drivers/char/pcmcia/ipwireless/network.c

   1 /*
   2  * IPWireless 3G PCMCIA Network Driver
   3  *
   4  * Original code
   5  *   by Stephen Blackheath <stephen@blacksapphire.com>,
   6  *      Ben Martel <benm@symmetric.co.nz>
   7  *
   8  * Copyrighted as follows:
   9  *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
  10  *
  11  * Various driver changes and rewrites, port to new kernels
  12  *   Copyright (C) 2006-2007 Jiri Kosina
  13  *
  14  * Misc code cleanups and updates
  15  *   Copyright (C) 2007 David Sterba
  16  */
  17
  18 #include <linux/interrupt.h>
  19 #include <linux/kernel.h>
  20 #include <linux/mutex.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/ppp_channel.h>
  23 #include <linux/ppp_defs.h>
  24 #include <linux/if_ppp.h>
  25 #include <linux/skbuff.h>
  26
  27 #include "network.h"
  28 #include "hardware.h"
  29 #include "main.h"
  30 #include "tty.h"
  31
  32 #define MAX_OUTGOING_PACKETS_QUEUED   ipwireless_out_queue
  33 #define MAX_ASSOCIATED_TTYS 2
  34
  35 #define SC_RCV_BITS     (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
  36
  37 struct ipw_network {
  38         /* Hardware context, used for calls to hardware layer. */
  39         struct ipw_hardware *hardware;
  40         /* Context for kernel 'generic_ppp' functionality */
  41         struct ppp_channel *ppp_channel;
  42         /* tty context connected with IPW console */
  43         struct ipw_tty *associated_ttys[NO_OF_IPW_CHANNELS][MAX_ASSOCIATED_TTYS];
  44         /* True if ppp needs waking up once we're ready to xmit */
  45         int ppp_blocked;
  46         /* Number of packets queued up in hardware module. */
  47         int outgoing_packets_queued;
  48         /* Spinlock to avoid interrupts during shutdown */
  49         spinlock_t spinlock;
  50         struct mutex close_lock;
  51
  52         /* PPP ioctl data, not actually used anywere */
  53         unsigned int flags;
  54         unsigned int rbits;
  55         u32 xaccm[8];
  56         u32 raccm;
  57         int mru;
  58
  59         int shutting_down;
  60         unsigned int ras_control_lines;
  61
  62         struct work_struct work_go_online;
  63         struct work_struct work_go_offline;
  64 };
  65
  66
  67 #ifdef IPWIRELESS_STATE_DEBUG
  68 int ipwireless_dump_network_state(char *p, size_t limit,
  69                                   struct ipw_network *network)
  70 {
  71         return snprintf(p, limit,
  72                         "debug: ppp_blocked=%d\n"
  73                         "debug: outgoing_packets_queued=%d\n"
  74                         "debug: network.shutting_down=%d\n",
  75                         network->ppp_blocked,
  76                         network->outgoing_packets_queued,
  77                         network->shutting_down);
  78 }
  79 #endif
  80
  81 static void notify_packet_sent(void *callback_data, unsigned int packet_length)
  82 {
  83         struct ipw_network *network = callback_data;
  84         unsigned long flags;
  85
  86         spin_lock_irqsave(&network->spinlock, flags);
  87         network->outgoing_packets_queued--;
  88         if (network->ppp_channel != NULL) {
  89                 if (network->ppp_blocked) {
  90                         network->ppp_blocked = 0;
  91                         spin_unlock_irqrestore(&network->spinlock, flags);
  92                         ppp_output_wakeup(network->ppp_channel);
  93                         if (ipwireless_debug)
  94                                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
  95                                        ": ppp unblocked\n");
  96                 } else
  97                         spin_unlock_irqrestore(&network->spinlock, flags);
  98         } else
  99                 spin_unlock_irqrestore(&network->spinlock, flags);
 100 }
 101
 102 /*
 103  * Called by the ppp system when it has a packet to send to the hardware.
 104  */
 105 static int ipwireless_ppp_start_xmit(struct ppp_channel *ppp_channel,
 106                                      struct sk_buff *skb)
 107 {
 108         struct ipw_network *network = ppp_channel->private;
 109         unsigned long flags;
 110
 111         spin_lock_irqsave(&network->spinlock, flags);
 112         if (network->outgoing_packets_queued < MAX_OUTGOING_PACKETS_QUEUED) {
 113                 unsigned char *buf;
 114                 static unsigned char header[] = {
 115                         PPP_ALLSTATIONS, /* 0xff */
 116                         PPP_UI,          /* 0x03 */
 117                 };
 118                 int ret;
 119
 120                 network->outgoing_packets_queued++;
 121                 spin_unlock_irqrestore(&network->spinlock, flags);
 122
 123                 /*
 124                  * If we have the requested amount of headroom in the skb we
 125                  * were handed, then we can add the header efficiently.
