linux/net/can/isotp.c
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   1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2/* isotp.c - ISO 15765-2 CAN transport protocol for protocol family CAN
   3 *
   4 * This implementation does not provide ISO-TP specific return values to the
   5 * userspace.
   6 *
   7 * - RX path timeout of data reception leads to -ETIMEDOUT
   8 * - RX path SN mismatch leads to -EILSEQ
   9 * - RX path data reception with wrong padding leads to -EBADMSG
  10 * - TX path flowcontrol reception timeout leads to -ECOMM
  11 * - TX path flowcontrol reception overflow leads to -EMSGSIZE
  12 * - TX path flowcontrol reception with wrong layout/padding leads to -EBADMSG
  13 * - when a transfer (tx) is on the run the next write() blocks until it's done
  14 * - use CAN_ISOTP_WAIT_TX_DONE flag to block the caller until the PDU is sent
  15 * - as we have static buffers the check whether the PDU fits into the buffer
  16 *   is done at FF reception time (no support for sending 'wait frames')
  17 * - take care of the tx-queue-len as traffic shaping is still on the TODO list
  18 *
  19 * Copyright (c) 2020 Volkswagen Group Electronic Research
  20 * All rights reserved.
  21 *
  22 * Redistribution and use in source and binary forms, with or without
  23 * modification, are permitted provided that the following conditions
  24 * are met:
  25 * 1. Redistributions of source code must retain the above copyright
  26 *    notice, this list of conditions and the following disclaimer.
  27 * 2. Redistributions in binary form must reproduce the above copyright
  28 *    notice, this list of conditions and the following disclaimer in the
  29 *    documentation and/or other materials provided with the distribution.
  30 * 3. Neither the name of Volkswagen nor the names of its contributors
  31 *    may be used to endorse or promote products derived from this software
  32 *    without specific prior written permission.
  33 *
  34 * Alternatively, provided that this notice is retained in full, this
  35 * software may be distributed under the terms of the GNU General
  36 * Public License ("GPL") version 2, in which case the provisions of the
  37 * GPL apply INSTEAD OF those given above.
  38 *
  39 * The provided data structures and external interfaces from this code
  40 * are not restricted to be used by modules with a GPL compatible license.
  41 *
  42 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  43 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  44 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  45 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  46 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  47 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  48 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  49 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  50 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  51 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  52 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  53 * DAMAGE.
  54 */
  55
  56#include <linux/module.h>
  57#include <linux/init.h>
  58#include <linux/interrupt.h>
  59#include <linux/hrtimer.h>
  60#include <linux/wait.h>
  61#include <linux/uio.h>
  62#include <linux/net.h>
  63#include <linux/netdevice.h>
  64#include <linux/socket.h>
  65#include <linux/if_arp.h>
  66#include <linux/skbuff.h>
  67#include <linux/can.h>
  68#include <linux/can/core.h>
  69#include <linux/can/skb.h>
  70#include <linux/can/isotp.h>
  71#include <linux/slab.h>
  72#include <net/sock.h>
  73#include <net/net_namespace.h>
  74
  75MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
  76MODULE_LICENSE("Dual BSD/GPL");
  77MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
  78MODULE_ALIAS("can-proto-6");
  79
  80#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
  81
  82#define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
  83                         (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
  84                         (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
  85
  86/* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
  87 * take full 32 bit values (4 Gbyte). We would need some good concept to handle
  88 * this between user space and kernel space. For now increase the static buffer
  89 * to something about 8 kbyte to be able to test this new functionality.
  90 */
  91#define MAX_MSG_LENGTH 8200
  92
  93/* N_PCI type values in bits 7-4 of N_PCI bytes */
  94#define N_PCI_SF 0x00   /* single frame */
  95#define N_PCI_FF 0x10   /* first frame */
  96#define N_PCI_CF 0x20   /* consecutive frame */
  97#define N_PCI_FC 0x30   /* flow control */
  98
  99#define N_PCI_SZ 1      /* size of the PCI byte #1 */
 100#define SF_PCI_SZ4 1    /* size of SingleFrame PCI including 4 bit SF_DL */
 101#define SF_PCI_SZ8 2    /* size of SingleFrame PCI including 8 bit SF_DL */
 102#define FF_PCI_SZ12 2   /* size of FirstFrame PCI including 12 bit FF_DL */
 103#define FF_PCI_SZ32 6   /* size of FirstFrame PCI including 32 bit FF_DL */
 104#define FC_CONTENT_SZ 3 /* flow control content size in byte (FS/BS/STmin) */
 105
 106#define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
 107
 108/* Flow Status given in FC frame */
 109#define ISOTP_FC_CTS 0          /* clear to send */
 110#define ISOTP_FC_WT 1           /* wait */
 111#define ISOTP_FC_OVFLW 2        /* overflow */
 112
 113enum {
 114        ISOTP_IDLE = 0,
 115        ISOTP_WAIT_FIRST_FC,
 116        ISOTP_WAIT_FC,
 117        ISOTP_WAIT_DATA,
 118        ISOTP_SENDING
 119};
 120
 121struct tpcon {
 122        int idx;
 123        int len;
 124        u8 state;
 125        u8 bs;
 126        u8 sn;
 127        u8 ll_dl;
 128        u8 buf[MAX_MSG_LENGTH + 1];
 129};
 130
 131struct isotp_sock {
