linux/net/can/bcm.c
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   1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2/*
   3 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
   4 *
   5 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
   6 * All rights reserved.
   7 *
   8 * Redistribution and use in source and binary forms, with or without
   9 * modification, are permitted provided that the following conditions
  10 * are met:
  11 * 1. Redistributions of source code must retain the above copyright
  12 *    notice, this list of conditions and the following disclaimer.
  13 * 2. Redistributions in binary form must reproduce the above copyright
  14 *    notice, this list of conditions and the following disclaimer in the
  15 *    documentation and/or other materials provided with the distribution.
  16 * 3. Neither the name of Volkswagen nor the names of its contributors
  17 *    may be used to endorse or promote products derived from this software
  18 *    without specific prior written permission.
  19 *
  20 * Alternatively, provided that this notice is retained in full, this
  21 * software may be distributed under the terms of the GNU General
  22 * Public License ("GPL") version 2, in which case the provisions of the
  23 * GPL apply INSTEAD OF those given above.
  24 *
  25 * The provided data structures and external interfaces from this code
  26 * are not restricted to be used by modules with a GPL compatible license.
  27 *
  28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  39 * DAMAGE.
  40 *
  41 */
  42
  43#include <linux/module.h>
  44#include <linux/init.h>
  45#include <linux/interrupt.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/skb.h>
  59#include <linux/can/bcm.h>
  60#include <linux/slab.h>
  61#include <net/sock.h>
  62#include <net/net_namespace.h>
  63
  64/*
  65 * To send multiple CAN frame content within TX_SETUP or to filter
  66 * CAN messages with multiplex index within RX_SETUP, the number of
  67 * different filters is limited to 256 due to the one byte index value.
  68 */
  69#define MAX_NFRAMES 256
  70
  71/* limit timers to 400 days for sending/timeouts */
  72#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
  73
  74/* use of last_frames[index].flags */
  75#define RX_RECV    0x40 /* received data for this element */
  76#define RX_THR     0x80 /* element not been sent due to throttle feature */
  77#define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
  78
  79/* get best masking value for can_rx_register() for a given single can_id */
  80#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
  81                     (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
  82                     (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
  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#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
  90
  91/*
  92 * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
  93 * 64 bit aligned so the offset has to be multiples of 8 which is ensured
  94 * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
  95 */
  96static inline u64 get_u64(const struct canfd_frame *cp, int offset)
  97{
  98        return *(u64 *)(cp->data + offset);
  99}
 100
 101struct bcm_op {
 102        struct list_head list;
 103        int ifindex;
 104        canid_t can_id;
 105        u32 flags;
 106        unsigned long frames_abs, frames_filtered;
 107        struct bcm_timeval ival1, ival2;
 108        struct hrtimer timer, thrtimer;
 109        ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
 110        int rx_ifindex;
 111        int cfsiz;
 112        u32 count;
 113        u32 nframes;
 114        u32 currframe;
 115        /* void pointers to arrays of struct can[fd]_frame */
 116        void *frames;
 117        void *last_frames;
 118        struct canfd_frame sframe;
 119        struct canfd_frame last_sframe;
 120        struct sock *sk;
 121        struct net_device *rx_reg_dev;
 122};
 123
 124struct bcm_sock {
 125        struct sock sk;
 126        int bound;
 127        int ifindex;
 128        struct list_head notifier;
 129        struct list_head rx_ops;
 130        struct list_head tx_ops;
 131        unsigned long dropped_usr_msgs;
 132        struct proc_dir_entry *bcm_proc_read;
 133        char procname [32]; /* inode number in decimal with \0 */
 134};
 135
 136static LIST_HEAD(bcm_notifier_list);
 137static DEFINE_SPINLOCK(bcm_notifier_lock);
 138static struct bcm_sock *bcm_busy_notifier;
 139
 140static inline struct bcm_sock *bcm_sk(const struct sock *sk)
 141{
 142        return (struct bcm_sock *)sk;
 143}
 144
 145static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
 146{
 147        return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
 148}
 149
 150/* check limitations for timeval provided by user */
 151static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
 152{
 153        if ((msg_head->ival1.tv_sec < 0) ||
 154            (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
 155            (msg_head->ival1.tv_usec < 0) ||
 156            (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
 157            (msg_head->ival2.tv_sec < 0) ||
 158            (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
 159            (msg_head->ival2.tv_usec < 0) ||
 160            (msg_head->ival2.tv_usec >= USEC_PER_SEC))
 161                return true;
 162
 163        return false;
 164}
 165
 166#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
 167#define OPSIZ sizeof(struct bcm_op)
 168#define MHSIZ sizeof(struct bcm_msg_head)
 169
 170/*
 171 * procfs functions
 172 */
 173#if IS_ENABLED(CONFIG_PROC_FS)
 174static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
 175{
 176        struct net_device *dev;
 177
 178        if (!ifindex)
 179                return "any";
 180
 181        rcu_read_lock();
 182        dev = dev_get_by_index_rcu(net, ifindex);
 183        if (dev)
 184                strcpy(result, dev->name);
 185        else
 186                strcpy(result, "???");
 187        rcu_read_unlock();
 188
 189        return result;
 190}
 191
 192static int bcm_proc_show(struct seq_file *m, void *v)
 193{
 194        char ifname[IFNAMSIZ];
 195        struct net *net = m->private;
 196        struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode);
 197        struct bcm_sock *bo = bcm_sk(sk);
 198        struct bcm_op *op;
 199
 200        seq_printf(m, ">>> socket %pK", sk->sk_socket);
 201        seq_printf(m, " / sk %pK", sk);
 202        seq_printf(m, " / bo %pK", bo);
 203        seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
 204        seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
 205        seq_printf(m, " <<<\n");
 206
 207        list_for_each_entry(op, &bo->rx_ops, list) {
 208
 209                unsigned long reduction;
 210
 211                /* print only active entries & prevent division by zero */
 212                if (!op->frames_abs)
 213                        continue;
 214
 215                seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
 216                           bcm_proc_getifname(net, ifname, op->ifindex));
 217
 218                if (op->flags & CAN_FD_FRAME)
 219                        seq_printf(m, "(%u)", op->nframes);
 220                else
