net/can/bcm.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
get_u64
bcm_sk
bcm_timeval_to_ktime
bcm_is_invalid_tv
bcm_proc_show
bcm_can_tx
bcm_send_to_user
bcm_tx_set_expiry
bcm_tx_start_timer
bcm_tx_timeout_handler
bcm_rx_changed
bcm_rx_update_and_send
bcm_rx_cmp_to_index
bcm_rx_starttimer
bcm_rx_timeout_handler
bcm_rx_do_flush
bcm_rx_thr_flush
bcm_rx_thr_handler
bcm_rx_handler
bcm_find_op
bcm_remove_op
bcm_rx_unreg
bcm_delete_rx_op
bcm_delete_tx_op
bcm_read_op
bcm_tx_setup
bcm_rx_setup
bcm_tx_send
bcm_sendmsg
bcm_notifier
bcm_init
bcm_release
bcm_connect
bcm_recvmsg
bcm_sock_no_ioctlcmd
canbcm_pernet_init
canbcm_pernet_exit
bcm_module_init
bcm_module_exit
   1 // SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) 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 
  84 #define CAN_BCM_VERSION "20170425"
  85 
  86 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
  87 MODULE_LICENSE("Dual BSD/GPL");
  88 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
  89 MODULE_ALIAS("can-proto-2");
  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  */
  96 static inline u64 get_u64(const struct canfd_frame *cp, int offset)
  97 {
  98         return *(u64 *)(cp->data + offset);
  99 }
 100 
 101 struct 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 
 124 struct bcm_sock {
 125         struct sock sk;
 126         int bound;
 127         int ifindex;
 128         struct notifier_block 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 
 136 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
 137 {
 138         return (struct bcm_sock *)sk;
 139 }
 140 
 141 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
 142 {
 143         return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
 144 }
 145 
 146 /* check limitations for timeval provided by user */
 147 static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
 148 {
 149         if ((msg_head->ival1.tv_sec < 0) ||
 150             (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
 151             (msg_head->ival1.tv_usec < 0) ||
 152             (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
 153             (msg_head->ival2.tv_sec < 0) ||
 154             (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
 155             (msg_head->ival2.tv_usec < 0) ||
 156             (msg_head->ival2.tv_usec >= USEC_PER_SEC))
 157                 return true;
 158 
 159         return false;
 160 }
 161 
 162 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
 163 #define OPSIZ sizeof(struct bcm_op)
 164 #define MHSIZ sizeof(struct bcm_msg_head)
 165 
 166 /*
 167  * procfs functions
 168  */
 169 #if IS_ENABLED(CONFIG_PROC_FS)
 170 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
 171 {
 172         struct net_device *dev;
 173 
 174         if (!ifindex)
 175                 return "any";
 176 
 177         rcu_read_lock();
 178         dev = dev_get_by_index_rcu(net, ifindex);
 179         if (dev)
 180                 strcpy(result, dev->name);
 181         else
 182                 strcpy(result, "???");
 183         rcu_read_unlock();
 184 
 185         return result;
 186 }
 187 
 188 static int bcm_proc_show(struct seq_file *m, void *v)
 189 {
 190         char ifname[IFNAMSIZ];
 191         struct net *net = m->private;
 192         struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode);
 193         struct bcm_sock *bo = bcm_sk(sk);
 194         struct bcm_op *op;
 195 
 196         seq_printf(m, ">>> socket %pK", sk->sk_socket);
 197         seq_printf(m, " / sk %pK", sk);
 198         seq_printf(m, " / bo %pK", bo);
 199         seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
 200         seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
 201         seq_printf(m, " <<<\n");
 202 
 203         list_for_each_entry(op, &bo->rx_ops, list) {
 204 
 205                 unsigned long reduction;
 206 
 207                 /* print only active entries & prevent division by zero */
 208                 if (!op->frames_abs)
 209                         continue;
 210 
 211                 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
 212                            bcm_proc_getifname(net, ifname, op->ifindex));
 213 
 214                 if (op->flags & CAN_FD_FRAME)
 215                         seq_printf(m, "(%u)", op->nframes);
 216                 else
 217                         seq_printf(m, "[%u]", op->nframes);
 218 
 219                 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
 220 
 221                 if (op->kt_ival1)
 222                         seq_printf(m, "timeo=%lld ",
 223                                    (long long)ktime_to_us(op->kt_ival1));
 224 
 225                 if (op->kt_ival2)
 226                         seq_printf(m, "thr=%lld ",
 227                                    (long long)ktime_to_us(op->kt_ival2));
 228 
 229                 seq_printf(m, "# recv %ld (%ld) => reduction: ",
 230                            op->frames_filtered, op->frames_abs);
 231 
 232                 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
 233 
 234                 seq_printf(m, "%s%ld%%\n",
 235                            (reduction == 100) ? "near " : "", reduction);
 236         }
 237 
 238         list_for_each_entry(op, &bo->tx_ops, list) {
 239 
 240                 seq_printf(m, "tx_op: %03X %s ", op->can_id,
 241                            bcm_proc_getifname(net, ifname, op->ifindex));
 242 
 243                 if (op->flags & CAN_FD_FRAME)
 244                         seq_printf(m, "(%u) ", op->nframes);
 245                 else
 246                         seq_printf(m, "[%u] ", op->nframes);
 247 
 248                 if (op->kt_ival1)
 249                         seq_printf(m, "t1=%lld ",
 250                                    (long long)ktime_to_us(op->kt_ival1));
 251 
 252                 if (op->kt_ival2)
 253                         seq_printf(m, "t2=%lld ",
 254                                    (long long)ktime_to_us(op->kt_ival2));
 255 
 256                 seq_printf(m, "# sent %ld\n", op->frames_abs);
 257         }
 258         seq_putc(m, '\n');
 259         return 0;
 260 }
 261 #endif /* CONFIG_PROC_FS */
 262 
 263 /*
 264  * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
 265  *              of the given bcm tx op
 266  */
 267 static void bcm_can_tx(struct bcm_op *op)
 268 {
 269         struct sk_buff *skb;
 270         struct net_device *dev;
 271         struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
 272 
 273         /* no target device? => exit */
 274         if (!op->ifindex)
 275                 return;
 276 
 277         dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
 278         if (!dev) {
 279                 /* RFC: should this bcm_op remove itself here? */
 280                 return;
 281         }
 282 
 283         skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
 284         if (!skb)
 285                 goto out;
 286 
 287         can_skb_reserve(skb);
