2 * Linux NET3: GRE over IP protocol decoder.
4 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/capability.h>
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
20 #include <asm/uaccess.h>
21 #include <linux/skbuff.h>
22 #include <linux/netdevice.h>
24 #include <linux/tcp.h>
25 #include <linux/udp.h>
26 #include <linux/if_arp.h>
27 #include <linux/mroute.h>
28 #include <linux/init.h>
29 #include <linux/in6.h>
30 #include <linux/inetdevice.h>
31 #include <linux/igmp.h>
32 #include <linux/netfilter_ipv4.h>
33 #include <linux/etherdevice.h>
34 #include <linux/if_ether.h>
39 #include <net/protocol.h>
42 #include <net/checksum.h>
43 #include <net/dsfield.h>
44 #include <net/inet_ecn.h>
46 #include <net/net_namespace.h>
47 #include <net/netns/generic.h>
48 #include <net/rtnetlink.h>
51 #if IS_ENABLED(CONFIG_IPV6)
53 #include <net/ip6_fib.h>
54 #include <net/ip6_route.h>
61 1. The most important issue is detecting local dead loops.
62 They would cause complete host lockup in transmit, which
63 would be "resolved" by stack overflow or, if queueing is enabled,
64 with infinite looping in net_bh.
66 We cannot track such dead loops during route installation,
67 it is infeasible task. The most general solutions would be
68 to keep skb->encapsulation counter (sort of local ttl),
69 and silently drop packet when it expires. It is a good
70 solution, but it supposes maintaining new variable in ALL
71 skb, even if no tunneling is used.
73 Current solution: xmit_recursion breaks dead loops. This is a percpu
74 counter, since when we enter the first ndo_xmit(), cpu migration is
75 forbidden. We force an exit if this counter reaches RECURSION_LIMIT
77 2. Networking dead loops would not kill routers, but would really
78 kill network. IP hop limit plays role of "t->recursion" in this case,
79 if we copy it from packet being encapsulated to upper header.
80 It is very good solution, but it introduces two problems:
82 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
83 do not work over tunnels.
84 - traceroute does not work. I planned to relay ICMP from tunnel,
85 so that this problem would be solved and traceroute output
86 would even more informative. This idea appeared to be wrong:
87 only Linux complies to rfc1812 now (yes, guys, Linux is the only
88 true router now :-)), all routers (at least, in neighbourhood of mine)
89 return only 8 bytes of payload. It is the end.
91 Hence, if we want that OSPF worked or traceroute said something reasonable,
92 we should search for another solution.
94 One of them is to parse packet trying to detect inner encapsulation
95 made by our node. It is difficult or even impossible, especially,
96 taking into account fragmentation. TO be short, ttl is not solution at all.
98 Current solution: The solution was UNEXPECTEDLY SIMPLE.
99 We force DF flag on tunnels with preconfigured hop limit,
100 that is ALL. :-) Well, it does not remove the problem completely,
101 but exponential growth of network traffic is changed to linear
102 (branches, that exceed pmtu are pruned) and tunnel mtu
103 rapidly degrades to value <68, where looping stops.
104 Yes, it is not good if there exists a router in the loop,
105 which does not force DF, even when encapsulating packets have DF set.
106 But it is not our problem! Nobody could accuse us, we made
107 all that we could make. Even if it is your gated who injected
108 fatal route to network, even if it were you who configured
109 fatal static route: you are innocent. :-)
113 3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
114 practically identical code. It would be good to glue them
115 together, but it is not very evident, how to make them modular.
116 sit is integral part of IPv6, ipip and gre are naturally modular.
117 We could extract common parts (hash table, ioctl etc)
118 to a separate module (ip_tunnel.c).
123 static bool log_ecn_error = true;
124 module_param(log_ecn_error, bool, 0644);
125 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
127 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
128 static int ipgre_tunnel_init(struct net_device *dev);
129 static void ipgre_tunnel_setup(struct net_device *dev);
130 static int ipgre_tunnel_bind_dev(struct net_device *dev);
132 /* Fallback tunnel: no source, no destination, no key, no options */
136 static int ipgre_net_id __read_mostly;
138 struct ip_tunnel __rcu *tunnels[4][HASH_SIZE];
140 struct net_device *fb_tunnel_dev;
143 /* Tunnel hash table */
153 We require exact key match i.e. if a key is present in packet
154 it will match only tunnel with the same key; if it is not present,
155 it will match only keyless tunnel.
157 All keysless packets, if not matched configured keyless tunnels
158 will match fallback tunnel.
