xref: /openbmc/linux/net/openvswitch/vport-geneve.c (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
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 /* Convert 64 bit tunnel ID to 24 bit VNI. */
50 static void tunnel_id_to_vni(__be64 tun_id, __u8 *vni)
51 {
52 #ifdef __BIG_ENDIAN
53 	vni[0] = (__force __u8)(tun_id >> 16);
54 	vni[1] = (__force __u8)(tun_id >> 8);
55 	vni[2] = (__force __u8)tun_id;
56 #else
57 	vni[0] = (__force __u8)((__force u64)tun_id >> 40);
58 	vni[1] = (__force __u8)((__force u64)tun_id >> 48);
59 	vni[2] = (__force __u8)((__force u64)tun_id >> 56);
60 #endif
61 }
62 
63 /* Convert 24 bit VNI to 64 bit tunnel ID. */
64 static __be64 vni_to_tunnel_id(const __u8 *vni)
65 {
66 #ifdef __BIG_ENDIAN
67 	return (vni[0] << 16) | (vni[1] << 8) | vni[2];
68 #else
69 	return (__force __be64)(((__force u64)vni[0] << 40) |
70 				((__force u64)vni[1] << 48) |
71 				((__force u64)vni[2] << 56));
72 #endif
73 }
74 
75 static void geneve_rcv(struct geneve_sock *gs, struct sk_buff *skb)
76 {
77 	struct vport *vport = gs->rcv_data;
78 	struct genevehdr *geneveh = geneve_hdr(skb);
79 	int opts_len;
80 	struct ip_tunnel_info tun_info;
81 	__be64 key;
82 	__be16 flags;
83 
84 	opts_len = geneveh->opt_len * 4;
85 
86 	flags = TUNNEL_KEY | TUNNEL_GENEVE_OPT |
87 		(udp_hdr(skb)->check != 0 ? TUNNEL_CSUM : 0) |
88 		(geneveh->oam ? TUNNEL_OAM : 0) |
89 		(geneveh->critical ? TUNNEL_CRIT_OPT : 0);
90 
91 	key = vni_to_tunnel_id(geneveh->vni);
92 
93 	ip_tunnel_info_init(&tun_info, ip_hdr(skb),
94 			    udp_hdr(skb)->source, udp_hdr(skb)->dest,
95 			    key, flags, geneveh->options, opts_len);
96 
97 	ovs_vport_receive(vport, skb, &tun_info);
98 }
99 
100 static int geneve_get_options(const struct vport *vport,
101 			      struct sk_buff *skb)
102 {
103 	struct geneve_port *geneve_port = geneve_vport(vport);
104 	struct inet_sock *sk = inet_sk(geneve_port->gs->sock->sk);
105 
106 	if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(sk->inet_sport)))
107 		return -EMSGSIZE;
108 	return 0;
109 }
110 
111 static void geneve_tnl_destroy(struct vport *vport)
112 {
113 	struct geneve_port *geneve_port = geneve_vport(vport);
114 
115 	geneve_sock_release(geneve_port->gs);
116 
117 	ovs_vport_deferred_free(vport);
118 }
119 
120 static struct vport *geneve_tnl_create(const struct vport_parms *parms)
121 {
122 	struct net *net = ovs_dp_get_net(parms->dp);
123 	struct nlattr *options = parms->options;
124 	struct geneve_port *geneve_port;
125 	struct geneve_sock *gs;
126 	struct vport *vport;
127 	struct nlattr *a;
128 	int err;
129 	u16 dst_port;
130 
131 	if (!options) {
132 		err = -EINVAL;
133 		goto error;
134 	}
135 
136 	a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
137 	if (a && nla_len(a) == sizeof(u16)) {
138 		dst_port = nla_get_u16(a);
139 	} else {
140 		/* Require destination port from userspace. */
141 		err = -EINVAL;
142 		goto error;
143 	}
144 
145 	vport = ovs_vport_alloc(sizeof(struct geneve_port),
146 				&ovs_geneve_vport_ops, parms);
147 	if (IS_ERR(vport))
148 		return vport;
149 
150 	geneve_port = geneve_vport(vport);
151 	strncpy(geneve_port->name, parms->name, IFNAMSIZ);
152 
153 	gs = geneve_sock_add(net, htons(dst_port), geneve_rcv, vport, true, 0);
154 	if (IS_ERR(gs)) {
155 		ovs_vport_free(vport);
156 		return (void *)gs;
