drivers/tty/ipwireless/network.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * IPWireless 3G PCMCIA Network Driver
   4  *
   5  * Original code
   6  *   by Stephen Blackheath <stephen@blacksapphire.com>,
   7  *      Ben Martel <benm@symmetric.co.nz>
   8  *
   9  * Copyrighted as follows:
  10  *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
  11  *
  12  * Various driver changes and rewrites, port to new kernels
  13  *   Copyright (C) 2006-2007 Jiri Kosina
  14  *
  15  * Misc code cleanups and updates
  16  *   Copyright (C) 2007 David Sterba
  17  */
  18
  19 #include <linux/interrupt.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mutex.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/ppp_channel.h>
  24 #include <linux/ppp_defs.h>
  25 #include <linux/slab.h>
  26 #include <linux/ppp-ioctl.h>
  27 #include <linux/skbuff.h>
  28
  29 #include "network.h"
  30 #include "hardware.h"
  31 #include "main.h"
  32 #include "tty.h"
  33
  34 #define MAX_ASSOCIATED_TTYS 2
  35
  36 #define SC_RCV_BITS     (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
  37
  38 struct ipw_network {
  39         /* Hardware context, used for calls to hardware layer. */
  40         struct ipw_hardware *hardware;
  41         /* Context for kernel 'generic_ppp' functionality */
  42         struct ppp_channel *ppp_channel;
  43         /* tty context connected with IPW console */
  44         struct ipw_tty *associated_ttys[NO_OF_IPW_CHANNELS][MAX_ASSOCIATED_TTYS];
  45         /* True if ppp needs waking up once we're ready to xmit */
  46         int ppp_blocked;
  47         /* Number of packets queued up in hardware module. */
  48         int outgoing_packets_queued;
  49         /* Spinlock to avoid interrupts during shutdown */
  50         spinlock_t lock;
  51         struct mutex close_lock;
  52
  53         /* PPP ioctl data, not actually used anywere */
  54         unsigned int flags;
  55         unsigned int rbits;
  56         u32 xaccm[8];
  57         u32 raccm;
  58         int mru;
  59
  60         int shutting_down;
  61         unsigned int ras_control_lines;
  62
  63         struct work_struct work_go_online;
  64         struct work_struct work_go_offline;
  65 };
  66
  67 static void notify_packet_sent(void *callback_data, unsigned int packet_length)
  68 {
  69         struct ipw_network *network = callback_data;
  70         unsigned long flags;
  71
  72         spin_lock_irqsave(&network->lock, flags);
  73         network->outgoing_packets_queued--;
  74         if (network->ppp_channel != NULL) {
  75                 if (network->ppp_blocked) {
  76                         network->ppp_blocked = 0;
  77                         spin_unlock_irqrestore(&network->lock, flags);
  78                         ppp_output_wakeup(network->ppp_channel);
  79                         if (ipwireless_debug)
  80                                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
  81                                        ": ppp unblocked\n");
  82                 } else
  83                         spin_unlock_irqrestore(&network->lock, flags);
  84         } else
  85                 spin_unlock_irqrestore(&network->lock, flags);
  86 }
  87
  88 /*
  89  * Called by the ppp system when it has a packet to send to the hardware.
  90  */
  91 static int ipwireless_ppp_start_xmit(struct ppp_channel *ppp_channel,
  92                                      struct sk_buff *skb)
  93 {
  94         struct ipw_network *network = ppp_channel->private;
  95         unsigned long flags;
  96
  97         spin_lock_irqsave(&network->lock, flags);
  98         if (network->outgoing_packets_queued < ipwireless_out_queue) {
  99                 unsigned char *buf;
 100                 static unsigned char header[] = {
 101                         PPP_ALLSTATIONS, /* 0xff */
 102                         PPP_UI,          /* 0x03 */
 103                 };
 104                 int ret;
 105
 106                 network->outgoing_packets_queued++;
 107                 spin_unlock_irqrestore(&network->lock, flags);
 108
 109                 /*
 110                  * If we have the requested amount of headroom in the skb we
 111                  * were handed, then we can add the header efficiently.
