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>
41 static const char* version
= "HDLC support module revision 1.21";
45 static struct hdlc_proto
*first_proto
= NULL
;
48 static int hdlc_change_mtu(struct net_device
*dev
, int new_mtu
)
50 if ((new_mtu
< 68) || (new_mtu
> HDLC_MAX_MTU
))
58 static struct net_device_stats
*hdlc_get_stats(struct net_device
*dev
)
60 return hdlc_stats(dev
);
65 static int hdlc_rcv(struct sk_buff
*skb
, struct net_device
*dev
,
66 struct packet_type
*p
, struct net_device
*orig_dev
)
68 struct hdlc_device_desc
*desc
= dev_to_desc(dev
);
70 return desc
->netif_rx(skb
);
72 desc
->stats
.rx_dropped
++; /* Shouldn't happen */
79 static inline void hdlc_proto_start(struct net_device
*dev
)
81 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
82 if (hdlc
->proto
->start
)
83 return hdlc
->proto
->start(dev
);
88 static inline void hdlc_proto_stop(struct net_device
*dev
)
90 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
91 if (hdlc
->proto
->stop
)
92 return hdlc
->proto
->stop(dev
);
97 static int hdlc_device_event(struct notifier_block
*this, unsigned long event
,
100 struct net_device
*dev
= ptr
;
105 if (dev
->get_stats
!= hdlc_get_stats
)
106 return NOTIFY_DONE
; /* not an HDLC device */
108 if (event
!= NETDEV_CHANGE
)
109 return NOTIFY_DONE
; /* Only interrested in carrier changes */
111 on
= netif_carrier_ok(dev
);
114 printk(KERN_DEBUG
"%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
118 hdlc
= dev_to_hdlc(dev
);
119 spin_lock_irqsave(&hdlc
->state_lock
, flags
);
121 if (hdlc
->carrier
== on
)
122 goto carrier_exit
; /* no change in DCD line level */
130 printk(KERN_INFO
"%s: Carrier detected\n", dev
->name
);
131 hdlc_proto_start(dev
);
133 printk(KERN_INFO
"%s: Carrier lost\n", dev
->name
);
134 hdlc_proto_stop(dev
);
138 spin_unlock_irqrestore(&hdlc
->state_lock
, flags
);
144 /* Must be called by hardware driver when HDLC device is being opened */
145 int hdlc_open(struct net_device
*dev
)
147 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
149 printk(KERN_DEBUG
"%s: hdlc_open() carrier %i open %i\n", dev
->name
,
150 hdlc
->carrier
, hdlc
->open
);
153 if (hdlc
->proto
== NULL
)
154 return -ENOSYS
; /* no protocol attached */
156 if (hdlc
->proto
->open
) {
157 int result
= hdlc
->proto
->open(dev
);
162 spin_lock_irq(&hdlc
->state_lock
);
165 printk(KERN_INFO
"%s: Carrier detected\n", dev
->name
);
166 hdlc_proto_start(dev
);
168 printk(KERN_INFO
"%s: No carrier\n", dev
->name
);
172 spin_unlock_irq(&hdlc
->state_lock
);
178 /* Must be called by hardware driver when HDLC device is being closed */
179 void hdlc_close(struct net_device
*dev
)
181 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
183 printk(KERN_DEBUG
"%s: hdlc_close() carrier %i open %i\n", dev
->name
,
184 hdlc
->carrier
, hdlc
->open
);
187 spin_lock_irq(&hdlc
->state_lock
);
191 hdlc_proto_stop(dev
);
193 spin_unlock_irq(&hdlc
->state_lock
);
195 if (hdlc
->proto
->close
)
196 hdlc
->proto
->close(dev
);
201 int hdlc_ioctl(struct net_device
*dev
, struct ifreq
*ifr
, int cmd
)
203 struct hdlc_proto
*proto
= first_proto
;
206 if (cmd
!= SIOCWANDEV
)
209 if (dev_to_hdlc(dev
)->proto
) {
210 result
= dev_to_hdlc(dev
)->proto
->ioctl(dev
, ifr
);
211 if (result
!= -EINVAL
)
215 /* Not handled by currently attached protocol (if any) */
218 if ((result
= proto
->ioctl(dev
, ifr
)) != -EINVAL
)
225 static void hdlc_setup_dev(struct net_device
*dev
)
227 /* Re-init all variables changed by HDLC protocol drivers,
228 * including ether_setup() called from hdlc_raw_eth.c.
