Initial import

1 files changed, 569 insertions, 0 deletions

diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
new file mode 100644
index 000000000..ff96396eb
--- /dev/null
+++ b/net/ipv4/ipip.c
@@ -0,0 +1,569 @@
+/*
+ *	Linux NET3:	IP/IP protocol decoder.
+ *
+ *	Authors:
+ *		Sam Lantinga (slouken@cs.ucdavis.edu)  02/01/95
+ *
+ *	Fixes:
+ *		Alan Cox	:	Merged and made usable non modular (its so tiny its silly as
+ *					a module taking up 2 pages).
+ *		Alan Cox	: 	Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
+ *					to keep ip_forward happy.
+ *		Alan Cox	:	More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
+ *		Kai Schulte	:	Fixed #defines for IP_FIREWALL->FIREWALL
+ *              David Woodhouse :       Perform some basic ICMP handling.
+ *                                      IPIP Routing without decapsulation.
+ *              Carlos Picoto   :       GRE over IP support
+ *		Alexey Kuznetsov:	Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
+ *					I do not want to merge them together.
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ */
+
+/* tunnel.c: an IP tunnel driver
+
+	The purpose of this driver is to provide an IP tunnel through
+	which you can tunnel network traffic transparently across subnets.
+
+	This was written by looking at Nick Holloway's dummy driver
+	Thanks for the great code!
+
+		-Sam Lantinga	(slouken@cs.ucdavis.edu)  02/01/95
+
+	Minor tweaks:
+		Cleaned up the code a little and added some pre-1.3.0 tweaks.
+		dev->hard_header/hard_header_len changed to use no headers.
+		Comments/bracketing tweaked.
+		Made the tunnels use dev->name not tunnel: when error reporting.
+		Added tx_dropped stat
+
+		-Alan Cox	(alan@lxorguk.ukuu.org.uk) 21 March 95
+
+	Reworked:
+		Changed to tunnel to destination gateway in addition to the
+			tunnel's pointopoint address
+		Almost completely rewritten
+		Note:  There is currently no firewall or ICMP handling done.
+
+		-Sam Lantinga	(slouken@cs.ucdavis.edu) 02/13/96
+
+*/
+
+/* Things I wish I had known when writing the tunnel driver:
+
+	When the tunnel_xmit() function is called, the skb contains the
+	packet to be sent (plus a great deal of extra info), and dev
+	contains the tunnel device that _we_ are.
+
+	When we are passed a packet, we are expected to fill in the
+	source address with our source IP address.
+
+	What is the proper way to allocate, copy and free a buffer?
+	After you allocate it, it is a "0 length" chunk of memory
+	starting at zero.  If you want to add headers to the buffer
+	later, you'll have to call "skb_reserve(skb, amount)" with
+	the amount of memory you want reserved.  Then, you call
+	"skb_put(skb, amount)" with the amount of space you want in
+	the buffer.  skb_put() returns a pointer to the top (#0) of
+	that buffer.  skb->len is set to the amount of space you have
+	"allocated" with skb_put().  You can then write up to skb->len
+	bytes to that buffer.  If you need more, you can call skb_put()
+	again with the additional amount of space you need.  You can
+	find out how much more space you can allocate by calling
+	"skb_tailroom(skb)".
+	Now, to add header space, call "skb_push(skb, header_len)".
+	This creates space at the beginning of the buffer and returns
+	a pointer to this new space.  If later you need to strip a
+	header from a buffer, call "skb_pull(skb, header_len)".
+	skb_headroom() will return how much space is left at the top
+	of the buffer (before the main data).  Remember, this headroom
+	space must be reserved before the skb_put() function is called.
+	*/
+
+/*
+   This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
+
+   For comments look at net/ipv4/ip_gre.c --ANK
+ */
+
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/if_arp.h>
+#include <linux/mroute.h>
+#include <linux/init.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/if_ether.h>
+
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/ip_tunnels.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+static bool log_ecn_error = true;
+module_param(log_ecn_error, bool, 0644);
+MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
+
+static int ipip_net_id __read_mostly;
+
+static int ipip_tunnel_init(struct net_device *dev);
+static struct rtnl_link_ops ipip_link_ops __read_mostly;
+
+static int ipip_err(struct sk_buff *skb, u32 info)
+{
+
+/* All the routers (except for Linux) return only
+   8 bytes of packet payload. It means, that precise relaying of
+   ICMP in the real Internet is absolutely infeasible.
