[linux.git] / net / ipv4 / ip_vti.c

/*
 *	Linux NET3: IP/IP protocol decoder modified to support
 *		    virtual tunnel interface
 *
 *	Authors:
 *		Saurabh Mohan ([email protected]) 05/07/2012
 *
 *	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.
 *
 */

/*
   This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.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/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 <linux/icmpv6.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 struct rtnl_link_ops vti_link_ops __read_mostly;

static int vti_net_id __read_mostly;
static int vti_tunnel_init(struct net_device *dev);

static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
		     int encap_type)
{
	struct ip_tunnel *tunnel;
	const struct iphdr *iph = ip_hdr(skb);
	struct net *net = dev_net(skb->dev);
	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);

	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
				  iph->saddr, iph->daddr, 0);
	if (tunnel != NULL) {
		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
			goto drop;

		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
		skb->mark = be32_to_cpu(tunnel->parms.i_key);

		return xfrm_input(skb, nexthdr, spi, encap_type);
	}

	return -EINVAL;
drop:
	kfree_skb(skb);
	return 0;
}

static int vti_rcv(struct sk_buff *skb)
{
	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);

	return vti_input(skb, ip_hdr(skb)->protocol, 0, 0);
}

static int vti_rcv_cb(struct sk_buff *skb, int err)
{
	unsigned short family;
	struct net_device *dev;
	struct pcpu_sw_netstats *tstats;
	struct xfrm_state *x;
	struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;

	if (!tunnel)
		return 1;

	dev = tunnel->dev;

	if (err) {
		dev->stats.rx_errors++;
		dev->stats.rx_dropped++;

		return 0;
	}

	x = xfrm_input_state(skb);
	family = x->inner_mode->afinfo->family;

	if (!xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family))
		return -EPERM;

	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
	skb->dev = dev;

	tstats = this_cpu_ptr(dev->tstats);

	u64_stats_update_begin(&tstats->syncp);
	tstats->rx_packets++;
	tstats->rx_bytes += skb->len;
	u64_stats_update_end(&tstats->syncp);

	return 0;
}

static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
{
	xfrm_address_t *daddr = (xfrm_address_t *)&dst;
	xfrm_address_t *saddr = (xfrm_address_t *)&src;

	/* if there is no transform then this tunnel is not functional.
	 * Or if the xfrm is not mode tunnel.
	 */
	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
	    x->props.family != AF_INET)
		return false;

	if (!dst)
		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);

	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
		return false;

	return true;
}

static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
			    struct flowi *fl)
{
	struct ip_tunnel *tunnel = netdev_priv(dev);
	struct ip_tunnel_parm *parms = &tunnel->parms;
	struct dst_entry *dst = skb_dst(skb);
	struct net_device *tdev;	/* Device to other host */
	int err;

	if (!dst) {
		dev->stats.tx_carrier_errors++;
		goto tx_error_icmp;
	}

	dst_hold(dst);
	dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
	if (IS_ERR(dst)) {
		dev->stats.tx_carrier_errors++;
		goto tx_error_icmp;
	}

	if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
		dev->stats.tx_carrier_errors++;
		dst_release(dst);
		goto tx_error_icmp;
	}

	tdev = dst->dev;

	if (tdev == dev) {
		dst_release(dst);
		dev->stats.collisions++;
		goto tx_error;
	}

	if (tunnel->err_count > 0) {
		if (time_before(jiffies,
				tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
			tunnel->err_count--;
			dst_link_failure(skb);
		} else
			tunnel->err_count = 0;
	}

	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
	skb_dst_set(skb, dst);
	skb->dev = skb_dst(skb)->dev;

	err = dst_output(skb);
	if (net_xmit_eval(err) == 0)
		err = skb->len;
	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
	return NETDEV_TX_OK;

tx_error_icmp:
	dst_link_failure(skb);
tx_error:
	dev->stats.tx_errors++;
	kfree_skb(skb);
	return NETDEV_TX_OK;
}

