o_flags&GRE_KEY)
 966			addend += 4;
 967		if (t->parms.o_flags&GRE_SEQ)
 968			addend += 4;
 969	}
 970	t->hlen = addend;
 971
 972	if (p->flags & IP6_TNL_F_CAP_XMIT) {
 973		int strict = (ipv6_addr_type(&p->raddr) &
 974			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
 975
 976		struct rt6_info *rt = rt6_lookup(t->net,
 977						 &p->raddr, &p->laddr,
 978						 p->link, strict);
 979
 980		if (!rt)
 981			return;
 982
 983		if (rt->dst.dev) {
 984			dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
 985
 986			if (set_mtu) {
 987				dev->mtu = rt->dst.dev->mtu - addend;
 988				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 989					dev->mtu -= 8;
 990
 991				if (dev->mtu < IPV6_MIN_MTU)
 992					dev->mtu = IPV6_MIN_MTU;
 993			}
 994		}
 995		ip6_rt_put(rt);
 996	}
 997}
 998
 999static int ip6gre_tnl_change(struct ip6_tnl *t,
1000	const struct __ip6_tnl_parm *p, int set_mtu)
1001{
1002	t->parms.laddr = p->laddr;
1003	t->parms.raddr = p->raddr;
1004	t->parms.flags = p->flags;
1005	t->parms.hop_limit = p->hop_limit;
1006	t->parms.encap_limit = p->encap_limit;
1007	t->parms.flowinfo = p->flowinfo;
1008	t->parms.link = p->link;
1009	t->parms.proto = p->proto;
1010	t->parms.i_key = p->i_key;
1011	t->parms.o_key = p->o_key;
1012	t->parms.i_flags = p->i_flags;
1013	t->parms.o_flags = p->o_flags;
1014	dst_cache_reset(&t->dst_cache);
1015	ip6gre_tnl_link_config(t, set_mtu);
1016	return 0;
1017}
1018
1019static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1020	const struct ip6_tnl_parm2 *u)
1021{
1022	p->laddr = u->laddr;
1023	p->raddr = u->raddr;
1024	p->flags = u->flags;
1025	p->hop_limit = u->hop_limit;
1026	p->encap_limit = u->encap_limit;
1027	p->flowinfo = u->flowinfo;
1028	p->link = u->link;
1029	p->i_key = u->i_key;
1030	p->o_key = u->o_key;
1031	p->i_flags = u->i_flags;
1032	p->o_flags = u->o_flags;
1033	memcpy(p->name, u->name, sizeof(u->name));
1034}
1035
1036static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1037	const struct __ip6_tnl_parm *p)
1038{
1039	u->proto = IPPROTO_GRE;
1040	u->laddr = p->laddr;
1041	u->raddr = p->raddr;
1042	u->flags = p->flags;
1043	u->hop_limit = p->hop_limit;
1044	u->encap_limit = p->encap_limit;
1045	u->flowinfo = p->flowinfo;
1046	u->link = p->link;
1047	u->i_key = p->i_key;
1048	u->o_key = p->o_key;
1049	u->i_flags = p->i_flags;
1050	u->o_flags = p->o_flags;
1051	memcpy(u->name, p->name, sizeof(u->name));
1052}
1053
1054static int ip6gre_tunnel_ioctl(struct net_device *dev,
1055	struct ifreq *ifr, int cmd)
1056{
1057	int err = 0;
1058	struct ip6_tnl_parm2 p;
1059	struct __ip6_tnl_parm p1;
1060	struct ip6_tnl *t = netdev_priv(dev);
1061	struct net *net = t->net;
1062	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1063
1064	switch (cmd) {
1065	case SIOCGETTUNNEL:
1066		if (dev == ign->fb_tunnel_dev) {
1067			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1068				err = -EFAULT;
1069				break;
1070			}
1071			ip6gre_tnl_parm_from_user(&p1, &p);
1072			t = ip6gre_tunnel_locate(net, &p1, 0);
1073			if (!t)
1074				t = netdev_priv(dev);
