xref: /linux/drivers/net/wan/hdlc_fr.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * Generic HDLC support routines for Linux
3  * Frame Relay support
4  *
5  * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of version 2 of the GNU General Public License
9  * as published by the Free Software Foundation.
10  *
11 
12             Theory of PVC state
13 
14  DCE mode:
15 
16  (exist,new) -> 0,0 when "PVC create" or if "link unreliable"
17          0,x -> 1,1 if "link reliable" when sending FULL STATUS
18          1,1 -> 1,0 if received FULL STATUS ACK
19 
20  (active)    -> 0 when "ifconfig PVC down" or "link unreliable" or "PVC create"
21              -> 1 when "PVC up" and (exist,new) = 1,0
22 
23  DTE mode:
24  (exist,new,active) = FULL STATUS if "link reliable"
25 		    = 0, 0, 0 if "link unreliable"
26  No LMI:
27  active = open and "link reliable"
28  exist = new = not used
29 
30  CCITT LMI: ITU-T Q.933 Annex A
31  ANSI LMI: ANSI T1.617 Annex D
32  CISCO LMI: the original, aka "Gang of Four" LMI
33 
34 */
35 
36 #include <linux/errno.h>
37 #include <linux/etherdevice.h>
38 #include <linux/hdlc.h>
39 #include <linux/if_arp.h>
40 #include <linux/inetdevice.h>
41 #include <linux/init.h>
42 #include <linux/kernel.h>
43 #include <linux/module.h>
44 #include <linux/pkt_sched.h>
45 #include <linux/poll.h>
46 #include <linux/rtnetlink.h>
47 #include <linux/skbuff.h>
48 #include <linux/slab.h>
49 
50 #undef DEBUG_PKT
51 #undef DEBUG_ECN
52 #undef DEBUG_LINK
53 #undef DEBUG_PROTO
54 #undef DEBUG_PVC
55 
56 #define FR_UI			0x03
57 #define FR_PAD			0x00
58 
59 #define NLPID_IP		0xCC
60 #define NLPID_IPV6		0x8E
61 #define NLPID_SNAP		0x80
62 #define NLPID_PAD		0x00
63 #define NLPID_CCITT_ANSI_LMI	0x08
64 #define NLPID_CISCO_LMI		0x09
65 
66 
67 #define LMI_CCITT_ANSI_DLCI	   0 /* LMI DLCI */
68 #define LMI_CISCO_DLCI		1023
69 
70 #define LMI_CALLREF		0x00 /* Call Reference */
71 #define LMI_ANSI_LOCKSHIFT	0x95 /* ANSI locking shift */
72 #define LMI_ANSI_CISCO_REPTYPE	0x01 /* report type */
73 #define LMI_CCITT_REPTYPE	0x51
74 #define LMI_ANSI_CISCO_ALIVE	0x03 /* keep alive */
75 #define LMI_CCITT_ALIVE		0x53
76 #define LMI_ANSI_CISCO_PVCSTAT	0x07 /* PVC status */
77 #define LMI_CCITT_PVCSTAT	0x57
78 
79 #define LMI_FULLREP		0x00 /* full report  */
80 #define LMI_INTEGRITY		0x01 /* link integrity report */
81 #define LMI_SINGLE		0x02 /* single PVC report */
82 
83 #define LMI_STATUS_ENQUIRY      0x75
84 #define LMI_STATUS              0x7D /* reply */
85 
86 #define LMI_REPT_LEN               1 /* report type element length */
87 #define LMI_INTEG_LEN              2 /* link integrity element length */
88 
89 #define LMI_CCITT_CISCO_LENGTH	  13 /* LMI frame lengths */
90 #define LMI_ANSI_LENGTH		  14
91 
92 
93 typedef struct {
94 #if defined(__LITTLE_ENDIAN_BITFIELD)
95 	unsigned ea1:	1;
96 	unsigned cr:	1;
97 	unsigned dlcih:	6;
98 
99 	unsigned ea2:	1;
100 	unsigned de:	1;
101 	unsigned becn:	1;
102 	unsigned fecn:	1;
103 	unsigned dlcil:	4;
104 #else
105 	unsigned dlcih:	6;
106 	unsigned cr:	1;
107 	unsigned ea1:	1;
108 
109 	unsigned dlcil:	4;
110 	unsigned fecn:	1;
111 	unsigned becn:	1;
112 	unsigned de:	1;
113 	unsigned ea2:	1;
114 #endif
115 }__packed fr_hdr;
116 
117 
118 typedef struct pvc_device_struct {
119 	struct net_device *frad;
120 	struct net_device *main;
121 	struct net_device *ether;	/* bridged Ethernet interface	*/
122 	struct pvc_device_struct *next;	/* Sorted in ascending DLCI order */
123 	int dlci;
124 	int open_count;
125 
126 	struct {
127 		unsigned int new: 1;
128 		unsigned int active: 1;
129 		unsigned int exist: 1;
130 		unsigned int deleted: 1;
131 		unsigned int fecn: 1;
132 		unsigned int becn: 1;
133 		unsigned int bandwidth;	/* Cisco LMI reporting only */
134 	}state;
135 }pvc_device;
136 
137 struct frad_state {
138 	fr_proto settings;
139 	pvc_device *first_pvc;
140 	int dce_pvc_count;
141 
142 	struct timer_list timer;
143 	unsigned long last_poll;
144 	int reliable;
145 	int dce_changed;
146 	int request;
147 	int fullrep_sent;
