net/can/j1939/transport.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2010-2011 EIA Electronics,
   3 //                         Kurt Van Dijck <kurt.van.dijck@eia.be>
   4 // Copyright (c) 2018 Protonic,
   5 //                         Robin van der Gracht <robin@protonic.nl>
   6 // Copyright (c) 2017-2019 Pengutronix,
   7 //                         Marc Kleine-Budde <kernel@pengutronix.de>
   8 // Copyright (c) 2017-2019 Pengutronix,
   9 //                         Oleksij Rempel <kernel@pengutronix.de>
  10
  11 #include <linux/can/skb.h>
  12
  13 #include "j1939-priv.h"
  14
  15 #define J1939_XTP_TX_RETRY_LIMIT 100
  16
  17 #define J1939_ETP_PGN_CTL 0xc800
  18 #define J1939_ETP_PGN_DAT 0xc700
  19 #define J1939_TP_PGN_CTL 0xec00
  20 #define J1939_TP_PGN_DAT 0xeb00
  21
  22 #define J1939_TP_CMD_RTS 0x10
  23 #define J1939_TP_CMD_CTS 0x11
  24 #define J1939_TP_CMD_EOMA 0x13
  25 #define J1939_TP_CMD_BAM 0x20
  26 #define J1939_TP_CMD_ABORT 0xff
  27
  28 #define J1939_ETP_CMD_RTS 0x14
  29 #define J1939_ETP_CMD_CTS 0x15
  30 #define J1939_ETP_CMD_DPO 0x16
  31 #define J1939_ETP_CMD_EOMA 0x17
  32 #define J1939_ETP_CMD_ABORT 0xff
  33
  34 enum j1939_xtp_abort {
  35         J1939_XTP_NO_ABORT = 0,
  36         J1939_XTP_ABORT_BUSY = 1,
  37         /* Already in one or more connection managed sessions and
  38          * cannot support another.
  39          *
  40          * EALREADY:
  41          * Operation already in progress
  42          */
  43
  44         J1939_XTP_ABORT_RESOURCE = 2,
  45         /* System resources were needed for another task so this
  46          * connection managed session was terminated.
  47          *
  48          * EMSGSIZE:
  49          * The socket type requires that message be sent atomically,
  50          * and the size of the message to be sent made this
  51          * impossible.
  52          */
  53
  54         J1939_XTP_ABORT_TIMEOUT = 3,
  55         /* A timeout occurred and this is the connection abort to
  56          * close the session.
  57          *
  58          * EHOSTUNREACH:
  59          * The destination host cannot be reached (probably because
  60          * the host is down or a remote router cannot reach it).
  61          */
  62
  63         J1939_XTP_ABORT_GENERIC = 4,
  64         /* CTS messages received when data transfer is in progress
  65          *
  66          * EBADMSG:
  67          * Not a data message
  68          */
  69
  70         J1939_XTP_ABORT_FAULT = 5,
  71         /* Maximal retransmit request limit reached
  72          *
  73          * ENOTRECOVERABLE:
  74          * State not recoverable
  75          */
  76
  77         J1939_XTP_ABORT_UNEXPECTED_DATA = 6,
  78         /* Unexpected data transfer packet
  79          *
  80          * ENOTCONN:
  81          * Transport endpoint is not connected
  82          */
  83
  84         J1939_XTP_ABORT_BAD_SEQ = 7,
  85         /* Bad sequence number (and software is not able to recover)
  86          *
  87          * EILSEQ:
  88          * Illegal byte sequence
  89          */
  90
  91         J1939_XTP_ABORT_DUP_SEQ = 8,
  92         /* Duplicate sequence number (and software is not able to
  93          * recover)
  94          */
  95
  96         J1939_XTP_ABORT_EDPO_UNEXPECTED = 9,
  97         /* Unexpected EDPO packet (ETP) or Message size > 1785 bytes
  98          * (TP)
  99          */
 100
 101         J1939_XTP_ABORT_BAD_EDPO_PGN = 10,
 102         /* Unexpected EDPO PGN (PGN in EDPO is bad) */
 103
 104         J1939_XTP_ABORT_EDPO_OUTOF_CTS = 11,
 105         /* EDPO number of packets is greater than CTS */
 106
 107         J1939_XTP_ABORT_BAD_EDPO_OFFSET = 12,
 108         /* Bad EDPO offset */
 109
 110         J1939_XTP_ABORT_OTHER_DEPRECATED = 13,
 111         /* Deprecated. Use 250 instead (Any other reason)  */
 112
 113         J1939_XTP_ABORT_ECTS_UNXPECTED_PGN = 14,
 114         /* Unexpected ECTS PGN (PGN in ECTS is bad) */
 115
 116         J1939_XTP_ABORT_ECTS_TOO_BIG = 15,
 117         /* ECTS requested packets exceeds message size */
 118
 119         J1939_XTP_ABORT_OTHER = 250,
 120         /* Any other reason (if a Connection Abort reason is
 121          * identified that is not listed in the table use code 250)
 122          */
 123 };
 124
 125 static unsigned int j1939_tp_block = 255;
 126 static unsigned int j1939_tp_packet_delay;
 127 static unsigned int j1939_tp_padding = 1;
 128
 129 /* helpers */
 130 static const char *j1939_xtp_abort_to_str(enum j1939_xtp_abort abort)
 131 {
 132         switch (abort) {
 133         case J1939_XTP_ABORT_BUSY:
 134                 return "Already in one or more connection managed sessions and cannot support another.";
 135         case J1939_XTP_ABORT_RESOURCE:
 136                 return "System resources were needed for another task so this connection managed session was terminated.";
 137         case J1939_XTP_ABORT_TIMEOUT:
 138                 return "A timeout occurred and this is the connection abort to close the session.";
 139         case J1939_XTP_ABORT_GENERIC:
 140                 return "CTS messages received when data transfer is in progress";
 141         case J1939_XTP_ABORT_FAULT:
 142                 return "Maximal retransmit request limit reached";
 143         case J1939_XTP_ABORT_UNEXPECTED_DATA:
 144                 return "Unexpected data transfer packet";
 145         case J1939_XTP_ABORT_BAD_SEQ:
 146                 return "Bad sequence number (and software is not able to recover)";
 147         case J1939_XTP_ABORT_DUP_SEQ:
 148                 return "Duplicate sequence number (and software is not able to recover)";
 149         case J1939_XTP_ABORT_EDPO_UNEXPECTED:
 150                 return "Unexpected EDPO packet (ETP) or Message size > 1785 bytes (TP)";
 151         case J1939_XTP_ABORT_BAD_EDPO_PGN:
 152                 return "Unexpected EDPO PGN (PGN in EDPO is bad)";
 153         case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
 154                 return "EDPO number of packets is greater than CTS";
 155         case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
 156                 return "Bad EDPO offset";
 157         case J1939_XTP_ABORT_OTHER_DEPRECATED:
 158                 return "Deprecated. Use 250 instead (Any other reason)";
 159         case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
 160                 return "Unexpected ECTS PGN (PGN in ECTS is bad)";
 161         case J1939_XTP_ABORT_ECTS_TOO_BIG:
 162                 return "ECTS requested packets exceeds message size";
 163         case J1939_XTP_ABORT_OTHER:
 164                 return "Any other reason (if a Connection Abort reason is identified that is not listed in the table use code 250)";
 165         default:
 166                 return "<unknown>";
 167         }
 168 }
 169
 170 static int j1939_xtp_abort_to_errno(struct j1939_priv *priv,
 171                                     enum j1939_xtp_abort abort)
 172 {
 173         int err;
 174
 175         switch (abort) {
 176         case J1939_XTP_NO_ABORT:
 177                 WARN_ON_ONCE(abort == J1939_XTP_NO_ABORT);
 178                 err = 0;
 179                 break;
 180         case J1939_XTP_ABORT_BUSY:
 181                 err = EALREADY;
 182                 break;
 183         case J1939_XTP_ABORT_RESOURCE:
 184                 err = EMSGSIZE;
 185                 break;
 186         case J1939_XTP_ABORT_TIMEOUT:
 187                 err = EHOSTUNREACH;
 188                 break;
 189         case J1939_XTP_ABORT_GENERIC:
 190                 err = EBADMSG;
 191                 break;
 192         case J1939_XTP_ABORT_FAULT:
 193                 err = ENOTRECOVERABLE;
 194                 break;
 195         case J1939_XTP_ABORT_UNEXPECTED_DATA:
 196                 err = ENOTCONN;
 197                 break;
 198         case J1939_XTP_ABORT_BAD_SEQ:
 199                 err = EILSEQ;
 200                 break;
 201         case J1939_XTP_ABORT_DUP_SEQ:
 202                 err = EPROTO;
 203                 break;
 204         case J1939_XTP_ABORT_EDPO_UNEXPECTED:
 205                 err = EPROTO;
 206                 break;
 207         case J1939_XTP_ABORT_BAD_EDPO_PGN:
 208                 err = EPROTO;
 209                 break;
 210         case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
 211                 err = EPROTO;
 212                 break;
 213         case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
 214                 err = EPROTO;
 215                 break;
 216         case J1939_XTP_ABORT_OTHER_DEPRECATED:
 217                 err = EPROTO;
 218                 break;
 219         case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
 220                 err = EPROTO;
 221                 break;
 222         case J1939_XTP_ABORT_ECTS_TOO_BIG:
 223                 err = EPROTO;
 224                 break;
 225         case J1939_XTP_ABORT_OTHER:
 226                 err = EPROTO;
 227                 break;
 228         default:
 229                 netdev_warn(priv->ndev, "Unknown abort code %i", abort);
 230                 err = EPROTO;
 231         }
 232
 233         return err;
 234 }
 235
 236 static inline void j1939_session_list_lock(struct j1939_priv *priv)
 237 {
 238         spin_lock_bh(&priv->active_session_list_lock);
 239 }
 240
 241 static inline void j1939_session_list_unlock(struct j1939_priv *priv)
 242 {
 243         spin_unlock_bh(&priv->active_session_list_lock);
 244 }
 245
 246 void j1939_session_get(struct j1939_session *session)
 247 {
 248         kref_get(&session->kref);
 249 }
 250
 251 /* session completion functions */
 252 static void __j1939_session_drop(struct j1939_session *session)
 253 {
 254         if (!session->transmission)
 255                 return;
 256
 257         j1939_sock_pending_del(session->sk);
 258         sock_put(session->sk);
 259 }
 260
 261 static void j1939_session_destroy(struct j1939_session *session)
 262 {
 263         if (session->err)
 264                 j1939_sk_errqueue(session, J1939_ERRQUEUE_ABORT);
 265         else
 266                 j1939_sk_errqueue(session, J1939_ERRQUEUE_ACK);
 267
 268         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 269
 270         WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry));
 271         WARN_ON_ONCE(!list_empty(&session->active_session_list_entry));
 272
 273         skb_queue_purge(&session->skb_queue);
