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;
976 if (skb->protocol == htons(ETH_P_IP))
977 iph->ttl = old_iph->ttl;
978 #if IS_ENABLED(CONFIG_IPV6)
979 else if (skb->protocol == htons(ETH_P_IPV6))
980 iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
983 iph->ttl = ip4_dst_hoplimit(&rt->dst);
986 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
987 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
988 htons(ETH_P_TEB) : skb->protocol;
990 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
991 __be32 *ptr = (__be32 *)(((u8 *)iph) + tunnel->hlen - 4);
993 if (tunnel->parms.o_flags&GRE_SEQ) {
995 *ptr = htonl(tunnel->o_seqno);
998 if (tunnel->parms.o_flags&GRE_KEY) {
999 *ptr = tunnel->parms.o_key;
1002 /* Skip GRE checksum if skb is getting offloaded. */
1003 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE) &&
1004 (tunnel->parms.o_flags&GRE_CSUM)) {
1005 int offset = skb_transport_offset(skb);
1007 if (skb_has_shared_frag(skb)) {
1008 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 /* device supports enc gso offload*/
1107 if (tdev->hw_enc_features & NETIF_F_GRE_GSO) {
1108 dev->features |= NETIF_F_TSO;
1109 dev->hw_features |= NETIF_F_TSO;
1111 dev->features |= NETIF_F_GSO_SOFTWARE;
1112 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1120 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1123 struct ip_tunnel_parm p;
1124 struct ip_tunnel *t;
1125 struct net *net = dev_net(dev);
1126 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1131 if (dev == ign->fb_tunnel_dev) {
1132 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1136 t = ipgre_tunnel_locate(net, &p, 0);
1139 t = netdev_priv(dev);
1140 memcpy(&p, &t->parms, sizeof(p));
1141 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1148 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1152 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1156 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1157 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1158 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1161 p.iph.frag_off |= htons(IP_DF);
1163 if (!(p.i_flags&GRE_KEY))
1165 if (!(p.o_flags&GRE_KEY))
1168 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1170 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1172 if (t->dev != dev) {
1177 unsigned int nflags = 0;
1179 t = netdev_priv(dev);
1181 if (ipv4_is_multicast(p.iph.daddr))
1182 nflags = IFF_BROADCAST;
1183 else if (p.iph.daddr)
1184 nflags = IFF_POINTOPOINT;
1186 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1190 ipgre_tunnel_unlink(ign, t);
1192 t->parms.iph.saddr = p.iph.saddr;
1193 t->parms.iph.daddr = p.iph.daddr;
1194 t->parms.i_key = p.i_key;
1195 t->parms.o_key = p.o_key;
1196 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1197 memcpy(dev->broadcast, &p.iph.daddr, 4);
1198 ipgre_tunnel_link(ign, t);
1199 netdev_state_change(dev);
1205 if (cmd == SIOCCHGTUNNEL) {
1206 t->parms.iph.ttl = p.iph.ttl;
1207 t->parms.iph.tos = p.iph.tos;
1208 t->parms.iph.frag_off = p.iph.frag_off;
1209 if (t->parms.link != p.link) {
1210 t->parms.link = p.link;
1211 dev->mtu = ipgre_tunnel_bind_dev(dev);
1212 netdev_state_change(dev);
1215 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1218 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1223 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1226 if (dev == ign->fb_tunnel_dev) {
1228 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1231 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1234 if (t == netdev_priv(ign->fb_tunnel_dev))
1238 unregister_netdevice(dev);
1250 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1252 struct ip_tunnel *tunnel = netdev_priv(dev);
1254 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1260 /* Nice toy. Unfortunately, useless in real life :-)
1261 It allows to construct virtual multiprotocol broadcast "LAN"
1262 over the Internet, provided multicast routing is tuned.
1265 I have no idea was this bicycle invented before me,
1266 so that I had to set ARPHRD_IPGRE to a random value.
1267 I have an impression, that Cisco could make something similar,
1268 but this feature is apparently missing in IOS<=11.2(8).
1270 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1271 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1273 ping -t 255 224.66.66.66
1275 If nobody answers, mbone does not work.
1277 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1278 ip addr add 10.66.66.<somewhat>/24 dev Universe
1279 ifconfig Universe up
1280 ifconfig Universe add fe80::<Your_real_addr>/10
1281 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1284 ftp fec0:6666:6666::193.233.7.65
1289 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1290 unsigned short type,
1291 const void *daddr, const void *saddr, unsigned int len)
1293 struct ip_tunnel *t = netdev_priv(dev);
1294 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1295 __be16 *p = (__be16 *)(iph+1);
1297 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1298 p[0] = t->parms.o_flags;
1302 * Set the source hardware address.
