1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Linux NET3: GRE over IP protocol decoder.
5 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 #include <linux/capability.h>
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/uaccess.h>
16 #include <linux/skbuff.h>
17 #include <linux/netdevice.h>
19 #include <linux/tcp.h>
20 #include <linux/udp.h>
21 #include <linux/if_arp.h>
22 #include <linux/if_vlan.h>
23 #include <linux/init.h>
24 #include <linux/in6.h>
25 #include <linux/inetdevice.h>
26 #include <linux/igmp.h>
27 #include <linux/netfilter_ipv4.h>
28 #include <linux/etherdevice.h>
29 #include <linux/if_ether.h>
34 #include <net/protocol.h>
35 #include <net/ip_tunnels.h>
37 #include <net/checksum.h>
38 #include <net/dsfield.h>
39 #include <net/inet_ecn.h>
41 #include <net/net_namespace.h>
42 #include <net/netns/generic.h>
43 #include <net/rtnetlink.h>
45 #include <net/dst_metadata.h>
46 #include <net/erspan.h>
52 1. The most important issue is detecting local dead loops.
53 They would cause complete host lockup in transmit, which
54 would be "resolved" by stack overflow or, if queueing is enabled,
55 with infinite looping in net_bh.
57 We cannot track such dead loops during route installation,
58 it is infeasible task. The most general solutions would be
59 to keep skb->encapsulation counter (sort of local ttl),
60 and silently drop packet when it expires. It is a good
61 solution, but it supposes maintaining new variable in ALL
62 skb, even if no tunneling is used.
64 Current solution: xmit_recursion breaks dead loops. This is a percpu
65 counter, since when we enter the first ndo_xmit(), cpu migration is
66 forbidden. We force an exit if this counter reaches RECURSION_LIMIT
68 2. Networking dead loops would not kill routers, but would really
69 kill network. IP hop limit plays role of "t->recursion" in this case,
70 if we copy it from packet being encapsulated to upper header.
71 It is very good solution, but it introduces two problems:
73 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
74 do not work over tunnels.
75 - traceroute does not work. I planned to relay ICMP from tunnel,
76 so that this problem would be solved and traceroute output
77 would even more informative. This idea appeared to be wrong:
78 only Linux complies to rfc1812 now (yes, guys, Linux is the only
79 true router now :-)), all routers (at least, in neighbourhood of mine)
80 return only 8 bytes of payload. It is the end.
82 Hence, if we want that OSPF worked or traceroute said something reasonable,
83 we should search for another solution.
85 One of them is to parse packet trying to detect inner encapsulation
86 made by our node. It is difficult or even impossible, especially,
87 taking into account fragmentation. TO be short, ttl is not solution at all.
89 Current solution: The solution was UNEXPECTEDLY SIMPLE.
90 We force DF flag on tunnels with preconfigured hop limit,
91 that is ALL. :-) Well, it does not remove the problem completely,
92 but exponential growth of network traffic is changed to linear
93 (branches, that exceed pmtu are pruned) and tunnel mtu
94 rapidly degrades to value <68, where looping stops.
95 Yes, it is not good if there exists a router in the loop,
96 which does not force DF, even when encapsulating packets have DF set.
97 But it is not our problem! Nobody could accuse us, we made
98 all that we could make. Even if it is your gated who injected
99 fatal route to network, even if it were you who configured
100 fatal static route: you are innocent. :-)
105 static bool log_ecn_error = true;
106 module_param(log_ecn_error, bool, 0644);
107 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
109 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
110 static const struct header_ops ipgre_header_ops;
112 static int ipgre_tunnel_init(struct net_device *dev);
113 static void erspan_build_header(struct sk_buff *skb,
115 bool truncate, bool is_ipv4);
117 static unsigned int ipgre_net_id __read_mostly;
118 static unsigned int gre_tap_net_id __read_mostly;
119 static unsigned int erspan_net_id __read_mostly;
121 static int ipgre_err(struct sk_buff *skb, u32 info,
122 const struct tnl_ptk_info *tpi)
125 /* All the routers (except for Linux) return only
126 8 bytes of packet payload. It means, that precise relaying of
127 ICMP in the real Internet is absolutely infeasible.
129 Moreover, Cisco "wise men" put GRE key to the third word
130 in GRE header. It makes impossible maintaining even soft
131 state for keyed GRE tunnels with enabled checksum. Tell
134 Well, I wonder, rfc1812 was written by Cisco employee,
135 what the hell these idiots break standards established
138 struct net *net = dev_net(skb->dev);
139 struct ip_tunnel_net *itn;
140 const struct iphdr *iph;
141 const int type = icmp_hdr(skb)->type;
142 const int code = icmp_hdr(skb)->code;
143 unsigned int data_len = 0;
146 if (tpi->proto == htons(ETH_P_TEB))
147 itn = net_generic(net, gre_tap_net_id);
148 else if (tpi->proto == htons(ETH_P_ERSPAN) ||
149 tpi->proto == htons(ETH_P_ERSPAN2))
150 itn = net_generic(net, erspan_net_id);
152 itn = net_generic(net, ipgre_net_id);
154 iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
155 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
156 iph->daddr, iph->saddr, tpi->key);
163 case ICMP_PARAMETERPROB:
166 case ICMP_DEST_UNREACH:
169 case ICMP_PORT_UNREACH:
170 /* Impossible event. */
173 /* All others are translated to HOST_UNREACH.
