xref: /linux/include/net/udp_tunnel.h (revision 0da908c291070d89482f6211dbe81d4d43c3f7cb)
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_err_rcv_t)(struct sock *sk,
71 					   struct sk_buff *skb, int err,
72 					   __be16 port, u32 info, u8 *payload);
73 typedef void (*udp_tunnel_encap_destroy_t)(struct sock *sk);
74 typedef struct sk_buff *(*udp_tunnel_gro_receive_t)(struct sock *sk,
75 						    struct list_head *head,
76 						    struct sk_buff *skb);
77 typedef int (*udp_tunnel_gro_complete_t)(struct sock *sk, struct sk_buff *skb,
78 					 int nhoff);
79 
80 struct udp_tunnel_sock_cfg {
81 	void *sk_user_data;     /* user data used by encap_rcv call back */
82 	/* Used for setting up udp_sock fields, see udp.h for details */
83 	__u8  encap_type;
84 	udp_tunnel_encap_rcv_t encap_rcv;
85 	udp_tunnel_encap_err_lookup_t encap_err_lookup;
86 	udp_tunnel_encap_err_rcv_t encap_err_rcv;
87 	udp_tunnel_encap_destroy_t encap_destroy;
88 	udp_tunnel_gro_receive_t gro_receive;
89 	udp_tunnel_gro_complete_t gro_complete;
90 };
91 
92 /* Setup the given (UDP) sock to receive UDP encapsulated packets */
93 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
94 			   struct udp_tunnel_sock_cfg *sock_cfg);
95 
96 /* -- List of parsable UDP tunnel types --
97  *
98  * Adding to this list will result in serious debate.  The main issue is
99  * that this list is essentially a list of workarounds for either poorly
100  * designed tunnels, or poorly designed device offloads.
101  *
102  * The parsing supported via these types should really be used for Rx
103  * traffic only as the network stack will have already inserted offsets for
104  * the location of the headers in the skb.  In addition any ports that are
105  * pushed should be kept within the namespace without leaking to other
106  * devices such as VFs or other ports on the same device.
107  *
108  * It is strongly encouraged to use CHECKSUM_COMPLETE for Rx to avoid the
109  * need to use this for Rx checksum offload.  It should not be necessary to
110  * call this function to perform Tx offloads on outgoing traffic.
111  */
112 enum udp_parsable_tunnel_type {
113 	UDP_TUNNEL_TYPE_VXLAN	  = BIT(0), /* RFC 7348 */
114 	UDP_TUNNEL_TYPE_GENEVE	  = BIT(1), /* draft-ietf-nvo3-geneve */
115 	UDP_TUNNEL_TYPE_VXLAN_GPE = BIT(2), /* draft-ietf-nvo3-vxlan-gpe */
116 };
117 
118 struct udp_tunnel_info {
119 	unsigned short type;
120 	sa_family_t sa_family;
121 	__be16 port;
122 	u8 hw_priv;
123 };
124 
125 /* Notify network devices of offloadable types */
126 void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
127 			     unsigned short type);
128 void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
129 			     unsigned short type);
130 void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type);
131 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type);
132 
133 static inline void udp_tunnel_get_rx_info(struct net_device *dev)
134 {
135 	ASSERT_RTNL();
136 	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
137 		return;
138 	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_PUSH_INFO, dev);
139 }
140 
141 static inline void udp_tunnel_drop_rx_info(struct net_device *dev)
142 {
143 	ASSERT_RTNL();
144 	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
145 		return;
146 	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_DROP_INFO, dev);
147 }
148 
149 /* Transmit the skb using UDP encapsulation. */
150 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
151 			 __be32 src, __be32 dst, __u8 tos, __u8 ttl,
152 			 __be16 df, __be16 src_port, __be16 dst_port,
153 			 bool xnet, bool nocheck);
154 
155 int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
156 			 struct sk_buff *skb,
157 			 struct net_device *dev, struct in6_addr *saddr,
158 			 struct in6_addr *daddr,
159 			 __u8 prio, __u8 ttl, __be32 label,
160 			 __be16 src_port, __be16 dst_port, bool nocheck);
161 
162 void udp_tunnel_sock_release(struct socket *sock);
163 
164 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
165 				    __be16 flags, __be64 tunnel_id,
166 				    int md_size);
167 
168 #ifdef CONFIG_INET
169 static inline int udp_tunnel_handle_offloads(struct sk_buff *skb, bool udp_csum)
170 {
171 	int type = udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
172 
173 	return iptunnel_handle_offloads(skb, type);
174 }
175 #endif
176 
177 static inline void udp_tunnel_encap_enable(struct socket *sock)
178 {
179 	struct udp_sock *up = udp_sk(sock->sk);
180 
181 	if (up->encap_enabled)
182 		return;
183 
184 	up->encap_enabled = 1;
185 #if IS_ENABLED(CONFIG_IPV6)
186 	if (sock->sk->sk_family == PF_INET6)
187 		ipv6_stub->udpv6_encap_enable();
188 #endif
189 	udp_encap_enable();
190 }
191 
192 #define UDP_TUNNEL_NIC_MAX_TABLES	4
193 
194 enum udp_tunnel_nic_info_flags {
195 	/* Device callbacks may sleep */
196 	UDP_TUNNEL_NIC_INFO_MAY_SLEEP	= BIT(0),
197 	/* Device only supports offloads when it's open, all ports
198 	 * will be removed before close and re-added after open.
