xref: /openbmc/linux/net/netrom/nr_loopback.c (revision 64c70b1c)
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/socket.h>
11 #include <linux/timer.h>
12 #include <net/ax25.h>
13 #include <linux/skbuff.h>
14 #include <net/netrom.h>
15 #include <linux/init.h>
16 
17 static void nr_loopback_timer(unsigned long);
18 
19 static struct sk_buff_head loopback_queue;
20 static DEFINE_TIMER(loopback_timer, nr_loopback_timer, 0, 0);
21 
22 void __init nr_loopback_init(void)
23 {
24 	skb_queue_head_init(&loopback_queue);
25 }
26 
27 static inline int nr_loopback_running(void)
28 {
29 	return timer_pending(&loopback_timer);
30 }
31 
32 int nr_loopback_queue(struct sk_buff *skb)
33 {
34 	struct sk_buff *skbn;
35 
36 	if ((skbn = alloc_skb(skb->len, GFP_ATOMIC)) != NULL) {
37 		skb_copy_from_linear_data(skb, skb_put(skbn, skb->len), skb->len);
38 		skb_reset_transport_header(skbn);
39 
40 		skb_queue_tail(&loopback_queue, skbn);
41 
42 		if (!nr_loopback_running())
43 			mod_timer(&loopback_timer, jiffies + 10);
44 	}
45 
46 	kfree_skb(skb);
47 	return 1;
48 }
49 
50 static void nr_loopback_timer(unsigned long param)
51 {
52 	struct sk_buff *skb;
53 	ax25_address *nr_dest;
54 	struct net_device *dev;
55 
56 	if ((skb = skb_dequeue(&loopback_queue)) != NULL) {
57 		nr_dest = (ax25_address *)(skb->data + 7);
58 
59 		dev = nr_dev_get(nr_dest);
60 
61 		if (dev == NULL || nr_rx_frame(skb, dev) == 0)
62 			kfree_skb(skb);
63 
64 		if (dev != NULL)
65 			dev_put(dev);
66 
67 		if (!skb_queue_empty(&loopback_queue) && !nr_loopback_running())
68 			mod_timer(&loopback_timer, jiffies + 10);
69 	}
70 }
71 
72 void __exit nr_loopback_clear(void)
73 {
74 	del_timer_sync(&loopback_timer);
75 	skb_queue_purge(&loopback_queue);
76 }
77