xref: /openbmc/linux/net/ipv6/sit.c (revision e8bd417a)
1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3   *	IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
4   *	Linux INET6 implementation
5   *
6   *	Authors:
7   *	Pedro Roque		<roque@di.fc.ul.pt>
8   *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
9   *
10   *	Changes:
11   * Roger Venning <r.venning@telstra.com>:	6to4 support
12   * Nate Thompson <nate@thebog.net>:		6to4 support
13   * Fred Templin <fred.l.templin@boeing.com>:	isatap support
14   */
15  
16  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17  
18  #include <linux/module.h>
19  #include <linux/capability.h>
20  #include <linux/errno.h>
21  #include <linux/types.h>
22  #include <linux/socket.h>
23  #include <linux/sockios.h>
24  #include <linux/net.h>
25  #include <linux/in6.h>
26  #include <linux/netdevice.h>
27  #include <linux/if_arp.h>
28  #include <linux/icmp.h>
29  #include <linux/slab.h>
30  #include <linux/uaccess.h>
31  #include <linux/init.h>
32  #include <linux/netfilter_ipv4.h>
33  #include <linux/if_ether.h>
34  
35  #include <net/sock.h>
36  #include <net/snmp.h>
37  
38  #include <net/ipv6.h>
39  #include <net/protocol.h>
40  #include <net/transp_v6.h>
41  #include <net/ip6_fib.h>
42  #include <net/ip6_route.h>
43  #include <net/ndisc.h>
44  #include <net/addrconf.h>
45  #include <net/ip.h>
46  #include <net/udp.h>
47  #include <net/icmp.h>
48  #include <net/ip_tunnels.h>
49  #include <net/inet_ecn.h>
50  #include <net/xfrm.h>
51  #include <net/dsfield.h>
52  #include <net/net_namespace.h>
53  #include <net/netns/generic.h>
54  
55  /*
56     This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
57  
58     For comments look at net/ipv4/ip_gre.c --ANK
59   */
60  
61  #define IP6_SIT_HASH_SIZE  16
62  #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
63  
64  static bool log_ecn_error = true;
65  module_param(log_ecn_error, bool, 0644);
66  MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
67  
68  static int ipip6_tunnel_init(struct net_device *dev);
69  static void ipip6_tunnel_setup(struct net_device *dev);
70  static void ipip6_dev_free(struct net_device *dev);
71  static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
72  		      __be32 *v4dst);
73  static struct rtnl_link_ops sit_link_ops __read_mostly;
74  
75  static unsigned int sit_net_id __read_mostly;
76  struct sit_net {
77  	struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
78  	struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
79  	struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
80  	struct ip_tunnel __rcu *tunnels_wc[1];
81  	struct ip_tunnel __rcu **tunnels[4];
82  
83  	struct net_device *fb_tunnel_dev;
84  };
85  
86  /*
87   * Must be invoked with rcu_read_lock
88   */
89  static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
90  					     struct net_device *dev,
91  					     __be32 remote, __be32 local,
92  					     int sifindex)
93  {
94  	unsigned int h0 = HASH(remote);
95  	unsigned int h1 = HASH(local);
96  	struct ip_tunnel *t;
97  	struct sit_net *sitn = net_generic(net, sit_net_id);
98  	int ifindex = dev ? dev->ifindex : 0;
99  
100  	for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
101  		if (local == t->parms.iph.saddr &&
102  		    remote == t->parms.iph.daddr &&
103  		    (!dev || !t->parms.link || ifindex == t->parms.link ||
104  		     sifindex == t->parms.link) &&
105  		    (t->dev->flags & IFF_UP))
106  			return t;
107  	}
108  	for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
109  		if (remote == t->parms.iph.daddr &&
110  		    (!dev || !t->parms.link || ifindex == t->parms.link ||
111  		     sifindex == t->parms.link) &&
112  		    (t->dev->flags & IFF_UP))
113  			return t;
114  	}
115  	for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
116  		if (local == t->parms.iph.saddr &&
117  		    (!dev || !t->parms.link || ifindex == t->parms.link ||
118  		     sifindex == t->parms.link) &&
119  		    (t->dev->flags & IFF_UP))
120  			return t;
121  	}
122  	t = rcu_dereference(sitn->tunnels_wc[0]);
123  	if (t && (t->dev->flags & IFF_UP))
124  		return t;
125  	return NULL;
126  }
127  
128  static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
129  		struct ip_tunnel_parm *parms)
130  {
131  	__be32 remote = parms->iph.daddr;
132  	__be32 local = parms->iph.saddr;
133  	unsigned int h = 0;
134  	int prio = 0;
135  
136  	if (remote) {
137  		prio |= 2;
138  		h ^= HASH(remote);
139  	}
140  	if (local) {
141  		prio |= 1;
142  		h ^= HASH(local);
143  	}
144  	return &sitn->tunnels[prio][h];
145  }
146  
147  static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
148  		struct ip_tunnel *t)
149  {
150  	return __ipip6_bucket(sitn, &t->parms);
151  }
152  
153  static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
154  {
155  	struct ip_tunnel __rcu **tp;
156  	struct ip_tunnel *iter;
157  
158  	for (tp = ipip6_bucket(sitn, t);
159  	     (iter = rtnl_dereference(*tp)) != NULL;
160  	     tp = &iter->next) {
161  		if (t == iter) {
162  			rcu_assign_pointer(*tp, t->next);
163  			break;
164  		}
165  	}
166  }
167  
168  static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
169  {
170  	struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
171  
172  	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
173  	rcu_assign_pointer(*tp, t);
174  }
175  
176  static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
177  {
178  #ifdef CONFIG_IPV6_SIT_6RD
179  	struct ip_tunnel *t = netdev_priv(dev);
180  
181  	if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
182  		ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
183  		t->ip6rd.relay_prefix = 0;
184  		t->ip6rd.prefixlen = 16;
185  		t->ip6rd.relay_prefixlen = 0;
186  	} else {
187  		struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
188  		memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
189  	}
190  #endif
191  }
192  
193  static int ipip6_tunnel_create(struct net_device *dev)
194  {
195  	struct ip_tunnel *t = netdev_priv(dev);
196  	struct net *net = dev_net(dev);
197  	struct sit_net *sitn = net_generic(net, sit_net_id);
198  	int err;
199  
200  	memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
201  	memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
202  
203  	if ((__force u16)t->parms.i_flags & SIT_ISATAP)
204  		dev->priv_flags |= IFF_ISATAP;
205  
206  	dev->rtnl_link_ops = &sit_link_ops;
207  
208  	err = register_netdevice(dev);
209  	if (err < 0)
210  		goto out;
211  
212  	ipip6_tunnel_clone_6rd(dev, sitn);
213  
214  	dev_hold(dev);
215  
216  	ipip6_tunnel_link(sitn, t);
217  	return 0;
218  
219  out:
220  	return err;
221  }
222  
223  static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
224  		struct ip_tunnel_parm *parms, int create)
225  {
226  	__be32 remote = parms->iph.daddr;
227  	__be32 local = parms->iph.saddr;
228  	struct ip_tunnel *t, *nt;
229  	struct ip_tunnel __rcu **tp;
230  	struct net_device *dev;
231  	char name[IFNAMSIZ];
232  	struct sit_net *sitn = net_generic(net, sit_net_id);
233  
234  	for (tp = __ipip6_bucket(sitn, parms);
235  	    (t = rtnl_dereference(*tp)) != NULL;
236  	     tp = &t->next) {
237  		if (local == t->parms.iph.saddr &&
238  		    remote == t->parms.iph.daddr &&
239  		    parms->link == t->parms.link) {
240  			if (create)
241  				return NULL;
242  			else
243  				return t;
244  		}
245  	}
246  	if (!create)
247  		goto failed;
248  
249  	if (parms->name[0]) {
250  		if (!dev_valid_name(parms->name))
251  			goto failed;
252  		strlcpy(name, parms->name, IFNAMSIZ);
253  	} else {
254  		strcpy(name, "sit%d");
255  	}
256  	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
257  			   ipip6_tunnel_setup);
258  	if (!dev)
259  		return NULL;
260  
261  	dev_net_set(dev, net);
262  
263  	nt = netdev_priv(dev);
264  
265  	nt->parms = *parms;
266  	if (ipip6_tunnel_create(dev) < 0)
267  		goto failed_free;
268  
269  	return nt;
270  
271  failed_free:
272  	free_netdev(dev);
273  failed:
274  	return NULL;
275  }
276  
277  #define for_each_prl_rcu(start)			\
278  	for (prl = rcu_dereference(start);	\
279  	     prl;				\
280  	     prl = rcu_dereference(prl->next))
281  
282  static struct ip_tunnel_prl_entry *
283  __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
284  {
285  	struct ip_tunnel_prl_entry *prl;
286  
287  	for_each_prl_rcu(t->prl)
288  		if (prl->addr == addr)
289  			break;
290  	return prl;
291  
292  }
293  
294  static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
295  				struct ip_tunnel_prl __user *a)
296  {
297  	struct ip_tunnel_prl kprl, *kp;
298  	struct ip_tunnel_prl_entry *prl;
299  	unsigned int cmax, c = 0, ca, len;
300  	int ret = 0;
301  
302  	if (copy_from_user(&kprl, a, sizeof(kprl)))
303  		return -EFAULT;
304  	cmax = kprl.datalen / sizeof(kprl);
305  	if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
306  		cmax = 1;
307  
308  	/* For simple GET or for root users,
309  	 * we try harder to allocate.
