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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/netns/vsock.h>
14#include <net/sock.h>
15#include <uapi/linux/vm_sockets.h>
16
17#include "vsock_addr.h"
18
19#define LAST_RESERVED_PORT 1023
20
21#define VSOCK_HASH_SIZE 251
22extern struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
23extern struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
24extern spinlock_t vsock_table_lock;
25
26#define vsock_sk(__sk) ((struct vsock_sock *)__sk)
27#define sk_vsock(__vsk) (&(__vsk)->sk)
28
29struct vsock_sock {
30 /* sk must be the first member. */
31 struct sock sk;
32 const struct vsock_transport *transport;
33 struct sockaddr_vm local_addr;
34 struct sockaddr_vm remote_addr;
35 /* Links for the global tables of bound and connected sockets. */
36 struct list_head bound_table;
37 struct list_head connected_table;
38 /* Accessed without the socket lock held. This means it can never be
39 * modified outsided of socket create or destruct.
40 */
41 bool trusted;
42 bool cached_peer_allow_dgram; /* Dgram communication allowed to
43 * cached peer?
44 */
45 u32 cached_peer; /* Context ID of last dgram destination check. */
46 const struct cred *owner;
47 /* Rest are SOCK_STREAM only. */
48 long connect_timeout;
49 /* Listening socket that this came from. */
50 struct sock *listener;
51 /* Used for pending list and accept queue during connection handshake.
52 * The listening socket is the head for both lists. Sockets created
53 * for connection requests are placed in the pending list until they
54 * are connected, at which point they are put in the accept queue list
55 * so they can be accepted in accept().
56 */
57 struct list_head pending_links;
58 struct list_head accept_queue;
59 struct delayed_work connect_work;
60 struct delayed_work pending_work;
61 struct delayed_work close_work;
62 bool close_work_scheduled;
63 u32 peer_shutdown;
64 bool sent_request;
65 bool ignore_connecting_rst;
66
67 /* Protected by lock_sock(sk) */
68 u64 buffer_size;
69 u64 buffer_min_size;
70 u64 buffer_max_size;
71
72 /* Private to transport. */
73 void *trans;
74};
75
76s64 vsock_connectible_has_data(struct vsock_sock *vsk);
77s64 vsock_stream_has_data(struct vsock_sock *vsk);
78s64 vsock_stream_has_space(struct vsock_sock *vsk);
79struct sock *vsock_create_connected(struct sock *parent);
80void vsock_data_ready(struct sock *sk);
81
82/**** TRANSPORT ****/
83
84struct vsock_transport_recv_notify_data {
85 u64 data1; /* Transport-defined. */
86 u64 data2; /* Transport-defined. */
87 bool notify_on_block;
88};
89
90struct vsock_transport_send_notify_data {
91 u64 data1; /* Transport-defined. */
92 u64 data2; /* Transport-defined. */
93};
94
95/* Transport features flags */
96/* Transport provides host->guest communication */
97#define VSOCK_TRANSPORT_F_H2G 0x00000001
98/* Transport provides guest->host communication */
99#define VSOCK_TRANSPORT_F_G2H 0x00000002
100/* Transport provides DGRAM communication */
101#define VSOCK_TRANSPORT_F_DGRAM 0x00000004
102/* Transport provides local (loopback) communication */
103#define VSOCK_TRANSPORT_F_LOCAL 0x00000008
104
105struct vsock_transport {
106 struct module *module;
107
108 /* Initialize/tear-down socket. */
