[deliverable/linux.git] / net / openvswitch / vport-gre.c

/*
 * Copyright (c) 2007-2014 Nicira, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/if.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/if_tunnel.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <linux/in_route.h>
#include <linux/inetdevice.h>
#include <linux/jhash.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/workqueue.h>
#include <linux/rculist.h>
#include <net/route.h>
#include <net/xfrm.h>

#include <net/icmp.h>
#include <net/ip.h>
#include <net/ip_tunnels.h>
#include <net/gre.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/protocol.h>

#include "datapath.h"
#include "vport.h"

/* Returns the least-significant 32 bits of a __be64. */
static __be32 be64_get_low32(__be64 x)
{
#ifdef __BIG_ENDIAN
	return (__force __be32)x;
#else
	return (__force __be32)((__force u64)x >> 32);
#endif
}

static __be16 filter_tnl_flags(__be16 flags)
{
	return flags & (TUNNEL_CSUM | TUNNEL_KEY);
}

static struct sk_buff *__build_header(struct sk_buff *skb,
				      int tunnel_hlen)
{
	const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->egress_tun_key;
	struct tnl_ptk_info tpi;

	skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM));
	if (IS_ERR(skb))
		return NULL;

	tpi.flags = filter_tnl_flags(tun_key->tun_flags);
	tpi.proto = htons(ETH_P_TEB);
	tpi.key = be64_get_low32(tun_key->tun_id);
	tpi.seq = 0;
	gre_build_header(skb, &tpi, tunnel_hlen);

	return skb;
}

static __be64 key_to_tunnel_id(__be32 key, __be32 seq)
{
#ifdef __BIG_ENDIAN
	return (__force __be64)((__force u64)seq << 32 | (__force u32)key);
#else
	return (__force __be64)((__force u64)key << 32 | (__force u32)seq);
#endif
}

/* Called with rcu_read_lock and BH disabled. */
static int gre_rcv(struct sk_buff *skb,
		   const struct tnl_ptk_info *tpi)
{
	struct ovs_key_ipv4_tunnel tun_key;
	struct ovs_net *ovs_net;
	struct vport *vport;
	__be64 key;

	ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
	vport = rcu_dereference(ovs_net->vport_net.gre_vport);
	if (unlikely(!vport))
		return PACKET_REJECT;

	key = key_to_tunnel_id(tpi->key, tpi->seq);
	ovs_flow_tun_key_init(&tun_key, ip_hdr(skb), key,
			      filter_tnl_flags(tpi->flags));

	ovs_vport_receive(vport, skb, &tun_key);
	return PACKET_RCVD;
}

/* Called with rcu_read_lock and BH disabled. */
static int gre_err(struct sk_buff *skb, u32 info,
		   const struct tnl_ptk_info *tpi)
{
	struct ovs_net *ovs_net;
	struct vport *vport;

	ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
	vport = rcu_dereference(ovs_net->vport_net.gre_vport);

	if (unlikely(!vport))
		return PACKET_REJECT;
	else
		return PACKET_RCVD;
}

static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
{
	struct net *net = ovs_dp_get_net(vport->dp);
	struct ovs_key_ipv4_tunnel *tun_key;
	struct flowi4 fl;
	struct rtable *rt;
	int min_headroom;
	int tunnel_hlen;
	__be16 df;
	int err;

	if (unlikely(!OVS_CB(skb)->egress_tun_key)) {
		err = -EINVAL;
		goto error;
	}

	tun_key = OVS_CB(skb)->egress_tun_key;
	/* Route lookup */
	memset(&fl, 0, sizeof(fl));
	fl.daddr = tun_key->ipv4_dst;
	fl.saddr = tun_key->ipv4_src;
	fl.flowi4_tos = RT_TOS(tun_key->ipv4_tos);
	fl.flowi4_mark = skb->mark;
	fl.flowi4_proto = IPPROTO_GRE;

	rt = ip_route_output_key(net, &fl);
	if (IS_ERR(rt))
		return PTR_ERR(rt);

	tunnel_hlen = ip_gre_calc_hlen(tun_key->tun_flags);

	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
			+ tunnel_hlen + sizeof(struct iphdr)
			+ (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
	if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
		int head_delta = SKB_DATA_ALIGN(min_headroom -
						skb_headroom(skb) +
						16);
		err = pskb_expand_head(skb, max_t(int, head_delta, 0),
					0, GFP_ATOMIC);
		if (unlikely(err))
			goto err_free_rt;
	}

	if (vlan_tx_tag_present(skb)) {
		if (unlikely(!__vlan_put_tag(skb,
					     skb->vlan_proto,
					     vlan_tx_tag_get(skb)))) {
			err = -ENOMEM;
			goto err_free_rt;
		}
		skb->vlan_tci = 0;
	}

