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/version.h>
13 
14 #include <linux/in.h>
15 #include <linux/ip.h>
16 #include <linux/net.h>
17 #include <linux/rculist.h>
18 #include <linux/udp.h>
19 #include <linux/if_vlan.h>
20 #include <linux/module.h>
21 
22 #include <net/geneve.h>
23 #include <net/icmp.h>
24 #include <net/ip.h>
25 #include <net/route.h>
26 #include <net/udp.h>
27 #include <net/xfrm.h>
28 
29 #include "datapath.h"
30 #include "vport.h"
31 
32 static struct vport_ops ovs_geneve_vport_ops;
33 
34 /**
35  * struct geneve_port - Keeps track of open UDP ports
36  * @gs: The socket created for this port number.
37  * @name: vport name.
38  */
39 struct geneve_port {
40 	struct geneve_sock *gs;
41 	char name[IFNAMSIZ];
42 };
43 
44 static LIST_HEAD(geneve_ports);
45 
46 static inline struct geneve_port *geneve_vport(const struct vport *vport)
47 {
48 	return vport_priv(vport);
49 }
50 
51 static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
52 {
53 	return (struct genevehdr *)(udp_hdr(skb) + 1);
54 }
55 
56 /* Convert 64 bit tunnel ID to 24 bit VNI. */
57 static void tunnel_id_to_vni(__be64 tun_id, __u8 *vni)
58 {
59 #ifdef __BIG_ENDIAN
60 	vni[0] = (__force __u8)(tun_id >> 16);
61 	vni[1] = (__force __u8)(tun_id >> 8);
62 	vni[2] = (__force __u8)tun_id;
63 #else
64 	vni[0] = (__force __u8)((__force u64)tun_id >> 40);
65 	vni[1] = (__force __u8)((__force u64)tun_id >> 48);
66 	vni[2] = (__force __u8)((__force u64)tun_id >> 56);
67 #endif
68 }
69 
70 /* Convert 24 bit VNI to 64 bit tunnel ID. */
71 static __be64 vni_to_tunnel_id(const __u8 *vni)
72 {
73 #ifdef __BIG_ENDIAN
74 	return (vni[0] << 16) | (vni[1] << 8) | vni[2];
75 #else
76 	return (__force __be64)(((__force u64)vni[0] << 40) |
77 				((__force u64)vni[1] << 48) |
78 				((__force u64)vni[2] << 56));
79 #endif
80 }
81 
82 static void geneve_rcv(struct geneve_sock *gs, struct sk_buff *skb)
83 {
84 	struct vport *vport = gs->rcv_data;
85 	struct genevehdr *geneveh = geneve_hdr(skb);
86 	int opts_len;
87 	struct ovs_tunnel_info tun_info;
88 	__be64 key;
89 	__be16 flags;
90 
91 	opts_len = geneveh->opt_len * 4;
92 
93 	flags = TUNNEL_KEY | TUNNEL_OPTIONS_PRESENT |
94 		(udp_hdr(skb)->check != 0 ? TUNNEL_CSUM : 0) |
95 		(geneveh->oam ? TUNNEL_OAM : 0) |
96 		(geneveh->critical ? TUNNEL_CRIT_OPT : 0);
97 
98 	key = vni_to_tunnel_id(geneveh->vni);
99 
100 	ovs_flow_tun_info_init(&tun_info, ip_hdr(skb),
101 			       udp_hdr(skb)->source, udp_hdr(skb)->dest,
102 			       key, flags,
103 			       geneveh->options, opts_len);
104 
105 	ovs_vport_receive(vport, skb, &tun_info);
106 }
107 
108 static int geneve_get_options(const struct vport *vport,
109 			      struct sk_buff *skb)
110 {
111 	struct geneve_port *geneve_port = geneve_vport(vport);
112 	struct inet_sock *sk = inet_sk(geneve_port->gs->sock->sk);
113 
114 	if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(sk->inet_sport)))
115 		return -EMSGSIZE;
116 	return 0;
117 }
118 
119 static void geneve_tnl_destroy(struct vport *vport)
120 {
121 	struct geneve_port *geneve_port = geneve_vport(vport);
122 
123 	geneve_sock_release(geneve_port->gs);
124 
125 	ovs_vport_deferred_free(vport);
126 }
127 
128 static struct vport *geneve_tnl_create(const struct vport_parms *parms)
129 {
130 	struct net *net = ovs_dp_get_net(parms->dp);
131 	struct nlattr *options = parms->options;
132 	struct geneve_port *geneve_port;
133 	struct geneve_sock *gs;
134 	struct vport *vport;
135 	struct nlattr *a;
136 	int err;
137 	u16 dst_port;
138 
139 	if (!options) {
140 		err = -EINVAL;
141 		goto error;
142 	}
143 
144 	a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
145 	if (a && nla_len(a) == sizeof(u16)) {
146 		dst_port = nla_get_u16(a);
147 	} else {
148 		/* Require destination port from userspace. */
