1 /* RxRPC packet reception 2 * 3 * Copyright (C) 2007, 2016 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/module.h> 15 #include <linux/net.h> 16 #include <linux/skbuff.h> 17 #include <linux/errqueue.h> 18 #include <linux/udp.h> 19 #include <linux/in.h> 20 #include <linux/in6.h> 21 #include <linux/icmp.h> 22 #include <linux/gfp.h> 23 #include <net/sock.h> 24 #include <net/af_rxrpc.h> 25 #include <net/ip.h> 26 #include <net/udp.h> 27 #include <net/net_namespace.h> 28 #include "ar-internal.h" 29 30 static void rxrpc_proto_abort(const char *why, 31 struct rxrpc_call *call, rxrpc_seq_t seq) 32 { 33 if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) { 34 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 35 rxrpc_queue_call(call); 36 } 37 } 38 39 /* 40 * Do TCP-style congestion management [RFC 5681]. 41 */ 42 static void rxrpc_congestion_management(struct rxrpc_call *call, 43 struct sk_buff *skb, 44 struct rxrpc_ack_summary *summary, 45 rxrpc_serial_t acked_serial) 46 { 47 enum rxrpc_congest_change change = rxrpc_cong_no_change; 48 unsigned int cumulative_acks = call->cong_cumul_acks; 49 unsigned int cwnd = call->cong_cwnd; 50 bool resend = false; 51 52 summary->flight_size = 53 (call->tx_top - call->tx_hard_ack) - summary->nr_acks; 54 55 if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) { 56 summary->retrans_timeo = true; 57 call->cong_ssthresh = max_t(unsigned int, 58 summary->flight_size / 2, 2); 59 cwnd = 1; 60 if (cwnd >= call->cong_ssthresh && 61 call->cong_mode == RXRPC_CALL_SLOW_START) { 62 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 63 call->cong_tstamp = skb->tstamp; 64 cumulative_acks = 0; 65 } 66 } 67 68 cumulative_acks += summary->nr_new_acks; 69 cumulative_acks += summary->nr_rot_new_acks; 70 if (cumulative_acks > 255) 71 cumulative_acks = 255; 72 73 summary->mode = call->cong_mode; 74 summary->cwnd = call->cong_cwnd; 75 summary->ssthresh = call->cong_ssthresh; 76 summary->cumulative_acks = cumulative_acks; 77 summary->dup_acks = call->cong_dup_acks; 78 79 switch (call->cong_mode) { 80 case RXRPC_CALL_SLOW_START: 81 if (summary->nr_nacks > 0) 82 goto packet_loss_detected; 83 if (summary->cumulative_acks > 0) 84 cwnd += 1; 85 if (cwnd >= call->cong_ssthresh) { 86 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 87 call->cong_tstamp = skb->tstamp; 88 } 89 goto out; 90 91 case RXRPC_CALL_CONGEST_AVOIDANCE: 92 if (summary->nr_nacks > 0) 93 goto packet_loss_detected; 94 95 /* We analyse the number of packets that get ACK'd per RTT 96 * period and increase the window if we managed to fill it. 97 */ 98 if (call->peer->rtt_usage == 0) 99 goto out; 100 if (ktime_before(skb->tstamp, 101 ktime_add_ns(call->cong_tstamp, 102 call->peer->rtt))) 103 goto out_no_clear_ca; 104 change = rxrpc_cong_rtt_window_end; 105 call->cong_tstamp = skb->tstamp; 106 if (cumulative_acks >= cwnd) 107 cwnd++; 108 goto out; 109 110 case RXRPC_CALL_PACKET_LOSS: 111 if (summary->nr_nacks == 0) 112 goto resume_normality; 113 114 if (summary->new_low_nack) { 115 change = rxrpc_cong_new_low_nack; 116 call->cong_dup_acks = 1; 117 if (call->cong_extra > 1) 118 call->cong_extra = 1; 119 goto send_extra_data; 120 } 121 122 call->cong_dup_acks++; 123 if (call->cong_dup_acks < 3) 124 goto send_extra_data; 125 126 change = rxrpc_cong_begin_retransmission; 127 call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT; 128 call->cong_ssthresh = max_t(unsigned int, 129 summary->flight_size / 2, 2); 130 cwnd = call->cong_ssthresh + 3; 131 call->cong_extra = 0; 132 call->cong_dup_acks = 0; 133 resend = true; 134 goto out; 135 136 case RXRPC_CALL_FAST_RETRANSMIT: 137 if (!summary->new_low_nack) { 138 if (summary->nr_new_acks == 0) 139 cwnd += 1; 140 call->cong_dup_acks++; 141 if (call->cong_dup_acks == 2) { 142 change = rxrpc_cong_retransmit_again; 143 call->cong_dup_acks = 0; 144 resend = true; 145 } 146 } else { 147 change = rxrpc_cong_progress; 148 cwnd = call->cong_ssthresh; 149 if (summary->nr_nacks == 0) 150 goto resume_normality; 151 } 152 goto out; 153 154 default: 155 BUG(); 156 goto out; 157 } 158 159 resume_normality: 160 change = rxrpc_cong_cleared_nacks; 161 call->cong_dup_acks = 0; 162 call->cong_extra = 0; 163 call->cong_tstamp = skb->tstamp; 164 if (cwnd < call->cong_ssthresh) 165 call->cong_mode = RXRPC_CALL_SLOW_START; 166 else 167 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 168 out: 169 cumulative_acks = 0; 170 out_no_clear_ca: 171 if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1) 172 cwnd = RXRPC_RXTX_BUFF_SIZE - 1; 173 call->cong_cwnd = cwnd; 174 call->cong_cumul_acks = cumulative_acks; 175 trace_rxrpc_congest(call, summary, acked_serial, change); 176 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 177 rxrpc_queue_call(call); 178 return; 179 180 packet_loss_detected: 181 change = rxrpc_cong_saw_nack; 182 call->cong_mode = RXRPC_CALL_PACKET_LOSS; 183 call->cong_dup_acks = 0; 184 goto send_extra_data; 185 186 send_extra_data: 187 /* Send some previously unsent DATA if we have some to advance the ACK 188 * state. 