xref: /openbmc/linux/drivers/net/wan/hdlc_fr.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * Generic HDLC support routines for Linux
3  * Frame Relay support
4  *
5  * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of version 2 of the GNU General Public License
9  * as published by the Free Software Foundation.
10  *
11 
12             Theory of PVC state
13 
14  DCE mode:
15 
16  (exist,new) -> 0,0 when "PVC create" or if "link unreliable"
17          0,x -> 1,1 if "link reliable" when sending FULL STATUS
18          1,1 -> 1,0 if received FULL STATUS ACK
19 
20  (active)    -> 0 when "ifconfig PVC down" or "link unreliable" or "PVC create"
21              -> 1 when "PVC up" and (exist,new) = 1,0
22 
23  DTE mode:
24  (exist,new,active) = FULL STATUS if "link reliable"
25 		    = 0, 0, 0 if "link unreliable"
26  No LMI:
27  active = open and "link reliable"
28  exist = new = not used
29 
30  CCITT LMI: ITU-T Q.933 Annex A
31  ANSI LMI: ANSI T1.617 Annex D
32  CISCO LMI: the original, aka "Gang of Four" LMI
33 
34 */
35 
36 #include <linux/errno.h>
37 #include <linux/etherdevice.h>
38 #include <linux/hdlc.h>
39 #include <linux/if_arp.h>
40 #include <linux/inetdevice.h>
41 #include <linux/init.h>
42 #include <linux/kernel.h>
43 #include <linux/module.h>
44 #include <linux/pkt_sched.h>
45 #include <linux/poll.h>
46 #include <linux/rtnetlink.h>
47 #include <linux/skbuff.h>
48 #include <linux/slab.h>
49 
50 #undef DEBUG_PKT
51 #undef DEBUG_ECN
52 #undef DEBUG_LINK
53 #undef DEBUG_PROTO
54 #undef DEBUG_PVC
55 
56 #define FR_UI			0x03
57 #define FR_PAD			0x00
58 
59 #define NLPID_IP		0xCC
60 #define NLPID_IPV6		0x8E
61 #define NLPID_SNAP		0x80
62 #define NLPID_PAD		0x00
63 #define NLPID_CCITT_ANSI_LMI	0x08
64 #define NLPID_CISCO_LMI		0x09
65 
66 
67 #define LMI_CCITT_ANSI_DLCI	   0 /* LMI DLCI */
68 #define LMI_CISCO_DLCI		1023
69 
70 #define LMI_CALLREF		0x00 /* Call Reference */
71 #define LMI_ANSI_LOCKSHIFT	0x95 /* ANSI locking shift */
72 #define LMI_ANSI_CISCO_REPTYPE	0x01 /* report type */
73 #define LMI_CCITT_REPTYPE	0x51
74 #define LMI_ANSI_CISCO_ALIVE	0x03 /* keep alive */
75 #define LMI_CCITT_ALIVE		0x53
76 #define LMI_ANSI_CISCO_PVCSTAT	0x07 /* PVC status */
77 #define LMI_CCITT_PVCSTAT	0x57
78 
79 #define LMI_FULLREP		0x00 /* full report  */
80 #define LMI_INTEGRITY		0x01 /* link integrity report */
81 #define LMI_SINGLE		0x02 /* single PVC report */
82 
83 #define LMI_STATUS_ENQUIRY      0x75
84 #define LMI_STATUS              0x7D /* reply */
85 
86 #define LMI_REPT_LEN               1 /* report type element length */
87 #define LMI_INTEG_LEN              2 /* link integrity element length */
88 
89 #define LMI_CCITT_CISCO_LENGTH	  13 /* LMI frame lengths */
90 #define LMI_ANSI_LENGTH		  14
91 
92 
93 typedef struct {
94 #if defined(__LITTLE_ENDIAN_BITFIELD)
95 	unsigned ea1:	1;
96 	unsigned cr:	1;
97 	unsigned dlcih:	6;
98 
99 	unsigned ea2:	1;
100 	unsigned de:	1;
101 	unsigned becn:	1;
102 	unsigned fecn:	1;
103 	unsigned dlcil:	4;
104 #else
105 	unsigned dlcih:	6;
106 	unsigned cr:	1;
107 	unsigned ea1:	1;
108 
109 	unsigned dlcil:	4;
110 	unsigned fecn:	1;
111 	unsigned becn:	1;
112 	unsigned de:	1;
113 	unsigned ea2:	1;
114 #endif
115 }__packed fr_hdr;
116 
117 
118 typedef struct pvc_device_struct {
119 	struct net_device *frad;
120 	struct net_device *main;
121 	struct net_device *ether;	/* bridged Ethernet interface	*/
122 	struct pvc_device_struct *next;	/* Sorted in ascending DLCI order */
123 	int dlci;
124 	int open_count;
125 
126 	struct {
127 		unsigned int new: 1;
128 		unsigned int active: 1;
129 		unsigned int exist: 1;
130 		unsigned int deleted: 1;
131 		unsigned int fecn: 1;
132 		unsigned int becn: 1;
133 		unsigned int bandwidth;	/* Cisco LMI reporting only */
134 	}state;
135 }pvc_device;
136 
137 struct frad_state {
138 	fr_proto settings;
139 	pvc_device *first_pvc;
140 	int dce_pvc_count;
141 
142 	struct timer_list timer;
143 	unsigned long last_poll;
144 	int reliable;
145 	int dce_changed;
146 	int request;
147 	int fullrep_sent;
148 	u32 last_errors; /* last errors bit list */
149 	u8 n391cnt;
150 	u8 txseq; /* TX sequence number */
151 	u8 rxseq; /* RX sequence number */
152 };
153 
154 
155 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr);
156 
157 
158 static inline u16 q922_to_dlci(u8 *hdr)
159 {
160 	return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
161 }
162 
163 
164 static inline void dlci_to_q922(u8 *hdr, u16 dlci)
165 {
