net/rxrpc/ar-input.c

   1 /* RxRPC packet reception
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/net.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/errqueue.h>
  16 #include <linux/udp.h>
  17 #include <linux/in.h>
  18 #include <linux/in6.h>
  19 #include <linux/icmp.h>
  20 #include <linux/gfp.h>
  21 #include <net/sock.h>
  22 #include <net/af_rxrpc.h>
  23 #include <net/ip.h>
  24 #include <net/udp.h>
  25 #include <net/net_namespace.h>
  26 #include "ar-internal.h"
  27
  28 /*
  29  * queue a packet for recvmsg to pass to userspace
  30  * - the caller must hold a lock on call->lock
  31  * - must not be called with interrupts disabled (sk_filter() disables BH's)
  32  * - eats the packet whether successful or not
  33  * - there must be just one reference to the packet, which the caller passes to
  34  *   this function
  35  */
  36 int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb,
  37                         bool force, bool terminal)
  38 {
  39         struct rxrpc_skb_priv *sp;
  40         struct rxrpc_sock *rx = call->socket;
  41         struct sock *sk;
  42         int ret;
  43
  44         _enter(",,%d,%d", force, terminal);
  45
  46         ASSERT(!irqs_disabled());
  47
  48         sp = rxrpc_skb(skb);
  49         ASSERTCMP(sp->call, ==, call);
  50
  51         /* if we've already posted the terminal message for a call, then we
  52          * don't post any more */
  53         if (test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
  54                 _debug("already terminated");
  55                 ASSERTCMP(call->state, >=, RXRPC_CALL_COMPLETE);
  56                 skb->destructor = NULL;
  57                 sp->call = NULL;
  58                 rxrpc_put_call(call);
  59                 rxrpc_free_skb(skb);
  60                 return 0;
  61         }
  62
  63         sk = &rx->sk;
  64
  65         if (!force) {
  66                 /* cast skb->rcvbuf to unsigned...  It's pointless, but
  67                  * reduces number of warnings when compiling with -W
  68                  * --ANK */
  69 //              ret = -ENOBUFS;
  70 //              if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
  71 //                  (unsigned int) sk->sk_rcvbuf)
  72 //                      goto out;
  73
  74                 ret = sk_filter(sk, skb);
  75                 if (ret < 0)
  76                         goto out;
  77         }
  78
  79         spin_lock_bh(&sk->sk_receive_queue.lock);
  80         if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags) &&
  81             !test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
  82             call->socket->sk.sk_state != RXRPC_CLOSE) {
  83                 skb->destructor = rxrpc_packet_destructor;
  84                 skb->dev = NULL;
  85                 skb->sk = sk;
  86                 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
  87
  88                 if (terminal) {
  89                         _debug("<<<< TERMINAL MESSAGE >>>>");
  90                         set_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags);
  91                 }
  92
  93                 /* allow interception by a kernel service */
  94                 if (rx->interceptor) {
  95                         rx->interceptor(sk, call->user_call_ID, skb);
  96                         spin_unlock_bh(&sk->sk_receive_queue.lock);
  97                 } else {
  98                         _net("post skb %p", skb);
  99                         __skb_queue_tail(&sk->sk_receive_queue, skb);
 100                         spin_unlock_bh(&sk->sk_receive_queue.lock);
 101
 102                         if (!sock_flag(sk, SOCK_DEAD))
 103                                 sk->sk_data_ready(sk);
 104                 }
 105                 skb = NULL;
 106         } else {
 107                 spin_unlock_bh(&sk->sk_receive_queue.lock);
 108         }
 109         ret = 0;
 110
 111 out:
 112         /* release the socket buffer */
 113         if (skb) {
 114                 skb->destructor = NULL;
 115                 sp->call = NULL;
 116                 rxrpc_put_call(call);
 117                 rxrpc_free_skb(skb);
 118         }
 119
 120         _leave(" = %d", ret);
 121         return ret;
 122 }
 123
 124 /*
 125  * process a DATA packet, posting the packet to the appropriate queue
 126  * - eats the packet if successful
 127  */
 128 static int rxrpc_fast_process_data(struct rxrpc_call *call,
 129                                    struct sk_buff *skb, u32 seq)
 130 {
