xref: /linux/drivers/net/wan/hdlc_fr.c (revision e7c22eeaff8565d9a8374f320238c251ca31480b)
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 
64 #define LMI_CCITT_ANSI_DLCI	   0 /* LMI DLCI */
65 #define LMI_CISCO_DLCI		1023
66 
67 #define LMI_CALLREF		0x00 /* Call Reference */
68 #define LMI_ANSI_LOCKSHIFT	0x95 /* ANSI locking shift */
69 #define LMI_ANSI_CISCO_REPTYPE	0x01 /* report type */
70 #define LMI_CCITT_REPTYPE	0x51
71 #define LMI_ANSI_CISCO_ALIVE	0x03 /* keep alive */
72 #define LMI_CCITT_ALIVE		0x53
73 #define LMI_ANSI_CISCO_PVCSTAT	0x07 /* PVC status */
74 #define LMI_CCITT_PVCSTAT	0x57
75 
76 #define LMI_FULLREP		0x00 /* full report  */
77 #define LMI_INTEGRITY		0x01 /* link integrity report */
78 #define LMI_SINGLE		0x02 /* single PVC report */
79 
80 #define LMI_STATUS_ENQUIRY      0x75
81 #define LMI_STATUS              0x7D /* reply */
82 
83 #define LMI_REPT_LEN               1 /* report type element length */
84 #define LMI_INTEG_LEN              2 /* link integrity element length */
85 
86 #define LMI_CCITT_CISCO_LENGTH	  13 /* LMI frame lengths */
87 #define LMI_ANSI_LENGTH		  14
88 
89 
90 struct fr_hdr {
91 #if defined(__LITTLE_ENDIAN_BITFIELD)
92 	unsigned ea1:	1;
93 	unsigned cr:	1;
94 	unsigned dlcih:	6;
95 
96 	unsigned ea2:	1;
97 	unsigned de:	1;
98 	unsigned becn:	1;
99 	unsigned fecn:	1;
100 	unsigned dlcil:	4;
101 #else
102 	unsigned dlcih:	6;
103 	unsigned cr:	1;
104 	unsigned ea1:	1;
105 
106 	unsigned dlcil:	4;
107 	unsigned fecn:	1;
108 	unsigned becn:	1;
109 	unsigned de:	1;
110 	unsigned ea2:	1;
111 #endif
112 } __packed;
113 
114 
115 struct pvc_device {
116 	struct net_device *frad;
117 	struct net_device *main;
118 	struct net_device *ether;	/* bridged Ethernet interface	*/
119 	struct pvc_device *next;	/* Sorted in ascending DLCI order */
120 	int dlci;
121 	int open_count;
122 
123 	struct {
124 		unsigned int new: 1;
125 		unsigned int active: 1;
126 		unsigned int exist: 1;
127 		unsigned int deleted: 1;
128 		unsigned int fecn: 1;
129 		unsigned int becn: 1;
130 		unsigned int bandwidth;	/* Cisco LMI reporting only */
131 	}state;
132 };
133 
134 struct frad_state {
135 	fr_proto settings;
136 	struct pvc_device *first_pvc;
137 	int dce_pvc_count;
138 
139 	struct timer_list timer;
140 	struct net_device *dev;
141 	unsigned long last_poll;
142 	int reliable;
143 	int dce_changed;
144 	int request;
145 	int fullrep_sent;
146 	u32 last_errors; /* last errors bit list */
147 	u8 n391cnt;
148 	u8 txseq; /* TX sequence number */
149 	u8 rxseq; /* RX sequence number */
150 };
151 
152 
153 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr);
154 
155 
156 static inline u16 q922_to_dlci(u8 *hdr)
157 {
158 	return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
159 }
160 
161 
162 static inline void dlci_to_q922(u8 *hdr, u16 dlci)
163 {
164 	hdr[0] = (dlci >> 2) & 0xFC;
165 	hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
166 }
167 
168 
169 static inline struct frad_state* state(hdlc_device *hdlc)
170 {
171 	return(struct frad_state *)(hdlc->state);
172 }
173 
174 
175 static inline struct pvc_device *find_pvc(hdlc_device *hdlc, u16 dlci)
176 {
177 	struct pvc_device *pvc = state(hdlc)->first_pvc;
178 
179 	while (pvc) {
180 		if (pvc->dlci == dlci)
181 			return pvc;
182 		if (pvc->dlci > dlci)
183 			return NULL; /* the list is sorted */
184 		pvc = pvc->next;
185 	}
186 
187 	return NULL;
188 }
189 
190 
191 static struct pvc_device *add_pvc(struct net_device *dev, u16 dlci)
192 {
193 	hdlc_device *hdlc = dev_to_hdlc(dev);
194 	struct pvc_device *pvc, **pvc_p = &state(hdlc)->first_pvc;
195 
196 	while (*pvc_p) {
197 		if ((*pvc_p)->dlci == dlci)
198 			return *pvc_p;
199 		if ((*pvc_p)->dlci > dlci)
200 			break;	/* the list is sorted */
201 		pvc_p = &(*pvc_p)->next;
202 	}
203 
204 	pvc = kzalloc(sizeof(*pvc), GFP_ATOMIC);
205 #ifdef DEBUG_PVC
206 	printk(KERN_DEBUG "add_pvc: allocated pvc %p, frad %p\n", pvc, dev);
207 #endif
208 	if (!pvc)
209 		return NULL;
210 
211 	pvc->dlci = dlci;
212 	pvc->frad = dev;
213 	pvc->next = *pvc_p;	/* Put it in the chain */
214 	*pvc_p = pvc;
215 	return pvc;
216 }
217 
218 
219 static inline int pvc_is_used(struct pvc_device *pvc)
220 {
221 	return pvc->main || pvc->ether;
222 }
223 
224 
225 static inline void pvc_carrier(int on, struct pvc_device *pvc)
226 {
227 	if (on) {
228 		if (pvc->main)
229 			if (!netif_carrier_ok(pvc->main))
230 				netif_carrier_on(pvc->main);
231 		if (pvc->ether)
232 			if (!netif_carrier_ok(pvc->ether))
233 				netif_carrier_on(pvc->ether);
234 	} else {
235 		if (pvc->main)
236 			if (netif_carrier_ok(pvc->main))
