xref: /linux/drivers/net/wan/hdlc_fr.c (revision 75a6faf617d107bdbc74d36ccf89f2280b96ac26)
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_p, u16 dlci)
275 {
276 	u16 head_len;
277 	struct sk_buff *skb = *skb_p;
278 
279 	switch (skb->protocol) {
280 	case cpu_to_be16(NLPID_CCITT_ANSI_LMI):
281 		head_len = 4;
282 		skb_push(skb, head_len);
283 		skb->data[3] = NLPID_CCITT_ANSI_LMI;
284 		break;
285 
286 	case cpu_to_be16(NLPID_CISCO_LMI):
287 		head_len = 4;
288 		skb_push(skb, head_len);
289 		skb->data[3] = NLPID_CISCO_LMI;
290 		break;
291 
292 	case cpu_to_be16(ETH_P_IP):
293 		head_len = 4;
294 		skb_push(skb, head_len);
295 		skb->data[3] = NLPID_IP;
296 		break;
297 
298 	case cpu_to_be16(ETH_P_IPV6):
299 		head_len = 4;
300 		skb_push(skb, head_len);
301 		skb->data[3] = NLPID_IPV6;
302 		break;
303 
304 	case cpu_to_be16(ETH_P_802_3):
305 		head_len = 10;
306 		if (skb_headroom(skb) < head_len) {
307 			struct sk_buff *skb2 = skb_realloc_headroom(skb,
308 								    head_len);
309 			if (!skb2)
310 				return -ENOBUFS;
311 			dev_kfree_skb(skb);
312 			skb = *skb_p = skb2;
313 		}
314 		skb_push(skb, head_len);
315 		skb->data[3] = FR_PAD;
316 		skb->data[4] = NLPID_SNAP;
317 		skb->data[5] = FR_PAD;
318 		skb->data[6] = 0x80;
319 		skb->data[7] = 0xC2;
320 		skb->data[8] = 0x00;
321 		skb->data[9] = 0x07; /* bridged Ethernet frame w/out FCS */
322 		break;
323 
324 	default:
325 		head_len = 10;
326 		skb_push(skb, head_len);
327 		skb->data[3] = FR_PAD;
328 		skb->data[4] = NLPID_SNAP;
329 		skb->data[5] = FR_PAD;
330 		skb->data[6] = FR_PAD;
331 		skb->data[7] = FR_PAD;
332 		*(__be16*)(skb->data + 8) = skb->protocol;
333 	}
334 
335 	dlci_to_q922(skb->data, dlci);
336 	skb->data[2] = FR_UI;
337 	return 0;
338 }
339 
340 
341 
342 static int pvc_open(struct net_device *dev)
343 {
344 	struct pvc_device *pvc = dev->ml_priv;
345 
346 	if ((pvc->frad->flags & IFF_UP) == 0)
347 		return -EIO;  /* Frad must be UP in order to activate PVC */
348 
349 	if (pvc->open_count++ == 0) {
350 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
351 		if (state(hdlc)->settings.lmi == LMI_NONE)
352 			pvc->state.active = netif_carrier_ok(pvc->frad);
353 
354 		pvc_carrier(pvc->state.active, pvc);
355 		state(hdlc)->dce_changed = 1;
356 	}
357 	return 0;
358 }
359 
360 
361 
362 static int pvc_close(struct net_device *dev)
363 {
364 	struct pvc_device *pvc = dev->ml_priv;
365 
366 	if (--pvc->open_count == 0) {
367 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
368 		if (state(hdlc)->settings.lmi == LMI_NONE)
369 			pvc->state.active = 0;
370 
371 		if (state(hdlc)->settings.dce) {
372 			state(hdlc)->dce_changed = 1;
373 			pvc->state.active = 0;
374 		}
375 	}
376 	return 0;
377 }
378 
379 
380 
381 static int pvc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
382 {
383 	struct pvc_device *pvc = dev->ml_priv;
384 	fr_proto_pvc_info info;
385 
386 	if (ifr->ifr_settings.type == IF_GET_PROTO) {
387 		if (dev->type == ARPHRD_ETHER)
388 			ifr->ifr_settings.type = IF_PROTO_FR_ETH_PVC;
389 		else
390 			ifr->ifr_settings.type = IF_PROTO_FR_PVC;
391 
392 		if (ifr->ifr_settings.size < sizeof(info)) {
393 			/* data size wanted */
394 			ifr->ifr_settings.size = sizeof(info);
395 			return -ENOBUFS;
396 		}
397 
398 		info.dlci = pvc->dlci;
399 		memcpy(info.master, pvc->frad->name, IFNAMSIZ);
400 		if (copy_to_user(ifr->ifr_settings.ifs_ifsu.fr_pvc_info,
401 				 &info, sizeof(info)))
402 			return -EFAULT;
403 		return 0;
404 	}
405 
406 	return -EINVAL;
407 }
408 
