drivers/tty/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/slab.h>
  25 #include <linux/if_ppp.h>
  26 #include <linux/skbuff.h>
  27
  28 #include "network.h"
  29 #include "hardware.h"
  30 #include "main.h"
  31 #include "tty.h"
  32
  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 lock;
  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->lock, 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->lock, flags);
  77                         ppp_output_wakeup(network->ppp_channel);
  78                         if (ipwireless_debug)
  79                                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
  80                                        ": ppp unblocked\n");
  81                 } else
  82                         spin_unlock_irqrestore(&network->lock, flags);
  83         } else
  84                 spin_unlock_irqrestore(&network->lock, 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->lock, flags);
  97         if (network->outgoing_packets_queued < ipwireless_out_queue) {
  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->lock, 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->lock, flags);
 148                 if (ipwireless_debug)
 149                         printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": ppp blocked\n");
 150                 return 0;
 151         }
 152 }
 153
 154 /* Handle an ioctl call that has come in via ppp. (copy of ppp_async_ioctl() */
 155 static int ipwireless_ppp_ioctl(struct ppp_channel *ppp_channel,
 156                                 unsigned int cmd, unsigned long arg)
 157 {
 158         struct ipw_network *network = ppp_channel->private;
 159         int err, val;
 160         u32 accm[8];
 161         int __user *user_arg = (int __user *) arg;
 162
 163         err = -EFAULT;
 164         switch (cmd) {
 165         case PPPIOCGFLAGS:
 166                 val = network->flags | network->rbits;
 167                 if (put_user(val, user_arg))
 168                         break;
 169                 err = 0;
 170                 break;
 171
 172         case PPPIOCSFLAGS:
 173                 if (get_user(val, user_arg))
 174                         break;
 175                 network->flags = val & ~SC_RCV_BITS;
 176                 network->rbits = val & SC_RCV_BITS;
 177                 err = 0;
 178                 break;
 179
 180         case PPPIOCGASYNCMAP:
 181                 if (put_user(network->xaccm[0], user_arg))
 182                         break;
 183                 err = 0;
 184                 break;
 185
 186         case PPPIOCSASYNCMAP:
 187                 if (get_user(network->xaccm[0], user_arg))
 188                         break;
 189                 err = 0;
 190                 break;
 191
 192         case PPPIOCGRASYNCMAP:
 193                 if (put_user(network->raccm, user_arg))
 194                         break;
 195                 err = 0;
 196                 break;
 197
 198         case PPPIOCSRASYNCMAP:
 199                 if (get_user(network->raccm, user_arg))
 200                         break;
 201                 err = 0;
 202                 break;
 203
 204         case PPPIOCGXASYNCMAP:
 205                 if (copy_to_user((void __user *) arg, network->xaccm,
 206                                         sizeof(network->xaccm)))
 207                         break;
 208                 err = 0;
 209                 break;
 210
 211         case PPPIOCSXASYNCMAP:
 212                 if (copy_from_user(accm, (void __user *) arg, sizeof(accm)))
 213                         break;
 214                 accm[2] &= ~0x40000000U;        /* can't escape 0x5e */
 215                 accm[3] |= 0x60000000U; /* must escape 0x7d, 0x7e */
 216                 memcpy(network->xaccm, accm, sizeof(network->xaccm));
 217                 err = 0;
 218                 break;
 219
 220         case PPPIOCGMRU:
 221                 if (put_user(network->mru, user_arg))
 222                         break;
 223                 err = 0;
 224                 break;
 225
 226         case PPPIOCSMRU:
 227                 if (get_user(val, user_arg))
 228                         break;
 229                 if (val < PPP_MRU)
 230                         val = PPP_MRU;
 231                 network->mru = val;
 232                 err = 0;
 233                 break;
 234
 235         default:
 236                 err = -ENOTTY;
 237         }
 238
 239         return err;
 240 }
 241
 242 static const struct ppp_channel_ops ipwireless_ppp_channel_ops = {
 243         .start_xmit = ipwireless_ppp_start_xmit,
 244         .ioctl      = ipwireless_ppp_ioctl
 245 };
 246
 247 static void do_go_online(struct work_struct *work_go_online)
 248 {
 249         struct ipw_network *network =
 250                 container_of(work_go_online, struct ipw_network,
 251                                 work_go_online);
 252         unsigned long flags;
 253
 254         spin_lock_irqsave(&network->lock, flags);
 255         if (!network->ppp_channel) {
 256                 struct ppp_channel *channel;
 257
