2 * Generic HDLC support routines for Linux
4 * Copyright (C) 1999 - 2008 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/errno.h>
26 #include <linux/hdlc.h>
27 #include <linux/if_arp.h>
28 #include <linux/inetdevice.h>
29 #include <linux/init.h>
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/notifier.h>
33 #include <linux/pkt_sched.h>
34 #include <linux/poll.h>
35 #include <linux/rtnetlink.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.h>
38 #include <net/net_namespace.h>
41 static const char* version
= "HDLC support module revision 1.22";
45 static struct hdlc_proto
*first_proto
;
47 int hdlc_change_mtu(struct net_device
*dev
, int new_mtu
)
49 if ((new_mtu
< 68) || (new_mtu
> HDLC_MAX_MTU
))
55 static int hdlc_rcv(struct sk_buff
*skb
, struct net_device
*dev
,
56 struct packet_type
*p
, struct net_device
*orig_dev
)
58 struct hdlc_device
*hdlc
= dev_to_hdlc(dev
);
60 if (!net_eq(dev_net(dev
), &init_net
)) {
65 BUG_ON(!hdlc
->proto
->netif_rx
);
66 return hdlc
->proto
->netif_rx(skb
);
69 netdev_tx_t
hdlc_start_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
71 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
73 if (hdlc
->proto
->xmit
)
74 return hdlc
->proto
->xmit(skb
, dev
);
76 return hdlc
->xmit(skb
, dev
); /* call hardware driver directly */
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 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 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 (!net_eq(dev_net(dev
), &init_net
))
108 if (!(dev
->priv_flags
& IFF_WAN_HDLC
))
109 return NOTIFY_DONE
; /* not an HDLC device */
111 if (event
!= NETDEV_CHANGE
)
112 return NOTIFY_DONE
; /* Only interested in carrier changes */
114 on
= netif_carrier_ok(dev
);
117 printk(KERN_DEBUG
"%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
121 hdlc
= dev_to_hdlc(dev
);
122 spin_lock_irqsave(&hdlc
->state_lock
, flags
);
124 if (hdlc
->carrier
== on
)
125 goto carrier_exit
; /* no change in DCD line level */
133 printk(KERN_INFO
"%s: Carrier detected\n", dev
->name
);
134 hdlc_proto_start(dev
);
136 printk(KERN_INFO
"%s: Carrier lost\n", dev
->name
);
137 hdlc_proto_stop(dev
);
141 spin_unlock_irqrestore(&hdlc
->state_lock
, flags
);
147 /* Must be called by hardware driver when HDLC device is being opened */
148 int hdlc_open(struct net_device
*dev
)
150 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
152 printk(KERN_DEBUG
"%s: hdlc_open() carrier %i open %i\n", dev
->name
,
153 hdlc
->carrier
, hdlc
->open
);
156 if (hdlc
->proto
== NULL
)
157 return -ENOSYS
; /* no protocol attached */
159 if (hdlc
->proto
->open
) {
160 int result
= hdlc
->proto
->open(dev
);
165 spin_lock_irq(&hdlc
->state_lock
);
168 printk(KERN_INFO
"%s: Carrier detected\n", dev
->name
);
169 hdlc_proto_start(dev
);
171 printk(KERN_INFO
"%s: No carrier\n", dev
->name
);
175 spin_unlock_irq(&hdlc
->state_lock
);
181 /* Must be called by hardware driver when HDLC device is being closed */
182 void hdlc_close(struct net_device
*dev
)
184 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
186 printk(KERN_DEBUG
"%s: hdlc_close() carrier %i open %i\n", dev
->name
,
187 hdlc
->carrier
, hdlc
->open
);
190 spin_lock_irq(&hdlc
->state_lock
);
194 hdlc_proto_stop(dev
);
196 spin_unlock_irq(&hdlc
->state_lock
);
198 if (hdlc
->proto
->close
)
199 hdlc
->proto
->close(dev
);
204 int hdlc_ioctl(struct net_device
*dev
, struct ifreq
*ifr
, int cmd
)
206 struct hdlc_proto
*proto
= first_proto
;
209 if (cmd
!= SIOCWANDEV
)
212 if (dev_to_hdlc(dev
)->proto
) {
213 result
= dev_to_hdlc(dev
)->proto
->ioctl(dev
, ifr
);
214 if (result
!= -EINVAL
)
218 /* Not handled by currently attached protocol (if any) */
221 if ((result
= proto
->ioctl(dev
, ifr
)) != -EINVAL
)
228 static const struct header_ops hdlc_null_ops
;
230 static void hdlc_setup_dev(struct net_device
*dev
)
232 /* Re-init all variables changed by HDLC protocol drivers,
233 * including ether_setup() called from hdlc_raw_eth.c.
