xref: /openbmc/linux/net/openvswitch/vport-vxlan.c (revision f7777dcc)
1 /*
2  * Copyright (c) 2013 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 
28 #include <net/icmp.h>
29 #include <net/ip.h>
30 #include <net/udp.h>
31 #include <net/ip_tunnels.h>
32 #include <net/udp.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 inline struct vxlan_port *vxlan_vport(const struct vport *vport)
55 {
56 	return vport_priv(vport);
57 }
58 
59 /* Called with rcu_read_lock and BH disabled. */
60 static void vxlan_rcv(struct vxlan_sock *vs, struct sk_buff *skb, __be32 vx_vni)
61 {
62 	struct ovs_key_ipv4_tunnel tun_key;
63 	struct vport *vport = vs->data;
64 	struct iphdr *iph;
65 	__be64 key;
66 
67 	/* Save outer tunnel values */
68 	iph = ip_hdr(skb);
69 	key = cpu_to_be64(ntohl(vx_vni) >> 8);
70 	ovs_flow_tun_key_init(&tun_key, iph, key, TUNNEL_KEY);
71 
72 	ovs_vport_receive(vport, skb, &tun_key);
73 }
74 
75 static int vxlan_get_options(const struct vport *vport, struct sk_buff *skb)
76 {
77 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
78 	__be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
79 
80 	if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(dst_port)))
81 		return -EMSGSIZE;
82 	return 0;
83 }
84 
85 static void vxlan_tnl_destroy(struct vport *vport)
86 {
87 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
88 
89 	vxlan_sock_release(vxlan_port->vs);
90 
91 	ovs_vport_deferred_free(vport);
92 }
93 
94 static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
95 {
96 	struct net *net = ovs_dp_get_net(parms->dp);
97 	struct nlattr *options = parms->options;
98 	struct vxlan_port *vxlan_port;
99 	struct vxlan_sock *vs;
100 	struct vport *vport;
101 	struct nlattr *a;
102 	u16 dst_port;
103 	int err;
104 
105 	if (!options) {
106 		err = -EINVAL;
107 		goto error;
108 	}
109 	a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
110 	if (a && nla_len(a) == sizeof(u16)) {
111 		dst_port = nla_get_u16(a);
112 	} else {
113 		/* Require destination port from userspace. */
114 		err = -EINVAL;
115 		goto error;
116 	}
117 
118 	vport = ovs_vport_alloc(sizeof(struct vxlan_port),
119 				&ovs_vxlan_vport_ops, parms);
120 	if (IS_ERR(vport))
121 		return vport;
122 
123 	vxlan_port = vxlan_vport(vport);
124 	strncpy(vxlan_port->name, parms->name, IFNAMSIZ);
125 
126 	vs = vxlan_sock_add(net, htons(dst_port), vxlan_rcv, vport, true, false);
127 	if (IS_ERR(vs)) {
128 		ovs_vport_free(vport);
129 		return (void *)vs;
130 	}
131 	vxlan_port->vs = vs;
132 
133 	return vport;
134 
135 error:
136 	return ERR_PTR(err);
137 }
138 
139 static int vxlan_tnl_send(struct vport *vport, struct sk_buff *skb)
140 {
141 	struct net *net = ovs_dp_get_net(vport->dp);
142 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
143 	__be16 dst_port = inet_sk(vxlan_port->vs->sock->sk)->inet_sport;
144 	struct rtable *rt;
145 	struct flowi4 fl;
146 	__be16 src_port;
147 	int port_min;
148 	int port_max;
149 	__be16 df;
150 	int err;
151 
152 	if (unlikely(!OVS_CB(skb)->tun_key)) {
153 		err = -EINVAL;
154 		goto error;
155 	}
156 
157 	/* Route lookup */
158 	memset(&fl, 0, sizeof(fl));
159 	fl.daddr = OVS_CB(skb)->tun_key->ipv4_dst;
160 	fl.saddr = OVS_CB(skb)->tun_key->ipv4_src;
161 	fl.flowi4_tos = RT_TOS(OVS_CB(skb)->tun_key->ipv4_tos);
162 	fl.flowi4_mark = skb->mark;
163 	fl.flowi4_proto = IPPROTO_UDP;
164 
165 	rt = ip_route_output_key(net, &fl);
166 	if (IS_ERR(rt)) {
167 		err = PTR_ERR(rt);
168 		goto error;
169 	}
170 
171 	df = OVS_CB(skb)->tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ?
172 		htons(IP_DF) : 0;
173 
174 	skb->local_df = 1;
175 
176 	inet_get_local_port_range(&port_min, &port_max);
177 	src_port = vxlan_src_port(port_min, port_max, skb);
178 
179 	err = vxlan_xmit_skb(vxlan_port->vs, rt, skb,
180 			     fl.saddr, OVS_CB(skb)->tun_key->ipv4_dst,
181 			     OVS_CB(skb)->tun_key->ipv4_tos,
182 			     OVS_CB(skb)->tun_key->ipv4_ttl, df,
183 			     src_port, dst_port,
184 			     htonl(be64_to_cpu(OVS_CB(skb)->tun_key->tun_id) << 8));
185 	if (err < 0)
186 		ip_rt_put(rt);
187 error:
188 	return err;
189 }
190 
191 static const char *vxlan_get_name(const struct vport *vport)
192 {
193 	struct vxlan_port *vxlan_port = vxlan_vport(vport);
194 	return vxlan_port->name;
195 }
196 
197 const struct vport_ops ovs_vxlan_vport_ops = {
198 	.type		= OVS_VPORT_TYPE_VXLAN,
199 	.create		= vxlan_tnl_create,
200 	.destroy	= vxlan_tnl_destroy,
201 	.get_name	= vxlan_get_name,
202 	.get_options	= vxlan_get_options,
203 	.send		= vxlan_tnl_send,
204 };
205