2 * Copyright (c) 2007-2014 Nicira, Inc.
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.
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.
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
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 #include <linux/skbuff.h>
24 #include <linux/if_tunnel.h>
25 #include <linux/if_vlan.h>
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/module.h>
33 #include <linux/workqueue.h>
34 #include <linux/rculist.h>
35 #include <net/route.h>
40 #include <net/ip_tunnels.h>
42 #include <net/net_namespace.h>
43 #include <net/netns/generic.h>
44 #include <net/protocol.h>
49 static struct vport_ops ovs_gre_vport_ops;
51 /* Returns the least-significant 32 bits of a __be64. */
52 static __be32 be64_get_low32(__be64 x)
55 return (__force __be32)x;
57 return (__force __be32)((__force u64)x >> 32);
61 static __be16 filter_tnl_flags(__be16 flags)
63 return flags & (TUNNEL_CSUM | TUNNEL_KEY);
66 static struct sk_buff *__build_header(struct sk_buff *skb,
69 struct tnl_ptk_info tpi;
70 const struct ovs_key_ipv4_tunnel *tun_key;
72 tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
74 skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM));
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);
82 gre_build_header(skb, &tpi, tunnel_hlen);
87 static __be64 key_to_tunnel_id(__be32 key, __be32 seq)
90 return (__force __be64)((__force u64)seq << 32 | (__force u32)key);
92 return (__force __be64)((__force u64)key << 32 | (__force u32)seq);
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)
100 struct ovs_tunnel_info tun_info;
101 struct ovs_net *ovs_net;
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;
110 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);
114 ovs_vport_receive(vport, skb, &tun_info);
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)
122 struct ovs_net *ovs_net;
125 ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
126 vport = rcu_dereference(ovs_net->vport_net.gre_vport);
128 if (unlikely(!vport))
129 return PACKET_REJECT;
134 static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
136 struct net *net = ovs_dp_get_net(vport->dp);
137 const struct ovs_key_ipv4_tunnel *tun_key;
145 if (unlikely(!OVS_CB(skb)->egress_tun_info)) {
150 tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
151 rt = ovs_tunnel_route_lookup(net, tun_key, skb->mark, &fl, IPPROTO_GRE);
157 tunnel_hlen = ip_gre_calc_hlen(tun_key->tun_flags);
159 min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
160 + tunnel_hlen + sizeof(struct iphdr)
161 + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
162 if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
163 int head_delta = SKB_DATA_ALIGN(min_headroom -
166 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
172 skb = vlan_hwaccel_push_inside(skb);
173 if (unlikely(!skb)) {
178 /* Push Tunnel header. */
179 skb = __build_header(skb, tunnel_hlen);
186 df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
191 return iptunnel_xmit(skb->sk, rt, skb, fl.saddr,
192 tun_key->ipv4_dst, IPPROTO_GRE,
193 tun_key->ipv4_tos, tun_key->ipv4_ttl, df, false);
201 static struct gre_cisco_protocol gre_protocol = {
203 .err_handler = gre_err,
207 static int gre_ports;
208 static int gre_init(void)
216 err = gre_cisco_register(&gre_protocol);
218 pr_warn("cannot register gre protocol handler\n");
223 static void gre_exit(void)
229 gre_cisco_unregister(&gre_protocol);
232 static const char *gre_get_name(const struct vport *vport)
234 return vport_priv(vport);
237 static struct vport *gre_create(const struct vport_parms *parms)
239 struct net *net = ovs_dp_get_net(parms->dp);
240 struct ovs_net *ovs_net;
248 ovs_net = net_generic(net, ovs_net_id);
249 if (ovsl_dereference(ovs_net->vport_net.gre_vport)) {
250 vport = ERR_PTR(-EEXIST);
254 vport = ovs_vport_alloc(IFNAMSIZ, &ovs_gre_vport_ops, parms);
258 strncpy(vport_priv(vport), parms->name, IFNAMSIZ);
259 rcu_assign_pointer(ovs_net->vport_net.gre_vport, vport);
267 static void gre_tnl_destroy(struct vport *vport)
269 struct net *net = ovs_dp_get_net(vport->dp);
270 struct ovs_net *ovs_net;
272 ovs_net = net_generic(net, ovs_net_id);
274 RCU_INIT_POINTER(ovs_net->vport_net.gre_vport, NULL);
275 ovs_vport_deferred_free(vport);
279 static int gre_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
280 struct ovs_tunnel_info *egress_tun_info)
282 return ovs_tunnel_get_egress_info(egress_tun_info,
283 ovs_dp_get_net(vport->dp),
284 OVS_CB(skb)->egress_tun_info,
285 IPPROTO_GRE, skb->mark, 0, 0);
288 static struct vport_ops ovs_gre_vport_ops = {
289 .type = OVS_VPORT_TYPE_GRE,
290 .create = gre_create,
291 .destroy = gre_tnl_destroy,
292 .get_name = gre_get_name,
293 .send = gre_tnl_send,
294 .get_egress_tun_info = gre_get_egress_tun_info,
295 .owner = THIS_MODULE,
298 static int __init ovs_gre_tnl_init(void)
300 return ovs_vport_ops_register(&ovs_gre_vport_ops);
303 static void __exit ovs_gre_tnl_exit(void)
305 ovs_vport_ops_unregister(&ovs_gre_vport_ops);
308 module_init(ovs_gre_tnl_init);
309 module_exit(ovs_gre_tnl_exit);
311 MODULE_DESCRIPTION("OVS: GRE switching port");
312 MODULE_LICENSE("GPL");
313 MODULE_ALIAS("vport-type-3");