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v6.8
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*****************************************************************************/
  3
  4/*
  5 *	hdlcdrv.c  -- HDLC packet radio network driver.
  6 *
  7 *	Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
  8 *
  9 *  Please note that the GPL allows you to use the driver, NOT the radio.
 10 *  In order to use the radio, you need a license from the communications
 11 *  authority of your country.
 12 *
 13 *  The driver was derived from Donald Beckers skeleton.c
 14 *	Written 1993-94 by Donald Becker.
 15 *
 16 *  History:
 17 *   0.1  21.09.1996  Started
 18 *        18.10.1996  Changed to new user space access routines 
 19 *                    (copy_{to,from}_user)
 20 *   0.2  21.11.1996  various small changes
 21 *   0.3  03.03.1997  fixed (hopefully) IP not working with ax.25 as a module
 22 *   0.4  16.04.1997  init code/data tagged
 23 *   0.5  30.07.1997  made HDLC buffers bigger (solves a problem with the
 24 *                    soundmodem driver)
 25 *   0.6  05.04.1998  add spinlocks
 26 *   0.7  03.08.1999  removed some old compatibility cruft
 27 *   0.8  12.02.2000  adapted to softnet driver interface
 28 */
 29
 30/*****************************************************************************/
 31
 32#include <linux/capability.h>
 33#include <linux/compat.h>
 34#include <linux/module.h>
 35#include <linux/types.h>
 36#include <linux/net.h>
 37#include <linux/in.h>
 38#include <linux/if.h>
 39#include <linux/errno.h>
 40#include <linux/init.h>
 41#include <linux/bitops.h>
 42
 43#include <linux/netdevice.h>
 44#include <linux/if_arp.h>
 45#include <linux/skbuff.h>
 46#include <linux/hdlcdrv.h>
 47#include <linux/random.h>
 48#include <net/ax25.h> 
 49#include <linux/uaccess.h>
 50
 51#include <linux/crc-ccitt.h>
 52
 53/* --------------------------------------------------------------------- */
 54
 55#define KISS_VERBOSE
 56
 57/* --------------------------------------------------------------------- */
 58
 59#define PARAM_TXDELAY   1
 60#define PARAM_PERSIST   2
 61#define PARAM_SLOTTIME  3
 62#define PARAM_TXTAIL    4
 63#define PARAM_FULLDUP   5
 64#define PARAM_HARDWARE  6
 65#define PARAM_RETURN    255
 66
 67/* --------------------------------------------------------------------- */
 68/*
 69 * the CRC routines are stolen from WAMPES
 70 * by Dieter Deyke
 71 */
 72
 73
 74/*---------------------------------------------------------------------------*/
 75
 76static inline void append_crc_ccitt(unsigned char *buffer, int len)
 77{
 78	unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff;
 79	buffer += len;
 80	*buffer++ = crc;
 81	*buffer++ = crc >> 8;
 82}
 83
 84/*---------------------------------------------------------------------------*/
 85
 86static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
 87{
 88	return (crc_ccitt(0xffff, buf, cnt) & 0xffff) == 0xf0b8;
 89}
 90
 91/*---------------------------------------------------------------------------*/
 92
 93#if 0
 94static int calc_crc_ccitt(const unsigned char *buf, int cnt)
 95{
 96	unsigned int crc = 0xffff;
 97
 98	for (; cnt > 0; cnt--)
 99		crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
100	crc ^= 0xffff;
101	return crc & 0xffff;
102}
103#endif
104
105/* ---------------------------------------------------------------------- */
106
107#define tenms_to_2flags(s,tenms) ((tenms * s->par.bitrate) / 100 / 16)
108
109/* ---------------------------------------------------------------------- */
110/*
111 * The HDLC routines
112 */
113
114static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits, 
115			     int num)
116{
117	int added = 0;
118	
119	while (s->hdlcrx.rx_state && num >= 8) {
120		if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
121			s->hdlcrx.rx_state = 0;
122			return 0;
123		}
124		*s->hdlcrx.bp++ = bits >> (32-num);
125		s->hdlcrx.len++;
126		num -= 8;
127		added += 8;
128	}
129	return added;
130}
131
132static void hdlc_rx_flag(struct net_device *dev, struct hdlcdrv_state *s)
133{
134	struct sk_buff *skb;
135	int pkt_len;
136	unsigned char *cp;
137
138	if (s->hdlcrx.len < 4) 
139		return;
140	if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len)) 
141		return;
142	pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
143	if (!(skb = dev_alloc_skb(pkt_len))) {
144		printk("%s: memory squeeze, dropping packet\n", dev->name);
145		dev->stats.rx_dropped++;
146		return;
147	}
148	cp = skb_put(skb, pkt_len);
149	*cp++ = 0; /* KISS kludge */
150	memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
151	skb->protocol = ax25_type_trans(skb, dev);
152	netif_rx(skb);
153	dev->stats.rx_packets++;
154}
155
156void hdlcdrv_receiver(struct net_device *dev, struct hdlcdrv_state *s)
157{
158	int i;
159	unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
160	
161	if (!s || s->magic != HDLCDRV_MAGIC) 
162		return;
163	if (test_and_set_bit(0, &s->hdlcrx.in_hdlc_rx))
164		return;
165
166	while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
167		word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);	
168
169#ifdef HDLCDRV_DEBUG
170		hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
171#endif /* HDLCDRV_DEBUG */
172	       	s->hdlcrx.bitstream >>= 16;
173		s->hdlcrx.bitstream |= word << 16;
174		s->hdlcrx.bitbuf >>= 16;
175		s->hdlcrx.bitbuf |= word << 16;
176		s->hdlcrx.numbits += 16;
177		for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
178		    mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff; 
179		    i >= 0; 
180		    i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1, 
181		    mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
182			if ((s->hdlcrx.bitstream & mask1) == mask1)
183				s->hdlcrx.rx_state = 0; /* abort received */
184			else if ((s->hdlcrx.bitstream & mask2) == mask3) {
185				/* flag received */
186				if (s->hdlcrx.rx_state) {
187					hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf 
188							  << (8+i),
189							  s->hdlcrx.numbits
190							  -8-i);
191					hdlc_rx_flag(dev, s);
192				}
193				s->hdlcrx.len = 0;
194				s->hdlcrx.bp = s->hdlcrx.buffer;
195				s->hdlcrx.rx_state = 1;
196				s->hdlcrx.numbits = i;
197			} else if ((s->hdlcrx.bitstream & mask4) == mask5) {
198				/* stuffed bit */
199				s->hdlcrx.numbits--;
200				s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
201					((s->hdlcrx.bitbuf & mask6) << 1);
