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/config.h>
  26 #include <linux/module.h>
  27 #include <linux/kernel.h>
  28 #include <linux/slab.h>
  29 #include <linux/poll.h>
  30 #include <linux/errno.h>
  31 #include <linux/if_arp.h>
  32 #include <linux/init.h>
  33 #include <linux/skbuff.h>
  34 #include <linux/pkt_sched.h>
  35 #include <linux/inetdevice.h>
  36 #include <linux/lapb.h>
  37 #include <linux/rtnetlink.h>
  38 #include <linux/hdlc.h>
  39
  40
  41 static const char* version = "HDLC support module revision 1.18";
  42
  43 #undef DEBUG_LINK
  44
  45
  46 static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
  47 {
  48         if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
  49                 return -EINVAL;
  50         dev->mtu = new_mtu;
  51         return 0;
  52 }
  53
  54
  55
  56 static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
  57 {
  58         return hdlc_stats(dev);
  59 }
  60
  61
  62
  63 static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
  64                     struct packet_type *p, struct net_device *orig_dev)
  65 {
  66         hdlc_device *hdlc = dev_to_hdlc(dev);
  67         if (hdlc->proto.netif_rx)
  68                 return hdlc->proto.netif_rx(skb);
  69
  70         hdlc->stats.rx_dropped++; /* Shouldn't happen */
  71         dev_kfree_skb(skb);
  72         return NET_RX_DROP;
  73 }
  74
  75
  76
  77 static void __hdlc_set_carrier_on(struct net_device *dev)
  78 {
  79         hdlc_device *hdlc = dev_to_hdlc(dev);
  80         if (hdlc->proto.start)
  81                 return hdlc->proto.start(dev);
  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 }
  88
  89
  90
  91 static void __hdlc_set_carrier_off(struct net_device *dev)
  92 {
  93         hdlc_device *hdlc = dev_to_hdlc(dev);
  94         if (hdlc->proto.stop)
  95                 return hdlc->proto.stop(dev);
  96
  97 #ifdef DEBUG_LINK
  98         if (!netif_carrier_ok(dev))
  99                 printk(KERN_ERR "hdlc_set_carrier_off(): already off\n");
 100 #endif
 101         netif_carrier_off(dev);
 102 }
 103
 104
 105
 106 void hdlc_set_carrier(int on, struct net_device *dev)
 107 {
 108         hdlc_device *hdlc = dev_to_hdlc(dev);
 109         unsigned long flags;
 110         on = on ? 1 : 0;
 111
 112 #ifdef DEBUG_LINK
 113         printk(KERN_DEBUG "hdlc_set_carrier %i\n", on);
 114 #endif
 115
 116         spin_lock_irqsave(&hdlc->state_lock, flags);
 117
 118         if (hdlc->carrier == on)
 119                 goto carrier_exit; /* no change in DCD line level */
 120
 121 #ifdef DEBUG_LINK
 122         printk(KERN_INFO "%s: carrier %s\n", dev->name, on ? "ON" : "off");
 123 #endif
 124         hdlc->carrier = on;
 125
 126         if (!hdlc->open)
 127                 goto carrier_exit;
 128
 129         if (hdlc->carrier) {
 130                 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
 131                 __hdlc_set_carrier_on(dev);
 132         } else {
 133                 printk(KERN_INFO "%s: Carrier lost\n", dev->name);
 134                 __hdlc_set_carrier_off(dev);
 135         }
 136
 137 carrier_exit:
 138         spin_unlock_irqrestore(&hdlc->state_lock, flags);
 139 }
 140
 141
 142
 143 /* Must be called by hardware driver when HDLC device is being opened */
 144 int hdlc_open(struct net_device *dev)
 145 {
 146         hdlc_device *hdlc = dev_to_hdlc(dev);
 147 #ifdef DEBUG_LINK
 148         printk(KERN_DEBUG "hdlc_open() carrier %i open %i\n",
 149                hdlc->carrier, hdlc->open);
 150 #endif
 151
 152         if (hdlc->proto.id == -1)
 153                 return -ENOSYS; /* no protocol attached */
 154
 155         if (hdlc->proto.open) {
 156                 int result = hdlc->proto.open(dev);
 157                 if (result)
 158                         return result;
 159         }
 160
 161         spin_lock_irq(&hdlc->state_lock);
 162
 163         if (hdlc->carrier) {
 164                 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
 165                 __hdlc_set_carrier_on(dev);
 166         } else
 167                 printk(KERN_INFO "%s: No carrier\n", dev->name);
 168
 169         hdlc->open = 1;
 170
 171         spin_unlock_irq(&hdlc->state_lock);
 172         return 0;
 173 }
 174
 175
 176
 177 /* Must be called by hardware driver when HDLC device is being closed */
 178 void hdlc_close(struct net_device *dev)
 179 {
 180         hdlc_device *hdlc = dev_to_hdlc(dev);
 181 #ifdef DEBUG_LINK
 182         printk(KERN_DEBUG "hdlc_close() carrier %i open %i\n",
 183                hdlc->carrier, hdlc->open);
