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                 kfree_skb(do_skb);
 334         }
 335         spin_unlock_irqrestore(&session->skb_queue.lock, flags);
 336 }
 337
 338 void j1939_session_skb_queue(struct j1939_session *session,
 339                              struct sk_buff *skb)
 340 {
 341         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
 342         struct j1939_priv *priv = session->priv;
 343
 344         j1939_ac_fixup(priv, skb);
 345
 346         if (j1939_address_is_unicast(skcb->addr.da) &&
 347             priv->ents[skcb->addr.da].nusers)
 348                 skcb->flags |= J1939_ECU_LOCAL_DST;
 349
 350         skcb->flags |= J1939_ECU_LOCAL_SRC;
 351
 352         skb_queue_tail(&session->skb_queue, skb);
 353 }
 354
 355 static struct
 356 sk_buff *j1939_session_skb_find_by_offset(struct j1939_session *session,
 357                                           unsigned int offset_start)
 358 {
 359         struct j1939_priv *priv = session->priv;
 360         struct j1939_sk_buff_cb *do_skcb;
 361         struct sk_buff *skb = NULL;
 362         struct sk_buff *do_skb;
 363         unsigned long flags;
 364
 365         spin_lock_irqsave(&session->skb_queue.lock, flags);
 366         skb_queue_walk(&session->skb_queue, do_skb) {
 367                 do_skcb = j1939_skb_to_cb(do_skb);
 368
 369                 if (offset_start >= do_skcb->offset &&
 370                     offset_start < (do_skcb->offset + do_skb->len)) {
 371                         skb = do_skb;
 372                 }
 373         }
 374         spin_unlock_irqrestore(&session->skb_queue.lock, flags);
 375
 376         if (!skb)
 377                 netdev_dbg(priv->ndev, "%s: 0x%p: no skb found for start: %i, queue size: %i\n",
 378                            __func__, session, offset_start,
 379                            skb_queue_len(&session->skb_queue));
 380
 381         return skb;
 382 }
 383
 384 static struct sk_buff *j1939_session_skb_find(struct j1939_session *session)
 385 {
 386         unsigned int offset_start;
 387
 388         offset_start = session->pkt.dpo * 7;
 389         return j1939_session_skb_find_by_offset(session, offset_start);
 390 }
 391
 392 /* see if we are receiver
 393  * returns 0 for broadcasts, although we will receive them
 394  */
 395 static inline int j1939_tp_im_receiver(const struct j1939_sk_buff_cb *skcb)
 396 {
 397         return skcb->flags & J1939_ECU_LOCAL_DST;
 398 }
 399
 400 /* see if we are sender */
 401 static inline int j1939_tp_im_transmitter(const struct j1939_sk_buff_cb *skcb)
 402 {
 403         return skcb->flags & J1939_ECU_LOCAL_SRC;
 404 }
 405
 406 /* see if we are involved as either receiver or transmitter */
 407 static int j1939_tp_im_involved(const struct j1939_sk_buff_cb *skcb, bool swap)
 408 {
 409         if (swap)
 410                 return j1939_tp_im_receiver(skcb);
 411         else
 412                 return j1939_tp_im_transmitter(skcb);
 413 }
 414
 415 static int j1939_tp_im_involved_anydir(struct j1939_sk_buff_cb *skcb)
 416 {
 417         return skcb->flags & (J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
 418 }
 419
 420 /* extract pgn from flow-ctl message */
 421 static inline pgn_t j1939_xtp_ctl_to_pgn(const u8 *dat)
 422 {
 423         pgn_t pgn;
 424
 425         pgn = (dat[7] << 16) | (dat[6] << 8) | (dat[5] << 0);
 426         if (j1939_pgn_is_pdu1(pgn))
 427                 pgn &= 0xffff00;
 428         return pgn;
 429 }
 430
 431 static inline unsigned int j1939_tp_ctl_to_size(const u8 *dat)
 432 {
 433         return (dat[2] << 8) + (dat[1] << 0);
 434 }
 435
 436 static inline unsigned int j1939_etp_ctl_to_packet(const u8 *dat)
 437 {
 438         return (dat[4] << 16) | (dat[3] << 8) | (dat[2] << 0);
 439 }
 440
 441 static inline unsigned int j1939_etp_ctl_to_size(const u8 *dat)
 442 {
 443         return (dat[4] << 24) | (dat[3] << 16) |
 444                 (dat[2] << 8) | (dat[1] << 0);
 445 }
 446
 447 /* find existing session:
 448  * reverse: swap cb's src & dst
 449  * there is no problem with matching broadcasts, since
 450  * broadcasts (no dst, no da) would never call this
 451  * with reverse == true
 452  */
 453 static bool j1939_session_match(struct j1939_addr *se_addr,
 454                                 struct j1939_addr *sk_addr, bool reverse)
 455 {
 456         if (se_addr->type != sk_addr->type)
 457                 return false;
 458
 459         if (reverse) {
 460                 if (se_addr->src_name) {
 461                         if (se_addr->src_name != sk_addr->dst_name)
 462                                 return false;
 463                 } else if (se_addr->sa != sk_addr->da) {
 464                         return false;
 465                 }
 466
 467                 if (se_addr->dst_name) {
 468                         if (se_addr->dst_name != sk_addr->src_name)
 469                                 return false;
 470                 } else if (se_addr->da != sk_addr->sa) {
 471                         return false;
 472                 }
 473         } else {
 474                 if (se_addr->src_name) {
 475                         if (se_addr->src_name != sk_addr->src_name)
 476                                 return false;
 477                 } else if (se_addr->sa != sk_addr->sa) {
 478                         return false;
 479                 }
 480
 481                 if (se_addr->dst_name) {
 482                         if (se_addr->dst_name != sk_addr->dst_name)
 483                                 return false;
 484                 } else if (se_addr->da != sk_addr->da) {
 485                         return false;
 486                 }
 487         }
 488
 489         return true;
 490 }
 491
 492 static struct
 493 j1939_session *j1939_session_get_by_addr_locked(struct j1939_priv *priv,
 494                                                 struct list_head *root,
 495                                                 struct j1939_addr *addr,
 496                                                 bool reverse, bool transmitter)
 497 {
 498         struct j1939_session *session;
 499
 500         lockdep_assert_held(&priv->active_session_list_lock);
 501
 502         list_for_each_entry(session, root, active_session_list_entry) {
 503                 j1939_session_get(session);
 504                 if (j1939_session_match(&session->skcb.addr, addr, reverse) &&
 505                     session->transmission == transmitter)
 506                         return session;
 507                 j1939_session_put(session);
 508         }
 509
 510         return NULL;
 511 }
 512
 513 static struct
 514 j1939_session *j1939_session_get_simple(struct j1939_priv *priv,
 515                                         struct sk_buff *skb)
 516 {
 517         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
 518         struct j1939_session *session;
 519
 520         lockdep_assert_held(&priv->active_session_list_lock);
 521
 522         list_for_each_entry(session, &priv->active_session_list,
 523                             active_session_list_entry) {
 524                 j1939_session_get(session);
 525                 if (session->skcb.addr.type == J1939_SIMPLE &&
 526                     session->tskey == skcb->tskey && session->sk == skb->sk)
 527                         return session;
 528                 j1939_session_put(session);
 529         }
 530
 531         return NULL;
 532 }
 533
 534 static struct
 535 j1939_session *j1939_session_get_by_addr(struct j1939_priv *priv,
 536                                          struct j1939_addr *addr,
 537                                          bool reverse, bool transmitter)
 538 {
 539         struct j1939_session *session;
 540
 541         j1939_session_list_lock(priv);
 542         session = j1939_session_get_by_addr_locked(priv,
 543                                                    &priv->active_session_list,
 544                                                    addr, reverse, transmitter);
 545         j1939_session_list_unlock(priv);
 546
 547         return session;
 548 }
 549