202			}
203		}
204		s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
205						       s->hdlcrx.numbits);
206	}
207	clear_bit(0, &s->hdlcrx.in_hdlc_rx);
208}
209
210/* ---------------------------------------------------------------------- */
211
212static inline void do_kiss_params(struct hdlcdrv_state *s,
213				  unsigned char *data, unsigned long len)
214{
215
216#ifdef KISS_VERBOSE
217#define PKP(a,b) printk(KERN_INFO "hdlcdrv.c: channel params: " a "\n", b)
218#else /* KISS_VERBOSE */	      
219#define PKP(a,b) 
220#endif /* KISS_VERBOSE */	      
221
222	if (len < 2)
223		return;
224	switch(data[0]) {
225	case PARAM_TXDELAY:
226		s->ch_params.tx_delay = data[1];
227		PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
228		break;
229	case PARAM_PERSIST:   
230		s->ch_params.ppersist = data[1];
231		PKP("p persistence = %u", s->ch_params.ppersist);
232		break;
233	case PARAM_SLOTTIME:  
234		s->ch_params.slottime = data[1];
235		PKP("slot time = %ums", s->ch_params.slottime);
236		break;
237	case PARAM_TXTAIL:    
238		s->ch_params.tx_tail = data[1];
239		PKP("TX tail = %ums", s->ch_params.tx_tail);
240		break;
241	case PARAM_FULLDUP:   
242		s->ch_params.fulldup = !!data[1];
243		PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
244		break;
245	default:
246		break;
247	}
248#undef PKP
249}
250
251/* ---------------------------------------------------------------------- */
252
253void hdlcdrv_transmitter(struct net_device *dev, struct hdlcdrv_state *s)
254{
255	unsigned int mask1, mask2, mask3;
256	int i;
257	struct sk_buff *skb;
258	int pkt_len;
259
260	if (!s || s->magic != HDLCDRV_MAGIC) 
261		return;
262	if (test_and_set_bit(0, &s->hdlctx.in_hdlc_tx))
263		return;
264	for (;;) {
265		if (s->hdlctx.numbits >= 16) {
266			if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
267				clear_bit(0, &s->hdlctx.in_hdlc_tx);
268				return;
269			}
270			hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
271			s->hdlctx.bitbuf >>= 16;
272			s->hdlctx.numbits -= 16;
273		}
274		switch (s->hdlctx.tx_state) {
275		default:
276			clear_bit(0, &s->hdlctx.in_hdlc_tx);
277			return;
278		case 0:
279		case 1:
280			if (s->hdlctx.numflags) {
281				s->hdlctx.numflags--;
282				s->hdlctx.bitbuf |= 
283					0x7e7e << s->hdlctx.numbits;
284				s->hdlctx.numbits += 16;
285				break;
286			}
287			if (s->hdlctx.tx_state == 1) {
288				clear_bit(0, &s->hdlctx.in_hdlc_tx);
289				return;
290			}
291			if (!(skb = s->skb)) {
292				int flgs = tenms_to_2flags(s, s->ch_params.tx_tail);
293				if (flgs < 2)
294					flgs = 2;
295				s->hdlctx.tx_state = 1;
296				s->hdlctx.numflags = flgs;
297				break;
298			}
299			s->skb = NULL;
300			netif_wake_queue(dev);
301			pkt_len = skb->len-1; /* strip KISS byte */
302			if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
303				s->hdlctx.tx_state = 0;
304				s->hdlctx.numflags = 1;
305				dev_kfree_skb_irq(skb);
306				break;
307			}
308			skb_copy_from_linear_data_offset(skb, 1,
309							 s->hdlctx.buffer,
310							 pkt_len);
311			dev_kfree_skb_irq(skb);
312			s->hdlctx.bp = s->hdlctx.buffer;
313			append_crc_ccitt(s->hdlctx.buffer, pkt_len);
314			s->hdlctx.len = pkt_len+2; /* the appended CRC */
315			s->hdlctx.tx_state = 2;
316			s->hdlctx.bitstream = 0;
317			dev->stats.tx_packets++;
318			break;
319		case 2:
320			if (!s->hdlctx.len) {
321				s->hdlctx.tx_state = 0;
322				s->hdlctx.numflags = 1;
323				break;
324			}
325			s->hdlctx.len--;
326			s->hdlctx.bitbuf |= *s->hdlctx.bp <<
327				s->hdlctx.numbits;
328			s->hdlctx.bitstream >>= 8;
329			s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
330			mask1 = 0x1f000;
331			mask2 = 0x10000;
332			mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
333			s->hdlctx.numbits += 8;
334			for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1, 
335			    mask3 = (mask3 << 1) | 1) {
336				if ((s->hdlctx.bitstream & mask1) != mask1) 
337					continue;
338				s->hdlctx.bitstream &= ~mask2;
339				s->hdlctx.bitbuf = 
340					(s->hdlctx.bitbuf & mask3) |
341						((s->hdlctx.bitbuf & 
342						 (~mask3)) << 1);
343				s->hdlctx.numbits++;
344				mask3 = (mask3 << 1) | 1;
345			}
346			break;
347		}
348	}
349}
350
351/* ---------------------------------------------------------------------- */
352
353static void start_tx(struct net_device *dev, struct hdlcdrv_state *s)
354{
355	s->hdlctx.tx_state = 0;
356	s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
357	s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
358	hdlcdrv_transmitter(dev, s);
359	s->hdlctx.ptt = 1;
360	s->ptt_keyed++;
361}
362
363/* ---------------------------------------------------------------------- */
364
365void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
366{
367	if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb) 
368		return;
369	if (s->ch_params.fulldup) {
370		start_tx(dev, s);
371		return;
372	}
373	if (s->hdlcrx.dcd) {
374		s->hdlctx.slotcnt = s->ch_params.slottime;
375		return;
376	}
377	if ((--s->hdlctx.slotcnt) > 0)
378		return;
379	s->hdlctx.slotcnt = s->ch_params.slottime;
380	if (get_random_u8() > s->ch_params.ppersist)
381		return;
382	start_tx(dev, s);
383}
384
385/* --------------------------------------------------------------------- */
386/*
387 * ===================== network driver interface =========================
388 */
389
390static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
391				       struct net_device *dev)
392{
393	struct hdlcdrv_state *sm = netdev_priv(dev);
394
395	if (skb->protocol == htons(ETH_P_IP))
396		return ax25_ip_xmit(skb);
397
398	if (skb->data[0] != 0) {
399		do_kiss_params(sm, skb->data, skb->len);
400		dev_kfree_skb(skb);
401		return NETDEV_TX_OK;
402	}
403	if (sm->skb) {
404		dev_kfree_skb(skb);
405		return NETDEV_TX_OK;
406	}
407	netif_stop_queue(dev);
408	sm->skb = skb;
409	return NETDEV_TX_OK;
410}
411
412/* --------------------------------------------------------------------- */
413
414static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
415{
416	struct sockaddr *sa = (struct sockaddr *)addr;
417
418	/* addr is an AX.25 shifted ASCII mac address */
419	dev_addr_set(dev, sa->sa_data);
420	return 0;                                         
421}
422
423/* --------------------------------------------------------------------- */
424/*
425 * Open/initialize the board. This is called (in the current kernel)
426 * sometime after booting when the 'ifconfig' program is run.
