1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* RxRPC packet reception 3 * 4 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/module.h> 11 #include <linux/net.h> 12 #include <linux/skbuff.h> 13 #include <linux/errqueue.h> 14 #include <linux/udp.h> 15 #include <linux/in.h> 16 #include <linux/in6.h> 17 #include <linux/icmp.h> 18 #include <linux/gfp.h> 19 #include <net/sock.h> 20 #include <net/af_rxrpc.h> 21 #include <net/ip.h> 22 #include <net/udp.h> 23 #include <net/net_namespace.h> 24 #include "ar-internal.h" 25 26 static void rxrpc_proto_abort(const char *why, 27 struct rxrpc_call *call, rxrpc_seq_t seq) 28 { 29 if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) { 30 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 31 rxrpc_queue_call(call); 32 } 33 } 34 35 /* 36 * Do TCP-style congestion management [RFC 5681]. 37 */ 38 static void rxrpc_congestion_management(struct rxrpc_call *call, 39 struct sk_buff *skb, 40 struct rxrpc_ack_summary *summary, 41 rxrpc_serial_t acked_serial) 42 { 43 enum rxrpc_congest_change change = rxrpc_cong_no_change; 44 unsigned int cumulative_acks = call->cong_cumul_acks; 45 unsigned int cwnd = call->cong_cwnd; 46 bool resend = false; 47 48 summary->flight_size = 49 (call->tx_top - call->tx_hard_ack) - summary->nr_acks; 50 51 if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) { 52 summary->retrans_timeo = true; 53 call->cong_ssthresh = max_t(unsigned int, 54 summary->flight_size / 2, 2); 55 cwnd = 1; 56 if (cwnd >= call->cong_ssthresh && 57 call->cong_mode == RXRPC_CALL_SLOW_START) { 58 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 59 call->cong_tstamp = skb->tstamp; 60 cumulative_acks = 0; 61 } 62 } 63 64 cumulative_acks += summary->nr_new_acks; 65 cumulative_acks += summary->nr_rot_new_acks; 66 if (cumulative_acks > 255) 67 cumulative_acks = 255; 68 69 summary->mode = call->cong_mode; 70 summary->cwnd = call->cong_cwnd; 71 summary->ssthresh = call->cong_ssthresh; 72 summary->cumulative_acks = cumulative_acks; 73 summary->dup_acks = call->cong_dup_acks; 74 75 switch (call->cong_mode) { 76 case RXRPC_CALL_SLOW_START: 77 if (summary->nr_nacks > 0) 78 goto packet_loss_detected; 79 if (summary->cumulative_acks > 0) 80 cwnd += 1; 81 if (cwnd >= call->cong_ssthresh) { 82 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 83 call->cong_tstamp = skb->tstamp; 84 } 85 goto out; 86 87 case RXRPC_CALL_CONGEST_AVOIDANCE: 88 if (summary->nr_nacks > 0) 89 goto packet_loss_detected; 90 91 /* We analyse the number of packets that get ACK'd per RTT 92 * period and increase the window if we managed to fill it. 93 */ 94 if (call->peer->rtt_usage == 0) 95 goto out; 96 if (ktime_before(skb->tstamp, 97 ktime_add_ns(call->cong_tstamp, 98 call->peer->rtt))) 99 goto out_no_clear_ca; 100 change = rxrpc_cong_rtt_window_end; 101 call->cong_tstamp = skb->tstamp; 102 if (cumulative_acks >= cwnd) 103 cwnd++; 104 goto out; 105 106 case RXRPC_CALL_PACKET_LOSS: 107 if (summary->nr_nacks == 0) 108 goto resume_normality; 109 110 if (summary->new_low_nack) { 111 change = rxrpc_cong_new_low_nack; 112 call->cong_dup_acks = 1; 113 if (call->cong_extra > 1) 114 call->cong_extra = 1; 115 goto send_extra_data; 116 } 117 118 call->cong_dup_acks++; 119 if (call->cong_dup_acks < 3) 120 goto send_extra_data; 121 122 change = rxrpc_cong_begin_retransmission; 123 call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT; 124 call->cong_ssthresh = max_t(unsigned int, 125 summary->flight_size / 2, 2); 126 cwnd = call->cong_ssthresh + 3; 127 call->cong_extra = 0; 128 call->cong_dup_acks = 0; 129 resend = true; 130 goto out; 131 132 case RXRPC_CALL_FAST_RETRANSMIT: 133 if (!summary->new_low_nack) { 134 if (summary->nr_new_acks == 0) 135 cwnd += 1; 136 call->cong_dup_acks++; 137 if (call->cong_dup_acks == 2) { 138 change = rxrpc_cong_retransmit_again; 139 call->cong_dup_acks = 0; 140 resend = true; 141 } 142 } else { 143 change = rxrpc_cong_progress; 144 cwnd = call->cong_ssthresh; 145 if (summary->nr_nacks == 0) 146 goto resume_normality; 147 } 148 goto out; 149 150 default: 151 BUG(); 152 goto out; 153 } 154 155 resume_normality: 156 change = rxrpc_cong_cleared_nacks; 