310  	 */
311  	kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
312  		kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) :
313  		NULL;
314  
315  	rcu_read_lock();
316  
317  	ca = t->prl_count < cmax ? t->prl_count : cmax;
318  
319  	if (!kp) {
320  		/* We don't try hard to allocate much memory for
321  		 * non-root users.
322  		 * For root users, retry allocating enough memory for
323  		 * the answer.
324  		 */
325  		kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
326  		if (!kp) {
327  			ret = -ENOMEM;
328  			goto out;
329  		}
330  	}
331  
332  	c = 0;
333  	for_each_prl_rcu(t->prl) {
334  		if (c >= cmax)
335  			break;
336  		if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
337  			continue;
338  		kp[c].addr = prl->addr;
339  		kp[c].flags = prl->flags;
340  		c++;
341  		if (kprl.addr != htonl(INADDR_ANY))
342  			break;
343  	}
344  out:
345  	rcu_read_unlock();
346  
347  	len = sizeof(*kp) * c;
348  	ret = 0;
349  	if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
350  		ret = -EFAULT;
351  
352  	kfree(kp);
353  
354  	return ret;
355  }
356  
357  static int
358  ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
359  {
360  	struct ip_tunnel_prl_entry *p;
361  	int err = 0;
362  
363  	if (a->addr == htonl(INADDR_ANY))
364  		return -EINVAL;
365  
366  	ASSERT_RTNL();
367  
368  	for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
369  		if (p->addr == a->addr) {
370  			if (chg) {
371  				p->flags = a->flags;
372  				goto out;
373  			}
374  			err = -EEXIST;
375  			goto out;
376  		}
377  	}
378  
379  	if (chg) {
380  		err = -ENXIO;
381  		goto out;
382  	}
383  
384  	p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
385  	if (!p) {
386  		err = -ENOBUFS;
387  		goto out;
388  	}
389  
390  	p->next = t->prl;
391  	p->addr = a->addr;
392  	p->flags = a->flags;
393  	t->prl_count++;
394  	rcu_assign_pointer(t->prl, p);
395  out:
396  	return err;
397  }
398  
399  static void prl_list_destroy_rcu(struct rcu_head *head)
400  {
401  	struct ip_tunnel_prl_entry *p, *n;
402  
403  	p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
404  	do {
405  		n = rcu_dereference_protected(p->next, 1);
406  		kfree(p);
407  		p = n;
408  	} while (p);
409  }
410  
411  static int
412  ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
413  {
414  	struct ip_tunnel_prl_entry *x;
415  	struct ip_tunnel_prl_entry __rcu **p;
416  	int err = 0;
417  
418  	ASSERT_RTNL();
419  
420  	if (a && a->addr != htonl(INADDR_ANY)) {
421  		for (p = &t->prl;
422  		     (x = rtnl_dereference(*p)) != NULL;
423  		     p = &x->next) {
424  			if (x->addr == a->addr) {
425  				*p = x->next;
426  				kfree_rcu(x, rcu_head);
427  				t->prl_count--;
428  				goto out;
429  			}
430  		}
431  		err = -ENXIO;
432  	} else {
433  		x = rtnl_dereference(t->prl);
434  		if (x) {
435  			t->prl_count = 0;
436  			call_rcu(&x->rcu_head, prl_list_destroy_rcu);
437  			t->prl = NULL;
438  		}
439  	}
440  out:
441  	return err;
442  }
443  
444  static int
445  isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
446  {
447  	struct ip_tunnel_prl_entry *p;
448  	int ok = 1;
449  
450  	rcu_read_lock();
451  	p = __ipip6_tunnel_locate_prl(t, iph->saddr);
452  	if (p) {
453  		if (p->flags & PRL_DEFAULT)
454  			skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
455  		else
456  			skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
457  	} else {
458  		const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
459  
460  		if (ipv6_addr_is_isatap(addr6) &&
461  		    (addr6->s6_addr32[3] == iph->saddr) &&
462  		    ipv6_chk_prefix(addr6, t->dev))
463  			skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
464  		else
465  			ok = 0;
466  	}
467  	rcu_read_unlock();
468  	return ok;
469  }
470  
471  static void ipip6_tunnel_uninit(struct net_device *dev)
472  {
473  	struct ip_tunnel *tunnel = netdev_priv(dev);
474  	struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
475  
476  	if (dev == sitn->fb_tunnel_dev) {
477  		RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
478  	} else {
479  		ipip6_tunnel_unlink(sitn, tunnel);
480  		ipip6_tunnel_del_prl(tunnel, NULL);
481  	}
482  	dst_cache_reset(&tunnel->dst_cache);
483  	dev_put(dev);
484  }
485  
486  static int ipip6_err(struct sk_buff *skb, u32 info)
487  {
488  	const struct iphdr *iph = (const struct iphdr *)skb->data;
489  	const int type = icmp_hdr(skb)->type;
490  	const int code = icmp_hdr(skb)->code;
491  	unsigned int data_len = 0;
492  	struct ip_tunnel *t;
493  	int sifindex;
494  	int err;
495  
496  	switch (type) {
497  	default:
498  	case ICMP_PARAMETERPROB:
499  		return 0;
500  
501  	case ICMP_DEST_UNREACH:
502  		switch (code) {
503  		case ICMP_SR_FAILED:
504  			/* Impossible event. */
505  			return 0;
506  		default:
507  			/* All others are translated to HOST_UNREACH.