 274         __j1939_session_drop(session);
 275         j1939_priv_put(session->priv);
 276         kfree(session);
 277 }
 278
 279 static void __j1939_session_release(struct kref *kref)
 280 {
 281         struct j1939_session *session = container_of(kref, struct j1939_session,
 282                                                      kref);
 283
 284         j1939_session_destroy(session);
 285 }
 286
 287 void j1939_session_put(struct j1939_session *session)
 288 {
 289         kref_put(&session->kref, __j1939_session_release);
 290 }
 291
 292 static void j1939_session_txtimer_cancel(struct j1939_session *session)
 293 {
 294         if (hrtimer_cancel(&session->txtimer))
 295                 j1939_session_put(session);
 296 }
 297
 298 static void j1939_session_rxtimer_cancel(struct j1939_session *session)
 299 {
 300         if (hrtimer_cancel(&session->rxtimer))
 301                 j1939_session_put(session);
 302 }
 303
 304 void j1939_session_timers_cancel(struct j1939_session *session)
 305 {
 306         j1939_session_txtimer_cancel(session);
 307         j1939_session_rxtimer_cancel(session);
 308 }
 309
 310 static inline bool j1939_cb_is_broadcast(const struct j1939_sk_buff_cb *skcb)
 311 {
 312         return (!skcb->addr.dst_name && (skcb->addr.da == 0xff));
 313 }
 314
 315 static void j1939_session_skb_drop_old(struct j1939_session *session)
 316 {
 317         struct sk_buff *do_skb;
 318         struct j1939_sk_buff_cb *do_skcb;
 319         unsigned int offset_start;
 320         unsigned long flags;
 321
 322         if (skb_queue_len(&session->skb_queue) < 2)
 323                 return;
 324
 325         offset_start = session->pkt.tx_acked * 7;
 326
 327         spin_lock_irqsave(&session->skb_queue.lock, flags);
 328         do_skb = skb_peek(&session->skb_queue);
 329         do_skcb = j1939_skb_to_cb(do_skb);
 330
 331         if ((do_skcb->offset + do_skb->len) < offset_start) {
 332                 __skb_unlink(do_skb, &session->skb_queue);
 333                 /* drop ref taken in j1939_session_skb_queue() */
 334                 skb_unref(do_skb);
 335
 336                 kfree_skb(do_skb);
 337         }
 338         spin_unlock_irqrestore(&session->skb_queue.lock, flags);
 339 }
 340
 341 void j1939_session_skb_queue(struct j1939_session *session,
 342                              struct sk_buff *skb)
 343 {
 344         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
 345         struct j1939_priv *priv = session->priv;
 346
 347         j1939_ac_fixup(priv, skb);
 348
 349         if (j1939_address_is_unicast(skcb->addr.da) &&
 350             priv->ents[skcb->addr.da].nusers)
 351                 skcb->flags |= J1939_ECU_LOCAL_DST;
 352
 353         skcb->flags |= J1939_ECU_LOCAL_SRC;
 354
 355         skb_get(skb);
 356         skb_queue_tail(&session->skb_queue, skb);
 357 }
 358
 359 static struct
 360 sk_buff *j1939_session_skb_get_by_offset(struct j1939_session *session,
 361                                          unsigned int offset_start)
 362 {
 363         struct j1939_priv *priv = session->priv;
 364         struct j1939_sk_buff_cb *do_skcb;
 365         struct sk_buff *skb = NULL;
 366         struct sk_buff *do_skb;
 367         unsigned long flags;
 368
 369         spin_lock_irqsave(&session->skb_queue.lock, flags);
 370         skb_queue_walk(&session->skb_queue, do_skb) {
 371                 do_skcb = j1939_skb_to_cb(do_skb);
 372
 373                 if (offset_start >= do_skcb->offset &&
 374                     offset_start < (do_skcb->offset + do_skb->len)) {
 375                         skb = do_skb;
 376                 }
 377         }
 378
 379         if (skb)
 380                 skb_get(skb);
 381
 382         spin_unlock_irqrestore(&session->skb_queue.lock, flags);
 383
 384         if (!skb)
 385                 netdev_dbg(priv->ndev, "%s: 0x%p: no skb found for start: %i, queue size: %i\n",
 386                            __func__, session, offset_start,
 387                            skb_queue_len(&session->skb_queue));
 388
 389         return skb;
 390 }
 391
 392 static struct sk_buff *j1939_session_skb_get(struct j1939_session *session)
 393 {
 394         unsigned int offset_start;
 395
 396         offset_start = session->pkt.dpo * 7;
 397         return j1939_session_skb_get_by_offset(session, offset_start);
 398 }
 399
 400 /* see if we are receiver
 401  * returns 0 for broadcasts, although we will receive them
 402  */
 403 static inline int j1939_tp_im_receiver(const struct j1939_sk_buff_cb *skcb)
 404 {
 405         return skcb->flags & J1939_ECU_LOCAL_DST;
 406 }
 407
 408 /* see if we are sender */
 409 static inline int j1939_tp_im_transmitter(const struct j1939_sk_buff_cb *skcb)
 410 {
 411         return skcb->flags & J1939_ECU_LOCAL_SRC;
 412 }
 413
 414 /* see if we are involved as either receiver or transmitter */
 415 static int j1939_tp_im_involved(const struct j1939_sk_buff_cb *skcb, bool swap)
 416 {
 417         if (swap)
 418                 return j1939_tp_im_receiver(skcb);
 419         else
 420                 return j1939_tp_im_transmitter(skcb);
 421 }
 422
 423 static int j1939_tp_im_involved_anydir(struct j1939_sk_buff_cb *skcb)
 424 {
 425         return skcb->flags & (J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
 426 }
 427
 428 /* extract pgn from flow-ctl message */
 429 static inline pgn_t j1939_xtp_ctl_to_pgn(const u8 *dat)
 430 {
 431         pgn_t pgn;
 432
 433         pgn = (dat[7] << 16) | (dat[6] << 8) | (dat[5] << 0);
 434         if (j1939_pgn_is_pdu1(pgn))
 435                 pgn &= 0xffff00;
 436         return pgn;
 437 }
 438
 439 static inline unsigned int j1939_tp_ctl_to_size(const u8 *dat)
 440 {
 441         return (dat[2] << 8) + (dat[1] << 0);
 442 }
 443
 444 static inline unsigned int j1939_etp_ctl_to_packet(const u8 *dat)
 445 {
 446         return (dat[4] << 16) | (dat[3] << 8) | (dat[2] << 0);
 447 }
 448
 449 static inline unsigned int j1939_etp_ctl_to_size(const u8 *dat)
 450 {
 451         return (dat[4] << 24) | (dat[3] << 16) |
 452                 (dat[2] << 8) | (dat[1] << 0);
 453 }
 454
 455 /* find existing session:
 456  * reverse: swap cb's src & dst
 457  * there is no problem with matching broadcasts, since
 458  * broadcasts (no dst, no da) would never call this
 459  * with reverse == true
 460  */
 461 static bool j1939_session_match(struct j1939_addr *se_addr,
 462                                 struct j1939_addr *sk_addr, bool reverse)
 463 {
 464         if (se_addr->type != sk_addr->type)
 465                 return false;
 466
 467         if (reverse) {
 468                 if (se_addr->src_name) {
 469                         if (se_addr->src_name != sk_addr->dst_name)
 470                                 return false;
 471                 } else if (se_addr->sa != sk_addr->da) {
 472                         return false;
 473                 }
 474
 475                 if (se_addr->dst_name) {
 476                         if (se_addr->dst_name != sk_addr->src_name)
 477                                 return false;
 478                 } else if (se_addr->da != sk_addr->sa) {
 479                         return false;
 480                 }
 481         } else {
 482                 if (se_addr->src_name) {
 483                         if (se_addr->src_name != sk_addr->src_name)
 484                                 return false;
 485                 } else if (se_addr->sa != sk_addr->sa) {
 486                         return false;
 487                 }
 488
 489                 if (se_addr->dst_name) {
 490                         if (se_addr->dst_name != sk_addr->dst_name)
 491                                 return false;
 492                 } else if (se_addr->da != sk_addr->da) {
 493                         return false;
 494                 }
 495         }
 496
 497         return true;
 498 }
 499
 500 static struct
 501 j1939_session *j1939_session_get_by_addr_locked(struct j1939_priv *priv,
 502                                                 struct list_head *root,
 503                                                 struct j1939_addr *addr,
 504                                                 bool reverse, bool transmitter)
 505 {
 506         struct j1939_session *session;
 507
 508         lockdep_assert_held(&priv->active_session_list_lock);
 509
 510         list_for_each_entry(session, root, active_session_list_entry) {
 511                 j1939_session_get(session);
 512                 if (j1939_session_match(&session->skcb.addr, addr, reverse) &&
 513                     session->transmission == transmitter)
 514                         return session;
 515                 j1939_session_put(session);
 516         }
 517
 518         return NULL;
 519 }
 520
 521 static struct
 522 j1939_session *j1939_session_get_simple(struct j1939_priv *priv,
 523                                         struct sk_buff *skb)
 524 {
 525         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
 526         struct j1939_session *session;
 527
 528         lockdep_assert_held(&priv->active_session_list_lock);
 529
 530         list_for_each_entry(session, &priv->active_session_list,
 531                             active_session_list_entry) {
 532                 j1939_session_get(session);
 533                 if (session->skcb.addr.type == J1939_SIMPLE &&
 534                     session->tskey == skcb->tskey && session->sk == skb->sk)
 535                         return session;
 536                 j1939_session_put(session);
 537         }
 538
 539         return NULL;
 540 }
 541
 542 static struct
 543 j1939_session *j1939_session_get_by_addr(struct j1939_priv *priv,
 544                                          struct j1939_addr *addr,
 545                                          bool reverse, bool transmitter)
 546 {
 547         struct j1939_session *session;
 548
 549         j1939_session_list_lock(priv);
 550         session = j1939_session_get_by_addr_locked(priv,
 551                                                    &priv->active_session_list,
 552                                                    addr, reverse, transmitter);
 553         j1939_session_list_unlock(priv);
 554
 555         return session;
 556 }
 557
 558 static void j1939_skbcb_swap(struct j1939_sk_buff_cb *skcb)
 559 {
 560         u8 tmp = 0;
 561
 562         swap(skcb->addr.dst_name, skcb->addr.src_name);
 563         swap(skcb->addr.da, skcb->addr.sa);
 564