109 int (*init)(struct vsock_sock *, struct vsock_sock *);
110 void (*destruct)(struct vsock_sock *);
111 void (*release)(struct vsock_sock *);
112
113 /* Cancel all pending packets sent on vsock. */
114 int (*cancel_pkt)(struct vsock_sock *vsk);
115
116 /* Connections. */
117 int (*connect)(struct vsock_sock *);
118
119 /* DGRAM. */
120 int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *);
121 int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
122 size_t len, int flags);
123 int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
124 struct msghdr *, size_t len);
125 bool (*dgram_allow)(struct vsock_sock *vsk, u32 cid, u32 port);
126
127 /* STREAM. */
128 /* TODO: stream_bind() */
129 ssize_t (*stream_dequeue)(struct vsock_sock *, struct msghdr *,
130 size_t len, int flags);
131 ssize_t (*stream_enqueue)(struct vsock_sock *, struct msghdr *,
132 size_t len);
133 s64 (*stream_has_data)(struct vsock_sock *);
134 s64 (*stream_has_space)(struct vsock_sock *);
135 u64 (*stream_rcvhiwat)(struct vsock_sock *);
136 bool (*stream_is_active)(struct vsock_sock *);
137 bool (*stream_allow)(struct vsock_sock *vsk, u32 cid, u32 port);
138
139 /* SEQ_PACKET. */
140 ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
141 int flags);
142 int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
143 size_t len);
144 bool (*seqpacket_allow)(struct vsock_sock *vsk, u32 remote_cid);
145 u32 (*seqpacket_has_data)(struct vsock_sock *vsk);
146
147 /* Notification. */
148 int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
149 int (*notify_poll_out)(struct vsock_sock *, size_t, bool *);
150 int (*notify_recv_init)(struct vsock_sock *, size_t,
151 struct vsock_transport_recv_notify_data *);
152 int (*notify_recv_pre_block)(struct vsock_sock *, size_t,
153 struct vsock_transport_recv_notify_data *);
154 int (*notify_recv_pre_dequeue)(struct vsock_sock *, size_t,
155 struct vsock_transport_recv_notify_data *);
156 int (*notify_recv_post_dequeue)(struct vsock_sock *, size_t,
157 ssize_t, bool, struct vsock_transport_recv_notify_data *);
158 int (*notify_send_init)(struct vsock_sock *,
159 struct vsock_transport_send_notify_data *);
160 int (*notify_send_pre_block)(struct vsock_sock *,
161 struct vsock_transport_send_notify_data *);
162 int (*notify_send_pre_enqueue)(struct vsock_sock *,
163 struct vsock_transport_send_notify_data *);
164 int (*notify_send_post_enqueue)(struct vsock_sock *, ssize_t,
165 struct vsock_transport_send_notify_data *);
166 /* sk_lock held by the caller */
167 void (*notify_buffer_size)(struct vsock_sock *, u64 *);
168 int (*notify_set_rcvlowat)(struct vsock_sock *vsk, int val);
169
170 /* SIOCOUTQ ioctl */
171 ssize_t (*unsent_bytes)(struct vsock_sock *vsk);
172
173 /* Shutdown. */
174 int (*shutdown)(struct vsock_sock *, int);
175
176 /* Addressing. */
177 u32 (*get_local_cid)(void);
178
179 /* Check if this transport serves a specific remote CID.
180 * For H2G transports: return true if the CID belongs to a registered
181 * guest. If not implemented, all CIDs > VMADDR_CID_HOST go to H2G.
182 * For G2H transports: return true if the transport can reach arbitrary
183 * CIDs via the hypervisor (i.e. supports the fallback overlay). VMCI
184 * does not implement this as it only serves CIDs 0 and 2.
