1 /*
2 * Copyright (c) 2013 Nicira, Inc.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16 * 02110-1301, USA
17 */
18
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21 #include <linux/capability.h>
22 #include <linux/module.h>
23 #include <linux/types.h>
24 #include <linux/kernel.h>
25 #include <linux/slab.h>
26 #include <linux/uaccess.h>
27 #include <linux/skbuff.h>
28 #include <linux/netdevice.h>
29 #include <linux/in.h>
30 #include <linux/tcp.h>
31 #include <linux/udp.h>
32 #include <linux/if_arp.h>
33 #include <linux/init.h>
34 #include <linux/in6.h>
35 #include <linux/inetdevice.h>
36 #include <linux/igmp.h>
37 #include <linux/netfilter_ipv4.h>
38 #include <linux/etherdevice.h>
39 #include <linux/if_ether.h>
40 #include <linux/if_vlan.h>
41 #include <linux/rculist.h>
42 #include <linux/err.h>
43
44 #include <net/sock.h>
45 #include <net/ip.h>
46 #include <net/icmp.h>
47 #include <net/protocol.h>
48 #include <net/ip_tunnels.h>
49 #include <net/arp.h>
50 #include <net/checksum.h>
51 #include <net/dsfield.h>
52 #include <net/inet_ecn.h>
53 #include <net/xfrm.h>
54 #include <net/net_namespace.h>
55 #include <net/netns/generic.h>
56 #include <net/rtnetlink.h>
57 #include <net/udp.h>
58 #include <net/dst_metadata.h>
59
60 #if IS_ENABLED(CONFIG_IPV6)
61 #include <net/ipv6.h>
62 #include <net/ip6_fib.h>
63 #include <net/ip6_route.h>
64 #endif
65
ip_tunnel_hash(__be32 key,__be32 remote)66 static unsigned int ip_tunnel_hash(__be32 key, __be32 remote)
67 {
68 return hash_32((__force u32)key ^ (__force u32)remote,
69 IP_TNL_HASH_BITS);
70 }
71
ip_tunnel_key_match(const struct ip_tunnel_parm * p,__be16 flags,__be32 key)72 static bool ip_tunnel_key_match(const struct ip_tunnel_parm *p,
73 __be16 flags, __be32 key)
74 {
75 if (p->i_flags & TUNNEL_KEY) {
76 if (flags & TUNNEL_KEY)
77 return key == p->i_key;
78 else
79 /* key expected, none present */
80 return false;
81 } else
82 return !(flags & TUNNEL_KEY);
83 }
84
85 /* Fallback tunnel: no source, no destination, no key, no options
86
87 Tunnel hash table:
88 We require exact key match i.e. if a key is present in packet
89 it will match only tunnel with the same key; if it is not present,
90 it will match only keyless tunnel.
91
92 All keysless packets, if not matched configured keyless tunnels
93 will match fallback tunnel.
94 Given src, dst and key, find appropriate for input tunnel.
95 */
ip_tunnel_lookup(struct ip_tunnel_net * itn,int link,__be16 flags,__be32 remote,__be32 local,__be32 key)96 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
97 int link, __be16 flags,
98 __be32 remote, __be32 local,
99 __be32 key)
100 {
101 unsigned int hash;
102 struct ip_tunnel *t, *cand = NULL;
103 struct hlist_head *head;
104
105 hash = ip_tunnel_hash(key, remote);
106 head = &itn->tunnels[hash];
107
108 hlist_for_each_entry_rcu(t, head, hash_node) {
109 if (local != t->parms.iph.saddr ||
110 remote != t->parms.iph.daddr ||
111 !(t->dev->flags & IFF_UP))
112 continue;
113
114 if (!ip_tunnel_key_match(&t->parms, flags, key))
115 continue;
116
117 if (t->parms.link == link)
118 return t;
119 else
120 cand = t;
121 }
122
123 hlist_for_each_entry_rcu(t, head, hash_node) {
124 if (remote != t->parms.iph.daddr ||
125 t->parms.iph.saddr != 0 ||
126 !(t->dev->flags & IFF_UP))
127 continue;
128
129 if (!ip_tunnel_key_match(&t->parms, flags, key))
130 continue;
131
132 if (t->parms.link == link)
133 return t;
134 else if (!cand)
135 cand = t;
136 }
137
138 hash = ip_tunnel_hash(key, 0);
139 head = &itn->tunnels[hash];
140
141 hlist_for_each_entry_rcu(t, head, hash_node) {
142 if ((local != t->parms.iph.saddr || t->parms.iph.daddr != 0) &&
143 (local != t->parms.iph.daddr || !ipv4_is_multicast(local)))
144 continue;
145
146 if (!(t->dev->flags & IFF_UP))
147 continue;
148
149 if (!ip_tunnel_key_match(&t->parms, flags, key))
150 continue;
151
152 if (t->parms.link == link)
153 return t;
154 else if (!cand)
155 cand = t;
156 }
157
158 if (flags & TUNNEL_NO_KEY)
159 goto skip_key_lookup;
160
161 hlist_for_each_entry_rcu(t, head, hash_node) {
162 if (t->parms.i_key != key ||
163 t->parms.iph.saddr != 0 ||
164 t->parms.iph.daddr != 0 ||
165 !(t->dev->flags & IFF_UP))
166 continue;
167
168 if (t->parms.link == link)
169 return t;
170 else if (!cand)