189 */ 190 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 191 RXRPC_TX_ANNO_LAST || 192 summary->nr_acks != call->tx_top - call->tx_hard_ack) { 193 call->cong_extra++; 194 wake_up(&call->waitq); 195 } 196 goto out_no_clear_ca; 197 } 198 199 /* 200 * Ping the other end to fill our RTT cache and to retrieve the rwind 201 * and MTU parameters. 202 */ 203 static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb, 204 int skew) 205 { 206 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 207 ktime_t now = skb->tstamp; 208 209 if (call->peer->rtt_usage < 3 || 210 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now)) 211 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, 212 true, true, 213 rxrpc_propose_ack_ping_for_params); 214 } 215 216 /* 217 * Apply a hard ACK by advancing the Tx window. 218 */ 219 static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to, 220 struct rxrpc_ack_summary *summary) 221 { 222 struct sk_buff *skb, *list = NULL; 223 int ix; 224 u8 annotation; 225 226 if (call->acks_lowest_nak == call->tx_hard_ack) { 227 call->acks_lowest_nak = to; 228 } else if (before_eq(call->acks_lowest_nak, to)) { 229 summary->new_low_nack = true; 230 call->acks_lowest_nak = to; 231 } 232 233 spin_lock(&call->lock); 234 235 while (before(call->tx_hard_ack, to)) { 236 call->tx_hard_ack++; 237 ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK; 238 skb = call->rxtx_buffer[ix]; 239 annotation = call->rxtx_annotations[ix]; 240 rxrpc_see_skb(skb, rxrpc_skb_tx_rotated); 241 call->rxtx_buffer[ix] = NULL; 242 call->rxtx_annotations[ix] = 0; 243 skb->next = list; 244 list = skb; 245 246 if (annotation & RXRPC_TX_ANNO_LAST) 247 set_bit(RXRPC_CALL_TX_LAST, &call->flags); 248 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK) 249 summary->nr_rot_new_acks++; 250 } 251 252 spin_unlock(&call->lock); 253 254 trace_rxrpc_transmit(call, (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ? 255 rxrpc_transmit_rotate_last : 256 rxrpc_transmit_rotate)); 257 wake_up(&call->waitq); 258 259 while (list) { 260 skb = list; 261 list = skb->next; 262 skb_mark_not_on_list(skb); 263 rxrpc_free_skb(skb, rxrpc_skb_tx_freed); 264 } 265 } 266 267 /* 268 * End the transmission phase of a call. 269 * 270 * This occurs when we get an ACKALL packet, the first DATA packet of a reply, 271 * or a final ACK packet. 272 */ 273 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun, 274 const char *abort_why) 275 { 276 277 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags)); 278 279 write_lock(&call->state_lock); 280 281 switch (call->state) { 282 case RXRPC_CALL_CLIENT_SEND_REQUEST: 283 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 284 if (reply_begun) 285 call->state = RXRPC_CALL_CLIENT_RECV_REPLY; 286 else 287 call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY; 288 break; 289 290 case RXRPC_CALL_SERVER_AWAIT_ACK: 291 __rxrpc_call_completed(call); 292 rxrpc_notify_socket(call); 293 break; 294 295 default: 296 goto bad_state; 297 } 298 299 write_unlock(&call->state_lock); 300 if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) { 301 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); 302 } else { 303 trace_rxrpc_transmit(call, rxrpc_transmit_end); 304 } 305 _leave(" = ok"); 306 return true; 307 308 bad_state: 309 write_unlock(&call->state_lock); 310 kdebug("end_tx %s", rxrpc_call_states[call->state]); 311 rxrpc_proto_abort(abort_why, call, call->tx_top); 312 return false; 313 } 314 315 /* 316 * Begin the reply reception phase of a call. 317 */ 318 static bool rxrpc_receiving_reply(struct rxrpc_call *call) 319 { 320 struct rxrpc_ack_summary summary = { 0 }; 321 unsigned long now, timo; 322 rxrpc_seq_t top = READ_ONCE(call->tx_top); 323 324 if (call->ackr_reason) { 325 spin_lock_bh(&call->lock); 326 call->ackr_reason = 0; 327 spin_unlock_bh(&call->lock); 328 now = jiffies; 329 timo = now + MAX_JIFFY_OFFSET; 330 WRITE_ONCE(call->resend_at, timo); 331 WRITE_ONCE(call->ack_at, timo); 332 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now); 333 } 334 335 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) 336 rxrpc_rotate_tx_window(call, top, &summary); 337 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { 338 rxrpc_proto_abort("TXL", call, top); 339 return false; 340 } 341 if (!rxrpc_end_tx_phase(call, true, "ETD")) 342 return false; 343 call->tx_phase = false; 344 return true; 345 } 346 347 /* 348 * Scan a jumbo packet to validate its structure and to work out how many 349 * subpackets it contains. 350 * 351 * A jumbo packet is a collection of consecutive packets glued together with 352 * little headers between that indicate how to change the initial header for 353 * each subpacket. 