1306 memcpy(&iph->saddr, saddr, 4);
1308 memcpy(&iph->daddr, daddr, 4);
1315 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1317 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
1318 memcpy(haddr, &iph->saddr, 4);
1322 static const struct header_ops ipgre_header_ops = {
1323 .create = ipgre_header,
1324 .parse = ipgre_header_parse,
1327 #ifdef CONFIG_NET_IPGRE_BROADCAST
1328 static int ipgre_open(struct net_device *dev)
1330 struct ip_tunnel *t = netdev_priv(dev);
1332 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1336 rt = ip_route_output_gre(dev_net(dev), &fl4,
1340 RT_TOS(t->parms.iph.tos),
1343 return -EADDRNOTAVAIL;
1346 if (__in_dev_get_rtnl(dev) == NULL)
1347 return -EADDRNOTAVAIL;
1348 t->mlink = dev->ifindex;
1349 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1354 static int ipgre_close(struct net_device *dev)
1356 struct ip_tunnel *t = netdev_priv(dev);
1358 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1359 struct in_device *in_dev;
1360 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1362 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1369 static const struct net_device_ops ipgre_netdev_ops = {
1370 .ndo_init = ipgre_tunnel_init,
1371 .ndo_uninit = ipgre_tunnel_uninit,
1372 #ifdef CONFIG_NET_IPGRE_BROADCAST
1373 .ndo_open = ipgre_open,
1374 .ndo_stop = ipgre_close,
1376 .ndo_start_xmit = ipgre_tunnel_xmit,
1377 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1378 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1379 .ndo_get_stats64 = ipgre_get_stats64,
1382 static void ipgre_dev_free(struct net_device *dev)
1384 struct ip_tunnel *tunnel = netdev_priv(dev);
1386 gro_cells_destroy(&tunnel->gro_cells);
1387 free_percpu(dev->tstats);
1391 #define GRE_FEATURES (NETIF_F_SG | \
1392 NETIF_F_FRAGLIST | \
1396 static void ipgre_tunnel_setup(struct net_device *dev)
1398 dev->netdev_ops = &ipgre_netdev_ops;
1399 dev->destructor = ipgre_dev_free;
1401 dev->type = ARPHRD_IPGRE;
1402 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1403 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1404 dev->flags = IFF_NOARP;
1407 dev->features |= NETIF_F_NETNS_LOCAL;
1408 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1410 dev->features |= GRE_FEATURES;
1411 dev->hw_features |= GRE_FEATURES;
1414 static int ipgre_tunnel_init(struct net_device *dev)
1416 struct ip_tunnel *tunnel;
1420 tunnel = netdev_priv(dev);
1421 iph = &tunnel->parms.iph;
1424 strcpy(tunnel->parms.name, dev->name);
1426 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1427 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1430 #ifdef CONFIG_NET_IPGRE_BROADCAST
1431 if (ipv4_is_multicast(iph->daddr)) {
1434 dev->flags = IFF_BROADCAST;
1435 dev->header_ops = &ipgre_header_ops;
1439 dev->header_ops = &ipgre_header_ops;
1441 dev->tstats = alloc_percpu(struct pcpu_tstats);
1445 err = gro_cells_init(&tunnel->gro_cells, dev);
1447 free_percpu(dev->tstats);
1454 static void ipgre_fb_tunnel_init(struct net_device *dev)
1456 struct ip_tunnel *tunnel = netdev_priv(dev);
1457 struct iphdr *iph = &tunnel->parms.iph;
1460 strcpy(tunnel->parms.name, dev->name);
1463 iph->protocol = IPPROTO_GRE;
1465 tunnel->hlen = sizeof(struct iphdr) + 4;
1471 static const struct gre_protocol ipgre_protocol = {
1472 .handler = ipgre_rcv,
1473 .err_handler = ipgre_err,
1476 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1480 for (prio = 0; prio < 4; prio++) {
1482 for (h = 0; h < HASH_SIZE; h++) {
1483 struct ip_tunnel *t;
1485 t = rtnl_dereference(ign->tunnels[prio][h]);
1488 unregister_netdevice_queue(t->dev, head);
1489 t = rtnl_dereference(t->next);
1495 static int __net_init ipgre_init_net(struct net *net)
1497 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1500 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1501 ipgre_tunnel_setup);
1502 if (!ign->fb_tunnel_dev) {
1506 dev_net_set(ign->fb_tunnel_dev, net);
1508 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1509 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1511 if ((err = register_netdev(ign->fb_tunnel_dev)))
1514 rcu_assign_pointer(ign->tunnels_wc[0],
1515 netdev_priv(ign->fb_tunnel_dev));
1519 ipgre_dev_free(ign->fb_tunnel_dev);