 288         can_skb_prv(skb)->ifindex = dev->ifindex;
 289         can_skb_prv(skb)->skbcnt = 0;
 290 
 291         skb_put_data(skb, cf, op->cfsiz);
 292 
 293         /* send with loopback */
 294         skb->dev = dev;
 295         can_skb_set_owner(skb, op->sk);
 296         can_send(skb, 1);
 297 
 298         /* update statistics */
 299         op->currframe++;
 300         op->frames_abs++;
 301 
 302         /* reached last frame? */
 303         if (op->currframe >= op->nframes)
 304                 op->currframe = 0;
 305 out:
 306         dev_put(dev);
 307 }
 308 
 309 /*
 310  * bcm_send_to_user - send a BCM message to the userspace
 311  *                    (consisting of bcm_msg_head + x CAN frames)
 312  */
 313 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
 314                              struct canfd_frame *frames, int has_timestamp)
 315 {
 316         struct sk_buff *skb;
 317         struct canfd_frame *firstframe;
 318         struct sockaddr_can *addr;
 319         struct sock *sk = op->sk;
 320         unsigned int datalen = head->nframes * op->cfsiz;
 321         int err;
 322 
 323         skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
 324         if (!skb)
 325                 return;
 326 
 327         skb_put_data(skb, head, sizeof(*head));
 328 
 329         if (head->nframes) {
 330                 /* CAN frames starting here */
 331                 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
 332 
 333                 skb_put_data(skb, frames, datalen);
 334 
 335                 /*
 336                  * the BCM uses the flags-element of the canfd_frame
 337                  * structure for internal purposes. This is only
 338                  * relevant for updates that are generated by the
 339                  * BCM, where nframes is 1
 340                  */
 341                 if (head->nframes == 1)
 342                         firstframe->flags &= BCM_CAN_FLAGS_MASK;
 343         }
 344 
 345         if (has_timestamp) {
 346                 /* restore rx timestamp */
 347                 skb->tstamp = op->rx_stamp;
 348         }
 349 
 350         /*
 351          *  Put the datagram to the queue so that bcm_recvmsg() can
 352          *  get it from there.  We need to pass the interface index to
 353          *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
 354          *  containing the interface index.
 355          */
 356 
 357         sock_skb_cb_check_size(sizeof(struct sockaddr_can));
 358         addr = (struct sockaddr_can *)skb->cb;
 359         memset(addr, 0, sizeof(*addr));
 360         addr->can_family  = AF_CAN;
 361         addr->can_ifindex = op->rx_ifindex;
 362 
 363         err = sock_queue_rcv_skb(sk, skb);
 364         if (err < 0) {
 365                 struct bcm_sock *bo = bcm_sk(sk);
 366 
 367                 kfree_skb(skb);
 368                 /* don't care about overflows in this statistic */
 369                 bo->dropped_usr_msgs++;
 370         }
 371 }
 372 
 373 static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
 374 {
 375         ktime_t ival;
 376 
 377         if (op->kt_ival1 && op->count)
 378                 ival = op->kt_ival1;
 379         else if (op->kt_ival2)
 380                 ival = op->kt_ival2;
 381         else
 382                 return false;
 383 
 384         hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
 385         return true;
 386 }
 387 
 388 static void bcm_tx_start_timer(struct bcm_op *op)
 389 {
 390         if (bcm_tx_set_expiry(op, &op->timer))
 391                 hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
 392 }
 393 
 394 /* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */
 395 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
 396 {
 397         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
 398         struct bcm_msg_head msg_head;
 399 
 400         if (op->kt_ival1 && (op->count > 0)) {
 401                 op->count--;
 402                 if (!op->count && (op->flags & TX_COUNTEVT)) {
 403 
 404                         /* create notification to user */
 405                         msg_head.opcode  = TX_EXPIRED;
 406                         msg_head.flags   = op->flags;
 407                         msg_head.count   = op->count;
 408                         msg_head.ival1   = op->ival1;
 409                         msg_head.ival2   = op->ival2;
 410                         msg_head.can_id  = op->can_id;
 411                         msg_head.nframes = 0;
 412 
 413                         bcm_send_to_user(op, &msg_head, NULL, 0);
 414                 }
 415                 bcm_can_tx(op);
 416 
 417         } else if (op->kt_ival2) {
 418                 bcm_can_tx(op);
 419         }
 420 
 421         return bcm_tx_set_expiry(op, &op->timer) ?
 422                 HRTIMER_RESTART : HRTIMER_NORESTART;
 423 }
 424 
 425 /*
 426  * bcm_rx_changed - create a RX_CHANGED notification due to changed content
 427  */
 428 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
 429 {
 430         struct bcm_msg_head head;
 431 
 432         /* update statistics */
 433         op->frames_filtered++;
 434 
 435         /* prevent statistics overflow */
 436         if (op->frames_filtered > ULONG_MAX/100)
 437                 op->frames_filtered = op->frames_abs = 0;
 438 
 439         /* this element is not throttled anymore */
 440         data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
 441 
 442         head.opcode  = RX_CHANGED;
 443         head.flags   = op->flags;
 444         head.count   = op->count;
 445         head.ival1   = op->ival1;
 446         head.ival2   = op->ival2;
 447         head.can_id  = op->can_id;
 448         head.nframes = 1;
 449 
 450         bcm_send_to_user(op, &head, data, 1);
 451 }
 452 
 453 /*
 454  * bcm_rx_update_and_send - process a detected relevant receive content change
 455  *                          1. update the last received data
 456  *                          2. send a notification to the user (if possible)
 457  */
 458 static void bcm_rx_update_and_send(struct bcm_op *op,
 459                                    struct canfd_frame *lastdata,
 460                                    const struct canfd_frame *rxdata)
 461 {
 462         memcpy(lastdata, rxdata, op->cfsiz);
 463 
 464         /* mark as used and throttled by default */
 465         lastdata->flags |= (RX_RECV|RX_THR);
 466 
 467         /* throttling mode inactive ? */
 468         if (!op->kt_ival2) {
 469                 /* send RX_CHANGED to the user immediately */
 470                 bcm_rx_changed(op, lastdata);
 471                 return;
 472         }
 473 
 474         /* with active throttling timer we are just done here */
 475         if (hrtimer_active(&op->thrtimer))
 476                 return;
 477 
 478         /* first reception with enabled throttling mode */
 479         if (!op->kt_lastmsg)
 480                 goto rx_changed_settime;
 481 
 482         /* got a second frame inside a potential throttle period? */