 550 static void j1939_skbcb_swap(struct j1939_sk_buff_cb *skcb)
 551 {
 552         u8 tmp = 0;
 553
 554         swap(skcb->addr.dst_name, skcb->addr.src_name);
 555         swap(skcb->addr.da, skcb->addr.sa);
 556
 557         /* swap SRC and DST flags, leave other untouched */
 558         if (skcb->flags & J1939_ECU_LOCAL_SRC)
 559                 tmp |= J1939_ECU_LOCAL_DST;
 560         if (skcb->flags & J1939_ECU_LOCAL_DST)
 561                 tmp |= J1939_ECU_LOCAL_SRC;
 562         skcb->flags &= ~(J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
 563         skcb->flags |= tmp;
 564 }
 565
 566 static struct
 567 sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
 568                              const struct j1939_sk_buff_cb *re_skcb,
 569                              bool ctl,
 570                              bool swap_src_dst)
 571 {
 572         struct sk_buff *skb;
 573         struct j1939_sk_buff_cb *skcb;
 574
 575         skb = alloc_skb(sizeof(struct can_frame) + sizeof(struct can_skb_priv),
 576                         GFP_ATOMIC);
 577         if (unlikely(!skb))
 578                 return ERR_PTR(-ENOMEM);
 579
 580         skb->dev = priv->ndev;
 581         can_skb_reserve(skb);
 582         can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
 583         /* reserve CAN header */
 584         skb_reserve(skb, offsetof(struct can_frame, data));
 585
 586         memcpy(skb->cb, re_skcb, sizeof(skb->cb));
 587         skcb = j1939_skb_to_cb(skb);
 588         if (swap_src_dst)
 589                 j1939_skbcb_swap(skcb);
 590
 591         if (ctl) {
 592                 if (skcb->addr.type == J1939_ETP)
 593                         skcb->addr.pgn = J1939_ETP_PGN_CTL;
 594                 else
 595                         skcb->addr.pgn = J1939_TP_PGN_CTL;
 596         } else {
 597                 if (skcb->addr.type == J1939_ETP)
 598                         skcb->addr.pgn = J1939_ETP_PGN_DAT;
 599                 else
 600                         skcb->addr.pgn = J1939_TP_PGN_DAT;
 601         }
 602
 603         return skb;
 604 }
 605
 606 /* TP transmit packet functions */
 607 static int j1939_tp_tx_dat(struct j1939_session *session,
 608                            const u8 *dat, int len)
 609 {
 610         struct j1939_priv *priv = session->priv;
 611         struct sk_buff *skb;
 612
 613         skb = j1939_tp_tx_dat_new(priv, &session->skcb,
 614                                   false, false);
 615         if (IS_ERR(skb))
 616                 return PTR_ERR(skb);
 617
 618         skb_put_data(skb, dat, len);
 619         if (j1939_tp_padding && len < 8)
 620                 memset(skb_put(skb, 8 - len), 0xff, 8 - len);
 621
 622         return j1939_send_one(priv, skb);
 623 }
 624
 625 static int j1939_xtp_do_tx_ctl(struct j1939_priv *priv,
 626                                const struct j1939_sk_buff_cb *re_skcb,
 627                                bool swap_src_dst, pgn_t pgn, const u8 *dat)
 628 {
 629         struct sk_buff *skb;
 630         u8 *skdat;
 631
 632         if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
 633                 return 0;
 634
 635         skb = j1939_tp_tx_dat_new(priv, re_skcb, true, swap_src_dst);
 636         if (IS_ERR(skb))
 637                 return PTR_ERR(skb);
 638
 639         skdat = skb_put(skb, 8);
 640         memcpy(skdat, dat, 5);
 641         skdat[5] = (pgn >> 0);
 642         skdat[6] = (pgn >> 8);
 643         skdat[7] = (pgn >> 16);
 644
 645         return j1939_send_one(priv, skb);
 646 }
 647
 648 static inline int j1939_tp_tx_ctl(struct j1939_session *session,
 649                                   bool swap_src_dst, const u8 *dat)
 650 {
 651         struct j1939_priv *priv = session->priv;
 652
 653         return j1939_xtp_do_tx_ctl(priv, &session->skcb,
 654                                    swap_src_dst,
 655                                    session->skcb.addr.pgn, dat);
 656 }
 657
 658 static int j1939_xtp_tx_abort(struct j1939_priv *priv,
 659                               const struct j1939_sk_buff_cb *re_skcb,
 660                               bool swap_src_dst,
 661                               enum j1939_xtp_abort err,
 662                               pgn_t pgn)
 663 {
 664         u8 dat[5];
 665
 666         if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
 667                 return 0;
 668
 669         memset(dat, 0xff, sizeof(dat));
 670         dat[0] = J1939_TP_CMD_ABORT;
 671         dat[1] = err;
 672         return j1939_xtp_do_tx_ctl(priv, re_skcb, swap_src_dst, pgn, dat);
 673 }
 674
 675 void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec)
 676 {
 677         j1939_session_get(session);
 678         hrtimer_start(&session->txtimer, ms_to_ktime(msec),
 679                       HRTIMER_MODE_REL_SOFT);
 680 }
 681
 682 static inline void j1939_tp_set_rxtimeout(struct j1939_session *session,
 683                                           int msec)
 684 {
 685         j1939_session_rxtimer_cancel(session);
 686         j1939_session_get(session);
 687         hrtimer_start(&session->rxtimer, ms_to_ktime(msec),
 688                       HRTIMER_MODE_REL_SOFT);
 689 }
 690
 691 static int j1939_session_tx_rts(struct j1939_session *session)
 692 {
 693         u8 dat[8];
 694         int ret;
 695
 696         memset(dat, 0xff, sizeof(dat));
 697
 698         dat[1] = (session->total_message_size >> 0);
 699         dat[2] = (session->total_message_size >> 8);
 700         dat[3] = session->pkt.total;
 701
 702         if (session->skcb.addr.type == J1939_ETP) {
 703                 dat[0] = J1939_ETP_CMD_RTS;
 704                 dat[1] = (session->total_message_size >> 0);
 705                 dat[2] = (session->total_message_size >> 8);
 706                 dat[3] = (session->total_message_size >> 16);
 707                 dat[4] = (session->total_message_size >> 24);
 708         } else if (j1939_cb_is_broadcast(&session->skcb)) {
 709                 dat[0] = J1939_TP_CMD_BAM;
 710                 /* fake cts for broadcast */
 711                 session->pkt.tx = 0;
 712         } else {
 713                 dat[0] = J1939_TP_CMD_RTS;
 714                 dat[4] = dat[3];
 715         }
 716
 717         if (dat[0] == session->last_txcmd)
 718                 /* done already */
 719                 return 0;
 720
 721         ret = j1939_tp_tx_ctl(session, false, dat);
 722         if (ret < 0)
 723                 return ret;
 724
 725         session->last_txcmd = dat[0];
 726         if (dat[0] == J1939_TP_CMD_BAM) {
 727                 j1939_tp_schedule_txtimer(session, 50);
 728                 j1939_tp_set_rxtimeout(session, 250);
 729         } else {
 730                 j1939_tp_set_rxtimeout(session, 1250);
 731         }
 732
 733         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 734
 735         return 0;
 736 }
 737
 738 static int j1939_session_tx_dpo(struct j1939_session *session)
 739 {
 740         unsigned int pkt;
 741         u8 dat[8];
 742         int ret;
 743
 744         memset(dat, 0xff, sizeof(dat));
 745
 746         dat[0] = J1939_ETP_CMD_DPO;
 747         session->pkt.dpo = session->pkt.tx_acked;
 748         pkt = session->pkt.dpo;
 749         dat[1] = session->pkt.last - session->pkt.tx_acked;
 750         dat[2] = (pkt >> 0);
 751         dat[3] = (pkt >> 8);
 752         dat[4] = (pkt >> 16);
 753
 754         ret = j1939_tp_tx_ctl(session, false, dat);
 755         if (ret < 0)
 756                 return ret;
 757
 758         session->last_txcmd = dat[0];
 759         j1939_tp_set_rxtimeout(session, 1250);
 760         session->pkt.tx = session->pkt.tx_acked;
 761
 762         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 763
 764         return 0;
 765 }
 766
 767 static int j1939_session_tx_dat(struct j1939_session *session)
 768 {
 769         struct j1939_priv *priv = session->priv;
 770         struct j1939_sk_buff_cb *skcb;
 771         int offset, pkt_done, pkt_end;
 772         unsigned int len, pdelay;
 773         struct sk_buff *se_skb;
 774         const u8 *tpdat;
 775         int ret = 0;