157 call->cong_dup_acks = 0; 158 call->cong_extra = 0; 159 call->cong_tstamp = skb->tstamp; 160 if (cwnd < call->cong_ssthresh) 161 call->cong_mode = RXRPC_CALL_SLOW_START; 162 else 163 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 164 out: 165 cumulative_acks = 0; 166 out_no_clear_ca: 167 if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1) 168 cwnd = RXRPC_RXTX_BUFF_SIZE - 1; 169 call->cong_cwnd = cwnd; 170 call->cong_cumul_acks = cumulative_acks; 171 trace_rxrpc_congest(call, summary, acked_serial, change); 172 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 173 rxrpc_queue_call(call); 174 return; 175 176 packet_loss_detected: 177 change = rxrpc_cong_saw_nack; 178 call->cong_mode = RXRPC_CALL_PACKET_LOSS; 179 call->cong_dup_acks = 0; 180 goto send_extra_data; 181 182 send_extra_data: 183 /* Send some previously unsent DATA if we have some to advance the ACK 184 * state. 185 */ 186 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 187 RXRPC_TX_ANNO_LAST || 188 summary->nr_acks != call->tx_top - call->tx_hard_ack) { 189 call->cong_extra++; 190 wake_up(&call->waitq); 191 } 192 goto out_no_clear_ca; 193 } 194 195 /* 196 * Apply a hard ACK by advancing the Tx window. 197 */ 198 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to, 199 struct rxrpc_ack_summary *summary) 200 { 201 struct sk_buff *skb, *list = NULL; 202 bool rot_last = false; 203 int ix; 204 u8 annotation; 205 206 if (call->acks_lowest_nak == call->tx_hard_ack) { 207 call->acks_lowest_nak = to; 208 } else if (before_eq(call->acks_lowest_nak, to)) { 209 summary->new_low_nack = true; 210 call->acks_lowest_nak = to; 211 } 212 213 spin_lock(&call->lock); 214 215 while (before(call->tx_hard_ack, to)) { 216 call->tx_hard_ack++; 217 ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK; 218 skb = call->rxtx_buffer[ix]; 219 annotation = call->rxtx_annotations[ix]; 220 rxrpc_see_skb(skb, rxrpc_skb_rotated); 221 call->rxtx_buffer[ix] = NULL; 222 call->rxtx_annotations[ix] = 0; 223 skb->next = list; 224 list = skb; 225 226 if (annotation & RXRPC_TX_ANNO_LAST) { 227 set_bit(RXRPC_CALL_TX_LAST, &call->flags); 228 rot_last = true; 229 } 230 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK) 231 summary->nr_rot_new_acks++; 232 } 233 234 spin_unlock(&call->lock); 235 236 trace_rxrpc_transmit(call, (rot_last ? 237 rxrpc_transmit_rotate_last : 238 rxrpc_transmit_rotate)); 239 wake_up(&call->waitq); 240 241 while (list) { 242 skb = list; 243 list = skb->next; 244 skb_mark_not_on_list(skb); 245 rxrpc_free_skb(skb, rxrpc_skb_freed); 246 } 247 248 return rot_last; 249 } 250 251 /* 252 * End the transmission phase of a call. 253 * 254 * This occurs when we get an ACKALL packet, the first DATA packet of a reply, 255 * or a final ACK packet. 256 */ 257 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun, 258 const char *abort_why) 259 { 260 unsigned int state; 261 262 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags)); 263 264 write_lock(&call->state_lock); 265 266 state = call->state; 267 switch (state) { 268 case RXRPC_CALL_CLIENT_SEND_REQUEST: 269 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 270 if (reply_begun) 271 call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY; 272 else 273 call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY; 274 break; 275 276 case RXRPC_CALL_SERVER_AWAIT_ACK: 277 __rxrpc_call_completed(call); 278 rxrpc_notify_socket(call); 279 state = call->state; 280 break; 281 282 default: 283 goto bad_state; 284 } 285 286 write_unlock(&call->state_lock); 287 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY) 288 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); 289 else 290 trace_rxrpc_transmit(call, rxrpc_transmit_end); 291 _leave(" = ok"); 292 return true; 293 294 bad_state: 295 write_unlock(&call->state_lock); 296 kdebug("end_tx %s", rxrpc_call_states[call->state]); 297 rxrpc_proto_abort(abort_why, call, call->tx_top); 298 return false; 299 } 300 301 /* 302 * Begin the reply reception phase of a call. 303 */ 304 static bool rxrpc_receiving_reply(struct rxrpc_call *call) 305 { 306 struct rxrpc_ack_summary summary = { 0 }; 307 unsigned long now, timo; 