 483         if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
 484             ktime_to_us(op->kt_ival2)) {
 485                 /* do not send the saved data - only start throttle timer */
 486                 hrtimer_start(&op->thrtimer,
 487                               ktime_add(op->kt_lastmsg, op->kt_ival2),
 488                               HRTIMER_MODE_ABS_SOFT);
 489                 return;
 490         }
 491 
 492         /* the gap was that big, that throttling was not needed here */
 493 rx_changed_settime:
 494         bcm_rx_changed(op, lastdata);
 495         op->kt_lastmsg = ktime_get();
 496 }
 497 
 498 /*
 499  * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
 500  *                       received data stored in op->last_frames[]
 501  */
 502 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
 503                                 const struct canfd_frame *rxdata)
 504 {
 505         struct canfd_frame *cf = op->frames + op->cfsiz * index;
 506         struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
 507         int i;
 508 
 509         /*
 510          * no one uses the MSBs of flags for comparison,
 511          * so we use it here to detect the first time of reception
 512          */
 513 
 514         if (!(lcf->flags & RX_RECV)) {
 515                 /* received data for the first time => send update to user */
 516                 bcm_rx_update_and_send(op, lcf, rxdata);
 517                 return;
 518         }
 519 
 520         /* do a real check in CAN frame data section */
 521         for (i = 0; i < rxdata->len; i += 8) {
 522                 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
 523                     (get_u64(cf, i) & get_u64(lcf, i))) {
 524                         bcm_rx_update_and_send(op, lcf, rxdata);
 525                         return;
 526                 }
 527         }
 528 
 529         if (op->flags & RX_CHECK_DLC) {
 530                 /* do a real check in CAN frame length */
 531                 if (rxdata->len != lcf->len) {
 532                         bcm_rx_update_and_send(op, lcf, rxdata);
 533                         return;
 534                 }
 535         }
 536 }
 537 
 538 /*
 539  * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
 540  */
 541 static void bcm_rx_starttimer(struct bcm_op *op)
 542 {
 543         if (op->flags & RX_NO_AUTOTIMER)
 544                 return;
 545 
 546         if (op->kt_ival1)
 547                 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT);
 548 }
 549 
 550 /* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */
 551 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
 552 {
 553         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
 554         struct bcm_msg_head msg_head;
 555 
 556         /* if user wants to be informed, when cyclic CAN-Messages come back */
 557         if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
 558                 /* clear received CAN frames to indicate 'nothing received' */
 559                 memset(op->last_frames, 0, op->nframes * op->cfsiz);
 560         }
 561 
 562         /* create notification to user */
 563         msg_head.opcode  = RX_TIMEOUT;
 564         msg_head.flags   = op->flags;
 565         msg_head.count   = op->count;
 566         msg_head.ival1   = op->ival1;
 567         msg_head.ival2   = op->ival2;
 568         msg_head.can_id  = op->can_id;
 569         msg_head.nframes = 0;
 570 
 571         bcm_send_to_user(op, &msg_head, NULL, 0);
 572 
 573         return HRTIMER_NORESTART;
 574 }
 575 
 576 /*
 577  * bcm_rx_do_flush - helper for bcm_rx_thr_flush
 578  */
 579 static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
 580 {
 581         struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
 582 
 583         if ((op->last_frames) && (lcf->flags & RX_THR)) {
 584                 bcm_rx_changed(op, lcf);
 585                 return 1;
 586         }
 587         return 0;
 588 }
 589 
 590 /*
 591  * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
 592  */
 593 static int bcm_rx_thr_flush(struct bcm_op *op)
 594 {
 595         int updated = 0;
 596 
 597         if (op->nframes > 1) {
 598                 unsigned int i;
 599 
 600                 /* for MUX filter we start at index 1 */
 601                 for (i = 1; i < op->nframes; i++)
 602                         updated += bcm_rx_do_flush(op, i);
 603 
 604         } else {
 605                 /* for RX_FILTER_ID and simple filter */
 606                 updated += bcm_rx_do_flush(op, 0);
 607         }
 608 
 609         return updated;
 610 }
 611 
 612 /*
 613  * bcm_rx_thr_handler - the time for blocked content updates is over now:
 614  *                      Check for throttled data and send it to the userspace
 615  */
 616 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
 617 {
 618         struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
 619 
 620         if (bcm_rx_thr_flush(op)) {
 621                 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
 622                 return HRTIMER_RESTART;
 623         } else {
 624                 /* rearm throttle handling */
 625                 op->kt_lastmsg = 0;
 626                 return HRTIMER_NORESTART;
 627         }
 628 }
 629 
 630 /*
 631  * bcm_rx_handler - handle a CAN frame reception
 632  */
 633 static void bcm_rx_handler(struct sk_buff *skb, void *data)
 634 {
 635         struct bcm_op *op = (struct bcm_op *)data;
 636         const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
 637         unsigned int i;
 638 
 639         if (op->can_id != rxframe->can_id)
 640                 return;
 641 
 642         /* make sure to handle the correct frame type (CAN / CAN FD) */
 643         if (skb->len != op->cfsiz)
 644                 return;
 645 
 646         /* disable timeout */
 647         hrtimer_cancel(&op->timer);
 648 
 649         /* save rx timestamp */
 650         op->rx_stamp = skb->tstamp;
 651         /* save originator for recvfrom() */
 652         op->rx_ifindex = skb->dev->ifindex;
 653         /* update statistics */
 654         op->frames_abs++;
 655 
 656         if (op->flags & RX_RTR_FRAME) {
 657                 /* send reply for RTR-request (placed in op->frames[0]) */
 658                 bcm_can_tx(op);
 659                 return;
 660         }
 661 
 662         if (op->flags & RX_FILTER_ID) {
 663                 /* the easiest case */
 664                 bcm_rx_update_and_send(op, op->last_frames, rxframe);
 665                 goto rx_starttimer;
 666         }
 667 
 668         if (op->nframes == 1) {
 669                 /* simple compare with index 0 */
 670                 bcm_rx_cmp_to_index(op, 0, rxframe);
 671                 goto rx_starttimer;
 672         }
 673 
 674         if (op->nframes > 1) {
 675                 /*
 676                  * multiplex compare
 677                  *
 678                  * find the first multiplex mask that fits.
