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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>
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>
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
49static struct vport_ops ovs_gre_vport_ops;
50
51
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 struct tnl_ptk_info tpi;
70 const struct ovs_key_ipv4_tunnel *tun_key;
71
72 tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
73
74 skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM));
75 if (IS_ERR(skb))
76 return skb;
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
87static __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
97static int gre_rcv(struct sk_buff *skb,
98 const struct tnl_ptk_info *tpi)
99{
100 struct ovs_tunnel_info tun_info;
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);
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 return PACKET_RCVD;
116}
117
118
119static 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
134static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
135{
136 struct net *net = ovs_dp_get_net(vport->dp);
137 const struct ovs_key_ipv4_tunnel *tun_key;
138 struct flowi4 fl;
139 struct rtable *rt;
140 int min_headroom;
141 int tunnel_hlen;
142 __be16 df;
143 int err;
144
145 if (unlikely(!OVS_CB(skb)->egress_tun_info)) {
146 err = -EINVAL;
147 goto err_free_skb;
148 }
149
150 tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
151 rt = ovs_tunnel_route_lookup(net, tun_key, skb->mark, &fl, IPPROTO_GRE);
152 if (IS_ERR(rt)) {
153 err = PTR_ERR(rt);
154 goto err_free_skb;
155 }
156
157 tunnel_hlen = ip_gre_calc_hlen(tun_key->tun_flags);
158
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 -
164 skb_headroom(skb) +
165 16);
166 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
167 0, GFP_ATOMIC);
168 if (unlikely(err))
169 goto err_free_rt;
170 }
171
172 skb = vlan_hwaccel_push_inside(skb);
173 if (unlikely(!skb)) {
174 err = -ENOMEM;
175 goto err_free_rt;
176 }
177
178
179 skb = __build_header(skb, tunnel_hlen);
180 if (IS_ERR(skb)) {
181 err = PTR_ERR(skb);
182 skb = NULL;
183 goto err_free_rt;
184 }
185
186 df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
187 htons(IP_DF) : 0;
188
189 skb->ignore_df = 1;
190
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);
194err_free_rt:
195 ip_rt_put(rt);
196err_free_skb:
197 kfree_skb(skb);
198 return err;
199}
200
201static struct gre_cisco_protocol gre_protocol = {
202 .handler = gre_rcv,
203 .err_handler = gre_err,
204 .priority = 1,
205};
206
207static int gre_ports;
208static int gre_init(void)
209{
210 int err;
211
212 gre_ports++;
213 if (gre_ports > 1)
214 return 0;
215
216 err = gre_cisco_register(&gre_protocol);
217 if (err)
218 pr_warn("cannot register gre protocol handler\n");
219
220 return err;
221}
222
223static void gre_exit(void)
224{
225 gre_ports--;
226 if (gre_ports > 0)
227 return;
228
229 gre_cisco_unregister(&gre_protocol);
230}
231
232static const char *gre_get_name(const struct vport *vport)
233{
234 return vport_priv(vport);
235}
236
237static struct vport *gre_create(const struct vport_parms *parms)
238{
239 struct net *net = ovs_dp_get_net(parms->dp);
240 struct ovs_net *ovs_net;
241 struct vport *vport;
242 int err;
243
244 err = gre_init();
245 if (err)
246 return ERR_PTR(err);
247
248 ovs_net = net_generic(net, ovs_net_id);
249 if (ovsl_dereference(ovs_net->vport_net.gre_vport)) {
250 vport = ERR_PTR(-EEXIST);
251 goto error;
252 }
253
254 vport = ovs_vport_alloc(IFNAMSIZ, &ovs_gre_vport_ops, parms);
255 if (IS_ERR(vport))
256 goto error;
257
258 strncpy(vport_priv(vport), parms->name, IFNAMSIZ);
259 rcu_assign_pointer(ovs_net->vport_net.gre_vport, vport);
260 return vport;
261
262error:
263 gre_exit();
264 return vport;
265}
266
267static void gre_tnl_destroy(struct vport *vport)
268{
269 struct net *net = ovs_dp_get_net(vport->dp);
270 struct ovs_net *ovs_net;
271
272 ovs_net = net_generic(net, ovs_net_id);
273
274 RCU_INIT_POINTER(ovs_net->vport_net.gre_vport, NULL);
275 ovs_vport_deferred_free(vport);
276 gre_exit();
277}
278
279static int gre_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
280 struct ovs_tunnel_info *egress_tun_info)
281{
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);
286}
287
288static 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,
296};
297
298static int __init ovs_gre_tnl_init(void)
299{
300 return ovs_vport_ops_register(&ovs_gre_vport_ops);
301}
302
303static void __exit ovs_gre_tnl_exit(void)
304{
305 ovs_vport_ops_unregister(&ovs_gre_vport_ops);
306}
307
308module_init(ovs_gre_tnl_init);
309module_exit(ovs_gre_tnl_exit);
310
311MODULE_DESCRIPTION("OVS: GRE switching port");
312MODULE_LICENSE("GPL");
313MODULE_ALIAS("vport-type-3");
314