171 cand = t;
172 }
173
174 skip_key_lookup:
175 if (cand)
176 return cand;
177
178 t = rcu_dereference(itn->collect_md_tun);
179 if (t && t->dev->flags & IFF_UP)
180 return t;
181
182 if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP)
183 return netdev_priv(itn->fb_tunnel_dev);
184
185 return NULL;
186 }
187 EXPORT_SYMBOL_GPL(ip_tunnel_lookup);
188
ip_bucket(struct ip_tunnel_net * itn,struct ip_tunnel_parm * parms)189 static struct hlist_head *ip_bucket(struct ip_tunnel_net *itn,
190 struct ip_tunnel_parm *parms)
191 {
192 unsigned int h;
193 __be32 remote;
194 __be32 i_key = parms->i_key;
195
196 if (parms->iph.daddr && !ipv4_is_multicast(parms->iph.daddr))
197 remote = parms->iph.daddr;
198 else
199 remote = 0;
200
201 if (!(parms->i_flags & TUNNEL_KEY) && (parms->i_flags & VTI_ISVTI))
202 i_key = 0;
203
204 h = ip_tunnel_hash(i_key, remote);
205 return &itn->tunnels[h];
206 }
207
ip_tunnel_add(struct ip_tunnel_net * itn,struct ip_tunnel * t)208 static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t)
209 {
210 struct hlist_head *head = ip_bucket(itn, &t->parms);
211
212 if (t->collect_md)
213 rcu_assign_pointer(itn->collect_md_tun, t);
214 hlist_add_head_rcu(&t->hash_node, head);
215 }
216
ip_tunnel_del(struct ip_tunnel_net * itn,struct ip_tunnel * t)217 static void ip_tunnel_del(struct ip_tunnel_net *itn, struct ip_tunnel *t)
218 {
219 if (t->collect_md)
220 rcu_assign_pointer(itn->collect_md_tun, NULL);
221 hlist_del_init_rcu(&t->hash_node);
222 }
223
ip_tunnel_find(struct ip_tunnel_net * itn,struct ip_tunnel_parm * parms,int type)224 static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn,
225 struct ip_tunnel_parm *parms,
226 int type)
227 {
228 __be32 remote = parms->iph.daddr;
229 __be32 local = parms->iph.saddr;
230 __be32 key = parms->i_key;
231 __be16 flags = parms->i_flags;
232 int link = parms->link;
233 struct ip_tunnel *t = NULL;
234 struct hlist_head *head = ip_bucket(itn, parms);
235
236 hlist_for_each_entry_rcu(t, head, hash_node) {
237 if (local == t->parms.iph.saddr &&
238 remote == t->parms.iph.daddr &&
239 link == t->parms.link &&
240 type == t->dev->type &&
241 ip_tunnel_key_match(&t->parms, flags, key))
242 break;
243 }
244 return t;
245 }
246
__ip_tunnel_create(struct net * net,const struct rtnl_link_ops * ops,struct ip_tunnel_parm * parms)247 static struct net_device *__ip_tunnel_create(struct net *net,
248 const struct rtnl_link_ops *ops,
249 struct ip_tunnel_parm *parms)
250 {
251 int err;
252 struct ip_tunnel *tunnel;
253 struct net_device *dev;
254 char name[IFNAMSIZ];
255
256 err = -E2BIG;
257 if (parms->name[0]) {
258 if (!dev_valid_name(parms->name))
259 goto failed;
260 strlcpy(name, parms->name, IFNAMSIZ);
261 } else {
262 if (strlen(ops->kind) > (IFNAMSIZ - 3))
263 goto failed;
264 strcpy(name, ops->kind);
265 strcat(name, "%d");
266 }
267
268 ASSERT_RTNL();
269 dev = alloc_netdev(ops->priv_size, name, NET_NAME_UNKNOWN, ops->setup);
270 if (!dev) {
271 err = -ENOMEM;
272 goto failed;
273 }
274 dev_net_set(dev, net);
275
276 dev->rtnl_link_ops = ops;
277
278 tunnel = netdev_priv(dev);
279 tunnel->parms = *parms;
280 tunnel->net = net;
281
282 err = register_netdevice(dev);
283 if (err)
284 goto failed_free;
285
286 return dev;
287
288 failed_free:
289 free_netdev(dev);
290 failed:
291 return ERR_PTR(err);
292 }
293
ip_tunnel_bind_dev(struct net_device * dev)294 static int ip_tunnel_bind_dev(struct net_device *dev)
295 {
296 struct net_device *tdev = NULL;
297 struct ip_tunnel *tunnel = netdev_priv(dev);
298 const struct iphdr *iph;
299 int hlen = LL_MAX_HEADER;
300 int mtu = ETH_DATA_LEN;
301 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
302
303 iph = &tunnel->parms.iph;
304
305 /* Guess output device to choose reasonable mtu and needed_headroom */
306 if (iph->daddr) {
307 struct flowi4 fl4;
308 struct rtable *rt;
309
310 ip_tunnel_init_flow(&fl4, iph->protocol, iph->daddr,
311 iph->saddr, tunnel->parms.o_key,
312 RT_TOS(iph->tos), tunnel->parms.link,
313 tunnel->fwmark);
314 rt = ip_route_output_key(tunnel->net, &fl4);
315
316 if (!IS_ERR(rt)) {
317 tdev = rt->dst.dev;
318 ip_rt_put(rt);
319 }
320 if (dev->type != ARPHRD_ETHER)
321 dev->flags |= IFF_POINTOPOINT;
322
323 dst_cache_reset(&tunnel->dst_cache);
324 }