 679                  * Remark: The MUX-mask is stored in index 0 - but only the
 680                  * first 64 bits of the frame data[] are relevant (CAN FD)
 681                  */
 682 
 683                 for (i = 1; i < op->nframes; i++) {
 684                         if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
 685                             (get_u64(op->frames, 0) &
 686                              get_u64(op->frames + op->cfsiz * i, 0))) {
 687                                 bcm_rx_cmp_to_index(op, i, rxframe);
 688                                 break;
 689                         }
 690                 }
 691         }
 692 
 693 rx_starttimer:
 694         bcm_rx_starttimer(op);
 695 }
 696 
 697 /*
 698  * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
 699  */
 700 static struct bcm_op *bcm_find_op(struct list_head *ops,
 701                                   struct bcm_msg_head *mh, int ifindex)
 702 {
 703         struct bcm_op *op;
 704 
 705         list_for_each_entry(op, ops, list) {
 706                 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 707                     (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
 708                         return op;
 709         }
 710 
 711         return NULL;
 712 }
 713 
 714 static void bcm_remove_op(struct bcm_op *op)
 715 {
 716         hrtimer_cancel(&op->timer);
 717         hrtimer_cancel(&op->thrtimer);
 718 
 719         if ((op->frames) && (op->frames != &op->sframe))
 720                 kfree(op->frames);
 721 
 722         if ((op->last_frames) && (op->last_frames != &op->last_sframe))
 723                 kfree(op->last_frames);
 724 
 725         kfree(op);
 726 }
 727 
 728 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
 729 {
 730         if (op->rx_reg_dev == dev) {
 731                 can_rx_unregister(dev_net(dev), dev, op->can_id,
 732                                   REGMASK(op->can_id), bcm_rx_handler, op);
 733 
 734                 /* mark as removed subscription */
 735                 op->rx_reg_dev = NULL;
 736         } else
 737                 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
 738                        "mismatch %p %p\n", op->rx_reg_dev, dev);
 739 }
 740 
 741 /*
 742  * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
 743  */
 744 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
 745                             int ifindex)
 746 {
 747         struct bcm_op *op, *n;
 748 
 749         list_for_each_entry_safe(op, n, ops, list) {
 750                 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 751                     (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
 752 
 753                         /*
 754                          * Don't care if we're bound or not (due to netdev
 755                          * problems) can_rx_unregister() is always a save
 756                          * thing to do here.
 757                          */
 758                         if (op->ifindex) {
 759                                 /*
 760                                  * Only remove subscriptions that had not
 761                                  * been removed due to NETDEV_UNREGISTER
 762                                  * in bcm_notifier()
 763                                  */
 764                                 if (op->rx_reg_dev) {
 765                                         struct net_device *dev;
 766 
 767                                         dev = dev_get_by_index(sock_net(op->sk),
 768                                                                op->ifindex);
 769                                         if (dev) {
 770                                                 bcm_rx_unreg(dev, op);
 771                                                 dev_put(dev);
 772                                         }
 773                                 }
 774                         } else
 775                                 can_rx_unregister(sock_net(op->sk), NULL,
 776                                                   op->can_id,
 777                                                   REGMASK(op->can_id),
 778                                                   bcm_rx_handler, op);
 779 
 780                         list_del(&op->list);
 781                         bcm_remove_op(op);
 782                         return 1; /* done */
 783                 }
 784         }
 785 
 786         return 0; /* not found */
 787 }
 788 
 789 /*
 790  * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
 791  */
 792 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
 793                             int ifindex)
 794 {
 795         struct bcm_op *op, *n;
 796 
 797         list_for_each_entry_safe(op, n, ops, list) {
 798                 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
 799                     (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
 800                         list_del(&op->list);
 801                         bcm_remove_op(op);
 802                         return 1; /* done */
 803                 }
 804         }
 805 
 806         return 0; /* not found */
 807 }
 808 
 809 /*
 810  * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
 811  */
 812 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
 813                        int ifindex)
 814 {
 815         struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
 816 
 817         if (!op)
 818                 return -EINVAL;
 819 
 820         /* put current values into msg_head */
 821         msg_head->flags   = op->flags;
 822         msg_head->count   = op->count;
 823         msg_head->ival1   = op->ival1;
 824         msg_head->ival2   = op->ival2;
 825         msg_head->nframes = op->nframes;
 826 
 827         bcm_send_to_user(op, msg_head, op->frames, 0);
 828 
 829         return MHSIZ;
 830 }
 831 
 832 /*
 833  * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
 834  */
 835 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
 836                         int ifindex, struct sock *sk)
 837 {
 838         struct bcm_sock *bo = bcm_sk(sk);
 839         struct bcm_op *op;
 840         struct canfd_frame *cf;
 841         unsigned int i;
 842         int err;
 843 
 844         /* we need a real device to send frames */
 845         if (!ifindex)
 846                 return -ENODEV;
 847 
 848         /* check nframes boundaries - we need at least one CAN frame */
 849         if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
 850                 return -EINVAL;
 851 
 852         /* check timeval limitations */
 853         if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
 854                 return -EINVAL;
 855 
 856         /* check the given can_id */
 857         op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
 858         if (op) {
 859                 /* update existing BCM operation */
 860 
 861                 /*
 862                  * Do we need more space for the CAN frames than currently
 863                  * allocated? -> This is a _really_ unusual use-case and
 864                  * therefore (complexity / locking) it is not supported.