166 	hdr[0] = (dlci >> 2) & 0xFC;
167 	hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
168 }
169 
170 
171 static inline struct frad_state* state(hdlc_device *hdlc)
172 {
173 	return(struct frad_state *)(hdlc->state);
174 }
175 
176 
177 static inline pvc_device* find_pvc(hdlc_device *hdlc, u16 dlci)
178 {
179 	pvc_device *pvc = state(hdlc)->first_pvc;
180 
181 	while (pvc) {
182 		if (pvc->dlci == dlci)
183 			return pvc;
184 		if (pvc->dlci > dlci)
185 			return NULL; /* the list is sorted */
186 		pvc = pvc->next;
187 	}
188 
189 	return NULL;
190 }
191 
192 
193 static pvc_device* add_pvc(struct net_device *dev, u16 dlci)
194 {
195 	hdlc_device *hdlc = dev_to_hdlc(dev);
196 	pvc_device *pvc, **pvc_p = &state(hdlc)->first_pvc;
197 
198 	while (*pvc_p) {
199 		if ((*pvc_p)->dlci == dlci)
200 			return *pvc_p;
201 		if ((*pvc_p)->dlci > dlci)
202 			break;	/* the list is sorted */
203 		pvc_p = &(*pvc_p)->next;
204 	}
205 
206 	pvc = kzalloc(sizeof(pvc_device), GFP_ATOMIC);
207 #ifdef DEBUG_PVC
208 	printk(KERN_DEBUG "add_pvc: allocated pvc %p, frad %p\n", pvc, dev);
209 #endif
210 	if (!pvc)
211 		return NULL;
212 
213 	pvc->dlci = dlci;
214 	pvc->frad = dev;
215 	pvc->next = *pvc_p;	/* Put it in the chain */
216 	*pvc_p = pvc;
217 	return pvc;
218 }
219 
220 
221 static inline int pvc_is_used(pvc_device *pvc)
222 {
223 	return pvc->main || pvc->ether;
224 }
225 
226 
227 static inline void pvc_carrier(int on, pvc_device *pvc)
228 {
229 	if (on) {
230 		if (pvc->main)
231 			if (!netif_carrier_ok(pvc->main))
232 				netif_carrier_on(pvc->main);
233 		if (pvc->ether)
234 			if (!netif_carrier_ok(pvc->ether))
235 				netif_carrier_on(pvc->ether);
236 	} else {
237 		if (pvc->main)
238 			if (netif_carrier_ok(pvc->main))
239 				netif_carrier_off(pvc->main);
240 		if (pvc->ether)
241 			if (netif_carrier_ok(pvc->ether))
242 				netif_carrier_off(pvc->ether);
243 	}
244 }
245 
246 
247 static inline void delete_unused_pvcs(hdlc_device *hdlc)
248 {
249 	pvc_device **pvc_p = &state(hdlc)->first_pvc;
250 
251 	while (*pvc_p) {
252 		if (!pvc_is_used(*pvc_p)) {
253 			pvc_device *pvc = *pvc_p;
254 #ifdef DEBUG_PVC
255 			printk(KERN_DEBUG "freeing unused pvc: %p\n", pvc);
256 #endif
257 			*pvc_p = pvc->next;
258 			kfree(pvc);
259 			continue;
260 		}
261 		pvc_p = &(*pvc_p)->next;
262 	}
263 }
264 
265 
266 static inline struct net_device** get_dev_p(pvc_device *pvc, int type)
267 {
268 	if (type == ARPHRD_ETHER)
269 		return &pvc->ether;
270 	else
271 		return &pvc->main;
272 }
273 
274 
275 static int fr_hard_header(struct sk_buff **skb_p, u16 dlci)
276 {
277 	u16 head_len;
278 	struct sk_buff *skb = *skb_p;
279 
280 	switch (skb->protocol) {
281 	case cpu_to_be16(NLPID_CCITT_ANSI_LMI):
282 		head_len = 4;
283 		skb_push(skb, head_len);
284 		skb->data[3] = NLPID_CCITT_ANSI_LMI;
285 		break;
286 
287 	case cpu_to_be16(NLPID_CISCO_LMI):
288 		head_len = 4;
289 		skb_push(skb, head_len);
290 		skb->data[3] = NLPID_CISCO_LMI;
291 		break;
292 
293 	case cpu_to_be16(ETH_P_IP):
294 		head_len = 4;
295 		skb_push(skb, head_len);
296 		skb->data[3] = NLPID_IP;
297 		break;
298 
299 	case cpu_to_be16(ETH_P_IPV6):
300 		head_len = 4;
301 		skb_push(skb, head_len);
302 		skb->data[3] = NLPID_IPV6;
303 		break;
304 
305 	case cpu_to_be16(ETH_P_802_3):
306 		head_len = 10;
307 		if (skb_headroom(skb) < head_len) {
308 			struct sk_buff *skb2 = skb_realloc_headroom(skb,
309 								    head_len);
310 			if (!skb2)
311 				return -ENOBUFS;
312 			dev_kfree_skb(skb);
313 			skb = *skb_p = skb2;
314 		}
315 		skb_push(skb, head_len);
316 		skb->data[3] = FR_PAD;
317 		skb->data[4] = NLPID_SNAP;
318 		skb->data[5] = FR_PAD;
319 		skb->data[6] = 0x80;
320 		skb->data[7] = 0xC2;
321 		skb->data[8] = 0x00;
322 		skb->data[9] = 0x07; /* bridged Ethernet frame w/out FCS */
323 		break;
324 
325 	default:
326 		head_len = 10;
327 		skb_push(skb, head_len);
328 		skb->data[3] = FR_PAD;
329 		skb->data[4] = NLPID_SNAP;
330 		skb->data[5] = FR_PAD;
331 		skb->data[6] = FR_PAD;
332 		skb->data[7] = FR_PAD;
333 		*(__be16*)(skb->data + 8) = skb->protocol;
334 	}
335 
336 	dlci_to_q922(skb->data, dlci);
337 	skb->data[2] = FR_UI;
338 	return 0;
339 }
340 
341 
342 
343 static int pvc_open(struct net_device *dev)
344 {
345 	pvc_device *pvc = dev->ml_priv;
346 
347 	if ((pvc->frad->flags & IFF_UP) == 0)
348 		return -EIO;  /* Frad must be UP in order to activate PVC */
349 
350 	if (pvc->open_count++ == 0) {