409 static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev)
410 {
411 	struct pvc_device *pvc = dev->ml_priv;
412 
413 	if (pvc->state.active) {
414 		if (dev->type == ARPHRD_ETHER) {
415 			int pad = ETH_ZLEN - skb->len;
416 			if (pad > 0) { /* Pad the frame with zeros */
417 				int len = skb->len;
418 				if (skb_tailroom(skb) < pad)
419 					if (pskb_expand_head(skb, 0, pad,
420 							     GFP_ATOMIC)) {
421 						dev->stats.tx_dropped++;
422 						dev_kfree_skb(skb);
423 						return NETDEV_TX_OK;
424 					}
425 				skb_put(skb, pad);
426 				memset(skb->data + len, 0, pad);
427 			}
428 			skb->protocol = cpu_to_be16(ETH_P_802_3);
429 		}
430 		if (!fr_hard_header(&skb, pvc->dlci)) {
431 			dev->stats.tx_bytes += skb->len;
432 			dev->stats.tx_packets++;
433 			if (pvc->state.fecn) /* TX Congestion counter */
434 				dev->stats.tx_compressed++;
435 			skb->dev = pvc->frad;
436 			dev_queue_xmit(skb);
437 			return NETDEV_TX_OK;
438 		}
439 	}
440 
441 	dev->stats.tx_dropped++;
442 	dev_kfree_skb(skb);
443 	return NETDEV_TX_OK;
444 }
445 
446 static inline void fr_log_dlci_active(struct pvc_device *pvc)
447 {
448 	netdev_info(pvc->frad, "DLCI %d [%s%s%s]%s %s\n",
449 		    pvc->dlci,
450 		    pvc->main ? pvc->main->name : "",
451 		    pvc->main && pvc->ether ? " " : "",
452 		    pvc->ether ? pvc->ether->name : "",
453 		    pvc->state.new ? " new" : "",
454 		    !pvc->state.exist ? "deleted" :
455 		    pvc->state.active ? "active" : "inactive");
456 }
457 
458 
459 
460 static inline u8 fr_lmi_nextseq(u8 x)
461 {
462 	x++;
463 	return x ? x : 1;
464 }
465 
466 
467 static void fr_lmi_send(struct net_device *dev, int fullrep)
468 {
469 	hdlc_device *hdlc = dev_to_hdlc(dev);
470 	struct sk_buff *skb;
471 	struct pvc_device *pvc = state(hdlc)->first_pvc;
472 	int lmi = state(hdlc)->settings.lmi;
473 	int dce = state(hdlc)->settings.dce;
474 	int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
475 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
476 	u8 *data;
477 	int i = 0;
478 
479 	if (dce && fullrep) {
480 		len += state(hdlc)->dce_pvc_count * (2 + stat_len);
481 		if (len > HDLC_MAX_MRU) {
482 			netdev_warn(dev, "Too many PVCs while sending LMI full report\n");
483 			return;
484 		}
485 	}
486 
487 	skb = dev_alloc_skb(len);
488 	if (!skb) {
489 		netdev_warn(dev, "Memory squeeze on fr_lmi_send()\n");
490 		return;
491 	}
492 	memset(skb->data, 0, len);
493 	skb_reserve(skb, 4);
494 	if (lmi == LMI_CISCO) {
495 		skb->protocol = cpu_to_be16(NLPID_CISCO_LMI);
496 		fr_hard_header(&skb, LMI_CISCO_DLCI);
497 	} else {
498 		skb->protocol = cpu_to_be16(NLPID_CCITT_ANSI_LMI);
499 		fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI);
500 	}
501 	data = skb_tail_pointer(skb);
502 	data[i++] = LMI_CALLREF;
503 	data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
504 	if (lmi == LMI_ANSI)
505 		data[i++] = LMI_ANSI_LOCKSHIFT;
506 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
507 		LMI_ANSI_CISCO_REPTYPE;
508 	data[i++] = LMI_REPT_LEN;
509 	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
510 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
511 	data[i++] = LMI_INTEG_LEN;
512 	data[i++] = state(hdlc)->txseq =
513 		fr_lmi_nextseq(state(hdlc)->txseq);
514 	data[i++] = state(hdlc)->rxseq;
515 
516 	if (dce && fullrep) {
517 		while (pvc) {
518 			data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
519 				LMI_ANSI_CISCO_PVCSTAT;
520 			data[i++] = stat_len;
521 
522 			/* LMI start/restart */
523 			if (state(hdlc)->reliable && !pvc->state.exist) {