161 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
163 #define tunnels_r_l tunnels[3]
164 #define tunnels_r tunnels[2]
165 #define tunnels_l tunnels[1]
166 #define tunnels_wc tunnels[0]
168 static struct rtnl_link_stats64 *ipgre_get_stats64(struct net_device *dev,
169 struct rtnl_link_stats64 *tot)
173 for_each_possible_cpu(i) {
174 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
175 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
179 start = u64_stats_fetch_begin_bh(&tstats->syncp);
180 rx_packets = tstats->rx_packets;
181 tx_packets = tstats->tx_packets;
182 rx_bytes = tstats->rx_bytes;
183 tx_bytes = tstats->tx_bytes;
184 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
186 tot->rx_packets += rx_packets;
187 tot->tx_packets += tx_packets;
188 tot->rx_bytes += rx_bytes;
189 tot->tx_bytes += tx_bytes;
192 tot->multicast = dev->stats.multicast;
193 tot->rx_crc_errors = dev->stats.rx_crc_errors;
194 tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
195 tot->rx_length_errors = dev->stats.rx_length_errors;
196 tot->rx_frame_errors = dev->stats.rx_frame_errors;
197 tot->rx_errors = dev->stats.rx_errors;
199 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
200 tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
201 tot->tx_dropped = dev->stats.tx_dropped;
202 tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
203 tot->tx_errors = dev->stats.tx_errors;
208 /* Does key in tunnel parameters match packet */
209 static bool ipgre_key_match(const struct ip_tunnel_parm *p,
210 __be16 flags, __be32 key)
212 if (p->i_flags & GRE_KEY) {
214 return key == p->i_key;
216 return false; /* key expected, none present */
218 return !(flags & GRE_KEY);
221 /* Given src, dst and key, find appropriate for input tunnel. */
223 static struct ip_tunnel *ipgre_tunnel_lookup(struct net_device *dev,
224 __be32 remote, __be32 local,
225 __be16 flags, __be32 key,
228 struct net *net = dev_net(dev);
229 int link = dev->ifindex;
230 unsigned int h0 = HASH(remote);
231 unsigned int h1 = HASH(key);
232 struct ip_tunnel *t, *cand = NULL;
233 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
234 int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
235 ARPHRD_ETHER : ARPHRD_IPGRE;
236 int score, cand_score = 4;
238 for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
239 if (local != t->parms.iph.saddr ||
240 remote != t->parms.iph.daddr ||
241 !(t->dev->flags & IFF_UP))
244 if (!ipgre_key_match(&t->parms, flags, key))
247 if (t->dev->type != ARPHRD_IPGRE &&
248 t->dev->type != dev_type)
252 if (t->parms.link != link)
254 if (t->dev->type != dev_type)
259 if (score < cand_score) {
265 for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
266 if (remote != t->parms.iph.daddr ||
267 !(t->dev->flags & IFF_UP))
270 if (!ipgre_key_match(&t->parms, flags, key))
273 if (t->dev->type != ARPHRD_IPGRE &&
274 t->dev->type != dev_type)
278 if (t->parms.link != link)
280 if (t->dev->type != dev_type)
285 if (score < cand_score) {
291 for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
292 if ((local != t->parms.iph.saddr &&
293 (local != t->parms.iph.daddr ||
294 !ipv4_is_multicast(local))) ||
295 !(t->dev->flags & IFF_UP))
298 if (!ipgre_key_match(&t->parms, flags, key))
301 if (t->dev->type != ARPHRD_IPGRE &&
302 t->dev->type != dev_type)
306 if (t->parms.link != link)
308 if (t->dev->type != dev_type)
313 if (score < cand_score) {
319 for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
320 if (t->parms.i_key != key ||
321 !(t->dev->flags & IFF_UP))
324 if (t->dev->type != ARPHRD_IPGRE &&
325 t->dev->type != dev_type)
329 if (t->parms.link != link)
331 if (t->dev->type != dev_type)
336 if (score < cand_score) {
345 dev = ign->fb_tunnel_dev;
346 if (dev->flags & IFF_UP)
347 return netdev_priv(dev);
352 static struct ip_tunnel __rcu **__ipgre_bucket(struct ipgre_net *ign,
353 struct ip_tunnel_parm *parms)
355 __be32 remote = parms->iph.daddr;
356 __be32 local = parms->iph.saddr;
357 __be32 key = parms->i_key;
358 unsigned int h = HASH(key);
363 if (remote && !ipv4_is_multicast(remote)) {
368 return &ign->tunnels[prio][h];
371 static inline struct ip_tunnel __rcu **ipgre_bucket(struct ipgre_net *ign,
374 return __ipgre_bucket(ign, &t->parms);
377 static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
379 struct ip_tunnel __rcu **tp = ipgre_bucket(ign, t);
381 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
382 rcu_assign_pointer(*tp, t);
385 static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
387 struct ip_tunnel __rcu **tp;
388 struct ip_tunnel *iter;
390 for (tp = ipgre_bucket(ign, t);
391 (iter = rtnl_dereference(*tp)) != NULL;
394 rcu_assign_pointer(*tp, t->next);
400 static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
401 struct ip_tunnel_parm *parms,
404 __be32 remote = parms->iph.daddr;
405 __be32 local = parms->iph.saddr;
406 __be32 key = parms->i_key;
407 int link = parms->link;
409 struct ip_tunnel __rcu **tp;
410 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
412 for (tp = __ipgre_bucket(ign, parms);
413 (t = rtnl_dereference(*tp)) != NULL;
415 if (local == t->parms.iph.saddr &&
416 remote == t->parms.iph.daddr &&
417 key == t->parms.i_key &&
418 link == t->parms.link &&
419 type == t->dev->type)
425 static struct ip_tunnel *ipgre_tunnel_locate(struct net *net,
426 struct ip_tunnel_parm *parms, int create)
428 struct ip_tunnel *t, *nt;
429 struct net_device *dev;
431 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
433 t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
438 strlcpy(name, parms->name, IFNAMSIZ);
440 strcpy(name, "gre%d");
442 dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
446 dev_net_set(dev, net);
448 nt = netdev_priv(dev);
450 dev->rtnl_link_ops = &ipgre_link_ops;
452 dev->mtu = ipgre_tunnel_bind_dev(dev);
454 if (register_netdevice(dev) < 0)
457 /* Can use a lockless transmit, unless we generate output sequences */
458 if (!(nt->parms.o_flags & GRE_SEQ))
459 dev->features |= NETIF_F_LLTX;
462 ipgre_tunnel_link(ign, nt);
470 static void ipgre_tunnel_uninit(struct net_device *dev)
472 struct net *net = dev_net(dev);
473 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
475 ipgre_tunnel_unlink(ign, netdev_priv(dev));
480 static void ipgre_err(struct sk_buff *skb, u32 info)
