xref: /openbmc/linux/drivers/net/wan/hdlc_fr.c (revision 384740dc)
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 }__attribute__ ((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 listed 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 __constant_htons(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 __constant_htons(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 __constant_htons(ETH_P_IP):
294 		head_len = 4;
295 		skb_push(skb, head_len);
296 		skb->data[3] = NLPID_IP;
297 		break;
298 
299 	case __constant_htons(ETH_P_IPV6):
300 		head_len = 4;
301 		skb_push(skb, head_len);
302 		skb->data[3] = NLPID_IPV6;
303 		break;
304 
305 	case __constant_htons(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->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->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->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 int pvc_xmit(struct sk_buff *skb, struct net_device *dev)
411 {
412 	pvc_device *pvc = dev->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 0;
425 					}
426 				skb_put(skb, pad);
427 				memset(skb->data + len, 0, pad);
428 			}
429 			skb->protocol = __constant_htons(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 0;
439 		}
440 	}
441 
442 	dev->stats.tx_dropped++;
443 	dev_kfree_skb(skb);
444 	return 0;
445 }
446 
447 
448 
449 static int pvc_change_mtu(struct net_device *dev, int new_mtu)
450 {
451 	if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
452 		return -EINVAL;
453 	dev->mtu = new_mtu;
454 	return 0;
455 }
456 
457 
458 
459 static inline void fr_log_dlci_active(pvc_device *pvc)
460 {
461 	printk(KERN_INFO "%s: DLCI %d [%s%s%s]%s %s\n",
462 	       pvc->frad->name,
463 	       pvc->dlci,
464 	       pvc->main ? pvc->main->name : "",
465 	       pvc->main && pvc->ether ? " " : "",
466 	       pvc->ether ? pvc->ether->name : "",
467 	       pvc->state.new ? " new" : "",
468 	       !pvc->state.exist ? "deleted" :
469 	       pvc->state.active ? "active" : "inactive");
470 }
471 
472 
473 
474 static inline u8 fr_lmi_nextseq(u8 x)
475 {
476 	x++;
477 	return x ? x : 1;
478 }
479 
480 
481 static void fr_lmi_send(struct net_device *dev, int fullrep)
482 {
483 	hdlc_device *hdlc = dev_to_hdlc(dev);
484 	struct sk_buff *skb;
485 	pvc_device *pvc = state(hdlc)->first_pvc;
486 	int lmi = state(hdlc)->settings.lmi;
487 	int dce = state(hdlc)->settings.dce;
488 	int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
489 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
490 	u8 *data;
491 	int i = 0;
492 
493 	if (dce && fullrep) {
494 		len += state(hdlc)->dce_pvc_count * (2 + stat_len);
495 		if (len > HDLC_MAX_MRU) {
496 			printk(KERN_WARNING "%s: Too many PVCs while sending "
497 			       "LMI full report\n", dev->name);
498 			return;
499 		}
500 	}
501 
502 	skb = dev_alloc_skb(len);
503 	if (!skb) {
504 		printk(KERN_WARNING "%s: Memory squeeze on fr_lmi_send()\n",
505 		       dev->name);
506 		return;
507 	}
508 	memset(skb->data, 0, len);
509 	skb_reserve(skb, 4);
510 	if (lmi == LMI_CISCO) {
511 		skb->protocol = __constant_htons(NLPID_CISCO_LMI);
512 		fr_hard_header(&skb, LMI_CISCO_DLCI);
513 	} else {
514 		skb->protocol = __constant_htons(NLPID_CCITT_ANSI_LMI);