/* This function assumes it is being called from dev_queue_xmit()
 * and that skb is filled properly by that function.
 */
static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct ip_tunnel *tunnel = netdev_priv(dev);
	struct flowi fl;

	memset(&fl, 0, sizeof(fl));

	skb->mark = be32_to_cpu(tunnel->parms.o_key);

	switch (skb->protocol) {
	case htons(ETH_P_IP):
		xfrm_decode_session(skb, &fl, AF_INET);
		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
		break;
	case htons(ETH_P_IPV6):
		xfrm_decode_session(skb, &fl, AF_INET6);
		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
		break;
	default:
		dev->stats.tx_errors++;
		dev_kfree_skb(skb);
		return NETDEV_TX_OK;
	}

	return vti_xmit(skb, dev, &fl);
}

static int vti4_err(struct sk_buff *skb, u32 info)
{
	__be32 spi;
	__u32 mark;
	struct xfrm_state *x;
	struct ip_tunnel *tunnel;
	struct ip_esp_hdr *esph;
	struct ip_auth_hdr *ah ;
	struct ip_comp_hdr *ipch;
	struct net *net = dev_net(skb->dev);
	const struct iphdr *iph = (const struct iphdr *)skb->data;
	int protocol = iph->protocol;
	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);

	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
				  iph->daddr, iph->saddr, 0);
	if (!tunnel)
		return -1;

	mark = be32_to_cpu(tunnel->parms.o_key);

	switch (protocol) {
	case IPPROTO_ESP:
		esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
		spi = esph->spi;
		break;
	case IPPROTO_AH:
		ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
		spi = ah->spi;
		break;
	case IPPROTO_COMP:
		ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
		spi = htonl(ntohs(ipch->cpi));
		break;
	default:
		return 0;
	}

	switch (icmp_hdr(skb)->type) {
	case ICMP_DEST_UNREACH:
		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
			return 0;
	case ICMP_REDIRECT:
		break;
	default:
		return 0;
	}

	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
			      spi, protocol, AF_INET);
	if (!x)
		return 0;

	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
		ipv4_update_pmtu(skb, net, info, 0, 0, protocol, 0);
	else
		ipv4_redirect(skb, net, 0, 0, protocol, 0);
	xfrm_state_put(x);

	return 0;
}

static int
vti_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)
			return -EINVAL;
	}

	if (!(p.i_flags & GRE_KEY))
		p.i_key = 0;
	if (!(p.o_flags & GRE_KEY))
		p.o_key = 0;

	p.i_flags = VTI_ISVTI;

	err = ip_tunnel_ioctl(dev, &p, cmd);
	if (err)
		return err;

	if (cmd != SIOCDELTUNNEL) {
		p.i_flags |= GRE_KEY;
		p.o_flags |= GRE_KEY;
	}

	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
		return -EFAULT;
	return 0;
}

static const struct net_device_ops vti_netdev_ops = {
	.ndo_init	= vti_tunnel_init,
	.ndo_uninit	= ip_tunnel_uninit,
	.ndo_start_xmit	= vti_tunnel_xmit,
	.ndo_do_ioctl	= vti_tunnel_ioctl,
	.ndo_change_mtu	= ip_tunnel_change_mtu,
	.ndo_get_stats64 = ip_tunnel_get_stats64,
};

static void vti_tunnel_setup(struct net_device *dev)
{
	dev->netdev_ops		= &vti_netdev_ops;
	dev->type		= ARPHRD_TUNNEL;
	ip_tunnel_setup(dev, vti_net_id);
}

static int vti_tunnel_init(struct net_device *dev)
{
	struct ip_tunnel *tunnel = netdev_priv(dev);
	struct iphdr *iph = &tunnel->parms.iph;

	memcpy(dev->dev_addr, &iph->saddr, 4);
	memcpy(dev->broadcast, &iph->daddr, 4);

	dev->hard_header_len	= LL_MAX_HEADER + sizeof(struct iphdr);
	dev->mtu		= ETH_DATA_LEN;
	dev->flags		= IFF_NOARP;
	dev->iflink		= 0;
	dev->addr_len		= 4;
	dev->features		|= NETIF_F_LLTX;
	netif_keep_dst(dev);

	return ip_tunnel_init(dev);
}

static void __net_init vti_fb_tunnel_init(struct net_device *dev)
{
	struct ip_tunnel *tunnel = netdev_priv(dev);
	struct iphdr *iph = &tunnel->parms.iph;

	iph->version		= 4;
	iph->protocol		= IPPROTO_IPIP;
	iph->ihl		= 5;
}

static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
	.handler	=	vti_rcv,
	.input_handler	=	vti_input,
	.cb_handler	=	vti_rcv_cb,
	.err_handler	=	vti4_err,
	.priority	=	100,
};

static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
	.handler	=	vti_rcv,
	.input_handler	=	vti_input,
	.cb_handler	=	vti_rcv_cb,
	.err_handler	=	vti4_err,
	.priority	=	100,
};