237 				netif_carrier_off(pvc->main);
238 		if (pvc->ether)
239 			if (netif_carrier_ok(pvc->ether))
240 				netif_carrier_off(pvc->ether);
241 	}
242 }
243 
244 
245 static inline void delete_unused_pvcs(hdlc_device *hdlc)
246 {
247 	struct pvc_device **pvc_p = &state(hdlc)->first_pvc;
248 
249 	while (*pvc_p) {
250 		if (!pvc_is_used(*pvc_p)) {
251 			struct pvc_device *pvc = *pvc_p;
252 #ifdef DEBUG_PVC
253 			printk(KERN_DEBUG "freeing unused pvc: %p\n", pvc);
254 #endif
255 			*pvc_p = pvc->next;
256 			kfree(pvc);
257 			continue;
258 		}
259 		pvc_p = &(*pvc_p)->next;
260 	}
261 }
262 
263 
264 static inline struct net_device **get_dev_p(struct pvc_device *pvc,
265 					    int type)
266 {
267 	if (type == ARPHRD_ETHER)
268 		return &pvc->ether;
269 	else
270 		return &pvc->main;
271 }
272 
273 
274 static int fr_hard_header(struct sk_buff *skb, u16 dlci)
275 {
276 	if (!skb->dev) { /* Control packets */
277 		switch (dlci) {
278 		case LMI_CCITT_ANSI_DLCI:
279 			skb_push(skb, 4);
280 			skb->data[3] = NLPID_CCITT_ANSI_LMI;
281 			break;
282 
283 		case LMI_CISCO_DLCI:
284 			skb_push(skb, 4);
285 			skb->data[3] = NLPID_CISCO_LMI;
286 			break;
287 
288 		default:
289 			return -EINVAL;
290 		}
291 
292 	} else if (skb->dev->type == ARPHRD_DLCI) {
293 		switch (skb->protocol) {
294 		case htons(ETH_P_IP):
295 			skb_push(skb, 4);
296 			skb->data[3] = NLPID_IP;
297 			break;
298 
299 		case htons(ETH_P_IPV6):
300 			skb_push(skb, 4);
301 			skb->data[3] = NLPID_IPV6;
302 			break;
303 
304 		default:
305 			skb_push(skb, 10);
306 			skb->data[3] = FR_PAD;
307 			skb->data[4] = NLPID_SNAP;
308 			/* OUI 00-00-00 indicates an Ethertype follows */
309 			skb->data[5] = 0x00;
310 			skb->data[6] = 0x00;
311 			skb->data[7] = 0x00;
312 			/* This should be an Ethertype: */
313 			*(__be16 *)(skb->data + 8) = skb->protocol;
314 		}
315 
316 	} else if (skb->dev->type == ARPHRD_ETHER) {
317 		skb_push(skb, 10);
318 		skb->data[3] = FR_PAD;
319 		skb->data[4] = NLPID_SNAP;
320 		/* OUI 00-80-C2 stands for the 802.1 organization */
321 		skb->data[5] = 0x00;
322 		skb->data[6] = 0x80;
323 		skb->data[7] = 0xC2;
324 		/* PID 00-07 stands for Ethernet frames without FCS */
325 		skb->data[8] = 0x00;
326 		skb->data[9] = 0x07;
327 
328 	} else {
329 		return -EINVAL;
330 	}
331 
332 	dlci_to_q922(skb->data, dlci);
333 	skb->data[2] = FR_UI;
334 	return 0;
335 }
336 
337 
338 
339 static int pvc_open(struct net_device *dev)
340 {
341 	struct pvc_device *pvc = dev->ml_priv;
342 
343 	if ((pvc->frad->flags & IFF_UP) == 0)
344 		return -EIO;  /* Frad must be UP in order to activate PVC */
345 
346 	if (pvc->open_count++ == 0) {
347 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
348 		if (state(hdlc)->settings.lmi == LMI_NONE)
349 			pvc->state.active = netif_carrier_ok(pvc->frad);
350 
351 		pvc_carrier(pvc->state.active, pvc);
352 		state(hdlc)->dce_changed = 1;
353 	}
354 	return 0;
355 }
356 
357 
358 
359 static int pvc_close(struct net_device *dev)
360 {
361 	struct pvc_device *pvc = dev->ml_priv;
362 
363 	if (--pvc->open_count == 0) {
364 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
365 		if (state(hdlc)->settings.lmi == LMI_NONE)
366 			pvc->state.active = 0;
367 
368 		if (state(hdlc)->settings.dce) {
369 			state(hdlc)->dce_changed = 1;
370 			pvc->state.active = 0;
371 		}
372 	}
373 	return 0;
374 }
375 
376 
377 
378 static int pvc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
379 {
380 	struct pvc_device *pvc = dev->ml_priv;
381 	fr_proto_pvc_info info;
382 
383 	if (ifr->ifr_settings.type == IF_GET_PROTO) {
384 		if (dev->type == ARPHRD_ETHER)
385 			ifr->ifr_settings.type = IF_PROTO_FR_ETH_PVC;
386 		else
387 			ifr->ifr_settings.type = IF_PROTO_FR_PVC;
388 
389 		if (ifr->ifr_settings.size < sizeof(info)) {
390 			/* data size wanted */
391 			ifr->ifr_settings.size = sizeof(info);
392 			return -ENOBUFS;
393 		}
394 
395 		info.dlci = pvc->dlci;
396 		memcpy(info.master, pvc->frad->name, IFNAMSIZ);
397 		if (copy_to_user(ifr->ifr_settings.ifs_ifsu.fr_pvc_info,
398 				 &info, sizeof(info)))
399 			return -EFAULT;
400 		return 0;
401 	}
402 
403 	return -EINVAL;
404 }
405 
406 static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev)
407 {
408 	struct pvc_device *pvc = dev->ml_priv;
409 
410 	if (!pvc->state.active)
411 		goto drop;
412 
413 	if (dev->type == ARPHRD_ETHER) {
414 		int pad = ETH_ZLEN - skb->len;
415 
416 		if (pad > 0) { /* Pad the frame with zeros */
417 			if (__skb_pad(skb, pad, false))
418 				goto drop;
419 			skb_put(skb, pad);
420 		}
421 	}
422 
423 	/* We already requested the header space with dev->needed_headroom.
