xref: /openbmc/linux/include/net/udp_tunnel.h (revision 13dd8710)
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 	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_PUSH_INFO, dev);
133 }
134 
135 static inline void udp_tunnel_drop_rx_info(struct net_device *dev)
136 {
137 	ASSERT_RTNL();
138 	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_DROP_INFO, dev);
139 }
140 
141 /* Transmit the skb using UDP encapsulation. */
142 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
143 			 __be32 src, __be32 dst, __u8 tos, __u8 ttl,
144 			 __be16 df, __be16 src_port, __be16 dst_port,
145 			 bool xnet, bool nocheck);
146 
147 int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
148 			 struct sk_buff *skb,
149 			 struct net_device *dev, struct in6_addr *saddr,
150 			 struct in6_addr *daddr,
151 			 __u8 prio, __u8 ttl, __be32 label,
152 			 __be16 src_port, __be16 dst_port, bool nocheck);
153 
154 void udp_tunnel_sock_release(struct socket *sock);
155 
156 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
157 				    __be16 flags, __be64 tunnel_id,
158 				    int md_size);
159 
160 #ifdef CONFIG_INET
161 static inline int udp_tunnel_handle_offloads(struct sk_buff *skb, bool udp_csum)
162 {
163 	int type = udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
164 
165 	return iptunnel_handle_offloads(skb, type);
166 }
167 #endif
168 
169 static inline void udp_tunnel_encap_enable(struct socket *sock)
170 {
171 	struct udp_sock *up = udp_sk(sock->sk);
172 
173 	if (up->encap_enabled)
174 		return;
175 
176 	up->encap_enabled = 1;
177 #if IS_ENABLED(CONFIG_IPV6)
178 	if (sock->sk->sk_family == PF_INET6)
179 		ipv6_stub->udpv6_encap_enable();
180 	else
181 #endif
182 		udp_encap_enable();
183 }
184 
185 #define UDP_TUNNEL_NIC_MAX_TABLES	4
186 
187 enum udp_tunnel_nic_info_flags {
188 	/* Device callbacks may sleep */
189 	UDP_TUNNEL_NIC_INFO_MAY_SLEEP	= BIT(0),
190 	/* Device only supports offloads when it's open, all ports
191 	 * will be removed before close and re-added after open.
192 	 */
193 	UDP_TUNNEL_NIC_INFO_OPEN_ONLY	= BIT(1),
194 	/* Device supports only IPv4 tunnels */
195 	UDP_TUNNEL_NIC_INFO_IPV4_ONLY	= BIT(2),
196 	/* Device has hard-coded the IANA VXLAN port (4789) as VXLAN.
197 	 * This port must not be counted towards n_entries of any table.
198 	 * Driver will not receive any callback associated with port 4789.
199 	 */
200 	UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN	= BIT(3),
201 };
202 
203 struct udp_tunnel_nic;
204 
205 #define UDP_TUNNEL_NIC_MAX_SHARING_DEVICES	(U16_MAX / 2)
206 
207 struct udp_tunnel_nic_shared {
208 	struct udp_tunnel_nic *udp_tunnel_nic_info;
209 
210 	struct list_head devices;
211 };
212 
213 struct udp_tunnel_nic_shared_node {
214 	struct net_device *dev;
215 	struct list_head list;
216 };
217 
218 /**
219  * struct udp_tunnel_nic_info - driver UDP tunnel offload information
220  * @set_port:	callback for adding a new port
221  * @unset_port:	callback for removing a port
222  * @sync_table:	callback for syncing the entire port table at once
223  * @shared:	reference to device global state (optional)
224  * @flags:	device flags from enum udp_tunnel_nic_info_flags
225  * @tables:	UDP port tables this device has
226  * @tables.n_entries:		number of entries in this table
227  * @tables.tunnel_types:	types of tunnels this table accepts
228  *
229  * Drivers are expected to provide either @set_port and @unset_port callbacks
230  * or the @sync_table callback. Callbacks are invoked with rtnl lock held.
231  *
232  * Devices which (misguidedly) share the UDP tunnel port table across multiple
233  * netdevs should allocate an instance of struct udp_tunnel_nic_shared and
234  * point @shared at it.
235  * There must never be more than %UDP_TUNNEL_NIC_MAX_SHARING_DEVICES devices
236  * sharing a table.
237  *
238  * Known limitations:
239  *  - UDP tunnel port notifications are fundamentally best-effort -
240  *    it is likely the driver will both see skbs which use a UDP tunnel port,
241  *    while not being a tunneled skb, and tunnel skbs from other ports -
242  *    drivers should only use these ports for non-critical RX-side offloads,
243  *    e.g. the checksum offload;
244  *  - none of the devices care about the socket family at present, so we don't
245  *    track it. Please extend this code if you care.