325
326 if (!tdev && tunnel->parms.link)
327 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
328
329 if (tdev) {
330 hlen = tdev->hard_header_len + tdev->needed_headroom;
331 mtu = min(tdev->mtu, IP_MAX_MTU);
332 }
333
334 dev->needed_headroom = t_hlen + hlen;
335 mtu -= (dev->hard_header_len + t_hlen);
336
337 if (mtu < IPV4_MIN_MTU)
338 mtu = IPV4_MIN_MTU;
339
340 return mtu;
341 }
342
ip_tunnel_create(struct net * net,struct ip_tunnel_net * itn,struct ip_tunnel_parm * parms)343 static struct ip_tunnel *ip_tunnel_create(struct net *net,
344 struct ip_tunnel_net *itn,
345 struct ip_tunnel_parm *parms)
346 {
347 struct ip_tunnel *nt;
348 struct net_device *dev;
349 int t_hlen;
350 int mtu;
351 int err;
352
353 dev = __ip_tunnel_create(net, itn->rtnl_link_ops, parms);
354 if (IS_ERR(dev))
355 return ERR_CAST(dev);
356
357 mtu = ip_tunnel_bind_dev(dev);
358 err = dev_set_mtu(dev, mtu);
359 if (err)
360 goto err_dev_set_mtu;
361
362 nt = netdev_priv(dev);
363 t_hlen = nt->hlen + sizeof(struct iphdr);
364 dev->min_mtu = ETH_MIN_MTU;
365 dev->max_mtu = IP_MAX_MTU - dev->hard_header_len - t_hlen;
366 ip_tunnel_add(itn, nt);
367 return nt;
368
369 err_dev_set_mtu:
370 unregister_netdevice(dev);
371 return ERR_PTR(err);
372 }
373
ip_tunnel_rcv(struct ip_tunnel * tunnel,struct sk_buff * skb,const struct tnl_ptk_info * tpi,struct metadata_dst * tun_dst,bool log_ecn_error)374 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
375 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
376 bool log_ecn_error)
377 {
378 struct pcpu_sw_netstats *tstats;
379 const struct iphdr *iph = ip_hdr(skb);
380 int err;
381
382 #ifdef CONFIG_NET_IPGRE_BROADCAST
383 if (ipv4_is_multicast(iph->daddr)) {
384 tunnel->dev->stats.multicast++;
385 skb->pkt_type = PACKET_BROADCAST;
386 }
387 #endif
388
389 if ((!(tpi->flags&TUNNEL_CSUM) && (tunnel->parms.i_flags&TUNNEL_CSUM)) ||
390 ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) {
391 tunnel->dev->stats.rx_crc_errors++;
392 tunnel->dev->stats.rx_errors++;
393 goto drop;
394 }
395
396 if (tunnel->parms.i_flags&TUNNEL_SEQ) {
397 if (!(tpi->flags&TUNNEL_SEQ) ||
398 (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
399 tunnel->dev->stats.rx_fifo_errors++;
400 tunnel->dev->stats.rx_errors++;
401 goto drop;
402 }
403 tunnel->i_seqno = ntohl(tpi->seq) + 1;
404 }
405
406 skb_reset_network_header(skb);
407
408 err = IP_ECN_decapsulate(iph, skb);
409 if (unlikely(err)) {
410 if (log_ecn_error)
411 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
412 &iph->saddr, iph->tos);
413 if (err > 1) {
414 ++tunnel->dev->stats.rx_frame_errors;
415 ++tunnel->dev->stats.rx_errors;
416 goto drop;
417 }
418 }
419
420 tstats = this_cpu_ptr(tunnel->dev->tstats);
421 u64_stats_update_begin(&tstats->syncp);
422 tstats->rx_packets++;
423 tstats->rx_bytes += skb->len;
424 u64_stats_update_end(&tstats->syncp);
425
426 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
427
428 if (tunnel->dev->type == ARPHRD_ETHER) {
429 skb->protocol = eth_type_trans(skb, tunnel->dev);
430 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
431 } else {
432 skb->dev = tunnel->dev;
433 }
434
435 if (tun_dst)
436 skb_dst_set(skb, (struct dst_entry *)tun_dst);
437
438 gro_cells_receive(&tunnel->gro_cells, skb);
439 return 0;
440
441 drop:
442 if (tun_dst)
443 dst_release((struct dst_entry *)tun_dst);
444 kfree_skb(skb);
445 return 0;
446 }
447 EXPORT_SYMBOL_GPL(ip_tunnel_rcv);
448
ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops * ops,unsigned int num)449 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *ops,
450 unsigned int num)
451 {
452 if (num >= MAX_IPTUN_ENCAP_OPS)
453 return -ERANGE;
454
455 return !cmpxchg((const struct ip_tunnel_encap_ops **)
456 &iptun_encaps[num],
457 NULL, ops) ? 0 : -1;
458 }
459 EXPORT_SYMBOL(ip_tunnel_encap_add_ops);
460
ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops * ops,unsigned int num)461 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *ops,
462 unsigned int num)
463 {
464 int ret;
465
466 if (num >= MAX_IPTUN_ENCAP_OPS)
467 return -ERANGE;
468
469 ret = (cmpxchg((const struct ip_tunnel_encap_ops **)
470 &iptun_encaps[num],
471 ops, NULL) == ops) ? 0 : -1;
472
473 synchronize_net();
474
475 return ret;
476 }
