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
13struct 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
40int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
41		     struct socket **sockp);
42
43#if IS_ENABLED(CONFIG_IPV6)
44int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
45		     struct socket **sockp);
46#else
47static 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
54static 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
67typedef int (*udp_tunnel_encap_rcv_t)(struct sock *sk, struct sk_buff *skb);
68typedef int (*udp_tunnel_encap_err_lookup_t)(struct sock *sk,
69					     struct sk_buff *skb);
70typedef void (*udp_tunnel_encap_destroy_t)(struct sock *sk);
71typedef struct sk_buff *(*udp_tunnel_gro_receive_t)(struct sock *sk,
72						    struct list_head *head,
73						    struct sk_buff *skb);
74typedef int (*udp_tunnel_gro_complete_t)(struct sock *sk, struct sk_buff *skb,
75					 int nhoff);
76
77struct 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 */
89void 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 */
108enum 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
114struct 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 */
122void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
123			     unsigned short type);
124void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
125			     unsigned short type);
126void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type);
127void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type);
128
129static 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
135static 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. */
142void 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
147int 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
154void udp_tunnel_sock_release(struct socket *sock);
155
156struct 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
161static 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
169static 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#endif
181	udp_encap_enable();
182}
183
184#define UDP_TUNNEL_NIC_MAX_TABLES	4
185
186enum udp_tunnel_nic_info_flags {
187	/* Device callbacks may sleep */
188	UDP_TUNNEL_NIC_INFO_MAY_SLEEP	= BIT(0),
189	/* Device only supports offloads when it's open, all ports
190	 * will be removed before close and re-added after open.
191	 */
192	UDP_TUNNEL_NIC_INFO_OPEN_ONLY	= BIT(1),
193	/* Device supports only IPv4 tunnels */
194	UDP_TUNNEL_NIC_INFO_IPV4_ONLY	= BIT(2),
195	/* Device has hard-coded the IANA VXLAN port (4789) as VXLAN.
196	 * This port must not be counted towards n_entries of any table.
197	 * Driver will not receive any callback associated with port 4789.
198	 */
199	UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN	= BIT(3),
200};
201
202struct udp_tunnel_nic;
203
204#define UDP_TUNNEL_NIC_MAX_SHARING_DEVICES	(U16_MAX / 2)
205
206struct udp_tunnel_nic_shared {
207	struct udp_tunnel_nic *udp_tunnel_nic_info;
208
209	struct list_head devices;
210};
211
212struct udp_tunnel_nic_shared_node {
213	struct net_device *dev;
214	struct list_head list;
215};
216
217/**
218 * struct udp_tunnel_nic_info - driver UDP tunnel offload information
219 * @set_port:	callback for adding a new port
220 * @unset_port:	callback for removing a port
221 * @sync_table:	callback for syncing the entire port table at once
222 * @shared:	reference to device global state (optional)
223 * @flags:	device flags from enum udp_tunnel_nic_info_flags
224 * @tables:	UDP port tables this device has
225 * @tables.n_entries:		number of entries in this table
226 * @tables.tunnel_types:	types of tunnels this table accepts
227 *
228 * Drivers are expected to provide either @set_port and @unset_port callbacks
229 * or the @sync_table callback. Callbacks are invoked with rtnl lock held.
230 *
231 * Devices which (misguidedly) share the UDP tunnel port table across multiple
232 * netdevs should allocate an instance of struct udp_tunnel_nic_shared and
233 * point @shared at it.
234 * There must never be more than %UDP_TUNNEL_NIC_MAX_SHARING_DEVICES devices
235 * sharing a table.
236 *
237 * Known limitations:
238 *  - UDP tunnel port notifications are fundamentally best-effort -
239 *    it is likely the driver will both see skbs which use a UDP tunnel port,
240 *    while not being a tunneled skb, and tunnel skbs from other ports -
241 *    drivers should only use these ports for non-critical RX-side offloads,
242 *    e.g. the checksum offload;
243 *  - none of the devices care about the socket family at present, so we don't
244 *    track it. Please extend this code if you care.