+ */
+	struct net *net = dev_net(skb->dev);
+	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
+	const struct iphdr *iph = (const struct iphdr *)skb->data;
+	struct ip_tunnel *t;
+	int err;
+	const int type = icmp_hdr(skb)->type;
+	const int code = icmp_hdr(skb)->code;
+
+	err = -ENOENT;
+	t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
+			     iph->daddr, iph->saddr, 0);
+	if (!t)
+		goto out;
+
+	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
+		ipv4_update_pmtu(skb, dev_net(skb->dev), info,
+				 t->parms.link, 0, IPPROTO_IPIP, 0);
+		err = 0;
+		goto out;
+	}
+
+	if (type == ICMP_REDIRECT) {
+		ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
+			      IPPROTO_IPIP, 0);
+		err = 0;
+		goto out;
+	}
+
+	if (t->parms.iph.daddr == 0)
+		goto out;
+
+	err = 0;
+	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
+		goto out;
+
+	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
+		t->err_count++;
+	else
+		t->err_count = 1;
+	t->err_time = jiffies;
+
+out:
+	return err;
+}
+
+static const struct tnl_ptk_info tpi = {
+	/* no tunnel info required for ipip. */
+	.proto = htons(ETH_P_IP),
+};
+
+static int ipip_rcv(struct sk_buff *skb)
+{
+	struct net *net = dev_net(skb->dev);
+	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
+	struct ip_tunnel *tunnel;
+	const struct iphdr *iph;
+
+	iph = ip_hdr(skb);
+	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
+			iph->saddr, iph->daddr, 0);
+	if (tunnel) {
+		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
+			goto drop;
+		if (iptunnel_pull_header(skb, 0, tpi.proto))
+			goto drop;
+		return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error);
+	}
+
+	return -1;
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+/*
+ *	This function assumes it is being called from dev_queue_xmit()
+ *	and that skb is filled properly by that function.
+ */
+static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	const struct iphdr  *tiph = &tunnel->parms.iph;
+
+	if (unlikely(skb->protocol != htons(ETH_P_IP)))
+		goto tx_error;
+
+	skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
+	if (IS_ERR(skb))
+		goto out;
+
+	skb_set_inner_ipproto(skb, IPPROTO_IPIP);
+
+	ip_tunnel_xmit(skb, dev, tiph, tiph->protocol);
+	return NETDEV_TX_OK;
+
+tx_error:
+	kfree_skb(skb);
+out:
+	dev->stats.tx_errors++;
+	return NETDEV_TX_OK;
+}
+
+static int
+ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	int err = 0;
+	struct ip_tunnel_parm p;
+
+	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+		return -EFAULT;
+
+	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
+		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
+		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
+			return -EINVAL;
+	}
+
+	p.i_key = p.o_key = p.i_flags = p.o_flags = 0;
+	if (p.iph.ttl)
+		p.iph.frag_off |= htons(IP_DF);
+
+	err = ip_tunnel_ioctl(dev, &p, cmd);
+	if (err)
+		return err;
+
+	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static const struct net_device_ops ipip_netdev_ops = {
+	.ndo_init       = ipip_tunnel_init,
+	.ndo_uninit     = ip_tunnel_uninit,
+	.ndo_start_xmit	= ipip_tunnel_xmit,
+	.ndo_do_ioctl	= ipip_tunnel_ioctl,
+	.ndo_change_mtu = ip_tunnel_change_mtu,
+	.ndo_get_stats64 = ip_tunnel_get_stats64,
+	.ndo_get_iflink = ip_tunnel_get_iflink,
+};
+
+#define IPIP_FEATURES (NETIF_F_SG |		\
+		       NETIF_F_FRAGLIST |	\
+		       NETIF_F_HIGHDMA |	\
+		       NETIF_F_GSO_SOFTWARE |	\
+		       NETIF_F_HW_CSUM)
+
+static void ipip_tunnel_setup(struct net_device *dev)
+{
+	dev->netdev_ops		= &ipip_netdev_ops;
+
+	dev->type		= ARPHRD_TUNNEL;
+	dev->flags		= IFF_NOARP;