 132        struct sock sk;
 133        int bound;
 134        int ifindex;
 135        canid_t txid;
 136        canid_t rxid;
 137        ktime_t tx_gap;
 138        ktime_t lastrxcf_tstamp;
 139        struct hrtimer rxtimer, txtimer;
 140        struct can_isotp_options opt;
 141        struct can_isotp_fc_options rxfc, txfc;
 142        struct can_isotp_ll_options ll;
 143        u32 force_tx_stmin;
 144        u32 force_rx_stmin;
 145        struct tpcon rx, tx;
 146        struct list_head notifier;
 147        wait_queue_head_t wait;
 148};
 149
 150static LIST_HEAD(isotp_notifier_list);
 151static DEFINE_SPINLOCK(isotp_notifier_lock);
 152static struct isotp_sock *isotp_busy_notifier;
 153
 154static inline struct isotp_sock *isotp_sk(const struct sock *sk)
 155{
 156        return (struct isotp_sock *)sk;
 157}
 158
 159static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
 160{
 161        struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
 162                                             rxtimer);
 163        struct sock *sk = &so->sk;
 164
 165        if (so->rx.state == ISOTP_WAIT_DATA) {
 166                /* we did not get new data frames in time */
 167
 168                /* report 'connection timed out' */
 169                sk->sk_err = ETIMEDOUT;
 170                if (!sock_flag(sk, SOCK_DEAD))
 171                        sk_error_report(sk);
 172
 173                /* reset rx state */
 174                so->rx.state = ISOTP_IDLE;
 175        }
 176
 177        return HRTIMER_NORESTART;
 178}
 179
 180static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
 181{
 182        struct net_device *dev;
 183        struct sk_buff *nskb;
 184        struct canfd_frame *ncf;
 185        struct isotp_sock *so = isotp_sk(sk);
 186        int can_send_ret;
 187
 188        nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
 189        if (!nskb)
 190                return 1;
 191
 192        dev = dev_get_by_index(sock_net(sk), so->ifindex);
 193        if (!dev) {
 194                kfree_skb(nskb);
 195                return 1;
 196        }
 197
 198        can_skb_reserve(nskb);
 199        can_skb_prv(nskb)->ifindex = dev->ifindex;
 200        can_skb_prv(nskb)->skbcnt = 0;
 201
 202        nskb->dev = dev;
 203        can_skb_set_owner(nskb, sk);
 204        ncf = (struct canfd_frame *)nskb->data;
 205        skb_put_zero(nskb, so->ll.mtu);
 206
 207        /* create & send flow control reply */
 208        ncf->can_id = so->txid;
 209
 210        if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
 211                memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
 212                ncf->len = CAN_MAX_DLEN;
 213        } else {
 214                ncf->len = ae + FC_CONTENT_SZ;
 215        }
 216
 217        ncf->data[ae] = N_PCI_FC | flowstatus;
 218        ncf->data[ae + 1] = so->rxfc.bs;
 219        ncf->data[ae + 2] = so->rxfc.stmin;
 220
 221        if (ae)
 222                ncf->data[0] = so->opt.ext_address;
 223
 224        ncf->flags = so->ll.tx_flags;
 225
 226        can_send_ret = can_send(nskb, 1);
 227        if (can_send_ret)
 228                pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
 229                               __func__, ERR_PTR(can_send_ret));
 230
 231        dev_put(dev);
 232
 233        /* reset blocksize counter */
 234        so->rx.bs = 0;
 235
 236        /* reset last CF frame rx timestamp for rx stmin enforcement */
 237        so->lastrxcf_tstamp = ktime_set(0, 0);
 238
 239        /* start rx timeout watchdog */
 240        hrtimer_start(&so->rxtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
 241        return 0;
 242}
 243
 244static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
 245{
 246        struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
 247
 248        BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
 249
 250        memset(addr, 0, sizeof(*addr));
 251        addr->can_family = AF_CAN;
 252        addr->can_ifindex = skb->dev->ifindex;
 253
 254        if (sock_queue_rcv_skb(sk, skb) < 0)
 255                kfree_skb(skb);
 256}
 257
 258static u8 padlen(u8 datalen)
 259{
 260        static const u8 plen[] = {
 261                8, 8, 8, 8, 8, 8, 8, 8, 8,      /* 0 - 8 */
 262                12, 12, 12, 12,                 /* 9 - 12 */
 263                16, 16, 16, 16,                 /* 13 - 16 */
 264                20, 20, 20, 20,                 /* 17 - 20 */
 265                24, 24, 24, 24,                 /* 21 - 24 */
 266                32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
 267                48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
 268                48, 48, 48, 48, 48, 48, 48, 48  /* 41 - 48 */
 269        };
 270
 271        if (datalen > 48)
 272                return 64;
 273
 274        return plen[datalen];
 275}
 276
 277/* check for length optimization and return 1/true when the check fails */
 278static int check_optimized(struct canfd_frame *cf, int start_index)
 279{
 280        /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
 281         * padding would start at this point. E.g. if the padding would
 282         * start at cf.data[7] cf->len has to be 7 to be optimal.
 283         * Note: The data[] index starts with zero.
 284         */
 285        if (cf->len <= CAN_MAX_DLEN)
 286                return (cf->len != start_index);
 287
 288        /* This relation is also valid in the non-linear DLC range, where
 289         * we need to take care of the minimal next possible CAN_DL.
 290         * The correct check would be (padlen(cf->len) != padlen(start_index)).
 291         * But as cf->len can only take discrete values from 12, .., 64 at this
 292         * point the padlen(cf->len) is always equal to cf->len.