185 */
186 bool (*has_remote_cid)(struct vsock_sock *vsk, u32 remote_cid);
187
188 /* Read a single skb */
189 int (*read_skb)(struct vsock_sock *, skb_read_actor_t);
190
191 /* Zero-copy. */
192 bool (*msgzerocopy_allow)(void);
193};
194
195/**** CORE ****/
196
197int vsock_core_register(const struct vsock_transport *t, int features);
198void vsock_core_unregister(const struct vsock_transport *t);
199
200/* The transport may downcast this to access transport-specific functions */
201const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk);
202
203/**** UTILS ****/
204
205/* vsock_table_lock must be held */
206static inline bool __vsock_in_bound_table(struct vsock_sock *vsk)
207{
208 return !list_empty(&vsk->bound_table);
209}
210
211/* vsock_table_lock must be held */
212static inline bool __vsock_in_connected_table(struct vsock_sock *vsk)
213{
214 return !list_empty(&vsk->connected_table);
215}
216
217void vsock_add_pending(struct sock *listener, struct sock *pending);
218void vsock_remove_pending(struct sock *listener, struct sock *pending);
219void vsock_enqueue_accept(struct sock *listener, struct sock *connected);
220void vsock_pending_to_accept(struct sock *listener, struct sock *pending);
221void vsock_insert_connected(struct vsock_sock *vsk);
222void vsock_remove_bound(struct vsock_sock *vsk);
223void vsock_remove_connected(struct vsock_sock *vsk);
224struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr);
225struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
226 struct sockaddr_vm *dst);
227struct sock *vsock_find_bound_socket_net(struct sockaddr_vm *addr,
228 struct net *net);
229struct sock *vsock_find_connected_socket_net(struct sockaddr_vm *src,
230 struct sockaddr_vm *dst,
231 struct net *net);
232bool vsock_check_source(const struct vsock_sock *vsk,
233 const struct vsock_transport *transport,
234 const struct sockaddr_vm *src);
235void vsock_remove_sock(struct vsock_sock *vsk);
236void vsock_for_each_connected_socket(struct vsock_transport *transport,
237 void (*fn)(struct sock *sk));
238int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
239bool vsock_find_cid(unsigned int cid);
240void vsock_linger(struct sock *sk);
241
242/**** TAP ****/
243
244struct vsock_tap {
245 struct net_device *dev;
246 struct module *module;
247 struct list_head list;
248};
249
250int vsock_add_tap(struct vsock_tap *vt);
251int vsock_remove_tap(struct vsock_tap *vt);
252void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque);
253int __vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
254 int flags);
255int vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
256 int flags);
257int __vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
258 size_t len, int flags);
259int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
260 size_t len, int flags);
261
262extern struct proto vsock_proto;
263#ifdef CONFIG_BPF_SYSCALL
264int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
265void __init vsock_bpf_build_proto(void);
266#else
267static inline void __init vsock_bpf_build_proto(void)
268{}
269#endif
270
271static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t)
272{
273 return t->msgzerocopy_allow && t->msgzerocopy_allow();
274}
275
276static inline enum vsock_net_mode vsock_net_mode(struct net *net)
277{
278 if (!net)
279 return VSOCK_NET_MODE_GLOBAL;
280
281 return READ_ONCE(net->vsock.mode);
282}
283
284static inline bool vsock_net_mode_global(struct vsock_sock *vsk)
285{
286 return vsock_net_mode(sock_net(sk_vsock(vsk))) == VSOCK_NET_MODE_GLOBAL;
287}
288
289static inline bool vsock_net_set_child_mode(struct net *net,
290 enum vsock_net_mode mode)
291{
292 int new_locked = mode + 1;
293 int old_locked = 0; /* unlocked */
294
295 if (try_cmpxchg(&net->vsock.child_ns_mode_locked,
296 &old_locked, new_locked)) {
297 WRITE_ONCE(net->vsock.child_ns_mode, mode);
298 return true;
299 }
300
301 return old_locked == new_locked;
302}
303
304static inline enum vsock_net_mode vsock_net_child_mode(struct net *net)
305{
306 return READ_ONCE(net->vsock.child_ns_mode);
307}
308
309/* Return true if two namespaces pass the mode rules. Otherwise, return false.
310 *
311 * A NULL namespace is treated as VSOCK_NET_MODE_GLOBAL.
312 *
313 * Read more about modes in the comment header of net/vmw_vsock/af_vsock.c.
314 */
315static inline bool vsock_net_check_mode(struct net *ns0, struct net *ns1)
316{
317 enum vsock_net_mode mode0, mode1;
318
319 /* Any vsocks within the same network namespace are always reachable,
320 * regardless of the mode.
321 */
322 if (net_eq(ns0, ns1))
323 return true;
324
325 mode0 = vsock_net_mode(ns0);
326 mode1 = vsock_net_mode(ns1);
327
328 /* Different namespaces are only reachable if they are both
329 * global mode.
330 */
331 return mode0 == VSOCK_NET_MODE_GLOBAL && mode0 == mode1;
332}
333#endif /* __AF_VSOCK_H__ */