189 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * cn_test.c4 * 5 * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>6 * All rights reserved.7 */8 9#define pr_fmt(fmt) "cn_test: " fmt10 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 as35 * this is an example of how to get notifications about new36 * connector user registration37 */38#if 039static 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#endif113 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