 865                  */
 866                 if (msg_head->nframes > op->nframes)
 867                         return -E2BIG;
 868 
 869                 /* update CAN frames content */
 870                 for (i = 0; i < msg_head->nframes; i++) {
 871 
 872                         cf = op->frames + op->cfsiz * i;
 873                         err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
 874 
 875                         if (op->flags & CAN_FD_FRAME) {
 876                                 if (cf->len > 64)
 877                                         err = -EINVAL;
 878                         } else {
 879                                 if (cf->len > 8)
 880                                         err = -EINVAL;
 881                         }
 882 
 883                         if (err < 0)
 884                                 return err;
 885 
 886                         if (msg_head->flags & TX_CP_CAN_ID) {
 887                                 /* copy can_id into frame */
 888                                 cf->can_id = msg_head->can_id;
 889                         }
 890                 }
 891                 op->flags = msg_head->flags;
 892 
 893         } else {
 894                 /* insert new BCM operation for the given can_id */
 895 
 896                 op = kzalloc(OPSIZ, GFP_KERNEL);
 897                 if (!op)
 898                         return -ENOMEM;
 899 
 900                 op->can_id = msg_head->can_id;
 901                 op->cfsiz = CFSIZ(msg_head->flags);
 902                 op->flags = msg_head->flags;
 903 
 904                 /* create array for CAN frames and copy the data */
 905                 if (msg_head->nframes > 1) {
 906                         op->frames = kmalloc_array(msg_head->nframes,
 907                                                    op->cfsiz,
 908                                                    GFP_KERNEL);
 909                         if (!op->frames) {
 910                                 kfree(op);
 911                                 return -ENOMEM;
 912                         }
 913                 } else
 914                         op->frames = &op->sframe;
 915 
 916                 for (i = 0; i < msg_head->nframes; i++) {
 917 
 918                         cf = op->frames + op->cfsiz * i;
 919                         err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
 920 
 921                         if (op->flags & CAN_FD_FRAME) {
 922                                 if (cf->len > 64)
 923                                         err = -EINVAL;
 924                         } else {
 925                                 if (cf->len > 8)
 926                                         err = -EINVAL;
 927                         }
 928 
 929                         if (err < 0) {
 930                                 if (op->frames != &op->sframe)
 931                                         kfree(op->frames);
 932                                 kfree(op);
 933                                 return err;
 934                         }
 935 
 936                         if (msg_head->flags & TX_CP_CAN_ID) {
 937                                 /* copy can_id into frame */
 938                                 cf->can_id = msg_head->can_id;
 939                         }
 940                 }
 941 
 942                 /* tx_ops never compare with previous received messages */
 943                 op->last_frames = NULL;
 944 
 945                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
 946                 op->sk = sk;
 947                 op->ifindex = ifindex;
 948 
 949                 /* initialize uninitialized (kzalloc) structure */
 950                 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
 951                              HRTIMER_MODE_REL_SOFT);
 952                 op->timer.function = bcm_tx_timeout_handler;
 953 
 954                 /* currently unused in tx_ops */
 955                 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
 956                              HRTIMER_MODE_REL_SOFT);
 957 
 958                 /* add this bcm_op to the list of the tx_ops */
 959                 list_add(&op->list, &bo->tx_ops);
 960 
 961         } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
 962 
 963         if (op->nframes != msg_head->nframes) {
 964                 op->nframes   = msg_head->nframes;
 965                 /* start multiple frame transmission with index 0 */
 966                 op->currframe = 0;
 967         }
 968 
 969         /* check flags */
 970 
 971         if (op->flags & TX_RESET_MULTI_IDX) {
 972                 /* start multiple frame transmission with index 0 */
 973                 op->currframe = 0;
 974         }
 975 
 976         if (op->flags & SETTIMER) {
 977                 /* set timer values */
 978                 op->count = msg_head->count;
 979                 op->ival1 = msg_head->ival1;
 980                 op->ival2 = msg_head->ival2;
 981                 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
 982                 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
 983 
 984                 /* disable an active timer due to zero values? */
 985                 if (!op->kt_ival1 && !op->kt_ival2)
 986                         hrtimer_cancel(&op->timer);
 987         }
 988 
 989         if (op->flags & STARTTIMER) {
 990                 hrtimer_cancel(&op->timer);
 991                 /* spec: send CAN frame when starting timer */
 992                 op->flags |= TX_ANNOUNCE;
 993         }
 994 
 995         if (op->flags & TX_ANNOUNCE) {
 996                 bcm_can_tx(op);
 997                 if (op->count)
 998                         op->count--;
 999         }
1000 
1001         if (op->flags & STARTTIMER)
1002                 bcm_tx_start_timer(op);
1003 
1004         return msg_head->nframes * op->cfsiz + MHSIZ;
1005 }
1006 
1007 /*
1008  * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1009  */
1010 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1011                         int ifindex, struct sock *sk)
1012 {
1013         struct bcm_sock *bo = bcm_sk(sk);
1014         struct bcm_op *op;
1015         int do_rx_register;
1016         int err = 0;
1017 
1018         if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1019                 /* be robust against wrong usage ... */
1020                 msg_head->flags |= RX_FILTER_ID;
1021                 /* ignore trailing garbage */
1022                 msg_head->nframes = 0;
1023         }
1024 
1025         /* the first element contains the mux-mask => MAX_NFRAMES + 1  */
1026         if (msg_head->nframes > MAX_NFRAMES + 1)
1027                 return -EINVAL;
1028 
1029         if ((msg_head->flags & RX_RTR_FRAME) &&
1030             ((msg_head->nframes != 1) ||
1031              (!(msg_head->can_id & CAN_RTR_FLAG))))
1032                 return -EINVAL;
1033 
1034         /* check timeval limitations */
1035         if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
1036                 return -EINVAL;
1037 
1038         /* check the given can_id */
1039         op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1040         if (op) {
1041                 /* update existing BCM operation */
1042 
1043                 /*
1044                  * Do we need more space for the CAN frames than currently
1045                  * allocated? -> This is a _really_ unusual use-case and
1046                  * therefore (complexity / locking) it is not supported.