515 		fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI);
516 	}
517 	data = skb_tail_pointer(skb);
518 	data[i++] = LMI_CALLREF;
519 	data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
520 	if (lmi == LMI_ANSI)
521 		data[i++] = LMI_ANSI_LOCKSHIFT;
522 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
523 		LMI_ANSI_CISCO_REPTYPE;
524 	data[i++] = LMI_REPT_LEN;
525 	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
526 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
527 	data[i++] = LMI_INTEG_LEN;
528 	data[i++] = state(hdlc)->txseq =
529 		fr_lmi_nextseq(state(hdlc)->txseq);
530 	data[i++] = state(hdlc)->rxseq;
531 
532 	if (dce && fullrep) {
533 		while (pvc) {
534 			data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
535 				LMI_ANSI_CISCO_PVCSTAT;
536 			data[i++] = stat_len;
537 
538 			/* LMI start/restart */
539 			if (state(hdlc)->reliable && !pvc->state.exist) {
540 				pvc->state.exist = pvc->state.new = 1;
541 				fr_log_dlci_active(pvc);
542 			}
543 
544 			/* ifconfig PVC up */
545 			if (pvc->open_count && !pvc->state.active &&
546 			    pvc->state.exist && !pvc->state.new) {
547 				pvc_carrier(1, pvc);
548 				pvc->state.active = 1;
549 				fr_log_dlci_active(pvc);
550 			}
551 
552 			if (lmi == LMI_CISCO) {
553 				data[i] = pvc->dlci >> 8;
554 				data[i + 1] = pvc->dlci & 0xFF;
555 			} else {
556 				data[i] = (pvc->dlci >> 4) & 0x3F;
557 				data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
558 				data[i + 2] = 0x80;
559 			}
560 
561 			if (pvc->state.new)
562 				data[i + 2] |= 0x08;
563 			else if (pvc->state.active)
564 				data[i + 2] |= 0x02;
565 
566 			i += stat_len;
567 			pvc = pvc->next;
568 		}
569 	}
570 
571 	skb_put(skb, i);
572 	skb->priority = TC_PRIO_CONTROL;
573 	skb->dev = dev;
574 	skb_reset_network_header(skb);
575 
576 	dev_queue_xmit(skb);
577 }
578 
579 
580 
581 static void fr_set_link_state(int reliable, struct net_device *dev)
582 {
583 	hdlc_device *hdlc = dev_to_hdlc(dev);
584 	pvc_device *pvc = state(hdlc)->first_pvc;
585 
586 	state(hdlc)->reliable = reliable;
587 	if (reliable) {
588 		netif_dormant_off(dev);
589 		state(hdlc)->n391cnt = 0; /* Request full status */
590 		state(hdlc)->dce_changed = 1;
591 
592 		if (state(hdlc)->settings.lmi == LMI_NONE) {
593 			while (pvc) {	/* Activate all PVCs */
594 				pvc_carrier(1, pvc);
595 				pvc->state.exist = pvc->state.active = 1;
596 				pvc->state.new = 0;
597 				pvc = pvc->next;
598 			}
599 		}
600 	} else {
601 		netif_dormant_on(dev);
602 		while (pvc) {		/* Deactivate all PVCs */
603 			pvc_carrier(0, pvc);
604 			pvc->state.exist = pvc->state.active = 0;
605 			pvc->state.new = 0;
606 			if (!state(hdlc)->settings.dce)
607 				pvc->state.bandwidth = 0;
608 			pvc = pvc->next;
609 		}
610 	}
611 }
612 
613 
614 static void fr_timer(unsigned long arg)
615 {
616 	struct net_device *dev = (struct net_device *)arg;
617 	hdlc_device *hdlc = dev_to_hdlc(dev);
618 	int i, cnt = 0, reliable;
619 	u32 list;
620 
621 	if (state(hdlc)->settings.dce) {
622 		reliable = state(hdlc)->request &&
623 			time_before(jiffies, state(hdlc)->last_poll +
624 				    state(hdlc)->settings.t392 * HZ);
625 		state(hdlc)->request = 0;