1075		}
1076		memset(&p, 0, sizeof(p));
1077		ip6gre_tnl_parm_to_user(&p, &t->parms);
1078		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1079			err = -EFAULT;
1080		break;
1081
1082	case SIOCADDTUNNEL:
1083	case SIOCCHGTUNNEL:
1084		err = -EPERM;
1085		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1086			goto done;
1087
1088		err = -EFAULT;
1089		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1090			goto done;
1091
1092		err = -EINVAL;
1093		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1094			goto done;
1095
1096		if (!(p.i_flags&GRE_KEY))
1097			p.i_key = 0;
1098		if (!(p.o_flags&GRE_KEY))
1099			p.o_key = 0;
1100
1101		ip6gre_tnl_parm_from_user(&p1, &p);
1102		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1103
1104		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1105			if (t) {
1106				if (t->dev != dev) {
1107					err = -EEXIST;
1108					break;
1109				}
1110			} else {
1111				t = netdev_priv(dev);
1112
1113				ip6gre_tunnel_unlink(ign, t);
1114				synchronize_net();
1115				ip6gre_tnl_change(t, &p1, 1);
1116				ip6gre_tunnel_link(ign, t);
1117				netdev_state_change(dev);
1118			}
1119		}
1120
1121		if (t) {
1122			err = 0;
1123
1124			memset(&p, 0, sizeof(p));
1125			ip6gre_tnl_parm_to_user(&p, &t->parms);
1126			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1127				err = -EFAULT;
1128		} else
1129			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1130		break;
1131
1132	case SIOCDELTUNNEL:
1133		err = -EPERM;
1134		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1135			goto done;
1136
1137		if (dev == ign->fb_tunnel_dev) {
1138			err = -EFAULT;
1139			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1140				goto done;
1141			err = -ENOENT;
1142			ip6gre_tnl_parm_from_user(&p1, &p);
1143			t = ip6gre_tunnel_locate(net, &p1, 0);
1144			if (!t)
1145				goto done;
1146			err = -EPERM;
1147			if (t == netdev_priv(ign->fb_tunnel_dev))
1148				goto done;
1149			dev = t->dev;
1150		}
1151		unregister_netdevice(dev);
1152		err = 0;
1153		break;
1154
1155	default:
1156		err = -EINVAL;
1157	}
1158
1159done:
1160	return err;
1161}
1162
1163static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1164{
1165	if (new_mtu < 68 ||
1166	    new_mtu > 0xFFF8 - dev->hard_header_len)
1167		return -EINVAL;
1168	dev->mtu = new_mtu;
1169	return 0;
1170}
1171
1172static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1173			unsigned short type,
1174			const void *daddr, const void *saddr, unsigned int len)
1175{
1176	struct ip6_tnl *t = netdev_priv(dev);
1177	struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1178	__be16 *p = (__be16 *)(ipv6h+1);
1179
1180	ip6_flow_hdr(ipv6h, 0,
1181		     ip6_make_flowlabel(dev_net(dev), skb,
1182					t->fl.u.ip6.flowlabel, true,
1183					&t->fl.u.ip6));
1184	ipv6h->hop_limit = t->parms.hop_limit;
1185	ipv6h->nexthdr = NEXTHDR_GRE;
1186	ipv6h->saddr = t->parms.laddr;
1187	ipv6h->daddr = t->parms.raddr;
1188
1189	p[0]		= t->parms.o_flags;
1190	p[1]		= htons(type);
1191
1192	/*
1193	 *	Set the source hardware address.