354 * 355 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but 356 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any 357 * size. 358 */ 359 static bool rxrpc_validate_jumbo(struct sk_buff *skb) 360 { 361 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 362 unsigned int offset = sizeof(struct rxrpc_wire_header); 363 unsigned int len = skb->len; 364 int nr_jumbo = 1; 365 u8 flags = sp->hdr.flags; 366 367 do { 368 nr_jumbo++; 369 if (len - offset < RXRPC_JUMBO_SUBPKTLEN) 370 goto protocol_error; 371 if (flags & RXRPC_LAST_PACKET) 372 goto protocol_error; 373 offset += RXRPC_JUMBO_DATALEN; 374 if (skb_copy_bits(skb, offset, &flags, 1) < 0) 375 goto protocol_error; 376 offset += sizeof(struct rxrpc_jumbo_header); 377 } while (flags & RXRPC_JUMBO_PACKET); 378 379 sp->nr_jumbo = nr_jumbo; 380 return true; 381 382 protocol_error: 383 return false; 384 } 385 386 /* 387 * Handle reception of a duplicate packet. 388 * 389 * We have to take care to avoid an attack here whereby we're given a series of 390 * jumbograms, each with a sequence number one before the preceding one and 391 * filled up to maximum UDP size. If they never send us the first packet in 392 * the sequence, they can cause us to have to hold on to around 2MiB of kernel 393 * space until the call times out. 394 * 395 * We limit the space usage by only accepting three duplicate jumbo packets per 396 * call. After that, we tell the other side we're no longer accepting jumbos 397 * (that information is encoded in the ACK packet). 398 */ 399 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, 400 u8 annotation, bool *_jumbo_bad) 401 { 402 /* Discard normal packets that are duplicates. */ 403 if (annotation == 0) 404 return; 405 406 /* Skip jumbo subpackets that are duplicates. When we've had three or 407 * more partially duplicate jumbo packets, we refuse to take any more 408 * jumbos for this call. 409 */ 410 if (!*_jumbo_bad) { 411 call->nr_jumbo_bad++; 412 *_jumbo_bad = true; 413 } 414 } 415 416 /* 417 * Process a DATA packet, adding the packet to the Rx ring. 418 */ 419 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb, 420 u16 skew) 421 { 422 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 423 enum rxrpc_call_state state; 424 unsigned int offset = sizeof(struct rxrpc_wire_header); 425 unsigned int ix; 426 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0; 427 rxrpc_seq_t seq = sp->hdr.seq, hard_ack; 428 bool immediate_ack = false, jumbo_bad = false, queued; 429 u16 len; 430 u8 ack = 0, flags, annotation = 0; 431 432 _enter("{%u,%u},{%u,%u}", 433 call->rx_hard_ack, call->rx_top, skb->len, seq); 434 435 _proto("Rx DATA %%%u { #%u f=%02x }", 436 sp->hdr.serial, seq, sp->hdr.flags); 437 438 state = READ_ONCE(call->state); 439 if (state >= RXRPC_CALL_COMPLETE) 440 return; 441 442 if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) { 443 unsigned long timo = READ_ONCE(call->next_req_timo); 444 unsigned long now, expect_req_by; 445 446 if (timo) { 447 now = jiffies; 448 expect_req_by = now + timo; 449 WRITE_ONCE(call->expect_req_by, expect_req_by); 450 rxrpc_reduce_call_timer(call, expect_req_by, now, 451 rxrpc_timer_set_for_idle); 452 } 453 } 454 455 /* Received data implicitly ACKs all of the request packets we sent 456 * when we're acting as a client. 457 */ 458 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST || 459 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) && 460 !rxrpc_receiving_reply(call)) 461 return; 462 463 call->ackr_prev_seq = seq; 464 465 hard_ack = READ_ONCE(call->rx_hard_ack); 466 if (after(seq, hard_ack + call->rx_winsize)) { 467 ack = RXRPC_ACK_EXCEEDS_WINDOW; 468 ack_serial = serial; 469 goto ack; 470 } 471 472 flags = sp->hdr.flags; 473 if (flags & RXRPC_JUMBO_PACKET) { 474 if (call->nr_jumbo_bad > 3) { 475 ack = RXRPC_ACK_NOSPACE; 476 ack_serial = serial; 477 goto ack; 478 } 479 annotation = 1; 480 } 481 482 next_subpacket: 483 queued = false; 484 ix = seq & RXRPC_RXTX_BUFF_MASK; 485 len = skb->len; 486 if (flags & RXRPC_JUMBO_PACKET) 487 len = RXRPC_JUMBO_DATALEN; 488 489 if (flags & RXRPC_LAST_PACKET) { 490 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 491 seq != call->rx_top) 492 return rxrpc_proto_abort("LSN", call, seq); 493 } else { 494 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 495 after_eq(seq, call->rx_top)) 496 return rxrpc_proto_abort("LSA", call, seq); 497 } 498 499 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation); 500 if (before_eq(seq, hard_ack)) { 501 ack = RXRPC_ACK_DUPLICATE; 502 ack_serial = serial; 503 goto skip; 504 } 505 506 if (flags & RXRPC_REQUEST_ACK && !ack) { 507 ack = RXRPC_ACK_REQUESTED; 508 ack_serial = serial; 509 } 510 511 if (call->rxtx_buffer[ix]) { 512 rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad); 513 if (ack != RXRPC_ACK_DUPLICATE) { 514 ack = RXRPC_ACK_DUPLICATE; 515 ack_serial = serial; 516 } 517 immediate_ack = true; 518 goto skip; 519 } 520 521 /* Queue the packet. We use a couple of memory barriers here as need 522 * to make sure that rx_top is perceived to be set after the buffer 523 * pointer and that the buffer pointer is set after the annotation and 524 * the skb data. 525 * 526 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() 527 * and also rxrpc_fill_out_ack(). 