626 	} else {
627 		state(hdlc)->last_errors <<= 1; /* Shift the list */
628 		if (state(hdlc)->request) {
629 			if (state(hdlc)->reliable)
630 				printk(KERN_INFO "%s: No LMI status reply "
631 				       "received\n", dev->name);
632 			state(hdlc)->last_errors |= 1;
633 		}
634 
635 		list = state(hdlc)->last_errors;
636 		for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
637 			cnt += (list & 1);	/* errors count */
638 
639 		reliable = (cnt < state(hdlc)->settings.n392);
640 	}
641 
642 	if (state(hdlc)->reliable != reliable) {
643 		printk(KERN_INFO "%s: Link %sreliable\n", dev->name,
644 		       reliable ? "" : "un");
645 		fr_set_link_state(reliable, dev);
646 	}
647 
648 	if (state(hdlc)->settings.dce)
649 		state(hdlc)->timer.expires = jiffies +
650 			state(hdlc)->settings.t392 * HZ;
651 	else {
652 		if (state(hdlc)->n391cnt)
653 			state(hdlc)->n391cnt--;
654 
655 		fr_lmi_send(dev, state(hdlc)->n391cnt == 0);
656 
657 		state(hdlc)->last_poll = jiffies;
658 		state(hdlc)->request = 1;
659 		state(hdlc)->timer.expires = jiffies +
660 			state(hdlc)->settings.t391 * HZ;
661 	}
662 
663 	state(hdlc)->timer.function = fr_timer;
664 	state(hdlc)->timer.data = arg;
665 	add_timer(&state(hdlc)->timer);
666 }
667 
668 
669 static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
670 {
671 	hdlc_device *hdlc = dev_to_hdlc(dev);
672 	pvc_device *pvc;
673 	u8 rxseq, txseq;
674 	int lmi = state(hdlc)->settings.lmi;
675 	int dce = state(hdlc)->settings.dce;
676 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
677 
678 	if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
679 			LMI_CCITT_CISCO_LENGTH)) {
680 		printk(KERN_INFO "%s: Short LMI frame\n", dev->name);
681 		return 1;
682 	}
683 
684 	if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
685 			     NLPID_CCITT_ANSI_LMI)) {
686 		printk(KERN_INFO "%s: Received non-LMI frame with LMI DLCI\n",
687 		       dev->name);
688 		return 1;
689 	}
690 
691 	if (skb->data[4] != LMI_CALLREF) {
692 		printk(KERN_INFO "%s: Invalid LMI Call reference (0x%02X)\n",
693 		       dev->name, skb->data[4]);
694 		return 1;
695 	}
696 
697 	if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
698 		printk(KERN_INFO "%s: Invalid LMI Message type (0x%02X)\n",
699 		       dev->name, skb->data[5]);
700 		return 1;
701 	}
702 
703 	if (lmi == LMI_ANSI) {
704 		if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
705 			printk(KERN_INFO "%s: Not ANSI locking shift in LMI"
706 			       " message (0x%02X)\n", dev->name, skb->data[6]);
707 			return 1;
708 		}
709 		i = 7;
710 	} else
711 		i = 6;
712 
713 	if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
714 			     LMI_ANSI_CISCO_REPTYPE)) {
715 		printk(KERN_INFO "%s: Not an LMI Report type IE (0x%02X)\n",
716 		       dev->name, skb->data[i]);
717 		return 1;
718 	}
719 
720 	if (skb->data[++i] != LMI_REPT_LEN) {
721 		printk(KERN_INFO "%s: Invalid LMI Report type IE length"
722 		       " (%u)\n", dev->name, skb->data[i]);
723 		return 1;
724 	}
725 
726 	reptype = skb->data[++i];
727 	if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
728 		printk(KERN_INFO "%s: Unsupported LMI Report type (0x%02X)\n",
729 		       dev->name, reptype);
