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 #if 0
  83 #ifdef DEBUG_LINK
  84         if (netif_carrier_ok(dev))
  85                 printk(KERN_ERR "hdlc_set_carrier_on(): already on\n");
  86 #endif
  87         netif_carrier_on(dev);
  88 #endif
  89 }
  90
  91
  92
  93 static void __hdlc_set_carrier_off(struct net_device *dev)
  94 {
  95         hdlc_device *hdlc = dev_to_hdlc(dev);
  96         if (hdlc->proto.stop)
  97                 return hdlc->proto.stop(dev);
  98
  99 #if 0
 100 #ifdef DEBUG_LINK
 101         if (!netif_carrier_ok(dev))
 102                 printk(KERN_ERR "hdlc_set_carrier_off(): already off\n");
 103 #endif
 104         netif_carrier_off(dev);
 105 #endif
 106 }
 107
 108
 109
 110 void hdlc_set_carrier(int on, struct net_device *dev)
 111 {
 112         hdlc_device *hdlc = dev_to_hdlc(dev);
 113         unsigned long flags;
 114         on = on ? 1 : 0;
 115
 116 #ifdef DEBUG_LINK
 117         printk(KERN_DEBUG "hdlc_set_carrier %i\n", on);
 118 #endif
 119
 120         spin_lock_irqsave(&hdlc->state_lock, flags);
 121
 122         if (hdlc->carrier == on)
 123                 goto carrier_exit; /* no change in DCD line level */
 124
 125 #ifdef DEBUG_LINK
 126         printk(KERN_INFO "%s: carrier %s\n", dev->name, on ? "ON" : "off");
 127 #endif
 128         hdlc->carrier = on;
 129
 130         if (!hdlc->open)
 131                 goto carrier_exit;
 132
 133         if (hdlc->carrier) {
 134                 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
 135                 __hdlc_set_carrier_on(dev);
 136         } else {
 137                 printk(KERN_INFO "%s: Carrier lost\n", dev->name);
 138                 __hdlc_set_carrier_off(dev);
 139         }
 140
 141 carrier_exit:
 142         spin_unlock_irqrestore(&hdlc->state_lock, flags);
 143 }
 144
 145
 146
 147 /* Must be called by hardware driver when HDLC device is being opened */
 148 int hdlc_open(struct net_device *dev)
 149 {
 150         hdlc_device *hdlc = dev_to_hdlc(dev);
 151 #ifdef DEBUG_LINK
 152         printk(KERN_DEBUG "hdlc_open() carrier %i open %i\n",
 153                hdlc->carrier, hdlc->open);
 154 #endif
 155
 156         if (hdlc->proto.id == -1)
 157                 return -ENOSYS; /* no protocol attached */
 158
 159         if (hdlc->proto.open) {
 160                 int result = hdlc->proto.open(dev);
 161                 if (result)
 162                         return result;
 163         }
 164
 165         spin_lock_irq(&hdlc->state_lock);
 166
 167         if (hdlc->carrier) {
 168                 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
 169                 __hdlc_set_carrier_on(dev);
 170         } else
 171                 printk(KERN_INFO "%s: No carrier\n", dev->name);
 172
 173         hdlc->open = 1;
 174
 175         spin_unlock_irq(&hdlc->state_lock);
 176         return 0;
 177 }
 178
 179
 180
 181 /* Must be called by hardware driver when HDLC device is being closed */
 182 void hdlc_close(struct net_device *dev)
 183 {
 184         hdlc_device *hdlc = dev_to_hdlc(dev);
 185 #ifdef DEBUG_LINK
 186         printk(KERN_DEBUG "hdlc_close() carrier %i open %i\n",
 187                hdlc->carrier, hdlc->open);
 188 #endif
 189
 190         spin_lock_irq(&hdlc->state_lock);
 191
 192         hdlc->open = 0;
 193         if (hdlc->carrier)
 194                 __hdlc_set_carrier_off(dev);
 195
 196         spin_unlock_irq(&hdlc->state_lock);
 197
 198         if (hdlc->proto.close)
 199                 hdlc->proto.close(dev);
 200 }
 201
 202
 203
 204 #ifndef CONFIG_HDLC_RAW
 205 #define hdlc_raw_ioctl(dev, ifr)        -ENOSYS
 206 #endif
 207
 208 #ifndef CONFIG_HDLC_RAW_ETH