524 				pvc->state.exist = pvc->state.new = 1;
525 				fr_log_dlci_active(pvc);
526 			}
527 
528 			/* ifconfig PVC up */
529 			if (pvc->open_count && !pvc->state.active &&
530 			    pvc->state.exist && !pvc->state.new) {
531 				pvc_carrier(1, pvc);
532 				pvc->state.active = 1;
533 				fr_log_dlci_active(pvc);
534 			}
535 
536 			if (lmi == LMI_CISCO) {
537 				data[i] = pvc->dlci >> 8;
538 				data[i + 1] = pvc->dlci & 0xFF;
539 			} else {
540 				data[i] = (pvc->dlci >> 4) & 0x3F;
541 				data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
542 				data[i + 2] = 0x80;
543 			}
544 
545 			if (pvc->state.new)
546 				data[i + 2] |= 0x08;
547 			else if (pvc->state.active)
548 				data[i + 2] |= 0x02;
549 
550 			i += stat_len;
551 			pvc = pvc->next;
552 		}
553 	}
554 
555 	skb_put(skb, i);
556 	skb->priority = TC_PRIO_CONTROL;
557 	skb->dev = dev;
558 	skb_reset_network_header(skb);
559 
560 	dev_queue_xmit(skb);
561 }
562 
563 
564 
565 static void fr_set_link_state(int reliable, struct net_device *dev)
566 {
567 	hdlc_device *hdlc = dev_to_hdlc(dev);
568 	struct pvc_device *pvc = state(hdlc)->first_pvc;
569 
570 	state(hdlc)->reliable = reliable;
571 	if (reliable) {
572 		netif_dormant_off(dev);
573 		state(hdlc)->n391cnt = 0; /* Request full status */
574 		state(hdlc)->dce_changed = 1;
575 
576 		if (state(hdlc)->settings.lmi == LMI_NONE) {
577 			while (pvc) {	/* Activate all PVCs */
578 				pvc_carrier(1, pvc);
579 				pvc->state.exist = pvc->state.active = 1;
580 				pvc->state.new = 0;
581 				pvc = pvc->next;
582 			}
583 		}
584 	} else {
585 		netif_dormant_on(dev);
586 		while (pvc) {		/* Deactivate all PVCs */
587 			pvc_carrier(0, pvc);
588 			pvc->state.exist = pvc->state.active = 0;
589 			pvc->state.new = 0;
590 			if (!state(hdlc)->settings.dce)
591 				pvc->state.bandwidth = 0;
592 			pvc = pvc->next;
593 		}
594 	}
595 }
596 
597 
598 static void fr_timer(struct timer_list *t)
599 {
600 	struct frad_state *st = from_timer(st, t, timer);
601 	struct net_device *dev = st->dev;
602 	hdlc_device *hdlc = dev_to_hdlc(dev);
603 	int i, cnt = 0, reliable;
604 	u32 list;
605 
606 	if (state(hdlc)->settings.dce) {
607 		reliable = state(hdlc)->request &&
608 			time_before(jiffies, state(hdlc)->last_poll +
609 				    state(hdlc)->settings.t392 * HZ);
610 		state(hdlc)->request = 0;
611 	} else {
612 		state(hdlc)->last_errors <<= 1; /* Shift the list */
613 		if (state(hdlc)->request) {
614 			if (state(hdlc)->reliable)
615 				netdev_info(dev, "No LMI status reply received\n");
616 			state(hdlc)->last_errors |= 1;
617 		}
618 
619 		list = state(hdlc)->last_errors;
620 		for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
621 			cnt += (list & 1);	/* errors count */
622 
623 		reliable = (cnt < state(hdlc)->settings.n392);
624 	}
625 
626 	if (state(hdlc)->reliable != reliable) {
627 		netdev_info(dev, "Link %sreliable\n", reliable ? "" : "un");
628 		fr_set_link_state(reliable, dev);
629 	}
630 
631 	if (state(hdlc)->settings.dce)
632 		state(hdlc)->timer.expires = jiffies +
633 			state(hdlc)->settings.t392 * HZ;
634 	else {
635 		if (state(hdlc)->n391cnt)
636 			state(hdlc)->n391cnt--;
637 
638 		fr_lmi_send(dev, state(hdlc)->n391cnt == 0);
639 
640 		state(hdlc)->last_poll = jiffies;
641 		state(hdlc)->request = 1;
642 		state(hdlc)->timer.expires = jiffies +
643 			state(hdlc)->settings.t391 * HZ;
644 	}
645 
646 	add_timer(&state(hdlc)->timer);
647 }
648 
649 
650 static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
651 {