477 EXPORT_SYMBOL(ip_tunnel_encap_del_ops);
478
ip_tunnel_encap_setup(struct ip_tunnel * t,struct ip_tunnel_encap * ipencap)479 int ip_tunnel_encap_setup(struct ip_tunnel *t,
480 struct ip_tunnel_encap *ipencap)
481 {
482 int hlen;
483
484 memset(&t->encap, 0, sizeof(t->encap));
485
486 hlen = ip_encap_hlen(ipencap);
487 if (hlen < 0)
488 return hlen;
489
490 t->encap.type = ipencap->type;
491 t->encap.sport = ipencap->sport;
492 t->encap.dport = ipencap->dport;
493 t->encap.flags = ipencap->flags;
494
495 t->encap_hlen = hlen;
496 t->hlen = t->encap_hlen + t->tun_hlen;
497
498 return 0;
499 }
500 EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup);
501
tnl_update_pmtu(struct net_device * dev,struct sk_buff * skb,struct rtable * rt,__be16 df,const struct iphdr * inner_iph)502 static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb,
503 struct rtable *rt, __be16 df,
504 const struct iphdr *inner_iph)
505 {
506 struct ip_tunnel *tunnel = netdev_priv(dev);
507 int pkt_size = skb->len - tunnel->hlen - dev->hard_header_len;
508 int mtu;
509
510 if (df)
511 mtu = dst_mtu(&rt->dst) - dev->hard_header_len
512 - sizeof(struct iphdr) - tunnel->hlen;
513 else
514 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
515
516 skb_dst_update_pmtu(skb, mtu);
517
518 if (skb->protocol == htons(ETH_P_IP)) {
519 if (!skb_is_gso(skb) &&
520 (inner_iph->frag_off & htons(IP_DF)) &&
521 mtu < pkt_size) {
522 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
523 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
524 return -E2BIG;
525 }
526 }
527 #if IS_ENABLED(CONFIG_IPV6)
528 else if (skb->protocol == htons(ETH_P_IPV6)) {
529 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
530
531 if (rt6 && mtu < dst_mtu(skb_dst(skb)) &&
532 mtu >= IPV6_MIN_MTU) {
533 if ((tunnel->parms.iph.daddr &&
534 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
535 rt6->rt6i_dst.plen == 128) {
536 rt6->rt6i_flags |= RTF_MODIFIED;
537 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
538 }
539 }
540
541 if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU &&
542 mtu < pkt_size) {
543 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
544 return -E2BIG;
545 }
546 }
547 #endif
548 return 0;
549 }
550
ip_md_tunnel_xmit(struct sk_buff * skb,struct net_device * dev,u8 proto)551 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, u8 proto)
552 {
553 struct ip_tunnel *tunnel = netdev_priv(dev);
554 u32 headroom = sizeof(struct iphdr);
555 struct ip_tunnel_info *tun_info;
556 const struct ip_tunnel_key *key;
557 const struct iphdr *inner_iph;
558 struct rtable *rt;
559 struct flowi4 fl4;
560 __be16 df = 0;
561 u8 tos, ttl;
562
563 tun_info = skb_tunnel_info(skb);
564 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
565 ip_tunnel_info_af(tun_info) != AF_INET))
566 goto tx_error;
567 key = &tun_info->key;
568 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
569 inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
570 tos = key->tos;
571 if (tos == 1) {
572 if (skb->protocol == htons(ETH_P_IP))
573 tos = inner_iph->tos;
574 else if (skb->protocol == htons(ETH_P_IPV6))
575 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
576 }
577 ip_tunnel_init_flow(&fl4, proto, key->u.ipv4.dst, key->u.ipv4.src, 0,
578 RT_TOS(tos), tunnel->parms.link, tunnel->fwmark);
579 if (tunnel->encap.type != TUNNEL_ENCAP_NONE)
580 goto tx_error;
581 rt = ip_route_output_key(tunnel->net, &fl4);
582 if (IS_ERR(rt)) {
583 dev->stats.tx_carrier_errors++;
584 goto tx_error;
585 }
586 if (rt->dst.dev == dev) {
587 ip_rt_put(rt);
588 dev->stats.collisions++;
589 goto tx_error;
590 }
591 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb);
592 ttl = key->ttl;
593 if (ttl == 0) {
594 if (skb->protocol == htons(ETH_P_IP))
595 ttl = inner_iph->ttl;
596 else if (skb->protocol == htons(ETH_P_IPV6))
597 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
598 else
599 ttl = ip4_dst_hoplimit(&rt->dst);
600 }
601 if (key->tun_flags & TUNNEL_DONT_FRAGMENT)
602 df = htons(IP_DF);
603 else if (skb->protocol == htons(ETH_P_IP))
604 df = inner_iph->frag_off & htons(IP_DF);
605 headroom += LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len;
606 if (headroom > dev->needed_headroom)
607 dev->needed_headroom = headroom;
