1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Generic netlink handshake service
4  *
5  * Author: Chuck Lever <chuck.lever@oracle.com>
6  *
7  * Copyright (c) 2023, Oracle and/or its affiliates.
8  */
9 
10 #ifndef _INTERNAL_HANDSHAKE_H
11 #define _INTERNAL_HANDSHAKE_H
12 
13 /* Per-net namespace context */
14 struct handshake_net {
15 	spinlock_t		hn_lock;	/* protects next 3 fields */
16 	int			hn_pending;
17 	int			hn_pending_max;
18 	struct list_head	hn_requests;
19 
20 	unsigned long		hn_flags;
21 };
22 
23 enum hn_flags_bits {
24 	HANDSHAKE_F_NET_DRAINING,
25 };
26 
27 struct handshake_proto;
28 
29 /* One handshake request */
30 struct handshake_req {
31 	struct list_head		hr_list;
32 	struct rhash_head		hr_rhash;
33 	unsigned long			hr_flags;
34 	const struct handshake_proto	*hr_proto;
35 	struct sock			*hr_sk;
36 	void				(*hr_odestruct)(struct sock *sk);
37 
38 	/* Always the last field */
39 	char				hr_priv[];
40 };
41 
42 enum hr_flags_bits {
43 	HANDSHAKE_F_REQ_COMPLETED,
44 	HANDSHAKE_F_REQ_SESSION,
45 };
46 
47 struct genl_info;
48 
49 /* Invariants for all handshake requests for one transport layer
50  * security protocol
51  */
52 struct handshake_proto {
53 	int			hp_handler_class;
54 	size_t			hp_privsize;
55 	unsigned long		hp_flags;
56 
57 	int			(*hp_accept)(struct handshake_req *req,
58 					     struct genl_info *info, int fd);
59 	void			(*hp_done)(struct handshake_req *req,
60 					   unsigned int status,
61 					   struct genl_info *info);
62 	void			(*hp_destroy)(struct handshake_req *req);
63 };
64 
65 enum hp_flags_bits {
66 	HANDSHAKE_F_PROTO_NOTIFY,
67 };
68 
69 /* alert.c */
70 int tls_alert_send(struct socket *sock, u8 level, u8 description);
71 
72 /* netlink.c */
73 int handshake_genl_notify(struct net *net, const struct handshake_proto *proto,
74 			  gfp_t flags);
75 struct nlmsghdr *handshake_genl_put(struct sk_buff *msg,
76 				    struct genl_info *info);
77 struct handshake_net *handshake_pernet(struct net *net);
78 
79 /* request.c */
80 struct handshake_req *handshake_req_alloc(const struct handshake_proto *proto,
81 					  gfp_t flags);
82 int handshake_req_hash_init(void);
83 void handshake_req_hash_destroy(void);
84 void *handshake_req_private(struct handshake_req *req);
85 struct handshake_req *handshake_req_hash_lookup(struct sock *sk);
86 struct handshake_req *handshake_req_next(struct handshake_net *hn, int class);
87 int handshake_req_submit(struct socket *sock, struct handshake_req *req,
88 			 gfp_t flags);
89 void handshake_complete(struct handshake_req *req, unsigned int status,
90 			struct genl_info *info);
91 bool handshake_req_cancel(struct sock *sk);
92 
93 #endif /* _INTERNAL_HANDSHAKE_H */
94