351 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
352 		if (state(hdlc)->settings.lmi == LMI_NONE)
353 			pvc->state.active = netif_carrier_ok(pvc->frad);
354 
355 		pvc_carrier(pvc->state.active, pvc);
356 		state(hdlc)->dce_changed = 1;
357 	}
358 	return 0;
359 }
360 
361 
362 
363 static int pvc_close(struct net_device *dev)
364 {
365 	pvc_device *pvc = dev->ml_priv;
366 
367 	if (--pvc->open_count == 0) {
368 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
369 		if (state(hdlc)->settings.lmi == LMI_NONE)
370 			pvc->state.active = 0;
371 
372 		if (state(hdlc)->settings.dce) {
373 			state(hdlc)->dce_changed = 1;
374 			pvc->state.active = 0;
375 		}
376 	}
377 	return 0;
378 }
379 
380 
381 
382 static int pvc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
383 {
384 	pvc_device *pvc = dev->ml_priv;
385 	fr_proto_pvc_info info;
386 
387 	if (ifr->ifr_settings.type == IF_GET_PROTO) {
388 		if (dev->type == ARPHRD_ETHER)
389 			ifr->ifr_settings.type = IF_PROTO_FR_ETH_PVC;
390 		else
391 			ifr->ifr_settings.type = IF_PROTO_FR_PVC;
392 
393 		if (ifr->ifr_settings.size < sizeof(info)) {
394 			/* data size wanted */
395 			ifr->ifr_settings.size = sizeof(info);
396 			return -ENOBUFS;
397 		}
398 
399 		info.dlci = pvc->dlci;
400 		memcpy(info.master, pvc->frad->name, IFNAMSIZ);
401 		if (copy_to_user(ifr->ifr_settings.ifs_ifsu.fr_pvc_info,
402 				 &info, sizeof(info)))
403 			return -EFAULT;
404 		return 0;
405 	}
406 
407 	return -EINVAL;
408 }
409 
410 static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev)
411 {
412 	pvc_device *pvc = dev->ml_priv;
413 
414 	if (pvc->state.active) {
415 		if (dev->type == ARPHRD_ETHER) {
416 			int pad = ETH_ZLEN - skb->len;
417 			if (pad > 0) { /* Pad the frame with zeros */
418 				int len = skb->len;
419 				if (skb_tailroom(skb) < pad)
420 					if (pskb_expand_head(skb, 0, pad,
421 							     GFP_ATOMIC)) {
422 						dev->stats.tx_dropped++;
423 						dev_kfree_skb(skb);
424 						return NETDEV_TX_OK;
425 					}
426 				skb_put(skb, pad);
427 				memset(skb->data + len, 0, pad);
428 			}
429 			skb->protocol = cpu_to_be16(ETH_P_802_3);
430 		}
431 		if (!fr_hard_header(&skb, pvc->dlci)) {
432 			dev->stats.tx_bytes += skb->len;
433 			dev->stats.tx_packets++;
434 			if (pvc->state.fecn) /* TX Congestion counter */
435 				dev->stats.tx_compressed++;
436 			skb->dev = pvc->frad;
437 			dev_queue_xmit(skb);
438 			return NETDEV_TX_OK;
439 		}
440 	}
441 
442 	dev->stats.tx_dropped++;
443 	dev_kfree_skb(skb);
444 	return NETDEV_TX_OK;
445 }
446 
447 static inline void fr_log_dlci_active(pvc_device *pvc)
448 {
449 	printk(KERN_INFO "%s: DLCI %d [%s%s%s]%s %s\n",
450 	       pvc->frad->name,
451 	       pvc->dlci,
452 	       pvc->main ? pvc->main->name : "",
453 	       pvc->main && pvc->ether ? " " : "",
454 	       pvc->ether ? pvc->ether->name : "",
455 	       pvc->state.new ? " new" : "",
456 	       !pvc->state.exist ? "deleted" :
457 	       pvc->state.active ? "active" : "inactive");
458 }
459 
460 
461 
462 static inline u8 fr_lmi_nextseq(u8 x)
463 {
464 	x++;
465 	return x ? x : 1;
466 }
467 
468 
469 static void fr_lmi_send(struct net_device *dev, int fullrep)
470 {
471 	hdlc_device *hdlc = dev_to_hdlc(dev);
472 	struct sk_buff *skb;
473 	pvc_device *pvc = state(hdlc)->first_pvc;
474 	int lmi = state(hdlc)->settings.lmi;
475 	int dce = state(hdlc)->settings.dce;
476 	int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
477 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
478 	u8 *data;
479 	int i = 0;
480 
481 	if (dce && fullrep) {
482 		len += state(hdlc)->dce_pvc_count * (2 + stat_len);
483 		if (len > HDLC_MAX_MRU) {
484 			printk(KERN_WARNING "%s: Too many PVCs while sending "
485 			       "LMI full report\n", dev->name);
486 			return;
487 		}
488 	}
489 
490 	skb = dev_alloc_skb(len);
491 	if (!skb) {
492 		printk(KERN_WARNING "%s: Memory squeeze on fr_lmi_send()\n",
493 		       dev->name);
494 		return;
495 	}
496 	memset(skb->data, 0, len);
497 	skb_reserve(skb, 4);
498 	if (lmi == LMI_CISCO) {
499 		skb->protocol = cpu_to_be16(NLPID_CISCO_LMI);
500 		fr_hard_header(&skb, LMI_CISCO_DLCI);
501 	} else {
502 		skb->protocol = cpu_to_be16(NLPID_CCITT_ANSI_LMI);
503 		fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI);
504 	}
505 	data = skb_tail_pointer(skb);
506 	data[i++] = LMI_CALLREF;
507 	data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
508 	if (lmi == LMI_ANSI)
509 		data[i++] = LMI_ANSI_LOCKSHIFT;
