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 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;
749 if (skb->ip_summed != CHECKSUM_PARTIAL)
750 skb->ip_summed = CHECKSUM_NONE;
759 static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
761 struct pcpu_tstats *tstats = this_cpu_ptr(dev->tstats);
762 struct ip_tunnel *tunnel = netdev_priv(dev);
763 const struct iphdr *old_iph;
764 const struct iphdr *tiph;
768 struct rtable *rt; /* Route to the other host */
769 struct net_device *tdev; /* Device to other host */
770 struct iphdr *iph; /* Our new IP header */
771 unsigned int max_headroom; /* The extra header space needed */
779 skb = handle_offloads(skb);
781 dev->stats.tx_dropped++;
785 if (!skb->encapsulation) {
786 skb_reset_inner_headers(skb);
787 skb->encapsulation = 1;
790 old_iph = ip_hdr(skb);
792 if (dev->type == ARPHRD_ETHER)
793 IPCB(skb)->flags = 0;
795 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
797 if (skb->protocol == htons(ETH_P_IP))
798 tiph = (const struct iphdr *)skb->data;
800 tiph = &tunnel->parms.iph;
802 gre_hlen = tunnel->hlen;
803 tiph = &tunnel->parms.iph;
806 if ((dst = tiph->daddr) == 0) {
809 if (skb_dst(skb) == NULL) {
810 dev->stats.tx_fifo_errors++;
814 if (skb->protocol == htons(ETH_P_IP)) {
815 rt = skb_rtable(skb);
816 dst = rt_nexthop(rt, old_iph->daddr);
818 #if IS_ENABLED(CONFIG_IPV6)
819 else if (skb->protocol == htons(ETH_P_IPV6)) {
820 const struct in6_addr *addr6;
821 struct neighbour *neigh;
822 bool do_tx_error_icmp;
825 neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr);
829 addr6 = (const struct in6_addr *)&neigh->primary_key;
830 addr_type = ipv6_addr_type(addr6);
832 if (addr_type == IPV6_ADDR_ANY) {
833 addr6 = &ipv6_hdr(skb)->daddr;
834 addr_type = ipv6_addr_type(addr6);
837 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
838 do_tx_error_icmp = true;
840 do_tx_error_icmp = false;
841 dst = addr6->s6_addr32[3];
843 neigh_release(neigh);
844 if (do_tx_error_icmp)
856 if (skb->protocol == htons(ETH_P_IP))
858 else if (skb->protocol == htons(ETH_P_IPV6))
859 tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
862 rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
863 tunnel->parms.o_key, RT_TOS(tos),
866 dev->stats.tx_carrier_errors++;
873 dev->stats.collisions++;
879 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
881 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
884 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
886 if (skb->protocol == htons(ETH_P_IP)) {
887 df |= (old_iph->frag_off&htons(IP_DF));
889 if (!skb_is_gso(skb) &&
890 (old_iph->frag_off&htons(IP_DF)) &&
891 mtu < ntohs(old_iph->tot_len)) {
892 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
897 #if IS_ENABLED(CONFIG_IPV6)
898 else if (skb->protocol == htons(ETH_P_IPV6)) {
899 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
901 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
902 if ((tunnel->parms.iph.daddr &&
903 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
904 rt6->rt6i_dst.plen == 128) {
905 rt6->rt6i_flags |= RTF_MODIFIED;
906 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
910 if (!skb_is_gso(skb) &&
911 mtu >= IPV6_MIN_MTU &&
912 mtu < skb->len - tunnel->hlen + gre_hlen) {
913 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
920 if (tunnel->err_count > 0) {
921 if (time_before(jiffies,
922 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
925 dst_link_failure(skb);
927 tunnel->err_count = 0;
930 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
932 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
933 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
934 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
935 if (max_headroom > dev->needed_headroom)
936 dev->needed_headroom = max_headroom;
939 dev->stats.tx_dropped++;
944 skb_set_owner_w(new_skb, skb->sk);
947 old_iph = ip_hdr(skb);
948 /* Warning : tiph value might point to freed memory */
951 skb_push(skb, gre_hlen);
952 skb_reset_network_header(skb);
953 skb_set_transport_header(skb, sizeof(*iph));
954 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
955 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
958 skb_dst_set(skb, &rt->dst);
961 * Push down and install the IPIP header.