 565         /* swap SRC and DST flags, leave other untouched */
 566         if (skcb->flags & J1939_ECU_LOCAL_SRC)
 567                 tmp |= J1939_ECU_LOCAL_DST;
 568         if (skcb->flags & J1939_ECU_LOCAL_DST)
 569                 tmp |= J1939_ECU_LOCAL_SRC;
 570         skcb->flags &= ~(J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
 571         skcb->flags |= tmp;
 572 }
 573
 574 static struct
 575 sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
 576                              const struct j1939_sk_buff_cb *re_skcb,
 577                              bool ctl,
 578                              bool swap_src_dst)
 579 {
 580         struct sk_buff *skb;
 581         struct j1939_sk_buff_cb *skcb;
 582
 583         skb = alloc_skb(sizeof(struct can_frame) + sizeof(struct can_skb_priv),
 584                         GFP_ATOMIC);
 585         if (unlikely(!skb))
 586                 return ERR_PTR(-ENOMEM);
 587
 588         skb->dev = priv->ndev;
 589         can_skb_reserve(skb);
 590         can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
 591         can_skb_prv(skb)->skbcnt = 0;
 592         /* reserve CAN header */
 593         skb_reserve(skb, offsetof(struct can_frame, data));
 594
 595         memcpy(skb->cb, re_skcb, sizeof(skb->cb));
 596         skcb = j1939_skb_to_cb(skb);
 597         if (swap_src_dst)
 598                 j1939_skbcb_swap(skcb);
 599
 600         if (ctl) {
 601                 if (skcb->addr.type == J1939_ETP)
 602                         skcb->addr.pgn = J1939_ETP_PGN_CTL;
 603                 else
 604                         skcb->addr.pgn = J1939_TP_PGN_CTL;
 605         } else {
 606                 if (skcb->addr.type == J1939_ETP)
 607                         skcb->addr.pgn = J1939_ETP_PGN_DAT;
 608                 else
 609                         skcb->addr.pgn = J1939_TP_PGN_DAT;
 610         }
 611
 612         return skb;
 613 }
 614
 615 /* TP transmit packet functions */
 616 static int j1939_tp_tx_dat(struct j1939_session *session,
 617                            const u8 *dat, int len)
 618 {
 619         struct j1939_priv *priv = session->priv;
 620         struct sk_buff *skb;
 621
 622         skb = j1939_tp_tx_dat_new(priv, &session->skcb,
 623                                   false, false);
 624         if (IS_ERR(skb))
 625                 return PTR_ERR(skb);
 626
 627         skb_put_data(skb, dat, len);
 628         if (j1939_tp_padding && len < 8)
 629                 memset(skb_put(skb, 8 - len), 0xff, 8 - len);
 630
 631         return j1939_send_one(priv, skb);
 632 }
 633
 634 static int j1939_xtp_do_tx_ctl(struct j1939_priv *priv,
 635                                const struct j1939_sk_buff_cb *re_skcb,
 636                                bool swap_src_dst, pgn_t pgn, const u8 *dat)
 637 {
 638         struct sk_buff *skb;
 639         u8 *skdat;
 640
 641         if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
 642                 return 0;
 643
 644         skb = j1939_tp_tx_dat_new(priv, re_skcb, true, swap_src_dst);
 645         if (IS_ERR(skb))
 646                 return PTR_ERR(skb);
 647
 648         skdat = skb_put(skb, 8);
 649         memcpy(skdat, dat, 5);
 650         skdat[5] = (pgn >> 0);
 651         skdat[6] = (pgn >> 8);
 652         skdat[7] = (pgn >> 16);
 653
 654         return j1939_send_one(priv, skb);
 655 }
 656
 657 static inline int j1939_tp_tx_ctl(struct j1939_session *session,
 658                                   bool swap_src_dst, const u8 *dat)
 659 {
 660         struct j1939_priv *priv = session->priv;
 661
 662         return j1939_xtp_do_tx_ctl(priv, &session->skcb,
 663                                    swap_src_dst,
 664                                    session->skcb.addr.pgn, dat);
 665 }
 666
 667 static int j1939_xtp_tx_abort(struct j1939_priv *priv,
 668                               const struct j1939_sk_buff_cb *re_skcb,
 669                               bool swap_src_dst,
 670                               enum j1939_xtp_abort err,
 671                               pgn_t pgn)
 672 {
 673         u8 dat[5];
 674
 675         if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
 676                 return 0;
 677
 678         memset(dat, 0xff, sizeof(dat));
 679         dat[0] = J1939_TP_CMD_ABORT;
 680         dat[1] = err;
 681         return j1939_xtp_do_tx_ctl(priv, re_skcb, swap_src_dst, pgn, dat);
 682 }
 683
 684 void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec)
 685 {
 686         j1939_session_get(session);
 687         hrtimer_start(&session->txtimer, ms_to_ktime(msec),
 688                       HRTIMER_MODE_REL_SOFT);
 689 }
 690
 691 static inline void j1939_tp_set_rxtimeout(struct j1939_session *session,
 692                                           int msec)
 693 {
 694         j1939_session_rxtimer_cancel(session);
 695         j1939_session_get(session);
 696         hrtimer_start(&session->rxtimer, ms_to_ktime(msec),
 697                       HRTIMER_MODE_REL_SOFT);
 698 }
 699
 700 static int j1939_session_tx_rts(struct j1939_session *session)
 701 {
 702         u8 dat[8];
 703         int ret;
 704
 705         memset(dat, 0xff, sizeof(dat));
 706
 707         dat[1] = (session->total_message_size >> 0);
 708         dat[2] = (session->total_message_size >> 8);
 709         dat[3] = session->pkt.total;
 710
 711         if (session->skcb.addr.type == J1939_ETP) {
 712                 dat[0] = J1939_ETP_CMD_RTS;
 713                 dat[1] = (session->total_message_size >> 0);
 714                 dat[2] = (session->total_message_size >> 8);
 715                 dat[3] = (session->total_message_size >> 16);
 716                 dat[4] = (session->total_message_size >> 24);
 717         } else if (j1939_cb_is_broadcast(&session->skcb)) {
 718                 dat[0] = J1939_TP_CMD_BAM;
 719                 /* fake cts for broadcast */
 720                 session->pkt.tx = 0;
 721         } else {
 722                 dat[0] = J1939_TP_CMD_RTS;
 723                 dat[4] = dat[3];
 724         }
 725
 726         if (dat[0] == session->last_txcmd)
 727                 /* done already */
 728                 return 0;
 729
 730         ret = j1939_tp_tx_ctl(session, false, dat);
 731         if (ret < 0)
 732                 return ret;
 733
 734         session->last_txcmd = dat[0];
 735         if (dat[0] == J1939_TP_CMD_BAM) {
 736                 j1939_tp_schedule_txtimer(session, 50);
 737                 j1939_tp_set_rxtimeout(session, 250);
 738         } else {
 739                 j1939_tp_set_rxtimeout(session, 1250);
 740         }
 741
 742         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 743
 744         return 0;
 745 }
 746
 747 static int j1939_session_tx_dpo(struct j1939_session *session)
 748 {
 749         unsigned int pkt;
 750         u8 dat[8];
 751         int ret;
 752
 753         memset(dat, 0xff, sizeof(dat));
 754
 755         dat[0] = J1939_ETP_CMD_DPO;
 756         session->pkt.dpo = session->pkt.tx_acked;
 757         pkt = session->pkt.dpo;
 758         dat[1] = session->pkt.last - session->pkt.tx_acked;
 759         dat[2] = (pkt >> 0);
 760         dat[3] = (pkt >> 8);
 761         dat[4] = (pkt >> 16);
 762
 763         ret = j1939_tp_tx_ctl(session, false, dat);
 764         if (ret < 0)
 765                 return ret;
 766
 767         session->last_txcmd = dat[0];
 768         j1939_tp_set_rxtimeout(session, 1250);
 769         session->pkt.tx = session->pkt.tx_acked;
 770
 771         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 772
 773         return 0;
 774 }
 775
 776 static int j1939_session_tx_dat(struct j1939_session *session)
 777 {
 778         struct j1939_priv *priv = session->priv;
 779         struct j1939_sk_buff_cb *skcb;
 780         int offset, pkt_done, pkt_end;
 781         unsigned int len, pdelay;
 782         struct sk_buff *se_skb;
 783         const u8 *tpdat;
 784         int ret = 0;
 785         u8 dat[8];
 786
 787         se_skb = j1939_session_skb_get_by_offset(session, session->pkt.tx * 7);
 788         if (!se_skb)
 789                 return -ENOBUFS;
 790
 791         skcb = j1939_skb_to_cb(se_skb);
 792         tpdat = se_skb->data;
 793         ret = 0;
 794         pkt_done = 0;
 795         if (session->skcb.addr.type != J1939_ETP &&
 796             j1939_cb_is_broadcast(&session->skcb))
 797                 pkt_end = session->pkt.total;
 798         else
 799                 pkt_end = session->pkt.last;
 800
 801         while (session->pkt.tx < pkt_end) {
 802                 dat[0] = session->pkt.tx - session->pkt.dpo + 1;
 803                 offset = (session->pkt.tx * 7) - skcb->offset;
 804                 len =  se_skb->len - offset;
 805                 if (len > 7)
 806                         len = 7;
 807
 808                 if (offset + len > se_skb->len) {
 809                         netdev_err_once(priv->ndev,
 810                                         "%s: 0x%p: requested data outside of queued buffer: offset %i, len %i, pkt.tx: %i\n",
 811                                         __func__, session, skcb->offset, se_skb->len , session->pkt.tx);
 812                         ret = -EOVERFLOW;
 813                         goto out_free;
 814                 }
 815
 816                 if (!len) {
 817                         ret = -ENOBUFS;
 818                         break;
 819                 }
 820
 821                 memcpy(&dat[1], &tpdat[offset], len);
 822                 ret = j1939_tp_tx_dat(session, dat, len + 1);
 823                 if (ret < 0) {
 824                         /* ENOBUS == CAN interface TX queue is full */
 825                         if (ret != -ENOBUFS)
 826                                 netdev_alert(priv->ndev,
 827                                              "%s: 0x%p: queue data error: %i\n",
 828                                              __func__, session, ret);
 829                         break;
 830                 }
 831
 832                 session->last_txcmd = 0xff;
 833                 pkt_done++;
 834                 session->pkt.tx++;
 835                 pdelay = j1939_cb_is_broadcast(&session->skcb) ? 50 :
 836                         j1939_tp_packet_delay;
 837
 838                 if (session->pkt.tx < session->pkt.total && pdelay) {
 839                         j1939_tp_schedule_txtimer(session, pdelay);
 840                         break;
 841                 }
 842         }
 843
 844         if (pkt_done)