 131         struct rxrpc_skb_priv *sp;
 132         bool terminal;
 133         int ret, ackbit, ack;
 134
 135         _enter("{%u,%u},,{%u}", call->rx_data_post, call->rx_first_oos, seq);
 136
 137         sp = rxrpc_skb(skb);
 138         ASSERTCMP(sp->call, ==, NULL);
 139
 140         spin_lock(&call->lock);
 141
 142         if (call->state > RXRPC_CALL_COMPLETE)
 143                 goto discard;
 144
 145         ASSERTCMP(call->rx_data_expect, >=, call->rx_data_post);
 146         ASSERTCMP(call->rx_data_post, >=, call->rx_data_recv);
 147         ASSERTCMP(call->rx_data_recv, >=, call->rx_data_eaten);
 148
 149         if (seq < call->rx_data_post) {
 150                 _debug("dup #%u [-%u]", seq, call->rx_data_post);
 151                 ack = RXRPC_ACK_DUPLICATE;
 152                 ret = -ENOBUFS;
 153                 goto discard_and_ack;
 154         }
 155
 156         /* we may already have the packet in the out of sequence queue */
 157         ackbit = seq - (call->rx_data_eaten + 1);
 158         ASSERTCMP(ackbit, >=, 0);
 159         if (__test_and_set_bit(ackbit, call->ackr_window)) {
 160                 _debug("dup oos #%u [%u,%u]",
 161                        seq, call->rx_data_eaten, call->rx_data_post);
 162                 ack = RXRPC_ACK_DUPLICATE;
 163                 goto discard_and_ack;
 164         }
 165
 166         if (seq >= call->ackr_win_top) {
 167                 _debug("exceed #%u [%u]", seq, call->ackr_win_top);
 168                 __clear_bit(ackbit, call->ackr_window);
 169                 ack = RXRPC_ACK_EXCEEDS_WINDOW;
 170                 goto discard_and_ack;
 171         }
 172
 173         if (seq == call->rx_data_expect) {
 174                 clear_bit(RXRPC_CALL_EXPECT_OOS, &call->flags);
 175                 call->rx_data_expect++;
 176         } else if (seq > call->rx_data_expect) {
 177                 _debug("oos #%u [%u]", seq, call->rx_data_expect);
 178                 call->rx_data_expect = seq + 1;
 179                 if (test_and_set_bit(RXRPC_CALL_EXPECT_OOS, &call->flags)) {
 180                         ack = RXRPC_ACK_OUT_OF_SEQUENCE;
 181                         goto enqueue_and_ack;
 182                 }
 183                 goto enqueue_packet;
 184         }
 185
 186         if (seq != call->rx_data_post) {
 187                 _debug("ahead #%u [%u]", seq, call->rx_data_post);
 188                 goto enqueue_packet;
 189         }
 190
 191         if (test_bit(RXRPC_CALL_RCVD_LAST, &call->flags))
 192                 goto protocol_error;
 193
 194         /* if the packet need security things doing to it, then it goes down
 195          * the slow path */
 196         if (call->conn->security_ix)
 197                 goto enqueue_packet;
 198
 199         sp->call = call;
 200         rxrpc_get_call(call);
 201         terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
 202                     !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
 203         ret = rxrpc_queue_rcv_skb(call, skb, false, terminal);
 204         if (ret < 0) {
 205                 if (ret == -ENOMEM || ret == -ENOBUFS) {
 206                         __clear_bit(ackbit, call->ackr_window);
 207                         ack = RXRPC_ACK_NOSPACE;
 208                         goto discard_and_ack;
 209                 }
 210                 goto out;
 211         }
 212
 213         skb = NULL;
 214
 215         _debug("post #%u", seq);
 216         ASSERTCMP(call->rx_data_post, ==, seq);
 217         call->rx_data_post++;
 218
 219         if (sp->hdr.flags & RXRPC_LAST_PACKET)
 220                 set_bit(RXRPC_CALL_RCVD_LAST, &call->flags);
 221
 222         /* if we've reached an out of sequence packet then we need to drain
 223          * that queue into the socket Rx queue now */
 224         if (call->rx_data_post == call->rx_first_oos) {
 225                 _debug("drain rx oos now");
 226                 read_lock(&call->state_lock);
 227                 if (call->state < RXRPC_CALL_COMPLETE &&
 228                     !test_and_set_bit(RXRPC_CALL_EV_DRAIN_RX_OOS, &call->events))
 229                         rxrpc_queue_call(call);
 230                 read_unlock(&call->state_lock);
 231         }
 232
 233         spin_unlock(&call->lock);
 234         atomic_inc(&call->ackr_not_idle);
 235         rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, sp->hdr.serial, false);
 236         _leave(" = 0 [posted]");
 237         return 0;
 238
 239 protocol_error:
 240         ret = -EBADMSG;
 241 out:
 242         spin_unlock(&call->lock);
