release/src-rt-6.x.4708/linux/linux-2.6.36/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/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/netrom.h>
  16 #include <linux/init.h>
  17
  18 static void nr_loopback_timer(unsigned long);
  19
  20 static struct sk_buff_head loopback_queue;
  21 static DEFINE_TIMER(loopback_timer, nr_loopback_timer, 0, 0);
  22
  23 void __init nr_loopback_init(void)
  24 {
  25         skb_queue_head_init(&loopback_queue);
  26 }
  27
  28 static inline int nr_loopback_running(void)
  29 {
  30         return timer_pending(&loopback_timer);
  31 }
  32
  33 int nr_loopback_queue(struct sk_buff *skb)
  34 {
  35         struct sk_buff *skbn;
  36
  37         if ((skbn = alloc_skb(skb->len, GFP_ATOMIC)) != NULL) {
  38                 skb_copy_from_linear_data(skb, skb_put(skbn, skb->len), skb->len);
  39                 skb_reset_transport_header(skbn);
  40
  41                 skb_queue_tail(&loopback_queue, skbn);
  42
  43                 if (!nr_loopback_running())
  44                         mod_timer(&loopback_timer, jiffies + 10);
  45         }
  46
  47         kfree_skb(skb);
  48         return 1;
  49 }
  50
  51 static void nr_loopback_timer(unsigned long param)
  52 {
  53         struct sk_buff *skb;
  54         ax25_address *nr_dest;
  55         struct net_device *dev;
  56
  57         if ((skb = skb_dequeue(&loopback_queue)) != NULL) {
  58                 nr_dest = (ax25_address *)(skb->data + 7);
  59
  60                 dev = nr_dev_get(nr_dest);
  61
  62                 if (dev == NULL || nr_rx_frame(skb, dev) == 0)
  63                         kfree_skb(skb);
  64
  65                 if (dev != NULL)
  66                         dev_put(dev);
  67
  68                 if (!skb_queue_empty(&loopback_queue) && !nr_loopback_running())
  69                         mod_timer(&loopback_timer, jiffies + 10);
  70         }
  71 }
  72
  73 void __exit nr_loopback_clear(void)
  74 {
  75         del_timer_sync(&loopback_timer);
  76         skb_queue_purge(&loopback_queue);
  77 }