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
88struct 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
112struct 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
131struct 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
149static int fr_ioctl(struct net_device *dev, struct if_settings *ifs);
150
151static inline u16 q922_to_dlci(u8 *hdr)
152{
153	return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
154}
155
156static 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
162static inline struct frad_state *state(hdlc_device *hdlc)
163{
164	return (struct frad_state *)(hdlc->state);
165}
166
167static 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
182static 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
209static inline int pvc_is_used(struct pvc_device *pvc)
210{
211	return pvc->main || pvc->ether;
212}
213
214static 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
233static 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
251static 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
260static 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
323static 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
342static 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
360static int pvc_ioctl(struct net_device *dev, struct if_settings *ifs)
361{
362	struct pvc_device *pvc = dev->ml_priv;
363	fr_proto_pvc_info info;
364
365	if (ifs->type == IF_GET_PROTO) {
366		if (dev->type == ARPHRD_ETHER)
367			ifs->type = IF_PROTO_FR_ETH_PVC;
368		else
369			ifs->type = IF_PROTO_FR_PVC;
370
371		if (ifs->size < sizeof(info)) {
372			/* data size wanted */
373			ifs->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(ifs->ifs_ifsu.fr_pvc_info,
380				 &info, sizeof(info)))
381			return -EFAULT;
382		return 0;
383	}
384
385	return -EINVAL;
386}
387
388static 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
432drop:
433	dev->stats.tx_dropped++;
434	kfree_skb(skb);
435	return NETDEV_TX_OK;
436}
437
438static 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
450static inline u8 fr_lmi_nextseq(u8 x)
451{
452	x++;
453	return x ? x : 1;
454}
455
456static 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
550static 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
582static 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
633static 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
849static 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
889static 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
989rx_error:
990	frad->stats.rx_errors++; /* Mark error */
991rx_drop:
992	dev_kfree_skb_any(skb);
993	return NET_RX_DROP;
994}
995
996static 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
1021static 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
1032static 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
1046static 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
1055static 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_siocwandev = pvc_ioctl,
1060};
1061
1062static 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 addr = htons(dlci);
1097
1098		dev_addr_set(dev, (u8 *)&addr);
1099		dlci_to_q922(dev->broadcast, dlci);
1100	}
1101	dev->netdev_ops = &pvc_ops;
1102	dev->mtu = HDLC_MAX_MTU;
1103	dev->min_mtu = 68;
1104	dev->max_mtu = HDLC_MAX_MTU;
1105	dev->needed_headroom = 10;
1106	dev->priv_flags |= IFF_NO_QUEUE;
1107	dev->ml_priv = pvc;
1108
1109	if (register_netdevice(dev) != 0) {
1110		free_netdev(dev);
1111		delete_unused_pvcs(hdlc);
1112		return -EIO;
1113	}
1114
1115	dev->needs_free_netdev = true;
1116	*get_dev_p(pvc, type) = dev;
1117	if (!used) {
1118		state(hdlc)->dce_changed = 1;
1119		state(hdlc)->dce_pvc_count++;
1120	}
1121	return 0;
1122}
1123
1124static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1125{
1126	struct pvc_device *pvc;
1127	struct net_device *dev;
1128
1129	pvc = find_pvc(hdlc, dlci);
1130	if (!pvc)
1131		return -ENOENT;
1132
1133	dev = *get_dev_p(pvc, type);
1134	if (!dev)
1135		return -ENOENT;
1136
1137	if (dev->flags & IFF_UP)
1138		return -EBUSY;		/* PVC in use */
1139
1140	unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1141	*get_dev_p(pvc, type) = NULL;
1142
1143	if (!pvc_is_used(pvc)) {
1144		state(hdlc)->dce_pvc_count--;
1145		state(hdlc)->dce_changed = 1;
1146	}
1147	delete_unused_pvcs(hdlc);