427 *
428 * This routine should set everything up anew at each open, even
429 * registers that "should" only need to be set once at boot, so that
430 * there is non-reboot way to recover if something goes wrong.
431 */
432
433static int hdlcdrv_open(struct net_device *dev)
434{
435	struct hdlcdrv_state *s = netdev_priv(dev);
436	int i;
437
438	if (!s->ops || !s->ops->open)
439		return -ENODEV;
440
441	/*
442	 * initialise some variables
443	 */
444	s->opened = 1;
445	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
446	s->hdlcrx.in_hdlc_rx = 0;
447	s->hdlcrx.rx_state = 0;
448	
449	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
450	s->hdlctx.in_hdlc_tx = 0;
451	s->hdlctx.tx_state = 1;
452	s->hdlctx.numflags = 0;
453	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
454	s->hdlctx.ptt = 0;
455	s->hdlctx.slotcnt = s->ch_params.slottime;
456	s->hdlctx.calibrate = 0;
457
458	i = s->ops->open(dev);
459	if (i)
460		return i;
461	netif_start_queue(dev);
462	return 0;
463}
464
465/* --------------------------------------------------------------------- */
466/* 
467 * The inverse routine to hdlcdrv_open(). 
468 */
469
470static int hdlcdrv_close(struct net_device *dev)
471{
472	struct hdlcdrv_state *s = netdev_priv(dev);
473	int i = 0;
474
475	netif_stop_queue(dev);
476
477	if (s->ops && s->ops->close)
478		i = s->ops->close(dev);
479	dev_kfree_skb(s->skb);
480	s->skb = NULL;
481	s->opened = 0;
482	return i;
483}
484
485/* --------------------------------------------------------------------- */
486
487static int hdlcdrv_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
488				  void __user *data, int cmd)
489{
490	struct hdlcdrv_state *s = netdev_priv(dev);
491	struct hdlcdrv_ioctl bi;
492
493	if (cmd != SIOCDEVPRIVATE)
494		return -ENOIOCTLCMD;
495
496	if (in_compat_syscall()) /* to be implemented */
497		return -ENOIOCTLCMD;
498
499	if (copy_from_user(&bi, data, sizeof(bi)))
500		return -EFAULT;
501
502	switch (bi.cmd) {
503	default:
504		if (s->ops && s->ops->ioctl)
505			return s->ops->ioctl(dev, data, &bi, cmd);
506		return -ENOIOCTLCMD;
507
508	case HDLCDRVCTL_GETCHANNELPAR:
509		bi.data.cp.tx_delay = s->ch_params.tx_delay;
510		bi.data.cp.tx_tail = s->ch_params.tx_tail;
511		bi.data.cp.slottime = s->ch_params.slottime;
512		bi.data.cp.ppersist = s->ch_params.ppersist;
513		bi.data.cp.fulldup = s->ch_params.fulldup;
514		break;
515
516	case HDLCDRVCTL_SETCHANNELPAR:
517		if (!capable(CAP_NET_ADMIN))
518			return -EACCES;
519		s->ch_params.tx_delay = bi.data.cp.tx_delay;
520		s->ch_params.tx_tail = bi.data.cp.tx_tail;
521		s->ch_params.slottime = bi.data.cp.slottime;
522		s->ch_params.ppersist = bi.data.cp.ppersist;
523		s->ch_params.fulldup = bi.data.cp.fulldup;
524		s->hdlctx.slotcnt = 1;
525		return 0;
526		
527	case HDLCDRVCTL_GETMODEMPAR:
528		bi.data.mp.iobase = dev->base_addr;
529		bi.data.mp.irq = dev->irq;
530		bi.data.mp.dma = dev->dma;
531		bi.data.mp.dma2 = s->ptt_out.dma2;
532		bi.data.mp.seriobase = s->ptt_out.seriobase;
533		bi.data.mp.pariobase = s->ptt_out.pariobase;
534		bi.data.mp.midiiobase = s->ptt_out.midiiobase;
535		break;
536
537	case HDLCDRVCTL_SETMODEMPAR:
538		if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
539			return -EACCES;
540		dev->base_addr = bi.data.mp.iobase;
541		dev->irq = bi.data.mp.irq;
542		dev->dma = bi.data.mp.dma;
543		s->ptt_out.dma2 = bi.data.mp.dma2;
544		s->ptt_out.seriobase = bi.data.mp.seriobase;
545		s->ptt_out.pariobase = bi.data.mp.pariobase;
546		s->ptt_out.midiiobase = bi.data.mp.midiiobase;
547		return 0;	
548	
549	case HDLCDRVCTL_GETSTAT:
550		bi.data.cs.ptt = hdlcdrv_ptt(s);
551		bi.data.cs.dcd = s->hdlcrx.dcd;
552		bi.data.cs.ptt_keyed = s->ptt_keyed;
553		bi.data.cs.tx_packets = dev->stats.tx_packets;
554		bi.data.cs.tx_errors = dev->stats.tx_errors;
555		bi.data.cs.rx_packets = dev->stats.rx_packets;
556		bi.data.cs.rx_errors = dev->stats.rx_errors;
557		break;		
558
559	case HDLCDRVCTL_OLDGETSTAT:
560		bi.data.ocs.ptt = hdlcdrv_ptt(s);
561		bi.data.ocs.dcd = s->hdlcrx.dcd;
562		bi.data.ocs.ptt_keyed = s->ptt_keyed;
563		break;		
564
565	case HDLCDRVCTL_CALIBRATE:
566		if(!capable(CAP_SYS_RAWIO))
567			return -EPERM;
568		if (s->par.bitrate <= 0)
569			return -EINVAL;
570		if (bi.data.calibrate > INT_MAX / s->par.bitrate)
571			return -EINVAL;
572		s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
573		return 0;
574
575	case HDLCDRVCTL_GETSAMPLES:
576#ifndef HDLCDRV_DEBUG
577		return -EPERM;
578#else /* HDLCDRV_DEBUG */
579		if (s->bitbuf_channel.rd == s->bitbuf_channel.wr) 
580			return -EAGAIN;
581		bi.data.bits = 
582			s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
583		s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
584			sizeof(s->bitbuf_channel.buffer);
585		break;
586#endif /* HDLCDRV_DEBUG */
587				
588	case HDLCDRVCTL_GETBITS:
589#ifndef HDLCDRV_DEBUG
590		return -EPERM;
591#else /* HDLCDRV_DEBUG */
592		if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr) 
593			return -EAGAIN;
594		bi.data.bits = 
595			s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
596		s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
