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
22 struct 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
32 struct cn_callback_id {
33 unsigned char name[CN_CBQ_NAMELEN];
34 struct cb_id id;
35 };
36
37 struct 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
48 struct 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 */
67 int cn_add_callback(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 */
74 void cn_del_callback(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 *
94 * It can be safely called from softirq context, but may silently
95 * fail under strong memory pressure.
96 *
97 * If there are no listeners for given group %-ESRCH can be returned.
98 */
99 int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 group, gfp_t gfp_mask);
100
101 /**
102 * cn_netlink_send_mult - Sends message to the specified groups.
103 *
104 * @msg: message header(with attached data).
105 * @portid: destination port.
106 * If non-zero the message will be sent to the given port,
107 * which should be set to the original sender.
108 * @group: destination group.
109 * If @portid and @group is zero, then appropriate group will
110 * be searched through all registered connector users, and
111 * message will be delivered to the group which was created
112 * for user with the same ID as in @msg.
113 * If @group is not zero, then message will be delivered
114 * to the specified group.
115 * @gfp_mask: GFP mask.
116 *
117 * It can be safely called from softirq context, but may silently
118 * fail under strong memory pressure.
119 *
120 * If there are no listeners for given group %-ESRCH can be returned.
121 */
122 int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask);
123
124 int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
125 struct cb_id *id,
126 void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
127 void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id);
128 void cn_queue_release_callback(struct cn_callback_entry *);
129
130 struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *);
131 void cn_queue_free_dev(struct cn_queue_dev *dev);
132
133 int cn_cb_equal(struct cb_id *, struct cb_id *);
134
135 #endif /* __CONNECTOR_H */