652 	hdlc_device *hdlc = dev_to_hdlc(dev);
653 	struct pvc_device *pvc;
654 	u8 rxseq, txseq;
655 	int lmi = state(hdlc)->settings.lmi;
656 	int dce = state(hdlc)->settings.dce;
657 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
658 
659 	if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
660 			LMI_CCITT_CISCO_LENGTH)) {
661 		netdev_info(dev, "Short LMI frame\n");
662 		return 1;
663 	}
664 
665 	if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
666 			     NLPID_CCITT_ANSI_LMI)) {
667 		netdev_info(dev, "Received non-LMI frame with LMI DLCI\n");
668 		return 1;
669 	}
670 
671 	if (skb->data[4] != LMI_CALLREF) {
672 		netdev_info(dev, "Invalid LMI Call reference (0x%02X)\n",
673 			    skb->data[4]);
674 		return 1;
675 	}
676 
677 	if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
678 		netdev_info(dev, "Invalid LMI Message type (0x%02X)\n",
679 			    skb->data[5]);
680 		return 1;
681 	}
682 
683 	if (lmi == LMI_ANSI) {
684 		if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
685 			netdev_info(dev, "Not ANSI locking shift in LMI message (0x%02X)\n",
686 				    skb->data[6]);
687 			return 1;
688 		}
689 		i = 7;
690 	} else
691 		i = 6;
692 
693 	if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
694 			     LMI_ANSI_CISCO_REPTYPE)) {
695 		netdev_info(dev, "Not an LMI Report type IE (0x%02X)\n",
696 			    skb->data[i]);
697 		return 1;
698 	}
699 
700 	if (skb->data[++i] != LMI_REPT_LEN) {
701 		netdev_info(dev, "Invalid LMI Report type IE length (%u)\n",
702 			    skb->data[i]);
703 		return 1;
704 	}
705 
706 	reptype = skb->data[++i];
707 	if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
708 		netdev_info(dev, "Unsupported LMI Report type (0x%02X)\n",
709 			    reptype);
710 		return 1;
711 	}
712 
713 	if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
714 			       LMI_ANSI_CISCO_ALIVE)) {
715 		netdev_info(dev, "Not an LMI Link integrity verification IE (0x%02X)\n",
716 			    skb->data[i]);
717 		return 1;
718 	}
719 
720 	if (skb->data[++i] != LMI_INTEG_LEN) {
721 		netdev_info(dev, "Invalid LMI Link integrity verification IE length (%u)\n",
722 			    skb->data[i]);
723 		return 1;
724 	}
725 	i++;
726 
727 	state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
728 	rxseq = skb->data[i++];	/* Should confirm our sequence */
729 
730 	txseq = state(hdlc)->txseq;
731 
732 	if (dce)
733 		state(hdlc)->last_poll = jiffies;
734 
735 	error = 0;
736 	if (!state(hdlc)->reliable)
737 		error = 1;
738 
739 	if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
740 		state(hdlc)->n391cnt = 0;
741 		error = 1;
742 	}
743 
744 	if (dce) {
745 		if (state(hdlc)->fullrep_sent && !error) {
746 /* Stop sending full report - the last one has been confirmed by DTE */
747 			state(hdlc)->fullrep_sent = 0;
748 			pvc = state(hdlc)->first_pvc;
749 			while (pvc) {
750 				if (pvc->state.new) {
751 					pvc->state.new = 0;
752 
753 /* Tell DTE that new PVC is now active */
754 					state(hdlc)->dce_changed = 1;
755 				}
756 				pvc = pvc->next;
757 			}
758 		}
759 
760 		if (state(hdlc)->dce_changed) {
761 			reptype = LMI_FULLREP;
762 			state(hdlc)->fullrep_sent = 1;
763 			state(hdlc)->dce_changed = 0;
764 		}
765 
766 		state(hdlc)->request = 1; /* got request */
767 		fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
768 		return 0;
769 	}
770 
771 	/* DTE */
772 
773 	state(hdlc)->request = 0; /* got response, no request pending */
774 
775 	if (error)
776 		return 0;
777 
778 	if (reptype != LMI_FULLREP)
779 		return 0;
780 