149 		err = -EINVAL;
150 		goto error;
151 	}
152 
153 	vport = ovs_vport_alloc(sizeof(struct geneve_port),
154 				&ovs_geneve_vport_ops, parms);
155 	if (IS_ERR(vport))
156 		return vport;
157 
158 	geneve_port = geneve_vport(vport);
159 	strncpy(geneve_port->name, parms->name, IFNAMSIZ);
160 
161 	gs = geneve_sock_add(net, htons(dst_port), geneve_rcv, vport, true, 0);
162 	if (IS_ERR(gs)) {
163 		ovs_vport_free(vport);
164 		return (void *)gs;
165 	}
166 	geneve_port->gs = gs;
167 
168 	return vport;
169 error:
170 	return ERR_PTR(err);
171 }
172 
173 static int geneve_tnl_send(struct vport *vport, struct sk_buff *skb)
174 {
175 	struct ovs_key_ipv4_tunnel *tun_key;
176 	struct ovs_tunnel_info *tun_info;
177 	struct net *net = ovs_dp_get_net(vport->dp);
178 	struct geneve_port *geneve_port = geneve_vport(vport);
179 	__be16 dport = inet_sk(geneve_port->gs->sock->sk)->inet_sport;
180 	__be16 sport;
181 	struct rtable *rt;
182 	struct flowi4 fl;
183 	u8 vni[3];
184 	__be16 df;
185 	int err;
186 
187 	tun_info = OVS_CB(skb)->egress_tun_info;
188 	if (unlikely(!tun_info)) {
189 		err = -EINVAL;
190 		goto error;
191 	}
192 
193 	tun_key = &tun_info->tunnel;
194 
195 	/* Route lookup */
196 	memset(&fl, 0, sizeof(fl));
197 	fl.daddr = tun_key->ipv4_dst;
198 	fl.saddr = tun_key->ipv4_src;
199 	fl.flowi4_tos = RT_TOS(tun_key->ipv4_tos);
200 	fl.flowi4_mark = skb->mark;
201 	fl.flowi4_proto = IPPROTO_UDP;
202 
203 	rt = ip_route_output_key(net, &fl);
204 	if (IS_ERR(rt)) {
205 		err = PTR_ERR(rt);
206 		goto error;
207 	}
208 
209 	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
210 	sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
211 	tunnel_id_to_vni(tun_key->tun_id, vni);
212 	skb->ignore_df = 1;
213 
214 	err = geneve_xmit_skb(geneve_port->gs, rt, skb, fl.saddr,
215 			      tun_key->ipv4_dst, tun_key->ipv4_tos,
216 			      tun_key->ipv4_ttl, df, sport, dport,
217 			      tun_key->tun_flags, vni,
218 			      tun_info->options_len, (u8 *)tun_info->options,
219 			      false);
220 	if (err < 0)
221 		ip_rt_put(rt);
222 	return err;
223 
224 error:
225 	kfree_skb(skb);
226 	return err;
227 }
228 
229 static const char *geneve_get_name(const struct vport *vport)
230 {
231 	struct geneve_port *geneve_port = geneve_vport(vport);
232 
233 	return geneve_port->name;
234 }
235 
236 static int geneve_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
237 				      struct ovs_tunnel_info *egress_tun_info)
238 {
239 	struct geneve_port *geneve_port = geneve_vport(vport);
240 	struct net *net = ovs_dp_get_net(vport->dp);
241 	__be16 dport = inet_sk(geneve_port->gs->sock->sk)->inet_sport;
242 	__be16 sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
243 
244 	/* Get tp_src and tp_dst, refert to geneve_build_header().
245 	 */
246 	return ovs_tunnel_get_egress_info(egress_tun_info,
247 					  ovs_dp_get_net(vport->dp),
248 					  OVS_CB(skb)->egress_tun_info,
249 					  IPPROTO_UDP, skb->mark, sport, dport);
250 }
251 
252 static struct vport_ops ovs_geneve_vport_ops = {
253 	.type		= OVS_VPORT_TYPE_GENEVE,
254 	.create		= geneve_tnl_create,
255 	.destroy	= geneve_tnl_destroy,
256 	.get_name	= geneve_get_name,
257 	.get_options	= geneve_get_options,
258 	.send		= geneve_tnl_send,
259 	.owner          = THIS_MODULE,
260 	.get_egress_tun_info	= geneve_get_egress_tun_info,
261 };
262 
263 static int __init ovs_geneve_tnl_init(void)
264 {
265 	return ovs_vport_ops_register(&ovs_geneve_vport_ops);
266 }
267 
268 static void __exit ovs_geneve_tnl_exit(void)
269 {
270 	ovs_vport_ops_unregister(&ovs_geneve_vport_ops);
271 }
272 
273 module_init(ovs_geneve_tnl_init);
274 module_exit(ovs_geneve_tnl_exit);
275 
276 MODULE_DESCRIPTION("OVS: Geneve swiching port");
277 MODULE_LICENSE("GPL");
278 MODULE_ALIAS("vport-type-5");
279