 126                  */
 127                 if (skb_headroom(skb) >= 2) {
 128                         memcpy(skb_push(skb, 2), header, 2);
 129                         ret = ipwireless_send_packet(network->hardware,
 130                                                IPW_CHANNEL_RAS, skb->data,
 131                                                skb->len,
 132                                                notify_packet_sent,
 133                                                network);
 134                         if (ret == -1) {
 135                                 skb_pull(skb, 2);
 136                                 return 0;
 137                         }
 138                 } else {
 139                         /* Otherwise (rarely) we do it inefficiently. */
 140                         buf = kmalloc(skb->len + 2, GFP_ATOMIC);
 141                         if (!buf)
 142                                 return 0;
 143                         memcpy(buf + 2, skb->data, skb->len);
 144                         memcpy(buf, header, 2);
 145                         ret = ipwireless_send_packet(network->hardware,
 146                                                IPW_CHANNEL_RAS, buf,
 147                                                skb->len + 2,
 148                                                notify_packet_sent,
 149                                                network);
 150                         kfree(buf);
 151                         if (ret == -1)
 152                                 return 0;
 153                 }
 154                 kfree_skb(skb);
 155                 return 1;
 156         } else {
 157                 /*
 158                  * Otherwise reject the packet, and flag that the ppp system
 159                  * needs to be unblocked once we are ready to send.
 160                  */
 161                 network->ppp_blocked = 1;
 162                 spin_unlock_irqrestore(&network->spinlock, flags);
 163                 return 0;
 164         }
 165 }
 166
 167 /* Handle an ioctl call that has come in via ppp. (copy of ppp_async_ioctl() */
 168 static int ipwireless_ppp_ioctl(struct ppp_channel *ppp_channel,
 169                                 unsigned int cmd, unsigned long arg)
 170 {
 171         struct ipw_network *network = ppp_channel->private;
 172         int err, val;
 173         u32 accm[8];
 174         int __user *user_arg = (int __user *) arg;
 175
 176         err = -EFAULT;
 177         switch (cmd) {
 178         case PPPIOCGFLAGS:
 179                 val = network->flags | network->rbits;
 180                 if (put_user(val, user_arg))
 181                         break;
 182                 err = 0;
 183                 break;
 184
 185         case PPPIOCSFLAGS:
 186                 if (get_user(val, user_arg))
 187                         break;
 188                 network->flags = val & ~SC_RCV_BITS;
 189                 network->rbits = val & SC_RCV_BITS;
 190                 err = 0;
 191                 break;
 192
 193         case PPPIOCGASYNCMAP:
 194                 if (put_user(network->xaccm[0], user_arg))
 195                         break;
 196                 err = 0;
 197                 break;
 198
 199         case PPPIOCSASYNCMAP:
 200                 if (get_user(network->xaccm[0], user_arg))
 201                         break;
 202                 err = 0;
 203                 break;
 204
 205         case PPPIOCGRASYNCMAP:
 206                 if (put_user(network->raccm, user_arg))
 207                         break;
 208                 err = 0;
 209                 break;
 210
 211         case PPPIOCSRASYNCMAP:
 212                 if (get_user(network->raccm, user_arg))
 213                         break;
 214                 err = 0;
 215                 break;
 216
 217         case PPPIOCGXASYNCMAP:
 218                 if (copy_to_user((void __user *) arg, network->xaccm,
 219                                         sizeof(network->xaccm)))
 220                         break;
 221                 err = 0;
 222                 break;
 223
 224         case PPPIOCSXASYNCMAP:
 225                 if (copy_from_user(accm, (void __user *) arg, sizeof(accm)))
 226                         break;
 227                 accm[2] &= ~0x40000000U;        /* can't escape 0x5e */
 228                 accm[3] |= 0x60000000U; /* must escape 0x7d, 0x7e */
 229                 memcpy(network->xaccm, accm, sizeof(network->xaccm));
 230                 err = 0;
 231                 break;
 232
 233         case PPPIOCGMRU:
 234                 if (put_user(network->mru, user_arg))
 235                         break;
 236                 err = 0;
 237                 break;
 238
 239         case PPPIOCSMRU:
 240                 if (get_user(val, user_arg))
 241                         break;
 242                 if (val < PPP_MRU)
 243                         val = PPP_MRU;
 244                 network->mru = val;
 245                 err = 0;
 246                 break;
 247
 248         default:
 249                 err = -ENOTTY;
 250         }
 251
 252         return err;
 253 }
 254
 255 static struct ppp_channel_ops ipwireless_ppp_channel_ops = {
 256         .start_xmit = ipwireless_ppp_start_xmit,
 257         .ioctl      = ipwireless_ppp_ioctl
 258 };
 259
 260 static void do_go_online(struct work_struct *work_go_online)
 261 {
 262         struct ipw_network *network =
