[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/module.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"

static struct vport_ops ovs_gre_vport_ops;

/* 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)
{
	struct tnl_ptk_info tpi;
	const struct ovs_key_ipv4_tunnel *tun_key;

	tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;

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

	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_tunnel_info tun_info;
	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_info_init(&tun_info, ip_hdr(skb), 0, 0, key,
			       filter_tnl_flags(tpi->flags), NULL, 0);

	ovs_vport_receive(vport, skb, &tun_info);
	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_info)) {
		err = -EINVAL;
		goto err_free_skb;
	}

	tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
	/* 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)) {
		err = PTR_ERR(rt);
		goto err_free_skb;
	}

	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)
			+ (skb_vlan_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;
	}

	skb = vlan_hwaccel_push_inside(skb);
	if (unlikely(!skb)) {
		err = -ENOMEM;
		goto err_free_rt;
	}

	/* Push Tunnel header. */
	skb = __build_header(skb, tunnel_hlen);
	if (IS_ERR(skb)) {
		err = PTR_ERR(skb);
		skb = NULL;
		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);
err_free_skb:
	kfree_skb(skb);
	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();
}

static int gre_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
				   struct ovs_tunnel_info *egress_tun_info)
{
	return ovs_tunnel_get_egress_info(egress_tun_info,
					  ovs_dp_get_net(vport->dp),
					  OVS_CB(skb)->egress_tun_info,
					  IPPROTO_GRE, skb->mark, 0, 0);
}

static 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,
	.get_egress_tun_info	= gre_get_egress_tun_info,
	.owner		= THIS_MODULE,
};

static int __init ovs_gre_tnl_init(void)
{
	return ovs_vport_ops_register(&ovs_gre_vport_ops);
}

static void __exit ovs_gre_tnl_exit(void)
{
	ovs_vport_ops_unregister(&ovs_gre_vport_ops);
}

module_init(ovs_gre_tnl_init);
module_exit(ovs_gre_tnl_exit);