157 	}
158 	geneve_port->gs = gs;
159 
160 	return vport;
161 error:
162 	return ERR_PTR(err);
163 }
164 
165 static int geneve_tnl_send(struct vport *vport, struct sk_buff *skb)
166 {
167 	const struct ip_tunnel_key *tun_key;
168 	struct ip_tunnel_info *tun_info;
169 	struct net *net = ovs_dp_get_net(vport->dp);
170 	struct geneve_port *geneve_port = geneve_vport(vport);
171 	__be16 dport = inet_sk(geneve_port->gs->sock->sk)->inet_sport;
172 	__be16 sport;
173 	struct rtable *rt;
174 	struct flowi4 fl;
175 	u8 vni[3], opts_len, *opts;
176 	__be16 df;
177 	int err;
178 
179 	tun_info = OVS_CB(skb)->egress_tun_info;
180 	if (unlikely(!tun_info)) {
181 		err = -EINVAL;
182 		goto error;
183 	}
184 
185 	tun_key = &tun_info->key;
186 	rt = ovs_tunnel_route_lookup(net, tun_key, skb->mark, &fl, IPPROTO_UDP);
187 	if (IS_ERR(rt)) {
188 		err = PTR_ERR(rt);
189 		goto error;
190 	}
191 
192 	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
193 	sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
194 	tunnel_id_to_vni(tun_key->tun_id, vni);
195 	skb->ignore_df = 1;
196 
197 	if (tun_key->tun_flags & TUNNEL_GENEVE_OPT) {
198 		opts = (u8 *)tun_info->options;
199 		opts_len = tun_info->options_len;
200 	} else {
201 		opts = NULL;
202 		opts_len = 0;
203 	}
204 
205 	err = geneve_xmit_skb(geneve_port->gs, rt, skb, fl.saddr,
206 			      tun_key->ipv4_dst, tun_key->ipv4_tos,
207 			      tun_key->ipv4_ttl, df, sport, dport,
208 			      tun_key->tun_flags, vni, opts_len, opts,
209 			      !!(tun_key->tun_flags & TUNNEL_CSUM), false);
210 	if (err < 0)
211 		ip_rt_put(rt);
212 	return err;
213 
214 error:
215 	kfree_skb(skb);
216 	return err;
217 }
218 
219 static const char *geneve_get_name(const struct vport *vport)
220 {
221 	struct geneve_port *geneve_port = geneve_vport(vport);
222 
223 	return geneve_port->name;
224 }
225 
226 static int geneve_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
227 				      struct ip_tunnel_info *egress_tun_info)
228 {
229 	struct geneve_port *geneve_port = geneve_vport(vport);
230 	struct net *net = ovs_dp_get_net(vport->dp);
231 	__be16 dport = inet_sk(geneve_port->gs->sock->sk)->inet_sport;
232 	__be16 sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
233 
234 	/* Get tp_src and tp_dst, refert to geneve_build_header().
235 	 */
236 	return ovs_tunnel_get_egress_info(egress_tun_info,
237 					  ovs_dp_get_net(vport->dp),
238 					  OVS_CB(skb)->egress_tun_info,
239 					  IPPROTO_UDP, skb->mark, sport, dport);
240 }
241 
242 static struct vport_ops ovs_geneve_vport_ops = {
243 	.type		= OVS_VPORT_TYPE_GENEVE,
244 	.create		= geneve_tnl_create,
245 	.destroy	= geneve_tnl_destroy,
246 	.get_name	= geneve_get_name,
247 	.get_options	= geneve_get_options,
248 	.send		= geneve_tnl_send,
249 	.owner          = THIS_MODULE,
250 	.get_egress_tun_info	= geneve_get_egress_tun_info,
251 };
252 
253 static int __init ovs_geneve_tnl_init(void)
254 {
255 	return ovs_vport_ops_register(&ovs_geneve_vport_ops);
256 }
257 
258 static void __exit ovs_geneve_tnl_exit(void)
259 {
260 	ovs_vport_ops_unregister(&ovs_geneve_vport_ops);
261 }
262 
263 module_init(ovs_geneve_tnl_init);
264 module_exit(ovs_geneve_tnl_exit);
265 
266 MODULE_DESCRIPTION("OVS: Geneve swiching port");
267 MODULE_LICENSE("GPL");
268 MODULE_ALIAS("vport-type-5");
269