 112                  */
 113                 if (skb_headroom(skb) >= 2) {
 114                         memcpy(skb_push(skb, 2), header, 2);
 115                         ret = ipwireless_send_packet(network->hardware,
 116                                                IPW_CHANNEL_RAS, skb->data,
 117                                                skb->len,
 118                                                notify_packet_sent,
 119                                                network);
 120                         if (ret < 0) {
 121                                 skb_pull(skb, 2);
 122                                 return 0;
 123                         }
 124                 } else {
 125                         /* Otherwise (rarely) we do it inefficiently. */
 126                         buf = kmalloc(skb->len + 2, GFP_ATOMIC);
 127                         if (!buf)
 128                                 return 0;
 129                         memcpy(buf + 2, skb->data, skb->len);
 130                         memcpy(buf, header, 2);
 131                         ret = ipwireless_send_packet(network->hardware,
 132                                                IPW_CHANNEL_RAS, buf,
 133                                                skb->len + 2,
 134                                                notify_packet_sent,
 135                                                network);
 136                         kfree(buf);
 137                         if (ret < 0)
 138                                 return 0;
 139                 }
 140                 kfree_skb(skb);
 141                 return 1;
 142         } else {
 143                 /*
 144                  * Otherwise reject the packet, and flag that the ppp system
 145                  * needs to be unblocked once we are ready to send.
 146                  */
 147                 network->ppp_blocked = 1;
 148                 spin_unlock_irqrestore(&network->lock, flags);
 149                 if (ipwireless_debug)
 150                         printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": ppp blocked\n");
 151                 return 0;
 152         }
 153 }
 154
 155 /* Handle an ioctl call that has come in via ppp. (copy of ppp_async_ioctl() */
 156 static int ipwireless_ppp_ioctl(struct ppp_channel *ppp_channel,
 157                                 unsigned int cmd, unsigned long arg)
 158 {
 159         struct ipw_network *network = ppp_channel->private;
 160         int err, val;
 161         u32 accm[8];
 162         int __user *user_arg = (int __user *) arg;
 163
 164         err = -EFAULT;
 165         switch (cmd) {
 166         case PPPIOCGFLAGS:
 167                 val = network->flags | network->rbits;
 168                 if (put_user(val, user_arg))
 169                         break;
 170                 err = 0;
 171                 break;
 172
 173         case PPPIOCSFLAGS:
 174                 if (get_user(val, user_arg))
 175                         break;
 176                 network->flags = val & ~SC_RCV_BITS;
 177                 network->rbits = val & SC_RCV_BITS;
 178                 err = 0;
 179                 break;
 180
 181         case PPPIOCGASYNCMAP:
 182                 if (put_user(network->xaccm[0], user_arg))
 183                         break;
 184                 err = 0;
 185                 break;
 186
 187         case PPPIOCSASYNCMAP:
 188                 if (get_user(network->xaccm[0], user_arg))
 189                         break;
 190                 err = 0;
 191                 break;
 192
 193         case PPPIOCGRASYNCMAP:
 194                 if (put_user(network->raccm, user_arg))
 195                         break;
 196                 err = 0;
 197                 break;
 198
 199         case PPPIOCSRASYNCMAP:
 200                 if (get_user(network->raccm, user_arg))
 201                         break;
 202                 err = 0;
 203                 break;
 204
 205         case PPPIOCGXASYNCMAP:
 206                 if (copy_to_user((void __user *) arg, network->xaccm,
 207                                         sizeof(network->xaccm)))
 208                         break;
 209                 err = 0;
 210                 break;
 211
 212         case PPPIOCSXASYNCMAP:
 213                 if (copy_from_user(accm, (void __user *) arg, sizeof(accm)))
 214                         break;
 215                 accm[2] &= ~0x40000000U;        /* can't escape 0x5e */
 216                 accm[3] |= 0x60000000U; /* must escape 0x7d, 0x7e */
 217                 memcpy(network->xaccm, accm, sizeof(network->xaccm));
 218                 err = 0;
 219                 break;
 220
 221         case PPPIOCGMRU:
 222                 if (put_user(network->mru, user_arg))
 223                         break;
 224                 err = 0;
 225                 break;
 226
 227         case PPPIOCSMRU:
 228                 if (get_user(val, user_arg))
 229                         break;
 230                 if (val < PPP_MRU)
 231                         val = PPP_MRU;
 232                 network->mru = val;
 233                 err = 0;
 234                 break;
 235
 236         default:
 237                 err = -ENOTTY;
 238         }
 239
 240         return err;
 241 }
 242
 243 static const struct ppp_channel_ops ipwireless_ppp_channel_ops = {
 244         .start_xmit = ipwireless_ppp_start_xmit,
 245         .ioctl      = ipwireless_ppp_ioctl
 246 };
 247
 248 static void do_go_online(struct work_struct *work_go_online)
 249 {
 250         struct ipw_network *network =
 251                 container_of(work_go_online, struct ipw_network,
 252                                 work_go_online);