MODULE_DESCRIPTION("OVS: GRE switching port");
MODULE_LICENSE("GPL");
MODULE_ALIAS("vport-type-3");
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>
62b9c8d0	32	#include <linux/module.h>
aa310701 PS	33	#include <linux/workqueue.h>
	34	#include <linux/rculist.h>
	35	#include <net/route.h>
	36	#include <net/xfrm.h>
	37
	38	#include <net/icmp.h>
	39	#include <net/ip.h>
	40	#include <net/ip_tunnels.h>
	41	#include <net/gre.h>
	42	#include <net/net_namespace.h>
	43	#include <net/netns/generic.h>
	44	#include <net/protocol.h>
	45
	46	#include "datapath.h"
	47	#include "vport.h"
	48
62b9c8d0 TG	49	static struct vport_ops ovs_gre_vport_ops;
62b9c8d0 TG	50
aa310701 PS	51	/* Returns the least-significant 32 bits of a __be64. */
	52	static __be32 be64_get_low32(__be64 x)
	53	{
	54	#ifdef __BIG_ENDIAN
	55	return (__force __be32)x;
	56	#else
	57	return (__force __be32)((__force u64)x >> 32);
	58	#endif
	59	}
	60
	61	static __be16 filter_tnl_flags(__be16 flags)
	62	{
	63	return flags & (TUNNEL_CSUM \| TUNNEL_KEY);
	64	}
	65
	66	static struct sk_buff __build_header(struct sk_buff skb,
	67	int tunnel_hlen)
	68	{
aa310701	69	struct tnl_ptk_info tpi;
f0b128c1 JG	70	const struct ovs_key_ipv4_tunnel *tun_key;
	71
	72	tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
aa310701 PS	73
	74	skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM));
	75	if (IS_ERR(skb))
997e068e	76	return skb;
aa310701 PS	77
	78	tpi.flags = filter_tnl_flags(tun_key->tun_flags);
	79	tpi.proto = htons(ETH_P_TEB);
	80	tpi.key = be64_get_low32(tun_key->tun_id);
	81	tpi.seq = 0;
	82	gre_build_header(skb, &tpi, tunnel_hlen);
	83
	84	return skb;
	85	}
	86
	87	static __be64 key_to_tunnel_id(__be32 key, __be32 seq)
	88	{
	89	#ifdef __BIG_ENDIAN
	90	return (__force __be64)((__force u64)seq << 32 \| (__force u32)key);
	91	#else
	92	return (__force __be64)((__force u64)key << 32 \| (__force u32)seq);
	93	#endif
	94	}
	95
	96	/* Called with rcu_read_lock and BH disabled. */
	97	static int gre_rcv(struct sk_buff *skb,
	98	const struct tnl_ptk_info *tpi)
	99	{
f0b128c1	100	struct ovs_tunnel_info tun_info;
aa310701 PS	101	struct ovs_net *ovs_net;
	102	struct vport *vport;
	103	__be64 key;
	104
	105	ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
	106	vport = rcu_dereference(ovs_net->vport_net.gre_vport);
	107	if (unlikely(!vport))
	108	return PACKET_REJECT;
	109
	110	key = key_to_tunnel_id(tpi->key, tpi->seq);
8f0aad6f	111	ovs_flow_tun_info_init(&tun_info, ip_hdr(skb), 0, 0, key,
f5796684	112	filter_tnl_flags(tpi->flags), NULL, 0);
aa310701	113
f0b128c1	114	ovs_vport_receive(vport, skb, &tun_info);
aa310701 PS	115	return PACKET_RCVD;
	116	}
	117
e0bb8c44 WZ	118	/* Called with rcu_read_lock and BH disabled. */
	119	static int gre_err(struct sk_buff *skb, u32 info,
	120	const struct tnl_ptk_info *tpi)
	121	{
	122	struct ovs_net *ovs_net;
	123	struct vport *vport;
	124
	125	ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
	126	vport = rcu_dereference(ovs_net->vport_net.gre_vport);
	127
	128	if (unlikely(!vport))
	129	return PACKET_REJECT;
	130	else
	131	return PACKET_RCVD;
	132	}
	133
aa310701 PS	134	static int gre_tnl_send(struct vport vport, struct sk_buff skb)
	135	{
	136	struct net *net = ovs_dp_get_net(vport->dp);
8c8b1b83	137	struct ovs_key_ipv4_tunnel *tun_key;
aa310701 PS	138	struct flowi4 fl;
	139	struct rtable *rt;
	140	int min_headroom;
	141	int tunnel_hlen;
	142	__be16 df;
	143	int err;
	144
f0b128c1	145	if (unlikely(!OVS_CB(skb)->egress_tun_info)) {
aa310701	146	err = -EINVAL;
997e068e	147	goto err_free_skb;
aa310701 PS	148	}
aa310701 PS	149
f0b128c1	150	tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
aa310701 PS	151	/* Route lookup */
aa310701 PS	152	memset(&fl, 0, sizeof(fl));
8c8b1b83 PS	153	fl.daddr = tun_key->ipv4_dst;
	154	fl.saddr = tun_key->ipv4_src;
	155	fl.flowi4_tos = RT_TOS(tun_key->ipv4_tos);
aa310701 PS	156	fl.flowi4_mark = skb->mark;
	157	fl.flowi4_proto = IPPROTO_GRE;
	158
	159	rt = ip_route_output_key(net, &fl);
997e068e PS	160	if (IS_ERR(rt)) {
	161	err = PTR_ERR(rt);
	162	goto err_free_skb;
	163	}
aa310701	164
8c8b1b83	165	tunnel_hlen = ip_gre_calc_hlen(tun_key->tun_flags);
aa310701 PS	166
	167	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