 776         u8 dat[8];
 777
 778         se_skb = j1939_session_skb_find_by_offset(session, session->pkt.tx * 7);
 779         if (!se_skb)
 780                 return -ENOBUFS;
 781
 782         skcb = j1939_skb_to_cb(se_skb);
 783         tpdat = se_skb->data;
 784         ret = 0;
 785         pkt_done = 0;
 786         if (session->skcb.addr.type != J1939_ETP &&
 787             j1939_cb_is_broadcast(&session->skcb))
 788                 pkt_end = session->pkt.total;
 789         else
 790                 pkt_end = session->pkt.last;
 791
 792         while (session->pkt.tx < pkt_end) {
 793                 dat[0] = session->pkt.tx - session->pkt.dpo + 1;
 794                 offset = (session->pkt.tx * 7) - skcb->offset;
 795                 len =  se_skb->len - offset;
 796                 if (len > 7)
 797                         len = 7;
 798
 799                 if (offset + len > se_skb->len) {
 800                         netdev_err_once(priv->ndev,
 801                                         "%s: 0x%p: requested data outside of queued buffer: offset %i, len %i, pkt.tx: %i\n",
 802                                         __func__, session, skcb->offset, se_skb->len , session->pkt.tx);
 803                         return -EOVERFLOW;
 804                 }
 805
 806                 if (!len) {
 807                         ret = -ENOBUFS;
 808                         break;
 809                 }
 810
 811                 memcpy(&dat[1], &tpdat[offset], len);
 812                 ret = j1939_tp_tx_dat(session, dat, len + 1);
 813                 if (ret < 0) {
 814                         /* ENOBUS == CAN interface TX queue is full */
 815                         if (ret != -ENOBUFS)
 816                                 netdev_alert(priv->ndev,
 817                                              "%s: 0x%p: queue data error: %i\n",
 818                                              __func__, session, ret);
 819                         break;
 820                 }
 821
 822                 session->last_txcmd = 0xff;
 823                 pkt_done++;
 824                 session->pkt.tx++;
 825                 pdelay = j1939_cb_is_broadcast(&session->skcb) ? 50 :
 826                         j1939_tp_packet_delay;
 827
 828                 if (session->pkt.tx < session->pkt.total && pdelay) {
 829                         j1939_tp_schedule_txtimer(session, pdelay);
 830                         break;
 831                 }
 832         }
 833
 834         if (pkt_done)
 835                 j1939_tp_set_rxtimeout(session, 250);
 836
 837         return ret;
 838 }
 839
 840 static int j1939_xtp_txnext_transmiter(struct j1939_session *session)
 841 {
 842         struct j1939_priv *priv = session->priv;
 843         int ret = 0;
 844
 845         if (!j1939_tp_im_transmitter(&session->skcb)) {
 846                 netdev_alert(priv->ndev, "%s: 0x%p: called by not transmitter!\n",
 847                              __func__, session);
 848                 return -EINVAL;
 849         }
 850
 851         switch (session->last_cmd) {
 852         case 0:
 853                 ret = j1939_session_tx_rts(session);
 854                 break;
 855
 856         case J1939_ETP_CMD_CTS:
 857                 if (session->last_txcmd != J1939_ETP_CMD_DPO) {
 858                         ret = j1939_session_tx_dpo(session);
 859                         if (ret)
 860                                 return ret;
 861                 }
 862
 863                 fallthrough;
 864         case J1939_TP_CMD_CTS:
 865         case 0xff: /* did some data */
 866         case J1939_ETP_CMD_DPO:
 867         case J1939_TP_CMD_BAM:
 868                 ret = j1939_session_tx_dat(session);
 869
 870                 break;
 871         default:
 872                 netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
 873                              __func__, session, session->last_cmd);
 874         }
 875
 876         return ret;
 877 }
 878
 879 static int j1939_session_tx_cts(struct j1939_session *session)
 880 {
 881         struct j1939_priv *priv = session->priv;
 882         unsigned int pkt, len;
 883         int ret;
 884         u8 dat[8];
 885
 886         if (!j1939_sk_recv_match(priv, &session->skcb))
 887                 return -ENOENT;
 888
 889         len = session->pkt.total - session->pkt.rx;
 890         len = min3(len, session->pkt.block, j1939_tp_block ?: 255);
 891         memset(dat, 0xff, sizeof(dat));
 892
 893         if (session->skcb.addr.type == J1939_ETP) {
 894                 pkt = session->pkt.rx + 1;
 895                 dat[0] = J1939_ETP_CMD_CTS;
 896                 dat[1] = len;
 897                 dat[2] = (pkt >> 0);
 898                 dat[3] = (pkt >> 8);
 899                 dat[4] = (pkt >> 16);
 900         } else {
 901                 dat[0] = J1939_TP_CMD_CTS;
 902                 dat[1] = len;
 903                 dat[2] = session->pkt.rx + 1;
 904         }
 905
 906         if (dat[0] == session->last_txcmd)
 907                 /* done already */
 908                 return 0;
 909
 910         ret = j1939_tp_tx_ctl(session, true, dat);
 911         if (ret < 0)
 912                 return ret;
 913
 914         if (len)
 915                 /* only mark cts done when len is set */
 916                 session->last_txcmd = dat[0];
 917         j1939_tp_set_rxtimeout(session, 1250);
 918
 919         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 920
 921         return 0;
 922 }
 923
 924 static int j1939_session_tx_eoma(struct j1939_session *session)
 925 {
 926         struct j1939_priv *priv = session->priv;
 927         u8 dat[8];
 928         int ret;
 929
 930         if (!j1939_sk_recv_match(priv, &session->skcb))
 931                 return -ENOENT;
 932
 933         memset(dat, 0xff, sizeof(dat));
 934
 935         if (session->skcb.addr.type == J1939_ETP) {
 936                 dat[0] = J1939_ETP_CMD_EOMA;
 937                 dat[1] = session->total_message_size >> 0;
 938                 dat[2] = session->total_message_size >> 8;
 939                 dat[3] = session->total_message_size >> 16;
 940                 dat[4] = session->total_message_size >> 24;
 941         } else {
 942                 dat[0] = J1939_TP_CMD_EOMA;
 943                 dat[1] = session->total_message_size;
 944                 dat[2] = session->total_message_size >> 8;
 945                 dat[3] = session->pkt.total;
 946         }
 947
 948         if (dat[0] == session->last_txcmd)
 949                 /* done already */
 950                 return 0;
 951
 952         ret = j1939_tp_tx_ctl(session, true, dat);
 953         if (ret < 0)
 954                 return ret;
 955
 956         session->last_txcmd = dat[0];
 957
 958         /* wait for the EOMA packet to come in */
 959         j1939_tp_set_rxtimeout(session, 1250);
 960
 961         netdev_dbg(session->priv->ndev, "%p: 0x%p\n", __func__, session);
 962
 963         return 0;
 964 }
 965
 966 static int j1939_xtp_txnext_receiver(struct j1939_session *session)
 967 {
 968         struct j1939_priv *priv = session->priv;
 969         int ret = 0;
 970
 971         if (!j1939_tp_im_receiver(&session->skcb)) {
 972                 netdev_alert(priv->ndev, "%s: 0x%p: called by not receiver!\n",
 973                              __func__, session);
 974                 return -EINVAL;
 975         }
 976
 977         switch (session->last_cmd) {
 978         case J1939_TP_CMD_RTS:
 979         case J1939_ETP_CMD_RTS:
 980                 ret = j1939_session_tx_cts(session);
 981                 break;
 982
 983         case J1939_ETP_CMD_CTS:
 984         case J1939_TP_CMD_CTS:
 985         case 0xff: /* did some data */
 986         case J1939_ETP_CMD_DPO:
 987                 if ((session->skcb.addr.type == J1939_TP &&
 988                      j1939_cb_is_broadcast(&session->skcb)))
 989                         break;
 990
 991                 if (session->pkt.rx >= session->pkt.total) {
 992                         ret = j1939_session_tx_eoma(session);
 993                 } else if (session->pkt.rx >= session->pkt.last) {
