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TOMOYO Linux Cross Reference
Linux/net/ipv6/ip6_vti.c

Version: ~ [ linux-6.1-rc7 ] ~ [ linux-6.0.10 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.80 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.156 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.225 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.267 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.300 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.334 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
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  1 /*
  2  *      IPv6 virtual tunneling interface
  3  *
  4  *      Copyright (C) 2013 secunet Security Networks AG
  5  *
  6  *      Author:
  7  *      Steffen Klassert <steffen.klassert@secunet.com>
  8  *
  9  *      Based on:
 10  *      net/ipv6/ip6_tunnel.c
 11  *
 12  *      This program is free software; you can redistribute it and/or
 13  *      modify it under the terms of the GNU General Public License
 14  *      as published by the Free Software Foundation; either version
 15  *      2 of the License, or (at your option) any later version.
 16  */
 17 
 18 #include <linux/module.h>
 19 #include <linux/capability.h>
 20 #include <linux/errno.h>
 21 #include <linux/types.h>
 22 #include <linux/sockios.h>
 23 #include <linux/icmp.h>
 24 #include <linux/if.h>
 25 #include <linux/in.h>
 26 #include <linux/ip.h>
 27 #include <linux/net.h>
 28 #include <linux/in6.h>
 29 #include <linux/netdevice.h>
 30 #include <linux/if_arp.h>
 31 #include <linux/icmpv6.h>
 32 #include <linux/init.h>
 33 #include <linux/route.h>
 34 #include <linux/rtnetlink.h>
 35 #include <linux/netfilter_ipv6.h>
 36 #include <linux/slab.h>
 37 #include <linux/hash.h>
 38 
 39 #include <linux/uaccess.h>
 40 #include <linux/atomic.h>
 41 
 42 #include <net/icmp.h>
 43 #include <net/ip.h>
 44 #include <net/ip_tunnels.h>
 45 #include <net/ipv6.h>
 46 #include <net/ip6_route.h>
 47 #include <net/addrconf.h>
 48 #include <net/ip6_tunnel.h>
 49 #include <net/xfrm.h>
 50 #include <net/net_namespace.h>
 51 #include <net/netns/generic.h>
 52 
 53 #define HASH_SIZE_SHIFT  5
 54 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
 55 
 56 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
 57 {
 58         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
 59 
 60         return hash_32(hash, HASH_SIZE_SHIFT);
 61 }
 62 
 63 static int vti6_dev_init(struct net_device *dev);
 64 static void vti6_dev_setup(struct net_device *dev);
 65 static struct rtnl_link_ops vti6_link_ops __read_mostly;
 66 
 67 static int vti6_net_id __read_mostly;
 68 struct vti6_net {
 69         /* the vti6 tunnel fallback device */
 70         struct net_device *fb_tnl_dev;
 71         /* lists for storing tunnels in use */
 72         struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
 73         struct ip6_tnl __rcu *tnls_wc[1];
 74         struct ip6_tnl __rcu **tnls[2];
 75 };
 76 
 77 #define for_each_vti6_tunnel_rcu(start) \
 78         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 79 
 80 /**
 81  * vti6_tnl_lookup - fetch tunnel matching the end-point addresses
 82  *   @net: network namespace
 83  *   @remote: the address of the tunnel exit-point
 84  *   @local: the address of the tunnel entry-point
 85  *
 86  * Return:
 87  *   tunnel matching given end-points if found,
 88  *   else fallback tunnel if its device is up,
 89  *   else %NULL
 90  **/
 91 static struct ip6_tnl *
 92 vti6_tnl_lookup(struct net *net, const struct in6_addr *remote,
 93                 const struct in6_addr *local)
 94 {
 95         unsigned int hash = HASH(remote, local);
 96         struct ip6_tnl *t;
 97         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 98         struct in6_addr any;
 99 
100         for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
101                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
102                     ipv6_addr_equal(remote, &t->parms.raddr) &&
103                     (t->dev->flags & IFF_UP))
104                         return t;
105         }
106 
107         memset(&any, 0, sizeof(any));
108         hash = HASH(&any, local);
109         for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
110                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
111                     (t->dev->flags & IFF_UP))
112                         return t;
113         }
114 
115         hash = HASH(remote, &any);
116         for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
117                 if (ipv6_addr_equal(remote, &t->parms.raddr) &&
118                     (t->dev->flags & IFF_UP))
119                         return t;
120         }
121 
122         t = rcu_dereference(ip6n->tnls_wc[0]);
123         if (t && (t->dev->flags & IFF_UP))
124                 return t;
125 
126         return NULL;
127 }
128 
129 /**
130  * vti6_tnl_bucket - get head of list matching given tunnel parameters
131  *   @p: parameters containing tunnel end-points
132  *
133  * Description:
134  *   vti6_tnl_bucket() returns the head of the list matching the
135  *   &struct in6_addr entries laddr and raddr in @p.
