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>
40 #include <net/ip_tunnels.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. :-)
114 static bool log_ecn_error = true;
115 module_param(log_ecn_error, bool, 0644);
116 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
118 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
119 static int ipgre_tunnel_init(struct net_device *dev);
121 static int ipgre_net_id __read_mostly;
122 static int gre_tap_net_id __read_mostly;
124 static int ipgre_err(struct sk_buff *skb, u32 info,
125 const struct tnl_ptk_info *tpi)
128 /* All the routers (except for Linux) return only
129 8 bytes of packet payload. It means, that precise relaying of
130 ICMP in the real Internet is absolutely infeasible.
132 Moreover, Cisco "wise men" put GRE key to the third word
133 in GRE header. It makes impossible maintaining even soft
134 state for keyed GRE tunnels with enabled checksum. Tell
137 Well, I wonder, rfc1812 was written by Cisco employee,
138 what the hell these idiots break standards established
141 struct net *net = dev_net(skb->dev);
142 struct ip_tunnel_net *itn;
143 const struct iphdr *iph;
144 const int type = icmp_hdr(skb)->type;
145 const int code = icmp_hdr(skb)->code;
150 case ICMP_PARAMETERPROB:
153 case ICMP_DEST_UNREACH:
156 case ICMP_PORT_UNREACH:
157 /* Impossible event. */
160 /* All others are translated to HOST_UNREACH.
161 rfc2003 contains "deep thoughts" about NET_UNREACH,
162 I believe they are just ether pollution. --ANK
167 case ICMP_TIME_EXCEEDED:
168 if (code != ICMP_EXC_TTL)
176 if (tpi->proto == htons(ETH_P_TEB))
177 itn = net_generic(net, gre_tap_net_id);
179 itn = net_generic(net, ipgre_net_id);
181 iph = (const struct iphdr *)skb->data;
182 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
183 iph->daddr, iph->saddr, tpi->key);
186 return PACKET_REJECT;
188 if (t->parms.iph.daddr == 0 ||
189 ipv4_is_multicast(t->parms.iph.daddr))
192 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
195 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
199 t->err_time = jiffies;
203 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
205 struct net *net = dev_net(skb->dev);
206 struct ip_tunnel_net *itn;
207 const struct iphdr *iph;
208 struct ip_tunnel *tunnel;
210 if (tpi->proto == htons(ETH_P_TEB))
211 itn = net_generic(net, gre_tap_net_id);
213 itn = net_generic(net, ipgre_net_id);
216 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
217 iph->saddr, iph->daddr, tpi->key);
220 ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error);
223 return PACKET_REJECT;
226 static struct sk_buff *handle_offloads(struct ip_tunnel *tunnel, struct sk_buff *skb)
230 if (skb_is_gso(skb)) {
231 err = skb_unclone(skb, GFP_ATOMIC);
234 skb_shinfo(skb)->gso_type |= SKB_GSO_GRE;
236 } else if (skb->ip_summed == CHECKSUM_PARTIAL &&
237 tunnel->parms.o_flags&TUNNEL_CSUM) {
238 err = skb_checksum_help(skb);
241 } else if (skb->ip_summed != CHECKSUM_PARTIAL)
242 skb->ip_summed = CHECKSUM_NONE;
251 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
252 const struct iphdr *tnl_params,
255 struct ip_tunnel *tunnel = netdev_priv(dev);
256 struct tnl_ptk_info tpi;
258 if (likely(!skb->encapsulation)) {
259 skb_reset_inner_headers(skb);
260 skb->encapsulation = 1;
263 tpi.flags = tunnel->parms.o_flags;
265 tpi.key = tunnel->parms.o_key;
266 if (tunnel->parms.o_flags & TUNNEL_SEQ)
268 tpi.seq = htonl(tunnel->o_seqno);
270 /* Push GRE header. */
271 gre_build_header(skb, &tpi, tunnel->hlen);
273 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
276 static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
277 struct net_device *dev)
279 struct ip_tunnel *tunnel = netdev_priv(dev);
280 const struct iphdr *tnl_params;
282 skb = handle_offloads(tunnel, skb);
286 if (dev->header_ops) {
287 /* Need space for new headers */
288 if (skb_cow_head(skb, dev->needed_headroom -
289 (tunnel->hlen + sizeof(struct iphdr))))
292 tnl_params = (const struct iphdr *)skb->data;
294 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
297 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
299 if (skb_cow_head(skb, dev->needed_headroom))
302 tnl_params = &tunnel->parms.iph;