308 rxrpc_seq_t top = READ_ONCE(call->tx_top); 309 310 if (call->ackr_reason) { 311 spin_lock_bh(&call->lock); 312 call->ackr_reason = 0; 313 spin_unlock_bh(&call->lock); 314 now = jiffies; 315 timo = now + MAX_JIFFY_OFFSET; 316 WRITE_ONCE(call->resend_at, timo); 317 WRITE_ONCE(call->ack_at, timo); 318 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now); 319 } 320 321 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { 322 if (!rxrpc_rotate_tx_window(call, top, &summary)) { 323 rxrpc_proto_abort("TXL", call, top); 324 return false; 325 } 326 } 327 if (!rxrpc_end_tx_phase(call, true, "ETD")) 328 return false; 329 call->tx_phase = false; 330 return true; 331 } 332 333 /* 334 * Scan a data packet to validate its structure and to work out how many 335 * subpackets it contains. 336 * 337 * A jumbo packet is a collection of consecutive packets glued together with 338 * little headers between that indicate how to change the initial header for 339 * each subpacket. 340 * 341 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but 342 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any 343 * size. 344 */ 345 static bool rxrpc_validate_data(struct sk_buff *skb) 346 { 347 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 348 unsigned int offset = sizeof(struct rxrpc_wire_header); 349 unsigned int len = skb->len; 350 u8 flags = sp->hdr.flags; 351 352 for (;;) { 353 if (flags & RXRPC_REQUEST_ACK) 354 __set_bit(sp->nr_subpackets, sp->rx_req_ack); 355 sp->nr_subpackets++; 356 357 if (!(flags & RXRPC_JUMBO_PACKET)) 358 break; 359 360 if (len - offset < RXRPC_JUMBO_SUBPKTLEN) 361 goto protocol_error; 362 if (flags & RXRPC_LAST_PACKET) 363 goto protocol_error; 364 offset += RXRPC_JUMBO_DATALEN; 365 if (skb_copy_bits(skb, offset, &flags, 1) < 0) 366 goto protocol_error; 367 offset += sizeof(struct rxrpc_jumbo_header); 368 } 369 370 if (flags & RXRPC_LAST_PACKET) 371 sp->rx_flags |= RXRPC_SKB_INCL_LAST; 372 return true; 373 374 protocol_error: 375 return false; 376 } 377 378 /* 379 * Handle reception of a duplicate packet. 380 * 381 * We have to take care to avoid an attack here whereby we're given a series of 382 * jumbograms, each with a sequence number one before the preceding one and 383 * filled up to maximum UDP size. If they never send us the first packet in 384 * the sequence, they can cause us to have to hold on to around 2MiB of kernel 385 * space until the call times out. 386 * 387 * We limit the space usage by only accepting three duplicate jumbo packets per 388 * call. After that, we tell the other side we're no longer accepting jumbos 389 * (that information is encoded in the ACK packet). 390 */ 391 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, 392 bool is_jumbo, bool *_jumbo_bad) 393 { 394 /* Discard normal packets that are duplicates. */ 395 if (is_jumbo) 396 return; 397 398 /* Skip jumbo subpackets that are duplicates. When we've had three or 399 * more partially duplicate jumbo packets, we refuse to take any more 400 * jumbos for this call. 401 */ 402 if (!*_jumbo_bad) { 403 call->nr_jumbo_bad++; 404 *_jumbo_bad = true; 405 } 406 } 407 408 /* 409 * Process a DATA packet, adding the packet to the Rx ring. The caller's 410 * packet ref must be passed on or discarded. 411 */ 412 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb) 413 { 414 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 415 enum rxrpc_call_state state; 416 unsigned int j, nr_subpackets; 417 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0; 418 rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack; 419 bool immediate_ack = false, jumbo_bad = false; 420 u8 ack = 0; 421 422 _enter("{%u,%u},{%u,%u}", 423 call->rx_hard_ack, call->rx_top, skb->len, seq0); 424 425 _proto("Rx DATA %%%u { #%u f=%02x n=%u }", 426 sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets); 427 428 state = READ_ONCE(call->state); 429 if (state >= RXRPC_CALL_COMPLETE) { 430 rxrpc_free_skb(skb, rxrpc_skb_freed); 431 return; 432 } 433 434 if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) { 435 unsigned long timo = READ_ONCE(call->next_req_timo); 436 unsigned long now, expect_req_by; 437 438 if (timo) { 439 now = jiffies; 440 expect_req_by = now + timo; 441 WRITE_ONCE(call->expect_req_by, expect_req_by); 442 rxrpc_reduce_call_timer(call, expect_req_by, now, 443 rxrpc_timer_set_for_idle); 444 } 445 } 446 447 spin_lock(&call->input_lock); 448 449 /* Received data implicitly ACKs all of the request packets we sent 450 * when we're acting as a client. 