510 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
511 		LMI_ANSI_CISCO_REPTYPE;
512 	data[i++] = LMI_REPT_LEN;
513 	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
514 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
515 	data[i++] = LMI_INTEG_LEN;
516 	data[i++] = state(hdlc)->txseq =
517 		fr_lmi_nextseq(state(hdlc)->txseq);
518 	data[i++] = state(hdlc)->rxseq;
519 
520 	if (dce && fullrep) {
521 		while (pvc) {
522 			data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
523 				LMI_ANSI_CISCO_PVCSTAT;
524 			data[i++] = stat_len;
525 
526 			/* LMI start/restart */
527 			if (state(hdlc)->reliable && !pvc->state.exist) {
528 				pvc->state.exist = pvc->state.new = 1;
529 				fr_log_dlci_active(pvc);
530 			}
531 
532 			/* ifconfig PVC up */
533 			if (pvc->open_count && !pvc->state.active &&
534 			    pvc->state.exist && !pvc->state.new) {
535 				pvc_carrier(1, pvc);
536 				pvc->state.active = 1;
537 				fr_log_dlci_active(pvc);
538 			}
539 
540 			if (lmi == LMI_CISCO) {
541 				data[i] = pvc->dlci >> 8;
542 				data[i + 1] = pvc->dlci & 0xFF;
543 			} else {
544 				data[i] = (pvc->dlci >> 4) & 0x3F;
545 				data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
546 				data[i + 2] = 0x80;
547 			}
548 
549 			if (pvc->state.new)
550 				data[i + 2] |= 0x08;
551 			else if (pvc->state.active)
552 				data[i + 2] |= 0x02;
553 
554 			i += stat_len;
555 			pvc = pvc->next;
556 		}
557 	}
558 
559 	skb_put(skb, i);
560 	skb->priority = TC_PRIO_CONTROL;
561 	skb->dev = dev;
562 	skb_reset_network_header(skb);
563 
564 	dev_queue_xmit(skb);
565 }
566 
567 
568 
569 static void fr_set_link_state(int reliable, struct net_device *dev)
570 {
571 	hdlc_device *hdlc = dev_to_hdlc(dev);
572 	pvc_device *pvc = state(hdlc)->first_pvc;
573 
574 	state(hdlc)->reliable = reliable;
575 	if (reliable) {
576 		netif_dormant_off(dev);
577 		state(hdlc)->n391cnt = 0; /* Request full status */
578 		state(hdlc)->dce_changed = 1;
579 
580 		if (state(hdlc)->settings.lmi == LMI_NONE) {
581 			while (pvc) {	/* Activate all PVCs */
582 				pvc_carrier(1, pvc);
583 				pvc->state.exist = pvc->state.active = 1;
584 				pvc->state.new = 0;
585 				pvc = pvc->next;
586 			}
587 		}
588 	} else {
589 		netif_dormant_on(dev);
590 		while (pvc) {		/* Deactivate all PVCs */
591 			pvc_carrier(0, pvc);
592 			pvc->state.exist = pvc->state.active = 0;
593 			pvc->state.new = 0;
594 			if (!state(hdlc)->settings.dce)
595 				pvc->state.bandwidth = 0;
596 			pvc = pvc->next;
597 		}
598 	}
599 }
600 
601 
602 static void fr_timer(unsigned long arg)
603 {
604 	struct net_device *dev = (struct net_device *)arg;
605 	hdlc_device *hdlc = dev_to_hdlc(dev);
606 	int i, cnt = 0, reliable;
607 	u32 list;
608 
609 	if (state(hdlc)->settings.dce) {
610 		reliable = state(hdlc)->request &&
611 			time_before(jiffies, state(hdlc)->last_poll +
612 				    state(hdlc)->settings.t392 * HZ);
613 		state(hdlc)->request = 0;
614 	} else {
615 		state(hdlc)->last_errors <<= 1; /* Shift the list */
616 		if (state(hdlc)->request) {
617 			if (state(hdlc)->reliable)
618 				printk(KERN_INFO "%s: No LMI status reply "
619 				       "received\n", dev->name);
620 			state(hdlc)->last_errors |= 1;
621 		}
622 
623 		list = state(hdlc)->last_errors;
624 		for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
625 			cnt += (list & 1);	/* errors count */
626 
627 		reliable = (cnt < state(hdlc)->settings.n392);
628 	}
629 
630 	if (state(hdlc)->reliable != reliable) {
631 		printk(KERN_INFO "%s: Link %sreliable\n", dev->name,
632 		       reliable ? "" : "un");
633 		fr_set_link_state(reliable, dev);
634 	}
635 
636 	if (state(hdlc)->settings.dce)
637 		state(hdlc)->timer.expires = jiffies +
638 			state(hdlc)->settings.t392 * HZ;
639 	else {
640 		if (state(hdlc)->n391cnt)
641 			state(hdlc)->n391cnt--;
642 
643 		fr_lmi_send(dev, state(hdlc)->n391cnt == 0);
644 
645 		state(hdlc)->last_poll = jiffies;
646 		state(hdlc)->request = 1;
647 		state(hdlc)->timer.expires = jiffies +
648 			state(hdlc)->settings.t391 * HZ;
649 	}
650 
651 	state(hdlc)->timer.function = fr_timer;
652 	state(hdlc)->timer.data = arg;
653 	add_timer(&state(hdlc)->timer);
654 }
655 
656 
657 static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
658 {
659 	hdlc_device *hdlc = dev_to_hdlc(dev);
660 	pvc_device *pvc;
661 	u8 rxseq, txseq;
662 	int lmi = state(hdlc)->settings.lmi;
663 	int dce = state(hdlc)->settings.dce;
664 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
