Documentation/connector/cn_test.c

   1 /*
   2  *      cn_test.c
   3  *
   4  * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
   5  * All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #define pr_fmt(fmt) "cn_test: " fmt
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/slab.h>
  29 #include <linux/timer.h>
  30
  31 #include <linux/connector.h>
  32
  33 static struct cb_id cn_test_id = { CN_NETLINK_USERS + 3, 0x456 };
  34 static char cn_test_name[] = "cn_test";
  35 static struct sock *nls;
  36 static struct timer_list cn_test_timer;
  37
  38 static void cn_test_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
  39 {
  40         pr_info("%s: %lu: idx=%x, val=%x, seq=%u, ack=%u, len=%d: %s.\n",
  41                 __func__, jiffies, msg->id.idx, msg->id.val,
  42                 msg->seq, msg->ack, msg->len,
  43                 msg->len ? (char *)msg->data : "");
  44 }
  45
  46 /*
  47  * Do not remove this function even if no one is using it as
  48  * this is an example of how to get notifications about new
  49  * connector user registration
  50  */
  51 #if 0
  52 static int cn_test_want_notify(void)
  53 {
  54         struct cn_ctl_msg *ctl;
  55         struct cn_notify_req *req;
  56         struct cn_msg *msg = NULL;
  57         int size, size0;
  58         struct sk_buff *skb;
  59         struct nlmsghdr *nlh;
  60         u32 group = 1;
  61
  62         size0 = sizeof(*msg) + sizeof(*ctl) + 3 * sizeof(*req);
  63
  64         size = NLMSG_SPACE(size0);
  65
  66         skb = alloc_skb(size, GFP_ATOMIC);
  67         if (!skb) {
  68                 pr_err("failed to allocate new skb with size=%u\n", size);
  69                 return -ENOMEM;
  70         }
  71
  72         nlh = nlmsg_put(skb, 0, 0x123, NLMSG_DONE, size - sizeof(*nlh), 0);
  73         if (!nlh) {
  74                 kfree_skb(skb);
  75                 return -EMSGSIZE;
  76         }
  77
  78         msg = nlmsg_data(nlh);
  79
  80         memset(msg, 0, size0);
  81
  82         msg->id.idx = -1;
  83         msg->id.val = -1;
  84         msg->seq = 0x123;
  85         msg->ack = 0x345;
  86         msg->len = size0 - sizeof(*msg);
  87
  88         ctl = (struct cn_ctl_msg *)(msg + 1);
  89
  90         ctl->idx_notify_num = 1;
  91         ctl->val_notify_num = 2;
  92         ctl->group = group;
  93         ctl->len = msg->len - sizeof(*ctl);
  94
  95         req = (struct cn_notify_req *)(ctl + 1);
  96
  97         /*
  98          * Idx.
  99          */
 100         req->first = cn_test_id.idx;
 101         req->range = 10;
 102
 103         /*
 104          * Val 0.
 105          */
 106         req++;
 107         req->first = cn_test_id.val;
 108         req->range = 10;
 109
 110         /*
 111          * Val 1.
 112          */
 113         req++;
 114         req->first = cn_test_id.val + 20;
 115         req->range = 10;
 116
 117         NETLINK_CB(skb).dst_group = ctl->group;
 118         //netlink_broadcast(nls, skb, 0, ctl->group, GFP_ATOMIC);
 119         netlink_unicast(nls, skb, 0, 0);
 120
 121         pr_info("request was sent: group=0x%x\n", ctl->group);
 122
 123         return 0;
 124 }
 125 #endif
 126
 127 static u32 cn_test_timer_counter;
 128 static void cn_test_timer_func(unsigned long __data)
 129 {
 130         struct cn_msg *m;
 131         char data[32];
 132
 133         pr_debug("%s: timer fired with data %lu\n", __func__, __data);
 134
 135         m = kzalloc(sizeof(*m) + sizeof(data), GFP_ATOMIC);
 136         if (m) {
 137
 138                 memcpy(&m->id, &cn_test_id, sizeof(m->id));
 139                 m->seq = cn_test_timer_counter;
 140                 m->len = sizeof(data);
 141
 142                 m->len =
 143                     scnprintf(data, sizeof(data), "counter = %u",
 144                               cn_test_timer_counter) + 1;
 145
 146                 memcpy(m + 1, data, m->len);
 147
 148                 cn_netlink_send(m, 0, 0, GFP_ATOMIC);
 149                 kfree(m);
 150         }
 151
 152         cn_test_timer_counter++;
 153
 154         mod_timer(&cn_test_timer, jiffies + msecs_to_jiffies(1000));
 155 }
 156
 157 static int cn_test_init(void)
 158 {
 159         int err;
 160
 161         err = cn_add_callback(&cn_test_id, cn_test_name, cn_test_callback);
 162         if (err)
 163                 goto err_out;
 164         cn_test_id.val++;
 165         err = cn_add_callback(&cn_test_id, cn_test_name, cn_test_callback);
 166         if (err) {
 167                 cn_del_callback(&cn_test_id);
 168                 goto err_out;
 169         }
 170
 171         setup_timer(&cn_test_timer, cn_test_timer_func, 0);
 172         mod_timer(&cn_test_timer, jiffies + msecs_to_jiffies(1000));
 173
 174         pr_info("initialized with id={%u.%u}\n",
 175                 cn_test_id.idx, cn_test_id.val);
 176
 177         return 0;
 178
 179       err_out:
 180         if (nls && nls->sk_socket)
 181                 sock_release(nls->sk_socket);
 182
 183         return err;
 184 }
 185
 186 static void cn_test_fini(void)
 187 {
 188         del_timer_sync(&cn_test_timer);
 189         cn_del_callback(&cn_test_id);
 190         cn_test_id.val--;
 191         cn_del_callback(&cn_test_id);
 192         if (nls && nls->sk_socket)
 193                 sock_release(nls->sk_socket);
 194 }
 195
 196 module_init(cn_test_init);
 197 module_exit(cn_test_fini);
 198
 199 MODULE_LICENSE("GPL");
 200 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
 201 MODULE_DESCRIPTION("Connector's test module");