linux/net/can/bcm.c
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   1/*
   2 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
   3 *
   4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
   5 * All rights reserved.
   6 *
   7 * Redistribution and use in source and binary forms, with or without
   8 * modification, are permitted provided that the following conditions
   9 * are met:
  10 * 1. Redistributions of source code must retain the above copyright
  11 *    notice, this list of conditions and the following disclaimer.
  12 * 2. Redistributions in binary form must reproduce the above copyright
  13 *    notice, this list of conditions and the following disclaimer in the
  14 *    documentation and/or other materials provided with the distribution.
  15 * 3. Neither the name of Volkswagen nor the names of its contributors
  16 *    may be used to endorse or promote products derived from this software
  17 *    without specific prior written permission.
  18 *
  19 * Alternatively, provided that this notice is retained in full, this
  20 * software may be distributed under the terms of the GNU General
  21 * Public License ("GPL") version 2, in which case the provisions of the
  22 * GPL apply INSTEAD OF those given above.
  23 *
  24 * The provided data structures and external interfaces from this code
  25 * are not restricted to be used by modules with a GPL compatible license.
  26 *
  27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  38 * DAMAGE.
  39 *
  40 */
  41
  42#include <linux/module.h>
  43#include <linux/init.h>
  44#include <linux/interrupt.h>
  45#include <linux/hrtimer.h>
  46#include <linux/list.h>
  47#include <linux/proc_fs.h>
  48#include <linux/seq_file.h>
  49#include <linux/uio.h>
  50#include <linux/net.h>
  51#include <linux/netdevice.h>
  52#include <linux/socket.h>
  53#include <linux/if_arp.h>
  54#include <linux/skbuff.h>
  55#include <linux/can.h>
  56#include <linux/can/core.h>
  57#include <linux/can/bcm.h>
  58#include <linux/slab.h>
  59#include <net/sock.h>
  60#include <net/net_namespace.h>
  61
  62/*
  63 * To send multiple CAN frame content within TX_SETUP or to filter
  64 * CAN messages with multiplex index within RX_SETUP, the number of
  65 * different filters is limited to 256 due to the one byte index value.
  66 */
  67#define MAX_NFRAMES 256
  68
  69/* use of last_frames[index].can_dlc */
  70#define RX_RECV    0x40 /* received data for this element */
  71#define RX_THR     0x80 /* element not been sent due to throttle feature */
  72#define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
  73
  74/* get best masking value for can_rx_register() for a given single can_id */
  75#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
  76                     (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
  77                     (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
  78
  79#define CAN_BCM_VERSION CAN_VERSION
  80static __initdata const char banner[] = KERN_INFO
  81        "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
  82
  83MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
  84MODULE_LICENSE("Dual BSD/GPL");
  85MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
  86MODULE_ALIAS("can-proto-2");
  87
  88/* easy access to can_frame payload */
  89static inline u64 GET_U64(const struct can_frame *cp)
  90{
  91        return *(u64 *)cp->data;
  92}
  93
  94struct bcm_op {
  95        struct list_head list;
  96        int ifindex;
  97        canid_t can_id;
  98        u32 flags;
  99        unsigned long frames_abs, frames_filtered;
 100        struct timeval ival1, ival2;
 101        struct hrtimer timer, thrtimer;
 102        struct tasklet_struct tsklet, thrtsklet;
 103        ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
 104        int rx_ifindex;
 105        u32 count;
 106        u32 nframes;
 107        u32 currframe;
 108        struct can_frame *frames;
 109        struct can_frame *last_frames;
 110        struct can_frame sframe;
 111        struct can_frame last_sframe;
 112        struct sock *sk;
 113        struct net_device *rx_reg_dev;
 114};
 115
 116static struct proc_dir_entry *proc_dir;
 117
 118struct bcm_sock {
 119        struct sock sk;
 120        int bound;
 121        int ifindex;
 122        struct notifier_block notifier;
 123        struct list_head rx_ops;
 124        struct list_head tx_ops;
 125        unsigned long dropped_usr_msgs;
 126        struct proc_dir_entry *bcm_proc_read;
 127        char procname [32]; /* inode number in decimal with \0 */
 128};
 129
 130static inline struct bcm_sock *bcm_sk(const struct sock *sk)
 131{
 132        return (struct bcm_sock *)sk;
 133}
 134
 135#define CFSIZ sizeof(struct can_frame)
 136#define OPSIZ sizeof(struct bcm_op)
 137#define MHSIZ sizeof(struct bcm_msg_head)
 138
 139/*
 140 * procfs functions
 141 */
 142static char *bcm_proc_getifname(char *result, int ifindex)
 143{
 144        struct net_device *dev;
 145
 146        if (!ifindex)
 147                return "any";
 148
 149        rcu_read_lock();
 150        dev = dev_get_by_index_rcu(&init_net, ifindex);
 151        if (dev)
 152                strcpy(result, dev->name);
 153        else
 154                strcpy(result, "???");
 155        rcu_read_unlock();
 156
 157        return result;
 158}
 159
 160static int bcm_proc_show(struct seq_file *m, void *v)
 161{
 162        char ifname[IFNAMSIZ];
 163        struct sock *sk = (struct sock *)m->private;
 164        struct bcm_sock *bo = bcm_sk(sk);
 165        struct bcm_op *op;
 166
 167        seq_printf(m, ">>> socket %pK", sk->sk_socket);
 168        seq_printf(m, " / sk %pK", sk);
 169        seq_printf(m, " / bo %pK", bo);
 170        seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
