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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * cn_test.c
4 *
5 * 2004+ Copyright (c) Evgeniy Polyakov <[email protected]>
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 timer_delete_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 <[email protected]>");
188MODULE_DESCRIPTION("Connector's test module");