483 /* All the routers (except for Linux) return only
484 8 bytes of packet payload. It means, that precise relaying of
485 ICMP in the real Internet is absolutely infeasible.
487 Moreover, Cisco "wise men" put GRE key to the third word
488 in GRE header. It makes impossible maintaining even soft state for keyed
489 GRE tunnels with enabled checksum. Tell them "thank you".
491 Well, I wonder, rfc1812 was written by Cisco employee,
492 what the hell these idiots break standards established
496 const struct iphdr *iph = (const struct iphdr *)skb->data;
497 __be16 *p = (__be16 *)(skb->data+(iph->ihl<<2));
498 int grehlen = (iph->ihl<<2) + 4;
499 const int type = icmp_hdr(skb)->type;
500 const int code = icmp_hdr(skb)->code;
506 if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
507 if (flags&(GRE_VERSION|GRE_ROUTING))
516 /* If only 8 bytes returned, keyed message will be dropped here */
517 if (skb_headlen(skb) < grehlen)
521 key = *(((__be32 *)p) + (grehlen / 4) - 1);
525 case ICMP_PARAMETERPROB:
528 case ICMP_DEST_UNREACH:
531 case ICMP_PORT_UNREACH:
532 /* Impossible event. */
535 /* All others are translated to HOST_UNREACH.
536 rfc2003 contains "deep thoughts" about NET_UNREACH,
537 I believe they are just ether pollution. --ANK
542 case ICMP_TIME_EXCEEDED:
543 if (code != ICMP_EXC_TTL)
551 t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
557 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
558 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
559 t->parms.link, 0, IPPROTO_GRE, 0);
562 if (type == ICMP_REDIRECT) {
563 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
567 if (t->parms.iph.daddr == 0 ||
568 ipv4_is_multicast(t->parms.iph.daddr))
571 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
574 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
578 t->err_time = jiffies;
582 ipgre_ecn_encapsulate(u8 tos, const struct iphdr *old_iph, struct sk_buff *skb)
585 if (skb->protocol == htons(ETH_P_IP))
586 inner = old_iph->tos;
587 else if (skb->protocol == htons(ETH_P_IPV6))
588 inner = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
589 return INET_ECN_encapsulate(tos, inner);
592 static int ipgre_rcv(struct sk_buff *skb)
594 const struct iphdr *iph;
600 struct ip_tunnel *tunnel;
605 if (!pskb_may_pull(skb, 16))
610 flags = *(__be16 *)h;
612 if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
613 /* - Version must be 0.
614 - We do not support routing headers.
616 if (flags&(GRE_VERSION|GRE_ROUTING))
619 if (flags&GRE_CSUM) {
620 switch (skb->ip_summed) {
621 case CHECKSUM_COMPLETE:
622 csum = csum_fold(skb->csum);
628 csum = __skb_checksum_complete(skb);
629 skb->ip_summed = CHECKSUM_COMPLETE;
634 key = *(__be32 *)(h + offset);
638 seqno = ntohl(*(__be32 *)(h + offset));
643 gre_proto = *(__be16 *)(h + 2);
645 tunnel = ipgre_tunnel_lookup(skb->dev,
646 iph->saddr, iph->daddr, flags, key,
649 struct pcpu_tstats *tstats;
653 skb->protocol = gre_proto;
654 /* WCCP version 1 and 2 protocol decoding.
