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(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 | */ |
74 | void 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 | */ |
101 | int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, |
102 | u32 group, gfp_t gfp_mask, |
103 | int (*filter)(struct sock *dsk, struct sk_buff *skb, |
104 | void *data), |
105 | void *filter_data); |
106 | |
107 | /** |
108 | * cn_netlink_send - Sends message to the specified groups. |
109 | * |
110 | * @msg: message header(with attached data). |
111 | * @portid: destination port. |
112 | * If non-zero the message will be sent to the given port, |
113 | * which should be set to the original sender. |
114 | * @group: destination group. |
115 | * If @portid and @group is zero, then appropriate group will |
116 | * be searched through all registered connector users, and |
117 | * message will be delivered to the group which was created |
118 | * for user with the same ID as in @msg. |
119 | * If @group is not zero, then message will be delivered |
120 | * to the specified group. |
121 | * @gfp_mask: GFP mask. |
122 | * |
123 | * It can be safely called from softirq context, but may silently |
124 | * fail under strong memory pressure. |
125 | * |
126 | * If there are no listeners for given group %-ESRCH can be returned. |
127 | */ |
128 | int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask); |
129 | |
130 | int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name, |
131 | const struct cb_id *id, |
132 | void (*callback)(struct cn_msg *, struct netlink_skb_parms *)); |
133 | void cn_queue_del_callback(struct cn_queue_dev *dev, const struct cb_id *id); |
134 | void cn_queue_release_callback(struct cn_callback_entry *); |
135 | |
136 | struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *); |
137 | void cn_queue_free_dev(struct cn_queue_dev *dev); |
138 | |
139 | int cn_cb_equal(const struct cb_id *, const struct cb_id *); |
140 | |
141 | #endif /* __CONNECTOR_H */ |
142 | |