966 iph->ihl = sizeof(struct iphdr) >> 2;
968 iph->protocol = IPPROTO_GRE;
969 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
970 iph->daddr = fl4.daddr;
971 iph->saddr = fl4.saddr;
974 tunnel_ip_select_ident(skb, old_iph, &rt->dst);
977 if (skb->protocol == htons(ETH_P_IP))
978 iph->ttl = old_iph->ttl;
979 #if IS_ENABLED(CONFIG_IPV6)
980 else if (skb->protocol == htons(ETH_P_IPV6))
981 iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
984 iph->ttl = ip4_dst_hoplimit(&rt->dst);
987 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
988 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
989 htons(ETH_P_TEB) : skb->protocol;
991 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
992 __be32 *ptr = (__be32 *)(((u8 *)iph) + tunnel->hlen - 4);
994 if (tunnel->parms.o_flags&GRE_SEQ) {
996 *ptr = htonl(tunnel->o_seqno);
999 if (tunnel->parms.o_flags&GRE_KEY) {
1000 *ptr = tunnel->parms.o_key;
1003 /* Skip GRE checksum if skb is getting offloaded. */
1004 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE) &&
1005 (tunnel->parms.o_flags&GRE_CSUM)) {
1006 int offset = skb_transport_offset(skb);
1008 if (skb_has_shared_frag(skb)) {
1009 err = __skb_linearize(skb);
1015 *(__sum16 *)ptr = csum_fold(skb_checksum(skb, offset,
1023 pkt_len = skb->len - skb_transport_offset(skb);
1024 err = ip_local_out(skb);
1025 if (likely(net_xmit_eval(err) == 0)) {
1026 u64_stats_update_begin(&tstats->syncp);
1027 tstats->tx_bytes += pkt_len;
1028 tstats->tx_packets++;
1029 u64_stats_update_end(&tstats->syncp);
1031 dev->stats.tx_errors++;
1032 dev->stats.tx_aborted_errors++;
1034 return NETDEV_TX_OK;
1036 #if IS_ENABLED(CONFIG_IPV6)
1038 dst_link_failure(skb);
1041 dev->stats.tx_errors++;
1043 return NETDEV_TX_OK;
1046 static int ipgre_tunnel_bind_dev(struct net_device *dev)
1048 struct net_device *tdev = NULL;
1049 struct ip_tunnel *tunnel;
1050 const struct iphdr *iph;
1051 int hlen = LL_MAX_HEADER;
1052 int mtu = ETH_DATA_LEN;
1053 int addend = sizeof(struct iphdr) + 4;
1055 tunnel = netdev_priv(dev);
1056 iph = &tunnel->parms.iph;
1058 /* Guess output device to choose reasonable mtu and needed_headroom */
1064 rt = ip_route_output_gre(dev_net(dev), &fl4,
1065 iph->daddr, iph->saddr,
1066 tunnel->parms.o_key,
1068 tunnel->parms.link);
1074 if (dev->type != ARPHRD_ETHER)
1075 dev->flags |= IFF_POINTOPOINT;
1078 if (!tdev && tunnel->parms.link)
1079 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
1082 hlen = tdev->hard_header_len + tdev->needed_headroom;
1085 dev->iflink = tunnel->parms.link;
1087 /* Precalculate GRE options length */
1088 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
1089 if (tunnel->parms.o_flags&GRE_CSUM)
1091 if (tunnel->parms.o_flags&GRE_KEY)
1093 if (tunnel->parms.o_flags&GRE_SEQ)
1096 dev->needed_headroom = addend + hlen;
1097 mtu -= dev->hard_header_len + addend;
1102 tunnel->hlen = addend;
1103 /* TCP offload with GRE SEQ is not supported. */
1104 if (!(tunnel->parms.o_flags & GRE_SEQ)) {
1105 /* device supports enc gso offload*/
1106 if (tdev->hw_enc_features & NETIF_F_GRE_GSO) {
1107 dev->features |= NETIF_F_TSO;
1108 dev->hw_features |= NETIF_F_TSO;
1110 dev->features |= NETIF_F_GSO_SOFTWARE;
1111 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1119 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1122 struct ip_tunnel_parm p;
1123 struct ip_tunnel *t;
1124 struct net *net = dev_net(dev);
1125 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1130 if (dev == ign->fb_tunnel_dev) {