148 	u32 last_errors; /* last errors bit list */
149 	u8 n391cnt;
150 	u8 txseq; /* TX sequence number */
151 	u8 rxseq; /* RX sequence number */
152 };
153 
154 
155 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr);
156 
157 
158 static inline u16 q922_to_dlci(u8 *hdr)
159 {
160 	return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
161 }
162 
163 
164 static inline void dlci_to_q922(u8 *hdr, u16 dlci)
165 {
166 	hdr[0] = (dlci >> 2) & 0xFC;
167 	hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
168 }
169 
170 
171 static inline struct frad_state* state(hdlc_device *hdlc)
172 {
173 	return(struct frad_state *)(hdlc->state);
174 }
175 
176 
177 static inline pvc_device* find_pvc(hdlc_device *hdlc, u16 dlci)
178 {
179 	pvc_device *pvc = state(hdlc)->first_pvc;
180 
181 	while (pvc) {
182 		if (pvc->dlci == dlci)
183 			return pvc;
184 		if (pvc->dlci > dlci)
185 			return NULL; /* the list is sorted */
186 		pvc = pvc->next;
187 	}
188 
189 	return NULL;
190 }
191 
192 
193 static pvc_device* add_pvc(struct net_device *dev, u16 dlci)
194 {
195 	hdlc_device *hdlc = dev_to_hdlc(dev);
196 	pvc_device *pvc, **pvc_p = &state(hdlc)->first_pvc;
197 
198 	while (*pvc_p) {
199 		if ((*pvc_p)->dlci == dlci)
200 			return *pvc_p;
201 		if ((*pvc_p)->dlci > dlci)
202 			break;	/* the list is sorted */
203 		pvc_p = &(*pvc_p)->next;
204 	}
205 
206 	pvc = kzalloc(sizeof(pvc_device), GFP_ATOMIC);
207 #ifdef DEBUG_PVC
208 	printk(KERN_DEBUG "add_pvc: allocated pvc %p, frad %p\n", pvc, dev);
209 #endif
210 	if (!pvc)
211 		return NULL;
212 
213 	pvc->dlci = dlci;
214 	pvc->frad = dev;
215 	pvc->next = *pvc_p;	/* Put it in the chain */
216 	*pvc_p = pvc;
217 	return pvc;
218 }
219 
220 
221 static inline int pvc_is_used(pvc_device *pvc)
222 {
223 	return pvc->main || pvc->ether;
224 }
225 
226 
227 static inline void pvc_carrier(int on, pvc_device *pvc)
228 {
229 	if (on) {
230 		if (pvc->main)
231 			if (!netif_carrier_ok(pvc->main))
232 				netif_carrier_on(pvc->main);
233 		if (pvc->ether)
234 			if (!netif_carrier_ok(pvc->ether))
235 				netif_carrier_on(pvc->ether);
236 	} else {
237 		if (pvc->main)
238 			if (netif_carrier_ok(pvc->main))
239 				netif_carrier_off(pvc->main);
240 		if (pvc->ether)
241 			if (netif_carrier_ok(pvc->ether))
242 				netif_carrier_off(pvc->ether);
243 	}
244 }
245 
246 
247 static inline void delete_unused_pvcs(hdlc_device *hdlc)
248 {
249 	pvc_device **pvc_p = &state(hdlc)->first_pvc;
250 
251 	while (*pvc_p) {
252 		if (!pvc_is_used(*pvc_p)) {
253 			pvc_device *pvc = *pvc_p;
254 #ifdef DEBUG_PVC
255 			printk(KERN_DEBUG "freeing unused pvc: %p\n", pvc);
256 #endif
257 			*pvc_p = pvc->next;
258 			kfree(pvc);
259 			continue;
260 		}
261 		pvc_p = &(*pvc_p)->next;
262 	}
263 }
264 
265 
266 static inline struct net_device** get_dev_p(pvc_device *pvc, int type)
267 {
268 	if (type == ARPHRD_ETHER)
269 		return &pvc->ether;
270 	else
271 		return &pvc->main;
272 }
273 
274 
275 static int fr_hard_header(struct sk_buff **skb_p, u16 dlci)
276 {
277 	u16 head_len;
278 	struct sk_buff *skb = *skb_p;
279 
280 	switch (skb->protocol) {
281 	case cpu_to_be16(NLPID_CCITT_ANSI_LMI):
282 		head_len = 4;
283 		skb_push(skb, head_len);
284 		skb->data[3] = NLPID_CCITT_ANSI_LMI;
285 		break;
286 
287 	case cpu_to_be16(NLPID_CISCO_LMI):
288 		head_len = 4;
289 		skb_push(skb, head_len);
290 		skb->data[3] = NLPID_CISCO_LMI;
291 		break;
292 
293 	case cpu_to_be16(ETH_P_IP):
294 		head_len = 4;
295 		skb_push(skb, head_len);
296 		skb->data[3] = NLPID_IP;
297 		break;
298 
299 	case cpu_to_be16(ETH_P_IPV6):
300 		head_len = 4;
301 		skb_push(skb, head_len);
302 		skb->data[3] = NLPID_IPV6;
303 		break;
304 
305 	case cpu_to_be16(ETH_P_802_3):
306 		head_len = 10;
307 		if (skb_headroom(skb) < head_len) {
308 			struct sk_buff *skb2 = skb_realloc_headroom(skb,
309 								    head_len);
310 			if (!skb2)
311 				return -ENOBUFS;
312 			dev_kfree_skb(skb);
313 			skb = *skb_p = skb2;
314 		}
315 		skb_push(skb, head_len);
316 		skb->data[3] = FR_PAD;
317 		skb->data[4] = NLPID_SNAP;
