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 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 */ 127 int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask); 128 129 int 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 *)); 132 void cn_queue_del_callback(struct cn_queue_dev *dev, const struct cb_id *id); 133 void cn_queue_release_callback(struct cn_callback_entry *); 134 135 struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *); 136 void cn_queue_free_dev(struct cn_queue_dev *dev); 137 138 int cn_cb_equal(const struct cb_id *, const struct cb_id *); 139 140 #endif /* __CONNECTOR_H */ 141