608
609 if (skb_cow_head(skb, dev->needed_headroom)) {
610 ip_rt_put(rt);
611 goto tx_dropped;
612 }
613 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, proto, tos, ttl,
614 df, !net_eq(tunnel->net, dev_net(dev)));
615 return;
616 tx_error:
617 dev->stats.tx_errors++;
618 goto kfree;
619 tx_dropped:
620 dev->stats.tx_dropped++;
621 kfree:
622 kfree_skb(skb);
623 }
624 EXPORT_SYMBOL_GPL(ip_md_tunnel_xmit);
625
ip_tunnel_xmit(struct sk_buff * skb,struct net_device * dev,const struct iphdr * tnl_params,u8 protocol)626 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
627 const struct iphdr *tnl_params, u8 protocol)
628 {
629 struct ip_tunnel *tunnel = netdev_priv(dev);
630 unsigned int inner_nhdr_len = 0;
631 const struct iphdr *inner_iph;
632 struct flowi4 fl4;
633 u8 tos, ttl;
634 __be16 df;
635 struct rtable *rt; /* Route to the other host */
636 unsigned int max_headroom; /* The extra header space needed */
637 __be32 dst;
638 bool connected;
639
640 /* ensure we can access the inner net header, for several users below */
641 if (skb->protocol == htons(ETH_P_IP))
642 inner_nhdr_len = sizeof(struct iphdr);
643 else if (skb->protocol == htons(ETH_P_IPV6))
644 inner_nhdr_len = sizeof(struct ipv6hdr);
645 if (unlikely(!pskb_may_pull(skb, inner_nhdr_len)))
646 goto tx_error;
647
648 inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
649 connected = (tunnel->parms.iph.daddr != 0);
650
651 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
652
653 dst = tnl_params->daddr;
654 if (dst == 0) {
655 /* NBMA tunnel */
656
657 if (!skb_dst(skb)) {
658 dev->stats.tx_fifo_errors++;
659 goto tx_error;
660 }
661
662 if (skb->protocol == htons(ETH_P_IP)) {
663 rt = skb_rtable(skb);
664 dst = rt_nexthop(rt, inner_iph->daddr);
665 }
666 #if IS_ENABLED(CONFIG_IPV6)
667 else if (skb->protocol == htons(ETH_P_IPV6)) {
668 const struct in6_addr *addr6;
669 struct neighbour *neigh;
670 bool do_tx_error_icmp;
671 int addr_type;
672
673 neigh = dst_neigh_lookup(skb_dst(skb),
674 &ipv6_hdr(skb)->daddr);
675 if (!neigh)
676 goto tx_error;
677
678 addr6 = (const struct in6_addr *)&neigh->primary_key;
679 addr_type = ipv6_addr_type(addr6);
680
681 if (addr_type == IPV6_ADDR_ANY) {
682 addr6 = &ipv6_hdr(skb)->daddr;
683 addr_type = ipv6_addr_type(addr6);
684 }
685
686 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
687 do_tx_error_icmp = true;
688 else {
689 do_tx_error_icmp = false;
690 dst = addr6->s6_addr32[3];
691 }
692 neigh_release(neigh);
693 if (do_tx_error_icmp)
694 goto tx_error_icmp;
695 }
696 #endif
697 else
698 goto tx_error;
699
700 connected = false;
701 }
702
703 tos = tnl_params->tos;
704 if (tos & 0x1) {
705 tos &= ~0x1;
706 if (skb->protocol == htons(ETH_P_IP)) {
707 tos = inner_iph->tos;
708 connected = false;
709 } else if (skb->protocol == htons(ETH_P_IPV6)) {
710 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
711 connected = false;
712 }
713 }
714
715 ip_tunnel_init_flow(&fl4, protocol, dst, tnl_params->saddr,
716 tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link,
717 tunnel->fwmark);
718
719 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0)
720 goto tx_error;
721
722 rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr) :
723 NULL;
724
725 if (!rt) {
726 rt = ip_route_output_key(tunnel->net, &fl4);
727
728 if (IS_ERR(rt)) {
729 dev->stats.tx_carrier_errors++;
730 goto tx_error;
731 }
732 if (connected)
733 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst,
734 fl4.saddr);
735 }
736
737 if (rt->dst.dev == dev) {
738 ip_rt_put(rt);
739 dev->stats.collisions++;
740 goto tx_error;
741 }
742
743 if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off, inner_iph)) {
744 ip_rt_put(rt);
745 goto tx_error;
746 }
747
748 if (tunnel->err_count > 0) {
749 if (time_before(jiffies,
750 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
751 tunnel->err_count--;
752
753 dst_link_failure(skb);
754 } else
755 tunnel->err_count = 0;
756 }
757
758 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb);
759 ttl = tnl_params->ttl;
760 if (ttl == 0) {
761 if (skb->protocol == htons(ETH_P_IP))
762 ttl = inner_iph->ttl;
763 #if IS_ENABLED(CONFIG_IPV6)
764 else if (skb->protocol == htons(ETH_P_IPV6))
765 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