 845                 j1939_tp_set_rxtimeout(session, 250);
 846
 847  out_free:
 848         if (ret)
 849                 kfree_skb(se_skb);
 850         else
 851                 consume_skb(se_skb);
 852
 853         return ret;
 854 }
 855
 856 static int j1939_xtp_txnext_transmiter(struct j1939_session *session)
 857 {
 858         struct j1939_priv *priv = session->priv;
 859         int ret = 0;
 860
 861         if (!j1939_tp_im_transmitter(&session->skcb)) {
 862                 netdev_alert(priv->ndev, "%s: 0x%p: called by not transmitter!\n",
 863                              __func__, session);
 864                 return -EINVAL;
 865         }
 866
 867         switch (session->last_cmd) {
 868         case 0:
 869                 ret = j1939_session_tx_rts(session);
 870                 break;
 871
 872         case J1939_ETP_CMD_CTS:
 873                 if (session->last_txcmd != J1939_ETP_CMD_DPO) {
 874                         ret = j1939_session_tx_dpo(session);
 875                         if (ret)
 876                                 return ret;
 877                 }
 878
 879                 fallthrough;
 880         case J1939_TP_CMD_CTS:
 881         case 0xff: /* did some data */
 882         case J1939_ETP_CMD_DPO:
 883         case J1939_TP_CMD_BAM:
 884                 ret = j1939_session_tx_dat(session);
 885
 886                 break;
 887         default:
 888                 netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
 889                              __func__, session, session->last_cmd);
 890         }
 891
 892         return ret;
 893 }
 894
 895 static int j1939_session_tx_cts(struct j1939_session *session)
 896 {
 897         struct j1939_priv *priv = session->priv;
 898         unsigned int pkt, len;
 899         int ret;
 900         u8 dat[8];
 901
 902         if (!j1939_sk_recv_match(priv, &session->skcb))
 903                 return -ENOENT;
 904
 905         len = session->pkt.total - session->pkt.rx;
 906         len = min3(len, session->pkt.block, j1939_tp_block ?: 255);
 907         memset(dat, 0xff, sizeof(dat));
 908
 909         if (session->skcb.addr.type == J1939_ETP) {
 910                 pkt = session->pkt.rx + 1;
 911                 dat[0] = J1939_ETP_CMD_CTS;
 912                 dat[1] = len;
 913                 dat[2] = (pkt >> 0);
 914                 dat[3] = (pkt >> 8);
 915                 dat[4] = (pkt >> 16);
 916         } else {
 917                 dat[0] = J1939_TP_CMD_CTS;
 918                 dat[1] = len;
 919                 dat[2] = session->pkt.rx + 1;
 920         }
 921
 922         if (dat[0] == session->last_txcmd)
 923                 /* done already */
 924                 return 0;
 925
 926         ret = j1939_tp_tx_ctl(session, true, dat);
 927         if (ret < 0)
 928                 return ret;
 929
 930         if (len)
 931                 /* only mark cts done when len is set */
 932                 session->last_txcmd = dat[0];
 933         j1939_tp_set_rxtimeout(session, 1250);
 934
 935         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 936
 937         return 0;
 938 }
 939
 940 static int j1939_session_tx_eoma(struct j1939_session *session)
 941 {
 942         struct j1939_priv *priv = session->priv;
 943         u8 dat[8];
 944         int ret;
 945
 946         if (!j1939_sk_recv_match(priv, &session->skcb))
 947                 return -ENOENT;
 948
 949         memset(dat, 0xff, sizeof(dat));
 950
 951         if (session->skcb.addr.type == J1939_ETP) {
 952                 dat[0] = J1939_ETP_CMD_EOMA;
 953                 dat[1] = session->total_message_size >> 0;
 954                 dat[2] = session->total_message_size >> 8;
 955                 dat[3] = session->total_message_size >> 16;
 956                 dat[4] = session->total_message_size >> 24;
 957         } else {
 958                 dat[0] = J1939_TP_CMD_EOMA;
 959                 dat[1] = session->total_message_size;
 960                 dat[2] = session->total_message_size >> 8;
 961                 dat[3] = session->pkt.total;
 962         }
 963
 964         if (dat[0] == session->last_txcmd)
 965                 /* done already */
 966                 return 0;
 967
 968         ret = j1939_tp_tx_ctl(session, true, dat);
 969         if (ret < 0)
 970                 return ret;
 971
 972         session->last_txcmd = dat[0];
 973
 974         /* wait for the EOMA packet to come in */
 975         j1939_tp_set_rxtimeout(session, 1250);
 976
 977         netdev_dbg(session->priv->ndev, "%p: 0x%p\n", __func__, session);
 978
 979         return 0;
 980 }
 981
 982 static int j1939_xtp_txnext_receiver(struct j1939_session *session)
 983 {
 984         struct j1939_priv *priv = session->priv;
 985         int ret = 0;
 986
 987         if (!j1939_tp_im_receiver(&session->skcb)) {
 988                 netdev_alert(priv->ndev, "%s: 0x%p: called by not receiver!\n",
 989                              __func__, session);
 990                 return -EINVAL;
 991         }
 992
 993         switch (session->last_cmd) {
 994         case J1939_TP_CMD_RTS:
 995         case J1939_ETP_CMD_RTS:
 996                 ret = j1939_session_tx_cts(session);
 997                 break;
 998
 999         case J1939_ETP_CMD_CTS:
1000         case J1939_TP_CMD_CTS:
1001         case 0xff: /* did some data */
1002         case J1939_ETP_CMD_DPO:
1003                 if ((session->skcb.addr.type == J1939_TP &&
1004                      j1939_cb_is_broadcast(&session->skcb)))
1005                         break;
1006
1007                 if (session->pkt.rx >= session->pkt.total) {
1008                         ret = j1939_session_tx_eoma(session);
1009                 } else if (session->pkt.rx >= session->pkt.last) {
1010                         session->last_txcmd = 0;
1011                         ret = j1939_session_tx_cts(session);
1012                 }
1013                 break;
1014         default:
1015                 netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
1016                              __func__, session, session->last_cmd);
1017         }
1018
1019         return ret;
1020 }
1021
1022 static int j1939_simple_txnext(struct j1939_session *session)
1023 {
1024         struct j1939_priv *priv = session->priv;
1025         struct sk_buff *se_skb = j1939_session_skb_get(session);
1026         struct sk_buff *skb;
1027         int ret;
1028
1029         if (!se_skb)
1030                 return 0;
1031
1032         skb = skb_clone(se_skb, GFP_ATOMIC);
1033         if (!skb) {
1034                 ret = -ENOMEM;
1035                 goto out_free;
1036         }
1037
1038         can_skb_set_owner(skb, se_skb->sk);
1039
1040         j1939_tp_set_rxtimeout(session, J1939_SIMPLE_ECHO_TIMEOUT_MS);
1041
1042         ret = j1939_send_one(priv, skb);
1043         if (ret)
1044                 goto out_free;
1045
1046         j1939_sk_errqueue(session, J1939_ERRQUEUE_SCHED);
1047         j1939_sk_queue_activate_next(session);
1048
1049  out_free:
1050         if (ret)
1051                 kfree_skb(se_skb);
1052         else
1053                 consume_skb(se_skb);
1054
1055         return ret;
1056 }
1057
1058 static bool j1939_session_deactivate_locked(struct j1939_session *session)
1059 {
1060         bool active = false;
1061
1062         lockdep_assert_held(&session->priv->active_session_list_lock);
1063
1064         if (session->state >= J1939_SESSION_ACTIVE &&
1065             session->state < J1939_SESSION_ACTIVE_MAX) {
1066                 active = true;
1067
1068                 list_del_init(&session->active_session_list_entry);
1069                 session->state = J1939_SESSION_DONE;
1070                 j1939_session_put(session);
1071         }
1072
1073         return active;
1074 }
1075
1076 static bool j1939_session_deactivate(struct j1939_session *session)
1077 {
1078         bool active;
1079
1080         j1939_session_list_lock(session->priv);
1081         active = j1939_session_deactivate_locked(session);
1082         j1939_session_list_unlock(session->priv);
1083
1084         return active;
1085 }
1086
1087 static void
1088 j1939_session_deactivate_activate_next(struct j1939_session *session)
1089 {
1090         if (j1939_session_deactivate(session))
1091                 j1939_sk_queue_activate_next(session);
1092 }
1093
1094 static void __j1939_session_cancel(struct j1939_session *session,
1095                                  enum j1939_xtp_abort err)
1096 {
1097         struct j1939_priv *priv = session->priv;
1098
1099         WARN_ON_ONCE(!err);
1100         lockdep_assert_held(&session->priv->active_session_list_lock);
1101
1102         session->err = j1939_xtp_abort_to_errno(priv, err);
1103         session->state = J1939_SESSION_WAITING_ABORT;
1104         /* do not send aborts on incoming broadcasts */
1105         if (!j1939_cb_is_broadcast(&session->skcb)) {
1106                 j1939_xtp_tx_abort(priv, &session->skcb,
1107                                    !session->transmission,
1108                                    err, session->skcb.addr.pgn);
1109         }
1110
1111         if (session->sk)
1112                 j1939_sk_send_loop_abort(session->sk, session->err);
1113 }
1114
1115 static void j1939_session_cancel(struct j1939_session *session,
1116                                  enum j1939_xtp_abort err)
1117 {
1118         j1939_session_list_lock(session->priv);
1119
1120         if (session->state >= J1939_SESSION_ACTIVE &&
1121             session->state < J1939_SESSION_WAITING_ABORT) {
1122                 j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
1123                 __j1939_session_cancel(session, err);
1124         }
1125
1126         j1939_session_list_unlock(session->priv);
1127 }
1128
1129 static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
1130 {
1131         struct j1939_session *session =
1132                 container_of(hrtimer, struct j1939_session, txtimer);
1133         struct j1939_priv *priv = session->priv;
1134         int ret = 0;
1135
1136         if (session->skcb.addr.type == J1939_SIMPLE) {
1137                 ret = j1939_simple_txnext(session);
1138         } else {
1139                 if (session->transmission)
1140                         ret = j1939_xtp_txnext_transmiter(session);
1141                 else
1142                         ret = j1939_xtp_txnext_receiver(session);
1143         }
1144
1145         switch (ret) {
1146         case -ENOBUFS:
1147                 /* Retry limit is currently arbitrary chosen */
1148                 if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
1149                         session->tx_retry++;
1150                         j1939_tp_schedule_txtimer(session,
1151                                                   10 + prandom_u32_max(16));
1152                 } else {
1153                         netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
1154                                      __func__, session);
1155                         session->err = -ENETUNREACH;
1156                         j1939_session_rxtimer_cancel(session);
1157                         j1939_session_deactivate_activate_next(session);
1158                 }
1159                 break;
1160         case -ENETDOWN:
1161                 /* In this case we should get a netdev_event(), all active
1162                  * sessions will be cleared by
1163                  * j1939_cancel_all_active_sessions(). So handle this as an
1164                  * error, but let j1939_cancel_all_active_sessions() do the
1165                  * cleanup including propagation of the error to user space.
1166                  */
1167                 break;
1168         case -EOVERFLOW:
1169                 j1939_session_cancel(session, J1939_XTP_ABORT_ECTS_TOO_BIG);
1170                 break;
1171         case 0:
1172                 session->tx_retry = 0;
1173                 break;
1174         default:
1175                 netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
1176                              __func__, session, ret);
1177                 if (session->skcb.addr.type != J1939_SIMPLE) {
1178                         j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
1179                 } else {
1180                         session->err = ret;
1181                         j1939_session_rxtimer_cancel(session);
1182                         j1939_session_deactivate_activate_next(session);
1183                 }
1184         }
1185
1186         j1939_session_put(session);
1187
1188         return HRTIMER_NORESTART;
1189 }
1190
1191 static void j1939_session_completed(struct j1939_session *session)
1192 {
1193         struct sk_buff *skb;
1194
1195         if (!session->transmission) {
1196                 skb = j1939_session_skb_get(session);
1197                 /* distribute among j1939 receivers */
1198                 j1939_sk_recv(session->priv, skb);
1199                 consume_skb(skb);
1200         }
1201
1202         j1939_session_deactivate_activate_next(session);
1203 }
1204
1205 static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
1206 {
1207         struct j1939_session *session = container_of(hrtimer,
1208                                                      struct j1939_session,
1209                                                      rxtimer);
1210         struct j1939_priv *priv = session->priv;
1211
1212         if (session->state == J1939_SESSION_WAITING_ABORT) {
1213                 netdev_alert(priv->ndev, "%s: 0x%p: abort rx timeout. Force session deactivation\n",
1214                              __func__, session);
1215
1216                 j1939_session_deactivate_activate_next(session);
1217
1218         } else if (session->skcb.addr.type == J1939_SIMPLE) {
1219                 netdev_alert(priv->ndev, "%s: 0x%p: Timeout. Failed to send simple message.\n",
1220                              __func__, session);
1221
1222                 /* The message is probably stuck in the CAN controller and can
1223                  * be send as soon as CAN bus is in working state again.
1224                  */
1225                 session->err = -ETIME;
1226                 j1939_session_deactivate(session);
1227         } else {
1228                 netdev_alert(priv->ndev, "%s: 0x%p: rx timeout, send abort\n",
1229                              __func__, session);
1230
1231                 j1939_session_list_lock(session->priv);
1232                 if (session->state >= J1939_SESSION_ACTIVE &&
1233                     session->state < J1939_SESSION_ACTIVE_MAX) {
1234                         j1939_session_get(session);
1235                         hrtimer_start(&session->rxtimer,
1236                                       ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
1237                                       HRTIMER_MODE_REL_SOFT);
1238                         __j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
1239                 }
1240                 j1939_session_list_unlock(session->priv);
1241         }
1242
1243         j1939_session_put(session);
1244
1245         return HRTIMER_NORESTART;
1246 }
1247
1248 static bool j1939_xtp_rx_cmd_bad_pgn(struct j1939_session *session,
1249                                      const struct sk_buff *skb)
1250 {
1251         const struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1252         pgn_t pgn = j1939_xtp_ctl_to_pgn(skb->data);
1253         struct j1939_priv *priv = session->priv;
1254         enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1255         u8 cmd = skb->data[0];
1256
1257         if (session->skcb.addr.pgn == pgn)
1258                 return false;
1259
1260         switch (cmd) {
1261         case J1939_TP_CMD_BAM:
1262                 abort = J1939_XTP_NO_ABORT;
1263                 break;
1264
1265         case J1939_ETP_CMD_RTS:
1266         case J1939_TP_CMD_RTS: /* fall through */
1267                 abort = J1939_XTP_ABORT_BUSY;
1268                 break;
1269
1270         case J1939_ETP_CMD_CTS:
1271         case J1939_TP_CMD_CTS: /* fall through */
1272                 abort = J1939_XTP_ABORT_ECTS_UNXPECTED_PGN;
1273                 break;
1274
1275         case J1939_ETP_CMD_DPO:
1276                 abort = J1939_XTP_ABORT_BAD_EDPO_PGN;
1277                 break;
1278
1279         case J1939_ETP_CMD_EOMA:
1280         case J1939_TP_CMD_EOMA: /* fall through */
1281                 abort = J1939_XTP_ABORT_OTHER;
1282                 break;
1283
1284         case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
1285                 abort = J1939_XTP_NO_ABORT;
1286                 break;
1287
1288         default:
1289                 WARN_ON_ONCE(1);
1290                 break;
1291         }
1292
1293         netdev_warn(priv->ndev, "%s: 0x%p: CMD 0x%02x with PGN 0x%05x for running session with different PGN 0x%05x.\n",
1294                     __func__, session, cmd, pgn, session->skcb.addr.pgn);
1295         if (abort != J1939_XTP_NO_ABORT)
1296                 j1939_xtp_tx_abort(priv, skcb, true, abort, pgn);
1297
1298         return true;
1299 }
1300
1301 static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
1302                                    bool reverse, bool transmitter)
1303 {
1304         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1305         struct j1939_session *session;
1306         u8 abort = skb->data[1];
1307
1308         session = j1939_session_get_by_addr(priv, &skcb->addr, reverse,
1309                                             transmitter);
1310         if (!session)
1311                 return;
1312
1313         if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1314                 goto abort_put;
1315
1316         netdev_info(priv->ndev, "%s: 0x%p: 0x%05x: (%u) %s\n", __func__,
1317                     session, j1939_xtp_ctl_to_pgn(skb->data), abort,
1318                     j1939_xtp_abort_to_str(abort));
1319
1320         j1939_session_timers_cancel(session);
1321         session->err = j1939_xtp_abort_to_errno(priv, abort);
1322         if (session->sk)
1323                 j1939_sk_send_loop_abort(session->sk, session->err);
1324         j1939_session_deactivate_activate_next(session);
1325
1326 abort_put:
1327         j1939_session_put(session);
1328 }
1329
1330 /* abort packets may come in 2 directions */
1331 static void
1332 j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
1333                    bool transmitter)
1334 {
1335         j1939_xtp_rx_abort_one(priv, skb, false, transmitter);
1336         j1939_xtp_rx_abort_one(priv, skb, true, transmitter);
1337 }
1338
1339 static void
1340 j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
1341 {
1342         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1343         const u8 *dat;
1344         int len;
1345
1346         if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1347                 return;
1348
1349         dat = skb->data;
1350
1351         if (skcb->addr.type == J1939_ETP)
1352                 len = j1939_etp_ctl_to_size(dat);
1353         else
1354                 len = j1939_tp_ctl_to_size(dat);
1355
1356         if (session->total_message_size != len) {
1357                 netdev_warn_once(session->priv->ndev,
1358                                  "%s: 0x%p: Incorrect size. Expected: %i; got: %i.\n",
1359                                  __func__, session, session->total_message_size,
1360                                  len);
1361         }
1362
1363         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1364
1365         session->pkt.tx_acked = session->pkt.total;
1366         j1939_session_timers_cancel(session);
1367         /* transmitted without problems */
1368         j1939_session_completed(session);
1369 }
1370
1371 static void
1372 j1939_xtp_rx_eoma(struct j1939_priv *priv, struct sk_buff *skb,
1373                   bool transmitter)
1374 {
1375         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1376         struct j1939_session *session;
1377
1378         session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1379                                             transmitter);
1380         if (!session)
1381                 return;
1382
1383         j1939_xtp_rx_eoma_one(session, skb);
1384         j1939_session_put(session);
1385 }
1386
1387 static void
1388 j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
1389 {
1390         enum j1939_xtp_abort err = J1939_XTP_ABORT_FAULT;
1391         unsigned int pkt;
1392         const u8 *dat;
1393
1394         dat = skb->data;
1395
1396         if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1397                 return;
1398
1399         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1400
1401         if (session->last_cmd == dat[0]) {
1402                 err = J1939_XTP_ABORT_DUP_SEQ;
1403                 goto out_session_cancel;
1404         }
1405
1406         if (session->skcb.addr.type == J1939_ETP)
