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-rw-r--r--net/openvswitch/vport-gre.c274
1 files changed, 274 insertions, 0 deletions
diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
new file mode 100644
index 000000000000..3a8d1900aa78
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+++ b/net/openvswitch/vport-gre.c
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1/*
2 * Copyright (c) 2007-2013 Nicira, Inc.
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
19#ifdef CONFIG_NET_IPGRE_DEMUX
20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/if.h>
23#include <linux/skbuff.h>
24#include <linux/ip.h>
25#include <linux/if_tunnel.h>
26#include <linux/if_vlan.h>
27#include <linux/in.h>
28#include <linux/if_vlan.h>
29#include <linux/in.h>
30#include <linux/in_route.h>
31#include <linux/inetdevice.h>
32#include <linux/jhash.h>
33#include <linux/list.h>
34#include <linux/kernel.h>
35#include <linux/workqueue.h>
36#include <linux/rculist.h>
37#include <net/route.h>
38#include <net/xfrm.h>
39
40#include <net/icmp.h>
41#include <net/ip.h>
42#include <net/ip_tunnels.h>
43#include <net/gre.h>
44#include <net/net_namespace.h>
45#include <net/netns/generic.h>
46#include <net/protocol.h>
47
48#include "datapath.h"
49#include "vport.h"
50
51/* Returns the least-significant 32 bits of a __be64. */
52static __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
61static __be16 filter_tnl_flags(__be16 flags)
62{
63 return flags & (TUNNEL_CSUM | TUNNEL_KEY);
64}
65
66static struct sk_buff *__build_header(struct sk_buff *skb,
67 int tunnel_hlen)
68{
69 const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->tun_key;
70 struct tnl_ptk_info tpi;
71
72 skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM));
73 if (IS_ERR(skb))
74 return NULL;
75
76 tpi.flags = filter_tnl_flags(tun_key->tun_flags);
77 tpi.proto = htons(ETH_P_TEB);
78 tpi.key = be64_get_low32(tun_key->tun_id);
79 tpi.seq = 0;
80 gre_build_header(skb, &tpi, tunnel_hlen);
81
82 return skb;
83}
84
85static __be64 key_to_tunnel_id(__be32 key, __be32 seq)
86{
87#ifdef __BIG_ENDIAN
88 return (__force __be64)((__force u64)seq << 32 | (__force u32)key);
89#else
90 return (__force __be64)((__force u64)key << 32 | (__force u32)seq);
91#endif
92}
93
94/* Called with rcu_read_lock and BH disabled. */
95static int gre_rcv(struct sk_buff *skb,
96 const struct tnl_ptk_info *tpi)
97{
98 struct ovs_key_ipv4_tunnel tun_key;
99 struct ovs_net *ovs_net;
100 struct vport *vport;
101 __be64 key;
102
103 ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
104 vport = rcu_dereference(ovs_net->vport_net.gre_vport);
105 if (unlikely(!vport))
106 return PACKET_REJECT;
107
108 key = key_to_tunnel_id(tpi->key, tpi->seq);
109 ovs_flow_tun_key_init(&tun_key, ip_hdr(skb), key,
110 filter_tnl_flags(tpi->flags));
111
112 ovs_vport_receive(vport, skb, &tun_key);
113 return PACKET_RCVD;
114}
115
116static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
117{
118 struct net *net = ovs_dp_get_net(vport->dp);
119 struct flowi4 fl;
120 struct rtable *rt;
121 int min_headroom;
122 int tunnel_hlen;
123 __be16 df;
124 int err;
125
126 if (unlikely(!OVS_CB(skb)->tun_key)) {
127 err = -EINVAL;
128 goto error;
129 }
130
131 /* Route lookup */
132 memset(&fl, 0, sizeof(fl));
133 fl.daddr = OVS_CB(skb)->tun_key->ipv4_dst;
