xref: /linux/net/openvswitch/vport-geneve.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  * Copyright (c) 2014 Nicira, Inc.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 
12 #include <linux/in.h>
13 #include <linux/ip.h>
14 #include <linux/net.h>
15 #include <linux/rculist.h>
16 #include <linux/udp.h>
17 #include <linux/if_vlan.h>
18 #include <linux/module.h>
19 
20 #include <net/geneve.h>
21 #include <net/icmp.h>
22 #include <net/ip.h>
23 #include <net/route.h>
24 #include <net/udp.h>
25 #include <net/xfrm.h>
26 
27 #include "datapath.h"
28 #include "vport.h"
29 
30 static struct vport_ops ovs_geneve_vport_ops;
31 
32 /**
33  * struct geneve_port - Keeps track of open UDP ports
34  * @gs: The socket created for this port number.
35  * @name: vport name.
36  */
37 struct geneve_port {
38 	struct geneve_sock *gs;
39 	char name[IFNAMSIZ];
40 };
41 
42 static LIST_HEAD(geneve_ports);
43 
44 static inline struct geneve_port *geneve_vport(const struct vport *vport)
45 {
46 	return vport_priv(vport);
47 }
48 
49 static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
50 {
51 	return (struct genevehdr *)(udp_hdr(skb) + 1);
52 }
53 
54 /* Convert 64 bit tunnel ID to 24 bit VNI. */
55 static void tunnel_id_to_vni(__be64 tun_id, __u8 *vni)
56 {
57 #ifdef __BIG_ENDIAN
58 	vni[0] = (__force __u8)(tun_id >> 16);
59 	vni[1] = (__force __u8)(tun_id >> 8);
60 	vni[2] = (__force __u8)tun_id;
61 #else
62 	vni[0] = (__force __u8)((__force u64)tun_id >> 40);
63 	vni[1] = (__force __u8)((__force u64)tun_id >> 48);
64 	vni[2] = (__force __u8)((__force u64)tun_id >> 56);
65 #endif
66 }
67 
68 /* Convert 24 bit VNI to 64 bit tunnel ID. */
69 static __be64 vni_to_tunnel_id(const __u8 *vni)
70 {
71 #ifdef __BIG_ENDIAN
72 	return (vni[0] << 16) | (vni[1] << 8) | vni[2];
73 #else
74 	return (__force __be64)(((__force u64)vni[0] << 40) |
75 				((__force u64)vni[1] << 48) |
76 				((__force u64)vni[2] << 56));
77 #endif
78 }
79 
80 static void geneve_rcv(struct geneve_sock *gs, struct sk_buff *skb)
81 {
82 	struct vport *vport = gs->rcv_data;
83 	struct genevehdr *geneveh = geneve_hdr(skb);
84 	int opts_len;
85 	struct ovs_tunnel_info tun_info;
86 	__be64 key;
87 	__be16 flags;
88 
89 	opts_len = geneveh->opt_len * 4;
90 
91 	flags = TUNNEL_KEY | TUNNEL_GENEVE_OPT |
92 		(udp_hdr(skb)->check != 0 ? TUNNEL_CSUM : 0) |
93 		(geneveh->oam ? TUNNEL_OAM : 0) |
94 		(geneveh->critical ? TUNNEL_CRIT_OPT : 0);
95 
96 	key = vni_to_tunnel_id(geneveh->vni);
97 
98 	ovs_flow_tun_info_init(&tun_info, ip_hdr(skb),
99 			       udp_hdr(skb)->source, udp_hdr(skb)->dest,
100 			       key, flags,
101 			       geneveh->options, opts_len);
102 
103 	ovs_vport_receive(vport, skb, &tun_info);
104 }
105 
106 static int geneve_get_options(const struct vport *vport,
107 			      struct sk_buff *skb)
108 {
109 	struct geneve_port *geneve_port = geneve_vport(vport);
110 	struct inet_sock *sk = inet_sk(geneve_port->gs->sock->sk);
111 
112 	if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(sk->inet_sport)))
113 		return -EMSGSIZE;
114 	return 0;
115 }
116 
117 static void geneve_tnl_destroy(struct vport *vport)
118 {
119 	struct geneve_port *geneve_port = geneve_vport(vport);
120 
121 	geneve_sock_release(geneve_port->gs);
122 
123 	ovs_vport_deferred_free(vport);
124 }
125 
126 static struct vport *geneve_tnl_create(const struct vport_parms *parms)
127 {
128 	struct net *net = ovs_dp_get_net(parms->dp);
129 	struct nlattr *options = parms->options;
130 	struct geneve_port *geneve_port;
131 	struct geneve_sock *gs;
132 	struct vport *vport;
133 	struct nlattr *a;
134 	int err;
135 	u16 dst_port;
136 
137 	if (!options) {
138 		err = -EINVAL;
139 		goto error;
140 	}
141 
142 	a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
143 	if (a && nla_len(a) == sizeof(u16)) {
144 		dst_port = nla_get_u16(a);