136  *
137  * Return: head of IPv6 tunnel list
138  **/
139 static struct ip6_tnl __rcu **
140 vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p)
141 {
142         const struct in6_addr *remote = &p->raddr;
143         const struct in6_addr *local = &p->laddr;
144         unsigned int h = 0;
145         int prio = 0;
146 
147         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
148                 prio = 1;
149                 h = HASH(remote, local);
150         }
151         return &ip6n->tnls[prio][h];
152 }
153 
154 static void
155 vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t)
156 {
157         struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms);
158 
159         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
160         rcu_assign_pointer(*tp, t);
161 }
162 
163 static void
164 vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
165 {
166         struct ip6_tnl __rcu **tp;
167         struct ip6_tnl *iter;
168 
169         for (tp = vti6_tnl_bucket(ip6n, &t->parms);
170              (iter = rtnl_dereference(*tp)) != NULL;
171              tp = &iter->next) {
172                 if (t == iter) {
173                         rcu_assign_pointer(*tp, t->next);
174                         break;
175                 }
176         }
177 }
178 
179 static void vti6_dev_free(struct net_device *dev)
180 {
181         free_percpu(dev->tstats);
182         free_netdev(dev);
183 }
184 
185 static int vti6_tnl_create2(struct net_device *dev)
186 {
187         struct ip6_tnl *t = netdev_priv(dev);
188         struct net *net = dev_net(dev);
189         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
190         int err;
191 
192         err = register_netdevice(dev);
193         if (err < 0)
194                 goto out;
195 
196         strcpy(t->parms.name, dev->name);
197         dev->rtnl_link_ops = &vti6_link_ops;
198 
199         dev_hold(dev);
200         vti6_tnl_link(ip6n, t);
201 
202         return 0;
203 
204 out:
205         return err;
206 }
207 
208 static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
209 {
210         struct net_device *dev;
211         struct ip6_tnl *t;
212         char name[IFNAMSIZ];
213         int err;
214 
215         if (p->name[0])
216                 strlcpy(name, p->name, IFNAMSIZ);
217         else
218                 sprintf(name, "ip6_vti%%d");
219 
220         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup);
221         if (!dev)
222                 goto failed;
223 
224         dev_net_set(dev, net);
225 
226         t = netdev_priv(dev);
227         t->parms = *p;
228         t->net = dev_net(dev);
229 
230         err = vti6_tnl_create2(dev);
231         if (err < 0)
232                 goto failed_free;
233 
234         return t;
235 
236 failed_free:
237         vti6_dev_free(dev);
238 failed:
239         return NULL;
240 }
241 
242 /**
243  * vti6_locate - find or create tunnel matching given parameters
244  *   @net: network namespace
245  *   @p: tunnel parameters
246  *   @create: != 0 if allowed to create new tunnel if no match found
247  *
248  * Description:
249  *   vti6_locate() first tries to locate an existing tunnel
250  *   based on @parms. If this is unsuccessful, but @create is set a new
251  *   tunnel device is created and registered for use.