655 * - Change protocol to IP
656 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
658 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
659 skb->protocol = htons(ETH_P_IP);
660 if ((*(h + offset) & 0xF0) != 0x40)
664 skb->mac_header = skb->network_header;
665 __pskb_pull(skb, offset);
666 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
667 skb->pkt_type = PACKET_HOST;
668 #ifdef CONFIG_NET_IPGRE_BROADCAST
669 if (ipv4_is_multicast(iph->daddr)) {
670 /* Looped back packet, drop it! */
671 if (rt_is_output_route(skb_rtable(skb)))
673 tunnel->dev->stats.multicast++;
674 skb->pkt_type = PACKET_BROADCAST;
678 if (((flags&GRE_CSUM) && csum) ||
679 (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
680 tunnel->dev->stats.rx_crc_errors++;
681 tunnel->dev->stats.rx_errors++;
684 if (tunnel->parms.i_flags&GRE_SEQ) {
685 if (!(flags&GRE_SEQ) ||
686 (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
687 tunnel->dev->stats.rx_fifo_errors++;
688 tunnel->dev->stats.rx_errors++;
691 tunnel->i_seqno = seqno + 1;
694 /* Warning: All skb pointers will be invalidated! */
695 if (tunnel->dev->type == ARPHRD_ETHER) {
696 if (!pskb_may_pull(skb, ETH_HLEN)) {
697 tunnel->dev->stats.rx_length_errors++;
698 tunnel->dev->stats.rx_errors++;
703 skb->protocol = eth_type_trans(skb, tunnel->dev);
704 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
707 __skb_tunnel_rx(skb, tunnel->dev);
709 skb_reset_network_header(skb);
710 err = IP_ECN_decapsulate(iph, skb);
713 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
714 &iph->saddr, iph->tos);
716 ++tunnel->dev->stats.rx_frame_errors;
717 ++tunnel->dev->stats.rx_errors;
722 tstats = this_cpu_ptr(tunnel->dev->tstats);
723 u64_stats_update_begin(&tstats->syncp);
724 tstats->rx_packets++;
725 tstats->rx_bytes += skb->len;
726 u64_stats_update_end(&tstats->syncp);
728 gro_cells_receive(&tunnel->gro_cells, skb);
731 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
738 static struct sk_buff *handle_offloads(struct ip_tunnel *tunnel, struct sk_buff *skb)
742 if (skb_is_gso(skb)) {
743 err = skb_unclone(skb, GFP_ATOMIC);
746 skb_shinfo(skb)->gso_type |= SKB_GSO_GRE;
748 } else if (skb->ip_summed == CHECKSUM_PARTIAL &&
749 tunnel->parms.o_flags&GRE_CSUM) {
750 err = skb_checksum_help(skb);
753 } else if (skb->ip_summed != CHECKSUM_PARTIAL)
754 skb->ip_summed = CHECKSUM_NONE;
763 static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
765 struct pcpu_tstats *tstats = this_cpu_ptr(dev->tstats);
766 struct ip_tunnel *tunnel = netdev_priv(dev);
767 const struct iphdr *old_iph;
768 const struct iphdr *tiph;
772 struct rtable *rt; /* Route to the other host */
773 struct net_device *tdev; /* Device to other host */
774 struct iphdr *iph; /* Our new IP header */
775 unsigned int max_headroom; /* The extra header space needed */
783 skb = handle_offloads(tunnel, skb);
785 dev->stats.tx_dropped++;
789 if (!skb->encapsulation) {
790 skb_reset_inner_headers(skb);
791 skb->encapsulation = 1;
794 old_iph = ip_hdr(skb);
796 if (dev->type == ARPHRD_ETHER)
797 IPCB(skb)->flags = 0;
799 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
801 tiph = (const struct iphdr *)skb->data;
803 gre_hlen = tunnel->hlen;
804 tiph = &tunnel->parms.iph;
807 if ((dst = tiph->daddr) == 0) {
810 if (skb_dst(skb) == NULL) {
811 dev->stats.tx_fifo_errors++;
815 if (skb->protocol == htons(ETH_P_IP)) {
816 rt = skb_rtable(skb);
817 dst = rt_nexthop(rt, old_iph->daddr);
819 #if IS_ENABLED(CONFIG_IPV6)
820 else if (skb->protocol == htons(ETH_P_IPV6)) {
821 const struct in6_addr *addr6;
822 struct neighbour *neigh;
823 bool do_tx_error_icmp;
826 neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr);
830 addr6 = (const struct in6_addr *)&neigh->primary_key;
831 addr_type = ipv6_addr_type(addr6);
833 if (addr_type == IPV6_ADDR_ANY) {
834 addr6 = &ipv6_hdr(skb)->daddr;
835 addr_type = ipv6_addr_type(addr6);
838 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
839 do_tx_error_icmp = true;
841 do_tx_error_icmp = false;
842 dst = addr6->s6_addr32[3];
844 neigh_release(neigh);
845 if (do_tx_error_icmp)
857 if (skb->protocol == htons(ETH_P_IP))
859 else if (skb->protocol == htons(ETH_P_IPV6))
860 tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
863 rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
864 tunnel->parms.o_key, RT_TOS(tos),
867 dev->stats.tx_carrier_errors++;
874 dev->stats.collisions++;
880 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
882 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
885 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
887 if (skb->protocol == htons(ETH_P_IP)) {
888 df |= (old_iph->frag_off&htons(IP_DF));
890 if (!skb_is_gso(skb) &&
891 (old_iph->frag_off&htons(IP_DF)) &&
892 mtu < ntohs(old_iph->tot_len)) {
893 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
898 #if IS_ENABLED(CONFIG_IPV6)
899 else if (skb->protocol == htons(ETH_P_IPV6)) {
900 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
902 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
903 if ((tunnel->parms.iph.daddr &&
904 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
905 rt6->rt6i_dst.plen == 128) {
906 rt6->rt6i_flags |= RTF_MODIFIED;
907 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
911 if (!skb_is_gso(skb) &&
912 mtu >= IPV6_MIN_MTU &&
913 mtu < skb->len - tunnel->hlen + gre_hlen) {
914 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
921 if (tunnel->err_count > 0) {
922 if (time_before(jiffies,
923 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
926 dst_link_failure(skb);
928 tunnel->err_count = 0;
931 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
933 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
934 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
935 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
936 if (max_headroom > dev->needed_headroom)
937 dev->needed_headroom = max_headroom;
940 dev->stats.tx_dropped++;
945 skb_set_owner_w(new_skb, skb->sk);
948 old_iph = ip_hdr(skb);
949 /* Warning : tiph value might point to freed memory */
952 skb_push(skb, gre_hlen);
953 skb_reset_network_header(skb);
954 skb_set_transport_header(skb, sizeof(*iph));
955 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
956 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
959 skb_dst_set(skb, &rt->dst);
962 * Push down and install the IPIP header.
