1 files changed, 603 insertions, 0 deletions
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
new file mode 100644
index 00000000000..b8960f3527f
--- /dev/null
+++ b/net/ipv4/ip_vti.c
@@ -0,0 +1,603 @@
+/*
+ *	Linux NET3: IP/IP protocol decoder modified to support
+ *		    virtual tunnel interface
+ *
+ *	Authors:
+ *		Saurabh Mohan (saurabh.mohan@vyatta.com) 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;
+	dev->priv_flags		&= ~IFF_XMIT_DST_RELEASE;
+
+	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_be32(data[IFLA_VTI_LOCAL]);
+
+	if (data[IFLA_VTI_REMOTE])
+		parms->iph.daddr = nla_get_be32(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_be32(skb, IFLA_VTI_LOCAL, p->iph.saddr);
+	nla_put_be32(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,
+	.get_size	= vti_get_size,
+	.fill_info	= vti_fill_info,
+};
+
+static int __init vti_init(void)
+{
+	int err;
+
+	pr_info("IPv4 over IPSec tunneling driver\n");
+
+	err = register_pernet_device(&vti_net_ops);
+	if (err < 0)
+		return err;
+	err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
+	if (err < 0) {
+		unregister_pernet_device(&vti_net_ops);
+		pr_info("vti init: can't register tunnel\n");
+
+		return err;
+	}
+
+	err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
+	if (err < 0) {
+		xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
+		unregister_pernet_device(&vti_net_ops);
+		pr_info("vti init: can't register tunnel\n");
+
+		return err;
+	}
+
+	err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
+	if (err < 0) {
+		xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
+		xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
+		unregister_pernet_device(&vti_net_ops);
+		pr_info("vti init: can't register tunnel\n");
+
+		return err;
+	}
+
+	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);
+	xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
+	xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
+	unregister_pernet_device(&vti_net_ops);
+	return err;
+}
+
+static void __exit vti_fini(void)
+{
+	rtnl_link_unregister(&vti_link_ops);
+	if (xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP))
+		pr_info("vti close: can't deregister tunnel\n");
+	if (xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH))
+		pr_info("vti close: can't deregister tunnel\n");
+	if (xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP))
+		pr_info("vti close: can't deregister tunnel\n");
+
+
+	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");