305 __gre_xmit(skb, dev, tnl_params, skb->protocol);
312 dev->stats.tx_dropped++;
316 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
317 struct net_device *dev)
319 struct ip_tunnel *tunnel = netdev_priv(dev);
321 skb = handle_offloads(tunnel, skb);
325 if (skb_cow_head(skb, dev->needed_headroom))
328 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
335 dev->stats.tx_dropped++;
339 static int ipgre_tunnel_ioctl(struct net_device *dev,
340 struct ifreq *ifr, int cmd)
343 struct ip_tunnel_parm p;
345 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
347 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
348 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
349 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) {
352 p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
353 p.o_flags = gre_flags_to_tnl_flags(p.o_flags);
355 err = ip_tunnel_ioctl(dev, &p, cmd);
359 p.i_flags = tnl_flags_to_gre_flags(p.i_flags);
360 p.o_flags = tnl_flags_to_gre_flags(p.o_flags);
362 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
367 /* Nice toy. Unfortunately, useless in real life :-)
368 It allows to construct virtual multiprotocol broadcast "LAN"
369 over the Internet, provided multicast routing is tuned.
372 I have no idea was this bicycle invented before me,
373 so that I had to set ARPHRD_IPGRE to a random value.
374 I have an impression, that Cisco could make something similar,
375 but this feature is apparently missing in IOS<=11.2(8).
377 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
378 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
380 ping -t 255 224.66.66.66
382 If nobody answers, mbone does not work.
384 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
385 ip addr add 10.66.66.<somewhat>/24 dev Universe
387 ifconfig Universe add fe80::<Your_real_addr>/10
388 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
391 ftp fec0:6666:6666::193.233.7.65
394 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
396 const void *daddr, const void *saddr, unsigned int len)
398 struct ip_tunnel *t = netdev_priv(dev);
400 struct gre_base_hdr *greh;
402 iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph));
403 greh = (struct gre_base_hdr *)(iph+1);
404 greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags);
405 greh->protocol = htons(type);
407 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
409 /* Set the source hardware address. */
411 memcpy(&iph->saddr, saddr, 4);
413 memcpy(&iph->daddr, daddr, 4);
417 return -(t->hlen + sizeof(*iph));
420 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
422 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
423 memcpy(haddr, &iph->saddr, 4);
427 static const struct header_ops ipgre_header_ops = {
428 .create = ipgre_header,
429 .parse = ipgre_header_parse,
432 #ifdef CONFIG_NET_IPGRE_BROADCAST
433 static int ipgre_open(struct net_device *dev)
435 struct ip_tunnel *t = netdev_priv(dev);
437 if (ipv4_is_multicast(t->parms.iph.daddr)) {
441 rt = ip_route_output_gre(dev_net(dev), &fl4,
445 RT_TOS(t->parms.iph.tos),
448 return -EADDRNOTAVAIL;
451 if (__in_dev_get_rtnl(dev) == NULL)
452 return -EADDRNOTAVAIL;
453 t->mlink = dev->ifindex;
454 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
459 static int ipgre_close(struct net_device *dev)
461 struct ip_tunnel *t = netdev_priv(dev);
463 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
464 struct in_device *in_dev;
465 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
467 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
473 static const struct net_device_ops ipgre_netdev_ops = {
474 .ndo_init = ipgre_tunnel_init,
475 .ndo_uninit = ip_tunnel_uninit,
476 #ifdef CONFIG_NET_IPGRE_BROADCAST
477 .ndo_open = ipgre_open,
478 .ndo_stop = ipgre_close,
480 .ndo_start_xmit = ipgre_xmit,
481 .ndo_do_ioctl = ipgre_tunnel_ioctl,
482 .ndo_change_mtu = ip_tunnel_change_mtu,
483 .ndo_get_stats64 = ip_tunnel_get_stats64,
486 #define GRE_FEATURES (NETIF_F_SG | \
491 static void ipgre_tunnel_setup(struct net_device *dev)
493 dev->netdev_ops = &ipgre_netdev_ops;
494 ip_tunnel_setup(dev, ipgre_net_id);
497 static void __gre_tunnel_init(struct net_device *dev)
499 struct ip_tunnel *tunnel;
501 tunnel = netdev_priv(dev);