967 iph->ihl = sizeof(struct iphdr) >> 2;
969 iph->protocol = IPPROTO_GRE;
970 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
971 iph->daddr = fl4.daddr;
972 iph->saddr = fl4.saddr;
975 tunnel_ip_select_ident(skb, old_iph, &rt->dst);
978 if (skb->protocol == htons(ETH_P_IP))
979 iph->ttl = old_iph->ttl;
980 #if IS_ENABLED(CONFIG_IPV6)
981 else if (skb->protocol == htons(ETH_P_IPV6))
982 iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
985 iph->ttl = ip4_dst_hoplimit(&rt->dst);
988 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
989 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
990 htons(ETH_P_TEB) : skb->protocol;
992 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
993 __be32 *ptr = (__be32 *)(((u8 *)iph) + tunnel->hlen - 4);
995 if (tunnel->parms.o_flags&GRE_SEQ) {
997 *ptr = htonl(tunnel->o_seqno);
1000 if (tunnel->parms.o_flags&GRE_KEY) {
1001 *ptr = tunnel->parms.o_key;
1004 /* Skip GRE checksum if skb is getting offloaded. */
1005 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE) &&
1006 (tunnel->parms.o_flags&GRE_CSUM)) {
1007 int offset = skb_transport_offset(skb);
1009 if (skb_has_shared_frag(skb)) {
1010 err = __skb_linearize(skb);
1016 *(__sum16 *)ptr = csum_fold(skb_checksum(skb, offset,
1024 pkt_len = skb->len - skb_transport_offset(skb);
1025 err = ip_local_out(skb);
1026 if (likely(net_xmit_eval(err) == 0)) {
1027 u64_stats_update_begin(&tstats->syncp);
1028 tstats->tx_bytes += pkt_len;
1029 tstats->tx_packets++;
1030 u64_stats_update_end(&tstats->syncp);
1032 dev->stats.tx_errors++;
1033 dev->stats.tx_aborted_errors++;
1035 return NETDEV_TX_OK;
1037 #if IS_ENABLED(CONFIG_IPV6)
1039 dst_link_failure(skb);
1042 dev->stats.tx_errors++;
1044 return NETDEV_TX_OK;
1047 static int ipgre_tunnel_bind_dev(struct net_device *dev)
1049 struct net_device *tdev = NULL;
1050 struct ip_tunnel *tunnel;
1051 const struct iphdr *iph;
1052 int hlen = LL_MAX_HEADER;
1053 int mtu = ETH_DATA_LEN;
1054 int addend = sizeof(struct iphdr) + 4;
1056 tunnel = netdev_priv(dev);
1057 iph = &tunnel->parms.iph;
1059 /* Guess output device to choose reasonable mtu and needed_headroom */
1065 rt = ip_route_output_gre(dev_net(dev), &fl4,
1066 iph->daddr, iph->saddr,
1067 tunnel->parms.o_key,
1069 tunnel->parms.link);
1075 if (dev->type != ARPHRD_ETHER)
1076 dev->flags |= IFF_POINTOPOINT;
1079 if (!tdev && tunnel->parms.link)
1080 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
1083 hlen = tdev->hard_header_len + tdev->needed_headroom;
1086 dev->iflink = tunnel->parms.link;
1088 /* Precalculate GRE options length */
1089 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
1090 if (tunnel->parms.o_flags&GRE_CSUM)
1092 if (tunnel->parms.o_flags&GRE_KEY)
1094 if (tunnel->parms.o_flags&GRE_SEQ)
1097 dev->needed_headroom = addend + hlen;
1098 mtu -= dev->hard_header_len + addend;
1103 tunnel->hlen = addend;
1104 /* TCP offload with GRE SEQ is not supported. */
1105 if (!(tunnel->parms.o_flags & GRE_SEQ)) {
1106 dev->features |= NETIF_F_GSO_SOFTWARE;
1107 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1114 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1117 struct ip_tunnel_parm p;
1118 struct ip_tunnel *t;
1119 struct net *net = dev_net(dev);
1120 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1125 if (dev == ign->fb_tunnel_dev) {
1126 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1130 t = ipgre_tunnel_locate(net, &p, 0);
1133 t = netdev_priv(dev);
1134 memcpy(&p, &t->parms, sizeof(p));
1135 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1142 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1146 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1150 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1151 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1152 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1155 p.iph.frag_off |= htons(IP_DF);
1157 if (!(p.i_flags&GRE_KEY))
1159 if (!(p.o_flags&GRE_KEY))
1162 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1164 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1166 if (t->dev != dev) {
1171 unsigned int nflags = 0;
1173 t = netdev_priv(dev);
1175 if (ipv4_is_multicast(p.iph.daddr))
1176 nflags = IFF_BROADCAST;
1177 else if (p.iph.daddr)
1178 nflags = IFF_POINTOPOINT;
1180 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1184 ipgre_tunnel_unlink(ign, t);
1186 t->parms.iph.saddr = p.iph.saddr;
1187 t->parms.iph.daddr = p.iph.daddr;
1188 t->parms.i_key = p.i_key;
1189 t->parms.o_key = p.o_key;
1190 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1191 memcpy(dev->broadcast, &p.iph.daddr, 4);
1192 ipgre_tunnel_link(ign, t);
1193 netdev_state_change(dev);
1199 if (cmd == SIOCCHGTUNNEL) {
1200 t->parms.iph.ttl = p.iph.ttl;
1201 t->parms.iph.tos = p.iph.tos;
1202 t->parms.iph.frag_off = p.iph.frag_off;
1203 if (t->parms.link != p.link) {
1204 t->parms.link = p.link;