508  			   rfc2003 contains "deep thoughts" about NET_UNREACH,
509  			   I believe they are just ether pollution. --ANK
510  			 */
511  			break;
512  		}
513  		break;
514  	case ICMP_TIME_EXCEEDED:
515  		if (code != ICMP_EXC_TTL)
516  			return 0;
517  		data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
518  		break;
519  	case ICMP_REDIRECT:
520  		break;
521  	}
522  
523  	err = -ENOENT;
524  
525  	sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
526  	t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
527  				iph->daddr, iph->saddr, sifindex);
528  	if (!t)
529  		goto out;
530  
531  	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
532  		ipv4_update_pmtu(skb, dev_net(skb->dev), info,
533  				 t->parms.link, iph->protocol);
534  		err = 0;
535  		goto out;
536  	}
537  	if (type == ICMP_REDIRECT) {
538  		ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
539  			      iph->protocol);
540  		err = 0;
541  		goto out;
542  	}
543  
544  	err = 0;
545  	if (__in6_dev_get(skb->dev) &&
546  	    !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
547  		goto out;
548  
549  	if (t->parms.iph.daddr == 0)
550  		goto out;
551  
552  	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
553  		goto out;
554  
555  	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
556  		t->err_count++;
557  	else
558  		t->err_count = 1;
559  	t->err_time = jiffies;
560  out:
561  	return err;
562  }
563  
564  static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
565  				  const struct in6_addr *v6addr)
566  {
567  	__be32 v4embed = 0;
568  	if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
569  		return true;
570  	return false;
571  }
572  
573  /* Checks if an address matches an address on the tunnel interface.
574   * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
575   * Long story:
576   * This function is called after we considered the packet as spoofed
577   * in is_spoofed_6rd.
578   * We may have a router that is doing NAT for proto 41 packets
579   * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
580   * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
581   * function will return true, dropping the packet.
582   * But, we can still check if is spoofed against the IP
583   * addresses associated with the interface.
584   */
585  static bool only_dnatted(const struct ip_tunnel *tunnel,
586  	const struct in6_addr *v6dst)
587  {
588  	int prefix_len;
589  
590  #ifdef CONFIG_IPV6_SIT_6RD
591  	prefix_len = tunnel->ip6rd.prefixlen + 32
592  		- tunnel->ip6rd.relay_prefixlen;
593  #else
594  	prefix_len = 48;
595  #endif
596  	return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
597  }
598  
599  /* Returns true if a packet is spoofed */
600  static bool packet_is_spoofed(struct sk_buff *skb,
601  			      const struct iphdr *iph,
602  			      struct ip_tunnel *tunnel)
603  {
604  	const struct ipv6hdr *ipv6h;
605  
606  	if (tunnel->dev->priv_flags & IFF_ISATAP) {
607  		if (!isatap_chksrc(skb, iph, tunnel))
608  			return true;
609  
610  		return false;
611  	}
612  
613  	if (tunnel->dev->flags & IFF_POINTOPOINT)
614  		return false;
615  
616  	ipv6h = ipv6_hdr(skb);
617  
618  	if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
619  		net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
620  				     &iph->saddr, &ipv6h->saddr,
621  				     &iph->daddr, &ipv6h->daddr);
622  		return true;
623  	}
624  
625  	if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
626  		return false;
627  
628  	if (only_dnatted(tunnel, &ipv6h->daddr))
629  		return false;
630  
631  	net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
632  			     &iph->saddr, &ipv6h->saddr,
633  			     &iph->daddr, &ipv6h->daddr);
634  	return true;
635  }
636  
637  static int ipip6_rcv(struct sk_buff *skb)
638  {
639  	const struct iphdr *iph = ip_hdr(skb);
640  	struct ip_tunnel *tunnel;
641  	int sifindex;
642  	int err;
643  
644  	sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
645  	tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
646  				     iph->saddr, iph->daddr, sifindex);
647  	if (tunnel) {
648  		struct pcpu_sw_netstats *tstats;
649  
650  		if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
651  		    tunnel->parms.iph.protocol != 0)
652  			goto out;
653  
654  		skb->mac_header = skb->network_header;
655  		skb_reset_network_header(skb);
656  		IPCB(skb)->flags = 0;
657  		skb->dev = tunnel->dev;
658  
659  		if (packet_is_spoofed(skb, iph, tunnel)) {
660  			tunnel->dev->stats.rx_errors++;
661  			goto out;
662  		}
663  
664  		if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
665  		    !net_eq(tunnel->net, dev_net(tunnel->dev))))
666  			goto out;
667  
668  		/* skb can be uncloned in iptunnel_pull_header, so
669  		 * old iph is no longer valid
670  		 */
671  		iph = (const struct iphdr *)skb_mac_header(skb);
672  		err = IP_ECN_decapsulate(iph, skb);
673  		if (unlikely(err)) {
674  			if (log_ecn_error)
675  				net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
676  						     &iph->saddr, iph->tos);
677  			if (err > 1) {
678  				++tunnel->dev->stats.rx_frame_errors;
679  				++tunnel->dev->stats.rx_errors;
680  				goto out;
681  			}
682  		}
683  
684  		tstats = this_cpu_ptr(tunnel->dev->tstats);
685  		u64_stats_update_begin(&tstats->syncp);
686  		tstats->rx_packets++;
687  		tstats->rx_bytes += skb->len;
688  		u64_stats_update_end(&tstats->syncp);
689  
690  		netif_rx(skb);
691  
692  		return 0;
693  	}
694  
695  	/* no tunnel matched,  let upstream know, ipsec may handle it */
696  	return 1;
697  out:
698  	kfree_skb(skb);
699  	return 0;
700  }
701  
702  static const struct tnl_ptk_info ipip_tpi = {
703  	/* no tunnel info required for ipip. */
704  	.proto = htons(ETH_P_IP),
705  };
706  
707  #if IS_ENABLED(CONFIG_MPLS)
708  static const struct tnl_ptk_info mplsip_tpi = {
709  	/* no tunnel info required for mplsip. */
710  	.proto = htons(ETH_P_MPLS_UC),
711  };
712  #endif
713  
714  static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
715  {
716  	const struct iphdr *iph;
717  	struct ip_tunnel *tunnel;
718  	int sifindex;
719  
720  	sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
721  
722  	iph = ip_hdr(skb);
723  	tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
724  				     iph->saddr, iph->daddr, sifindex);
725  	if (tunnel) {
726  		const struct tnl_ptk_info *tpi;
727  
728  		if (tunnel->parms.iph.protocol != ipproto &&
729  		    tunnel->parms.iph.protocol != 0)
730  			goto drop;
731  
732  		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
733  			goto drop;
734  #if IS_ENABLED(CONFIG_MPLS)
735  		if (ipproto == IPPROTO_MPLS)
736  			tpi = &mplsip_tpi;
737  		else
738  #endif
739  			tpi = &ipip_tpi;
740  		if (iptunnel_pull_header(skb, 0, tpi->proto, false))
741  			goto drop;
742  		return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
743  	}
744  
745  	return 1;
746  
747  drop:
748  	kfree_skb(skb);
749  	return 0;
750  }
751  
752  static int ipip_rcv(struct sk_buff *skb)
753  {
754  	return sit_tunnel_rcv(skb, IPPROTO_IPIP);
755  }
756  
757  #if IS_ENABLED(CONFIG_MPLS)
758  static int mplsip_rcv(struct sk_buff *skb)
759  {
760  	return sit_tunnel_rcv(skb, IPPROTO_MPLS);
761  }
762  #endif
763  
764  /*
765   * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
766   * stores the embedded IPv4 address in v4dst and returns true.
767   */
768  static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
769  		      __be32 *v4dst)
770  {
771  #ifdef CONFIG_IPV6_SIT_6RD
772  	if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
773  			      tunnel->ip6rd.prefixlen)) {
774  		unsigned int pbw0, pbi0;
775  		int pbi1;
776  		u32 d;
777  
778  		pbw0 = tunnel->ip6rd.prefixlen >> 5;
779  		pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
780  
781  		d = tunnel->ip6rd.relay_prefixlen < 32 ?
782  			(ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
783  		    tunnel->ip6rd.relay_prefixlen : 0;
784  
785  		pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
786  		if (pbi1 > 0)
787  			d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
788  			     (32 - pbi1);
789  
790  		*v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
791  		return true;
792  	}
793  #else
794  	if (v6dst->s6_addr16[0] == htons(0x2002)) {
795  		/* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
796  		memcpy(v4dst, &v6dst->s6_addr16[1], 4);
797  		return true;
798  	}
799  #endif
800  	return false;
801  }
802  
803  static inline __be32 try_6rd(struct ip_tunnel *tunnel,
804  			     const struct in6_addr *v6dst)
805  {
806  	__be32 dst = 0;
807  	check_6rd(tunnel, v6dst, &dst);
808  	return dst;
809  }
810  
811  /*
812   *	This function assumes it is being called from dev_queue_xmit()
813   *	and that skb is filled properly by that function.