1131 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1135 t = ipgre_tunnel_locate(net, &p, 0);
1138 t = netdev_priv(dev);
1139 memcpy(&p, &t->parms, sizeof(p));
1140 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1147 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1151 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1155 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1156 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1157 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1160 p.iph.frag_off |= htons(IP_DF);
1162 if (!(p.i_flags&GRE_KEY))
1164 if (!(p.o_flags&GRE_KEY))
1167 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1169 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1171 if (t->dev != dev) {
1176 unsigned int nflags = 0;
1178 t = netdev_priv(dev);
1180 if (ipv4_is_multicast(p.iph.daddr))
1181 nflags = IFF_BROADCAST;
1182 else if (p.iph.daddr)
1183 nflags = IFF_POINTOPOINT;
1185 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1189 ipgre_tunnel_unlink(ign, t);
1191 t->parms.iph.saddr = p.iph.saddr;
1192 t->parms.iph.daddr = p.iph.daddr;
1193 t->parms.i_key = p.i_key;
1194 t->parms.o_key = p.o_key;
1195 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1196 memcpy(dev->broadcast, &p.iph.daddr, 4);
1197 ipgre_tunnel_link(ign, t);
1198 netdev_state_change(dev);
1204 if (cmd == SIOCCHGTUNNEL) {
1205 t->parms.iph.ttl = p.iph.ttl;
1206 t->parms.iph.tos = p.iph.tos;
1207 t->parms.iph.frag_off = p.iph.frag_off;
1208 if (t->parms.link != p.link) {
1209 t->parms.link = p.link;
1210 dev->mtu = ipgre_tunnel_bind_dev(dev);
1211 netdev_state_change(dev);
1214 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1217 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1222 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1225 if (dev == ign->fb_tunnel_dev) {
1227 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1230 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1233 if (t == netdev_priv(ign->fb_tunnel_dev))
1237 unregister_netdevice(dev);
1249 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1251 struct ip_tunnel *tunnel = netdev_priv(dev);
1253 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1259 /* Nice toy. Unfortunately, useless in real life :-)
1260 It allows to construct virtual multiprotocol broadcast "LAN"
1261 over the Internet, provided multicast routing is tuned.
1264 I have no idea was this bicycle invented before me,
1265 so that I had to set ARPHRD_IPGRE to a random value.
1266 I have an impression, that Cisco could make something similar,
1267 but this feature is apparently missing in IOS<=11.2(8).
1269 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1270 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1272 ping -t 255 224.66.66.66
1274 If nobody answers, mbone does not work.
1276 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1277 ip addr add 10.66.66.<somewhat>/24 dev Universe
1278 ifconfig Universe up
1279 ifconfig Universe add fe80::<Your_real_addr>/10
1280 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1283 ftp fec0:6666:6666::193.233.7.65
1288 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1289 unsigned short type,
1290 const void *daddr, const void *saddr, unsigned int len)
1292 struct ip_tunnel *t = netdev_priv(dev);
1293 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1294 __be16 *p = (__be16 *)(iph+1);
1296 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1297 p[0] = t->parms.o_flags;
1301 * Set the source hardware address.