318 		skb->data[5] = FR_PAD;
319 		skb->data[6] = 0x80;
320 		skb->data[7] = 0xC2;
321 		skb->data[8] = 0x00;
322 		skb->data[9] = 0x07; /* bridged Ethernet frame w/out FCS */
323 		break;
324 
325 	default:
326 		head_len = 10;
327 		skb_push(skb, head_len);
328 		skb->data[3] = FR_PAD;
329 		skb->data[4] = NLPID_SNAP;
330 		skb->data[5] = FR_PAD;
331 		skb->data[6] = FR_PAD;
332 		skb->data[7] = FR_PAD;
333 		*(__be16*)(skb->data + 8) = skb->protocol;
334 	}
335 
336 	dlci_to_q922(skb->data, dlci);
337 	skb->data[2] = FR_UI;
338 	return 0;
339 }
340 
341 
342 
343 static int pvc_open(struct net_device *dev)
344 {
345 	pvc_device *pvc = dev->ml_priv;
346 
347 	if ((pvc->frad->flags & IFF_UP) == 0)
348 		return -EIO;  /* Frad must be UP in order to activate PVC */
349 
350 	if (pvc->open_count++ == 0) {
351 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
352 		if (state(hdlc)->settings.lmi == LMI_NONE)
353 			pvc->state.active = netif_carrier_ok(pvc->frad);
354 
355 		pvc_carrier(pvc->state.active, pvc);
356 		state(hdlc)->dce_changed = 1;
357 	}
358 	return 0;
359 }
360 
361 
362 
363 static int pvc_close(struct net_device *dev)
364 {
365 	pvc_device *pvc = dev->ml_priv;
366 
367 	if (--pvc->open_count == 0) {
368 		hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
369 		if (state(hdlc)->settings.lmi == LMI_NONE)
370 			pvc->state.active = 0;
371 
372 		if (state(hdlc)->settings.dce) {
373 			state(hdlc)->dce_changed = 1;
374 			pvc->state.active = 0;
375 		}
376 	}
377 	return 0;
378 }
379 
380 
381 
382 static int pvc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
383 {
384 	pvc_device *pvc = dev->ml_priv;
385 	fr_proto_pvc_info info;
386 
387 	if (ifr->ifr_settings.type == IF_GET_PROTO) {
388 		if (dev->type == ARPHRD_ETHER)
389 			ifr->ifr_settings.type = IF_PROTO_FR_ETH_PVC;
390 		else
391 			ifr->ifr_settings.type = IF_PROTO_FR_PVC;
392 
393 		if (ifr->ifr_settings.size < sizeof(info)) {
394 			/* data size wanted */
395 			ifr->ifr_settings.size = sizeof(info);
396 			return -ENOBUFS;
397 		}
398 
399 		info.dlci = pvc->dlci;
400 		memcpy(info.master, pvc->frad->name, IFNAMSIZ);
401 		if (copy_to_user(ifr->ifr_settings.ifs_ifsu.fr_pvc_info,
402 				 &info, sizeof(info)))
403 			return -EFAULT;
404 		return 0;
405 	}
406 
407 	return -EINVAL;
408 }
409 
410 static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev)
411 {
412 	pvc_device *pvc = dev->ml_priv;
413 
414 	if (pvc->state.active) {
415 		if (dev->type == ARPHRD_ETHER) {
416 			int pad = ETH_ZLEN - skb->len;
417 			if (pad > 0) { /* Pad the frame with zeros */
418 				int len = skb->len;
419 				if (skb_tailroom(skb) < pad)
420 					if (pskb_expand_head(skb, 0, pad,
421 							     GFP_ATOMIC)) {
422 						dev->stats.tx_dropped++;
423 						dev_kfree_skb(skb);
424 						return NETDEV_TX_OK;
425 					}
426 				skb_put(skb, pad);
427 				memset(skb->data + len, 0, pad);
428 			}
429 			skb->protocol = cpu_to_be16(ETH_P_802_3);
430 		}
431 		if (!fr_hard_header(&skb, pvc->dlci)) {
432 			dev->stats.tx_bytes += skb->len;
433 			dev->stats.tx_packets++;
434 			if (pvc->state.fecn) /* TX Congestion counter */
435 				dev->stats.tx_compressed++;
436 			skb->dev = pvc->frad;
437 			dev_queue_xmit(skb);
438 			return NETDEV_TX_OK;
439 		}
440 	}
441 
442 	dev->stats.tx_dropped++;
443 	dev_kfree_skb(skb);
444 	return NETDEV_TX_OK;
445 }
446 
447 static inline void fr_log_dlci_active(pvc_device *pvc)
448 {
449 	netdev_info(pvc->frad, "DLCI %d [%s%s%s]%s %s\n",
450 		    pvc->dlci,
451 		    pvc->main ? pvc->main->name : "",
452 		    pvc->main && pvc->ether ? " " : "",
453 		    pvc->ether ? pvc->ether->name : "",
454 		    pvc->state.new ? " new" : "",
455 		    !pvc->state.exist ? "deleted" :
456 		    pvc->state.active ? "active" : "inactive");
457 }
458 
459 
460 
461 static inline u8 fr_lmi_nextseq(u8 x)
462 {
463 	x++;
464 	return x ? x : 1;
465 }
466 
467 
468 static void fr_lmi_send(struct net_device *dev, int fullrep)
469 {
470 	hdlc_device *hdlc = dev_to_hdlc(dev);
471 	struct sk_buff *skb;