424 	 * So this is just a protection in case the upper layer didn't take
425 	 * dev->needed_headroom into consideration.
426 	 */
427 	if (skb_headroom(skb) < 10) {
428 		struct sk_buff *skb2 = skb_realloc_headroom(skb, 10);
429 
430 		if (!skb2)
431 			goto drop;
432 		dev_kfree_skb(skb);
433 		skb = skb2;
434 	}
435 
436 	skb->dev = dev;
437 	if (fr_hard_header(skb, pvc->dlci))
438 		goto drop;
439 
440 	dev->stats.tx_bytes += skb->len;
441 	dev->stats.tx_packets++;
442 	if (pvc->state.fecn) /* TX Congestion counter */
443 		dev->stats.tx_compressed++;
444 	skb->dev = pvc->frad;
445 	skb->protocol = htons(ETH_P_HDLC);
446 	skb_reset_network_header(skb);
447 	dev_queue_xmit(skb);
448 	return NETDEV_TX_OK;
449 
450 drop:
451 	dev->stats.tx_dropped++;
452 	kfree_skb(skb);
453 	return NETDEV_TX_OK;
454 }
455 
456 static inline void fr_log_dlci_active(struct pvc_device *pvc)
457 {
458 	netdev_info(pvc->frad, "DLCI %d [%s%s%s]%s %s\n",
459 		    pvc->dlci,
460 		    pvc->main ? pvc->main->name : "",
461 		    pvc->main && pvc->ether ? " " : "",
462 		    pvc->ether ? pvc->ether->name : "",
463 		    pvc->state.new ? " new" : "",
464 		    !pvc->state.exist ? "deleted" :
465 		    pvc->state.active ? "active" : "inactive");
466 }
467 
468 
469 
470 static inline u8 fr_lmi_nextseq(u8 x)
471 {
472 	x++;
473 	return x ? x : 1;
474 }
475 
476 
477 static void fr_lmi_send(struct net_device *dev, int fullrep)
478 {
479 	hdlc_device *hdlc = dev_to_hdlc(dev);
480 	struct sk_buff *skb;
481 	struct pvc_device *pvc = state(hdlc)->first_pvc;
482 	int lmi = state(hdlc)->settings.lmi;
483 	int dce = state(hdlc)->settings.dce;
484 	int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
485 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
486 	u8 *data;
487 	int i = 0;
488 
489 	if (dce && fullrep) {
490 		len += state(hdlc)->dce_pvc_count * (2 + stat_len);
491 		if (len > HDLC_MAX_MRU) {
492 			netdev_warn(dev, "Too many PVCs while sending LMI full report\n");
493 			return;
494 		}
495 	}
496 
497 	skb = dev_alloc_skb(len);
498 	if (!skb) {
499 		netdev_warn(dev, "Memory squeeze on fr_lmi_send()\n");
500 		return;
501 	}
502 	memset(skb->data, 0, len);
503 	skb_reserve(skb, 4);
504 	if (lmi == LMI_CISCO) {
505 		fr_hard_header(skb, LMI_CISCO_DLCI);
506 	} else {
507 		fr_hard_header(skb, LMI_CCITT_ANSI_DLCI);
508 	}
509 	data = skb_tail_pointer(skb);
510 	data[i++] = LMI_CALLREF;
511 	data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
512 	if (lmi == LMI_ANSI)
513 		data[i++] = LMI_ANSI_LOCKSHIFT;
514 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
515 		LMI_ANSI_CISCO_REPTYPE;
516 	data[i++] = LMI_REPT_LEN;
517 	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
518 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
519 	data[i++] = LMI_INTEG_LEN;
520 	data[i++] = state(hdlc)->txseq =
521 		fr_lmi_nextseq(state(hdlc)->txseq);
522 	data[i++] = state(hdlc)->rxseq;
523 
524 	if (dce && fullrep) {
525 		while (pvc) {
526 			data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
527 				LMI_ANSI_CISCO_PVCSTAT;
528 			data[i++] = stat_len;
529 
530 			/* LMI start/restart */
531 			if (state(hdlc)->reliable && !pvc->state.exist) {
532 				pvc->state.exist = pvc->state.new = 1;
533 				fr_log_dlci_active(pvc);
534 			}
535 
536 			/* ifconfig PVC up */
537 			if (pvc->open_count && !pvc->state.active &&
538 			    pvc->state.exist && !pvc->state.new) {
539 				pvc_carrier(1, pvc);
540 				pvc->state.active = 1;
541 				fr_log_dlci_active(pvc);
542 			}
543 
544 			if (lmi == LMI_CISCO) {
545 				data[i] = pvc->dlci >> 8;
546 				data[i + 1] = pvc->dlci & 0xFF;
547 			} else {
548 				data[i] = (pvc->dlci >> 4) & 0x3F;
549 				data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
550 				data[i + 2] = 0x80;
551 			}
552 
553 			if (pvc->state.new)
554 				data[i + 2] |= 0x08;
555 			else if (pvc->state.active)
556 				data[i + 2] |= 0x02;
557 
558 			i += stat_len;
559 			pvc = pvc->next;
560 		}
561 	}
562 
563 	skb_put(skb, i);
564 	skb->priority = TC_PRIO_CONTROL;
565 	skb->dev = dev;
566 	skb->protocol = htons(ETH_P_HDLC);
567 	skb_reset_network_header(skb);
568 
569 	dev_queue_xmit(skb);
570 }
571 
572 
573 