 994                         session->last_txcmd = 0;
 995                         ret = j1939_session_tx_cts(session);
 996                 }
 997                 break;
 998         default:
 999                 netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
1000                              __func__, session, session->last_cmd);
1001         }
1002
1003         return ret;
1004 }
1005
1006 static int j1939_simple_txnext(struct j1939_session *session)
1007 {
1008         struct j1939_priv *priv = session->priv;
1009         struct sk_buff *se_skb = j1939_session_skb_find(session);
1010         struct sk_buff *skb;
1011         int ret;
1012
1013         if (!se_skb)
1014                 return 0;
1015
1016         skb = skb_clone(se_skb, GFP_ATOMIC);
1017         if (!skb)
1018                 return -ENOMEM;
1019
1020         can_skb_set_owner(skb, se_skb->sk);
1021
1022         j1939_tp_set_rxtimeout(session, J1939_SIMPLE_ECHO_TIMEOUT_MS);
1023
1024         ret = j1939_send_one(priv, skb);
1025         if (ret)
1026                 return ret;
1027
1028         j1939_sk_errqueue(session, J1939_ERRQUEUE_SCHED);
1029         j1939_sk_queue_activate_next(session);
1030
1031         return 0;
1032 }
1033
1034 static bool j1939_session_deactivate_locked(struct j1939_session *session)
1035 {
1036         bool active = false;
1037
1038         lockdep_assert_held(&session->priv->active_session_list_lock);
1039
1040         if (session->state >= J1939_SESSION_ACTIVE &&
1041             session->state < J1939_SESSION_ACTIVE_MAX) {
1042                 active = true;
1043
1044                 list_del_init(&session->active_session_list_entry);
1045                 session->state = J1939_SESSION_DONE;
1046                 j1939_session_put(session);
1047         }
1048
1049         return active;
1050 }
1051
1052 static bool j1939_session_deactivate(struct j1939_session *session)
1053 {
1054         bool active;
1055
1056         j1939_session_list_lock(session->priv);
1057         active = j1939_session_deactivate_locked(session);
1058         j1939_session_list_unlock(session->priv);
1059
1060         return active;
1061 }
1062
1063 static void
1064 j1939_session_deactivate_activate_next(struct j1939_session *session)
1065 {
1066         if (j1939_session_deactivate(session))
1067                 j1939_sk_queue_activate_next(session);
1068 }
1069
1070 static void __j1939_session_cancel(struct j1939_session *session,
1071                                  enum j1939_xtp_abort err)
1072 {
1073         struct j1939_priv *priv = session->priv;
1074
1075         WARN_ON_ONCE(!err);
1076         lockdep_assert_held(&session->priv->active_session_list_lock);
1077
1078         session->err = j1939_xtp_abort_to_errno(priv, err);
1079         session->state = J1939_SESSION_WAITING_ABORT;
1080         /* do not send aborts on incoming broadcasts */
1081         if (!j1939_cb_is_broadcast(&session->skcb)) {
1082                 j1939_xtp_tx_abort(priv, &session->skcb,
1083                                    !session->transmission,
1084                                    err, session->skcb.addr.pgn);
1085         }
1086
1087         if (session->sk)
1088                 j1939_sk_send_loop_abort(session->sk, session->err);
1089 }
1090
1091 static void j1939_session_cancel(struct j1939_session *session,
1092                                  enum j1939_xtp_abort err)
1093 {
1094         j1939_session_list_lock(session->priv);
1095
1096         if (session->state >= J1939_SESSION_ACTIVE &&
1097             session->state < J1939_SESSION_WAITING_ABORT) {
1098                 j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
1099                 __j1939_session_cancel(session, err);
1100         }
1101
1102         j1939_session_list_unlock(session->priv);
1103 }
1104
1105 static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
1106 {
1107         struct j1939_session *session =
1108                 container_of(hrtimer, struct j1939_session, txtimer);
1109         struct j1939_priv *priv = session->priv;
1110         int ret = 0;
1111
1112         if (session->skcb.addr.type == J1939_SIMPLE) {
1113                 ret = j1939_simple_txnext(session);
1114         } else {
1115                 if (session->transmission)
1116                         ret = j1939_xtp_txnext_transmiter(session);
1117                 else
1118                         ret = j1939_xtp_txnext_receiver(session);
1119         }
1120
1121         switch (ret) {
1122         case -ENOBUFS:
1123                 /* Retry limit is currently arbitrary chosen */
1124                 if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
1125                         session->tx_retry++;
1126                         j1939_tp_schedule_txtimer(session,
1127                                                   10 + prandom_u32_max(16));
1128                 } else {
1129                         netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
1130                                      __func__, session);
1131                         session->err = -ENETUNREACH;
1132                         j1939_session_rxtimer_cancel(session);
1133                         j1939_session_deactivate_activate_next(session);
1134                 }
1135                 break;
1136         case -ENETDOWN:
1137                 /* In this case we should get a netdev_event(), all active
1138                  * sessions will be cleared by
1139                  * j1939_cancel_all_active_sessions(). So handle this as an
1140                  * error, but let j1939_cancel_all_active_sessions() do the
1141                  * cleanup including propagation of the error to user space.
1142                  */
1143                 break;
1144         case -EOVERFLOW:
1145                 j1939_session_cancel(session, J1939_XTP_ABORT_ECTS_TOO_BIG);
1146                 break;
1147         case 0:
1148                 session->tx_retry = 0;
1149                 break;
1150         default:
1151                 netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
1152                              __func__, session, ret);
1153                 if (session->skcb.addr.type != J1939_SIMPLE) {
1154                         j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
1155                 } else {
1156                         session->err = ret;
1157                         j1939_session_rxtimer_cancel(session);
1158                         j1939_session_deactivate_activate_next(session);
1159                 }
1160         }
1161
1162         j1939_session_put(session);
1163
1164         return HRTIMER_NORESTART;
1165 }
1166
1167 static void j1939_session_completed(struct j1939_session *session)
1168 {
1169         struct sk_buff *skb;
1170
1171         if (!session->transmission) {
1172                 skb = j1939_session_skb_find(session);
1173                 /* distribute among j1939 receivers */
1174                 j1939_sk_recv(session->priv, skb);
1175         }
1176
1177         j1939_session_deactivate_activate_next(session);
1178 }
1179
1180 static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
1181 {
1182         struct j1939_session *session = container_of(hrtimer,
1183                                                      struct j1939_session,
1184                                                      rxtimer);
1185         struct j1939_priv *priv = session->priv;
1186
1187         if (session->state == J1939_SESSION_WAITING_ABORT) {
1188                 netdev_alert(priv->ndev, "%s: 0x%p: abort rx timeout. Force session deactivation\n",
1189                              __func__, session);
1190
1191                 j1939_session_deactivate_activate_next(session);
1192
1193         } else if (session->skcb.addr.type == J1939_SIMPLE) {
1194                 netdev_alert(priv->ndev, "%s: 0x%p: Timeout. Failed to send simple message.\n",
1195                              __func__, session);
1196
1197                 /* The message is probably stuck in the CAN controller and can
1198                  * be send as soon as CAN bus is in working state again.