 171        seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
 172        seq_printf(m, " <<<\n");
 173
 174        list_for_each_entry(op, &bo->rx_ops, list) {
 175
 176                unsigned long reduction;
 177
 178                /* print only active entries & prevent division by zero */
 179                if (!op->frames_abs)
 180                        continue;
 181
 182                seq_printf(m, "rx_op: %03X %-5s ",
 183                                op->can_id, bcm_proc_getifname(ifname, op->ifindex));
 184                seq_printf(m, "[%u]%c ", op->nframes,
 185                                (op->flags & RX_CHECK_DLC)?'d':' ');
 186                if (op->kt_ival1.tv64)
 187                        seq_printf(m, "timeo=%lld ",
 188                                        (long long)
 189                                        ktime_to_us(op->kt_ival1));
 190
 191                if (op->kt_ival2.tv64)
 192                        seq_printf(m, "thr=%lld ",
 193                                        (long long)
 194                                        ktime_to_us(op->kt_ival2));
 195
 196                seq_printf(m, "# recv %ld (%ld) => reduction: ",
 197                                op->frames_filtered, op->frames_abs);
 198
 199                reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
 200
 201                seq_printf(m, "%s%ld%%\n",
 202                                (reduction == 100)?"near ":"", reduction);
 203        }
 204
 205        list_for_each_entry(op, &bo->tx_ops, list) {
 206
 207                seq_printf(m, "tx_op: %03X %s [%u] ",
 208                                op->can_id,
 209                                bcm_proc_getifname(ifname, op->ifindex),
 210                                op->nframes);
 211
 212                if (op->kt_ival1.tv64)
 213                        seq_printf(m, "t1=%lld ",
 214                                        (long long) ktime_to_us(op->kt_ival1));
 215
 216                if (op->kt_ival2.tv64)
 217                        seq_printf(m, "t2=%lld ",
 218                                        (long long) ktime_to_us(op->kt_ival2));
 219
 220                seq_printf(m, "# sent %ld\n", op->frames_abs);
 221        }
 222        seq_putc(m, '\n');
 223        return 0;
 224}
 225
 226static int bcm_proc_open(struct inode *inode, struct file *file)
 227{
 228        return single_open(file, bcm_proc_show, PDE(inode)->data);
 229}
 230
 231static const struct file_operations bcm_proc_fops = {
 232        .owner          = THIS_MODULE,
 233        .open           = bcm_proc_open,
 234        .read           = seq_read,
 235        .llseek         = seq_lseek,
 236        .release        = single_release,
 237};
 238
 239/*
 240 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
 241 *              of the given bcm tx op
 242 */
 243static void bcm_can_tx(struct bcm_op *op)
 244{
 245        struct sk_buff *skb;
 246        struct net_device *dev;
 247        struct can_frame *cf = &op->frames[op->currframe];
 248
 249        /* no target device? => exit */
 250        if (!op->ifindex)
 251                return;
 252
 253        dev = dev_get_by_index(&init_net, op->ifindex);
 254        if (!dev) {
 255                /* RFC: should this bcm_op remove itself here? */
 256                return;
 257        }
 258
 259        skb = alloc_skb(CFSIZ, gfp_any());
 260        if (!skb)
 261                goto out;
 262
 263        memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
 264
 265        /* send with loopback */
 266        skb->dev = dev;
 267        skb->sk = op->sk;
 268        can_send(skb, 1);
 269
 270        /* update statistics */
 271        op->currframe++;
 272        op->frames_abs++;
 273
 274        /* reached last frame? */
 275        if (op->currframe >= op->nframes)
 276                op->currframe = 0;
 277 out:
 278        dev_put(dev);
 279}
 280
 281/*
 282 * bcm_send_to_user - send a BCM message to the userspace
 283 *                    (consisting of bcm_msg_head + x CAN frames)
 284 */
 285static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
 286                             struct can_frame *frames, int has_timestamp)
 287{
 288        struct sk_buff *skb;
 289        struct can_frame *firstframe;
 290        struct sockaddr_can *addr;
 291        struct sock *sk = op->sk;
 292        unsigned int datalen = head->nframes * CFSIZ;
 293        int err;
 294
 295        skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
 296        if (!skb)
 297                return;
 298
 299        memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
 300
 301        if (head->nframes) {
 302                /* can_frames starting here */
 303                firstframe = (struct can_frame *)skb_tail_pointer(skb);
 304
 305                memcpy(skb_put(skb, datalen), frames, datalen);
 306
 307                /*
 308                 * the BCM uses the can_dlc-element of the can_frame
 309                 * structure for internal purposes. This is only
 310                 * relevant for updates that are generated by the
 311                 * BCM, where nframes is 1
 312                 */
 313                if (head->nframes == 1)
 314                        firstframe->can_dlc &= BCM_CAN_DLC_MASK;
 315        }
 316
 317        if (has_timestamp) {
 318                /* restore rx timestamp */
 319                skb->tstamp = op->rx_stamp;
 320        }
 321
 322        /*
 323         *  Put the datagram to the queue so that bcm_recvmsg() can
 324         *  get it from there.  We need to pass the interface index to
 325         *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
 326         *  containing the interface index.