 258                 spin_unlock_irqrestore(&network->lock, flags);
 259                 channel = kzalloc(sizeof(struct ppp_channel), GFP_KERNEL);
 260                 if (!channel) {
 261                         printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 262                                         ": unable to allocate PPP channel\n");
 263                         return;
 264                 }
 265                 channel->private = network;
 266                 channel->mtu = 16384;   /* Wild guess */
 267                 channel->hdrlen = 2;
 268                 channel->ops = &ipwireless_ppp_channel_ops;
 269
 270                 network->flags = 0;
 271                 network->rbits = 0;
 272                 network->mru = PPP_MRU;
 273                 memset(network->xaccm, 0, sizeof(network->xaccm));
 274                 network->xaccm[0] = ~0U;
 275                 network->xaccm[3] = 0x60000000U;
 276                 network->raccm = ~0U;
 277                 ppp_register_channel(channel);
 278                 spin_lock_irqsave(&network->lock, flags);
 279                 network->ppp_channel = channel;
 280         }
 281         spin_unlock_irqrestore(&network->lock, flags);
 282 }
 283
 284 static void do_go_offline(struct work_struct *work_go_offline)
 285 {
 286         struct ipw_network *network =
 287                 container_of(work_go_offline, struct ipw_network,
 288                                 work_go_offline);
 289         unsigned long flags;
 290
 291         mutex_lock(&network->close_lock);
 292         spin_lock_irqsave(&network->lock, flags);
 293         if (network->ppp_channel != NULL) {
 294                 struct ppp_channel *channel = network->ppp_channel;
 295
 296                 network->ppp_channel = NULL;
 297                 spin_unlock_irqrestore(&network->lock, flags);
 298                 mutex_unlock(&network->close_lock);
 299                 ppp_unregister_channel(channel);
 300         } else {
 301                 spin_unlock_irqrestore(&network->lock, flags);
 302                 mutex_unlock(&network->close_lock);
 303         }
 304 }
 305
 306 void ipwireless_network_notify_control_line_change(struct ipw_network *network,
 307                                                    unsigned int channel_idx,
 308                                                    unsigned int control_lines,
 309                                                    unsigned int changed_mask)
 310 {
 311         int i;
 312
 313         if (channel_idx == IPW_CHANNEL_RAS)
 314                 network->ras_control_lines = control_lines;
 315
 316         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
 317                 struct ipw_tty *tty =
 318                         network->associated_ttys[channel_idx][i];
 319
 320                 /*
 321                  * If it's associated with a tty (other than the RAS channel
 322                  * when we're online), then send the data to that tty.  The RAS
 323                  * channel's data is handled above - it always goes through
 324                  * ppp_generic.
 325                  */
 326                 if (tty)
 327                         ipwireless_tty_notify_control_line_change(tty,
 328                                                                   channel_idx,
 329                                                                   control_lines,
 330                                                                   changed_mask);
 331         }
 332 }
 333
 334 /*
 335  * Some versions of firmware stuff packets with 0xff 0x03 (PPP: ALLSTATIONS, UI)
 336  * bytes, which are required on sent packet, but not always present on received
 337  * packets
 338  */
 339 static struct sk_buff *ipw_packet_received_skb(unsigned char *data,
 340                                                unsigned int length)
 341 {
 342         struct sk_buff *skb;
 343
 344         if (length > 2 && data[0] == PPP_ALLSTATIONS && data[1] == PPP_UI) {
 345                 length -= 2;
 346                 data += 2;
 347         }
 348
 349         skb = dev_alloc_skb(length + 4);
 350         skb_reserve(skb, 2);
 351         memcpy(skb_put(skb, length), data, length);
 352
 353         return skb;
 354 }
 355
 356 void ipwireless_network_packet_received(struct ipw_network *network,
 357                                         unsigned int channel_idx,
 358                                         unsigned char *data,
 359                                         unsigned int length)
 360 {
 361         int i;
 362         unsigned long flags;
 363
 364         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
 365                 struct ipw_tty *tty = network->associated_ttys[channel_idx][i];
 366
 367                 if (!tty)
 368                         continue;
 369
 370                 /*
 371                  * If it's associated with a tty (other than the RAS channel
 372                  * when we're online), then send the data to that tty.  The RAS
 373                  * channel's data is handled above - it always goes through
 374                  * ppp_generic.