766 #endif
767 else
768 ttl = ip4_dst_hoplimit(&rt->dst);
769 }
770
771 df = tnl_params->frag_off;
772 if (skb->protocol == htons(ETH_P_IP) && !tunnel->ignore_df)
773 df |= (inner_iph->frag_off&htons(IP_DF));
774
775 max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr)
776 + rt->dst.header_len + ip_encap_hlen(&tunnel->encap);
777 if (max_headroom > dev->needed_headroom)
778 dev->needed_headroom = max_headroom;
779
780 if (skb_cow_head(skb, dev->needed_headroom)) {
781 ip_rt_put(rt);
782 dev->stats.tx_dropped++;
783 kfree_skb(skb);
784 return;
785 }
786
787 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
788 df, !net_eq(tunnel->net, dev_net(dev)));
789 return;
790
791 #if IS_ENABLED(CONFIG_IPV6)
792 tx_error_icmp:
793 dst_link_failure(skb);
794 #endif
795 tx_error:
796 dev->stats.tx_errors++;
797 kfree_skb(skb);
798 }
799 EXPORT_SYMBOL_GPL(ip_tunnel_xmit);
800
ip_tunnel_update(struct ip_tunnel_net * itn,struct ip_tunnel * t,struct net_device * dev,struct ip_tunnel_parm * p,bool set_mtu,__u32 fwmark)801 static void ip_tunnel_update(struct ip_tunnel_net *itn,
802 struct ip_tunnel *t,
803 struct net_device *dev,
804 struct ip_tunnel_parm *p,
805 bool set_mtu,
806 __u32 fwmark)
807 {
808 ip_tunnel_del(itn, t);
809 t->parms.iph.saddr = p->iph.saddr;
810 t->parms.iph.daddr = p->iph.daddr;
811 t->parms.i_key = p->i_key;
812 t->parms.o_key = p->o_key;
813 if (dev->type != ARPHRD_ETHER) {
814 memcpy(dev->dev_addr, &p->iph.saddr, 4);
815 memcpy(dev->broadcast, &p->iph.daddr, 4);
816 }
817 ip_tunnel_add(itn, t);
818
819 t->parms.iph.ttl = p->iph.ttl;
820 t->parms.iph.tos = p->iph.tos;
821 t->parms.iph.frag_off = p->iph.frag_off;
822
823 if (t->parms.link != p->link || t->fwmark != fwmark) {
824 int mtu;
825
826 t->parms.link = p->link;
827 t->fwmark = fwmark;
828 mtu = ip_tunnel_bind_dev(dev);
829 if (set_mtu)
830 dev->mtu = mtu;
831 }
832 dst_cache_reset(&t->dst_cache);
833 netdev_state_change(dev);
834 }
835
ip_tunnel_ioctl(struct net_device * dev,struct ip_tunnel_parm * p,int cmd)836 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
837 {
838 int err = 0;
839 struct ip_tunnel *t = netdev_priv(dev);
840 struct net *net = t->net;
841 struct ip_tunnel_net *itn = net_generic(net, t->ip_tnl_net_id);
842
843 switch (cmd) {
844 case SIOCGETTUNNEL:
845 if (dev == itn->fb_tunnel_dev) {
846 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
847 if (!t)
848 t = netdev_priv(dev);
849 }
850 memcpy(p, &t->parms, sizeof(*p));
851 break;
852
853 case SIOCADDTUNNEL:
854 case SIOCCHGTUNNEL:
855 err = -EPERM;
856 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
857 goto done;
858 if (p->iph.ttl)
859 p->iph.frag_off |= htons(IP_DF);
860 if (!(p->i_flags & VTI_ISVTI)) {
861 if (!(p->i_flags & TUNNEL_KEY))
862 p->i_key = 0;
863 if (!(p->o_flags & TUNNEL_KEY))
864 p->o_key = 0;
865 }
866
867 t = ip_tunnel_find(itn, p, itn->type);
868
869 if (cmd == SIOCADDTUNNEL) {
870 if (!t) {
871 t = ip_tunnel_create(net, itn, p);
872 err = PTR_ERR_OR_ZERO(t);
873 break;
874 }
875
876 err = -EEXIST;
877 break;
878 }
879 if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
880 if (t) {
881 if (t->dev != dev) {
882 err = -EEXIST;
883 break;
884 }
885 } else {
886 unsigned int nflags = 0;
887
888 if (ipv4_is_multicast(p->iph.daddr))
889 nflags = IFF_BROADCAST;
890 else if (p->iph.daddr)
891 nflags = IFF_POINTOPOINT;
892
893 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
894 err = -EINVAL;
895 break;
896 }
897
898 t = netdev_priv(dev);
899 }
900 }
901
902 if (t) {
903 err = 0;
904 ip_tunnel_update(itn, t, dev, p, true, 0);
905 } else {
906 err = -ENOENT;
907 }
908 break;
909
910 case SIOCDELTUNNEL:
911 err = -EPERM;
912 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
913 goto done;
914
915 if (dev == itn->fb_tunnel_dev) {
916 err = -ENOENT;
917 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
918 if (!t)
919 goto done;
920 err = -EPERM;
921 if (t == netdev_priv(itn->fb_tunnel_dev))
922 goto done;
923 dev = t->dev;
924 }
925 unregister_netdevice(dev);
926 err = 0;
927 break;
928
929 default:
930 err = -EINVAL;
931 }
932
933 done:
934 return err;
935 }
936 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl);
937
