drivers/net/wan/hdlc_generic.c

   1 /*
   2  * Generic HDLC support routines for Linux
   3  *
   4  * Copyright (C) 1999 - 2005 Krzysztof Halasa <khc@pm.waw.pl>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation.
   9  *
  10  * Currently supported:
  11  *      * raw IP-in-HDLC
  12  *      * Cisco HDLC
  13  *      * Frame Relay with ANSI or CCITT LMI (both user and network side)
  14  *      * PPP
  15  *      * X.25
  16  *
  17  * Use sethdlc utility to set line parameters, protocol and PVCs
  18  *
  19  * How does it work:
  20  * - proto.open(), close(), start(), stop() calls are serialized.
  21  *   The order is: open, [ start, stop ... ] close ...
  22  * - proto.start() and stop() are called with spin_lock_irq held.
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/kernel.h>
  27 #include <linux/slab.h>
  28 #include <linux/poll.h>
  29 #include <linux/errno.h>
  30 #include <linux/if_arp.h>
  31 #include <linux/init.h>
  32 #include <linux/skbuff.h>
  33 #include <linux/pkt_sched.h>
  34 #include <linux/inetdevice.h>
  35 #include <linux/lapb.h>
  36 #include <linux/rtnetlink.h>
  37 #include <linux/hdlc.h>
  38
  39
  40 static const char* version = "HDLC support module revision 1.18";
  41
  42 #undef DEBUG_LINK
  43
  44
  45 static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
  46 {
  47         if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
  48                 return -EINVAL;
  49         dev->mtu = new_mtu;
  50         return 0;
  51 }
  52
  53
  54
  55 static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
  56 {
  57         return hdlc_stats(dev);
  58 }
  59
  60
  61
  62 static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
  63                     struct packet_type *p, struct net_device *orig_dev)
  64 {
  65         hdlc_device *hdlc = dev_to_hdlc(dev);
  66         if (hdlc->proto.netif_rx)
  67                 return hdlc->proto.netif_rx(skb);
  68
  69         hdlc->stats.rx_dropped++; /* Shouldn't happen */
  70         dev_kfree_skb(skb);
  71         return NET_RX_DROP;
  72 }
  73
  74
  75
  76 static void __hdlc_set_carrier_on(struct net_device *dev)
  77 {
  78         hdlc_device *hdlc = dev_to_hdlc(dev);
  79         if (hdlc->proto.start)
  80                 return hdlc->proto.start(dev);
  81 #if 0
  82 #ifdef DEBUG_LINK
  83         if (netif_carrier_ok(dev))
  84                 printk(KERN_ERR "hdlc_set_carrier_on(): already on\n");
  85 #endif
  86         netif_carrier_on(dev);
  87 #endif
  88 }
  89
  90
  91
  92 static void __hdlc_set_carrier_off(struct net_device *dev)
  93 {
  94         hdlc_device *hdlc = dev_to_hdlc(dev);
  95         if (hdlc->proto.stop)
  96                 return hdlc->proto.stop(dev);
  97
  98 #if 0
  99 #ifdef DEBUG_LINK
 100         if (!netif_carrier_ok(dev))
 101                 printk(KERN_ERR "hdlc_set_carrier_off(): already off\n");
 102 #endif
 103         netif_carrier_off(dev);
 104 #endif
 105 }
 106
 107
 108
 109 void hdlc_set_carrier(int on, struct net_device *dev)
 110 {
 111         hdlc_device *hdlc = dev_to_hdlc(dev);
 112         unsigned long flags;
 113         on = on ? 1 : 0;
 114
 115 #ifdef DEBUG_LINK
