patch-2.1.7 linux/drivers/net/hdlcdrv.c

• Lines: 935
• Date: Wed Oct 30 14:15:12 1996
• Orig file: v2.1.6/linux/drivers/net/hdlcdrv.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.6/linux/drivers/net/hdlcdrv.c linux/drivers/net/hdlcdrv.c
@@ -0,0 +1,934 @@
+/*****************************************************************************/
+
+/*
+ *	hdlcdrv.c  -- HDLC packet radio network driver.
+ *
+ *	Copyright (C) 1996  Thomas Sailer (sailer@ife.ee.ethz.ch)
+ *
+ *	This program is free software; you can redistribute it and/or modify
+ *	it under the terms of the GNU General Public License as published by
+ *	the Free Software Foundation; either version 2 of the License, or
+ *	(at your option) any later version.
+ *
+ *	This program is distributed in the hope that it will be useful,
+ *	but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *	GNU General Public License for more details.
+ *
+ *	You should have received a copy of the GNU General Public License
+ *	along with this program; if not, write to the Free Software
+ *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *  Please note that the GPL allows you to use the driver, NOT the radio.
+ *  In order to use the radio, you need a license from the communications
+ *  authority of your country.
+ *
+ *  The driver was derived from Donald Beckers skeleton.c
+ *	Written 1993-94 by Donald Becker.
+ *
+ *  History:
+ *   0.1  21.09.96  Started
+ *        18.10.96  Changed to new user space access routines (copy_{to,from}_user)
+ */
+
+/*****************************************************************************/
+
+#include <linux/module.h>
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/in.h>
+#include <linux/if.h>
+#include <linux/malloc.h>
+#include <linux/errno.h>
+#include <asm/bitops.h>
+#include <asm/uaccess.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/hdlcdrv.h>
+
+/* make genksyms happy */
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <linux/tcp.h>
+#include <linux/net_alias.h>
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * The name of the card. Is used for messages and in the requests for
+ * io regions, irqs and dma channels
+ */
+
+static char ax25_bcast[7] =
+{'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, '0' << 1};
+static char ax25_test[7] =
+{'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, '1' << 1};
+
+/* --------------------------------------------------------------------- */
+
+#define KISS_VERBOSE
+
+/* --------------------------------------------------------------------- */
+
+#define PARAM_TXDELAY   1
+#define PARAM_PERSIST   2
+#define PARAM_SLOTTIME  3
+#define PARAM_TXTAIL    4
+#define PARAM_FULLDUP   5
+#define PARAM_HARDWARE  6
+#define PARAM_RETURN    255
+
+/* --------------------------------------------------------------------- */
+
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+#define max(a, b) (((a) > (b)) ? (a) : (b))
+
+/* --------------------------------------------------------------------- */
+/*
+ * the CRC routines are stolen from WAMPES
+ * by Dieter Deyke
+ */
+
+static const unsigned short crc_ccitt_table[] = {
+	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
+};
+
+/*---------------------------------------------------------------------------*/
+
+static inline void append_crc_ccitt(unsigned char *buffer, int len)
+{
+ 	unsigned int crc = 0xffff;
+
+	for (;len>0;len--)
+		crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buffer++) & 0xff];
+	crc ^= 0xffff;
+	*buffer++ = crc;
+	*buffer++ = crc >> 8;
+}
+
+/*---------------------------------------------------------------------------*/
+
+static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
+{
+	unsigned int crc = 0xffff;
+
+	for (; cnt > 0; cnt--)
+		crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
+	return (crc & 0xffff) == 0xf0b8;