246  */
247 struct udp_tunnel_nic_info {
248 	/* one-by-one */
249 	int (*set_port)(struct net_device *dev,
250 			unsigned int table, unsigned int entry,
251 			struct udp_tunnel_info *ti);
252 	int (*unset_port)(struct net_device *dev,
253 			  unsigned int table, unsigned int entry,
254 			  struct udp_tunnel_info *ti);
255 
256 	/* all at once */
257 	int (*sync_table)(struct net_device *dev, unsigned int table);
258 
259 	struct udp_tunnel_nic_shared *shared;
260 
261 	unsigned int flags;
262 
263 	struct udp_tunnel_nic_table_info {
264 		unsigned int n_entries;
265 		unsigned int tunnel_types;
266 	} tables[UDP_TUNNEL_NIC_MAX_TABLES];
267 };
268 
269 /* UDP tunnel module dependencies
270  *
271  * Tunnel drivers are expected to have a hard dependency on the udp_tunnel
272  * module. NIC drivers are not, they just attach their
273  * struct udp_tunnel_nic_info to the netdev and wait for callbacks to come.
274  * Loading a tunnel driver will cause the udp_tunnel module to be loaded
275  * and only then will all the required state structures be allocated.
276  * Since we want a weak dependency from the drivers and the core to udp_tunnel
277  * we call things through the following stubs.
278  */
279 struct udp_tunnel_nic_ops {
280 	void (*get_port)(struct net_device *dev, unsigned int table,
281 			 unsigned int idx, struct udp_tunnel_info *ti);
282 	void (*set_port_priv)(struct net_device *dev, unsigned int table,
283 			      unsigned int idx, u8 priv);
284 	void (*add_port)(struct net_device *dev, struct udp_tunnel_info *ti);
285 	void (*del_port)(struct net_device *dev, struct udp_tunnel_info *ti);
286 	void (*reset_ntf)(struct net_device *dev);
287 
288 	size_t (*dump_size)(struct net_device *dev, unsigned int table);
289 	int (*dump_write)(struct net_device *dev, unsigned int table,
290 			  struct sk_buff *skb);
291 };
292 
293 #ifdef CONFIG_INET
294 extern const struct udp_tunnel_nic_ops *udp_tunnel_nic_ops;
295 #else
296 #define udp_tunnel_nic_ops	((struct udp_tunnel_nic_ops *)NULL)
297 #endif
298 
299 static inline void
300 udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table,
301 			unsigned int idx, struct udp_tunnel_info *ti)
302 {
303 	/* This helper is used from .sync_table, we indicate empty entries
304 	 * by zero'ed @ti. Drivers which need to know the details of a port
305 	 * when it gets deleted should use the .set_port / .unset_port
306 	 * callbacks.
307 	 * Zero out here, otherwise !CONFIG_INET causes uninitilized warnings.
308 	 */
309 	memset(ti, 0, sizeof(*ti));
310 
311 	if (udp_tunnel_nic_ops)
312 		udp_tunnel_nic_ops->get_port(dev, table, idx, ti);
313 }
314 
315 static inline void
316 udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
317 			     unsigned int idx, u8 priv)
318 {
319 	if (udp_tunnel_nic_ops)
320 		udp_tunnel_nic_ops->set_port_priv(dev, table, idx, priv);
321 }
322 
323 static inline void
324 udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti)
325 {
326 	if (udp_tunnel_nic_ops)
327 		udp_tunnel_nic_ops->add_port(dev, ti);
328 }
329 
330 static inline void
331 udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti)
332 {
333 	if (udp_tunnel_nic_ops)
334 		udp_tunnel_nic_ops->del_port(dev, ti);
335 }
336 
337 /**
338  * udp_tunnel_nic_reset_ntf() - device-originating reset notification
339  * @dev: network interface device structure
340  *
341  * Called by the driver to inform the core that the entire UDP tunnel port
342  * state has been lost, usually due to device reset. Core will assume device
343  * forgot all the ports and issue .set_port and .sync_table callbacks as
344  * necessary.
345  *
346  * This function must be called with rtnl lock held, and will issue all
347  * the callbacks before returning.
348  */
349 static inline void udp_tunnel_nic_reset_ntf(struct net_device *dev)
350 {
351 	if (udp_tunnel_nic_ops)
352 		udp_tunnel_nic_ops->reset_ntf(dev);
353 }
354 
355 static inline size_t
356 udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
357 {
358 	if (!udp_tunnel_nic_ops)
359 		return 0;
360 	return udp_tunnel_nic_ops->dump_size(dev, table);
361 }
362 
363 static inline int
364 udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
365 			  struct sk_buff *skb)
366 {
367 	if (!udp_tunnel_nic_ops)
368 		return 0;
369 	return udp_tunnel_nic_ops->dump_write(dev, table, skb);
370 }
371 #endif
372