Linux Kernel  3.7.1
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rose_loopback.c
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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 ([email protected])
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 
24 {
25  skb_queue_head_init(&loopback_queue);
26 
27  init_timer(&loopback_timer);
28 }
29 
30 static int rose_loopback_running(void)
31 {
32  return timer_pending(&loopback_timer);
33 }
34 
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 
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 
66 static void rose_loopback_timer(unsigned long param)
67 {
68  struct sk_buff *skb;
69  struct net_device *dev;
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 &&
86  kfree_skb(skb);
87  continue;
88  }
90  lci_o = ROSE_DEFAULT_MAXVC + 1 - lci_i;
91 
92  skb_reset_transport_header(skb);
93 
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 
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 }