235 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
;
236 dev
->priv_flags
= IFF_WAN_HDLC
;
237 dev
->mtu
= HDLC_MAX_MTU
;
238 dev
->type
= ARPHRD_RAWHDLC
;
239 dev
->hard_header_len
= 16;
241 dev
->header_ops
= &hdlc_null_ops
;
244 static void hdlc_setup(struct net_device
*dev
)
246 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
251 spin_lock_init(&hdlc
->state_lock
);
254 struct net_device
*alloc_hdlcdev(void *priv
)
256 struct net_device
*dev
;
257 dev
= alloc_netdev(sizeof(struct hdlc_device
), "hdlc%d", hdlc_setup
);
259 dev_to_hdlc(dev
)->priv
= priv
;
263 void unregister_hdlc_device(struct net_device
*dev
)
266 unregister_netdevice(dev
);
267 detach_hdlc_protocol(dev
);
273 int attach_hdlc_protocol(struct net_device
*dev
, struct hdlc_proto
*proto
,
276 detach_hdlc_protocol(dev
);
278 if (!try_module_get(proto
->module
))
282 if ((dev_to_hdlc(dev
)->state
= kmalloc(size
,
283 GFP_KERNEL
)) == NULL
) {
284 printk(KERN_WARNING
"Memory squeeze on"
285 " hdlc_proto_attach()\n");
286 module_put(proto
->module
);
289 dev_to_hdlc(dev
)->proto
= proto
;
294 void detach_hdlc_protocol(struct net_device
*dev
)
296 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
299 if (hdlc
->proto
->detach
)
300 hdlc
->proto
->detach(dev
);
301 module_put(hdlc
->proto
->module
);
310 void register_hdlc_protocol(struct hdlc_proto
*proto
)
313 proto
->next
= first_proto
;
319 void unregister_hdlc_protocol(struct hdlc_proto
*proto
)
321 struct hdlc_proto
**p
;
325 while (*p
!= proto
) {
335 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
336 MODULE_DESCRIPTION("HDLC support module");
337 MODULE_LICENSE("GPL v2");
339 EXPORT_SYMBOL(hdlc_change_mtu
);
340 EXPORT_SYMBOL(hdlc_start_xmit
);
341 EXPORT_SYMBOL(hdlc_open
);
342 EXPORT_SYMBOL(hdlc_close
);
343 EXPORT_SYMBOL(hdlc_ioctl
);
344 EXPORT_SYMBOL(alloc_hdlcdev
);
345 EXPORT_SYMBOL(unregister_hdlc_device
);
346 EXPORT_SYMBOL(register_hdlc_protocol
);
347 EXPORT_SYMBOL(unregister_hdlc_protocol
);
348 EXPORT_SYMBOL(attach_hdlc_protocol
);
349 EXPORT_SYMBOL(detach_hdlc_protocol
);
351 static struct packet_type hdlc_packet_type __read_mostly
= {
352 .type
= cpu_to_be16(ETH_P_HDLC
),
357 static struct notifier_block hdlc_notifier
= {
358 .notifier_call
= hdlc_device_event
,
362 static int __init
hdlc_module_init(void)
366 printk(KERN_INFO
"%s\n", version
);
367 if ((result
= register_netdevice_notifier(&hdlc_notifier
)) != 0)
369 dev_add_pack(&hdlc_packet_type
);
375 static void __exit
hdlc_module_exit(void)
377 dev_remove_pack(&hdlc_packet_type
);
378 unregister_netdevice_notifier(&hdlc_notifier
);
382 module_init(hdlc_module_init
);
383 module_exit(hdlc_module_exit
);