781 	pvc = state(hdlc)->first_pvc;
782 
783 	while (pvc) {
784 		pvc->state.deleted = 1;
785 		pvc = pvc->next;
786 	}
787 
788 	no_ram = 0;
789 	while (skb->len >= i + 2 + stat_len) {
790 		u16 dlci;
791 		u32 bw;
792 		unsigned int active, new;
793 
794 		if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
795 				       LMI_ANSI_CISCO_PVCSTAT)) {
796 			netdev_info(dev, "Not an LMI PVC status IE (0x%02X)\n",
797 				    skb->data[i]);
798 			return 1;
799 		}
800 
801 		if (skb->data[++i] != stat_len) {
802 			netdev_info(dev, "Invalid LMI PVC status IE length (%u)\n",
803 				    skb->data[i]);
804 			return 1;
805 		}
806 		i++;
807 
808 		new = !! (skb->data[i + 2] & 0x08);
809 		active = !! (skb->data[i + 2] & 0x02);
810 		if (lmi == LMI_CISCO) {
811 			dlci = (skb->data[i] << 8) | skb->data[i + 1];
812 			bw = (skb->data[i + 3] << 16) |
813 				(skb->data[i + 4] << 8) |
814 				(skb->data[i + 5]);
815 		} else {
816 			dlci = ((skb->data[i] & 0x3F) << 4) |
817 				((skb->data[i + 1] & 0x78) >> 3);
818 			bw = 0;
819 		}
820 
821 		pvc = add_pvc(dev, dlci);
822 
823 		if (!pvc && !no_ram) {
824 			netdev_warn(dev, "Memory squeeze on fr_lmi_recv()\n");
825 			no_ram = 1;
826 		}
827 
828 		if (pvc) {
829 			pvc->state.exist = 1;
830 			pvc->state.deleted = 0;
831 			if (active != pvc->state.active ||
832 			    new != pvc->state.new ||
833 			    bw != pvc->state.bandwidth ||
834 			    !pvc->state.exist) {
835 				pvc->state.new = new;
836 				pvc->state.active = active;
837 				pvc->state.bandwidth = bw;
838 				pvc_carrier(active, pvc);
839 				fr_log_dlci_active(pvc);
840 			}
841 		}
842 
843 		i += stat_len;
844 	}
845 
846 	pvc = state(hdlc)->first_pvc;
847 
848 	while (pvc) {
849 		if (pvc->state.deleted && pvc->state.exist) {
850 			pvc_carrier(0, pvc);
851 			pvc->state.active = pvc->state.new = 0;
852 			pvc->state.exist = 0;
853 			pvc->state.bandwidth = 0;
854 			fr_log_dlci_active(pvc);
855 		}
856 		pvc = pvc->next;
857 	}
858 
859 	/* Next full report after N391 polls */
860 	state(hdlc)->n391cnt = state(hdlc)->settings.n391;
861 
862 	return 0;
863 }
864 
865 
866 static int fr_rx(struct sk_buff *skb)
867 {
868 	struct net_device *frad = skb->dev;
869 	hdlc_device *hdlc = dev_to_hdlc(frad);
870 	struct fr_hdr *fh = (struct fr_hdr *)skb->data;
871 	u8 *data = skb->data;
872 	u16 dlci;
873 	struct pvc_device *pvc;
874 	struct net_device *dev = NULL;
875 
876 	if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI)
877 		goto rx_error;
878 
879 	dlci = q922_to_dlci(skb->data);
880 
881 	if ((dlci == LMI_CCITT_ANSI_DLCI &&
882 	     (state(hdlc)->settings.lmi == LMI_ANSI ||
883 	      state(hdlc)->settings.lmi == LMI_CCITT)) ||
884 	    (dlci == LMI_CISCO_DLCI &&
885 	     state(hdlc)->settings.lmi == LMI_CISCO)) {
886 		if (fr_lmi_recv(frad, skb))
887 			goto rx_error;
888 		dev_kfree_skb_any(skb);
889 		return NET_RX_SUCCESS;
890 	}
891 
892 	pvc = find_pvc(hdlc, dlci);
893 	if (!pvc) {
894 #ifdef DEBUG_PKT
895 		netdev_info(frad, "No PVC for received frame's DLCI %d\n",
896 			    dlci);
897 #endif
898 		dev_kfree_skb_any(skb);
899 		return NET_RX_DROP;
900 	}
901 
902 	if (pvc->state.fecn != fh->fecn) {
903 #ifdef DEBUG_ECN
904 		printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", frad->name,
905 		       dlci, fh->fecn ? "N" : "FF");
906 #endif
907 		pvc->state.fecn ^= 1;
908 	}
909 
910 	if (pvc->state.becn != fh->becn) {
911 #ifdef DEBUG_ECN
912 		printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", frad->name,
913 		       dlci, fh->becn ? "N" : "FF");