134 fl.saddr = OVS_CB(skb)->tun_key->ipv4_src;
135 fl.flowi4_tos = RT_TOS(OVS_CB(skb)->tun_key->ipv4_tos);
136 fl.flowi4_mark = skb->mark;
137 fl.flowi4_proto = IPPROTO_GRE;
138
139 rt = ip_route_output_key(net, &fl);
140 if (IS_ERR(rt))
141 return PTR_ERR(rt);
142
143 tunnel_hlen = ip_gre_calc_hlen(OVS_CB(skb)->tun_key->tun_flags);
144
145 min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
146 + tunnel_hlen + sizeof(struct iphdr)
147 + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
148 if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
149 int head_delta = SKB_DATA_ALIGN(min_headroom -
150 skb_headroom(skb) +
151 16);
152 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
153 0, GFP_ATOMIC);
154 if (unlikely(err))
155 goto err_free_rt;
156 }
157
158 if (vlan_tx_tag_present(skb)) {
159 if (unlikely(!__vlan_put_tag(skb,
160 skb->vlan_proto,
161 vlan_tx_tag_get(skb)))) {
162 err = -ENOMEM;
163 goto err_free_rt;
164 }
165 skb->vlan_tci = 0;
166 }
167
168 /* Push Tunnel header. */
169 skb = __build_header(skb, tunnel_hlen);
170 if (unlikely(!skb)) {
171 err = 0;
172 goto err_free_rt;
173 }
174
175 df = OVS_CB(skb)->tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
176 htons(IP_DF) : 0;
177
178 skb->local_df = 1;
179
180 return iptunnel_xmit(net, rt, skb, fl.saddr,
181 OVS_CB(skb)->tun_key->ipv4_dst, IPPROTO_GRE,
182 OVS_CB(skb)->tun_key->ipv4_tos,
183 OVS_CB(skb)->tun_key->ipv4_ttl, df);
184err_free_rt:
185 ip_rt_put(rt);
186error:
187 return err;
188}
189
190static struct gre_cisco_protocol gre_protocol = {
191 .handler = gre_rcv,
192 .priority = 1,
193};
194
195static int gre_ports;
196static int gre_init(void)
197{
198 int err;
199
200 gre_ports++;
201 if (gre_ports > 1)
202 return 0;
203
204 err = gre_cisco_register(&gre_protocol);
205 if (err)
206 pr_warn("cannot register gre protocol handler\n");
207
208 return err;
209}
210
211static void gre_exit(void)
212{
213 gre_ports--;
214 if (gre_ports > 0)
215 return;
216
217 gre_cisco_unregister(&gre_protocol);
218}
219
220static const char *gre_get_name(const struct vport *vport)
221{
222 return vport_priv(vport);
223}
224
225static struct vport *gre_create(const struct vport_parms *parms)
226{
227 struct net *net = ovs_dp_get_net(parms->dp);
228 struct ovs_net *ovs_net;
229 struct vport *vport;
230 int err;
231
232 err = gre_init();
233 if (err)
234 return ERR_PTR(err);
235
236 ovs_net = net_generic(net, ovs_net_id);
237 if (ovsl_dereference(ovs_net->vport_net.gre_vport)) {
238 vport = ERR_PTR(-EEXIST);
239 goto error;
240 }
241
242 vport = ovs_vport_alloc(IFNAMSIZ, &ovs_gre_vport_ops, parms);
243 if (IS_ERR(vport))
244 goto error;
245
246 strncpy(vport_priv(vport), parms->name, IFNAMSIZ);
247 rcu_assign_pointer(ovs_net->vport_net.gre_vport, vport);
248 return vport;
249
250error:
251 gre_exit();
252 return vport;
253}
254
255static void gre_tnl_destroy(struct vport *vport)
256{
257 struct net *net = ovs_dp_get_net(vport->dp);
258 struct ovs_net *ovs_net;
259
260 ovs_net = net_generic(net, ovs_net_id);
261
262 rcu_assign_pointer(ovs_net->vport_net.gre_vport, NULL);
263 ovs_vport_deferred_free(vport);
264 gre_exit();
265}
266
267const struct vport_ops ovs_gre_vport_ops = {
268 .type = OVS_VPORT_TYPE_GRE,
269 .create = gre_create,
270 .destroy = gre_tnl_destroy,
271 .get_name = gre_get_name,
272 .send = gre_tnl_send,
273};
274#endif