1199                  */
1200                 session->err = -ETIME;
1201                 j1939_session_deactivate(session);
1202         } else {
1203                 netdev_alert(priv->ndev, "%s: 0x%p: rx timeout, send abort\n",
1204                              __func__, session);
1205
1206                 j1939_session_list_lock(session->priv);
1207                 if (session->state >= J1939_SESSION_ACTIVE &&
1208                     session->state < J1939_SESSION_ACTIVE_MAX) {
1209                         j1939_session_get(session);
1210                         hrtimer_start(&session->rxtimer,
1211                                       ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
1212                                       HRTIMER_MODE_REL_SOFT);
1213                         __j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
1214                 }
1215                 j1939_session_list_unlock(session->priv);
1216         }
1217
1218         j1939_session_put(session);
1219
1220         return HRTIMER_NORESTART;
1221 }
1222
1223 static bool j1939_xtp_rx_cmd_bad_pgn(struct j1939_session *session,
1224                                      const struct sk_buff *skb)
1225 {
1226         const struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1227         pgn_t pgn = j1939_xtp_ctl_to_pgn(skb->data);
1228         struct j1939_priv *priv = session->priv;
1229         enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1230         u8 cmd = skb->data[0];
1231
1232         if (session->skcb.addr.pgn == pgn)
1233                 return false;
1234
1235         switch (cmd) {
1236         case J1939_TP_CMD_BAM:
1237                 abort = J1939_XTP_NO_ABORT;
1238                 break;
1239
1240         case J1939_ETP_CMD_RTS:
1241         case J1939_TP_CMD_RTS: /* fall through */
1242                 abort = J1939_XTP_ABORT_BUSY;
1243                 break;
1244
1245         case J1939_ETP_CMD_CTS:
1246         case J1939_TP_CMD_CTS: /* fall through */
1247                 abort = J1939_XTP_ABORT_ECTS_UNXPECTED_PGN;
1248                 break;
1249
1250         case J1939_ETP_CMD_DPO:
1251                 abort = J1939_XTP_ABORT_BAD_EDPO_PGN;
1252                 break;
1253
1254         case J1939_ETP_CMD_EOMA:
1255         case J1939_TP_CMD_EOMA: /* fall through */
1256                 abort = J1939_XTP_ABORT_OTHER;
1257                 break;
1258
1259         case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
1260                 abort = J1939_XTP_NO_ABORT;
1261                 break;
1262
1263         default:
1264                 WARN_ON_ONCE(1);
1265                 break;
1266         }
1267
1268         netdev_warn(priv->ndev, "%s: 0x%p: CMD 0x%02x with PGN 0x%05x for running session with different PGN 0x%05x.\n",
1269                     __func__, session, cmd, pgn, session->skcb.addr.pgn);
1270         if (abort != J1939_XTP_NO_ABORT)
1271                 j1939_xtp_tx_abort(priv, skcb, true, abort, pgn);
1272
1273         return true;
1274 }
1275
1276 static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
1277                                    bool reverse, bool transmitter)
1278 {
1279         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1280         struct j1939_session *session;
1281         u8 abort = skb->data[1];
1282
1283         session = j1939_session_get_by_addr(priv, &skcb->addr, reverse,
1284                                             transmitter);
1285         if (!session)
1286                 return;
1287
1288         if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1289                 goto abort_put;
1290
1291         netdev_info(priv->ndev, "%s: 0x%p: 0x%05x: (%u) %s\n", __func__,
1292                     session, j1939_xtp_ctl_to_pgn(skb->data), abort,
1293                     j1939_xtp_abort_to_str(abort));
1294
1295         j1939_session_timers_cancel(session);
1296         session->err = j1939_xtp_abort_to_errno(priv, abort);
1297         if (session->sk)
1298                 j1939_sk_send_loop_abort(session->sk, session->err);
1299         j1939_session_deactivate_activate_next(session);
1300
1301 abort_put:
1302         j1939_session_put(session);
1303 }
1304
1305 /* abort packets may come in 2 directions */
1306 static void
1307 j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
1308                    bool transmitter)
1309 {
1310         j1939_xtp_rx_abort_one(priv, skb, false, transmitter);
1311         j1939_xtp_rx_abort_one(priv, skb, true, transmitter);
1312 }
1313
1314 static void
1315 j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
1316 {
1317         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1318         const u8 *dat;
1319         int len;
1320
1321         if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1322                 return;
1323
1324         dat = skb->data;
1325
1326         if (skcb->addr.type == J1939_ETP)
1327                 len = j1939_etp_ctl_to_size(dat);
1328         else
1329                 len = j1939_tp_ctl_to_size(dat);
1330
1331         if (session->total_message_size != len) {
1332                 netdev_warn_once(session->priv->ndev,
1333                                  "%s: 0x%p: Incorrect size. Expected: %i; got: %i.\n",
1334                                  __func__, session, session->total_message_size,
1335                                  len);
1336         }
1337
1338         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1339
1340         session->pkt.tx_acked = session->pkt.total;
1341         j1939_session_timers_cancel(session);
1342         /* transmitted without problems */
1343         j1939_session_completed(session);
1344 }
1345
1346 static void
1347 j1939_xtp_rx_eoma(struct j1939_priv *priv, struct sk_buff *skb,
1348                   bool transmitter)
1349 {
1350         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1351         struct j1939_session *session;
1352
1353         session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1354                                             transmitter);
1355         if (!session)
1356                 return;
1357
1358         j1939_xtp_rx_eoma_one(session, skb);
1359         j1939_session_put(session);
1360 }
1361
1362 static void
1363 j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
1364 {
1365         enum j1939_xtp_abort err = J1939_XTP_ABORT_FAULT;
1366         unsigned int pkt;
1367         const u8 *dat;
1368
1369         dat = skb->data;
1370
1371         if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1372                 return;
1373
1374         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1375
1376         if (session->last_cmd == dat[0]) {
1377                 err = J1939_XTP_ABORT_DUP_SEQ;
1378                 goto out_session_cancel;
1379         }
1380
1381         if (session->skcb.addr.type == J1939_ETP)
1382                 pkt = j1939_etp_ctl_to_packet(dat);
1383         else
1384                 pkt = dat[2];
1385
1386         if (!pkt)
1387                 goto out_session_cancel;
1388         else if (dat[1] > session->pkt.block /* 0xff for etp */)
1389                 goto out_session_cancel;
1390
1391         /* set packet counters only when not CTS(0) */
1392         session->pkt.tx_acked = pkt - 1;
1393         j1939_session_skb_drop_old(session);
1394         session->pkt.last = session->pkt.tx_acked + dat[1];
1395         if (session->pkt.last > session->pkt.total)
1396                 /* safety measure */
1397                 session->pkt.last = session->pkt.total;
1398         /* TODO: do not set tx here, do it in txtimer */
1399         session->pkt.tx = session->pkt.tx_acked;
1400
1401         session->last_cmd = dat[0];
1402         if (dat[1]) {
1403                 j1939_tp_set_rxtimeout(session, 1250);
1404                 if (session->transmission) {
1405                         if (session->pkt.tx_acked)
1406                                 j1939_sk_errqueue(session,
1407                                                   J1939_ERRQUEUE_SCHED);
1408                         j1939_session_txtimer_cancel(session);
1409                         j1939_tp_schedule_txtimer(session, 0);
1410                 }
1411         } else {
1412                 /* CTS(0) */
1413                 j1939_tp_set_rxtimeout(session, 550);
1414         }
1415         return;
1416
1417  out_session_cancel:
1418         j1939_session_timers_cancel(session);
1419         j1939_session_cancel(session, err);
1420 }
1421
1422 static void
1423 j1939_xtp_rx_cts(struct j1939_priv *priv, struct sk_buff *skb, bool transmitter)
1424 {
1425         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1426         struct j1939_session *session;
1427
1428         session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1429                                             transmitter);
1430         if (!session)
1431                 return;
1432         j1939_xtp_rx_cts_one(session, skb);
1433         j1939_session_put(session);
1434 }
1435
1436 static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
1437                                                struct sk_buff *skb, size_t size)
1438 {
1439         struct j1939_session *session;
1440         struct j1939_sk_buff_cb *skcb;
1441
1442         session = kzalloc(sizeof(*session), gfp_any());