174 rfc2003 contains "deep thoughts" about NET_UNREACH,
175 I believe they are just ether pollution. --ANK
181 case ICMP_TIME_EXCEEDED:
182 if (code != ICMP_EXC_TTL)
184 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
191 #if IS_ENABLED(CONFIG_IPV6)
192 if (tpi->proto == htons(ETH_P_IPV6) &&
193 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
198 if (t->parms.iph.daddr == 0 ||
199 ipv4_is_multicast(t->parms.iph.daddr))
202 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
205 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
209 t->err_time = jiffies;
214 static void gre_err(struct sk_buff *skb, u32 info)
216 /* All the routers (except for Linux) return only
217 * 8 bytes of packet payload. It means, that precise relaying of
218 * ICMP in the real Internet is absolutely infeasible.
220 * Moreover, Cisco "wise men" put GRE key to the third word
221 * in GRE header. It makes impossible maintaining even soft
223 * GRE tunnels with enabled checksum. Tell them "thank you".
225 * Well, I wonder, rfc1812 was written by Cisco employee,
226 * what the hell these idiots break standards established
230 const struct iphdr *iph = (struct iphdr *)skb->data;
231 const int type = icmp_hdr(skb)->type;
232 const int code = icmp_hdr(skb)->code;
233 struct tnl_ptk_info tpi;
235 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP),
239 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
240 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
241 skb->dev->ifindex, IPPROTO_GRE);
244 if (type == ICMP_REDIRECT) {
245 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex,
250 ipgre_err(skb, info, &tpi);
253 static bool is_erspan_type1(int gre_hdr_len)
255 /* Both ERSPAN type I (version 0) and type II (version 1) use
256 * protocol 0x88BE, but the type I has only 4-byte GRE header,
257 * while type II has 8-byte.
259 return gre_hdr_len == 4;
262 static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
265 struct net *net = dev_net(skb->dev);
266 struct metadata_dst *tun_dst = NULL;
267 struct erspan_base_hdr *ershdr;
268 struct ip_tunnel_net *itn;
269 struct ip_tunnel *tunnel;
270 const struct iphdr *iph;
271 struct erspan_md2 *md2;
275 itn = net_generic(net, erspan_net_id);
277 if (is_erspan_type1(gre_hdr_len)) {
279 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
280 tpi->flags | TUNNEL_NO_KEY,
281 iph->saddr, iph->daddr, 0);
283 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
285 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
286 tpi->flags | TUNNEL_KEY,
287 iph->saddr, iph->daddr, tpi->key);
291 if (is_erspan_type1(gre_hdr_len))
294 len = gre_hdr_len + erspan_hdr_len(ver);
296 if (unlikely(!pskb_may_pull(skb, len)))
297 return PACKET_REJECT;
299 if (__iptunnel_pull_header(skb,
305 if (tunnel->collect_md) {
306 struct erspan_metadata *pkt_md, *md;
307 struct ip_tunnel_info *info;
312 tpi->flags |= TUNNEL_KEY;
314 tun_id = key32_to_tunnel_id(tpi->key);
316 tun_dst = ip_tun_rx_dst(skb, flags,
317 tun_id, sizeof(*md));
319 return PACKET_REJECT;
321 /* skb can be uncloned in __iptunnel_pull_header, so
322 * old pkt_md is no longer valid and we need to reset
325 gh = skb_network_header(skb) +
326 skb_network_header_len(skb);
327 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
329 md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
332 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
335 info = &tun_dst->u.tun_info;
336 info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
337 info->options_len = sizeof(*md);
340 skb_reset_mac_header(skb);
341 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
344 return PACKET_REJECT;
351 static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
352 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
354 struct metadata_dst *tun_dst = NULL;
355 const struct iphdr *iph;
356 struct ip_tunnel *tunnel;
359 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
360 iph->saddr, iph->daddr, tpi->key);
363 const struct iphdr *tnl_params;
365 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto,
366 raw_proto, false) < 0)
369 /* Special case for ipgre_header_parse(), which expects the
370 * mac_header to point to the outer IP header.
372 if (tunnel->dev->header_ops == &ipgre_header_ops)
373 skb_pop_mac_header(skb);
375 skb_reset_mac_header(skb);
377 tnl_params = &tunnel->parms.iph;
378 if (tunnel->collect_md || tnl_params->daddr == 0) {
382 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY);
383 tun_id = key32_to_tunnel_id(tpi->key);
384 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
386 return PACKET_REJECT;
389 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
399 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
402 struct net *net = dev_net(skb->dev);
403 struct ip_tunnel_net *itn;
406 if (tpi->proto == htons(ETH_P_TEB))
407 itn = net_generic(net, gre_tap_net_id);
409 itn = net_generic(net, ipgre_net_id);
411 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false);
412 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) {
413 /* ipgre tunnels in collect metadata mode should receive
414 * also ETH_P_TEB traffic.