665 
666 	if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
667 			LMI_CCITT_CISCO_LENGTH)) {
668 		printk(KERN_INFO "%s: Short LMI frame\n", dev->name);
669 		return 1;
670 	}
671 
672 	if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
673 			     NLPID_CCITT_ANSI_LMI)) {
674 		printk(KERN_INFO "%s: Received non-LMI frame with LMI DLCI\n",
675 		       dev->name);
676 		return 1;
677 	}
678 
679 	if (skb->data[4] != LMI_CALLREF) {
680 		printk(KERN_INFO "%s: Invalid LMI Call reference (0x%02X)\n",
681 		       dev->name, skb->data[4]);
682 		return 1;
683 	}
684 
685 	if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
686 		printk(KERN_INFO "%s: Invalid LMI Message type (0x%02X)\n",
687 		       dev->name, skb->data[5]);
688 		return 1;
689 	}
690 
691 	if (lmi == LMI_ANSI) {
692 		if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
693 			printk(KERN_INFO "%s: Not ANSI locking shift in LMI"
694 			       " message (0x%02X)\n", dev->name, skb->data[6]);
695 			return 1;
696 		}
697 		i = 7;
698 	} else
699 		i = 6;
700 
701 	if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
702 			     LMI_ANSI_CISCO_REPTYPE)) {
703 		printk(KERN_INFO "%s: Not an LMI Report type IE (0x%02X)\n",
704 		       dev->name, skb->data[i]);
705 		return 1;
706 	}
707 
708 	if (skb->data[++i] != LMI_REPT_LEN) {
709 		printk(KERN_INFO "%s: Invalid LMI Report type IE length"
710 		       " (%u)\n", dev->name, skb->data[i]);
711 		return 1;
712 	}
713 
714 	reptype = skb->data[++i];
715 	if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
716 		printk(KERN_INFO "%s: Unsupported LMI Report type (0x%02X)\n",
717 		       dev->name, reptype);
718 		return 1;
719 	}
720 
721 	if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
722 			       LMI_ANSI_CISCO_ALIVE)) {
723 		printk(KERN_INFO "%s: Not an LMI Link integrity verification"
724 		       " IE (0x%02X)\n", dev->name, skb->data[i]);
725 		return 1;
726 	}
727 
728 	if (skb->data[++i] != LMI_INTEG_LEN) {
729 		printk(KERN_INFO "%s: Invalid LMI Link integrity verification"
730 		       " IE length (%u)\n", dev->name, skb->data[i]);
731 		return 1;
732 	}
733 	i++;
734 
735 	state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
736 	rxseq = skb->data[i++];	/* Should confirm our sequence */
737 
738 	txseq = state(hdlc)->txseq;
739 
740 	if (dce)
741 		state(hdlc)->last_poll = jiffies;
742 
743 	error = 0;
744 	if (!state(hdlc)->reliable)
745 		error = 1;
746 
747 	if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
748 		state(hdlc)->n391cnt = 0;
749 		error = 1;
750 	}
751 
752 	if (dce) {
753 		if (state(hdlc)->fullrep_sent && !error) {
754 /* Stop sending full report - the last one has been confirmed by DTE */
755 			state(hdlc)->fullrep_sent = 0;
756 			pvc = state(hdlc)->first_pvc;
757 			while (pvc) {
758 				if (pvc->state.new) {
759 					pvc->state.new = 0;
760 
761 /* Tell DTE that new PVC is now active */
762 					state(hdlc)->dce_changed = 1;
763 				}
764 				pvc = pvc->next;
765 			}
766 		}
767 
768 		if (state(hdlc)->dce_changed) {
769 			reptype = LMI_FULLREP;
770 			state(hdlc)->fullrep_sent = 1;
771 			state(hdlc)->dce_changed = 0;
772 		}
773 
774 		state(hdlc)->request = 1; /* got request */
775 		fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
776 		return 0;
777 	}
778 
779 	/* DTE */
780 
781 	state(hdlc)->request = 0; /* got response, no request pending */
782 
783 	if (error)
784 		return 0;
785 
786 	if (reptype != LMI_FULLREP)
787 		return 0;
788 
789 	pvc = state(hdlc)->first_pvc;
790 
791 	while (pvc) {
792 		pvc->state.deleted = 1;
793 		pvc = pvc->next;
794 	}
795 
796 	no_ram = 0;
797 	while (skb->len >= i + 2 + stat_len) {
798 		u16 dlci;
799 		u32 bw;
800 		unsigned int active, new;
801 
802 		if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
803 				       LMI_ANSI_CISCO_PVCSTAT)) {
804 			printk(KERN_INFO "%s: Not an LMI PVC status IE"
805 			       " (0x%02X)\n", dev->name, skb->data[i]);
806 			return 1;
807 		}
808 
809 		if (skb->data[++i] != stat_len) {
810 			printk(KERN_INFO "%s: Invalid LMI PVC status IE length"
811 			       " (%u)\n", dev->name, skb->data[i]);
812 			return 1;
813 		}
814 		i++;
815 
816 		new = !! (skb->data[i + 2] & 0x08);
817 		active = !! (skb->data[i + 2] & 0x02);
818 		if (lmi == LMI_CISCO) {
819 			dlci = (skb->data[i] << 8) | skb->data[i + 1];
820 			bw = (skb->data[i + 3] << 16) |
821 				(skb->data[i + 4] << 8) |
822 				(skb->data[i + 5]);