static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
	.handler	=	vti_rcv,
	.input_handler	=	vti_input,
	.cb_handler	=	vti_rcv_cb,
	.err_handler	=	vti4_err,
	.priority	=	100,
};

static int __net_init vti_init_net(struct net *net)
{
	int err;
	struct ip_tunnel_net *itn;

	err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
	if (err)
		return err;
	itn = net_generic(net, vti_net_id);
	vti_fb_tunnel_init(itn->fb_tunnel_dev);
	return 0;
}

static void __net_exit vti_exit_net(struct net *net)
{
	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
	ip_tunnel_delete_net(itn, &vti_link_ops);
}

static struct pernet_operations vti_net_ops = {
	.init = vti_init_net,
	.exit = vti_exit_net,
	.id   = &vti_net_id,
	.size = sizeof(struct ip_tunnel_net),
};

static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
{
	return 0;
}

static void vti_netlink_parms(struct nlattr *data[],
			      struct ip_tunnel_parm *parms)
{
	memset(parms, 0, sizeof(*parms));

	parms->iph.protocol = IPPROTO_IPIP;

	if (!data)
		return;

	parms->i_flags = VTI_ISVTI;

	if (data[IFLA_VTI_LINK])
		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);

	if (data[IFLA_VTI_IKEY])
		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);

	if (data[IFLA_VTI_OKEY])
		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);

	if (data[IFLA_VTI_LOCAL])
		parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);

	if (data[IFLA_VTI_REMOTE])
		parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);

}

static int vti_newlink(struct net *src_net, struct net_device *dev,
		       struct nlattr *tb[], struct nlattr *data[])
{
	struct ip_tunnel_parm parms;

	vti_netlink_parms(data, &parms);
	return ip_tunnel_newlink(dev, tb, &parms);
}

static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
			  struct nlattr *data[])
{
	struct ip_tunnel_parm p;

	vti_netlink_parms(data, &p);
	return ip_tunnel_changelink(dev, tb, &p);
}

static size_t vti_get_size(const struct net_device *dev)
{
	return
		/* IFLA_VTI_LINK */
		nla_total_size(4) +
		/* IFLA_VTI_IKEY */
		nla_total_size(4) +
		/* IFLA_VTI_OKEY */
		nla_total_size(4) +
		/* IFLA_VTI_LOCAL */
		nla_total_size(4) +
		/* IFLA_VTI_REMOTE */
		nla_total_size(4) +
		0;
}

static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
	struct ip_tunnel *t = netdev_priv(dev);
	struct ip_tunnel_parm *p = &t->parms;

	nla_put_u32(skb, IFLA_VTI_LINK, p->link);
	nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key);
	nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key);
	nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr);
	nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr);

	return 0;
}

static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
	[IFLA_VTI_LOCAL]	= { .len = FIELD_SIZEOF(struct iphdr, saddr) },
	[IFLA_VTI_REMOTE]	= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
};

static struct rtnl_link_ops vti_link_ops __read_mostly = {
	.kind		= "vti",
	.maxtype	= IFLA_VTI_MAX,
	.policy		= vti_policy,
	.priv_size	= sizeof(struct ip_tunnel),
	.setup		= vti_tunnel_setup,
	.validate	= vti_tunnel_validate,
	.newlink	= vti_newlink,
	.changelink	= vti_changelink,
	.dellink        = ip_tunnel_dellink,
	.get_size	= vti_get_size,
	.fill_info	= vti_fill_info,
	.get_link_net	= ip_tunnel_get_link_net,
};

static int __init vti_init(void)
{
	const char *msg;
	int err;

	pr_info("IPv4 over IPsec tunneling driver\n");

	msg = "tunnel device";
	err = register_pernet_device(&vti_net_ops);
	if (err < 0)
		goto pernet_dev_failed;

	msg = "tunnel protocols";
	err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
	if (err < 0)
		goto xfrm_proto_esp_failed;
	err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
	if (err < 0)
		goto xfrm_proto_ah_failed;
	err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
	if (err < 0)
		goto xfrm_proto_comp_failed;

	msg = "netlink interface";
	err = rtnl_link_register(&vti_link_ops);
	if (err < 0)
		goto rtnl_link_failed;

	return err;

rtnl_link_failed:
	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
xfrm_proto_comp_failed:
	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
xfrm_proto_ah_failed:
	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
xfrm_proto_esp_failed:
	unregister_pernet_device(&vti_net_ops);
pernet_dev_failed:
	pr_err("vti init: failed to register %s\n", msg);
	return err;
}