1194	 */
1195
1196	if (saddr)
1197		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1198	if (daddr)
1199		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1200	if (!ipv6_addr_any(&ipv6h->daddr))
1201		return t->hlen;
1202
1203	return -t->hlen;
1204}
1205
1206static const struct header_ops ip6gre_header_ops = {
1207	.create	= ip6gre_header,
1208};
1209
1210static const struct net_device_ops ip6gre_netdev_ops = {
1211	.ndo_init		= ip6gre_tunnel_init,
1212	.ndo_uninit		= ip6gre_tunnel_uninit,
1213	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1214	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1215	.ndo_change_mtu		= ip6gre_tunnel_change_mtu,
1216	.ndo_get_stats64	= ip_tunnel_get_stats64,
1217	.ndo_get_iflink		= ip6_tnl_get_iflink,
1218};
1219
1220static void ip6gre_dev_free(struct net_device *dev)
1221{
1222	struct ip6_tnl *t = netdev_priv(dev);
1223
1224	dst_cache_destroy(&t->dst_cache);
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->addr_len = sizeof(struct in6_addr);
1244	netif_keep_dst(dev);
1245}
1246
1247static int ip6gre_tunnel_init_common(struct net_device *dev)
1248{
1249	struct ip6_tnl *tunnel;
1250	int ret;
1251
1252	tunnel = netdev_priv(dev);
1253
1254	tunnel->dev = dev;
1255	tunnel->net = dev_net(dev);
1256	strcpy(tunnel->parms.name, dev->name);
1257
1258	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1259	if (!dev->tstats)
1260		return -ENOMEM;
1261
1262	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1263	if (ret) {
1264		free_percpu(dev->tstats);
1265		dev->tstats = NULL;
1266		return ret;
1267	}
1268
1269	return 0;
1270}
1271
1272static int ip6gre_tunnel_init(struct net_device *dev)
1273{
1274	struct ip6_tnl *tunnel;
1275	int ret;
1276
1277	ret = ip6gre_tunnel_init_common(dev);
1278	if (ret)
1279		return ret;
1280
1281	tunnel = netdev_priv(dev);
1282
1283	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1284	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1285
1286	if (ipv6_addr_any(&tunnel->parms.raddr))
1287		dev->header_ops = &ip6gre_header_ops;
1288
1289	return 0;
1290}
1291
1292static void ip6gre_fb_tunnel_init(struct net_device *dev)
1293{
1294	struct ip6_tnl *tunnel = netdev_priv(dev);
1295
1296	tunnel->dev = dev;
1297	tunnel->net = dev_net(dev);
1298	strcpy(tunnel->parms.name, dev->name);
1299
1300	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1301
1302	dev_hold(dev);
1303}
1304
1305
1306static struct inet6_protocol ip6gre_protocol __read_mostly = {
1307	.handler     = ip6gre_rcv,
1308	.err_handler = ip6gre_err,
1309	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1310};
1311
1312static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1313{
1314	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1315	struct net_device *dev, *aux;
1316	int prio;
1317
1318	for_each_netdev_safe(net, dev, aux)
1319		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1320		    dev->rtnl_link_ops == &ip6gre_tap_ops)
1321			unregister_netdevice_queue(dev, head);
1322
1323	for (prio = 0; prio < 4; prio++) {
1324		int h;
1325		for (h = 0; h < HASH_SIZE; h++) {
1326			struct ip6_tnl *t;
1327
1328			t = rtnl_dereference(ign->tunnels[prio][h]);
1329
1330			while (t) {
1331				/* If dev is in the same netns, it has already
1332				 * been added to the list by the previous loop.
1333				 */
1334				if (!net_eq(dev_net(t->dev), net))
1335					unregister_netdevice_queue(t->dev,
1336								   head);
1337				t = rtnl_dereference(t->next);
1338			}
1339		}
1340	}
1341}
1342
1343static int __net_init ip6gre_init_net(struct net *net)
1344{
1345	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1346	int err;
1347
1348	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1349					  NET_NAME_UNKNOWN,
1350					  ip6gre_tunnel_setup);
1351	if (!ign->fb_tunnel_dev) {
1352		err = -ENOMEM;
1353		goto err_alloc_dev;
1354	}
1355	dev_net_set(ign->fb_tunnel_dev, net);
1356	/* FB netdevice is special: we have one, and only one per netns.
