linux/drivers/tty/ipwireless/network.c
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   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
  38struct 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
  67static 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 */
  91static 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 == -1) {
 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 == -1)
 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() */
 156static 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
 243static const struct ppp_channel_ops ipwireless_ppp_channel_ops = {
 244        .start_xmit = ipwireless_ppp_start_xmit,
 245        .ioctl      = ipwireless_ppp_ioctl
 246};
 247
 248static 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
 290static 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
 312void 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 */
 345static 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
 364void 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
 416struct 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
 437void 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
 451void 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
 464void 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
 473void 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
 480void 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
 488int 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
 501int 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
 514int ipwireless_ppp_mru(const struct ipw_network *network)
 515{
 516        return network->mru;
 517}
 518