 263                 container_of(work_go_online, struct ipw_network,
 264                                 work_go_online);
 265         unsigned long flags;
 266
 267         spin_lock_irqsave(&network->spinlock, flags);
 268         if (!network->ppp_channel) {
 269                 struct ppp_channel *channel;
 270
 271                 spin_unlock_irqrestore(&network->spinlock, flags);
 272                 channel = kzalloc(sizeof(struct ppp_channel), GFP_KERNEL);
 273                 if (!channel) {
 274                         printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 275                                         ": unable to allocate PPP channel\n");
 276                         return;
 277                 }
 278                 channel->private = network;
 279                 channel->mtu = 16384;   /* Wild guess */
 280                 channel->hdrlen = 2;
 281                 channel->ops = &ipwireless_ppp_channel_ops;
 282
 283                 network->flags = 0;
 284                 network->rbits = 0;
 285                 network->mru = PPP_MRU;
 286                 memset(network->xaccm, 0, sizeof(network->xaccm));
 287                 network->xaccm[0] = ~0U;
 288                 network->xaccm[3] = 0x60000000U;
 289                 network->raccm = ~0U;
 290                 ppp_register_channel(channel);
 291                 spin_lock_irqsave(&network->spinlock, flags);
 292                 network->ppp_channel = channel;
 293         }
 294         spin_unlock_irqrestore(&network->spinlock, flags);
 295 }
 296
 297 static void do_go_offline(struct work_struct *work_go_offline)
 298 {
 299         struct ipw_network *network =
 300                 container_of(work_go_offline, struct ipw_network,
 301                                 work_go_offline);
 302         unsigned long flags;
 303
 304         mutex_lock(&network->close_lock);
 305         spin_lock_irqsave(&network->spinlock, flags);
 306         if (network->ppp_channel != NULL) {
 307                 struct ppp_channel *channel = network->ppp_channel;
 308
 309                 network->ppp_channel = NULL;
 310                 spin_unlock_irqrestore(&network->spinlock, flags);
 311                 mutex_unlock(&network->close_lock);
 312                 ppp_unregister_channel(channel);
 313         } else {
 314                 spin_unlock_irqrestore(&network->spinlock, flags);
 315                 mutex_unlock(&network->close_lock);
 316         }
 317 }
 318
 319 void ipwireless_network_notify_control_line_change(struct ipw_network *network,
 320                                                    unsigned int channel_idx,
 321                                                    unsigned int control_lines,
 322                                                    unsigned int changed_mask)
 323 {
 324         int i;
 325
 326         if (channel_idx == IPW_CHANNEL_RAS)
 327                 network->ras_control_lines = control_lines;
 328
 329         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
 330                 struct ipw_tty *tty =
 331                         network->associated_ttys[channel_idx][i];
 332
 333                 /*
 334                  * If it's associated with a tty (other than the RAS channel
 335                  * when we're online), then send the data to that tty.  The RAS
 336                  * channel's data is handled above - it always goes through
 337                  * ppp_generic.
 338                  */
 339                 if (tty)
 340                         ipwireless_tty_notify_control_line_change(tty,
 341                                                                   channel_idx,
 342                                                                   control_lines,
 343                                                                   changed_mask);
 344         }
 345 }
 346
 347 /*
 348  * Some versions of firmware stuff packets with 0xff 0x03 (PPP: ALLSTATIONS, UI)
 349  * bytes, which are required on sent packet, but not always present on received
 350  * packets
 351  */
 352 static struct sk_buff *ipw_packet_received_skb(unsigned char *data,
 353                                                unsigned int length)
 354 {
 355         struct sk_buff *skb;
 356
 357         if (length > 2 && data[0] == PPP_ALLSTATIONS && data[1] == PPP_UI) {
 358                 length -= 2;
 359                 data += 2;
 360         }
 361
 362         skb = dev_alloc_skb(length + 4);
 363         skb_reserve(skb, 2);
 364         memcpy(skb_put(skb, length), data, length);
 365
 366         return skb;
 367 }
 368
 369 void ipwireless_network_packet_received(struct ipw_network *network,
 370                                         unsigned int channel_idx,
 371                                         unsigned char *data,
 372                                         unsigned int length)
 373 {
 374         int i;
 375         unsigned long flags;
 376
 377         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
 378                 struct ipw_tty *tty = network->associated_ttys[channel_idx][i];
 379
 380                 if (!tty)
 381                         continue;
 382
 383                 /*
 384                  * If it's associated with a tty (other than the RAS channel
 385                  * when we're online), then send the data to that tty.  The RAS
 386                  * channel's data is handled above - it always goes through
 387                  * ppp_generic.