252  *
253  * Return:
254  *   matching tunnel or NULL
255  **/
256 static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
257                                    int create)
258 {
259         const struct in6_addr *remote = &p->raddr;
260         const struct in6_addr *local = &p->laddr;
261         struct ip6_tnl __rcu **tp;
262         struct ip6_tnl *t;
263         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
264 
265         for (tp = vti6_tnl_bucket(ip6n, p);
266              (t = rtnl_dereference(*tp)) != NULL;
267              tp = &t->next) {
268                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
269                     ipv6_addr_equal(remote, &t->parms.raddr)) {
270                         if (create)
271                                 return NULL;
272 
273                         return t;
274                 }
275         }
276         if (!create)
277                 return NULL;
278         return vti6_tnl_create(net, p);
279 }
280 
281 /**
282  * vti6_dev_uninit - tunnel device uninitializer
283  *   @dev: the device to be destroyed
284  *
285  * Description:
286  *   vti6_dev_uninit() removes tunnel from its list
287  **/
288 static void vti6_dev_uninit(struct net_device *dev)
289 {
290         struct ip6_tnl *t = netdev_priv(dev);
291         struct vti6_net *ip6n = net_generic(t->net, vti6_net_id);
292 
293         if (dev == ip6n->fb_tnl_dev)
294                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
295         else
296                 vti6_tnl_unlink(ip6n, t);
297         dev_put(dev);
298 }
299 
300 static int vti6_rcv(struct sk_buff *skb)
301 {
302         struct ip6_tnl *t;
303         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
304 
305         rcu_read_lock();
306         t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
307         if (t) {
308                 if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) {
309                         rcu_read_unlock();
310                         goto discard;
311                 }
312 
313                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
314                         rcu_read_unlock();
315                         return 0;
316                 }
317 
318                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
319                         t->dev->stats.rx_dropped++;
320                         rcu_read_unlock();
321                         goto discard;
322                 }
323 
324                 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
325 
326                 rcu_read_unlock();
327 
328                 return xfrm6_rcv(skb);
329         }
330         rcu_read_unlock();
331         return -EINVAL;
332 discard:
333         kfree_skb(skb);
334         return 0;
335 }
336 
337 static int vti6_rcv_cb(struct sk_buff *skb, int err)
338 {
339         unsigned short family;
340         struct net_device *dev;
341         struct pcpu_sw_netstats *tstats;
342         struct xfrm_state *x;
343         struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6;
344         u32 orig_mark = skb->mark;
345         int ret;
346 
347         if (!t)
348                 return 1;
349 
350         dev = t->dev;
351 
352         if (err) {
353                 dev->stats.rx_errors++;
354                 dev->stats.rx_dropped++;
355 
356                 return 0;
357         }
358 
359         x = xfrm_input_state(skb);
360         family = x->inner_mode->afinfo->family;
361 
362         skb->mark = be32_to_cpu(t->parms.i_key);
363         ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
364         skb->mark = orig_mark;
365 
366         if (!ret)
367                 return -EPERM;
368 
369         skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev)));
370         skb->dev = dev;
371 
372         tstats = this_cpu_ptr(dev->tstats);
373         u64_stats_update_begin(&tstats->syncp);
374         tstats->rx_packets++;
375         tstats->rx_bytes += skb->len;
376         u64_stats_update_end(&tstats->syncp);
377 
378         return 0;
379 }
380 
381 /**
382  * vti6_addr_conflict - compare packet addresses to tunnel's own
383  *   @t: the outgoing tunnel device
384  *   @hdr: IPv6 header from the incoming packet
385  *
386  * Description:
387  *   Avoid trivial tunneling loop by checking that tunnel exit-point
388  *   doesn't match source of incoming packet.
389  *
390  * Return:
391  *   1 if conflict,
392  *   0 else
393  **/
394 static inline bool
395 vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
396 {
397         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
398 }
399 
400 static bool vti6_state_check(const struct xfrm_state *x,
401                              const struct in6_addr *dst,
402                              const struct in6_addr *src)
403 {
404         xfrm_address_t *daddr = (xfrm_address_t *)dst;
405         xfrm_address_t *saddr = (xfrm_address_t *)src;
406 
407         /* if there is no transform then this tunnel is not functional.
408          * Or if the xfrm is not mode tunnel.
409          */
410         if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
411             x->props.family != AF_INET6)
412                 return false;
413 
414         if (ipv6_addr_any(dst))
415                 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6);
416 