 327         */
 328
 329        BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
 330        addr = (struct sockaddr_can *)skb->cb;
 331        memset(addr, 0, sizeof(*addr));
 332        addr->can_family  = AF_CAN;
 333        addr->can_ifindex = op->rx_ifindex;
 334
 335        err = sock_queue_rcv_skb(sk, skb);
 336        if (err < 0) {
 337                struct bcm_sock *bo = bcm_sk(sk);
 338
 339                kfree_skb(skb);
 340                /* don't care about overflows in this statistic */
 341                bo->dropped_usr_msgs++;
 342        }
 343}
 344
 345static void bcm_tx_start_timer(struct bcm_op *op)
 346{
 347        if (op->kt_ival1.tv64 && op->count)
 348                hrtimer_start(&op->timer,
 349                              ktime_add(ktime_get(), op->kt_ival1),
 350                              HRTIMER_MODE_ABS);
 351        else if (op->kt_ival2.tv64)
 352                hrtimer_start(&op->timer,
 353                              ktime_add(ktime_get(), op->kt_ival2),
 354                              HRTIMER_MODE_ABS);
 355}
 356
 357static void bcm_tx_timeout_tsklet(unsigned long data)
 358{
 359        struct bcm_op *op = (struct bcm_op *)data;
 360        struct bcm_msg_head msg_head;
 361
 362        if (op->kt_ival1.tv64 && (op->count > 0)) {
 363
 364                op->count--;
 365                if (!op->count && (op->flags & TX_COUNTEVT)) {
 366
 367                        /* create notification to user */
 368                        msg_head.opcode  = TX_EXPIRED;
 369                        msg_head.flags   = op->flags;
 370                        msg_head.count   = op->count;
 371                        msg_head.ival1   = op->ival1;
 372                        msg_head.ival2   = op->ival2;
 373                        msg_head.can_id  = op->can_id;
 374                        msg_head.nframes = 0;
 375
 376                        bcm_send_to_user(op, &msg_head, NULL, 0);
 377                }
 378                bcm_can_tx(op);
 379
 380        } else if (op->kt_ival2.tv64)
 381                bcm_can_tx(op);
 382
 383        bcm_tx_start_timer(op);
 384}
 385
 386/*
 387 * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
 388 */
 389static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
 390{
 391        struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
 392
 393        tasklet_schedule(&op->tsklet);
 394
 395        return HRTIMER_NORESTART;
 396}
 397
 398/*
 399 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
 400 */
 401static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
 402{
 403        struct bcm_msg_head head;
 404
 405        /* update statistics */
 406        op->frames_filtered++;
 407
 408        /* prevent statistics overflow */
 409        if (op->frames_filtered > ULONG_MAX/100)
 410                op->frames_filtered = op->frames_abs = 0;
 411
 412        /* this element is not throttled anymore */
 413        data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
 414
 415        head.opcode  = RX_CHANGED;
 416        head.flags   = op->flags;
 417        head.count   = op->count;
 418        head.ival1   = op->ival1;
 419        head.ival2   = op->ival2;
 420        head.can_id  = op->can_id;
 421        head.nframes = 1;
 422
 423        bcm_send_to_user(op, &head, data, 1);
 424}
 425
 426/*
 427 * bcm_rx_update_and_send - process a detected relevant receive content change
 428 *                          1. update the last received data
 429 *                          2. send a notification to the user (if possible)
 430 */
 431static void bcm_rx_update_and_send(struct bcm_op *op,
 432                                   struct can_frame *lastdata,
 433                                   const struct can_frame *rxdata)
 434{
 435        memcpy(lastdata, rxdata, CFSIZ);
 436
 437        /* mark as used and throttled by default */
 438        lastdata->can_dlc |= (RX_RECV|RX_THR);
 439
 440        /* throtteling mode inactive ? */
 441        if (!op->kt_ival2.tv64) {
 442                /* send RX_CHANGED to the user immediately */
 443                bcm_rx_changed(op, lastdata);
 444                return;
 445        }
 446
 447        /* with active throttling timer we are just done here */
 448        if (hrtimer_active(&op->thrtimer))
 449                return;
 450
 451        /* first receiption with enabled throttling mode */
 452        if (!op->kt_lastmsg.tv64)
 453                goto rx_changed_settime;
 454
 455        /* got a second frame inside a potential throttle period? */
 456        if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
 457            ktime_to_us(op->kt_ival2)) {
 458                /* do not send the saved data - only start throttle timer */
 459                hrtimer_start(&op->thrtimer,
 460                              ktime_add(op->kt_lastmsg, op->kt_ival2),
 461                              HRTIMER_MODE_ABS);
 462                return;
 463        }
 464
 465        /* the gap was that big, that throttling was not needed here */
 466rx_changed_settime:
 467        bcm_rx_changed(op, lastdata);
 468        op->kt_lastmsg = ktime_get();
 469}
 470
 471/*
 472 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
 473 *                       received data stored in op->last_frames[]
 474 */
 475static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
 476                                const struct can_frame *rxdata)
 477{
 478        /*
 479         * no one uses the MSBs of can_dlc for comparation,
 480         * so we use it here to detect the first time of reception
 481         */
 482
 483        if (!(op->last_frames[index].can_dlc & RX_RECV)) {
 484                /* received data for the first time => send update to user */
 485                bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
 486                return;
 487        }
 488
 489        /* do a real check in can_frame data section */
 490
 491        if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
 492            (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
 493                bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
 494                return;
 495        }
 496
 497        if (op->flags & RX_CHECK_DLC) {
 498                /* do a real check in can_frame dlc */
 499                if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
 500                                        BCM_CAN_DLC_MASK)) {
 501                        bcm_rx_update_and_send(op, &op->last_frames[index],
 502                                               rxdata);
 503                        return;
 504                }
 505        }
 506}
 507
 508/*
 509 * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
 510 */
 511static void bcm_rx_starttimer(struct bcm_op *op)
 512{
 513        if (op->flags & RX_NO_AUTOTIMER)
 514                return;
 515
 516        if (op->kt_ival1.tv64)
 517                hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
 518}
 519
 520static void bcm_rx_timeout_tsklet(unsigned long data)
 521{
 522        struct bcm_op *op = (struct bcm_op *)data;
 523        struct bcm_msg_head msg_head;
 524
 525        /* create notification to user */
 526        msg_head.opcode  = RX_TIMEOUT;
 527        msg_head.flags   = op->flags;
 528        msg_head.count   = op->count;
 529        msg_head.ival1   = op->ival1;
 530        msg_head.ival2   = op->ival2;
 531        msg_head.can_id  = op->can_id;
 532        msg_head.nframes = 0;
 533
 534        bcm_send_to_user(op, &msg_head, NULL, 0);
 535}
 536
 537/*
 538 * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
 539 */
 540static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
 541{
 542        struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
 543
 544        /* schedule before NET_RX_SOFTIRQ */
 545        tasklet_hi_schedule(&op->tsklet);
 546
 547        /* no restart of the timer is done here! */
 548
 549        /* if user wants to be informed, when cyclic CAN-Messages come back */
 550        if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
 551                /* clear received can_frames to indicate 'nothing received' */
 552                memset(op->last_frames, 0, op->nframes * CFSIZ);
 553        }
 554
 555        return HRTIMER_NORESTART;
 556}
 557
 558/*
 559 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
 560 */
 561static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
 562                                  unsigned int index)
 563{
 564        if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
 565                if (update)
 566                        bcm_rx_changed(op, &op->last_frames[index]);
 567                return 1;
 568        }
 569        return 0;
 570}
 571
 572/*
 573 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
 574 *
 575 * update == 0 : just check if throttled data is available  (any irq context)
 576 * update == 1 : check and send throttled data to userspace (soft_irq context)
 577 */
 578static int bcm_rx_thr_flush(struct bcm_op *op, int update)
 579{
 580        int updated = 0;
 581
 582        if (op->nframes > 1) {
 583                unsigned int i;
 584
 585                /* for MUX filter we start at index 1 */