 388                  */
 389                 if (channel_idx == IPW_CHANNEL_RAS
 390                                 && (network->ras_control_lines &
 391                                         IPW_CONTROL_LINE_DCD) != 0
 392                                 && ipwireless_tty_is_modem(tty)) {
 393                         /*
 394                          * If data came in on the RAS channel and this tty is
 395                          * the modem tty, and we are online, then we send it to
 396                          * the PPP layer.
 397                          */
 398                         mutex_lock(&network->close_lock);
 399                         spin_lock_irqsave(&network->spinlock, flags);
 400                         if (network->ppp_channel != NULL) {
 401                                 struct sk_buff *skb;
 402
 403                                 spin_unlock_irqrestore(&network->spinlock,
 404                                                 flags);
 405
 406                                 /* Send the data to the ppp_generic module. */
 407                                 skb = ipw_packet_received_skb(data, length);
 408                                 ppp_input(network->ppp_channel, skb);
 409                         } else
 410                                 spin_unlock_irqrestore(&network->spinlock,
 411                                                 flags);
 412                         mutex_unlock(&network->close_lock);
 413                 }
 414                 /* Otherwise we send it out the tty. */
 415                 else
 416                         ipwireless_tty_received(tty, data, length);
 417         }
 418 }
 419
 420 struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw)
 421 {
 422         struct ipw_network *network =
 423                 kzalloc(sizeof(struct ipw_network), GFP_ATOMIC);
 424
 425         if (!network)
 426                 return NULL;
 427
 428         spin_lock_init(&network->spinlock);
 429         mutex_init(&network->close_lock);
 430
 431         network->hardware = hw;
 432
 433         INIT_WORK(&network->work_go_online, do_go_online);
 434         INIT_WORK(&network->work_go_offline, do_go_offline);
 435
 436         ipwireless_associate_network(hw, network);
 437
 438         return network;
 439 }
 440
 441 void ipwireless_network_free(struct ipw_network *network)
 442 {
 443         network->shutting_down = 1;
 444
 445         ipwireless_ppp_close(network);
 446         flush_scheduled_work();
 447
 448         ipwireless_stop_interrupts(network->hardware);
 449         ipwireless_associate_network(network->hardware, NULL);
 450
 451         kfree(network);
 452 }
 453
 454 void ipwireless_associate_network_tty(struct ipw_network *network,
 455                                       unsigned int channel_idx,
 456                                       struct ipw_tty *tty)
 457 {
 458         int i;
 459
 460         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
 461                 if (network->associated_ttys[channel_idx][i] == NULL) {
 462                         network->associated_ttys[channel_idx][i] = tty;
 463                         break;
 464                 }
 465 }
 466
 467 void ipwireless_disassociate_network_ttys(struct ipw_network *network,
 468                                           unsigned int channel_idx)
 469 {
 470         int i;
 471
 472         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
 473                 network->associated_ttys[channel_idx][i] = NULL;
 474 }
 475
 476 void ipwireless_ppp_open(struct ipw_network *network)
 477 {
 478         if (ipwireless_debug)
 479                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": online\n");
 480         schedule_work(&network->work_go_online);
 481 }
 482
 483 void ipwireless_ppp_close(struct ipw_network *network)
 484 {
 485         /* Disconnect from the wireless network. */
 486         if (ipwireless_debug)
 487                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": offline\n");
 488         schedule_work(&network->work_go_offline);
 489 }
 490
 491 int ipwireless_ppp_channel_index(struct ipw_network *network)
 492 {
 493         int ret = -1;
 494         unsigned long flags;
 495
 496         spin_lock_irqsave(&network->spinlock, flags);
 497         if (network->ppp_channel != NULL)
 498                 ret = ppp_channel_index(network->ppp_channel);
 499         spin_unlock_irqrestore(&network->spinlock, flags);
 500
 501         return ret;
 502 }
 503
 504 int ipwireless_ppp_unit_number(struct ipw_network *network)
 505 {
 506         int ret = -1;
 507         unsigned long flags;
 508
 509         spin_lock_irqsave(&network->spinlock, flags);
 510         if (network->ppp_channel != NULL)
 511                 ret = ppp_unit_number(network->ppp_channel);
 512         spin_unlock_irqrestore(&network->spinlock, flags);
 513
 514         return ret;
 515 }