drivers/char/pcmcia/ipwireless/network.c

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