xref: /linux/include/net/udp_tunnel.h (revision 6c363eafc4d637ac4bd83d4a7dd06dd3cfbe7c5f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_UDP_TUNNEL_H
3 #define __NET_UDP_TUNNEL_H
4 
5 #include <net/ip_tunnels.h>
6 #include <net/udp.h>
7 
8 #if IS_ENABLED(CONFIG_IPV6)
9 #include <net/ipv6.h>
10 #include <net/ipv6_stubs.h>
11 #endif
12 
13 struct udp_port_cfg {
14 	u8			family;
15 
16 	/* Used only for kernel-created sockets */
17 	union {
18 		struct in_addr		local_ip;
19 #if IS_ENABLED(CONFIG_IPV6)
20 		struct in6_addr		local_ip6;
21 #endif
22 	};
23 
24 	union {
25 		struct in_addr		peer_ip;
26 #if IS_ENABLED(CONFIG_IPV6)
27 		struct in6_addr		peer_ip6;
28 #endif
29 	};
30 
31 	__be16			local_udp_port;
32 	__be16			peer_udp_port;
33 	int			bind_ifindex;
34 	unsigned int		use_udp_checksums:1,
35 				use_udp6_tx_checksums:1,
36 				use_udp6_rx_checksums:1,
37 				ipv6_v6only:1;
38 };
39 
40 int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
41 		     struct socket **sockp);
42 
43 #if IS_ENABLED(CONFIG_IPV6)
44 int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
45 		     struct socket **sockp);
46 #else
47 static inline int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
48 				   struct socket **sockp)
49 {
50 	return 0;
51 }
52 #endif
53 
54 static inline int udp_sock_create(struct net *net,
55 				  struct udp_port_cfg *cfg,
56 				  struct socket **sockp)
57 {
58 	if (cfg->family == AF_INET)
59 		return udp_sock_create4(net, cfg, sockp);
60 
61 	if (cfg->family == AF_INET6)
62 		return udp_sock_create6(net, cfg, sockp);
63 
64 	return -EPFNOSUPPORT;
65 }
66 
67 typedef int (*udp_tunnel_encap_rcv_t)(struct sock *sk, struct sk_buff *skb);
68 typedef int (*udp_tunnel_encap_err_lookup_t)(struct sock *sk,
69 					     struct sk_buff *skb);
70 typedef void (*udp_tunnel_encap_destroy_t)(struct sock *sk);
71 typedef struct sk_buff *(*udp_tunnel_gro_receive_t)(struct sock *sk,
72 						    struct list_head *head,
73 						    struct sk_buff *skb);
74 typedef int (*udp_tunnel_gro_complete_t)(struct sock *sk, struct sk_buff *skb,
75 					 int nhoff);
76 
77 struct udp_tunnel_sock_cfg {
78 	void *sk_user_data;     /* user data used by encap_rcv call back */
79 	/* Used for setting up udp_sock fields, see udp.h for details */
80 	__u8  encap_type;
81 	udp_tunnel_encap_rcv_t encap_rcv;
82 	udp_tunnel_encap_err_lookup_t encap_err_lookup;
83 	udp_tunnel_encap_destroy_t encap_destroy;
84 	udp_tunnel_gro_receive_t gro_receive;
85 	udp_tunnel_gro_complete_t gro_complete;
86 };
87 
88 /* Setup the given (UDP) sock to receive UDP encapsulated packets */
89 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
90 			   struct udp_tunnel_sock_cfg *sock_cfg);
91 
92 /* -- List of parsable UDP tunnel types --
93  *
94  * Adding to this list will result in serious debate.  The main issue is
95  * that this list is essentially a list of workarounds for either poorly
96  * designed tunnels, or poorly designed device offloads.
97  *
98  * The parsing supported via these types should really be used for Rx
99  * traffic only as the network stack will have already inserted offsets for
100  * the location of the headers in the skb.  In addition any ports that are
101  * pushed should be kept within the namespace without leaking to other
102  * devices such as VFs or other ports on the same device.
103  *
104  * It is strongly encouraged to use CHECKSUM_COMPLETE for Rx to avoid the
105  * need to use this for Rx checksum offload.  It should not be necessary to
106  * call this function to perform Tx offloads on outgoing traffic.
