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 *)(icmp_hdr(skb) + 1);
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 skb_pop_mac_header(skb);
221 ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error);
224 return PACKET_REJECT;
227 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
228 const struct iphdr *tnl_params,
231 struct ip_tunnel *tunnel = netdev_priv(dev);
232 struct tnl_ptk_info tpi;
234 tpi.flags = tunnel->parms.o_flags;
236 tpi.key = tunnel->parms.o_key;
237 if (tunnel->parms.o_flags & TUNNEL_SEQ)
239 tpi.seq = htonl(tunnel->o_seqno);
241 /* Push GRE header. */
242 gre_build_header(skb, &tpi, tunnel->hlen);
244 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
247 static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
248 struct net_device *dev)
250 struct ip_tunnel *tunnel = netdev_priv(dev);
251 const struct iphdr *tnl_params;
253 if (dev->header_ops) {
254 /* Need space for new headers */
255 if (skb_cow_head(skb, dev->needed_headroom -
256 (tunnel->hlen + sizeof(struct iphdr))))
259 tnl_params = (const struct iphdr *)skb->data;
261 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
264 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
265 skb_reset_mac_header(skb);
267 if (skb_cow_head(skb, dev->needed_headroom))
270 tnl_params = &tunnel->parms.iph;
273 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));
277 __gre_xmit(skb, dev, tnl_params, skb->protocol);
284 dev->stats.tx_dropped++;
288 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
289 struct net_device *dev)
291 struct ip_tunnel *tunnel = netdev_priv(dev);
293 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));
297 if (skb_cow_head(skb, dev->needed_headroom))
300 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
307 dev->stats.tx_dropped++;
311 static int ipgre_tunnel_ioctl(struct net_device *dev,
312 struct ifreq *ifr, int cmd)
315 struct ip_tunnel_parm p;
317 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
319 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
320 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
321 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
322 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
325 p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
326 p.o_flags = gre_flags_to_tnl_flags(p.o_flags);
328 err = ip_tunnel_ioctl(dev, &p, cmd);
332 p.i_flags = tnl_flags_to_gre_flags(p.i_flags);
333 p.o_flags = tnl_flags_to_gre_flags(p.o_flags);
335 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
340 /* Nice toy. Unfortunately, useless in real life :-)
341 It allows to construct virtual multiprotocol broadcast "LAN"
342 over the Internet, provided multicast routing is tuned.
345 I have no idea was this bicycle invented before me,
346 so that I had to set ARPHRD_IPGRE to a random value.
347 I have an impression, that Cisco could make something similar,
348 but this feature is apparently missing in IOS<=11.2(8).
350 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
351 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
353 ping -t 255 224.66.66.66
355 If nobody answers, mbone does not work.
357 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
358 ip addr add 10.66.66.<somewhat>/24 dev Universe
360 ifconfig Universe add fe80::<Your_real_addr>/10
361 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
364 ftp fec0:6666:6666::193.233.7.65
367 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
369 const void *daddr, const void *saddr, unsigned int len)
371 struct ip_tunnel *t = netdev_priv(dev);
373 struct gre_base_hdr *greh;
375 iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph));
376 greh = (struct gre_base_hdr *)(iph+1);
377 greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags);
378 greh->protocol = htons(type);
380 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
382 /* Set the source hardware address. */
384 memcpy(&iph->saddr, saddr, 4);
386 memcpy(&iph->daddr, daddr, 4);
388 return t->hlen + sizeof(*iph);
390 return -(t->hlen + sizeof(*iph));
393 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
395 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
396 memcpy(haddr, &iph->saddr, 4);
400 static const struct header_ops ipgre_header_ops = {
401 .create = ipgre_header,
402 .parse = ipgre_header_parse,
405 #ifdef CONFIG_NET_IPGRE_BROADCAST
406 static int ipgre_open(struct net_device *dev)
408 struct ip_tunnel *t = netdev_priv(dev);
410 if (ipv4_is_multicast(t->parms.iph.daddr)) {
414 rt = ip_route_output_gre(dev_net(dev), &fl4,
418 RT_TOS(t->parms.iph.tos),
421 return -EADDRNOTAVAIL;
424 if (__in_dev_get_rtnl(dev) == NULL)
425 return -EADDRNOTAVAIL;
426 t->mlink = dev->ifindex;
427 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