1357	 * Allowing to move it to another netns is clearly unsafe.
1358	 */
1359	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1360
1361
1362	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1363	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1364
1365	err = register_netdev(ign->fb_tunnel_dev);
1366	if (err)
1367		goto err_reg_dev;
1368
1369	rcu_assign_pointer(ign->tunnels_wc[0],
1370			   netdev_priv(ign->fb_tunnel_dev));
1371	return 0;
1372
1373err_reg_dev:
1374	ip6gre_dev_free(ign->fb_tunnel_dev);
1375err_alloc_dev:
1376	return err;
1377}
1378
1379static void __net_exit ip6gre_exit_net(struct net *net)
1380{
1381	LIST_HEAD(list);
1382
1383	rtnl_lock();
1384	ip6gre_destroy_tunnels(net, &list);
1385	unregister_netdevice_many(&list);
1386	rtnl_unlock();
1387}
1388
1389static struct pernet_operations ip6gre_net_ops = {
1390	.init = ip6gre_init_net,
1391	.exit = ip6gre_exit_net,
1392	.id   = &ip6gre_net_id,
1393	.size = sizeof(struct ip6gre_net),
1394};
1395
1396static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1397{
1398	__be16 flags;
1399
1400	if (!data)
1401		return 0;
1402
1403	flags = 0;
1404	if (data[IFLA_GRE_IFLAGS])
1405		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1406	if (data[IFLA_GRE_OFLAGS])
1407		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1408	if (flags & (GRE_VERSION|GRE_ROUTING))
1409		return -EINVAL;
1410
1411	return 0;
1412}
1413
1414static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1415{
1416	struct in6_addr daddr;
1417
1418	if (tb[IFLA_ADDRESS]) {
1419		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1420			return -EINVAL;
1421		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1422			return -EADDRNOTAVAIL;
1423	}
1424
1425	if (!data)
1426		goto out;
1427
1428	if (data[IFLA_GRE_REMOTE]) {
1429		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1430		if (ipv6_addr_any(&daddr))
1431			return -EINVAL;
1432	}
1433
1434out:
1435	return ip6gre_tunnel_validate(tb, data);
1436}
1437
1438
1439static void ip6gre_netlink_parms(struct nlattr *data[],
1440				struct __ip6_tnl_parm *parms)
1441{
1442	memset(parms, 0, sizeof(*parms));
1443
1444	if (!data)
1445		return;
1446
1447	if (data[IFLA_GRE_LINK])
1448		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1449
1450	if (data[IFLA_GRE_IFLAGS])
1451		parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1452
1453	if (data[IFLA_GRE_OFLAGS])
1454		parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1455
1456	if (data[IFLA_GRE_IKEY])
1457		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1458
1459	if (data[IFLA_GRE_OKEY])
1460		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1461
1462	if (data[IFLA_GRE_LOCAL])
1463		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1464
1465	if (data[IFLA_GRE_REMOTE])
1466		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1467
1468	if (data[IFLA_GRE_TTL])
1469		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1470
1471	if (data[IFLA_GRE_ENCAP_LIMIT])
1472		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1473
1474	if (data[IFLA_GRE_FLOWINFO])
1475		parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1476
1477	if (data[IFLA_GRE_FLAGS])
1478		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1479}
1480
1481static int ip6gre_tap_init(struct net_device *dev)
1482{
1483	struct ip6_tnl *tunnel;
1484	int ret;
1485
1486	ret = ip6gre_tunnel_init_common(dev);
1487	if (ret)
1488		return ret;
1489
1490	tunnel = netdev_priv(dev);
1491
1492	ip6gre_tnl_link_config(tunnel, 1);
1493
1494	return 0;
1495}
1496
1497static const struct net_device_ops ip6gre_tap_netdev_ops = {
1498	.ndo_init = ip6gre_tap_init,
1499	.ndo_uninit = ip6gre_tunnel_uninit,