1305 memcpy(&iph->saddr, saddr, 4);
1307 memcpy(&iph->daddr, daddr, 4);
1314 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1316 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
1317 memcpy(haddr, &iph->saddr, 4);
1321 static const struct header_ops ipgre_header_ops = {
1322 .create = ipgre_header,
1323 .parse = ipgre_header_parse,
1326 #ifdef CONFIG_NET_IPGRE_BROADCAST
1327 static int ipgre_open(struct net_device *dev)
1329 struct ip_tunnel *t = netdev_priv(dev);
1331 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1335 rt = ip_route_output_gre(dev_net(dev), &fl4,
1339 RT_TOS(t->parms.iph.tos),
1342 return -EADDRNOTAVAIL;
1345 if (__in_dev_get_rtnl(dev) == NULL)
1346 return -EADDRNOTAVAIL;
1347 t->mlink = dev->ifindex;
1348 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1353 static int ipgre_close(struct net_device *dev)
1355 struct ip_tunnel *t = netdev_priv(dev);
1357 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1358 struct in_device *in_dev;
1359 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1361 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1368 static const struct net_device_ops ipgre_netdev_ops = {
1369 .ndo_init = ipgre_tunnel_init,
1370 .ndo_uninit = ipgre_tunnel_uninit,
1371 #ifdef CONFIG_NET_IPGRE_BROADCAST
1372 .ndo_open = ipgre_open,
1373 .ndo_stop = ipgre_close,
1375 .ndo_start_xmit = ipgre_tunnel_xmit,
1376 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1377 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1378 .ndo_get_stats64 = ipgre_get_stats64,
1381 static void ipgre_dev_free(struct net_device *dev)
1383 struct ip_tunnel *tunnel = netdev_priv(dev);
1385 gro_cells_destroy(&tunnel->gro_cells);
1386 free_percpu(dev->tstats);
1390 #define GRE_FEATURES (NETIF_F_SG | \
1391 NETIF_F_FRAGLIST | \
1395 static void ipgre_tunnel_setup(struct net_device *dev)
1397 dev->netdev_ops = &ipgre_netdev_ops;
1398 dev->destructor = ipgre_dev_free;
1400 dev->type = ARPHRD_IPGRE;
1401 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1402 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1403 dev->flags = IFF_NOARP;
1406 dev->features |= NETIF_F_NETNS_LOCAL;
1407 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1409 dev->features |= GRE_FEATURES;
1410 dev->hw_features |= GRE_FEATURES;
1413 static int ipgre_tunnel_init(struct net_device *dev)
1415 struct ip_tunnel *tunnel;
1419 tunnel = netdev_priv(dev);
1420 iph = &tunnel->parms.iph;
1423 strcpy(tunnel->parms.name, dev->name);
1425 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1426 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1429 #ifdef CONFIG_NET_IPGRE_BROADCAST
1430 if (ipv4_is_multicast(iph->daddr)) {
1433 dev->flags = IFF_BROADCAST;
1434 dev->header_ops = &ipgre_header_ops;
1438 dev->header_ops = &ipgre_header_ops;
1440 dev->tstats = alloc_percpu(struct pcpu_tstats);
1444 err = gro_cells_init(&tunnel->gro_cells, dev);
1446 free_percpu(dev->tstats);
1453 static void ipgre_fb_tunnel_init(struct net_device *dev)
1455 struct ip_tunnel *tunnel = netdev_priv(dev);
1456 struct iphdr *iph = &tunnel->parms.iph;
1459 strcpy(tunnel->parms.name, dev->name);
1462 iph->protocol = IPPROTO_GRE;
1464 tunnel->hlen = sizeof(struct iphdr) + 4;
1470 static const struct gre_protocol ipgre_protocol = {
1471 .handler = ipgre_rcv,
1472 .err_handler = ipgre_err,
1475 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1479 for (prio = 0; prio < 4; prio++) {
1481 for (h = 0; h < HASH_SIZE; h++) {
1482 struct ip_tunnel *t;
1484 t = rtnl_dereference(ign->tunnels[prio][h]);
1487 unregister_netdevice_queue(t->dev, head);
1488 t = rtnl_dereference(t->next);
1494 static int __net_init ipgre_init_net(struct net *net)
1496 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1499 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1500 ipgre_tunnel_setup);
1501 if (!ign->fb_tunnel_dev) {
1505 dev_net_set(ign->fb_tunnel_dev, net);
1507 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1508 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1510 if ((err = register_netdev(ign->fb_tunnel_dev)))
1513 rcu_assign_pointer(ign->tunnels_wc[0],
1514 netdev_priv(ign->fb_tunnel_dev));
1518 ipgre_dev_free(ign->fb_tunnel_dev);