 221                        seq_printf(m, "[%u]", op->nframes);
 222
 223                seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
 224
 225                if (op->kt_ival1)
 226                        seq_printf(m, "timeo=%lld ",
 227                                   (long long)ktime_to_us(op->kt_ival1));
 228
 229                if (op->kt_ival2)
 230                        seq_printf(m, "thr=%lld ",
 231                                   (long long)ktime_to_us(op->kt_ival2));
 232
 233                seq_printf(m, "# recv %ld (%ld) => reduction: ",
 234                           op->frames_filtered, op->frames_abs);
 235
 236                reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
 237
 238                seq_printf(m, "%s%ld%%\n",
 239                           (reduction == 100) ? "near " : "", reduction);
 240        }
 241
 242        list_for_each_entry(op, &bo->tx_ops, list) {
 243
 244                seq_printf(m, "tx_op: %03X %s ", op->can_id,
 245                           bcm_proc_getifname(net, ifname, op->ifindex));
 246
 247                if (op->flags & CAN_FD_FRAME)
 248                        seq_printf(m, "(%u) ", op->nframes);
 249                else
 250                        seq_printf(m, "[%u] ", op->nframes);
 251
 252                if (op->kt_ival1)
 253                        seq_printf(m, "t1=%lld ",
 254                                   (long long)ktime_to_us(op->kt_ival1));
 255
 256                if (op->kt_ival2)
 257                        seq_printf(m, "t2=%lld ",
 258                                   (long long)ktime_to_us(op->kt_ival2));
 259
 260                seq_printf(m, "# sent %ld\n", op->frames_abs);
 261        }
 262        seq_putc(m, '\n');
 263        return 0;
 264}
 265#endif /* CONFIG_PROC_FS */
 266
 267/*
 268 * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
 269 *              of the given bcm tx op
 270 */
 271static void bcm_can_tx(struct bcm_op *op)
 272{
 273        struct sk_buff *skb;
 274        struct net_device *dev;
 275        struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
 276
 277        /* no target device? => exit */
 278        if (!op->ifindex)
 279                return;
 280
 281        dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
 282        if (!dev) {
 283                /* RFC: should this bcm_op remove itself here? */
 284                return;
 285        }
 286
 287        skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
 288        if (!skb)
 289                goto out;
 290
 291        can_skb_reserve(skb);
 292        can_skb_prv(skb)->ifindex = dev->ifindex;
 293        can_skb_prv(skb)->skbcnt = 0;
 294
 295        skb_put_data(skb, cf, op->cfsiz);
 296
 297        /* send with loopback */
 298        skb->dev = dev;
 299        can_skb_set_owner(skb, op->sk);
 300        can_send(skb, 1);
 301
 302        /* update statistics */
 303        op->currframe++;
 304        op->frames_abs++;
 305
 306        /* reached last frame? */
 307        if (op->currframe >= op->nframes)
 308                op->currframe = 0;
 309out:
 310        dev_put(dev);
 311}
 312
 313/*
 314 * bcm_send_to_user - send a BCM message to the userspace
 315 *                    (consisting of bcm_msg_head + x CAN frames)
 316 */
 317static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
 318                             struct canfd_frame *frames, int has_timestamp)
 319{
 320        struct sk_buff *skb;
 321        struct canfd_frame *firstframe;
 322        struct sockaddr_can *addr;
 323        struct sock *sk = op->sk;
 324        unsigned int datalen = head->nframes * op->cfsiz;
 325        int err;
 326
 327        skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
 328        if (!skb)
 329                return;
 330
 331        skb_put_data(skb, head, sizeof(*head));
 332
 333        if (head->nframes) {
 334                /* CAN frames starting here */
 335                firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
 336
 337                skb_put_data(skb, frames, datalen);
 338
 339                /*
 340                 * the BCM uses the flags-element of the canfd_frame
 341                 * structure for internal purposes. This is only
 342                 * relevant for updates that are generated by the
 343                 * BCM, where nframes is 1
 344                 */
 345                if (head->nframes == 1)
 346                        firstframe->flags &= BCM_CAN_FLAGS_MASK;
 347        }
 348
 349        if (has_timestamp) {
 350                /* restore rx timestamp */
 351                skb->tstamp = op->rx_stamp;
 352        }
 353
 354        /*
 355         *  Put the datagram to the queue so that bcm_recvmsg() can
 356         *  get it from there.  We need to pass the interface index to
 357         *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
 358         *  containing the interface index.
 359         */
 360
 361        sock_skb_cb_check_size(sizeof(struct sockaddr_can));
 362        addr = (struct sockaddr_can *)skb->cb;
 363        memset(addr, 0, sizeof(*addr));
 364        addr->can_family  = AF_CAN;
 365        addr->can_ifindex = op->rx_ifindex;
 366
 367        err = sock_queue_rcv_skb(sk, skb);
 368        if (err < 0) {
 369                struct bcm_sock *bo = bcm_sk(sk);
 370
 371                kfree_skb(skb);
 372                /* don't care about overflows in this statistic */
 373                bo->dropped_usr_msgs++;
 374        }
 375}
 376
 377static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
 378{
 379        ktime_t ival;
 380
 381        if (op->kt_ival1 && op->count)
 382                ival = op->kt_ival1;
 383        else if (op->kt_ival2)
 384                ival = op->kt_ival2;
 385        else
 386                return false;
 387
 388        hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
 389        return true;
 390}
 391
 392static void bcm_tx_start_timer(struct bcm_op *op)
 393{
 394        if (bcm_tx_set_expiry(op, &op->timer))
 395                hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
 396}
 397
 398/* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */
 399static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
 400{
 401        struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
 402        struct bcm_msg_head msg_head;
 403
 404        if (op->kt_ival1 && (op->count > 0)) {
 405                op->count--;
 406                if (!op->count && (op->flags & TX_COUNTEVT)) {
 407
 408                        /* create notification to user */
 409                        memset(&msg_head, 0, sizeof(msg_head));
 410                        msg_head.opcode  = TX_EXPIRED;
 411                        msg_head.flags   = op->flags;
 412                        msg_head.count   = op->count;
 413                        msg_head.ival1   = op->ival1;
 414                        msg_head.ival2   = op->ival2;
 415                        msg_head.can_id  = op->can_id;
 416                        msg_head.nframes = 0;
 417
 418                        bcm_send_to_user(op, &msg_head, NULL, 0);
 419                }
 420                bcm_can_tx(op);
 421
 422        } else if (op->kt_ival2) {
 423                bcm_can_tx(op);
 424        }
 425
 426        return bcm_tx_set_expiry(op, &op->timer) ?
