1
/*****************************************************************************/
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* hdlcdrv.c -- HDLC packet radio network driver.
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* Copyright (C) 1996-2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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* Please note that the GPL allows you to use the driver, NOT the radio.
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* In order to use the radio, you need a license from the communications
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* authority of your country.
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* The driver was derived from Donald Beckers skeleton.c
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* Written 1993-94 by Donald Becker.
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* 0.1 21.09.1996 Started
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* 18.10.1996 Changed to new user space access routines
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* (copy_{to,from}_user)
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* 0.2 21.11.1996 various small changes
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* 0.3 03.03.1997 fixed (hopefully) IP not working with ax.25 as a module
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* 0.4 16.04.1997 init code/data tagged
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* 0.5 30.07.1997 made HDLC buffers bigger (solves a problem with the
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* 0.6 05.04.1998 add spinlocks
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* 0.7 03.08.1999 removed some old compatibility cruft
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* 0.8 12.02.2000 adapted to softnet driver interface
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/*****************************************************************************/
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#include <linux/capability.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/net.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/bitops.h>
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#include <linux/netdevice.h>
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#include <linux/if_arp.h>
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#include <linux/skbuff.h>
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#include <linux/hdlcdrv.h>
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#include <linux/random.h>
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#include <asm/uaccess.h>
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#include <linux/crc-ccitt.h>
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/* --------------------------------------------------------------------- */
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/* --------------------------------------------------------------------- */
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#define PARAM_TXDELAY 1
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#define PARAM_PERSIST 2
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#define PARAM_SLOTTIME 3
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#define PARAM_TXTAIL 4
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#define PARAM_FULLDUP 5
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#define PARAM_HARDWARE 6
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#define PARAM_RETURN 255
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/* --------------------------------------------------------------------- */
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* the CRC routines are stolen from WAMPES
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/*---------------------------------------------------------------------------*/
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static inline void append_crc_ccitt(unsigned char *buffer, int len)
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unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff;
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/*---------------------------------------------------------------------------*/
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static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
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return (crc_ccitt(0xffff, buf, cnt) & 0xffff) == 0xf0b8;
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/*---------------------------------------------------------------------------*/
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static int calc_crc_ccitt(const unsigned char *buf, int cnt)
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unsigned int crc = 0xffff;
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for (; cnt > 0; cnt--)
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crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
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/* ---------------------------------------------------------------------- */
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#define tenms_to_2flags(s,tenms) ((tenms * s->par.bitrate) / 100 / 16)
121
/* ---------------------------------------------------------------------- */
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static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits,
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while (s->hdlcrx.rx_state && num >= 8) {
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if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
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s->hdlcrx.rx_state = 0;
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*s->hdlcrx.bp++ = bits >> (32-num);
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static void hdlc_rx_flag(struct net_device *dev, struct hdlcdrv_state *s)
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if (s->hdlcrx.len < 4)
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if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len))
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pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
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if (!(skb = dev_alloc_skb(pkt_len))) {
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printk("%s: memory squeeze, dropping packet\n", dev->name);
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dev->stats.rx_dropped++;
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cp = skb_put(skb, pkt_len);
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*cp++ = 0; /* KISS kludge */
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memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
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skb->protocol = ax25_type_trans(skb, dev);
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dev->stats.rx_packets++;
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void hdlcdrv_receiver(struct net_device *dev, struct hdlcdrv_state *s)
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unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
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if (!s || s->magic != HDLCDRV_MAGIC)
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if (test_and_set_bit(0, &s->hdlcrx.in_hdlc_rx))
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while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
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word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);
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hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
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#endif /* HDLCDRV_DEBUG */
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s->hdlcrx.bitstream >>= 16;
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s->hdlcrx.bitstream |= word << 16;
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s->hdlcrx.bitbuf >>= 16;
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s->hdlcrx.bitbuf |= word << 16;
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s->hdlcrx.numbits += 16;
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for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
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mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff;
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i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1,
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mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
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if ((s->hdlcrx.bitstream & mask1) == mask1)
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s->hdlcrx.rx_state = 0; /* abort received */
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else if ((s->hdlcrx.bitstream & mask2) == mask3) {
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if (s->hdlcrx.rx_state) {
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hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf
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hdlc_rx_flag(dev, s);
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s->hdlcrx.bp = s->hdlcrx.buffer;
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s->hdlcrx.rx_state = 1;
