LXR linux/include/linux/connector.h

   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 *
  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 */
  99int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 group, gfp_t gfp_mask);
 100
 101/**
 102 * cn_netlink_send - 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 */
 122int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask);
 123
 124int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
 125                          const struct cb_id *id,
 126                          void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
 127void cn_queue_del_callback(struct cn_queue_dev *dev, const struct cb_id *id);
 128void cn_queue_release_callback(struct cn_callback_entry *);
 129
 130struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *);
 131void cn_queue_free_dev(struct cn_queue_dev *dev);
 132
 133int cn_cb_equal(const struct cb_id *, const struct cb_id *);
 134
 135#endif                          /* __CONNECTOR_H */
 136