 427                HRTIMER_RESTART : HRTIMER_NORESTART;
 428}
 429
 430/*
 431 * bcm_rx_changed - create a RX_CHANGED notification due to changed content
 432 */
 433static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
 434{
 435        struct bcm_msg_head head;
 436
 437        /* update statistics */
 438        op->frames_filtered++;
 439
 440        /* prevent statistics overflow */
 441        if (op->frames_filtered > ULONG_MAX/100)
 442                op->frames_filtered = op->frames_abs = 0;
 443
 444        /* this element is not throttled anymore */
 445        data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
 446
 447        memset(&head, 0, sizeof(head));
 448        head.opcode  = RX_CHANGED;
 449        head.flags   = op->flags;
 450        head.count   = op->count;
 451        head.ival1   = op->ival1;
 452        head.ival2   = op->ival2;
 453        head.can_id  = op->can_id;
 454        head.nframes = 1;
 455
 456        bcm_send_to_user(op, &head, data, 1);
 457}
 458
 459/*
 460 * bcm_rx_update_and_send - process a detected relevant receive content change
 461 *                          1. update the last received data
 462 *                          2. send a notification to the user (if possible)
 463 */
 464static void bcm_rx_update_and_send(struct bcm_op *op,
 465                                   struct canfd_frame *lastdata,
 466                                   const struct canfd_frame *rxdata)
 467{
 468        memcpy(lastdata, rxdata, op->cfsiz);
 469
 470        /* mark as used and throttled by default */
 471        lastdata->flags |= (RX_RECV|RX_THR);
 472
 473        /* throttling mode inactive ? */
 474        if (!op->kt_ival2) {
 475                /* send RX_CHANGED to the user immediately */
 476                bcm_rx_changed(op, lastdata);
 477                return;
 478        }
 479
 480        /* with active throttling timer we are just done here */
 481        if (hrtimer_active(&op->thrtimer))
 482                return;
 483
 484        /* first reception with enabled throttling mode */
 485        if (!op->kt_lastmsg)
 486                goto rx_changed_settime;
 487
 488        /* got a second frame inside a potential throttle period? */
 489        if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
 490            ktime_to_us(op->kt_ival2)) {
 491                /* do not send the saved data - only start throttle timer */
 492                hrtimer_start(&op->thrtimer,
 493                              ktime_add(op->kt_lastmsg, op->kt_ival2),
 494                              HRTIMER_MODE_ABS_SOFT);
 495                return;
 496        }
 497
 498        /* the gap was that big, that throttling was not needed here */
 499rx_changed_settime:
 500        bcm_rx_changed(op, lastdata);
 501        op->kt_lastmsg = ktime_get();
 502}
 503
 504/*
 505 * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
 506 *                       received data stored in op->last_frames[]
 507 */
 508static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
 509                                const struct canfd_frame *rxdata)
 510{
 511        struct canfd_frame *cf = op->frames + op->cfsiz * index;
 512        struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
 513        int i;
 514
 515        /*
 516         * no one uses the MSBs of flags for comparison,
 517         * so we use it here to detect the first time of reception
 518         */
 519
 520        if (!(lcf->flags & RX_RECV)) {
 521                /* received data for the first time => send update to user */
 522                bcm_rx_update_and_send(op, lcf, rxdata);
 523                return;
 524        }
 525
 526        /* do a real check in CAN frame data section */
 527        for (i = 0; i < rxdata->len; i += 8) {
 528                if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
 529                    (get_u64(cf, i) & get_u64(lcf, i))) {
 530                        bcm_rx_update_and_send(op, lcf, rxdata);
 531                        return;
 532                }
 533        }
 534
 535        if (op->flags & RX_CHECK_DLC) {
 536                /* do a real check in CAN frame length */
 537                if (rxdata->len != lcf->len) {
 538                        bcm_rx_update_and_send(op, lcf, rxdata);
 539                        return;
 540                }
 541        }
 542}
 543
 544/*
 545 * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
 546 */
 547static void bcm_rx_starttimer(struct bcm_op *op)
 548{
 549        if (op->flags & RX_NO_AUTOTIMER)
 550                return;
 551
 552        if (op->kt_ival1)
 553                hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT);
 554}
 555
 556/* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */
 557static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
 558{
 559        struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
 560        struct bcm_msg_head msg_head;
 561
 562        /* if user wants to be informed, when cyclic CAN-Messages come back */
 563        if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
 564                /* clear received CAN frames to indicate 'nothing received' */
 565                memset(op->last_frames, 0, op->nframes * op->cfsiz);
 566        }
 567
 568        /* create notification to user */
 569        memset(&msg_head, 0, sizeof(msg_head));
 570        msg_head.opcode  = RX_TIMEOUT;
 571        msg_head.flags   = op->flags;
 572        msg_head.count   = op->count;
 573        msg_head.ival1   = op->ival1;
 574        msg_head.ival2   = op->ival2;
 575        msg_head.can_id  = op->can_id;
 576        msg_head.nframes = 0;
 577
 578        bcm_send_to_user(op, &msg_head, NULL, 0);
 579
 580        return HRTIMER_NORESTART;
 581}
 582
 583/*
 584 * bcm_rx_do_flush - helper for bcm_rx_thr_flush
 585 */
 586static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
 587{
 588        struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
 589
 590        if ((op->last_frames) && (lcf->flags & RX_THR)) {
 591                bcm_rx_changed(op, lcf);
 592                return 1;
 593        }
 594        return 0;
 595}
 596
 597/*
 598 * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
 599 */
 600static int bcm_rx_thr_flush(struct bcm_op *op)
 601{
 602        int updated = 0;
 603
 604        if (op->nframes > 1) {
 605                unsigned int i;
 606
 607                /* for MUX filter we start at index 1 */
 608                for (i = 1; i < op->nframes; i++)
 609                        updated += bcm_rx_do_flush(op, i);
 610
 611        } else {
 612                /* for RX_FILTER_ID and simple filter */
 613                updated += bcm_rx_do_flush(op, 0);
 614        }
 615
 616        return updated;
 617}
 618
 619/*
 620 * bcm_rx_thr_handler - the time for blocked content updates is over now:
 621 *                      Check for throttled data and send it to the userspace
 622 */
 623static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
 624{
 625        struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
 626
 627        if (bcm_rx_thr_flush(op)) {
 628                hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
 629                return HRTIMER_RESTART;
 630        } else {
 631                /* rearm throttle handling */
 632                op->kt_lastmsg = 0;
 633                return HRTIMER_NORESTART;
 634        }
 635}
 636
 637/*
 638 * bcm_rx_handler - handle a CAN frame reception
 639 */
 640static void bcm_rx_handler(struct sk_buff *skb, void *data)
 641{
 642        struct bcm_op *op = (struct bcm_op *)data;
 643        const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
 644        unsigned int i;
 645
 646        if (op->can_id != rxframe->can_id)
 647                return;
 648
 649        /* make sure to handle the correct frame type (CAN / CAN FD) */
 650        if (skb->len != op->cfsiz)
 651                return;
 652
 653        /* disable timeout */
 654        hrtimer_cancel(&op->timer);
 655
 656        /* save rx timestamp */
 657        op->rx_stamp = skb->tstamp;
 658        /* save originator for recvfrom() */
 659        op->rx_ifindex = skb->dev->ifindex;
 660        /* update statistics */
 661        op->frames_abs++;
 662
 663        if (op->flags & RX_RTR_FRAME) {
 664                /* send reply for RTR-request (placed in op->frames[0]) */
 665                bcm_can_tx(op);
 666                return;
 667        }
 668
 669        if (op->flags & RX_FILTER_ID) {
 670                /* the easiest case */
 671                bcm_rx_update_and_send(op, op->last_frames, rxframe);
 672                goto rx_starttimer;
 673        }
 674
 675        if (op->nframes == 1) {
 676                /* simple compare with index 0 */
 677                bcm_rx_cmp_to_index(op, 0, rxframe);
 678                goto rx_starttimer;
 679        }
 680
 681        if (op->nframes > 1) {
 682                /*
 683                 * multiplex compare
 684                 *
 685                 * find the first multiplex mask that fits.