+	dev->addr_len		= 4;
+	dev->features		|= NETIF_F_LLTX;
+	netif_keep_dst(dev);
+
+	dev->features		|= IPIP_FEATURES;
+	dev->hw_features	|= IPIP_FEATURES;
+	ip_tunnel_setup(dev, ipip_net_id);
+}
+
+static int ipip_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+
+	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
+	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
+
+	tunnel->tun_hlen = 0;
+	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
+	tunnel->parms.iph.protocol = IPPROTO_IPIP;
+	return ip_tunnel_init(dev);
+}
+
+static void ipip_netlink_parms(struct nlattr *data[],
+			       struct ip_tunnel_parm *parms)
+{
+	memset(parms, 0, sizeof(*parms));
+
+	parms->iph.version = 4;
+	parms->iph.protocol = IPPROTO_IPIP;
+	parms->iph.ihl = 5;
+
+	if (!data)
+		return;
+
+	if (data[IFLA_IPTUN_LINK])
+		parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
+
+	if (data[IFLA_IPTUN_LOCAL])
+		parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]);
+
+	if (data[IFLA_IPTUN_REMOTE])
+		parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]);
+
+	if (data[IFLA_IPTUN_TTL]) {
+		parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
+		if (parms->iph.ttl)
+			parms->iph.frag_off = htons(IP_DF);
+	}
+
+	if (data[IFLA_IPTUN_TOS])
+		parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
+
+	if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
+		parms->iph.frag_off = htons(IP_DF);
+}
+
+/* This function returns true when ENCAP attributes are present in the nl msg */
+static bool ipip_netlink_encap_parms(struct nlattr *data[],
+				     struct ip_tunnel_encap *ipencap)
+{
+	bool ret = false;
+
+	memset(ipencap, 0, sizeof(*ipencap));
+
+	if (!data)
+		return ret;
+
+	if (data[IFLA_IPTUN_ENCAP_TYPE]) {
+		ret = true;
+		ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
+	}
+
+	if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
+		ret = true;
+		ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
+	}
+
+	if (data[IFLA_IPTUN_ENCAP_SPORT]) {
+		ret = true;
+		ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
+	}
+
+	if (data[IFLA_IPTUN_ENCAP_DPORT]) {
+		ret = true;
+		ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
+	}
+
+	return ret;
+}
+
+static int ipip_newlink(struct net *src_net, struct net_device *dev,
+			struct nlattr *tb[], struct nlattr *data[])
+{
+	struct ip_tunnel_parm p;
+	struct ip_tunnel_encap ipencap;
+
+	if (ipip_netlink_encap_parms(data, &ipencap)) {
+		struct ip_tunnel *t = netdev_priv(dev);
+		int err = ip_tunnel_encap_setup(t, &ipencap);
+
+		if (err < 0)
+			return err;
+	}
+
+	ipip_netlink_parms(data, &p);
+	return ip_tunnel_newlink(dev, tb, &p);
+}
+
+static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
+			   struct nlattr *data[])
+{
+	struct ip_tunnel_parm p;
+	struct ip_tunnel_encap ipencap;
+
+	if (ipip_netlink_encap_parms(data, &ipencap)) {
+		struct ip_tunnel *t = netdev_priv(dev);
+		int err = ip_tunnel_encap_setup(t, &ipencap);
+
+		if (err < 0)
+			return err;
+	}
+
+	ipip_netlink_parms(data, &p);
+
+	if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
+	    (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
+		return -EINVAL;
+
+	return ip_tunnel_changelink(dev, tb, &p);
+}
+
+static size_t ipip_get_size(const struct net_device *dev)
+{
+	return
+		/* IFLA_IPTUN_LINK */
+		nla_total_size(4) +
+		/* IFLA_IPTUN_LOCAL */
+		nla_total_size(4) +
+		/* IFLA_IPTUN_REMOTE */
+		nla_total_size(4) +
+		/* IFLA_IPTUN_TTL */
+		nla_total_size(1) +
+		/* IFLA_IPTUN_TOS */
+		nla_total_size(1) +
+		/* IFLA_IPTUN_PMTUDISC */
+		nla_total_size(1) +
+		/* IFLA_IPTUN_ENCAP_TYPE */