 184 #endif
 185
 186         spin_lock_irq(&hdlc->state_lock);
 187
 188         hdlc->open = 0;
 189         if (hdlc->carrier)
 190                 __hdlc_set_carrier_off(dev);
 191
 192         spin_unlock_irq(&hdlc->state_lock);
 193
 194         if (hdlc->proto.close)
 195                 hdlc->proto.close(dev);
 196 }
 197
 198
 199
 200 #ifndef CONFIG_HDLC_RAW
 201 #define hdlc_raw_ioctl(dev, ifr)        -ENOSYS
 202 #endif
 203
 204 #ifndef CONFIG_HDLC_RAW_ETH
 205 #define hdlc_raw_eth_ioctl(dev, ifr)    -ENOSYS
 206 #endif
 207
 208 #ifndef CONFIG_HDLC_PPP
 209 #define hdlc_ppp_ioctl(dev, ifr)        -ENOSYS
 210 #endif
 211
 212 #ifndef CONFIG_HDLC_CISCO
 213 #define hdlc_cisco_ioctl(dev, ifr)      -ENOSYS
 214 #endif
 215
 216 #ifndef CONFIG_HDLC_FR
 217 #define hdlc_fr_ioctl(dev, ifr)         -ENOSYS
 218 #endif
 219
 220 #ifndef CONFIG_HDLC_X25
 221 #define hdlc_x25_ioctl(dev, ifr)        -ENOSYS
 222 #endif
 223
 224
 225 int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 226 {
 227         hdlc_device *hdlc = dev_to_hdlc(dev);
 228         unsigned int proto;
 229
 230         if (cmd != SIOCWANDEV)
 231                 return -EINVAL;
 232
 233         switch(ifr->ifr_settings.type) {
 234         case IF_PROTO_HDLC:
 235         case IF_PROTO_HDLC_ETH:
 236         case IF_PROTO_PPP:
 237         case IF_PROTO_CISCO:
 238         case IF_PROTO_FR:
 239         case IF_PROTO_X25:
 240                 proto = ifr->ifr_settings.type;
 241                 break;
 242
 243         default:
 244                 proto = hdlc->proto.id;
 245         }
 246
 247         switch(proto) {
 248         case IF_PROTO_HDLC:     return hdlc_raw_ioctl(dev, ifr);
 249         case IF_PROTO_HDLC_ETH: return hdlc_raw_eth_ioctl(dev, ifr);
 250         case IF_PROTO_PPP:      return hdlc_ppp_ioctl(dev, ifr);
 251         case IF_PROTO_CISCO:    return hdlc_cisco_ioctl(dev, ifr);
 252         case IF_PROTO_FR:       return hdlc_fr_ioctl(dev, ifr);
 253         case IF_PROTO_X25:      return hdlc_x25_ioctl(dev, ifr);
 254         default:                return -EINVAL;
 255         }
 256 }
 257
 258 static void hdlc_setup(struct net_device *dev)
 259 {
 260         hdlc_device *hdlc = dev_to_hdlc(dev);
 261
 262         dev->get_stats = hdlc_get_stats;
 263         dev->change_mtu = hdlc_change_mtu;
 264         dev->mtu = HDLC_MAX_MTU;
 265
 266         dev->type = ARPHRD_RAWHDLC;
 267         dev->hard_header_len = 16;
 268
 269         dev->flags = IFF_POINTOPOINT | IFF_NOARP;
 270
 271         hdlc->proto.id = -1;
 272         hdlc->proto.detach = NULL;
 273         hdlc->carrier = 1;
 274         hdlc->open = 0;
 275         spin_lock_init(&hdlc->state_lock);
 276 }
 277
 278 struct net_device *alloc_hdlcdev(void *priv)
 279 {
 280         struct net_device *dev;
 281         dev = alloc_netdev(sizeof(hdlc_device), "hdlc%d", hdlc_setup);
 282         if (dev)
 283                 dev_to_hdlc(dev)->priv = priv;
 284         return dev;
 285 }
 286
 287 int register_hdlc_device(struct net_device *dev)
 288 {
 289         int result = dev_alloc_name(dev, "hdlc%d");
 290         if (result < 0)
 291                 return result;
 292
 293         result = register_netdev(dev);
 294         if (result != 0)
 295                 return -EIO;
 296
 297         if (netif_carrier_ok(dev))
 298                 netif_carrier_off(dev); /* no carrier until DCD goes up */
 299
 300         return 0;
 301 }
 302
 303
 304
 305 void unregister_hdlc_device(struct net_device *dev)
 306 {
 307         rtnl_lock();
 308         hdlc_proto_detach(dev_to_hdlc(dev));
 309         unregister_netdevice(dev);
 310         rtnl_unlock();
 311 }
 312
 313
 314
 315 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 316 MODULE_DESCRIPTION("HDLC support module");
 317 MODULE_LICENSE("GPL v2");
 318
 319 EXPORT_SYMBOL(hdlc_open);
 320 EXPORT_SYMBOL(hdlc_close);
 321 EXPORT_SYMBOL(hdlc_set_carrier);
 322 EXPORT_SYMBOL(hdlc_ioctl);
 323 EXPORT_SYMBOL(alloc_hdlcdev);
 324 EXPORT_SYMBOL(register_hdlc_device);
 325 EXPORT_SYMBOL(unregister_hdlc_device);
 326
 327 static struct packet_type hdlc_packet_type = {
 328         .type = __constant_htons(ETH_P_HDLC),
 329         .func = hdlc_rcv,
 330 };
 331
 332
 333 static int __init hdlc_module_init(void)
 334 {
 335         printk(KERN_INFO "%s\n", version);
 336         dev_add_pack(&hdlc_packet_type);
 337         return 0;
 338 }
 339
 340
 341
 342 static void __exit hdlc_module_exit(void)
 343 {
 344         dev_remove_pack(&hdlc_packet_type);
 345 }
 346
 347
 348 module_init(hdlc_module_init);
 349 module_exit(hdlc_module_exit);