416 itn = net_generic(net, ipgre_net_id);
417 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true);
422 static int gre_rcv(struct sk_buff *skb)
424 struct tnl_ptk_info tpi;
425 bool csum_err = false;
428 #ifdef CONFIG_NET_IPGRE_BROADCAST
429 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
430 /* Looped back packet, drop it! */
431 if (rt_is_output_route(skb_rtable(skb)))
436 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0);
440 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
441 tpi.proto == htons(ETH_P_ERSPAN2))) {
442 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
447 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
451 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
457 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
458 const struct iphdr *tnl_params,
461 struct ip_tunnel *tunnel = netdev_priv(dev);
463 if (tunnel->parms.o_flags & TUNNEL_SEQ)
466 /* Push GRE header. */
467 gre_build_header(skb, tunnel->tun_hlen,
468 tunnel->parms.o_flags, proto, tunnel->parms.o_key,
469 htonl(tunnel->o_seqno));
471 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
474 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
476 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
479 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
482 struct ip_tunnel *tunnel = netdev_priv(dev);
483 struct ip_tunnel_info *tun_info;
484 const struct ip_tunnel_key *key;
488 tun_info = skb_tunnel_info(skb);
489 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
490 ip_tunnel_info_af(tun_info) != AF_INET))
493 key = &tun_info->key;
494 tunnel_hlen = gre_calc_hlen(key->tun_flags);
496 if (skb_cow_head(skb, dev->needed_headroom))
499 /* Push Tunnel header. */
500 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
503 flags = tun_info->key.tun_flags &
504 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
505 gre_build_header(skb, tunnel_hlen, flags, proto,
506 tunnel_id_to_key32(tun_info->key.tun_id),
507 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0);
509 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
515 dev->stats.tx_dropped++;
518 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
520 struct ip_tunnel *tunnel = netdev_priv(dev);
521 struct ip_tunnel_info *tun_info;
522 const struct ip_tunnel_key *key;
523 struct erspan_metadata *md;
524 bool truncate = false;
531 tun_info = skb_tunnel_info(skb);
532 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
533 ip_tunnel_info_af(tun_info) != AF_INET))
536 key = &tun_info->key;
537 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
539 if (tun_info->options_len < sizeof(*md))
541 md = ip_tunnel_info_opts(tun_info);
543 /* ERSPAN has fixed 8 byte GRE header */
544 version = md->version;
545 tunnel_hlen = 8 + erspan_hdr_len(version);
547 if (skb_cow_head(skb, dev->needed_headroom))
550 if (gre_handle_offloads(skb, false))
553 if (skb->len > dev->mtu + dev->hard_header_len) {
554 pskb_trim(skb, dev->mtu + dev->hard_header_len);
558 nhoff = skb_network_header(skb) - skb_mac_header(skb);
559 if (skb->protocol == htons(ETH_P_IP) &&
560 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
563 thoff = skb_transport_header(skb) - skb_mac_header(skb);
564 if (skb->protocol == htons(ETH_P_IPV6) &&
565 (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
569 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
570 ntohl(md->u.index), truncate, true);
571 proto = htons(ETH_P_ERSPAN);
572 } else if (version == 2) {
573 erspan_build_header_v2(skb,
574 ntohl(tunnel_id_to_key32(key->tun_id)),
576 get_hwid(&md->u.md2),
578 proto = htons(ETH_P_ERSPAN2);
583 gre_build_header(skb, 8, TUNNEL_SEQ,
584 proto, 0, htonl(tunnel->o_seqno++));
586 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
592 dev->stats.tx_dropped++;
595 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
597 struct ip_tunnel_info *info = skb_tunnel_info(skb);
598 const struct ip_tunnel_key *key;
602 if (ip_tunnel_info_af(info) != AF_INET)
606 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
607 tunnel_id_to_key32(key->tun_id), key->tos, 0,
608 skb->mark, skb_get_hash(skb));
609 rt = ip_route_output_key(dev_net(dev), &fl4);
614 info->key.u.ipv4.src = fl4.saddr;
618 static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
619 struct net_device *dev)
621 struct ip_tunnel *tunnel = netdev_priv(dev);
622 const struct iphdr *tnl_params;
624 if (!pskb_inet_may_pull(skb))
627 if (tunnel->collect_md) {
628 gre_fb_xmit(skb, dev, skb->protocol);
632 if (dev->header_ops) {
633 if (skb_cow_head(skb, 0))
636 tnl_params = (const struct iphdr *)skb->data;
638 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
641 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
642 skb_reset_mac_header(skb);
644 if (skb_cow_head(skb, dev->needed_headroom))
647 tnl_params = &tunnel->parms.iph;
650 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
653 __gre_xmit(skb, dev, tnl_params, skb->protocol);
658 dev->stats.tx_dropped++;
662 static netdev_tx_t erspan_xmit(struct sk_buff *skb,
