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