static void __exit vti_fini(void)
{
	rtnl_link_unregister(&vti_link_ops);
	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
	unregister_pernet_device(&vti_net_ops);
}

module_init(vti_init);
module_exit(vti_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("vti");
MODULE_ALIAS_NETDEV("ip_vti0");
Commit	Line	Data
1181412c S	1	/*
	2	* Linux NET3: IP/IP protocol decoder modified to support
	3	* virtual tunnel interface
	4	*
	5	* Authors:
	6	* Saurabh Mohan ([email protected]) 05/07/2012
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* as published by the Free Software Foundation; either version
	11	* 2 of the License, or (at your option) any later version.
	12	*
	13	*/
	14
	15	/*
	16	This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c
	17
	18	For comments look at net/ipv4/ip_gre.c --ANK
	19	*/
	20
	21
	22	#include <linux/capability.h>
	23	#include <linux/module.h>
	24	#include <linux/types.h>
	25	#include <linux/kernel.h>
	26	#include <linux/uaccess.h>
	27	#include <linux/skbuff.h>
	28	#include <linux/netdevice.h>
	29	#include <linux/in.h>
	30	#include <linux/tcp.h>
	31	#include <linux/udp.h>
	32	#include <linux/if_arp.h>
	33	#include <linux/mroute.h>
	34	#include <linux/init.h>
	35	#include <linux/netfilter_ipv4.h>
	36	#include <linux/if_ether.h>
78a010cc	37	#include <linux/icmpv6.h>
1181412c S	38
	39	#include <net/sock.h>
	40	#include <net/ip.h>
	41	#include <net/icmp.h>
c5441932	42	#include <net/ip_tunnels.h>
1181412c S	43	#include <net/inet_ecn.h>
	44	#include <net/xfrm.h>
	45	#include <net/net_namespace.h>
	46	#include <net/netns/generic.h>
	47
1181412c S	48	static struct rtnl_link_ops vti_link_ops __read_mostly;
	49
	50	static int vti_net_id __read_mostly;
1181412c	51	static int vti_tunnel_init(struct net_device *dev);
1181412c	52
df3893c1 SK	53	static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
df3893c1 SK	54	int encap_type)
1181412c S	55	{
	56	struct ip_tunnel *tunnel;
	57	const struct iphdr *iph = ip_hdr(skb);
b9959fd3 AW	58	struct net *net = dev_net(skb->dev);
b9959fd3 AW	59	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
1181412c	60
b9959fd3 AW	61	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
b9959fd3 AW	62	iph->saddr, iph->daddr, 0);
1181412c	63	if (tunnel != NULL) {
df3893c1 SK	64	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
	65	goto drop;
	66
	67	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
	68	skb->mark = be32_to_cpu(tunnel->parms.i_key);
	69
	70	return xfrm_input(skb, nexthdr, spi, encap_type);
	71	}
	72
	73	return -EINVAL;
	74	drop:
	75	kfree_skb(skb);
	76	return 0;
	77	}
	78
	79	static int vti_rcv(struct sk_buff *skb)
	80	{
	81	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
	82	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
	83
	84	return vti_input(skb, ip_hdr(skb)->protocol, 0, 0);
	85	}
	86
	87	static int vti_rcv_cb(struct sk_buff *skb, int err)
	88	{
	89	unsigned short family;
	90	struct net_device *dev;
	91	struct pcpu_sw_netstats *tstats;
	92	struct xfrm_state *x;
	93	struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
	94
	95	if (!tunnel)
1181412c	96	return 1;
df3893c1 SK	97
	98	dev = tunnel->dev;
	99
	100	if (err) {
	101	dev->stats.rx_errors++;
	102	dev->stats.rx_dropped++;
	103
	104	return 0;
1181412c	105	}
1181412c	106
df3893c1 SK	107	x = xfrm_input_state(skb);
	108	family = x->inner_mode->afinfo->family;
	109
	110	if (!xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family))
	111	return -EPERM;
	112
	113	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
	114	skb->dev = dev;
	115
	116	tstats = this_cpu_ptr(dev->tstats);
	117
	118	u64_stats_update_begin(&tstats->syncp);
	119	tstats->rx_packets++;