663 struct net_device *dev)
665 struct ip_tunnel *tunnel = netdev_priv(dev);
666 bool truncate = false;
669 if (!pskb_inet_may_pull(skb))
672 if (tunnel->collect_md) {
673 erspan_fb_xmit(skb, dev);
677 if (gre_handle_offloads(skb, false))
680 if (skb_cow_head(skb, dev->needed_headroom))
683 if (skb->len > dev->mtu + dev->hard_header_len) {
684 pskb_trim(skb, dev->mtu + dev->hard_header_len);
688 /* Push ERSPAN header */
689 if (tunnel->erspan_ver == 0) {
690 proto = htons(ETH_P_ERSPAN);
691 tunnel->parms.o_flags &= ~TUNNEL_SEQ;
692 } else if (tunnel->erspan_ver == 1) {
693 erspan_build_header(skb, ntohl(tunnel->parms.o_key),
696 proto = htons(ETH_P_ERSPAN);
697 } else if (tunnel->erspan_ver == 2) {
698 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
699 tunnel->dir, tunnel->hwid,
701 proto = htons(ETH_P_ERSPAN2);
706 tunnel->parms.o_flags &= ~TUNNEL_KEY;
707 __gre_xmit(skb, dev, &tunnel->parms.iph, proto);
712 dev->stats.tx_dropped++;
716 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
717 struct net_device *dev)
719 struct ip_tunnel *tunnel = netdev_priv(dev);
721 if (!pskb_inet_may_pull(skb))
724 if (tunnel->collect_md) {
725 gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
729 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
732 if (skb_cow_head(skb, dev->needed_headroom))
735 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
740 dev->stats.tx_dropped++;
744 static void ipgre_link_update(struct net_device *dev, bool set_mtu)
746 struct ip_tunnel *tunnel = netdev_priv(dev);
749 len = tunnel->tun_hlen;
750 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
751 len = tunnel->tun_hlen - len;
752 tunnel->hlen = tunnel->hlen + len;
755 dev->hard_header_len += len;
757 dev->needed_headroom += len;
760 dev->mtu = max_t(int, dev->mtu - len, 68);
762 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
763 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
764 tunnel->encap.type == TUNNEL_ENCAP_NONE) {
765 dev->features |= NETIF_F_GSO_SOFTWARE;
766 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
768 dev->features &= ~NETIF_F_GSO_SOFTWARE;
769 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
771 dev->features |= NETIF_F_LLTX;
773 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
774 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE);
778 static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p,
783 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
784 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
785 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) ||
786 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING)))
790 p->i_flags = gre_flags_to_tnl_flags(p->i_flags);
791 p->o_flags = gre_flags_to_tnl_flags(p->o_flags);
793 err = ip_tunnel_ctl(dev, p, cmd);
797 if (cmd == SIOCCHGTUNNEL) {
798 struct ip_tunnel *t = netdev_priv(dev);
800 t->parms.i_flags = p->i_flags;
801 t->parms.o_flags = p->o_flags;
803 if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
804 ipgre_link_update(dev, true);
807 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
808 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
812 /* Nice toy. Unfortunately, useless in real life :-)
813 It allows to construct virtual multiprotocol broadcast "LAN"
814 over the Internet, provided multicast routing is tuned.
817 I have no idea was this bicycle invented before me,
818 so that I had to set ARPHRD_IPGRE to a random value.
819 I have an impression, that Cisco could make something similar,
820 but this feature is apparently missing in IOS<=11.2(8).
822 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
823 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
825 ping -t 255 224.66.66.66
827 If nobody answers, mbone does not work.
829 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
830 ip addr add 10.66.66.<somewhat>/24 dev Universe
832 ifconfig Universe add fe80::<Your_real_addr>/10
833 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
836 ftp fec0:6666:6666::193.233.7.65
839 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
841 const void *daddr, const void *saddr, unsigned int len)
843 struct ip_tunnel *t = netdev_priv(dev);
845 struct gre_base_hdr *greh;
847 iph = skb_push(skb, t->hlen + sizeof(*iph));
848 greh = (struct gre_base_hdr *)(iph+1);
849 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);
850 greh->protocol = htons(type);
852 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
854 /* Set the source hardware address. */
856 memcpy(&iph->saddr, saddr, 4);
858 memcpy(&iph->daddr, daddr, 4);
860 return t->hlen + sizeof(*iph);
862 return -(t->hlen + sizeof(*iph));
865 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
867 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
868 memcpy(haddr, &iph->saddr, 4);
872 static const struct header_ops ipgre_header_ops = {
873 .create = ipgre_header,
874 .parse = ipgre_header_parse,
877 #ifdef CONFIG_NET_IPGRE_BROADCAST
878 static int ipgre_open(struct net_device *dev)
880 struct ip_tunnel *t = netdev_priv(dev);
