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 netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
740 struct ip_tunnel *tunnel = netdev_priv(dev);
741 const struct iphdr *old_iph;
742 const struct iphdr *tiph;
746 struct rtable *rt; /* Route to the other host */
747 struct net_device *tdev; /* Device to other host */
748 struct iphdr *iph; /* Our new IP header */
749 unsigned int max_headroom; /* The extra header space needed */
755 if (skb->ip_summed == CHECKSUM_PARTIAL &&
756 skb_checksum_help(skb))
759 old_iph = ip_hdr(skb);
761 if (dev->type == ARPHRD_ETHER)
762 IPCB(skb)->flags = 0;
764 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
766 if (skb->protocol == htons(ETH_P_IP))
767 tiph = (const struct iphdr *)skb->data;
769 tiph = &tunnel->parms.iph;
771 gre_hlen = tunnel->hlen;
772 tiph = &tunnel->parms.iph;
775 if ((dst = tiph->daddr) == 0) {
778 if (skb_dst(skb) == NULL) {
779 dev->stats.tx_fifo_errors++;
783 if (skb->protocol == htons(ETH_P_IP)) {
784 rt = skb_rtable(skb);
785 dst = rt_nexthop(rt, old_iph->daddr);
787 #if IS_ENABLED(CONFIG_IPV6)
788 else if (skb->protocol == htons(ETH_P_IPV6)) {
789 const struct in6_addr *addr6;
790 struct neighbour *neigh;
791 bool do_tx_error_icmp;
794 neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr);
798 addr6 = (const struct in6_addr *)&neigh->primary_key;
799 addr_type = ipv6_addr_type(addr6);
801 if (addr_type == IPV6_ADDR_ANY) {
802 addr6 = &ipv6_hdr(skb)->daddr;
803 addr_type = ipv6_addr_type(addr6);
806 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
807 do_tx_error_icmp = true;
809 do_tx_error_icmp = false;
810 dst = addr6->s6_addr32[3];
812 neigh_release(neigh);
813 if (do_tx_error_icmp)
825 if (skb->protocol == htons(ETH_P_IP))
827 else if (skb->protocol == htons(ETH_P_IPV6))
828 tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
831 rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
832 tunnel->parms.o_key, RT_TOS(tos),
835 dev->stats.tx_carrier_errors++;
842 dev->stats.collisions++;
848 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
850 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
853 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
855 if (skb->protocol == htons(ETH_P_IP)) {
856 df |= (old_iph->frag_off&htons(IP_DF));
858 if ((old_iph->frag_off&htons(IP_DF)) &&
859 mtu < ntohs(old_iph->tot_len)) {
860 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
865 #if IS_ENABLED(CONFIG_IPV6)
866 else if (skb->protocol == htons(ETH_P_IPV6)) {
867 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
869 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
870 if ((tunnel->parms.iph.daddr &&
871 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
872 rt6->rt6i_dst.plen == 128) {
873 rt6->rt6i_flags |= RTF_MODIFIED;
874 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
878 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
879 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
886 if (tunnel->err_count > 0) {
887 if (time_before(jiffies,
888 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
891 dst_link_failure(skb);
893 tunnel->err_count = 0;
896 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
898 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
899 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
900 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
901 if (max_headroom > dev->needed_headroom)
902 dev->needed_headroom = max_headroom;
905 dev->stats.tx_dropped++;
910 skb_set_owner_w(new_skb, skb->sk);
913 old_iph = ip_hdr(skb);
914 /* Warning : tiph value might point to freed memory */
917 skb_push(skb, gre_hlen);
918 skb_reset_network_header(skb);
919 skb_set_transport_header(skb, sizeof(*iph));
920 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
921 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
924 skb_dst_set(skb, &rt->dst);
927 * Push down and install the IPIP header.