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s->hdlcrx.numbits = i;
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} else if ((s->hdlcrx.bitstream & mask4) == mask5) {
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s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
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((s->hdlcrx.bitbuf & mask6) << 1);
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s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
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clear_bit(0, &s->hdlcrx.in_hdlc_rx);
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/* ---------------------------------------------------------------------- */
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static inline void do_kiss_params(struct hdlcdrv_state *s,
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unsigned char *data, unsigned long len)
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#define PKP(a,b) printk(KERN_INFO "hdlcdrv.c: channel params: " a "\n", b)
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#else /* KISS_VERBOSE */
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#endif /* KISS_VERBOSE */
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s->ch_params.tx_delay = data[1];
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PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
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s->ch_params.ppersist = data[1];
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PKP("p persistence = %u", s->ch_params.ppersist);
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s->ch_params.slottime = data[1];
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PKP("slot time = %ums", s->ch_params.slottime);
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s->ch_params.tx_tail = data[1];
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PKP("TX tail = %ums", s->ch_params.tx_tail);
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s->ch_params.fulldup = !!data[1];
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PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
263
/* ---------------------------------------------------------------------- */
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void hdlcdrv_transmitter(struct net_device *dev, struct hdlcdrv_state *s)
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unsigned int mask1, mask2, mask3;
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if (!s || s->magic != HDLCDRV_MAGIC)
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if (test_and_set_bit(0, &s->hdlctx.in_hdlc_tx))
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if (s->hdlctx.numbits >= 16) {
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if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
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clear_bit(0, &s->hdlctx.in_hdlc_tx);
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hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
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s->hdlctx.bitbuf >>= 16;
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s->hdlctx.numbits -= 16;
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switch (s->hdlctx.tx_state) {
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clear_bit(0, &s->hdlctx.in_hdlc_tx);
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if (s->hdlctx.numflags) {
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s->hdlctx.numflags--;
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0x7e7e << s->hdlctx.numbits;
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s->hdlctx.numbits += 16;
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if (s->hdlctx.tx_state == 1) {
300
clear_bit(0, &s->hdlctx.in_hdlc_tx);
303
if (!(skb = s->skb)) {
304
int flgs = tenms_to_2flags(s, s->ch_params.tx_tail);
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s->hdlctx.tx_state = 1;
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s->hdlctx.numflags = flgs;
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netif_wake_queue(dev);
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pkt_len = skb->len-1; /* strip KISS byte */
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if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
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s->hdlctx.tx_state = 0;
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s->hdlctx.numflags = 1;
317
dev_kfree_skb_irq(skb);
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skb_copy_from_linear_data_offset(skb, 1,
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dev_kfree_skb_irq(skb);
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s->hdlctx.bp = s->hdlctx.buffer;
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append_crc_ccitt(s->hdlctx.buffer, pkt_len);
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s->hdlctx.len = pkt_len+2; /* the appended CRC */
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s->hdlctx.tx_state = 2;
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s->hdlctx.bitstream = 0;
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dev->stats.tx_packets++;
332
if (!s->hdlctx.len) {
333
s->hdlctx.tx_state = 0;
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s->hdlctx.numflags = 1;
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s->hdlctx.bitbuf |= *s->hdlctx.bp <<
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s->hdlctx.bitstream >>= 8;
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s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
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mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
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s->hdlctx.numbits += 8;
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for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1,
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mask3 = (mask3 << 1) | 1) {
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if ((s->hdlctx.bitstream & mask1) != mask1)
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s->hdlctx.bitstream &= ~mask2;
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(s->hdlctx.bitbuf & mask3) |
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mask3 = (mask3 << 1) | 1;
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/* ---------------------------------------------------------------------- */
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static void start_tx(struct net_device *dev, struct hdlcdrv_state *s)
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s->hdlctx.tx_state = 0;
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s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
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s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
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hdlcdrv_transmitter(dev, s);
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/* ---------------------------------------------------------------------- */
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void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
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if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb)
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if (s->ch_params.fulldup) {
386
s->hdlctx.slotcnt = s->ch_params.slottime;
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if ((--s->hdlctx.slotcnt) > 0)
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s->hdlctx.slotcnt = s->ch_params.slottime;
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if ((random32() % 256) > s->ch_params.ppersist)
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/* --------------------------------------------------------------------- */
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* ===================== network driver interface =========================
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static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
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struct net_device *dev)
405
struct hdlcdrv_state *sm = netdev_priv(dev);
407
if (skb->data[0] != 0) {
408
do_kiss_params(sm, skb->data, skb->len);
413
return NETDEV_TX_LOCKED;
414
netif_stop_queue(dev);
419
/* --------------------------------------------------------------------- */
421
static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
423
struct sockaddr *sa = (struct sockaddr *)addr;
425
/* addr is an AX.25 shifted ASCII mac address */
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memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
430
/* --------------------------------------------------------------------- */
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* Open/initialize the board. This is called (in the current kernel)
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* sometime after booting when the 'ifconfig' program is run.
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* This routine should set everything up anew at each open, even
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* registers that "should" only need to be set once at boot, so that
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* there is non-reboot way to recover if something goes wrong.