 243         _leave(" = %d", ret);
 244         return ret;
 245
 246 discard_and_ack:
 247         _debug("discard and ACK packet %p", skb);
 248         __rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
 249 discard:
 250         spin_unlock(&call->lock);
 251         rxrpc_free_skb(skb);
 252         _leave(" = 0 [discarded]");
 253         return 0;
 254
 255 enqueue_and_ack:
 256         __rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
 257 enqueue_packet:
 258         _net("defer skb %p", skb);
 259         spin_unlock(&call->lock);
 260         skb_queue_tail(&call->rx_queue, skb);
 261         atomic_inc(&call->ackr_not_idle);
 262         read_lock(&call->state_lock);
 263         if (call->state < RXRPC_CALL_DEAD)
 264                 rxrpc_queue_call(call);
 265         read_unlock(&call->state_lock);
 266         _leave(" = 0 [queued]");
 267         return 0;
 268 }
 269
 270 /*
 271  * assume an implicit ACKALL of the transmission phase of a client socket upon
 272  * reception of the first reply packet
 273  */
 274 static void rxrpc_assume_implicit_ackall(struct rxrpc_call *call, u32 serial)
 275 {
 276         write_lock_bh(&call->state_lock);
 277
 278         switch (call->state) {
 279         case RXRPC_CALL_CLIENT_AWAIT_REPLY:
 280                 call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
 281                 call->acks_latest = serial;
 282
 283                 _debug("implicit ACKALL %%%u", call->acks_latest);
 284                 set_bit(RXRPC_CALL_EV_RCVD_ACKALL, &call->events);
 285                 write_unlock_bh(&call->state_lock);
 286
 287                 if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
 288                         clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);
 289                         clear_bit(RXRPC_CALL_EV_RESEND, &call->events);
 290                         clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
 291                 }
 292                 break;
 293
 294         default:
 295                 write_unlock_bh(&call->state_lock);
 296                 break;
 297         }
 298 }
 299
 300 /*
 301  * post an incoming packet to the nominated call to deal with
 302  * - must get rid of the sk_buff, either by freeing it or by queuing it
 303  */
 304 void rxrpc_fast_process_packet(struct rxrpc_call *call, struct sk_buff *skb)
 305 {
 306         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 307         __be32 wtmp;
 308         u32 hi_serial, abort_code;
 309
 310         _enter("%p,%p", call, skb);
 311
 312         ASSERT(!irqs_disabled());
 313
 314 #if 0 // INJECT RX ERROR
 315         if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
 316                 static int skip = 0;
 317                 if (++skip == 3) {
 318                         printk("DROPPED 3RD PACKET!!!!!!!!!!!!!\n");
 319                         skip = 0;
 320                         goto free_packet;
 321                 }
 322         }
 323 #endif
 324
 325         /* track the latest serial number on this connection for ACK packet
 326          * information */
 327         hi_serial = atomic_read(&call->conn->hi_serial);
 328         while (sp->hdr.serial > hi_serial)
 329                 hi_serial = atomic_cmpxchg(&call->conn->hi_serial, hi_serial,
 330                                            sp->hdr.serial);
 331
 332         /* request ACK generation for any ACK or DATA packet that requests
 333          * it */
 334         if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
 335                 _proto("ACK Requested on %%%u", sp->hdr.serial);
 336                 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, sp->hdr.serial, false);
 337         }
 338
 339         switch (sp->hdr.type) {
 340         case RXRPC_PACKET_TYPE_ABORT:
 341                 _debug("abort");
 342
 343                 if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0)
 344                         goto protocol_error;
 345
 346                 abort_code = ntohl(wtmp);
 347                 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
 348
 349                 write_lock_bh(&call->state_lock);
 350                 if (call->state < RXRPC_CALL_COMPLETE) {
 351                         call->state = RXRPC_CALL_REMOTELY_ABORTED;
 352                         call->remote_abort = abort_code;
 353                         set_bit(RXRPC_CALL_EV_RCVD_ABORT, &call->events);
 354                         rxrpc_queue_call(call);
 355                 }
 356                 goto free_packet_unlock;
 357