 586                for (i = 1; i < op->nframes; i++)
 587                        updated += bcm_rx_do_flush(op, update, i);
 588
 589        } else {
 590                /* for RX_FILTER_ID and simple filter */
 591                updated += bcm_rx_do_flush(op, update, 0);
 592        }
 593
 594        return updated;
 595}
 596
 597static void bcm_rx_thr_tsklet(unsigned long data)
 598{
 599        struct bcm_op *op = (struct bcm_op *)data;
 600
 601        /* push the changed data to the userspace */
 602        bcm_rx_thr_flush(op, 1);
 603}
 604
 605/*
 606 * bcm_rx_thr_handler - the time for blocked content updates is over now:
 607 *                      Check for throttled data and send it to the userspace
 608 */
 609static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
 610{
 611        struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
 612
 613        tasklet_schedule(&op->thrtsklet);
 614
 615        if (bcm_rx_thr_flush(op, 0)) {
 616                hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
 617                return HRTIMER_RESTART;
 618        } else {
 619                /* rearm throttle handling */
 620                op->kt_lastmsg = ktime_set(0, 0);
 621                return HRTIMER_NORESTART;
 622        }
 623}
 624
 625/*
 626 * bcm_rx_handler - handle a CAN frame receiption
 627 */
 628static void bcm_rx_handler(struct sk_buff *skb, void *data)
 629{
 630        struct bcm_op *op = (struct bcm_op *)data;
 631        const struct can_frame *rxframe = (struct can_frame *)skb->data;
 632        unsigned int i;
 633
 634        /* disable timeout */
 635        hrtimer_cancel(&op->timer);
 636
 637        if (op->can_id != rxframe->can_id)
 638                return;
 639
 640        /* save rx timestamp */
 641        op->rx_stamp = skb->tstamp;
 642        /* save originator for recvfrom() */
 643        op->rx_ifindex = skb->dev->ifindex;
 644        /* update statistics */
 645        op->frames_abs++;
 646
 647        if (op->flags & RX_RTR_FRAME) {
 648                /* send reply for RTR-request (placed in op->frames[0]) */
 649                bcm_can_tx(op);
 650                return;
 651        }
 652
 653        if (op->flags & RX_FILTER_ID) {
 654                /* the easiest case */
 655                bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
 656                goto rx_starttimer;
 657        }
 658
 659        if (op->nframes == 1) {
 660                /* simple compare with index 0 */
 661                bcm_rx_cmp_to_index(op, 0, rxframe);
 662                goto rx_starttimer;
 663        }
 664
 665        if (op->nframes > 1) {
 666                /*
 667                 * multiplex compare
 668                 *
 669                 * find the first multiplex mask that fits.
 670                 * Remark: The MUX-mask is stored in index 0
 671                 */
 672
 673                for (i = 1; i < op->nframes; i++) {
 674                        if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
 675                            (GET_U64(&op->frames[0]) &
 676                             GET_U64(&op->frames[i]))) {
 677                                bcm_rx_cmp_to_index(op, i, rxframe);
 678                                break;
 679                        }
 680                }
 681        }
 682
 683rx_starttimer:
 684        bcm_rx_starttimer(op);
 685}
 686
 687/*
 688 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
 689 */
 690static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
 691                                  int ifindex)
 692{
 693        struct bcm_op *op;
 694
 695        list_for_each_entry(op, ops, list) {
 696                if ((op->can_id == can_id) && (op->ifindex == ifindex))
 697                        return op;
 698        }
 699
 700        return NULL;
 701}
 702
 703static void bcm_remove_op(struct bcm_op *op)
 704{
 705        hrtimer_cancel(&op->timer);
 706        hrtimer_cancel(&op->thrtimer);
 707
 708        if (op->tsklet.func)
 709                tasklet_kill(&op->tsklet);
 710
 711        if (op->thrtsklet.func)
 712                tasklet_kill(&op->thrtsklet);
 713
 714        if ((op->frames) && (op->frames != &op->sframe))
 715                kfree(op->frames);
 716
 717        if ((op->last_frames) && (op->last_frames != &op->last_sframe))
 718                kfree(op->last_frames);
 719
 720        kfree(op);
 721}
 722
 723static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
 724{
 725        if (op->rx_reg_dev == dev) {
 726                can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
 727                                  bcm_rx_handler, op);
 728
 729                /* mark as removed subscription */
 730                op->rx_reg_dev = NULL;
 731        } else
 732                printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
 733                       "mismatch %p %p\n", op->rx_reg_dev, dev);
 734}
 735
 736/*
 737 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
 738 */
 739static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
 740{
 741        struct bcm_op *op, *n;
 742
 743        list_for_each_entry_safe(op, n, ops, list) {
 744                if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
 745
 746                        /*
 747                         * Don't care if we're bound or not (due to netdev
 748                         * problems) can_rx_unregister() is always a save
 749                         * thing to do here.
 750                         */
 751                        if (op->ifindex) {
 752                                /*
 753                                 * Only remove subscriptions that had not
 754                                 * been removed due to NETDEV_UNREGISTER
 755                                 * in bcm_notifier()
 756                                 */
 757                                if (op->rx_reg_dev) {
 758                                        struct net_device *dev;
 759
 760                                        dev = dev_get_by_index(&init_net,
 761                                                               op->ifindex);
 762                                        if (dev) {
 763                                                bcm_rx_unreg(dev, op);
 764                                                dev_put(dev);
 765                                        }
 766                                }
 767                        } else
 768                                can_rx_unregister(NULL, op->can_id,
 769                                                  REGMASK(op->can_id),
 770                                                  bcm_rx_handler, op);
 771
 772                        list_del(&op->list);
 773                        bcm_remove_op(op);
 774                        return 1; /* done */
 775                }
 776        }
 777
 778        return 0; /* not found */
 779}
 780
 781/*
 782 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
 783 */
 784static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
 785{
 786        struct bcm_op *op, *n;
 787
 788        list_for_each_entry_safe(op, n, ops, list) {
 789                if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
 790                        list_del(&op->list);
 791                        bcm_remove_op(op);
 792                        return 1; /* done */
 793                }
 794        }
 795
 796        return 0; /* not found */
 797}
 798
 799/*
 800 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
 801 */
 802static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
 803                       int ifindex)
 804{
 805        struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
 806
 807        if (!op)
 808                return -EINVAL;
 809
 810        /* put current values into msg_head */
 811        msg_head->flags   = op->flags;
 812        msg_head->count   = op->count;
 813        msg_head->ival1   = op->ival1;
 814        msg_head->ival2   = op->ival2;
 815        msg_head->nframes = op->nframes;
 816
 817        bcm_send_to_user(op, msg_head, op->frames, 0);
 818
 819        return MHSIZ;
 820}
 821
 822/*
 823 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
 824 */
 825static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
 826                        int ifindex, struct sock *sk)
 827{
 828        struct bcm_sock *bo = bcm_sk(sk);
 829        struct bcm_op *op;
 830        unsigned int i;
 831        int err;
 832
 833        /* we need a real device to send frames */
 834        if (!ifindex)
 835                return -ENODEV;
 836
 837        /* check nframes boundaries - we need at least one can_frame */
 838        if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
 839                return -EINVAL;
 840
 841        /* check the given can_id */
 842        op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
 843
 844        if (op) {
 845                /* update existing BCM operation */
 846
 847                /*
 848                 * Do we need more space for the can_frames than currently
 849                 * allocated? -> This is a _really_ unusual use-case and
 850                 * therefore (complexity / locking) it is not supported.