	/* Push Tunnel header. */
	skb = __build_header(skb, tunnel_hlen);
	if (unlikely(!skb)) {
		err = 0;
		goto err_free_rt;
	}

	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
		htons(IP_DF) : 0;

	skb->ignore_df = 1;

	return iptunnel_xmit(skb->sk, rt, skb, fl.saddr,
			     tun_key->ipv4_dst, IPPROTO_GRE,
			     tun_key->ipv4_tos, tun_key->ipv4_ttl, df, false);
err_free_rt:
	ip_rt_put(rt);
error:
	return err;
}

static struct gre_cisco_protocol gre_protocol = {
	.handler        = gre_rcv,
	.err_handler    = gre_err,
	.priority       = 1,
};

static int gre_ports;
static int gre_init(void)
{
	int err;

	gre_ports++;
	if (gre_ports > 1)
		return 0;

	err = gre_cisco_register(&gre_protocol);
	if (err)
		pr_warn("cannot register gre protocol handler\n");

	return err;
}

static void gre_exit(void)
{
	gre_ports--;
	if (gre_ports > 0)
		return;

	gre_cisco_unregister(&gre_protocol);
}

static const char *gre_get_name(const struct vport *vport)
{
	return vport_priv(vport);
}

static struct vport *gre_create(const struct vport_parms *parms)
{
	struct net *net = ovs_dp_get_net(parms->dp);
	struct ovs_net *ovs_net;
	struct vport *vport;
	int err;

	err = gre_init();
	if (err)
		return ERR_PTR(err);

	ovs_net = net_generic(net, ovs_net_id);
	if (ovsl_dereference(ovs_net->vport_net.gre_vport)) {
		vport = ERR_PTR(-EEXIST);
		goto error;
	}

	vport = ovs_vport_alloc(IFNAMSIZ, &ovs_gre_vport_ops, parms);
	if (IS_ERR(vport))
		goto error;

	strncpy(vport_priv(vport), parms->name, IFNAMSIZ);
	rcu_assign_pointer(ovs_net->vport_net.gre_vport, vport);
	return vport;

error:
	gre_exit();
	return vport;
}

static void gre_tnl_destroy(struct vport *vport)
{
	struct net *net = ovs_dp_get_net(vport->dp);
	struct ovs_net *ovs_net;

	ovs_net = net_generic(net, ovs_net_id);

	RCU_INIT_POINTER(ovs_net->vport_net.gre_vport, NULL);
	ovs_vport_deferred_free(vport);
	gre_exit();
}

