LXR linux/samples/connector/cn

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *      cn_test.c
   4 * 
   5 * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
   6 * All rights reserved.
   7 */
   8
   9#define pr_fmt(fmt) "cn_test: " fmt
  10
  11#include <linux/kernel.h>
  12#include <linux/module.h>
  13#include <linux/moduleparam.h>
  14#include <linux/skbuff.h>
  15#include <linux/slab.h>
  16#include <linux/timer.h>
  17
  18#include <linux/connector.h>
  19
  20static struct cb_id cn_test_id = { CN_NETLINK_USERS + 3, 0x456 };
  21static char cn_test_name[] = "cn_test";
  22static struct sock *nls;
  23static struct timer_list cn_test_timer;
  24
  25static void cn_test_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
  26{
  27        pr_info("%s: %lu: idx=%x, val=%x, seq=%u, ack=%u, len=%d: %s.\n",
  28                __func__, jiffies, msg->id.idx, msg->id.val,
  29                msg->seq, msg->ack, msg->len,
  30                msg->len ? (char *)msg->data : "");
  31}
  32
  33/*
  34 * Do not remove this function even if no one is using it as
  35 * this is an example of how to get notifications about new
  36 * connector user registration
  37 */
  38#if 0
  39static int cn_test_want_notify(void)
  40{
  41        struct cn_ctl_msg *ctl;
  42        struct cn_notify_req *req;
  43        struct cn_msg *msg = NULL;
  44        int size, size0;
  45        struct sk_buff *skb;
  46        struct nlmsghdr *nlh;
  47        u32 group = 1;
  48
  49        size0 = sizeof(*msg) + sizeof(*ctl) + 3 * sizeof(*req);
  50
  51        size = NLMSG_SPACE(size0);
  52
  53        skb = alloc_skb(size, GFP_ATOMIC);
  54        if (!skb) {
  55                pr_err("failed to allocate new skb with size=%u\n", size);
  56                return -ENOMEM;
  57        }
  58
  59        nlh = nlmsg_put(skb, 0, 0x123, NLMSG_DONE, size - sizeof(*nlh), 0);
  60        if (!nlh) {
  61                kfree_skb(skb);
  62                return -EMSGSIZE;
  63        }
  64
  65        msg = nlmsg_data(nlh);
  66
  67        memset(msg, 0, size0);
  68
  69        msg->id.idx = -1;
  70        msg->id.val = -1;
  71        msg->seq = 0x123;
  72        msg->ack = 0x345;
  73        msg->len = size0 - sizeof(*msg);
  74
  75        ctl = (struct cn_ctl_msg *)(msg + 1);
  76
  77        ctl->idx_notify_num = 1;
  78        ctl->val_notify_num = 2;
  79        ctl->group = group;
  80        ctl->len = msg->len - sizeof(*ctl);
  81
  82        req = (struct cn_notify_req *)(ctl + 1);
  83
  84        /*
  85         * Idx.
  86         */
  87        req->first = cn_test_id.idx;
  88        req->range = 10;
  89
  90        /*
  91         * Val 0.
  92         */
  93        req++;
  94        req->first = cn_test_id.val;
  95        req->range = 10;
  96
  97        /*
  98         * Val 1.
  99         */
 100        req++;
 101        req->first = cn_test_id.val + 20;
 102        req->range = 10;
 103
 104        NETLINK_CB(skb).dst_group = ctl->group;
 105        //netlink_broadcast(nls, skb, 0, ctl->group, GFP_ATOMIC);
 106        netlink_unicast(nls, skb, 0, 0);
 107
 108        pr_info("request was sent: group=0x%x\n", ctl->group);
 109
 110        return 0;
 111}
 112#endif
 113
 114static u32 cn_test_timer_counter;
 115static void cn_test_timer_func(struct timer_list *unused)
 116{
 117        struct cn_msg *m;
 118        char data[32];
 119
 120        pr_debug("%s: timer fired\n", __func__);
 121
 122        m = kzalloc(sizeof(*m) + sizeof(data), GFP_ATOMIC);
 123        if (m) {
 124
 125                memcpy(&m->id, &cn_test_id, sizeof(m->id));
 126                m->seq = cn_test_timer_counter;
 127                m->len = sizeof(data);
 128
 129                m->len =
 130                    scnprintf(data, sizeof(data), "counter = %u",
 131                              cn_test_timer_counter) + 1;
 132
 133                memcpy(m + 1, data, m->len);
 134
 135                cn_netlink_send(m, 0, 0, GFP_ATOMIC);
 136                kfree(m);
 137        }
 138
 139        cn_test_timer_counter++;
 140
 141        mod_timer(&cn_test_timer, jiffies + msecs_to_jiffies(1000));
 142}
 143
 144static int cn_test_init(void)
 145{
 146        int err;
 147
 148        err = cn_add_callback(&cn_test_id, cn_test_name, cn_test_callback);
 149        if (err)
 150                goto err_out;
 151        cn_test_id.val++;
 152        err = cn_add_callback(&cn_test_id, cn_test_name, cn_test_callback);
 153        if (err) {
 154                cn_del_callback(&cn_test_id);
 155                goto err_out;
 156        }
 157
 158        timer_setup(&cn_test_timer, cn_test_timer_func, 0);
 159        mod_timer(&cn_test_timer, jiffies + msecs_to_jiffies(1000));
 160
 161        pr_info("initialized with id={%u.%u}\n",
 162                cn_test_id.idx, cn_test_id.val);
 163
 164        return 0;
 165
 166      err_out:
 167        if (nls && nls->sk_socket)
 168                sock_release(nls->sk_socket);
 169
 170        return err;
 171}
 172
 173static void cn_test_fini(void)
 174{
 175        del_timer_sync(&cn_test_timer);
 176        cn_del_callback(&cn_test_id);
 177        cn_test_id.val--;
 178        cn_del_callback(&cn_test_id);
 179        if (nls && nls->sk_socket)
 180                sock_release(nls->sk_socket);
 181}
 182
 183module_init(cn_test_init);
 184module_exit(cn_test_fini);
 185
 186MODULE_LICENSE("GPL");
 187MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
 188MODULE_DESCRIPTION("Connector's test module");
 189