+}
+
+/*---------------------------------------------------------------------------*/
+
+#if 0
+static int calc_crc_ccitt(const unsigned char *buf, int cnt)
+{
+	unsigned int crc = 0xffff;
+
+	for (; cnt > 0; cnt--)
+		crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
+	crc ^= 0xffff;
+	return (crc & 0xffff);
+}
+#endif
+
+/* ---------------------------------------------------------------------- */
+
+#define tenms_to_2flags(s,tenms) ((tenms * s->ops->bitrate) / 100 / 16)
+
+/* ---------------------------------------------------------------------- */
+/*
+ * The HDLC routines
+ */
+
+static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits, 
+			     int num)
+{
+	int added = 0;
+	
+	while (s->hdlcrx.rx_state && num >= 8) {
+		if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
+			s->hdlcrx.rx_state = 0;
+			return 0;
+		}
+		*s->hdlcrx.bp++ = bits >> (32-num);
+		s->hdlcrx.len++;
+		num -= 8;
+		added += 8;
+	}
+	return added;
+}
+
+static void hdlc_rx_flag(struct device *dev, struct hdlcdrv_state *s)
+{
+	struct sk_buff *skb;
+	int pkt_len;
+	unsigned char *cp;
+
+	if (s->hdlcrx.len < 4) 
+		return;
+	if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len)) 
+		return;
+	pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
+	if (!(skb = dev_alloc_skb(pkt_len))) {
+		printk("%s: memory squeeze, dropping packet\n", 
+		       s->ifname);
+		s->stats.rx_dropped++;
+		return;
+	}
+	skb->dev = dev;
+	cp = skb_put(skb, pkt_len);
+	*cp++ = 0; /* KISS kludge */
+	memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
+	skb->protocol = htons(ETH_P_AX25);
+	skb->mac.raw = skb->data;
+	IS_SKB(skb);
+	netif_rx(skb);
+	s->stats.rx_packets++;
+}
+
+void hdlcdrv_receiver(struct device *dev, struct hdlcdrv_state *s)
+{
+	int i;
+	unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
+	
+	if (!s || s->magic != HDLCDRV_MAGIC) 
+		return;
+	if (set_bit(0, &s->hdlcrx.in_hdlc_rx))
+		return;
+
+	while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
+		word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);	
+
+#ifdef HDLCDRV_DEBUG
+		hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
+#endif /* HDLCDRV_DEBUG */
+	       	s->hdlcrx.bitstream >>= 16;
+		s->hdlcrx.bitstream |= word << 16;
+		s->hdlcrx.bitbuf >>= 16;
+		s->hdlcrx.bitbuf |= word << 16;
+		s->hdlcrx.numbits += 16;
+		for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
+		    mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff; 
+		    i >= 0; 
+		    i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1, 
+		    mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
+			if ((s->hdlcrx.bitstream & mask1) == mask1)
+				s->hdlcrx.rx_state = 0; /* abort received */
+			else if ((s->hdlcrx.bitstream & mask2) == mask3) {
+				/* flag received */
+				if (s->hdlcrx.rx_state) {
+					hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf 
+							  << (8+i),
+							  s->hdlcrx.numbits
+							  -8-i);
+					hdlc_rx_flag(dev, s);
+				}
+				s->hdlcrx.len = 0;
+				s->hdlcrx.bp = s->hdlcrx.buffer;
+				s->hdlcrx.rx_state = 1;
+				s->hdlcrx.numbits = i;
+			} else if ((s->hdlcrx.bitstream & mask4) == mask5) {
+				/* stuffed bit */
+				s->hdlcrx.numbits--;
+				s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
+					((s->hdlcrx.bitbuf & mask6) << 1);
+			}
+		}
+		s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
+						       s->hdlcrx.numbits);
+	}
+	clear_bit(0, &s->hdlcrx.in_hdlc_rx);
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void inline do_kiss_params(struct hdlcdrv_state *s,
+				  unsigned char *data, unsigned long len)
+{
+
+#ifdef KISS_VERBOSE
+#define PKP(a,b) printk(KERN_INFO "%s: channel params: " a "\n", s->ifname, b)
+#else /* KISS_VERBOSE */	      
+#define PKP(a,b) 
+#endif /* KISS_VERBOSE */	      
+
+	if (len < 2)
+		return;
+	switch(data[0]) {