 851                 */
 852                if (msg_head->nframes > op->nframes)
 853                        return -E2BIG;
 854
 855                /* update can_frames content */
 856                for (i = 0; i < msg_head->nframes; i++) {
 857                        err = memcpy_fromiovec((u8 *)&op->frames[i],
 858                                               msg->msg_iov, CFSIZ);
 859
 860                        if (op->frames[i].can_dlc > 8)
 861                                err = -EINVAL;
 862
 863                        if (err < 0)
 864                                return err;
 865
 866                        if (msg_head->flags & TX_CP_CAN_ID) {
 867                                /* copy can_id into frame */
 868                                op->frames[i].can_id = msg_head->can_id;
 869                        }
 870                }
 871
 872        } else {
 873                /* insert new BCM operation for the given can_id */
 874
 875                op = kzalloc(OPSIZ, GFP_KERNEL);
 876                if (!op)
 877                        return -ENOMEM;
 878
 879                op->can_id    = msg_head->can_id;
 880
 881                /* create array for can_frames and copy the data */
 882                if (msg_head->nframes > 1) {
 883                        op->frames = kmalloc(msg_head->nframes * CFSIZ,
 884                                             GFP_KERNEL);
 885                        if (!op->frames) {
 886                                kfree(op);
 887                                return -ENOMEM;
 888                        }
 889                } else
 890                        op->frames = &op->sframe;
 891
 892                for (i = 0; i < msg_head->nframes; i++) {
 893                        err = memcpy_fromiovec((u8 *)&op->frames[i],
 894                                               msg->msg_iov, CFSIZ);
 895
 896                        if (op->frames[i].can_dlc > 8)
 897                                err = -EINVAL;
 898
 899                        if (err < 0) {
 900                                if (op->frames != &op->sframe)
 901                                        kfree(op->frames);
 902                                kfree(op);
 903                                return err;
 904                        }
 905
 906                        if (msg_head->flags & TX_CP_CAN_ID) {
 907                                /* copy can_id into frame */
 908                                op->frames[i].can_id = msg_head->can_id;
 909                        }
 910                }
 911
 912                /* tx_ops never compare with previous received messages */
 913                op->last_frames = NULL;
 914
 915                /* bcm_can_tx / bcm_tx_timeout_handler needs this */
 916                op->sk = sk;
 917                op->ifindex = ifindex;
 918
 919                /* initialize uninitialized (kzalloc) structure */
 920                hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 921                op->timer.function = bcm_tx_timeout_handler;
 922
 923                /* initialize tasklet for tx countevent notification */
 924                tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
 925                             (unsigned long) op);
 926
 927                /* currently unused in tx_ops */
 928                hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 929
 930                /* add this bcm_op to the list of the tx_ops */
 931                list_add(&op->list, &bo->tx_ops);
 932
 933        } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
 934
 935        if (op->nframes != msg_head->nframes) {
 936                op->nframes   = msg_head->nframes;
 937                /* start multiple frame transmission with index 0 */
 938                op->currframe = 0;
 939        }
 940
 941        /* check flags */
 942
 943        op->flags = msg_head->flags;
 944
 945        if (op->flags & TX_RESET_MULTI_IDX) {
 946                /* start multiple frame transmission with index 0 */
 947                op->currframe = 0;
 948        }
 949
 950        if (op->flags & SETTIMER) {
 951                /* set timer values */
 952                op->count = msg_head->count;
 953                op->ival1 = msg_head->ival1;
 954                op->ival2 = msg_head->ival2;
 955                op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
 956                op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
 957
 958                /* disable an active timer due to zero values? */
 959                if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
 960                        hrtimer_cancel(&op->timer);
 961        }
 962
 963        if (op->flags & STARTTIMER) {
 964                hrtimer_cancel(&op->timer);
 965                /* spec: send can_frame when starting timer */
 966                op->flags |= TX_ANNOUNCE;
 967        }
 968
 969        if (op->flags & TX_ANNOUNCE) {
 970                bcm_can_tx(op);
 971                if (op->count)
 972                        op->count--;
 973        }
 974
 975        if (op->flags & STARTTIMER)
 976                bcm_tx_start_timer(op);
 977
 978        return msg_head->nframes * CFSIZ + MHSIZ;
 979}
 980
 981/*
 982 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
 983 */
 984static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
 985                        int ifindex, struct sock *sk)
 986{
 987        struct bcm_sock *bo = bcm_sk(sk);
 988        struct bcm_op *op;
 989        int do_rx_register;
 990        int err = 0;
 991
 992        if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
 993                /* be robust against wrong usage ... */
 994                msg_head->flags |= RX_FILTER_ID;
 995                /* ignore trailing garbage */
 996                msg_head->nframes = 0;
 997        }
 998
 999        /* the first element contains the mux-mask => MAX_NFRAMES + 1  */
1000        if (msg_head->nframes > MAX_NFRAMES + 1)
1001                return -EINVAL;
1002
1003        if ((msg_head->flags & RX_RTR_FRAME) &&
1004            ((msg_head->nframes != 1) ||
1005             (!(msg_head->can_id & CAN_RTR_FLAG))))
1006                return -EINVAL;
1007
1008        /* check the given can_id */
1009        op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1010        if (op) {
1011                /* update existing BCM operation */
1012
1013                /*
1014                 * Do we need more space for the can_frames than currently
1015                 * allocated? -> This is a _really_ unusual use-case and
1016                 * therefore (complexity / locking) it is not supported.