 293         */
 294        return (cf->len != padlen(start_index));
 295}
 296
 297/* check padding and return 1/true when the check fails */
 298static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
 299                     int start_index, u8 content)
 300{
 301        int i;
 302
 303        /* no RX_PADDING value => check length of optimized frame length */
 304        if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
 305                if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
 306                        return check_optimized(cf, start_index);
 307
 308                /* no valid test against empty value => ignore frame */
 309                return 1;
 310        }
 311
 312        /* check datalength of correctly padded CAN frame */
 313        if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
 314            cf->len != padlen(cf->len))
 315                return 1;
 316
 317        /* check padding content */
 318        if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
 319                for (i = start_index; i < cf->len; i++)
 320                        if (cf->data[i] != content)
 321                                return 1;
 322        }
 323        return 0;
 324}
 325
 326static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
 327{
 328        struct sock *sk = &so->sk;
 329
 330        if (so->tx.state != ISOTP_WAIT_FC &&
 331            so->tx.state != ISOTP_WAIT_FIRST_FC)
 332                return 0;
 333
 334        hrtimer_cancel(&so->txtimer);
 335
 336        if ((cf->len < ae + FC_CONTENT_SZ) ||
 337            ((so->opt.flags & ISOTP_CHECK_PADDING) &&
 338             check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
 339                /* malformed PDU - report 'not a data message' */
 340                sk->sk_err = EBADMSG;
 341                if (!sock_flag(sk, SOCK_DEAD))
 342                        sk_error_report(sk);
 343
 344                so->tx.state = ISOTP_IDLE;
 345                wake_up_interruptible(&so->wait);
 346                return 1;
 347        }
 348
 349        /* get communication parameters only from the first FC frame */
 350        if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
 351                so->txfc.bs = cf->data[ae + 1];
 352                so->txfc.stmin = cf->data[ae + 2];
 353
 354                /* fix wrong STmin values according spec */
 355                if (so->txfc.stmin > 0x7F &&
 356                    (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
 357                        so->txfc.stmin = 0x7F;
 358
 359                so->tx_gap = ktime_set(0, 0);
 360                /* add transmission time for CAN frame N_As */
 361                so->tx_gap = ktime_add_ns(so->tx_gap, so->opt.frame_txtime);
 362                /* add waiting time for consecutive frames N_Cs */
 363                if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
 364                        so->tx_gap = ktime_add_ns(so->tx_gap,
 365                                                  so->force_tx_stmin);
 366                else if (so->txfc.stmin < 0x80)
 367                        so->tx_gap = ktime_add_ns(so->tx_gap,
 368                                                  so->txfc.stmin * 1000000);
 369                else
 370                        so->tx_gap = ktime_add_ns(so->tx_gap,
 371                                                  (so->txfc.stmin - 0xF0)
 372                                                  * 100000);
 373                so->tx.state = ISOTP_WAIT_FC;
 374        }
 375
 376        switch (cf->data[ae] & 0x0F) {
 377        case ISOTP_FC_CTS:
 378                so->tx.bs = 0;
 379                so->tx.state = ISOTP_SENDING;
 380                /* start cyclic timer for sending CF frame */
 381                hrtimer_start(&so->txtimer, so->tx_gap,
 382                              HRTIMER_MODE_REL_SOFT);
 383                break;
 384
 385        case ISOTP_FC_WT:
 386                /* start timer to wait for next FC frame */
 387                hrtimer_start(&so->txtimer, ktime_set(1, 0),
 388                              HRTIMER_MODE_REL_SOFT);
 389                break;
 390
 391        case ISOTP_FC_OVFLW:
 392                /* overflow on receiver side - report 'message too long' */
 393                sk->sk_err = EMSGSIZE;
 394                if (!sock_flag(sk, SOCK_DEAD))
 395                        sk_error_report(sk);
 396                fallthrough;
 397
 398        default:
 399                /* stop this tx job */
 400                so->tx.state = ISOTP_IDLE;
 401                wake_up_interruptible(&so->wait);
 402        }
 403        return 0;
 404}
 405
 406static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
 407                        struct sk_buff *skb, int len)
 408{
 409        struct isotp_sock *so = isotp_sk(sk);
 410        struct sk_buff *nskb;
 411
 412        hrtimer_cancel(&so->rxtimer);
 413        so->rx.state = ISOTP_IDLE;
 414
 415        if (!len || len > cf->len - pcilen)
 416                return 1;
 417
 418        if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
 419            check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
 420                /* malformed PDU - report 'not a data message' */
 421                sk->sk_err = EBADMSG;
 422                if (!sock_flag(sk, SOCK_DEAD))
 423                        sk_error_report(sk);
 424                return 1;
 425        }
 426
 427        nskb = alloc_skb(len, gfp_any());
 428        if (!nskb)
 429                return 1;
 430
 431        memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
 432
 433        nskb->tstamp = skb->tstamp;
 434        nskb->dev = skb->dev;
 435        isotp_rcv_skb(nskb, sk);
 436        return 0;
 437}
 438
 439static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
 440{
 441        struct isotp_sock *so = isotp_sk(sk);
 442        int i;
 443        int off;
 444        int ff_pci_sz;
 445
 446        hrtimer_cancel(&so->rxtimer);
 447        so->rx.state = ISOTP_IDLE;
 448
 449        /* get the used sender LL_DL from the (first) CAN frame data length */
 450        so->rx.ll_dl = padlen(cf->len);
 451
 452        /* the first frame has to use the entire frame up to LL_DL length */
 453        if (cf->len != so->rx.ll_dl)
 454                return 1;
 455
 456        /* get the FF_DL */
 457        so->rx.len = (cf->data[ae] & 0x0F) << 8;
 458        so->rx.len += cf->data[ae + 1];
 459
 460        /* Check for FF_DL escape sequence supporting 32 bit PDU length */
 461        if (so->rx.len) {
 462                ff_pci_sz = FF_PCI_SZ12;
 463        } else {
 464                /* FF_DL = 0 => get real length from next 4 bytes */
 465                so->rx.len = cf->data[ae + 2] << 24;
 466                so->rx.len += cf->data[ae + 3] << 16;
 467                so->rx.len += cf->data[ae + 4] << 8;
 468                so->rx.len += cf->data[ae + 5];
 469                ff_pci_sz = FF_PCI_SZ32;
 470        }
 471
 472        /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
 473        off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