+	case PARAM_TXDELAY:
+		s->ch_params.tx_delay = data[1];
+		PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
+		break;
+	case PARAM_PERSIST:   
+		s->ch_params.ppersist = data[1];
+		PKP("p persistence = %u", s->ch_params.ppersist);
+		break;
+	case PARAM_SLOTTIME:  
+		s->ch_params.slottime = data[1];
+		PKP("slot time = %ums", s->ch_params.slottime);
+		break;
+	case PARAM_TXTAIL:    
+		s->ch_params.tx_tail = data[1];
+		PKP("TX tail = %ums", s->ch_params.tx_tail);
+		break;
+	case PARAM_FULLDUP:   
+		s->ch_params.fulldup = !!data[1];
+		PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
+		break;
+	default:
+		break;
+	}
+#undef PKP
+}
+
+/* ---------------------------------------------------------------------- */
+
+void hdlcdrv_transmitter(struct device *dev, struct hdlcdrv_state *s)
+{
+	unsigned int mask1, mask2, mask3;
+	int i;
+	struct sk_buff *skb;
+	int pkt_len;
+
+	if (!s || s->magic != HDLCDRV_MAGIC) 
+		return;
+	if (set_bit(0, &s->hdlctx.in_hdlc_tx))
+		return;
+	for (;;) {
+		if (s->hdlctx.numbits >= 16) {
+			if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
+				clear_bit(0, &s->hdlctx.in_hdlc_tx);
+				return;
+			}
+			hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
+			s->hdlctx.bitbuf >>= 16;
+			s->hdlctx.numbits -= 16;
+		}
+		switch (s->hdlctx.tx_state) {
+		default:
+			clear_bit(0, &s->hdlctx.in_hdlc_tx);
+			return;
+		case 0:
+		case 1:
+			if (s->hdlctx.numflags) {
+				s->hdlctx.numflags--;
+				s->hdlctx.bitbuf |= 
+					0x7e7e << s->hdlctx.numbits;
+				s->hdlctx.numbits += 16;
+				break;
+			}
+			if (s->hdlctx.tx_state == 1) {
+				clear_bit(0, &s->hdlctx.in_hdlc_tx);
+				return;
+			}
+			if (!(skb = skb_dequeue(&s->send_queue))) {
+				int flgs = tenms_to_2flags
+					(s, s->ch_params.tx_tail);
+				if (flgs < 2)
+					flgs = 2;
+				s->hdlctx.tx_state = 1;
+				s->hdlctx.numflags = flgs;
+				break;
+			}
+			if (skb->data[0] != 0) {
+				do_kiss_params(s, skb->data, skb->len);
+				dev_kfree_skb(skb, FREE_WRITE);
+				break;
+			}
+			pkt_len = skb->len-1; /* strip KISS byte */
+			if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
+				s->hdlctx.tx_state = 0;
+				s->hdlctx.numflags = 1;
+				dev_kfree_skb(skb, FREE_WRITE);
+				break;
+			}
+			memcpy(s->hdlctx.buffer, skb->data+1, pkt_len);
+			dev_kfree_skb(skb, FREE_WRITE);
+			s->hdlctx.bp = s->hdlctx.buffer;
+			append_crc_ccitt(s->hdlctx.buffer, pkt_len);
+			s->hdlctx.len = pkt_len+2; /* the appended CRC */
+			s->hdlctx.tx_state = 2;
+			s->hdlctx.bitstream = 0;
+			s->stats.tx_packets++;
+			break;
+		case 2:
+			if (!s->hdlctx.len) {
+				s->hdlctx.tx_state = 0;
+				s->hdlctx.numflags = 1;
+				break;
+			}
+			s->hdlctx.len--;
+			s->hdlctx.bitbuf |= *s->hdlctx.bp <<
+				s->hdlctx.numbits;
+			s->hdlctx.bitstream >>= 8;
+			s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
+			mask1 = 0x1f000;
+			mask2 = 0x10000;
+			mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
+			s->hdlctx.numbits += 8;
+			for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1, 
+			    mask3 = (mask3 << 1) | 1) {
+				if ((s->hdlctx.bitstream & mask1) != mask1) 
+					continue;
+				s->hdlctx.bitstream &= ~mask2;
+				s->hdlctx.bitbuf = 
+					(s->hdlctx.bitbuf & mask3) |
+						((s->hdlctx.bitbuf & 
+						 (~mask3)) << 1);
+				s->hdlctx.numbits++;
+				mask3 = (mask3 << 1) | 1;
+			}
+			break;
+		}
+	}
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void start_tx(struct device *dev, struct hdlcdrv_state *s)
+{
+	s->hdlctx.tx_state = 0;
+	s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
+	s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
+	hdlcdrv_transmitter(dev, s);
+	s->hdlctx.ptt = 1;
+	s->ptt_keyed++;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static unsigned short random_seed;
+
+static inline unsigned short random_num(void)