502 tunnel->hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);
503 tunnel->parms.iph.protocol = IPPROTO_GRE;
505 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
506 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
508 dev->features |= NETIF_F_NETNS_LOCAL | GRE_FEATURES;
509 dev->hw_features |= GRE_FEATURES;
511 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
512 /* TCP offload with GRE SEQ is not supported. */
513 dev->features |= NETIF_F_GSO_SOFTWARE;
514 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
515 /* Can use a lockless transmit, unless we generate
518 dev->features |= NETIF_F_LLTX;
522 static int ipgre_tunnel_init(struct net_device *dev)
524 struct ip_tunnel *tunnel = netdev_priv(dev);
525 struct iphdr *iph = &tunnel->parms.iph;
527 __gre_tunnel_init(dev);
529 memcpy(dev->dev_addr, &iph->saddr, 4);
530 memcpy(dev->broadcast, &iph->daddr, 4);
532 dev->type = ARPHRD_IPGRE;
533 dev->flags = IFF_NOARP;
534 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
538 #ifdef CONFIG_NET_IPGRE_BROADCAST
539 if (ipv4_is_multicast(iph->daddr)) {
542 dev->flags = IFF_BROADCAST;
543 dev->header_ops = &ipgre_header_ops;
547 dev->header_ops = &ipgre_header_ops;
549 return ip_tunnel_init(dev);
552 static struct gre_cisco_protocol ipgre_protocol = {
553 .handler = ipgre_rcv,
554 .err_handler = ipgre_err,
558 static int __net_init ipgre_init_net(struct net *net)
560 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
563 static void __net_exit ipgre_exit_net(struct net *net)
565 struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id);
566 ip_tunnel_delete_net(itn);
569 static struct pernet_operations ipgre_net_ops = {
570 .init = ipgre_init_net,
571 .exit = ipgre_exit_net,
573 .size = sizeof(struct ip_tunnel_net),
576 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
584 if (data[IFLA_GRE_IFLAGS])
585 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
586 if (data[IFLA_GRE_OFLAGS])
587 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
588 if (flags & (GRE_VERSION|GRE_ROUTING))
594 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
598 if (tb[IFLA_ADDRESS]) {
599 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
601 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
602 return -EADDRNOTAVAIL;
608 if (data[IFLA_GRE_REMOTE]) {
609 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
615 return ipgre_tunnel_validate(tb, data);
618 static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[],
619 struct ip_tunnel_parm *parms)
621 memset(parms, 0, sizeof(*parms));
623 parms->iph.protocol = IPPROTO_GRE;
628 if (data[IFLA_GRE_LINK])
629 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
631 if (data[IFLA_GRE_IFLAGS])
632 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
634 if (data[IFLA_GRE_OFLAGS])
635 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
637 if (data[IFLA_GRE_IKEY])
638 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
640 if (data[IFLA_GRE_OKEY])
641 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
643 if (data[IFLA_GRE_LOCAL])
644 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
646 if (data[IFLA_GRE_REMOTE])
647 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
649 if (data[IFLA_GRE_TTL])
650 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
652 if (data[IFLA_GRE_TOS])
653 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
655 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
656 parms->iph.frag_off = htons(IP_DF);
659 static int gre_tap_init(struct net_device *dev)
661 __gre_tunnel_init(dev);
663 return ip_tunnel_init(dev);
666 static const struct net_device_ops gre_tap_netdev_ops = {
667 .ndo_init = gre_tap_init,
668 .ndo_uninit = ip_tunnel_uninit,
669 .ndo_start_xmit = gre_tap_xmit,
670 .ndo_set_mac_address = eth_mac_addr,
671 .ndo_validate_addr = eth_validate_addr,
672 .ndo_change_mtu = ip_tunnel_change_mtu,
673 .ndo_get_stats64 = ip_tunnel_get_stats64,
676 static void ipgre_tap_setup(struct net_device *dev)
679 dev->netdev_ops = &gre_tap_netdev_ops;
680 ip_tunnel_setup(dev, gre_tap_net_id);
683 static int ipgre_newlink(struct net *src_net, struct net_device *dev,
684 struct nlattr *tb[], struct nlattr *data[])
686 struct ip_tunnel_parm p;