1523 static void __net_exit ipgre_exit_net(struct net *net)
1525 struct ipgre_net *ign;
1528 ign = net_generic(net, ipgre_net_id);
1530 ipgre_destroy_tunnels(ign, &list);
1531 unregister_netdevice_many(&list);
1535 static struct pernet_operations ipgre_net_ops = {
1536 .init = ipgre_init_net,
1537 .exit = ipgre_exit_net,
1538 .id = &ipgre_net_id,
1539 .size = sizeof(struct ipgre_net),
1542 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1550 if (data[IFLA_GRE_IFLAGS])
1551 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1552 if (data[IFLA_GRE_OFLAGS])
1553 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1554 if (flags & (GRE_VERSION|GRE_ROUTING))
1560 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1564 if (tb[IFLA_ADDRESS]) {
1565 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1567 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1568 return -EADDRNOTAVAIL;
1574 if (data[IFLA_GRE_REMOTE]) {
1575 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1581 return ipgre_tunnel_validate(tb, data);
1584 static void ipgre_netlink_parms(struct nlattr *data[],
1585 struct ip_tunnel_parm *parms)
1587 memset(parms, 0, sizeof(*parms));
1589 parms->iph.protocol = IPPROTO_GRE;
1594 if (data[IFLA_GRE_LINK])
1595 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1597 if (data[IFLA_GRE_IFLAGS])
1598 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1600 if (data[IFLA_GRE_OFLAGS])
1601 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1603 if (data[IFLA_GRE_IKEY])
1604 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1606 if (data[IFLA_GRE_OKEY])
1607 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1609 if (data[IFLA_GRE_LOCAL])
1610 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1612 if (data[IFLA_GRE_REMOTE])
1613 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1615 if (data[IFLA_GRE_TTL])
1616 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1618 if (data[IFLA_GRE_TOS])
1619 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1621 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1622 parms->iph.frag_off = htons(IP_DF);
1625 static int ipgre_tap_init(struct net_device *dev)
1627 struct ip_tunnel *tunnel;
1629 tunnel = netdev_priv(dev);
1632 strcpy(tunnel->parms.name, dev->name);
1634 ipgre_tunnel_bind_dev(dev);
1636 dev->tstats = alloc_percpu(struct pcpu_tstats);
1643 static const struct net_device_ops ipgre_tap_netdev_ops = {
1644 .ndo_init = ipgre_tap_init,
1645 .ndo_uninit = ipgre_tunnel_uninit,
1646 .ndo_start_xmit = ipgre_tunnel_xmit,
1647 .ndo_set_mac_address = eth_mac_addr,
1648 .ndo_validate_addr = eth_validate_addr,
1649 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1650 .ndo_get_stats64 = ipgre_get_stats64,
1653 static void ipgre_tap_setup(struct net_device *dev)
1658 dev->netdev_ops = &ipgre_tap_netdev_ops;
1659 dev->destructor = ipgre_dev_free;
1662 dev->features |= NETIF_F_NETNS_LOCAL;
1664 dev->features |= GRE_FEATURES;
1665 dev->hw_features |= GRE_FEATURES;
1668 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1669 struct nlattr *data[])
1671 struct ip_tunnel *nt;
1672 struct net *net = dev_net(dev);
1673 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1677 nt = netdev_priv(dev);
1678 ipgre_netlink_parms(data, &nt->parms);
1680 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1683 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1684 eth_hw_addr_random(dev);
1686 mtu = ipgre_tunnel_bind_dev(dev);
1690 /* Can use a lockless transmit, unless we generate output sequences */
1691 if (!(nt->parms.o_flags & GRE_SEQ))
1692 dev->features |= NETIF_F_LLTX;
1694 err = register_netdevice(dev);
1699 ipgre_tunnel_link(ign, nt);
1705 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1706 struct nlattr *data[])
1708 struct ip_tunnel *t, *nt;
1709 struct net *net = dev_net(dev);
1710 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1711 struct ip_tunnel_parm p;
1714 if (dev == ign->fb_tunnel_dev)
1717 nt = netdev_priv(dev);
1718 ipgre_netlink_parms(data, &p);
1720 t = ipgre_tunnel_locate(net, &p, 0);
1728 if (dev->type != ARPHRD_ETHER) {
1729 unsigned int nflags = 0;
1731 if (ipv4_is_multicast(p.iph.daddr))
1732 nflags = IFF_BROADCAST;
1733 else if (p.iph.daddr)