417         if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6))
418                 return false;
419 
420         return true;
421 }
422 
423 /**
424  * vti6_xmit - send a packet
425  *   @skb: the outgoing socket buffer
426  *   @dev: the outgoing tunnel device
427  *   @fl: the flow informations for the xfrm_lookup
428  **/
429 static int
430 vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
431 {
432         struct ip6_tnl *t = netdev_priv(dev);
433         struct net_device_stats *stats = &t->dev->stats;
434         struct dst_entry *dst = skb_dst(skb);
435         struct net_device *tdev;
436         struct xfrm_state *x;
437         int err = -1;
438         int mtu;
439 
440         if (!dst)
441                 goto tx_err_link_failure;
442 
443         dst_hold(dst);
444         dst = xfrm_lookup(t->net, dst, fl, NULL, 0);
445         if (IS_ERR(dst)) {
446                 err = PTR_ERR(dst);
447                 dst = NULL;
448                 goto tx_err_link_failure;
449         }
450 
451         x = dst->xfrm;
452         if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr))
453                 goto tx_err_link_failure;
454 
455         if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr,
456                               (const struct in6_addr *)&x->id.daddr))
457                 goto tx_err_link_failure;
458 
459         tdev = dst->dev;
460 
461         if (tdev == dev) {
462                 stats->collisions++;
463                 net_warn_ratelimited("%s: Local routing loop detected!\n",
464                                      t->parms.name);
465                 goto tx_err_dst_release;
466         }
467 
468         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
469         skb_dst_set(skb, dst);
470         skb->dev = skb_dst(skb)->dev;
471 
472         mtu = dst_mtu(dst);
473         if (!skb->ignore_df && skb->len > mtu) {
474                 skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu);
475 
476                 if (skb->protocol == htons(ETH_P_IPV6))
477                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
478                 else
479                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
480                                   htonl(mtu));
481 
482                 return -EMSGSIZE;
483         }
484 
485         err = dst_output(t->net, skb->sk, skb);
486         if (net_xmit_eval(err) == 0) {
487                 struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);
488 
489                 u64_stats_update_begin(&tstats->syncp);
490                 tstats->tx_bytes += skb->len;
491                 tstats->tx_packets++;
492                 u64_stats_update_end(&tstats->syncp);
493         } else {
494                 stats->tx_errors++;
495                 stats->tx_aborted_errors++;
496         }
497 
498         return 0;
499 tx_err_link_failure:
500         stats->tx_carrier_errors++;
501         dst_link_failure(skb);
502 tx_err_dst_release:
503         dst_release(dst);
504         return err;
505 }
506 
507 static netdev_tx_t
508 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
509 {
510         struct ip6_tnl *t = netdev_priv(dev);
511         struct net_device_stats *stats = &t->dev->stats;
512         struct ipv6hdr *ipv6h;
513         struct flowi fl;
514         int ret;
515 
516         memset(&fl, 0, sizeof(fl));
517 
518         switch (skb->protocol) {
519         case htons(ETH_P_IPV6):
520                 ipv6h = ipv6_hdr(skb);
521 
522                 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
523                     vti6_addr_conflict(t, ipv6h))
524                         goto tx_err;
525 
526                 xfrm_decode_session(skb, &fl, AF_INET6);
527                 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
528                 break;
529         case htons(ETH_P_IP):
530                 xfrm_decode_session(skb, &fl, AF_INET);
531                 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
532                 break;
533         default:
534                 goto tx_err;
535         }
536 
537         /* override mark with tunnel output key */
538         fl.flowi_mark = be32_to_cpu(t->parms.o_key);
539 
540         ret = vti6_xmit(skb, dev, &fl);
541         if (ret < 0)
542                 goto tx_err;
543 
544         return NETDEV_TX_OK;
545 
546 tx_err:
547         stats->tx_errors++;
548         stats->tx_dropped++;
549         kfree_skb(skb);
550         return NETDEV_TX_OK;
551 }
552 
553 static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
554                     u8 type, u8 code, int offset, __be32 info)
555 {
556         __be32 spi;
557         __u32 mark;
558         struct xfrm_state *x;
559         struct ip6_tnl *t;
560         struct ip_esp_hdr *esph;
561         struct ip_auth_hdr *ah;
562         struct ip_comp_hdr *ipch;
563         struct net *net = dev_net(skb->dev);
564         const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
565         int protocol = iph->nexthdr;
566 
567         t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr);
568         if (!t)
569                 return -1;
570 
571         mark = be32_to_cpu(t->parms.o_key);
572 
573         switch (protocol) {
574         case IPPROTO_ESP:
575                 esph = (struct ip_esp_hdr *)(skb->data + offset);
576                 spi = esph->spi;