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static int hdlcdrv_open(struct net_device *dev)
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struct hdlcdrv_state *s = netdev_priv(dev);
445
if (!s->ops || !s->ops->open)
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* initialise some variables
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s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
453
s->hdlcrx.in_hdlc_rx = 0;
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s->hdlcrx.rx_state = 0;
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s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
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s->hdlctx.in_hdlc_tx = 0;
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s->hdlctx.tx_state = 1;
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s->hdlctx.numflags = 0;
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s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
462
s->hdlctx.slotcnt = s->ch_params.slottime;
463
s->hdlctx.calibrate = 0;
465
i = s->ops->open(dev);
468
netif_start_queue(dev);
472
/* --------------------------------------------------------------------- */
474
* The inverse routine to hdlcdrv_open().
477
static int hdlcdrv_close(struct net_device *dev)
479
struct hdlcdrv_state *s = netdev_priv(dev);
482
netif_stop_queue(dev);
484
if (s->ops && s->ops->close)
485
i = s->ops->close(dev);
487
dev_kfree_skb(s->skb);
493
/* --------------------------------------------------------------------- */
495
static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
497
struct hdlcdrv_state *s = netdev_priv(dev);
498
struct hdlcdrv_ioctl bi;
500
if (cmd != SIOCDEVPRIVATE) {
501
if (s->ops && s->ops->ioctl)
502
return s->ops->ioctl(dev, ifr, &bi, cmd);
505
if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
510
if (s->ops && s->ops->ioctl)
511
return s->ops->ioctl(dev, ifr, &bi, cmd);
514
case HDLCDRVCTL_GETCHANNELPAR:
515
bi.data.cp.tx_delay = s->ch_params.tx_delay;
516
bi.data.cp.tx_tail = s->ch_params.tx_tail;
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bi.data.cp.slottime = s->ch_params.slottime;
518
bi.data.cp.ppersist = s->ch_params.ppersist;
519
bi.data.cp.fulldup = s->ch_params.fulldup;
522
case HDLCDRVCTL_SETCHANNELPAR:
523
if (!capable(CAP_NET_ADMIN))
525
s->ch_params.tx_delay = bi.data.cp.tx_delay;
526
s->ch_params.tx_tail = bi.data.cp.tx_tail;
527
s->ch_params.slottime = bi.data.cp.slottime;
528
s->ch_params.ppersist = bi.data.cp.ppersist;
529
s->ch_params.fulldup = bi.data.cp.fulldup;
530
s->hdlctx.slotcnt = 1;
533
case HDLCDRVCTL_GETMODEMPAR:
534
bi.data.mp.iobase = dev->base_addr;
535
bi.data.mp.irq = dev->irq;
536
bi.data.mp.dma = dev->dma;
537
bi.data.mp.dma2 = s->ptt_out.dma2;
538
bi.data.mp.seriobase = s->ptt_out.seriobase;
539
bi.data.mp.pariobase = s->ptt_out.pariobase;
540
bi.data.mp.midiiobase = s->ptt_out.midiiobase;
543
case HDLCDRVCTL_SETMODEMPAR:
544
if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
546
dev->base_addr = bi.data.mp.iobase;
547
dev->irq = bi.data.mp.irq;
548
dev->dma = bi.data.mp.dma;
549
s->ptt_out.dma2 = bi.data.mp.dma2;
550
s->ptt_out.seriobase = bi.data.mp.seriobase;
551
s->ptt_out.pariobase = bi.data.mp.pariobase;
552
s->ptt_out.midiiobase = bi.data.mp.midiiobase;
555
case HDLCDRVCTL_GETSTAT:
556
bi.data.cs.ptt = hdlcdrv_ptt(s);
557
bi.data.cs.dcd = s->hdlcrx.dcd;
558
bi.data.cs.ptt_keyed = s->ptt_keyed;
559
bi.data.cs.tx_packets = dev->stats.tx_packets;
560
bi.data.cs.tx_errors = dev->stats.tx_errors;
561
bi.data.cs.rx_packets = dev->stats.rx_packets;
562
bi.data.cs.rx_errors = dev->stats.rx_errors;
565
case HDLCDRVCTL_OLDGETSTAT:
566
bi.data.ocs.ptt = hdlcdrv_ptt(s);
567
bi.data.ocs.dcd = s->hdlcrx.dcd;
568
bi.data.ocs.ptt_keyed = s->ptt_keyed;
571
case HDLCDRVCTL_CALIBRATE:
572
if(!capable(CAP_SYS_RAWIO))
574
s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
577
case HDLCDRVCTL_GETSAMPLES:
578
#ifndef HDLCDRV_DEBUG
580
#else /* HDLCDRV_DEBUG */
581
if (s->bitbuf_channel.rd == s->bitbuf_channel.wr)
584
s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
585
s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
586
sizeof(s->bitbuf_channel.buffer);
588
#endif /* HDLCDRV_DEBUG */
590
case HDLCDRVCTL_GETBITS:
591
#ifndef HDLCDRV_DEBUG
593
#else /* HDLCDRV_DEBUG */
594
if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr)