730 		return 1;
731 	}
732 
733 	if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
734 			       LMI_ANSI_CISCO_ALIVE)) {
735 		printk(KERN_INFO "%s: Not an LMI Link integrity verification"
736 		       " IE (0x%02X)\n", dev->name, skb->data[i]);
737 		return 1;
738 	}
739 
740 	if (skb->data[++i] != LMI_INTEG_LEN) {
741 		printk(KERN_INFO "%s: Invalid LMI Link integrity verification"
742 		       " IE length (%u)\n", dev->name, skb->data[i]);
743 		return 1;
744 	}
745 	i++;
746 
747 	state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
748 	rxseq = skb->data[i++];	/* Should confirm our sequence */
749 
750 	txseq = state(hdlc)->txseq;
751 
752 	if (dce)
753 		state(hdlc)->last_poll = jiffies;
754 
755 	error = 0;
756 	if (!state(hdlc)->reliable)
757 		error = 1;
758 
759 	if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
760 		state(hdlc)->n391cnt = 0;
761 		error = 1;
762 	}
763 
764 	if (dce) {
765 		if (state(hdlc)->fullrep_sent && !error) {
766 /* Stop sending full report - the last one has been confirmed by DTE */
767 			state(hdlc)->fullrep_sent = 0;
768 			pvc = state(hdlc)->first_pvc;
769 			while (pvc) {
770 				if (pvc->state.new) {
771 					pvc->state.new = 0;
772 
773 /* Tell DTE that new PVC is now active */
774 					state(hdlc)->dce_changed = 1;
775 				}
776 				pvc = pvc->next;
777 			}
778 		}
779 
780 		if (state(hdlc)->dce_changed) {
781 			reptype = LMI_FULLREP;
782 			state(hdlc)->fullrep_sent = 1;
783 			state(hdlc)->dce_changed = 0;
784 		}
785 
786 		state(hdlc)->request = 1; /* got request */
787 		fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
788 		return 0;
789 	}
790 
791 	/* DTE */
792 
793 	state(hdlc)->request = 0; /* got response, no request pending */
794 
795 	if (error)
796 		return 0;
797 
798 	if (reptype != LMI_FULLREP)
799 		return 0;
800 
801 	pvc = state(hdlc)->first_pvc;
802 
803 	while (pvc) {
804 		pvc->state.deleted = 1;
805 		pvc = pvc->next;
806 	}
807 
808 	no_ram = 0;
809 	while (skb->len >= i + 2 + stat_len) {
810 		u16 dlci;
811 		u32 bw;
812 		unsigned int active, new;
813 
814 		if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
815 				       LMI_ANSI_CISCO_PVCSTAT)) {
816 			printk(KERN_INFO "%s: Not an LMI PVC status IE"
817 			       " (0x%02X)\n", dev->name, skb->data[i]);
818 			return 1;
819 		}
820 
821 		if (skb->data[++i] != stat_len) {
822 			printk(KERN_INFO "%s: Invalid LMI PVC status IE length"
823 			       " (%u)\n", dev->name, skb->data[i]);
824 			return 1;
825 		}
826 		i++;
827 
828 		new = !! (skb->data[i + 2] & 0x08);
829 		active = !! (skb->data[i + 2] & 0x02);
830 		if (lmi == LMI_CISCO) {
831 			dlci = (skb->data[i] << 8) | skb->data[i + 1];
832 			bw = (skb->data[i + 3] << 16) |
833 				(skb->data[i + 4] << 8) |
834 				(skb->data[i + 5]);
835 		} else {
836 			dlci = ((skb->data[i] & 0x3F) << 4) |
837 				((skb->data[i + 1] & 0x78) >> 3);
838 			bw = 0;
839 		}
840 
841 		pvc = add_pvc(dev, dlci);
842 
843 		if (!pvc && !no_ram) {
844 			printk(KERN_WARNING
845 			       "%s: Memory squeeze on fr_lmi_recv()\n",
846 			       dev->name);
847 			no_ram = 1;
848 		}
849 
850 		if (pvc) {
851 			pvc->state.exist = 1;
852 			pvc->state.deleted = 0;