932 iph->ihl = sizeof(struct iphdr) >> 2;
934 iph->protocol = IPPROTO_GRE;
935 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
936 iph->daddr = fl4.daddr;
937 iph->saddr = fl4.saddr;
941 if (skb->protocol == htons(ETH_P_IP))
942 iph->ttl = old_iph->ttl;
943 #if IS_ENABLED(CONFIG_IPV6)
944 else if (skb->protocol == htons(ETH_P_IPV6))
945 iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
948 iph->ttl = ip4_dst_hoplimit(&rt->dst);
951 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
952 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
953 htons(ETH_P_TEB) : skb->protocol;
955 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
956 __be32 *ptr = (__be32 *)(((u8 *)iph) + tunnel->hlen - 4);
958 if (tunnel->parms.o_flags&GRE_SEQ) {
960 *ptr = htonl(tunnel->o_seqno);
963 if (tunnel->parms.o_flags&GRE_KEY) {
964 *ptr = tunnel->parms.o_key;
967 if (tunnel->parms.o_flags&GRE_CSUM) {
968 int offset = skb_transport_offset(skb);
971 *(__sum16 *)ptr = csum_fold(skb_checksum(skb, offset,
977 iptunnel_xmit(skb, dev);
980 #if IS_ENABLED(CONFIG_IPV6)
982 dst_link_failure(skb);
985 dev->stats.tx_errors++;
990 static int ipgre_tunnel_bind_dev(struct net_device *dev)
992 struct net_device *tdev = NULL;
993 struct ip_tunnel *tunnel;
994 const struct iphdr *iph;
995 int hlen = LL_MAX_HEADER;
996 int mtu = ETH_DATA_LEN;
997 int addend = sizeof(struct iphdr) + 4;
999 tunnel = netdev_priv(dev);
1000 iph = &tunnel->parms.iph;
1002 /* Guess output device to choose reasonable mtu and needed_headroom */
1008 rt = ip_route_output_gre(dev_net(dev), &fl4,
1009 iph->daddr, iph->saddr,
1010 tunnel->parms.o_key,
1012 tunnel->parms.link);
1018 if (dev->type != ARPHRD_ETHER)
1019 dev->flags |= IFF_POINTOPOINT;
1022 if (!tdev && tunnel->parms.link)
1023 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
1026 hlen = tdev->hard_header_len + tdev->needed_headroom;
1029 dev->iflink = tunnel->parms.link;
1031 /* Precalculate GRE options length */
1032 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
1033 if (tunnel->parms.o_flags&GRE_CSUM)
1035 if (tunnel->parms.o_flags&GRE_KEY)
1037 if (tunnel->parms.o_flags&GRE_SEQ)
1040 dev->needed_headroom = addend + hlen;
1041 mtu -= dev->hard_header_len + addend;
1046 tunnel->hlen = addend;
1052 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1055 struct ip_tunnel_parm p;
1056 struct ip_tunnel *t;
1057 struct net *net = dev_net(dev);
1058 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1063 if (dev == ign->fb_tunnel_dev) {
1064 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1068 t = ipgre_tunnel_locate(net, &p, 0);
1071 t = netdev_priv(dev);
1072 memcpy(&p, &t->parms, sizeof(p));
1073 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1080 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1084 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1088 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1089 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1090 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1093 p.iph.frag_off |= htons(IP_DF);
1095 if (!(p.i_flags&GRE_KEY))
1097 if (!(p.o_flags&GRE_KEY))
1100 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1102 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1104 if (t->dev != dev) {
1109 unsigned int nflags = 0;
1111 t = netdev_priv(dev);
1113 if (ipv4_is_multicast(p.iph.daddr))
1114 nflags = IFF_BROADCAST;
1115 else if (p.iph.daddr)
1116 nflags = IFF_POINTOPOINT;
1118 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1122 ipgre_tunnel_unlink(ign, t);
1124 t->parms.iph.saddr = p.iph.saddr;
1125 t->parms.iph.daddr = p.iph.daddr;
1126 t->parms.i_key = p.i_key;
1127 t->parms.o_key = p.o_key;
1128 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1129 memcpy(dev->broadcast, &p.iph.daddr, 4);
1130 ipgre_tunnel_link(ign, t);
1131 netdev_state_change(dev);
1137 if (cmd == SIOCCHGTUNNEL) {
1138 t->parms.iph.ttl = p.iph.ttl;
1139 t->parms.iph.tos = p.iph.tos;
1140 t->parms.iph.frag_off = p.iph.frag_off;
1141 if (t->parms.link != p.link) {
1142 t->parms.link = p.link;
1143 dev->mtu = ipgre_tunnel_bind_dev(dev);
1144 netdev_state_change(dev);
1147 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1150 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1155 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1158 if (dev == ign->fb_tunnel_dev) {
1160 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1163 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1166 if (t == netdev_priv(ign->fb_tunnel_dev))
1170 unregister_netdevice(dev);
1182 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1184 struct ip_tunnel *tunnel = netdev_priv(dev);
1186 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1192 /* Nice toy. Unfortunately, useless in real life :-)
1193 It allows to construct virtual multiprotocol broadcast "LAN"
1194 over the Internet, provided multicast routing is tuned.
1197 I have no idea was this bicycle invented before me,
1198 so that I had to set ARPHRD_IPGRE to a random value.
1199 I have an impression, that Cisco could make something similar,
1200 but this feature is apparently missing in IOS<=11.2(8).
