xref: /linux/net/openvswitch/vport-vxlan.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1 /*
2  * Copyright (c) 2014 Nicira, Inc.
3  * Copyright (c) 2013 Cisco Systems, Inc.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of version 2 of the GNU General Public
7  * License as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA
18  */
19 
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 
22 #include <linux/in.h>
23 #include <linux/ip.h>
24 #include <linux/net.h>
25 #include <linux/rculist.h>
26 #include <linux/udp.h>
27 #include <linux/module.h>
28 
29 #include <net/icmp.h>
30 #include <net/ip.h>
31 #include <net/udp.h>
32 #include <net/ip_tunnels.h>
33 #include <net/rtnetlink.h>
34 #include <net/route.h>
35 #include <net/dsfield.h>
36 #include <net/inet_ecn.h>
37 #include <net/net_namespace.h>
38 #include <net/netns/generic.h>
39 #include <net/vxlan.h>
40 
41 #include "datapath.h"
42 #include "vport.h"
43 
44 /**
45  * struct vxlan_port - Keeps track of open UDP ports
46  * @vs: vxlan_sock created for the port.
47  * @name: vport name.
48  */
49 struct vxlan_port {
50 	struct vxlan_sock *vs;
51 	char name[IFNAMSIZ];
52 };
53 
54 static struct vport_ops ovs_vxlan_vport_ops;
55 
56 static inline struct vxlan_port *vxlan_vport(const struct vport *vport)
57 {
58 	return vport_priv(vport);
59 }
60 
61 /* Called with rcu_read_lock and BH disabled. */
62 static void vxlan_rcv(struct vxlan_sock *vs, struct sk_buff *skb, __be32 vx_vni)
63 {
64 	struct ovs_tunnel_info tun_info;
65 	struct vport *vport = vs->data;
66 	struct iphdr *iph;
67 	__be64 key;
68 
69 	/* Save outer tunnel values */
70 	iph = ip_hdr(skb);
71 	key = cpu_to_be64(ntohl(vx_vni) >> 8);
72 	ovs_flow_tun_info_init(&tun_info, iph,
73 			       udp_hdr(skb)->source, udp_hdr(skb)->dest,
74 			       key, TUNNEL_KEY, NULL, 0);
75 
76 	ovs_vport_receive(vport, skb, &tun_info);
77 }
78 
79 static int vxlan_get_options(const struct vport *vport, struct sk_buff *skb)
80 {
81 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
82 	__be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
83 
84 	if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(dst_port)))
85 		return -EMSGSIZE;
86 	return 0;
87 }
88 
89 static void vxlan_tnl_destroy(struct vport *vport)
90 {
91 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
92 
93 	vxlan_sock_release(vxlan_port->vs);
94 
95 	ovs_vport_deferred_free(vport);
96 }
97 
98 static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
99 {
100 	struct net *net = ovs_dp_get_net(parms->dp);
101 	struct nlattr *options = parms->options;
102 	struct vxlan_port *vxlan_port;
103 	struct vxlan_sock *vs;
104 	struct vport *vport;
105 	struct nlattr *a;
106 	u16 dst_port;
107 	int err;
108 
109 	if (!options) {
110 		err = -EINVAL;
111 		goto error;
112 	}
113 	a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
114 	if (a && nla_len(a) == sizeof(u16)) {
115 		dst_port = nla_get_u16(a);
116 	} else {
117 		/* Require destination port from userspace. */
118 		err = -EINVAL;
119 		goto error;
120 	}
121 
122 	vport = ovs_vport_alloc(sizeof(struct vxlan_port),
123 				&ovs_vxlan_vport_ops, parms);
124 	if (IS_ERR(vport))
125 		return vport;
126 
127 	vxlan_port = vxlan_vport(vport);
128 	strncpy(vxlan_port->name, parms->name, IFNAMSIZ);
129 