1017                 */
1018                if (msg_head->nframes > op->nframes)
1019                        return -E2BIG;
1020
1021                if (msg_head->nframes) {
1022                        /* update can_frames content */
1023                        err = memcpy_fromiovec((u8 *)op->frames,
1024                                               msg->msg_iov,
1025                                               msg_head->nframes * CFSIZ);
1026                        if (err < 0)
1027                                return err;
1028
1029                        /* clear last_frames to indicate 'nothing received' */
1030                        memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1031                }
1032
1033                op->nframes = msg_head->nframes;
1034
1035                /* Only an update -> do not call can_rx_register() */
1036                do_rx_register = 0;
1037
1038        } else {
1039                /* insert new BCM operation for the given can_id */
1040                op = kzalloc(OPSIZ, GFP_KERNEL);
1041                if (!op)
1042                        return -ENOMEM;
1043
1044                op->can_id    = msg_head->can_id;
1045                op->nframes   = msg_head->nframes;
1046
1047                if (msg_head->nframes > 1) {
1048                        /* create array for can_frames and copy the data */
1049                        op->frames = kmalloc(msg_head->nframes * CFSIZ,
1050                                             GFP_KERNEL);
1051                        if (!op->frames) {
1052                                kfree(op);
1053                                return -ENOMEM;
1054                        }
1055
1056                        /* create and init array for received can_frames */
1057                        op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1058                                                  GFP_KERNEL);
1059                        if (!op->last_frames) {
1060                                kfree(op->frames);
1061                                kfree(op);
1062                                return -ENOMEM;
1063                        }
1064
1065                } else {
1066                        op->frames = &op->sframe;
1067                        op->last_frames = &op->last_sframe;
1068                }
1069
1070                if (msg_head->nframes) {
1071                        err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1072                                               msg_head->nframes * CFSIZ);
1073                        if (err < 0) {
1074                                if (op->frames != &op->sframe)
1075                                        kfree(op->frames);
1076                                if (op->last_frames != &op->last_sframe)
1077                                        kfree(op->last_frames);
1078                                kfree(op);
1079                                return err;
1080                        }
1081                }
1082
1083                /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1084                op->sk = sk;
1085                op->ifindex = ifindex;
1086
1087                /* initialize uninitialized (kzalloc) structure */
1088                hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1089                op->timer.function = bcm_rx_timeout_handler;
1090
1091                /* initialize tasklet for rx timeout notification */
1092                tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1093                             (unsigned long) op);
1094
1095                hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1096                op->thrtimer.function = bcm_rx_thr_handler;
1097
1098                /* initialize tasklet for rx throttle handling */
1099                tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1100                             (unsigned long) op);
1101
1102                /* add this bcm_op to the list of the rx_ops */
1103                list_add(&op->list, &bo->rx_ops);
1104
1105                /* call can_rx_register() */
1106                do_rx_register = 1;
1107
1108        } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1109
1110        /* check flags */
1111        op->flags = msg_head->flags;
1112
1113        if (op->flags & RX_RTR_FRAME) {
1114
1115                /* no timers in RTR-mode */
1116                hrtimer_cancel(&op->thrtimer);
1117                hrtimer_cancel(&op->timer);
1118
1119                /*
1120                 * funny feature in RX(!)_SETUP only for RTR-mode:
1121                 * copy can_id into frame BUT without RTR-flag to
1122                 * prevent a full-load-loopback-test ... ;-]
1123                 */
1124                if ((op->flags & TX_CP_CAN_ID) ||
1125                    (op->frames[0].can_id == op->can_id))
1126                        op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1127
1128        } else {
1129                if (op->flags & SETTIMER) {
1130
1131                        /* set timer value */
1132                        op->ival1 = msg_head->ival1;
1133                        op->ival2 = msg_head->ival2;
1134                        op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1135                        op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1136
1137                        /* disable an active timer due to zero value? */
1138                        if (!op->kt_ival1.tv64)
1139                                hrtimer_cancel(&op->timer);
1140
1141                        /*
1142                         * In any case cancel the throttle timer, flush
1143                         * potentially blocked msgs and reset throttle handling
1144                         */
1145                        op->kt_lastmsg = ktime_set(0, 0);
1146                        hrtimer_cancel(&op->thrtimer);
1147                        bcm_rx_thr_flush(op, 1);
1148                }
1149
1150                if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1151                        hrtimer_start(&op->timer, op->kt_ival1,
1152                                      HRTIMER_MODE_REL);
1153        }
1154
1155        /* now we can register for can_ids, if we added a new bcm_op */
1156        if (do_rx_register) {
1157                if (ifindex) {
1158                        struct net_device *dev;
1159
1160                        dev = dev_get_by_index(&init_net, ifindex);
1161                        if (dev) {
1162                                err = can_rx_register(dev, op->can_id,
1163                                                      REGMASK(op->can_id),
1164                                                      bcm_rx_handler, op,
1165                                                      "bcm");
1166
1167                                op->rx_reg_dev = dev;
1168                                dev_put(dev);
1169                        }
1170
1171                } else
1172                        err = can_rx_register(NULL, op->can_id,
1173                                              REGMASK(op->can_id),
1174                                              bcm_rx_handler, op, "bcm");
1175                if (err) {
1176                        /* this bcm rx op is broken -> remove it */
1177                        list_del(&op->list);
1178                        bcm_remove_op(op);
1179                        return err;
1180                }
1181        }
1182
1183        return msg_head->nframes * CFSIZ + MHSIZ;
1184}
1185
1186/*
1187 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1188 */
1189static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1190{
1191        struct sk_buff *skb;
1192        struct net_device *dev;
1193        int err;
1194
1195        /* we need a real device to send frames */
1196        if (!ifindex)
1197                return -ENODEV;
1198
1199        skb = alloc_skb(CFSIZ, GFP_KERNEL);