 358         case RXRPC_PACKET_TYPE_BUSY:
 359                 _proto("Rx BUSY %%%u", sp->hdr.serial);
 360
 361                 if (call->conn->out_clientflag)
 362                         goto protocol_error;
 363
 364                 write_lock_bh(&call->state_lock);
 365                 switch (call->state) {
 366                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 367                         call->state = RXRPC_CALL_SERVER_BUSY;
 368                         set_bit(RXRPC_CALL_EV_RCVD_BUSY, &call->events);
 369                         rxrpc_queue_call(call);
 370                 case RXRPC_CALL_SERVER_BUSY:
 371                         goto free_packet_unlock;
 372                 default:
 373                         goto protocol_error_locked;
 374                 }
 375
 376         default:
 377                 _proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], sp->hdr.serial);
 378                 goto protocol_error;
 379
 380         case RXRPC_PACKET_TYPE_DATA:
 381                 _proto("Rx DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);
 382
 383                 if (sp->hdr.seq == 0)
 384                         goto protocol_error;
 385
 386                 call->ackr_prev_seq = sp->hdr.seq;
 387
 388                 /* received data implicitly ACKs all of the request packets we
 389                  * sent when we're acting as a client */
 390                 if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
 391                         rxrpc_assume_implicit_ackall(call, sp->hdr.serial);
 392
 393                 switch (rxrpc_fast_process_data(call, skb, sp->hdr.seq)) {
 394                 case 0:
 395                         skb = NULL;
 396                         goto done;
 397
 398                 default:
 399                         BUG();
 400
 401                         /* data packet received beyond the last packet */
 402                 case -EBADMSG:
 403                         goto protocol_error;
 404                 }
 405
 406         case RXRPC_PACKET_TYPE_ACKALL:
 407         case RXRPC_PACKET_TYPE_ACK:
 408                 /* ACK processing is done in process context */
 409                 read_lock_bh(&call->state_lock);
 410                 if (call->state < RXRPC_CALL_DEAD) {
 411                         skb_queue_tail(&call->rx_queue, skb);
 412                         rxrpc_queue_call(call);
 413                         skb = NULL;
 414                 }
 415                 read_unlock_bh(&call->state_lock);
 416                 goto free_packet;
 417         }
 418
 419 protocol_error:
 420         _debug("protocol error");
 421         write_lock_bh(&call->state_lock);
 422 protocol_error_locked:
 423         if (call->state <= RXRPC_CALL_COMPLETE) {
 424                 call->state = RXRPC_CALL_LOCALLY_ABORTED;
 425                 call->local_abort = RX_PROTOCOL_ERROR;
 426                 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 427                 rxrpc_queue_call(call);
 428         }
 429 free_packet_unlock:
 430         write_unlock_bh(&call->state_lock);
 431 free_packet:
 432         rxrpc_free_skb(skb);
 433 done:
 434         _leave("");
 435 }
 436
 437 /*
 438  * split up a jumbo data packet
 439  */
 440 static void rxrpc_process_jumbo_packet(struct rxrpc_call *call,
 441                                        struct sk_buff *jumbo)
 442 {
 443         struct rxrpc_jumbo_header jhdr;
 444         struct rxrpc_skb_priv *sp;
 445         struct sk_buff *part;
 446
 447         _enter(",{%u,%u}", jumbo->data_len, jumbo->len);
 448
 449         sp = rxrpc_skb(jumbo);
 450
 451         do {
 452                 sp->hdr.flags &= ~RXRPC_JUMBO_PACKET;
 453
 454                 /* make a clone to represent the first subpacket in what's left
 455                  * of the jumbo packet */
 456                 part = skb_clone(jumbo, GFP_ATOMIC);
 457                 if (!part) {
 458                         /* simply ditch the tail in the event of ENOMEM */
 459                         pskb_trim(jumbo, RXRPC_JUMBO_DATALEN);
 460                         break;
 461                 }
 462                 rxrpc_new_skb(part);
 463
 464                 pskb_trim(part, RXRPC_JUMBO_DATALEN);
 465
 466                 if (!pskb_pull(jumbo, RXRPC_JUMBO_DATALEN))
 467                         goto protocol_error;
 468
 469                 if (skb_copy_bits(jumbo, 0, &jhdr, sizeof(jhdr)) < 0)
 470                         goto protocol_error;
 471                 if (!pskb_pull(jumbo, sizeof(jhdr)))