451 */ 452 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST || 453 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) && 454 !rxrpc_receiving_reply(call)) 455 goto unlock; 456 457 call->ackr_prev_seq = seq0; 458 hard_ack = READ_ONCE(call->rx_hard_ack); 459 460 nr_subpackets = sp->nr_subpackets; 461 if (nr_subpackets > 1) { 462 if (call->nr_jumbo_bad > 3) { 463 ack = RXRPC_ACK_NOSPACE; 464 ack_serial = serial; 465 goto ack; 466 } 467 } 468 469 for (j = 0; j < nr_subpackets; j++) { 470 rxrpc_serial_t serial = sp->hdr.serial + j; 471 rxrpc_seq_t seq = seq0 + j; 472 unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK; 473 bool terminal = (j == nr_subpackets - 1); 474 bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST); 475 u8 flags, annotation = j; 476 477 _proto("Rx DATA+%u %%%u { #%x t=%u l=%u }", 478 j, serial, seq, terminal, last); 479 480 if (last) { 481 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 482 seq != call->rx_top) { 483 rxrpc_proto_abort("LSN", call, seq); 484 goto unlock; 485 } 486 } else { 487 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 488 after_eq(seq, call->rx_top)) { 489 rxrpc_proto_abort("LSA", call, seq); 490 goto unlock; 491 } 492 } 493 494 flags = 0; 495 if (last) 496 flags |= RXRPC_LAST_PACKET; 497 if (!terminal) 498 flags |= RXRPC_JUMBO_PACKET; 499 if (test_bit(j, sp->rx_req_ack)) 500 flags |= RXRPC_REQUEST_ACK; 501 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation); 502 503 if (before_eq(seq, hard_ack)) { 504 ack = RXRPC_ACK_DUPLICATE; 505 ack_serial = serial; 506 continue; 507 } 508 509 if (call->rxtx_buffer[ix]) { 510 rxrpc_input_dup_data(call, seq, nr_subpackets > 1, 511 &jumbo_bad); 512 if (ack != RXRPC_ACK_DUPLICATE) { 513 ack = RXRPC_ACK_DUPLICATE; 514 ack_serial = serial; 515 } 516 immediate_ack = true; 517 continue; 518 } 519 520 if (after(seq, hard_ack + call->rx_winsize)) { 521 ack = RXRPC_ACK_EXCEEDS_WINDOW; 522 ack_serial = serial; 523 if (flags & RXRPC_JUMBO_PACKET) { 524 if (!jumbo_bad) { 525 call->nr_jumbo_bad++; 526 jumbo_bad = true; 527 } 528 } 529 530 goto ack; 531 } 532 533 if (flags & RXRPC_REQUEST_ACK && !ack) { 534 ack = RXRPC_ACK_REQUESTED; 535 ack_serial = serial; 536 } 537 538 /* Queue the packet. We use a couple of memory barriers here as need 539 * to make sure that rx_top is perceived to be set after the buffer 540 * pointer and that the buffer pointer is set after the annotation and 541 * the skb data. 542 * 543 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() 544 * and also rxrpc_fill_out_ack(). 545 */ 546 if (!terminal) 547 rxrpc_get_skb(skb, rxrpc_skb_got); 548 call->rxtx_annotations[ix] = annotation; 549 smp_wmb(); 550 call->rxtx_buffer[ix] = skb; 551 if (after(seq, call->rx_top)) { 552 smp_store_release(&call->rx_top, seq); 553 } else if (before(seq, call->rx_top)) { 554 /* Send an immediate ACK if we fill in a hole */ 555 if (!ack) { 556 ack = RXRPC_ACK_DELAY; 557 ack_serial = serial; 558 } 559 immediate_ack = true; 560 } 561 562 if (terminal) { 563 /* From this point on, we're not allowed to touch the 564 * packet any longer as its ref now belongs to the Rx 565 * ring. 566 */ 567 skb = NULL; 568 sp = NULL; 569 } 570 571 if (last) { 572 set_bit(RXRPC_CALL_RX_LAST, &call->flags); 573 if (!ack) { 574 ack = RXRPC_ACK_DELAY; 575 ack_serial = serial; 576 } 577 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); 578 } else { 579 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); 580 } 581 582 if (after_eq(seq, call->rx_expect_next)) { 583 if (after(seq, call->rx_expect_next)) { 584 _net("OOS %u > %u", seq, call->rx_expect_next); 585 ack = RXRPC_ACK_OUT_OF_SEQUENCE; 586 ack_serial = serial; 587 } 588 call->rx_expect_next = seq + 1; 589 } 590 } 591 592 ack: 593 if (ack) 594 rxrpc_propose_ACK(call, ack, ack_serial, 