net/netrom/nr_loopback.c

   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 }