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_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_INFO 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                 return 0;
 148         }
 149 }
 150
 151 /* Handle an ioctl call that has come in via ppp. (copy of ppp_async_ioctl() */
 152 static int ipwireless_ppp_ioctl(struct ppp_channel *ppp_channel,
 153                                 unsigned int cmd, unsigned long arg)
 154 {
 155         struct ipw_network *network = ppp_channel->private;
 156         int err, val;
 157         u32 accm[8];
 158         int __user *user_arg = (int __user *) arg;
 159
 160         err = -EFAULT;
 161         switch (cmd) {
 162         case PPPIOCGFLAGS:
 163                 val = network->flags | network->rbits;
 164                 if (put_user(val, user_arg))
 165                         break;
 166                 err = 0;
 167                 break;
 168
 169         case PPPIOCSFLAGS:
 170                 if (get_user(val, user_arg))
 171                         break;
 172                 network->flags = val & ~SC_RCV_BITS;
 173                 network->rbits = val & SC_RCV_BITS;
 174                 err = 0;
 175                 break;
 176
 177         case PPPIOCGASYNCMAP:
 178                 if (put_user(network->xaccm[0], user_arg))
 179                         break;
 180                 err = 0;
 181                 break;
 182
 183         case PPPIOCSASYNCMAP:
 184                 if (get_user(network->xaccm[0], user_arg))
 185                         break;
 186                 err = 0;
 187                 break;
 188
 189         case PPPIOCGRASYNCMAP:
 190                 if (put_user(network->raccm, user_arg))
 191                         break;
 192                 err = 0;
 193                 break;
 194
 195         case PPPIOCSRASYNCMAP:
 196                 if (get_user(network->raccm, user_arg))
 197                         break;
 198                 err = 0;
 199                 break;
 200
 201         case PPPIOCGXASYNCMAP:
 202                 if (copy_to_user((void __user *) arg, network->xaccm,
 203                                         sizeof(network->xaccm)))
 204                         break;
 205                 err = 0;
 206                 break;
 207
 208         case PPPIOCSXASYNCMAP:
 209                 if (copy_from_user(accm, (void __user *) arg, sizeof(accm)))
 210                         break;
 211                 accm[2] &= ~0x40000000U;        /* can't escape 0x5e */
 212                 accm[3] |= 0x60000000U; /* must escape 0x7d, 0x7e */
 213                 memcpy(network->xaccm, accm, sizeof(network->xaccm));
 214                 err = 0;
 215                 break;
 216
 217         case PPPIOCGMRU:
 218                 if (put_user(network->mru, user_arg))
 219                         break;
 220                 err = 0;
 221                 break;
 222
 223         case PPPIOCSMRU:
 224                 if (get_user(val, user_arg))
 225                         break;
 226                 if (val < PPP_MRU)
 227                         val = PPP_MRU;
 228                 network->mru = val;
 229                 err = 0;
 230                 break;
 231
 232         default:
 233                 err = -ENOTTY;
 234         }
 235
 236         return err;
 237 }
 238
 239 static struct ppp_channel_ops ipwireless_ppp_channel_ops = {
 240         .start_xmit = ipwireless_ppp_start_xmit,
 241         .ioctl      = ipwireless_ppp_ioctl
 242 };
 243
 244 static void do_go_online(struct work_struct *work_go_online)
 245 {
 246         struct ipw_network *network =
 247                 container_of(work_go_online, struct ipw_network,
 248                                 work_go_online);
 249         unsigned long flags;
 250
 251         spin_lock_irqsave(&network->lock, flags);
 252         if (!network->ppp_channel) {
 253                 struct ppp_channel *channel;
 254
 255                 spin_unlock_irqrestore(&network->lock, flags);
 256                 channel = kzalloc(sizeof(struct ppp_channel), GFP_KERNEL);
 257                 if (!channel) {
 258                         printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 259                                         ": unable to allocate PPP channel\n");
 260                         return;
 261                 }
 262                 channel->private = network;
 263                 channel->mtu = 16384;   /* Wild guess */
 264                 channel->hdrlen = 2;
 265                 channel->ops = &ipwireless_ppp_channel_ops;