 474
 475        if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
 476                return 1;
 477
 478        if (so->rx.len > MAX_MSG_LENGTH) {
 479                /* send FC frame with overflow status */
 480                isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
 481                return 1;
 482        }
 483
 484        /* copy the first received data bytes */
 485        so->rx.idx = 0;
 486        for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
 487                so->rx.buf[so->rx.idx++] = cf->data[i];
 488
 489        /* initial setup for this pdu reception */
 490        so->rx.sn = 1;
 491        so->rx.state = ISOTP_WAIT_DATA;
 492
 493        /* no creation of flow control frames */
 494        if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
 495                return 0;
 496
 497        /* send our first FC frame */
 498        isotp_send_fc(sk, ae, ISOTP_FC_CTS);
 499        return 0;
 500}
 501
 502static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
 503                        struct sk_buff *skb)
 504{
 505        struct isotp_sock *so = isotp_sk(sk);
 506        struct sk_buff *nskb;
 507        int i;
 508
 509        if (so->rx.state != ISOTP_WAIT_DATA)
 510                return 0;
 511
 512        /* drop if timestamp gap is less than force_rx_stmin nano secs */
 513        if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
 514                if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
 515                    so->force_rx_stmin)
 516                        return 0;
 517
 518                so->lastrxcf_tstamp = skb->tstamp;
 519        }
 520
 521        hrtimer_cancel(&so->rxtimer);
 522
 523        /* CFs are never longer than the FF */
 524        if (cf->len > so->rx.ll_dl)
 525                return 1;
 526
 527        /* CFs have usually the LL_DL length */
 528        if (cf->len < so->rx.ll_dl) {
 529                /* this is only allowed for the last CF */
 530                if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
 531                        return 1;
 532        }
 533
 534        if ((cf->data[ae] & 0x0F) != so->rx.sn) {
 535                /* wrong sn detected - report 'illegal byte sequence' */
 536                sk->sk_err = EILSEQ;
 537                if (!sock_flag(sk, SOCK_DEAD))
 538                        sk_error_report(sk);
 539
 540                /* reset rx state */
 541                so->rx.state = ISOTP_IDLE;
 542                return 1;
 543        }
 544        so->rx.sn++;
 545        so->rx.sn %= 16;
 546
 547        for (i = ae + N_PCI_SZ; i < cf->len; i++) {
 548                so->rx.buf[so->rx.idx++] = cf->data[i];
 549                if (so->rx.idx >= so->rx.len)
 550                        break;
 551        }
 552
 553        if (so->rx.idx >= so->rx.len) {
 554                /* we are done */
 555                so->rx.state = ISOTP_IDLE;
 556
 557                if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
 558                    check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
 559                        /* malformed PDU - report 'not a data message' */
 560                        sk->sk_err = EBADMSG;
 561                        if (!sock_flag(sk, SOCK_DEAD))
 562                                sk_error_report(sk);
 563                        return 1;
 564                }
 565
 566                nskb = alloc_skb(so->rx.len, gfp_any());
 567                if (!nskb)
 568                        return 1;
 569
 570                memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
 571                       so->rx.len);
 572
 573                nskb->tstamp = skb->tstamp;
 574                nskb->dev = skb->dev;
 575                isotp_rcv_skb(nskb, sk);
 576                return 0;
 577        }
 578
 579        /* perform blocksize handling, if enabled */
 580        if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
 581                /* start rx timeout watchdog */
 582                hrtimer_start(&so->rxtimer, ktime_set(1, 0),
 583                              HRTIMER_MODE_REL_SOFT);
 584                return 0;
 585        }
 586
 587        /* no creation of flow control frames */
 588        if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
 589                return 0;
 590
 591        /* we reached the specified blocksize so->rxfc.bs */
 592        isotp_send_fc(sk, ae, ISOTP_FC_CTS);
 593        return 0;
 594}
 595
 596static void isotp_rcv(struct sk_buff *skb, void *data)
 597{
 598        struct sock *sk = (struct sock *)data;
 599        struct isotp_sock *so = isotp_sk(sk);
 600        struct canfd_frame *cf;
 601        int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
 602        u8 n_pci_type, sf_dl;
 603
 604        /* Strictly receive only frames with the configured MTU size
 605         * => clear separation of CAN2.0 / CAN FD transport channels
 606         */
 607        if (skb->len != so->ll.mtu)
 608                return;
 609
 610        cf = (struct canfd_frame *)skb->data;
 611
 612        /* if enabled: check reception of my configured extended address */
 613        if (ae && cf->data[0] != so->opt.rx_ext_address)
 614                return;
 615
 616        n_pci_type = cf->data[ae] & 0xF0;
 617
 618        if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
 619                /* check rx/tx path half duplex expectations */
 620                if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
 621                    (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
 622                        return;
 623        }
 624
 625        switch (n_pci_type) {
 626        case N_PCI_FC:
 627                /* tx path: flow control frame containing the FC parameters */
 628                isotp_rcv_fc(so, cf, ae);
 629                break;
 630
 631        case N_PCI_SF:
 632                /* rx path: single frame
 633                 *
 634                 * As we do not have a rx.ll_dl configuration, we can only test
 635                 * if the CAN frames payload length matches the LL_DL == 8
 636                 * requirements - no matter if it's CAN 2.0 or CAN FD
 637                 */
 638
 639                /* get the SF_DL from the N_PCI byte */
 640                sf_dl = cf->data[ae] & 0x0F;
 641
 642                if (cf->len <= CAN_MAX_DLEN) {
 643                        isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
 644                } else {
 645                        if (skb->len == CANFD_MTU) {
 646                                /* We have a CAN FD frame and CAN_DL is greater than 8:
 647                                 * Only frames with the SF_DL == 0 ESC value are valid.
 648                                 *
 649                                 * If so take care of the increased SF PCI size
 650                                 * (SF_PCI_SZ8) to point to the message content behind
 651                                 * the extended SF PCI info and get the real SF_DL
 652                                 * length value from the formerly first data byte.