+{
+	random_seed = 28629 * random_seed + 157;
+	return random_seed;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void hdlcdrv_arbitrate(struct device *dev, struct hdlcdrv_state *s)
+{
+	if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || 
+	    skb_queue_empty(&s->send_queue)) 
+		return;
+	if (s->ch_params.fulldup) {
+		start_tx(dev, s);
+		return;
+	}
+	if (s->hdlcrx.dcd) {
+		s->hdlctx.slotcnt = s->ch_params.slottime;
+		return;
+	}
+	if ((--s->hdlctx.slotcnt) > 0)
+		return;
+	s->hdlctx.slotcnt = s->ch_params.slottime;
+	if ((random_num() % 256) > s->ch_params.ppersist)
+		return;
+	start_tx(dev, s);
+}
+
+/* --------------------------------------------------------------------- */
+/*
+ * ===================== network driver interface =========================
+ */
+
+static inline int hdlcdrv_paranoia_check(struct device *dev,
+					const char *routine)
+{
+	if (!dev || !dev->priv || 
+	    ((struct hdlcdrv_state *)dev->priv)->magic != HDLCDRV_MAGIC) {
+		printk(KERN_ERR "hdlcdrv: bad magic number for hdlcdrv_state "
+		       "struct in routine %s\n", routine);
+		return 1;
+	}
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int hdlcdrv_send_packet(struct sk_buff *skb, struct device *dev)
+{
+	struct hdlcdrv_state *sm;
+
+	if (hdlcdrv_paranoia_check(dev, "hdlcdrv_send_packet"))
+		return 0;
+	sm = (struct hdlcdrv_state *)dev->priv;
+	/*
+	 * If some higher layer thinks we've missed an tx-done interrupt
+         * we are passed NULL. Caution: dev_tint() handles the cli()/sti()
+	 * itself. 
+	 */
+	if (skb == NULL) {
+		dev_tint(dev);
+		return 0;
+	}
+	skb_queue_tail(&sm->send_queue, skb);
+	dev->trans_start = jiffies;	
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int hdlcdrv_set_mac_address(struct device *dev, void *addr)
+{
+	struct sockaddr *sa = (struct sockaddr *)addr;
+
+	/* addr is an AX.25 shifted ASCII mac address */
+	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); 
+	return 0;                                         
+}
+
+/* --------------------------------------------------------------------- */
+
+static struct enet_statistics *hdlcdrv_get_stats(struct device *dev)
+{
+	struct hdlcdrv_state *sm;
+
+	if (hdlcdrv_paranoia_check(dev, "hdlcdrv_get_stats"))
+		return NULL;
+	sm = (struct hdlcdrv_state *)dev->priv;
+	/* 
+	 * Get the current statistics.  This may be called with the
+	 * card open or closed. 
+	 */
+	return &sm->stats;
+}
+
+/* --------------------------------------------------------------------- */
+/*
+ * Open/initialize the board. This is called (in the current kernel)
+ * sometime after booting when the 'ifconfig' program is run.
+ *
+ * This routine should set everything up anew at each open, even
+ * registers that "should" only need to be set once at boot, so that
+ * there is non-reboot way to recover if something goes wrong.
+ */
+
+static int hdlcdrv_open(struct device *dev)
+{
+	struct hdlcdrv_state *s;
+	int i;
+
+	if (hdlcdrv_paranoia_check(dev, "hdlcdrv_open"))
+		return -EINVAL;
+	s = (struct hdlcdrv_state *)dev->priv;
+
+	if (dev->start)
+		return 0;
+	if (!s->ops || !s->ops->open)
+		return -ENODEV;
+
+	dev->start = 1;
+	/*
+	 * initialise some variables
+	 */
+	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
+	s->hdlcrx.in_hdlc_rx = 0;
+	s->hdlcrx.rx_state = 0;
+	
+	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
+	s->hdlctx.in_hdlc_tx = 0;
+	s->hdlctx.tx_state = 1;
+	s->hdlctx.numflags = 0;
+	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
+	s->hdlctx.ptt = 0;
+	s->hdlctx.slotcnt = s->ch_params.slottime;
+	s->hdlctx.calibrate = 0;
+
+	i = s->ops->open(dev);
+	if (i) {
+		dev->start = 0;
+		return i;
+	}
+
+	dev->tbusy = 0;
+	dev->interrupt = 0;
+
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+/* 
+ * The inverse routine to hdlcdrv_open(). 