597
s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
598
s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
599
sizeof(s->bitbuf_hdlc.buffer);
601
#endif /* HDLCDRV_DEBUG */
603
case HDLCDRVCTL_DRIVERNAME:
604
if (s->ops && s->ops->drvname) {
605
strncpy(bi.data.drivername, s->ops->drvname,
606
sizeof(bi.data.drivername));
609
bi.data.drivername[0] = '\0';
613
if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
619
/* --------------------------------------------------------------------- */
621
static const struct net_device_ops hdlcdrv_netdev = {
622
.ndo_open = hdlcdrv_open,
623
.ndo_stop = hdlcdrv_close,
624
.ndo_start_xmit = hdlcdrv_send_packet,
625
.ndo_do_ioctl = hdlcdrv_ioctl,
626
.ndo_set_mac_address = hdlcdrv_set_mac_address,
630
* Initialize fields in hdlcdrv
632
static void hdlcdrv_setup(struct net_device *dev)
634
static const struct hdlcdrv_channel_params dflt_ch_params = {
637
struct hdlcdrv_state *s = netdev_priv(dev);
640
* initialize the hdlcdrv_state struct
642
s->ch_params = dflt_ch_params;
645
spin_lock_init(&s->hdlcrx.hbuf.lock);
646
s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
647
s->hdlcrx.in_hdlc_rx = 0;
648
s->hdlcrx.rx_state = 0;
650
spin_lock_init(&s->hdlctx.hbuf.lock);
651
s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
652
s->hdlctx.in_hdlc_tx = 0;
653
s->hdlctx.tx_state = 1;
654
s->hdlctx.numflags = 0;
655
s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
657
s->hdlctx.slotcnt = s->ch_params.slottime;
658
s->hdlctx.calibrate = 0;
661
s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
662
s->bitbuf_channel.shreg = 0x80;
664
s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
665
s->bitbuf_hdlc.shreg = 0x80;
666
#endif /* HDLCDRV_DEBUG */
669
/* Fill in the fields of the device structure */
673
dev->netdev_ops = &hdlcdrv_netdev;
674
dev->header_ops = &ax25_header_ops;
676
dev->type = ARPHRD_AX25; /* AF_AX25 device */
677
dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
678
dev->mtu = AX25_DEF_PACLEN; /* eth_mtu is the default */
679
dev->addr_len = AX25_ADDR_LEN; /* sizeof an ax.25 address */
680
memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
681
memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
682
dev->tx_queue_len = 16;
685
/* --------------------------------------------------------------------- */
686
struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
687
unsigned int privsize, const char *ifname,
688
unsigned int baseaddr, unsigned int irq,
691
struct net_device *dev;
692
struct hdlcdrv_state *s;
697
if (privsize < sizeof(struct hdlcdrv_state))
698
privsize = sizeof(struct hdlcdrv_state);
700
dev = alloc_netdev(privsize, ifname, hdlcdrv_setup);
702
return ERR_PTR(-ENOMEM);
705
* initialize part of the hdlcdrv_state struct
707
s = netdev_priv(dev);
708
s->magic = HDLCDRV_MAGIC;
710
dev->base_addr = baseaddr;
714
err = register_netdev(dev);
716
printk(KERN_WARNING "hdlcdrv: cannot register net "
717
"device %s\n", dev->name);
724
/* --------------------------------------------------------------------- */
726
void hdlcdrv_unregister(struct net_device *dev)
728
struct hdlcdrv_state *s = netdev_priv(dev);
730
BUG_ON(s->magic != HDLCDRV_MAGIC);
732
if (s->opened && s->ops->close)
734
unregister_netdev(dev);
739
/* --------------------------------------------------------------------- */
741
EXPORT_SYMBOL(hdlcdrv_receiver);
742
EXPORT_SYMBOL(hdlcdrv_transmitter);
743
EXPORT_SYMBOL(hdlcdrv_arbitrate);
744
EXPORT_SYMBOL(hdlcdrv_register);
745
EXPORT_SYMBOL(hdlcdrv_unregister);
747
/* --------------------------------------------------------------------- */
749
static int __init hdlcdrv_init_driver(void)
751
printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
752
printk(KERN_INFO "hdlcdrv: version 0.8\n");
756
/* --------------------------------------------------------------------- */
758
static void __exit hdlcdrv_cleanup_driver(void)
760
printk(KERN_INFO "hdlcdrv: cleanup\n");
763
/* --------------------------------------------------------------------- */
765
MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
766
MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
767
MODULE_LICENSE("GPL");
768
module_init(hdlcdrv_init_driver);
769
module_exit(hdlcdrv_cleanup_driver);
771
/* --------------------------------------------------------------------- */