432 static int ipgre_close(struct net_device *dev)
434 struct ip_tunnel *t = netdev_priv(dev);
436 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
437 struct in_device *in_dev;
438 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
440 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
446 static const struct net_device_ops ipgre_netdev_ops = {
447 .ndo_init = ipgre_tunnel_init,
448 .ndo_uninit = ip_tunnel_uninit,
449 #ifdef CONFIG_NET_IPGRE_BROADCAST
450 .ndo_open = ipgre_open,
451 .ndo_stop = ipgre_close,
453 .ndo_start_xmit = ipgre_xmit,
454 .ndo_do_ioctl = ipgre_tunnel_ioctl,
455 .ndo_change_mtu = ip_tunnel_change_mtu,
456 .ndo_get_stats64 = ip_tunnel_get_stats64,
459 #define GRE_FEATURES (NETIF_F_SG | \
464 static void ipgre_tunnel_setup(struct net_device *dev)
466 dev->netdev_ops = &ipgre_netdev_ops;
467 dev->type = ARPHRD_IPGRE;
468 ip_tunnel_setup(dev, ipgre_net_id);
471 static void __gre_tunnel_init(struct net_device *dev)
473 struct ip_tunnel *tunnel;
475 tunnel = netdev_priv(dev);
476 tunnel->hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);
477 tunnel->parms.iph.protocol = IPPROTO_GRE;
479 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
480 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
482 dev->features |= NETIF_F_NETNS_LOCAL | GRE_FEATURES;
483 dev->hw_features |= GRE_FEATURES;
485 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
486 /* TCP offload with GRE SEQ is not supported. */
487 dev->features |= NETIF_F_GSO_SOFTWARE;
488 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
489 /* Can use a lockless transmit, unless we generate
492 dev->features |= NETIF_F_LLTX;
496 static int ipgre_tunnel_init(struct net_device *dev)
498 struct ip_tunnel *tunnel = netdev_priv(dev);
499 struct iphdr *iph = &tunnel->parms.iph;
501 __gre_tunnel_init(dev);
503 memcpy(dev->dev_addr, &iph->saddr, 4);
504 memcpy(dev->broadcast, &iph->daddr, 4);
506 dev->flags = IFF_NOARP;
507 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
511 #ifdef CONFIG_NET_IPGRE_BROADCAST
512 if (ipv4_is_multicast(iph->daddr)) {
515 dev->flags = IFF_BROADCAST;
516 dev->header_ops = &ipgre_header_ops;
520 dev->header_ops = &ipgre_header_ops;
522 return ip_tunnel_init(dev);
525 static struct gre_cisco_protocol ipgre_protocol = {
526 .handler = ipgre_rcv,
527 .err_handler = ipgre_err,
531 static int __net_init ipgre_init_net(struct net *net)
533 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
536 static void __net_exit ipgre_exit_net(struct net *net)
538 struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id);
539 ip_tunnel_delete_net(itn, &ipgre_link_ops);
542 static struct pernet_operations ipgre_net_ops = {
543 .init = ipgre_init_net,
544 .exit = ipgre_exit_net,
546 .size = sizeof(struct ip_tunnel_net),
549 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
557 if (data[IFLA_GRE_IFLAGS])
558 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
559 if (data[IFLA_GRE_OFLAGS])
560 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
561 if (flags & (GRE_VERSION|GRE_ROUTING))
567 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
571 if (tb[IFLA_ADDRESS]) {
572 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
574 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
575 return -EADDRNOTAVAIL;
581 if (data[IFLA_GRE_REMOTE]) {
582 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
588 return ipgre_tunnel_validate(tb, data);
591 static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[],
592 struct ip_tunnel_parm *parms)
594 memset(parms, 0, sizeof(*parms));
596 parms->iph.protocol = IPPROTO_GRE;
601 if (data[IFLA_GRE_LINK])
602 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
604 if (data[IFLA_GRE_IFLAGS])
605 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
607 if (data[IFLA_GRE_OFLAGS])
608 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
610 if (data[IFLA_GRE_IKEY])
611 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
613 if (data[IFLA_GRE_OKEY])
614 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
616 if (data[IFLA_GRE_LOCAL])
617 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
619 if (data[IFLA_GRE_REMOTE])
620 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
622 if (data[IFLA_GRE_TTL])
623 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
625 if (data[IFLA_GRE_TOS])
626 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
628 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
629 parms->iph.frag_off = htons(IP_DF);
632 static int gre_tap_init(struct net_device *dev)
634 __gre_tunnel_init(dev);
636 return ip_tunnel_init(dev);
639 static const struct net_device_ops gre_tap_netdev_ops = {
640 .ndo_init = gre_tap_init,
641 .ndo_uninit = ip_tunnel_uninit,