882 if (ipv4_is_multicast(t->parms.iph.daddr)) {
886 rt = ip_route_output_gre(t->net, &fl4,
890 RT_TOS(t->parms.iph.tos),
893 return -EADDRNOTAVAIL;
896 if (!__in_dev_get_rtnl(dev))
897 return -EADDRNOTAVAIL;
898 t->mlink = dev->ifindex;
899 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
904 static int ipgre_close(struct net_device *dev)
906 struct ip_tunnel *t = netdev_priv(dev);
908 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
909 struct in_device *in_dev;
910 in_dev = inetdev_by_index(t->net, t->mlink);
912 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
918 static const struct net_device_ops ipgre_netdev_ops = {
919 .ndo_init = ipgre_tunnel_init,
920 .ndo_uninit = ip_tunnel_uninit,
921 #ifdef CONFIG_NET_IPGRE_BROADCAST
922 .ndo_open = ipgre_open,
923 .ndo_stop = ipgre_close,
925 .ndo_start_xmit = ipgre_xmit,
926 .ndo_do_ioctl = ip_tunnel_ioctl,
927 .ndo_change_mtu = ip_tunnel_change_mtu,
928 .ndo_get_stats64 = dev_get_tstats64,
929 .ndo_get_iflink = ip_tunnel_get_iflink,
930 .ndo_tunnel_ctl = ipgre_tunnel_ctl,
933 #define GRE_FEATURES (NETIF_F_SG | \
938 static void ipgre_tunnel_setup(struct net_device *dev)
940 dev->netdev_ops = &ipgre_netdev_ops;
941 dev->type = ARPHRD_IPGRE;
942 ip_tunnel_setup(dev, ipgre_net_id);
945 static void __gre_tunnel_init(struct net_device *dev)
947 struct ip_tunnel *tunnel;
949 tunnel = netdev_priv(dev);
950 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
951 tunnel->parms.iph.protocol = IPPROTO_GRE;
953 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
954 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph);
956 dev->features |= GRE_FEATURES;
957 dev->hw_features |= GRE_FEATURES;
959 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
960 /* TCP offload with GRE SEQ is not supported, nor
961 * can we support 2 levels of outer headers requiring
964 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
965 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) {
966 dev->features |= NETIF_F_GSO_SOFTWARE;
967 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
970 /* Can use a lockless transmit, unless we generate
973 dev->features |= NETIF_F_LLTX;
977 static int ipgre_tunnel_init(struct net_device *dev)
979 struct ip_tunnel *tunnel = netdev_priv(dev);
980 struct iphdr *iph = &tunnel->parms.iph;
982 __gre_tunnel_init(dev);
984 memcpy(dev->dev_addr, &iph->saddr, 4);
985 memcpy(dev->broadcast, &iph->daddr, 4);
987 dev->flags = IFF_NOARP;
991 if (iph->daddr && !tunnel->collect_md) {
992 #ifdef CONFIG_NET_IPGRE_BROADCAST
993 if (ipv4_is_multicast(iph->daddr)) {
996 dev->flags = IFF_BROADCAST;
997 dev->header_ops = &ipgre_header_ops;
998 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
999 dev->needed_headroom = 0;
1002 } else if (!tunnel->collect_md) {
1003 dev->header_ops = &ipgre_header_ops;
1004 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1005 dev->needed_headroom = 0;
1008 return ip_tunnel_init(dev);
1011 static const struct gre_protocol ipgre_protocol = {
1013 .err_handler = gre_err,
1016 static int __net_init ipgre_init_net(struct net *net)
1018 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
1021 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net)
1023 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops);
1026 static struct pernet_operations ipgre_net_ops = {
1027 .init = ipgre_init_net,
1028 .exit_batch = ipgre_exit_batch_net,
1029 .id = &ipgre_net_id,
1030 .size = sizeof(struct ip_tunnel_net),
1033 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1034 struct netlink_ext_ack *extack)
1042 if (data[IFLA_GRE_IFLAGS])
1043 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1044 if (data[IFLA_GRE_OFLAGS])
1045 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1046 if (flags & (GRE_VERSION|GRE_ROUTING))
1049 if (data[IFLA_GRE_COLLECT_METADATA] &&
1050 data[IFLA_GRE_ENCAP_TYPE] &&
1051 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
1057 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1058 struct netlink_ext_ack *extack)
1062 if (tb[IFLA_ADDRESS]) {
1063 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1065 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1066 return -EADDRNOTAVAIL;
1072 if (data[IFLA_GRE_REMOTE]) {
1073 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1079 return ipgre_tunnel_validate(tb, data, extack);
1082 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
1083 struct netlink_ext_ack *extack)
1091 ret = ipgre_tap_validate(tb, data, extack);
1095 if (data[IFLA_GRE_ERSPAN_VER] &&
1096 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0)
1099 /* ERSPAN type II/III should only have GRE sequence and key flag */
1100 if (data[IFLA_GRE_OFLAGS])
1101 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1102 if (data[IFLA_GRE_IFLAGS])
1103 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1104 if (!data[IFLA_GRE_COLLECT_METADATA] &&
1105 flags != (GRE_SEQ | GRE_KEY))
1108 /* ERSPAN Session ID only has 10-bit. Since we reuse
1109 * 32-bit key field as ID, check it's range.
