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/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/rose.h>
16 #include <linux/init.h>
17
18 static struct sk_buff_head loopback_queue;
19 static struct timer_list loopback_timer;
20
21 static void rose_set_loopback_timer(void);
22
rose_loopback_init(void)23 void rose_loopback_init(void)
24 {
25 skb_queue_head_init(&loopback_queue);
26
27 init_timer(&loopback_timer);
28 }
29
rose_loopback_running(void)30 static int rose_loopback_running(void)
31 {
32 return timer_pending(&loopback_timer);
33 }
34
rose_loopback_queue(struct sk_buff * skb,struct rose_neigh * neigh)35 int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh)
36 {
37 struct sk_buff *skbn;
38
39 skbn = skb_clone(skb, GFP_ATOMIC);
40
41 kfree_skb(skb);
42
43 if (skbn != NULL) {
44 skb_queue_tail(&loopback_queue, skbn);
45
46 if (!rose_loopback_running())
47 rose_set_loopback_timer();
48 }
49
50 return 1;
51 }
52
53 static void rose_loopback_timer(unsigned long);
54
rose_set_loopback_timer(void)55 static void rose_set_loopback_timer(void)
56 {
57 del_timer(&loopback_timer);
58
59 loopback_timer.data = 0;
60 loopback_timer.function = &rose_loopback_timer;
61 loopback_timer.expires = jiffies + 10;
62
63 add_timer(&loopback_timer);
64 }
65
rose_loopback_timer(unsigned long param)66 static void rose_loopback_timer(unsigned long param)
67 {
68 struct sk_buff *skb;
69 struct net_device *dev;
70 rose_address *dest;
71 struct sock *sk;
72 unsigned short frametype;
73 unsigned int lci_i, lci_o;
74
75 while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
76 if (skb->len < ROSE_MIN_LEN) {
77 kfree_skb(skb);
78 continue;
79 }
80 lci_i = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
81 frametype = skb->data[2];
82 if (frametype == ROSE_CALL_REQUEST &&
83 (skb->len <= ROSE_CALL_REQ_FACILITIES_OFF ||
84 skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] !=
85 ROSE_CALL_REQ_ADDR_LEN_VAL)) {
86 kfree_skb(skb);
87 continue;
88 }
89 dest = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF);
90 lci_o = ROSE_DEFAULT_MAXVC + 1 - lci_i;
91
92 skb_reset_transport_header(skb);
93
94 sk = rose_find_socket(lci_o, rose_loopback_neigh);
95 if (sk) {
96 if (rose_process_rx_frame(sk, skb) == 0)
97 kfree_skb(skb);
98 continue;
99 }
100
101 if (frametype == ROSE_CALL_REQUEST) {
102 if ((dev = rose_dev_get(dest)) != NULL) {
103 if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0)
104 kfree_skb(skb);
105 } else {
106 kfree_skb(skb);
107 }
108 } else {
109 kfree_skb(skb);
110 }
111 }
112 }
113
rose_loopback_clear(void)114 void __exit rose_loopback_clear(void)
115 {
116 struct sk_buff *skb;
117
118 del_timer(&loopback_timer);
119
120 while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
121 skb->sk = NULL;
122 kfree_skb(skb);
123 }
124 }
125