823 		} else {
824 			dlci = ((skb->data[i] & 0x3F) << 4) |
825 				((skb->data[i + 1] & 0x78) >> 3);
826 			bw = 0;
827 		}
828 
829 		pvc = add_pvc(dev, dlci);
830 
831 		if (!pvc && !no_ram) {
832 			printk(KERN_WARNING
833 			       "%s: Memory squeeze on fr_lmi_recv()\n",
834 			       dev->name);
835 			no_ram = 1;
836 		}
837 
838 		if (pvc) {
839 			pvc->state.exist = 1;
840 			pvc->state.deleted = 0;
841 			if (active != pvc->state.active ||
842 			    new != pvc->state.new ||
843 			    bw != pvc->state.bandwidth ||
844 			    !pvc->state.exist) {
845 				pvc->state.new = new;
846 				pvc->state.active = active;
847 				pvc->state.bandwidth = bw;
848 				pvc_carrier(active, pvc);
849 				fr_log_dlci_active(pvc);
850 			}
851 		}
852 
853 		i += stat_len;
854 	}
855 
856 	pvc = state(hdlc)->first_pvc;
857 
858 	while (pvc) {
859 		if (pvc->state.deleted && pvc->state.exist) {
860 			pvc_carrier(0, pvc);
861 			pvc->state.active = pvc->state.new = 0;
862 			pvc->state.exist = 0;
863 			pvc->state.bandwidth = 0;
864 			fr_log_dlci_active(pvc);
865 		}
866 		pvc = pvc->next;
867 	}
868 
869 	/* Next full report after N391 polls */
870 	state(hdlc)->n391cnt = state(hdlc)->settings.n391;
871 
872 	return 0;
873 }
874 
875 
876 static int fr_rx(struct sk_buff *skb)
877 {
878 	struct net_device *frad = skb->dev;
879 	hdlc_device *hdlc = dev_to_hdlc(frad);
880 	fr_hdr *fh = (fr_hdr*)skb->data;
881 	u8 *data = skb->data;
882 	u16 dlci;
883 	pvc_device *pvc;
884 	struct net_device *dev = NULL;
885 
886 	if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI)
887 		goto rx_error;
888 
889 	dlci = q922_to_dlci(skb->data);
890 
891 	if ((dlci == LMI_CCITT_ANSI_DLCI &&
892 	     (state(hdlc)->settings.lmi == LMI_ANSI ||
893 	      state(hdlc)->settings.lmi == LMI_CCITT)) ||
894 	    (dlci == LMI_CISCO_DLCI &&
895 	     state(hdlc)->settings.lmi == LMI_CISCO)) {
896 		if (fr_lmi_recv(frad, skb))
897 			goto rx_error;
898 		dev_kfree_skb_any(skb);
899 		return NET_RX_SUCCESS;
900 	}
901 
902 	pvc = find_pvc(hdlc, dlci);
903 	if (!pvc) {
904 #ifdef DEBUG_PKT
905 		printk(KERN_INFO "%s: No PVC for received frame's DLCI %d\n",
906 		       frad->name, dlci);
907 #endif
908 		dev_kfree_skb_any(skb);
909 		return NET_RX_DROP;
910 	}
911 
912 	if (pvc->state.fecn != fh->fecn) {
913 #ifdef DEBUG_ECN
914 		printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", frad->name,
915 		       dlci, fh->fecn ? "N" : "FF");
916 #endif
917 		pvc->state.fecn ^= 1;
918 	}
919 
920 	if (pvc->state.becn != fh->becn) {
921 #ifdef DEBUG_ECN
922 		printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", frad->name,
923 		       dlci, fh->becn ? "N" : "FF");
924 #endif
925 		pvc->state.becn ^= 1;
926 	}
927 
928 
929 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
930 		frad->stats.rx_dropped++;
931 		return NET_RX_DROP;
932 	}
933 
934 	if (data[3] == NLPID_IP) {
935 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
936 		dev = pvc->main;
937 		skb->protocol = htons(ETH_P_IP);
938 
939 	} else if (data[3] == NLPID_IPV6) {
940 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
941 		dev = pvc->main;
942 		skb->protocol = htons(ETH_P_IPV6);
943 
944 	} else if (skb->len > 10 && data[3] == FR_PAD &&
945 		   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
946 		u16 oui = ntohs(*(__be16*)(data + 6));
947 		u16 pid = ntohs(*(__be16*)(data + 8));
948 		skb_pull(skb, 10);
949 
950 		switch ((((u32)oui) << 16) | pid) {
951 		case ETH_P_ARP: /* routed frame with SNAP */
952 		case ETH_P_IPX:
953 		case ETH_P_IP:	/* a long variant */
954 		case ETH_P_IPV6:
955 			dev = pvc->main;
956 			skb->protocol = htons(pid);
957 			break;
958 
959 		case 0x80C20007: /* bridged Ethernet frame */
960 			if ((dev = pvc->ether) != NULL)
961 				skb->protocol = eth_type_trans(skb, dev);
962 			break;
963 
964 		default:
965 			printk(KERN_INFO "%s: Unsupported protocol, OUI=%x "
966 			       "PID=%x\n", frad->name, oui, pid);
967 			dev_kfree_skb_any(skb);
968 			return NET_RX_DROP;
969 		}
970 	} else {
971 		printk(KERN_INFO "%s: Unsupported protocol, NLPID=%x "
972 		       "length = %i\n", frad->name, data[3], skb->len);
973 		dev_kfree_skb_any(skb);
974 		return NET_RX_DROP;
975 	}
976 
977 	if (dev) {
978 		dev->stats.rx_packets++; /* PVC traffic */
979 		dev->stats.rx_bytes += skb->len;
980 		if (pvc->state.becn)
981 			dev->stats.rx_compressed++;
982 		skb->dev = dev;
983 		netif_rx(skb);
984 		return NET_RX_SUCCESS;
985 	} else {