595 immediate_ack, true, 596 rxrpc_propose_ack_input_data); 597 else 598 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial, 599 false, true, 600 rxrpc_propose_ack_input_data); 601 602 trace_rxrpc_notify_socket(call->debug_id, serial); 603 rxrpc_notify_socket(call); 604 605 unlock: 606 spin_unlock(&call->input_lock); 607 rxrpc_free_skb(skb, rxrpc_skb_freed); 608 _leave(" [queued]"); 609 } 610 611 /* 612 * Process a requested ACK. 613 */ 614 static void rxrpc_input_requested_ack(struct rxrpc_call *call, 615 ktime_t resp_time, 616 rxrpc_serial_t orig_serial, 617 rxrpc_serial_t ack_serial) 618 { 619 struct rxrpc_skb_priv *sp; 620 struct sk_buff *skb; 621 ktime_t sent_at; 622 int ix; 623 624 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) { 625 skb = call->rxtx_buffer[ix]; 626 if (!skb) 627 continue; 628 629 sent_at = skb->tstamp; 630 smp_rmb(); /* Read timestamp before serial. */ 631 sp = rxrpc_skb(skb); 632 if (sp->hdr.serial != orig_serial) 633 continue; 634 goto found; 635 } 636 637 return; 638 639 found: 640 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack, 641 orig_serial, ack_serial, sent_at, resp_time); 642 } 643 644 /* 645 * Process the response to a ping that we sent to find out if we lost an ACK. 646 * 647 * If we got back a ping response that indicates a lower tx_top than what we 648 * had at the time of the ping transmission, we adjudge all the DATA packets 649 * sent between the response tx_top and the ping-time tx_top to have been lost. 650 */ 651 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call) 652 { 653 rxrpc_seq_t top, bottom, seq; 654 bool resend = false; 655 656 spin_lock_bh(&call->lock); 657 658 bottom = call->tx_hard_ack + 1; 659 top = call->acks_lost_top; 660 if (before(bottom, top)) { 661 for (seq = bottom; before_eq(seq, top); seq++) { 662 int ix = seq & RXRPC_RXTX_BUFF_MASK; 663 u8 annotation = call->rxtx_annotations[ix]; 664 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK; 665 666 if (anno_type != RXRPC_TX_ANNO_UNACK) 667 continue; 668 annotation &= ~RXRPC_TX_ANNO_MASK; 669 annotation |= RXRPC_TX_ANNO_RETRANS; 670 call->rxtx_annotations[ix] = annotation; 671 resend = true; 672 } 673 } 674 675 spin_unlock_bh(&call->lock); 676 677 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 678 rxrpc_queue_call(call); 679 } 680 681 /* 682 * Process a ping response. 683 */ 684 static void rxrpc_input_ping_response(struct rxrpc_call *call, 685 ktime_t resp_time, 686 rxrpc_serial_t orig_serial, 687 rxrpc_serial_t ack_serial) 688 { 689 rxrpc_serial_t ping_serial; 690 ktime_t ping_time; 691 692 ping_time = call->ping_time; 693 smp_rmb(); 694 ping_serial = READ_ONCE(call->ping_serial); 695 696 if (orig_serial == call->acks_lost_ping) 697 rxrpc_input_check_for_lost_ack(call); 698 699 if (before(orig_serial, ping_serial) || 700 !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags)) 701 return; 702 if (after(orig_serial, ping_serial)) 703 return; 704 705 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response, 706 orig_serial, ack_serial, ping_time, resp_time); 707 } 708 709 /* 710 * Process the extra information that may be appended to an ACK packet 711 */ 712 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 713 struct rxrpc_ackinfo *ackinfo) 714 { 715 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 716 struct rxrpc_peer *peer; 717 unsigned int mtu; 718 bool wake = false; 719 u32 rwind = ntohl(ackinfo->rwind); 720 721 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 722 sp->hdr.serial, 723 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU), 724 rwind, ntohl(ackinfo->jumbo_max)); 725 726 if (call->tx_winsize != rwind) { 727 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) 728 rwind = RXRPC_RXTX_BUFF_SIZE - 1; 729 if (rwind > call->tx_winsize) 730 wake = true; 731 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, 732 ntohl(ackinfo->rwind), wake); 733 call->tx_winsize = rwind; 734 } 735 736 if (call->cong_ssthresh > rwind) 737 call->cong_ssthresh = rwind; 738 739 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); 740 741 peer = call->peer; 742 if (mtu < peer->maxdata) { 743 spin_lock_bh(&peer->lock); 