914 #endif
915 		pvc->state.becn ^= 1;
916 	}
917 
918 
919 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
920 		frad->stats.rx_dropped++;
921 		return NET_RX_DROP;
922 	}
923 
924 	if (data[3] == NLPID_IP) {
925 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
926 		dev = pvc->main;
927 		skb->protocol = htons(ETH_P_IP);
928 
929 	} else if (data[3] == NLPID_IPV6) {
930 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
931 		dev = pvc->main;
932 		skb->protocol = htons(ETH_P_IPV6);
933 
934 	} else if (skb->len > 10 && data[3] == FR_PAD &&
935 		   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
936 		u16 oui = ntohs(*(__be16*)(data + 6));
937 		u16 pid = ntohs(*(__be16*)(data + 8));
938 		skb_pull(skb, 10);
939 
940 		switch ((((u32)oui) << 16) | pid) {
941 		case ETH_P_ARP: /* routed frame with SNAP */
942 		case ETH_P_IPX:
943 		case ETH_P_IP:	/* a long variant */
944 		case ETH_P_IPV6:
945 			dev = pvc->main;
946 			skb->protocol = htons(pid);
947 			break;
948 
949 		case 0x80C20007: /* bridged Ethernet frame */
950 			if ((dev = pvc->ether) != NULL)
951 				skb->protocol = eth_type_trans(skb, dev);
952 			break;
953 
954 		default:
955 			netdev_info(frad, "Unsupported protocol, OUI=%x PID=%x\n",
956 				    oui, pid);
957 			dev_kfree_skb_any(skb);
958 			return NET_RX_DROP;
959 		}
960 	} else {
961 		netdev_info(frad, "Unsupported protocol, NLPID=%x length=%i\n",
962 			    data[3], skb->len);
963 		dev_kfree_skb_any(skb);
964 		return NET_RX_DROP;
965 	}
966 
967 	if (dev) {
968 		dev->stats.rx_packets++; /* PVC traffic */
969 		dev->stats.rx_bytes += skb->len;
970 		if (pvc->state.becn)
971 			dev->stats.rx_compressed++;
972 		skb->dev = dev;
973 		netif_rx(skb);
974 		return NET_RX_SUCCESS;
975 	} else {
976 		dev_kfree_skb_any(skb);
977 		return NET_RX_DROP;
978 	}
979 
980  rx_error:
981 	frad->stats.rx_errors++; /* Mark error */
982 	dev_kfree_skb_any(skb);
983 	return NET_RX_DROP;
984 }
985 
986 
987 
988 static void fr_start(struct net_device *dev)
989 {
990 	hdlc_device *hdlc = dev_to_hdlc(dev);
991 #ifdef DEBUG_LINK
992 	printk(KERN_DEBUG "fr_start\n");
993 #endif
994 	if (state(hdlc)->settings.lmi != LMI_NONE) {
995 		state(hdlc)->reliable = 0;
996 		state(hdlc)->dce_changed = 1;
997 		state(hdlc)->request = 0;
998 		state(hdlc)->fullrep_sent = 0;
999 		state(hdlc)->last_errors = 0xFFFFFFFF;
1000 		state(hdlc)->n391cnt = 0;
1001 		state(hdlc)->txseq = state(hdlc)->rxseq = 0;
1002 
1003 		state(hdlc)->dev = dev;
1004 		timer_setup(&state(hdlc)->timer, fr_timer, 0);
1005 		/* First poll after 1 s */
1006 		state(hdlc)->timer.expires = jiffies + HZ;
1007 		add_timer(&state(hdlc)->timer);
1008 	} else
1009 		fr_set_link_state(1, dev);
1010 }
1011 
1012 
1013 static void fr_stop(struct net_device *dev)
1014 {
1015 	hdlc_device *hdlc = dev_to_hdlc(dev);
1016 #ifdef DEBUG_LINK
1017 	printk(KERN_DEBUG "fr_stop\n");
1018 #endif
1019 	if (state(hdlc)->settings.lmi != LMI_NONE)
1020 		del_timer_sync(&state(hdlc)->timer);
1021 	fr_set_link_state(0, dev);
1022 }
1023 
1024 
1025 static void fr_close(struct net_device *dev)
1026 {
1027 	hdlc_device *hdlc = dev_to_hdlc(dev);
1028 	struct pvc_device *pvc = state(hdlc)->first_pvc;
1029 
1030 	while (pvc) {		/* Shutdown all PVCs for this FRAD */
1031 		if (pvc->main)
1032 			dev_close(pvc->main);
1033 		if (pvc->ether)
1034 			dev_close(pvc->ether);
1035 		pvc = pvc->next;
1036 	}
1037 }
1038 
1039 
1040 static void pvc_setup(struct net_device *dev)
1041 {
1042 	dev->type = ARPHRD_DLCI;