 686                 * Remark: The MUX-mask is stored in index 0 - but only the
 687                 * first 64 bits of the frame data[] are relevant (CAN FD)
 688                 */
 689
 690                for (i = 1; i < op->nframes; i++) {
 691                        if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
 692                            (get_u64(op->frames, 0) &
 693                             get_u64(op->frames + op->cfsiz * i, 0))) {
 694                                bcm_rx_cmp_to_index(op, i, rxframe);
 695                                break;
 696                        }
 697                }
 698        }
 699
 700rx_starttimer:
 701        bcm_rx_starttimer(op);
 702}
 703
 704/*
 705 * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
 706 */
 707static struct bcm_op *bcm_find_op(struct list_head *ops,
 708                                  struct bcm_msg_head *mh, int ifindex)
 709{
 710        struct bcm_op *op;
 711
 712        list_for_each_entry(op, ops, list) {
 713                if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 714                    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
 715                        return op;
 716        }
 717
 718        return NULL;
 719}
 720
 721static void bcm_remove_op(struct bcm_op *op)
 722{
 723        hrtimer_cancel(&op->timer);
 724        hrtimer_cancel(&op->thrtimer);
 725
 726        if ((op->frames) && (op->frames != &op->sframe))
 727                kfree(op->frames);
 728
 729        if ((op->last_frames) && (op->last_frames != &op->last_sframe))
 730                kfree(op->last_frames);
 731
 732        kfree(op);
 733}
 734
 735static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
 736{
 737        if (op->rx_reg_dev == dev) {
 738                can_rx_unregister(dev_net(dev), dev, op->can_id,
 739                                  REGMASK(op->can_id), bcm_rx_handler, op);
 740
 741                /* mark as removed subscription */
 742                op->rx_reg_dev = NULL;
 743        } else
 744                printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
 745                       "mismatch %p %p\n", op->rx_reg_dev, dev);
 746}
 747
 748/*
 749 * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
 750 */
 751static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
 752                            int ifindex)
 753{
 754        struct bcm_op *op, *n;
 755
 756        list_for_each_entry_safe(op, n, ops, list) {
 757                if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 758                    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
 759
 760                        /*
 761                         * Don't care if we're bound or not (due to netdev
 762                         * problems) can_rx_unregister() is always a save
 763                         * thing to do here.
 764                         */
 765                        if (op->ifindex) {
 766                                /*
 767                                 * Only remove subscriptions that had not
 768                                 * been removed due to NETDEV_UNREGISTER
 769                                 * in bcm_notifier()
 770                                 */
 771                                if (op->rx_reg_dev) {
 772                                        struct net_device *dev;
 773
 774                                        dev = dev_get_by_index(sock_net(op->sk),
 775                                                               op->ifindex);
 776                                        if (dev) {
 777                                                bcm_rx_unreg(dev, op);
 778                                                dev_put(dev);
 779                                        }
 780                                }
 781                        } else
 782                                can_rx_unregister(sock_net(op->sk), NULL,
 783                                                  op->can_id,
 784                                                  REGMASK(op->can_id),
 785                                                  bcm_rx_handler, op);
 786
 787                        list_del(&op->list);
 788                        synchronize_rcu();
 789                        bcm_remove_op(op);
 790                        return 1; /* done */
 791                }
 792        }
 793
 794        return 0; /* not found */
 795}
 796
 797/*
 798 * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
 799 */
 800static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
 801                            int ifindex)
 802{
 803        struct bcm_op *op, *n;
 804
 805        list_for_each_entry_safe(op, n, ops, list) {
 806                if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 807                    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
 808                        list_del(&op->list);
 809                        bcm_remove_op(op);
 810                        return 1; /* done */
 811                }
 812        }
 813
 814        return 0; /* not found */
 815}
 816
 817/*
 818 * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
 819 */
 820static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
 821                       int ifindex)
 822{
 823        struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
 824
 825        if (!op)
 826                return -EINVAL;
 827
 828        /* put current values into msg_head */
 829        msg_head->flags   = op->flags;
 830        msg_head->count   = op->count;
 831        msg_head->ival1   = op->ival1;
 832        msg_head->ival2   = op->ival2;
 833        msg_head->nframes = op->nframes;
 834
 835        bcm_send_to_user(op, msg_head, op->frames, 0);
 836
 837        return MHSIZ;
 838}
 839
 840/*
 841 * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
 842 */
 843static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
 844                        int ifindex, struct sock *sk)
 845{
 846        struct bcm_sock *bo = bcm_sk(sk);
 847        struct bcm_op *op;
 848        struct canfd_frame *cf;
 849        unsigned int i;
 850        int err;
 851
 852        /* we need a real device to send frames */
 853        if (!ifindex)
 854                return -ENODEV;
 855
 856        /* check nframes boundaries - we need at least one CAN frame */
 857        if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
 858                return -EINVAL;
 859
 860        /* check timeval limitations */
 861        if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
 862                return -EINVAL;
 863
 864        /* check the given can_id */
 865        op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
 866        if (op) {
 867                /* update existing BCM operation */
 868
 869                /*
 870                 * Do we need more space for the CAN frames than currently
 871                 * allocated? -> This is a _really_ unusual use-case and
 872                 * therefore (complexity / locking) it is not supported.
