2 * Linux NET3: IP/IP protocol decoder.
8 * Alan Cox : Merged and made usable non modular (its so tiny its silly as
9 * a module taking up 2 pages).
10 * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
11 * to keep ip_forward happy.
12 * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
13 * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL
14 * David Woodhouse : Perform some basic ICMP handling.
15 * IPIP Routing without decapsulation.
16 * Carlos Picoto : GRE over IP support
17 * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
18 * I do not want to merge them together.
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
27 /* tunnel.c: an IP tunnel driver
29 The purpose of this driver is to provide an IP tunnel through
30 which you can tunnel network traffic transparently across subnets.
32 This was written by looking at Nick Holloway's dummy driver
33 Thanks for the great code!
38 Cleaned up the code a little and added some pre-1.3.0 tweaks.
39 dev->hard_header/hard_header_len changed to use no headers.
40 Comments/bracketing tweaked.
41 Made the tunnels use dev->name not tunnel: when error reporting.
47 Changed to tunnel to destination gateway in addition to the
48 tunnel's pointopoint address
49 Almost completely rewritten
50 Note: There is currently no firewall or ICMP handling done.
56 /* Things I wish I had known when writing the tunnel driver:
58 When the tunnel_xmit() function is called, the skb contains the
59 packet to be sent (plus a great deal of extra info), and dev
60 contains the tunnel device that _we_ are.
62 When we are passed a packet, we are expected to fill in the
63 source address with our source IP address.
65 What is the proper way to allocate, copy and free a buffer?
66 After you allocate it, it is a "0 length" chunk of memory
67 starting at zero. If you want to add headers to the buffer
68 later, you'll have to call "skb_reserve(skb, amount)" with
69 the amount of memory you want reserved. Then, you call
70 "skb_put(skb, amount)" with the amount of space you want in
71 the buffer. skb_put() returns a pointer to the top (#0) of
72 that buffer. skb->len is set to the amount of space you have
73 "allocated" with skb_put(). You can then write up to skb->len
74 bytes to that buffer. If you need more, you can call skb_put()
75 again with the additional amount of space you need. You can
76 find out how much more space you can allocate by calling
78 Now, to add header space, call "skb_push(skb, header_len)".
79 This creates space at the beginning of the buffer and returns
80 a pointer to this new space. If later you need to strip a
81 header from a buffer, call "skb_pull(skb, header_len)".
82 skb_headroom() will return how much space is left at the top
83 of the buffer (before the main data). Remember, this headroom
84 space must be reserved before the skb_put() function is called.
88 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
90 For comments look at net/ipv4/ip_gre.c --ANK
94 #include <linux/capability.h>
95 #include <linux/module.h>
96 #include <linux/types.h>
97 #include <linux/kernel.h>
98 #include <linux/slab.h>
99 #include <linux/uaccess.h>
100 #include <linux/skbuff.h>
101 #include <linux/netdevice.h>
102 #include <linux/in.h>
103 #include <linux/tcp.h>
104 #include <linux/udp.h>
105 #include <linux/if_arp.h>
106 #include <linux/init.h>
107 #include <linux/netfilter_ipv4.h>
108 #include <linux/if_ether.h>
110 #include <net/sock.h>
112 #include <net/icmp.h>
113 #include <net/ip_tunnels.h>
114 #include <net/inet_ecn.h>
115 #include <net/xfrm.h>
116 #include <net/net_namespace.h>
117 #include <net/netns/generic.h>
118 #include <net/dst_metadata.h>
120 static bool log_ecn_error = true;
121 module_param(log_ecn_error, bool, 0644);
122 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
124 static unsigned int ipip_net_id __read_mostly;
126 static int ipip_tunnel_init(struct net_device *dev);
127 static struct rtnl_link_ops ipip_link_ops __read_mostly;
129 static int ipip_err(struct sk_buff *skb, u32 info)