574 static void fr_set_link_state(int reliable, struct net_device *dev)
575 {
576 	hdlc_device *hdlc = dev_to_hdlc(dev);
577 	struct pvc_device *pvc = state(hdlc)->first_pvc;
578 
579 	state(hdlc)->reliable = reliable;
580 	if (reliable) {
581 		netif_dormant_off(dev);
582 		state(hdlc)->n391cnt = 0; /* Request full status */
583 		state(hdlc)->dce_changed = 1;
584 
585 		if (state(hdlc)->settings.lmi == LMI_NONE) {
586 			while (pvc) {	/* Activate all PVCs */
587 				pvc_carrier(1, pvc);
588 				pvc->state.exist = pvc->state.active = 1;
589 				pvc->state.new = 0;
590 				pvc = pvc->next;
591 			}
592 		}
593 	} else {
594 		netif_dormant_on(dev);
595 		while (pvc) {		/* Deactivate all PVCs */
596 			pvc_carrier(0, pvc);
597 			pvc->state.exist = pvc->state.active = 0;
598 			pvc->state.new = 0;
599 			if (!state(hdlc)->settings.dce)
600 				pvc->state.bandwidth = 0;
601 			pvc = pvc->next;
602 		}
603 	}
604 }
605 
606 
607 static void fr_timer(struct timer_list *t)
608 {
609 	struct frad_state *st = from_timer(st, t, timer);
610 	struct net_device *dev = st->dev;
611 	hdlc_device *hdlc = dev_to_hdlc(dev);
612 	int i, cnt = 0, reliable;
613 	u32 list;
614 
615 	if (state(hdlc)->settings.dce) {
616 		reliable = state(hdlc)->request &&
617 			time_before(jiffies, state(hdlc)->last_poll +
618 				    state(hdlc)->settings.t392 * HZ);
619 		state(hdlc)->request = 0;
620 	} else {
621 		state(hdlc)->last_errors <<= 1; /* Shift the list */
622 		if (state(hdlc)->request) {
623 			if (state(hdlc)->reliable)
624 				netdev_info(dev, "No LMI status reply received\n");
625 			state(hdlc)->last_errors |= 1;
626 		}
627 
628 		list = state(hdlc)->last_errors;
629 		for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
630 			cnt += (list & 1);	/* errors count */
631 
632 		reliable = (cnt < state(hdlc)->settings.n392);
633 	}
634 
635 	if (state(hdlc)->reliable != reliable) {
636 		netdev_info(dev, "Link %sreliable\n", reliable ? "" : "un");
637 		fr_set_link_state(reliable, dev);
638 	}
639 
640 	if (state(hdlc)->settings.dce)
641 		state(hdlc)->timer.expires = jiffies +
642 			state(hdlc)->settings.t392 * HZ;
643 	else {
644 		if (state(hdlc)->n391cnt)
645 			state(hdlc)->n391cnt--;
646 
647 		fr_lmi_send(dev, state(hdlc)->n391cnt == 0);
648 
649 		state(hdlc)->last_poll = jiffies;
650 		state(hdlc)->request = 1;
651 		state(hdlc)->timer.expires = jiffies +
652 			state(hdlc)->settings.t391 * HZ;
653 	}
654 
655 	add_timer(&state(hdlc)->timer);
656 }
657 
658 
659 static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
660 {
661 	hdlc_device *hdlc = dev_to_hdlc(dev);
662 	struct pvc_device *pvc;
663 	u8 rxseq, txseq;
664 	int lmi = state(hdlc)->settings.lmi;
665 	int dce = state(hdlc)->settings.dce;
666 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
667 
668 	if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
669 			LMI_CCITT_CISCO_LENGTH)) {
670 		netdev_info(dev, "Short LMI frame\n");
671 		return 1;
672 	}
673 
674 	if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
675 			     NLPID_CCITT_ANSI_LMI)) {
676 		netdev_info(dev, "Received non-LMI frame with LMI DLCI\n");
677 		return 1;
678 	}
679 
680 	if (skb->data[4] != LMI_CALLREF) {
681 		netdev_info(dev, "Invalid LMI Call reference (0x%02X)\n",
682 			    skb->data[4]);
683 		return 1;
684 	}
685 
686 	if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
687 		netdev_info(dev, "Invalid LMI Message type (0x%02X)\n",
688 			    skb->data[5]);
689 		return 1;
690 	}
691 
692 	if (lmi == LMI_ANSI) {
693 		if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
694 			netdev_info(dev, "Not ANSI locking shift in LMI message (0x%02X)\n",
695 				    skb->data[6]);
696 			return 1;
697 		}
698 		i = 7;
699 	} else
700 		i = 6;
701 
702 	if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
703 			     LMI_ANSI_CISCO_REPTYPE)) {
704 		netdev_info(dev, "Not an LMI Report type IE (0x%02X)\n",
705 			    skb->data[i]);
706 		return 1;
707 	}
708 
709 	if (skb->data[++i] != LMI_REPT_LEN) {
710 		netdev_info(dev, "Invalid LMI Report type IE length (%u)\n",
711 			    skb->data[i]);
712 		return 1;
713 	}
714 
715 	reptype = skb->data[++i];