1500	.ndo_start_xmit = ip6gre_tunnel_xmit,
1501	.ndo_set_mac_address = eth_mac_addr,
1502	.ndo_validate_addr = eth_validate_addr,
1503	.ndo_change_mtu = ip6gre_tunnel_change_mtu,
1504	.ndo_get_stats64 = ip_tunnel_get_stats64,
1505	.ndo_get_iflink = ip6_tnl_get_iflink,
1506};
1507
1508static void ip6gre_tap_setup(struct net_device *dev)
1509{
1510
1511	ether_setup(dev);
1512
1513	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1514	dev->destructor = ip6gre_dev_free;
1515
1516	dev->features |= NETIF_F_NETNS_LOCAL;
1517	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1518}
1519
1520static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1521	struct nlattr *tb[], struct nlattr *data[])
1522{
1523	struct ip6_tnl *nt;
1524	struct net *net = dev_net(dev);
1525	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1526	int err;
1527
1528	nt = netdev_priv(dev);
1529	ip6gre_netlink_parms(data, &nt->parms);
1530
1531	if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1532		return -EEXIST;
1533
1534	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1535		eth_hw_addr_random(dev);
1536
1537	nt->dev = dev;
1538	nt->net = dev_net(dev);
1539	ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1540
1541	/* Can use a lockless transmit, unless we generate output sequences */
1542	if (!(nt->parms.o_flags & GRE_SEQ))
1543		dev->features |= NETIF_F_LLTX;
1544
1545	err = register_netdevice(dev);
1546	if (err)
1547		goto out;
1548
1549	dev_hold(dev);
1550	ip6gre_tunnel_link(ign, nt);
1551
1552out:
1553	return err;
1554}
1555
1556static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1557			    struct nlattr *data[])
1558{
1559	struct ip6_tnl *t, *nt = netdev_priv(dev);
1560	struct net *net = nt->net;
1561	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1562	struct __ip6_tnl_parm p;
1563
1564	if (dev == ign->fb_tunnel_dev)
1565		return -EINVAL;
1566
1567	ip6gre_netlink_parms(data, &p);
1568
1569	t = ip6gre_tunnel_locate(net, &p, 0);
1570
1571	if (t) {
1572		if (t->dev != dev)
1573			return -EEXIST;
1574	} else {
1575		t = nt;
1576	}
1577
1578	ip6gre_tunnel_unlink(ign, t);
1579	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1580	ip6gre_tunnel_link(ign, t);
1581	return 0;
1582}
1583
1584static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1585{
1586	struct net *net = dev_net(dev);
1587	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1588
1589	if (dev != ign->fb_tunnel_dev)
1590		unregister_netdevice_queue(dev, head);
1591}
1592
1593static size_t ip6gre_get_size(const struct net_device *dev)
1594{
1595	return
1596		/* IFLA_GRE_LINK */
1597		nla_total_size(4) +
1598		/* IFLA_GRE_IFLAGS */
1599		nla_total_size(2) +
1600		/* IFLA_GRE_OFLAGS */
1601		nla_total_size(2) +
1602		/* IFLA_GRE_IKEY */
1603		nla_total_size(4) +
1604		/* IFLA_GRE_OKEY */
1605		nla_total_size(4) +
1606		/* IFLA_GRE_LOCAL */
1607		nla_total_size(sizeof(struct in6_addr)) +
1608		/* IFLA_GRE_REMOTE */
1609		nla_total_size(sizeof(struct in6_addr)) +
1610		/* IFLA_GRE_TTL */
1611		nla_total_size(1) +
1612		/* IFLA_GRE_TOS */
1613		nla_total_size(1) +
1614		/* IFLA_GRE_ENCAP_LIMIT */
1615		nla_total_size(1) +
1616		/* IFLA_GRE_FLOWINFO */
1617		nla_total_size(4) +
1618		/* IFLA_GRE_FLAGS */
1619		nla_total_size(4) +
1620		0;
1621}
1622
1623static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1624{
1625	struct ip6_tnl *t = netdev_priv(dev);
1626	struct __ip6_tnl_parm *p = &t->parms;
1627