	120	tstats->rx_bytes += skb->len;
	121	u64_stats_update_end(&tstats->syncp);
	122
	123	return 0;
1181412c S	124	}
1181412c S	125
6e2de802 SK	126	static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
	127	{
	128	xfrm_address_t daddr = (xfrm_address_t )&dst;
	129	xfrm_address_t saddr = (xfrm_address_t )&src;
	130
	131	/* if there is no transform then this tunnel is not functional.
	132	* Or if the xfrm is not mode tunnel.
	133	*/
	134	if (!x \|\| x->props.mode != XFRM_MODE_TUNNEL \|\|
	135	x->props.family != AF_INET)
	136	return false;
	137
	138	if (!dst)
	139	return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
	140
	141	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
	142	return false;
	143
	144	return true;
	145	}
	146
78a010cc SK	147	static netdev_tx_t vti_xmit(struct sk_buff skb, struct net_device dev,
78a010cc SK	148	struct flowi *fl)
1181412c S	149	{
1181412c S	150	struct ip_tunnel *tunnel = netdev_priv(dev);
6e2de802	151	struct ip_tunnel_parm *parms = &tunnel->parms;
a34cd4f3	152	struct dst_entry *dst = skb_dst(skb);
1181412c	153	struct net_device tdev; / Device to other host */
b9959fd3	154	int err;
1181412c	155
a34cd4f3	156	if (!dst) {
df3893c1 SK	157	dev->stats.tx_carrier_errors++;
	158	goto tx_error_icmp;
	159	}
1181412c	160
a34cd4f3	161	dst_hold(dst);
78a010cc	162	dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
a34cd4f3	163	if (IS_ERR(dst)) {
1181412c S	164	dev->stats.tx_carrier_errors++;
	165	goto tx_error_icmp;
	166	}
df3893c1	167
6e2de802	168	if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
1181412c	169	dev->stats.tx_carrier_errors++;
a34cd4f3	170	dst_release(dst);
1181412c S	171	goto tx_error_icmp;
1181412c S	172	}
6e2de802	173
a34cd4f3	174	tdev = dst->dev;
1181412c S	175
1181412c S	176	if (tdev == dev) {
a34cd4f3	177	dst_release(dst);
1181412c S	178	dev->stats.collisions++;
	179	goto tx_error;
	180	}
	181
	182	if (tunnel->err_count > 0) {
	183	if (time_before(jiffies,
	184	tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
	185	tunnel->err_count--;
	186	dst_link_failure(skb);
	187	} else
	188	tunnel->err_count = 0;
	189	}
	190
df3893c1	191	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
a34cd4f3	192	skb_dst_set(skb, dst);
1181412c S	193	skb->dev = skb_dst(skb)->dev;
1181412c S	194
b9959fd3 AW	195	err = dst_output(skb);
	196	if (net_xmit_eval(err) == 0)
	197	err = skb->len;
	198	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
1181412c S	199	return NETDEV_TX_OK;
	200
	201	tx_error_icmp:
	202	dst_link_failure(skb);
	203	tx_error:
	204	dev->stats.tx_errors++;
3acfa1e7	205	kfree_skb(skb);
1181412c S	206	return NETDEV_TX_OK;
	207	}
	208
78a010cc SK	209	/* This function assumes it is being called from dev_queue_xmit()
	210	* and that skb is filled properly by that function.
	211	*/
	212	static netdev_tx_t vti_tunnel_xmit(struct sk_buff skb, struct net_device dev)
	213	{
	214	struct ip_tunnel *tunnel = netdev_priv(dev);
	215	struct flowi fl;
	216
	217	memset(&fl, 0, sizeof(fl));
	218
	219	skb->mark = be32_to_cpu(tunnel->parms.o_key);
	220
	221	switch (skb->protocol) {
	222	case htons(ETH_P_IP):
	223	xfrm_decode_session(skb, &fl, AF_INET);
	224	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
	225	break;
	226	case htons(ETH_P_IPV6):
	227	xfrm_decode_session(skb, &fl, AF_INET6);
	228	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
	229	break;
	230	default:
	231	dev->stats.tx_errors++;
	232	dev_kfree_skb(skb);
	233	return NETDEV_TX_OK;
	234	}
	235
	236	return vti_xmit(skb, dev, &fl);
	237	}
	238
df3893c1 SK	239	static int vti4_err(struct sk_buff *skb, u32 info)
	240	{
	241	__be32 spi;
6d004d6c	242	__u32 mark;
df3893c1 SK	243	struct xfrm_state *x;