853 			if (active != pvc->state.active ||
854 			    new != pvc->state.new ||
855 			    bw != pvc->state.bandwidth ||
856 			    !pvc->state.exist) {
857 				pvc->state.new = new;
858 				pvc->state.active = active;
859 				pvc->state.bandwidth = bw;
860 				pvc_carrier(active, pvc);
861 				fr_log_dlci_active(pvc);
862 			}
863 		}
864 
865 		i += stat_len;
866 	}
867 
868 	pvc = state(hdlc)->first_pvc;
869 
870 	while (pvc) {
871 		if (pvc->state.deleted && pvc->state.exist) {
872 			pvc_carrier(0, pvc);
873 			pvc->state.active = pvc->state.new = 0;
874 			pvc->state.exist = 0;
875 			pvc->state.bandwidth = 0;
876 			fr_log_dlci_active(pvc);
877 		}
878 		pvc = pvc->next;
879 	}
880 
881 	/* Next full report after N391 polls */
882 	state(hdlc)->n391cnt = state(hdlc)->settings.n391;
883 
884 	return 0;
885 }
886 
887 
888 static int fr_rx(struct sk_buff *skb)
889 {
890 	struct net_device *frad = skb->dev;
891 	hdlc_device *hdlc = dev_to_hdlc(frad);
892 	fr_hdr *fh = (fr_hdr*)skb->data;
893 	u8 *data = skb->data;
894 	u16 dlci;
895 	pvc_device *pvc;
896 	struct net_device *dev = NULL;
897 
898 	if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI)
899 		goto rx_error;
900 
901 	dlci = q922_to_dlci(skb->data);
902 
903 	if ((dlci == LMI_CCITT_ANSI_DLCI &&
904 	     (state(hdlc)->settings.lmi == LMI_ANSI ||
905 	      state(hdlc)->settings.lmi == LMI_CCITT)) ||
906 	    (dlci == LMI_CISCO_DLCI &&
907 	     state(hdlc)->settings.lmi == LMI_CISCO)) {
908 		if (fr_lmi_recv(frad, skb))
909 			goto rx_error;
910 		dev_kfree_skb_any(skb);
911 		return NET_RX_SUCCESS;
912 	}
913 
914 	pvc = find_pvc(hdlc, dlci);
915 	if (!pvc) {
916 #ifdef DEBUG_PKT
917 		printk(KERN_INFO "%s: No PVC for received frame's DLCI %d\n",
918 		       frad->name, dlci);
919 #endif
920 		dev_kfree_skb_any(skb);
921 		return NET_RX_DROP;
922 	}
923 
924 	if (pvc->state.fecn != fh->fecn) {
925 #ifdef DEBUG_ECN
926 		printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", frad->name,
927 		       dlci, fh->fecn ? "N" : "FF");
928 #endif
929 		pvc->state.fecn ^= 1;
930 	}
931 
932 	if (pvc->state.becn != fh->becn) {
933 #ifdef DEBUG_ECN
934 		printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", frad->name,
935 		       dlci, fh->becn ? "N" : "FF");
936 #endif
937 		pvc->state.becn ^= 1;
938 	}
939 
940 
941 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
942 		frad->stats.rx_dropped++;
943 		return NET_RX_DROP;
944 	}
945 
946 	if (data[3] == NLPID_IP) {
947 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
948 		dev = pvc->main;
949 		skb->protocol = htons(ETH_P_IP);
950 
951 	} else if (data[3] == NLPID_IPV6) {
952 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
953 		dev = pvc->main;
954 		skb->protocol = htons(ETH_P_IPV6);
955 
956 	} else if (skb->len > 10 && data[3] == FR_PAD &&
957 		   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
958 		u16 oui = ntohs(*(__be16*)(data + 6));
959 		u16 pid = ntohs(*(__be16*)(data + 8));
960 		skb_pull(skb, 10);
961 
962 		switch ((((u32)oui) << 16) | pid) {
963 		case ETH_P_ARP: /* routed frame with SNAP */
964 		case ETH_P_IPX:
965 		case ETH_P_IP:	/* a long variant */
966 		case ETH_P_IPV6:
967 			dev = pvc->main;
968 			skb->protocol = htons(pid);