__ip_tunnel_change_mtu(struct net_device * dev,int new_mtu,bool strict)938 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict)
939 {
940 struct ip_tunnel *tunnel = netdev_priv(dev);
941 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
942 int max_mtu = IP_MAX_MTU - dev->hard_header_len - t_hlen;
943
944 if (new_mtu < ETH_MIN_MTU)
945 return -EINVAL;
946
947 if (new_mtu > max_mtu) {
948 if (strict)
949 return -EINVAL;
950
951 new_mtu = max_mtu;
952 }
953
954 dev->mtu = new_mtu;
955 return 0;
956 }
957 EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu);
958
ip_tunnel_change_mtu(struct net_device * dev,int new_mtu)959 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
960 {
961 return __ip_tunnel_change_mtu(dev, new_mtu, true);
962 }
963 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu);
964
ip_tunnel_dev_free(struct net_device * dev)965 static void ip_tunnel_dev_free(struct net_device *dev)
966 {
967 struct ip_tunnel *tunnel = netdev_priv(dev);
968
969 gro_cells_destroy(&tunnel->gro_cells);
970 dst_cache_destroy(&tunnel->dst_cache);
971 free_percpu(dev->tstats);
972 }
973
ip_tunnel_dellink(struct net_device * dev,struct list_head * head)974 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head)
975 {
976 struct ip_tunnel *tunnel = netdev_priv(dev);
977 struct ip_tunnel_net *itn;
978
979 itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id);
980
981 if (itn->fb_tunnel_dev != dev) {
982 ip_tunnel_del(itn, netdev_priv(dev));
983 unregister_netdevice_queue(dev, head);
984 }
985 }
986 EXPORT_SYMBOL_GPL(ip_tunnel_dellink);
987
ip_tunnel_get_link_net(const struct net_device * dev)988 struct net *ip_tunnel_get_link_net(const struct net_device *dev)
989 {
990 struct ip_tunnel *tunnel = netdev_priv(dev);
991
992 return tunnel->net;
993 }
994 EXPORT_SYMBOL(ip_tunnel_get_link_net);
995
ip_tunnel_get_iflink(const struct net_device * dev)996 int ip_tunnel_get_iflink(const struct net_device *dev)
997 {
998 struct ip_tunnel *tunnel = netdev_priv(dev);
999
1000 return tunnel->parms.link;
1001 }
1002 EXPORT_SYMBOL(ip_tunnel_get_iflink);
1003
ip_tunnel_init_net(struct net * net,unsigned int ip_tnl_net_id,struct rtnl_link_ops * ops,char * devname)1004 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
1005 struct rtnl_link_ops *ops, char *devname)
1006 {
1007 struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id);
1008 struct ip_tunnel_parm parms;
1009 unsigned int i;
1010
1011 itn->rtnl_link_ops = ops;
1012 for (i = 0; i < IP_TNL_HASH_SIZE; i++)
1013 INIT_HLIST_HEAD(&itn->tunnels[i]);
1014
1015 if (!ops || !net_has_fallback_tunnels(net)) {
1016 struct ip_tunnel_net *it_init_net;
1017
1018 it_init_net = net_generic(&init_net, ip_tnl_net_id);
1019 itn->type = it_init_net->type;
1020 itn->fb_tunnel_dev = NULL;
1021 return 0;
1022 }
1023
1024 memset(&parms, 0, sizeof(parms));
1025 if (devname)
1026 strlcpy(parms.name, devname, IFNAMSIZ);
1027
1028 rtnl_lock();
1029 itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms);
1030 /* FB netdevice is special: we have one, and only one per netns.
1031 * Allowing to move it to another netns is clearly unsafe.
1032 */
1033 if (!IS_ERR(itn->fb_tunnel_dev)) {
1034 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1035 itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev);
1036 ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev));
1037 itn->type = itn->fb_tunnel_dev->type;
1038 }
1039 rtnl_unlock();
1040
1041 return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev);
1042 }
1043 EXPORT_SYMBOL_GPL(ip_tunnel_init_net);
1044
ip_tunnel_destroy(struct net * net,struct ip_tunnel_net * itn,struct list_head * head,struct rtnl_link_ops * ops)1045 static void ip_tunnel_destroy(struct net *net, struct ip_tunnel_net *itn,
1046 struct list_head *head,
1047 struct rtnl_link_ops *ops)
1048 {
1049 struct net_device *dev, *aux;
1050 int h;
1051
1052 for_each_netdev_safe(net, dev, aux)
1053 if (dev->rtnl_link_ops == ops)
1054 unregister_netdevice_queue(dev, head);
1055
1056 for (h = 0; h < IP_TNL_HASH_SIZE; h++) {
1057 struct ip_tunnel *t;
1058 struct hlist_node *n;
1059 struct hlist_head *thead = &itn->tunnels[h];
1060
1061 hlist_for_each_entry_safe(t, n, thead, hash_node)
1062 /* If dev is in the same netns, it has already
1063 * been added to the list by the previous loop.