	244	struct ip_tunnel *tunnel;
	245	struct ip_esp_hdr *esph;
	246	struct ip_auth_hdr *ah ;
	247	struct ip_comp_hdr *ipch;
	248	struct net *net = dev_net(skb->dev);
	249	const struct iphdr iph = (const struct iphdr )skb->data;
	250	int protocol = iph->protocol;
	251	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
	252
	253	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
	254	iph->daddr, iph->saddr, 0);
	255	if (!tunnel)
	256	return -1;
	257
6d004d6c SK	258	mark = be32_to_cpu(tunnel->parms.o_key);
6d004d6c SK	259
df3893c1 SK	260	switch (protocol) {
	261	case IPPROTO_ESP:
	262	esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
	263	spi = esph->spi;
	264	break;
	265	case IPPROTO_AH:
	266	ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
	267	spi = ah->spi;
	268	break;
	269	case IPPROTO_COMP:
	270	ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
	271	spi = htonl(ntohs(ipch->cpi));
	272	break;
	273	default:
	274	return 0;
	275	}
	276
	277	switch (icmp_hdr(skb)->type) {
	278	case ICMP_DEST_UNREACH:
	279	if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
	280	return 0;
	281	case ICMP_REDIRECT:
	282	break;
	283	default:
	284	return 0;
	285	}
	286
6d004d6c	287	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
df3893c1 SK	288	spi, protocol, AF_INET);
	289	if (!x)
	290	return 0;
	291
	292	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
	293	ipv4_update_pmtu(skb, net, info, 0, 0, protocol, 0);
	294	else
	295	ipv4_redirect(skb, net, 0, 0, protocol, 0);
	296	xfrm_state_put(x);
	297
	298	return 0;
	299	}
	300
1181412c S	301	static int
	302	vti_tunnel_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
	303	{
	304	int err = 0;
	305	struct ip_tunnel_parm p;
1181412c	306
b9959fd3 AW	307	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
b9959fd3 AW	308	return -EFAULT;
1181412c	309
b9959fd3	310	if (cmd == SIOCADDTUNNEL \|\| cmd == SIOCCHGTUNNEL) {
1181412c S	311	if (p.iph.version != 4 \|\| p.iph.protocol != IPPROTO_IPIP \|\|
1181412c S	312	p.iph.ihl != 5)
b9959fd3 AW	313	return -EINVAL;
b9959fd3 AW	314	}
1181412c	315
7c8e6b9c DP	316	if (!(p.i_flags & GRE_KEY))
	317	p.i_key = 0;
	318	if (!(p.o_flags & GRE_KEY))
	319	p.o_key = 0;
	320
	321	p.i_flags = VTI_ISVTI;
	322
b9959fd3 AW	323	err = ip_tunnel_ioctl(dev, &p, cmd);
	324	if (err)
	325	return err;
1181412c	326
b9959fd3	327	if (cmd != SIOCDELTUNNEL) {
df3893c1	328	p.i_flags \|= GRE_KEY;
b9959fd3	329	p.o_flags \|= GRE_KEY;
1181412c S	330	}
1181412c S	331
b9959fd3 AW	332	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
b9959fd3 AW	333	return -EFAULT;
1181412c S	334	return 0;
	335	}
	336
	337	static const struct net_device_ops vti_netdev_ops = {
	338	.ndo_init = vti_tunnel_init,
b9959fd3	339	.ndo_uninit = ip_tunnel_uninit,
1181412c S	340	.ndo_start_xmit = vti_tunnel_xmit,
1181412c S	341	.ndo_do_ioctl = vti_tunnel_ioctl,
b9959fd3	342	.ndo_change_mtu = ip_tunnel_change_mtu,
f61dd388	343	.ndo_get_stats64 = ip_tunnel_get_stats64,
1181412c S	344	};
1181412c S	345
b9959fd3	346	static void vti_tunnel_setup(struct net_device *dev)
1181412c	347	{
b9959fd3	348	dev->netdev_ops = &vti_netdev_ops;
8d89dcdf	349	dev->type = ARPHRD_TUNNEL;
b9959fd3	350	ip_tunnel_setup(dev, vti_net_id);
1181412c S	351	}
1181412c S	352
b9959fd3	353	static int vti_tunnel_init(struct net_device *dev)
1181412c	354	{
b9959fd3 AW	355	struct ip_tunnel *tunnel = netdev_priv(dev);
	356	struct iphdr *iph = &tunnel->parms.iph;
	357
	358	memcpy(dev->dev_addr, &iph->saddr, 4);
	359	memcpy(dev->broadcast, &iph->daddr, 4);
1181412c	360
1181412c S	361	dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
	362	dev->mtu = ETH_DATA_LEN;
	363	dev->flags = IFF_NOARP;
	364	dev->iflink = 0;