199 	 */
200 	UDP_TUNNEL_NIC_INFO_OPEN_ONLY	= BIT(1),
201 	/* Device supports only IPv4 tunnels */
202 	UDP_TUNNEL_NIC_INFO_IPV4_ONLY	= BIT(2),
203 	/* Device has hard-coded the IANA VXLAN port (4789) as VXLAN.
204 	 * This port must not be counted towards n_entries of any table.
205 	 * Driver will not receive any callback associated with port 4789.
206 	 */
207 	UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN	= BIT(3),
208 };
209 
210 struct udp_tunnel_nic;
211 
212 #define UDP_TUNNEL_NIC_MAX_SHARING_DEVICES	(U16_MAX / 2)
213 
214 struct udp_tunnel_nic_shared {
215 	struct udp_tunnel_nic *udp_tunnel_nic_info;
216 
217 	struct list_head devices;
218 };
219 
220 struct udp_tunnel_nic_shared_node {
221 	struct net_device *dev;
222 	struct list_head list;
223 };
224 
225 /**
226  * struct udp_tunnel_nic_info - driver UDP tunnel offload information
227  * @set_port:	callback for adding a new port
228  * @unset_port:	callback for removing a port
229  * @sync_table:	callback for syncing the entire port table at once
230  * @shared:	reference to device global state (optional)
231  * @flags:	device flags from enum udp_tunnel_nic_info_flags
232  * @tables:	UDP port tables this device has
233  * @tables.n_entries:		number of entries in this table
234  * @tables.tunnel_types:	types of tunnels this table accepts
235  *
236  * Drivers are expected to provide either @set_port and @unset_port callbacks
237  * or the @sync_table callback. Callbacks are invoked with rtnl lock held.
238  *
239  * Devices which (misguidedly) share the UDP tunnel port table across multiple
240  * netdevs should allocate an instance of struct udp_tunnel_nic_shared and
241  * point @shared at it.
242  * There must never be more than %UDP_TUNNEL_NIC_MAX_SHARING_DEVICES devices
243  * sharing a table.
244  *
245  * Known limitations:
246  *  - UDP tunnel port notifications are fundamentally best-effort -
247  *    it is likely the driver will both see skbs which use a UDP tunnel port,
248  *    while not being a tunneled skb, and tunnel skbs from other ports -
249  *    drivers should only use these ports for non-critical RX-side offloads,
250  *    e.g. the checksum offload;
251  *  - none of the devices care about the socket family at present, so we don't
252  *    track it. Please extend this code if you care.
253  */
254 struct udp_tunnel_nic_info {
255 	/* one-by-one */
256 	int (*set_port)(struct net_device *dev,
257 			unsigned int table, unsigned int entry,
258 			struct udp_tunnel_info *ti);
259 	int (*unset_port)(struct net_device *dev,
260 			  unsigned int table, unsigned int entry,
261 			  struct udp_tunnel_info *ti);
262 
263 	/* all at once */
264 	int (*sync_table)(struct net_device *dev, unsigned int table);
265 
266 	struct udp_tunnel_nic_shared *shared;
267 
268 	unsigned int flags;
269 
270 	struct udp_tunnel_nic_table_info {
271 		unsigned int n_entries;
272 		unsigned int tunnel_types;
273 	} tables[UDP_TUNNEL_NIC_MAX_TABLES];
274 };
275 
276 /* UDP tunnel module dependencies
277  *
278  * Tunnel drivers are expected to have a hard dependency on the udp_tunnel
279  * module. NIC drivers are not, they just attach their
280  * struct udp_tunnel_nic_info to the netdev and wait for callbacks to come.