1407                 pkt = j1939_etp_ctl_to_packet(dat);
1408         else
1409                 pkt = dat[2];
1410
1411         if (!pkt)
1412                 goto out_session_cancel;
1413         else if (dat[1] > session->pkt.block /* 0xff for etp */)
1414                 goto out_session_cancel;
1415
1416         /* set packet counters only when not CTS(0) */
1417         session->pkt.tx_acked = pkt - 1;
1418         j1939_session_skb_drop_old(session);
1419         session->pkt.last = session->pkt.tx_acked + dat[1];
1420         if (session->pkt.last > session->pkt.total)
1421                 /* safety measure */
1422                 session->pkt.last = session->pkt.total;
1423         /* TODO: do not set tx here, do it in txtimer */
1424         session->pkt.tx = session->pkt.tx_acked;
1425
1426         session->last_cmd = dat[0];
1427         if (dat[1]) {
1428                 j1939_tp_set_rxtimeout(session, 1250);
1429                 if (session->transmission) {
1430                         if (session->pkt.tx_acked)
1431                                 j1939_sk_errqueue(session,
1432                                                   J1939_ERRQUEUE_SCHED);
1433                         j1939_session_txtimer_cancel(session);
1434                         j1939_tp_schedule_txtimer(session, 0);
1435                 }
1436         } else {
1437                 /* CTS(0) */
1438                 j1939_tp_set_rxtimeout(session, 550);
1439         }
1440         return;
1441
1442  out_session_cancel:
1443         j1939_session_timers_cancel(session);
1444         j1939_session_cancel(session, err);
1445 }
1446
1447 static void
1448 j1939_xtp_rx_cts(struct j1939_priv *priv, struct sk_buff *skb, bool transmitter)
1449 {
1450         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1451         struct j1939_session *session;
1452
1453         session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1454                                             transmitter);
1455         if (!session)
1456                 return;
1457         j1939_xtp_rx_cts_one(session, skb);
1458         j1939_session_put(session);
1459 }
1460
1461 static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
1462                                                struct sk_buff *skb, size_t size)
1463 {
1464         struct j1939_session *session;
1465         struct j1939_sk_buff_cb *skcb;
1466
1467         session = kzalloc(sizeof(*session), gfp_any());
1468         if (!session)
1469                 return NULL;
1470
1471         INIT_LIST_HEAD(&session->active_session_list_entry);
1472         INIT_LIST_HEAD(&session->sk_session_queue_entry);
1473         kref_init(&session->kref);
1474
1475         j1939_priv_get(priv);
1476         session->priv = priv;
1477         session->total_message_size = size;
1478         session->state = J1939_SESSION_NEW;
1479
1480         skb_queue_head_init(&session->skb_queue);
1481         skb_queue_tail(&session->skb_queue, skb);
1482
1483         skcb = j1939_skb_to_cb(skb);
1484         memcpy(&session->skcb, skcb, sizeof(session->skcb));
1485
1486         hrtimer_init(&session->txtimer, CLOCK_MONOTONIC,
1487                      HRTIMER_MODE_REL_SOFT);
1488         session->txtimer.function = j1939_tp_txtimer;
1489         hrtimer_init(&session->rxtimer, CLOCK_MONOTONIC,
1490                      HRTIMER_MODE_REL_SOFT);
1491         session->rxtimer.function = j1939_tp_rxtimer;
1492
1493         netdev_dbg(priv->ndev, "%s: 0x%p: sa: %02x, da: %02x\n",
1494                    __func__, session, skcb->addr.sa, skcb->addr.da);
1495
1496         return session;
1497 }
1498
1499 static struct
1500 j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
1501                                        int size,
1502                                        const struct j1939_sk_buff_cb *rel_skcb)
1503 {
1504         struct sk_buff *skb;
1505         struct j1939_sk_buff_cb *skcb;
1506         struct j1939_session *session;
1507
1508         skb = alloc_skb(size + sizeof(struct can_skb_priv), GFP_ATOMIC);
1509         if (unlikely(!skb))
1510                 return NULL;
1511
1512         skb->dev = priv->ndev;
1513         can_skb_reserve(skb);
1514         can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
1515         can_skb_prv(skb)->skbcnt = 0;
1516         skcb = j1939_skb_to_cb(skb);
1517         memcpy(skcb, rel_skcb, sizeof(*skcb));
1518
1519         session = j1939_session_new(priv, skb, size);
1520         if (!session) {
1521                 kfree_skb(skb);
1522                 return NULL;
1523         }
1524
1525         /* alloc data area */
1526         skb_put(skb, size);
1527         /* skb is recounted in j1939_session_new() */
1528         return session;
1529 }
1530
1531 int j1939_session_activate(struct j1939_session *session)
1532 {
1533         struct j1939_priv *priv = session->priv;
1534         struct j1939_session *active = NULL;
1535         int ret = 0;
1536
1537         j1939_session_list_lock(priv);
1538         if (session->skcb.addr.type != J1939_SIMPLE)
1539                 active = j1939_session_get_by_addr_locked(priv,
1540                                                           &priv->active_session_list,
1541                                                           &session->skcb.addr, false,
1542                                                           session->transmission);
1543         if (active) {
1544                 j1939_session_put(active);
1545                 ret = -EAGAIN;
1546         } else {
1547                 WARN_ON_ONCE(session->state != J1939_SESSION_NEW);
1548                 list_add_tail(&session->active_session_list_entry,
1549                               &priv->active_session_list);
1550                 j1939_session_get(session);
1551                 session->state = J1939_SESSION_ACTIVE;
1552
1553                 netdev_dbg(session->priv->ndev, "%s: 0x%p\n",
1554                            __func__, session);
1555         }
1556         j1939_session_list_unlock(priv);
1557
1558         return ret;
1559 }
1560
1561 static struct
1562 j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
1563                                             struct sk_buff *skb)
1564 {
1565         enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1566         struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
1567         struct j1939_session *session;
1568         const u8 *dat;
1569         pgn_t pgn;
1570         int len;
1571
1572         netdev_dbg(priv->ndev, "%s\n", __func__);
1573
1574         dat = skb->data;
1575         pgn = j1939_xtp_ctl_to_pgn(dat);
1576         skcb.addr.pgn = pgn;
1577
1578         if (!j1939_sk_recv_match(priv, &skcb))
1579                 return NULL;
1580
1581         if (skcb.addr.type == J1939_ETP) {
1582                 len = j1939_etp_ctl_to_size(dat);
1583                 if (len > J1939_MAX_ETP_PACKET_SIZE)
1584                         abort = J1939_XTP_ABORT_FAULT;
1585                 else if (len > priv->tp_max_packet_size)
1586                         abort = J1939_XTP_ABORT_RESOURCE;
1587                 else if (len <= J1939_MAX_TP_PACKET_SIZE)
1588                         abort = J1939_XTP_ABORT_FAULT;
1589         } else {
1590                 len = j1939_tp_ctl_to_size(dat);
1591                 if (len > J1939_MAX_TP_PACKET_SIZE)
1592                         abort = J1939_XTP_ABORT_FAULT;
1593                 else if (len > priv->tp_max_packet_size)
1594                         abort = J1939_XTP_ABORT_RESOURCE;
1595         }
1596
1597         if (abort != J1939_XTP_NO_ABORT) {
1598                 j1939_xtp_tx_abort(priv, &skcb, true, abort, pgn);
1599                 return NULL;
1600         }
1601
1602         session = j1939_session_fresh_new(priv, len, &skcb);
1603         if (!session) {
1604                 j1939_xtp_tx_abort(priv, &skcb, true,
1605                                    J1939_XTP_ABORT_RESOURCE, pgn);
1606                 return NULL;
1607         }
1608
1609         /* initialize the control buffer: plain copy */
1610         session->pkt.total = (len + 6) / 7;
1611         session->pkt.block = 0xff;
1612         if (skcb.addr.type != J1939_ETP) {
1613                 if (dat[3] != session->pkt.total)
1614                         netdev_alert(priv->ndev, "%s: 0x%p: strange total, %u != %u\n",
1615                                      __func__, session, session->pkt.total,
1616                                      dat[3]);
1617                 session->pkt.total = dat[3];
1618                 session->pkt.block = min(dat[3], dat[4]);
1619         }
1620
1621         session->pkt.rx = 0;
1622         session->pkt.tx = 0;
1623
1624         WARN_ON_ONCE(j1939_session_activate(session));
1625
1626         return session;
1627 }
1628
1629 static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
1630                                            struct sk_buff *skb)
1631 {
1632         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1633         struct j1939_priv *priv = session->priv;
1634
1635         if (!session->transmission) {
1636                 if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1637                         return -EBUSY;
1638
1639                 /* RTS on active session */
1640                 j1939_session_timers_cancel(session);
1641                 j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1642         }
1643
1644         if (session->last_cmd != 0) {
1645                 /* we received a second rts on the same connection */
1646                 netdev_alert(priv->ndev, "%s: 0x%p: connection exists (%02x %02x). last cmd: %x\n",
1647                              __func__, session, skcb->addr.sa, skcb->addr.da,
1648                              session->last_cmd);
1649
1650                 j1939_session_timers_cancel(session);
1651                 j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1652
1653                 return -EBUSY;
1654         }
1655
1656         if (session->skcb.addr.sa != skcb->addr.sa ||
1657             session->skcb.addr.da != skcb->addr.da)
1658                 netdev_warn(priv->ndev, "%s: 0x%p: session->skcb.addr.sa=0x%02x skcb->addr.sa=0x%02x session->skcb.addr.da=0x%02x skcb->addr.da=0x%02x\n",
1659                             __func__, session,
1660                             session->skcb.addr.sa, skcb->addr.sa,
1661                             session->skcb.addr.da, skcb->addr.da);
1662         /* make sure 'sa' & 'da' are correct !
