xref: /openbmc/linux/drivers/net/wan/hdlc_fr.c (revision b923cda9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Generic HDLC support routines for Linux
4  * Frame Relay support
5  *
6  * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
7  *
8 
9 	Theory of PVC state
10 
11  DCE mode:
12 
13  (exist,new) -> 0,0 when "PVC create" or if "link unreliable"
14 	 0,x -> 1,1 if "link reliable" when sending FULL STATUS
15 	 1,1 -> 1,0 if received FULL STATUS ACK
16 
17  (active)    -> 0 when "ifconfig PVC down" or "link unreliable" or "PVC create"
18 	     -> 1 when "PVC up" and (exist,new) = 1,0
19 
20  DTE mode:
21  (exist,new,active) = FULL STATUS if "link reliable"
22 		    = 0, 0, 0 if "link unreliable"
23  No LMI:
24  active = open and "link reliable"
25  exist = new = not used
26 
27  CCITT LMI: ITU-T Q.933 Annex A
28  ANSI LMI: ANSI T1.617 Annex D
29  CISCO LMI: the original, aka "Gang of Four" LMI
30 
31 */
32 
33 #include <linux/errno.h>
34 #include <linux/etherdevice.h>
35 #include <linux/hdlc.h>
36 #include <linux/if_arp.h>
37 #include <linux/inetdevice.h>
38 #include <linux/init.h>
39 #include <linux/kernel.h>
40 #include <linux/module.h>
41 #include <linux/pkt_sched.h>
42 #include <linux/poll.h>
43 #include <linux/rtnetlink.h>
44 #include <linux/skbuff.h>
45 #include <linux/slab.h>
46 
47 #undef DEBUG_PKT
48 #undef DEBUG_ECN
49 #undef DEBUG_LINK
50 #undef DEBUG_PROTO
51 #undef DEBUG_PVC
52 
53 #define FR_UI			0x03
54 #define FR_PAD			0x00
55 
56 #define NLPID_IP		0xCC
57 #define NLPID_IPV6		0x8E
58 #define NLPID_SNAP		0x80
59 #define NLPID_PAD		0x00
60 #define NLPID_CCITT_ANSI_LMI	0x08
61 #define NLPID_CISCO_LMI		0x09
62 
63 #define LMI_CCITT_ANSI_DLCI	   0 /* LMI DLCI */
64 #define LMI_CISCO_DLCI		1023
65 
66 #define LMI_CALLREF		0x00 /* Call Reference */
67 #define LMI_ANSI_LOCKSHIFT	0x95 /* ANSI locking shift */
68 #define LMI_ANSI_CISCO_REPTYPE	0x01 /* report type */
69 #define LMI_CCITT_REPTYPE	0x51
70 #define LMI_ANSI_CISCO_ALIVE	0x03 /* keep alive */
71 #define LMI_CCITT_ALIVE		0x53
72 #define LMI_ANSI_CISCO_PVCSTAT	0x07 /* PVC status */
73 #define LMI_CCITT_PVCSTAT	0x57
74 
75 #define LMI_FULLREP		0x00 /* full report  */
76 #define LMI_INTEGRITY		0x01 /* link integrity report */
77 #define LMI_SINGLE		0x02 /* single PVC report */
78 
79 #define LMI_STATUS_ENQUIRY      0x75
80 #define LMI_STATUS              0x7D /* reply */
81 
82 #define LMI_REPT_LEN               1 /* report type element length */
83 #define LMI_INTEG_LEN              2 /* link integrity element length */
84 
85 #define LMI_CCITT_CISCO_LENGTH	  13 /* LMI frame lengths */
86 #define LMI_ANSI_LENGTH		  14
87 
88 struct fr_hdr {
89 #if defined(__LITTLE_ENDIAN_BITFIELD)
90 	unsigned ea1:	1;
91 	unsigned cr:	1;
92 	unsigned dlcih:	6;
93 
94 	unsigned ea2:	1;
95 	unsigned de:	1;
96 	unsigned becn:	1;
97 	unsigned fecn:	1;
98 	unsigned dlcil:	4;
99 #else
100 	unsigned dlcih:	6;
101 	unsigned cr:	1;
102 	unsigned ea1:	1;
103 
104 	unsigned dlcil:	4;
105 	unsigned fecn:	1;
106 	unsigned becn:	1;
107 	unsigned de:	1;
108 	unsigned ea2:	1;
109 #endif
110 } __packed;
111 
112 struct pvc_device {
113 	struct net_device *frad;
114 	struct net_device *main;
115 	struct net_device *ether;	/* bridged Ethernet interface	*/
116 	struct pvc_device *next;	/* Sorted in ascending DLCI order */
117 	int dlci;
118 	int open_count;
119 
120 	struct {
121 		unsigned int new: 1;
122 		unsigned int active: 1;
123 		unsigned int exist: 1;
124 		unsigned int deleted: 1;
125 		unsigned int fecn: 1;
126 		unsigned int becn: 1;
127 		unsigned int bandwidth;	/* Cisco LMI reporting only */
128 	} state;
129 };
130 
131 struct frad_state {
132 	fr_proto settings;
133 	struct pvc_device *first_pvc;
134 	int dce_pvc_count;
135 
136 	struct timer_list timer;
137 	struct net_device *dev;
138 	unsigned long last_poll;
139 	int reliable;
140 	int dce_changed;
141 	int request;
142 	int fullrep_sent;
143 	u32 last_errors; /* last errors bit list */
144 	u8 n391cnt;
145 	u8 txseq; /* TX sequence number */
146 	u8 rxseq; /* RX sequence number */
147 };
148 
149 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr);
150 
151 static inline u16 q922_to_dlci(u8 *hdr)
152 {
153 	return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
154 }
155 
156 static inline void dlci_to_q922(u8 *hdr, u16 dlci)
157 {
158 	hdr[0] = (dlci >> 2) & 0xFC;
159 	hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