472 	pvc_device *pvc = state(hdlc)->first_pvc;
473 	int lmi = state(hdlc)->settings.lmi;
474 	int dce = state(hdlc)->settings.dce;
475 	int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
476 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
477 	u8 *data;
478 	int i = 0;
479 
480 	if (dce && fullrep) {
481 		len += state(hdlc)->dce_pvc_count * (2 + stat_len);
482 		if (len > HDLC_MAX_MRU) {
483 			netdev_warn(dev, "Too many PVCs while sending LMI full report\n");
484 			return;
485 		}
486 	}
487 
488 	skb = dev_alloc_skb(len);
489 	if (!skb) {
490 		netdev_warn(dev, "Memory squeeze on fr_lmi_send()\n");
491 		return;
492 	}
493 	memset(skb->data, 0, len);
494 	skb_reserve(skb, 4);
495 	if (lmi == LMI_CISCO) {
496 		skb->protocol = cpu_to_be16(NLPID_CISCO_LMI);
497 		fr_hard_header(&skb, LMI_CISCO_DLCI);
498 	} else {
499 		skb->protocol = cpu_to_be16(NLPID_CCITT_ANSI_LMI);
500 		fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI);
501 	}
502 	data = skb_tail_pointer(skb);
503 	data[i++] = LMI_CALLREF;
504 	data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
505 	if (lmi == LMI_ANSI)
506 		data[i++] = LMI_ANSI_LOCKSHIFT;
507 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
508 		LMI_ANSI_CISCO_REPTYPE;
509 	data[i++] = LMI_REPT_LEN;
510 	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
511 	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
512 	data[i++] = LMI_INTEG_LEN;
513 	data[i++] = state(hdlc)->txseq =
514 		fr_lmi_nextseq(state(hdlc)->txseq);
515 	data[i++] = state(hdlc)->rxseq;
516 
517 	if (dce && fullrep) {
518 		while (pvc) {
519 			data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
520 				LMI_ANSI_CISCO_PVCSTAT;
521 			data[i++] = stat_len;
522 
523 			/* LMI start/restart */
524 			if (state(hdlc)->reliable && !pvc->state.exist) {
525 				pvc->state.exist = pvc->state.new = 1;
526 				fr_log_dlci_active(pvc);
527 			}
528 
529 			/* ifconfig PVC up */
530 			if (pvc->open_count && !pvc->state.active &&
531 			    pvc->state.exist && !pvc->state.new) {
532 				pvc_carrier(1, pvc);
533 				pvc->state.active = 1;
534 				fr_log_dlci_active(pvc);
535 			}
536 
537 			if (lmi == LMI_CISCO) {
538 				data[i] = pvc->dlci >> 8;
539 				data[i + 1] = pvc->dlci & 0xFF;
540 			} else {
541 				data[i] = (pvc->dlci >> 4) & 0x3F;
542 				data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
543 				data[i + 2] = 0x80;
544 			}
545 
546 			if (pvc->state.new)
547 				data[i + 2] |= 0x08;
548 			else if (pvc->state.active)
549 				data[i + 2] |= 0x02;
550 
551 			i += stat_len;
552 			pvc = pvc->next;
553 		}
554 	}
555 
556 	skb_put(skb, i);
557 	skb->priority = TC_PRIO_CONTROL;
558 	skb->dev = dev;
559 	skb_reset_network_header(skb);
560 
561 	dev_queue_xmit(skb);
562 }
563 
564 
565 
566 static void fr_set_link_state(int reliable, struct net_device *dev)
567 {
568 	hdlc_device *hdlc = dev_to_hdlc(dev);
569 	pvc_device *pvc = state(hdlc)->first_pvc;
570 
571 	state(hdlc)->reliable = reliable;
572 	if (reliable) {
573 		netif_dormant_off(dev);
574 		state(hdlc)->n391cnt = 0; /* Request full status */
575 		state(hdlc)->dce_changed = 1;
576 
577 		if (state(hdlc)->settings.lmi == LMI_NONE) {
578 			while (pvc) {	/* Activate all PVCs */
579 				pvc_carrier(1, pvc);
580 				pvc->state.exist = pvc->state.active = 1;
581 				pvc->state.new = 0;
582 				pvc = pvc->next;
583 			}
584 		}
585 	} else {
586 		netif_dormant_on(dev);
587 		while (pvc) {		/* Deactivate all PVCs */
588 			pvc_carrier(0, pvc);
589 			pvc->state.exist = pvc->state.active = 0;
590 			pvc->state.new = 0;
591 			if (!state(hdlc)->settings.dce)
592 				pvc->state.bandwidth = 0;
593 			pvc = pvc->next;
594 		}
595 	}
596 }
597 
598 
599 static void fr_timer(unsigned long arg)
600 {
601 	struct net_device *dev = (struct net_device *)arg;
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 	state(hdlc)->timer.function = fr_timer;
647 	state(hdlc)->timer.data = arg;
648 	add_timer(&state(hdlc)->timer);
649 }
650 
651 
652 static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