986 		dev_kfree_skb_any(skb);
987 		return NET_RX_DROP;
988 	}
989 
990  rx_error:
991 	frad->stats.rx_errors++; /* Mark error */
992 	dev_kfree_skb_any(skb);
993 	return NET_RX_DROP;
994 }
995 
996 
997 
998 static void fr_start(struct net_device *dev)
999 {
1000 	hdlc_device *hdlc = dev_to_hdlc(dev);
1001 #ifdef DEBUG_LINK
1002 	printk(KERN_DEBUG "fr_start\n");
1003 #endif
1004 	if (state(hdlc)->settings.lmi != LMI_NONE) {
1005 		state(hdlc)->reliable = 0;
1006 		state(hdlc)->dce_changed = 1;
1007 		state(hdlc)->request = 0;
1008 		state(hdlc)->fullrep_sent = 0;
1009 		state(hdlc)->last_errors = 0xFFFFFFFF;
1010 		state(hdlc)->n391cnt = 0;
1011 		state(hdlc)->txseq = state(hdlc)->rxseq = 0;
1012 
1013 		init_timer(&state(hdlc)->timer);
1014 		/* First poll after 1 s */
1015 		state(hdlc)->timer.expires = jiffies + HZ;
1016 		state(hdlc)->timer.function = fr_timer;
1017 		state(hdlc)->timer.data = (unsigned long)dev;
1018 		add_timer(&state(hdlc)->timer);
1019 	} else
1020 		fr_set_link_state(1, dev);
1021 }
1022 
1023 
1024 static void fr_stop(struct net_device *dev)
1025 {
1026 	hdlc_device *hdlc = dev_to_hdlc(dev);
1027 #ifdef DEBUG_LINK
1028 	printk(KERN_DEBUG "fr_stop\n");
1029 #endif
1030 	if (state(hdlc)->settings.lmi != LMI_NONE)
1031 		del_timer_sync(&state(hdlc)->timer);
1032 	fr_set_link_state(0, dev);
1033 }
1034 
1035 
1036 static void fr_close(struct net_device *dev)
1037 {
1038 	hdlc_device *hdlc = dev_to_hdlc(dev);
1039 	pvc_device *pvc = state(hdlc)->first_pvc;
1040 
1041 	while (pvc) {		/* Shutdown all PVCs for this FRAD */
1042 		if (pvc->main)
1043 			dev_close(pvc->main);
1044 		if (pvc->ether)
1045 			dev_close(pvc->ether);
1046 		pvc = pvc->next;
1047 	}
1048 }
1049 
1050 
1051 static void pvc_setup(struct net_device *dev)
1052 {
1053 	dev->type = ARPHRD_DLCI;
1054 	dev->flags = IFF_POINTOPOINT;
1055 	dev->hard_header_len = 10;
1056 	dev->addr_len = 2;
1057 	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1058 }
1059 
1060 static const struct net_device_ops pvc_ops = {
1061 	.ndo_open       = pvc_open,
1062 	.ndo_stop       = pvc_close,
1063 	.ndo_change_mtu = hdlc_change_mtu,
1064 	.ndo_start_xmit = pvc_xmit,
1065 	.ndo_do_ioctl   = pvc_ioctl,
1066 };
1067 
1068 static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
1069 {
1070 	hdlc_device *hdlc = dev_to_hdlc(frad);
1071 	pvc_device *pvc;
1072 	struct net_device *dev;
1073 	int result, used;
1074 
1075 	if ((pvc = add_pvc(frad, dlci)) == NULL) {
1076 		printk(KERN_WARNING "%s: Memory squeeze on fr_add_pvc()\n",
1077 		       frad->name);
1078 		return -ENOBUFS;
1079 	}
1080 
1081 	if (*get_dev_p(pvc, type))
1082 		return -EEXIST;
1083 
1084 	used = pvc_is_used(pvc);
1085 
1086 	if (type == ARPHRD_ETHER)
1087 		dev = alloc_netdev(0, "pvceth%d", ether_setup);
1088 	else
1089 		dev = alloc_netdev(0, "pvc%d", pvc_setup);
1090 
1091 	if (!dev) {
1092 		printk(KERN_WARNING "%s: Memory squeeze on fr_pvc()\n",
1093 		       frad->name);
1094 		delete_unused_pvcs(hdlc);
1095 		return -ENOBUFS;
1096 	}
1097 
1098 	if (type == ARPHRD_ETHER)
1099 		random_ether_addr(dev->dev_addr);
1100 	else {
1101 		*(__be16*)dev->dev_addr = htons(dlci);
1102 		dlci_to_q922(dev->broadcast, dlci);
1103 	}
1104 	dev->netdev_ops = &pvc_ops;
1105 	dev->mtu = HDLC_MAX_MTU;
1106 	dev->tx_queue_len = 0;
1107 	dev->ml_priv = pvc;
1108 
1109 	result = dev_alloc_name(dev, dev->name);
1110 	if (result < 0) {
1111 		free_netdev(dev);
1112 		delete_unused_pvcs(hdlc);
1113 		return result;
1114 	}
1115 
1116 	if (register_netdevice(dev) != 0) {
1117 		free_netdev(dev);
1118 		delete_unused_pvcs(hdlc);
1119 		return -EIO;
1120 	}
1121 
1122 	dev->destructor = free_netdev;
1123 	*get_dev_p(pvc, type) = dev;
1124 	if (!used) {
1125 		state(hdlc)->dce_changed = 1;
1126 		state(hdlc)->dce_pvc_count++;
1127 	}
1128 	return 0;
1129 }
1130 
1131 
1132 
1133 static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1134 {
1135 	pvc_device *pvc;
1136 	struct net_device *dev;
1137 
1138 	if ((pvc = find_pvc(hdlc, dlci)) == NULL)
1139 		return -ENOENT;
1140 
1141 	if ((dev = *get_dev_p(pvc, type)) == NULL)
1142 		return -ENOENT;
1143 
1144 	if (dev->flags & IFF_UP)
1145 		return -EBUSY;		/* PVC in use */
1146 
1147 	unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1148 	*get_dev_p(pvc, type) = NULL;
1149 
1150 	if (!pvc_is_used(pvc)) {
1151 		state(hdlc)->dce_pvc_count--;
1152 		state(hdlc)->dce_changed = 1;
1153 	}
1154 	delete_unused_pvcs(hdlc);
1155 	return 0;
