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