 253         unsigned long flags;
 254
 255         spin_lock_irqsave(&network->lock, flags);
 256         if (!network->ppp_channel) {
 257                 struct ppp_channel *channel;
 258
 259                 spin_unlock_irqrestore(&network->lock, flags);
 260                 channel = kzalloc(sizeof(struct ppp_channel), GFP_KERNEL);
 261                 if (!channel) {
 262                         printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 263                                         ": unable to allocate PPP channel\n");
 264                         return;
 265                 }
 266                 channel->private = network;
 267                 channel->mtu = 16384;   /* Wild guess */
 268                 channel->hdrlen = 2;
 269                 channel->ops = &ipwireless_ppp_channel_ops;
 270
 271                 network->flags = 0;
 272                 network->rbits = 0;
 273                 network->mru = PPP_MRU;
 274                 memset(network->xaccm, 0, sizeof(network->xaccm));
 275                 network->xaccm[0] = ~0U;
 276                 network->xaccm[3] = 0x60000000U;
 277                 network->raccm = ~0U;
 278                 if (ppp_register_channel(channel) < 0) {
 279                         printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 280                                         ": unable to register PPP channel\n");
 281                         kfree(channel);
 282                         return;
 283                 }
 284                 spin_lock_irqsave(&network->lock, flags);
 285                 network->ppp_channel = channel;
 286         }
 287         spin_unlock_irqrestore(&network->lock, flags);
 288 }
 289
 290 static void do_go_offline(struct work_struct *work_go_offline)
 291 {
 292         struct ipw_network *network =
 293                 container_of(work_go_offline, struct ipw_network,
 294                                 work_go_offline);
 295         unsigned long flags;
 296
 297         mutex_lock(&network->close_lock);
 298         spin_lock_irqsave(&network->lock, flags);
 299         if (network->ppp_channel != NULL) {
 300                 struct ppp_channel *channel = network->ppp_channel;
 301
 302                 network->ppp_channel = NULL;
 303                 spin_unlock_irqrestore(&network->lock, flags);
 304                 mutex_unlock(&network->close_lock);
 305                 ppp_unregister_channel(channel);
 306         } else {
 307                 spin_unlock_irqrestore(&network->lock, flags);
 308                 mutex_unlock(&network->close_lock);
 309         }
 310 }
 311
 312 void ipwireless_network_notify_control_line_change(struct ipw_network *network,
 313                                                    unsigned int channel_idx,
 314                                                    unsigned int control_lines,
 315                                                    unsigned int changed_mask)
 316 {
 317         int i;
 318
 319         if (channel_idx == IPW_CHANNEL_RAS)
 320                 network->ras_control_lines = control_lines;
 321
 322         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
 323                 struct ipw_tty *tty =
 324                         network->associated_ttys[channel_idx][i];
 325
 326                 /*
 327                  * If it's associated with a tty (other than the RAS channel
 328                  * when we're online), then send the data to that tty.  The RAS
 329                  * channel's data is handled above - it always goes through
 330                  * ppp_generic.
 331                  */
 332                 if (tty)
 333                         ipwireless_tty_notify_control_line_change(tty,
 334                                                                   channel_idx,
 335                                                                   control_lines,
 336                                                                   changed_mask);
 337         }
 338 }
 339
 340 /*
 341  * Some versions of firmware stuff packets with 0xff 0x03 (PPP: ALLSTATIONS, UI)
 342  * bytes, which are required on sent packet, but not always present on received
 343  * packets
 344  */
 345 static struct sk_buff *ipw_packet_received_skb(unsigned char *data,
 346                                                unsigned int length)
 347 {
 348         struct sk_buff *skb;
 349
 350         if (length > 2 && data[0] == PPP_ALLSTATIONS && data[1] == PPP_UI) {
 351                 length -= 2;
 352                 data += 2;
 353         }
 354
 355         skb = dev_alloc_skb(length + 4);
 356         if (skb == NULL)
 357                 return NULL;
 358         skb_reserve(skb, 2);
 359         skb_put_data(skb, data, length);
 360
 361         return skb;
 362 }
 363
 364 void ipwireless_network_packet_received(struct ipw_network *network,
 365                                         unsigned int channel_idx,
 366                                         unsigned char *data,
 367                                         unsigned int length)
 368 {
 369         int i;
 370         unsigned long flags;
 371
 372         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
 373                 struct ipw_tty *tty = network->associated_ttys[channel_idx][i];
 374
 375                 if (!tty)
 376                         continue;
 377
 378                 /*
 379                  * If it's associated with a tty (other than the RAS channel
 380                  * when we're online), then send the data to that tty.  The RAS
 381                  * channel's data is handled above - it always goes through
 382                  * ppp_generic.