653 {
654 	hdlc_device *hdlc = dev_to_hdlc(dev);
655 	pvc_device *pvc;
656 	u8 rxseq, txseq;
657 	int lmi = state(hdlc)->settings.lmi;
658 	int dce = state(hdlc)->settings.dce;
659 	int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
660 
661 	if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
662 			LMI_CCITT_CISCO_LENGTH)) {
663 		netdev_info(dev, "Short LMI frame\n");
664 		return 1;
665 	}
666 
667 	if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
668 			     NLPID_CCITT_ANSI_LMI)) {
669 		netdev_info(dev, "Received non-LMI frame with LMI DLCI\n");
670 		return 1;
671 	}
672 
673 	if (skb->data[4] != LMI_CALLREF) {
674 		netdev_info(dev, "Invalid LMI Call reference (0x%02X)\n",
675 			    skb->data[4]);
676 		return 1;
677 	}
678 
679 	if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
680 		netdev_info(dev, "Invalid LMI Message type (0x%02X)\n",
681 			    skb->data[5]);
682 		return 1;
683 	}
684 
685 	if (lmi == LMI_ANSI) {
686 		if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
687 			netdev_info(dev, "Not ANSI locking shift in LMI message (0x%02X)\n",
688 				    skb->data[6]);
689 			return 1;
690 		}
691 		i = 7;
692 	} else
693 		i = 6;
694 
695 	if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
696 			     LMI_ANSI_CISCO_REPTYPE)) {
697 		netdev_info(dev, "Not an LMI Report type IE (0x%02X)\n",
698 			    skb->data[i]);
699 		return 1;
700 	}
701 
702 	if (skb->data[++i] != LMI_REPT_LEN) {
703 		netdev_info(dev, "Invalid LMI Report type IE length (%u)\n",
704 			    skb->data[i]);
705 		return 1;
706 	}
707 
708 	reptype = skb->data[++i];
709 	if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
710 		netdev_info(dev, "Unsupported LMI Report type (0x%02X)\n",
711 			    reptype);
712 		return 1;
713 	}
714 
715 	if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
716 			       LMI_ANSI_CISCO_ALIVE)) {
717 		netdev_info(dev, "Not an LMI Link integrity verification IE (0x%02X)\n",
718 			    skb->data[i]);
719 		return 1;
720 	}
721 
722 	if (skb->data[++i] != LMI_INTEG_LEN) {
723 		netdev_info(dev, "Invalid LMI Link integrity verification IE length (%u)\n",
724 			    skb->data[i]);
725 		return 1;
726 	}
727 	i++;
728 
729 	state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
730 	rxseq = skb->data[i++];	/* Should confirm our sequence */
731 
732 	txseq = state(hdlc)->txseq;
733 
734 	if (dce)
735 		state(hdlc)->last_poll = jiffies;
736 
737 	error = 0;
738 	if (!state(hdlc)->reliable)
739 		error = 1;
740 
741 	if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
742 		state(hdlc)->n391cnt = 0;
743 		error = 1;
744 	}
745 
746 	if (dce) {
747 		if (state(hdlc)->fullrep_sent && !error) {
748 /* Stop sending full report - the last one has been confirmed by DTE */
749 			state(hdlc)->fullrep_sent = 0;
750 			pvc = state(hdlc)->first_pvc;
751 			while (pvc) {
752 				if (pvc->state.new) {
753 					pvc->state.new = 0;
754 
755 /* Tell DTE that new PVC is now active */
756 					state(hdlc)->dce_changed = 1;
757 				}
758 				pvc = pvc->next;
759 			}
760 		}
761 
762 		if (state(hdlc)->dce_changed) {
763 			reptype = LMI_FULLREP;
764 			state(hdlc)->fullrep_sent = 1;
765 			state(hdlc)->dce_changed = 0;
766 		}
767 
768 		state(hdlc)->request = 1; /* got request */
769 		fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
770 		return 0;
771 	}
772 
773 	/* DTE */
774 
775 	state(hdlc)->request = 0; /* got response, no request pending */
776 
777 	if (error)
778 		return 0;
779 
780 	if (reptype != LMI_FULLREP)
781 		return 0;
782 
783 	pvc = state(hdlc)->first_pvc;
784 
785 	while (pvc) {
786 		pvc->state.deleted = 1;
787 		pvc = pvc->next;
788 	}
789 
790 	no_ram = 0;
791 	while (skb->len >= i + 2 + stat_len) {
792 		u16 dlci;
793 		u32 bw;
794 		unsigned int active, new;
795 
796 		if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
797 				       LMI_ANSI_CISCO_PVCSTAT)) {
798 			netdev_info(dev, "Not an LMI PVC status IE (0x%02X)\n",
799 				    skb->data[i]);
800 			return 1;
801 		}
802 
