1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright Tomi Manninen OH2BNS (oh2bns@sral.fi)
5 */
6#include <linux/types.h>
7#include <linux/slab.h>
8#include <linux/socket.h>
9#include <linux/timer.h>
10#include <net/ax25.h>
11#include <linux/skbuff.h>
12#include <net/netrom.h>
13#include <linux/init.h>
14
15static void nr_loopback_timer(struct timer_list *);
16
17static struct sk_buff_head loopback_queue;
18static DEFINE_TIMER(loopback_timer, nr_loopback_timer);
19
20void __init nr_loopback_init(void)
21{
22 skb_queue_head_init(list: &loopback_queue);
23}
24
25static inline int nr_loopback_running(void)
26{
27 return timer_pending(timer: &loopback_timer);
28}
29
30int nr_loopback_queue(struct sk_buff *skb)
31{
32 struct sk_buff *skbn;
33
34 if ((skbn = alloc_skb(size: skb->len, GFP_ATOMIC)) != NULL) {
35 skb_copy_from_linear_data(skb, to: skb_put(skb: skbn, len: skb->len), len: skb->len);
36 skb_reset_transport_header(skb: skbn);
37
38 skb_queue_tail(list: &loopback_queue, newsk: skbn);
39
40 if (!nr_loopback_running())
41 mod_timer(timer: &loopback_timer, expires: jiffies + 10);
42 }
43
44 kfree_skb(skb);
45 return 1;
46}
47
48static void nr_loopback_timer(struct timer_list *unused)
49{
50 struct sk_buff *skb;
51 ax25_address *nr_dest;
52 struct net_device *dev;
53
54 if ((skb = skb_dequeue(list: &loopback_queue)) != NULL) {
55 nr_dest = (ax25_address *)(skb->data + 7);
56
57 dev = nr_dev_get(nr_dest);
58
59 if (dev == NULL || nr_rx_frame(skb, dev) == 0)
60 kfree_skb(skb);
61
62 dev_put(dev);
63
64 if (!skb_queue_empty(list: &loopback_queue) && !nr_loopback_running())
65 mod_timer(timer: &loopback_timer, expires: jiffies + 10);
66 }
67}
68
69void nr_loopback_clear(void)
70{
71 del_timer_sync(timer: &loopback_timer);
72 skb_queue_purge(list: &loopback_queue);
73}
74

source code of linux/net/netrom/nr_loopback.c