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