 375                  */
 376                 if (channel_idx == IPW_CHANNEL_RAS
 377                                 && (network->ras_control_lines &
 378                                         IPW_CONTROL_LINE_DCD) != 0
 379                                 && ipwireless_tty_is_modem(tty)) {
 380                         /*
 381                          * If data came in on the RAS channel and this tty is
 382                          * the modem tty, and we are online, then we send it to
 383                          * the PPP layer.
 384                          */
 385                         mutex_lock(&network->close_lock);
 386                         spin_lock_irqsave(&network->lock, flags);
 387                         if (network->ppp_channel != NULL) {
 388                                 struct sk_buff *skb;
 389
 390                                 spin_unlock_irqrestore(&network->lock,
 391                                                 flags);
 392
 393                                 /* Send the data to the ppp_generic module. */
 394                                 skb = ipw_packet_received_skb(data, length);
 395                                 ppp_input(network->ppp_channel, skb);
 396                         } else
 397                                 spin_unlock_irqrestore(&network->lock,
 398                                                 flags);
 399                         mutex_unlock(&network->close_lock);
 400                 }
 401                 /* Otherwise we send it out the tty. */
 402                 else
 403                         ipwireless_tty_received(tty, data, length);
 404         }
 405 }
 406
 407 struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw)
 408 {
 409         struct ipw_network *network =
 410                 kzalloc(sizeof(struct ipw_network), GFP_ATOMIC);
 411
 412         if (!network)
 413                 return NULL;
 414
 415         spin_lock_init(&network->lock);
 416         mutex_init(&network->close_lock);
 417
 418         network->hardware = hw;
 419
 420         INIT_WORK(&network->work_go_online, do_go_online);
 421         INIT_WORK(&network->work_go_offline, do_go_offline);
 422
 423         ipwireless_associate_network(hw, network);
 424
 425         return network;
 426 }
 427
 428 void ipwireless_network_free(struct ipw_network *network)
 429 {
 430         network->shutting_down = 1;
 431
 432         ipwireless_ppp_close(network);
 433         flush_work_sync(&network->work_go_online);
 434         flush_work_sync(&network->work_go_offline);
 435
 436         ipwireless_stop_interrupts(network->hardware);
 437         ipwireless_associate_network(network->hardware, NULL);
 438
 439         kfree(network);
 440 }
 441
 442 void ipwireless_associate_network_tty(struct ipw_network *network,
 443                                       unsigned int channel_idx,
 444                                       struct ipw_tty *tty)
 445 {
 446         int i;
 447
 448         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
 449                 if (network->associated_ttys[channel_idx][i] == NULL) {
 450                         network->associated_ttys[channel_idx][i] = tty;
 451                         break;
 452                 }
 453 }
 454
 455 void ipwireless_disassociate_network_ttys(struct ipw_network *network,
 456                                           unsigned int channel_idx)
 457 {
 458         int i;
 459
 460         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
 461                 network->associated_ttys[channel_idx][i] = NULL;
 462 }
 463
 464 void ipwireless_ppp_open(struct ipw_network *network)
 465 {
 466         if (ipwireless_debug)
 467                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": online\n");
 468         schedule_work(&network->work_go_online);
 469 }
 470
 471 void ipwireless_ppp_close(struct ipw_network *network)
 472 {
 473         /* Disconnect from the wireless network. */
 474         if (ipwireless_debug)
 475                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": offline\n");
 476         schedule_work(&network->work_go_offline);
 477 }
 478
 479 int ipwireless_ppp_channel_index(struct ipw_network *network)
 480 {
 481         int ret = -1;
 482         unsigned long flags;
 483
 484         spin_lock_irqsave(&network->lock, flags);
 485         if (network->ppp_channel != NULL)
 486                 ret = ppp_channel_index(network->ppp_channel);
 487         spin_unlock_irqrestore(&network->lock, flags);
 488
 489         return ret;
 490 }
 491
 492 int ipwireless_ppp_unit_number(struct ipw_network *network)
 493 {
 494         int ret = -1;
 495         unsigned long flags;
 496
 497         spin_lock_irqsave(&network->lock, flags);
 498         if (network->ppp_channel != NULL)
 499                 ret = ppp_unit_number(network->ppp_channel);
 500         spin_unlock_irqrestore(&network->lock, flags);
 501
 502         return ret;
 503 }
 504
 505 int ipwireless_ppp_mru(const struct ipw_network *network)
 506 {
 507         return network->mru;
 508 }