 266
 267                 network->flags = 0;
 268                 network->rbits = 0;
 269                 network->mru = PPP_MRU;
 270                 memset(network->xaccm, 0, sizeof(network->xaccm));
 271                 network->xaccm[0] = ~0U;
 272                 network->xaccm[3] = 0x60000000U;
 273                 network->raccm = ~0U;
 274                 ppp_register_channel(channel);
 275                 spin_lock_irqsave(&network->lock, flags);
 276                 network->ppp_channel = channel;
 277         }
 278         spin_unlock_irqrestore(&network->lock, flags);
 279 }
 280
 281 static void do_go_offline(struct work_struct *work_go_offline)
 282 {
 283         struct ipw_network *network =
 284                 container_of(work_go_offline, struct ipw_network,
 285                                 work_go_offline);
 286         unsigned long flags;
 287
 288         mutex_lock(&network->close_lock);
 289         spin_lock_irqsave(&network->lock, flags);
 290         if (network->ppp_channel != NULL) {
 291                 struct ppp_channel *channel = network->ppp_channel;
 292
 293                 network->ppp_channel = NULL;
 294                 spin_unlock_irqrestore(&network->lock, flags);
 295                 mutex_unlock(&network->close_lock);
 296                 ppp_unregister_channel(channel);
 297         } else {
 298                 spin_unlock_irqrestore(&network->lock, flags);
 299                 mutex_unlock(&network->close_lock);
 300         }
 301 }
 302
 303 void ipwireless_network_notify_control_line_change(struct ipw_network *network,
 304                                                    unsigned int channel_idx,
 305                                                    unsigned int control_lines,
 306                                                    unsigned int changed_mask)
 307 {
 308         int i;
 309
 310         if (channel_idx == IPW_CHANNEL_RAS)
 311                 network->ras_control_lines = control_lines;
 312
 313         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
 314                 struct ipw_tty *tty =
 315                         network->associated_ttys[channel_idx][i];
 316
 317                 /*
 318                  * If it's associated with a tty (other than the RAS channel
 319                  * when we're online), then send the data to that tty.  The RAS
 320                  * channel's data is handled above - it always goes through
 321                  * ppp_generic.
 322                  */
 323                 if (tty)
 324                         ipwireless_tty_notify_control_line_change(tty,
 325                                                                   channel_idx,
 326                                                                   control_lines,
 327                                                                   changed_mask);
 328         }
 329 }
 330
 331 /*
 332  * Some versions of firmware stuff packets with 0xff 0x03 (PPP: ALLSTATIONS, UI)
 333  * bytes, which are required on sent packet, but not always present on received
 334  * packets
 335  */
 336 static struct sk_buff *ipw_packet_received_skb(unsigned char *data,
 337                                                unsigned int length)
 338 {
 339         struct sk_buff *skb;
 340
 341         if (length > 2 && data[0] == PPP_ALLSTATIONS && data[1] == PPP_UI) {
 342                 length -= 2;
 343                 data += 2;
 344         }
 345
 346         skb = dev_alloc_skb(length + 4);
 347         skb_reserve(skb, 2);
 348         memcpy(skb_put(skb, length), data, length);
 349
 350         return skb;
 351 }
 352
 353 void ipwireless_network_packet_received(struct ipw_network *network,
 354                                         unsigned int channel_idx,
 355                                         unsigned char *data,
 356                                         unsigned int length)
 357 {
 358         int i;
 359         unsigned long flags;
 360
 361         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
 362                 struct ipw_tty *tty = network->associated_ttys[channel_idx][i];
 363
 364                 if (!tty)
 365                         continue;
 366
 367                 /*
 368                  * If it's associated with a tty (other than the RAS channel
 369                  * when we're online), then send the data to that tty.  The RAS
 370                  * channel's data is handled above - it always goes through
 371                  * ppp_generic.