1443         if (!session)
1444                 return NULL;
1445
1446         INIT_LIST_HEAD(&session->active_session_list_entry);
1447         INIT_LIST_HEAD(&session->sk_session_queue_entry);
1448         kref_init(&session->kref);
1449
1450         j1939_priv_get(priv);
1451         session->priv = priv;
1452         session->total_message_size = size;
1453         session->state = J1939_SESSION_NEW;
1454
1455         skb_queue_head_init(&session->skb_queue);
1456         skb_queue_tail(&session->skb_queue, skb);
1457
1458         skcb = j1939_skb_to_cb(skb);
1459         memcpy(&session->skcb, skcb, sizeof(session->skcb));
1460
1461         hrtimer_init(&session->txtimer, CLOCK_MONOTONIC,
1462                      HRTIMER_MODE_REL_SOFT);
1463         session->txtimer.function = j1939_tp_txtimer;
1464         hrtimer_init(&session->rxtimer, CLOCK_MONOTONIC,
1465                      HRTIMER_MODE_REL_SOFT);
1466         session->rxtimer.function = j1939_tp_rxtimer;
1467
1468         netdev_dbg(priv->ndev, "%s: 0x%p: sa: %02x, da: %02x\n",
1469                    __func__, session, skcb->addr.sa, skcb->addr.da);
1470
1471         return session;
1472 }
1473
1474 static struct
1475 j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
1476                                        int size,
1477                                        const struct j1939_sk_buff_cb *rel_skcb)
1478 {
1479         struct sk_buff *skb;
1480         struct j1939_sk_buff_cb *skcb;
1481         struct j1939_session *session;
1482
1483         skb = alloc_skb(size + sizeof(struct can_skb_priv), GFP_ATOMIC);
1484         if (unlikely(!skb))
1485                 return NULL;
1486
1487         skb->dev = priv->ndev;
1488         can_skb_reserve(skb);
1489         can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
1490         skcb = j1939_skb_to_cb(skb);
1491         memcpy(skcb, rel_skcb, sizeof(*skcb));
1492
1493         session = j1939_session_new(priv, skb, size);
1494         if (!session) {
1495                 kfree_skb(skb);
1496                 return NULL;
1497         }
1498
1499         /* alloc data area */
1500         skb_put(skb, size);
1501         /* skb is recounted in j1939_session_new() */
1502         return session;
1503 }
1504
1505 int j1939_session_activate(struct j1939_session *session)
1506 {
1507         struct j1939_priv *priv = session->priv;
1508         struct j1939_session *active = NULL;
1509         int ret = 0;
1510
1511         j1939_session_list_lock(priv);
1512         if (session->skcb.addr.type != J1939_SIMPLE)
1513                 active = j1939_session_get_by_addr_locked(priv,
1514                                                           &priv->active_session_list,
1515                                                           &session->skcb.addr, false,
1516                                                           session->transmission);
1517         if (active) {
1518                 j1939_session_put(active);
1519                 ret = -EAGAIN;
1520         } else {
1521                 WARN_ON_ONCE(session->state != J1939_SESSION_NEW);
1522                 list_add_tail(&session->active_session_list_entry,
1523                               &priv->active_session_list);
1524                 j1939_session_get(session);
1525                 session->state = J1939_SESSION_ACTIVE;
1526
1527                 netdev_dbg(session->priv->ndev, "%s: 0x%p\n",
1528                            __func__, session);
1529         }
1530         j1939_session_list_unlock(priv);
1531
1532         return ret;
1533 }
1534
1535 static struct
1536 j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
1537                                             struct sk_buff *skb)
1538 {
1539         enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1540         struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
1541         struct j1939_session *session;
1542         const u8 *dat;
1543         pgn_t pgn;
1544         int len;
1545
1546         netdev_dbg(priv->ndev, "%s\n", __func__);
1547
1548         dat = skb->data;
1549         pgn = j1939_xtp_ctl_to_pgn(dat);
1550         skcb.addr.pgn = pgn;
1551
1552         if (!j1939_sk_recv_match(priv, &skcb))
1553                 return NULL;
1554
1555         if (skcb.addr.type == J1939_ETP) {
1556                 len = j1939_etp_ctl_to_size(dat);
1557                 if (len > J1939_MAX_ETP_PACKET_SIZE)
1558                         abort = J1939_XTP_ABORT_FAULT;
1559                 else if (len > priv->tp_max_packet_size)
1560                         abort = J1939_XTP_ABORT_RESOURCE;
1561                 else if (len <= J1939_MAX_TP_PACKET_SIZE)
1562                         abort = J1939_XTP_ABORT_FAULT;
1563         } else {
1564                 len = j1939_tp_ctl_to_size(dat);
1565                 if (len > J1939_MAX_TP_PACKET_SIZE)
1566                         abort = J1939_XTP_ABORT_FAULT;
1567                 else if (len > priv->tp_max_packet_size)
1568                         abort = J1939_XTP_ABORT_RESOURCE;
1569         }
1570
1571         if (abort != J1939_XTP_NO_ABORT) {
1572                 j1939_xtp_tx_abort(priv, &skcb, true, abort, pgn);
1573                 return NULL;
1574         }
1575
1576         session = j1939_session_fresh_new(priv, len, &skcb);
1577         if (!session) {
1578                 j1939_xtp_tx_abort(priv, &skcb, true,
1579                                    J1939_XTP_ABORT_RESOURCE, pgn);
1580                 return NULL;
1581         }
1582
1583         /* initialize the control buffer: plain copy */
1584         session->pkt.total = (len + 6) / 7;
1585         session->pkt.block = 0xff;
1586         if (skcb.addr.type != J1939_ETP) {
1587                 if (dat[3] != session->pkt.total)
1588                         netdev_alert(priv->ndev, "%s: 0x%p: strange total, %u != %u\n",
1589                                      __func__, session, session->pkt.total,
1590                                      dat[3]);
1591                 session->pkt.total = dat[3];
1592                 session->pkt.block = min(dat[3], dat[4]);
1593         }
1594
1595         session->pkt.rx = 0;
1596         session->pkt.tx = 0;
1597
1598         WARN_ON_ONCE(j1939_session_activate(session));
1599
1600         return session;
1601 }
1602
1603 static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
1604                                            struct sk_buff *skb)
1605 {
1606         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1607         struct j1939_priv *priv = session->priv;
1608
1609         if (!session->transmission) {
1610                 if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1611                         return -EBUSY;
1612
1613                 /* RTS on active session */
1614                 j1939_session_timers_cancel(session);
1615                 j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1616         }
1617
1618         if (session->last_cmd != 0) {
1619                 /* we received a second rts on the same connection */
1620                 netdev_alert(priv->ndev, "%s: 0x%p: connection exists (%02x %02x). last cmd: %x\n",
1621                              __func__, session, skcb->addr.sa, skcb->addr.da,
1622                              session->last_cmd);
1623
1624                 j1939_session_timers_cancel(session);
1625                 j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1626
1627                 return -EBUSY;
1628         }
1629
1630         if (session->skcb.addr.sa != skcb->addr.sa ||
1631             session->skcb.addr.da != skcb->addr.da)
1632                 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",
1633                             __func__, session,
1634                             session->skcb.addr.sa, skcb->addr.sa,
1635                             session->skcb.addr.da, skcb->addr.da);
1636         /* make sure 'sa' & 'da' are correct !
1637          * They may be 'not filled in yet' for sending
1638          * skb's, since they did not pass the Address Claim ever.
1639          */
1640         session->skcb.addr.sa = skcb->addr.sa;
1641         session->skcb.addr.da = skcb->addr.da;
1642
1643         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1644
1645         return 0;
1646 }
1647
1648 static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
1649                              bool transmitter)
1650 {
1651         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1652         struct j1939_session *session;
1653         u8 cmd = skb->data[0];
1654
1655         session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1656                                             transmitter);
1657
1658         if (!session) {
1659                 if (transmitter) {
1660                         /* If we're the transmitter and this function is called,
1661                          * we received our own RTS. A session has already been
1662                          * created.
1663                          *
1664                          * For some reasons however it might have been destroyed
1665                          * already. So don't create a new one here (using
1666                          * "j1939_xtp_rx_rts_session_new()") as this will be a
1667                          * receiver session.