160 }
161 
162 static inline struct frad_state *state(hdlc_device *hdlc)
163 {
164 	return (struct frad_state *)(hdlc->state);
165 }
166 
167 static inline struct pvc_device *find_pvc(hdlc_device *hdlc, u16 dlci)
168 {
169 	struct pvc_device *pvc = state(hdlc)->first_pvc;
170 
171 	while (pvc) {
172 		if (pvc->dlci == dlci)
173 			return pvc;
174 		if (pvc->dlci > dlci)
175 			return NULL; /* the list is sorted */
176 		pvc = pvc->next;
177 	}
178 
179 	return NULL;
180 }
181 
182 static struct pvc_device *add_pvc(struct net_device *dev, u16 dlci)
183 {
184 	hdlc_device *hdlc = dev_to_hdlc(dev);
185 	struct pvc_device *pvc, **pvc_p = &state(hdlc)->first_pvc;
186 
187 	while (*pvc_p) {
188 		if ((*pvc_p)->dlci == dlci)
189 			return *pvc_p;
190 		if ((*pvc_p)->dlci > dlci)
191 			break;	/* the list is sorted */
192 		pvc_p = &(*pvc_p)->next;
193 	}
194 
195 	pvc = kzalloc(sizeof(*pvc), GFP_ATOMIC);
196 #ifdef DEBUG_PVC
197 	printk(KERN_DEBUG "add_pvc: allocated pvc %p, frad %p\n", pvc, dev);
198 #endif
199 	if (!pvc)
200 		return NULL;
201 
202 	pvc->dlci = dlci;
203 	pvc->frad = dev;
204 	pvc->next = *pvc_p;	/* Put it in the chain */
205 	*pvc_p = pvc;
206 	return pvc;
207 }
208 
209 static inline int pvc_is_used(struct pvc_device *pvc)
210 {
211 	return pvc->main || pvc->ether;
212 }
213 
214 static inline void pvc_carrier(int on, struct pvc_device *pvc)
215 {
216 	if (on) {
217 		if (pvc->main)
218 			if (!netif_carrier_ok(pvc->main))
219 				netif_carrier_on(pvc->main);
220 		if (pvc->ether)
221 			if (!netif_carrier_ok(pvc->ether))
222 				netif_carrier_on(pvc->ether);
223 	} else {
224 		if (pvc->main)
225 			if (netif_carrier_ok(pvc->main))
226 				netif_carrier_off(pvc->main);
227 		if (pvc->ether)
228 			if (netif_carrier_ok(pvc->ether))
229 				netif_carrier_off(pvc->ether);
230 	}
231 }
232 
233 static inline void delete_unused_pvcs(hdlc_device *hdlc)
234 {
235 	struct pvc_device **pvc_p = &state(hdlc)->first_pvc;
236 
237 	while (*pvc_p) {
238 		if (!pvc_is_used(*pvc_p)) {
239 			struct pvc_device *pvc = *pvc_p;
240 #ifdef DEBUG_PVC
241 			printk(KERN_DEBUG "freeing unused pvc: %p\n", pvc);
242 #endif
243 			*pvc_p = pvc->next;
244 			kfree(pvc);
245 			continue;
246 		}
247 		pvc_p = &(*pvc_p)->next;
248 	}
249 }
250 
251 static inline struct net_device **get_dev_p(struct pvc_device *pvc,
252 					    int type)
253 {
254 	if (type == ARPHRD_ETHER)
255 		return &pvc->ether;
256 	else
257 		return &pvc->main;
258 }
259 
260 static int fr_hard_header(struct sk_buff *skb, u16 dlci)
261 {
262 	if (!skb->dev) { /* Control packets */
263 		switch (dlci) {
264 		case LMI_CCITT_ANSI_DLCI:
265 			skb_push(skb, 4);
266 			skb->data[3] = NLPID_CCITT_ANSI_LMI;
267 			break;
268 
269 		case LMI_CISCO_DLCI:
270 			skb_push(skb, 4);
271 			skb->data[3] = NLPID_CISCO_LMI;
272 			break;
273 
274 		default:
275 			return -EINVAL;
276 		}
277 
278 	} else if (skb->dev->type == ARPHRD_DLCI) {
279 		switch (skb->protocol) {
280 		case htons(ETH_P_IP):
281 			skb_push(skb, 4);
282 			skb->data[3] = NLPID_IP;
283 			break;
284 
285 		case htons(ETH_P_IPV6):
286 			skb_push(skb, 4);
287 			skb->data[3] = NLPID_IPV6;
288 			break;
289 
290 		default:
291 			skb_push(skb, 10);
292 			skb->data[3] = FR_PAD;
293 			skb->data[4] = NLPID_SNAP;
294 			/* OUI 00-00-00 indicates an Ethertype follows */
295 			skb->data[5] = 0x00;
296 			skb->data[6] = 0x00;
297 			skb->data[7] = 0x00;
298 			/* This should be an Ethertype: */
299 			*(__be16 *)(skb->data + 8) = skb->protocol;
300 		}
301 
302 	} else if (skb->dev->type == ARPHRD_ETHER) {
303 		skb_push(skb, 10);
304 		skb->data[3] = FR_PAD;
305 		skb->data[4] = NLPID_SNAP;
306 		/* OUI 00-80-C2 stands for the 802.1 organization */
307 		skb->data[5] = 0x00;
308 		skb->data[6] = 0x80;
309 		skb->data[7] = 0xC2;
310 		/* PID 00-07 stands for Ethernet frames without FCS */
311 		skb->data[8] = 0x00;
312 		skb->data[9] = 0x07;
313 
314 	} else {
315 		return -EINVAL;
316 	}
317 
318 	dlci_to_q922(skb->data, dlci);
319 	skb->data[2] = FR_UI;
320 	return 0;
321 }
322 
323 static int pvc_open(struct net_device *dev)
324 {
325 	struct pvc_device *pvc = dev->ml_priv;
326 
327 	if ((pvc->frad->flags & IFF_UP) == 0)
328 		return -EIO;  /* Frad must be UP in order to activate PVC */
329 
330 	if (pvc->open_count++ == 0) {
331 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
332 
333 		if (state(hdlc)->settings.lmi == LMI_NONE)