 653                                 */
 654                                if (sf_dl == 0)
 655                                        isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
 656                                                     cf->data[SF_PCI_SZ4 + ae]);
 657                        }
 658                }
 659                break;
 660
 661        case N_PCI_FF:
 662                /* rx path: first frame */
 663                isotp_rcv_ff(sk, cf, ae);
 664                break;
 665
 666        case N_PCI_CF:
 667                /* rx path: consecutive frame */
 668                isotp_rcv_cf(sk, cf, ae, skb);
 669                break;
 670        }
 671}
 672
 673static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
 674                                 int ae, int off)
 675{
 676        int pcilen = N_PCI_SZ + ae + off;
 677        int space = so->tx.ll_dl - pcilen;
 678        int num = min_t(int, so->tx.len - so->tx.idx, space);
 679        int i;
 680
 681        cf->can_id = so->txid;
 682        cf->len = num + pcilen;
 683
 684        if (num < space) {
 685                if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
 686                        /* user requested padding */
 687                        cf->len = padlen(cf->len);
 688                        memset(cf->data, so->opt.txpad_content, cf->len);
 689                } else if (cf->len > CAN_MAX_DLEN) {
 690                        /* mandatory padding for CAN FD frames */
 691                        cf->len = padlen(cf->len);
 692                        memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
 693                               cf->len);
 694                }
 695        }
 696
 697        for (i = 0; i < num; i++)
 698                cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
 699
 700        if (ae)
 701                cf->data[0] = so->opt.ext_address;
 702}
 703
 704static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
 705                                int ae)
 706{
 707        int i;
 708        int ff_pci_sz;
 709
 710        cf->can_id = so->txid;
 711        cf->len = so->tx.ll_dl;
 712        if (ae)
 713                cf->data[0] = so->opt.ext_address;
 714
 715        /* create N_PCI bytes with 12/32 bit FF_DL data length */
 716        if (so->tx.len > 4095) {
 717                /* use 32 bit FF_DL notation */
 718                cf->data[ae] = N_PCI_FF;
 719                cf->data[ae + 1] = 0;
 720                cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
 721                cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
 722                cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
 723                cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
 724                ff_pci_sz = FF_PCI_SZ32;
 725        } else {
 726                /* use 12 bit FF_DL notation */
 727                cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
 728                cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
 729                ff_pci_sz = FF_PCI_SZ12;
 730        }
 731
 732        /* add first data bytes depending on ae */
 733        for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
 734                cf->data[i] = so->tx.buf[so->tx.idx++];
 735
 736        so->tx.sn = 1;
 737        so->tx.state = ISOTP_WAIT_FIRST_FC;
 738}
 739
 740static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
 741{
 742        struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
 743                                             txtimer);
 744        struct sock *sk = &so->sk;
 745        struct sk_buff *skb;
 746        struct net_device *dev;
 747        struct canfd_frame *cf;
 748        enum hrtimer_restart restart = HRTIMER_NORESTART;
 749        int can_send_ret;
 750        int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
 751
 752        switch (so->tx.state) {
 753        case ISOTP_WAIT_FC:
 754        case ISOTP_WAIT_FIRST_FC:
 755
 756                /* we did not get any flow control frame in time */
 757
 758                /* report 'communication error on send' */
 759                sk->sk_err = ECOMM;
 760                if (!sock_flag(sk, SOCK_DEAD))
 761                        sk_error_report(sk);
 762
 763                /* reset tx state */
 764                so->tx.state = ISOTP_IDLE;
 765                wake_up_interruptible(&so->wait);
 766                break;
 767
 768        case ISOTP_SENDING:
 769
 770                /* push out the next segmented pdu */
 771                dev = dev_get_by_index(sock_net(sk), so->ifindex);
 772                if (!dev)
 773                        break;
 774
 775isotp_tx_burst:
 776                skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
 777                                GFP_ATOMIC);
 778                if (!skb) {
 779                        dev_put(dev);
 780                        break;
 781                }
 782
 783                can_skb_reserve(skb);
 784                can_skb_prv(skb)->ifindex = dev->ifindex;
 785                can_skb_prv(skb)->skbcnt = 0;
 786
 787                cf = (struct canfd_frame *)skb->data;
 788                skb_put_zero(skb, so->ll.mtu);
 789
 790                /* create consecutive frame */
 791                isotp_fill_dataframe(cf, so, ae, 0);
 792
 793                /* place consecutive frame N_PCI in appropriate index */
 794                cf->data[ae] = N_PCI_CF | so->tx.sn++;
 795                so->tx.sn %= 16;
 796                so->tx.bs++;
 797
 798                cf->flags = so->ll.tx_flags;
 799
 800                skb->dev = dev;
 801                can_skb_set_owner(skb, sk);
 802
 803                can_send_ret = can_send(skb, 1);
 804                if (can_send_ret) {
 805                        pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
 806                                       __func__, ERR_PTR(can_send_ret));
 807                        if (can_send_ret == -ENOBUFS)
 808                                pr_notice_once("can-isotp: tx queue is full, increasing txqueuelen may prevent this error\n");
 809                }
 810                if (so->tx.idx >= so->tx.len) {
 811                        /* we are done */
 812                        so->tx.state = ISOTP_IDLE;
 813                        dev_put(dev);
 814                        wake_up_interruptible(&so->wait);
 815                        break;
 816                }
 817
 818                if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
 819                        /* stop and wait for FC */
 820                        so->tx.state = ISOTP_WAIT_FC;
 821                        dev_put(dev);
 822                        hrtimer_set_expires(&so->txtimer,
 823                                            ktime_add(ktime_get(),
 824                                                      ktime_set(1, 0)));
 825                        restart = HRTIMER_RESTART;
 826                        break;
 827                }
 828
 829                /* no gap between data frames needed => use burst mode */
 830                if (!so->tx_gap)
 831                        goto isotp_tx_burst;
 832
 833                /* start timer to send next data frame with correct delay */
 834                dev_put(dev);
 835                hrtimer_set_expires(&so->txtimer,
 836                                    ktime_add(ktime_get(), so->tx_gap));
 837                restart = HRTIMER_RESTART;
 838                break;
 839
 840        default:
 841                WARN_ON_ONCE(1);
 842        }
 843
 844        return restart;
 845}
 846
 847static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 848{
 849        struct sock *sk = sock->sk;
 850        struct isotp_sock *so = isotp_sk(sk);
 851        struct sk_buff *skb;
 852        struct net_device *dev;
 853        struct canfd_frame *cf;
 854        int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
 855        int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
 856        int off;
 857        int err;
 858
 859        if (!so->bound)
 860                return -EADDRNOTAVAIL;
 861
 862        /* we do not support multiple buffers - for now */
 863        if (so->tx.state != ISOTP_IDLE || wq_has_sleeper(&so->wait)) {
 864                if (msg->msg_flags & MSG_DONTWAIT)
 865                        return -EAGAIN;
 866
 867                /* wait for complete transmission of current pdu */
 868                wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
 869        }
 870
 871        if (!size || size > MAX_MSG_LENGTH)
 872                return -EINVAL;
 873
 874        /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
 875        off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
 876
 877        /* does the given data fit into a single frame for SF_BROADCAST? */
 878        if ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) &&
 879            (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off))
 880                return -EINVAL;
 881
 882        err = memcpy_from_msg(so->tx.buf, msg, size);
 883        if (err < 0)
 884                return err;
 885
 886        dev = dev_get_by_index(sock_net(sk), so->ifindex);
 887        if (!dev)
 888                return -ENXIO;
 889
 890        skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
 891                                  msg->msg_flags & MSG_DONTWAIT, &err);
 892        if (!skb) {
 893                dev_put(dev);
 894                return err;
 895        }
 896
 897        can_skb_reserve(skb);
 898        can_skb_prv(skb)->ifindex = dev->ifindex;
 899        can_skb_prv(skb)->skbcnt = 0;
 900
 901        so->tx.state = ISOTP_SENDING;
 902        so->tx.len = size;
 903        so->tx.idx = 0;
 904
 905        cf = (struct canfd_frame *)skb->data;
 906        skb_put_zero(skb, so->ll.mtu);
 907
 908        /* check for single frame transmission depending on TX_DL */
 909        if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
 910                /* The message size generally fits into a SingleFrame - good.