597			sizeof(s->bitbuf_hdlc.buffer);
598		break;		
599#endif /* HDLCDRV_DEBUG */
600
601	case HDLCDRVCTL_DRIVERNAME:
602		if (s->ops && s->ops->drvname) {
603			strscpy(bi.data.drivername, s->ops->drvname,
604				sizeof(bi.data.drivername));
605			break;
606		}
607		bi.data.drivername[0] = '\0';
608		break;
609		
610	}
611	if (copy_to_user(data, &bi, sizeof(bi)))
612		return -EFAULT;
613	return 0;
614
615}
616
617/* --------------------------------------------------------------------- */
618
619static const struct net_device_ops hdlcdrv_netdev = {
620	.ndo_open	= hdlcdrv_open,
621	.ndo_stop	= hdlcdrv_close,
622	.ndo_start_xmit = hdlcdrv_send_packet,
623	.ndo_siocdevprivate  = hdlcdrv_siocdevprivate,
624	.ndo_set_mac_address = hdlcdrv_set_mac_address,
625};
626
627/*
628 * Initialize fields in hdlcdrv
629 */
630static void hdlcdrv_setup(struct net_device *dev)
631{
632	static const struct hdlcdrv_channel_params dflt_ch_params = { 
633		20, 2, 10, 40, 0 
634	};
635	struct hdlcdrv_state *s = netdev_priv(dev);
636
637	/*
638	 * initialize the hdlcdrv_state struct
639	 */
640	s->ch_params = dflt_ch_params;
641	s->ptt_keyed = 0;
642
643	spin_lock_init(&s->hdlcrx.hbuf.lock);
644	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
645	s->hdlcrx.in_hdlc_rx = 0;
646	s->hdlcrx.rx_state = 0;
647	
648	spin_lock_init(&s->hdlctx.hbuf.lock);
649	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
650	s->hdlctx.in_hdlc_tx = 0;
651	s->hdlctx.tx_state = 1;
652	s->hdlctx.numflags = 0;
653	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
654	s->hdlctx.ptt = 0;
655	s->hdlctx.slotcnt = s->ch_params.slottime;
656	s->hdlctx.calibrate = 0;
657
658#ifdef HDLCDRV_DEBUG
659	s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
660	s->bitbuf_channel.shreg = 0x80;
661
662	s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
663	s->bitbuf_hdlc.shreg = 0x80;
664#endif /* HDLCDRV_DEBUG */
665
666
667	/* Fill in the fields of the device structure */
668
669	s->skb = NULL;
670	
671	dev->netdev_ops = &hdlcdrv_netdev;
672	dev->header_ops = &ax25_header_ops;
673	
674	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
675	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
676	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
677	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
678	memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
679	dev_addr_set(dev, (u8 *)&ax25_defaddr);
680	dev->tx_queue_len = 16;
681}
682
683/* --------------------------------------------------------------------- */
684struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
685				    unsigned int privsize, const char *ifname,
686				    unsigned int baseaddr, unsigned int irq, 
687				    unsigned int dma) 
688{
689	struct net_device *dev;
690	struct hdlcdrv_state *s;
691	int err;
 
 
692
693	if (privsize < sizeof(struct hdlcdrv_state))
694		privsize = sizeof(struct hdlcdrv_state);
695
696	dev = alloc_netdev(privsize, ifname, NET_NAME_UNKNOWN, hdlcdrv_setup);
697	if (!dev)
698		return ERR_PTR(-ENOMEM);
699
700	/*
701	 * initialize part of the hdlcdrv_state struct
702	 */
703	s = netdev_priv(dev);
704	s->magic = HDLCDRV_MAGIC;
705	s->ops = ops;
706	dev->base_addr = baseaddr;
707	dev->irq = irq;
708	dev->dma = dma;
709
710	err = register_netdev(dev);
711	if (err < 0) {
712		printk(KERN_WARNING "hdlcdrv: cannot register net "
713		       "device %s\n", dev->name);
714		free_netdev(dev);
715		dev = ERR_PTR(err);
716	}
717	return dev;
718}
719
720/* --------------------------------------------------------------------- */
721
722void hdlcdrv_unregister(struct net_device *dev) 
723{
724	struct hdlcdrv_state *s = netdev_priv(dev);
725
726	BUG_ON(s->magic != HDLCDRV_MAGIC);
727
728	if (s->opened && s->ops->close)
729		s->ops->close(dev);
730	unregister_netdev(dev);
731	
732	free_netdev(dev);
733}
734
735/* --------------------------------------------------------------------- */
736
737EXPORT_SYMBOL(hdlcdrv_receiver);
738EXPORT_SYMBOL(hdlcdrv_transmitter);
739EXPORT_SYMBOL(hdlcdrv_arbitrate);
740EXPORT_SYMBOL(hdlcdrv_register);
741EXPORT_SYMBOL(hdlcdrv_unregister);
742
743/* --------------------------------------------------------------------- */
744
745static int __init hdlcdrv_init_driver(void)
746{
747	printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
748	printk(KERN_INFO "hdlcdrv: version 0.8\n");
749	return 0;
750}
751
752/* --------------------------------------------------------------------- */
753
754static void __exit hdlcdrv_cleanup_driver(void)
755{
756	printk(KERN_INFO "hdlcdrv: cleanup\n");
757}
758
759/* --------------------------------------------------------------------- */
760
761MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
762MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
763MODULE_LICENSE("GPL");
764module_init(hdlcdrv_init_driver);
765module_exit(hdlcdrv_cleanup_driver);
766
767/* --------------------------------------------------------------------- */
v5.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*****************************************************************************/
  3
  4/*
  5 *	hdlcdrv.c  -- HDLC packet radio network driver.