1668                          *
1669                          * The reasons the session is already destroyed might
1670                          * be:
1671                          * - user space closed socket was and the session was
1672                          *   aborted
1673                          * - session was aborted due to external abort message
1674                          */
1675                         return;
1676                 }
1677                 session = j1939_xtp_rx_rts_session_new(priv, skb);
1678                 if (!session) {
1679                         if (cmd == J1939_TP_CMD_BAM && j1939_sk_recv_match(priv, skcb))
1680                                 netdev_info(priv->ndev, "%s: failed to create TP BAM session\n",
1681                                             __func__);
1682                         return;
1683                 }
1684         } else {
1685                 if (j1939_xtp_rx_rts_session_active(session, skb)) {
1686                         j1939_session_put(session);
1687                         return;
1688                 }
1689         }
1690         session->last_cmd = cmd;
1691
1692         if (cmd == J1939_TP_CMD_BAM) {
1693                 if (!session->transmission)
1694                         j1939_tp_set_rxtimeout(session, 750);
1695         } else {
1696                 if (!session->transmission) {
1697                         j1939_session_txtimer_cancel(session);
1698                         j1939_tp_schedule_txtimer(session, 0);
1699                 }
1700                 j1939_tp_set_rxtimeout(session, 1250);
1701         }
1702
1703         j1939_session_put(session);
1704 }
1705
1706 static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
1707                                  struct sk_buff *skb)
1708 {
1709         const u8 *dat = skb->data;
1710
1711         if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1712                 return;
1713
1714         netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1715
1716         /* transmitted without problems */
1717         session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
1718         session->last_cmd = dat[0];
1719         j1939_tp_set_rxtimeout(session, 750);
1720 }
1721
1722 static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,
1723                              bool transmitter)
1724 {
1725         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1726         struct j1939_session *session;
1727
1728         session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1729                                             transmitter);
1730         if (!session) {
1731                 netdev_info(priv->ndev,
1732                             "%s: no connection found\n", __func__);
1733                 return;
1734         }
1735
1736         j1939_xtp_rx_dpo_one(session, skb);
1737         j1939_session_put(session);
1738 }
1739
1740 static void j1939_xtp_rx_dat_one(struct j1939_session *session,
1741                                  struct sk_buff *skb)
1742 {
1743         struct j1939_priv *priv = session->priv;
1744         struct j1939_sk_buff_cb *skcb;
1745         struct sk_buff *se_skb;
1746         const u8 *dat;
1747         u8 *tpdat;
1748         int offset;
1749         int nbytes;
1750         bool final = false;
1751         bool remain = false;
1752         bool do_cts_eoma = false;
1753         int packet;
1754
1755         skcb = j1939_skb_to_cb(skb);
1756         dat = skb->data;
1757         if (skb->len <= 1)
1758                 /* makes no sense */
1759                 goto out_session_cancel;
1760
1761         switch (session->last_cmd) {
1762         case 0xff:
1763                 break;
1764         case J1939_ETP_CMD_DPO:
1765                 if (skcb->addr.type == J1939_ETP)
1766                         break;
1767                 fallthrough;
1768         case J1939_TP_CMD_BAM:
1769         case J1939_TP_CMD_CTS: /* fall through */
1770                 if (skcb->addr.type != J1939_ETP)
1771                         break;
1772                 fallthrough;
1773         default:
1774                 netdev_info(priv->ndev, "%s: 0x%p: last %02x\n", __func__,
1775                             session, session->last_cmd);
1776                 goto out_session_cancel;
1777         }
1778
1779         packet = (dat[0] - 1 + session->pkt.dpo);
1780         if (packet > session->pkt.total ||
1781             (session->pkt.rx + 1) > session->pkt.total) {
1782                 netdev_info(priv->ndev, "%s: 0x%p: should have been completed\n",
1783                             __func__, session);
1784                 goto out_session_cancel;
1785         }
1786
1787         se_skb = j1939_session_skb_find_by_offset(session, packet * 7);
1788         if (!se_skb) {
1789                 netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
1790                             session);
1791                 goto out_session_cancel;
1792         }
1793
1794         skcb = j1939_skb_to_cb(se_skb);
1795         offset = packet * 7 - skcb->offset;
1796         nbytes = se_skb->len - offset;
1797         if (nbytes > 7)
1798                 nbytes = 7;
1799         if (nbytes <= 0 || (nbytes + 1) > skb->len) {
1800                 netdev_info(priv->ndev, "%s: 0x%p: nbytes %i, len %i\n",
1801                             __func__, session, nbytes, skb->len);
1802                 goto out_session_cancel;
1803         }
1804
1805         tpdat = se_skb->data;
1806         if (!session->transmission) {
1807                 memcpy(&tpdat[offset], &dat[1], nbytes);
1808         } else {
1809                 int err;
1810
1811                 err = memcmp(&tpdat[offset], &dat[1], nbytes);
1812                 if (err)
1813                         netdev_err_once(priv->ndev,
1814                                         "%s: 0x%p: Data of RX-looped back packet (%*ph) doesn't match TX data (%*ph)!\n",
1815                                         __func__, session,
1816                                         nbytes, &dat[1],
1817                                         nbytes, &tpdat[offset]);
1818         }
1819
1820         if (packet == session->pkt.rx)
1821                 session->pkt.rx++;
1822
1823         if (skcb->addr.type != J1939_ETP &&
1824             j1939_cb_is_broadcast(&session->skcb)) {
1825                 if (session->pkt.rx >= session->pkt.total)
1826                         final = true;
1827                 else
1828                         remain = true;
1829         } else {
1830                 /* never final, an EOMA must follow */
1831                 if (session->pkt.rx >= session->pkt.last)
1832                         do_cts_eoma = true;
1833         }
1834
1835         if (final) {
1836                 j1939_session_timers_cancel(session);
1837                 j1939_session_completed(session);
1838         } else if (remain) {
1839                 if (!session->transmission)
1840                         j1939_tp_set_rxtimeout(session, 750);
1841         } else if (do_cts_eoma) {
1842                 j1939_tp_set_rxtimeout(session, 1250);
1843                 if (!session->transmission)
1844                         j1939_tp_schedule_txtimer(session, 0);
1845         } else {
1846                 j1939_tp_set_rxtimeout(session, 250);
1847         }
1848         session->last_cmd = 0xff;
1849         j1939_session_put(session);
1850
1851         return;
1852
1853  out_session_cancel:
1854         j1939_session_timers_cancel(session);
1855         j1939_session_cancel(session, J1939_XTP_ABORT_FAULT);
1856         j1939_session_put(session);
1857 }
1858
1859 static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
1860 {
1861         struct j1939_sk_buff_cb *skcb;
1862         struct j1939_session *session;
1863
1864         skcb = j1939_skb_to_cb(skb);
1865
1866         if (j1939_tp_im_transmitter(skcb)) {
1867                 session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1868                                                     true);
1869                 if (!session)
1870                         netdev_info(priv->ndev, "%s: no tx connection found\n",
1871                                     __func__);
1872                 else
1873                         j1939_xtp_rx_dat_one(session, skb);
1874         }
1875
1876         if (j1939_tp_im_receiver(skcb)) {
1877                 session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1878                                                     false);
1879                 if (!session)
1880                         netdev_info(priv->ndev, "%s: no rx connection found\n",
1881                                     __func__);
1882                 else
1883                         j1939_xtp_rx_dat_one(session, skb);
1884         }
1885
1886         if (j1939_cb_is_broadcast(skcb)) {
1887                 session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1888                                                     false);