334 			pvc->state.active = netif_carrier_ok(pvc->frad);
335 
336 		pvc_carrier(pvc->state.active, pvc);
337 		state(hdlc)->dce_changed = 1;
338 	}
339 	return 0;
340 }
341 
342 static int pvc_close(struct net_device *dev)
343 {
344 	struct pvc_device *pvc = dev->ml_priv;
345 
346 	if (--pvc->open_count == 0) {
347 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
348 
349 		if (state(hdlc)->settings.lmi == LMI_NONE)
350 			pvc->state.active = 0;
351 
352 		if (state(hdlc)->settings.dce) {
353 			state(hdlc)->dce_changed = 1;
354 			pvc->state.active = 0;
355 		}
356 	}
357 	return 0;
358 }
359 
360 static int pvc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
361 {
362 	struct pvc_device *pvc = dev->ml_priv;
363 	fr_proto_pvc_info info;
364 
365 	if (ifr->ifr_settings.type == IF_GET_PROTO) {
366 		if (dev->type == ARPHRD_ETHER)
367 			ifr->ifr_settings.type = IF_PROTO_FR_ETH_PVC;
368 		else
369 			ifr->ifr_settings.type = IF_PROTO_FR_PVC;
370 
371 		if (ifr->ifr_settings.size < sizeof(info)) {
372 			/* data size wanted */
373 			ifr->ifr_settings.size = sizeof(info);
374 			return -ENOBUFS;
375 		}
376 
377 		info.dlci = pvc->dlci;
378 		memcpy(info.master, pvc->frad->name, IFNAMSIZ);
379 		if (copy_to_user(ifr->ifr_settings.ifs_ifsu.fr_pvc_info,
380 				 &info, sizeof(info)))
381 			return -EFAULT;
382 		return 0;
383 	}
384 
385 	return -EINVAL;
386 }
387 
388 static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev)
389 {
390 	struct pvc_device *pvc = dev->ml_priv;
391 
392 	if (!pvc->state.active)
393 		goto drop;
394 
395 	if (dev->type == ARPHRD_ETHER) {
396 		int pad = ETH_ZLEN - skb->len;
397 
398 		if (pad > 0) { /* Pad the frame with zeros */
399 			if (__skb_pad(skb, pad, false))
400 				goto drop;
401 			skb_put(skb, pad);
402 		}
403 	}
404 
405 	/* We already requested the header space with dev->needed_headroom.
406 	 * So this is just a protection in case the upper layer didn't take
407 	 * dev->needed_headroom into consideration.
408 	 */
409 	if (skb_headroom(skb) < 10) {
410 		struct sk_buff *skb2 = skb_realloc_headroom(skb, 10);
411 
412 		if (!skb2)
413 			goto drop;
414 		dev_kfree_skb(skb);
415 		skb = skb2;
416 	}
417 
418 	skb->dev = dev;
419 	if (fr_hard_header(skb, pvc->dlci))
420 		goto drop;
421 
422 	dev->stats.tx_bytes += skb->len;
423 	dev->stats.tx_packets++;
424 	if (pvc->state.fecn) /* TX Congestion counter */
425 		dev->stats.tx_compressed++;
426 	skb->dev = pvc->frad;
427 	skb->protocol = htons(ETH_P_HDLC);
428 	skb_reset_network_header(skb);
429 	dev_queue_xmit(skb);
430 	return NETDEV_TX_OK;
431 
432 drop:
433 	dev->stats.tx_dropped++;
434 	kfree_skb(skb);
435 	return NETDEV_TX_OK;
436 }
437 
438 static inline void fr_log_dlci_active(struct pvc_device *pvc)
439 {
440 	netdev_info(pvc->frad, "DLCI %d [%s%s%s]%s %s\n",
441 		    pvc->dlci,
442 		    pvc->main ? pvc->main->name : "",
443 		    pvc->main && pvc->ether ? " " : "",
444 		    pvc->ether ? pvc->ether->name : "",
445 		    pvc->state.new ? " new" : "",
446 		    !pvc->state.exist ? "deleted" :
447 		    pvc->state.active ? "active" : "inactive");
448 }
449 
450 static inline u8 fr_lmi_nextseq(u8 x)
451 {
452 	x++;
453 	return x ? x : 1;
454 }
455 
456 static void fr_lmi_send(struct net_device *dev, int fullrep)
457 {
458 	hdlc_device *hdlc = dev_to_hdlc(dev);
459 	struct sk_buff *skb;
460 	struct pvc_device *pvc = state(hdlc)->first_pvc;
461 	int lmi = state(hdlc)->settings.lmi;
462 	int dce = state(hdlc)->settings.dce;
463 	int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
464 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
465 	u8 *data;
466 	int i = 0;
467 
468 	if (dce && fullrep) {
469 		len += state(hdlc)->dce_pvc_count * (2 + stat_len);
470 		if (len > HDLC_MAX_MRU) {
471 			netdev_warn(dev, "Too many PVCs while sending LMI full report\n");
472 			return;
473 		}
474 	}
475 
476 	skb = dev_alloc_skb(len);
477 	if (!skb)
478 		return;
479 
480 	memset(skb->data, 0, len);
481 	skb_reserve(skb, 4);
482 	if (lmi == LMI_CISCO)
483 		fr_hard_header(skb, LMI_CISCO_DLCI);
484 	else
485 		fr_hard_header(skb, LMI_CCITT_ANSI_DLCI);
486 
487 	data = skb_tail_pointer(skb);
488 	data[i++] = LMI_CALLREF;
489 	data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
490 	if (lmi == LMI_ANSI)
491 		data[i++] = LMI_ANSI_LOCKSHIFT;
492 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