1111 if (data[IFLA_GRE_IKEY] &&
1112 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1115 if (data[IFLA_GRE_OKEY] &&
1116 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1122 static int ipgre_netlink_parms(struct net_device *dev,
1123 struct nlattr *data[],
1124 struct nlattr *tb[],
1125 struct ip_tunnel_parm *parms,
1128 struct ip_tunnel *t = netdev_priv(dev);
1130 memset(parms, 0, sizeof(*parms));
1132 parms->iph.protocol = IPPROTO_GRE;
1137 if (data[IFLA_GRE_LINK])
1138 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1140 if (data[IFLA_GRE_IFLAGS])
1141 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
1143 if (data[IFLA_GRE_OFLAGS])
1144 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
1146 if (data[IFLA_GRE_IKEY])
1147 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1149 if (data[IFLA_GRE_OKEY])
1150 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1152 if (data[IFLA_GRE_LOCAL])
1153 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]);
1155 if (data[IFLA_GRE_REMOTE])
1156 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]);
1158 if (data[IFLA_GRE_TTL])
1159 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1161 if (data[IFLA_GRE_TOS])
1162 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1164 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) {
1167 parms->iph.frag_off = htons(IP_DF);
1170 if (data[IFLA_GRE_COLLECT_METADATA]) {
1171 t->collect_md = true;
1172 if (dev->type == ARPHRD_IPGRE)
1173 dev->type = ARPHRD_NONE;
1176 if (data[IFLA_GRE_IGNORE_DF]) {
1177 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF])
1178 && (parms->iph.frag_off & htons(IP_DF)))
1180 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]);
1183 if (data[IFLA_GRE_FWMARK])
1184 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1189 static int erspan_netlink_parms(struct net_device *dev,
1190 struct nlattr *data[],
1191 struct nlattr *tb[],
1192 struct ip_tunnel_parm *parms,
1195 struct ip_tunnel *t = netdev_priv(dev);
1198 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
1204 if (data[IFLA_GRE_ERSPAN_VER]) {
1205 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1207 if (t->erspan_ver > 2)
1211 if (t->erspan_ver == 1) {
1212 if (data[IFLA_GRE_ERSPAN_INDEX]) {
1213 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1214 if (t->index & ~INDEX_MASK)
1217 } else if (t->erspan_ver == 2) {
1218 if (data[IFLA_GRE_ERSPAN_DIR]) {
1219 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1220 if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
1223 if (data[IFLA_GRE_ERSPAN_HWID]) {
1224 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1225 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
1233 /* This function returns true when ENCAP attributes are present in the nl msg */
1234 static bool ipgre_netlink_encap_parms(struct nlattr *data[],
1235 struct ip_tunnel_encap *ipencap)
1239 memset(ipencap, 0, sizeof(*ipencap));
1244 if (data[IFLA_GRE_ENCAP_TYPE]) {
1246 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1249 if (data[IFLA_GRE_ENCAP_FLAGS]) {
1251 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1254 if (data[IFLA_GRE_ENCAP_SPORT]) {
1256 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1259 if (data[IFLA_GRE_ENCAP_DPORT]) {
1261 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1267 static int gre_tap_init(struct net_device *dev)
1269 __gre_tunnel_init(dev);
1270 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1271 netif_keep_dst(dev);
1273 return ip_tunnel_init(dev);
1276 static const struct net_device_ops gre_tap_netdev_ops = {
1277 .ndo_init = gre_tap_init,
1278 .ndo_uninit = ip_tunnel_uninit,
1279 .ndo_start_xmit = gre_tap_xmit,
1280 .ndo_set_mac_address = eth_mac_addr,
1281 .ndo_validate_addr = eth_validate_addr,
1282 .ndo_change_mtu = ip_tunnel_change_mtu,
1283 .ndo_get_stats64 = dev_get_tstats64,
1284 .ndo_get_iflink = ip_tunnel_get_iflink,
1285 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1288 static int erspan_tunnel_init(struct net_device *dev)
1290 struct ip_tunnel *tunnel = netdev_priv(dev);
1292 if (tunnel->erspan_ver == 0)
1293 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
1295 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
1297 tunnel->parms.iph.protocol = IPPROTO_GRE;
1298 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1299 erspan_hdr_len(tunnel->erspan_ver);
1301 dev->features |= GRE_FEATURES;
1302 dev->hw_features |= GRE_FEATURES;
1303 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1304 netif_keep_dst(dev);
1306 return ip_tunnel_init(dev);
1309 static const struct net_device_ops erspan_netdev_ops = {
1310 .ndo_init = erspan_tunnel_init,
1311 .ndo_uninit = ip_tunnel_uninit,
1312 .ndo_start_xmit = erspan_xmit,
1313 .ndo_set_mac_address = eth_mac_addr,
1314 .ndo_validate_addr = eth_validate_addr,
1315 .ndo_change_mtu = ip_tunnel_change_mtu,
1316 .ndo_get_stats64 = dev_get_tstats64,
1317 .ndo_get_iflink = ip_tunnel_get_iflink,
1318 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1321 static void ipgre_tap_setup(struct net_device *dev)
1325 dev->netdev_ops = &gre_tap_netdev_ops;
1326 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1327 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1328 ip_tunnel_setup(dev, gre_tap_net_id);
1332 ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
1334 struct ip_tunnel_encap ipencap;