1200
1201        if (!skb)
1202                return -ENOMEM;
1203
1204        err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1205        if (err < 0) {
1206                kfree_skb(skb);
1207                return err;
1208        }
1209
1210        dev = dev_get_by_index(&init_net, ifindex);
1211        if (!dev) {
1212                kfree_skb(skb);
1213                return -ENODEV;
1214        }
1215
1216        skb->dev = dev;
1217        skb->sk  = sk;
1218        err = can_send(skb, 1); /* send with loopback */
1219        dev_put(dev);
1220
1221        if (err)
1222                return err;
1223
1224        return CFSIZ + MHSIZ;
1225}
1226
1227/*
1228 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1229 */
1230static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1231                       struct msghdr *msg, size_t size)
1232{
1233        struct sock *sk = sock->sk;
1234        struct bcm_sock *bo = bcm_sk(sk);
1235        int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1236        struct bcm_msg_head msg_head;
1237        int ret; /* read bytes or error codes as return value */
1238
1239        if (!bo->bound)
1240                return -ENOTCONN;
1241
1242        /* check for valid message length from userspace */
1243        if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1244                return -EINVAL;
1245
1246        /* check for alternative ifindex for this bcm_op */
1247
1248        if (!ifindex && msg->msg_name) {
1249                /* no bound device as default => check msg_name */
1250                struct sockaddr_can *addr =
1251                        (struct sockaddr_can *)msg->msg_name;
1252
1253                if (msg->msg_namelen < sizeof(*addr))
1254                        return -EINVAL;
1255
1256                if (addr->can_family != AF_CAN)
1257                        return -EINVAL;
1258
1259                /* ifindex from sendto() */
1260                ifindex = addr->can_ifindex;
1261
1262                if (ifindex) {
1263                        struct net_device *dev;
1264
1265                        dev = dev_get_by_index(&init_net, ifindex);
1266                        if (!dev)
1267                                return -ENODEV;
1268
1269                        if (dev->type != ARPHRD_CAN) {
1270                                dev_put(dev);
1271                                return -ENODEV;
1272                        }
1273
1274                        dev_put(dev);
1275                }
1276        }
1277
1278        /* read message head information */
1279
1280        ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1281        if (ret < 0)
1282                return ret;
1283
1284        lock_sock(sk);
1285
1286        switch (msg_head.opcode) {
1287
1288        case TX_SETUP:
1289                ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1290                break;
1291
1292        case RX_SETUP:
1293                ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1294                break;
1295
1296        case TX_DELETE:
1297                if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1298                        ret = MHSIZ;
1299                else
1300                        ret = -EINVAL;
1301                break;
1302
1303        case RX_DELETE:
1304                if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1305                        ret = MHSIZ;
1306                else
1307                        ret = -EINVAL;
1308                break;
1309
1310        case TX_READ:
1311                /* reuse msg_head for the reply to TX_READ */
1312                msg_head.opcode  = TX_STATUS;
1313                ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1314                break;
1315
1316        case RX_READ:
1317                /* reuse msg_head for the reply to RX_READ */
1318                msg_head.opcode  = RX_STATUS;
1319                ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1320                break;
1321
1322        case TX_SEND:
1323                /* we need exactly one can_frame behind the msg head */
1324                if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1325                        ret = -EINVAL;
1326                else
1327                        ret = bcm_tx_send(msg, ifindex, sk);
1328                break;
1329
1330        default:
1331                ret = -EINVAL;
1332                break;
1333        }
1334
1335        release_sock(sk);
1336
1337        return ret;
1338}
1339
1340/*
1341 * notification handler for netdevice status changes
1342 */
1343static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1344                        void *data)
1345{
1346        struct net_device *dev = (struct net_device *)data;
1347        struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1348        struct sock *sk = &bo->sk;
1349        struct bcm_op *op;
1350        int notify_enodev = 0;
1351
1352        if (!net_eq(dev_net(dev), &init_net))
1353                return NOTIFY_DONE;
1354
1355        if (dev->type != ARPHRD_CAN)
1356                return NOTIFY_DONE;
1357
1358        switch (msg) {
1359
1360        case NETDEV_UNREGISTER:
1361                lock_sock(sk);
1362
1363                /* remove device specific receive entries */
1364                list_for_each_entry(op, &bo->rx_ops, list)
1365                        if (op->rx_reg_dev == dev)
1366                                bcm_rx_unreg(dev, op);
1367
1368                /* remove device reference, if this is our bound device */
1369                if (bo->bound && bo->ifindex == dev->ifindex) {
1370                        bo->bound   = 0;
1371                        bo->ifindex = 0;
1372                        notify_enodev = 1;
1373                }
1374
1375                release_sock(sk);
1376
1377                if (notify_enodev) {
1378                        sk->sk_err = ENODEV;
1379                        if (!sock_flag(sk, SOCK_DEAD))
1380                                sk->sk_error_report(sk);
1381                }
1382                break;
1383
1384        case NETDEV_DOWN:
1385                if (bo->bound && bo->ifindex == dev->ifindex) {
1386                        sk->sk_err = ENETDOWN;
1387                        if (!sock_flag(sk, SOCK_DEAD))
1388                                sk->sk_error_report(sk);
1389                }
1390        }
1391
1392        return NOTIFY_DONE;
1393}
1394
1395/*
1396 * initial settings for all BCM sockets to be set at socket creation time
1397 */
1398static int bcm_init(struct sock *sk)
1399{
1400        struct bcm_sock *bo = bcm_sk(sk);
1401
1402        bo->bound            = 0;
1403        bo->ifindex          = 0;
1404        bo->dropped_usr_msgs = 0;
1405        bo->bcm_proc_read    = NULL;
1406
1407        INIT_LIST_HEAD(&bo->tx_ops);
1408        INIT_LIST_HEAD(&bo->rx_ops);
1409
1410        /* set notifier */
1411        bo->notifier.notifier_call = bcm_notifier;
1412
1413        register_netdevice_notifier(&bo->notifier);
1414
1415        return 0;
1416}
1417
1418/*
1419 * standard socket functions
1420 */
1421static int bcm_release(struct socket *sock)
1422{
1423        struct sock *sk = sock->sk;
1424        struct bcm_sock *bo;
1425        struct bcm_op *op, *next;
1426
1427        if (sk == NULL)
1428                return 0;
1429
1430        bo = bcm_sk(sk);
1431
1432        /* remove bcm_ops, timer, rx_unregister(), etc. */
1433
1434        unregister_netdevice_notifier(&bo->notifier);
1435
1436        lock_sock(sk);
1437
1438        list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1439                bcm_remove_op(op);
1440
1441        list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1442                /*
1443                 * Don't care if we're bound or not (due to netdev problems)
1444                 * can_rx_unregister() is always a save thing to do here.