493 		LMI_ANSI_CISCO_REPTYPE;
494 	data[i++] = LMI_REPT_LEN;
495 	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
496 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
497 	data[i++] = LMI_INTEG_LEN;
498 	data[i++] = state(hdlc)->txseq =
499 		fr_lmi_nextseq(state(hdlc)->txseq);
500 	data[i++] = state(hdlc)->rxseq;
501 
502 	if (dce && fullrep) {
503 		while (pvc) {
504 			data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
505 				LMI_ANSI_CISCO_PVCSTAT;
506 			data[i++] = stat_len;
507 
508 			/* LMI start/restart */
509 			if (state(hdlc)->reliable && !pvc->state.exist) {
510 				pvc->state.exist = pvc->state.new = 1;
511 				fr_log_dlci_active(pvc);
512 			}
513 
514 			/* ifconfig PVC up */
515 			if (pvc->open_count && !pvc->state.active &&
516 			    pvc->state.exist && !pvc->state.new) {
517 				pvc_carrier(1, pvc);
518 				pvc->state.active = 1;
519 				fr_log_dlci_active(pvc);
520 			}
521 
522 			if (lmi == LMI_CISCO) {
523 				data[i] = pvc->dlci >> 8;
524 				data[i + 1] = pvc->dlci & 0xFF;
525 			} else {
526 				data[i] = (pvc->dlci >> 4) & 0x3F;
527 				data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
528 				data[i + 2] = 0x80;
529 			}
530 
531 			if (pvc->state.new)
532 				data[i + 2] |= 0x08;
533 			else if (pvc->state.active)
534 				data[i + 2] |= 0x02;
535 
536 			i += stat_len;
537 			pvc = pvc->next;
538 		}
539 	}
540 
541 	skb_put(skb, i);
542 	skb->priority = TC_PRIO_CONTROL;
543 	skb->dev = dev;
544 	skb->protocol = htons(ETH_P_HDLC);
545 	skb_reset_network_header(skb);
546 
547 	dev_queue_xmit(skb);
548 }
549 
550 static void fr_set_link_state(int reliable, struct net_device *dev)
551 {
552 	hdlc_device *hdlc = dev_to_hdlc(dev);
553 	struct pvc_device *pvc = state(hdlc)->first_pvc;
554 
555 	state(hdlc)->reliable = reliable;
556 	if (reliable) {
557 		netif_dormant_off(dev);
558 		state(hdlc)->n391cnt = 0; /* Request full status */
559 		state(hdlc)->dce_changed = 1;
560 
561 		if (state(hdlc)->settings.lmi == LMI_NONE) {
562 			while (pvc) {	/* Activate all PVCs */
563 				pvc_carrier(1, pvc);
564 				pvc->state.exist = pvc->state.active = 1;
565 				pvc->state.new = 0;
566 				pvc = pvc->next;
567 			}
568 		}
569 	} else {
570 		netif_dormant_on(dev);
571 		while (pvc) {		/* Deactivate all PVCs */
572 			pvc_carrier(0, pvc);
573 			pvc->state.exist = pvc->state.active = 0;
574 			pvc->state.new = 0;
575 			if (!state(hdlc)->settings.dce)
576 				pvc->state.bandwidth = 0;
577 			pvc = pvc->next;
578 		}
579 	}
580 }
581 
582 static void fr_timer(struct timer_list *t)
583 {
584 	struct frad_state *st = from_timer(st, t, timer);
585 	struct net_device *dev = st->dev;
586 	hdlc_device *hdlc = dev_to_hdlc(dev);
587 	int i, cnt = 0, reliable;
588 	u32 list;
589 
590 	if (state(hdlc)->settings.dce) {
591 		reliable = state(hdlc)->request &&
592 			time_before(jiffies, state(hdlc)->last_poll +
593 				    state(hdlc)->settings.t392 * HZ);
594 		state(hdlc)->request = 0;
595 	} else {
596 		state(hdlc)->last_errors <<= 1; /* Shift the list */
597 		if (state(hdlc)->request) {
598 			if (state(hdlc)->reliable)
599 				netdev_info(dev, "No LMI status reply received\n");
600 			state(hdlc)->last_errors |= 1;
601 		}
602 
603 		list = state(hdlc)->last_errors;
604 		for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
605 			cnt += (list & 1);	/* errors count */
606 
607 		reliable = (cnt < state(hdlc)->settings.n392);
608 	}
609 
610 	if (state(hdlc)->reliable != reliable) {
611 		netdev_info(dev, "Link %sreliable\n", reliable ? "" : "un");
612 		fr_set_link_state(reliable, dev);
613 	}
614 
615 	if (state(hdlc)->settings.dce) {
616 		state(hdlc)->timer.expires = jiffies +
617 			state(hdlc)->settings.t392 * HZ;
618 	} else {
619 		if (state(hdlc)->n391cnt)
620 			state(hdlc)->n391cnt--;
621 
622 		fr_lmi_send(dev, state(hdlc)->n391cnt == 0);
623 
624 		state(hdlc)->last_poll = jiffies;
625 		state(hdlc)->request = 1;
626 		state(hdlc)->timer.expires = jiffies +
627 			state(hdlc)->settings.t391 * HZ;
628 	}
629 
630 	add_timer(&state(hdlc)->timer);
631 }
632 
633 static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
634 {
635 	hdlc_device *hdlc = dev_to_hdlc(dev);
636 	struct pvc_device *pvc;
637 	u8 rxseq, txseq;
638 	int lmi = state(hdlc)->settings.lmi;
639 	int dce = state(hdlc)->settings.dce;
640 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
641 