1202 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1203 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1205 ping -t 255 224.66.66.66
1207 If nobody answers, mbone does not work.
1209 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1210 ip addr add 10.66.66.<somewhat>/24 dev Universe
1211 ifconfig Universe up
1212 ifconfig Universe add fe80::<Your_real_addr>/10
1213 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1216 ftp fec0:6666:6666::193.233.7.65
1221 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1222 unsigned short type,
1223 const void *daddr, const void *saddr, unsigned int len)
1225 struct ip_tunnel *t = netdev_priv(dev);
1226 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1227 __be16 *p = (__be16 *)(iph+1);
1229 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1230 p[0] = t->parms.o_flags;
1234 * Set the source hardware address.
1238 memcpy(&iph->saddr, saddr, 4);
1240 memcpy(&iph->daddr, daddr, 4);
1247 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1249 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
1250 memcpy(haddr, &iph->saddr, 4);
1254 static const struct header_ops ipgre_header_ops = {
1255 .create = ipgre_header,
1256 .parse = ipgre_header_parse,
1259 #ifdef CONFIG_NET_IPGRE_BROADCAST
1260 static int ipgre_open(struct net_device *dev)
1262 struct ip_tunnel *t = netdev_priv(dev);
1264 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1268 rt = ip_route_output_gre(dev_net(dev), &fl4,
1272 RT_TOS(t->parms.iph.tos),
1275 return -EADDRNOTAVAIL;
1278 if (__in_dev_get_rtnl(dev) == NULL)
1279 return -EADDRNOTAVAIL;
1280 t->mlink = dev->ifindex;
1281 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1286 static int ipgre_close(struct net_device *dev)
1288 struct ip_tunnel *t = netdev_priv(dev);
1290 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1291 struct in_device *in_dev;
1292 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1294 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1301 static const struct net_device_ops ipgre_netdev_ops = {
1302 .ndo_init = ipgre_tunnel_init,
1303 .ndo_uninit = ipgre_tunnel_uninit,
1304 #ifdef CONFIG_NET_IPGRE_BROADCAST
1305 .ndo_open = ipgre_open,
1306 .ndo_stop = ipgre_close,
1308 .ndo_start_xmit = ipgre_tunnel_xmit,
1309 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1310 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1311 .ndo_get_stats64 = ipgre_get_stats64,
1314 static void ipgre_dev_free(struct net_device *dev)
1316 struct ip_tunnel *tunnel = netdev_priv(dev);
1318 gro_cells_destroy(&tunnel->gro_cells);
1319 free_percpu(dev->tstats);
1323 #define GRE_FEATURES (NETIF_F_SG | \
1324 NETIF_F_FRAGLIST | \
1328 static void ipgre_tunnel_setup(struct net_device *dev)
1330 dev->netdev_ops = &ipgre_netdev_ops;
1331 dev->destructor = ipgre_dev_free;
1333 dev->type = ARPHRD_IPGRE;
1334 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1335 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1336 dev->flags = IFF_NOARP;
1339 dev->features |= NETIF_F_NETNS_LOCAL;
1340 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1342 dev->features |= GRE_FEATURES;
1343 dev->hw_features |= GRE_FEATURES;
1346 static int ipgre_tunnel_init(struct net_device *dev)
1348 struct ip_tunnel *tunnel;
1352 tunnel = netdev_priv(dev);
1353 iph = &tunnel->parms.iph;
1356 strcpy(tunnel->parms.name, dev->name);
1358 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1359 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1362 #ifdef CONFIG_NET_IPGRE_BROADCAST
1363 if (ipv4_is_multicast(iph->daddr)) {
1366 dev->flags = IFF_BROADCAST;
1367 dev->header_ops = &ipgre_header_ops;
1371 dev->header_ops = &ipgre_header_ops;
1373 dev->tstats = alloc_percpu(struct pcpu_tstats);
1377 err = gro_cells_init(&tunnel->gro_cells, dev);
1379 free_percpu(dev->tstats);
1386 static void ipgre_fb_tunnel_init(struct net_device *dev)
1388 struct ip_tunnel *tunnel = netdev_priv(dev);
1389 struct iphdr *iph = &tunnel->parms.iph;
1392 strcpy(tunnel->parms.name, dev->name);
1395 iph->protocol = IPPROTO_GRE;
1397 tunnel->hlen = sizeof(struct iphdr) + 4;
1403 static const struct gre_protocol ipgre_protocol = {
1404 .handler = ipgre_rcv,
1405 .err_handler = ipgre_err,
1408 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1412 for (prio = 0; prio < 4; prio++) {
1414 for (h = 0; h < HASH_SIZE; h++) {
1415 struct ip_tunnel *t;
1417 t = rtnl_dereference(ign->tunnels[prio][h]);
1420 unregister_netdevice_queue(t->dev, head);