577                 break;
578         case IPPROTO_AH:
579                 ah = (struct ip_auth_hdr *)(skb->data + offset);
580                 spi = ah->spi;
581                 break;
582         case IPPROTO_COMP:
583                 ipch = (struct ip_comp_hdr *)(skb->data + offset);
584                 spi = htonl(ntohs(ipch->cpi));
585                 break;
586         default:
587                 return 0;
588         }
589 
590         if (type != ICMPV6_PKT_TOOBIG &&
591             type != NDISC_REDIRECT)
592                 return 0;
593 
594         x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
595                               spi, protocol, AF_INET6);
596         if (!x)
597                 return 0;
598 
599         if (type == NDISC_REDIRECT)
600                 ip6_redirect(skb, net, skb->dev->ifindex, 0);
601         else
602                 ip6_update_pmtu(skb, net, info, 0, 0);
603         xfrm_state_put(x);
604 
605         return 0;
606 }
607 
608 static void vti6_link_config(struct ip6_tnl *t)
609 {
610         struct net_device *dev = t->dev;
611         struct __ip6_tnl_parm *p = &t->parms;
612 
613         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
614         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
615 
616         p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV |
617                       IP6_TNL_F_CAP_PER_PACKET);
618         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
619 
620         if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV)
621                 dev->flags |= IFF_POINTOPOINT;
622         else
623                 dev->flags &= ~IFF_POINTOPOINT;
624 }
625 
626 /**
627  * vti6_tnl_change - update the tunnel parameters
628  *   @t: tunnel to be changed
629  *   @p: tunnel configuration parameters
630  *
631  * Description:
632  *   vti6_tnl_change() updates the tunnel parameters
633  **/
634 static int
635 vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
636 {
637         t->parms.laddr = p->laddr;
638         t->parms.raddr = p->raddr;
639         t->parms.link = p->link;
640         t->parms.i_key = p->i_key;
641         t->parms.o_key = p->o_key;
642         t->parms.proto = p->proto;
643         ip6_tnl_dst_reset(t);
644         vti6_link_config(t);
645         return 0;
646 }
647 
648 static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
649 {
650         struct net *net = dev_net(t->dev);
651         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
652         int err;
653 
654         vti6_tnl_unlink(ip6n, t);
655         synchronize_net();
656         err = vti6_tnl_change(t, p);
657         vti6_tnl_link(ip6n, t);
658         netdev_state_change(t->dev);
659         return err;
660 }
661 
662 static void
663 vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u)
664 {
665         p->laddr = u->laddr;
666         p->raddr = u->raddr;
667         p->link = u->link;
668         p->i_key = u->i_key;
669         p->o_key = u->o_key;
670         p->proto = u->proto;
671 
672         memcpy(p->name, u->name, sizeof(u->name));
673 }
674 
675 static void
676 vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p)
677 {
678         u->laddr = p->laddr;
679         u->raddr = p->raddr;
680         u->link = p->link;
681         u->i_key = p->i_key;
682         u->o_key = p->o_key;
683         u->proto = p->proto;
684 
685         memcpy(u->name, p->name, sizeof(u->name));
686 }
687 
688 /**
689  * vti6_tnl_ioctl - configure vti6 tunnels from userspace
690  *   @dev: virtual device associated with tunnel
691  *   @ifr: parameters passed from userspace
692  *   @cmd: command to be performed
693  *
694  * Description:
695  *   vti6_ioctl() is used for managing vti6 tunnels
696  *   from userspace.
697  *
698  *   The possible commands are the following:
699  *     %SIOCGETTUNNEL: get tunnel parameters for device
700  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
701  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
702  *     %SIOCDELTUNNEL: delete tunnel
703  *
704  *   The fallback device "ip6_vti0", created during module
705  *   initialization, can be used for creating other tunnel devices.
706  *
707  * Return:
708  *   0 on success,
709  *   %-EFAULT if unable to copy data to or from userspace,
710  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
711  *   %-EINVAL if passed tunnel parameters are invalid,
712  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
713  *   %-ENODEV if attempting to change or delete a nonexisting device
714  **/
715 static int
716 vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
717 {
718         int err = 0;
719         struct ip6_tnl_parm2 p;
720         struct __ip6_tnl_parm p1;
721         struct ip6_tnl *t = NULL;
722         struct net *net = dev_net(dev);
723         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
724 
725         switch (cmd) {
726         case SIOCGETTUNNEL:
727                 if (dev == ip6n->fb_tnl_dev) {
728                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
729                                 err = -EFAULT;
730                                 break;
731                         }
732                         vti6_parm_from_user(&p1, &p);
733                         t = vti6_locate(net, &p1, 0);
734                 } else {
735                         memset(&p, 0, sizeof(p));
