1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * VMware vSockets Driver
4 *
5 * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
6 */
7
8#ifndef __AF_VSOCK_H__
9#define __AF_VSOCK_H__
10
11#include <linux/kernel.h>
12#include <linux/workqueue.h>
13#include <net/sock.h>
14#include <uapi/linux/vm_sockets.h>
15
16#include "vsock_addr.h"
17
18#define LAST_RESERVED_PORT 1023
19
20#define VSOCK_HASH_SIZE         251
21extern struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
22extern struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
23extern spinlock_t vsock_table_lock;
24
25#define vsock_sk(__sk)    ((struct vsock_sock *)__sk)
26#define sk_vsock(__vsk)   (&(__vsk)->sk)
27
28struct vsock_sock {
29	/* sk must be the first member. */
30	struct sock sk;
31	const struct vsock_transport *transport;
32	struct sockaddr_vm local_addr;
33	struct sockaddr_vm remote_addr;
34	/* Links for the global tables of bound and connected sockets. */
35	struct list_head bound_table;
36	struct list_head connected_table;
37	/* Accessed without the socket lock held. This means it can never be
38	 * modified outsided of socket create or destruct.
39	 */
40	bool trusted;
41	bool cached_peer_allow_dgram;	/* Dgram communication allowed to
42					 * cached peer?
43					 */
44	u32 cached_peer;  /* Context ID of last dgram destination check. */
45	const struct cred *owner;
46	/* Rest are SOCK_STREAM only. */
47	long connect_timeout;
48	/* Listening socket that this came from. */
49	struct sock *listener;
50	/* Used for pending list and accept queue during connection handshake.
51	 * The listening socket is the head for both lists.  Sockets created
52	 * for connection requests are placed in the pending list until they
53	 * are connected, at which point they are put in the accept queue list
54	 * so they can be accepted in accept().  If accept() cannot accept the
55	 * connection, it is marked as rejected so the cleanup function knows
56	 * to clean up the socket.
57	 */
58	struct list_head pending_links;
59	struct list_head accept_queue;
60	bool rejected;
61	struct delayed_work connect_work;
62	struct delayed_work pending_work;
63	struct delayed_work close_work;
64	bool close_work_scheduled;
65	u32 peer_shutdown;
66	bool sent_request;
67	bool ignore_connecting_rst;
68
69	/* Protected by lock_sock(sk) */
70	u64 buffer_size;
71	u64 buffer_min_size;
72	u64 buffer_max_size;
73
74	/* Private to transport. */
75	void *trans;
76};
77
78s64 vsock_connectible_has_data(struct vsock_sock *vsk);
79s64 vsock_stream_has_data(struct vsock_sock *vsk);
80s64 vsock_stream_has_space(struct vsock_sock *vsk);
81struct sock *vsock_create_connected(struct sock *parent);
82void vsock_data_ready(struct sock *sk);
83
84/**** TRANSPORT ****/
85
86struct vsock_transport_recv_notify_data {
87	u64 data1; /* Transport-defined. */
88	u64 data2; /* Transport-defined. */
89	bool notify_on_block;
90};
91
92struct vsock_transport_send_notify_data {
93	u64 data1; /* Transport-defined. */
94	u64 data2; /* Transport-defined. */
95};
96
97/* Transport features flags */
98/* Transport provides host->guest communication */
99#define VSOCK_TRANSPORT_F_H2G		0x00000001
100/* Transport provides guest->host communication */
101#define VSOCK_TRANSPORT_F_G2H		0x00000002
102/* Transport provides DGRAM communication */
103#define VSOCK_TRANSPORT_F_DGRAM		0x00000004
104/* Transport provides local (loopback) communication */
105#define VSOCK_TRANSPORT_F_LOCAL		0x00000008
106
107struct vsock_transport {
108	struct module *module;
109
110	/* Initialize/tear-down socket. */
111	int (*init)(struct vsock_sock *, struct vsock_sock *);
112	void (*destruct)(struct vsock_sock *);
113	void (*release)(struct vsock_sock *);
114
115	/* Cancel all pending packets sent on vsock. */
116	int (*cancel_pkt)(struct vsock_sock *vsk);
117
118	/* Connections. */
119	int (*connect)(struct vsock_sock *);
120
121	/* DGRAM. */
122	int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *);
123	int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
124			     size_t len, int flags);
125	int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
126			     struct msghdr *, size_t len);
127	bool (*dgram_allow)(u32 cid, u32 port);
128
129	/* STREAM. */
130	/* TODO: stream_bind() */
131	ssize_t (*stream_dequeue)(struct vsock_sock *, struct msghdr *,
132				  size_t len, int flags);
133	ssize_t (*stream_enqueue)(struct vsock_sock *, struct msghdr *,