814   */
815  
816  static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
817  				     struct net_device *dev)
818  {
819  	struct ip_tunnel *tunnel = netdev_priv(dev);
820  	const struct iphdr  *tiph = &tunnel->parms.iph;
821  	const struct ipv6hdr *iph6 = ipv6_hdr(skb);
822  	u8     tos = tunnel->parms.iph.tos;
823  	__be16 df = tiph->frag_off;
824  	struct rtable *rt;		/* Route to the other host */
825  	struct net_device *tdev;	/* Device to other host */
826  	unsigned int max_headroom;	/* The extra header space needed */
827  	__be32 dst = tiph->daddr;
828  	struct flowi4 fl4;
829  	int    mtu;
830  	const struct in6_addr *addr6;
831  	int addr_type;
832  	u8 ttl;
833  	u8 protocol = IPPROTO_IPV6;
834  	int t_hlen = tunnel->hlen + sizeof(struct iphdr);
835  
836  	if (tos == 1)
837  		tos = ipv6_get_dsfield(iph6);
838  
839  	/* ISATAP (RFC4214) - must come before 6to4 */
840  	if (dev->priv_flags & IFF_ISATAP) {
841  		struct neighbour *neigh = NULL;
842  		bool do_tx_error = false;
843  
844  		if (skb_dst(skb))
845  			neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
846  
847  		if (!neigh) {
848  			net_dbg_ratelimited("nexthop == NULL\n");
849  			goto tx_error;
850  		}
851  
852  		addr6 = (const struct in6_addr *)&neigh->primary_key;
853  		addr_type = ipv6_addr_type(addr6);
854  
855  		if ((addr_type & IPV6_ADDR_UNICAST) &&
856  		     ipv6_addr_is_isatap(addr6))
857  			dst = addr6->s6_addr32[3];
858  		else
859  			do_tx_error = true;
860  
861  		neigh_release(neigh);
862  		if (do_tx_error)
863  			goto tx_error;
864  	}
865  
866  	if (!dst)
867  		dst = try_6rd(tunnel, &iph6->daddr);
868  
869  	if (!dst) {
870  		struct neighbour *neigh = NULL;
871  		bool do_tx_error = false;
872  
873  		if (skb_dst(skb))
874  			neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
875  
876  		if (!neigh) {
877  			net_dbg_ratelimited("nexthop == NULL\n");
878  			goto tx_error;
879  		}
880  
881  		addr6 = (const struct in6_addr *)&neigh->primary_key;
882  		addr_type = ipv6_addr_type(addr6);
883  
884  		if (addr_type == IPV6_ADDR_ANY) {
885  			addr6 = &ipv6_hdr(skb)->daddr;
886  			addr_type = ipv6_addr_type(addr6);
887  		}
888  
889  		if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
890  			dst = addr6->s6_addr32[3];
891  		else
892  			do_tx_error = true;
893  
894  		neigh_release(neigh);
895  		if (do_tx_error)
896  			goto tx_error;
897  	}
898  
899  	flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
900  			   RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
901  			   0, dst, tiph->saddr, 0, 0,
902  			   sock_net_uid(tunnel->net, NULL));
903  
904  	rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
905  	if (!rt) {
906  		rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
907  		if (IS_ERR(rt)) {
908  			dev->stats.tx_carrier_errors++;
909  			goto tx_error_icmp;
910  		}
911  		dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
912  	}
913  
914  	if (rt->rt_type != RTN_UNICAST) {
915  		ip_rt_put(rt);
916  		dev->stats.tx_carrier_errors++;
917  		goto tx_error_icmp;
918  	}
919  	tdev = rt->dst.dev;
920  
921  	if (tdev == dev) {
922  		ip_rt_put(rt);
923  		dev->stats.collisions++;
924  		goto tx_error;
925  	}
926  
927  	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
928  		ip_rt_put(rt);
929  		goto tx_error;
930  	}
931  
932  	if (df) {
933  		mtu = dst_mtu(&rt->dst) - t_hlen;
934  
935  		if (mtu < 68) {
936  			dev->stats.collisions++;
937  			ip_rt_put(rt);
938  			goto tx_error;
939  		}
940  
941  		if (mtu < IPV6_MIN_MTU) {
942  			mtu = IPV6_MIN_MTU;
943  			df = 0;
944  		}
945  
946  		if (tunnel->parms.iph.daddr)
947  			skb_dst_update_pmtu(skb, mtu);
948  
949  		if (skb->len > mtu && !skb_is_gso(skb)) {
950  			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
951  			ip_rt_put(rt);
952  			goto tx_error;
953  		}
954  	}
955  
956  	if (tunnel->err_count > 0) {
957  		if (time_before(jiffies,
958  				tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
959  			tunnel->err_count--;
960  			dst_link_failure(skb);
961  		} else
962  			tunnel->err_count = 0;
963  	}
964  
965  	/*
966  	 * Okay, now see if we can stuff it in the buffer as-is.
967  	 */
968  	max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
969  
970  	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
971  	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
972  		struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
973  		if (!new_skb) {
974  			ip_rt_put(rt);
975  			dev->stats.tx_dropped++;
976  			kfree_skb(skb);
977  			return NETDEV_TX_OK;
978  		}
979  		if (skb->sk)
980  			skb_set_owner_w(new_skb, skb->sk);
981  		dev_kfree_skb(skb);
982  		skb = new_skb;
983  		iph6 = ipv6_hdr(skb);
984  	}
985  	ttl = tiph->ttl;
986  	if (ttl == 0)
987  		ttl = iph6->hop_limit;
988  	tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
989  
990  	if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
991  		ip_rt_put(rt);
992  		goto tx_error;
993  	}
994  
995  	skb_set_inner_ipproto(skb, IPPROTO_IPV6);
996  
997  	iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
998  		      df, !net_eq(tunnel->net, dev_net(dev)));
999  	return NETDEV_TX_OK;
1000  
1001  tx_error_icmp:
1002  	dst_link_failure(skb);
1003  tx_error:
1004  	kfree_skb(skb);
1005  	dev->stats.tx_errors++;
1006  	return NETDEV_TX_OK;
1007  }
1008  
1009  static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1010  				     struct net_device *dev, u8 ipproto)
1011  {
1012  	struct ip_tunnel *tunnel = netdev_priv(dev);
1013  	const struct iphdr  *tiph = &tunnel->parms.iph;
1014  
1015  	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1016  		goto tx_error;
1017  
1018  	skb_set_inner_ipproto(skb, ipproto);
1019  
1020  	ip_tunnel_xmit(skb, dev, tiph, ipproto);
1021  	return NETDEV_TX_OK;
1022  tx_error:
1023  	kfree_skb(skb);
1024  	dev->stats.tx_errors++;
1025  	return NETDEV_TX_OK;
1026  }
1027  
1028  static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1029  				   struct net_device *dev)
1030  {
1031  	if (!pskb_inet_may_pull(skb))
1032  		goto tx_err;
1033  
1034  	switch (skb->protocol) {
1035  	case htons(ETH_P_IP):
1036  		sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1037  		break;
1038  	case htons(ETH_P_IPV6):
1039  		ipip6_tunnel_xmit(skb, dev);
1040  		break;
1041  #if IS_ENABLED(CONFIG_MPLS)
1042  	case htons(ETH_P_MPLS_UC):
1043  		sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1044  		break;
1045  #endif
1046  	default:
1047  		goto tx_err;
1048  	}
1049  
1050  	return NETDEV_TX_OK;
1051  
1052  tx_err:
1053  	dev->stats.tx_errors++;
1054  	kfree_skb(skb);
1055  	return NETDEV_TX_OK;
1056  
1057  }
1058  
1059  static void ipip6_tunnel_bind_dev(struct net_device *dev)
1060  {
1061  	struct net_device *tdev = NULL;
1062  	struct ip_tunnel *tunnel;
1063  	const struct iphdr *iph;
1064  	struct flowi4 fl4;