1445                 */
1446                if (op->ifindex) {
1447                        /*
1448                         * Only remove subscriptions that had not
1449                         * been removed due to NETDEV_UNREGISTER
1450                         * in bcm_notifier()
1451                         */
1452                        if (op->rx_reg_dev) {
1453                                struct net_device *dev;
1454
1455                                dev = dev_get_by_index(&init_net, op->ifindex);
1456                                if (dev) {
1457                                        bcm_rx_unreg(dev, op);
1458                                        dev_put(dev);
1459                                }
1460                        }
1461                } else
1462                        can_rx_unregister(NULL, op->can_id,
1463                                          REGMASK(op->can_id),
1464                                          bcm_rx_handler, op);
1465
1466                bcm_remove_op(op);
1467        }
1468
1469        /* remove procfs entry */
1470        if (proc_dir && bo->bcm_proc_read)
1471                remove_proc_entry(bo->procname, proc_dir);
1472
1473        /* remove device reference */
1474        if (bo->bound) {
1475                bo->bound   = 0;
1476                bo->ifindex = 0;
1477        }
1478
1479        sock_orphan(sk);
1480        sock->sk = NULL;
1481
1482        release_sock(sk);
1483        sock_put(sk);
1484
1485        return 0;
1486}
1487
1488static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1489                       int flags)
1490{
1491        struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1492        struct sock *sk = sock->sk;
1493        struct bcm_sock *bo = bcm_sk(sk);
1494
1495        if (len < sizeof(*addr))
1496                return -EINVAL;
1497
1498        if (bo->bound)
1499                return -EISCONN;
1500
1501        /* bind a device to this socket */
1502        if (addr->can_ifindex) {
1503                struct net_device *dev;
1504
1505                dev = dev_get_by_index(&init_net, addr->can_ifindex);
1506                if (!dev)
1507                        return -ENODEV;
1508
1509                if (dev->type != ARPHRD_CAN) {
1510                        dev_put(dev);
1511                        return -ENODEV;
1512                }
1513
1514                bo->ifindex = dev->ifindex;
1515                dev_put(dev);
1516
1517        } else {
1518                /* no interface reference for ifindex = 0 ('any' CAN device) */
1519                bo->ifindex = 0;
1520        }
1521
1522        bo->bound = 1;
1523
1524        if (proc_dir) {
1525                /* unique socket address as filename */
1526                sprintf(bo->procname, "%lu", sock_i_ino(sk));
1527                bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1528                                                     proc_dir,
1529                                                     &bcm_proc_fops, sk);
1530        }
1531
1532        return 0;
1533}
1534
1535static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1536                       struct msghdr *msg, size_t size, int flags)
1537{
1538        struct sock *sk = sock->sk;
1539        struct sk_buff *skb;
1540        int error = 0;
1541        int noblock;
1542        int err;
1543
1544        noblock =  flags & MSG_DONTWAIT;
1545        flags   &= ~MSG_DONTWAIT;
1546        skb = skb_recv_datagram(sk, flags, noblock, &error);
1547        if (!skb)
1548                return error;
1549
1550        if (skb->len < size)
1551                size = skb->len;
1552
1553        err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1554        if (err < 0) {
1555                skb_free_datagram(sk, skb);
1556                return err;
1557        }
1558
1559        sock_recv_ts_and_drops(msg, sk, skb);
1560
1561        if (msg->msg_name) {
1562                msg->msg_namelen = sizeof(struct sockaddr_can);
1563                memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1564        }
1565
1566        skb_free_datagram(sk, skb);
1567
1568        return size;
1569}
1570
1571static const struct proto_ops bcm_ops = {
1572        .family        = PF_CAN,
1573        .release       = bcm_release,
1574        .bind          = sock_no_bind,
1575        .connect       = bcm_connect,
1576        .socketpair    = sock_no_socketpair,
1577        .accept        = sock_no_accept,
1578        .getname       = sock_no_getname,
1579        .poll          = datagram_poll,
1580        .ioctl         = can_ioctl,     /* use can_ioctl() from af_can.c */
1581        .listen        = sock_no_listen,
1582        .shutdown      = sock_no_shutdown,
1583        .setsockopt    = sock_no_setsockopt,
1584        .getsockopt    = sock_no_getsockopt,
1585        .sendmsg       = bcm_sendmsg,
1586        .recvmsg       = bcm_recvmsg,
1587        .mmap          = sock_no_mmap,
1588        .sendpage      = sock_no_sendpage,
1589};
1590
1591static struct proto bcm_proto __read_mostly = {
1592        .name       = "CAN_BCM",
1593        .owner      = THIS_MODULE,
1594        .obj_size   = sizeof(struct bcm_sock),
1595        .init       = bcm_init,
1596};
1597
1598static const struct can_proto bcm_can_proto = {
1599        .type       = SOCK_DGRAM,
1600        .protocol   = CAN_BCM,
1601        .ops        = &bcm_ops,
1602        .prot       = &bcm_proto,
1603};
1604
1605static int __init bcm_module_init(void)
1606{
1607        int err;
1608
1609        printk(banner);
1610
1611        err = can_proto_register(&bcm_can_proto);
1612        if (err < 0) {
1613                printk(KERN_ERR "can: registration of bcm protocol failed\n");
1614                return err;
1615        }
1616
1617        /* create /proc/net/can-bcm directory */
1618        proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1619        return 0;
1620}
1621
1622static void __exit bcm_module_exit(void)
1623{
1624        can_proto_unregister(&bcm_can_proto);
1625
1626        if (proc_dir)
1627                proc_net_remove(&init_net, "can-bcm");
1628}
1629
1630module_init(bcm_module_init);
1631module_exit(bcm_module_exit);
1632
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