  6 *
  7 *	Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
  8 *
  9 *  Please note that the GPL allows you to use the driver, NOT the radio.
 10 *  In order to use the radio, you need a license from the communications
 11 *  authority of your country.
 12 *
 13 *  The driver was derived from Donald Beckers skeleton.c
 14 *	Written 1993-94 by Donald Becker.
 15 *
 16 *  History:
 17 *   0.1  21.09.1996  Started
 18 *        18.10.1996  Changed to new user space access routines 
 19 *                    (copy_{to,from}_user)
 20 *   0.2  21.11.1996  various small changes
 21 *   0.3  03.03.1997  fixed (hopefully) IP not working with ax.25 as a module
 22 *   0.4  16.04.1997  init code/data tagged
 23 *   0.5  30.07.1997  made HDLC buffers bigger (solves a problem with the
 24 *                    soundmodem driver)
 25 *   0.6  05.04.1998  add spinlocks
 26 *   0.7  03.08.1999  removed some old compatibility cruft
 27 *   0.8  12.02.2000  adapted to softnet driver interface
 28 */
 29
 30/*****************************************************************************/
 31
 32#include <linux/capability.h>
 
 33#include <linux/module.h>
 34#include <linux/types.h>
 35#include <linux/net.h>
 36#include <linux/in.h>
 37#include <linux/if.h>
 38#include <linux/errno.h>
 39#include <linux/init.h>
 40#include <linux/bitops.h>
 41
 42#include <linux/netdevice.h>
 43#include <linux/if_arp.h>
 44#include <linux/skbuff.h>
 45#include <linux/hdlcdrv.h>
 46#include <linux/random.h>
 47#include <net/ax25.h> 
 48#include <linux/uaccess.h>
 49
 50#include <linux/crc-ccitt.h>
 51
 52/* --------------------------------------------------------------------- */
 53
 54#define KISS_VERBOSE
 55
 56/* --------------------------------------------------------------------- */
 57
 58#define PARAM_TXDELAY   1
 59#define PARAM_PERSIST   2
 60#define PARAM_SLOTTIME  3
 61#define PARAM_TXTAIL    4
 62#define PARAM_FULLDUP   5
 63#define PARAM_HARDWARE  6
 64#define PARAM_RETURN    255
 65
 66/* --------------------------------------------------------------------- */
 67/*
 68 * the CRC routines are stolen from WAMPES
 69 * by Dieter Deyke
 70 */
 71
 72
 73/*---------------------------------------------------------------------------*/
 74
 75static inline void append_crc_ccitt(unsigned char *buffer, int len)
 76{
 77 	unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff;
 78	buffer += len;
 79	*buffer++ = crc;
 80	*buffer++ = crc >> 8;
 81}
 82
 83/*---------------------------------------------------------------------------*/
 84
 85static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
 86{
 87	return (crc_ccitt(0xffff, buf, cnt) & 0xffff) == 0xf0b8;
 88}
 89
 90/*---------------------------------------------------------------------------*/
 91
 92#if 0
 93static int calc_crc_ccitt(const unsigned char *buf, int cnt)
 94{
 95	unsigned int crc = 0xffff;
 96
 97	for (; cnt > 0; cnt--)
 98		crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
 99	crc ^= 0xffff;
100	return crc & 0xffff;
101}
102#endif
103
104/* ---------------------------------------------------------------------- */
105
106#define tenms_to_2flags(s,tenms) ((tenms * s->par.bitrate) / 100 / 16)
107
108/* ---------------------------------------------------------------------- */
109/*
110 * The HDLC routines
111 */
112
113static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits, 
114			     int num)
115{
116	int added = 0;
117	
118	while (s->hdlcrx.rx_state && num >= 8) {
119		if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
120			s->hdlcrx.rx_state = 0;
121			return 0;
122		}
123		*s->hdlcrx.bp++ = bits >> (32-num);
124		s->hdlcrx.len++;
125		num -= 8;
126		added += 8;
127	}
128	return added;
129}
130
131static void hdlc_rx_flag(struct net_device *dev, struct hdlcdrv_state *s)
132{
133	struct sk_buff *skb;
134	int pkt_len;
135	unsigned char *cp;
136
137	if (s->hdlcrx.len < 4) 
138		return;
139	if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len)) 
140		return;
141	pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
142	if (!(skb = dev_alloc_skb(pkt_len))) {
143		printk("%s: memory squeeze, dropping packet\n", dev->name);
144		dev->stats.rx_dropped++;
145		return;
146	}
147	cp = skb_put(skb, pkt_len);
148	*cp++ = 0; /* KISS kludge */
149	memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
150	skb->protocol = ax25_type_trans(skb, dev);
151	netif_rx(skb);
152	dev->stats.rx_packets++;
153}
154
155void hdlcdrv_receiver(struct net_device *dev, struct hdlcdrv_state *s)
156{
157	int i;
158	unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
159	
160	if (!s || s->magic != HDLCDRV_MAGIC) 
161		return;
162	if (test_and_set_bit(0, &s->hdlcrx.in_hdlc_rx))
163		return;
164
165	while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
166		word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);	
167
168#ifdef HDLCDRV_DEBUG
169		hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
170#endif /* HDLCDRV_DEBUG */
171	       	s->hdlcrx.bitstream >>= 16;
172		s->hdlcrx.bitstream |= word << 16;
173		s->hdlcrx.bitbuf >>= 16;
174		s->hdlcrx.bitbuf |= word << 16;
175		s->hdlcrx.numbits += 16;
176		for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
177		    mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff; 
178		    i >= 0; 
179		    i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1, 
180		    mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
181			if ((s->hdlcrx.bitstream & mask1) == mask1)
182				s->hdlcrx.rx_state = 0; /* abort received */
183			else if ((s->hdlcrx.bitstream & mask2) == mask3) {
184				/* flag received */
185				if (s->hdlcrx.rx_state) {
186					hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf 
187							  << (8+i),
188							  s->hdlcrx.numbits
189							  -8-i);
190					hdlc_rx_flag(dev, s);
191				}
192				s->hdlcrx.len = 0;
193				s->hdlcrx.bp = s->hdlcrx.buffer;
194				s->hdlcrx.rx_state = 1;
195				s->hdlcrx.numbits = i;
196			} else if ((s->hdlcrx.bitstream & mask4) == mask5) {
197				/* stuffed bit */
198				s->hdlcrx.numbits--;
199				s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
200					((s->hdlcrx.bitbuf & mask6) << 1);
201			}
202		}
203		s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
204						       s->hdlcrx.numbits);
205	}
206	clear_bit(0, &s->hdlcrx.in_hdlc_rx);
