net/rose/rose_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 (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 }