642 	if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
643 			LMI_CCITT_CISCO_LENGTH)) {
644 		netdev_info(dev, "Short LMI frame\n");
645 		return 1;
646 	}
647 
648 	if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
649 			     NLPID_CCITT_ANSI_LMI)) {
650 		netdev_info(dev, "Received non-LMI frame with LMI DLCI\n");
651 		return 1;
652 	}
653 
654 	if (skb->data[4] != LMI_CALLREF) {
655 		netdev_info(dev, "Invalid LMI Call reference (0x%02X)\n",
656 			    skb->data[4]);
657 		return 1;
658 	}
659 
660 	if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
661 		netdev_info(dev, "Invalid LMI Message type (0x%02X)\n",
662 			    skb->data[5]);
663 		return 1;
664 	}
665 
666 	if (lmi == LMI_ANSI) {
667 		if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
668 			netdev_info(dev, "Not ANSI locking shift in LMI message (0x%02X)\n",
669 				    skb->data[6]);
670 			return 1;
671 		}
672 		i = 7;
673 	} else {
674 		i = 6;
675 	}
676 
677 	if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
678 			     LMI_ANSI_CISCO_REPTYPE)) {
679 		netdev_info(dev, "Not an LMI Report type IE (0x%02X)\n",
680 			    skb->data[i]);
681 		return 1;
682 	}
683 
684 	if (skb->data[++i] != LMI_REPT_LEN) {
685 		netdev_info(dev, "Invalid LMI Report type IE length (%u)\n",
686 			    skb->data[i]);
687 		return 1;
688 	}
689 
690 	reptype = skb->data[++i];
691 	if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
692 		netdev_info(dev, "Unsupported LMI Report type (0x%02X)\n",
693 			    reptype);
694 		return 1;
695 	}
696 
697 	if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
698 			       LMI_ANSI_CISCO_ALIVE)) {
699 		netdev_info(dev, "Not an LMI Link integrity verification IE (0x%02X)\n",
700 			    skb->data[i]);
701 		return 1;
702 	}
703 
704 	if (skb->data[++i] != LMI_INTEG_LEN) {
705 		netdev_info(dev, "Invalid LMI Link integrity verification IE length (%u)\n",
706 			    skb->data[i]);
707 		return 1;
708 	}
709 	i++;
710 
711 	state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
712 	rxseq = skb->data[i++];	/* Should confirm our sequence */
713 
714 	txseq = state(hdlc)->txseq;
715 
716 	if (dce)
717 		state(hdlc)->last_poll = jiffies;
718 
719 	error = 0;
720 	if (!state(hdlc)->reliable)
721 		error = 1;
722 
723 	if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
724 		state(hdlc)->n391cnt = 0;
725 		error = 1;
726 	}
727 
728 	if (dce) {
729 		if (state(hdlc)->fullrep_sent && !error) {
730 /* Stop sending full report - the last one has been confirmed by DTE */
731 			state(hdlc)->fullrep_sent = 0;
732 			pvc = state(hdlc)->first_pvc;
733 			while (pvc) {
734 				if (pvc->state.new) {
735 					pvc->state.new = 0;
736 
737 /* Tell DTE that new PVC is now active */
738 					state(hdlc)->dce_changed = 1;
739 				}
740 				pvc = pvc->next;
741 			}
742 		}
743 
744 		if (state(hdlc)->dce_changed) {
745 			reptype = LMI_FULLREP;
746 			state(hdlc)->fullrep_sent = 1;
747 			state(hdlc)->dce_changed = 0;
748 		}
749 
750 		state(hdlc)->request = 1; /* got request */
751 		fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
752 		return 0;
753 	}
754 
755 	/* DTE */
756 
757 	state(hdlc)->request = 0; /* got response, no request pending */
758 
759 	if (error)
760 		return 0;
761 
762 	if (reptype != LMI_FULLREP)
763 		return 0;
764 
765 	pvc = state(hdlc)->first_pvc;
766 
767 	while (pvc) {
768 		pvc->state.deleted = 1;
769 		pvc = pvc->next;
770 	}
771 
772 	no_ram = 0;
773 	while (skb->len >= i + 2 + stat_len) {
774 		u16 dlci;
775 		u32 bw;
776 		unsigned int active, new;
777 
778 		if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
779 				       LMI_ANSI_CISCO_PVCSTAT)) {
780 			netdev_info(dev, "Not an LMI PVC status IE (0x%02X)\n",
781 				    skb->data[i]);
782 			return 1;
783 		}
784 
785 		if (skb->data[++i] != stat_len) {
786 			netdev_info(dev, "Invalid LMI PVC status IE length (%u)\n",
787 				    skb->data[i]);
788 			return 1;
789 		}
790 		i++;
791 
792 		new = !!(skb->data[i + 2] & 0x08);
793 		active = !!(skb->data[i + 2] & 0x02);
794 		if (lmi == LMI_CISCO) {
795 			dlci = (skb->data[i] << 8) | skb->data[i + 1];
796 			bw = (skb->data[i + 3] << 16) |
797 				(skb->data[i + 4] << 8) |
798 				(skb->data[i + 5]);
799 		} else {
800 			dlci = ((skb->data[i] & 0x3F) << 4) |
801 				((skb->data[i + 1] & 0x78) >> 3);
802 			bw = 0;
803 		}
804 
805 		pvc = add_pvc(dev, dlci);
806 
807 		if (!pvc && !no_ram) {