1628	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1629	    nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1630	    nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1631	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1632	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1633	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1634	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1635	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1636	    /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1637	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1638	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1639	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1640		goto nla_put_failure;
1641	return 0;
1642
1643nla_put_failure:
1644	return -EMSGSIZE;
1645}
1646
1647static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1648	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
1649	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1650	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1651	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1652	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1653	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1654	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1655	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
1656	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1657	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1658	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1659};
1660
1661static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1662	.kind		= "ip6gre",
1663	.maxtype	= IFLA_GRE_MAX,
1664	.policy		= ip6gre_policy,
1665	.priv_size	= sizeof(struct ip6_tnl),
1666	.setup		= ip6gre_tunnel_setup,
1667	.validate	= ip6gre_tunnel_validate,
1668	.newlink	= ip6gre_newlink,
1669	.changelink	= ip6gre_changelink,
1670	.dellink	= ip6gre_dellink,
1671	.get_size	= ip6gre_get_size,
1672	.fill_info	= ip6gre_fill_info,
1673	.get_link_net	= ip6_tnl_get_link_net,
1674};
1675
1676static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1677	.kind		= "ip6gretap",
1678	.maxtype	= IFLA_GRE_MAX,
1679	.policy		= ip6gre_policy,
1680	.priv_size	= sizeof(struct ip6_tnl),
1681	.setup		= ip6gre_tap_setup,
1682	.validate	= ip6gre_tap_validate,
1683	.newlink	= ip6gre_newlink,
1684	.changelink	= ip6gre_changelink,
1685	.get_size	= ip6gre_get_size,
1686	.fill_info	= ip6gre_fill_info,
1687	.get_link_net	= ip6_tnl_get_link_net,
1688};
1689
1690/*
1691 *	And now the modules code and kernel interface.
1692 */
1693
1694static int __init ip6gre_init(void)
1695{
1696	int err;
1697
1698	pr_info("GRE over IPv6 tunneling driver\n");
1699
1700	err = register_pernet_device(&ip6gre_net_ops);
1701	if (err < 0)
1702		return err;
1703
1704	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1705	if (err < 0) {
1706		pr_info("%s: can't add protocol\n", __func__);
1707		goto add_proto_failed;
1708	}
1709
1710	err = rtnl_link_register(&ip6gre_link_ops);
1711	if (err < 0)
1712		goto rtnl_link_failed;
1713
1714	err = rtnl_link_register(&ip6gre_tap_ops);
1715	if (err < 0)
1716		goto tap_ops_failed;
1717
1718out:
1719	return err;
1720
1721tap_ops_failed:
1722	rtnl_link_unregister(&ip6gre_link_ops);
1723rtnl_link_failed:
1724	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1725add_proto_failed:
1726	unregister_pernet_device(&ip6gre_net_ops);
1727	goto out;
1728}
1729
1730static void __exit ip6gre_fini(void)
1731{
1732	rtnl_link_unregister(&ip6gre_tap_ops);
1733	rtnl_link_unregister(&ip6gre_link_ops);
1734	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1735	unregister_pernet_device(&ip6gre_net_ops);
1736}
1737
1738module_init(ip6gre_init);
1739module_exit(ip6gre_fini);
1740MODULE_LICENSE("GPL");
1741MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1742MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1743MODULE_ALIAS_RTNL_LINK("ip6gre");
1744MODULE_ALIAS_RTNL_LINK("ip6gretap");
1745MODULE_ALIAS_NETDEV("ip6gre0");