 372                  */
 373                 if (channel_idx == IPW_CHANNEL_RAS
 374                                 && (network->ras_control_lines &
 375                                         IPW_CONTROL_LINE_DCD) != 0
 376                                 && ipwireless_tty_is_modem(tty)) {
 377                         /*
 378                          * If data came in on the RAS channel and this tty is
 379                          * the modem tty, and we are online, then we send it to
 380                          * the PPP layer.
 381                          */
 382                         mutex_lock(&network->close_lock);
 383                         spin_lock_irqsave(&network->lock, flags);
 384                         if (network->ppp_channel != NULL) {
 385                                 struct sk_buff *skb;
 386
 387                                 spin_unlock_irqrestore(&network->lock,
 388                                                 flags);
 389
 390                                 /* Send the data to the ppp_generic module. */
 391                                 skb = ipw_packet_received_skb(data, length);
 392                                 ppp_input(network->ppp_channel, skb);
 393                         } else
 394                                 spin_unlock_irqrestore(&network->lock,
 395                                                 flags);
 396                         mutex_unlock(&network->close_lock);
 397                 }
 398                 /* Otherwise we send it out the tty. */
 399                 else
 400                         ipwireless_tty_received(tty, data, length);
 401         }
 402 }
 403
 404 struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw)
 405 {
 406         struct ipw_network *network =
 407                 kzalloc(sizeof(struct ipw_network), GFP_ATOMIC);
 408
 409         if (!network)
 410                 return NULL;
 411
 412         spin_lock_init(&network->lock);
 413         mutex_init(&network->close_lock);
 414
 415         network->hardware = hw;
 416
 417         INIT_WORK(&network->work_go_online, do_go_online);
 418         INIT_WORK(&network->work_go_offline, do_go_offline);
 419
 420         ipwireless_associate_network(hw, network);
 421
 422         return network;
 423 }
 424
 425 void ipwireless_network_free(struct ipw_network *network)
 426 {
 427         network->shutting_down = 1;
 428
 429         ipwireless_ppp_close(network);
 430         flush_scheduled_work();
 431
 432         ipwireless_stop_interrupts(network->hardware);
 433         ipwireless_associate_network(network->hardware, NULL);
 434
 435         kfree(network);
 436 }
 437
 438 void ipwireless_associate_network_tty(struct ipw_network *network,
 439                                       unsigned int channel_idx,
 440                                       struct ipw_tty *tty)
 441 {
 442         int i;
 443
 444         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
 445                 if (network->associated_ttys[channel_idx][i] == NULL) {
 446                         network->associated_ttys[channel_idx][i] = tty;
 447                         break;
 448                 }
 449 }
 450
 451 void ipwireless_disassociate_network_ttys(struct ipw_network *network,
 452                                           unsigned int channel_idx)
 453 {
 454         int i;
 455
 456         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
 457                 network->associated_ttys[channel_idx][i] = NULL;
 458 }
 459
 460 void ipwireless_ppp_open(struct ipw_network *network)
 461 {
 462         if (ipwireless_debug)
 463                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": online\n");
 464         schedule_work(&network->work_go_online);
 465 }
 466
 467 void ipwireless_ppp_close(struct ipw_network *network)
 468 {
 469         /* Disconnect from the wireless network. */
 470         if (ipwireless_debug)
 471                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": offline\n");
 472         schedule_work(&network->work_go_offline);
 473 }
 474
 475 int ipwireless_ppp_channel_index(struct ipw_network *network)
 476 {
 477         int ret = -1;
 478         unsigned long flags;
 479
 480         spin_lock_irqsave(&network->lock, flags);
 481         if (network->ppp_channel != NULL)
 482                 ret = ppp_channel_index(network->ppp_channel);
 483         spin_unlock_irqrestore(&network->lock, flags);
 484
 485         return ret;
 486 }
 487
 488 int ipwireless_ppp_unit_number(struct ipw_network *network)
 489 {
 490         int ret = -1;
 491         unsigned long flags;
 492
 493         spin_lock_irqsave(&network->lock, flags);
 494         if (network->ppp_channel != NULL)
 495                 ret = ppp_unit_number(network->ppp_channel);
 496         spin_unlock_irqrestore(&network->lock, flags);
 497
 498         return ret;
 499 }