2 * Generic HDLC support routines for Linux
4 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
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.
10 * Currently supported:
13 * * Frame Relay with ANSI or CCITT LMI (both user and network side)
17 * Use sethdlc utility to set line parameters, protocol and PVCs
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.
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/notifier.h>
38 #include <linux/hdlc.h>
39 #include <net/net_namespace.h>
42 static const char* version = "HDLC support module revision 1.21";
46 static struct hdlc_proto *first_proto = NULL;
49 static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
51 if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
59 static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
61 return hdlc_stats(dev);
66 static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
67 struct packet_type *p, struct net_device *orig_dev)
69 struct hdlc_device_desc *desc = dev_to_desc(dev);
71 if (dev->nd_net != &init_net) {
77 return desc->netif_rx(skb);
79 desc->stats.rx_dropped++; /* Shouldn't happen */
86 static inline void hdlc_proto_start(struct net_device *dev)
88 hdlc_device *hdlc = dev_to_hdlc(dev);
89 if (hdlc->proto->start)
90 return hdlc->proto->start(dev);
95 static inline void hdlc_proto_stop(struct net_device *dev)
97 hdlc_device *hdlc = dev_to_hdlc(dev);
98 if (hdlc->proto->stop)
99 return hdlc->proto->stop(dev);
104 static int hdlc_device_event(struct notifier_block *this, unsigned long event,
107 struct net_device *dev = ptr;
112 if (dev->get_stats != hdlc_get_stats)
113 return NOTIFY_DONE; /* not an HDLC device */
115 if (event != NETDEV_CHANGE)
116 return NOTIFY_DONE; /* Only interrested in carrier changes */
118 on = netif_carrier_ok(dev);
121 printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
125 hdlc = dev_to_hdlc(dev);
126 spin_lock_irqsave(&hdlc->state_lock, flags);
128 if (hdlc->carrier == on)
129 goto carrier_exit; /* no change in DCD line level */
137 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
138 hdlc_proto_start(dev);
140 printk(KERN_INFO "%s: Carrier lost\n", dev->name);
141 hdlc_proto_stop(dev);
145 spin_unlock_irqrestore(&hdlc->state_lock, flags);
151 /* Must be called by hardware driver when HDLC device is being opened */
152 int hdlc_open(struct net_device *dev)
154 hdlc_device *hdlc = dev_to_hdlc(dev);
156 printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
157 hdlc->carrier, hdlc->open);
160 if (hdlc->proto == NULL)
161 return -ENOSYS; /* no protocol attached */
163 if (hdlc->proto->open) {
164 int result = hdlc->proto->open(dev);
169 spin_lock_irq(&hdlc->state_lock);
172 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
173 hdlc_proto_start(dev);
175 printk(KERN_INFO "%s: No carrier\n", dev->name);
179 spin_unlock_irq(&hdlc->state_lock);
185 /* Must be called by hardware driver when HDLC device is being closed */
186 void hdlc_close(struct net_device *dev)
188 hdlc_device *hdlc = dev_to_hdlc(dev);
190 printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
191 hdlc->carrier, hdlc->open);
194 spin_lock_irq(&hdlc->state_lock);
198 hdlc_proto_stop(dev);
200 spin_unlock_irq(&hdlc->state_lock);
202 if (hdlc->proto->close)
203 hdlc->proto->close(dev);
208 int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
210 struct hdlc_proto *proto = first_proto;
213 if (cmd != SIOCWANDEV)
216 if (dev_to_hdlc(dev)->proto) {
217 result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
218 if (result != -EINVAL)
222 /* Not handled by currently attached protocol (if any) */
225 if ((result = proto->ioctl(dev, ifr)) != -EINVAL)
232 static void hdlc_setup_dev(struct net_device *dev)
234 /* Re-init all variables changed by HDLC protocol drivers,
235 * including ether_setup() called from hdlc_raw_eth.c.
237 dev->get_stats = hdlc_get_stats;
238 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
239 dev->mtu = HDLC_MAX_MTU;
240 dev->type = ARPHRD_RAWHDLC;
241 dev->hard_header_len = 16;
243 dev->hard_header = NULL;
244 dev->rebuild_header = NULL;
245 dev->set_mac_address = NULL;
246 dev->hard_header_cache = NULL;
247 dev->header_cache_update = NULL;
248 dev->change_mtu = hdlc_change_mtu;
249 dev->hard_header_parse = NULL;
252 static void hdlc_setup(struct net_device *dev)
254 hdlc_device *hdlc = dev_to_hdlc(dev);
259 spin_lock_init(&hdlc->state_lock);
262 struct net_device *alloc_hdlcdev(void *priv)
264 struct net_device *dev;
265 dev = alloc_netdev(sizeof(struct hdlc_device_desc) +
266 sizeof(hdlc_device), "hdlc%d", hdlc_setup);
268 dev_to_hdlc(dev)->priv = priv;
272 void unregister_hdlc_device(struct net_device *dev)
275 unregister_netdevice(dev);
276 detach_hdlc_protocol(dev);
282 int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
283 int (*rx)(struct sk_buff *skb), size_t size)
285 detach_hdlc_protocol(dev);
287 if (!try_module_get(proto->module))
291 if ((dev_to_hdlc(dev)->state = kmalloc(size,
292 GFP_KERNEL)) == NULL) {
293 printk(KERN_WARNING "Memory squeeze on"
294 " hdlc_proto_attach()\n");
295 module_put(proto->module);
298 dev_to_hdlc(dev)->proto = proto;
299 dev_to_desc(dev)->netif_rx = rx;
304 void detach_hdlc_protocol(struct net_device *dev)
306 hdlc_device *hdlc = dev_to_hdlc(dev);
309 if (hdlc->proto->detach)
310 hdlc->proto->detach(dev);
311 module_put(hdlc->proto->module);
320 void register_hdlc_protocol(struct hdlc_proto *proto)
322 proto->next = first_proto;
327 void unregister_hdlc_protocol(struct hdlc_proto *proto)
329 struct hdlc_proto **p = &first_proto;
341 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
342 MODULE_DESCRIPTION("HDLC support module");
343 MODULE_LICENSE("GPL v2");
345 EXPORT_SYMBOL(hdlc_open);
346 EXPORT_SYMBOL(hdlc_close);
347 EXPORT_SYMBOL(hdlc_ioctl);
348 EXPORT_SYMBOL(alloc_hdlcdev);
349 EXPORT_SYMBOL(unregister_hdlc_device);
350 EXPORT_SYMBOL(register_hdlc_protocol);
351 EXPORT_SYMBOL(unregister_hdlc_protocol);
352 EXPORT_SYMBOL(attach_hdlc_protocol);
353 EXPORT_SYMBOL(detach_hdlc_protocol);
355 static struct packet_type hdlc_packet_type = {
356 .type = __constant_htons(ETH_P_HDLC),
361 static struct notifier_block hdlc_notifier = {
362 .notifier_call = hdlc_device_event,
366 static int __init hdlc_module_init(void)
370 printk(KERN_INFO "%s\n", version);
371 if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
373 dev_add_pack(&hdlc_packet_type);
379 static void __exit hdlc_module_exit(void)
381 dev_remove_pack(&hdlc_packet_type);
382 unregister_netdevice_notifier(&hdlc_notifier);
386 module_init(hdlc_module_init);
387 module_exit(hdlc_module_exit);