528 */ 529 rxrpc_get_skb(skb, rxrpc_skb_rx_got); 530 call->rxtx_annotations[ix] = annotation; 531 smp_wmb(); 532 call->rxtx_buffer[ix] = skb; 533 if (after(seq, call->rx_top)) { 534 smp_store_release(&call->rx_top, seq); 535 } else if (before(seq, call->rx_top)) { 536 /* Send an immediate ACK if we fill in a hole */ 537 if (!ack) { 538 ack = RXRPC_ACK_DELAY; 539 ack_serial = serial; 540 } 541 immediate_ack = true; 542 } 543 if (flags & RXRPC_LAST_PACKET) { 544 set_bit(RXRPC_CALL_RX_LAST, &call->flags); 545 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); 546 } else { 547 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); 548 } 549 queued = true; 550 551 if (after_eq(seq, call->rx_expect_next)) { 552 if (after(seq, call->rx_expect_next)) { 553 _net("OOS %u > %u", seq, call->rx_expect_next); 554 ack = RXRPC_ACK_OUT_OF_SEQUENCE; 555 ack_serial = serial; 556 } 557 call->rx_expect_next = seq + 1; 558 } 559 560 skip: 561 offset += len; 562 if (flags & RXRPC_JUMBO_PACKET) { 563 if (skb_copy_bits(skb, offset, &flags, 1) < 0) 564 return rxrpc_proto_abort("XJF", call, seq); 565 offset += sizeof(struct rxrpc_jumbo_header); 566 seq++; 567 serial++; 568 annotation++; 569 if (flags & RXRPC_JUMBO_PACKET) 570 annotation |= RXRPC_RX_ANNO_JLAST; 571 if (after(seq, hard_ack + call->rx_winsize)) { 572 ack = RXRPC_ACK_EXCEEDS_WINDOW; 573 ack_serial = serial; 574 if (!jumbo_bad) { 575 call->nr_jumbo_bad++; 576 jumbo_bad = true; 577 } 578 goto ack; 579 } 580 581 _proto("Rx DATA Jumbo %%%u", serial); 582 goto next_subpacket; 583 } 584 585 if (queued && flags & RXRPC_LAST_PACKET && !ack) { 586 ack = RXRPC_ACK_DELAY; 587 ack_serial = serial; 588 } 589 590 ack: 591 if (ack) 592 rxrpc_propose_ACK(call, ack, skew, ack_serial, 593 immediate_ack, true, 594 rxrpc_propose_ack_input_data); 595 else 596 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, skew, serial, 597 false, true, 598 rxrpc_propose_ack_input_data); 599 600 if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1) { 601 trace_rxrpc_notify_socket(call->debug_id, serial); 602 rxrpc_notify_socket(call); 603 } 604 _leave(" [queued]"); 605 } 606 607 /* 608 * Process a requested ACK. 609 */ 610 static void rxrpc_input_requested_ack(struct rxrpc_call *call, 611 ktime_t resp_time, 612 rxrpc_serial_t orig_serial, 613 rxrpc_serial_t ack_serial) 614 { 615 struct rxrpc_skb_priv *sp; 616 struct sk_buff *skb; 617 ktime_t sent_at; 618 int ix; 619 620 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) { 621 skb = call->rxtx_buffer[ix]; 622 if (!skb) 623 continue; 624 625 sent_at = skb->tstamp; 626 smp_rmb(); /* Read timestamp before serial. */ 627 sp = rxrpc_skb(skb); 628 if (sp->hdr.serial != orig_serial) 629 continue; 630 goto found; 631 } 632 633 return; 634 635 found: 636 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack, 637 orig_serial, ack_serial, sent_at, resp_time); 638 } 639 640 /* 641 * Process the response to a ping that we sent to find out if we lost an ACK. 642 * 643 * If we got back a ping response that indicates a lower tx_top than what we 644 * had at the time of the ping transmission, we adjudge all the DATA packets 645 * sent between the response tx_top and the ping-time tx_top to have been lost. 646 */ 647 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call) 648 { 649 rxrpc_seq_t top, bottom, seq; 650 bool resend = false; 651 652 spin_lock_bh(&call->lock); 653 654 bottom = call->tx_hard_ack + 1; 655 top = call->acks_lost_top; 656 if (before(bottom, top)) { 657 for (seq = bottom; before_eq(seq, top); seq++) { 658 int ix = seq & RXRPC_RXTX_BUFF_MASK; 659 u8 annotation = call->rxtx_annotations[ix]; 660 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK; 661 662 if (anno_type != RXRPC_TX_ANNO_UNACK) 663 continue; 664 annotation &= ~RXRPC_TX_ANNO_MASK; 665 annotation |= RXRPC_TX_ANNO_RETRANS; 666 call->rxtx_annotations[ix] = annotation; 667 resend = true; 668 } 669 } 670 671 spin_unlock_bh(&call->lock); 672 673 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 674 rxrpc_queue_call(call); 675 } 676 677 /* 678 * Process a ping response. 679 */ 680 static void rxrpc_input_ping_response(struct rxrpc_call *call, 681 ktime_t resp_time, 682 rxrpc_serial_t orig_serial, 683 rxrpc_serial_t ack_serial) 684 { 685 rxrpc_serial_t ping_serial; 686 ktime_t ping_time; 687 688 ping_time = call->ping_time; 689 smp_rmb(); 690 ping_serial = call->ping_serial; 691 692 if (orig_serial == call->acks_lost_ping) 693 rxrpc_input_check_for_lost_ack(call); 694 695 if (!test_bit(RXRPC_CALL_PINGING, &call->flags) || 696 before(orig_serial, ping_serial)) 697 return; 698 clear_bit(RXRPC_CALL_PINGING, &call->flags); 699 if (after(orig_serial, ping_serial)) 700 return; 701 702 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response, 703 orig_serial, ack_serial, ping_time, resp_time); 704 } 705 706 /* 707 * Process the extra information that may be appended to an ACK packet 708 */ 709 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 710 struct rxrpc_ackinfo *ackinfo) 711 { 712 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 713 struct rxrpc_peer *peer; 714 unsigned int mtu; 715 bool wake = false; 716 u32 rwind = ntohl(ackinfo->rwind); 717 718 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 719 sp->hdr.serial, 720 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU), 721 rwind, ntohl(ackinfo->jumbo_max)); 722 723 if (call->tx_winsize != rwind) { 724 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) 725 rwind = RXRPC_RXTX_BUFF_SIZE - 1; 726 if (rwind > call->tx_winsize) 727 wake = true; 728 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, 729 ntohl(ackinfo->rwind), wake); 730 call->tx_winsize = rwind; 731 } 732 733 if (call->cong_ssthresh > rwind) 734 call->cong_ssthresh = rwind; 735 736 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); 737 738 peer = call->peer; 739 if (mtu < peer->maxdata) { 740 spin_lock_bh(&peer->lock); 741 peer->maxdata = mtu; 742 peer->mtu = mtu + peer->hdrsize; 743 spin_unlock_bh(&peer->lock); 744 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 745 } 746 747 if (wake) 748 wake_up(&call->waitq); 749 } 750 751 /* 752 * Process individual soft ACKs. 753 * 754 * Each ACK in the array corresponds to one packet and can be either an ACK or 755 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 756 * packets that lie beyond the end of the ACK list are scheduled for resend by 757 * the timer on the basis that the peer might just not have processed them at 758 * the time the ACK was sent. 759 */ 760 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, 761 rxrpc_seq_t seq, int nr_acks, 762 struct rxrpc_ack_summary *summary) 763 { 764 int ix; 765 u8 annotation, anno_type; 766 767 for (; nr_acks > 0; nr_acks--, seq++) { 768 ix = seq & RXRPC_RXTX_BUFF_MASK; 769 annotation = call->rxtx_annotations[ix]; 770 anno_type = annotation & RXRPC_TX_ANNO_MASK; 771 annotation &= ~RXRPC_TX_ANNO_MASK; 772 switch (*acks++) { 773 case RXRPC_ACK_TYPE_ACK: 774 summary->nr_acks++; 775 if (anno_type == RXRPC_TX_ANNO_ACK) 776 continue; 777 summary->nr_new_acks++; 778 call->rxtx_annotations[ix] = 779 RXRPC_TX_ANNO_ACK | annotation; 780 break; 781 case RXRPC_ACK_TYPE_NACK: 782 if (!summary->nr_nacks && 783 call->acks_lowest_nak != seq) { 784 call->acks_lowest_nak = seq; 785 summary->new_low_nack = true; 786 } 787 summary->nr_nacks++; 788 if (anno_type == RXRPC_TX_ANNO_NAK) 789 continue; 790 summary->nr_new_nacks++; 791 if (anno_type == RXRPC_TX_ANNO_RETRANS) 792 continue; 793 call->rxtx_annotations[ix] = 794 RXRPC_TX_ANNO_NAK | annotation; 795 break; 796 default: 797 return rxrpc_proto_abort("SFT", call, 0); 798 } 799 } 800 } 801 802 /* 803 * Process an ACK packet. 804 * 805 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 806 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 807 * 808 * A hard-ACK means that a packet has been processed and may be discarded; a 809 * soft-ACK means that the packet may be discarded and retransmission 810 * requested. A phase is complete when all packets are hard-ACK'd. 811 */ 812 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, 813 u16 skew) 814 { 815 struct rxrpc_ack_summary summary = { 0 }; 816 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 817 union { 818 struct rxrpc_ackpacket ack; 819 struct rxrpc_ackinfo info; 820 u8 acks[RXRPC_MAXACKS]; 821 } buf; 822 rxrpc_serial_t acked_serial; 823 rxrpc_seq_t first_soft_ack, hard_ack; 824 int nr_acks, offset, ioffset; 825 826 _enter(""); 827 828 offset = sizeof(struct rxrpc_wire_header); 829 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { 830 _debug("extraction failure"); 831 return rxrpc_proto_abort("XAK", call, 0); 832 } 833 offset += sizeof(buf.ack); 834 835 acked_serial = ntohl(buf.ack.serial); 836 first_soft_ack = ntohl(buf.ack.firstPacket); 837 hard_ack = first_soft_ack - 1; 838 nr_acks = buf.ack.nAcks; 839 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? 840 buf.ack.reason : RXRPC_ACK__INVALID); 841 842 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial, 843 first_soft_ack, ntohl(buf.ack.previousPacket), 844 summary.ack_reason, nr_acks); 845 846 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) 847 rxrpc_input_ping_response(call, skb->tstamp, acked_serial, 848 sp->hdr.serial); 849 if (buf.ack.reason == RXRPC_ACK_REQUESTED) 850 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial, 851 sp->hdr.serial); 852 853 if (buf.ack.reason == RXRPC_ACK_PING) { 854 _proto("Rx ACK %%%u PING Request", sp->hdr.serial); 855 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 856 skew, sp->hdr.serial, true, true, 857 rxrpc_propose_ack_respond_to_ping); 858 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { 859 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, 860 skew, sp->hdr.serial, true, true, 861 rxrpc_propose_ack_respond_to_ack); 862 } 863 864 ioffset = offset + nr_acks + 3; 865 if (skb->len >= ioffset + sizeof(buf.info)) { 866 if (skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) 867 return rxrpc_proto_abort("XAI", call, 