1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * connector.h
4 *
5 * 2004-2005 Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
6 * All rights reserved.
7 */
8#ifndef __CONNECTOR_H
9#define __CONNECTOR_H
10
11
12#include <linux/refcount.h>
13
14#include <linux/list.h>
15#include <linux/workqueue.h>
16
17#include <net/sock.h>
18#include <uapi/linux/connector.h>
19
20#define CN_CBQ_NAMELEN 32
21
22struct cn_queue_dev {
23 atomic_t refcnt;
24 unsigned char name[CN_CBQ_NAMELEN];
25
26 struct list_head queue_list;
27 spinlock_t queue_lock;
28
29 struct sock *nls;
30};
31
32struct cn_callback_id {
33 unsigned char name[CN_CBQ_NAMELEN];
34 struct cb_id id;
35};
36
37struct cn_callback_entry {
38 struct list_head callback_entry;
39 refcount_t refcnt;
40 struct cn_queue_dev *pdev;
41
42 struct cn_callback_id id;
43 void (*callback) (struct cn_msg *, struct netlink_skb_parms *);
44
45 u32 seq, group;
46};
47
48struct cn_dev {
49 struct cb_id id;
50
51 u32 seq, groups;
52 struct sock *nls;
53
54 struct cn_queue_dev *cbdev;
55};
56
57/**
58 * cn_add_callback() - Registers new callback with connector core.
59 *
60 * @id: unique connector's user identifier.
61 * It must be registered in connector.h for legal
62 * in-kernel users.
63 * @name: connector's callback symbolic name.
64 * @callback: connector's callback.
65 * parameters are %cn_msg and the sender's credentials
66 */
67int cn_add_callback(const struct cb_id *id, const char *name,
68 void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
69/**
70 * cn_del_callback() - Unregisters new callback with connector core.
71 *
72 * @id: unique connector's user identifier.
73 */
74void cn_del_callback(const struct cb_id *id);
75
76
77/**
78 * cn_netlink_send_mult - Sends message to the specified groups.
79 *
80 * @msg: message header(with attached data).
81 * @len: Number of @msg to be sent.
82 * @portid: destination port.
83 * If non-zero the message will be sent to the given port,
84 * which should be set to the original sender.
85 * @group: destination group.
86 * If @portid and @group is zero, then appropriate group will
87 * be searched through all registered connector users, and
88 * message will be delivered to the group which was created
89 * for user with the same ID as in @msg.
90 * If @group is not zero, then message will be delivered
91 * to the specified group.
92 * @gfp_mask: GFP mask.
93 * @filter: Filter function to be used at netlink layer.
94 * @filter_data:Filter data to be supplied to the filter function
95 *
96 * It can be safely called from softirq context, but may silently
97 * fail under strong memory pressure.
98 *
99 * If there are no listeners for given group %-ESRCH can be returned.
100 */
101int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid,
102 u32 group, gfp_t gfp_mask,
103 netlink_filter_fn filter,
104 void *filter_data);
105
106/**
107 * cn_netlink_send - Sends message to the specified groups.
108 *
109 * @msg: message header(with attached data).
110 * @portid: destination port.
111 * If non-zero the message will be sent to the given port,
112 * which should be set to the original sender.
113 * @group: destination group.
114 * If @portid and @group is zero, then appropriate group will
115 * be searched through all registered connector users, and
116 * message will be delivered to the group which was created
117 * for user with the same ID as in @msg.
118 * If @group is not zero, then message will be delivered
119 * to the specified group.
120 * @gfp_mask: GFP mask.
121 *
122 * It can be safely called from softirq context, but may silently
123 * fail under strong memory pressure.
124 *
125 * If there are no listeners for given group %-ESRCH can be returned.
126 */
127int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask);
128
129int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
130 const struct cb_id *id,
131 void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
132void cn_queue_del_callback(struct cn_queue_dev *dev, const struct cb_id *id);
133void cn_queue_release_callback(struct cn_callback_entry *);
134
135struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *);
136void cn_queue_free_dev(struct cn_queue_dev *dev);
137
138int cn_cb_equal(const struct cb_id *, const struct cb_id *);
139
140#endif /* __CONNECTOR_H */
141