 873                 */
 874                if (msg_head->nframes > op->nframes)
 875                        return -E2BIG;
 876
 877                /* update CAN frames content */
 878                for (i = 0; i < msg_head->nframes; i++) {
 879
 880                        cf = op->frames + op->cfsiz * i;
 881                        err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
 882
 883                        if (op->flags & CAN_FD_FRAME) {
 884                                if (cf->len > 64)
 885                                        err = -EINVAL;
 886                        } else {
 887                                if (cf->len > 8)
 888                                        err = -EINVAL;
 889                        }
 890
 891                        if (err < 0)
 892                                return err;
 893
 894                        if (msg_head->flags & TX_CP_CAN_ID) {
 895                                /* copy can_id into frame */
 896                                cf->can_id = msg_head->can_id;
 897                        }
 898                }
 899                op->flags = msg_head->flags;
 900
 901        } else {
 902                /* insert new BCM operation for the given can_id */
 903
 904                op = kzalloc(OPSIZ, GFP_KERNEL);
 905                if (!op)
 906                        return -ENOMEM;
 907
 908                op->can_id = msg_head->can_id;
 909                op->cfsiz = CFSIZ(msg_head->flags);
 910                op->flags = msg_head->flags;
 911
 912                /* create array for CAN frames and copy the data */
 913                if (msg_head->nframes > 1) {
 914                        op->frames = kmalloc_array(msg_head->nframes,
 915                                                   op->cfsiz,
 916                                                   GFP_KERNEL);
 917                        if (!op->frames) {
 918                                kfree(op);
 919                                return -ENOMEM;
 920                        }
 921                } else
 922                        op->frames = &op->sframe;
 923
 924                for (i = 0; i < msg_head->nframes; i++) {
 925
 926                        cf = op->frames + op->cfsiz * i;
 927                        err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
 928
 929                        if (op->flags & CAN_FD_FRAME) {
 930                                if (cf->len > 64)
 931                                        err = -EINVAL;
 932                        } else {
 933                                if (cf->len > 8)
 934                                        err = -EINVAL;
 935                        }
 936
 937                        if (err < 0) {
 938                                if (op->frames != &op->sframe)
 939                                        kfree(op->frames);
 940                                kfree(op);
 941                                return err;
 942                        }
 943
 944                        if (msg_head->flags & TX_CP_CAN_ID) {
 945                                /* copy can_id into frame */
 946                                cf->can_id = msg_head->can_id;
 947                        }
 948                }
 949
 950                /* tx_ops never compare with previous received messages */
 951                op->last_frames = NULL;
 952
 953                /* bcm_can_tx / bcm_tx_timeout_handler needs this */
 954                op->sk = sk;
 955                op->ifindex = ifindex;
 956
 957                /* initialize uninitialized (kzalloc) structure */
 958                hrtimer_init(&op->timer, CLOCK_MONOTONIC,
 959                             HRTIMER_MODE_REL_SOFT);
 960                op->timer.function = bcm_tx_timeout_handler;
 961
 962                /* currently unused in tx_ops */
 963                hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
 964                             HRTIMER_MODE_REL_SOFT);
 965
 966                /* add this bcm_op to the list of the tx_ops */
 967                list_add(&op->list, &bo->tx_ops);
 968
 969        } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
 970
 971        if (op->nframes != msg_head->nframes) {
 972                op->nframes   = msg_head->nframes;
 973                /* start multiple frame transmission with index 0 */
 974                op->currframe = 0;
 975        }
 976
 977        /* check flags */
 978
 979        if (op->flags & TX_RESET_MULTI_IDX) {
 980                /* start multiple frame transmission with index 0 */
 981                op->currframe = 0;
 982        }
 983
 984        if (op->flags & SETTIMER) {
 985                /* set timer values */
 986                op->count = msg_head->count;
 987                op->ival1 = msg_head->ival1;
 988                op->ival2 = msg_head->ival2;
 989                op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
 990                op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
 991
 992                /* disable an active timer due to zero values? */
 993                if (!op->kt_ival1 && !op->kt_ival2)
 994                        hrtimer_cancel(&op->timer);
 995        }
 996
 997        if (op->flags & STARTTIMER) {
 998                hrtimer_cancel(&op->timer);
 999                /* spec: send CAN frame when starting timer */
1000                op->flags |= TX_ANNOUNCE;
1001        }
1002
1003        if (op->flags & TX_ANNOUNCE) {
1004                bcm_can_tx(op);
1005                if (op->count)
1006                        op->count--;
1007        }
1008
1009        if (op->flags & STARTTIMER)
1010                bcm_tx_start_timer(op);
1011
1012        return msg_head->nframes * op->cfsiz + MHSIZ;
1013}
1014
1015/*
1016 * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1017 */
1018static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1019                        int ifindex, struct sock *sk)
1020{
1021        struct bcm_sock *bo = bcm_sk(sk);
1022        struct bcm_op *op;
1023        int do_rx_register;
1024        int err = 0;
1025
1026        if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1027                /* be robust against wrong usage ... */
1028                msg_head->flags |= RX_FILTER_ID;
1029                /* ignore trailing garbage */
1030                msg_head->nframes = 0;
1031        }
1032
1033        /* the first element contains the mux-mask => MAX_NFRAMES + 1  */
1034        if (msg_head->nframes > MAX_NFRAMES + 1)
1035                return -EINVAL;
1036
1037        if ((msg_head->flags & RX_RTR_FRAME) &&
1038            ((msg_head->nframes != 1) ||
1039             (!(msg_head->can_id & CAN_RTR_FLAG))))
1040                return -EINVAL;
1041
1042        /* check timeval limitations */
1043        if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1044                return -EINVAL;
1045
1046        /* check the given can_id */
1047        op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1048        if (op) {
1049                /* update existing BCM operation */
1050
1051                /*
1052                 * Do we need more space for the CAN frames than currently
1053                 * allocated? -> This is a _really_ unusual use-case and
1054                 * therefore (complexity / locking) it is not supported.