 116         printk(KERN_DEBUG "hdlc_set_carrier %i\n", on);
 117 #endif
 118
 119         spin_lock_irqsave(&hdlc->state_lock, flags);
 120
 121         if (hdlc->carrier == on)
 122                 goto carrier_exit; /* no change in DCD line level */
 123
 124 #ifdef DEBUG_LINK
 125         printk(KERN_INFO "%s: carrier %s\n", dev->name, on ? "ON" : "off");
 126 #endif
 127         hdlc->carrier = on;
 128
 129         if (!hdlc->open)
 130                 goto carrier_exit;
 131
 132         if (hdlc->carrier) {
 133                 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
 134                 __hdlc_set_carrier_on(dev);
 135         } else {
 136                 printk(KERN_INFO "%s: Carrier lost\n", dev->name);
 137                 __hdlc_set_carrier_off(dev);
 138         }
 139
 140 carrier_exit:
 141         spin_unlock_irqrestore(&hdlc->state_lock, flags);
 142 }
 143
 144
 145
 146 /* Must be called by hardware driver when HDLC device is being opened */
 147 int hdlc_open(struct net_device *dev)
 148 {
 149         hdlc_device *hdlc = dev_to_hdlc(dev);
 150 #ifdef DEBUG_LINK
 151         printk(KERN_DEBUG "hdlc_open() carrier %i open %i\n",
 152                hdlc->carrier, hdlc->open);
 153 #endif
 154
 155         if (hdlc->proto.id == -1)
 156                 return -ENOSYS; /* no protocol attached */
 157
 158         if (hdlc->proto.open) {
 159                 int result = hdlc->proto.open(dev);
 160                 if (result)
 161                         return result;
 162         }
 163
 164         spin_lock_irq(&hdlc->state_lock);
 165
 166         if (hdlc->carrier) {
 167                 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
 168                 __hdlc_set_carrier_on(dev);
 169         } else
 170                 printk(KERN_INFO "%s: No carrier\n", dev->name);
 171
 172         hdlc->open = 1;
 173
 174         spin_unlock_irq(&hdlc->state_lock);
 175         return 0;
 176 }
 177
 178
 179
 180 /* Must be called by hardware driver when HDLC device is being closed */
 181 void hdlc_close(struct net_device *dev)
 182 {
 183         hdlc_device *hdlc = dev_to_hdlc(dev);
 184 #ifdef DEBUG_LINK
 185         printk(KERN_DEBUG "hdlc_close() carrier %i open %i\n",
 186                hdlc->carrier, hdlc->open);
 187 #endif
 188
 189         spin_lock_irq(&hdlc->state_lock);
 190
 191         hdlc->open = 0;
 192         if (hdlc->carrier)
 193                 __hdlc_set_carrier_off(dev);
 194
 195         spin_unlock_irq(&hdlc->state_lock);
 196
 197         if (hdlc->proto.close)
 198                 hdlc->proto.close(dev);
 199 }
 200
 201
 202
 203 #ifndef CONFIG_HDLC_RAW
 204 #define hdlc_raw_ioctl(dev, ifr)        -ENOSYS
 205 #endif
 206
 207 #ifndef CONFIG_HDLC_RAW_ETH
 208 #define hdlc_raw_eth_ioctl(dev, ifr)    -ENOSYS
 209 #endif
 210
 211 #ifndef CONFIG_HDLC_PPP
 212 #define hdlc_ppp_ioctl(dev, ifr)        -ENOSYS
 213 #endif
 214
 215 #ifndef CONFIG_HDLC_CISCO
 216 #define hdlc_cisco_ioctl(dev, ifr)      -ENOSYS
 217 #endif
 218
 219 #ifndef CONFIG_HDLC_FR
 220 #define hdlc_fr_ioctl(dev, ifr)         -ENOSYS
 221 #endif
 222
 223 #ifndef CONFIG_HDLC_X25
 224 #define hdlc_x25_ioctl(dev, ifr)        -ENOSYS
 225 #endif