207}
208
209/* ---------------------------------------------------------------------- */
210
211static inline void do_kiss_params(struct hdlcdrv_state *s,
212				  unsigned char *data, unsigned long len)
213{
214
215#ifdef KISS_VERBOSE
216#define PKP(a,b) printk(KERN_INFO "hdlcdrv.c: channel params: " a "\n", b)
217#else /* KISS_VERBOSE */	      
218#define PKP(a,b) 
219#endif /* KISS_VERBOSE */	      
220
221	if (len < 2)
222		return;
223	switch(data[0]) {
224	case PARAM_TXDELAY:
225		s->ch_params.tx_delay = data[1];
226		PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
227		break;
228	case PARAM_PERSIST:   
229		s->ch_params.ppersist = data[1];
230		PKP("p persistence = %u", s->ch_params.ppersist);
231		break;
232	case PARAM_SLOTTIME:  
233		s->ch_params.slottime = data[1];
234		PKP("slot time = %ums", s->ch_params.slottime);
235		break;
236	case PARAM_TXTAIL:    
237		s->ch_params.tx_tail = data[1];
238		PKP("TX tail = %ums", s->ch_params.tx_tail);
239		break;
240	case PARAM_FULLDUP:   
241		s->ch_params.fulldup = !!data[1];
242		PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
243		break;
244	default:
245		break;
246	}
247#undef PKP
248}
249
250/* ---------------------------------------------------------------------- */
251
252void hdlcdrv_transmitter(struct net_device *dev, struct hdlcdrv_state *s)
253{
254	unsigned int mask1, mask2, mask3;
255	int i;
256	struct sk_buff *skb;
257	int pkt_len;
258
259	if (!s || s->magic != HDLCDRV_MAGIC) 
260		return;
261	if (test_and_set_bit(0, &s->hdlctx.in_hdlc_tx))
262		return;
263	for (;;) {
264		if (s->hdlctx.numbits >= 16) {
265			if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
266				clear_bit(0, &s->hdlctx.in_hdlc_tx);
267				return;
268			}
269			hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
270			s->hdlctx.bitbuf >>= 16;
271			s->hdlctx.numbits -= 16;
272		}
273		switch (s->hdlctx.tx_state) {
274		default:
275			clear_bit(0, &s->hdlctx.in_hdlc_tx);
276			return;
277		case 0:
278		case 1:
279			if (s->hdlctx.numflags) {
280				s->hdlctx.numflags--;
281				s->hdlctx.bitbuf |= 
282					0x7e7e << s->hdlctx.numbits;
283				s->hdlctx.numbits += 16;
284				break;
285			}
286			if (s->hdlctx.tx_state == 1) {
287				clear_bit(0, &s->hdlctx.in_hdlc_tx);
288				return;
289			}
290			if (!(skb = s->skb)) {
291				int flgs = tenms_to_2flags(s, s->ch_params.tx_tail);
292				if (flgs < 2)
293					flgs = 2;
294				s->hdlctx.tx_state = 1;
295				s->hdlctx.numflags = flgs;
296				break;
297			}
298			s->skb = NULL;
299			netif_wake_queue(dev);
300			pkt_len = skb->len-1; /* strip KISS byte */
301			if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
302				s->hdlctx.tx_state = 0;
303				s->hdlctx.numflags = 1;
304				dev_kfree_skb_irq(skb);
305				break;
306			}
307			skb_copy_from_linear_data_offset(skb, 1,
308							 s->hdlctx.buffer,
309							 pkt_len);
310			dev_kfree_skb_irq(skb);
311			s->hdlctx.bp = s->hdlctx.buffer;
312			append_crc_ccitt(s->hdlctx.buffer, pkt_len);
313			s->hdlctx.len = pkt_len+2; /* the appended CRC */
314			s->hdlctx.tx_state = 2;
315			s->hdlctx.bitstream = 0;
316			dev->stats.tx_packets++;
317			break;
318		case 2:
319			if (!s->hdlctx.len) {
320				s->hdlctx.tx_state = 0;
321				s->hdlctx.numflags = 1;
322				break;
323			}
324			s->hdlctx.len--;
325			s->hdlctx.bitbuf |= *s->hdlctx.bp <<
326				s->hdlctx.numbits;
327			s->hdlctx.bitstream >>= 8;
328			s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
329			mask1 = 0x1f000;
330			mask2 = 0x10000;
331			mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
332			s->hdlctx.numbits += 8;
333			for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1, 
334			    mask3 = (mask3 << 1) | 1) {
335				if ((s->hdlctx.bitstream & mask1) != mask1) 
336					continue;
337				s->hdlctx.bitstream &= ~mask2;
338				s->hdlctx.bitbuf = 
339					(s->hdlctx.bitbuf & mask3) |
340						((s->hdlctx.bitbuf & 
341						 (~mask3)) << 1);
342				s->hdlctx.numbits++;
343				mask3 = (mask3 << 1) | 1;
344			}
345			break;
346		}
347	}
348}
349
350/* ---------------------------------------------------------------------- */
351
352static void start_tx(struct net_device *dev, struct hdlcdrv_state *s)
353{
354	s->hdlctx.tx_state = 0;
355	s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
356	s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
357	hdlcdrv_transmitter(dev, s);
358	s->hdlctx.ptt = 1;
359	s->ptt_keyed++;
360}
361
362/* ---------------------------------------------------------------------- */
363
364void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
365{
366	if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb) 
367		return;
368	if (s->ch_params.fulldup) {
369		start_tx(dev, s);
370		return;
371	}
372	if (s->hdlcrx.dcd) {
373		s->hdlctx.slotcnt = s->ch_params.slottime;
374		return;
375	}
376	if ((--s->hdlctx.slotcnt) > 0)
377		return;
378	s->hdlctx.slotcnt = s->ch_params.slottime;
379	if ((prandom_u32() % 256) > s->ch_params.ppersist)
380		return;
381	start_tx(dev, s);
382}
383
384/* --------------------------------------------------------------------- */
385/*
386 * ===================== network driver interface =========================
387 */
388
389static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
390				       struct net_device *dev)
391{
392	struct hdlcdrv_state *sm = netdev_priv(dev);
393
394	if (skb->protocol == htons(ETH_P_IP))
395		return ax25_ip_xmit(skb);
396
397	if (skb->data[0] != 0) {
398		do_kiss_params(sm, skb->data, skb->len);
399		dev_kfree_skb(skb);
400		return NETDEV_TX_OK;
401	}
402	if (sm->skb) {
403		dev_kfree_skb(skb);
404		return NETDEV_TX_OK;
405	}
406	netif_stop_queue(dev);
407	sm->skb = skb;
408	return NETDEV_TX_OK;
409}
410
411/* --------------------------------------------------------------------- */
412
413static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
414{
415	struct sockaddr *sa = (struct sockaddr *)addr;
416
417	/* addr is an AX.25 shifted ASCII mac address */
418	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); 
419	return 0;                                         
420}
421
422/* --------------------------------------------------------------------- */
423/*
424 * Open/initialize the board. This is called (in the current kernel)
425 * sometime after booting when the 'ifconfig' program is run.
