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
);