1065  
1066  	tunnel = netdev_priv(dev);
1067  	iph = &tunnel->parms.iph;
1068  
1069  	if (iph->daddr) {
1070  		struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1071  							  NULL,
1072  							  iph->daddr, iph->saddr,
1073  							  0, 0,
1074  							  IPPROTO_IPV6,
1075  							  RT_TOS(iph->tos),
1076  							  tunnel->parms.link);
1077  
1078  		if (!IS_ERR(rt)) {
1079  			tdev = rt->dst.dev;
1080  			ip_rt_put(rt);
1081  		}
1082  		dev->flags |= IFF_POINTOPOINT;
1083  	}
1084  
1085  	if (!tdev && tunnel->parms.link)
1086  		tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1087  
1088  	if (tdev && !netif_is_l3_master(tdev)) {
1089  		int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1090  
1091  		dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1092  		dev->mtu = tdev->mtu - t_hlen;
1093  		if (dev->mtu < IPV6_MIN_MTU)
1094  			dev->mtu = IPV6_MIN_MTU;
1095  	}
1096  }
1097  
1098  static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1099  				__u32 fwmark)
1100  {
1101  	struct net *net = t->net;
1102  	struct sit_net *sitn = net_generic(net, sit_net_id);
1103  
1104  	ipip6_tunnel_unlink(sitn, t);
1105  	synchronize_net();
1106  	t->parms.iph.saddr = p->iph.saddr;
1107  	t->parms.iph.daddr = p->iph.daddr;
1108  	memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1109  	memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1110  	ipip6_tunnel_link(sitn, t);
1111  	t->parms.iph.ttl = p->iph.ttl;
1112  	t->parms.iph.tos = p->iph.tos;
1113  	t->parms.iph.frag_off = p->iph.frag_off;
1114  	if (t->parms.link != p->link || t->fwmark != fwmark) {
1115  		t->parms.link = p->link;
1116  		t->fwmark = fwmark;
1117  		ipip6_tunnel_bind_dev(t->dev);
1118  	}
1119  	dst_cache_reset(&t->dst_cache);
1120  	netdev_state_change(t->dev);
1121  }
1122  
1123  #ifdef CONFIG_IPV6_SIT_6RD
1124  static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1125  				   struct ip_tunnel_6rd *ip6rd)
1126  {
1127  	struct in6_addr prefix;
1128  	__be32 relay_prefix;
1129  
1130  	if (ip6rd->relay_prefixlen > 32 ||
1131  	    ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1132  		return -EINVAL;
1133  
1134  	ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1135  	if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1136  		return -EINVAL;
1137  	if (ip6rd->relay_prefixlen)
1138  		relay_prefix = ip6rd->relay_prefix &
1139  			       htonl(0xffffffffUL <<
1140  				     (32 - ip6rd->relay_prefixlen));
1141  	else
1142  		relay_prefix = 0;
1143  	if (relay_prefix != ip6rd->relay_prefix)
1144  		return -EINVAL;
1145  
1146  	t->ip6rd.prefix = prefix;
1147  	t->ip6rd.relay_prefix = relay_prefix;
1148  	t->ip6rd.prefixlen = ip6rd->prefixlen;
1149  	t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1150  	dst_cache_reset(&t->dst_cache);
1151  	netdev_state_change(t->dev);
1152  	return 0;
1153  }
1154  #endif
1155  
1156  static bool ipip6_valid_ip_proto(u8 ipproto)
1157  {
1158  	return ipproto == IPPROTO_IPV6 ||
1159  		ipproto == IPPROTO_IPIP ||
1160  #if IS_ENABLED(CONFIG_MPLS)
1161  		ipproto == IPPROTO_MPLS ||
1162  #endif
1163  		ipproto == 0;
1164  }
1165  
1166  static int
1167  ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1168  {
1169  	int err = 0;
1170  	struct ip_tunnel_parm p;
1171  	struct ip_tunnel_prl prl;
1172  	struct ip_tunnel *t = netdev_priv(dev);
1173  	struct net *net = t->net;
1174  	struct sit_net *sitn = net_generic(net, sit_net_id);
1175  #ifdef CONFIG_IPV6_SIT_6RD
1176  	struct ip_tunnel_6rd ip6rd;
1177  #endif
1178  
1179  	switch (cmd) {
1180  	case SIOCGETTUNNEL:
1181  #ifdef CONFIG_IPV6_SIT_6RD
1182  	case SIOCGET6RD:
1183  #endif
1184  		if (dev == sitn->fb_tunnel_dev) {
1185  			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1186  				err = -EFAULT;
1187  				break;
1188  			}
1189  			t = ipip6_tunnel_locate(net, &p, 0);
1190  			if (!t)
1191  				t = netdev_priv(dev);
1192  		}
1193  
1194  		err = -EFAULT;
1195  		if (cmd == SIOCGETTUNNEL) {
1196  			memcpy(&p, &t->parms, sizeof(p));
1197  			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1198  					 sizeof(p)))
1199  				goto done;
1200  #ifdef CONFIG_IPV6_SIT_6RD
1201  		} else {
1202  			ip6rd.prefix = t->ip6rd.prefix;
1203  			ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1204  			ip6rd.prefixlen = t->ip6rd.prefixlen;
1205  			ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1206  			if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1207  					 sizeof(ip6rd)))
1208  				goto done;
1209  #endif
1210  		}
1211  		err = 0;
1212  		break;
1213  
1214  	case SIOCADDTUNNEL:
1215  	case SIOCCHGTUNNEL:
1216  		err = -EPERM;
1217  		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1218  			goto done;
1219  
1220  		err = -EFAULT;
1221  		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1222  			goto done;
1223  
1224  		err = -EINVAL;
1225  		if (!ipip6_valid_ip_proto(p.iph.protocol))
1226  			goto done;
1227  		if (p.iph.version != 4 ||
1228  		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1229  			goto done;
1230  		if (p.iph.ttl)
1231  			p.iph.frag_off |= htons(IP_DF);
1232  
1233  		t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1234  
1235  		if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1236  			if (t) {
1237  				if (t->dev != dev) {
1238  					err = -EEXIST;
1239  					break;
1240  				}
1241  			} else {
1242  				if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1243  				    (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1244  					err = -EINVAL;
1245  					break;
1246  				}
1247  				t = netdev_priv(dev);
1248  			}
1249  
1250  			ipip6_tunnel_update(t, &p, t->fwmark);
1251  		}
1252  
1253  		if (t) {
1254  			err = 0;
1255  			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1256  				err = -EFAULT;
1257  		} else
1258  			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1259  		break;
1260  
1261  	case SIOCDELTUNNEL:
1262  		err = -EPERM;
1263  		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1264  			goto done;
1265  
1266  		if (dev == sitn->fb_tunnel_dev) {
1267  			err = -EFAULT;
1268  			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1269  				goto done;
1270  			err = -ENOENT;
1271  			t = ipip6_tunnel_locate(net, &p, 0);
1272  			if (!t)
1273  				goto done;
1274  			err = -EPERM;
1275  			if (t == netdev_priv(sitn->fb_tunnel_dev))
1276  				goto done;
1277  			dev = t->dev;
1278  		}
1279  		unregister_netdevice(dev);
1280  		err = 0;
1281  		break;
1282  
1283  	case SIOCGETPRL:
1284  		err = -EINVAL;
1285  		if (dev == sitn->fb_tunnel_dev)
1286  			goto done;
1287  		err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1288  		break;
1289  
1290  	case SIOCADDPRL:
1291  	case SIOCDELPRL:
1292  	case SIOCCHGPRL:
1293  		err = -EPERM;
1294  		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1295  			goto done;
1296  		err = -EINVAL;
1297  		if (dev == sitn->fb_tunnel_dev)