	168	+ tunnel_hlen + sizeof(struct iphdr)
df8a39de	169	+ (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
aa310701 PS	170	if (skb_headroom(skb) < min_headroom \|\| skb_header_cloned(skb)) {
	171	int head_delta = SKB_DATA_ALIGN(min_headroom -
	172	skb_headroom(skb) +
	173	16);
	174	err = pskb_expand_head(skb, max_t(int, head_delta, 0),
	175	0, GFP_ATOMIC);
	176	if (unlikely(err))
	177	goto err_free_rt;
	178	}
	179
5968250c JP	180	skb = vlan_hwaccel_push_inside(skb);
	181	if (unlikely(!skb)) {
	182	err = -ENOMEM;
	183	goto err_free_rt;
aa310701 PS	184	}
	185
	186	/* Push Tunnel header. */
	187	skb = __build_header(skb, tunnel_hlen);
997e068e	188	if (IS_ERR(skb)) {
4aa61188	189	err = PTR_ERR(skb);
997e068e	190	skb = NULL;
aa310701 PS	191	goto err_free_rt;
	192	}
	193
8c8b1b83	194	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
aa310701 PS	195	htons(IP_DF) : 0;
aa310701 PS	196
60ff7467	197	skb->ignore_df = 1;
aa310701	198
aad88724	199	return iptunnel_xmit(skb->sk, rt, skb, fl.saddr,
8c8b1b83 PS	200	tun_key->ipv4_dst, IPPROTO_GRE,
8c8b1b83 PS	201	tun_key->ipv4_tos, tun_key->ipv4_ttl, df, false);
aa310701 PS	202	err_free_rt:
aa310701 PS	203	ip_rt_put(rt);
997e068e PS	204	err_free_skb:
997e068e PS	205	kfree_skb(skb);
aa310701 PS	206	return err;
	207	}
	208
	209	static struct gre_cisco_protocol gre_protocol = {
	210	.handler = gre_rcv,
e0bb8c44	211	.err_handler = gre_err,
aa310701 PS	212	.priority = 1,
	213	};
	214
	215	static int gre_ports;
	216	static int gre_init(void)
	217	{
	218	int err;
	219
	220	gre_ports++;
	221	if (gre_ports > 1)
	222	return 0;
	223
	224	err = gre_cisco_register(&gre_protocol);
	225	if (err)
	226	pr_warn("cannot register gre protocol handler\n");
	227
	228	return err;
	229	}
	230
	231	static void gre_exit(void)
	232	{
	233	gre_ports--;
	234	if (gre_ports > 0)
	235	return;
	236
	237	gre_cisco_unregister(&gre_protocol);
	238	}
	239
	240	static const char gre_get_name(const struct vport vport)
	241	{
	242	return vport_priv(vport);
	243	}
	244
	245	static struct vport gre_create(const struct vport_parms parms)
	246	{
	247	struct net *net = ovs_dp_get_net(parms->dp);
	248	struct ovs_net *ovs_net;
	249	struct vport *vport;
	250	int err;
	251
	252	err = gre_init();
	253	if (err)
	254	return ERR_PTR(err);
	255
	256	ovs_net = net_generic(net, ovs_net_id);
	257	if (ovsl_dereference(ovs_net->vport_net.gre_vport)) {
	258	vport = ERR_PTR(-EEXIST);
	259	goto error;
	260	}
	261
	262	vport = ovs_vport_alloc(IFNAMSIZ, &ovs_gre_vport_ops, parms);
	263	if (IS_ERR(vport))
	264	goto error;
	265
	266	strncpy(vport_priv(vport), parms->name, IFNAMSIZ);
	267	rcu_assign_pointer(ovs_net->vport_net.gre_vport, vport);
	268	return vport;
	269
	270	error:
	271	gre_exit();
	272	return vport;
	273	}
	274
	275	static void gre_tnl_destroy(struct vport *vport)
276	{
277	struct net *net = ovs_dp_get_net(vport->dp);
278	struct ovs_net *ovs_net;
279
280	ovs_net = net_generic(net, ovs_net_id);
281
944df8ae	282	RCU_INIT_POINTER(ovs_net->vport_net.gre_vport, NULL);
aa310701 PS	283	ovs_vport_deferred_free(vport);
	284	gre_exit();
	285	}
	286
8f0aad6f WZ	287	static int gre_get_egress_tun_info(struct vport vport, struct sk_buff skb,
	288	struct ovs_tunnel_info *egress_tun_info)
	289	{
	290	return ovs_tunnel_get_egress_info(egress_tun_info,
	291	ovs_dp_get_net(vport->dp),
	292	OVS_CB(skb)->egress_tun_info,
	293	IPPROTO_GRE, skb->mark, 0, 0);
	294	}
	295
62b9c8d0	296	static struct vport_ops ovs_gre_vport_ops = {
aa310701 PS	297	.type = OVS_VPORT_TYPE_GRE,
	298	.create = gre_create,
	299	.destroy = gre_tnl_destroy,
	300	.get_name = gre_get_name,
	301	.send = gre_tnl_send,
8f0aad6f	302	.get_egress_tun_info = gre_get_egress_tun_info,
62b9c8d0	303	.owner = THIS_MODULE,
aa310701	304	};
62b9c8d0 TG	305
	306	static int __init ovs_gre_tnl_init(void)
	307	{
	308	return ovs_vport_ops_register(&ovs_gre_vport_ops);
	309	}
	310
	311	static void __exit ovs_gre_tnl_exit(void)
	312	{
	313	ovs_vport_ops_unregister(&ovs_gre_vport_ops);
	314	}
	315
	316	module_init(ovs_gre_tnl_init);
	317	module_exit(ovs_gre_tnl_exit);
	318
	319	MODULE_DESCRIPTION("OVS: GRE switching port");
	320	MODULE_LICENSE("GPL");
	321	MODULE_ALIAS("vport-type-3");