 383                  */
 384                 if (channel_idx == IPW_CHANNEL_RAS
 385                                 && (network->ras_control_lines &
 386                                         IPW_CONTROL_LINE_DCD) != 0
 387                                 && ipwireless_tty_is_modem(tty)) {
 388                         /*
 389                          * If data came in on the RAS channel and this tty is
 390                          * the modem tty, and we are online, then we send it to
 391                          * the PPP layer.
 392                          */
 393                         mutex_lock(&network->close_lock);
 394                         spin_lock_irqsave(&network->lock, flags);
 395                         if (network->ppp_channel != NULL) {
 396                                 struct sk_buff *skb;
 397
 398                                 spin_unlock_irqrestore(&network->lock,
 399                                                 flags);
 400
 401                                 /* Send the data to the ppp_generic module. */
 402                                 skb = ipw_packet_received_skb(data, length);
 403                                 if (skb)
 404                                         ppp_input(network->ppp_channel, skb);
 405                         } else
 406                                 spin_unlock_irqrestore(&network->lock,
 407                                                 flags);
 408                         mutex_unlock(&network->close_lock);
 409                 }
 410                 /* Otherwise we send it out the tty. */
 411                 else
 412                         ipwireless_tty_received(tty, data, length);
 413         }
 414 }
 415
 416 struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw)
 417 {
 418         struct ipw_network *network =
 419                 kzalloc(sizeof(struct ipw_network), GFP_KERNEL);
 420
 421         if (!network)
 422                 return NULL;
 423
 424         spin_lock_init(&network->lock);
 425         mutex_init(&network->close_lock);
 426
 427         network->hardware = hw;
 428
 429         INIT_WORK(&network->work_go_online, do_go_online);
 430         INIT_WORK(&network->work_go_offline, do_go_offline);
 431
 432         ipwireless_associate_network(hw, network);
 433
 434         return network;
 435 }
 436
 437 void ipwireless_network_free(struct ipw_network *network)
 438 {
 439         network->shutting_down = 1;
 440
 441         ipwireless_ppp_close(network);
 442         flush_work(&network->work_go_online);
 443         flush_work(&network->work_go_offline);
 444
 445         ipwireless_stop_interrupts(network->hardware);
 446         ipwireless_associate_network(network->hardware, NULL);
 447
 448         kfree(network);
 449 }
 450
 451 void ipwireless_associate_network_tty(struct ipw_network *network,
 452                                       unsigned int channel_idx,
 453                                       struct ipw_tty *tty)
 454 {
 455         int i;
 456
 457         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
 458                 if (network->associated_ttys[channel_idx][i] == NULL) {
 459                         network->associated_ttys[channel_idx][i] = tty;
 460                         break;
 461                 }
 462 }
 463
 464 void ipwireless_disassociate_network_ttys(struct ipw_network *network,
 465                                           unsigned int channel_idx)
 466 {
 467         int i;
 468
 469         for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
 470                 network->associated_ttys[channel_idx][i] = NULL;
 471 }
 472
 473 void ipwireless_ppp_open(struct ipw_network *network)
 474 {
 475         if (ipwireless_debug)
 476                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": online\n");
 477         schedule_work(&network->work_go_online);
 478 }
 479
 480 void ipwireless_ppp_close(struct ipw_network *network)
 481 {
 482         /* Disconnect from the wireless network. */
 483         if (ipwireless_debug)
 484                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": offline\n");
 485         schedule_work(&network->work_go_offline);
 486 }
 487
 488 int ipwireless_ppp_channel_index(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_channel_index(network->ppp_channel);
 496         spin_unlock_irqrestore(&network->lock, flags);
 497
 498         return ret;
 499 }
 500
 501 int ipwireless_ppp_unit_number(struct ipw_network *network)
 502 {
 503         int ret = -1;
 504         unsigned long flags;
 505
 506         spin_lock_irqsave(&network->lock, flags);
 507         if (network->ppp_channel != NULL)
 508                 ret = ppp_unit_number(network->ppp_channel);
 509         spin_unlock_irqrestore(&network->lock, flags);
 510
 511         return ret;
 512 }
 513
 514 int ipwireless_ppp_mru(const struct ipw_network *network)
 515 {
 516         return network->mru;
 517 }