1205 dev->mtu = ipgre_tunnel_bind_dev(dev);
1206 netdev_state_change(dev);
1209 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1212 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1217 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1220 if (dev == ign->fb_tunnel_dev) {
1222 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1225 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1228 if (t == netdev_priv(ign->fb_tunnel_dev))
1232 unregister_netdevice(dev);
1244 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1246 struct ip_tunnel *tunnel = netdev_priv(dev);
1248 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1254 /* Nice toy. Unfortunately, useless in real life :-)
1255 It allows to construct virtual multiprotocol broadcast "LAN"
1256 over the Internet, provided multicast routing is tuned.
1259 I have no idea was this bicycle invented before me,
1260 so that I had to set ARPHRD_IPGRE to a random value.
1261 I have an impression, that Cisco could make something similar,
1262 but this feature is apparently missing in IOS<=11.2(8).
1264 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1265 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1267 ping -t 255 224.66.66.66
1269 If nobody answers, mbone does not work.
1271 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1272 ip addr add 10.66.66.<somewhat>/24 dev Universe
1273 ifconfig Universe up
1274 ifconfig Universe add fe80::<Your_real_addr>/10
1275 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1278 ftp fec0:6666:6666::193.233.7.65
1283 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1284 unsigned short type,
1285 const void *daddr, const void *saddr, unsigned int len)
1287 struct ip_tunnel *t = netdev_priv(dev);
1288 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1289 __be16 *p = (__be16 *)(iph+1);
1291 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1292 p[0] = t->parms.o_flags;
1296 * Set the source hardware address.
1300 memcpy(&iph->saddr, saddr, 4);
1302 memcpy(&iph->daddr, daddr, 4);
1309 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1311 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
1312 memcpy(haddr, &iph->saddr, 4);
1316 static const struct header_ops ipgre_header_ops = {
1317 .create = ipgre_header,
1318 .parse = ipgre_header_parse,
1321 #ifdef CONFIG_NET_IPGRE_BROADCAST
1322 static int ipgre_open(struct net_device *dev)
1324 struct ip_tunnel *t = netdev_priv(dev);
1326 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1330 rt = ip_route_output_gre(dev_net(dev), &fl4,
1334 RT_TOS(t->parms.iph.tos),
1337 return -EADDRNOTAVAIL;
1340 if (__in_dev_get_rtnl(dev) == NULL)
1341 return -EADDRNOTAVAIL;
1342 t->mlink = dev->ifindex;
1343 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1348 static int ipgre_close(struct net_device *dev)
1350 struct ip_tunnel *t = netdev_priv(dev);
1352 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1353 struct in_device *in_dev;
1354 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1356 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1363 static const struct net_device_ops ipgre_netdev_ops = {
1364 .ndo_init = ipgre_tunnel_init,
1365 .ndo_uninit = ipgre_tunnel_uninit,
1366 #ifdef CONFIG_NET_IPGRE_BROADCAST
1367 .ndo_open = ipgre_open,
1368 .ndo_stop = ipgre_close,
1370 .ndo_start_xmit = ipgre_tunnel_xmit,
1371 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1372 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1373 .ndo_get_stats64 = ipgre_get_stats64,
1376 static void ipgre_dev_free(struct net_device *dev)
1378 struct ip_tunnel *tunnel = netdev_priv(dev);
1380 gro_cells_destroy(&tunnel->gro_cells);
1381 free_percpu(dev->tstats);
1385 #define GRE_FEATURES (NETIF_F_SG | \
1386 NETIF_F_FRAGLIST | \
1390 static void ipgre_tunnel_setup(struct net_device *dev)
1392 dev->netdev_ops = &ipgre_netdev_ops;
1393 dev->destructor = ipgre_dev_free;
1395 dev->type = ARPHRD_IPGRE;
1396 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1397 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1398 dev->flags = IFF_NOARP;
1401 dev->features |= NETIF_F_NETNS_LOCAL;
1402 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1404 dev->features |= GRE_FEATURES;
1405 dev->hw_features |= GRE_FEATURES;
1408 static int ipgre_tunnel_init(struct net_device *dev)
1410 struct ip_tunnel *tunnel;
1414 tunnel = netdev_priv(dev);
1415 iph = &tunnel->parms.iph;
1418 strcpy(tunnel->parms.name, dev->name);
1420 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1421 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1424 #ifdef CONFIG_NET_IPGRE_BROADCAST
1425 if (ipv4_is_multicast(iph->daddr)) {
1428 dev->flags = IFF_BROADCAST;
1429 dev->header_ops = &ipgre_header_ops;
1433 dev->header_ops = &ipgre_header_ops;
1435 dev->tstats = alloc_percpu(struct pcpu_tstats);
1439 err = gro_cells_init(&tunnel->gro_cells, dev);
