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 20 static struct cb_id cn_test_id = { CN_NETLINK_USERS + 3, 0x456 }; 21 static char cn_test_name[] = "cn_test"; 22 static struct sock *nls; 23 static struct timer_list cn_test_timer; 24 25 static 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 39 static 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 113 114 static u32 cn_test_timer_counter; 115 static 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 } 143 144 static 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 } 172 173 static 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 } 182 183 module_init(cn_test_init); 184 module_exit(cn_test_fini); 185 186 MODULE_LICENSE("GPL"); 187 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 188 MODULE_DESCRIPTION("Connector's test module"); 189