744 peer->maxdata = mtu; 745 peer->mtu = mtu + peer->hdrsize; 746 spin_unlock_bh(&peer->lock); 747 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 748 } 749 750 if (wake) 751 wake_up(&call->waitq); 752 } 753 754 /* 755 * Process individual soft ACKs. 756 * 757 * Each ACK in the array corresponds to one packet and can be either an ACK or 758 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 759 * packets that lie beyond the end of the ACK list are scheduled for resend by 760 * the timer on the basis that the peer might just not have processed them at 761 * the time the ACK was sent. 762 */ 763 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, 764 rxrpc_seq_t seq, int nr_acks, 765 struct rxrpc_ack_summary *summary) 766 { 767 int ix; 768 u8 annotation, anno_type; 769 770 for (; nr_acks > 0; nr_acks--, seq++) { 771 ix = seq & RXRPC_RXTX_BUFF_MASK; 772 annotation = call->rxtx_annotations[ix]; 773 anno_type = annotation & RXRPC_TX_ANNO_MASK; 774 annotation &= ~RXRPC_TX_ANNO_MASK; 775 switch (*acks++) { 776 case RXRPC_ACK_TYPE_ACK: 777 summary->nr_acks++; 778 if (anno_type == RXRPC_TX_ANNO_ACK) 779 continue; 780 summary->nr_new_acks++; 781 call->rxtx_annotations[ix] = 782 RXRPC_TX_ANNO_ACK | annotation; 783 break; 784 case RXRPC_ACK_TYPE_NACK: 785 if (!summary->nr_nacks && 786 call->acks_lowest_nak != seq) { 787 call->acks_lowest_nak = seq; 788 summary->new_low_nack = true; 789 } 790 summary->nr_nacks++; 791 if (anno_type == RXRPC_TX_ANNO_NAK) 792 continue; 793 summary->nr_new_nacks++; 794 if (anno_type == RXRPC_TX_ANNO_RETRANS) 795 continue; 796 call->rxtx_annotations[ix] = 797 RXRPC_TX_ANNO_NAK | annotation; 798 break; 799 default: 800 return rxrpc_proto_abort("SFT", call, 0); 801 } 802 } 803 } 804 805 /* 806 * Process an ACK packet. 807 * 808 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 809 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 810 * 811 * A hard-ACK means that a packet has been processed and may be discarded; a 812 * soft-ACK means that the packet may be discarded and retransmission 813 * requested. A phase is complete when all packets are hard-ACK'd. 814 */ 815 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb) 816 { 817 struct rxrpc_ack_summary summary = { 0 }; 818 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 819 union { 820 struct rxrpc_ackpacket ack; 821 struct rxrpc_ackinfo info; 822 u8 acks[RXRPC_MAXACKS]; 823 } buf; 824 rxrpc_serial_t acked_serial; 825 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; 826 int nr_acks, offset, ioffset; 827 828 _enter(""); 829 830 offset = sizeof(struct rxrpc_wire_header); 831 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { 832 _debug("extraction failure"); 833 return rxrpc_proto_abort("XAK", call, 0); 834 } 835 offset += sizeof(buf.ack); 836 837 acked_serial = ntohl(buf.ack.serial); 838 first_soft_ack = ntohl(buf.ack.firstPacket); 839 prev_pkt = ntohl(buf.ack.previousPacket); 840 hard_ack = first_soft_ack - 1; 841 nr_acks = buf.ack.nAcks; 842 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? 843 buf.ack.reason : RXRPC_ACK__INVALID); 844 845 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial, 846 first_soft_ack, prev_pkt, 847 summary.ack_reason, nr_acks); 848 849 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) 850 rxrpc_input_ping_response(call, skb->tstamp, acked_serial, 851 sp->hdr.serial); 852 if (buf.ack.reason == RXRPC_ACK_REQUESTED) 853 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial, 854 sp->hdr.serial); 855 856 if (buf.ack.reason == RXRPC_ACK_PING) { 857 _proto("Rx ACK %%%u PING Request", sp->hdr.serial); 858 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 859 sp->hdr.serial, true, true, 860 rxrpc_propose_ack_respond_to_ping); 861 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { 862 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, 863 sp->hdr.serial, true, true, 864 rxrpc_propose_ack_respond_to_ack); 865 } 866 867 /* Discard any out-of-order or duplicate ACKs (outside lock). */ 868 if (before(first_soft_ack, call->ackr_first_seq) || 869 before(prev_pkt, call->ackr_prev_seq)) 870 return; 871 872 buf.info.rxMTU = 0; 873 