130 	vs = vxlan_sock_add(net, htons(dst_port), vxlan_rcv, vport, true, 0);
131 	if (IS_ERR(vs)) {
132 		ovs_vport_free(vport);
133 		return (void *)vs;
134 	}
135 	vxlan_port->vs = vs;
136 
137 	return vport;
138 
139 error:
140 	return ERR_PTR(err);
141 }
142 
143 static int vxlan_tnl_send(struct vport *vport, struct sk_buff *skb)
144 {
145 	struct net *net = ovs_dp_get_net(vport->dp);
146 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
147 	__be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
148 	struct ovs_key_ipv4_tunnel *tun_key;
149 	struct rtable *rt;
150 	struct flowi4 fl;
151 	__be16 src_port;
152 	__be16 df;
153 	int err;
154 
155 	if (unlikely(!OVS_CB(skb)->egress_tun_info)) {
156 		err = -EINVAL;
157 		goto error;
158 	}
159 
160 	tun_key = &OVS_CB(skb)->egress_tun_info->tunnel;
161 	/* Route lookup */
162 	memset(&fl, 0, sizeof(fl));
163 	fl.daddr = tun_key->ipv4_dst;
164 	fl.saddr = tun_key->ipv4_src;
165 	fl.flowi4_tos = RT_TOS(tun_key->ipv4_tos);
166 	fl.flowi4_mark = skb->mark;
167 	fl.flowi4_proto = IPPROTO_UDP;
168 
169 	rt = ip_route_output_key(net, &fl);
170 	if (IS_ERR(rt)) {
171 		err = PTR_ERR(rt);
172 		goto error;
173 	}
174 
175 	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
176 		htons(IP_DF) : 0;
177 
178 	skb->ignore_df = 1;
179 
180 	src_port = udp_flow_src_port(net, skb, 0, 0, true);
181 
182 	err = vxlan_xmit_skb(vxlan_port->vs, rt, skb,
183 			     fl.saddr, tun_key->ipv4_dst,
184 			     tun_key->ipv4_tos, tun_key->ipv4_ttl, df,
185 			     src_port, dst_port,
186 			     htonl(be64_to_cpu(tun_key->tun_id) << 8),
187 			     false);
188 	if (err < 0)
189 		ip_rt_put(rt);
190 	return err;
191 error:
192 	kfree_skb(skb);
193 	return err;
194 }
195 
196 static int vxlan_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
197 				     struct ovs_tunnel_info *egress_tun_info)
198 {
199 	struct net *net = ovs_dp_get_net(vport->dp);
200 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
201 	__be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
202 	__be16 src_port;
203 	int port_min;
204 	int port_max;
205 
206 	inet_get_local_port_range(net, &port_min, &port_max);
207 	src_port = udp_flow_src_port(net, skb, 0, 0, true);
208 
209 	return ovs_tunnel_get_egress_info(egress_tun_info, net,
210 					  OVS_CB(skb)->egress_tun_info,
211 					  IPPROTO_UDP, skb->mark,
212 					  src_port, dst_port);
213 }
214 
215 static const char *vxlan_get_name(const struct vport *vport)
216 {
217 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
218 	return vxlan_port->name;
219 }
220 
221 static struct vport_ops ovs_vxlan_vport_ops = {
222 	.type		= OVS_VPORT_TYPE_VXLAN,
223 	.create		= vxlan_tnl_create,
224 	.destroy	= vxlan_tnl_destroy,
225 	.get_name	= vxlan_get_name,
226 	.get_options	= vxlan_get_options,
227 	.send		= vxlan_tnl_send,
228 	.get_egress_tun_info	= vxlan_get_egress_tun_info,
229 	.owner		= THIS_MODULE,
230 };
231 
232 static int __init ovs_vxlan_tnl_init(void)
233 {
234 	return ovs_vport_ops_register(&ovs_vxlan_vport_ops);
235 }
236 
237 static void __exit ovs_vxlan_tnl_exit(void)
238 {
239 	ovs_vport_ops_unregister(&ovs_vxlan_vport_ops);
240 }
241 
242 module_init(ovs_vxlan_tnl_init);
243 module_exit(ovs_vxlan_tnl_exit);
244 
245 MODULE_DESCRIPTION("OVS: VXLAN switching port");
246 MODULE_LICENSE("GPL");
247 MODULE_ALIAS("vport-type-4");
248