 911                 *
 912                 * SF_DL ESC offset optimization:
 913                 *
 914                 * When TX_DL is greater 8 but the message would still fit
 915                 * into a 8 byte CAN frame, we can omit the offset.
 916                 * This prevents a protocol caused length extension from
 917                 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
 918                 */
 919                if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
 920                        off = 0;
 921
 922                isotp_fill_dataframe(cf, so, ae, off);
 923
 924                /* place single frame N_PCI w/o length in appropriate index */
 925                cf->data[ae] = N_PCI_SF;
 926
 927                /* place SF_DL size value depending on the SF_DL ESC offset */
 928                if (off)
 929                        cf->data[SF_PCI_SZ4 + ae] = size;
 930                else
 931                        cf->data[ae] |= size;
 932
 933                so->tx.state = ISOTP_IDLE;
 934                wake_up_interruptible(&so->wait);
 935
 936                /* don't enable wait queue for a single frame transmission */
 937                wait_tx_done = 0;
 938        } else {
 939                /* send first frame and wait for FC */
 940
 941                isotp_create_fframe(cf, so, ae);
 942
 943                /* start timeout for FC */
 944                hrtimer_start(&so->txtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
 945        }
 946
 947        /* send the first or only CAN frame */
 948        cf->flags = so->ll.tx_flags;
 949
 950        skb->dev = dev;
 951        skb->sk = sk;
 952        err = can_send(skb, 1);
 953        dev_put(dev);
 954        if (err) {
 955                pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
 956                               __func__, ERR_PTR(err));
 957                return err;
 958        }
 959
 960        if (wait_tx_done) {
 961                /* wait for complete transmission of current pdu */
 962                wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
 963        }
 964
 965        return size;
 966}
 967
 968static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 969                         int flags)
 970{
 971        struct sock *sk = sock->sk;
 972        struct sk_buff *skb;
 973        int err = 0;
 974        int noblock;
 975
 976        noblock = flags & MSG_DONTWAIT;
 977        flags &= ~MSG_DONTWAIT;
 978
 979        skb = skb_recv_datagram(sk, flags, noblock, &err);
 980        if (!skb)
 981                return err;
 982
 983        if (size < skb->len)
 984                msg->msg_flags |= MSG_TRUNC;
 985        else
 986                size = skb->len;
 987
 988        err = memcpy_to_msg(msg, skb->data, size);
 989        if (err < 0) {
 990                skb_free_datagram(sk, skb);
 991                return err;
 992        }
 993
 994        sock_recv_timestamp(msg, sk, skb);
 995
 996        if (msg->msg_name) {
 997                __sockaddr_check_size(ISOTP_MIN_NAMELEN);
 998                msg->msg_namelen = ISOTP_MIN_NAMELEN;
 999                memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1000        }
1001
1002        skb_free_datagram(sk, skb);
1003
1004        return size;
1005}
1006
1007static int isotp_release(struct socket *sock)
1008{
1009        struct sock *sk = sock->sk;
1010        struct isotp_sock *so;
1011        struct net *net;
1012
1013        if (!sk)
1014                return 0;
1015
1016        so = isotp_sk(sk);
1017        net = sock_net(sk);
1018
1019        /* wait for complete transmission of current pdu */
1020        wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1021
1022        spin_lock(&isotp_notifier_lock);
1023        while (isotp_busy_notifier == so) {
1024                spin_unlock(&isotp_notifier_lock);
1025                schedule_timeout_uninterruptible(1);
1026                spin_lock(&isotp_notifier_lock);
1027        }
1028        list_del(&so->notifier);
1029        spin_unlock(&isotp_notifier_lock);
1030
1031        lock_sock(sk);
1032
1033        /* remove current filters & unregister */
1034        if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) {
1035                if (so->ifindex) {
1036                        struct net_device *dev;
1037
1038                        dev = dev_get_by_index(net, so->ifindex);
1039                        if (dev) {
1040                                can_rx_unregister(net, dev, so->rxid,
1041                                                  SINGLE_MASK(so->rxid),
1042                                                  isotp_rcv, sk);
1043                                dev_put(dev);
1044                                synchronize_rcu();
1045                        }
1046                }
1047        }
1048
1049        hrtimer_cancel(&so->txtimer);
1050        hrtimer_cancel(&so->rxtimer);
1051
1052        so->ifindex = 0;
1053        so->bound = 0;
1054
1055        sock_orphan(sk);
1056        sock->sk = NULL;
1057
1058        release_sock(sk);
1059        sock_put(sk);
1060
1061        return 0;
1062}
1063
1064static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1065{
1066        struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1067        struct sock *sk = sock->sk;
1068        struct isotp_sock *so = isotp_sk(sk);
1069        struct net *net = sock_net(sk);
1070        int ifindex;
1071        struct net_device *dev;
1072        int err = 0;
1073        int notify_enetdown = 0;
1074        int do_rx_reg = 1;
1075
1076        if (len < ISOTP_MIN_NAMELEN)
1077                return -EINVAL;
1078
1079        if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))
1080                return -EADDRNOTAVAIL;
1081
1082        if (!addr->can_ifindex)
1083                return -ENODEV;
1084
1085        lock_sock(sk);
1086
1087        /* do not register frame reception for functional addressing */
1088        if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
1089                do_rx_reg = 0;
1090
1091        /* do not validate rx address for functional addressing */
1092        if (do_rx_reg) {
1093                if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id) {
1094                        err = -EADDRNOTAVAIL;
1095                        goto out;
1096                }
1097
1098                if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) {
1099                        err = -EADDRNOTAVAIL;
1100                        goto out;
1101                }
1102        }
1103
1104        if (so->bound && addr->can_ifindex == so->ifindex &&
1105            addr->can_addr.tp.rx_id == so->rxid &&
1106            addr->can_addr.tp.tx_id == so->txid)
1107                goto out;
1108
1109        dev = dev_get_by_index(net, addr->can_ifindex);