1055                 */
1056                if (msg_head->nframes > op->nframes)
1057                        return -E2BIG;
1058
1059                if (msg_head->nframes) {
1060                        /* update CAN frames content */
1061                        err = memcpy_from_msg(op->frames, msg,
1062                                              msg_head->nframes * op->cfsiz);
1063                        if (err < 0)
1064                                return err;
1065
1066                        /* clear last_frames to indicate 'nothing received' */
1067                        memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1068                }
1069
1070                op->nframes = msg_head->nframes;
1071                op->flags = msg_head->flags;
1072
1073                /* Only an update -> do not call can_rx_register() */
1074                do_rx_register = 0;
1075
1076        } else {
1077                /* insert new BCM operation for the given can_id */
1078                op = kzalloc(OPSIZ, GFP_KERNEL);
1079                if (!op)
1080                        return -ENOMEM;
1081
1082                op->can_id = msg_head->can_id;
1083                op->nframes = msg_head->nframes;
1084                op->cfsiz = CFSIZ(msg_head->flags);
1085                op->flags = msg_head->flags;
1086
1087                if (msg_head->nframes > 1) {
1088                        /* create array for CAN frames and copy the data */
1089                        op->frames = kmalloc_array(msg_head->nframes,
1090                                                   op->cfsiz,
1091                                                   GFP_KERNEL);
1092                        if (!op->frames) {
1093                                kfree(op);
1094                                return -ENOMEM;
1095                        }
1096
1097                        /* create and init array for received CAN frames */
1098                        op->last_frames = kcalloc(msg_head->nframes,
1099                                                  op->cfsiz,
1100                                                  GFP_KERNEL);
1101                        if (!op->last_frames) {
1102                                kfree(op->frames);
1103                                kfree(op);
1104                                return -ENOMEM;
1105                        }
1106
1107                } else {
1108                        op->frames = &op->sframe;
1109                        op->last_frames = &op->last_sframe;
1110                }
1111
1112                if (msg_head->nframes) {
1113                        err = memcpy_from_msg(op->frames, msg,
1114                                              msg_head->nframes * op->cfsiz);
1115                        if (err < 0) {
1116                                if (op->frames != &op->sframe)
1117                                        kfree(op->frames);
1118                                if (op->last_frames != &op->last_sframe)
1119                                        kfree(op->last_frames);
1120                                kfree(op);
1121                                return err;
1122                        }
1123                }
1124
1125                /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1126                op->sk = sk;
1127                op->ifindex = ifindex;
1128
1129                /* ifindex for timeout events w/o previous frame reception */
1130                op->rx_ifindex = ifindex;
1131
1132                /* initialize uninitialized (kzalloc) structure */
1133                hrtimer_init(&op->timer, CLOCK_MONOTONIC,
1134                             HRTIMER_MODE_REL_SOFT);
1135                op->timer.function = bcm_rx_timeout_handler;
1136
1137                hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
1138                             HRTIMER_MODE_REL_SOFT);
1139                op->thrtimer.function = bcm_rx_thr_handler;
1140
1141                /* add this bcm_op to the list of the rx_ops */
1142                list_add(&op->list, &bo->rx_ops);
1143
1144                /* call can_rx_register() */
1145                do_rx_register = 1;
1146
1147        } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1148
1149        /* check flags */
1150
1151        if (op->flags & RX_RTR_FRAME) {
1152                struct canfd_frame *frame0 = op->frames;
1153
1154                /* no timers in RTR-mode */
1155                hrtimer_cancel(&op->thrtimer);
1156                hrtimer_cancel(&op->timer);
1157
1158                /*
1159                 * funny feature in RX(!)_SETUP only for RTR-mode:
1160                 * copy can_id into frame BUT without RTR-flag to
1161                 * prevent a full-load-loopback-test ... ;-]
1162                 */
1163                if ((op->flags & TX_CP_CAN_ID) ||
1164                    (frame0->can_id == op->can_id))
1165                        frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1166
1167        } else {
1168                if (op->flags & SETTIMER) {
1169
1170                        /* set timer value */
1171                        op->ival1 = msg_head->ival1;
1172                        op->ival2 = msg_head->ival2;
1173                        op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1174                        op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1175
1176                        /* disable an active timer due to zero value? */
1177                        if (!op->kt_ival1)
1178                                hrtimer_cancel(&op->timer);
1179
1180                        /*
1181                         * In any case cancel the throttle timer, flush
1182                         * potentially blocked msgs and reset throttle handling
1183                         */
1184                        op->kt_lastmsg = 0;
1185                        hrtimer_cancel(&op->thrtimer);
1186                        bcm_rx_thr_flush(op);
1187                }
1188
1189                if ((op->flags & STARTTIMER) && op->kt_ival1)
1190                        hrtimer_start(&op->timer, op->kt_ival1,
1191                                      HRTIMER_MODE_REL_SOFT);
1192        }
1193
1194        /* now we can register for can_ids, if we added a new bcm_op */
1195        if (do_rx_register) {
1196                if (ifindex) {
1197                        struct net_device *dev;
1198
1199                        dev = dev_get_by_index(sock_net(sk), ifindex);
1200                        if (dev) {
1201                                err = can_rx_register(sock_net(sk), dev,
1202                                                      op->can_id,
1203                                                      REGMASK(op->can_id),
1204                                                      bcm_rx_handler, op,
1205                                                      "bcm", sk);
1206
1207                                op->rx_reg_dev = dev;
1208                                dev_put(dev);
1209                        }
1210
1211                } else
1212                        err = can_rx_register(sock_net(sk), NULL, op->can_id,
1213                                              REGMASK(op->can_id),
1214                                              bcm_rx_handler, op, "bcm", sk);
1215                if (err) {
1216                        /* this bcm rx op is broken -> remove it */
1217                        list_del(&op->list);
1218                        bcm_remove_op(op);
1219                        return err;
1220                }
1221        }
1222
1223        return msg_head->nframes * op->cfsiz + MHSIZ;
1224}
1225
1226/*
1227 * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1228 */
1229static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1230                       int cfsiz)
1231{
1232        struct sk_buff *skb;
1233        struct net_device *dev;
1234        int err;
1235
1236        /* we need a real device to send frames */
1237        if (!ifindex)
1238                return -ENODEV;
1239
1240        skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1241        if (!skb)
1242                return -ENOMEM;
1243
1244        can_skb_reserve(skb);
1245
1246        err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1247        if (err < 0) {
1248                kfree_skb(skb);
1249                return err;
1250        }
1251
1252        dev = dev_get_by_index(sock_net(sk), ifindex);
1253        if (!dev) {
1254                kfree_skb(skb);
1255                return -ENODEV;
1256        }
1257
1258        can_skb_prv(skb)->ifindex = dev->ifindex;