642 .ndo_start_xmit = gre_tap_xmit,
643 .ndo_set_mac_address = eth_mac_addr,
644 .ndo_validate_addr = eth_validate_addr,
645 .ndo_change_mtu = ip_tunnel_change_mtu,
646 .ndo_get_stats64 = ip_tunnel_get_stats64,
649 static void ipgre_tap_setup(struct net_device *dev)
652 dev->netdev_ops = &gre_tap_netdev_ops;
653 ip_tunnel_setup(dev, gre_tap_net_id);
656 static int ipgre_newlink(struct net *src_net, struct net_device *dev,
657 struct nlattr *tb[], struct nlattr *data[])
659 struct ip_tunnel_parm p;
661 ipgre_netlink_parms(data, tb, &p);
662 return ip_tunnel_newlink(dev, tb, &p);
665 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
666 struct nlattr *data[])
668 struct ip_tunnel_parm p;
670 ipgre_netlink_parms(data, tb, &p);
671 return ip_tunnel_changelink(dev, tb, &p);
674 static size_t ipgre_get_size(const struct net_device *dev)
679 /* IFLA_GRE_IFLAGS */
681 /* IFLA_GRE_OFLAGS */
689 /* IFLA_GRE_REMOTE */
695 /* IFLA_GRE_PMTUDISC */
700 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
702 struct ip_tunnel *t = netdev_priv(dev);
703 struct ip_tunnel_parm *p = &t->parms;
705 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
706 nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) ||
707 nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) ||
708 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
709 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
710 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
711 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
712 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
713 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
714 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
715 !!(p->iph.frag_off & htons(IP_DF))))
716 goto nla_put_failure;
723 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
724 [IFLA_GRE_LINK] = { .type = NLA_U32 },
725 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
726 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
727 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
728 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
729 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
730 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
731 [IFLA_GRE_TTL] = { .type = NLA_U8 },
732 [IFLA_GRE_TOS] = { .type = NLA_U8 },
733 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
736 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
738 .maxtype = IFLA_GRE_MAX,
739 .policy = ipgre_policy,
740 .priv_size = sizeof(struct ip_tunnel),
741 .setup = ipgre_tunnel_setup,
742 .validate = ipgre_tunnel_validate,
743 .newlink = ipgre_newlink,
744 .changelink = ipgre_changelink,
745 .dellink = ip_tunnel_dellink,
746 .get_size = ipgre_get_size,
747 .fill_info = ipgre_fill_info,
750 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
752 .maxtype = IFLA_GRE_MAX,
753 .policy = ipgre_policy,
754 .priv_size = sizeof(struct ip_tunnel),
755 .setup = ipgre_tap_setup,
756 .validate = ipgre_tap_validate,
757 .newlink = ipgre_newlink,
758 .changelink = ipgre_changelink,
759 .dellink = ip_tunnel_dellink,
760 .get_size = ipgre_get_size,
761 .fill_info = ipgre_fill_info,
764 static int __net_init ipgre_tap_init_net(struct net *net)
766 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, NULL);
769 static void __net_exit ipgre_tap_exit_net(struct net *net)
771 struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id);
772 ip_tunnel_delete_net(itn, &ipgre_tap_ops);
775 static struct pernet_operations ipgre_tap_net_ops = {
776 .init = ipgre_tap_init_net,
777 .exit = ipgre_tap_exit_net,
778 .id = &gre_tap_net_id,
779 .size = sizeof(struct ip_tunnel_net),
782 static int __init ipgre_init(void)
786 pr_info("GRE over IPv4 tunneling driver\n");
788 err = register_pernet_device(&ipgre_net_ops);
792 err = register_pernet_device(&ipgre_tap_net_ops);
796 err = gre_cisco_register(&ipgre_protocol);
798 pr_info("%s: can't add protocol\n", __func__);
799 goto add_proto_failed;
802 err = rtnl_link_register(&ipgre_link_ops);
804 goto rtnl_link_failed;
806 err = rtnl_link_register(&ipgre_tap_ops);
813 rtnl_link_unregister(&ipgre_link_ops);
815 gre_cisco_unregister(&ipgre_protocol);
817 unregister_pernet_device(&ipgre_tap_net_ops);
819 unregister_pernet_device(&ipgre_net_ops);
823 static void __exit ipgre_fini(void)
825 rtnl_link_unregister(&ipgre_tap_ops);
826 rtnl_link_unregister(&ipgre_link_ops);
827 gre_cisco_unregister(&ipgre_protocol);
828 unregister_pernet_device(&ipgre_tap_net_ops);
829 unregister_pernet_device(&ipgre_net_ops);
832 module_init(ipgre_init);
833 module_exit(ipgre_fini);
834 MODULE_LICENSE("GPL");
835 MODULE_ALIAS_RTNL_LINK("gre");
836 MODULE_ALIAS_RTNL_LINK("gretap");
837 MODULE_ALIAS_NETDEV("gre0");
838 MODULE_ALIAS_NETDEV("gretap0");