0); 868 rxrpc_input_ackinfo(call, skb, &buf.info); 869 } 870 871 if (first_soft_ack == 0) 872 return rxrpc_proto_abort("AK0", call, 0); 873 874 /* Ignore ACKs unless we are or have just been transmitting. */ 875 switch (READ_ONCE(call->state)) { 876 case RXRPC_CALL_CLIENT_SEND_REQUEST: 877 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 878 case RXRPC_CALL_SERVER_SEND_REPLY: 879 case RXRPC_CALL_SERVER_AWAIT_ACK: 880 break; 881 default: 882 return; 883 } 884 885 /* Discard any out-of-order or duplicate ACKs. */ 886 if (before_eq(sp->hdr.serial, call->acks_latest)) { 887 _debug("discard ACK %d <= %d", 888 sp->hdr.serial, call->acks_latest); 889 return; 890 } 891 call->acks_latest_ts = skb->tstamp; 892 call->acks_latest = sp->hdr.serial; 893 894 if (before(hard_ack, call->tx_hard_ack) || 895 after(hard_ack, call->tx_top)) 896 return rxrpc_proto_abort("AKW", call, 0); 897 if (nr_acks > call->tx_top - hard_ack) 898 return rxrpc_proto_abort("AKN", call, 0); 899 900 if (after(hard_ack, call->tx_hard_ack)) 901 rxrpc_rotate_tx_window(call, hard_ack, &summary); 902 903 if (nr_acks > 0) { 904 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) 905 return rxrpc_proto_abort("XSA", call, 0); 906 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, 907 &summary); 908 } 909 910 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { 911 rxrpc_end_tx_phase(call, false, "ETA"); 912 return; 913 } 914 915 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 916 RXRPC_TX_ANNO_LAST && 917 summary.nr_acks == call->tx_top - hard_ack && 918 rxrpc_is_client_call(call)) 919 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, 920 false, true, 921 rxrpc_propose_ack_ping_for_lost_reply); 922 923 return rxrpc_congestion_management(call, skb, &summary, acked_serial); 924 } 925 926 /* 927 * Process an ACKALL packet. 928 */ 929 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 930 { 931 struct rxrpc_ack_summary summary = { 0 }; 932 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 933 934 _proto("Rx ACKALL %%%u", sp->hdr.serial); 935 936 rxrpc_rotate_tx_window(call, call->tx_top, &summary); 937 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags)) 938 rxrpc_end_tx_phase(call, false, "ETL"); 939 } 940 941 /* 942 * Process an ABORT packet directed at a call. 943 */ 944 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 945 { 946 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 947 __be32 wtmp; 948 u32 abort_code = RX_CALL_DEAD; 949 950 _enter(""); 951 952 if (skb->len >= 4 && 953 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 954 &wtmp, sizeof(wtmp)) >= 0) 955 abort_code = ntohl(wtmp); 956 957 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code); 958 959 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); 960 961 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 962 abort_code, -ECONNABORTED)) 963 rxrpc_notify_socket(call); 964 } 965 966 /* 967 * Process an incoming call packet. 968 */ 969 static void rxrpc_input_call_packet(struct rxrpc_call *call, 970 struct sk_buff *skb, u16 skew) 971 { 972 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 973 unsigned long timo; 974 975 _enter("%p,%p", call, skb); 976 977 timo = READ_ONCE(call->next_rx_timo); 978 if (timo) { 979 unsigned long now = jiffies, expect_rx_by; 980 981 expect_rx_by = now + timo; 982 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 983 rxrpc_reduce_call_timer(call, expect_rx_by, now, 984 rxrpc_timer_set_for_normal); 985 } 986 987 switch (sp->hdr.type) { 988 case RXRPC_PACKET_TYPE_DATA: 989 rxrpc_input_data(call, skb, skew); 990 break; 991 992 case RXRPC_PACKET_TYPE_ACK: 993 rxrpc_input_ack(call, skb, skew); 994 break; 995 996 case RXRPC_PACKET_TYPE_BUSY: 997 _proto("Rx BUSY %%%u", sp->hdr.serial); 998 999 /* Just ignore BUSY packets from the server; the retry and 1000 * lifespan timers will take care of business. BUSY packets 1001 * from the client don't make sense. 1002 */ 1003 break; 1004 1005 case RXRPC_PACKET_TYPE_ABORT: 1006 rxrpc_input_abort(call, skb); 1007 break; 1008 1009 case RXRPC_PACKET_TYPE_ACKALL: 1010 rxrpc_input_ackall(call, skb); 1011 break; 1012 1013 default: 1014 break; 1015 } 1016 1017 _leave(""); 1018 } 1019 1020 /* 1021 * Handle a new call on a channel implicitly completing the preceding call on 1022 * that channel. 1023 * 1024 * TODO: If callNumber > call_id + 1, renegotiate security. 1025 */ 1026 static void rxrpc_input_implicit_end_call(struct rxrpc_connection *conn, 1027 struct rxrpc_call *call) 1028 { 1029 switch (READ_ONCE(call->state)) { 1030 case RXRPC_CALL_SERVER_AWAIT_ACK: 1031 rxrpc_call_completed(call); 1032 break; 1033 case RXRPC_CALL_COMPLETE: 1034 break; 1035 default: 1036 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) { 1037 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 1038 rxrpc_queue_call(call); 1039 } 1040 break; 1041 } 1042 1043 trace_rxrpc_improper_term(call); 1044 __rxrpc_disconnect_call(conn, call); 1045 rxrpc_notify_socket(call); 1046 } 1047 1048 /* 1049 * post connection-level events to the connection 1050 * - this includes challenges, responses, some aborts and call terminal packet 1051 * retransmission. 