281  * Loading a tunnel driver will cause the udp_tunnel module to be loaded
282  * and only then will all the required state structures be allocated.
283  * Since we want a weak dependency from the drivers and the core to udp_tunnel
284  * we call things through the following stubs.
285  */
286 struct udp_tunnel_nic_ops {
287 	void (*get_port)(struct net_device *dev, unsigned int table,
288 			 unsigned int idx, struct udp_tunnel_info *ti);
289 	void (*set_port_priv)(struct net_device *dev, unsigned int table,
290 			      unsigned int idx, u8 priv);
291 	void (*add_port)(struct net_device *dev, struct udp_tunnel_info *ti);
292 	void (*del_port)(struct net_device *dev, struct udp_tunnel_info *ti);
293 	void (*reset_ntf)(struct net_device *dev);
294 
295 	size_t (*dump_size)(struct net_device *dev, unsigned int table);
296 	int (*dump_write)(struct net_device *dev, unsigned int table,
297 			  struct sk_buff *skb);
298 };
299 
300 #ifdef CONFIG_INET
301 extern const struct udp_tunnel_nic_ops *udp_tunnel_nic_ops;
302 #else
303 #define udp_tunnel_nic_ops	((struct udp_tunnel_nic_ops *)NULL)
304 #endif
305 
306 static inline void
307 udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table,
308 			unsigned int idx, struct udp_tunnel_info *ti)
309 {
310 	/* This helper is used from .sync_table, we indicate empty entries
311 	 * by zero'ed @ti. Drivers which need to know the details of a port
312 	 * when it gets deleted should use the .set_port / .unset_port
313 	 * callbacks.
314 	 * Zero out here, otherwise !CONFIG_INET causes uninitilized warnings.
315 	 */
316 	memset(ti, 0, sizeof(*ti));
317 
318 	if (udp_tunnel_nic_ops)
319 		udp_tunnel_nic_ops->get_port(dev, table, idx, ti);
320 }
321 
322 static inline void
323 udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
324 			     unsigned int idx, u8 priv)
325 {
326 	if (udp_tunnel_nic_ops)
327 		udp_tunnel_nic_ops->set_port_priv(dev, table, idx, priv);
328 }
329 
330 static inline void
331 udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti)
332 {
333 	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
334 		return;
335 	if (udp_tunnel_nic_ops)
336 		udp_tunnel_nic_ops->add_port(dev, ti);
337 }
338 
339 static inline void
340 udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti)
341 {
342 	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
343 		return;
344 	if (udp_tunnel_nic_ops)
345 		udp_tunnel_nic_ops->del_port(dev, ti);
346 }
347 
348 /**
349  * udp_tunnel_nic_reset_ntf() - device-originating reset notification
350  * @dev: network interface device structure
351  *
352  * Called by the driver to inform the core that the entire UDP tunnel port
353  * state has been lost, usually due to device reset. Core will assume device
354  * forgot all the ports and issue .set_port and .sync_table callbacks as
355  * necessary.
356  *
357  * This function must be called with rtnl lock held, and will issue all
358  * the callbacks before returning.
359  */
360 static inline void udp_tunnel_nic_reset_ntf(struct net_device *dev)
361 {
362 	if (udp_tunnel_nic_ops)
363 		udp_tunnel_nic_ops->reset_ntf(dev);
364 }
365 
366 static inline size_t
367 udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
368 {
369 	if (!udp_tunnel_nic_ops)
370 		return 0;
371 	return udp_tunnel_nic_ops->dump_size(dev, table);
372 }
373 
374 static inline int
375 udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
376 			  struct sk_buff *skb)
377 {
378 	if (!udp_tunnel_nic_ops)
379 		return 0;
380 	return udp_tunnel_nic_ops->dump_write(dev, table, skb);
381 }
382 #endif
383