688 ipgre_netlink_parms(data, tb, &p);
689 return ip_tunnel_newlink(dev, tb, &p);
692 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
693 struct nlattr *data[])
695 struct ip_tunnel_parm p;
697 ipgre_netlink_parms(data, tb, &p);
698 return ip_tunnel_changelink(dev, tb, &p);
701 static size_t ipgre_get_size(const struct net_device *dev)
706 /* IFLA_GRE_IFLAGS */
708 /* IFLA_GRE_OFLAGS */
716 /* IFLA_GRE_REMOTE */
722 /* IFLA_GRE_PMTUDISC */
727 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
729 struct ip_tunnel *t = netdev_priv(dev);
730 struct ip_tunnel_parm *p = &t->parms;
732 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
733 nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) ||
734 nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) ||
735 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
736 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
737 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
738 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
739 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
740 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
741 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
742 !!(p->iph.frag_off & htons(IP_DF))))
743 goto nla_put_failure;
750 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
751 [IFLA_GRE_LINK] = { .type = NLA_U32 },
752 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
753 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
754 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
755 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
756 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
757 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
758 [IFLA_GRE_TTL] = { .type = NLA_U8 },
759 [IFLA_GRE_TOS] = { .type = NLA_U8 },
760 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
763 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
765 .maxtype = IFLA_GRE_MAX,
766 .policy = ipgre_policy,
767 .priv_size = sizeof(struct ip_tunnel),
768 .setup = ipgre_tunnel_setup,
769 .validate = ipgre_tunnel_validate,
770 .newlink = ipgre_newlink,
771 .changelink = ipgre_changelink,
772 .dellink = ip_tunnel_dellink,
773 .get_size = ipgre_get_size,
774 .fill_info = ipgre_fill_info,
777 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
779 .maxtype = IFLA_GRE_MAX,
780 .policy = ipgre_policy,
781 .priv_size = sizeof(struct ip_tunnel),
782 .setup = ipgre_tap_setup,
783 .validate = ipgre_tap_validate,
784 .newlink = ipgre_newlink,
785 .changelink = ipgre_changelink,
786 .dellink = ip_tunnel_dellink,
787 .get_size = ipgre_get_size,
788 .fill_info = ipgre_fill_info,
791 static int __net_init ipgre_tap_init_net(struct net *net)
793 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, NULL);
796 static void __net_exit ipgre_tap_exit_net(struct net *net)
798 struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id);
799 ip_tunnel_delete_net(itn);
802 static struct pernet_operations ipgre_tap_net_ops = {
803 .init = ipgre_tap_init_net,
804 .exit = ipgre_tap_exit_net,
805 .id = &gre_tap_net_id,
806 .size = sizeof(struct ip_tunnel_net),
809 static int __init ipgre_init(void)
813 pr_info("GRE over IPv4 tunneling driver\n");
815 err = register_pernet_device(&ipgre_net_ops);
819 err = register_pernet_device(&ipgre_tap_net_ops);
823 err = gre_cisco_register(&ipgre_protocol);
825 pr_info("%s: can't add protocol\n", __func__);
826 goto add_proto_failed;
829 err = rtnl_link_register(&ipgre_link_ops);
831 goto rtnl_link_failed;
833 err = rtnl_link_register(&ipgre_tap_ops);
840 rtnl_link_unregister(&ipgre_link_ops);
842 gre_cisco_unregister(&ipgre_protocol);
844 unregister_pernet_device(&ipgre_tap_net_ops);
846 unregister_pernet_device(&ipgre_net_ops);
850 static void __exit ipgre_fini(void)
852 rtnl_link_unregister(&ipgre_tap_ops);
853 rtnl_link_unregister(&ipgre_link_ops);
854 gre_cisco_unregister(&ipgre_protocol);
855 unregister_pernet_device(&ipgre_tap_net_ops);
856 unregister_pernet_device(&ipgre_net_ops);
859 module_init(ipgre_init);
860 module_exit(ipgre_fini);
861 MODULE_LICENSE("GPL");
862 MODULE_ALIAS_RTNL_LINK("gre");
863 MODULE_ALIAS_RTNL_LINK("gretap");
864 MODULE_ALIAS_NETDEV("gre0");
865 MODULE_ALIAS_NETDEV("gretap0");