 226
 227
 228 int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 229 {
 230         hdlc_device *hdlc = dev_to_hdlc(dev);
 231         unsigned int proto;
 232
 233         if (cmd != SIOCWANDEV)
 234                 return -EINVAL;
 235
 236         switch(ifr->ifr_settings.type) {
 237         case IF_PROTO_HDLC:
 238         case IF_PROTO_HDLC_ETH:
 239         case IF_PROTO_PPP:
 240         case IF_PROTO_CISCO:
 241         case IF_PROTO_FR:
 242         case IF_PROTO_X25:
 243                 proto = ifr->ifr_settings.type;
 244                 break;
 245
 246         default:
 247                 proto = hdlc->proto.id;
 248         }
 249
 250         switch(proto) {
 251         case IF_PROTO_HDLC:     return hdlc_raw_ioctl(dev, ifr);
 252         case IF_PROTO_HDLC_ETH: return hdlc_raw_eth_ioctl(dev, ifr);
 253         case IF_PROTO_PPP:      return hdlc_ppp_ioctl(dev, ifr);
 254         case IF_PROTO_CISCO:    return hdlc_cisco_ioctl(dev, ifr);
 255         case IF_PROTO_FR:       return hdlc_fr_ioctl(dev, ifr);
 256         case IF_PROTO_X25:      return hdlc_x25_ioctl(dev, ifr);
 257         default:                return -EINVAL;
 258         }
 259 }
 260
 261 void hdlc_setup(struct net_device *dev)
 262 {
 263         hdlc_device *hdlc = dev_to_hdlc(dev);
 264
 265         dev->get_stats = hdlc_get_stats;
 266         dev->change_mtu = hdlc_change_mtu;
 267         dev->mtu = HDLC_MAX_MTU;
 268
 269         dev->type = ARPHRD_RAWHDLC;
 270         dev->hard_header_len = 16;
 271
 272         dev->flags = IFF_POINTOPOINT | IFF_NOARP;
 273
 274         hdlc->proto.id = -1;
 275         hdlc->proto.detach = NULL;
 276         hdlc->carrier = 1;
 277         hdlc->open = 0;
 278         spin_lock_init(&hdlc->state_lock);
 279 }
 280
 281 struct net_device *alloc_hdlcdev(void *priv)
 282 {
 283         struct net_device *dev;
 284         dev = alloc_netdev(sizeof(hdlc_device), "hdlc%d", hdlc_setup);
 285         if (dev)
 286                 dev_to_hdlc(dev)->priv = priv;
 287         return dev;
 288 }
 289
 290 void unregister_hdlc_device(struct net_device *dev)
 291 {
 292         rtnl_lock();
 293         hdlc_proto_detach(dev_to_hdlc(dev));
 294         unregister_netdevice(dev);
 295         rtnl_unlock();
 296 }
 297
 298
 299
 300 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 301 MODULE_DESCRIPTION("HDLC support module");
 302 MODULE_LICENSE("GPL v2");
 303
 304 EXPORT_SYMBOL(hdlc_open);
 305 EXPORT_SYMBOL(hdlc_close);
 306 EXPORT_SYMBOL(hdlc_set_carrier);
 307 EXPORT_SYMBOL(hdlc_ioctl);
 308 EXPORT_SYMBOL(hdlc_setup);
 309 EXPORT_SYMBOL(alloc_hdlcdev);
 310 EXPORT_SYMBOL(unregister_hdlc_device);
 311
 312 static struct packet_type hdlc_packet_type = {
 313         .type = __constant_htons(ETH_P_HDLC),
 314         .func = hdlc_rcv,
 315 };
 316
 317
 318 static int __init hdlc_module_init(void)
 319 {
 320         printk(KERN_INFO "%s\n", version);
 321         dev_add_pack(&hdlc_packet_type);
 322         return 0;
 323 }
 324
 325
 326
 327 static void __exit hdlc_module_exit(void)
 328 {
 329         dev_remove_pack(&hdlc_packet_type);
 330 }
 331
 332
 333 module_init(hdlc_module_init);
 334 module_exit(hdlc_module_exit);