+ */
+
+static int hdlcdrv_close(struct device *dev)
+{
+	struct hdlcdrv_state *s;
+	struct sk_buff *skb;
+	int i = 0;
+
+	if (hdlcdrv_paranoia_check(dev, "hdlcdrv_close"))
+		return -EINVAL;
+	s = (struct hdlcdrv_state *)dev->priv;
+
+	if (!dev->start)
+		return 0;
+	dev->start = 0;
+	dev->tbusy = 1;
+
+	if (s->ops && s->ops->close)
+		i = s->ops->close(dev);
+        /* Free any buffers left in the hardware transmit queue */
+        while ((skb = skb_dequeue(&s->send_queue)))
+			dev_kfree_skb(skb, FREE_WRITE);
+	return i;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int hdlcdrv_ioctl(struct device *dev, struct ifreq *ifr, int cmd)
+{
+	struct hdlcdrv_state *s;
+	struct hdlcdrv_ioctl bi;
+		
+	if (hdlcdrv_paranoia_check(dev, "hdlcdrv_ioctl"))
+		return -EINVAL;
+	s = (struct hdlcdrv_state *)dev->priv;
+
+	if (cmd != SIOCDEVPRIVATE) {
+		if (s->ops->ioctl)
+			return s->ops->ioctl(dev, ifr, cmd);
+		return -ENOIOCTLCMD;
+	}
+	if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
+		return -EFAULT;
+
+	switch (bi.cmd) {
+	default:
+		if (s->ops->ioctl)
+			return s->ops->ioctl(dev, ifr, cmd);
+		return -ENOIOCTLCMD;
+
+	case HDLCDRVCTL_GETCHANNELPAR:
+		bi.data.cp.tx_delay = s->ch_params.tx_delay;
+		bi.data.cp.tx_tail = s->ch_params.tx_tail;
+		bi.data.cp.slottime = s->ch_params.slottime;
+		bi.data.cp.ppersist = s->ch_params.ppersist;
+		bi.data.cp.fulldup = s->ch_params.fulldup;
+		break;
+
+	case HDLCDRVCTL_SETCHANNELPAR:
+		if (!suser())
+			return -EACCES;
+		s->ch_params.tx_delay = bi.data.cp.tx_delay;
+		s->ch_params.tx_tail = bi.data.cp.tx_tail;
+		s->ch_params.slottime = bi.data.cp.slottime;
+		s->ch_params.ppersist = bi.data.cp.ppersist;
+		s->ch_params.fulldup = bi.data.cp.fulldup;
+		s->hdlctx.slotcnt = 1;
+		return 0;
+		
+	case HDLCDRVCTL_GETMODEMPAR:
+		bi.data.mp.iobase = dev->base_addr;
+		bi.data.mp.irq = dev->irq;
+		bi.data.mp.dma = dev->dma;
+		bi.data.mp.seriobase = s->ptt_out.seriobase;
+		bi.data.mp.pariobase = s->ptt_out.pariobase;
+		bi.data.mp.midiiobase = s->ptt_out.midiiobase;
+		break;
+
+	case HDLCDRVCTL_SETMODEMPAR:
+		if ((!suser()) || dev->start)
+			return -EACCES;
+		dev->base_addr = bi.data.mp.iobase;
+		dev->irq = bi.data.mp.irq;
+		dev->dma = bi.data.mp.dma;
+		s->ptt_out.seriobase = bi.data.mp.seriobase;
+		s->ptt_out.pariobase = bi.data.mp.pariobase;
+		s->ptt_out.midiiobase = bi.data.mp.midiiobase;
+		return 0;	
+	
+	case HDLCDRVCTL_GETSTAT:
+		bi.data.cs.ptt = hdlcdrv_ptt(s);
+		bi.data.cs.dcd = s->hdlcrx.dcd;
+		bi.data.cs.ptt_keyed = s->ptt_keyed;
+		bi.data.cs.stats = s->stats;
+		break;		
+
+	case HDLCDRVCTL_CALIBRATE:
+		s->hdlctx.calibrate = bi.data.calibrate * s->ops->bitrate / 16;
+		return 0;
+
+	case HDLCDRVCTL_GETSAMPLES:
+#ifndef HDLCDRV_DEBUG
+		return -EPERM;
+#else /* HDLCDRV_DEBUG */
+		if (s->bitbuf_channel.rd == s->bitbuf_channel.wr) 
+			return -EAGAIN;
+		bi.data.bits = 
+			s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
+		s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
+			sizeof(s->bitbuf_channel.buffer);
+		break;