const struct vport_ops ovs_gre_vport_ops = {
	.type		= OVS_VPORT_TYPE_GRE,
	.create		= gre_create,
	.destroy	= gre_tnl_destroy,
	.get_name	= gre_get_name,
	.send		= gre_tnl_send,
};
Commit	Line	Data
aa310701	1	/*
8c8b1b83	2	* Copyright (c) 2007-2014 Nicira, Inc.
aa310701 PS	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of version 2 of the GNU General Public
	6	* License as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public License
	14	* along with this program; if not, write to the Free Software
	15	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	16	* 02110-1301, USA
	17	*/
	18
aa310701 PS	19	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	20
	21	#include <linux/if.h>
	22	#include <linux/skbuff.h>
	23	#include <linux/ip.h>
	24	#include <linux/if_tunnel.h>
	25	#include <linux/if_vlan.h>
	26	#include <linux/in.h>
aa310701 PS	27	#include <linux/in_route.h>
	28	#include <linux/inetdevice.h>
	29	#include <linux/jhash.h>
	30	#include <linux/list.h>
	31	#include <linux/kernel.h>
	32	#include <linux/workqueue.h>
	33	#include <linux/rculist.h>
	34	#include <net/route.h>
	35	#include <net/xfrm.h>
	36
	37	#include <net/icmp.h>
	38	#include <net/ip.h>
	39	#include <net/ip_tunnels.h>
	40	#include <net/gre.h>
	41	#include <net/net_namespace.h>
	42	#include <net/netns/generic.h>
	43	#include <net/protocol.h>
	44
	45	#include "datapath.h"
	46	#include "vport.h"
	47
	48	/* Returns the least-significant 32 bits of a __be64. */
	49	static __be32 be64_get_low32(__be64 x)
	50	{
	51	#ifdef __BIG_ENDIAN
	52	return (__force __be32)x;
	53	#else
	54	return (__force __be32)((__force u64)x >> 32);
	55	#endif
	56	}
	57
	58	static __be16 filter_tnl_flags(__be16 flags)
	59	{
	60	return flags & (TUNNEL_CSUM \| TUNNEL_KEY);
	61	}
	62
	63	static struct sk_buff __build_header(struct sk_buff skb,
	64	int tunnel_hlen)
	65	{
8c8b1b83	66	const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->egress_tun_key;
aa310701 PS	67	struct tnl_ptk_info tpi;
	68
	69	skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM));
	70	if (IS_ERR(skb))
	71	return NULL;
	72
	73	tpi.flags = filter_tnl_flags(tun_key->tun_flags);
	74	tpi.proto = htons(ETH_P_TEB);
	75	tpi.key = be64_get_low32(tun_key->tun_id);
	76	tpi.seq = 0;
	77	gre_build_header(skb, &tpi, tunnel_hlen);
	78
	79	return skb;
	80	}
	81
	82	static __be64 key_to_tunnel_id(__be32 key, __be32 seq)
	83	{
	84	#ifdef __BIG_ENDIAN
	85	return (__force __be64)((__force u64)seq << 32 \| (__force u32)key);
	86	#else
	87	return (__force __be64)((__force u64)key << 32 \| (__force u32)seq);
	88	#endif
	89	}
	90
	91	/* Called with rcu_read_lock and BH disabled. */
	92	static int gre_rcv(struct sk_buff *skb,
	93	const struct tnl_ptk_info *tpi)
	94	{
	95	struct ovs_key_ipv4_tunnel tun_key;
	96	struct ovs_net *ovs_net;
	97	struct vport *vport;
	98	__be64 key;
	99
	100	ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
	101	vport = rcu_dereference(ovs_net->vport_net.gre_vport);
	102	if (unlikely(!vport))
	103	return PACKET_REJECT;
	104
	105	key = key_to_tunnel_id(tpi->key, tpi->seq);
	106	ovs_flow_tun_key_init(&tun_key, ip_hdr(skb), key,
	107	filter_tnl_flags(tpi->flags));
	108
	109	ovs_vport_receive(vport, skb, &tun_key);
	110	return PACKET_RCVD;
	111	}
	112
e0bb8c44 WZ	113	/* Called with rcu_read_lock and BH disabled. */
	114	static int gre_err(struct sk_buff *skb, u32 info,
	115	const struct tnl_ptk_info *tpi)
	116	{
	117	struct ovs_net *ovs_net;
	118	struct vport *vport;
	119
	120	ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
	121	vport = rcu_dereference(ovs_net->vport_net.gre_vport);
	122
	123	if (unlikely(!vport))
	124	return PACKET_REJECT;
	125	else
	126	return PACKET_RCVD;
	127	}
	128
aa310701 PS	129	static int gre_tnl_send(struct vport vport, struct sk_buff skb)
	130	{
	131	struct net *net = ovs_dp_get_net(vport->dp);
8c8b1b83	132	struct ovs_key_ipv4_tunnel *tun_key;
aa310701 PS	133	struct flowi4 fl;
	134	struct rtable *rt;
	135	int min_headroom;