716 	if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
717 		netdev_info(dev, "Unsupported LMI Report type (0x%02X)\n",
718 			    reptype);
719 		return 1;
720 	}
721 
722 	if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
723 			       LMI_ANSI_CISCO_ALIVE)) {
724 		netdev_info(dev, "Not an LMI Link integrity verification IE (0x%02X)\n",
725 			    skb->data[i]);
726 		return 1;
727 	}
728 
729 	if (skb->data[++i] != LMI_INTEG_LEN) {
730 		netdev_info(dev, "Invalid LMI Link integrity verification IE length (%u)\n",
731 			    skb->data[i]);
732 		return 1;
733 	}
734 	i++;
735 
736 	state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
737 	rxseq = skb->data[i++];	/* Should confirm our sequence */
738 
739 	txseq = state(hdlc)->txseq;
740 
741 	if (dce)
742 		state(hdlc)->last_poll = jiffies;
743 
744 	error = 0;
745 	if (!state(hdlc)->reliable)
746 		error = 1;
747 
748 	if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
749 		state(hdlc)->n391cnt = 0;
750 		error = 1;
751 	}
752 
753 	if (dce) {
754 		if (state(hdlc)->fullrep_sent && !error) {
755 /* Stop sending full report - the last one has been confirmed by DTE */
756 			state(hdlc)->fullrep_sent = 0;
757 			pvc = state(hdlc)->first_pvc;
758 			while (pvc) {
759 				if (pvc->state.new) {
760 					pvc->state.new = 0;
761 
762 /* Tell DTE that new PVC is now active */
763 					state(hdlc)->dce_changed = 1;
764 				}
765 				pvc = pvc->next;
766 			}
767 		}
768 
769 		if (state(hdlc)->dce_changed) {
770 			reptype = LMI_FULLREP;
771 			state(hdlc)->fullrep_sent = 1;
772 			state(hdlc)->dce_changed = 0;
773 		}
774 
775 		state(hdlc)->request = 1; /* got request */
776 		fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
777 		return 0;
778 	}
779 
780 	/* DTE */
781 
782 	state(hdlc)->request = 0; /* got response, no request pending */
783 
784 	if (error)
785 		return 0;
786 
787 	if (reptype != LMI_FULLREP)
788 		return 0;
789 
790 	pvc = state(hdlc)->first_pvc;
791 
792 	while (pvc) {
793 		pvc->state.deleted = 1;
794 		pvc = pvc->next;
795 	}
796 
797 	no_ram = 0;
798 	while (skb->len >= i + 2 + stat_len) {
799 		u16 dlci;
800 		u32 bw;
801 		unsigned int active, new;
802 
803 		if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
804 				       LMI_ANSI_CISCO_PVCSTAT)) {
805 			netdev_info(dev, "Not an LMI PVC status IE (0x%02X)\n",
806 				    skb->data[i]);
807 			return 1;
808 		}
809 
810 		if (skb->data[++i] != stat_len) {
811 			netdev_info(dev, "Invalid LMI PVC status IE length (%u)\n",
812 				    skb->data[i]);
813 			return 1;
814 		}
815 		i++;
816 
817 		new = !! (skb->data[i + 2] & 0x08);
818 		active = !! (skb->data[i + 2] & 0x02);
819 		if (lmi == LMI_CISCO) {
820 			dlci = (skb->data[i] << 8) | skb->data[i + 1];
821 			bw = (skb->data[i + 3] << 16) |
822 				(skb->data[i + 4] << 8) |
823 				(skb->data[i + 5]);
824 		} else {
825 			dlci = ((skb->data[i] & 0x3F) << 4) |
826 				((skb->data[i + 1] & 0x78) >> 3);
827 			bw = 0;
828 		}
829 
830 		pvc = add_pvc(dev, dlci);
831 
832 		if (!pvc && !no_ram) {
833 			netdev_warn(dev, "Memory squeeze on fr_lmi_recv()\n");
834 			no_ram = 1;
835 		}
836 
837 		if (pvc) {
838 			pvc->state.exist = 1;
839 			pvc->state.deleted = 0;
840 			if (active != pvc->state.active ||
841 			    new != pvc->state.new ||
842 			    bw != pvc->state.bandwidth ||
843 			    !pvc->state.exist) {
844 				pvc->state.new = new;
845 				pvc->state.active = active;
846 				pvc->state.bandwidth = bw;
847 				pvc_carrier(active, pvc);
848 				fr_log_dlci_active(pvc);
849 			}
850 		}
851 
852 		i += stat_len;
853 	}
854 
855 	pvc = state(hdlc)->first_pvc;
856 
857 	while (pvc) {
858 		if (pvc->state.deleted && pvc->state.exist) {
859 			pvc_carrier(0, pvc);
860 			pvc->state.active = pvc->state.new = 0;
861 			pvc->state.exist = 0;
862 			pvc->state.bandwidth = 0;
863 			fr_log_dlci_active(pvc);
864 		}
865 		pvc = pvc->next;
866 	}
867 
868 	/* Next full report after N391 polls */
869 	state(hdlc)->n391cnt = state(hdlc)->settings.n391;
870 
871 	return 0;
872 }
873 
874 static int fr_snap_parse(struct sk_buff *skb, struct pvc_device *pvc)
875 {
876 	/* OUI 00-00-00 indicates an Ethertype follows */
877 	if (skb->data[0] == 0x00 &&