808 			netdev_warn(dev, "Memory squeeze on fr_lmi_recv()\n");
809 			no_ram = 1;
810 		}
811 
812 		if (pvc) {
813 			pvc->state.exist = 1;
814 			pvc->state.deleted = 0;
815 			if (active != pvc->state.active ||
816 			    new != pvc->state.new ||
817 			    bw != pvc->state.bandwidth ||
818 			    !pvc->state.exist) {
819 				pvc->state.new = new;
820 				pvc->state.active = active;
821 				pvc->state.bandwidth = bw;
822 				pvc_carrier(active, pvc);
823 				fr_log_dlci_active(pvc);
824 			}
825 		}
826 
827 		i += stat_len;
828 	}
829 
830 	pvc = state(hdlc)->first_pvc;
831 
832 	while (pvc) {
833 		if (pvc->state.deleted && pvc->state.exist) {
834 			pvc_carrier(0, pvc);
835 			pvc->state.active = pvc->state.new = 0;
836 			pvc->state.exist = 0;
837 			pvc->state.bandwidth = 0;
838 			fr_log_dlci_active(pvc);
839 		}
840 		pvc = pvc->next;
841 	}
842 
843 	/* Next full report after N391 polls */
844 	state(hdlc)->n391cnt = state(hdlc)->settings.n391;
845 
846 	return 0;
847 }
848 
849 static int fr_snap_parse(struct sk_buff *skb, struct pvc_device *pvc)
850 {
851 	/* OUI 00-00-00 indicates an Ethertype follows */
852 	if (skb->data[0] == 0x00 &&
853 	    skb->data[1] == 0x00 &&
854 	    skb->data[2] == 0x00) {
855 		if (!pvc->main)
856 			return -1;
857 		skb->dev = pvc->main;
858 		skb->protocol = *(__be16 *)(skb->data + 3); /* Ethertype */
859 		skb_pull(skb, 5);
860 		skb_reset_mac_header(skb);
861 		return 0;
862 
863 	/* OUI 00-80-C2 stands for the 802.1 organization */
864 	} else if (skb->data[0] == 0x00 &&
865 		   skb->data[1] == 0x80 &&
866 		   skb->data[2] == 0xC2) {
867 		/* PID 00-07 stands for Ethernet frames without FCS */
868 		if (skb->data[3] == 0x00 &&
869 		    skb->data[4] == 0x07) {
870 			if (!pvc->ether)
871 				return -1;
872 			skb_pull(skb, 5);
873 			if (skb->len < ETH_HLEN)
874 				return -1;
875 			skb->protocol = eth_type_trans(skb, pvc->ether);
876 			return 0;
877 
878 		/* PID unsupported */
879 		} else {
880 			return -1;
881 		}
882 
883 	/* OUI unsupported */
884 	} else {
885 		return -1;
886 	}
887 }
888 
889 static int fr_rx(struct sk_buff *skb)
890 {
891 	struct net_device *frad = skb->dev;
892 	hdlc_device *hdlc = dev_to_hdlc(frad);
893 	struct fr_hdr *fh = (struct fr_hdr *)skb->data;
894 	u8 *data = skb->data;
895 	u16 dlci;
896 	struct pvc_device *pvc;
897 	struct net_device *dev;
898 
899 	if (skb->len < 4 || fh->ea1 || !fh->ea2 || data[2] != FR_UI)
900 		goto rx_error;
901 
902 	dlci = q922_to_dlci(skb->data);
903 
904 	if ((dlci == LMI_CCITT_ANSI_DLCI &&
905 	     (state(hdlc)->settings.lmi == LMI_ANSI ||
906 	      state(hdlc)->settings.lmi == LMI_CCITT)) ||
907 	    (dlci == LMI_CISCO_DLCI &&
908 	     state(hdlc)->settings.lmi == LMI_CISCO)) {
909 		if (fr_lmi_recv(frad, skb))
910 			goto rx_error;
911 		dev_kfree_skb_any(skb);
912 		return NET_RX_SUCCESS;
913 	}
914 
915 	pvc = find_pvc(hdlc, dlci);
916 	if (!pvc) {
917 #ifdef DEBUG_PKT
918 		netdev_info(frad, "No PVC for received frame's DLCI %d\n",
919 			    dlci);
920 #endif
921 		goto 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 	skb = skb_share_check(skb, GFP_ATOMIC);
941 	if (!skb) {
942 		frad->stats.rx_dropped++;
943 		return NET_RX_DROP;
944 	}
945 
946 	if (data[3] == NLPID_IP) {
947 		if (!pvc->main)
948 			goto rx_drop;
949 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
950 		skb->dev = pvc->main;
951 		skb->protocol = htons(ETH_P_IP);
952 		skb_reset_mac_header(skb);
953 
954 	} else if (data[3] == NLPID_IPV6) {
955 		if (!pvc->main)
956 			goto rx_drop;
957 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
958 		skb->dev = pvc->main;
959 		skb->protocol = htons(ETH_P_IPV6);
960 		skb_reset_mac_header(skb);
961 
962 	} else if (data[3] == FR_PAD) {
963 		if (skb->len < 5)
964 			goto rx_error;
965 		if (data[4] == NLPID_SNAP) { /* A SNAP header follows */
966 			skb_pull(skb, 5);
967 			if (skb->len < 5) /* Incomplete SNAP header */
968 				goto rx_error;
969 			if (fr_snap_parse(skb, pvc))
970 				goto rx_drop;
971 		} else {
972 			goto rx_drop;
973 		}
974 
975 	} else {
976 		netdev_info(frad, "Unsupported protocol, NLPID=%x length=%i\n",
977 			    data[3], skb->len);
978 		goto rx_drop;
979 	}
980 
981 	dev = skb->dev;
982 	dev->stats.rx_packets++; /* PVC traffic */
983 	dev->stats.rx_bytes += skb->len;
984 	if (pvc->state.becn)
985 		dev->stats.rx_compressed++;
986 	netif_rx(skb);
987 	return NET_RX_SUCCESS;
