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/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
  75 static 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
  85 static 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
  93 static 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
 113 static 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
 131 static 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
 155 void 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
 211 static 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
 252 void 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
 352 static 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
 364 void 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
 389 static 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
 413 static 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
 432 static 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
 469 static 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
 486 static 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                         strlcpy(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
 616 static 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  */
 627 static 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 /* --------------------------------------------------------------------- */
 681 struct 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         if (privsize < sizeof(struct hdlcdrv_state))
 691                 privsize = sizeof(struct hdlcdrv_state);
 692
 693         dev = alloc_netdev(privsize, ifname, NET_NAME_UNKNOWN, hdlcdrv_setup);
 694         if (!dev)
 695                 return ERR_PTR(-ENOMEM);
 696
 697         /*
 698          * initialize part of the hdlcdrv_state struct
 699          */
 700         s = netdev_priv(dev);
 701         s->magic = HDLCDRV_MAGIC;
 702         s->ops = ops;
 703         dev->base_addr = baseaddr;
 704         dev->irq = irq;
 705         dev->dma = dma;
 706
 707         err = register_netdev(dev);
 708         if (err < 0) {
 709                 printk(KERN_WARNING "hdlcdrv: cannot register net "
 710                        "device %s\n", dev->name);
 711                 free_netdev(dev);
 712                 dev = ERR_PTR(err);
 713         }
 714         return dev;
 715 }
 716
 717 /* --------------------------------------------------------------------- */
 718
 719 void hdlcdrv_unregister(struct net_device *dev)
 720 {
 721         struct hdlcdrv_state *s = netdev_priv(dev);
 722
 723         BUG_ON(s->magic != HDLCDRV_MAGIC);
 724
 725         if (s->opened && s->ops->close)
 726                 s->ops->close(dev);
 727         unregister_netdev(dev);
 728
 729         free_netdev(dev);
 730 }
 731
 732 /* --------------------------------------------------------------------- */
 733
 734 EXPORT_SYMBOL(hdlcdrv_receiver);
 735 EXPORT_SYMBOL(hdlcdrv_transmitter);
 736 EXPORT_SYMBOL(hdlcdrv_arbitrate);
 737 EXPORT_SYMBOL(hdlcdrv_register);
 738 EXPORT_SYMBOL(hdlcdrv_unregister);
 739
 740 /* --------------------------------------------------------------------- */
 741
 742 static int __init hdlcdrv_init_driver(void)
 743 {
 744         printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
 745         printk(KERN_INFO "hdlcdrv: version 0.8\n");
 746         return 0;
 747 }
 748
 749 /* --------------------------------------------------------------------- */
 750
 751 static void __exit hdlcdrv_cleanup_driver(void)
 752 {
 753         printk(KERN_INFO "hdlcdrv: cleanup\n");
 754 }
 755
 756 /* --------------------------------------------------------------------- */
 757
 758 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 759 MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
 760 MODULE_LICENSE("GPL");
 761 module_init(hdlcdrv_init_driver);
 762 module_exit(hdlcdrv_cleanup_driver);
 763
 764 /* --------------------------------------------------------------------- */