1336 if (ipgre_netlink_encap_parms(data, &ipencap)) {
1337 struct ip_tunnel *t = netdev_priv(dev);
1338 int err = ip_tunnel_encap_setup(t, &ipencap);
1347 static int ipgre_newlink(struct net *src_net, struct net_device *dev,
1348 struct nlattr *tb[], struct nlattr *data[],
1349 struct netlink_ext_ack *extack)
1351 struct ip_tunnel_parm p;
1355 err = ipgre_newlink_encap_setup(dev, data);
1359 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1362 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1365 static int erspan_newlink(struct net *src_net, struct net_device *dev,
1366 struct nlattr *tb[], struct nlattr *data[],
1367 struct netlink_ext_ack *extack)
1369 struct ip_tunnel_parm p;
1373 err = ipgre_newlink_encap_setup(dev, data);
1377 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1380 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1383 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1384 struct nlattr *data[],
1385 struct netlink_ext_ack *extack)
1387 struct ip_tunnel *t = netdev_priv(dev);
1388 __u32 fwmark = t->fwmark;
1389 struct ip_tunnel_parm p;
1392 err = ipgre_newlink_encap_setup(dev, data);
1396 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1400 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1404 t->parms.i_flags = p.i_flags;
1405 t->parms.o_flags = p.o_flags;
1407 ipgre_link_update(dev, !tb[IFLA_MTU]);
1412 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
1413 struct nlattr *data[],
1414 struct netlink_ext_ack *extack)
1416 struct ip_tunnel *t = netdev_priv(dev);
1417 __u32 fwmark = t->fwmark;
1418 struct ip_tunnel_parm p;
1421 err = ipgre_newlink_encap_setup(dev, data);
1425 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1429 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1433 t->parms.i_flags = p.i_flags;
1434 t->parms.o_flags = p.o_flags;
1439 static size_t ipgre_get_size(const struct net_device *dev)
1444 /* IFLA_GRE_IFLAGS */
1446 /* IFLA_GRE_OFLAGS */
1452 /* IFLA_GRE_LOCAL */
1454 /* IFLA_GRE_REMOTE */
1460 /* IFLA_GRE_PMTUDISC */
1462 /* IFLA_GRE_ENCAP_TYPE */
1464 /* IFLA_GRE_ENCAP_FLAGS */
1466 /* IFLA_GRE_ENCAP_SPORT */
1468 /* IFLA_GRE_ENCAP_DPORT */
1470 /* IFLA_GRE_COLLECT_METADATA */
1472 /* IFLA_GRE_IGNORE_DF */
1474 /* IFLA_GRE_FWMARK */
1476 /* IFLA_GRE_ERSPAN_INDEX */
1478 /* IFLA_GRE_ERSPAN_VER */
1480 /* IFLA_GRE_ERSPAN_DIR */
1482 /* IFLA_GRE_ERSPAN_HWID */
1487 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1489 struct ip_tunnel *t = netdev_priv(dev);
1490 struct ip_tunnel_parm *p = &t->parms;
1491 __be16 o_flags = p->o_flags;
1493 if (t->erspan_ver <= 2) {
1494 if (t->erspan_ver != 0 && !t->collect_md)
1495 o_flags |= TUNNEL_KEY;
1497 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
1498 goto nla_put_failure;
1500 if (t->erspan_ver == 1) {
1501 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
1502 goto nla_put_failure;
1503 } else if (t->erspan_ver == 2) {
1504 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
1505 goto nla_put_failure;
1506 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
1507 goto nla_put_failure;
1511 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1512 nla_put_be16(skb, IFLA_GRE_IFLAGS,
1513 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1514 nla_put_be16(skb, IFLA_GRE_OFLAGS,
1515 gre_tnl_flags_to_gre_flags(o_flags)) ||
1516 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1517 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1518 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1519 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1520 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1521 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1522 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1523 !!(p->iph.frag_off & htons(IP_DF))) ||
1524 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark))
1525 goto nla_put_failure;
1527 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1529 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1531 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1533 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1535 goto nla_put_failure;
1537 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df))
1538 goto nla_put_failure;
1540 if (t->collect_md) {
1541 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
1542 goto nla_put_failure;
1551 static void erspan_setup(struct net_device *dev)
1553 struct ip_tunnel *t = netdev_priv(dev);
1557 dev->netdev_ops = &erspan_netdev_ops;
1558 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1559 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1560 ip_tunnel_setup(dev, erspan_net_id);
1564 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1565 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1566 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1567 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1568 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1569 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1570 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) },
1571 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
1572 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1573 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1574 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1575 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
1576 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