736                 }
737                 if (!t)
738                         t = netdev_priv(dev);
739                 vti6_parm_to_user(&p, &t->parms);
740                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
741                         err = -EFAULT;
742                 break;
743         case SIOCADDTUNNEL:
744         case SIOCCHGTUNNEL:
745                 err = -EPERM;
746                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
747                         break;
748                 err = -EFAULT;
749                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
750                         break;
751                 err = -EINVAL;
752                 if (p.proto != IPPROTO_IPV6  && p.proto != 0)
753                         break;
754                 vti6_parm_from_user(&p1, &p);
755                 t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL);
756                 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
757                         if (t) {
758                                 if (t->dev != dev) {
759                                         err = -EEXIST;
760                                         break;
761                                 }
762                         } else
763                                 t = netdev_priv(dev);
764 
765                         err = vti6_update(t, &p1);
766                 }
767                 if (t) {
768                         err = 0;
769                         vti6_parm_to_user(&p, &t->parms);
770                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
771                                 err = -EFAULT;
772 
773                 } else
774                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
775                 break;
776         case SIOCDELTUNNEL:
777                 err = -EPERM;
778                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
779                         break;
780 
781                 if (dev == ip6n->fb_tnl_dev) {
782                         err = -EFAULT;
783                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
784                                 break;
785                         err = -ENOENT;
786                         vti6_parm_from_user(&p1, &p);
787                         t = vti6_locate(net, &p1, 0);
788                         if (!t)
789                                 break;
790                         err = -EPERM;
791                         if (t->dev == ip6n->fb_tnl_dev)
792                                 break;
793                         dev = t->dev;
794                 }
795                 err = 0;
796                 unregister_netdevice(dev);
797                 break;
798         default:
799                 err = -EINVAL;
800         }
801         return err;
802 }
803 
804 /**
805  * vti6_tnl_change_mtu - change mtu manually for tunnel device
806  *   @dev: virtual device associated with tunnel
807  *   @new_mtu: the new mtu
808  *
809  * Return:
810  *   0 on success,
811  *   %-EINVAL if mtu too small
812  **/
813 static int vti6_change_mtu(struct net_device *dev, int new_mtu)
814 {
815         if (new_mtu < IPV6_MIN_MTU)
816                 return -EINVAL;
817 
818         dev->mtu = new_mtu;
819         return 0;
820 }
821 
822 static const struct net_device_ops vti6_netdev_ops = {
823         .ndo_init       = vti6_dev_init,
824         .ndo_uninit     = vti6_dev_uninit,
825         .ndo_start_xmit = vti6_tnl_xmit,
826         .ndo_do_ioctl   = vti6_ioctl,
827         .ndo_change_mtu = vti6_change_mtu,
828         .ndo_get_stats64 = ip_tunnel_get_stats64,
829         .ndo_get_iflink = ip6_tnl_get_iflink,
830 };
831 
832 /**
833  * vti6_dev_setup - setup virtual tunnel device
834  *   @dev: virtual device associated with tunnel
835  *
836  * Description:
837  *   Initialize function pointers and device parameters
838  **/
839 static void vti6_dev_setup(struct net_device *dev)
840 {
841         dev->netdev_ops = &vti6_netdev_ops;
842         dev->destructor = vti6_dev_free;
843 
844         dev->type = ARPHRD_TUNNEL6;
845         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);
846         dev->mtu = ETH_DATA_LEN;
847         dev->flags |= IFF_NOARP;
848         dev->addr_len = sizeof(struct in6_addr);
849         netif_keep_dst(dev);
850 }
851 
852 /**
853  * vti6_dev_init_gen - general initializer for all tunnel devices
854  *   @dev: virtual device associated with tunnel
855  **/
856 static inline int vti6_dev_init_gen(struct net_device *dev)
857 {
858         struct ip6_tnl *t = netdev_priv(dev);
859 
860         t->dev = dev;
861         t->net = dev_net(dev);
862         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
863         if (!dev->tstats)
864                 return -ENOMEM;
865         return 0;
866 }
867 
868 /**
869  * vti6_dev_init - initializer for all non fallback tunnel devices
870  *   @dev: virtual device associated with tunnel
871  **/
872 static int vti6_dev_init(struct net_device *dev)
873 {
874         struct ip6_tnl *t = netdev_priv(dev);
875         int err = vti6_dev_init_gen(dev);
876 
877         if (err)
878                 return err;
879         vti6_link_config(t);
880         return 0;
881 }
882 
883 /**
884  * vti6_fb_tnl_dev_init - initializer for fallback tunnel device
885  *   @dev: fallback device
886  *