+		nla_total_size(2) +
+		/* IFLA_IPTUN_ENCAP_FLAGS */
+		nla_total_size(2) +
+		/* IFLA_IPTUN_ENCAP_SPORT */
+		nla_total_size(2) +
+		/* IFLA_IPTUN_ENCAP_DPORT */
+		nla_total_size(2) +
+		0;
+}
+
+static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct ip_tunnel_parm *parm = &tunnel->parms;
+
+	if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
+	    nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
+	    nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
+	    nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
+	    nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
+	    nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
+		       !!(parm->iph.frag_off & htons(IP_DF))))
+		goto nla_put_failure;
+
+	if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
+			tunnel->encap.type) ||
+	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
+			 tunnel->encap.sport) ||
+	    nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
+			 tunnel->encap.dport) ||
+	    nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
+			tunnel->encap.flags))
+		goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
+	[IFLA_IPTUN_LINK]		= { .type = NLA_U32 },
+	[IFLA_IPTUN_LOCAL]		= { .type = NLA_U32 },
+	[IFLA_IPTUN_REMOTE]		= { .type = NLA_U32 },
+	[IFLA_IPTUN_TTL]		= { .type = NLA_U8 },
+	[IFLA_IPTUN_TOS]		= { .type = NLA_U8 },
+	[IFLA_IPTUN_PMTUDISC]		= { .type = NLA_U8 },
+	[IFLA_IPTUN_ENCAP_TYPE]		= { .type = NLA_U16 },
+	[IFLA_IPTUN_ENCAP_FLAGS]	= { .type = NLA_U16 },
+	[IFLA_IPTUN_ENCAP_SPORT]	= { .type = NLA_U16 },
+	[IFLA_IPTUN_ENCAP_DPORT]	= { .type = NLA_U16 },
+};
+
+static struct rtnl_link_ops ipip_link_ops __read_mostly = {
+	.kind		= "ipip",
+	.maxtype	= IFLA_IPTUN_MAX,
+	.policy		= ipip_policy,
+	.priv_size	= sizeof(struct ip_tunnel),
+	.setup		= ipip_tunnel_setup,
+	.newlink	= ipip_newlink,
+	.changelink	= ipip_changelink,
+	.dellink	= ip_tunnel_dellink,
+	.get_size	= ipip_get_size,
+	.fill_info	= ipip_fill_info,
+	.get_link_net	= ip_tunnel_get_link_net,
+};
+
+static struct xfrm_tunnel ipip_handler __read_mostly = {
+	.handler	=	ipip_rcv,
+	.err_handler	=	ipip_err,
+	.priority	=	1,
+};
+
+static int __net_init ipip_init_net(struct net *net)
+{
+	return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
+}
+
+static void __net_exit ipip_exit_net(struct net *net)
+{
+	struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
+	ip_tunnel_delete_net(itn, &ipip_link_ops);
+}
+
+static struct pernet_operations ipip_net_ops = {
+	.init = ipip_init_net,
+	.exit = ipip_exit_net,
+	.id   = &ipip_net_id,
+	.size = sizeof(struct ip_tunnel_net),
+};
+
+static int __init ipip_init(void)
+{
+	int err;
+
+	pr_info("ipip: IPv4 over IPv4 tunneling driver\n");
+
+	err = register_pernet_device(&ipip_net_ops);
+	if (err < 0)
+		return err;
+	err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
+	if (err < 0) {
+		pr_info("%s: can't register tunnel\n", __func__);
+		goto xfrm_tunnel_failed;
+	}
+	err = rtnl_link_register(&ipip_link_ops);
+	if (err < 0)
+		goto rtnl_link_failed;
+
+out:
+	return err;
+
+rtnl_link_failed:
+	xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
+xfrm_tunnel_failed:
+	unregister_pernet_device(&ipip_net_ops);
+	goto out;
+}
+
+static void __exit ipip_fini(void)
+{
+	rtnl_link_unregister(&ipip_link_ops);
+	if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
+		pr_info("%s: can't deregister tunnel\n", __func__);
+
+	unregister_pernet_device(&ipip_net_ops);
+}
+
+module_init(ipip_init);
+module_exit(ipip_fini);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("ipip");
+MODULE_ALIAS_NETDEV("tunl0");