969 			break;
970 
971 		case 0x80C20007: /* bridged Ethernet frame */
972 			if ((dev = pvc->ether) != NULL)
973 				skb->protocol = eth_type_trans(skb, dev);
974 			break;
975 
976 		default:
977 			printk(KERN_INFO "%s: Unsupported protocol, OUI=%x "
978 			       "PID=%x\n", frad->name, oui, pid);
979 			dev_kfree_skb_any(skb);
980 			return NET_RX_DROP;
981 		}
982 	} else {
983 		printk(KERN_INFO "%s: Unsupported protocol, NLPID=%x "
984 		       "length = %i\n", frad->name, data[3], skb->len);
985 		dev_kfree_skb_any(skb);
986 		return NET_RX_DROP;
987 	}
988 
989 	if (dev) {
990 		dev->stats.rx_packets++; /* PVC traffic */
991 		dev->stats.rx_bytes += skb->len;
992 		if (pvc->state.becn)
993 			dev->stats.rx_compressed++;
994 		skb->dev = dev;
995 		netif_rx(skb);
996 		return NET_RX_SUCCESS;
997 	} else {
998 		dev_kfree_skb_any(skb);
999 		return NET_RX_DROP;
1000 	}
1001 
1002  rx_error:
1003 	frad->stats.rx_errors++; /* Mark error */
1004 	dev_kfree_skb_any(skb);
1005 	return NET_RX_DROP;
1006 }
1007 
1008 
1009 
1010 static void fr_start(struct net_device *dev)
1011 {
1012 	hdlc_device *hdlc = dev_to_hdlc(dev);
1013 #ifdef DEBUG_LINK
1014 	printk(KERN_DEBUG "fr_start\n");
1015 #endif
1016 	if (state(hdlc)->settings.lmi != LMI_NONE) {
1017 		state(hdlc)->reliable = 0;
1018 		state(hdlc)->dce_changed = 1;
1019 		state(hdlc)->request = 0;
1020 		state(hdlc)->fullrep_sent = 0;
1021 		state(hdlc)->last_errors = 0xFFFFFFFF;
1022 		state(hdlc)->n391cnt = 0;
1023 		state(hdlc)->txseq = state(hdlc)->rxseq = 0;
1024 
1025 		init_timer(&state(hdlc)->timer);
1026 		/* First poll after 1 s */
1027 		state(hdlc)->timer.expires = jiffies + HZ;
1028 		state(hdlc)->timer.function = fr_timer;
1029 		state(hdlc)->timer.data = (unsigned long)dev;
1030 		add_timer(&state(hdlc)->timer);
1031 	} else
1032 		fr_set_link_state(1, dev);
1033 }
1034 
1035 
1036 static void fr_stop(struct net_device *dev)
1037 {
1038 	hdlc_device *hdlc = dev_to_hdlc(dev);
1039 #ifdef DEBUG_LINK
1040 	printk(KERN_DEBUG "fr_stop\n");
1041 #endif
1042 	if (state(hdlc)->settings.lmi != LMI_NONE)
1043 		del_timer_sync(&state(hdlc)->timer);
1044 	fr_set_link_state(0, dev);
1045 }
1046 
1047 
1048 static void fr_close(struct net_device *dev)
1049 {
1050 	hdlc_device *hdlc = dev_to_hdlc(dev);
1051 	pvc_device *pvc = state(hdlc)->first_pvc;
1052 
1053 	while (pvc) {		/* Shutdown all PVCs for this FRAD */
1054 		if (pvc->main)
1055 			dev_close(pvc->main);
1056 		if (pvc->ether)
1057 			dev_close(pvc->ether);
1058 		pvc = pvc->next;
1059 	}
1060 }
1061 
1062 
1063 static void pvc_setup(struct net_device *dev)
1064 {
1065 	dev->type = ARPHRD_DLCI;
1066 	dev->flags = IFF_POINTOPOINT;
1067 	dev->hard_header_len = 10;
1068 	dev->addr_len = 2;
1069 }
1070 
1071 static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
1072 {
1073 	hdlc_device *hdlc = dev_to_hdlc(frad);
1074 	pvc_device *pvc;
1075 	struct net_device *dev;
1076 	int result, used;
1077 
1078 	if ((pvc = add_pvc(frad, dlci)) == NULL) {
1079 		printk(KERN_WARNING "%s: Memory squeeze on fr_add_pvc()\n",
1080 		       frad->name);
1081 		return -ENOBUFS;
1082 	}
1083 
1084 	if (*get_dev_p(pvc, type))
1085 		return -EEXIST;
1086 