	365	dev->addr_len = 4;
1181412c	366	dev->features \|= NETIF_F_LLTX;
02875878	367	netif_keep_dst(dev);
1181412c	368
b9959fd3	369	return ip_tunnel_init(dev);
1181412c S	370	}
1181412c S	371
b9959fd3	372	static void __net_init vti_fb_tunnel_init(struct net_device *dev)
1181412c S	373	{
	374	struct ip_tunnel *tunnel = netdev_priv(dev);
	375	struct iphdr *iph = &tunnel->parms.iph;
1181412c	376
1181412c S	377	iph->version = 4;
	378	iph->protocol = IPPROTO_IPIP;
	379	iph->ihl = 5;
1181412c S	380	}
1181412c S	381
df3893c1	382	static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
1181412c	383	.handler = vti_rcv,
df3893c1 SK	384	.input_handler = vti_input,
	385	.cb_handler = vti_rcv_cb,
	386	.err_handler = vti4_err,
	387	.priority = 100,
	388	};
	389
	390	static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
	391	.handler = vti_rcv,
	392	.input_handler = vti_input,
	393	.cb_handler = vti_rcv_cb,
	394	.err_handler = vti4_err,
	395	.priority = 100,
	396	};
	397
	398	static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
	399	.handler = vti_rcv,
	400	.input_handler = vti_input,
	401	.cb_handler = vti_rcv_cb,
	402	.err_handler = vti4_err,
	403	.priority = 100,
1181412c S	404	};
1181412c S	405
1181412c S	406	static int __net_init vti_init_net(struct net *net)
	407	{
	408	int err;
b9959fd3	409	struct ip_tunnel_net *itn;
1181412c	410
b9959fd3	411	err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
1181412c	412	if (err)
b9959fd3 AW	413	return err;
	414	itn = net_generic(net, vti_net_id);
	415	vti_fb_tunnel_init(itn->fb_tunnel_dev);
1181412c	416	return 0;
1181412c S	417	}
	418
	419	static void __net_exit vti_exit_net(struct net *net)
	420	{
b9959fd3	421	struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
6c742e71	422	ip_tunnel_delete_net(itn, &vti_link_ops);
1181412c S	423	}
	424
	425	static struct pernet_operations vti_net_ops = {
	426	.init = vti_init_net,
	427	.exit = vti_exit_net,
	428	.id = &vti_net_id,
b9959fd3	429	.size = sizeof(struct ip_tunnel_net),
1181412c S	430	};
	431
	432	static int vti_tunnel_validate(struct nlattr tb[], struct nlattr data[])
	433	{
	434	return 0;
	435	}
	436
	437	static void vti_netlink_parms(struct nlattr *data[],
	438	struct ip_tunnel_parm *parms)
	439	{
	440	memset(parms, 0, sizeof(*parms));
	441
	442	parms->iph.protocol = IPPROTO_IPIP;
	443
	444	if (!data)
	445	return;
	446
df3893c1 SK	447	parms->i_flags = VTI_ISVTI;
df3893c1 SK	448
1181412c S	449	if (data[IFLA_VTI_LINK])
	450	parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
	451
	452	if (data[IFLA_VTI_IKEY])
	453	parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
	454
	455	if (data[IFLA_VTI_OKEY])
	456	parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
	457
	458	if (data[IFLA_VTI_LOCAL])
67b61f6c	459	parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
1181412c S	460
1181412c S	461	if (data[IFLA_VTI_REMOTE])
67b61f6c	462	parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
1181412c S	463
	464	}
	465
	466	static int vti_newlink(struct net src_net, struct net_device dev,
	467	struct nlattr tb[], struct nlattr data[])
	468	{
b9959fd3	469	struct ip_tunnel_parm parms;
1181412c	470
b9959fd3 AW	471	vti_netlink_parms(data, &parms);
b9959fd3 AW	472	return ip_tunnel_newlink(dev, tb, &parms);
1181412c S	473	}
	474
	475	static int vti_changelink(struct net_device dev, struct nlattr tb[],
	476	struct nlattr *data[])
	477	{
1181412c	478	struct ip_tunnel_parm p;
1181412c	479
1181412c	480	vti_netlink_parms(data, &p);
b9959fd3	481	return ip_tunnel_changelink(dev, tb, &p);
1181412c S	482	}
	483
	484	static size_t vti_get_size(const struct net_device *dev)
	485	{
	486	return
	487	/* IFLA_VTI_LINK */
