drivers/net/wan/hdlc_x25.c

   1 /*
   2  * Generic HDLC support routines for Linux
   3  * X.25 support
   4  *
   5  * Copyright (C) 1999 - 2003 Krzysztof Halasa <khc@pm.waw.pl>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of version 2 of the GNU General Public License
   9  * as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/poll.h>
  16 #include <linux/errno.h>
  17 #include <linux/if_arp.h>
  18 #include <linux/init.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/pkt_sched.h>
  21 #include <linux/inetdevice.h>
  22 #include <linux/lapb.h>
  23 #include <linux/rtnetlink.h>
  24 #include <linux/hdlc.h>
  25
  26 #include <net/x25device.h>
  27
  28 /* These functions are callbacks called by LAPB layer */
  29
  30 static void x25_connect_disconnect(struct net_device *dev, int reason, int code)
  31 {
  32         struct sk_buff *skb;
  33         unsigned char *ptr;
  34
  35         if ((skb = dev_alloc_skb(1)) == NULL) {
  36                 printk(KERN_ERR "%s: out of memory\n", dev->name);
  37                 return;
  38         }
  39
  40         ptr = skb_put(skb, 1);
  41         *ptr = code;
  42
  43         skb->protocol = x25_type_trans(skb, dev);
  44         netif_rx(skb);
  45 }
  46
  47
  48
  49 static void x25_connected(struct net_device *dev, int reason)
  50 {
  51         x25_connect_disconnect(dev, reason, 1);
  52 }
  53
  54
  55
  56 static void x25_disconnected(struct net_device *dev, int reason)
  57 {
  58         x25_connect_disconnect(dev, reason, 2);
  59 }
  60
  61
  62
  63 static int x25_data_indication(struct net_device *dev, struct sk_buff *skb)
  64 {
  65         unsigned char *ptr;
  66
  67         skb_push(skb, 1);
  68
  69         if (skb_cow(skb, 1))
  70                 return NET_RX_DROP;
  71
  72         ptr  = skb->data;
  73         *ptr = 0;
  74
  75         skb->protocol = x25_type_trans(skb, dev);
  76         return netif_rx(skb);
  77 }
  78
  79
  80
  81 static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb)
  82 {
  83         hdlc_device *hdlc = dev_to_hdlc(dev);
  84         hdlc->xmit(skb, dev); /* Ignore return value :-( */
  85 }
  86
  87
  88
  89 static int x25_xmit(struct sk_buff *skb, struct net_device *dev)
  90 {
  91         int result;
  92
  93
  94         /* X.25 to LAPB */
  95         switch (skb->data[0]) {
  96         case 0:         /* Data to be transmitted */
  97                 skb_pull(skb, 1);
  98                 if ((result = lapb_data_request(dev, skb)) != LAPB_OK)
  99                         dev_kfree_skb(skb);
 100                 return 0;
 101
 102         case 1:
 103                 if ((result = lapb_connect_request(dev))!= LAPB_OK) {
 104                         if (result == LAPB_CONNECTED)
 105                                 /* Send connect confirm. msg to level 3 */
 106                                 x25_connected(dev, 0);
 107                         else
 108                                 printk(KERN_ERR "%s: LAPB connect request "
 109                                        "failed, error code = %i\n",
 110                                        dev->name, result);
 111                 }
 112                 break;
 113
 114         case 2:
 115                 if ((result = lapb_disconnect_request(dev)) != LAPB_OK) {
 116                         if (result == LAPB_NOTCONNECTED)
 117                                 /* Send disconnect confirm. msg to level 3 */
 118                                 x25_disconnected(dev, 0);
 119                         else
 120                                 printk(KERN_ERR "%s: LAPB disconnect request "
 121                                        "failed, error code = %i\n",
 122                                        dev->name, result);
 123                 }
 124                 break;
 125
 126         default:                /* to be defined */
 127                 break;
 128         }
 129
 130         dev_kfree_skb(skb);
 131         return 0;
 132 }
 133
 134
 135
 136 static int x25_open(struct net_device *dev)
 137 {
 138         struct lapb_register_struct cb;
 139         int result;
 140
 141         cb.connect_confirmation = x25_connected;
 142         cb.connect_indication = x25_connected;
 143         cb.disconnect_confirmation = x25_disconnected;
 144         cb.disconnect_indication = x25_disconnected;
 145         cb.data_indication = x25_data_indication;
 146         cb.data_transmit = x25_data_transmit;
 147
 148         result = lapb_register(dev, &cb);
 149         if (result != LAPB_OK)
 150                 return result;
 151         return 0;
 152 }
 153
 154
 155
 156 static void x25_close(struct net_device *dev)
 157 {
 158         lapb_unregister(dev);
 159 }
 160
 161
 162
 163 static int x25_rx(struct sk_buff *skb)
 164 {
 165         hdlc_device *hdlc = dev_to_hdlc(skb->dev);
 166
 167         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
 168                 hdlc->stats.rx_dropped++;
 169                 return NET_RX_DROP;
 170         }
 171
 172         if (lapb_data_received(skb->dev, skb) == LAPB_OK)
 173                 return NET_RX_SUCCESS;
 174
 175         hdlc->stats.rx_errors++;
 176         dev_kfree_skb_any(skb);
 177         return NET_RX_DROP;
 178 }
 179
 180
 181
 182 int hdlc_x25_ioctl(struct net_device *dev, struct ifreq *ifr)
 183 {
 184         hdlc_device *hdlc = dev_to_hdlc(dev);
 185         int result;
 186
 187         switch (ifr->ifr_settings.type) {
 188         case IF_GET_PROTO:
 189                 ifr->ifr_settings.type = IF_PROTO_X25;
 190                 return 0; /* return protocol only, no settable parameters */
 191
 192         case IF_PROTO_X25:
 193                 if(!capable(CAP_NET_ADMIN))
 194                         return -EPERM;
 195
 196                 if(dev->flags & IFF_UP)
 197                         return -EBUSY;
 198
 199                 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
 200                 if (result)
 201                         return result;
 202
 203                 hdlc_proto_detach(hdlc);
 204                 memset(&hdlc->proto, 0, sizeof(hdlc->proto));
 205
 206                 hdlc->proto.open = x25_open;
 207                 hdlc->proto.close = x25_close;
 208                 hdlc->proto.netif_rx = x25_rx;
 209                 hdlc->proto.type_trans = NULL;
 210                 hdlc->proto.id = IF_PROTO_X25;
 211                 dev->hard_start_xmit = x25_xmit;
 212                 dev->hard_header = NULL;
 213                 dev->type = ARPHRD_X25;
 214                 dev->addr_len = 0;
 215                 return 0;
 216         }
 217
 218         return -EINVAL;
 219 }