 472                         BUG();
 473
 474                 sp->hdr.seq     += 1;
 475                 sp->hdr.serial  += 1;
 476                 sp->hdr.flags   = jhdr.flags;
 477                 sp->hdr._rsvd   = jhdr._rsvd;
 478
 479                 _proto("Rx DATA Jumbo %%%u", sp->hdr.serial - 1);
 480
 481                 rxrpc_fast_process_packet(call, part);
 482                 part = NULL;
 483
 484         } while (sp->hdr.flags & RXRPC_JUMBO_PACKET);
 485
 486         rxrpc_fast_process_packet(call, jumbo);
 487         _leave("");
 488         return;
 489
 490 protocol_error:
 491         _debug("protocol error");
 492         rxrpc_free_skb(part);
 493         rxrpc_free_skb(jumbo);
 494         write_lock_bh(&call->state_lock);
 495         if (call->state <= RXRPC_CALL_COMPLETE) {
 496                 call->state = RXRPC_CALL_LOCALLY_ABORTED;
 497                 call->local_abort = RX_PROTOCOL_ERROR;
 498                 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
 499                 rxrpc_queue_call(call);
 500         }
 501         write_unlock_bh(&call->state_lock);
 502         _leave("");
 503 }
 504
 505 /*
 506  * post an incoming packet to the appropriate call/socket to deal with
 507  * - must get rid of the sk_buff, either by freeing it or by queuing it
 508  */
 509 static void rxrpc_post_packet_to_call(struct rxrpc_call *call,
 510                                       struct sk_buff *skb)
 511 {
 512         struct rxrpc_skb_priv *sp;
 513
 514         _enter("%p,%p", call, skb);
 515
 516         sp = rxrpc_skb(skb);
 517
 518         _debug("extant call [%d]", call->state);
 519
 520         read_lock(&call->state_lock);
 521         switch (call->state) {
 522         case RXRPC_CALL_LOCALLY_ABORTED:
 523                 if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events)) {
 524                         rxrpc_queue_call(call);
 525                         goto free_unlock;
 526                 }
 527         case RXRPC_CALL_REMOTELY_ABORTED:
 528         case RXRPC_CALL_NETWORK_ERROR:
 529         case RXRPC_CALL_DEAD:
 530                 goto dead_call;
 531         case RXRPC_CALL_COMPLETE:
 532         case RXRPC_CALL_CLIENT_FINAL_ACK:
 533                 /* complete server call */
 534                 if (call->conn->in_clientflag)
 535                         goto dead_call;
 536                 /* resend last packet of a completed call */
 537                 _debug("final ack again");
 538                 rxrpc_get_call(call);
 539                 set_bit(RXRPC_CALL_EV_ACK_FINAL, &call->events);
 540                 rxrpc_queue_call(call);
 541                 goto free_unlock;
 542         default:
 543                 break;
 544         }
 545
 546         read_unlock(&call->state_lock);
 547         rxrpc_get_call(call);
 548
 549         if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
 550             sp->hdr.flags & RXRPC_JUMBO_PACKET)
 551                 rxrpc_process_jumbo_packet(call, skb);
 552         else
 553                 rxrpc_fast_process_packet(call, skb);
 554
 555         rxrpc_put_call(call);
 556         goto done;
 557
 558 dead_call:
 559         if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
 560                 skb->priority = RX_CALL_DEAD;
 561                 rxrpc_reject_packet(call->conn->trans->local, skb);
 562                 goto unlock;
 563         }
 564 free_unlock:
 565         rxrpc_free_skb(skb);
 566 unlock:
 567         read_unlock(&call->state_lock);
 568 done:
 569         _leave("");
 570 }
 571
 572 /*
 573  * post connection-level events to the connection
 574  * - this includes challenges, responses and some aborts
 575  */
 576 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
 577                                       struct sk_buff *skb)
 578 {
 579         _enter("%p,%p", conn, skb);
 580
 581         atomic_inc(&conn->usage);
 582         skb_queue_tail(&conn->rx_queue, skb);
 583         rxrpc_queue_conn(conn);
 584 }
 585
 586 /*
 587  * post endpoint-level events to the local endpoint
 588  * - this includes debug and version messages
 589  */
 590 static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
 591                                        struct sk_buff *skb)
 592 {
 593         _enter("%p,%p", local, skb);
 594
 595         atomic_inc(&local->usage);
 596         skb_queue_tail(&local->event_queue, skb);
 597         rxrpc_queue_work(&local->event_processor);
 598 }
 599
 600 /*
 601  * Extract the wire header from a packet and translate the byte order.