887  * Return: 0
888  **/
889 static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev)
890 {
891         struct ip6_tnl *t = netdev_priv(dev);
892         struct net *net = dev_net(dev);
893         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
894 
895         t->parms.proto = IPPROTO_IPV6;
896         dev_hold(dev);
897 
898         rcu_assign_pointer(ip6n->tnls_wc[0], t);
899         return 0;
900 }
901 
902 static int vti6_validate(struct nlattr *tb[], struct nlattr *data[])
903 {
904         return 0;
905 }
906 
907 static void vti6_netlink_parms(struct nlattr *data[],
908                                struct __ip6_tnl_parm *parms)
909 {
910         memset(parms, 0, sizeof(*parms));
911 
912         if (!data)
913                 return;
914 
915         if (data[IFLA_VTI_LINK])
916                 parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
917 
918         if (data[IFLA_VTI_LOCAL])
919                 parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]);
920 
921         if (data[IFLA_VTI_REMOTE])
922                 parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]);
923 
924         if (data[IFLA_VTI_IKEY])
925                 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
926 
927         if (data[IFLA_VTI_OKEY])
928                 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
929 }
930 
931 static int vti6_newlink(struct net *src_net, struct net_device *dev,
932                         struct nlattr *tb[], struct nlattr *data[])
933 {
934         struct net *net = dev_net(dev);
935         struct ip6_tnl *nt;
936 
937         nt = netdev_priv(dev);
938         vti6_netlink_parms(data, &nt->parms);
939 
940         nt->parms.proto = IPPROTO_IPV6;
941 
942         if (vti6_locate(net, &nt->parms, 0))
943                 return -EEXIST;
944 
945         return vti6_tnl_create2(dev);
946 }
947 
948 static void vti6_dellink(struct net_device *dev, struct list_head *head)
949 {
950         struct net *net = dev_net(dev);
951         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
952 
953         if (dev != ip6n->fb_tnl_dev)
954                 unregister_netdevice_queue(dev, head);
955 }
956 
957 static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
958                            struct nlattr *data[])
959 {
960         struct ip6_tnl *t;
961         struct __ip6_tnl_parm p;
962         struct net *net = dev_net(dev);
963         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
964 
965         if (dev == ip6n->fb_tnl_dev)
966                 return -EINVAL;
967 
968         vti6_netlink_parms(data, &p);
969 
970         t = vti6_locate(net, &p, 0);
971 
972         if (t) {
973                 if (t->dev != dev)
974                         return -EEXIST;
975         } else
976                 t = netdev_priv(dev);
977 
978         return vti6_update(t, &p);
979 }
980 
981 static size_t vti6_get_size(const struct net_device *dev)
982 {
983         return
984                 /* IFLA_VTI_LINK */
985                 nla_total_size(4) +
986                 /* IFLA_VTI_LOCAL */
987                 nla_total_size(sizeof(struct in6_addr)) +
988                 /* IFLA_VTI_REMOTE */
989                 nla_total_size(sizeof(struct in6_addr)) +
990                 /* IFLA_VTI_IKEY */
991                 nla_total_size(4) +
992                 /* IFLA_VTI_OKEY */
993                 nla_total_size(4) +
994                 0;
995 }
996 
997 static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev)
998 {
999         struct ip6_tnl *tunnel = netdev_priv(dev);
1000         struct __ip6_tnl_parm *parm = &tunnel->parms;
1001 
1002         if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) ||
1003             nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) ||
1004             nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) ||
1005             nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) ||
1006             nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key))
1007                 goto nla_put_failure;
1008         return 0;
1009 
1010 nla_put_failure:
1011         return -EMSGSIZE;
1012 }
1013 
1014 static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = {
1015         [IFLA_VTI_LINK]         = { .type = NLA_U32 },
1016         [IFLA_VTI_LOCAL]        = { .len = sizeof(struct in6_addr) },
1017         [IFLA_VTI_REMOTE]       = { .len = sizeof(struct in6_addr) },
1018         [IFLA_VTI_IKEY]         = { .type = NLA_U32 },
1019         [IFLA_VTI_OKEY]         = { .type = NLA_U32 },
1020 };
1021 
1022 static struct rtnl_link_ops vti6_link_ops __read_mostly = {
1023         .kind           = "vti6",
1024         .maxtype        = IFLA_VTI_MAX,
1025         .policy         = vti6_policy,
1026         .priv_size      = sizeof(struct ip6_tnl),
1027         .setup          = vti6_dev_setup,
1028         .validate       = vti6_validate,
1029         .newlink        = vti6_newlink,
1030         .dellink        = vti6_dellink,
1031         .changelink     = vti6_changelink,
1032         .get_size       = vti6_get_size,
1033         .fill_info      = vti6_fill_info,
1034         .get_link_net   = ip6_tnl_get_link_net,
1035 };
1036 
1037 static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n)
1038 {
1039         int h;
1040         struct ip6_tnl *t;
1041         LIST_HEAD(list);