1064 */
1065 if (!net_eq(dev_net(t->dev), net))
1066 unregister_netdevice_queue(t->dev, head);
1067 }
1068 }
1069
ip_tunnel_delete_nets(struct list_head * net_list,unsigned int id,struct rtnl_link_ops * ops)1070 void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id,
1071 struct rtnl_link_ops *ops)
1072 {
1073 struct ip_tunnel_net *itn;
1074 struct net *net;
1075 LIST_HEAD(list);
1076
1077 rtnl_lock();
1078 list_for_each_entry(net, net_list, exit_list) {
1079 itn = net_generic(net, id);
1080 ip_tunnel_destroy(net, itn, &list, ops);
1081 }
1082 unregister_netdevice_many(&list);
1083 rtnl_unlock();
1084 }
1085 EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets);
1086
ip_tunnel_newlink(struct net_device * dev,struct nlattr * tb[],struct ip_tunnel_parm * p,__u32 fwmark)1087 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
1088 struct ip_tunnel_parm *p, __u32 fwmark)
1089 {
1090 struct ip_tunnel *nt;
1091 struct net *net = dev_net(dev);
1092 struct ip_tunnel_net *itn;
1093 int mtu;
1094 int err;
1095
1096 nt = netdev_priv(dev);
1097 itn = net_generic(net, nt->ip_tnl_net_id);
1098
1099 if (nt->collect_md) {
1100 if (rtnl_dereference(itn->collect_md_tun))
1101 return -EEXIST;
1102 } else {
1103 if (ip_tunnel_find(itn, p, dev->type))
1104 return -EEXIST;
1105 }
1106
1107 nt->net = net;
1108 nt->parms = *p;
1109 nt->fwmark = fwmark;
1110 err = register_netdevice(dev);
1111 if (err)
1112 goto err_register_netdevice;
1113
1114 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1115 eth_hw_addr_random(dev);
1116
1117 mtu = ip_tunnel_bind_dev(dev);
1118 if (tb[IFLA_MTU]) {
1119 unsigned int max = IP_MAX_MTU - dev->hard_header_len - nt->hlen;
1120
1121 mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU,
1122 (unsigned int)(max - sizeof(struct iphdr)));
1123 }
1124
1125 err = dev_set_mtu(dev, mtu);
1126 if (err)
1127 goto err_dev_set_mtu;
1128
1129 ip_tunnel_add(itn, nt);
1130 return 0;
1131
1132 err_dev_set_mtu:
1133 unregister_netdevice(dev);
1134 err_register_netdevice:
1135 return err;
1136 }
1137 EXPORT_SYMBOL_GPL(ip_tunnel_newlink);
1138
ip_tunnel_changelink(struct net_device * dev,struct nlattr * tb[],struct ip_tunnel_parm * p,__u32 fwmark)1139 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
1140 struct ip_tunnel_parm *p, __u32 fwmark)
1141 {
1142 struct ip_tunnel *t;
1143 struct ip_tunnel *tunnel = netdev_priv(dev);
1144 struct net *net = tunnel->net;
1145 struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id);
1146
1147 if (dev == itn->fb_tunnel_dev)
1148 return -EINVAL;
1149
1150 t = ip_tunnel_find(itn, p, dev->type);
1151
1152 if (t) {
1153 if (t->dev != dev)
1154 return -EEXIST;
1155 } else {
1156 t = tunnel;
1157
1158 if (dev->type != ARPHRD_ETHER) {
1159 unsigned int nflags = 0;
1160
1161 if (ipv4_is_multicast(p->iph.daddr))
1162 nflags = IFF_BROADCAST;
1163 else if (p->iph.daddr)
1164 nflags = IFF_POINTOPOINT;
1165
1166 if ((dev->flags ^ nflags) &
1167 (IFF_POINTOPOINT | IFF_BROADCAST))
1168 return -EINVAL;
1169 }
1170 }
1171
1172 ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU], fwmark);
1173 return 0;
1174 }
1175 EXPORT_SYMBOL_GPL(ip_tunnel_changelink);
1176
ip_tunnel_init(struct net_device * dev)1177 int ip_tunnel_init(struct net_device *dev)
1178 {
1179 struct ip_tunnel *tunnel = netdev_priv(dev);
1180 struct iphdr *iph = &tunnel->parms.iph;
1181 int err;
1182
1183 dev->needs_free_netdev = true;
1184 dev->priv_destructor = ip_tunnel_dev_free;
1185 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1186 if (!dev->tstats)
1187 return -ENOMEM;
1188
1189 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1190 if (err) {
1191 free_percpu(dev->tstats);
1192 return err;
1193 }
1194
1195 err = gro_cells_init(&tunnel->gro_cells, dev);
1196 if (err) {
1197 dst_cache_destroy(&tunnel->dst_cache);
1198 free_percpu(dev->tstats);
1199 return err;
1200 }
1201
1202 tunnel->dev = dev;
1203 tunnel->net = dev_net(dev);
1204 strcpy(tunnel->parms.name, dev->name);
1205 iph->version = 4;
1206 iph->ihl = 5;
1207
1208 if (tunnel->collect_md) {
1209 dev->features |= NETIF_F_NETNS_LOCAL;
1210 netif_keep_dst(dev);
1211 }
1212 return 0;
1213 }
1214 EXPORT_SYMBOL_GPL(ip_tunnel_init);
1215
ip_tunnel_uninit(struct net_device * dev)1216 void ip_tunnel_uninit(struct net_device *dev)
1217 {
1218 struct ip_tunnel *tunnel = netdev_priv(dev);
1219 struct net *net = tunnel->net;
1220 struct ip_tunnel_net *itn;
1221
1222 itn = net_generic(net, tunnel->ip_tnl_net_id);
1223 /* fb_tunnel_dev will be unregisted in net-exit call. */
1224 if (itn->fb_tunnel_dev != dev)
1225 ip_tunnel_del(itn, netdev_priv(dev));
1226
1227 dst_cache_reset(&tunnel->dst_cache);
1228 }
1229 EXPORT_SYMBOL_GPL(ip_tunnel_uninit);
1230
1231 /* Do least required initialization, rest of init is done in tunnel_init call */
ip_tunnel_setup(struct net_device * dev,unsigned int net_id)1232 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id)
1233 {
1234 struct ip_tunnel *tunnel = netdev_priv(dev);
1235 tunnel->ip_tnl_net_id = net_id;
1236 }
1237 EXPORT_SYMBOL_GPL(ip_tunnel_setup);
1238
1239 MODULE_LICENSE("GPL");
1240