1663          * They may be 'not filled in yet' for sending
1664          * skb's, since they did not pass the Address Claim ever.
1665          */
1666         session->skcb.addr.sa = skcb->addr.sa;
1667         session->skcb.addr.da = skcb->addr.da;
1668
1669         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1670
1671         return 0;
1672 }
1673
1674 static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
1675                              bool transmitter)
1676 {
1677         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1678         struct j1939_session *session;
1679         u8 cmd = skb->data[0];
1680
1681         session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1682                                             transmitter);
1683
1684         if (!session) {
1685                 if (transmitter) {
1686                         /* If we're the transmitter and this function is called,
1687                          * we received our own RTS. A session has already been
1688                          * created.
1689                          *
1690                          * For some reasons however it might have been destroyed
1691                          * already. So don't create a new one here (using
1692                          * "j1939_xtp_rx_rts_session_new()") as this will be a
1693                          * receiver session.
1694                          *
1695                          * The reasons the session is already destroyed might
1696                          * be:
1697                          * - user space closed socket was and the session was
1698                          *   aborted
1699                          * - session was aborted due to external abort message
1700                          */
1701                         return;
1702                 }
1703                 session = j1939_xtp_rx_rts_session_new(priv, skb);
1704                 if (!session) {
1705                         if (cmd == J1939_TP_CMD_BAM && j1939_sk_recv_match(priv, skcb))
1706                                 netdev_info(priv->ndev, "%s: failed to create TP BAM session\n",
1707                                             __func__);
1708                         return;
1709                 }
1710         } else {
1711                 if (j1939_xtp_rx_rts_session_active(session, skb)) {
1712                         j1939_session_put(session);
1713                         return;
1714                 }
1715         }
1716         session->last_cmd = cmd;
1717
1718         if (cmd == J1939_TP_CMD_BAM) {
1719                 if (!session->transmission)
1720                         j1939_tp_set_rxtimeout(session, 750);
1721         } else {
1722                 if (!session->transmission) {
1723                         j1939_session_txtimer_cancel(session);
1724                         j1939_tp_schedule_txtimer(session, 0);
1725                 }
1726                 j1939_tp_set_rxtimeout(session, 1250);
1727         }
1728
1729         j1939_session_put(session);
1730 }
1731
1732 static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
1733                                  struct sk_buff *skb)
1734 {
1735         const u8 *dat = skb->data;
1736
1737         if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1738                 return;
1739
1740         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1741
1742         /* transmitted without problems */
1743         session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
1744         session->last_cmd = dat[0];
1745         j1939_tp_set_rxtimeout(session, 750);
1746 }
1747
1748 static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,
1749                              bool transmitter)
1750 {
1751         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1752         struct j1939_session *session;
1753
1754         session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1755                                             transmitter);
1756         if (!session) {
1757                 netdev_info(priv->ndev,
1758                             "%s: no connection found\n", __func__);
1759                 return;
1760         }
1761
1762         j1939_xtp_rx_dpo_one(session, skb);
1763         j1939_session_put(session);
1764 }
1765
1766 static void j1939_xtp_rx_dat_one(struct j1939_session *session,
1767                                  struct sk_buff *skb)
1768 {
1769         struct j1939_priv *priv = session->priv;
1770         struct j1939_sk_buff_cb *skcb;
1771         struct sk_buff *se_skb = NULL;
1772         const u8 *dat;
1773         u8 *tpdat;
1774         int offset;
1775         int nbytes;
1776         bool final = false;
1777         bool remain = false;
1778         bool do_cts_eoma = false;
1779         int packet;
1780
1781         skcb = j1939_skb_to_cb(skb);
1782         dat = skb->data;
1783         if (skb->len <= 1)
1784                 /* makes no sense */
1785                 goto out_session_cancel;
1786
1787         switch (session->last_cmd) {
1788         case 0xff:
1789                 break;
1790         case J1939_ETP_CMD_DPO:
1791                 if (skcb->addr.type == J1939_ETP)
1792                         break;
1793                 fallthrough;
1794         case J1939_TP_CMD_BAM:
1795         case J1939_TP_CMD_CTS: /* fall through */
1796                 if (skcb->addr.type != J1939_ETP)
1797                         break;
1798                 fallthrough;
1799         default:
1800                 netdev_info(priv->ndev, "%s: 0x%p: last %02x\n", __func__,
1801                             session, session->last_cmd);
1802                 goto out_session_cancel;
1803         }
1804
1805         packet = (dat[0] - 1 + session->pkt.dpo);
1806         if (packet > session->pkt.total ||
1807             (session->pkt.rx + 1) > session->pkt.total) {
1808                 netdev_info(priv->ndev, "%s: 0x%p: should have been completed\n",
1809                             __func__, session);
1810                 goto out_session_cancel;
1811         }
1812
1813         se_skb = j1939_session_skb_get_by_offset(session, packet * 7);
1814         if (!se_skb) {
1815                 netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
1816                             session);
1817                 goto out_session_cancel;
1818         }
1819
1820         skcb = j1939_skb_to_cb(se_skb);
1821         offset = packet * 7 - skcb->offset;
1822         nbytes = se_skb->len - offset;
1823         if (nbytes > 7)
1824                 nbytes = 7;
1825         if (nbytes <= 0 || (nbytes + 1) > skb->len) {
1826                 netdev_info(priv->ndev, "%s: 0x%p: nbytes %i, len %i\n",
1827                             __func__, session, nbytes, skb->len);
1828                 goto out_session_cancel;
1829         }
1830
1831         tpdat = se_skb->data;
1832         if (!session->transmission) {
1833                 memcpy(&tpdat[offset], &dat[1], nbytes);
1834         } else {
1835                 int err;
1836
1837                 err = memcmp(&tpdat[offset], &dat[1], nbytes);
1838                 if (err)
1839                         netdev_err_once(priv->ndev,
1840                                         "%s: 0x%p: Data of RX-looped back packet (%*ph) doesn't match TX data (%*ph)!\n",
1841                                         __func__, session,
1842                                         nbytes, &dat[1],
1843                                         nbytes, &tpdat[offset]);
1844         }
1845
1846         if (packet == session->pkt.rx)
1847                 session->pkt.rx++;
1848
1849         if (skcb->addr.type != J1939_ETP &&
1850             j1939_cb_is_broadcast(&session->skcb)) {
1851                 if (session->pkt.rx >= session->pkt.total)
1852                         final = true;
1853                 else
1854                         remain = true;
1855         } else {
1856                 /* never final, an EOMA must follow */
1857                 if (session->pkt.rx >= session->pkt.last)
1858                         do_cts_eoma = true;
1859         }
1860
1861         if (final) {
1862                 j1939_session_timers_cancel(session);
1863                 j1939_session_completed(session);
1864         } else if (remain) {
1865                 if (!session->transmission)
1866                         j1939_tp_set_rxtimeout(session, 750);
1867         } else if (do_cts_eoma) {
1868                 j1939_tp_set_rxtimeout(session, 1250);
1869                 if (!session->transmission)
1870                         j1939_tp_schedule_txtimer(session, 0);
1871         } else {
1872                 j1939_tp_set_rxtimeout(session, 250);
1873         }
1874         session->last_cmd = 0xff;
1875         consume_skb(se_skb);
1876         j1939_session_put(session);
1877
1878         return;
1879
1880  out_session_cancel:
1881         kfree_skb(se_skb);
1882         j1939_session_timers_cancel(session);
1883         j1939_session_cancel(session, J1939_XTP_ABORT_FAULT);
1884         j1939_session_put(session);
1885 }
1886
1887 static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
1888 {
1889         struct j1939_sk_buff_cb *skcb;
1890         struct j1939_session *session;
1891
1892         skcb = j1939_skb_to_cb(skb);
1893
1894         if (j1939_tp_im_transmitter(skcb)) {
1895                 session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1896                                                     true);
1897                 if (!session)
1898                         netdev_info(priv->ndev, "%s: no tx connection found\n",
1899                                     __func__);
