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
  23 void rose_loopback_init(void)
  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;
  70         rose_address *dest;
  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 &&
  83                     (skb->len <= ROSE_CALL_REQ_FACILITIES_OFF ||
  84                      skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] !=
  85                      ROSE_CALL_REQ_ADDR_LEN_VAL)) {
  86                         kfree_skb(skb);
  87                         continue;
  88                 }
  89                 dest      = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF);
  90                 lci_o     = ROSE_DEFAULT_MAXVC + 1 - lci_i;
  91
  92                 skb_reset_transport_header(skb);
  93
  94                 sk = rose_find_socket(lci_o, rose_loopback_neigh);
  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
 114 void __exit rose_loopback_clear(void)
 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 }