vport-gre.c 7.4 KB
Newer Older
1
/*
2
 * Copyright (c) 2007-2014 Nicira, Inc.
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
 *
 * 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>
32
#include <linux/module.h>
33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
#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"

49 50
static struct vport_ops ovs_gre_vport_ops;

51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69
/* 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;
70 71 72
	const struct ovs_key_ipv4_tunnel *tun_key;

	tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

	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)
{
100
	struct ovs_tunnel_info tun_info;
101 102 103 104 105 106 107 108 109 110
	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);
111
	ovs_flow_tun_info_init(&tun_info, ip_hdr(skb), 0, 0, key,
112
			       filter_tnl_flags(tpi->flags), NULL, 0);
113

114
	ovs_vport_receive(vport, skb, &tun_info);
115 116 117
	return PACKET_RCVD;
}

118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133
/* 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;
}

134 135 136
static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
{
	struct net *net = ovs_dp_get_net(vport->dp);
137
	struct ovs_key_ipv4_tunnel *tun_key;
138 139 140 141 142 143 144
	struct flowi4 fl;
	struct rtable *rt;
	int min_headroom;
	int tunnel_hlen;
	__be16 df;
	int err;

145
	if (unlikely(!OVS_CB(skb)->egress_tun_info)) {
146 147 148 149
		err = -EINVAL;
		goto error;
	}

150
	tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
151 152
	/* Route lookup */
	memset(&fl, 0, sizeof(fl));
153 154 155
	fl.daddr = tun_key->ipv4_dst;
	fl.saddr = tun_key->ipv4_src;
	fl.flowi4_tos = RT_TOS(tun_key->ipv4_tos);
156 157 158 159 160 161 162
	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);

163
	tunnel_hlen = ip_gre_calc_hlen(tun_key->tun_flags);
164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194

	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;
	}

195
	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
196 197
		htons(IP_DF) : 0;

W
WANG Cong 已提交
198
	skb->ignore_df = 1;
199

200
	return iptunnel_xmit(skb->sk, rt, skb, fl.saddr,
201 202
			     tun_key->ipv4_dst, IPPROTO_GRE,
			     tun_key->ipv4_tos, tun_key->ipv4_ttl, df, false);
203 204 205 206 207 208 209 210
err_free_rt:
	ip_rt_put(rt);
error:
	return err;
}

static struct gre_cisco_protocol gre_protocol = {
	.handler        = gre_rcv,
211
	.err_handler    = gre_err,
212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281
	.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);

282
	RCU_INIT_POINTER(ovs_net->vport_net.gre_vport, NULL);
283 284 285 286
	ovs_vport_deferred_free(vport);
	gre_exit();
}

287 288 289 290 291 292 293 294 295
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);
}

296
static struct vport_ops ovs_gre_vport_ops = {
297 298 299 300 301
	.type		= OVS_VPORT_TYPE_GRE,
	.create		= gre_create,
	.destroy	= gre_tnl_destroy,
	.get_name	= gre_get_name,
	.send		= gre_tnl_send,
302
	.get_egress_tun_info	= gre_get_egress_tun_info,
303
	.owner		= THIS_MODULE,
304
};
305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321

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");