1577 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
1578 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
1579 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
1580 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 },
1581 [IFLA_GRE_FWMARK] = { .type = NLA_U32 },
1582 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
1583 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 },
1584 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 },
1585 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 },
1588 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1590 .maxtype = IFLA_GRE_MAX,
1591 .policy = ipgre_policy,
1592 .priv_size = sizeof(struct ip_tunnel),
1593 .setup = ipgre_tunnel_setup,
1594 .validate = ipgre_tunnel_validate,
1595 .newlink = ipgre_newlink,
1596 .changelink = ipgre_changelink,
1597 .dellink = ip_tunnel_dellink,
1598 .get_size = ipgre_get_size,
1599 .fill_info = ipgre_fill_info,
1600 .get_link_net = ip_tunnel_get_link_net,
1603 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1605 .maxtype = IFLA_GRE_MAX,
1606 .policy = ipgre_policy,
1607 .priv_size = sizeof(struct ip_tunnel),
1608 .setup = ipgre_tap_setup,
1609 .validate = ipgre_tap_validate,
1610 .newlink = ipgre_newlink,
1611 .changelink = ipgre_changelink,
1612 .dellink = ip_tunnel_dellink,
1613 .get_size = ipgre_get_size,
1614 .fill_info = ipgre_fill_info,
1615 .get_link_net = ip_tunnel_get_link_net,
1618 static struct rtnl_link_ops erspan_link_ops __read_mostly = {
1620 .maxtype = IFLA_GRE_MAX,
1621 .policy = ipgre_policy,
1622 .priv_size = sizeof(struct ip_tunnel),
1623 .setup = erspan_setup,
1624 .validate = erspan_validate,
1625 .newlink = erspan_newlink,
1626 .changelink = erspan_changelink,
1627 .dellink = ip_tunnel_dellink,
1628 .get_size = ipgre_get_size,
1629 .fill_info = ipgre_fill_info,
1630 .get_link_net = ip_tunnel_get_link_net,
1633 struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1634 u8 name_assign_type)
1636 struct nlattr *tb[IFLA_MAX + 1];
1637 struct net_device *dev;
1638 LIST_HEAD(list_kill);
1639 struct ip_tunnel *t;
1642 memset(&tb, 0, sizeof(tb));
1644 dev = rtnl_create_link(net, name, name_assign_type,
1645 &ipgre_tap_ops, tb, NULL);
1649 /* Configure flow based GRE device. */
1650 t = netdev_priv(dev);
1651 t->collect_md = true;
1653 err = ipgre_newlink(net, dev, tb, NULL, NULL);
1656 return ERR_PTR(err);
1659 /* openvswitch users expect packet sizes to be unrestricted,
1660 * so set the largest MTU we can.
1662 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
1666 err = rtnl_configure_link(dev, NULL);
1672 ip_tunnel_dellink(dev, &list_kill);
1673 unregister_netdevice_many(&list_kill);
1674 return ERR_PTR(err);
1676 EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1678 static int __net_init ipgre_tap_init_net(struct net *net)
1680 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
1683 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net)
1685 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops);
1688 static struct pernet_operations ipgre_tap_net_ops = {
1689 .init = ipgre_tap_init_net,
1690 .exit_batch = ipgre_tap_exit_batch_net,
1691 .id = &gre_tap_net_id,
1692 .size = sizeof(struct ip_tunnel_net),
1695 static int __net_init erspan_init_net(struct net *net)
1697 return ip_tunnel_init_net(net, erspan_net_id,
1698 &erspan_link_ops, "erspan0");
1701 static void __net_exit erspan_exit_batch_net(struct list_head *net_list)
1703 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops);
1706 static struct pernet_operations erspan_net_ops = {
1707 .init = erspan_init_net,
1708 .exit_batch = erspan_exit_batch_net,
1709 .id = &erspan_net_id,
1710 .size = sizeof(struct ip_tunnel_net),
1713 static int __init ipgre_init(void)
1717 pr_info("GRE over IPv4 tunneling driver\n");
1719 err = register_pernet_device(&ipgre_net_ops);
1723 err = register_pernet_device(&ipgre_tap_net_ops);
1725 goto pnet_tap_failed;
1727 err = register_pernet_device(&erspan_net_ops);
1729 goto pnet_erspan_failed;
1731 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1733 pr_info("%s: can't add protocol\n", __func__);
1734 goto add_proto_failed;
1737 err = rtnl_link_register(&ipgre_link_ops);
1739 goto rtnl_link_failed;
1741 err = rtnl_link_register(&ipgre_tap_ops);
1743 goto tap_ops_failed;
1745 err = rtnl_link_register(&erspan_link_ops);
1747 goto erspan_link_failed;
1752 rtnl_link_unregister(&ipgre_tap_ops);
1754 rtnl_link_unregister(&ipgre_link_ops);
1756 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1758 unregister_pernet_device(&erspan_net_ops);
1760 unregister_pernet_device(&ipgre_tap_net_ops);
1762 unregister_pernet_device(&ipgre_net_ops);
1766 static void __exit ipgre_fini(void)
1768 rtnl_link_unregister(&ipgre_tap_ops);
1769 rtnl_link_unregister(&ipgre_link_ops);
1770 rtnl_link_unregister(&erspan_link_ops);
1771 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1772 unregister_pernet_device(&ipgre_tap_net_ops);
1773 unregister_pernet_device(&ipgre_net_ops);
1774 unregister_pernet_device(&erspan_net_ops);
1777 module_init(ipgre_init);
1778 module_exit(ipgre_fini);
1779 MODULE_LICENSE("GPL");
1780 MODULE_ALIAS_RTNL_LINK("gre");
1781 MODULE_ALIAS_RTNL_LINK("gretap");
1782 MODULE_ALIAS_RTNL_LINK("erspan");
1783 MODULE_ALIAS_NETDEV("gre0");
1784 MODULE_ALIAS_NETDEV("gretap0");
1785 MODULE_ALIAS_NETDEV("erspan0");