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