drivers/net/hamradio/hdlcdrv.c

   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
  76 static 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
  86 static 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
  94 static 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
 114 static 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
 132 static 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
 156 void 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
 212 static 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
 253 void 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
 353 static 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
 365 void 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
 390 static 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
 414 static 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
 433 static 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
 470 static 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
 487 static 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
 619 static 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  */
 630 static 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 /* --------------------------------------------------------------------- */
 684 struct 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
 722 void 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
 737 EXPORT_SYMBOL(hdlcdrv_receiver);
 738 EXPORT_SYMBOL(hdlcdrv_transmitter);
 739 EXPORT_SYMBOL(hdlcdrv_arbitrate);
 740 EXPORT_SYMBOL(hdlcdrv_register);
 741 EXPORT_SYMBOL(hdlcdrv_unregister);
 742
 743 /* --------------------------------------------------------------------- */
 744
 745 static 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
 754 static void __exit hdlcdrv_cleanup_driver(void)
 755 {
 756         printk(KERN_INFO "hdlcdrv: cleanup\n");
 757 }
 758
 759 /* --------------------------------------------------------------------- */
 760
 761 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 762 MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
 763 MODULE_LICENSE("GPL");
 764 module_init(hdlcdrv_init_driver);
 765 module_exit(hdlcdrv_cleanup_driver);
 766
 767 /* --------------------------------------------------------------------- */