803 		if (skb->data[++i] != stat_len) {
804 			netdev_info(dev, "Invalid LMI PVC status IE length (%u)\n",
805 				    skb->data[i]);
806 			return 1;
807 		}
808 		i++;
809 
810 		new = !! (skb->data[i + 2] & 0x08);
811 		active = !! (skb->data[i + 2] & 0x02);
812 		if (lmi == LMI_CISCO) {
813 			dlci = (skb->data[i] << 8) | skb->data[i + 1];
814 			bw = (skb->data[i + 3] << 16) |
815 				(skb->data[i + 4] << 8) |
816 				(skb->data[i + 5]);
817 		} else {
818 			dlci = ((skb->data[i] & 0x3F) << 4) |
819 				((skb->data[i + 1] & 0x78) >> 3);
820 			bw = 0;
821 		}
822 
823 		pvc = add_pvc(dev, dlci);
824 
825 		if (!pvc && !no_ram) {
826 			netdev_warn(dev, "Memory squeeze on fr_lmi_recv()\n");
827 			no_ram = 1;
828 		}
829 
830 		if (pvc) {
831 			pvc->state.exist = 1;
832 			pvc->state.deleted = 0;
833 			if (active != pvc->state.active ||
834 			    new != pvc->state.new ||
835 			    bw != pvc->state.bandwidth ||
836 			    !pvc->state.exist) {
837 				pvc->state.new = new;
838 				pvc->state.active = active;
839 				pvc->state.bandwidth = bw;
840 				pvc_carrier(active, pvc);
841 				fr_log_dlci_active(pvc);
842 			}
843 		}
844 
845 		i += stat_len;
846 	}
847 
848 	pvc = state(hdlc)->first_pvc;
849 
850 	while (pvc) {
851 		if (pvc->state.deleted && pvc->state.exist) {
852 			pvc_carrier(0, pvc);
853 			pvc->state.active = pvc->state.new = 0;
854 			pvc->state.exist = 0;
855 			pvc->state.bandwidth = 0;
856 			fr_log_dlci_active(pvc);
857 		}
858 		pvc = pvc->next;
859 	}
860 
861 	/* Next full report after N391 polls */
862 	state(hdlc)->n391cnt = state(hdlc)->settings.n391;
863 
864 	return 0;
865 }
866 
867 
868 static int fr_rx(struct sk_buff *skb)
869 {
870 	struct net_device *frad = skb->dev;
871 	hdlc_device *hdlc = dev_to_hdlc(frad);
872 	fr_hdr *fh = (fr_hdr*)skb->data;
873 	u8 *data = skb->data;
874 	u16 dlci;
875 	pvc_device *pvc;
876 	struct net_device *dev = NULL;
877 
878 	if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI)
879 		goto rx_error;
880 
881 	dlci = q922_to_dlci(skb->data);
882 
883 	if ((dlci == LMI_CCITT_ANSI_DLCI &&
884 	     (state(hdlc)->settings.lmi == LMI_ANSI ||
885 	      state(hdlc)->settings.lmi == LMI_CCITT)) ||
886 	    (dlci == LMI_CISCO_DLCI &&
887 	     state(hdlc)->settings.lmi == LMI_CISCO)) {
888 		if (fr_lmi_recv(frad, skb))
889 			goto rx_error;
890 		dev_kfree_skb_any(skb);
891 		return NET_RX_SUCCESS;
892 	}
893 
894 	pvc = find_pvc(hdlc, dlci);
895 	if (!pvc) {
896 #ifdef DEBUG_PKT
897 		netdev_info(frad, "No PVC for received frame's DLCI %d\n",
898 			    dlci);
899 #endif
900 		dev_kfree_skb_any(skb);
901 		return NET_RX_DROP;
902 	}
903 
904 	if (pvc->state.fecn != fh->fecn) {
905 #ifdef DEBUG_ECN
906 		printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", frad->name,
907 		       dlci, fh->fecn ? "N" : "FF");
908 #endif
909 		pvc->state.fecn ^= 1;
910 	}
911 
912 	if (pvc->state.becn != fh->becn) {
913 #ifdef DEBUG_ECN
914 		printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", frad->name,
915 		       dlci, fh->becn ? "N" : "FF");
916 #endif
917 		pvc->state.becn ^= 1;
918 	}
919 
920 
921 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
922 		frad->stats.rx_dropped++;
923 		return NET_RX_DROP;
924 	}
925 
926 	if (data[3] == NLPID_IP) {
927 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
928 		dev = pvc->main;
929 		skb->protocol = htons(ETH_P_IP);
930 
931 	} else if (data[3] == NLPID_IPV6) {
932 		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
933 		dev = pvc->main;
934 		skb->protocol = htons(ETH_P_IPV6);
935 
936 	} else if (skb->len > 10 && data[3] == FR_PAD &&
937 		   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
938 		u16 oui = ntohs(*(__be16*)(data + 6));
939 		u16 pid = ntohs(*(__be16*)(data + 8));
940 		skb_pull(skb, 10);
941 
942 		switch ((((u32)oui) << 16) | pid) {
943 		case ETH_P_ARP: /* routed frame with SNAP */
944 		case ETH_P_IPX:
945 		case ETH_P_IP:	/* a long variant */
946 		case ETH_P_IPV6:
947 			dev = pvc->main;
948 			skb->protocol = htons(pid);
949 			break;