	488	nla_total_size(4) +
	489	/* IFLA_VTI_IKEY */
	490	nla_total_size(4) +
	491	/* IFLA_VTI_OKEY */
	492	nla_total_size(4) +
	493	/* IFLA_VTI_LOCAL */
	494	nla_total_size(4) +
	495	/* IFLA_VTI_REMOTE */
	496	nla_total_size(4) +
	497	0;
	498	}
	499
	500	static int vti_fill_info(struct sk_buff skb, const struct net_device dev)
	501	{
	502	struct ip_tunnel *t = netdev_priv(dev);
	503	struct ip_tunnel_parm *p = &t->parms;
	504
	505	nla_put_u32(skb, IFLA_VTI_LINK, p->link);
	506	nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key);
	507	nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key);
930345ea JB	508	nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr);
930345ea JB	509	nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr);
1181412c S	510
	511	return 0;
	512	}
	513
	514	static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
	515	[IFLA_VTI_LINK] = { .type = NLA_U32 },
	516	[IFLA_VTI_IKEY] = { .type = NLA_U32 },
	517	[IFLA_VTI_OKEY] = { .type = NLA_U32 },
	518	[IFLA_VTI_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
	519	[IFLA_VTI_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
	520	};
	521
	522	static struct rtnl_link_ops vti_link_ops __read_mostly = {
	523	.kind = "vti",
	524	.maxtype = IFLA_VTI_MAX,
	525	.policy = vti_policy,
	526	.priv_size = sizeof(struct ip_tunnel),
	527	.setup = vti_tunnel_setup,
	528	.validate = vti_tunnel_validate,
	529	.newlink = vti_newlink,
	530	.changelink = vti_changelink,
20ea60ca	531	.dellink = ip_tunnel_dellink,
1181412c S	532	.get_size = vti_get_size,
1181412c S	533	.fill_info = vti_fill_info,
1728d4fa	534	.get_link_net = ip_tunnel_get_link_net,
1181412c S	535	};
	536
	537	static int __init vti_init(void)
	538	{
1990e4f8	539	const char *msg;
1181412c S	540	int err;
1181412c S	541
1990e4f8	542	pr_info("IPv4 over IPsec tunneling driver\n");
1181412c	543
1990e4f8	544	msg = "tunnel device";
1181412c S	545	err = register_pernet_device(&vti_net_ops);
1181412c S	546	if (err < 0)
1990e4f8	547	goto pernet_dev_failed;
df3893c1	548
1990e4f8 MK	549	msg = "tunnel protocols";
	550	err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
	551	if (err < 0)
	552	goto xfrm_proto_esp_failed;
df3893c1	553	err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
1990e4f8 MK	554	if (err < 0)
1990e4f8 MK	555	goto xfrm_proto_ah_failed;
df3893c1	556	err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
1990e4f8 MK	557	if (err < 0)
1990e4f8 MK	558	goto xfrm_proto_comp_failed;
1181412c	559
1990e4f8	560	msg = "netlink interface";
1181412c S	561	err = rtnl_link_register(&vti_link_ops);
	562	if (err < 0)
	563	goto rtnl_link_failed;
	564
	565	return err;
	566
	567	rtnl_link_failed:
df3893c1	568	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
1990e4f8	569	xfrm_proto_comp_failed:
df3893c1	570	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
1990e4f8	571	xfrm_proto_ah_failed:
df3893c1	572	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
1990e4f8	573	xfrm_proto_esp_failed:
1181412c	574	unregister_pernet_device(&vti_net_ops);
1990e4f8 MK	575	pernet_dev_failed:
1990e4f8 MK	576	pr_err("vti init: failed to register %s\n", msg);
1181412c S	577	return err;
	578	}
	579
	580	static void __exit vti_fini(void)
	581	{
	582	rtnl_link_unregister(&vti_link_ops);
1990e4f8 MK	583	xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
	584	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
	585	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
1181412c S	586	unregister_pernet_device(&vti_net_ops);
	587	}
	588
	589	module_init(vti_init);
	590	module_exit(vti_fini);
	591	MODULE_LICENSE("GPL");
	592	MODULE_ALIAS_RTNL_LINK("vti");
	593	MODULE_ALIAS_NETDEV("ip_vti0");