1298  			goto done;
1299  		err = -EFAULT;
1300  		if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1301  			goto done;
1302  
1303  		switch (cmd) {
1304  		case SIOCDELPRL:
1305  			err = ipip6_tunnel_del_prl(t, &prl);
1306  			break;
1307  		case SIOCADDPRL:
1308  		case SIOCCHGPRL:
1309  			err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1310  			break;
1311  		}
1312  		dst_cache_reset(&t->dst_cache);
1313  		netdev_state_change(dev);
1314  		break;
1315  
1316  #ifdef CONFIG_IPV6_SIT_6RD
1317  	case SIOCADD6RD:
1318  	case SIOCCHG6RD:
1319  	case SIOCDEL6RD:
1320  		err = -EPERM;
1321  		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1322  			goto done;
1323  
1324  		err = -EFAULT;
1325  		if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1326  				   sizeof(ip6rd)))
1327  			goto done;
1328  
1329  		if (cmd != SIOCDEL6RD) {
1330  			err = ipip6_tunnel_update_6rd(t, &ip6rd);
1331  			if (err < 0)
1332  				goto done;
1333  		} else
1334  			ipip6_tunnel_clone_6rd(dev, sitn);
1335  
1336  		err = 0;
1337  		break;
1338  #endif
1339  
1340  	default:
1341  		err = -EINVAL;
1342  	}
1343  
1344  done:
1345  	return err;
1346  }
1347  
1348  static const struct net_device_ops ipip6_netdev_ops = {
1349  	.ndo_init	= ipip6_tunnel_init,
1350  	.ndo_uninit	= ipip6_tunnel_uninit,
1351  	.ndo_start_xmit	= sit_tunnel_xmit,
1352  	.ndo_do_ioctl	= ipip6_tunnel_ioctl,
1353  	.ndo_get_stats64 = ip_tunnel_get_stats64,
1354  	.ndo_get_iflink = ip_tunnel_get_iflink,
1355  };
1356  
1357  static void ipip6_dev_free(struct net_device *dev)
1358  {
1359  	struct ip_tunnel *tunnel = netdev_priv(dev);
1360  
1361  	dst_cache_destroy(&tunnel->dst_cache);
1362  	free_percpu(dev->tstats);
1363  }
1364  
1365  #define SIT_FEATURES (NETIF_F_SG	   | \
1366  		      NETIF_F_FRAGLIST	   | \
1367  		      NETIF_F_HIGHDMA	   | \
1368  		      NETIF_F_GSO_SOFTWARE | \
1369  		      NETIF_F_HW_CSUM)
1370  
1371  static void ipip6_tunnel_setup(struct net_device *dev)
1372  {
1373  	struct ip_tunnel *tunnel = netdev_priv(dev);
1374  	int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1375  
1376  	dev->netdev_ops		= &ipip6_netdev_ops;
1377  	dev->needs_free_netdev	= true;
1378  	dev->priv_destructor	= ipip6_dev_free;
1379  
1380  	dev->type		= ARPHRD_SIT;
1381  	dev->hard_header_len	= LL_MAX_HEADER + t_hlen;
1382  	dev->mtu		= ETH_DATA_LEN - t_hlen;
1383  	dev->min_mtu		= IPV6_MIN_MTU;
1384  	dev->max_mtu		= IP6_MAX_MTU - t_hlen;
1385  	dev->flags		= IFF_NOARP;
1386  	netif_keep_dst(dev);
1387  	dev->addr_len		= 4;
1388  	dev->features		|= NETIF_F_LLTX;
1389  	dev->features		|= SIT_FEATURES;
1390  	dev->hw_features	|= SIT_FEATURES;
1391  }
1392  
1393  static int ipip6_tunnel_init(struct net_device *dev)
1394  {
1395  	struct ip_tunnel *tunnel = netdev_priv(dev);
1396  	int err;
1397  
1398  	tunnel->dev = dev;
1399  	tunnel->net = dev_net(dev);
1400  	strcpy(tunnel->parms.name, dev->name);
1401  
1402  	ipip6_tunnel_bind_dev(dev);
1403  	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1404  	if (!dev->tstats)
1405  		return -ENOMEM;
1406  
1407  	err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1408  	if (err) {
1409  		free_percpu(dev->tstats);
1410  		dev->tstats = NULL;
1411  		return err;
1412  	}
1413  
1414  	return 0;
1415  }
1416  
1417  static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1418  {
1419  	struct ip_tunnel *tunnel = netdev_priv(dev);
1420  	struct iphdr *iph = &tunnel->parms.iph;
1421  	struct net *net = dev_net(dev);
1422  	struct sit_net *sitn = net_generic(net, sit_net_id);
1423  
1424  	iph->version		= 4;
1425  	iph->protocol		= IPPROTO_IPV6;
1426  	iph->ihl		= 5;
1427  	iph->ttl		= 64;
1428  
1429  	dev_hold(dev);
1430  	rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1431  }
1432  
1433  static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1434  			  struct netlink_ext_ack *extack)
1435  {
1436  	u8 proto;
1437  
1438  	if (!data || !data[IFLA_IPTUN_PROTO])
1439  		return 0;
1440  
1441  	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1442  	if (!ipip6_valid_ip_proto(proto))
1443  		return -EINVAL;
1444  
1445  	return 0;
1446  }
1447  
1448  static void ipip6_netlink_parms(struct nlattr *data[],
1449  				struct ip_tunnel_parm *parms,
1450  				__u32 *fwmark)
1451  {
1452  	memset(parms, 0, sizeof(*parms));
1453  
1454  	parms->iph.version = 4;
1455  	parms->iph.protocol = IPPROTO_IPV6;
1456  	parms->iph.ihl = 5;
1457  	parms->iph.ttl = 64;
1458  
1459  	if (!data)
1460  		return;
1461  
1462  	if (data[IFLA_IPTUN_LINK])
1463  		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1464  
1465  	if (data[IFLA_IPTUN_LOCAL])
1466  		parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1467  
1468  	if (data[IFLA_IPTUN_REMOTE])
1469  		parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1470  
1471  	if (data[IFLA_IPTUN_TTL]) {
1472  		parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1473  		if (parms->iph.ttl)
1474  			parms->iph.frag_off = htons(IP_DF);
1475  	}
1476  
1477  	if (data[IFLA_IPTUN_TOS])
1478  		parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1479  
1480  	if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1481  		parms->iph.frag_off = htons(IP_DF);
1482  
1483  	if (data[IFLA_IPTUN_FLAGS])
1484  		parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1485  
1486  	if (data[IFLA_IPTUN_PROTO])
1487  		parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1488  
1489  	if (data[IFLA_IPTUN_FWMARK])
1490  		*fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1491  }
1492  
1493  /* This function returns true when ENCAP attributes are present in the nl msg */
1494  static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1495  				      struct ip_tunnel_encap *ipencap)
1496  {
1497  	bool ret = false;
1498  
1499  	memset(ipencap, 0, sizeof(*ipencap));
1500  
1501  	if (!data)
1502  		return ret;
1503  
1504  	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1505  		ret = true;
1506  		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1507  	}
1508  
1509  	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1510  		ret = true;
1511  		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1512  	}
1513  
1514  	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1515  		ret = true;
1516  		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1517  	}
1518  
1519  	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1520  		ret = true;
1521  		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1522  	}
1523  
1524  	return ret;
1525  }
1526  
1527  #ifdef CONFIG_IPV6_SIT_6RD
1528  /* This function returns true when 6RD attributes are present in the nl msg */
1529  static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1530  				    struct ip_tunnel_6rd *ip6rd)
1531  {
1532  	bool ret = false;
1533  	memset(ip6rd, 0, sizeof(*ip6rd));
1534  
1535  	if (!data)
1536  		return ret;