1889                 if (session)
1890                         j1939_xtp_rx_dat_one(session, skb);
1891         }
1892 }
1893
1894 /* j1939 main intf */
1895 struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
1896                                     struct sk_buff *skb, size_t size)
1897 {
1898         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1899         struct j1939_session *session;
1900         int ret;
1901
1902         if (skcb->addr.pgn == J1939_TP_PGN_DAT ||
1903             skcb->addr.pgn == J1939_TP_PGN_CTL ||
1904             skcb->addr.pgn == J1939_ETP_PGN_DAT ||
1905             skcb->addr.pgn == J1939_ETP_PGN_CTL)
1906                 /* avoid conflict */
1907                 return ERR_PTR(-EDOM);
1908
1909         if (size > priv->tp_max_packet_size)
1910                 return ERR_PTR(-EMSGSIZE);
1911
1912         if (size <= 8)
1913                 skcb->addr.type = J1939_SIMPLE;
1914         else if (size > J1939_MAX_TP_PACKET_SIZE)
1915                 skcb->addr.type = J1939_ETP;
1916         else
1917                 skcb->addr.type = J1939_TP;
1918
1919         if (skcb->addr.type == J1939_ETP &&
1920             j1939_cb_is_broadcast(skcb))
1921                 return ERR_PTR(-EDESTADDRREQ);
1922
1923         /* fill in addresses from names */
1924         ret = j1939_ac_fixup(priv, skb);
1925         if (unlikely(ret))
1926                 return ERR_PTR(ret);
1927
1928         /* fix DST flags, it may be used there soon */
1929         if (j1939_address_is_unicast(skcb->addr.da) &&
1930             priv->ents[skcb->addr.da].nusers)
1931                 skcb->flags |= J1939_ECU_LOCAL_DST;
1932
1933         /* src is always local, I'm sending ... */
1934         skcb->flags |= J1939_ECU_LOCAL_SRC;
1935
1936         /* prepare new session */
1937         session = j1939_session_new(priv, skb, size);
1938         if (!session)
1939                 return ERR_PTR(-ENOMEM);
1940
1941         /* skb is recounted in j1939_session_new() */
1942         sock_hold(skb->sk);
1943         session->sk = skb->sk;
1944         session->transmission = true;
1945         session->pkt.total = (size + 6) / 7;
1946         session->pkt.block = skcb->addr.type == J1939_ETP ? 255 :
1947                 min(j1939_tp_block ?: 255, session->pkt.total);
1948
1949         if (j1939_cb_is_broadcast(&session->skcb))
1950                 /* set the end-packet for broadcast */
1951                 session->pkt.last = session->pkt.total;
1952
1953         skcb->tskey = session->sk->sk_tskey++;
1954         session->tskey = skcb->tskey;
1955
1956         return session;
1957 }
1958
1959 static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
1960 {
1961         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1962         int extd = J1939_TP;
1963         u8 cmd = skb->data[0];
1964
1965         switch (cmd) {
1966         case J1939_ETP_CMD_RTS:
1967                 extd = J1939_ETP;
1968                 fallthrough;
1969         case J1939_TP_CMD_BAM:
1970         case J1939_TP_CMD_RTS: /* fall through */
1971                 if (skcb->addr.type != extd)
1972                         return;
1973
1974                 if (cmd == J1939_TP_CMD_RTS && j1939_cb_is_broadcast(skcb)) {
1975                         netdev_alert(priv->ndev, "%s: rts without destination (%02x)\n",
1976                                      __func__, skcb->addr.sa);
1977                         return;
1978                 }
1979
1980                 if (j1939_tp_im_transmitter(skcb))
1981                         j1939_xtp_rx_rts(priv, skb, true);
1982
1983                 if (j1939_tp_im_receiver(skcb) || j1939_cb_is_broadcast(skcb))
1984                         j1939_xtp_rx_rts(priv, skb, false);
1985
1986                 break;
1987
1988         case J1939_ETP_CMD_CTS:
1989                 extd = J1939_ETP;
1990                 fallthrough;
1991         case J1939_TP_CMD_CTS:
1992                 if (skcb->addr.type != extd)
1993                         return;
1994
1995                 if (j1939_tp_im_transmitter(skcb))
1996                         j1939_xtp_rx_cts(priv, skb, false);
1997
1998                 if (j1939_tp_im_receiver(skcb))
1999                         j1939_xtp_rx_cts(priv, skb, true);
2000
2001                 break;
2002
2003         case J1939_ETP_CMD_DPO:
2004                 if (skcb->addr.type != J1939_ETP)
2005                         return;
2006
2007                 if (j1939_tp_im_transmitter(skcb))
2008                         j1939_xtp_rx_dpo(priv, skb, true);
2009
2010                 if (j1939_tp_im_receiver(skcb))
2011                         j1939_xtp_rx_dpo(priv, skb, false);
2012
2013                 break;
2014
2015         case J1939_ETP_CMD_EOMA:
2016                 extd = J1939_ETP;
2017                 fallthrough;
2018         case J1939_TP_CMD_EOMA:
2019                 if (skcb->addr.type != extd)
2020                         return;
2021
2022                 if (j1939_tp_im_transmitter(skcb))
2023                         j1939_xtp_rx_eoma(priv, skb, false);
2024
2025                 if (j1939_tp_im_receiver(skcb))
2026                         j1939_xtp_rx_eoma(priv, skb, true);
2027
2028                 break;
2029
2030         case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
2031                 if (j1939_tp_im_transmitter(skcb))
2032                         j1939_xtp_rx_abort(priv, skb, true);
2033
2034                 if (j1939_tp_im_receiver(skcb))
2035                         j1939_xtp_rx_abort(priv, skb, false);
2036
2037                 break;
2038         default:
2039                 return;
2040         }
2041 }
2042
2043 int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
2044 {
2045         struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
2046
2047         if (!j1939_tp_im_involved_anydir(skcb) && !j1939_cb_is_broadcast(skcb))
2048                 return 0;
2049
2050         switch (skcb->addr.pgn) {
2051         case J1939_ETP_PGN_DAT:
2052                 skcb->addr.type = J1939_ETP;
2053                 fallthrough;
2054         case J1939_TP_PGN_DAT:
2055                 j1939_xtp_rx_dat(priv, skb);
2056                 break;
2057
2058         case J1939_ETP_PGN_CTL:
2059                 skcb->addr.type = J1939_ETP;
2060                 fallthrough;
2061         case J1939_TP_PGN_CTL:
2062                 if (skb->len < 8)
2063                         return 0; /* Don't care. Nothing to extract here */
2064
2065                 j1939_tp_cmd_recv(priv, skb);
2066                 break;
2067         default:
2068                 return 0; /* no problem */
2069         }
2070         return 1; /* "I processed the message" */
2071 }
2072
2073 void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
2074 {
2075         struct j1939_session *session;
2076
2077         if (!skb->sk)
2078                 return;
2079
2080         if (skb->sk->sk_family != AF_CAN ||
2081             skb->sk->sk_protocol != CAN_J1939)
2082                 return;
2083
2084         j1939_session_list_lock(priv);
2085         session = j1939_session_get_simple(priv, skb);
2086         j1939_session_list_unlock(priv);
2087         if (!session) {
2088                 netdev_warn(priv->ndev,
2089                             "%s: Received already invalidated message\n",
2090                             __func__);
2091                 return;
2092         }
2093
2094         j1939_session_timers_cancel(session);
2095         j1939_session_deactivate(session);
2096         j1939_session_put(session);
2097 }
2098
2099 int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
2100 {
2101         struct j1939_session *session, *saved;
2102
2103         netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
2104         j1939_session_list_lock(priv);
2105         list_for_each_entry_safe(session, saved,
2106                                  &priv->active_session_list,
2107                                  active_session_list_entry) {
2108                 if (!sk || sk == session->sk) {
2109                         if (hrtimer_try_to_cancel(&session->txtimer) == 1)
2110                                 j1939_session_put(session);
2111                         if (hrtimer_try_to_cancel(&session->rxtimer) == 1)
2112                                 j1939_session_put(session);
2113
2114                         session->err = ESHUTDOWN;
2115                         j1939_session_deactivate_locked(session);
2116                 }
2117         }
2118         j1939_session_list_unlock(priv);
2119         return NOTIFY_DONE;
2120 }
2121
2122 void j1939_tp_init(struct j1939_priv *priv)
2123 {
2124         spin_lock_init(&priv->active_session_list_lock);
2125         INIT_LIST_HEAD(&priv->active_session_list);
2126         priv->tp_max_packet_size = J1939_MAX_ETP_PACKET_SIZE;
2127 }