988 
989 rx_error:
990 	frad->stats.rx_errors++; /* Mark error */
991 rx_drop:
992 	dev_kfree_skb_any(skb);
993 	return NET_RX_DROP;
994 }
995 
996 static void fr_start(struct net_device *dev)
997 {
998 	hdlc_device *hdlc = dev_to_hdlc(dev);
999 #ifdef DEBUG_LINK
1000 	printk(KERN_DEBUG "fr_start\n");
1001 #endif
1002 	if (state(hdlc)->settings.lmi != LMI_NONE) {
1003 		state(hdlc)->reliable = 0;
1004 		state(hdlc)->dce_changed = 1;
1005 		state(hdlc)->request = 0;
1006 		state(hdlc)->fullrep_sent = 0;
1007 		state(hdlc)->last_errors = 0xFFFFFFFF;
1008 		state(hdlc)->n391cnt = 0;
1009 		state(hdlc)->txseq = state(hdlc)->rxseq = 0;
1010 
1011 		state(hdlc)->dev = dev;
1012 		timer_setup(&state(hdlc)->timer, fr_timer, 0);
1013 		/* First poll after 1 s */
1014 		state(hdlc)->timer.expires = jiffies + HZ;
1015 		add_timer(&state(hdlc)->timer);
1016 	} else {
1017 		fr_set_link_state(1, dev);
1018 	}
1019 }
1020 
1021 static void fr_stop(struct net_device *dev)
1022 {
1023 	hdlc_device *hdlc = dev_to_hdlc(dev);
1024 #ifdef DEBUG_LINK
1025 	printk(KERN_DEBUG "fr_stop\n");
1026 #endif
1027 	if (state(hdlc)->settings.lmi != LMI_NONE)
1028 		del_timer_sync(&state(hdlc)->timer);
1029 	fr_set_link_state(0, dev);
1030 }
1031 
1032 static void fr_close(struct net_device *dev)
1033 {
1034 	hdlc_device *hdlc = dev_to_hdlc(dev);
1035 	struct pvc_device *pvc = state(hdlc)->first_pvc;
1036 
1037 	while (pvc) {		/* Shutdown all PVCs for this FRAD */
1038 		if (pvc->main)
1039 			dev_close(pvc->main);
1040 		if (pvc->ether)
1041 			dev_close(pvc->ether);
1042 		pvc = pvc->next;
1043 	}
1044 }
1045 
1046 static void pvc_setup(struct net_device *dev)
1047 {
1048 	dev->type = ARPHRD_DLCI;
1049 	dev->flags = IFF_POINTOPOINT;
1050 	dev->hard_header_len = 0;
1051 	dev->addr_len = 2;
1052 	netif_keep_dst(dev);
1053 }
1054 
1055 static const struct net_device_ops pvc_ops = {
1056 	.ndo_open       = pvc_open,
1057 	.ndo_stop       = pvc_close,
1058 	.ndo_start_xmit = pvc_xmit,
1059 	.ndo_do_ioctl   = pvc_ioctl,
1060 };
1061 
1062 static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
1063 {
1064 	hdlc_device *hdlc = dev_to_hdlc(frad);
1065 	struct pvc_device *pvc;
1066 	struct net_device *dev;
1067 	int used;
1068 
1069 	pvc = add_pvc(frad, dlci);
1070 	if (!pvc) {
1071 		netdev_warn(frad, "Memory squeeze on fr_add_pvc()\n");
1072 		return -ENOBUFS;
1073 	}
1074 
1075 	if (*get_dev_p(pvc, type))
1076 		return -EEXIST;
1077 
1078 	used = pvc_is_used(pvc);
1079 
1080 	if (type == ARPHRD_ETHER)
1081 		dev = alloc_netdev(0, "pvceth%d", NET_NAME_UNKNOWN,
1082 				   ether_setup);
1083 	else
1084 		dev = alloc_netdev(0, "pvc%d", NET_NAME_UNKNOWN, pvc_setup);
1085 
1086 	if (!dev) {
1087 		netdev_warn(frad, "Memory squeeze on fr_pvc()\n");
1088 		delete_unused_pvcs(hdlc);
1089 		return -ENOBUFS;
1090 	}
1091 
1092 	if (type == ARPHRD_ETHER) {
1093 		dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1094 		eth_hw_addr_random(dev);
1095 	} else {
1096 		*(__be16 *)dev->dev_addr = htons(dlci);
1097 		dlci_to_q922(dev->broadcast, dlci);
1098 	}
1099 	dev->netdev_ops = &pvc_ops;
1100 	dev->mtu = HDLC_MAX_MTU;
1101 	dev->min_mtu = 68;
1102 	dev->max_mtu = HDLC_MAX_MTU;
1103 	dev->needed_headroom = 10;
1104 	dev->priv_flags |= IFF_NO_QUEUE;
1105 	dev->ml_priv = pvc;
1106 
1107 	if (register_netdevice(dev) != 0) {
1108 		free_netdev(dev);
1109 		delete_unused_pvcs(hdlc);
1110 		return -EIO;
1111 	}
1112 
1113 	dev->needs_free_netdev = true;
1114 	*get_dev_p(pvc, type) = dev;
1115 	if (!used) {
1116 		state(hdlc)->dce_changed = 1;
1117 		state(hdlc)->dce_pvc_count++;
1118 	}
1119 	return 0;
1120 }
1121 
1122 static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1123 {
1124 	struct pvc_device *pvc;
1125 	struct net_device *dev;
1126 
1127 	pvc = find_pvc(hdlc, dlci);
1128 	if (!pvc)
1129 		return -ENOENT;
1130 
1131 	dev = *get_dev_p(pvc, type);
1132 	if (!dev)
1133 		return -ENOENT;
1134 
1135 	if (dev->flags & IFF_UP)
1136 		return -EBUSY;		/* PVC in use */
1137 
1138 	unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1139 	*get_dev_p(pvc, type) = NULL;
1140 
1141 	if (!pvc_is_used(pvc)) {
1142 		state(hdlc)->dce_pvc_count--;
1143 		state(hdlc)->dce_changed = 1;
1144 	}
1145 	delete_unused_pvcs(hdlc);
1146 	return 0;
1147 }
1148 
1149 static void fr_destroy(struct net_device *frad)
1150 {
1151 	hdlc_device *hdlc = dev_to_hdlc(frad);