1110        if (!dev) {
1111                err = -ENODEV;
1112                goto out;
1113        }
1114        if (dev->type != ARPHRD_CAN) {
1115                dev_put(dev);
1116                err = -ENODEV;
1117                goto out;
1118        }
1119        if (dev->mtu < so->ll.mtu) {
1120                dev_put(dev);
1121                err = -EINVAL;
1122                goto out;
1123        }
1124        if (!(dev->flags & IFF_UP))
1125                notify_enetdown = 1;
1126
1127        ifindex = dev->ifindex;
1128
1129        if (do_rx_reg)
1130                can_rx_register(net, dev, addr->can_addr.tp.rx_id,
1131                                SINGLE_MASK(addr->can_addr.tp.rx_id),
1132                                isotp_rcv, sk, "isotp", sk);
1133
1134        dev_put(dev);
1135
1136        if (so->bound && do_rx_reg) {
1137                /* unregister old filter */
1138                if (so->ifindex) {
1139                        dev = dev_get_by_index(net, so->ifindex);
1140                        if (dev) {
1141                                can_rx_unregister(net, dev, so->rxid,
1142                                                  SINGLE_MASK(so->rxid),
1143                                                  isotp_rcv, sk);
1144                                dev_put(dev);
1145                        }
1146                }
1147        }
1148
1149        /* switch to new settings */
1150        so->ifindex = ifindex;
1151        so->rxid = addr->can_addr.tp.rx_id;
1152        so->txid = addr->can_addr.tp.tx_id;
1153        so->bound = 1;
1154
1155out:
1156        release_sock(sk);
1157
1158        if (notify_enetdown) {
1159                sk->sk_err = ENETDOWN;
1160                if (!sock_flag(sk, SOCK_DEAD))
1161                        sk_error_report(sk);
1162        }
1163
1164        return err;
1165}
1166
1167static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1168{
1169        struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1170        struct sock *sk = sock->sk;
1171        struct isotp_sock *so = isotp_sk(sk);
1172
1173        if (peer)
1174                return -EOPNOTSUPP;
1175
1176        memset(addr, 0, ISOTP_MIN_NAMELEN);
1177        addr->can_family = AF_CAN;
1178        addr->can_ifindex = so->ifindex;
1179        addr->can_addr.tp.rx_id = so->rxid;
1180        addr->can_addr.tp.tx_id = so->txid;
1181
1182        return ISOTP_MIN_NAMELEN;
1183}
1184
1185static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
1186                            sockptr_t optval, unsigned int optlen)
1187{
1188        struct sock *sk = sock->sk;
1189        struct isotp_sock *so = isotp_sk(sk);
1190        int ret = 0;
1191
1192        if (so->bound)
1193                return -EISCONN;
1194
1195        switch (optname) {
1196        case CAN_ISOTP_OPTS:
1197                if (optlen != sizeof(struct can_isotp_options))
1198                        return -EINVAL;
1199
1200                if (copy_from_sockptr(&so->opt, optval, optlen))
1201                        return -EFAULT;
1202
1203                /* no separate rx_ext_address is given => use ext_address */
1204                if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1205                        so->opt.rx_ext_address = so->opt.ext_address;
1206                break;
1207
1208        case CAN_ISOTP_RECV_FC:
1209                if (optlen != sizeof(struct can_isotp_fc_options))
1210                        return -EINVAL;
1211
1212                if (copy_from_sockptr(&so->rxfc, optval, optlen))
1213                        return -EFAULT;
1214                break;
1215
1216        case CAN_ISOTP_TX_STMIN:
1217                if (optlen != sizeof(u32))
1218                        return -EINVAL;
1219
1220                if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1221                        return -EFAULT;
1222                break;
1223
1224        case CAN_ISOTP_RX_STMIN:
1225                if (optlen != sizeof(u32))
1226                        return -EINVAL;
1227
1228                if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1229                        return -EFAULT;
1230                break;
1231
1232        case CAN_ISOTP_LL_OPTS:
1233                if (optlen == sizeof(struct can_isotp_ll_options)) {
1234                        struct can_isotp_ll_options ll;
1235
1236                        if (copy_from_sockptr(&ll, optval, optlen))
1237                                return -EFAULT;
1238
1239                        /* check for correct ISO 11898-1 DLC data length */
1240                        if (ll.tx_dl != padlen(ll.tx_dl))
1241                                return -EINVAL;
1242
1243                        if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1244                                return -EINVAL;
1245
1246                        if (ll.mtu == CAN_MTU &&
1247                            (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
1248                                return -EINVAL;
1249
1250                        memcpy(&so->ll, &ll, sizeof(ll));
1251
1252                        /* set ll_dl for tx path to similar place as for rx */
1253                        so->tx.ll_dl = ll.tx_dl;
1254                } else {
1255                        return -EINVAL;
1256                }
1257                break;
1258
1259        default:
1260                ret = -ENOPROTOOPT;
1261        }
1262
1263        return ret;
1264}
1265
1266static int isotp_setsockopt(struct socket *sock, int level, int optname,
1267                            sockptr_t optval, unsigned int optlen)
1268
1269{
1270        struct sock *sk = sock->sk;
1271        int ret;
1272
1273        if (level != SOL_CAN_ISOTP)
1274                return -EINVAL;
1275
1276        lock_sock(sk);
1277        ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
1278        release_sock(sk);
1279        return ret;
1280}
1281
1282static int isotp_getsockopt(struct socket *sock, int level, int optname,
1283                            char __user *optval, int __user *optlen)
1284{
1285        struct sock *sk = sock->sk;
1286        struct isotp_sock *so = isotp_sk(sk);
1287        int len;
1288        void *val;
1289
1290        if (level != SOL_CAN_ISOTP)
1291                return -EINVAL;
1292        if (get_user(len, optlen))
1293                return -EFAULT;
1294        if (len < 0)
1295                return -EINVAL;
1296
1297        switch (optname) {
1298        case CAN_ISOTP_OPTS:
1299                len = min_t(int, len, sizeof(struct can_isotp_options));
1300                val = &so->opt;
1301                break;
1302
1303        case CAN_ISOTP_RECV_FC:
1304                len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1305                val = &so->rxfc;
1306                break;
1307