+#endif /* HDLCDRV_DEBUG */
+				
+	case HDLCDRVCTL_GETBITS:
+#ifndef HDLCDRV_DEBUG
+		return -EPERM;
+#else /* HDLCDRV_DEBUG */
+		if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr) 
+			return -EAGAIN;
+		bi.data.bits = 
+			s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
+		s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
+			sizeof(s->bitbuf_hdlc.buffer);
+		break;		
+#endif /* HDLCDRV_DEBUG */
+
+	}
+	if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
+		return -EFAULT;
+	return 0;
+
+}
+
+/* --------------------------------------------------------------------- */
+/*
+ * Fill in the MAC-level header 
+ */
+
+#ifdef CONFIG_AX25
+static int hdlcdrv_header(struct sk_buff *skb, struct device *dev, 
+			 unsigned short type, void *daddr, void *saddr, 
+			 unsigned len)
+{
+        return ax25_encapsulate(skb, dev, type, daddr, saddr, len);
+}
+
+/* --------------------------------------------------------------------- */
+/*
+ * Rebuild the MAC-level header
+ */
+
+static int hdlcdrv_rebuild_header(void *buff, struct device *dev,
+				 unsigned long raddr,
+				 struct sk_buff *skb)
+{
+        return ax25_rebuild_header(buff, dev, raddr, skb);
+}
+#endif /* CONFIG_AX25 */
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * Check for a network adaptor of this type, and return '0' if one exists.
+ * If dev->base_addr == 0, probe all likely locations.
+ * If dev->base_addr == 1, always return failure.
+ * If dev->base_addr == 2, allocate space for the device and return success
+ * (detachable devices only).
+ */
+static int hdlcdrv_probe(struct device *dev)
+{
+	struct hdlcdrv_channel_params dflt_ch_params = { 20, 2, 10, 40, 0 };
+	int i;
+	struct hdlcdrv_state *s;
+
+	if (!dev)
+		return -ENXIO;
+	/*
+	 * not a real probe! only initialize data structures
+	 */
+	s = (struct hdlcdrv_state *)dev->priv;
+	/*
+	 * initialize the hdlcdrv_state struct
+	 */
+	s->ch_params = dflt_ch_params;
+	s->ptt_keyed = 0;
+
+	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
+	s->hdlcrx.in_hdlc_rx = 0;
+	s->hdlcrx.rx_state = 0;
+	
+	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
+	s->hdlctx.in_hdlc_tx = 0;
+	s->hdlctx.tx_state = 1;
+	s->hdlctx.numflags = 0;
+	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
+	s->hdlctx.ptt = 0;
+	s->hdlctx.slotcnt = s->ch_params.slottime;
+	s->hdlctx.calibrate = 0;
+
+#ifdef HDLCDRV_DEBUG
+	s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
+	s->bitbuf_channel.shreg = 0x80;
+
+	s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
+	s->bitbuf_hdlc.shreg = 0x80;
+#endif /* HDLCDRV_DEBUG */
+
+	/*
+	 * initialize the device struct
+	 */
+	dev->open = hdlcdrv_open;
+	dev->stop = hdlcdrv_close;
+	dev->do_ioctl = hdlcdrv_ioctl;
+	dev->hard_start_xmit = hdlcdrv_send_packet;
+	dev->get_stats = hdlcdrv_get_stats;
+
+	/* Fill in the fields of the device structure */
+	for (i=0; i < DEV_NUMBUFFS; i++)
+		skb_queue_head_init(&dev->buffs[i]);
+
+	skb_queue_head_init(&s->send_queue);
+	
+#ifdef CONFIG_AX25
+	dev->hard_header = hdlcdrv_header;