1148	return 0;
1149}
1150
1151static void fr_destroy(struct net_device *frad)
1152{
1153	hdlc_device *hdlc = dev_to_hdlc(frad);
1154	struct pvc_device *pvc = state(hdlc)->first_pvc;
1155
1156	state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1157	state(hdlc)->dce_pvc_count = 0;
1158	state(hdlc)->dce_changed = 1;
1159
1160	while (pvc) {
1161		struct pvc_device *next = pvc->next;
1162		/* destructors will free_netdev() main and ether */
1163		if (pvc->main)
1164			unregister_netdevice(pvc->main);
1165
1166		if (pvc->ether)
1167			unregister_netdevice(pvc->ether);
1168
1169		kfree(pvc);
1170		pvc = next;
1171	}
1172}
1173
1174static struct hdlc_proto proto = {
1175	.close		= fr_close,
1176	.start		= fr_start,
1177	.stop		= fr_stop,
1178	.detach		= fr_destroy,
1179	.ioctl		= fr_ioctl,
1180	.netif_rx	= fr_rx,
1181	.module		= THIS_MODULE,
1182};
1183
1184static int fr_ioctl(struct net_device *dev, struct if_settings *ifs)
1185{
1186	fr_proto __user *fr_s = ifs->ifs_ifsu.fr;
1187	const size_t size = sizeof(fr_proto);
1188	fr_proto new_settings;
1189	hdlc_device *hdlc = dev_to_hdlc(dev);
1190	fr_proto_pvc pvc;
1191	int result;
1192
1193	switch (ifs->type) {
1194	case IF_GET_PROTO:
1195		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1196			return -EINVAL;
1197		ifs->type = IF_PROTO_FR;
1198		if (ifs->size < size) {
1199			ifs->size = size; /* data size wanted */
1200			return -ENOBUFS;
1201		}
1202		if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1203			return -EFAULT;
1204		return 0;
1205
1206	case IF_PROTO_FR:
1207		if (!capable(CAP_NET_ADMIN))
1208			return -EPERM;
1209
1210		if (dev->flags & IFF_UP)
1211			return -EBUSY;
1212
1213		if (copy_from_user(&new_settings, fr_s, size))
1214			return -EFAULT;
1215
1216		if (new_settings.lmi == LMI_DEFAULT)
1217			new_settings.lmi = LMI_ANSI;
1218
1219		if ((new_settings.lmi != LMI_NONE &&
1220		     new_settings.lmi != LMI_ANSI &&
1221		     new_settings.lmi != LMI_CCITT &&
1222		     new_settings.lmi != LMI_CISCO) ||
1223		    new_settings.t391 < 1 ||
1224		    new_settings.t392 < 2 ||
1225		    new_settings.n391 < 1 ||
1226		    new_settings.n392 < 1 ||
1227		    new_settings.n393 < new_settings.n392 ||
1228		    new_settings.n393 > 32 ||
1229		    (new_settings.dce != 0 &&
1230		     new_settings.dce != 1))
1231			return -EINVAL;
1232
1233		result = hdlc->attach(dev, ENCODING_NRZ,
1234				      PARITY_CRC16_PR1_CCITT);
1235		if (result)
1236			return result;
1237
1238		if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1239			result = attach_hdlc_protocol(dev, &proto,
1240						      sizeof(struct frad_state));
1241			if (result)
1242				return result;
1243			state(hdlc)->first_pvc = NULL;
1244			state(hdlc)->dce_pvc_count = 0;
1245		}
1246		memcpy(&state(hdlc)->settings, &new_settings, size);
1247		dev->type = ARPHRD_FRAD;
1248		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
1249		return 0;
1250
1251	case IF_PROTO_FR_ADD_PVC:
1252	case IF_PROTO_FR_DEL_PVC:
1253	case IF_PROTO_FR_ADD_ETH_PVC:
1254	case IF_PROTO_FR_DEL_ETH_PVC:
1255		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1256			return -EINVAL;
1257
1258		if (!capable(CAP_NET_ADMIN))
1259			return -EPERM;
1260
1261		if (copy_from_user(&pvc, ifs->ifs_ifsu.fr_pvc,
1262				   sizeof(fr_proto_pvc)))
1263			return -EFAULT;
1264
1265		if (pvc.dlci <= 0 || pvc.dlci >= 1024)
1266			return -EINVAL;	/* Only 10 bits, DLCI 0 reserved */
1267
1268		if (ifs->type == IF_PROTO_FR_ADD_ETH_PVC ||
1269		    ifs->type == IF_PROTO_FR_DEL_ETH_PVC)
1270			result = ARPHRD_ETHER; /* bridged Ethernet device */
1271		else
1272			result = ARPHRD_DLCI;
1273
1274		if (ifs->type == IF_PROTO_FR_ADD_PVC ||
1275		    ifs->type == IF_PROTO_FR_ADD_ETH_PVC)
1276			return fr_add_pvc(dev, pvc.dlci, result);
1277		else
1278			return fr_del_pvc(hdlc, pvc.dlci, result);
1279	}
1280
1281	return -EINVAL;
1282}
1283
1284static int __init hdlc_fr_init(void)
1285{
1286	register_hdlc_protocol(&proto);
1287	return 0;
1288}
1289
1290static void __exit hdlc_fr_exit(void)
1291{
1292	unregister_hdlc_protocol(&proto);
1293}
1294
1295module_init(hdlc_fr_init);
1296module_exit(hdlc_fr_exit);
1297
1298MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
1299MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
1300MODULE_LICENSE("GPL v2");
1301