878 	    skb->data[1] == 0x00 &&
879 	    skb->data[2] == 0x00) {
880 		if (!pvc->main)
881 			return -1;
882 		skb->dev = pvc->main;
883 		skb->protocol = *(__be16 *)(skb->data + 3); /* Ethertype */
884 		skb_pull(skb, 5);
885 		skb_reset_mac_header(skb);
886 		return 0;
887 
888 	/* OUI 00-80-C2 stands for the 802.1 organization */
889 	} else if (skb->data[0] == 0x00 &&
890 		   skb->data[1] == 0x80 &&
891 		   skb->data[2] == 0xC2) {
892 		/* PID 00-07 stands for Ethernet frames without FCS */
893 		if (skb->data[3] == 0x00 &&
894 		    skb->data[4] == 0x07) {
895 			if (!pvc->ether)
896 				return -1;
897 			skb_pull(skb, 5);
898 			if (skb->len < ETH_HLEN)
899 				return -1;
900 			skb->protocol = eth_type_trans(skb, pvc->ether);
901 			return 0;
902 
903 		/* PID unsupported */
904 		} else {
905 			return -1;
906 		}
907 
908 	/* OUI unsupported */
909 	} else {
910 		return -1;
911 	}
912 }
913 
914 static int fr_rx(struct sk_buff *skb)
915 {
916 	struct net_device *frad = skb->dev;
917 	hdlc_device *hdlc = dev_to_hdlc(frad);
918 	struct fr_hdr *fh = (struct fr_hdr *)skb->data;
919 	u8 *data = skb->data;
920 	u16 dlci;
921 	struct pvc_device *pvc;
922 	struct net_device *dev;
923 
924 	if (skb->len < 4 || fh->ea1 || !fh->ea2 || data[2] != FR_UI)
925 		goto rx_error;
926 
927 	dlci = q922_to_dlci(skb->data);
928 
929 	if ((dlci == LMI_CCITT_ANSI_DLCI &&
930 	     (state(hdlc)->settings.lmi == LMI_ANSI ||
931 	      state(hdlc)->settings.lmi == LMI_CCITT)) ||
932 	    (dlci == LMI_CISCO_DLCI &&
933 	     state(hdlc)->settings.lmi == LMI_CISCO)) {
934 		if (fr_lmi_recv(frad, skb))
935 			goto rx_error;
936 		dev_kfree_skb_any(skb);
937 		return NET_RX_SUCCESS;
938 	}
939 
940 	pvc = find_pvc(hdlc, dlci);
941 	if (!pvc) {
942 #ifdef DEBUG_PKT
943 		netdev_info(frad, "No PVC for received frame's DLCI %d\n",
944 			    dlci);
945 #endif
946 		goto rx_drop;
947 	}
948 
949 	if (pvc->state.fecn != fh->fecn) {
950 #ifdef DEBUG_ECN
951 		printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", frad->name,
952 		       dlci, fh->fecn ? "N" : "FF");
953 #endif
954 		pvc->state.fecn ^= 1;
955 	}
956 
957 	if (pvc->state.becn != fh->becn) {
958 #ifdef DEBUG_ECN
959 		printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", frad->name,
960 		       dlci, fh->becn ? "N" : "FF");
961 #endif
962 		pvc->state.becn ^= 1;
963 	}
964 
965 
966 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
967 		frad->stats.rx_dropped++;
968 		return NET_RX_DROP;
969 	}
970 
971 	if (data[3] == NLPID_IP) {
972 		if (!pvc->main)
973 			goto rx_drop;
974 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
975 		skb->dev = pvc->main;
976 		skb->protocol = htons(ETH_P_IP);
977 		skb_reset_mac_header(skb);
978 
979 	} else if (data[3] == NLPID_IPV6) {
980 		if (!pvc->main)
981 			goto rx_drop;
982 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
983 		skb->dev = pvc->main;
984 		skb->protocol = htons(ETH_P_IPV6);
985 		skb_reset_mac_header(skb);
986 
987 	} else if (data[3] == FR_PAD) {
988 		if (skb->len < 5)
989 			goto rx_error;
990 		if (data[4] == NLPID_SNAP) { /* A SNAP header follows */
991 			skb_pull(skb, 5);
992 			if (skb->len < 5) /* Incomplete SNAP header */
993 				goto rx_error;
994 			if (fr_snap_parse(skb, pvc))
995 				goto rx_drop;
996 		} else {
997 			goto rx_drop;
998 		}
999 
1000 	} else {
1001 		netdev_info(frad, "Unsupported protocol, NLPID=%x length=%i\n",
1002 			    data[3], skb->len);
1003 		goto rx_drop;
1004 	}
1005 
1006 	dev = skb->dev;
1007 	dev->stats.rx_packets++; /* PVC traffic */
1008 	dev->stats.rx_bytes += skb->len;
1009 	if (pvc->state.becn)
1010 		dev->stats.rx_compressed++;
1011 	netif_rx(skb);
1012 	return NET_RX_SUCCESS;
1013 
1014 rx_error:
1015 	frad->stats.rx_errors++; /* Mark error */
1016 rx_drop:
1017 	dev_kfree_skb_any(skb);
1018 	return NET_RX_DROP;
1019 }
1020 
1021 
1022 
1023 static void fr_start(struct net_device *dev)
1024 {
1025 	hdlc_device *hdlc = dev_to_hdlc(dev);
1026 #ifdef DEBUG_LINK
1027 	printk(KERN_DEBUG "fr_start\n");
1028 #endif
1029 	if (state(hdlc)->settings.lmi != LMI_NONE) {
1030 		state(hdlc)->reliable = 0;
1031 		state(hdlc)->dce_changed = 1;