1047                  */
1048                 if (msg_head->nframes > op->nframes)
1049                         return -E2BIG;
1050 
1051                 if (msg_head->nframes) {
1052                         /* update CAN frames content */
1053                         err = memcpy_from_msg(op->frames, msg,
1054                                               msg_head->nframes * op->cfsiz);
1055                         if (err < 0)
1056                                 return err;
1057 
1058                         /* clear last_frames to indicate 'nothing received' */
1059                         memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1060                 }
1061 
1062                 op->nframes = msg_head->nframes;
1063                 op->flags = msg_head->flags;
1064 
1065                 /* Only an update -> do not call can_rx_register() */
1066                 do_rx_register = 0;
1067 
1068         } else {
1069                 /* insert new BCM operation for the given can_id */
1070                 op = kzalloc(OPSIZ, GFP_KERNEL);
1071                 if (!op)
1072                         return -ENOMEM;
1073 
1074                 op->can_id = msg_head->can_id;
1075                 op->nframes = msg_head->nframes;
1076                 op->cfsiz = CFSIZ(msg_head->flags);
1077                 op->flags = msg_head->flags;
1078 
1079                 if (msg_head->nframes > 1) {
1080                         /* create array for CAN frames and copy the data */
1081                         op->frames = kmalloc_array(msg_head->nframes,
1082                                                    op->cfsiz,
1083                                                    GFP_KERNEL);
1084                         if (!op->frames) {
1085                                 kfree(op);
1086                                 return -ENOMEM;
1087                         }
1088 
1089                         /* create and init array for received CAN frames */
1090                         op->last_frames = kcalloc(msg_head->nframes,
1091                                                   op->cfsiz,
1092                                                   GFP_KERNEL);
1093                         if (!op->last_frames) {
1094                                 kfree(op->frames);
1095                                 kfree(op);
1096                                 return -ENOMEM;
1097                         }
1098 
1099                 } else {
1100                         op->frames = &op->sframe;
1101                         op->last_frames = &op->last_sframe;
1102                 }
1103 
1104                 if (msg_head->nframes) {
1105                         err = memcpy_from_msg(op->frames, msg,
1106                                               msg_head->nframes * op->cfsiz);
1107                         if (err < 0) {
1108                                 if (op->frames != &op->sframe)
1109                                         kfree(op->frames);
1110                                 if (op->last_frames != &op->last_sframe)
1111                                         kfree(op->last_frames);
1112                                 kfree(op);
1113                                 return err;
1114                         }
1115                 }
1116 
1117                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1118                 op->sk = sk;
1119                 op->ifindex = ifindex;
1120 
1121                 /* ifindex for timeout events w/o previous frame reception */
1122                 op->rx_ifindex = ifindex;
1123 
1124                 /* initialize uninitialized (kzalloc) structure */
1125                 hrtimer_init(&op->timer, CLOCK_MONOTONIC,
1126                              HRTIMER_MODE_REL_SOFT);
1127                 op->timer.function = bcm_rx_timeout_handler;
1128 
1129                 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
1130                              HRTIMER_MODE_REL_SOFT);
1131                 op->thrtimer.function = bcm_rx_thr_handler;
1132 
1133                 /* add this bcm_op to the list of the rx_ops */
1134                 list_add(&op->list, &bo->rx_ops);
1135 
1136                 /* call can_rx_register() */
1137                 do_rx_register = 1;
1138 
1139         } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1140 
1141         /* check flags */
1142 
1143         if (op->flags & RX_RTR_FRAME) {
1144                 struct canfd_frame *frame0 = op->frames;
1145 
1146                 /* no timers in RTR-mode */
1147                 hrtimer_cancel(&op->thrtimer);
1148                 hrtimer_cancel(&op->timer);
1149 
1150                 /*
1151                  * funny feature in RX(!)_SETUP only for RTR-mode:
1152                  * copy can_id into frame BUT without RTR-flag to
1153                  * prevent a full-load-loopback-test ... ;-]
1154                  */
1155                 if ((op->flags & TX_CP_CAN_ID) ||
1156                     (frame0->can_id == op->can_id))
1157                         frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1158 
1159         } else {
1160                 if (op->flags & SETTIMER) {
1161 
1162                         /* set timer value */
1163                         op->ival1 = msg_head->ival1;
1164                         op->ival2 = msg_head->ival2;
1165                         op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1166                         op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1167 
1168                         /* disable an active timer due to zero value? */
1169                         if (!op->kt_ival1)
1170                                 hrtimer_cancel(&op->timer);
1171 
1172                         /*
1173                          * In any case cancel the throttle timer, flush
1174                          * potentially blocked msgs and reset throttle handling
1175                          */
1176                         op->kt_lastmsg = 0;
1177                         hrtimer_cancel(&op->thrtimer);
1178                         bcm_rx_thr_flush(op);
1179                 }
1180 
1181                 if ((op->flags & STARTTIMER) && op->kt_ival1)
1182                         hrtimer_start(&op->timer, op->kt_ival1,
1183                                       HRTIMER_MODE_REL_SOFT);
1184         }
1185 
1186         /* now we can register for can_ids, if we added a new bcm_op */
1187         if (do_rx_register) {
1188                 if (ifindex) {
1189                         struct net_device *dev;
1190 
1191                         dev = dev_get_by_index(sock_net(sk), ifindex);
1192                         if (dev) {
1193                                 err = can_rx_register(sock_net(sk), dev,
1194                                                       op->can_id,
1195                                                       REGMASK(op->can_id),
1196                                                       bcm_rx_handler, op,
1197                                                       "bcm", sk);
1198 
1199                                 op->rx_reg_dev = dev;
1200                                 dev_put(dev);
1201                         }
1202 
1203                 } else
1204                         err = can_rx_register(sock_net(sk), NULL, op->can_id,
1205                                               REGMASK(op->can_id),
1206                                               bcm_rx_handler, op, "bcm", sk);
1207                 if (err) {
1208                         /* this bcm rx op is broken -> remove it */
1209                         list_del(&op->list);
1210                         bcm_remove_op(op);
1211                         return err;
1212                 }
1213         }
1214 
1215         return msg_head->nframes * op->cfsiz + MHSIZ;
1216 }
1217 
1218 /*
1219  * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1220  */
1221 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1222                        int cfsiz)
1223 {
1224         struct sk_buff *skb;
1225         struct net_device *dev;
1226         int err;
1227 
1228         /* we need a real device to send frames */
1229         if (!ifindex)
1230                 return -ENODEV;
1231 
1232         skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1233         if (!skb)
1234                 return -ENOMEM;