132 /* All the routers (except for Linux) return only
133 8 bytes of packet payload. It means, that precise relaying of
134 ICMP in the real Internet is absolutely infeasible.
136 struct net *net = dev_net(skb->dev);
137 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
138 const struct iphdr *iph = (const struct iphdr *)skb->data;
141 const int type = icmp_hdr(skb)->type;
142 const int code = icmp_hdr(skb)->code;
145 t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
146 iph->daddr, iph->saddr, 0);
150 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
151 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
152 t->parms.link, 0, iph->protocol, 0);
157 if (type == ICMP_REDIRECT) {
158 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
164 if (t->parms.iph.daddr == 0)
168 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
171 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
175 t->err_time = jiffies;
181 static const struct tnl_ptk_info ipip_tpi = {
182 /* no tunnel info required for ipip. */
183 .proto = htons(ETH_P_IP),
186 #if IS_ENABLED(CONFIG_MPLS)
187 static const struct tnl_ptk_info mplsip_tpi = {
188 /* no tunnel info required for mplsip. */
189 .proto = htons(ETH_P_MPLS_UC),
193 static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
195 struct net *net = dev_net(skb->dev);
196 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
197 struct metadata_dst *tun_dst = NULL;
198 struct ip_tunnel *tunnel;
199 const struct iphdr *iph;
202 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
203 iph->saddr, iph->daddr, 0);
205 const struct tnl_ptk_info *tpi;
207 if (tunnel->parms.iph.protocol != ipproto &&
208 tunnel->parms.iph.protocol != 0)
211 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
213 #if IS_ENABLED(CONFIG_MPLS)
214 if (ipproto == IPPROTO_MPLS)
219 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
221 if (tunnel->collect_md) {
222 tun_dst = ip_tun_rx_dst(skb, 0, 0, 0);
226 return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
236 static int ipip_rcv(struct sk_buff *skb)
238 return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
241 #if IS_ENABLED(CONFIG_MPLS)
242 static int mplsip_rcv(struct sk_buff *skb)
244 return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
249 * This function assumes it is being called from dev_queue_xmit()
250 * and that skb is filled properly by that function.
252 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
253 struct net_device *dev)
255 struct ip_tunnel *tunnel = netdev_priv(dev);
256 const struct iphdr *tiph = &tunnel->parms.iph;
259 switch (skb->protocol) {
260 case htons(ETH_P_IP):
261 ipproto = IPPROTO_IPIP;
263 #if IS_ENABLED(CONFIG_MPLS)
264 case htons(ETH_P_MPLS_UC):
265 ipproto = IPPROTO_MPLS;
272 if (tiph->protocol != ipproto && tiph->protocol != 0)
275 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
278 skb_set_inner_ipproto(skb, ipproto);
280 if (tunnel->collect_md)
281 ip_md_tunnel_xmit(skb, dev, ipproto);
283 ip_tunnel_xmit(skb, dev, tiph, ipproto);
289 dev->stats.tx_errors++;
293 static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
298 #if IS_ENABLED(CONFIG_MPLS)
308 ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
311 struct ip_tunnel_parm p;
313 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
316 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
317 if (p.iph.version != 4 ||
318 !ipip_tunnel_ioctl_verify_protocol(p.iph.protocol) ||
319 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
323 p.i_key = p.o_key = 0;
324 p.i_flags = p.o_flags = 0;
325 err = ip_tunnel_ioctl(dev, &p, cmd);
329 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
335 static const struct net_device_ops ipip_netdev_ops = {
336 .ndo_init = ipip_tunnel_init,
337 .ndo_uninit = ip_tunnel_uninit,
338 .ndo_start_xmit = ipip_tunnel_xmit,
339 .ndo_do_ioctl = ipip_tunnel_ioctl,
340 .ndo_change_mtu = ip_tunnel_change_mtu,
341 .ndo_get_stats64 = ip_tunnel_get_stats64,
342 .ndo_get_iflink = ip_tunnel_get_iflink,
345 #define IPIP_FEATURES (NETIF_F_SG | \
348 NETIF_F_GSO_SOFTWARE | \
351 static void ipip_tunnel_setup(struct net_device *dev)
353 dev->netdev_ops = &ipip_netdev_ops;
355 dev->type = ARPHRD_TUNNEL;