245 */
246struct udp_tunnel_nic_info {
247	/* one-by-one */
248	int (*set_port)(struct net_device *dev,
249			unsigned int table, unsigned int entry,
250			struct udp_tunnel_info *ti);
251	int (*unset_port)(struct net_device *dev,
252			  unsigned int table, unsigned int entry,
253			  struct udp_tunnel_info *ti);
254
255	/* all at once */
256	int (*sync_table)(struct net_device *dev, unsigned int table);
257
258	struct udp_tunnel_nic_shared *shared;
259
260	unsigned int flags;
261
262	struct udp_tunnel_nic_table_info {
263		unsigned int n_entries;
264		unsigned int tunnel_types;
265	} tables[UDP_TUNNEL_NIC_MAX_TABLES];
266};
267
268/* UDP tunnel module dependencies
269 *
270 * Tunnel drivers are expected to have a hard dependency on the udp_tunnel
271 * module. NIC drivers are not, they just attach their
272 * struct udp_tunnel_nic_info to the netdev and wait for callbacks to come.
273 * Loading a tunnel driver will cause the udp_tunnel module to be loaded
274 * and only then will all the required state structures be allocated.
275 * Since we want a weak dependency from the drivers and the core to udp_tunnel
276 * we call things through the following stubs.
277 */
278struct udp_tunnel_nic_ops {
279	void (*get_port)(struct net_device *dev, unsigned int table,
280			 unsigned int idx, struct udp_tunnel_info *ti);
281	void (*set_port_priv)(struct net_device *dev, unsigned int table,
282			      unsigned int idx, u8 priv);
283	void (*add_port)(struct net_device *dev, struct udp_tunnel_info *ti);
284	void (*del_port)(struct net_device *dev, struct udp_tunnel_info *ti);
285	void (*reset_ntf)(struct net_device *dev);
286
287	size_t (*dump_size)(struct net_device *dev, unsigned int table);
288	int (*dump_write)(struct net_device *dev, unsigned int table,
289			  struct sk_buff *skb);
290};
291
292#ifdef CONFIG_INET
293extern const struct udp_tunnel_nic_ops *udp_tunnel_nic_ops;
294#else
295#define udp_tunnel_nic_ops	((struct udp_tunnel_nic_ops *)NULL)
296#endif
297
298static inline void
299udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table,
300			unsigned int idx, struct udp_tunnel_info *ti)
301{
302	/* This helper is used from .sync_table, we indicate empty entries
303	 * by zero'ed @ti. Drivers which need to know the details of a port
304	 * when it gets deleted should use the .set_port / .unset_port
305	 * callbacks.
306	 * Zero out here, otherwise !CONFIG_INET causes uninitilized warnings.
307	 */
308	memset(ti, 0, sizeof(*ti));
309
310	if (udp_tunnel_nic_ops)
311		udp_tunnel_nic_ops->get_port(dev, table, idx, ti);
312}
313
314static inline void
315udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
316			     unsigned int idx, u8 priv)
317{
318	if (udp_tunnel_nic_ops)
319		udp_tunnel_nic_ops->set_port_priv(dev, table, idx, priv);
320}
321
322static inline void
323udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti)
324{
325	if (udp_tunnel_nic_ops)
326		udp_tunnel_nic_ops->add_port(dev, ti);
327}
328
329static inline void
330udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti)
331{
332	if (udp_tunnel_nic_ops)
333		udp_tunnel_nic_ops->del_port(dev, ti);
334}
335
336/**
337 * udp_tunnel_nic_reset_ntf() - device-originating reset notification
338 * @dev: network interface device structure
339 *
340 * Called by the driver to inform the core that the entire UDP tunnel port
341 * state has been lost, usually due to device reset. Core will assume device
342 * forgot all the ports and issue .set_port and .sync_table callbacks as
343 * necessary.
344 *
345 * This function must be called with rtnl lock held, and will issue all
346 * the callbacks before returning.
347 */
348static inline void udp_tunnel_nic_reset_ntf(struct net_device *dev)
349{
350	if (udp_tunnel_nic_ops)
351		udp_tunnel_nic_ops->reset_ntf(dev);
352}
353
354static inline size_t
355udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
356{
357	if (!udp_tunnel_nic_ops)
358		return 0;
359	return udp_tunnel_nic_ops->dump_size(dev, table);
360}
361
362static inline int
363udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
364			  struct sk_buff *skb)
365{
366	if (!udp_tunnel_nic_ops)
367		return 0;
368	return udp_tunnel_nic_ops->dump_write(dev, table, skb);
369}
370#endif
371