1734 nflags = IFF_POINTOPOINT;
1736 if ((dev->flags ^ nflags) &
1737 (IFF_POINTOPOINT | IFF_BROADCAST))
1741 ipgre_tunnel_unlink(ign, t);
1742 t->parms.iph.saddr = p.iph.saddr;
1743 t->parms.iph.daddr = p.iph.daddr;
1744 t->parms.i_key = p.i_key;
1745 if (dev->type != ARPHRD_ETHER) {
1746 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1747 memcpy(dev->broadcast, &p.iph.daddr, 4);
1749 ipgre_tunnel_link(ign, t);
1750 netdev_state_change(dev);
1753 t->parms.o_key = p.o_key;
1754 t->parms.iph.ttl = p.iph.ttl;
1755 t->parms.iph.tos = p.iph.tos;
1756 t->parms.iph.frag_off = p.iph.frag_off;
1758 if (t->parms.link != p.link) {
1759 t->parms.link = p.link;
1760 mtu = ipgre_tunnel_bind_dev(dev);
1763 netdev_state_change(dev);
1769 static size_t ipgre_get_size(const struct net_device *dev)
1774 /* IFLA_GRE_IFLAGS */
1776 /* IFLA_GRE_OFLAGS */
1782 /* IFLA_GRE_LOCAL */
1784 /* IFLA_GRE_REMOTE */
1790 /* IFLA_GRE_PMTUDISC */
1795 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1797 struct ip_tunnel *t = netdev_priv(dev);
1798 struct ip_tunnel_parm *p = &t->parms;
1800 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1801 nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1802 nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1803 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1804 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1805 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1806 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1807 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1808 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1809 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1810 !!(p->iph.frag_off & htons(IP_DF))))
1811 goto nla_put_failure;
1818 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1819 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1820 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1821 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1822 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1823 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1824 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1825 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1826 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1827 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1828 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1831 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1833 .maxtype = IFLA_GRE_MAX,
1834 .policy = ipgre_policy,
1835 .priv_size = sizeof(struct ip_tunnel),
1836 .setup = ipgre_tunnel_setup,
1837 .validate = ipgre_tunnel_validate,
1838 .newlink = ipgre_newlink,
1839 .changelink = ipgre_changelink,
1840 .get_size = ipgre_get_size,
1841 .fill_info = ipgre_fill_info,
1844 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1846 .maxtype = IFLA_GRE_MAX,
1847 .policy = ipgre_policy,
1848 .priv_size = sizeof(struct ip_tunnel),
1849 .setup = ipgre_tap_setup,
1850 .validate = ipgre_tap_validate,
1851 .newlink = ipgre_newlink,
1852 .changelink = ipgre_changelink,
1853 .get_size = ipgre_get_size,
1854 .fill_info = ipgre_fill_info,
1858 * And now the modules code and kernel interface.
1861 static int __init ipgre_init(void)
1865 pr_info("GRE over IPv4 tunneling driver\n");
1867 err = register_pernet_device(&ipgre_net_ops);
1871 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1873 pr_info("%s: can't add protocol\n", __func__);
1874 goto add_proto_failed;
1877 err = rtnl_link_register(&ipgre_link_ops);
1879 goto rtnl_link_failed;
1881 err = rtnl_link_register(&ipgre_tap_ops);
1883 goto tap_ops_failed;
1889 rtnl_link_unregister(&ipgre_link_ops);
1891 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1893 unregister_pernet_device(&ipgre_net_ops);
1897 static void __exit ipgre_fini(void)
1899 rtnl_link_unregister(&ipgre_tap_ops);
1900 rtnl_link_unregister(&ipgre_link_ops);
1901 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1902 pr_info("%s: can't remove protocol\n", __func__);
1903 unregister_pernet_device(&ipgre_net_ops);
1906 module_init(ipgre_init);
1907 module_exit(ipgre_fini);
1908 MODULE_LICENSE("GPL");
1909 MODULE_ALIAS_RTNL_LINK("gre");
1910 MODULE_ALIAS_RTNL_LINK("gretap");
1911 MODULE_ALIAS_NETDEV("gre0");