426 *
427 * This routine should set everything up anew at each open, even
428 * registers that "should" only need to be set once at boot, so that
429 * there is non-reboot way to recover if something goes wrong.
430 */
431
432static int hdlcdrv_open(struct net_device *dev)
433{
434	struct hdlcdrv_state *s = netdev_priv(dev);
435	int i;
436
437	if (!s->ops || !s->ops->open)
438		return -ENODEV;
439
440	/*
441	 * initialise some variables
442	 */
443	s->opened = 1;
444	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
445	s->hdlcrx.in_hdlc_rx = 0;
446	s->hdlcrx.rx_state = 0;
447	
448	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
449	s->hdlctx.in_hdlc_tx = 0;
450	s->hdlctx.tx_state = 1;
451	s->hdlctx.numflags = 0;
452	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
453	s->hdlctx.ptt = 0;
454	s->hdlctx.slotcnt = s->ch_params.slottime;
455	s->hdlctx.calibrate = 0;
456
457	i = s->ops->open(dev);
458	if (i)
459		return i;
460	netif_start_queue(dev);
461	return 0;
462}
463
464/* --------------------------------------------------------------------- */
465/* 
466 * The inverse routine to hdlcdrv_open(). 
467 */
468
469static int hdlcdrv_close(struct net_device *dev)
470{
471	struct hdlcdrv_state *s = netdev_priv(dev);
472	int i = 0;
473
474	netif_stop_queue(dev);
475
476	if (s->ops && s->ops->close)
477		i = s->ops->close(dev);
478	dev_kfree_skb(s->skb);
479	s->skb = NULL;
480	s->opened = 0;
481	return i;
482}
483
484/* --------------------------------------------------------------------- */
485
486static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 
487{
488	struct hdlcdrv_state *s = netdev_priv(dev);
489	struct hdlcdrv_ioctl bi;
490
491	if (cmd != SIOCDEVPRIVATE) {
492		if (s->ops && s->ops->ioctl)
493			return s->ops->ioctl(dev, ifr, &bi, cmd);
 
494		return -ENOIOCTLCMD;
495	}
496	if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
497		return -EFAULT;
498
499	switch (bi.cmd) {
500	default:
501		if (s->ops && s->ops->ioctl)
502			return s->ops->ioctl(dev, ifr, &bi, cmd);
503		return -ENOIOCTLCMD;
504
505	case HDLCDRVCTL_GETCHANNELPAR:
506		bi.data.cp.tx_delay = s->ch_params.tx_delay;
507		bi.data.cp.tx_tail = s->ch_params.tx_tail;
508		bi.data.cp.slottime = s->ch_params.slottime;
509		bi.data.cp.ppersist = s->ch_params.ppersist;
510		bi.data.cp.fulldup = s->ch_params.fulldup;
511		break;
512
513	case HDLCDRVCTL_SETCHANNELPAR:
514		if (!capable(CAP_NET_ADMIN))
515			return -EACCES;
516		s->ch_params.tx_delay = bi.data.cp.tx_delay;
517		s->ch_params.tx_tail = bi.data.cp.tx_tail;
518		s->ch_params.slottime = bi.data.cp.slottime;
519		s->ch_params.ppersist = bi.data.cp.ppersist;
520		s->ch_params.fulldup = bi.data.cp.fulldup;
521		s->hdlctx.slotcnt = 1;
522		return 0;
523		
524	case HDLCDRVCTL_GETMODEMPAR:
525		bi.data.mp.iobase = dev->base_addr;
526		bi.data.mp.irq = dev->irq;
527		bi.data.mp.dma = dev->dma;
528		bi.data.mp.dma2 = s->ptt_out.dma2;
529		bi.data.mp.seriobase = s->ptt_out.seriobase;
530		bi.data.mp.pariobase = s->ptt_out.pariobase;
531		bi.data.mp.midiiobase = s->ptt_out.midiiobase;
532		break;
533
534	case HDLCDRVCTL_SETMODEMPAR:
535		if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
536			return -EACCES;
537		dev->base_addr = bi.data.mp.iobase;
538		dev->irq = bi.data.mp.irq;
539		dev->dma = bi.data.mp.dma;
540		s->ptt_out.dma2 = bi.data.mp.dma2;
541		s->ptt_out.seriobase = bi.data.mp.seriobase;
542		s->ptt_out.pariobase = bi.data.mp.pariobase;
543		s->ptt_out.midiiobase = bi.data.mp.midiiobase;
544		return 0;	
545	
546	case HDLCDRVCTL_GETSTAT:
547		bi.data.cs.ptt = hdlcdrv_ptt(s);
548		bi.data.cs.dcd = s->hdlcrx.dcd;
549		bi.data.cs.ptt_keyed = s->ptt_keyed;
550		bi.data.cs.tx_packets = dev->stats.tx_packets;
551		bi.data.cs.tx_errors = dev->stats.tx_errors;
552		bi.data.cs.rx_packets = dev->stats.rx_packets;
553		bi.data.cs.rx_errors = dev->stats.rx_errors;
554		break;		
555
556	case HDLCDRVCTL_OLDGETSTAT:
557		bi.data.ocs.ptt = hdlcdrv_ptt(s);
558		bi.data.ocs.dcd = s->hdlcrx.dcd;
559		bi.data.ocs.ptt_keyed = s->ptt_keyed;
560		break;		
561
562	case HDLCDRVCTL_CALIBRATE:
563		if(!capable(CAP_SYS_RAWIO))
564			return -EPERM;
565		if (s->par.bitrate <= 0)
566			return -EINVAL;
567		if (bi.data.calibrate > INT_MAX / s->par.bitrate)
568			return -EINVAL;
569		s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
570		return 0;
571
572	case HDLCDRVCTL_GETSAMPLES:
573#ifndef HDLCDRV_DEBUG
574		return -EPERM;
575#else /* HDLCDRV_DEBUG */
576		if (s->bitbuf_channel.rd == s->bitbuf_channel.wr) 
577			return -EAGAIN;
578		bi.data.bits = 
579			s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
580		s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
581			sizeof(s->bitbuf_channel.buffer);
582		break;
583#endif /* HDLCDRV_DEBUG */
584				
585	case HDLCDRVCTL_GETBITS:
586#ifndef HDLCDRV_DEBUG
587		return -EPERM;
588#else /* HDLCDRV_DEBUG */
589		if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr) 
590			return -EAGAIN;
591		bi.data.bits = 
592			s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