1259        can_skb_prv(skb)->skbcnt = 0;
1260        skb->dev = dev;
1261        can_skb_set_owner(skb, sk);
1262        err = can_send(skb, 1); /* send with loopback */
1263        dev_put(dev);
1264
1265        if (err)
1266                return err;
1267
1268        return cfsiz + MHSIZ;
1269}
1270
1271/*
1272 * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1273 */
1274static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1275{
1276        struct sock *sk = sock->sk;
1277        struct bcm_sock *bo = bcm_sk(sk);
1278        int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1279        struct bcm_msg_head msg_head;
1280        int cfsiz;
1281        int ret; /* read bytes or error codes as return value */
1282
1283        if (!bo->bound)
1284                return -ENOTCONN;
1285
1286        /* check for valid message length from userspace */
1287        if (size < MHSIZ)
1288                return -EINVAL;
1289
1290        /* read message head information */
1291        ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1292        if (ret < 0)
1293                return ret;
1294
1295        cfsiz = CFSIZ(msg_head.flags);
1296        if ((size - MHSIZ) % cfsiz)
1297                return -EINVAL;
1298
1299        /* check for alternative ifindex for this bcm_op */
1300
1301        if (!ifindex && msg->msg_name) {
1302                /* no bound device as default => check msg_name */
1303                DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1304
1305                if (msg->msg_namelen < BCM_MIN_NAMELEN)
1306                        return -EINVAL;
1307
1308                if (addr->can_family != AF_CAN)
1309                        return -EINVAL;
1310
1311                /* ifindex from sendto() */
1312                ifindex = addr->can_ifindex;
1313
1314                if (ifindex) {
1315                        struct net_device *dev;
1316
1317                        dev = dev_get_by_index(sock_net(sk), ifindex);
1318                        if (!dev)
1319                                return -ENODEV;
1320
1321                        if (dev->type != ARPHRD_CAN) {
1322                                dev_put(dev);
1323                                return -ENODEV;
1324                        }
1325
1326                        dev_put(dev);
1327                }
1328        }
1329
1330        lock_sock(sk);
1331
1332        switch (msg_head.opcode) {
1333
1334        case TX_SETUP:
1335                ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1336                break;
1337
1338        case RX_SETUP:
1339                ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1340                break;
1341
1342        case TX_DELETE:
1343                if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1344                        ret = MHSIZ;
1345                else
1346                        ret = -EINVAL;
1347                break;
1348
1349        case RX_DELETE:
1350                if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1351                        ret = MHSIZ;
1352                else
1353                        ret = -EINVAL;
1354                break;
1355
1356        case TX_READ:
1357                /* reuse msg_head for the reply to TX_READ */
1358                msg_head.opcode  = TX_STATUS;
1359                ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1360                break;
1361
1362        case RX_READ:
1363                /* reuse msg_head for the reply to RX_READ */
1364                msg_head.opcode  = RX_STATUS;
1365                ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1366                break;
1367
1368        case TX_SEND:
1369                /* we need exactly one CAN frame behind the msg head */
1370                if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1371                        ret = -EINVAL;
1372                else
1373                        ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1374                break;
1375
1376        default:
1377                ret = -EINVAL;
1378                break;
1379        }
1380
1381        release_sock(sk);
1382
1383        return ret;
1384}
1385
1386/*
1387 * notification handler for netdevice status changes
1388 */
1389static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
1390                       struct net_device *dev)
1391{
1392        struct sock *sk = &bo->sk;
1393        struct bcm_op *op;
1394        int notify_enodev = 0;
1395
1396        if (!net_eq(dev_net(dev), sock_net(sk)))
1397                return;
1398
1399        switch (msg) {
1400
1401        case NETDEV_UNREGISTER:
1402                lock_sock(sk);
1403
1404                /* remove device specific receive entries */
1405                list_for_each_entry(op, &bo->rx_ops, list)
1406                        if (op->rx_reg_dev == dev)
1407                                bcm_rx_unreg(dev, op);
1408
1409                /* remove device reference, if this is our bound device */
1410                if (bo->bound && bo->ifindex == dev->ifindex) {
1411                        bo->bound   = 0;
1412                        bo->ifindex = 0;
1413                        notify_enodev = 1;
1414                }
1415
1416                release_sock(sk);
1417
1418                if (notify_enodev) {
1419                        sk->sk_err = ENODEV;
1420                        if (!sock_flag(sk, SOCK_DEAD))
1421                                sk_error_report(sk);
1422                }
1423                break;
1424
1425        case NETDEV_DOWN:
1426                if (bo->bound && bo->ifindex == dev->ifindex) {
1427                        sk->sk_err = ENETDOWN;
1428                        if (!sock_flag(sk, SOCK_DEAD))
1429                                sk_error_report(sk);
1430                }
1431        }
1432}
1433
1434static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1435                        void *ptr)
1436{
1437        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1438
1439        if (dev->type != ARPHRD_CAN)
1440                return NOTIFY_DONE;
1441        if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1442                return NOTIFY_DONE;
1443        if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
1444                return NOTIFY_DONE;
1445
1446        spin_lock(&bcm_notifier_lock);
1447        list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
1448                spin_unlock(&bcm_notifier_lock);
1449                bcm_notify(bcm_busy_notifier, msg, dev);
1450                spin_lock(&bcm_notifier_lock);
1451        }
1452        bcm_busy_notifier = NULL;
1453        spin_unlock(&bcm_notifier_lock);
1454        return NOTIFY_DONE;
1455}
1456
1457/*
1458 * initial settings for all BCM sockets to be set at socket creation time
1459 */
1460static int bcm_init(struct sock *sk)
1461{
1462        struct bcm_sock *bo = bcm_sk(sk);
1463
1464        bo->bound            = 0;
1465        bo->ifindex          = 0;
1466        bo->dropped_usr_msgs = 0;
1467        bo->bcm_proc_read    = NULL;
1468
1469        INIT_LIST_HEAD(&bo->tx_ops);
1470        INIT_LIST_HEAD(&bo->rx_ops);
1471
1472        /* set notifier */
1473        spin_lock(&bcm_notifier_lock);
1474        list_add_tail(&bo->notifier, &bcm_notifier_list);
1475        spin_unlock(&bcm_notifier_lock);
1476
1477        return 0;
1478}
1479
1480/*
1481 * standard socket functions
1482 */
1483static int bcm_release(struct socket *sock)
1484{
1485        struct sock *sk = sock->sk;
1486        struct net *net;
1487        struct bcm_sock *bo;
1488        struct bcm_op *op, *next;
1489
1490        if (!sk)
1491                return 0;
1492
1493        net = sock_net(sk);
1494        bo = bcm_sk(sk);
1495
1496        /* remove bcm_ops, timer, rx_unregister(), etc. */
1497
1498        spin_lock(&bcm_notifier_lock);
1499        while (bcm_busy_notifier == bo) {
1500                spin_unlock(&bcm_notifier_lock);
1501                schedule_timeout_uninterruptible(1);
1502                spin_lock(&bcm_notifier_lock);
1503        }
1504        list_del(&bo->notifier);
1505        spin_unlock(&bcm_notifier_lock);
1506
1507        lock_sock(sk);
1508
1509        list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1510                bcm_remove_op(op);
1511
1512        list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1513                /*
1514                 * Don't care if we're bound or not (due to netdev problems)
1515                 * can_rx_unregister() is always a save thing to do here.