1537  
1538  	if (data[IFLA_IPTUN_6RD_PREFIX]) {
1539  		ret = true;
1540  		ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1541  	}
1542  
1543  	if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1544  		ret = true;
1545  		ip6rd->relay_prefix =
1546  			nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1547  	}
1548  
1549  	if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1550  		ret = true;
1551  		ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1552  	}
1553  
1554  	if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1555  		ret = true;
1556  		ip6rd->relay_prefixlen =
1557  			nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1558  	}
1559  
1560  	return ret;
1561  }
1562  #endif
1563  
1564  static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1565  			 struct nlattr *tb[], struct nlattr *data[],
1566  			 struct netlink_ext_ack *extack)
1567  {
1568  	struct net *net = dev_net(dev);
1569  	struct ip_tunnel *nt;
1570  	struct ip_tunnel_encap ipencap;
1571  #ifdef CONFIG_IPV6_SIT_6RD
1572  	struct ip_tunnel_6rd ip6rd;
1573  #endif
1574  	int err;
1575  
1576  	nt = netdev_priv(dev);
1577  
1578  	if (ipip6_netlink_encap_parms(data, &ipencap)) {
1579  		err = ip_tunnel_encap_setup(nt, &ipencap);
1580  		if (err < 0)
1581  			return err;
1582  	}
1583  
1584  	ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1585  
1586  	if (ipip6_tunnel_locate(net, &nt->parms, 0))
1587  		return -EEXIST;
1588  
1589  	err = ipip6_tunnel_create(dev);
1590  	if (err < 0)
1591  		return err;
1592  
1593  	if (tb[IFLA_MTU]) {
1594  		u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1595  
1596  		if (mtu >= IPV6_MIN_MTU &&
1597  		    mtu <= IP6_MAX_MTU - dev->hard_header_len)
1598  			dev->mtu = mtu;
1599  	}
1600  
1601  #ifdef CONFIG_IPV6_SIT_6RD
1602  	if (ipip6_netlink_6rd_parms(data, &ip6rd))
1603  		err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1604  #endif
1605  
1606  	return err;
1607  }
1608  
1609  static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1610  			    struct nlattr *data[],
1611  			    struct netlink_ext_ack *extack)
1612  {
1613  	struct ip_tunnel *t = netdev_priv(dev);
1614  	struct ip_tunnel_parm p;
1615  	struct ip_tunnel_encap ipencap;
1616  	struct net *net = t->net;
1617  	struct sit_net *sitn = net_generic(net, sit_net_id);
1618  #ifdef CONFIG_IPV6_SIT_6RD
1619  	struct ip_tunnel_6rd ip6rd;
1620  #endif
1621  	__u32 fwmark = t->fwmark;
1622  	int err;
1623  
1624  	if (dev == sitn->fb_tunnel_dev)
1625  		return -EINVAL;
1626  
1627  	if (ipip6_netlink_encap_parms(data, &ipencap)) {
1628  		err = ip_tunnel_encap_setup(t, &ipencap);
1629  		if (err < 0)
1630  			return err;
1631  	}
1632  
1633  	ipip6_netlink_parms(data, &p, &fwmark);
1634  
1635  	if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1636  	    (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1637  		return -EINVAL;
1638  
1639  	t = ipip6_tunnel_locate(net, &p, 0);
1640  
1641  	if (t) {
1642  		if (t->dev != dev)
1643  			return -EEXIST;
1644  	} else
1645  		t = netdev_priv(dev);
1646  
1647  	ipip6_tunnel_update(t, &p, fwmark);
1648  
1649  #ifdef CONFIG_IPV6_SIT_6RD
1650  	if (ipip6_netlink_6rd_parms(data, &ip6rd))
1651  		return ipip6_tunnel_update_6rd(t, &ip6rd);
1652  #endif
1653  
1654  	return 0;
1655  }
1656  
1657  static size_t ipip6_get_size(const struct net_device *dev)
1658  {
1659  	return
1660  		/* IFLA_IPTUN_LINK */
1661  		nla_total_size(4) +
1662  		/* IFLA_IPTUN_LOCAL */
1663  		nla_total_size(4) +
1664  		/* IFLA_IPTUN_REMOTE */
1665  		nla_total_size(4) +
1666  		/* IFLA_IPTUN_TTL */
1667  		nla_total_size(1) +
1668  		/* IFLA_IPTUN_TOS */
1669  		nla_total_size(1) +
1670  		/* IFLA_IPTUN_PMTUDISC */
1671  		nla_total_size(1) +
1672  		/* IFLA_IPTUN_FLAGS */
1673  		nla_total_size(2) +
1674  		/* IFLA_IPTUN_PROTO */
1675  		nla_total_size(1) +
1676  #ifdef CONFIG_IPV6_SIT_6RD
1677  		/* IFLA_IPTUN_6RD_PREFIX */
1678  		nla_total_size(sizeof(struct in6_addr)) +
1679  		/* IFLA_IPTUN_6RD_RELAY_PREFIX */
1680  		nla_total_size(4) +
1681  		/* IFLA_IPTUN_6RD_PREFIXLEN */
1682  		nla_total_size(2) +
1683  		/* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1684  		nla_total_size(2) +
1685  #endif
1686  		/* IFLA_IPTUN_ENCAP_TYPE */
1687  		nla_total_size(2) +
1688  		/* IFLA_IPTUN_ENCAP_FLAGS */
1689  		nla_total_size(2) +
1690  		/* IFLA_IPTUN_ENCAP_SPORT */
1691  		nla_total_size(2) +
1692  		/* IFLA_IPTUN_ENCAP_DPORT */
1693  		nla_total_size(2) +
1694  		/* IFLA_IPTUN_FWMARK */
1695  		nla_total_size(4) +
1696  		0;
1697  }
1698  
1699  static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1700  {
1701  	struct ip_tunnel *tunnel = netdev_priv(dev);
1702  	struct ip_tunnel_parm *parm = &tunnel->parms;
1703  
1704  	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1705  	    nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1706  	    nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1707  	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1708  	    nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1709  	    nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1710  		       !!(parm->iph.frag_off & htons(IP_DF))) ||
1711  	    nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1712  	    nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1713  	    nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1714  		goto nla_put_failure;
1715  
1716  #ifdef CONFIG_IPV6_SIT_6RD
1717  	if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1718  			     &tunnel->ip6rd.prefix) ||
1719  	    nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1720  			    tunnel->ip6rd.relay_prefix) ||
1721  	    nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1722  			tunnel->ip6rd.prefixlen) ||
1723  	    nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1724  			tunnel->ip6rd.relay_prefixlen))
1725  		goto nla_put_failure;
1726  #endif
1727  
1728  	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1729  			tunnel->encap.type) ||
1730  	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1731  			tunnel->encap.sport) ||
1732  	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1733  			tunnel->encap.dport) ||
1734  	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1735  			tunnel->encap.flags))
1736  		goto nla_put_failure;
1737  
1738  	return 0;
1739  
1740  nla_put_failure:
1741  	return -EMSGSIZE;
1742  }
1743  
1744  static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1745  	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
1746  	[IFLA_IPTUN_LOCAL]		= { .type = NLA_U32 },
1747  	[IFLA_IPTUN_REMOTE]		= { .type = NLA_U32 },
1748  	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
1749  	[IFLA_IPTUN_TOS]		= { .type = NLA_U8 },
1750  	[IFLA_IPTUN_PMTUDISC]		= { .type = NLA_U8 },
1751  	[IFLA_IPTUN_FLAGS]		= { .type = NLA_U16 },
1752  	[IFLA_IPTUN_PROTO]		= { .type = NLA_U8 },