	136	int tunnel_hlen;
	137	__be16 df;
	138	int err;
	139
8c8b1b83	140	if (unlikely(!OVS_CB(skb)->egress_tun_key)) {
aa310701 PS	141	err = -EINVAL;
	142	goto error;
	143	}
	144
8c8b1b83	145	tun_key = OVS_CB(skb)->egress_tun_key;
aa310701 PS	146	/* Route lookup */
aa310701 PS	147	memset(&fl, 0, sizeof(fl));
8c8b1b83 PS	148	fl.daddr = tun_key->ipv4_dst;
	149	fl.saddr = tun_key->ipv4_src;
	150	fl.flowi4_tos = RT_TOS(tun_key->ipv4_tos);
aa310701 PS	151	fl.flowi4_mark = skb->mark;
	152	fl.flowi4_proto = IPPROTO_GRE;
	153
	154	rt = ip_route_output_key(net, &fl);
	155	if (IS_ERR(rt))
	156	return PTR_ERR(rt);
	157
8c8b1b83	158	tunnel_hlen = ip_gre_calc_hlen(tun_key->tun_flags);
aa310701 PS	159
	160	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
	161	+ tunnel_hlen + sizeof(struct iphdr)
	162	+ (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
	163	if (skb_headroom(skb) < min_headroom \|\| skb_header_cloned(skb)) {
	164	int head_delta = SKB_DATA_ALIGN(min_headroom -
	165	skb_headroom(skb) +
	166	16);
	167	err = pskb_expand_head(skb, max_t(int, head_delta, 0),
	168	0, GFP_ATOMIC);
	169	if (unlikely(err))
	170	goto err_free_rt;
	171	}
	172
	173	if (vlan_tx_tag_present(skb)) {
	174	if (unlikely(!__vlan_put_tag(skb,
	175	skb->vlan_proto,
	176	vlan_tx_tag_get(skb)))) {
	177	err = -ENOMEM;
	178	goto err_free_rt;
	179	}
	180	skb->vlan_tci = 0;
	181	}
	182
	183	/* Push Tunnel header. */
	184	skb = __build_header(skb, tunnel_hlen);
	185	if (unlikely(!skb)) {
	186	err = 0;
	187	goto err_free_rt;
	188	}
	189
8c8b1b83	190	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
aa310701 PS	191	htons(IP_DF) : 0;
aa310701 PS	192
60ff7467	193	skb->ignore_df = 1;
aa310701	194
aad88724	195	return iptunnel_xmit(skb->sk, rt, skb, fl.saddr,
8c8b1b83 PS	196	tun_key->ipv4_dst, IPPROTO_GRE,
8c8b1b83 PS	197	tun_key->ipv4_tos, tun_key->ipv4_ttl, df, false);
aa310701 PS	198	err_free_rt:
	199	ip_rt_put(rt);
	200	error:
	201	return err;
	202	}
	203
	204	static struct gre_cisco_protocol gre_protocol = {
	205	.handler = gre_rcv,
e0bb8c44	206	.err_handler = gre_err,
aa310701 PS	207	.priority = 1,
	208	};
	209
	210	static int gre_ports;
	211	static int gre_init(void)
	212	{
	213	int err;
	214
	215	gre_ports++;
	216	if (gre_ports > 1)
	217	return 0;
	218
	219	err = gre_cisco_register(&gre_protocol);
	220	if (err)
	221	pr_warn("cannot register gre protocol handler\n");
	222
	223	return err;
	224	}
	225
	226	static void gre_exit(void)
	227	{
	228	gre_ports--;
	229	if (gre_ports > 0)
	230	return;
	231
	232	gre_cisco_unregister(&gre_protocol);
	233	}
	234
	235	static const char gre_get_name(const struct vport vport)
	236	{
	237	return vport_priv(vport);
	238	}
	239
	240	static struct vport gre_create(const struct vport_parms parms)
	241	{
	242	struct net *net = ovs_dp_get_net(parms->dp);
	243	struct ovs_net *ovs_net;
	244	struct vport *vport;
	245	int err;
	246
	247	err = gre_init();
	248	if (err)
	249	return ERR_PTR(err);
	250
	251	ovs_net = net_generic(net, ovs_net_id);
	252	if (ovsl_dereference(ovs_net->vport_net.gre_vport)) {
	253	vport = ERR_PTR(-EEXIST);
	254	goto error;
	255	}
	256
	257	vport = ovs_vport_alloc(IFNAMSIZ, &ovs_gre_vport_ops, parms);
	258	if (IS_ERR(vport))
	259	goto error;
	260
	261	strncpy(vport_priv(vport), parms->name, IFNAMSIZ);
	262	rcu_assign_pointer(ovs_net->vport_net.gre_vport, vport);
	263	return vport;
	264
	265	error:
	266	gre_exit();
	267	return vport;
	268	}
	269
	270	static void gre_tnl_destroy(struct vport *vport)
271	{
272	struct net *net = ovs_dp_get_net(vport->dp);
273	struct ovs_net *ovs_net;
274
275	ovs_net = net_generic(net, ovs_net_id);
276
944df8ae	277	RCU_INIT_POINTER(ovs_net->vport_net.gre_vport, NULL);
aa310701 PS	278	ovs_vport_deferred_free(vport);
	279	gre_exit();
	280	}
	281
	282	const struct vport_ops ovs_gre_vport_ops = {
	283	.type = OVS_VPORT_TYPE_GRE,
	284	.create = gre_create,
	285	.destroy = gre_tnl_destroy,
	286	.get_name = gre_get_name,
	287	.send = gre_tnl_send,
	288	};