1052 */ 1053 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 1054 struct sk_buff *skb) 1055 { 1056 _enter("%p,%p", conn, skb); 1057 1058 skb_queue_tail(&conn->rx_queue, skb); 1059 rxrpc_queue_conn(conn); 1060 } 1061 1062 /* 1063 * post endpoint-level events to the local endpoint 1064 * - this includes debug and version messages 1065 */ 1066 static void rxrpc_post_packet_to_local(struct rxrpc_local *local, 1067 struct sk_buff *skb) 1068 { 1069 _enter("%p,%p", local, skb); 1070 1071 skb_queue_tail(&local->event_queue, skb); 1072 rxrpc_queue_local(local); 1073 } 1074 1075 /* 1076 * put a packet up for transport-level abort 1077 */ 1078 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 1079 { 1080 CHECK_SLAB_OKAY(&local->usage); 1081 1082 skb_queue_tail(&local->reject_queue, skb); 1083 rxrpc_queue_local(local); 1084 } 1085 1086 /* 1087 * Extract the wire header from a packet and translate the byte order. 1088 */ 1089 static noinline 1090 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) 1091 { 1092 struct rxrpc_wire_header whdr; 1093 1094 /* dig out the RxRPC connection details */ 1095 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) { 1096 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 1097 tracepoint_string("bad_hdr")); 1098 return -EBADMSG; 1099 } 1100 1101 memset(sp, 0, sizeof(*sp)); 1102 sp->hdr.epoch = ntohl(whdr.epoch); 1103 sp->hdr.cid = ntohl(whdr.cid); 1104 sp->hdr.callNumber = ntohl(whdr.callNumber); 1105 sp->hdr.seq = ntohl(whdr.seq); 1106 sp->hdr.serial = ntohl(whdr.serial); 1107 sp->hdr.flags = whdr.flags; 1108 sp->hdr.type = whdr.type; 1109 sp->hdr.userStatus = whdr.userStatus; 1110 sp->hdr.securityIndex = whdr.securityIndex; 1111 sp->hdr._rsvd = ntohs(whdr._rsvd); 1112 sp->hdr.serviceId = ntohs(whdr.serviceId); 1113 return 0; 1114 } 1115 1116 /* 1117 * handle data received on the local endpoint 1118 * - may be called in interrupt context 1119 * 1120 * The socket is locked by the caller and this prevents the socket from being 1121 * shut down and the local endpoint from going away, thus sk_user_data will not 1122 * be cleared until this function returns. 1123 */ 1124 void rxrpc_data_ready(struct sock *udp_sk) 1125 { 1126 struct rxrpc_connection *conn; 1127 struct rxrpc_channel *chan; 1128 struct rxrpc_call *call = NULL; 1129 struct rxrpc_skb_priv *sp; 1130 struct rxrpc_local *local = udp_sk->sk_user_data; 1131 struct rxrpc_peer *peer = NULL; 1132 struct rxrpc_sock *rx = NULL; 1133 struct sk_buff *skb; 1134 unsigned int channel; 1135 int ret, skew = 0; 1136 1137 _enter("%p", udp_sk); 1138 1139 ASSERT(!irqs_disabled()); 1140 1141 skb = skb_recv_udp(udp_sk, 0, 1, &ret); 1142 if (!skb) { 1143 if (ret == -EAGAIN) 1144 return; 1145 _debug("UDP socket error %d", ret); 1146 return; 1147 } 1148 1149 if (skb->tstamp == 0) 1150 skb->tstamp = ktime_get_real(); 1151 1152 rxrpc_new_skb(skb, rxrpc_skb_rx_received); 1153 1154 _net("recv skb %p", skb); 1155 1156 /* we'll probably need to checksum it (didn't call sock_recvmsg) */ 1157 if (skb_checksum_complete(skb)) { 1158 rxrpc_free_skb(skb, rxrpc_skb_rx_freed); 1159 __UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0); 1160 _leave(" [CSUM failed]"); 1161 return; 1162 } 1163 1164 __UDP_INC_STATS(&init_net, UDP_MIB_INDATAGRAMS, 0); 1165 1166 /* The UDP protocol already released all skb resources; 1167 * we are free to add our own data there. 1168 */ 1169 sp = rxrpc_skb(skb); 1170 1171 /* dig out the RxRPC connection details */ 1172 if (rxrpc_extract_header(sp, skb) < 0) 1173 goto bad_message; 1174 1175 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { 1176 static int lose; 1177 if ((lose++ & 7) == 7) { 1178 trace_rxrpc_rx_lose(sp); 1179 rxrpc_free_skb(skb, rxrpc_skb_rx_lost); 1180 return; 1181 } 1182 } 1183 1184 trace_rxrpc_rx_packet(sp); 1185 1186 switch (sp->hdr.type) { 1187 case RXRPC_PACKET_TYPE_VERSION: 1188 if (rxrpc_to_client(sp)) 1189 goto discard; 1190 rxrpc_post_packet_to_local(local, skb); 1191 goto out; 1192 1193 case RXRPC_PACKET_TYPE_BUSY: 1194 if (rxrpc_to_server(sp)) 1195 goto discard; 1196 /* Fall through */ 1197 case RXRPC_PACKET_TYPE_ACK: 1198 case RXRPC_PACKET_TYPE_ACKALL: 1199 if (sp->hdr.callNumber == 0) 1200 goto bad_message; 1201 /* Fall through */ 1202 case RXRPC_PACKET_TYPE_ABORT: 1203 break; 1204 1205 case RXRPC_PACKET_TYPE_DATA: 1206 if (sp->hdr.callNumber == 0 || 1207 sp->hdr.seq == 0) 1208 goto bad_message; 1209 if (sp->hdr.flags & RXRPC_JUMBO_PACKET && 1210 !rxrpc_validate_jumbo(skb)) 1211 goto bad_message; 1212 break; 1213 1214 case RXRPC_PACKET_TYPE_CHALLENGE: 1215 if (rxrpc_to_server(sp)) 1216 goto discard; 1217 break; 1218 case RXRPC_PACKET_TYPE_RESPONSE: 1219 if (rxrpc_to_client(sp)) 1220 goto discard; 1221 break; 1222 1223 /* Packet types 9-11 should just be ignored. */ 1224 case RXRPC_PACKET_TYPE_PARAMS: 1225 case RXRPC_PACKET_TYPE_10: 1226 case RXRPC_PACKET_TYPE_11: 1227 goto discard; 1228 1229 default: 1230 _proto("Rx Bad Packet Type %u", sp->hdr.type); 1231 goto bad_message; 1232 } 1233 1234 if (sp->hdr.serviceId == 0) 1235 goto bad_message; 1236 1237 rcu_read_lock(); 1238 1239 if (rxrpc_to_server(sp)) { 1240 /* Weed out packets to services we're not offering. Packets 1241 * that would begin a call are explicitly rejected and the rest 1242 * are just discarded. 