net/x25/x25_dev.c

   1 /*
   2  *      X.25 Packet Layer release 002
   3  *
   4  *      This is ALPHA test software. This code may break your machine, randomly fail to work with new
   5  *      releases, misbehave and/or generally screw up. It might even work.
   6  *
   7  *      This code REQUIRES 2.1.15 or higher
   8  *
   9  *      This module:
  10  *              This module is free software; you can redistribute it and/or
  11  *              modify it under the terms of the GNU General Public License
  12  *              as published by the Free Software Foundation; either version
  13  *              2 of the License, or (at your option) any later version.
  14  *
  15  *      History
  16  *      X.25 001        Jonathan Naylor Started coding.
  17  */
  18
  19 #include <linux/config.h>
  20 #if defined(CONFIG_X25) || defined(CONFIG_X25_MODULE)
  21 #include <linux/errno.h>
  22 #include <linux/types.h>
  23 #include <linux/socket.h>
  24 #include <linux/in.h>
  25 #include <linux/kernel.h>
  26 #include <linux/sched.h>
  27 #include <linux/timer.h>
  28 #include <linux/string.h>
  29 #include <linux/sockios.h>
  30 #include <linux/net.h>
  31 #include <linux/stat.h>
  32 #include <linux/inet.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/if_arp.h>
  35 #include <linux/skbuff.h>
  36 #include <net/sock.h>
  37 #include <asm/segment.h>
  38 #include <asm/system.h>
  39 #include <asm/uaccess.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/termios.h>      /* For TIOCINQ/OUTQ */
  42 #include <linux/mm.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/notifier.h>
  45 #include <linux/proc_fs.h>
  46 #include <linux/firewall.h>
  47 #include <net/x25.h>
  48
  49 static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *neigh)
  50 {
  51         struct sock *sk;
  52         unsigned short frametype;
  53         unsigned int lci;
  54
  55         if (call_in_firewall(PF_X25, skb->dev, skb->data, NULL, &skb) != FW_ACCEPT) {
  56                 kfree_skb(skb);
  57                 return 0;
  58         }
  59
  60         frametype = skb->data[2];
  61         lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
  62
  63         /*
  64          *      LCI of zero is always for us, and its always a link control
  65          *      frame.
  66          */
  67         if (lci == 0) {
  68                 x25_link_control(skb, neigh, frametype);
  69                 return 0;
  70         }
  71
  72         /*
  73          *      Find an existing socket.
  74          */
  75         if ((sk = x25_find_socket(lci, neigh)) != NULL) {
  76                 skb->h.raw = skb->data;
  77                 return x25_process_rx_frame(sk, skb);
  78         }
  79
  80         /*
  81          *      Is is a Call Request ? if so process it.
  82          */
  83         if (frametype == X25_CALL_REQUEST)
  84                 return x25_rx_call_request(skb, neigh, lci);
  85
  86         /*
  87          *      Its not a Call Request, nor is it a control frame, throw it awa
  88          */
  89 /*
  90         x25_transmit_clear_request(neigh, lci, 0x0D);
  91 */
  92         kfree_skb(skb);
  93
  94         return 0;
  95 }
  96
  97 int x25_lapb_receive_frame(struct sk_buff *skb, struct device *dev, struct packet_type *ptype)
  98 {
  99         struct x25_neigh *neigh;
 100         int queued;
 101
 102         skb->sk = NULL;
 103
 104         /*
 105          *      Packet received from unrecognised device, throw it away.
 106          */
 107         if ((neigh = x25_get_neigh(dev)) == NULL) {
 108                 printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
 109                 kfree_skb(skb);
 110                 return 0;
 111         }
 112
 113         switch (skb->data[0]) {
 114                 case 0x00:
 115                         skb_pull(skb, 1);
 116                         queued = x25_receive_data(skb, neigh);
 117                         if( ! queued )
 118                                 /* We need to free the skb ourselves because
 119                                  * net_bh() won't care about our return code.
 120                                  */
 121                                 kfree_skb(skb);
 122                         return 0;
 123
 124                 case 0x01:
 125                         x25_link_established(neigh);
 126                         kfree_skb(skb);
 127                         return 0;
 128
 129                 case 0x02:
 130                         x25_link_terminated(neigh);
 131                         kfree_skb(skb);
 132                         return 0;
 133
 134                 case 0x03:
 135                         kfree_skb(skb);
 136                         return 0;
 137
 138                 default:
 139                         kfree_skb(skb);
 140                         return 0;
 141         }
 142 }
 143
 144 int x25_llc_receive_frame(struct sk_buff *skb, struct device *dev, struct packet_type *ptype)
 145 {
 146         struct x25_neigh *neigh;
 147
 148         skb->sk = NULL;
 149
 150         /*
 151          *      Packet received from unrecognised device, throw it away.
 152          */
 153         if ((neigh = x25_get_neigh(dev)) == NULL) {
 154                 printk(KERN_DEBUG "X.25: unknown_neighbour - %s\n", dev->name);
 155                 kfree_skb(skb);
 156                 return 0;
 157         }
 158
 159         return x25_receive_data(skb, neigh);
 160 }
 161
 162 void x25_establish_link(struct x25_neigh *neigh)
 163 {
 164         struct sk_buff *skb;
 165         unsigned char *ptr;
 166
 167         switch (neigh->dev->type) {
 168                 case ARPHRD_X25:
 169                         if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
 170                                 printk(KERN_ERR "x25_dev: out of memory\n");
 171                                 return;
 172                         }
 173                         ptr  = skb_put(skb, 1);
 174                         *ptr = 0x01;
 175                         break;
 176
 177 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
 178                 case ARPHRD_ETHER:
 179                         return;
 180 #endif
 181                 default:
 182                         return;
 183         }
 184
 185         skb->protocol = htons(ETH_P_X25);
 186         skb->dev      = neigh->dev;
 187
 188         dev_queue_xmit(skb);
 189 }
 190
 191 void x25_terminate_link(struct x25_neigh *neigh)
 192 {
 193         struct sk_buff *skb;
 194         unsigned char *ptr;
 195
 196         switch (neigh->dev->type) {
 197                 case ARPHRD_X25:
 198                         if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
 199                                 printk(KERN_ERR "x25_dev: out of memory\n");
 200                                 return;
 201                         }
 202                         ptr  = skb_put(skb, 1);
 203                         *ptr = 0x02;
 204                         break;
 205
 206 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
 207                 case ARPHRD_ETHER:
 208                         return;
 209 #endif
 210                 default:
 211                         return;
 212         }
 213
 214         skb->protocol = htons(ETH_P_X25);
 215         skb->dev      = neigh->dev;
 216
 217         dev_queue_xmit(skb);
 218 }
 219
 220 void x25_send_frame(struct sk_buff *skb, struct x25_neigh *neigh)
 221 {
 222         unsigned char *dptr;
 223
 224         skb->nh.raw = skb->data;
 225
 226         switch (neigh->dev->type) {
 227                 case ARPHRD_X25:
 228                         dptr  = skb_push(skb, 1);
 229                         *dptr = 0x00;
 230                         break;
 231
 232 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
 233                 case ARPHRD_ETHER:
 234                         kfree_skb(skb);
 235                         return;
 236 #endif
 237                 default:
 238                         kfree_skb(skb);
 239                         return;
 240         }
 241
 242         skb->protocol = htons(ETH_P_X25);
 243         skb->dev      = neigh->dev;
 244
 245         dev_queue_xmit(skb);
 246 }
 247
 248 #endif
 249
 250
 251