ioffset = offset + nr_acks + 3; 874 if (skb->len >= ioffset + sizeof(buf.info) && 875 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) 876 return rxrpc_proto_abort("XAI", call, 0); 877 878 spin_lock(&call->input_lock); 879 880 /* Discard any out-of-order or duplicate ACKs (inside lock). */ 881 if (before(first_soft_ack, call->ackr_first_seq) || 882 before(prev_pkt, call->ackr_prev_seq)) 883 goto out; 884 call->acks_latest_ts = skb->tstamp; 885 call->acks_latest = sp->hdr.serial; 886 887 call->ackr_first_seq = first_soft_ack; 888 call->ackr_prev_seq = prev_pkt; 889 890 /* Parse rwind and mtu sizes if provided. */ 891 if (buf.info.rxMTU) 892 rxrpc_input_ackinfo(call, skb, &buf.info); 893 894 if (first_soft_ack == 0) { 895 rxrpc_proto_abort("AK0", call, 0); 896 goto out; 897 } 898 899 /* Ignore ACKs unless we are or have just been transmitting. */ 900 switch (READ_ONCE(call->state)) { 901 case RXRPC_CALL_CLIENT_SEND_REQUEST: 902 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 903 case RXRPC_CALL_SERVER_SEND_REPLY: 904 case RXRPC_CALL_SERVER_AWAIT_ACK: 905 break; 906 default: 907 goto out; 908 } 909 910 if (before(hard_ack, call->tx_hard_ack) || 911 after(hard_ack, call->tx_top)) { 912 rxrpc_proto_abort("AKW", call, 0); 913 goto out; 914 } 915 if (nr_acks > call->tx_top - hard_ack) { 916 rxrpc_proto_abort("AKN", call, 0); 917 goto out; 918 } 919 920 if (after(hard_ack, call->tx_hard_ack)) { 921 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { 922 rxrpc_end_tx_phase(call, false, "ETA"); 923 goto out; 924 } 925 } 926 927 if (nr_acks > 0) { 928 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) { 929 rxrpc_proto_abort("XSA", call, 0); 930 goto out; 931 } 932 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, 933 &summary); 934 } 935 936 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 937 RXRPC_TX_ANNO_LAST && 938 summary.nr_acks == call->tx_top - hard_ack && 939 rxrpc_is_client_call(call)) 940 rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial, 941 false, true, 942 rxrpc_propose_ack_ping_for_lost_reply); 943 944 rxrpc_congestion_management(call, skb, &summary, acked_serial); 945 out: 946 spin_unlock(&call->input_lock); 947 } 948 949 /* 950 * Process an ACKALL packet. 951 */ 952 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 953 { 954 struct rxrpc_ack_summary summary = { 0 }; 955 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 956 957 _proto("Rx ACKALL %%%u", sp->hdr.serial); 958 959 spin_lock(&call->input_lock); 960 961 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) 962 rxrpc_end_tx_phase(call, false, "ETL"); 963 964 spin_unlock(&call->input_lock); 965 } 966 967 /* 968 * Process an ABORT packet directed at a call. 969 */ 970 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 971 { 972 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 973 __be32 wtmp; 974 u32 abort_code = RX_CALL_DEAD; 975 976 _enter(""); 977 978 if (skb->len >= 4 && 979 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 980 &wtmp, sizeof(wtmp)) >= 0) 981 abort_code = ntohl(wtmp); 982 983 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code); 984 985 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); 986 987 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 988 abort_code, -ECONNABORTED)) 989 rxrpc_notify_socket(call); 990 } 991 992 /* 993 * Process an incoming call packet. 994 */ 995 static void rxrpc_input_call_packet(struct rxrpc_call *call, 996 struct sk_buff *skb) 997 { 998 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 999 unsigned long timo; 1000 1001 _enter("%p,%p", call, skb); 1002 1003 timo = READ_ONCE(call->next_rx_timo); 1004 if (timo) { 1005 unsigned long now = jiffies, expect_rx_by; 1006 1007 expect_rx_by = now + timo; 1008 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 1009 rxrpc_reduce_call_timer(call, expect_rx_by, now, 1010 rxrpc_timer_set_for_normal); 1011 } 1012 1013 switch (sp->hdr.type) { 1014 case RXRPC_PACKET_TYPE_DATA: 1015 rxrpc_input_data(call, skb); 1016 goto no_free; 1017 1018 case RXRPC_PACKET_TYPE_ACK: 1019 rxrpc_input_ack(call, skb); 1020 break; 1021 1022 case RXRPC_PACKET_TYPE_BUSY: 1023 _proto("Rx BUSY %%%u", sp->hdr.serial); 1024 1025 /* Just ignore BUSY packets from the server; the retry and 1026 * lifespan timers will take care of business. BUSY packets 1027 * from the client don't make sense. 