145 	} else {
146 		/* Require destination port from userspace. */
147 		err = -EINVAL;
148 		goto error;
149 	}
150 
151 	vport = ovs_vport_alloc(sizeof(struct geneve_port),
152 				&ovs_geneve_vport_ops, parms);
153 	if (IS_ERR(vport))
154 		return vport;
155 
156 	geneve_port = geneve_vport(vport);
157 	strncpy(geneve_port->name, parms->name, IFNAMSIZ);
158 
159 	gs = geneve_sock_add(net, htons(dst_port), geneve_rcv, vport, true, 0);
160 	if (IS_ERR(gs)) {
161 		ovs_vport_free(vport);
162 		return (void *)gs;
163 	}
164 	geneve_port->gs = gs;
165 
166 	return vport;
167 error:
168 	return ERR_PTR(err);
169 }
170 
171 static int geneve_tnl_send(struct vport *vport, struct sk_buff *skb)
172 {
173 	const struct ovs_key_ipv4_tunnel *tun_key;
174 	struct ovs_tunnel_info *tun_info;
175 	struct net *net = ovs_dp_get_net(vport->dp);
176 	struct geneve_port *geneve_port = geneve_vport(vport);
177 	__be16 dport = inet_sk(geneve_port->gs->sock->sk)->inet_sport;
178 	__be16 sport;
179 	struct rtable *rt;
180 	struct flowi4 fl;
181 	u8 vni[3], opts_len, *opts;
182 	__be16 df;
183 	int err;
184 
185 	tun_info = OVS_CB(skb)->egress_tun_info;
186 	if (unlikely(!tun_info)) {
187 		err = -EINVAL;
188 		goto error;
189 	}
190 
191 	tun_key = &tun_info->tunnel;
192 	rt = ovs_tunnel_route_lookup(net, tun_key, skb->mark, &fl, IPPROTO_UDP);
193 	if (IS_ERR(rt)) {
194 		err = PTR_ERR(rt);
195 		goto error;
196 	}
197 
198 	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
199 	sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
200 	tunnel_id_to_vni(tun_key->tun_id, vni);
201 	skb->ignore_df = 1;
202 
203 	if (tun_key->tun_flags & TUNNEL_GENEVE_OPT) {
204 		opts = (u8 *)tun_info->options;
205 		opts_len = tun_info->options_len;
206 	} else {
207 		opts = NULL;
208 		opts_len = 0;
209 	}
210 
211 	err = geneve_xmit_skb(geneve_port->gs, rt, skb, fl.saddr,
212 			      tun_key->ipv4_dst, tun_key->ipv4_tos,
213 			      tun_key->ipv4_ttl, df, sport, dport,
214 			      tun_key->tun_flags, vni, opts_len, opts,
215 			      !!(tun_key->tun_flags & TUNNEL_CSUM), false);
216 	if (err < 0)
217 		ip_rt_put(rt);
218 	return err;
219 
220 error:
221 	kfree_skb(skb);
222 	return err;
223 }
224 
225 static const char *geneve_get_name(const struct vport *vport)
226 {
227 	struct geneve_port *geneve_port = geneve_vport(vport);
228 
229 	return geneve_port->name;
230 }
231 
232 static int geneve_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
233 				      struct ovs_tunnel_info *egress_tun_info)
234 {
235 	struct geneve_port *geneve_port = geneve_vport(vport);
236 	struct net *net = ovs_dp_get_net(vport->dp);
237 	__be16 dport = inet_sk(geneve_port->gs->sock->sk)->inet_sport;
238 	__be16 sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
239 
240 	/* Get tp_src and tp_dst, refert to geneve_build_header().
241 	 */
242 	return ovs_tunnel_get_egress_info(egress_tun_info,
243 					  ovs_dp_get_net(vport->dp),
244 					  OVS_CB(skb)->egress_tun_info,
245 					  IPPROTO_UDP, skb->mark, sport, dport);
246 }
247 
248 static struct vport_ops ovs_geneve_vport_ops = {
249 	.type		= OVS_VPORT_TYPE_GENEVE,
250 	.create		= geneve_tnl_create,
251 	.destroy	= geneve_tnl_destroy,
252 	.get_name	= geneve_get_name,
253 	.get_options	= geneve_get_options,
254 	.send		= geneve_tnl_send,
255 	.owner          = THIS_MODULE,
256 	.get_egress_tun_info	= geneve_get_egress_tun_info,
257 };
258 
259 static int __init ovs_geneve_tnl_init(void)
260 {
261 	return ovs_vport_ops_register(&ovs_geneve_vport_ops);
262 }
263 
264 static void __exit ovs_geneve_tnl_exit(void)
265 {
266 	ovs_vport_ops_unregister(&ovs_geneve_vport_ops);
267 }
268 
269 module_init(ovs_geneve_tnl_init);
270 module_exit(ovs_geneve_tnl_exit);
271 
272 MODULE_DESCRIPTION("OVS: Geneve swiching port");
273 MODULE_LICENSE("GPL");
274 MODULE_ALIAS("vport-type-5");
275