356 dev->flags = IFF_NOARP;
358 dev->features |= NETIF_F_LLTX;
361 dev->features |= IPIP_FEATURES;
362 dev->hw_features |= IPIP_FEATURES;
363 ip_tunnel_setup(dev, ipip_net_id);
366 static int ipip_tunnel_init(struct net_device *dev)
368 struct ip_tunnel *tunnel = netdev_priv(dev);
370 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
371 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
373 tunnel->tun_hlen = 0;
374 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
375 return ip_tunnel_init(dev);
378 static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
379 struct netlink_ext_ack *extack)
383 if (!data || !data[IFLA_IPTUN_PROTO])
386 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
387 if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
393 static void ipip_netlink_parms(struct nlattr *data[],
394 struct ip_tunnel_parm *parms, bool *collect_md,
397 memset(parms, 0, sizeof(*parms));
399 parms->iph.version = 4;
400 parms->iph.protocol = IPPROTO_IPIP;
407 if (data[IFLA_IPTUN_LINK])
408 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
410 if (data[IFLA_IPTUN_LOCAL])
411 parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]);
413 if (data[IFLA_IPTUN_REMOTE])
414 parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]);
416 if (data[IFLA_IPTUN_TTL]) {
417 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
419 parms->iph.frag_off = htons(IP_DF);
422 if (data[IFLA_IPTUN_TOS])
423 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
425 if (data[IFLA_IPTUN_PROTO])
426 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
428 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
429 parms->iph.frag_off = htons(IP_DF);
431 if (data[IFLA_IPTUN_COLLECT_METADATA])
434 if (data[IFLA_IPTUN_FWMARK])
435 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
438 /* This function returns true when ENCAP attributes are present in the nl msg */
439 static bool ipip_netlink_encap_parms(struct nlattr *data[],
440 struct ip_tunnel_encap *ipencap)
444 memset(ipencap, 0, sizeof(*ipencap));
449 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
451 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
454 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
456 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
459 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
461 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
464 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
466 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
472 static int ipip_newlink(struct net *src_net, struct net_device *dev,
473 struct nlattr *tb[], struct nlattr *data[],
474 struct netlink_ext_ack *extack)
476 struct ip_tunnel *t = netdev_priv(dev);
477 struct ip_tunnel_parm p;
478 struct ip_tunnel_encap ipencap;
481 if (ipip_netlink_encap_parms(data, &ipencap)) {
482 int err = ip_tunnel_encap_setup(t, &ipencap);
488 ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
489 return ip_tunnel_newlink(dev, tb, &p, fwmark);
492 static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
493 struct nlattr *data[],
494 struct netlink_ext_ack *extack)
496 struct ip_tunnel *t = netdev_priv(dev);
497 struct ip_tunnel_parm p;
498 struct ip_tunnel_encap ipencap;
500 __u32 fwmark = t->fwmark;
502 if (ipip_netlink_encap_parms(data, &ipencap)) {
503 int err = ip_tunnel_encap_setup(t, &ipencap);
509 ipip_netlink_parms(data, &p, &collect_md, &fwmark);
513 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
514 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
517 return ip_tunnel_changelink(dev, tb, &p, fwmark);
520 static size_t ipip_get_size(const struct net_device *dev)
523 /* IFLA_IPTUN_LINK */
525 /* IFLA_IPTUN_LOCAL */
527 /* IFLA_IPTUN_REMOTE */
533 /* IFLA_IPTUN_PROTO */
535 /* IFLA_IPTUN_PMTUDISC */
537 /* IFLA_IPTUN_ENCAP_TYPE */
539 /* IFLA_IPTUN_ENCAP_FLAGS */
541 /* IFLA_IPTUN_ENCAP_SPORT */
543 /* IFLA_IPTUN_ENCAP_DPORT */
545 /* IFLA_IPTUN_COLLECT_METADATA */
547 /* IFLA_IPTUN_FWMARK */
552 static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
554 struct ip_tunnel *tunnel = netdev_priv(dev);
555 struct ip_tunnel_parm *parm = &tunnel->parms;
557 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