 602  */
 603 static noinline
 604 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
 605 {
 606         struct rxrpc_wire_header whdr;
 607
 608         /* dig out the RxRPC connection details */
 609         if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)
 610                 return -EBADMSG;
 611         if (!pskb_pull(skb, sizeof(whdr)))
 612                 BUG();
 613
 614         memset(sp, 0, sizeof(*sp));
 615         sp->hdr.epoch           = ntohl(whdr.epoch);
 616         sp->hdr.cid             = ntohl(whdr.cid);
 617         sp->hdr.callNumber      = ntohl(whdr.callNumber);
 618         sp->hdr.seq             = ntohl(whdr.seq);
 619         sp->hdr.serial          = ntohl(whdr.serial);
 620         sp->hdr.flags           = whdr.flags;
 621         sp->hdr.type            = whdr.type;
 622         sp->hdr.userStatus      = whdr.userStatus;
 623         sp->hdr.securityIndex   = whdr.securityIndex;
 624         sp->hdr._rsvd           = ntohs(whdr._rsvd);
 625         sp->hdr.serviceId       = ntohs(whdr.serviceId);
 626         return 0;
 627 }
 628
 629 static struct rxrpc_connection *rxrpc_conn_from_local(struct rxrpc_local *local,
 630                                                struct sk_buff *skb,
 631                                                struct rxrpc_skb_priv *sp)
 632 {
 633         struct rxrpc_peer *peer;
 634         struct rxrpc_transport *trans;
 635         struct rxrpc_connection *conn;
 636
 637         peer = rxrpc_find_peer(local, ip_hdr(skb)->saddr,
 638                                 udp_hdr(skb)->source);
 639         if (IS_ERR(peer))
 640                 goto cant_find_conn;
 641
 642         trans = rxrpc_find_transport(local, peer);
 643         rxrpc_put_peer(peer);
 644         if (!trans)
 645                 goto cant_find_conn;
 646
 647         conn = rxrpc_find_connection(trans, &sp->hdr);
 648         rxrpc_put_transport(trans);
 649         if (!conn)
 650                 goto cant_find_conn;
 651
 652         return conn;
 653 cant_find_conn:
 654         return NULL;
 655 }
 656
 657 /*
 658  * handle data received on the local endpoint
 659  * - may be called in interrupt context
 660  */
 661 void rxrpc_data_ready(struct sock *sk)
 662 {
 663         struct rxrpc_skb_priv *sp;
 664         struct rxrpc_local *local;
 665         struct sk_buff *skb;
 666         int ret;
 667
 668         _enter("%p", sk);
 669
 670         ASSERT(!irqs_disabled());
 671
 672         read_lock_bh(&rxrpc_local_lock);
 673         local = sk->sk_user_data;
 674         if (local && atomic_read(&local->usage) > 0)
 675                 rxrpc_get_local(local);
 676         else
 677                 local = NULL;
 678         read_unlock_bh(&rxrpc_local_lock);
 679         if (!local) {
 680                 _leave(" [local dead]");
 681                 return;
 682         }
 683
 684         skb = skb_recv_datagram(sk, 0, 1, &ret);
 685         if (!skb) {
 686                 rxrpc_put_local(local);
 687                 if (ret == -EAGAIN)
 688                         return;
 689                 _debug("UDP socket error %d", ret);
 690                 return;
 691         }
 692
 693         rxrpc_new_skb(skb);
 694
 695         _net("recv skb %p", skb);
 696
 697         /* we'll probably need to checksum it (didn't call sock_recvmsg) */
 698         if (skb_checksum_complete(skb)) {
 699                 rxrpc_free_skb(skb);
 700                 rxrpc_put_local(local);
 701                 __UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0);
 702                 _leave(" [CSUM failed]");
 703                 return;
 704         }
 705
 706         __UDP_INC_STATS(&init_net, UDP_MIB_INDATAGRAMS, 0);
 707
 708         /* The socket buffer we have is owned by UDP, with UDP's data all over
 709          * it, but we really want our own data there.