1900                 else
1901                         j1939_xtp_rx_dat_one(session, skb);
1902         }
1903
1904         if (j1939_tp_im_receiver(skcb)) {
1905                 session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1906                                                     false);
1907                 if (!session)
1908                         netdev_info(priv->ndev, "%s: no rx connection found\n",
1909                                     __func__);
1910                 else
1911                         j1939_xtp_rx_dat_one(session, skb);
1912         }
1913
1914         if (j1939_cb_is_broadcast(skcb)) {
1915                 session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1916                                                     false);
1917                 if (session)
1918                         j1939_xtp_rx_dat_one(session, skb);
1919         }
1920 }
1921
1922 /* j1939 main intf */
1923 struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
1924                                     struct sk_buff *skb, size_t size)
1925 {
1926         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1927         struct j1939_session *session;
1928         int ret;
1929
1930         if (skcb->addr.pgn == J1939_TP_PGN_DAT ||
1931             skcb->addr.pgn == J1939_TP_PGN_CTL ||
1932             skcb->addr.pgn == J1939_ETP_PGN_DAT ||
1933             skcb->addr.pgn == J1939_ETP_PGN_CTL)
1934                 /* avoid conflict */
1935                 return ERR_PTR(-EDOM);
1936
1937         if (size > priv->tp_max_packet_size)
1938                 return ERR_PTR(-EMSGSIZE);
1939
1940         if (size <= 8)
1941                 skcb->addr.type = J1939_SIMPLE;
1942         else if (size > J1939_MAX_TP_PACKET_SIZE)
1943                 skcb->addr.type = J1939_ETP;
1944         else
1945                 skcb->addr.type = J1939_TP;
1946
1947         if (skcb->addr.type == J1939_ETP &&
1948             j1939_cb_is_broadcast(skcb))
1949                 return ERR_PTR(-EDESTADDRREQ);
1950
1951         /* fill in addresses from names */
1952         ret = j1939_ac_fixup(priv, skb);
1953         if (unlikely(ret))
1954                 return ERR_PTR(ret);
1955
1956         /* fix DST flags, it may be used there soon */
1957         if (j1939_address_is_unicast(skcb->addr.da) &&
1958             priv->ents[skcb->addr.da].nusers)
1959                 skcb->flags |= J1939_ECU_LOCAL_DST;
1960
1961         /* src is always local, I'm sending ... */
1962         skcb->flags |= J1939_ECU_LOCAL_SRC;
1963
1964         /* prepare new session */
1965         session = j1939_session_new(priv, skb, size);
1966         if (!session)
1967                 return ERR_PTR(-ENOMEM);
1968
1969         /* skb is recounted in j1939_session_new() */
1970         sock_hold(skb->sk);
1971         session->sk = skb->sk;
1972         session->transmission = true;
1973         session->pkt.total = (size + 6) / 7;
1974         session->pkt.block = skcb->addr.type == J1939_ETP ? 255 :
1975                 min(j1939_tp_block ?: 255, session->pkt.total);
1976
1977         if (j1939_cb_is_broadcast(&session->skcb))
1978                 /* set the end-packet for broadcast */
1979                 session->pkt.last = session->pkt.total;
1980
1981         skcb->tskey = session->sk->sk_tskey++;
1982         session->tskey = skcb->tskey;
1983
1984         return session;
1985 }
1986
1987 static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
1988 {
1989         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1990         int extd = J1939_TP;
1991         u8 cmd = skb->data[0];
1992
1993         switch (cmd) {
1994         case J1939_ETP_CMD_RTS:
1995                 extd = J1939_ETP;
1996                 fallthrough;
1997         case J1939_TP_CMD_BAM:
1998         case J1939_TP_CMD_RTS: /* fall through */
1999                 if (skcb->addr.type != extd)
2000                         return;
2001
2002                 if (cmd == J1939_TP_CMD_RTS && j1939_cb_is_broadcast(skcb)) {
2003                         netdev_alert(priv->ndev, "%s: rts without destination (%02x)\n",
2004                                      __func__, skcb->addr.sa);
2005                         return;
2006                 }
2007
2008                 if (j1939_tp_im_transmitter(skcb))
2009                         j1939_xtp_rx_rts(priv, skb, true);
2010
2011                 if (j1939_tp_im_receiver(skcb) || j1939_cb_is_broadcast(skcb))
2012                         j1939_xtp_rx_rts(priv, skb, false);
2013
2014                 break;
2015
2016         case J1939_ETP_CMD_CTS:
2017                 extd = J1939_ETP;
2018                 fallthrough;
2019         case J1939_TP_CMD_CTS:
2020                 if (skcb->addr.type != extd)
2021                         return;
2022
2023                 if (j1939_tp_im_transmitter(skcb))
2024                         j1939_xtp_rx_cts(priv, skb, false);
2025
2026                 if (j1939_tp_im_receiver(skcb))
2027                         j1939_xtp_rx_cts(priv, skb, true);
2028
2029                 break;
2030
2031         case J1939_ETP_CMD_DPO:
2032                 if (skcb->addr.type != J1939_ETP)
2033                         return;
2034
2035                 if (j1939_tp_im_transmitter(skcb))
2036                         j1939_xtp_rx_dpo(priv, skb, true);
2037
2038                 if (j1939_tp_im_receiver(skcb))
2039                         j1939_xtp_rx_dpo(priv, skb, false);
2040
2041                 break;
2042
2043         case J1939_ETP_CMD_EOMA:
2044                 extd = J1939_ETP;
2045                 fallthrough;
2046         case J1939_TP_CMD_EOMA:
2047                 if (skcb->addr.type != extd)
2048                         return;
2049
2050                 if (j1939_tp_im_transmitter(skcb))
2051                         j1939_xtp_rx_eoma(priv, skb, false);
2052
2053                 if (j1939_tp_im_receiver(skcb))
2054                         j1939_xtp_rx_eoma(priv, skb, true);
2055
2056                 break;
2057
2058         case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
2059                 if (j1939_tp_im_transmitter(skcb))
2060                         j1939_xtp_rx_abort(priv, skb, true);
2061
2062                 if (j1939_tp_im_receiver(skcb))
2063                         j1939_xtp_rx_abort(priv, skb, false);
2064
2065                 break;
2066         default:
2067                 return;
2068         }
2069 }
2070
2071 int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
2072 {
2073         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
2074
2075         if (!j1939_tp_im_involved_anydir(skcb) && !j1939_cb_is_broadcast(skcb))
2076                 return 0;
2077
2078         switch (skcb->addr.pgn) {
2079         case J1939_ETP_PGN_DAT:
2080                 skcb->addr.type = J1939_ETP;
2081                 fallthrough;
2082         case J1939_TP_PGN_DAT:
2083                 j1939_xtp_rx_dat(priv, skb);
2084                 break;
2085
2086         case J1939_ETP_PGN_CTL:
2087                 skcb->addr.type = J1939_ETP;
2088                 fallthrough;
2089         case J1939_TP_PGN_CTL:
2090                 if (skb->len < 8)
2091                         return 0; /* Don't care. Nothing to extract here */
2092
2093                 j1939_tp_cmd_recv(priv, skb);
2094                 break;
2095         default:
2096                 return 0; /* no problem */
2097         }
2098         return 1; /* "I processed the message" */
2099 }
2100
2101 void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
2102 {
2103         struct j1939_session *session;
2104
2105         if (!skb->sk)
2106                 return;
2107
2108         if (skb->sk->sk_family != AF_CAN ||
2109             skb->sk->sk_protocol != CAN_J1939)
2110                 return;
2111
2112         j1939_session_list_lock(priv);
2113         session = j1939_session_get_simple(priv, skb);
2114         j1939_session_list_unlock(priv);
2115         if (!session) {
2116                 netdev_warn(priv->ndev,
2117                             "%s: Received already invalidated message\n",
2118                             __func__);
2119                 return;
2120         }
2121
2122         j1939_session_timers_cancel(session);
2123         j1939_session_deactivate(session);
2124         j1939_session_put(session);
2125 }
2126
2127 int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
2128 {
2129         struct j1939_session *session, *saved;
2130
2131         netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
2132         j1939_session_list_lock(priv);
2133         list_for_each_entry_safe(session, saved,
2134                                  &priv->active_session_list,
2135                                  active_session_list_entry) {
2136                 if (!sk || sk == session->sk) {
2137                         if (hrtimer_try_to_cancel(&session->txtimer) == 1)
2138                                 j1939_session_put(session);
2139                         if (hrtimer_try_to_cancel(&session->rxtimer) == 1)
2140                                 j1939_session_put(session);
2141
2142                         session->err = ESHUTDOWN;
2143                         j1939_session_deactivate_locked(session);
2144                 }
2145         }
2146         j1939_session_list_unlock(priv);
2147         return NOTIFY_DONE;
2148 }
2149
2150 void j1939_tp_init(struct j1939_priv *priv)
2151 {
2152         spin_lock_init(&priv->active_session_list_lock);
2153         INIT_LIST_HEAD(&priv->active_session_list);
2154         priv->tp_max_packet_size = J1939_MAX_ETP_PACKET_SIZE;
2155 }