1032 		state(hdlc)->request = 0;
1033 		state(hdlc)->fullrep_sent = 0;
1034 		state(hdlc)->last_errors = 0xFFFFFFFF;
1035 		state(hdlc)->n391cnt = 0;
1036 		state(hdlc)->txseq = state(hdlc)->rxseq = 0;
1037 
1038 		state(hdlc)->dev = dev;
1039 		timer_setup(&state(hdlc)->timer, fr_timer, 0);
1040 		/* First poll after 1 s */
1041 		state(hdlc)->timer.expires = jiffies + HZ;
1042 		add_timer(&state(hdlc)->timer);
1043 	} else
1044 		fr_set_link_state(1, dev);
1045 }
1046 
1047 
1048 static void fr_stop(struct net_device *dev)
1049 {
1050 	hdlc_device *hdlc = dev_to_hdlc(dev);
1051 #ifdef DEBUG_LINK
1052 	printk(KERN_DEBUG "fr_stop\n");
1053 #endif
1054 	if (state(hdlc)->settings.lmi != LMI_NONE)
1055 		del_timer_sync(&state(hdlc)->timer);
1056 	fr_set_link_state(0, dev);
1057 }
1058 
1059 
1060 static void fr_close(struct net_device *dev)
1061 {
1062 	hdlc_device *hdlc = dev_to_hdlc(dev);
1063 	struct pvc_device *pvc = state(hdlc)->first_pvc;
1064 
1065 	while (pvc) {		/* Shutdown all PVCs for this FRAD */
1066 		if (pvc->main)
1067 			dev_close(pvc->main);
1068 		if (pvc->ether)
1069 			dev_close(pvc->ether);
1070 		pvc = pvc->next;
1071 	}
1072 }
1073 
1074 
1075 static void pvc_setup(struct net_device *dev)
1076 {
1077 	dev->type = ARPHRD_DLCI;
1078 	dev->flags = IFF_POINTOPOINT;
1079 	dev->hard_header_len = 0;
1080 	dev->addr_len = 2;
1081 	netif_keep_dst(dev);
1082 }
1083 
1084 static const struct net_device_ops pvc_ops = {
1085 	.ndo_open       = pvc_open,
1086 	.ndo_stop       = pvc_close,
1087 	.ndo_start_xmit = pvc_xmit,
1088 	.ndo_do_ioctl   = pvc_ioctl,
1089 };
1090 
1091 static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
1092 {
1093 	hdlc_device *hdlc = dev_to_hdlc(frad);
1094 	struct pvc_device *pvc;
1095 	struct net_device *dev;
1096 	int used;
1097 
1098 	if ((pvc = add_pvc(frad, dlci)) == NULL) {
1099 		netdev_warn(frad, "Memory squeeze on fr_add_pvc()\n");
1100 		return -ENOBUFS;
1101 	}
1102 
1103 	if (*get_dev_p(pvc, type))
1104 		return -EEXIST;
1105 
1106 	used = pvc_is_used(pvc);
1107 
1108 	if (type == ARPHRD_ETHER)
1109 		dev = alloc_netdev(0, "pvceth%d", NET_NAME_UNKNOWN,
1110 				   ether_setup);
1111 	else
1112 		dev = alloc_netdev(0, "pvc%d", NET_NAME_UNKNOWN, pvc_setup);
1113 
1114 	if (!dev) {
1115 		netdev_warn(frad, "Memory squeeze on fr_pvc()\n");
1116 		delete_unused_pvcs(hdlc);
1117 		return -ENOBUFS;
1118 	}
1119 
1120 	if (type == ARPHRD_ETHER) {
1121 		dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1122 		eth_hw_addr_random(dev);
1123 	} else {
1124 		*(__be16*)dev->dev_addr = htons(dlci);
1125 		dlci_to_q922(dev->broadcast, dlci);
1126 	}
1127 	dev->netdev_ops = &pvc_ops;
1128 	dev->mtu = HDLC_MAX_MTU;
1129 	dev->min_mtu = 68;
1130 	dev->max_mtu = HDLC_MAX_MTU;
1131 	dev->needed_headroom = 10;
1132 	dev->priv_flags |= IFF_NO_QUEUE;
1133 	dev->ml_priv = pvc;
1134 
1135 	if (register_netdevice(dev) != 0) {
1136 		free_netdev(dev);
1137 		delete_unused_pvcs(hdlc);
1138 		return -EIO;
1139 	}
1140 
1141 	dev->needs_free_netdev = true;
1142 	*get_dev_p(pvc, type) = dev;
1143 	if (!used) {
1144 		state(hdlc)->dce_changed = 1;
1145 		state(hdlc)->dce_pvc_count++;
1146 	}
1147 	return 0;
1148 }
1149 
1150 
1151 
1152 static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1153 {
1154 	struct pvc_device *pvc;
1155 	struct net_device *dev;
1156 
1157 	if ((pvc = find_pvc(hdlc, dlci)) == NULL)
1158 		return -ENOENT;
1159 
1160 	if ((dev = *get_dev_p(pvc, type)) == NULL)
1161 		return -ENOENT;
1162 
1163 	if (dev->flags & IFF_UP)
1164 		return -EBUSY;		/* PVC in use */
1165 
1166 	unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1167 	*get_dev_p(pvc, type) = NULL;
1168 
1169 	if (!pvc_is_used(pvc)) {
1170 		state(hdlc)->dce_pvc_count--;
1171 		state(hdlc)->dce_changed = 1;
1172 	}
1173 	delete_unused_pvcs(hdlc);
1174 	return 0;
1175 }
1176 
1177 
1178 
1179 static void fr_destroy(struct net_device *frad)
1180 {
1181 	hdlc_device *hdlc = dev_to_hdlc(frad);
1182 	struct pvc_device *pvc = state(hdlc)->first_pvc;
1183 	state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1184 	state(hdlc)->dce_pvc_count = 0;
1185 	state(hdlc)->dce_changed = 1;
1186 
1187 	while (pvc) {
