xref: /linux/net/rose/rose_loopback.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
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 (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
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/rose.h>
15 #include <linux/init.h>
16 
17 static struct sk_buff_head loopback_queue;
18 static struct timer_list loopback_timer;
19 
20 static void rose_set_loopback_timer(void);
21 
22 void rose_loopback_init(void)
23 {
24 	skb_queue_head_init(&loopback_queue);
25 
26 	init_timer(&loopback_timer);
27 }
28 
29 static int rose_loopback_running(void)
30 {
31 	return timer_pending(&loopback_timer);
32 }
33 
34 int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh)
35 {
36 	struct sk_buff *skbn;
37 
38 	skbn = skb_clone(skb, GFP_ATOMIC);
39 
40 	kfree_skb(skb);
41 
42 	if (skbn != NULL) {
43 		skb_queue_tail(&loopback_queue, skbn);
44 
45 		if (!rose_loopback_running())
46 			rose_set_loopback_timer();
47 	}
48 
49 	return 1;
50 }
51 
52 static void rose_loopback_timer(unsigned long);
53 
54 static void rose_set_loopback_timer(void)
55 {
56 	del_timer(&loopback_timer);
57 
58 	loopback_timer.data     = 0;
59 	loopback_timer.function = &rose_loopback_timer;
60 	loopback_timer.expires  = jiffies + 10;
61 
62 	add_timer(&loopback_timer);
63 }
64 
65 static void rose_loopback_timer(unsigned long param)
66 {
67 	struct sk_buff *skb;
68 	struct net_device *dev;
69 	rose_address *dest;
70 	struct sock *sk;
71 	unsigned short frametype;
72 	unsigned int lci_i, lci_o;
73 
74 	while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
75 		lci_i     = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
76 		frametype = skb->data[2];
77 		dest      = (rose_address *)(skb->data + 4);
78 		lci_o     = 0xFFF - lci_i;
79 
80 		skb_reset_transport_header(skb);
81 
82 		sk = rose_find_socket(lci_o, rose_loopback_neigh);
83 		if (sk) {
84 			if (rose_process_rx_frame(sk, skb) == 0)
85 				kfree_skb(skb);
86 			continue;
87 		}
88 
89 		if (frametype == ROSE_CALL_REQUEST) {
90 			if ((dev = rose_dev_get(dest)) != NULL) {
91 				if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0)
92 					kfree_skb(skb);
93 			} else {
94 				kfree_skb(skb);
95 			}
96 		} else {
97 			kfree_skb(skb);
98 		}
99 	}
100 }
101 
102 void __exit rose_loopback_clear(void)
103 {
104 	struct sk_buff *skb;
105 
106 	del_timer(&loopback_timer);
107 
108 	while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
109 		skb->sk = NULL;
110 		kfree_skb(skb);
111 	}
112 }
113