1441 free_percpu(dev->tstats);
1448 static void ipgre_fb_tunnel_init(struct net_device *dev)
1450 struct ip_tunnel *tunnel = netdev_priv(dev);
1451 struct iphdr *iph = &tunnel->parms.iph;
1454 strcpy(tunnel->parms.name, dev->name);
1457 iph->protocol = IPPROTO_GRE;
1459 tunnel->hlen = sizeof(struct iphdr) + 4;
1465 static const struct gre_protocol ipgre_protocol = {
1466 .handler = ipgre_rcv,
1467 .err_handler = ipgre_err,
1470 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1474 for (prio = 0; prio < 4; prio++) {
1476 for (h = 0; h < HASH_SIZE; h++) {
1477 struct ip_tunnel *t;
1479 t = rtnl_dereference(ign->tunnels[prio][h]);
1482 unregister_netdevice_queue(t->dev, head);
1483 t = rtnl_dereference(t->next);
1489 static int __net_init ipgre_init_net(struct net *net)
1491 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1494 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1495 ipgre_tunnel_setup);
1496 if (!ign->fb_tunnel_dev) {
1500 dev_net_set(ign->fb_tunnel_dev, net);
1502 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1503 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1505 if ((err = register_netdev(ign->fb_tunnel_dev)))
1508 rcu_assign_pointer(ign->tunnels_wc[0],
1509 netdev_priv(ign->fb_tunnel_dev));
1513 ipgre_dev_free(ign->fb_tunnel_dev);
1518 static void __net_exit ipgre_exit_net(struct net *net)
1520 struct ipgre_net *ign;
1523 ign = net_generic(net, ipgre_net_id);
1525 ipgre_destroy_tunnels(ign, &list);
1526 unregister_netdevice_many(&list);
1530 static struct pernet_operations ipgre_net_ops = {
1531 .init = ipgre_init_net,
1532 .exit = ipgre_exit_net,
1533 .id = &ipgre_net_id,
1534 .size = sizeof(struct ipgre_net),
1537 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1545 if (data[IFLA_GRE_IFLAGS])
1546 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1547 if (data[IFLA_GRE_OFLAGS])
1548 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1549 if (flags & (GRE_VERSION|GRE_ROUTING))
1555 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1559 if (tb[IFLA_ADDRESS]) {
1560 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1562 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1563 return -EADDRNOTAVAIL;
1569 if (data[IFLA_GRE_REMOTE]) {
1570 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1576 return ipgre_tunnel_validate(tb, data);
1579 static void ipgre_netlink_parms(struct nlattr *data[],
1580 struct ip_tunnel_parm *parms)
1582 memset(parms, 0, sizeof(*parms));
1584 parms->iph.protocol = IPPROTO_GRE;
1589 if (data[IFLA_GRE_LINK])
1590 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1592 if (data[IFLA_GRE_IFLAGS])
1593 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1595 if (data[IFLA_GRE_OFLAGS])
1596 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1598 if (data[IFLA_GRE_IKEY])
1599 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1601 if (data[IFLA_GRE_OKEY])
1602 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1604 if (data[IFLA_GRE_LOCAL])
1605 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1607 if (data[IFLA_GRE_REMOTE])
1608 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1610 if (data[IFLA_GRE_TTL])
1611 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1613 if (data[IFLA_GRE_TOS])
1614 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1616 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1617 parms->iph.frag_off = htons(IP_DF);
1620 static int ipgre_tap_init(struct net_device *dev)
1622 struct ip_tunnel *tunnel;
1624 tunnel = netdev_priv(dev);
1627 strcpy(tunnel->parms.name, dev->name);
1629 ipgre_tunnel_bind_dev(dev);
1631 dev->tstats = alloc_percpu(struct pcpu_tstats);
1638 static const struct net_device_ops ipgre_tap_netdev_ops = {
1639 .ndo_init = ipgre_tap_init,
1640 .ndo_uninit = ipgre_tunnel_uninit,
1641 .ndo_start_xmit = ipgre_tunnel_xmit,
1642 .ndo_set_mac_address = eth_mac_addr,
1643 .ndo_validate_addr = eth_validate_addr,
1644 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1645 .ndo_get_stats64 = ipgre_get_stats64,
1648 static void ipgre_tap_setup(struct net_device *dev)
1653 dev->netdev_ops = &ipgre_tap_netdev_ops;
1654 dev->destructor = ipgre_dev_free;
1657 dev->features |= NETIF_F_NETNS_LOCAL;
1659 dev->features |= GRE_FEATURES;
1660 dev->hw_features |= GRE_FEATURES;
1663 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1664 struct nlattr *data[])
1666 struct ip_tunnel *nt;
1667 struct net *net = dev_net(dev);
1668 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1672 nt = netdev_priv(dev);
1673 ipgre_netlink_parms(data, &nt->parms);
1675 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1678 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1679 eth_hw_addr_random(dev);
1681 mtu = ipgre_tunnel_bind_dev(dev);
1685 /* Can use a lockless transmit, unless we generate output sequences */
1686 if (!(nt->parms.o_flags & GRE_SEQ))