593		s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
594			sizeof(s->bitbuf_hdlc.buffer);
595		break;		
596#endif /* HDLCDRV_DEBUG */
597
598	case HDLCDRVCTL_DRIVERNAME:
599		if (s->ops && s->ops->drvname) {
600			strncpy(bi.data.drivername, s->ops->drvname, 
601				sizeof(bi.data.drivername));
602			break;
603		}
604		bi.data.drivername[0] = '\0';
605		break;
606		
607	}
608	if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
609		return -EFAULT;
610	return 0;
611
612}
613
614/* --------------------------------------------------------------------- */
615
616static const struct net_device_ops hdlcdrv_netdev = {
617	.ndo_open	= hdlcdrv_open,
618	.ndo_stop	= hdlcdrv_close,
619	.ndo_start_xmit = hdlcdrv_send_packet,
620	.ndo_do_ioctl	= hdlcdrv_ioctl,
621	.ndo_set_mac_address = hdlcdrv_set_mac_address,
622};
623
624/*
625 * Initialize fields in hdlcdrv
626 */
627static void hdlcdrv_setup(struct net_device *dev)
628{
629	static const struct hdlcdrv_channel_params dflt_ch_params = { 
630		20, 2, 10, 40, 0 
631	};
632	struct hdlcdrv_state *s = netdev_priv(dev);
633
634	/*
635	 * initialize the hdlcdrv_state struct
636	 */
637	s->ch_params = dflt_ch_params;
638	s->ptt_keyed = 0;
639
640	spin_lock_init(&s->hdlcrx.hbuf.lock);
641	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
642	s->hdlcrx.in_hdlc_rx = 0;
643	s->hdlcrx.rx_state = 0;
644	
645	spin_lock_init(&s->hdlctx.hbuf.lock);
646	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
647	s->hdlctx.in_hdlc_tx = 0;
648	s->hdlctx.tx_state = 1;
649	s->hdlctx.numflags = 0;
650	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
651	s->hdlctx.ptt = 0;
652	s->hdlctx.slotcnt = s->ch_params.slottime;
653	s->hdlctx.calibrate = 0;
654
655#ifdef HDLCDRV_DEBUG
656	s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
657	s->bitbuf_channel.shreg = 0x80;
658
659	s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
660	s->bitbuf_hdlc.shreg = 0x80;
661#endif /* HDLCDRV_DEBUG */
662
663
664	/* Fill in the fields of the device structure */
665
666	s->skb = NULL;
667	
668	dev->netdev_ops = &hdlcdrv_netdev;
669	dev->header_ops = &ax25_header_ops;
670	
671	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
672	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
673	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
674	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
675	memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
676	memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
677	dev->tx_queue_len = 16;
678}
679
680/* --------------------------------------------------------------------- */
681struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
682				    unsigned int privsize, const char *ifname,
683				    unsigned int baseaddr, unsigned int irq, 
684				    unsigned int dma) 
685{
686	struct net_device *dev;
687	struct hdlcdrv_state *s;
688	int err;
689
690	BUG_ON(ops == NULL);
691
692	if (privsize < sizeof(struct hdlcdrv_state))
693		privsize = sizeof(struct hdlcdrv_state);
694
695	dev = alloc_netdev(privsize, ifname, NET_NAME_UNKNOWN, hdlcdrv_setup);
696	if (!dev)
697		return ERR_PTR(-ENOMEM);
698
699	/*
700	 * initialize part of the hdlcdrv_state struct
701	 */
702	s = netdev_priv(dev);
703	s->magic = HDLCDRV_MAGIC;
704	s->ops = ops;
705	dev->base_addr = baseaddr;
706	dev->irq = irq;
707	dev->dma = dma;
708
709	err = register_netdev(dev);
710	if (err < 0) {
711		printk(KERN_WARNING "hdlcdrv: cannot register net "
712		       "device %s\n", dev->name);
713		free_netdev(dev);
714		dev = ERR_PTR(err);
715	}
716	return dev;
717}
718
719/* --------------------------------------------------------------------- */
720
721void hdlcdrv_unregister(struct net_device *dev) 
722{
723	struct hdlcdrv_state *s = netdev_priv(dev);
724
725	BUG_ON(s->magic != HDLCDRV_MAGIC);
726
727	if (s->opened && s->ops->close)
728		s->ops->close(dev);
729	unregister_netdev(dev);
730	
731	free_netdev(dev);
732}
733
734/* --------------------------------------------------------------------- */
735
736EXPORT_SYMBOL(hdlcdrv_receiver);
737EXPORT_SYMBOL(hdlcdrv_transmitter);
738EXPORT_SYMBOL(hdlcdrv_arbitrate);
739EXPORT_SYMBOL(hdlcdrv_register);
740EXPORT_SYMBOL(hdlcdrv_unregister);
741
742/* --------------------------------------------------------------------- */
743
744static int __init hdlcdrv_init_driver(void)
745{
746	printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
747	printk(KERN_INFO "hdlcdrv: version 0.8\n");
748	return 0;
749}
750
751/* --------------------------------------------------------------------- */
752
753static void __exit hdlcdrv_cleanup_driver(void)
754{
755	printk(KERN_INFO "hdlcdrv: cleanup\n");
756}
757
758/* --------------------------------------------------------------------- */
759
760MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
761MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
762MODULE_LICENSE("GPL");
763module_init(hdlcdrv_init_driver);
764module_exit(hdlcdrv_cleanup_driver);
765
766/* --------------------------------------------------------------------- */