1042 
1043         for (h = 0; h < HASH_SIZE; h++) {
1044                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1045                 while (t) {
1046                         unregister_netdevice_queue(t->dev, &list);
1047                         t = rtnl_dereference(t->next);
1048                 }
1049         }
1050 
1051         t = rtnl_dereference(ip6n->tnls_wc[0]);
1052         unregister_netdevice_queue(t->dev, &list);
1053         unregister_netdevice_many(&list);
1054 }
1055 
1056 static int __net_init vti6_init_net(struct net *net)
1057 {
1058         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1059         struct ip6_tnl *t = NULL;
1060         int err;
1061 
1062         ip6n->tnls[0] = ip6n->tnls_wc;
1063         ip6n->tnls[1] = ip6n->tnls_r_l;
1064 
1065         err = -ENOMEM;
1066         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0",
1067                                         NET_NAME_UNKNOWN, vti6_dev_setup);
1068 
1069         if (!ip6n->fb_tnl_dev)
1070                 goto err_alloc_dev;
1071         dev_net_set(ip6n->fb_tnl_dev, net);
1072         ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops;
1073 
1074         err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1075         if (err < 0)
1076                 goto err_register;
1077 
1078         err = register_netdev(ip6n->fb_tnl_dev);
1079         if (err < 0)
1080                 goto err_register;
1081 
1082         t = netdev_priv(ip6n->fb_tnl_dev);
1083 
1084         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1085         return 0;
1086 
1087 err_register:
1088         vti6_dev_free(ip6n->fb_tnl_dev);
1089 err_alloc_dev:
1090         return err;
1091 }
1092 
1093 static void __net_exit vti6_exit_net(struct net *net)
1094 {
1095         struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1096 
1097         rtnl_lock();
1098         vti6_destroy_tunnels(ip6n);
1099         rtnl_unlock();
1100 }
1101 
1102 static struct pernet_operations vti6_net_ops = {
1103         .init = vti6_init_net,
1104         .exit = vti6_exit_net,
1105         .id   = &vti6_net_id,
1106         .size = sizeof(struct vti6_net),
1107 };
1108 
1109 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = {
1110         .handler        =       vti6_rcv,
1111         .cb_handler     =       vti6_rcv_cb,
1112         .err_handler    =       vti6_err,
1113         .priority       =       100,
1114 };
1115 
1116 static struct xfrm6_protocol vti_ah6_protocol __read_mostly = {
1117         .handler        =       vti6_rcv,
1118         .cb_handler     =       vti6_rcv_cb,
1119         .err_handler    =       vti6_err,
1120         .priority       =       100,
1121 };
1122 
1123 static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = {
1124         .handler        =       vti6_rcv,
1125         .cb_handler     =       vti6_rcv_cb,
1126         .err_handler    =       vti6_err,
1127         .priority       =       100,
1128 };
1129 
1130 /**
1131  * vti6_tunnel_init - register protocol and reserve needed resources
1132  *
1133  * Return: 0 on success
1134  **/
1135 static int __init vti6_tunnel_init(void)
1136 {
1137         const char *msg;
1138         int err;
1139 
1140         msg = "tunnel device";
1141         err = register_pernet_device(&vti6_net_ops);
1142         if (err < 0)
1143                 goto pernet_dev_failed;
1144 
1145         msg = "tunnel protocols";
1146         err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP);
1147         if (err < 0)
1148                 goto xfrm_proto_esp_failed;
1149         err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH);
1150         if (err < 0)
1151                 goto xfrm_proto_ah_failed;
1152         err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP);
1153         if (err < 0)
1154                 goto xfrm_proto_comp_failed;
1155 
1156         msg = "netlink interface";
1157         err = rtnl_link_register(&vti6_link_ops);
1158         if (err < 0)
1159                 goto rtnl_link_failed;
1160 
1161         return 0;
1162 
1163 rtnl_link_failed:
1164         xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1165 xfrm_proto_comp_failed:
1166         xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1167 xfrm_proto_ah_failed:
1168         xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1169 xfrm_proto_esp_failed:
1170         unregister_pernet_device(&vti6_net_ops);
1171 pernet_dev_failed:
1172         pr_err("vti6 init: failed to register %s\n", msg);
1173         return err;
1174 }
1175 
1176 /**
1177  * vti6_tunnel_cleanup - free resources and unregister protocol
1178  **/
1179 static void __exit vti6_tunnel_cleanup(void)
1180 {
1181         rtnl_link_unregister(&vti6_link_ops);
1182         xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1183         xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1184         xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1185         unregister_pernet_device(&vti6_net_ops);
1186 }
1187 
1188 module_init(vti6_tunnel_init);
1189 module_exit(vti6_tunnel_cleanup);
1190 MODULE_LICENSE("GPL");
1191 MODULE_ALIAS_RTNL_LINK("vti6");
1192 MODULE_ALIAS_NETDEV("ip6_vti0");
1193 MODULE_AUTHOR("Steffen Klassert");
1194 MODULE_DESCRIPTION("IPv6 virtual tunnel interface");
1195 

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