1516                 */
1517                if (op->ifindex) {
1518                        /*
1519                         * Only remove subscriptions that had not
1520                         * been removed due to NETDEV_UNREGISTER
1521                         * in bcm_notifier()
1522                         */
1523                        if (op->rx_reg_dev) {
1524                                struct net_device *dev;
1525
1526                                dev = dev_get_by_index(net, op->ifindex);
1527                                if (dev) {
1528                                        bcm_rx_unreg(dev, op);
1529                                        dev_put(dev);
1530                                }
1531                        }
1532                } else
1533                        can_rx_unregister(net, NULL, op->can_id,
1534                                          REGMASK(op->can_id),
1535                                          bcm_rx_handler, op);
1536
1537        }
1538
1539        synchronize_rcu();
1540
1541        list_for_each_entry_safe(op, next, &bo->rx_ops, list)
1542                bcm_remove_op(op);
1543
1544#if IS_ENABLED(CONFIG_PROC_FS)
1545        /* remove procfs entry */
1546        if (net->can.bcmproc_dir && bo->bcm_proc_read)
1547                remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1548#endif /* CONFIG_PROC_FS */
1549
1550        /* remove device reference */
1551        if (bo->bound) {
1552                bo->bound   = 0;
1553                bo->ifindex = 0;
1554        }
1555
1556        sock_orphan(sk);
1557        sock->sk = NULL;
1558
1559        release_sock(sk);
1560        sock_put(sk);
1561
1562        return 0;
1563}
1564
1565static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1566                       int flags)
1567{
1568        struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1569        struct sock *sk = sock->sk;
1570        struct bcm_sock *bo = bcm_sk(sk);
1571        struct net *net = sock_net(sk);
1572        int ret = 0;
1573
1574        if (len < BCM_MIN_NAMELEN)
1575                return -EINVAL;
1576
1577        lock_sock(sk);
1578
1579        if (bo->bound) {
1580                ret = -EISCONN;
1581                goto fail;
1582        }
1583
1584        /* bind a device to this socket */
1585        if (addr->can_ifindex) {
1586                struct net_device *dev;
1587
1588                dev = dev_get_by_index(net, addr->can_ifindex);
1589                if (!dev) {
1590                        ret = -ENODEV;
1591                        goto fail;
1592                }
1593                if (dev->type != ARPHRD_CAN) {
1594                        dev_put(dev);
1595                        ret = -ENODEV;
1596                        goto fail;
1597                }
1598
1599                bo->ifindex = dev->ifindex;
1600                dev_put(dev);
1601
1602        } else {
1603                /* no interface reference for ifindex = 0 ('any' CAN device) */
1604                bo->ifindex = 0;
1605        }
1606
1607#if IS_ENABLED(CONFIG_PROC_FS)
1608        if (net->can.bcmproc_dir) {
1609                /* unique socket address as filename */
1610                sprintf(bo->procname, "%lu", sock_i_ino(sk));
1611                bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
1612                                                     net->can.bcmproc_dir,
1613                                                     bcm_proc_show, sk);
1614                if (!bo->bcm_proc_read) {
1615                        ret = -ENOMEM;
1616                        goto fail;
1617                }
1618        }
1619#endif /* CONFIG_PROC_FS */
1620
1621        bo->bound = 1;
1622
1623fail:
1624        release_sock(sk);
1625
1626        return ret;
1627}
1628
1629static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1630                       int flags)
1631{
1632        struct sock *sk = sock->sk;
1633        struct sk_buff *skb;
1634        int error = 0;
1635        int noblock;
1636        int err;
1637
1638        noblock =  flags & MSG_DONTWAIT;
1639        flags   &= ~MSG_DONTWAIT;
1640        skb = skb_recv_datagram(sk, flags, noblock, &error);
1641        if (!skb)
1642                return error;
1643
1644        if (skb->len < size)
1645                size = skb->len;
1646
1647        err = memcpy_to_msg(msg, skb->data, size);
1648        if (err < 0) {
1649                skb_free_datagram(sk, skb);
1650                return err;
1651        }
1652
1653        sock_recv_ts_and_drops(msg, sk, skb);
1654
1655        if (msg->msg_name) {
1656                __sockaddr_check_size(BCM_MIN_NAMELEN);
1657                msg->msg_namelen = BCM_MIN_NAMELEN;
1658                memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1659        }
1660
1661        skb_free_datagram(sk, skb);
1662
1663        return size;
1664}
1665
1666static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1667                                unsigned long arg)
1668{
1669        /* no ioctls for socket layer -> hand it down to NIC layer */
1670        return -ENOIOCTLCMD;
1671}
1672
1673static const struct proto_ops bcm_ops = {
1674        .family        = PF_CAN,
1675        .release       = bcm_release,
1676        .bind          = sock_no_bind,
1677        .connect       = bcm_connect,
1678        .socketpair    = sock_no_socketpair,
1679        .accept        = sock_no_accept,
1680        .getname       = sock_no_getname,
1681        .poll          = datagram_poll,
1682        .ioctl         = bcm_sock_no_ioctlcmd,
1683        .gettstamp     = sock_gettstamp,
1684        .listen        = sock_no_listen,
1685        .shutdown      = sock_no_shutdown,
1686        .sendmsg       = bcm_sendmsg,
1687        .recvmsg       = bcm_recvmsg,
1688        .mmap          = sock_no_mmap,
1689        .sendpage      = sock_no_sendpage,
1690};
1691
1692static struct proto bcm_proto __read_mostly = {
1693        .name       = "CAN_BCM",
1694        .owner      = THIS_MODULE,
1695        .obj_size   = sizeof(struct bcm_sock),
1696        .init       = bcm_init,
1697};
1698
1699static const struct can_proto bcm_can_proto = {
1700        .type       = SOCK_DGRAM,
1701        .protocol   = CAN_BCM,
1702        .ops        = &bcm_ops,
1703        .prot       = &bcm_proto,
1704};
1705
1706static int canbcm_pernet_init(struct net *net)
1707{
1708#if IS_ENABLED(CONFIG_PROC_FS)
1709        /* create /proc/net/can-bcm directory */
1710        net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1711#endif /* CONFIG_PROC_FS */
1712
1713        return 0;
1714}
1715
1716static void canbcm_pernet_exit(struct net *net)
1717{
1718#if IS_ENABLED(CONFIG_PROC_FS)
1719        /* remove /proc/net/can-bcm directory */
1720        if (net->can.bcmproc_dir)
1721                remove_proc_entry("can-bcm", net->proc_net);
1722#endif /* CONFIG_PROC_FS */
1723}
1724
1725static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1726        .init = canbcm_pernet_init,
1727        .exit = canbcm_pernet_exit,
1728};
1729
1730static struct notifier_block canbcm_notifier = {
1731        .notifier_call = bcm_notifier
1732};
1733
1734static int __init bcm_module_init(void)
1735{
1736        int err;
1737
1738        pr_info("can: broadcast manager protocol\n");
1739
1740        err = can_proto_register(&bcm_can_proto);
1741        if (err < 0) {
1742                printk(KERN_ERR "can: registration of bcm protocol failed\n");
1743                return err;
1744        }
1745
1746        register_pernet_subsys(&canbcm_pernet_ops);
1747        register_netdevice_notifier(&canbcm_notifier);
1748        return 0;
1749}
1750
1751static void __exit bcm_module_exit(void)
1752{
1753        can_proto_unregister(&bcm_can_proto);
1754        unregister_netdevice_notifier(&canbcm_notifier);
1755        unregister_pernet_subsys(&canbcm_pernet_ops);
1756}
1757
1758module_init(bcm_module_init);
1759module_exit(bcm_module_exit);
1760