1087 	used = pvc_is_used(pvc);
1088 
1089 	if (type == ARPHRD_ETHER)
1090 		dev = alloc_netdev(0, "pvceth%d", ether_setup);
1091 	else
1092 		dev = alloc_netdev(0, "pvc%d", pvc_setup);
1093 
1094 	if (!dev) {
1095 		printk(KERN_WARNING "%s: Memory squeeze on fr_pvc()\n",
1096 		       frad->name);
1097 		delete_unused_pvcs(hdlc);
1098 		return -ENOBUFS;
1099 	}
1100 
1101 	if (type == ARPHRD_ETHER)
1102 		random_ether_addr(dev->dev_addr);
1103 	else {
1104 		*(__be16*)dev->dev_addr = htons(dlci);
1105 		dlci_to_q922(dev->broadcast, dlci);
1106 	}
1107 	dev->hard_start_xmit = pvc_xmit;
1108 	dev->open = pvc_open;
1109 	dev->stop = pvc_close;
1110 	dev->do_ioctl = pvc_ioctl;
1111 	dev->change_mtu = pvc_change_mtu;
1112 	dev->mtu = HDLC_MAX_MTU;
1113 	dev->tx_queue_len = 0;
1114 	dev->priv = pvc;
1115 
1116 	result = dev_alloc_name(dev, dev->name);
1117 	if (result < 0) {
1118 		free_netdev(dev);
1119 		delete_unused_pvcs(hdlc);
1120 		return result;
1121 	}
1122 
1123 	if (register_netdevice(dev) != 0) {
1124 		free_netdev(dev);
1125 		delete_unused_pvcs(hdlc);
1126 		return -EIO;
1127 	}
1128 
1129 	dev->destructor = free_netdev;
1130 	*get_dev_p(pvc, type) = dev;
1131 	if (!used) {
1132 		state(hdlc)->dce_changed = 1;
1133 		state(hdlc)->dce_pvc_count++;
1134 	}
1135 	return 0;
1136 }
1137 
1138 
1139 
1140 static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1141 {
1142 	pvc_device *pvc;
1143 	struct net_device *dev;
1144 
1145 	if ((pvc = find_pvc(hdlc, dlci)) == NULL)
1146 		return -ENOENT;
1147 
1148 	if ((dev = *get_dev_p(pvc, type)) == NULL)
1149 		return -ENOENT;
1150 
1151 	if (dev->flags & IFF_UP)
1152 		return -EBUSY;		/* PVC in use */
1153 
1154 	unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1155 	*get_dev_p(pvc, type) = NULL;
1156 
1157 	if (!pvc_is_used(pvc)) {
1158 		state(hdlc)->dce_pvc_count--;
1159 		state(hdlc)->dce_changed = 1;
1160 	}
1161 	delete_unused_pvcs(hdlc);
1162 	return 0;
1163 }
1164 
1165 
1166 
1167 static void fr_destroy(struct net_device *frad)
1168 {
1169 	hdlc_device *hdlc = dev_to_hdlc(frad);
1170 	pvc_device *pvc = state(hdlc)->first_pvc;
1171 	state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1172 	state(hdlc)->dce_pvc_count = 0;
1173 	state(hdlc)->dce_changed = 1;
1174 
1175 	while (pvc) {
1176 		pvc_device *next = pvc->next;
1177 		/* destructors will free_netdev() main and ether */
1178 		if (pvc->main)
1179 			unregister_netdevice(pvc->main);
1180 
1181 		if (pvc->ether)
1182 			unregister_netdevice(pvc->ether);
1183 
1184 		kfree(pvc);
1185 		pvc = next;
1186 	}
1187 }
1188 
1189 
1190 static struct hdlc_proto proto = {
1191 	.close		= fr_close,
1192 	.start		= fr_start,
1193 	.stop		= fr_stop,
1194 	.detach		= fr_destroy,
1195 	.ioctl		= fr_ioctl,
1196 	.netif_rx	= fr_rx,
1197 	.module		= THIS_MODULE,
1198 };
1199 
1200 
1201 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr)
1202 {
1203 	fr_proto __user *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
1204 	const size_t size = sizeof(fr_proto);
1205 	fr_proto new_settings;
1206 	hdlc_device *hdlc = dev_to_hdlc(dev);
1207 	fr_proto_pvc pvc;
1208 	int result;
1209 
1210 	switch (ifr->ifr_settings.type) {
1211 	case IF_GET_PROTO:
1212 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1213 			return -EINVAL;
1214 		ifr->ifr_settings.type = IF_PROTO_FR;
1215 		if (ifr->ifr_settings.size < size) {
1216 			ifr->ifr_settings.size = size; /* data size wanted */
1217 			return -ENOBUFS;
1218 		}
1219 		if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1220 			return -EFAULT;
1221 		return 0;
1222 
1223 	case IF_PROTO_FR:
1224 		if(!capable(CAP_NET_ADMIN))
1225 			return -EPERM;
1226 
1227 		if(dev->flags & IFF_UP)
1228 			return -EBUSY;
1229 
1230 		if (copy_from_user(&new_settings, fr_s, size))
1231 			return -EFAULT;
1232 
1233 		if (new_settings.lmi == LMI_DEFAULT)
1234 			new_settings.lmi = LMI_ANSI;
1235 
1236 		if ((new_settings.lmi != LMI_NONE &&
1237 		     new_settings.lmi != LMI_ANSI &&
1238 		     new_settings.lmi != LMI_CCITT &&
1239 		     new_settings.lmi != LMI_CISCO) ||
1240 		    new_settings.t391 < 1 ||
1241 		    new_settings.t392 < 2 ||
1242 		    new_settings.n391 < 1 ||
1243 		    new_settings.n392 < 1 ||
1244 		    new_settings.n393 < new_settings.n392 ||
1245 		    new_settings.n393 > 32 ||
1246 		    (new_settings.dce != 0 &&
1247 		     new_settings.dce != 1))
1248 			return -EINVAL;
1249 
1250 		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
1251 		if (result)
1252 			return result;
1253 
1254 		if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1255 			result = attach_hdlc_protocol(dev, &proto,
1256 						      sizeof(struct frad_state));
1257 			if (result)
1258 				return result;
1259 			state(hdlc)->first_pvc = NULL;
1260 			state(hdlc)->dce_pvc_count = 0;
1261 		}
1262 		memcpy(&state(hdlc)->settings, &new_settings, size);
1263 
1264 		dev->hard_start_xmit = hdlc->xmit;
1265 		dev->type = ARPHRD_FRAD;
1266 		return 0;
1267 
1268 	case IF_PROTO_FR_ADD_PVC:
1269 	case IF_PROTO_FR_DEL_PVC:
1270 	case IF_PROTO_FR_ADD_ETH_PVC:
1271 	case IF_PROTO_FR_DEL_ETH_PVC:
1272 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1273 			return -EINVAL;
1274 
1275 		if(!capable(CAP_NET_ADMIN))
1276 			return -EPERM;
1277 
1278 		if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
1279 				   sizeof(fr_proto_pvc)))
1280 			return -EFAULT;
1281 
1282 		if (pvc.dlci <= 0 || pvc.dlci >= 1024)
1283 			return -EINVAL;	/* Only 10 bits, DLCI 0 reserved */
1284 
1285 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
1286 		    ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
1287 			result = ARPHRD_ETHER; /* bridged Ethernet device */
1288 		else
1289 			result = ARPHRD_DLCI;
1290 
1291 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
1292 		    ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
1293 			return fr_add_pvc(dev, pvc.dlci, result);
1294 		else
1295 			return fr_del_pvc(hdlc, pvc.dlci, result);
1296 	}
1297 
1298 	return -EINVAL;
1299 }
1300 
1301 
1302 static int __init mod_init(void)
1303 {
1304 	register_hdlc_protocol(&proto);
1305 	return 0;
1306 }
1307 
1308 
1309 static void __exit mod_exit(void)
1310 {
1311 	unregister_hdlc_protocol(&proto);
1312 }
1313 
1314 
1315 module_init(mod_init);
1316 module_exit(mod_exit);
1317 
1318 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
1319 MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
1320 MODULE_LICENSE("GPL v2");
1321