1421 t = rtnl_dereference(t->next);
1427 static int __net_init ipgre_init_net(struct net *net)
1429 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1432 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1433 ipgre_tunnel_setup);
1434 if (!ign->fb_tunnel_dev) {
1438 dev_net_set(ign->fb_tunnel_dev, net);
1440 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1441 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1443 if ((err = register_netdev(ign->fb_tunnel_dev)))
1446 rcu_assign_pointer(ign->tunnels_wc[0],
1447 netdev_priv(ign->fb_tunnel_dev));
1451 ipgre_dev_free(ign->fb_tunnel_dev);
1456 static void __net_exit ipgre_exit_net(struct net *net)
1458 struct ipgre_net *ign;
1461 ign = net_generic(net, ipgre_net_id);
1463 ipgre_destroy_tunnels(ign, &list);
1464 unregister_netdevice_many(&list);
1468 static struct pernet_operations ipgre_net_ops = {
1469 .init = ipgre_init_net,
1470 .exit = ipgre_exit_net,
1471 .id = &ipgre_net_id,
1472 .size = sizeof(struct ipgre_net),
1475 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1483 if (data[IFLA_GRE_IFLAGS])
1484 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1485 if (data[IFLA_GRE_OFLAGS])
1486 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1487 if (flags & (GRE_VERSION|GRE_ROUTING))
1493 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1497 if (tb[IFLA_ADDRESS]) {
1498 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1500 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1501 return -EADDRNOTAVAIL;
1507 if (data[IFLA_GRE_REMOTE]) {
1508 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1514 return ipgre_tunnel_validate(tb, data);
1517 static void ipgre_netlink_parms(struct nlattr *data[],
1518 struct ip_tunnel_parm *parms)
1520 memset(parms, 0, sizeof(*parms));
1522 parms->iph.protocol = IPPROTO_GRE;
1527 if (data[IFLA_GRE_LINK])
1528 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1530 if (data[IFLA_GRE_IFLAGS])
1531 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1533 if (data[IFLA_GRE_OFLAGS])
1534 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1536 if (data[IFLA_GRE_IKEY])
1537 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1539 if (data[IFLA_GRE_OKEY])
1540 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1542 if (data[IFLA_GRE_LOCAL])
1543 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1545 if (data[IFLA_GRE_REMOTE])
1546 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1548 if (data[IFLA_GRE_TTL])
1549 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1551 if (data[IFLA_GRE_TOS])
1552 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1554 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1555 parms->iph.frag_off = htons(IP_DF);
1558 static int ipgre_tap_init(struct net_device *dev)
1560 struct ip_tunnel *tunnel;
1562 tunnel = netdev_priv(dev);
1565 strcpy(tunnel->parms.name, dev->name);
1567 ipgre_tunnel_bind_dev(dev);
1569 dev->tstats = alloc_percpu(struct pcpu_tstats);
1576 static const struct net_device_ops ipgre_tap_netdev_ops = {
1577 .ndo_init = ipgre_tap_init,
1578 .ndo_uninit = ipgre_tunnel_uninit,
1579 .ndo_start_xmit = ipgre_tunnel_xmit,
1580 .ndo_set_mac_address = eth_mac_addr,
1581 .ndo_validate_addr = eth_validate_addr,
1582 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1583 .ndo_get_stats64 = ipgre_get_stats64,
1586 static void ipgre_tap_setup(struct net_device *dev)
1591 dev->netdev_ops = &ipgre_tap_netdev_ops;
1592 dev->destructor = ipgre_dev_free;
1595 dev->features |= NETIF_F_NETNS_LOCAL;
1598 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1599 struct nlattr *data[])
1601 struct ip_tunnel *nt;
1602 struct net *net = dev_net(dev);
1603 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1607 nt = netdev_priv(dev);
1608 ipgre_netlink_parms(data, &nt->parms);
1610 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1613 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1614 eth_hw_addr_random(dev);
1616 mtu = ipgre_tunnel_bind_dev(dev);
1620 /* Can use a lockless transmit, unless we generate output sequences */
1621 if (!(nt->parms.o_flags & GRE_SEQ))
1622 dev->features |= NETIF_F_LLTX;
1624 err = register_netdevice(dev);
1629 ipgre_tunnel_link(ign, nt);
1635 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1636 struct nlattr *data[])
1638 struct ip_tunnel *t, *nt;
1639 struct net *net = dev_net(dev);
1640 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1641 struct ip_tunnel_parm p;
1644 if (dev == ign->fb_tunnel_dev)