1188 		struct pvc_device *next = pvc->next;
1189 		/* destructors will free_netdev() main and ether */
1190 		if (pvc->main)
1191 			unregister_netdevice(pvc->main);
1192 
1193 		if (pvc->ether)
1194 			unregister_netdevice(pvc->ether);
1195 
1196 		kfree(pvc);
1197 		pvc = next;
1198 	}
1199 }
1200 
1201 
1202 static struct hdlc_proto proto = {
1203 	.close		= fr_close,
1204 	.start		= fr_start,
1205 	.stop		= fr_stop,
1206 	.detach		= fr_destroy,
1207 	.ioctl		= fr_ioctl,
1208 	.netif_rx	= fr_rx,
1209 	.module		= THIS_MODULE,
1210 };
1211 
1212 
1213 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr)
1214 {
1215 	fr_proto __user *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
1216 	const size_t size = sizeof(fr_proto);
1217 	fr_proto new_settings;
1218 	hdlc_device *hdlc = dev_to_hdlc(dev);
1219 	fr_proto_pvc pvc;
1220 	int result;
1221 
1222 	switch (ifr->ifr_settings.type) {
1223 	case IF_GET_PROTO:
1224 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1225 			return -EINVAL;
1226 		ifr->ifr_settings.type = IF_PROTO_FR;
1227 		if (ifr->ifr_settings.size < size) {
1228 			ifr->ifr_settings.size = size; /* data size wanted */
1229 			return -ENOBUFS;
1230 		}
1231 		if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1232 			return -EFAULT;
1233 		return 0;
1234 
1235 	case IF_PROTO_FR:
1236 		if (!capable(CAP_NET_ADMIN))
1237 			return -EPERM;
1238 
1239 		if (dev->flags & IFF_UP)
1240 			return -EBUSY;
1241 
1242 		if (copy_from_user(&new_settings, fr_s, size))
1243 			return -EFAULT;
1244 
1245 		if (new_settings.lmi == LMI_DEFAULT)
1246 			new_settings.lmi = LMI_ANSI;
1247 
1248 		if ((new_settings.lmi != LMI_NONE &&
1249 		     new_settings.lmi != LMI_ANSI &&
1250 		     new_settings.lmi != LMI_CCITT &&
1251 		     new_settings.lmi != LMI_CISCO) ||
1252 		    new_settings.t391 < 1 ||
1253 		    new_settings.t392 < 2 ||
1254 		    new_settings.n391 < 1 ||
1255 		    new_settings.n392 < 1 ||
1256 		    new_settings.n393 < new_settings.n392 ||
1257 		    new_settings.n393 > 32 ||
1258 		    (new_settings.dce != 0 &&
1259 		     new_settings.dce != 1))
1260 			return -EINVAL;
1261 
1262 		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
1263 		if (result)
1264 			return result;
1265 
1266 		if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1267 			result = attach_hdlc_protocol(dev, &proto,
1268 						      sizeof(struct frad_state));
1269 			if (result)
1270 				return result;
1271 			state(hdlc)->first_pvc = NULL;
1272 			state(hdlc)->dce_pvc_count = 0;
1273 		}
1274 		memcpy(&state(hdlc)->settings, &new_settings, size);
1275 		dev->type = ARPHRD_FRAD;
1276 		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
1277 		return 0;
1278 
1279 	case IF_PROTO_FR_ADD_PVC:
1280 	case IF_PROTO_FR_DEL_PVC:
1281 	case IF_PROTO_FR_ADD_ETH_PVC:
1282 	case IF_PROTO_FR_DEL_ETH_PVC:
1283 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1284 			return -EINVAL;
1285 
1286 		if (!capable(CAP_NET_ADMIN))
1287 			return -EPERM;
1288 
1289 		if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
1290 				   sizeof(fr_proto_pvc)))
1291 			return -EFAULT;
1292 
1293 		if (pvc.dlci <= 0 || pvc.dlci >= 1024)
1294 			return -EINVAL;	/* Only 10 bits, DLCI 0 reserved */
1295 
1296 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
1297 		    ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
1298 			result = ARPHRD_ETHER; /* bridged Ethernet device */
1299 		else
1300 			result = ARPHRD_DLCI;
1301 
1302 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
1303 		    ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
1304 			return fr_add_pvc(dev, pvc.dlci, result);
1305 		else
1306 			return fr_del_pvc(hdlc, pvc.dlci, result);
1307 	}
1308 
1309 	return -EINVAL;
1310 }
1311 
1312 
1313 static int __init mod_init(void)
1314 {
1315 	register_hdlc_protocol(&proto);
1316 	return 0;
1317 }
1318 
1319 
1320 static void __exit mod_exit(void)
1321 {
1322 	unregister_hdlc_protocol(&proto);
1323 }
1324 
1325 
1326 module_init(mod_init);
1327 module_exit(mod_exit);
1328 
1329 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
1330 MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
1331 MODULE_LICENSE("GPL v2");
1332