1308        case CAN_ISOTP_TX_STMIN:
1309                len = min_t(int, len, sizeof(u32));
1310                val = &so->force_tx_stmin;
1311                break;
1312
1313        case CAN_ISOTP_RX_STMIN:
1314                len = min_t(int, len, sizeof(u32));
1315                val = &so->force_rx_stmin;
1316                break;
1317
1318        case CAN_ISOTP_LL_OPTS:
1319                len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1320                val = &so->ll;
1321                break;
1322
1323        default:
1324                return -ENOPROTOOPT;
1325        }
1326
1327        if (put_user(len, optlen))
1328                return -EFAULT;
1329        if (copy_to_user(optval, val, len))
1330                return -EFAULT;
1331        return 0;
1332}
1333
1334static void isotp_notify(struct isotp_sock *so, unsigned long msg,
1335                         struct net_device *dev)
1336{
1337        struct sock *sk = &so->sk;
1338
1339        if (!net_eq(dev_net(dev), sock_net(sk)))
1340                return;
1341
1342        if (so->ifindex != dev->ifindex)
1343                return;
1344
1345        switch (msg) {
1346        case NETDEV_UNREGISTER:
1347                lock_sock(sk);
1348                /* remove current filters & unregister */
1349                if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST)))
1350                        can_rx_unregister(dev_net(dev), dev, so->rxid,
1351                                          SINGLE_MASK(so->rxid),
1352                                          isotp_rcv, sk);
1353
1354                so->ifindex = 0;
1355                so->bound  = 0;
1356                release_sock(sk);
1357
1358                sk->sk_err = ENODEV;
1359                if (!sock_flag(sk, SOCK_DEAD))
1360                        sk_error_report(sk);
1361                break;
1362
1363        case NETDEV_DOWN:
1364                sk->sk_err = ENETDOWN;
1365                if (!sock_flag(sk, SOCK_DEAD))
1366                        sk_error_report(sk);
1367                break;
1368        }
1369}
1370
1371static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1372                          void *ptr)
1373{
1374        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1375
1376        if (dev->type != ARPHRD_CAN)
1377                return NOTIFY_DONE;
1378        if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1379                return NOTIFY_DONE;
1380        if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
1381                return NOTIFY_DONE;
1382
1383        spin_lock(&isotp_notifier_lock);
1384        list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
1385                spin_unlock(&isotp_notifier_lock);
1386                isotp_notify(isotp_busy_notifier, msg, dev);
1387                spin_lock(&isotp_notifier_lock);
1388        }
1389        isotp_busy_notifier = NULL;
1390        spin_unlock(&isotp_notifier_lock);
1391        return NOTIFY_DONE;
1392}
1393
1394static int isotp_init(struct sock *sk)
1395{
1396        struct isotp_sock *so = isotp_sk(sk);
1397
1398        so->ifindex = 0;
1399        so->bound = 0;
1400
1401        so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1402        so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1403        so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1404        so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1405        so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1406        so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1407        so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1408        so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1409        so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1410        so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1411        so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1412        so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1413
1414        /* set ll_dl for tx path to similar place as for rx */
1415        so->tx.ll_dl = so->ll.tx_dl;
1416
1417        so->rx.state = ISOTP_IDLE;
1418        so->tx.state = ISOTP_IDLE;
1419
1420        hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1421        so->rxtimer.function = isotp_rx_timer_handler;
1422        hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1423        so->txtimer.function = isotp_tx_timer_handler;
1424
1425        init_waitqueue_head(&so->wait);
1426
1427        spin_lock(&isotp_notifier_lock);
1428        list_add_tail(&so->notifier, &isotp_notifier_list);
1429        spin_unlock(&isotp_notifier_lock);
1430
1431        return 0;
1432}
1433
1434static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1435                                  unsigned long arg)
1436{
1437        /* no ioctls for socket layer -> hand it down to NIC layer */
1438        return -ENOIOCTLCMD;
1439}
1440
1441static const struct proto_ops isotp_ops = {
1442        .family = PF_CAN,
1443        .release = isotp_release,
1444        .bind = isotp_bind,
1445        .connect = sock_no_connect,
1446        .socketpair = sock_no_socketpair,
1447        .accept = sock_no_accept,
1448        .getname = isotp_getname,
1449        .poll = datagram_poll,
1450        .ioctl = isotp_sock_no_ioctlcmd,
1451        .gettstamp = sock_gettstamp,
1452        .listen = sock_no_listen,
1453        .shutdown = sock_no_shutdown,
1454        .setsockopt = isotp_setsockopt,
1455        .getsockopt = isotp_getsockopt,
1456        .sendmsg = isotp_sendmsg,
1457        .recvmsg = isotp_recvmsg,
1458        .mmap = sock_no_mmap,
1459        .sendpage = sock_no_sendpage,
1460};
1461
1462static struct proto isotp_proto __read_mostly = {
1463        .name = "CAN_ISOTP",
1464        .owner = THIS_MODULE,
1465        .obj_size = sizeof(struct isotp_sock),
1466        .init = isotp_init,
1467};
1468
1469static const struct can_proto isotp_can_proto = {
1470        .type = SOCK_DGRAM,
1471        .protocol = CAN_ISOTP,
1472        .ops = &isotp_ops,
1473        .prot = &isotp_proto,
1474};
1475
1476static struct notifier_block canisotp_notifier = {
1477        .notifier_call = isotp_notifier
1478};
1479
1480static __init int isotp_module_init(void)
1481{
1482        int err;
1483
1484        pr_info("can: isotp protocol\n");
1485
1486        err = can_proto_register(&isotp_can_proto);
1487        if (err < 0)
1488                pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
1489        else
1490                register_netdevice_notifier(&canisotp_notifier);
1491
1492        return err;
1493}
1494
1495static __exit void isotp_module_exit(void)
1496{
1497        can_proto_unregister(&isotp_can_proto);
1498        unregister_netdevice_notifier(&canisotp_notifier);
1499}
1500
1501module_init(isotp_module_init);
1502module_exit(isotp_module_exit);
1503