1043 	dev->flags = IFF_POINTOPOINT;
1044 	dev->hard_header_len = 10;
1045 	dev->addr_len = 2;
1046 	netif_keep_dst(dev);
1047 }
1048 
1049 static const struct net_device_ops pvc_ops = {
1050 	.ndo_open       = pvc_open,
1051 	.ndo_stop       = pvc_close,
1052 	.ndo_start_xmit = pvc_xmit,
1053 	.ndo_do_ioctl   = pvc_ioctl,
1054 };
1055 
1056 static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
1057 {
1058 	hdlc_device *hdlc = dev_to_hdlc(frad);
1059 	struct pvc_device *pvc;
1060 	struct net_device *dev;
1061 	int used;
1062 
1063 	if ((pvc = add_pvc(frad, dlci)) == NULL) {
1064 		netdev_warn(frad, "Memory squeeze on fr_add_pvc()\n");
1065 		return -ENOBUFS;
1066 	}
1067 
1068 	if (*get_dev_p(pvc, type))
1069 		return -EEXIST;
1070 
1071 	used = pvc_is_used(pvc);
1072 
1073 	if (type == ARPHRD_ETHER)
1074 		dev = alloc_netdev(0, "pvceth%d", NET_NAME_UNKNOWN,
1075 				   ether_setup);
1076 	else
1077 		dev = alloc_netdev(0, "pvc%d", NET_NAME_UNKNOWN, pvc_setup);
1078 
1079 	if (!dev) {
1080 		netdev_warn(frad, "Memory squeeze on fr_pvc()\n");
1081 		delete_unused_pvcs(hdlc);
1082 		return -ENOBUFS;
1083 	}
1084 
1085 	if (type == ARPHRD_ETHER) {
1086 		dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1087 		eth_hw_addr_random(dev);
1088 	} else {
1089 		*(__be16*)dev->dev_addr = htons(dlci);
1090 		dlci_to_q922(dev->broadcast, dlci);
1091 	}
1092 	dev->netdev_ops = &pvc_ops;
1093 	dev->mtu = HDLC_MAX_MTU;
1094 	dev->min_mtu = 68;
1095 	dev->max_mtu = HDLC_MAX_MTU;
1096 	dev->priv_flags |= IFF_NO_QUEUE;
1097 	dev->ml_priv = pvc;
1098 
1099 	if (register_netdevice(dev) != 0) {
1100 		free_netdev(dev);
1101 		delete_unused_pvcs(hdlc);
1102 		return -EIO;
1103 	}
1104 
1105 	dev->needs_free_netdev = true;
1106 	*get_dev_p(pvc, type) = dev;
1107 	if (!used) {
1108 		state(hdlc)->dce_changed = 1;
1109 		state(hdlc)->dce_pvc_count++;
1110 	}
1111 	return 0;
1112 }
1113 
1114 
1115 
1116 static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1117 {
1118 	struct pvc_device *pvc;
1119 	struct net_device *dev;
1120 
1121 	if ((pvc = find_pvc(hdlc, dlci)) == NULL)
1122 		return -ENOENT;
1123 
1124 	if ((dev = *get_dev_p(pvc, type)) == NULL)
1125 		return -ENOENT;
1126 
1127 	if (dev->flags & IFF_UP)
1128 		return -EBUSY;		/* PVC in use */
1129 
1130 	unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1131 	*get_dev_p(pvc, type) = NULL;
1132 
1133 	if (!pvc_is_used(pvc)) {
1134 		state(hdlc)->dce_pvc_count--;
1135 		state(hdlc)->dce_changed = 1;
1136 	}
1137 	delete_unused_pvcs(hdlc);
1138 	return 0;
1139 }
1140 
1141 
1142 
1143 static void fr_destroy(struct net_device *frad)
1144 {
1145 	hdlc_device *hdlc = dev_to_hdlc(frad);
1146 	struct pvc_device *pvc = state(hdlc)->first_pvc;
1147 	state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1148 	state(hdlc)->dce_pvc_count = 0;
1149 	state(hdlc)->dce_changed = 1;
1150 
1151 	while (pvc) {
1152 		struct pvc_device *next = pvc->next;
1153 		/* destructors will free_netdev() main and ether */
1154 		if (pvc->main)
1155 			unregister_netdevice(pvc->main);
1156 
1157 		if (pvc->ether)
1158 			unregister_netdevice(pvc->ether);
1159 
1160 		kfree(pvc);
1161 		pvc = next;
1162 	}
1163 }
1164 
1165 
1166 static struct hdlc_proto proto = {
1167 	.close		= fr_close,
1168 	.start		= fr_start,
1169 	.stop		= fr_stop,
1170 	.detach		= fr_destroy,
1171 	.ioctl		= fr_ioctl,
1172 	.netif_rx	= fr_rx,
1173 	.module		= THIS_MODULE,
1174 };
1175 
1176 
1177 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr)
1178 {