1243 */ 1244 rx = rcu_dereference(local->service); 1245 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service && 1246 sp->hdr.serviceId != rx->second_service)) { 1247 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && 1248 sp->hdr.seq == 1) 1249 goto unsupported_service; 1250 goto discard_unlock; 1251 } 1252 } 1253 1254 conn = rxrpc_find_connection_rcu(local, skb, &peer); 1255 if (conn) { 1256 if (sp->hdr.securityIndex != conn->security_ix) 1257 goto wrong_security; 1258 1259 if (sp->hdr.serviceId != conn->service_id) { 1260 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) || 1261 conn->service_id != conn->params.service_id) 1262 goto reupgrade; 1263 conn->service_id = sp->hdr.serviceId; 1264 } 1265 1266 if (sp->hdr.callNumber == 0) { 1267 /* Connection-level packet */ 1268 _debug("CONN %p {%d}", conn, conn->debug_id); 1269 rxrpc_post_packet_to_conn(conn, skb); 1270 goto out_unlock; 1271 } 1272 1273 /* Note the serial number skew here */ 1274 skew = (int)sp->hdr.serial - (int)conn->hi_serial; 1275 if (skew >= 0) { 1276 if (skew > 0) 1277 conn->hi_serial = sp->hdr.serial; 1278 } else { 1279 skew = -skew; 1280 skew = min(skew, 65535); 1281 } 1282 1283 /* Call-bound packets are routed by connection channel. */ 1284 channel = sp->hdr.cid & RXRPC_CHANNELMASK; 1285 chan = &conn->channels[channel]; 1286 1287 /* Ignore really old calls */ 1288 if (sp->hdr.callNumber < chan->last_call) 1289 goto discard_unlock; 1290 1291 if (sp->hdr.callNumber == chan->last_call) { 1292 if (chan->call || 1293 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) 1294 goto discard_unlock; 1295 1296 /* For the previous service call, if completed 1297 * successfully, we discard all further packets. 1298 */ 1299 if (rxrpc_conn_is_service(conn) && 1300 chan->last_type == RXRPC_PACKET_TYPE_ACK) 1301 goto discard_unlock; 1302 1303 /* But otherwise we need to retransmit the final packet 1304 * from data cached in the connection record. 1305 */ 1306 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) 1307 trace_rxrpc_rx_data(chan->call_debug_id, 1308 sp->hdr.seq, 1309 sp->hdr.serial, 1310 sp->hdr.flags, 0); 1311 rxrpc_post_packet_to_conn(conn, skb); 1312 goto out_unlock; 1313 } 1314 1315 call = rcu_dereference(chan->call); 1316 1317 if (sp->hdr.callNumber > chan->call_id) { 1318 if (rxrpc_to_client(sp)) { 1319 rcu_read_unlock(); 1320 goto reject_packet; 1321 } 1322 if (call) 1323 rxrpc_input_implicit_end_call(conn, call); 1324 call = NULL; 1325 } 1326 1327 if (call) { 1328 if (sp->hdr.serviceId != call->service_id) 1329 call->service_id = sp->hdr.serviceId; 1330 if ((int)sp->hdr.serial - (int)call->rx_serial > 0) 1331 call->rx_serial = sp->hdr.serial; 1332 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) 1333 set_bit(RXRPC_CALL_RX_HEARD, &call->flags); 1334 } 1335 } 1336 1337 if (!call || atomic_read(&call->usage) == 0) { 1338 if (rxrpc_to_client(sp) || 1339 sp->hdr.type != RXRPC_PACKET_TYPE_DATA) 1340 goto bad_message_unlock; 1341 if (sp->hdr.seq != 1) 1342 goto discard_unlock; 1343 call = rxrpc_new_incoming_call(local, rx, peer, conn, skb); 1344 if (!call) { 1345 rcu_read_unlock(); 1346 goto reject_packet; 1347 } 1348 rxrpc_send_ping(call, skb, skew); 1349 mutex_unlock(&call->user_mutex); 1350 } 1351 1352 rxrpc_input_call_packet(call, skb, skew); 1353 goto discard_unlock; 1354 1355 discard_unlock: 1356 rcu_read_unlock(); 1357 discard: 1358 rxrpc_free_skb(skb, rxrpc_skb_rx_freed); 1359 out: 1360 trace_rxrpc_rx_done(0, 0); 1361 return; 1362 1363 out_unlock: 1364 rcu_read_unlock(); 1365 goto out; 1366 1367 wrong_security: 1368 rcu_read_unlock(); 1369 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1370 RXKADINCONSISTENCY, EBADMSG); 1371 skb->priority = RXKADINCONSISTENCY; 1372 goto post_abort; 1373 1374 unsupported_service: 1375 rcu_read_unlock(); 1376 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1377 RX_INVALID_OPERATION, EOPNOTSUPP); 1378 skb->priority = RX_INVALID_OPERATION; 1379 goto post_abort; 1380 1381 reupgrade: 1382 rcu_read_unlock(); 1383 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1384 RX_PROTOCOL_ERROR, EBADMSG); 1385 goto protocol_error; 1386 1387 bad_message_unlock: 1388 rcu_read_unlock(); 1389 bad_message: 1390 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1391 RX_PROTOCOL_ERROR, EBADMSG); 1392 protocol_error: 1393 skb->priority = RX_PROTOCOL_ERROR; 1394 post_abort: 1395 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT; 1396 reject_packet: 1397 trace_rxrpc_rx_done(skb->mark, skb->priority); 1398 rxrpc_reject_packet(local, skb); 1399 _leave(" [badmsg]"); 1400 } 1401