950 
951 		case 0x80C20007: /* bridged Ethernet frame */
952 			if ((dev = pvc->ether) != NULL)
953 				skb->protocol = eth_type_trans(skb, dev);
954 			break;
955 
956 		default:
957 			netdev_info(frad, "Unsupported protocol, OUI=%x PID=%x\n",
958 				    oui, pid);
959 			dev_kfree_skb_any(skb);
960 			return NET_RX_DROP;
961 		}
962 	} else {
963 		netdev_info(frad, "Unsupported protocol, NLPID=%x length=%i\n",
964 			    data[3], skb->len);
965 		dev_kfree_skb_any(skb);
966 		return NET_RX_DROP;
967 	}
968 
969 	if (dev) {
970 		dev->stats.rx_packets++; /* PVC traffic */
971 		dev->stats.rx_bytes += skb->len;
972 		if (pvc->state.becn)
973 			dev->stats.rx_compressed++;
974 		skb->dev = dev;
975 		netif_rx(skb);
976 		return NET_RX_SUCCESS;
977 	} else {
978 		dev_kfree_skb_any(skb);
979 		return NET_RX_DROP;
980 	}
981 
982  rx_error:
983 	frad->stats.rx_errors++; /* Mark error */
984 	dev_kfree_skb_any(skb);
985 	return NET_RX_DROP;
986 }
987 
988 
989 
990 static void fr_start(struct net_device *dev)
991 {
992 	hdlc_device *hdlc = dev_to_hdlc(dev);
993 #ifdef DEBUG_LINK
994 	printk(KERN_DEBUG "fr_start\n");
995 #endif
996 	if (state(hdlc)->settings.lmi != LMI_NONE) {
997 		state(hdlc)->reliable = 0;
998 		state(hdlc)->dce_changed = 1;
999 		state(hdlc)->request = 0;
1000 		state(hdlc)->fullrep_sent = 0;
1001 		state(hdlc)->last_errors = 0xFFFFFFFF;
1002 		state(hdlc)->n391cnt = 0;
1003 		state(hdlc)->txseq = state(hdlc)->rxseq = 0;
1004 
1005 		init_timer(&state(hdlc)->timer);
1006 		/* First poll after 1 s */
1007 		state(hdlc)->timer.expires = jiffies + HZ;
1008 		state(hdlc)->timer.function = fr_timer;
1009 		state(hdlc)->timer.data = (unsigned long)dev;
1010 		add_timer(&state(hdlc)->timer);
1011 	} else
1012 		fr_set_link_state(1, dev);
1013 }
1014 
1015 
1016 static void fr_stop(struct net_device *dev)
1017 {
1018 	hdlc_device *hdlc = dev_to_hdlc(dev);
1019 #ifdef DEBUG_LINK
1020 	printk(KERN_DEBUG "fr_stop\n");
1021 #endif
1022 	if (state(hdlc)->settings.lmi != LMI_NONE)
1023 		del_timer_sync(&state(hdlc)->timer);
1024 	fr_set_link_state(0, dev);
1025 }
1026 
1027 
1028 static void fr_close(struct net_device *dev)
1029 {
1030 	hdlc_device *hdlc = dev_to_hdlc(dev);
1031 	pvc_device *pvc = state(hdlc)->first_pvc;
1032 
1033 	while (pvc) {		/* Shutdown all PVCs for this FRAD */
1034 		if (pvc->main)
1035 			dev_close(pvc->main);
1036 		if (pvc->ether)
1037 			dev_close(pvc->ether);
1038 		pvc = pvc->next;
1039 	}
1040 }
1041 
1042 
1043 static void pvc_setup(struct net_device *dev)
1044 {
1045 	dev->type = ARPHRD_DLCI;
1046 	dev->flags = IFF_POINTOPOINT;
1047 	dev->hard_header_len = 10;
1048 	dev->addr_len = 2;
1049 	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1050 }
1051 
1052 static const struct net_device_ops pvc_ops = {
1053 	.ndo_open       = pvc_open,
1054 	.ndo_stop       = pvc_close,
1055 	.ndo_change_mtu = hdlc_change_mtu,
1056 	.ndo_start_xmit = pvc_xmit,
1057 	.ndo_do_ioctl   = pvc_ioctl,
1058 };
1059 
1060 static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
1061 {
1062 	hdlc_device *hdlc = dev_to_hdlc(frad);
1063 	pvc_device *pvc;
1064 	struct net_device *dev;
1065 	int used;
1066 
1067 	if ((pvc = add_pvc(frad, dlci)) == NULL) {
1068 		netdev_warn(frad, "Memory squeeze on fr_add_pvc()\n");
1069 		return -ENOBUFS;
1070 	}
1071 
1072 	if (*get_dev_p(pvc, type))
1073 		return -EEXIST;
1074 
1075 	used = pvc_is_used(pvc);
1076 
1077 	if (type == ARPHRD_ETHER) {
1078 		dev = alloc_netdev(0, "pvceth%d", ether_setup);
1079 		dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1080 	} else
1081 		dev = alloc_netdev(0, "pvc%d", pvc_setup);
1082 
1083 	if (!dev) {
1084 		netdev_warn(frad, "Memory squeeze on fr_pvc()\n");
1085 		delete_unused_pvcs(hdlc);
1086 		return -ENOBUFS;
1087 	}
1088 
1089 	if (type == ARPHRD_ETHER)
1090 		random_ether_addr(dev->dev_addr);
1091 	else {
1092 		*(__be16*)dev->dev_addr = htons(dlci);
1093 		dlci_to_q922(dev->broadcast, dlci);
1094 	}
1095 	dev->netdev_ops = &pvc_ops;
1096 	dev->mtu = HDLC_MAX_MTU;