1156 }
1157 
1158 
1159 
1160 static void fr_destroy(struct net_device *frad)
1161 {
1162 	hdlc_device *hdlc = dev_to_hdlc(frad);
1163 	pvc_device *pvc = state(hdlc)->first_pvc;
1164 	state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1165 	state(hdlc)->dce_pvc_count = 0;
1166 	state(hdlc)->dce_changed = 1;
1167 
1168 	while (pvc) {
1169 		pvc_device *next = pvc->next;
1170 		/* destructors will free_netdev() main and ether */
1171 		if (pvc->main)
1172 			unregister_netdevice(pvc->main);
1173 
1174 		if (pvc->ether)
1175 			unregister_netdevice(pvc->ether);
1176 
1177 		kfree(pvc);
1178 		pvc = next;
1179 	}
1180 }
1181 
1182 
1183 static struct hdlc_proto proto = {
1184 	.close		= fr_close,
1185 	.start		= fr_start,
1186 	.stop		= fr_stop,
1187 	.detach		= fr_destroy,
1188 	.ioctl		= fr_ioctl,
1189 	.netif_rx	= fr_rx,
1190 	.module		= THIS_MODULE,
1191 };
1192 
1193 
1194 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr)
1195 {
1196 	fr_proto __user *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
1197 	const size_t size = sizeof(fr_proto);
1198 	fr_proto new_settings;
1199 	hdlc_device *hdlc = dev_to_hdlc(dev);
1200 	fr_proto_pvc pvc;
1201 	int result;
1202 
1203 	switch (ifr->ifr_settings.type) {
1204 	case IF_GET_PROTO:
1205 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1206 			return -EINVAL;
1207 		ifr->ifr_settings.type = IF_PROTO_FR;
1208 		if (ifr->ifr_settings.size < size) {
1209 			ifr->ifr_settings.size = size; /* data size wanted */
1210 			return -ENOBUFS;
1211 		}
1212 		if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1213 			return -EFAULT;
1214 		return 0;
1215 
1216 	case IF_PROTO_FR:
1217 		if (!capable(CAP_NET_ADMIN))
1218 			return -EPERM;
1219 
1220 		if (dev->flags & IFF_UP)
1221 			return -EBUSY;
1222 
1223 		if (copy_from_user(&new_settings, fr_s, size))
1224 			return -EFAULT;
1225 
1226 		if (new_settings.lmi == LMI_DEFAULT)
1227 			new_settings.lmi = LMI_ANSI;
1228 
1229 		if ((new_settings.lmi != LMI_NONE &&
1230 		     new_settings.lmi != LMI_ANSI &&
1231 		     new_settings.lmi != LMI_CCITT &&
1232 		     new_settings.lmi != LMI_CISCO) ||
1233 		    new_settings.t391 < 1 ||
1234 		    new_settings.t392 < 2 ||
1235 		    new_settings.n391 < 1 ||
1236 		    new_settings.n392 < 1 ||
1237 		    new_settings.n393 < new_settings.n392 ||
1238 		    new_settings.n393 > 32 ||
1239 		    (new_settings.dce != 0 &&
1240 		     new_settings.dce != 1))
1241 			return -EINVAL;
1242 
1243 		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
1244 		if (result)
1245 			return result;
1246 
1247 		if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1248 			result = attach_hdlc_protocol(dev, &proto,
1249 						      sizeof(struct frad_state));
1250 			if (result)
1251 				return result;
1252 			state(hdlc)->first_pvc = NULL;
1253 			state(hdlc)->dce_pvc_count = 0;
1254 		}
1255 		memcpy(&state(hdlc)->settings, &new_settings, size);
1256 		dev->type = ARPHRD_FRAD;
1257 		return 0;
1258 
1259 	case IF_PROTO_FR_ADD_PVC:
1260 	case IF_PROTO_FR_DEL_PVC:
1261 	case IF_PROTO_FR_ADD_ETH_PVC:
1262 	case IF_PROTO_FR_DEL_ETH_PVC:
1263 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1264 			return -EINVAL;
1265 
1266 		if (!capable(CAP_NET_ADMIN))
1267 			return -EPERM;
1268 
1269 		if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
1270 				   sizeof(fr_proto_pvc)))
1271 			return -EFAULT;
1272 
1273 		if (pvc.dlci <= 0 || pvc.dlci >= 1024)
1274 			return -EINVAL;	/* Only 10 bits, DLCI 0 reserved */
1275 
1276 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
1277 		    ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
1278 			result = ARPHRD_ETHER; /* bridged Ethernet device */
1279 		else
1280 			result = ARPHRD_DLCI;
1281 
1282 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
1283 		    ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
1284 			return fr_add_pvc(dev, pvc.dlci, result);
1285 		else
1286 			return fr_del_pvc(hdlc, pvc.dlci, result);
1287 	}
1288 
1289 	return -EINVAL;
1290 }
1291 
1292 
1293 static int __init mod_init(void)
1294 {
1295 	register_hdlc_protocol(&proto);
1296 	return 0;
1297 }
1298 
1299 
1300 static void __exit mod_exit(void)
1301 {
1302 	unregister_hdlc_protocol(&proto);
1303 }
1304 
1305 
1306 module_init(mod_init);
1307 module_exit(mod_exit);
1308 
1309 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
1310 MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
1311 MODULE_LICENSE("GPL v2");
1312