 710          */
 711         skb_orphan(skb);
 712         sp = rxrpc_skb(skb);
 713
 714         _net("Rx UDP packet from %08x:%04hu",
 715              ntohl(ip_hdr(skb)->saddr), ntohs(udp_hdr(skb)->source));
 716
 717         /* dig out the RxRPC connection details */
 718         if (rxrpc_extract_header(sp, skb) < 0)
 719                 goto bad_message;
 720
 721         _net("Rx RxRPC %s ep=%x call=%x:%x",
 722              sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
 723              sp->hdr.epoch, sp->hdr.cid, sp->hdr.callNumber);
 724
 725         if (sp->hdr.type >= RXRPC_N_PACKET_TYPES ||
 726             !((RXRPC_SUPPORTED_PACKET_TYPES >> sp->hdr.type) & 1)) {
 727                 _proto("Rx Bad Packet Type %u", sp->hdr.type);
 728                 goto bad_message;
 729         }
 730
 731         if (sp->hdr.type == RXRPC_PACKET_TYPE_VERSION) {
 732                 rxrpc_post_packet_to_local(local, skb);
 733                 goto out;
 734         }
 735
 736         if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
 737             (sp->hdr.callNumber == 0 || sp->hdr.seq == 0))
 738                 goto bad_message;
 739
 740         if (sp->hdr.callNumber == 0) {
 741                 /* This is a connection-level packet. These should be
 742                  * fairly rare, so the extra overhead of looking them up the
 743                  * old-fashioned way doesn't really hurt */
 744                 struct rxrpc_connection *conn;
 745
 746                 conn = rxrpc_conn_from_local(local, skb, sp);
 747                 if (!conn)
 748                         goto cant_route_call;
 749
 750                 _debug("CONN %p {%d}", conn, conn->debug_id);
 751                 rxrpc_post_packet_to_conn(conn, skb);
 752                 rxrpc_put_connection(conn);
 753         } else {
 754                 struct rxrpc_call *call;
 755
 756                 call = rxrpc_find_call_hash(&sp->hdr, local,
 757                                             AF_INET, &ip_hdr(skb)->saddr);
 758                 if (call)
 759                         rxrpc_post_packet_to_call(call, skb);
 760                 else
 761                         goto cant_route_call;
 762         }
 763
 764 out:
 765         rxrpc_put_local(local);
 766         return;
 767
 768 cant_route_call:
 769         _debug("can't route call");
 770         if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
 771             sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
 772                 if (sp->hdr.seq == 1) {
 773                         _debug("first packet");
 774                         skb_queue_tail(&local->accept_queue, skb);
 775                         rxrpc_queue_work(&local->acceptor);
 776                         rxrpc_put_local(local);
 777                         _leave(" [incoming]");
 778                         return;
 779                 }
 780                 skb->priority = RX_INVALID_OPERATION;
 781         } else {
 782                 skb->priority = RX_CALL_DEAD;
 783         }
 784
 785         if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
 786                 _debug("reject type %d",sp->hdr.type);
 787                 rxrpc_reject_packet(local, skb);
 788         }
 789         rxrpc_put_local(local);
 790         _leave(" [no call]");
 791         return;
 792
 793 bad_message:
 794         skb->priority = RX_PROTOCOL_ERROR;
 795         rxrpc_reject_packet(local, skb);
 796         rxrpc_put_local(local);
 797         _leave(" [badmsg]");
 798 }