1647 nt = netdev_priv(dev);
1648 ipgre_netlink_parms(data, &p);
1650 t = ipgre_tunnel_locate(net, &p, 0);
1658 if (dev->type != ARPHRD_ETHER) {
1659 unsigned int nflags = 0;
1661 if (ipv4_is_multicast(p.iph.daddr))
1662 nflags = IFF_BROADCAST;
1663 else if (p.iph.daddr)
1664 nflags = IFF_POINTOPOINT;
1666 if ((dev->flags ^ nflags) &
1667 (IFF_POINTOPOINT | IFF_BROADCAST))
1671 ipgre_tunnel_unlink(ign, t);
1672 t->parms.iph.saddr = p.iph.saddr;
1673 t->parms.iph.daddr = p.iph.daddr;
1674 t->parms.i_key = p.i_key;
1675 if (dev->type != ARPHRD_ETHER) {
1676 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1677 memcpy(dev->broadcast, &p.iph.daddr, 4);
1679 ipgre_tunnel_link(ign, t);
1680 netdev_state_change(dev);
1683 t->parms.o_key = p.o_key;
1684 t->parms.iph.ttl = p.iph.ttl;
1685 t->parms.iph.tos = p.iph.tos;
1686 t->parms.iph.frag_off = p.iph.frag_off;
1688 if (t->parms.link != p.link) {
1689 t->parms.link = p.link;
1690 mtu = ipgre_tunnel_bind_dev(dev);
1693 netdev_state_change(dev);
1699 static size_t ipgre_get_size(const struct net_device *dev)
1704 /* IFLA_GRE_IFLAGS */
1706 /* IFLA_GRE_OFLAGS */
1712 /* IFLA_GRE_LOCAL */
1714 /* IFLA_GRE_REMOTE */
1720 /* IFLA_GRE_PMTUDISC */
1725 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1727 struct ip_tunnel *t = netdev_priv(dev);
1728 struct ip_tunnel_parm *p = &t->parms;
1730 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1731 nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1732 nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1733 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1734 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1735 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1736 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1737 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1738 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1739 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1740 !!(p->iph.frag_off & htons(IP_DF))))
1741 goto nla_put_failure;
1748 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1749 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1750 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1751 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1752 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1753 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1754 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1755 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1756 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1757 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1758 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1761 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1763 .maxtype = IFLA_GRE_MAX,
1764 .policy = ipgre_policy,
1765 .priv_size = sizeof(struct ip_tunnel),
1766 .setup = ipgre_tunnel_setup,
1767 .validate = ipgre_tunnel_validate,
1768 .newlink = ipgre_newlink,
1769 .changelink = ipgre_changelink,
1770 .get_size = ipgre_get_size,
1771 .fill_info = ipgre_fill_info,
1774 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1776 .maxtype = IFLA_GRE_MAX,
1777 .policy = ipgre_policy,
1778 .priv_size = sizeof(struct ip_tunnel),
1779 .setup = ipgre_tap_setup,
1780 .validate = ipgre_tap_validate,
1781 .newlink = ipgre_newlink,
1782 .changelink = ipgre_changelink,
1783 .get_size = ipgre_get_size,
1784 .fill_info = ipgre_fill_info,
1788 * And now the modules code and kernel interface.
1791 static int __init ipgre_init(void)
1795 pr_info("GRE over IPv4 tunneling driver\n");
1797 err = register_pernet_device(&ipgre_net_ops);
1801 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1803 pr_info("%s: can't add protocol\n", __func__);
1804 goto add_proto_failed;
1807 err = rtnl_link_register(&ipgre_link_ops);
1809 goto rtnl_link_failed;
1811 err = rtnl_link_register(&ipgre_tap_ops);
1813 goto tap_ops_failed;
1819 rtnl_link_unregister(&ipgre_link_ops);
1821 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1823 unregister_pernet_device(&ipgre_net_ops);
1827 static void __exit ipgre_fini(void)
1829 rtnl_link_unregister(&ipgre_tap_ops);
1830 rtnl_link_unregister(&ipgre_link_ops);
1831 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1832 pr_info("%s: can't remove protocol\n", __func__);
1833 unregister_pernet_device(&ipgre_net_ops);
1836 module_init(ipgre_init);
1837 module_exit(ipgre_fini);
1838 MODULE_LICENSE("GPL");
1839 MODULE_ALIAS_RTNL_LINK("gre");
1840 MODULE_ALIAS_RTNL_LINK("gretap");
1841 MODULE_ALIAS_NETDEV("gre0");