558 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
559 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
560 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
561 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
562 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
563 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
564 !!(parm->iph.frag_off & htons(IP_DF))) ||
565 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
566 goto nla_put_failure;
568 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
569 tunnel->encap.type) ||
570 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
571 tunnel->encap.sport) ||
572 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
573 tunnel->encap.dport) ||
574 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
575 tunnel->encap.flags))
576 goto nla_put_failure;
578 if (tunnel->collect_md)
579 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
580 goto nla_put_failure;
587 static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
588 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
589 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
590 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
591 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
592 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
593 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
594 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
595 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
596 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
597 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
598 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
599 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
600 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
603 static struct rtnl_link_ops ipip_link_ops __read_mostly = {
605 .maxtype = IFLA_IPTUN_MAX,
606 .policy = ipip_policy,
607 .priv_size = sizeof(struct ip_tunnel),
608 .setup = ipip_tunnel_setup,
609 .validate = ipip_tunnel_validate,
610 .newlink = ipip_newlink,
611 .changelink = ipip_changelink,
612 .dellink = ip_tunnel_dellink,
613 .get_size = ipip_get_size,
614 .fill_info = ipip_fill_info,
615 .get_link_net = ip_tunnel_get_link_net,
618 static struct xfrm_tunnel ipip_handler __read_mostly = {
620 .err_handler = ipip_err,
624 #if IS_ENABLED(CONFIG_MPLS)
625 static struct xfrm_tunnel mplsip_handler __read_mostly = {
626 .handler = mplsip_rcv,
627 .err_handler = ipip_err,
632 static int __net_init ipip_init_net(struct net *net)
634 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
637 static void __net_exit ipip_exit_net(struct net *net)
639 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
640 ip_tunnel_delete_net(itn, &ipip_link_ops);
643 static struct pernet_operations ipip_net_ops = {
644 .init = ipip_init_net,
645 .exit = ipip_exit_net,
647 .size = sizeof(struct ip_tunnel_net),
650 static int __init ipip_init(void)
654 pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
656 err = register_pernet_device(&ipip_net_ops);
659 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
661 pr_info("%s: can't register tunnel\n", __func__);
662 goto xfrm_tunnel_ipip_failed;
664 #if IS_ENABLED(CONFIG_MPLS)
665 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
667 pr_info("%s: can't register tunnel\n", __func__);
668 goto xfrm_tunnel_mplsip_failed;
671 err = rtnl_link_register(&ipip_link_ops);
673 goto rtnl_link_failed;
679 #if IS_ENABLED(CONFIG_MPLS)
680 xfrm4_tunnel_deregister(&mplsip_handler, AF_INET);
681 xfrm_tunnel_mplsip_failed:
684 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
685 xfrm_tunnel_ipip_failed:
686 unregister_pernet_device(&ipip_net_ops);
690 static void __exit ipip_fini(void)
692 rtnl_link_unregister(&ipip_link_ops);
693 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
694 pr_info("%s: can't deregister tunnel\n", __func__);
695 #if IS_ENABLED(CONFIG_MPLS)
696 if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
697 pr_info("%s: can't deregister tunnel\n", __func__);
699 unregister_pernet_device(&ipip_net_ops);
702 module_init(ipip_init);
703 module_exit(ipip_fini);
704 MODULE_LICENSE("GPL");
705 MODULE_ALIAS_RTNL_LINK("ipip");
706 MODULE_ALIAS_NETDEV("tunl0");