1235 
1236         can_skb_reserve(skb);
1237 
1238         err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1239         if (err < 0) {
1240                 kfree_skb(skb);
1241                 return err;
1242         }
1243 
1244         dev = dev_get_by_index(sock_net(sk), ifindex);
1245         if (!dev) {
1246                 kfree_skb(skb);
1247                 return -ENODEV;
1248         }
1249 
1250         can_skb_prv(skb)->ifindex = dev->ifindex;
1251         can_skb_prv(skb)->skbcnt = 0;
1252         skb->dev = dev;
1253         can_skb_set_owner(skb, sk);
1254         err = can_send(skb, 1); /* send with loopback */
1255         dev_put(dev);
1256 
1257         if (err)
1258                 return err;
1259 
1260         return cfsiz + MHSIZ;
1261 }
1262 
1263 /*
1264  * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1265  */
1266 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1267 {
1268         struct sock *sk = sock->sk;
1269         struct bcm_sock *bo = bcm_sk(sk);
1270         int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1271         struct bcm_msg_head msg_head;
1272         int cfsiz;
1273         int ret; /* read bytes or error codes as return value */
1274 
1275         if (!bo->bound)
1276                 return -ENOTCONN;
1277 
1278         /* check for valid message length from userspace */
1279         if (size < MHSIZ)
1280                 return -EINVAL;
1281 
1282         /* read message head information */
1283         ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1284         if (ret < 0)
1285                 return ret;
1286 
1287         cfsiz = CFSIZ(msg_head.flags);
1288         if ((size - MHSIZ) % cfsiz)
1289                 return -EINVAL;
1290 
1291         /* check for alternative ifindex for this bcm_op */
1292 
1293         if (!ifindex && msg->msg_name) {
1294                 /* no bound device as default => check msg_name */
1295                 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1296 
1297                 if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex))
1298                         return -EINVAL;
1299 
1300                 if (addr->can_family != AF_CAN)
1301                         return -EINVAL;
1302 
1303                 /* ifindex from sendto() */
1304                 ifindex = addr->can_ifindex;
1305 
1306                 if (ifindex) {
1307                         struct net_device *dev;
1308 
1309                         dev = dev_get_by_index(sock_net(sk), ifindex);
1310                         if (!dev)
1311                                 return -ENODEV;
1312 
1313                         if (dev->type != ARPHRD_CAN) {
1314                                 dev_put(dev);
1315                                 return -ENODEV;
1316                         }
1317 
1318                         dev_put(dev);
1319                 }
1320         }
1321 
1322         lock_sock(sk);
1323 
1324         switch (msg_head.opcode) {
1325 
1326         case TX_SETUP:
1327                 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1328                 break;
1329 
1330         case RX_SETUP:
1331                 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1332                 break;
1333 
1334         case TX_DELETE:
1335                 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1336                         ret = MHSIZ;
1337                 else
1338                         ret = -EINVAL;
1339                 break;
1340 
1341         case RX_DELETE:
1342                 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1343                         ret = MHSIZ;
1344                 else
1345                         ret = -EINVAL;
1346                 break;
1347 
1348         case TX_READ:
1349                 /* reuse msg_head for the reply to TX_READ */
1350                 msg_head.opcode  = TX_STATUS;
1351                 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1352                 break;
1353 
1354         case RX_READ:
1355                 /* reuse msg_head for the reply to RX_READ */
1356                 msg_head.opcode  = RX_STATUS;
1357                 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1358                 break;
1359 
1360         case TX_SEND:
1361                 /* we need exactly one CAN frame behind the msg head */
1362                 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1363                         ret = -EINVAL;
1364                 else
1365                         ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1366                 break;
1367 
1368         default:
1369                 ret = -EINVAL;
1370                 break;
1371         }
1372 
1373         release_sock(sk);
1374 
1375         return ret;
1376 }
1377 
1378 /*
1379  * notification handler for netdevice status changes
1380  */
1381 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1382                         void *ptr)
1383 {
1384         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1385         struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1386         struct sock *sk = &bo->sk;
1387         struct bcm_op *op;
1388         int notify_enodev = 0;
1389 
1390         if (!net_eq(dev_net(dev), sock_net(sk)))
1391                 return NOTIFY_DONE;
1392 
1393         if (dev->type != ARPHRD_CAN)
1394                 return NOTIFY_DONE;
1395 
1396         switch (msg) {
1397 
1398         case NETDEV_UNREGISTER:
1399                 lock_sock(sk);
1400 
1401                 /* remove device specific receive entries */
1402                 list_for_each_entry(op, &bo->rx_ops, list)
1403                         if (op->rx_reg_dev == dev)
1404                                 bcm_rx_unreg(dev, op);
1405 
1406                 /* remove device reference, if this is our bound device */
1407                 if (bo->bound && bo->ifindex == dev->ifindex) {
1408                         bo->bound   = 0;
1409                         bo->ifindex = 0;
1410                         notify_enodev = 1;
1411                 }
1412 
1413                 release_sock(sk);
1414 
1415                 if (notify_enodev) {
1416                         sk->sk_err = ENODEV;
1417                         if (!sock_flag(sk, SOCK_DEAD))
1418                                 sk->sk_error_report(sk);
1419                 }
1420                 break;
1421 
1422         case NETDEV_DOWN:
1423                 if (bo->bound && bo->ifindex == dev->ifindex) {
1424                         sk->sk_err = ENETDOWN;
1425                         if (!sock_flag(sk, SOCK_DEAD))
1426                                 sk->sk_error_report(sk);
1427                 }
1428         }
1429 
1430         return NOTIFY_DONE;
1431 }
1432 
1433 /*
1434  * initial settings for all BCM sockets to be set at socket creation time
1435  */
1436 static int bcm_init(struct sock *sk)
1437 {
1438         struct bcm_sock *bo = bcm_sk(sk);
1439 
1440         bo->bound            = 0;
1441         bo->ifindex          = 0;
1442         bo->dropped_usr_msgs = 0;
1443         bo->bcm_proc_read    = NULL;
1444 
1445         INIT_LIST_HEAD(&bo->tx_ops);
1446         INIT_LIST_HEAD(&bo->rx_ops);
1447 
1448         /* set notifier */
1449         bo->notifier.notifier_call = bcm_notifier;
1450 
1451         register_netdevice_notifier(&bo->notifier);
1452 
1453         return 0;
1454 }
1455 
1456 /*
1457  * standard socket functions
1458  */
1459 static int bcm_release(struct socket *sock)
1460 {
1461         struct sock *sk = sock->sk;
1462         struct net *net;
1463         struct bcm_sock *bo;
1464         struct bcm_op *op, *next;
1465 
1466         if (!sk)
1467                 return 0;
1468 
1469         net = sock_net(sk);
1470         bo = bcm_sk(sk);
1471 
1472         /* remove bcm_ops, timer, rx_unregister(), etc. */
1473 
1474         unregister_netdevice_notifier(&bo->notifier);
1475 
1476         lock_sock(sk);
1477 
1478         list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1479                 bcm_remove_op(op);
1480 
1481         list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1482                 /*
1483                  * Don't care if we're bound or not (due to netdev problems)
1484                  * can_rx_unregister() is always a save thing to do here.