1687 dev->features |= NETIF_F_LLTX;
1689 err = register_netdevice(dev);
1694 ipgre_tunnel_link(ign, nt);
1700 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1701 struct nlattr *data[])
1703 struct ip_tunnel *t, *nt;
1704 struct net *net = dev_net(dev);
1705 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1706 struct ip_tunnel_parm p;
1709 if (dev == ign->fb_tunnel_dev)
1712 nt = netdev_priv(dev);
1713 ipgre_netlink_parms(data, &p);
1715 t = ipgre_tunnel_locate(net, &p, 0);
1723 if (dev->type != ARPHRD_ETHER) {
1724 unsigned int nflags = 0;
1726 if (ipv4_is_multicast(p.iph.daddr))
1727 nflags = IFF_BROADCAST;
1728 else if (p.iph.daddr)
1729 nflags = IFF_POINTOPOINT;
1731 if ((dev->flags ^ nflags) &
1732 (IFF_POINTOPOINT | IFF_BROADCAST))
1736 ipgre_tunnel_unlink(ign, t);
1737 t->parms.iph.saddr = p.iph.saddr;
1738 t->parms.iph.daddr = p.iph.daddr;
1739 t->parms.i_key = p.i_key;
1740 if (dev->type != ARPHRD_ETHER) {
1741 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1742 memcpy(dev->broadcast, &p.iph.daddr, 4);
1744 ipgre_tunnel_link(ign, t);
1745 netdev_state_change(dev);
1748 t->parms.o_key = p.o_key;
1749 t->parms.iph.ttl = p.iph.ttl;
1750 t->parms.iph.tos = p.iph.tos;
1751 t->parms.iph.frag_off = p.iph.frag_off;
1753 if (t->parms.link != p.link) {
1754 t->parms.link = p.link;
1755 mtu = ipgre_tunnel_bind_dev(dev);
1758 netdev_state_change(dev);
1764 static size_t ipgre_get_size(const struct net_device *dev)
1769 /* IFLA_GRE_IFLAGS */
1771 /* IFLA_GRE_OFLAGS */
1777 /* IFLA_GRE_LOCAL */
1779 /* IFLA_GRE_REMOTE */
1785 /* IFLA_GRE_PMTUDISC */
1790 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1792 struct ip_tunnel *t = netdev_priv(dev);
1793 struct ip_tunnel_parm *p = &t->parms;
1795 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1796 nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1797 nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1798 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1799 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1800 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1801 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1802 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1803 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1804 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1805 !!(p->iph.frag_off & htons(IP_DF))))
1806 goto nla_put_failure;
1813 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1814 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1815 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1816 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1817 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1818 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1819 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1820 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1821 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1822 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1823 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1826 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1828 .maxtype = IFLA_GRE_MAX,
1829 .policy = ipgre_policy,
1830 .priv_size = sizeof(struct ip_tunnel),
1831 .setup = ipgre_tunnel_setup,
1832 .validate = ipgre_tunnel_validate,
1833 .newlink = ipgre_newlink,
1834 .changelink = ipgre_changelink,
1835 .get_size = ipgre_get_size,
1836 .fill_info = ipgre_fill_info,
1839 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1841 .maxtype = IFLA_GRE_MAX,
1842 .policy = ipgre_policy,
1843 .priv_size = sizeof(struct ip_tunnel),
1844 .setup = ipgre_tap_setup,
1845 .validate = ipgre_tap_validate,
1846 .newlink = ipgre_newlink,
1847 .changelink = ipgre_changelink,
1848 .get_size = ipgre_get_size,
1849 .fill_info = ipgre_fill_info,
1853 * And now the modules code and kernel interface.
1856 static int __init ipgre_init(void)
1860 pr_info("GRE over IPv4 tunneling driver\n");
1862 err = register_pernet_device(&ipgre_net_ops);
1866 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1868 pr_info("%s: can't add protocol\n", __func__);
1869 goto add_proto_failed;
1872 err = rtnl_link_register(&ipgre_link_ops);
1874 goto rtnl_link_failed;
1876 err = rtnl_link_register(&ipgre_tap_ops);
1878 goto tap_ops_failed;
1884 rtnl_link_unregister(&ipgre_link_ops);
1886 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1888 unregister_pernet_device(&ipgre_net_ops);
1892 static void __exit ipgre_fini(void)
1894 rtnl_link_unregister(&ipgre_tap_ops);
1895 rtnl_link_unregister(&ipgre_link_ops);
1896 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1897 pr_info("%s: can't remove protocol\n", __func__);
1898 unregister_pernet_device(&ipgre_net_ops);
1901 module_init(ipgre_init);
1902 module_exit(ipgre_fini);
1903 MODULE_LICENSE("GPL");
1904 MODULE_ALIAS_RTNL_LINK("gre");
1905 MODULE_ALIAS_RTNL_LINK("gretap");
1906 MODULE_ALIAS_NETDEV("gre0");