1152 	struct pvc_device *pvc = state(hdlc)->first_pvc;
1153 
1154 	state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1155 	state(hdlc)->dce_pvc_count = 0;
1156 	state(hdlc)->dce_changed = 1;
1157 
1158 	while (pvc) {
1159 		struct pvc_device *next = pvc->next;
1160 		/* destructors will free_netdev() main and ether */
1161 		if (pvc->main)
1162 			unregister_netdevice(pvc->main);
1163 
1164 		if (pvc->ether)
1165 			unregister_netdevice(pvc->ether);
1166 
1167 		kfree(pvc);
1168 		pvc = next;
1169 	}
1170 }
1171 
1172 static struct hdlc_proto proto = {
1173 	.close		= fr_close,
1174 	.start		= fr_start,
1175 	.stop		= fr_stop,
1176 	.detach		= fr_destroy,
1177 	.ioctl		= fr_ioctl,
1178 	.netif_rx	= fr_rx,
1179 	.module		= THIS_MODULE,
1180 };
1181 
1182 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr)
1183 {
1184 	fr_proto __user *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
1185 	const size_t size = sizeof(fr_proto);
1186 	fr_proto new_settings;
1187 	hdlc_device *hdlc = dev_to_hdlc(dev);
1188 	fr_proto_pvc pvc;
1189 	int result;
1190 
1191 	switch (ifr->ifr_settings.type) {
1192 	case IF_GET_PROTO:
1193 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1194 			return -EINVAL;
1195 		ifr->ifr_settings.type = IF_PROTO_FR;
1196 		if (ifr->ifr_settings.size < size) {
1197 			ifr->ifr_settings.size = size; /* data size wanted */
1198 			return -ENOBUFS;
1199 		}
1200 		if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1201 			return -EFAULT;
1202 		return 0;
1203 
1204 	case IF_PROTO_FR:
1205 		if (!capable(CAP_NET_ADMIN))
1206 			return -EPERM;
1207 
1208 		if (dev->flags & IFF_UP)
1209 			return -EBUSY;
1210 
1211 		if (copy_from_user(&new_settings, fr_s, size))
1212 			return -EFAULT;
1213 
1214 		if (new_settings.lmi == LMI_DEFAULT)
1215 			new_settings.lmi = LMI_ANSI;
1216 
1217 		if ((new_settings.lmi != LMI_NONE &&
1218 		     new_settings.lmi != LMI_ANSI &&
1219 		     new_settings.lmi != LMI_CCITT &&
1220 		     new_settings.lmi != LMI_CISCO) ||
1221 		    new_settings.t391 < 1 ||
1222 		    new_settings.t392 < 2 ||
1223 		    new_settings.n391 < 1 ||
1224 		    new_settings.n392 < 1 ||
1225 		    new_settings.n393 < new_settings.n392 ||
1226 		    new_settings.n393 > 32 ||
1227 		    (new_settings.dce != 0 &&
1228 		     new_settings.dce != 1))
1229 			return -EINVAL;
1230 
1231 		result = hdlc->attach(dev, ENCODING_NRZ,
1232 				      PARITY_CRC16_PR1_CCITT);
1233 		if (result)
1234 			return result;
1235 
1236 		if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1237 			result = attach_hdlc_protocol(dev, &proto,
1238 						      sizeof(struct frad_state));
1239 			if (result)
1240 				return result;
1241 			state(hdlc)->first_pvc = NULL;
1242 			state(hdlc)->dce_pvc_count = 0;
1243 		}
1244 		memcpy(&state(hdlc)->settings, &new_settings, size);
1245 		dev->type = ARPHRD_FRAD;
1246 		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
1247 		return 0;
1248 
1249 	case IF_PROTO_FR_ADD_PVC:
1250 	case IF_PROTO_FR_DEL_PVC:
1251 	case IF_PROTO_FR_ADD_ETH_PVC:
1252 	case IF_PROTO_FR_DEL_ETH_PVC:
1253 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1254 			return -EINVAL;
1255 
1256 		if (!capable(CAP_NET_ADMIN))
1257 			return -EPERM;
1258 
1259 		if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
1260 				   sizeof(fr_proto_pvc)))
1261 			return -EFAULT;
1262 
1263 		if (pvc.dlci <= 0 || pvc.dlci >= 1024)
1264 			return -EINVAL;	/* Only 10 bits, DLCI 0 reserved */
1265 
1266 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
1267 		    ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
1268 			result = ARPHRD_ETHER; /* bridged Ethernet device */
1269 		else
1270 			result = ARPHRD_DLCI;
1271 
1272 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
1273 		    ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
1274 			return fr_add_pvc(dev, pvc.dlci, result);
1275 		else
1276 			return fr_del_pvc(hdlc, pvc.dlci, result);
1277 	}
1278 
1279 	return -EINVAL;
1280 }
1281 
1282 static int __init mod_init(void)
1283 {
1284 	register_hdlc_protocol(&proto);
1285 	return 0;
1286 }
1287 
1288 static void __exit mod_exit(void)
1289 {
1290 	unregister_hdlc_protocol(&proto);
1291 }
1292 
1293 module_init(mod_init);
1294 module_exit(mod_exit);
1295 
1296 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
1297 MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
1298 MODULE_LICENSE("GPL v2");
1299