1485                  */
1486                 if (op->ifindex) {
1487                         /*
1488                          * Only remove subscriptions that had not
1489                          * been removed due to NETDEV_UNREGISTER
1490                          * in bcm_notifier()
1491                          */
1492                         if (op->rx_reg_dev) {
1493                                 struct net_device *dev;
1494 
1495                                 dev = dev_get_by_index(net, op->ifindex);
1496                                 if (dev) {
1497                                         bcm_rx_unreg(dev, op);
1498                                         dev_put(dev);
1499                                 }
1500                         }
1501                 } else
1502                         can_rx_unregister(net, NULL, op->can_id,
1503                                           REGMASK(op->can_id),
1504                                           bcm_rx_handler, op);
1505 
1506                 bcm_remove_op(op);
1507         }
1508 
1509 #if IS_ENABLED(CONFIG_PROC_FS)
1510         /* remove procfs entry */
1511         if (net->can.bcmproc_dir && bo->bcm_proc_read)
1512                 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1513 #endif /* CONFIG_PROC_FS */
1514 
1515         /* remove device reference */
1516         if (bo->bound) {
1517                 bo->bound   = 0;
1518                 bo->ifindex = 0;
1519         }
1520 
1521         sock_orphan(sk);
1522         sock->sk = NULL;
1523 
1524         release_sock(sk);
1525         sock_put(sk);
1526 
1527         return 0;
1528 }
1529 
1530 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1531                        int flags)
1532 {
1533         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1534         struct sock *sk = sock->sk;
1535         struct bcm_sock *bo = bcm_sk(sk);
1536         struct net *net = sock_net(sk);
1537         int ret = 0;
1538 
1539         if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex))
1540                 return -EINVAL;
1541 
1542         lock_sock(sk);
1543 
1544         if (bo->bound) {
1545                 ret = -EISCONN;
1546                 goto fail;
1547         }
1548 
1549         /* bind a device to this socket */
1550         if (addr->can_ifindex) {
1551                 struct net_device *dev;
1552 
1553                 dev = dev_get_by_index(net, addr->can_ifindex);
1554                 if (!dev) {
1555                         ret = -ENODEV;
1556                         goto fail;
1557                 }
1558                 if (dev->type != ARPHRD_CAN) {
1559                         dev_put(dev);
1560                         ret = -ENODEV;
1561                         goto fail;
1562                 }
1563 
1564                 bo->ifindex = dev->ifindex;
1565                 dev_put(dev);
1566 
1567         } else {
1568                 /* no interface reference for ifindex = 0 ('any' CAN device) */
1569                 bo->ifindex = 0;
1570         }
1571 
1572 #if IS_ENABLED(CONFIG_PROC_FS)
1573         if (net->can.bcmproc_dir) {
1574                 /* unique socket address as filename */
1575                 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1576                 bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
1577                                                      net->can.bcmproc_dir,
1578                                                      bcm_proc_show, sk);
1579                 if (!bo->bcm_proc_read) {
1580                         ret = -ENOMEM;
1581                         goto fail;
1582                 }
1583         }
1584 #endif /* CONFIG_PROC_FS */
1585 
1586         bo->bound = 1;
1587 
1588 fail:
1589         release_sock(sk);
1590 
1591         return ret;
1592 }
1593 
1594 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1595                        int flags)
1596 {
1597         struct sock *sk = sock->sk;
1598         struct sk_buff *skb;
1599         int error = 0;
1600         int noblock;
1601         int err;
1602 
1603         noblock =  flags & MSG_DONTWAIT;
1604         flags   &= ~MSG_DONTWAIT;
1605         skb = skb_recv_datagram(sk, flags, noblock, &error);
1606         if (!skb)
1607                 return error;
1608 
1609         if (skb->len < size)
1610                 size = skb->len;
1611 
1612         err = memcpy_to_msg(msg, skb->data, size);
1613         if (err < 0) {
1614                 skb_free_datagram(sk, skb);
1615                 return err;
1616         }
1617 
1618         sock_recv_ts_and_drops(msg, sk, skb);
1619 
1620         if (msg->msg_name) {
1621                 __sockaddr_check_size(sizeof(struct sockaddr_can));
1622                 msg->msg_namelen = sizeof(struct sockaddr_can);
1623                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1624         }
1625 
1626         skb_free_datagram(sk, skb);
1627 
1628         return size;
1629 }
1630 
1631 static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1632                                 unsigned long arg)
1633 {
1634         /* no ioctls for socket layer -> hand it down to NIC layer */
1635         return -ENOIOCTLCMD;
1636 }
1637 
1638 static const struct proto_ops bcm_ops = {
1639         .family        = PF_CAN,
1640         .release       = bcm_release,
1641         .bind          = sock_no_bind,
1642         .connect       = bcm_connect,
1643         .socketpair    = sock_no_socketpair,
1644         .accept        = sock_no_accept,
1645         .getname       = sock_no_getname,
1646         .poll          = datagram_poll,
1647         .ioctl         = bcm_sock_no_ioctlcmd,
1648         .gettstamp     = sock_gettstamp,
1649         .listen        = sock_no_listen,
1650         .shutdown      = sock_no_shutdown,
1651         .setsockopt    = sock_no_setsockopt,
1652         .getsockopt    = sock_no_getsockopt,
1653         .sendmsg       = bcm_sendmsg,
1654         .recvmsg       = bcm_recvmsg,
1655         .mmap          = sock_no_mmap,
1656         .sendpage      = sock_no_sendpage,
1657 };
1658 
1659 static struct proto bcm_proto __read_mostly = {
1660         .name       = "CAN_BCM",
1661         .owner      = THIS_MODULE,
1662         .obj_size   = sizeof(struct bcm_sock),
1663         .init       = bcm_init,
1664 };
1665 
1666 static const struct can_proto bcm_can_proto = {
1667         .type       = SOCK_DGRAM,
1668         .protocol   = CAN_BCM,
1669         .ops        = &bcm_ops,
1670         .prot       = &bcm_proto,
1671 };
1672 
1673 static int canbcm_pernet_init(struct net *net)
1674 {
1675 #if IS_ENABLED(CONFIG_PROC_FS)
1676         /* create /proc/net/can-bcm directory */
1677         net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1678 #endif /* CONFIG_PROC_FS */
1679 
1680         return 0;
1681 }
1682 
1683 static void canbcm_pernet_exit(struct net *net)
1684 {
1685 #if IS_ENABLED(CONFIG_PROC_FS)
1686         /* remove /proc/net/can-bcm directory */
1687         if (net->can.bcmproc_dir)
1688                 remove_proc_entry("can-bcm", net->proc_net);
1689 #endif /* CONFIG_PROC_FS */
1690 }
1691 
1692 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1693         .init = canbcm_pernet_init,
1694         .exit = canbcm_pernet_exit,
1695 };
1696 
1697 static int __init bcm_module_init(void)
1698 {
1699         int err;
1700 
1701         pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1702 
1703         err = can_proto_register(&bcm_can_proto);
1704         if (err < 0) {
1705                 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1706                 return err;
1707         }
1708 
1709         register_pernet_subsys(&canbcm_pernet_ops);
1710         return 0;
1711 }
1712 
1713 static void __exit bcm_module_exit(void)
1714 {
1715         can_proto_unregister(&bcm_can_proto);
1716         unregister_pernet_subsys(&canbcm_pernet_ops);
1717 }
1718 
1719 module_init(bcm_module_init);
1720 module_exit(bcm_module_exit);
/* [<][>][^][v][top][bottom][index][help] */
root/net/can/bcm.c

DEFINITIONS