+	dev->rebuild_header = hdlcdrv_rebuild_header;
+#else /* CONFIG_AX25 */
+	dev->hard_header = NULL;
+	dev->rebuild_header = NULL;
+#endif /* CONFIG_AX25 */
+	dev->set_mac_address = hdlcdrv_set_mac_address;
+	
+	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
+	dev->hard_header_len = 73;         /* We do digipeaters now */
+	dev->mtu = 1500;                   /* eth_mtu is the default */
+	dev->addr_len = 7;                 /* sizeof an ax.25 address */
+	memcpy(dev->broadcast, ax25_bcast, 7);
+	memcpy(dev->dev_addr, ax25_test, 7);
+
+	/* New style flags */
+	dev->flags = 0;
+	dev->family = AF_INET;
+	dev->pa_addr = 0;
+	dev->pa_brdaddr = 0;
+	dev->pa_mask = 0;
+	dev->pa_alen = sizeof(unsigned long);
+
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+int hdlcdrv_register_hdlcdrv(struct device *dev, const struct hdlcdrv_ops *ops,
+			     unsigned int privsize, char *ifname,
+			     unsigned int baseaddr, unsigned int irq, 
+			     unsigned int dma) 
+{
+	struct hdlcdrv_state *s;
+
+	if (!dev || !ops)
+		return -EACCES;
+	if (privsize < sizeof(struct hdlcdrv_state))
+		privsize = sizeof(struct hdlcdrv_state);
+	memset(dev, 0, sizeof(struct device));
+	if (!(s = dev->priv = kmalloc(privsize, GFP_KERNEL)))
+		return -ENOMEM;
+	/*
+	 * initialize part of the hdlcdrv_state struct
+	 */
+	memset(s, 0, privsize);
+	s->magic = HDLCDRV_MAGIC;
+	strncpy(s->ifname, ifname, sizeof(s->ifname));
+	s->ops = ops;
+	/*
+	 * initialize part of the device struct
+	 */
+	dev->name = s->ifname;
+	dev->if_port = 0;
+	dev->init = hdlcdrv_probe;
+	dev->start = 0;
+	dev->tbusy = 1;
+	dev->base_addr = baseaddr;
+	dev->irq = irq;
+	dev->dma = dma;
+	if (register_netdev(dev)) {
+		printk(KERN_WARNING "hdlcdrv: cannot register net "
+		       "device %s\n", s->ifname);
+		kfree(dev->priv);
+		return -ENXIO;
+	}
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+int hdlcdrv_unregister_hdlcdrv(struct device *dev) 
+{
+	struct hdlcdrv_state *s;
+
+	if (!dev)
+		return -EINVAL;
+	if (!(s = (struct hdlcdrv_state *)dev->priv))
+		return -EINVAL;
+	if (s->magic != HDLCDRV_MAGIC)
+		return -EINVAL;
+	if (dev->start && s->ops->close)
+		s->ops->close(dev);
+	unregister_netdev(dev);
+	kfree(s);
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static struct symbol_table hdlcdrv_syms = {
+#include <linux/symtab_begin.h>
+        X(hdlcdrv_receiver),
+        X(hdlcdrv_transmitter),
+        X(hdlcdrv_arbitrate),
+        X(hdlcdrv_register_hdlcdrv),
+        X(hdlcdrv_unregister_hdlcdrv),
+#include <linux/symtab_end.h>
+};
+
+/* --------------------------------------------------------------------- */
+
+#ifdef MODULE
+
+int init_module(void)
+{
+	printk(KERN_INFO "hdlcdrv: v0.1 (C) 1996 Thomas Sailer HB9JNX/AE4WA\n");
+	printk(KERN_INFO "hdlcdrv: compiled %s %s\n", __TIME__, __DATE__);
+
+        register_symtab(&hdlcdrv_syms);
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+void cleanup_module(void)
+{
+	printk(KERN_INFO "hdlcdrv: cleanup\n");
+}
+
+#endif /* MODULE */
+/* --------------------------------------------------------------------- */