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 /* These functions are callbacks called by LAPB layer */
  27
  28 static void x25_connect_disconnect(struct net_device *dev, int reason, int code)
  29 {
  30         struct sk_buff *skb;
  31         unsigned char *ptr;
  32
  33         if ((skb = dev_alloc_skb(1)) == NULL) {
  34                 printk(KERN_ERR "%s: out of memory\n", dev->name);
  35                 return;
  36         }
  37
  38         ptr = skb_put(skb, 1);
  39         *ptr = code;
  40
  41         skb->dev = dev;
  42         skb->protocol = htons(ETH_P_X25);
  43         skb->mac.raw = skb->data;
  44         skb->pkt_type = PACKET_HOST;
  45
  46         netif_rx(skb);
  47 }
  48
  49
  50
  51 static void x25_connected(struct net_device *dev, int reason)
  52 {
  53         x25_connect_disconnect(dev, reason, 1);
  54 }
  55
  56
  57
  58 static void x25_disconnected(struct net_device *dev, int reason)
  59 {
  60         x25_connect_disconnect(dev, reason, 2);
  61 }
  62
  63
  64
  65 static int x25_data_indication(struct net_device *dev, struct sk_buff *skb)
  66 {
  67         unsigned char *ptr;
  68
  69         skb_push(skb, 1);
  70
  71         if (skb_cow(skb, 1))
  72                 return NET_RX_DROP;
  73
  74         ptr  = skb->data;
  75         *ptr = 0;
  76
  77         skb->dev = dev;
  78         skb->protocol = htons(ETH_P_X25);
  79         skb->mac.raw = skb->data;
  80         skb->pkt_type = PACKET_HOST;
  81
  82         return netif_rx(skb);
  83 }
  84
  85
  86
  87 static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb)
  88 {
  89         hdlc_device *hdlc = dev_to_hdlc(dev);
  90         hdlc->xmit(skb, dev); /* Ignore return value :-( */
  91 }
  92
  93
  94
  95 static int x25_xmit(struct sk_buff *skb, struct net_device *dev)
  96 {
  97         int result;
  98
  99
 100         /* X.25 to LAPB */
 101         switch (skb->data[0]) {
 102         case 0:         /* Data to be transmitted */
 103                 skb_pull(skb, 1);
 104                 if ((result = lapb_data_request(dev, skb)) != LAPB_OK)
 105                         dev_kfree_skb(skb);
 106                 return 0;
 107
 108         case 1:
 109                 if ((result = lapb_connect_request(dev))!= LAPB_OK) {
 110                         if (result == LAPB_CONNECTED)
 111                                 /* Send connect confirm. msg to level 3 */
 112                                 x25_connected(dev, 0);
 113                         else
 114                                 printk(KERN_ERR "%s: LAPB connect request "
 115                                        "failed, error code = %i\n",
 116                                        dev->name, result);
 117                 }
 118                 break;
 119
 120         case 2:
 121                 if ((result = lapb_disconnect_request(dev)) != LAPB_OK) {
 122                         if (result == LAPB_NOTCONNECTED)
 123                                 /* Send disconnect confirm. msg to level 3 */
 124                                 x25_disconnected(dev, 0);
 125                         else
 126                                 printk(KERN_ERR "%s: LAPB disconnect request "
 127                                        "failed, error code = %i\n",
 128                                        dev->name, result);
 129                 }
 130                 break;
 131
 132         default:                /* to be defined */
 133                 break;
 134         }
 135
 136         dev_kfree_skb(skb);
 137         return 0;
 138 }
 139
 140
 141
 142 static int x25_open(struct net_device *dev)
 143 {
 144         struct lapb_register_struct cb;
 145         int result;
 146
 147         cb.connect_confirmation = x25_connected;
 148         cb.connect_indication = x25_connected;
 149         cb.disconnect_confirmation = x25_disconnected;
 150         cb.disconnect_indication = x25_disconnected;
 151         cb.data_indication = x25_data_indication;
 152         cb.data_transmit = x25_data_transmit;
 153
 154         result = lapb_register(dev, &cb);
 155         if (result != LAPB_OK)
 156                 return result;
 157         return 0;
 158 }
 159
 160
 161
 162 static void x25_close(struct net_device *dev)
 163 {
 164         lapb_unregister(dev);
 165 }
 166
 167
 168
 169 static int x25_rx(struct sk_buff *skb)
 170 {
 171         hdlc_device *hdlc = dev_to_hdlc(skb->dev);
 172
 173         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
 174                 hdlc->stats.rx_dropped++;
 175                 return NET_RX_DROP;
 176         }
 177
 178         if (lapb_data_received(skb->dev, skb) == LAPB_OK)
 179                 return NET_RX_SUCCESS;
 180
 181         hdlc->stats.rx_errors++;
 182         dev_kfree_skb_any(skb);
 183         return NET_RX_DROP;
 184 }
 185
 186
 187
 188 int hdlc_x25_ioctl(struct net_device *dev, struct ifreq *ifr)
 189 {
 190         hdlc_device *hdlc = dev_to_hdlc(dev);
 191         int result;
 192
 193         switch (ifr->ifr_settings.type) {
 194         case IF_GET_PROTO:
 195                 ifr->ifr_settings.type = IF_PROTO_X25;
 196                 return 0; /* return protocol only, no settable parameters */
 197
 198         case IF_PROTO_X25:
 199                 if(!capable(CAP_NET_ADMIN))
 200                         return -EPERM;
 201
 202                 if(dev->flags & IFF_UP)
 203                         return -EBUSY;
 204
 205                 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
 206                 if (result)
 207                         return result;
 208
 209                 hdlc_proto_detach(hdlc);
 210                 memset(&hdlc->proto, 0, sizeof(hdlc->proto));
 211
 212                 hdlc->proto.open = x25_open;
 213                 hdlc->proto.close = x25_close;
 214                 hdlc->proto.netif_rx = x25_rx;
 215                 hdlc->proto.type_trans = NULL;
 216                 hdlc->proto.id = IF_PROTO_X25;
 217                 dev->hard_start_xmit = x25_xmit;
 218                 dev->hard_header = NULL;
 219                 dev->type = ARPHRD_X25;
 220                 dev->addr_len = 0;
 221                 return 0;
 222         }
 223
 224         return -EINVAL;
 225 }