134				  size_t len);
135	s64 (*stream_has_data)(struct vsock_sock *);
136	s64 (*stream_has_space)(struct vsock_sock *);
137	u64 (*stream_rcvhiwat)(struct vsock_sock *);
138	bool (*stream_is_active)(struct vsock_sock *);
139	bool (*stream_allow)(u32 cid, u32 port);
140
141	/* SEQ_PACKET. */
142	ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
143				     int flags);
144	int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
145				 size_t len);
146	bool (*seqpacket_allow)(u32 remote_cid);
147	u32 (*seqpacket_has_data)(struct vsock_sock *vsk);
148
149	/* Notification. */
150	int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
151	int (*notify_poll_out)(struct vsock_sock *, size_t, bool *);
152	int (*notify_recv_init)(struct vsock_sock *, size_t,
153		struct vsock_transport_recv_notify_data *);
154	int (*notify_recv_pre_block)(struct vsock_sock *, size_t,
155		struct vsock_transport_recv_notify_data *);
156	int (*notify_recv_pre_dequeue)(struct vsock_sock *, size_t,
157		struct vsock_transport_recv_notify_data *);
158	int (*notify_recv_post_dequeue)(struct vsock_sock *, size_t,
159		ssize_t, bool, struct vsock_transport_recv_notify_data *);
160	int (*notify_send_init)(struct vsock_sock *,
161		struct vsock_transport_send_notify_data *);
162	int (*notify_send_pre_block)(struct vsock_sock *,
163		struct vsock_transport_send_notify_data *);
164	int (*notify_send_pre_enqueue)(struct vsock_sock *,
165		struct vsock_transport_send_notify_data *);
166	int (*notify_send_post_enqueue)(struct vsock_sock *, ssize_t,
167		struct vsock_transport_send_notify_data *);
168	/* sk_lock held by the caller */
169	void (*notify_buffer_size)(struct vsock_sock *, u64 *);
170	int (*notify_set_rcvlowat)(struct vsock_sock *vsk, int val);
171
172	/* Shutdown. */
173	int (*shutdown)(struct vsock_sock *, int);
174
175	/* Addressing. */
176	u32 (*get_local_cid)(void);
177
178	/* Read a single skb */
179	int (*read_skb)(struct vsock_sock *, skb_read_actor_t);
180
181	/* Zero-copy. */
182	bool (*msgzerocopy_allow)(void);
183};
184
185/**** CORE ****/
186
187int vsock_core_register(const struct vsock_transport *t, int features);
188void vsock_core_unregister(const struct vsock_transport *t);
189
190/* The transport may downcast this to access transport-specific functions */
191const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk);
192
193/**** UTILS ****/
194
195/* vsock_table_lock must be held */
196static inline bool __vsock_in_bound_table(struct vsock_sock *vsk)
197{
198	return !list_empty(&vsk->bound_table);
199}
200
201/* vsock_table_lock must be held */
202static inline bool __vsock_in_connected_table(struct vsock_sock *vsk)
203{
204	return !list_empty(&vsk->connected_table);
205}
206
207void vsock_add_pending(struct sock *listener, struct sock *pending);
208void vsock_remove_pending(struct sock *listener, struct sock *pending);
209void vsock_enqueue_accept(struct sock *listener, struct sock *connected);
210void vsock_insert_connected(struct vsock_sock *vsk);
211void vsock_remove_bound(struct vsock_sock *vsk);
212void vsock_remove_connected(struct vsock_sock *vsk);
213struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr);
214struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
215					 struct sockaddr_vm *dst);
216void vsock_remove_sock(struct vsock_sock *vsk);
217void vsock_for_each_connected_socket(struct vsock_transport *transport,
218				     void (*fn)(struct sock *sk));
219int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
220bool vsock_find_cid(unsigned int cid);
221
222/**** TAP ****/
223
224struct vsock_tap {
225	struct net_device *dev;
226	struct module *module;
227	struct list_head list;
228};
229
230int vsock_add_tap(struct vsock_tap *vt);
231int vsock_remove_tap(struct vsock_tap *vt);
232void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque);
233int vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
234			      int flags);
235int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
236			size_t len, int flags);
237
238#ifdef CONFIG_BPF_SYSCALL
239extern struct proto vsock_proto;
240int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
241void __init vsock_bpf_build_proto(void);
242#else
243static inline void __init vsock_bpf_build_proto(void)
244{}
245#endif
246
247static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t)
248{
249	return t->msgzerocopy_allow && t->msgzerocopy_allow();
250}
251#endif /* __AF_VSOCK_H__ */
252