1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 2 of the License, or
5  * (at your option) any later version.
6  *
7  * Copyright Tomi Manninen OH2BNS (oh2bns@sral.fi)
8  */
9 #include <linux/types.h>
10 #include <linux/slab.h>
11 #include <linux/socket.h>
12 #include <linux/timer.h>
13 #include <net/ax25.h>
14 #include <linux/skbuff.h>
15 #include <net/netrom.h>
16 #include <linux/init.h>
17 
18 static void nr_loopback_timer(unsigned long);
19 
20 static struct sk_buff_head loopback_queue;
21 static DEFINE_TIMER(loopback_timer, nr_loopback_timer, 0, 0);
22 
nr_loopback_init(void)23 void __init nr_loopback_init(void)
24 {
25 	skb_queue_head_init(&loopback_queue);
26 }
27 
nr_loopback_running(void)28 static inline int nr_loopback_running(void)
29 {
30 	return timer_pending(&loopback_timer);
31 }
32 
nr_loopback_queue(struct sk_buff * skb)33 int nr_loopback_queue(struct sk_buff *skb)
34 {
35 	struct sk_buff *skbn;
36 
37 	if ((skbn = alloc_skb(skb->len, GFP_ATOMIC)) != NULL) {
38 		skb_copy_from_linear_data(skb, skb_put(skbn, skb->len), skb->len);
39 		skb_reset_transport_header(skbn);
40 
41 		skb_queue_tail(&loopback_queue, skbn);
42 
43 		if (!nr_loopback_running())
44 			mod_timer(&loopback_timer, jiffies + 10);
45 	}
46 
47 	kfree_skb(skb);
48 	return 1;
49 }
50 
nr_loopback_timer(unsigned long param)51 static void nr_loopback_timer(unsigned long param)
52 {
53 	struct sk_buff *skb;
54 	ax25_address *nr_dest;
55 	struct net_device *dev;
56 
57 	if ((skb = skb_dequeue(&loopback_queue)) != NULL) {
58 		nr_dest = (ax25_address *)(skb->data + 7);
59 
60 		dev = nr_dev_get(nr_dest);
61 
62 		if (dev == NULL || nr_rx_frame(skb, dev) == 0)
63 			kfree_skb(skb);
64 
65 		if (dev != NULL)
66 			dev_put(dev);
67 
68 		if (!skb_queue_empty(&loopback_queue) && !nr_loopback_running())
69 			mod_timer(&loopback_timer, jiffies + 10);
70 	}
71 }
72 
nr_loopback_clear(void)73 void __exit nr_loopback_clear(void)
74 {
75 	del_timer_sync(&loopback_timer);
76 	skb_queue_purge(&loopback_queue);
77 }
78