107  */
108 enum udp_parsable_tunnel_type {
109 	UDP_TUNNEL_TYPE_VXLAN	  = BIT(0), /* RFC 7348 */
110 	UDP_TUNNEL_TYPE_GENEVE	  = BIT(1), /* draft-ietf-nvo3-geneve */
111 	UDP_TUNNEL_TYPE_VXLAN_GPE = BIT(2), /* draft-ietf-nvo3-vxlan-gpe */
112 };
113 
114 struct udp_tunnel_info {
115 	unsigned short type;
116 	sa_family_t sa_family;
117 	__be16 port;
118 	u8 hw_priv;
119 };
120 
121 /* Notify network devices of offloadable types */
122 void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
123 			     unsigned short type);
124 void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
125 			     unsigned short type);
126 void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type);
127 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type);
128 
129 static inline void udp_tunnel_get_rx_info(struct net_device *dev)
130 {
131 	ASSERT_RTNL();
132 	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
133 		return;
134 	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_PUSH_INFO, dev);
135 }
136 
137 static inline void udp_tunnel_drop_rx_info(struct net_device *dev)
138 {
139 	ASSERT_RTNL();
140 	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
141 		return;
142 	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_DROP_INFO, dev);
143 }
144 
145 /* Transmit the skb using UDP encapsulation. */
146 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
147 			 __be32 src, __be32 dst, __u8 tos, __u8 ttl,
148 			 __be16 df, __be16 src_port, __be16 dst_port,
149 			 bool xnet, bool nocheck);
150 
151 int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
152 			 struct sk_buff *skb,
153 			 struct net_device *dev, struct in6_addr *saddr,
154 			 struct in6_addr *daddr,
155 			 __u8 prio, __u8 ttl, __be32 label,
156 			 __be16 src_port, __be16 dst_port, bool nocheck);
157 
158 void udp_tunnel_sock_release(struct socket *sock);
159 
160 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
161 				    __be16 flags, __be64 tunnel_id,
162 				    int md_size);
163 
164 #ifdef CONFIG_INET
165 static inline int udp_tunnel_handle_offloads(struct sk_buff *skb, bool udp_csum)
166 {
167 	int type = udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
168 
169 	return iptunnel_handle_offloads(skb, type);
170 }
171 #endif
172 
173 static inline void udp_tunnel_encap_enable(struct socket *sock)
174 {
175 	struct udp_sock *up = udp_sk(sock->sk);
176 
177 	if (up->encap_enabled)
178 		return;
179 
180 	up->encap_enabled = 1;
181 #if IS_ENABLED(CONFIG_IPV6)
182 	if (sock->sk->sk_family == PF_INET6)
183 		ipv6_stub->udpv6_encap_enable();
184 #endif
185 	udp_encap_enable();
186 }
187 
188 #define UDP_TUNNEL_NIC_MAX_TABLES	4
189 
190 enum udp_tunnel_nic_info_flags {
191 	/* Device callbacks may sleep */
192 	UDP_TUNNEL_NIC_INFO_MAY_SLEEP	= BIT(0),
193 	/* Device only supports offloads when it's open, all ports
194 	 * will be removed before close and re-added after open.
195 	 */
196 	UDP_TUNNEL_NIC_INFO_OPEN_ONLY	= BIT(1),
197 	/* Device supports only IPv4 tunnels */
198 	UDP_TUNNEL_NIC_INFO_IPV4_ONLY	= BIT(2),
199 	/* Device has hard-coded the IANA VXLAN port (4789) as VXLAN.
200 	 * This port must not be counted towards n_entries of any table.
201 	 * Driver will not receive any callback associated with port 4789.
202 	 */
203 	UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN	= BIT(3),
204 };
205 
206 struct udp_tunnel_nic;
207 
208 #define UDP_TUNNEL_NIC_MAX_SHARING_DEVICES	(U16_MAX / 2)
209 
210 struct udp_tunnel_nic_shared {
211 	struct udp_tunnel_nic *udp_tunnel_nic_info;
212 
213 	struct list_head devices;
214 };
215 
216 struct udp_tunnel_nic_shared_node {
217 	struct net_device *dev;
218 	struct list_head list;
219 };
220 
221 /**
222  * struct udp_tunnel_nic_info - driver UDP tunnel offload information
223  * @set_port:	callback for adding a new port
224  * @unset_port:	callback for removing a port
225  * @sync_table:	callback for syncing the entire port table at once
226  * @shared:	reference to device global state (optional)
227  * @flags:	device flags from enum udp_tunnel_nic_info_flags
228  * @tables:	UDP port tables this device has
229  * @tables.n_entries:		number of entries in this table
230  * @tables.tunnel_types:	types of tunnels this table accepts
231  *
232  * Drivers are expected to provide either @set_port and @unset_port callbacks
233  * or the @sync_table callback. Callbacks are invoked with rtnl lock held.
234  *
235  * Devices which (misguidedly) share the UDP tunnel port table across multiple
236  * netdevs should allocate an instance of struct udp_tunnel_nic_shared and
237  * point @shared at it.
238  * There must never be more than %UDP_TUNNEL_NIC_MAX_SHARING_DEVICES devices
239  * sharing a table.
240  *
241  * Known limitations:
242  *  - UDP tunnel port notifications are fundamentally best-effort -
243  *    it is likely the driver will both see skbs which use a UDP tunnel port,
244  *    while not being a tunneled skb, and tunnel skbs from other ports -
245  *    drivers should only use these ports for non-critical RX-side offloads,
246  *    e.g. the checksum offload;
247  *  - none of the devices care about the socket family at present, so we don't
248  *    track it. Please extend this code if you care.