1179 	fr_proto __user *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
1180 	const size_t size = sizeof(fr_proto);
1181 	fr_proto new_settings;
1182 	hdlc_device *hdlc = dev_to_hdlc(dev);
1183 	fr_proto_pvc pvc;
1184 	int result;
1185 
1186 	switch (ifr->ifr_settings.type) {
1187 	case IF_GET_PROTO:
1188 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1189 			return -EINVAL;
1190 		ifr->ifr_settings.type = IF_PROTO_FR;
1191 		if (ifr->ifr_settings.size < size) {
1192 			ifr->ifr_settings.size = size; /* data size wanted */
1193 			return -ENOBUFS;
1194 		}
1195 		if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1196 			return -EFAULT;
1197 		return 0;
1198 
1199 	case IF_PROTO_FR:
1200 		if (!capable(CAP_NET_ADMIN))
1201 			return -EPERM;
1202 
1203 		if (dev->flags & IFF_UP)
1204 			return -EBUSY;
1205 
1206 		if (copy_from_user(&new_settings, fr_s, size))
1207 			return -EFAULT;
1208 
1209 		if (new_settings.lmi == LMI_DEFAULT)
1210 			new_settings.lmi = LMI_ANSI;
1211 
1212 		if ((new_settings.lmi != LMI_NONE &&
1213 		     new_settings.lmi != LMI_ANSI &&
1214 		     new_settings.lmi != LMI_CCITT &&
1215 		     new_settings.lmi != LMI_CISCO) ||
1216 		    new_settings.t391 < 1 ||
1217 		    new_settings.t392 < 2 ||
1218 		    new_settings.n391 < 1 ||
1219 		    new_settings.n392 < 1 ||
1220 		    new_settings.n393 < new_settings.n392 ||
1221 		    new_settings.n393 > 32 ||
1222 		    (new_settings.dce != 0 &&
1223 		     new_settings.dce != 1))
1224 			return -EINVAL;
1225 
1226 		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
1227 		if (result)
1228 			return result;
1229 
1230 		if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1231 			result = attach_hdlc_protocol(dev, &proto,
1232 						      sizeof(struct frad_state));
1233 			if (result)
1234 				return result;
1235 			state(hdlc)->first_pvc = NULL;
1236 			state(hdlc)->dce_pvc_count = 0;
1237 		}
1238 		memcpy(&state(hdlc)->settings, &new_settings, size);
1239 		dev->type = ARPHRD_FRAD;
1240 		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
1241 		return 0;
1242 
1243 	case IF_PROTO_FR_ADD_PVC:
1244 	case IF_PROTO_FR_DEL_PVC:
1245 	case IF_PROTO_FR_ADD_ETH_PVC:
1246 	case IF_PROTO_FR_DEL_ETH_PVC:
1247 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1248 			return -EINVAL;
1249 
1250 		if (!capable(CAP_NET_ADMIN))
1251 			return -EPERM;
1252 
1253 		if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
1254 				   sizeof(fr_proto_pvc)))
1255 			return -EFAULT;
1256 
1257 		if (pvc.dlci <= 0 || pvc.dlci >= 1024)
1258 			return -EINVAL;	/* Only 10 bits, DLCI 0 reserved */
1259 
1260 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
1261 		    ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
1262 			result = ARPHRD_ETHER; /* bridged Ethernet device */
1263 		else
1264 			result = ARPHRD_DLCI;
1265 
1266 		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
1267 		    ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
1268 			return fr_add_pvc(dev, pvc.dlci, result);
1269 		else
1270 			return fr_del_pvc(hdlc, pvc.dlci, result);
1271 	}
1272 
1273 	return -EINVAL;
1274 }
1275 
1276 
1277 static int __init mod_init(void)
1278 {
1279 	register_hdlc_protocol(&proto);
1280 	return 0;
1281 }
1282 
1283 
1284 static void __exit mod_exit(void)
1285 {
1286 	unregister_hdlc_protocol(&proto);
1287 }
1288 
1289 
1290 module_init(mod_init);
1291 module_exit(mod_exit);
1292 
1293 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
1294 MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
1295 MODULE_LICENSE("GPL v2");
1296