230 dev
->get_stats
= hdlc_get_stats
;
231 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
;
232 dev
->mtu
= HDLC_MAX_MTU
;
233 dev
->type
= ARPHRD_RAWHDLC
;
234 dev
->hard_header_len
= 16;
236 dev
->hard_header
= NULL
;
237 dev
->rebuild_header
= NULL
;
238 dev
->set_mac_address
= NULL
;
239 dev
->hard_header_cache
= NULL
;
240 dev
->header_cache_update
= NULL
;
241 dev
->change_mtu
= hdlc_change_mtu
;
242 dev
->hard_header_parse
= NULL
;
245 static void hdlc_setup(struct net_device
*dev
)
247 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
252 spin_lock_init(&hdlc
->state_lock
);
255 struct net_device
*alloc_hdlcdev(void *priv
)
257 struct net_device
*dev
;
258 dev
= alloc_netdev(sizeof(struct hdlc_device_desc
) +
259 sizeof(hdlc_device
), "hdlc%d", hdlc_setup
);
261 dev_to_hdlc(dev
)->priv
= priv
;
265 void unregister_hdlc_device(struct net_device
*dev
)
268 unregister_netdevice(dev
);
269 detach_hdlc_protocol(dev
);
275 int attach_hdlc_protocol(struct net_device
*dev
, struct hdlc_proto
*proto
,
276 int (*rx
)(struct sk_buff
*skb
), size_t size
)
278 detach_hdlc_protocol(dev
);
280 if (!try_module_get(proto
->module
))
284 if ((dev_to_hdlc(dev
)->state
= kmalloc(size
,
285 GFP_KERNEL
)) == NULL
) {
286 printk(KERN_WARNING
"Memory squeeze on"
287 " hdlc_proto_attach()\n");
288 module_put(proto
->module
);
291 dev_to_hdlc(dev
)->proto
= proto
;
292 dev_to_desc(dev
)->netif_rx
= rx
;
297 void detach_hdlc_protocol(struct net_device
*dev
)
299 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
302 if (hdlc
->proto
->detach
)
303 hdlc
->proto
->detach(dev
);
304 module_put(hdlc
->proto
->module
);
313 void register_hdlc_protocol(struct hdlc_proto
*proto
)
315 proto
->next
= first_proto
;
320 void unregister_hdlc_protocol(struct hdlc_proto
*proto
)
322 struct hdlc_proto
**p
= &first_proto
;
334 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
335 MODULE_DESCRIPTION("HDLC support module");
336 MODULE_LICENSE("GPL v2");
338 EXPORT_SYMBOL(hdlc_open
);
339 EXPORT_SYMBOL(hdlc_close
);
340 EXPORT_SYMBOL(hdlc_ioctl
);
341 EXPORT_SYMBOL(alloc_hdlcdev
);
342 EXPORT_SYMBOL(unregister_hdlc_device
);
343 EXPORT_SYMBOL(register_hdlc_protocol
);
344 EXPORT_SYMBOL(unregister_hdlc_protocol
);
345 EXPORT_SYMBOL(attach_hdlc_protocol
);
346 EXPORT_SYMBOL(detach_hdlc_protocol
);
348 static struct packet_type hdlc_packet_type
= {
349 .type
= __constant_htons(ETH_P_HDLC
),
354 static struct notifier_block hdlc_notifier
= {
355 .notifier_call
= hdlc_device_event
,
359 static int __init
hdlc_module_init(void)
363 printk(KERN_INFO
"%s\n", version
);
364 if ((result
= register_netdevice_notifier(&hdlc_notifier
)) != 0)
366 dev_add_pack(&hdlc_packet_type
);
372 static void __exit
hdlc_module_exit(void)
374 dev_remove_pack(&hdlc_packet_type
);
375 unregister_netdevice_notifier(&hdlc_notifier
);
379 module_init(hdlc_module_init
);
380 module_exit(hdlc_module_exit
);