1753  #ifdef CONFIG_IPV6_SIT_6RD
1754  	[IFLA_IPTUN_6RD_PREFIX]		= { .len = sizeof(struct in6_addr) },
1755  	[IFLA_IPTUN_6RD_RELAY_PREFIX]	= { .type = NLA_U32 },
1756  	[IFLA_IPTUN_6RD_PREFIXLEN]	= { .type = NLA_U16 },
1757  	[IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1758  #endif
1759  	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
1760  	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
1761  	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
1762  	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
1763  	[IFLA_IPTUN_FWMARK]		= { .type = NLA_U32 },
1764  };
1765  
1766  static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1767  {
1768  	struct net *net = dev_net(dev);
1769  	struct sit_net *sitn = net_generic(net, sit_net_id);
1770  
1771  	if (dev != sitn->fb_tunnel_dev)
1772  		unregister_netdevice_queue(dev, head);
1773  }
1774  
1775  static struct rtnl_link_ops sit_link_ops __read_mostly = {
1776  	.kind		= "sit",
1777  	.maxtype	= IFLA_IPTUN_MAX,
1778  	.policy		= ipip6_policy,
1779  	.priv_size	= sizeof(struct ip_tunnel),
1780  	.setup		= ipip6_tunnel_setup,
1781  	.validate	= ipip6_validate,
1782  	.newlink	= ipip6_newlink,
1783  	.changelink	= ipip6_changelink,
1784  	.get_size	= ipip6_get_size,
1785  	.fill_info	= ipip6_fill_info,
1786  	.dellink	= ipip6_dellink,
1787  	.get_link_net	= ip_tunnel_get_link_net,
1788  };
1789  
1790  static struct xfrm_tunnel sit_handler __read_mostly = {
1791  	.handler	=	ipip6_rcv,
1792  	.err_handler	=	ipip6_err,
1793  	.priority	=	1,
1794  };
1795  
1796  static struct xfrm_tunnel ipip_handler __read_mostly = {
1797  	.handler	=	ipip_rcv,
1798  	.err_handler	=	ipip6_err,
1799  	.priority	=	2,
1800  };
1801  
1802  #if IS_ENABLED(CONFIG_MPLS)
1803  static struct xfrm_tunnel mplsip_handler __read_mostly = {
1804  	.handler	=	mplsip_rcv,
1805  	.err_handler	=	ipip6_err,
1806  	.priority	=	2,
1807  };
1808  #endif
1809  
1810  static void __net_exit sit_destroy_tunnels(struct net *net,
1811  					   struct list_head *head)
1812  {
1813  	struct sit_net *sitn = net_generic(net, sit_net_id);
1814  	struct net_device *dev, *aux;
1815  	int prio;
1816  
1817  	for_each_netdev_safe(net, dev, aux)
1818  		if (dev->rtnl_link_ops == &sit_link_ops)
1819  			unregister_netdevice_queue(dev, head);
1820  
1821  	for (prio = 1; prio < 4; prio++) {
1822  		int h;
1823  		for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1824  			struct ip_tunnel *t;
1825  
1826  			t = rtnl_dereference(sitn->tunnels[prio][h]);
1827  			while (t) {
1828  				/* If dev is in the same netns, it has already
1829  				 * been added to the list by the previous loop.
1830  				 */
1831  				if (!net_eq(dev_net(t->dev), net))
1832  					unregister_netdevice_queue(t->dev,
1833  								   head);
1834  				t = rtnl_dereference(t->next);
1835  			}
1836  		}
1837  	}
1838  }
1839  
1840  static int __net_init sit_init_net(struct net *net)
1841  {
1842  	struct sit_net *sitn = net_generic(net, sit_net_id);
1843  	struct ip_tunnel *t;
1844  	int err;
1845  
1846  	sitn->tunnels[0] = sitn->tunnels_wc;
1847  	sitn->tunnels[1] = sitn->tunnels_l;
1848  	sitn->tunnels[2] = sitn->tunnels_r;
1849  	sitn->tunnels[3] = sitn->tunnels_r_l;
1850  
1851  	if (!net_has_fallback_tunnels(net))
1852  		return 0;
1853  
1854  	sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1855  					   NET_NAME_UNKNOWN,
1856  					   ipip6_tunnel_setup);
1857  	if (!sitn->fb_tunnel_dev) {
1858  		err = -ENOMEM;
1859  		goto err_alloc_dev;
1860  	}
1861  	dev_net_set(sitn->fb_tunnel_dev, net);
1862  	sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1863  	/* FB netdevice is special: we have one, and only one per netns.
1864  	 * Allowing to move it to another netns is clearly unsafe.
1865  	 */
1866  	sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1867  
1868  	err = register_netdev(sitn->fb_tunnel_dev);
1869  	if (err)
1870  		goto err_reg_dev;
1871  
1872  	ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1873  	ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1874  
1875  	t = netdev_priv(sitn->fb_tunnel_dev);
1876  
1877  	strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1878  	return 0;
1879  
1880  err_reg_dev:
1881  	ipip6_dev_free(sitn->fb_tunnel_dev);
1882  	free_netdev(sitn->fb_tunnel_dev);
1883  err_alloc_dev:
1884  	return err;
1885  }
1886  
1887  static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1888  {
1889  	LIST_HEAD(list);
1890  	struct net *net;
1891  
1892  	rtnl_lock();
1893  	list_for_each_entry(net, net_list, exit_list)
1894  		sit_destroy_tunnels(net, &list);
1895  
1896  	unregister_netdevice_many(&list);
1897  	rtnl_unlock();
1898  }
1899  
1900  static struct pernet_operations sit_net_ops = {
1901  	.init = sit_init_net,
1902  	.exit_batch = sit_exit_batch_net,
1903  	.id   = &sit_net_id,
1904  	.size = sizeof(struct sit_net),
1905  };
1906  
1907  static void __exit sit_cleanup(void)
1908  {
1909  	rtnl_link_unregister(&sit_link_ops);
1910  	xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1911  	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1912  #if IS_ENABLED(CONFIG_MPLS)
1913  	xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1914  #endif
1915  
1916  	unregister_pernet_device(&sit_net_ops);
1917  	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1918  }
1919  
1920  static int __init sit_init(void)
1921  {
1922  	int err;
1923  
1924  	pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1925  
1926  	err = register_pernet_device(&sit_net_ops);
1927  	if (err < 0)
1928  		return err;
1929  	err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1930  	if (err < 0) {
1931  		pr_info("%s: can't register ip6ip4\n", __func__);
1932  		goto xfrm_tunnel_failed;
1933  	}
1934  	err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1935  	if (err < 0) {
1936  		pr_info("%s: can't register ip4ip4\n", __func__);
1937  		goto xfrm_tunnel4_failed;
1938  	}
1939  #if IS_ENABLED(CONFIG_MPLS)
1940  	err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1941  	if (err < 0) {
1942  		pr_info("%s: can't register mplsip\n", __func__);
1943  		goto xfrm_tunnel_mpls_failed;
1944  	}
1945  #endif
1946  	err = rtnl_link_register(&sit_link_ops);
1947  	if (err < 0)
1948  		goto rtnl_link_failed;
1949  
1950  out:
1951  	return err;
1952  
1953  rtnl_link_failed:
1954  #if IS_ENABLED(CONFIG_MPLS)
1955  	xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1956  xfrm_tunnel_mpls_failed:
1957  #endif
1958  	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1959  xfrm_tunnel4_failed:
1960  	xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1961  xfrm_tunnel_failed:
1962  	unregister_pernet_device(&sit_net_ops);
1963  	goto out;
1964  }
1965  
1966  module_init(sit_init);
1967  module_exit(sit_cleanup);
1968  MODULE_LICENSE("GPL");
1969  MODULE_ALIAS_RTNL_LINK("sit");
1970  MODULE_ALIAS_NETDEV("sit0");
1971