 209 #define hdlc_raw_eth_ioctl(dev, ifr)    -ENOSYS
 210 #endif
 211
 212 #ifndef CONFIG_HDLC_PPP
 213 #define hdlc_ppp_ioctl(dev, ifr)        -ENOSYS
 214 #endif
 215
 216 #ifndef CONFIG_HDLC_CISCO
 217 #define hdlc_cisco_ioctl(dev, ifr)      -ENOSYS
 218 #endif
 219
 220 #ifndef CONFIG_HDLC_FR
 221 #define hdlc_fr_ioctl(dev, ifr)         -ENOSYS
 222 #endif
 223
 224 #ifndef CONFIG_HDLC_X25
 225 #define hdlc_x25_ioctl(dev, ifr)        -ENOSYS
 226 #endif
 227
 228
 229 int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 230 {
 231         hdlc_device *hdlc = dev_to_hdlc(dev);
 232         unsigned int proto;
 233
 234         if (cmd != SIOCWANDEV)
 235                 return -EINVAL;
 236
 237         switch(ifr->ifr_settings.type) {
 238         case IF_PROTO_HDLC:
 239         case IF_PROTO_HDLC_ETH:
 240         case IF_PROTO_PPP:
 241         case IF_PROTO_CISCO:
 242         case IF_PROTO_FR:
 243         case IF_PROTO_X25:
 244                 proto = ifr->ifr_settings.type;
 245                 break;
 246
 247         default:
 248                 proto = hdlc->proto.id;
 249         }
 250
 251         switch(proto) {
 252         case IF_PROTO_HDLC:     return hdlc_raw_ioctl(dev, ifr);
 253         case IF_PROTO_HDLC_ETH: return hdlc_raw_eth_ioctl(dev, ifr);
 254         case IF_PROTO_PPP:      return hdlc_ppp_ioctl(dev, ifr);
 255         case IF_PROTO_CISCO:    return hdlc_cisco_ioctl(dev, ifr);
 256         case IF_PROTO_FR:       return hdlc_fr_ioctl(dev, ifr);
 257         case IF_PROTO_X25:      return hdlc_x25_ioctl(dev, ifr);
 258         default:                return -EINVAL;
 259         }
 260 }
 261
 262 void hdlc_setup(struct net_device *dev)
 263 {
 264         hdlc_device *hdlc = dev_to_hdlc(dev);
 265
 266         dev->get_stats = hdlc_get_stats;
 267         dev->change_mtu = hdlc_change_mtu;
 268         dev->mtu = HDLC_MAX_MTU;
 269
 270         dev->type = ARPHRD_RAWHDLC;
 271         dev->hard_header_len = 16;
 272
 273         dev->flags = IFF_POINTOPOINT | IFF_NOARP;
 274
 275         hdlc->proto.id = -1;
 276         hdlc->proto.detach = NULL;
 277         hdlc->carrier = 1;
 278         hdlc->open = 0;
 279         spin_lock_init(&hdlc->state_lock);
 280 }
 281
 282 struct net_device *alloc_hdlcdev(void *priv)
 283 {
 284         struct net_device *dev;
 285         dev = alloc_netdev(sizeof(hdlc_device), "hdlc%d", hdlc_setup);
 286         if (dev)
 287                 dev_to_hdlc(dev)->priv = priv;
 288         return dev;
 289 }
 290
 291 void unregister_hdlc_device(struct net_device *dev)
 292 {
 293         rtnl_lock();
 294         hdlc_proto_detach(dev_to_hdlc(dev));
 295         unregister_netdevice(dev);
 296         rtnl_unlock();
 297 }
 298
 299
 300
 301 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 302 MODULE_DESCRIPTION("HDLC support module");
 303 MODULE_LICENSE("GPL v2");
 304
 305 EXPORT_SYMBOL(hdlc_open);
 306 EXPORT_SYMBOL(hdlc_close);
 307 EXPORT_SYMBOL(hdlc_set_carrier);
 308 EXPORT_SYMBOL(hdlc_ioctl);
 309 EXPORT_SYMBOL(hdlc_setup);
 310 EXPORT_SYMBOL(alloc_hdlcdev);
 311 EXPORT_SYMBOL(unregister_hdlc_device);
 312
 313 static struct packet_type hdlc_packet_type = {
 314         .type = __constant_htons(ETH_P_HDLC),
 315         .func = hdlc_rcv,
 316 };
 317
 318
 319 static int __init hdlc_module_init(void)
 320 {
 321         printk(KERN_INFO "%s\n", version);
 322         dev_add_pack(&hdlc_packet_type);
 323         return 0;
 324 }
 325
 326
 327
 328 static void __exit hdlc_module_exit(void)
 329 {
 330         dev_remove_pack(&hdlc_packet_type);
 331 }
 332
 333
 334 module_init(hdlc_module_init);
 335 module_exit(hdlc_module_exit);