249  */
250 struct udp_tunnel_nic_info {
251 	/* one-by-one */
252 	int (*set_port)(struct net_device *dev,
253 			unsigned int table, unsigned int entry,
254 			struct udp_tunnel_info *ti);
255 	int (*unset_port)(struct net_device *dev,
256 			  unsigned int table, unsigned int entry,
257 			  struct udp_tunnel_info *ti);
258 
259 	/* all at once */
260 	int (*sync_table)(struct net_device *dev, unsigned int table);
261 
262 	struct udp_tunnel_nic_shared *shared;
263 
264 	unsigned int flags;
265 
266 	struct udp_tunnel_nic_table_info {
267 		unsigned int n_entries;
268 		unsigned int tunnel_types;
269 	} tables[UDP_TUNNEL_NIC_MAX_TABLES];
270 };
271 
272 /* UDP tunnel module dependencies
273  *
274  * Tunnel drivers are expected to have a hard dependency on the udp_tunnel
275  * module. NIC drivers are not, they just attach their
276  * struct udp_tunnel_nic_info to the netdev and wait for callbacks to come.
277  * Loading a tunnel driver will cause the udp_tunnel module to be loaded
278  * and only then will all the required state structures be allocated.
279  * Since we want a weak dependency from the drivers and the core to udp_tunnel
280  * we call things through the following stubs.
281  */
282 struct udp_tunnel_nic_ops {
283 	void (*get_port)(struct net_device *dev, unsigned int table,
284 			 unsigned int idx, struct udp_tunnel_info *ti);
285 	void (*set_port_priv)(struct net_device *dev, unsigned int table,
286 			      unsigned int idx, u8 priv);
287 	void (*add_port)(struct net_device *dev, struct udp_tunnel_info *ti);
288 	void (*del_port)(struct net_device *dev, struct udp_tunnel_info *ti);
289 	void (*reset_ntf)(struct net_device *dev);
290 
291 	size_t (*dump_size)(struct net_device *dev, unsigned int table);
292 	int (*dump_write)(struct net_device *dev, unsigned int table,
293 			  struct sk_buff *skb);
294 };
295 
296 #ifdef CONFIG_INET
297 extern const struct udp_tunnel_nic_ops *udp_tunnel_nic_ops;
298 #else
299 #define udp_tunnel_nic_ops	((struct udp_tunnel_nic_ops *)NULL)
300 #endif
301 
302 static inline void
303 udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table,
304 			unsigned int idx, struct udp_tunnel_info *ti)
305 {
306 	/* This helper is used from .sync_table, we indicate empty entries
307 	 * by zero'ed @ti. Drivers which need to know the details of a port
308 	 * when it gets deleted should use the .set_port / .unset_port
309 	 * callbacks.
310 	 * Zero out here, otherwise !CONFIG_INET causes uninitilized warnings.
311 	 */
312 	memset(ti, 0, sizeof(*ti));
313 
314 	if (udp_tunnel_nic_ops)
315 		udp_tunnel_nic_ops->get_port(dev, table, idx, ti);
316 }
317 
318 static inline void
319 udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
320 			     unsigned int idx, u8 priv)
321 {
322 	if (udp_tunnel_nic_ops)
323 		udp_tunnel_nic_ops->set_port_priv(dev, table, idx, priv);
324 }
325 
326 static inline void
327 udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti)
328 {
329 	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
330 		return;
331 	if (udp_tunnel_nic_ops)
332 		udp_tunnel_nic_ops->add_port(dev, ti);
333 }
334 
335 static inline void
336 udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti)
337 {
338 	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
339 		return;
340 	if (udp_tunnel_nic_ops)
341 		udp_tunnel_nic_ops->del_port(dev, ti);
342 }
343 
344 /**
345  * udp_tunnel_nic_reset_ntf() - device-originating reset notification
346  * @dev: network interface device structure
347  *
348  * Called by the driver to inform the core that the entire UDP tunnel port
349  * state has been lost, usually due to device reset. Core will assume device
350  * forgot all the ports and issue .set_port and .sync_table callbacks as
351  * necessary.
352  *
353  * This function must be called with rtnl lock held, and will issue all
354  * the callbacks before returning.
355  */
356 static inline void udp_tunnel_nic_reset_ntf(struct net_device *dev)
357 {
358 	if (udp_tunnel_nic_ops)
359 		udp_tunnel_nic_ops->reset_ntf(dev);
360 }
361 
362 static inline size_t
363 udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
364 {
365 	if (!udp_tunnel_nic_ops)
366 		return 0;
367 	return udp_tunnel_nic_ops->dump_size(dev, table);
368 }
369 
370 static inline int
371 udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
372 			  struct sk_buff *skb)
373 {
374 	if (!udp_tunnel_nic_ops)
375 		return 0;
376 	return udp_tunnel_nic_ops->dump_write(dev, table, skb);
377 }
378 #endif
379