1097 	dev->tx_queue_len = 0;
1098 	dev->ml_priv = pvc;
1099 
1100 	if (register_netdevice(dev) != 0) {
1101 		free_netdev(dev);
1102 		delete_unused_pvcs(hdlc);
1103 		return -EIO;
1104 	}
1105 
1106 	dev->destructor = free_netdev;
1107 	*get_dev_p(pvc, type) = dev;
1108 	if (!used) {
1109 		state(hdlc)->dce_changed = 1;
1110 		state(hdlc)->dce_pvc_count++;
1111 	}
1112 	return 0;
1113 }
1114 
1115 
1116 
1117 static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1118 {
1119 	pvc_device *pvc;
1120 	struct net_device *dev;
1121 
1122 	if ((pvc = find_pvc(hdlc, dlci)) == NULL)
1123 		return -ENOENT;
1124 
1125 	if ((dev = *get_dev_p(pvc, type)) == NULL)
1126 		return -ENOENT;
1127 
1128 	if (dev->flags & IFF_UP)
1129 		return -EBUSY;		/* PVC in use */
1130 
1131 	unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1132 	*get_dev_p(pvc, type) = NULL;
1133 
1134 	if (!pvc_is_used(pvc)) {
1135 		state(hdlc)->dce_pvc_count--;
1136 		state(hdlc)->dce_changed = 1;
1137 	}
1138 	delete_unused_pvcs(hdlc);
1139 	return 0;
1140 }
1141 
1142 
1143 
1144 static void fr_destroy(struct net_device *frad)
1145 {
1146 	hdlc_device *hdlc = dev_to_hdlc(frad);
1147 	pvc_device *pvc = state(hdlc)->first_pvc;
1148 	state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1149 	state(hdlc)->dce_pvc_count = 0;
1150 	state(hdlc)->dce_changed = 1;
1151 
1152 	while (pvc) {
1153 		pvc_device *next = pvc->next;
1154 		/* destructors will free_netdev() main and ether */
1155 		if (pvc->main)
1156 			unregister_netdevice(pvc->main);
1157 
1158 		if (pvc->ether)
1159 			unregister_netdevice(pvc->ether);
1160 
1161 		kfree(pvc);
1162 		pvc = next;
1163 	}
1164 }
1165 
1166 
1167 static struct hdlc_proto proto = {
1168 	.close		= fr_close,
1169 	.start		= fr_start,
1170 	.stop		= fr_stop,
1171 	.detach		= fr_destroy,
1172 	.ioctl		= fr_ioctl,
1173 	.netif_rx	= fr_rx,
1174 	.module		= THIS_MODULE,
1175 };
1176 
1177 
1178 static int fr_ioctl(struct net_device *dev, struct ifreq *ifr)
1179 {
1180 	fr_proto __user *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
1181 	const size_t size = sizeof(fr_proto);
1182 	fr_proto new_settings;
1183 	hdlc_device *hdlc = dev_to_hdlc(dev);
1184 	fr_proto_pvc pvc;
1185 	int result;
1186 
1187 	switch (ifr->ifr_settings.type) {
1188 	case IF_GET_PROTO:
1189 		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1190 			return -EINVAL;
1191 		ifr->ifr_settings.type = IF_PROTO_FR;
1192 		if (ifr->ifr_settings.size < size) {
1193 			ifr->ifr_settings.size = size; /* data size wanted */
1194 			return -ENOBUFS;
1195 		}
1196 		if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1197 			return -EFAULT;
1198 		return 0;
1199 
1200 	case IF_PROTO_FR:
1201 		if (!capable(CAP_NET_ADMIN))
1202 			return -EPERM;
1203 
1204 		if (dev->flags & IFF_UP)
1205 			return -EBUSY;
1206 
1207 		if (copy_from_user(&new_settings, fr_s, size))
1208 			return -EFAULT;
1209 
1210 		if (new_settings.lmi == LMI_DEFAULT)
1211 			new_settings.lmi = LMI_ANSI;
1212 
1213 		if ((new_settings.lmi != LMI_NONE &&
1214 		     new_settings.lmi != LMI_ANSI &&
1215 		     new_settings.lmi != LMI_CCITT &&
1216 		     new_settings.lmi != LMI_CISCO) ||
1217 		    new_settings.t391 < 1 ||
1218 		    new_settings.t392 < 2 ||
1219 		    new_settings.n391 < 1 ||
1220 		    new_settings.n392 < 1 ||
1221 		    new_settings.n393 < new_settings.n392 ||
1222 		    new_settings.n393 > 32 ||
1223 		    (new_settings.dce != 0 &&
1224 		     new_settings.dce != 1))
1225 			return -EINVAL;
1226 
1227 		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
1228 		if (result)
1229 			return result;
1230 
1231 		if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1232 			result = attach_hdlc_protocol(dev, &proto,
1233 						      sizeof(struct frad_state));
1234 			if (result)
1235 				return result;
1236 			state(hdlc)->first_pvc = NULL;
1237 			state(hdlc)->dce_pvc_count = 0;
1238 		}
1239 		memcpy(&state(hdlc)->settings, &new_settings, size);
1240 		dev->type = ARPHRD_FRAD;
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