1524 static void __net_exit ipgre_exit_net(struct net *net)
1526 struct ipgre_net *ign;
1529 ign = net_generic(net, ipgre_net_id);
1531 ipgre_destroy_tunnels(ign, &list);
1532 unregister_netdevice_many(&list);
1536 static struct pernet_operations ipgre_net_ops = {
1537 .init = ipgre_init_net,
1538 .exit = ipgre_exit_net,
1539 .id = &ipgre_net_id,
1540 .size = sizeof(struct ipgre_net),
1543 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1551 if (data[IFLA_GRE_IFLAGS])
1552 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1553 if (data[IFLA_GRE_OFLAGS])
1554 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1555 if (flags & (GRE_VERSION|GRE_ROUTING))
1561 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1565 if (tb[IFLA_ADDRESS]) {
1566 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1568 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1569 return -EADDRNOTAVAIL;
1575 if (data[IFLA_GRE_REMOTE]) {
1576 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1582 return ipgre_tunnel_validate(tb, data);
1585 static void ipgre_netlink_parms(struct nlattr *data[],
1586 struct ip_tunnel_parm *parms)
1588 memset(parms, 0, sizeof(*parms));
1590 parms->iph.protocol = IPPROTO_GRE;
1595 if (data[IFLA_GRE_LINK])
1596 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1598 if (data[IFLA_GRE_IFLAGS])
1599 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1601 if (data[IFLA_GRE_OFLAGS])
1602 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1604 if (data[IFLA_GRE_IKEY])
1605 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1607 if (data[IFLA_GRE_OKEY])
1608 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1610 if (data[IFLA_GRE_LOCAL])
1611 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1613 if (data[IFLA_GRE_REMOTE])
1614 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1616 if (data[IFLA_GRE_TTL])
1617 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1619 if (data[IFLA_GRE_TOS])
1620 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1622 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1623 parms->iph.frag_off = htons(IP_DF);
1626 static int ipgre_tap_init(struct net_device *dev)
1628 struct ip_tunnel *tunnel;
1630 tunnel = netdev_priv(dev);
1633 strcpy(tunnel->parms.name, dev->name);
1635 ipgre_tunnel_bind_dev(dev);
1637 dev->tstats = alloc_percpu(struct pcpu_tstats);
1644 static const struct net_device_ops ipgre_tap_netdev_ops = {
1645 .ndo_init = ipgre_tap_init,
1646 .ndo_uninit = ipgre_tunnel_uninit,
1647 .ndo_start_xmit = ipgre_tunnel_xmit,
1648 .ndo_set_mac_address = eth_mac_addr,
1649 .ndo_validate_addr = eth_validate_addr,
1650 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1651 .ndo_get_stats64 = ipgre_get_stats64,
1654 static void ipgre_tap_setup(struct net_device *dev)
1659 dev->netdev_ops = &ipgre_tap_netdev_ops;
1660 dev->destructor = ipgre_dev_free;
1663 dev->features |= NETIF_F_NETNS_LOCAL;
1665 dev->features |= GRE_FEATURES;
1666 dev->hw_features |= GRE_FEATURES;
1669 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1670 struct nlattr *data[])
1672 struct ip_tunnel *nt;
1673 struct net *net = dev_net(dev);
1674 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1678 nt = netdev_priv(dev);
1679 ipgre_netlink_parms(data, &nt->parms);
1681 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1684 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1685 eth_hw_addr_random(dev);
1687 mtu = ipgre_tunnel_bind_dev(dev);
1691 /* Can use a lockless transmit, unless we generate output sequences */
1692 if (!(nt->parms.o_flags & GRE_SEQ))
1693 dev->features |= NETIF_F_LLTX;
1695 err = register_netdevice(dev);
1700 ipgre_tunnel_link(ign, nt);
1706 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1707 struct nlattr *data[])
1709 struct ip_tunnel *t, *nt;
1710 struct net *net = dev_net(dev);
1711 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1712 struct ip_tunnel_parm p;
1715 if (dev == ign->fb_tunnel_dev)
1718 nt = netdev_priv(dev);
1719 ipgre_netlink_parms(data, &p);
1721 t = ipgre_tunnel_locate(net, &p, 0);
1729 if (dev->type != ARPHRD_ETHER) {
1730 unsigned int nflags = 0;
1732 if (ipv4_is_multicast(p.iph.daddr))
1733 nflags = IFF_BROADCAST;
1734 else if (p.iph.daddr)
1735 nflags = IFF_POINTOPOINT;
1737 if ((dev->flags ^ nflags) &
1738 (IFF_POINTOPOINT | IFF_BROADCAST))
1742 ipgre_tunnel_unlink(ign, t);
1743 t->parms.iph.saddr = p.iph.saddr;
1744 t->parms.iph.daddr = p.iph.daddr;
1745 t->parms.i_key = p.i_key;
1746 if (dev->type != ARPHRD_ETHER) {
1747 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1748 memcpy(dev->broadcast, &p.iph.daddr, 4);
1750 ipgre_tunnel_link(ign, t);
1751 netdev_state_change(dev);
1754 t->parms.o_key = p.o_key;
1755 t->parms.iph.ttl = p.iph.ttl;
1756 t->parms.iph.tos = p.iph.tos;
1757 t->parms.iph.frag_off = p.iph.frag_off;
1759 if (t->parms.link != p.link) {
1760 t->parms.link = p.link;
1761 mtu = ipgre_tunnel_bind_dev(dev);
1764 netdev_state_change(dev);
1770 static size_t ipgre_get_size(const struct net_device *dev)
1775 /* IFLA_GRE_IFLAGS */
1777 /* IFLA_GRE_OFLAGS */
1783 /* IFLA_GRE_LOCAL */
1785 /* IFLA_GRE_REMOTE */
1791 /* IFLA_GRE_PMTUDISC */
1796 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1798 struct ip_tunnel *t = netdev_priv(dev);
1799 struct ip_tunnel_parm *p = &t->parms;
1801 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1802 nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1803 nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1804 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1805 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1806 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1807 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1808 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1809 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1810 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1811 !!(p->iph.frag_off & htons(IP_DF))))
1812 goto nla_put_failure;
1819 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1820 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1821 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1822 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1823 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1824 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1825 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1826 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1827 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1828 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1829 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1832 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1834 .maxtype = IFLA_GRE_MAX,
1835 .policy = ipgre_policy,
1836 .priv_size = sizeof(struct ip_tunnel),
1837 .setup = ipgre_tunnel_setup,
1838 .validate = ipgre_tunnel_validate,
1839 .newlink = ipgre_newlink,
1840 .changelink = ipgre_changelink,
1841 .get_size = ipgre_get_size,
1842 .fill_info = ipgre_fill_info,
1845 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1847 .maxtype = IFLA_GRE_MAX,
1848 .policy = ipgre_policy,
1849 .priv_size = sizeof(struct ip_tunnel),
1850 .setup = ipgre_tap_setup,
1851 .validate = ipgre_tap_validate,
1852 .newlink = ipgre_newlink,
1853 .changelink = ipgre_changelink,
1854 .get_size = ipgre_get_size,
1855 .fill_info = ipgre_fill_info,
1859 * And now the modules code and kernel interface.
1862 static int __init ipgre_init(void)
1866 pr_info("GRE over IPv4 tunneling driver\n");
1868 err = register_pernet_device(&ipgre_net_ops);
1872 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1874 pr_info("%s: can't add protocol\n", __func__);
1875 goto add_proto_failed;
1878 err = rtnl_link_register(&ipgre_link_ops);
1880 goto rtnl_link_failed;
1882 err = rtnl_link_register(&ipgre_tap_ops);
1884 goto tap_ops_failed;
1890 rtnl_link_unregister(&ipgre_link_ops);
1892 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1894 unregister_pernet_device(&ipgre_net_ops);
1898 static void __exit ipgre_fini(void)
1900 rtnl_link_unregister(&ipgre_tap_ops);
1901 rtnl_link_unregister(&ipgre_link_ops);
1902 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1903 pr_info("%s: can't remove protocol\n", __func__);
1904 unregister_pernet_device(&ipgre_net_ops);
1907 module_init(ipgre_init);
1908 module_exit(ipgre_fini);
1909 MODULE_LICENSE("GPL");
1910 MODULE_ALIAS_RTNL_LINK("gre");
1911 MODULE_ALIAS_RTNL_LINK("gretap");
1912 MODULE_ALIAS_NETDEV("gre0");