1028 */ 1029 break; 1030 1031 case RXRPC_PACKET_TYPE_ABORT: 1032 rxrpc_input_abort(call, skb); 1033 break; 1034 1035 case RXRPC_PACKET_TYPE_ACKALL: 1036 rxrpc_input_ackall(call, skb); 1037 break; 1038 1039 default: 1040 break; 1041 } 1042 1043 rxrpc_free_skb(skb, rxrpc_skb_freed); 1044 no_free: 1045 _leave(""); 1046 } 1047 1048 /* 1049 * Handle a new service call on a channel implicitly completing the preceding 1050 * call on that channel. This does not apply to client conns. 1051 * 1052 * TODO: If callNumber > call_id + 1, renegotiate security. 1053 */ 1054 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, 1055 struct rxrpc_connection *conn, 1056 struct rxrpc_call *call) 1057 { 1058 switch (READ_ONCE(call->state)) { 1059 case RXRPC_CALL_SERVER_AWAIT_ACK: 1060 rxrpc_call_completed(call); 1061 /* Fall through */ 1062 case RXRPC_CALL_COMPLETE: 1063 break; 1064 default: 1065 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) { 1066 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 1067 rxrpc_queue_call(call); 1068 } 1069 trace_rxrpc_improper_term(call); 1070 break; 1071 } 1072 1073 spin_lock(&rx->incoming_lock); 1074 __rxrpc_disconnect_call(conn, call); 1075 spin_unlock(&rx->incoming_lock); 1076 rxrpc_notify_socket(call); 1077 } 1078 1079 /* 1080 * post connection-level events to the connection 1081 * - this includes challenges, responses, some aborts and call terminal packet 1082 * retransmission. 1083 */ 1084 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 1085 struct sk_buff *skb) 1086 { 1087 _enter("%p,%p", conn, skb); 1088 1089 skb_queue_tail(&conn->rx_queue, skb); 1090 rxrpc_queue_conn(conn); 1091 } 1092 1093 /* 1094 * post endpoint-level events to the local endpoint 1095 * - this includes debug and version messages 1096 */ 1097 static void rxrpc_post_packet_to_local(struct rxrpc_local *local, 1098 struct sk_buff *skb) 1099 { 1100 _enter("%p,%p", local, skb); 1101 1102 if (rxrpc_get_local_maybe(local)) { 1103 skb_queue_tail(&local->event_queue, skb); 1104 rxrpc_queue_local(local); 1105 } else { 1106 rxrpc_free_skb(skb, rxrpc_skb_freed); 1107 } 1108 } 1109 1110 /* 1111 * put a packet up for transport-level abort 1112 */ 1113 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 1114 { 1115 CHECK_SLAB_OKAY(&local->usage); 1116 1117 if (rxrpc_get_local_maybe(local)) { 1118 skb_queue_tail(&local->reject_queue, skb); 1119 rxrpc_queue_local(local); 1120 } else { 1121 rxrpc_free_skb(skb, rxrpc_skb_freed); 1122 } 1123 } 1124 1125 /* 1126 * Extract the wire header from a packet and translate the byte order. 1127 */ 1128 static noinline 1129 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) 1130 { 1131 struct rxrpc_wire_header whdr; 1132 1133 /* dig out the RxRPC connection details */ 1134 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) { 1135 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 1136 tracepoint_string("bad_hdr")); 1137 return -EBADMSG; 1138 } 1139 1140 memset(sp, 0, sizeof(*sp)); 1141 sp->hdr.epoch = ntohl(whdr.epoch); 1142 sp->hdr.cid = ntohl(whdr.cid); 1143 sp->hdr.callNumber = ntohl(whdr.callNumber); 1144 sp->hdr.seq = ntohl(whdr.seq); 1145 sp->hdr.serial = ntohl(whdr.serial); 1146 sp->hdr.flags = whdr.flags; 1147 sp->hdr.type = whdr.type; 1148 sp->hdr.userStatus = whdr.userStatus; 1149 sp->hdr.securityIndex = whdr.securityIndex; 1150 sp->hdr._rsvd = ntohs(whdr._rsvd); 1151 sp->hdr.serviceId = ntohs(whdr.serviceId); 1152 return 0; 1153 } 1154 1155 /* 1156 * handle data received on the local endpoint 1157 * - may be called in interrupt context 1158 * 1159 * [!] Note that as this is called from the encap_rcv hook, the socket is not 1160 * held locked by the caller and nothing prevents sk_user_data on the UDP from 1161 * being cleared in the middle of processing this function. 1162 * 1163 * Called with the RCU read lock held from the IP layer via UDP. 1164 */ 1165 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb) 1166 { 1167 struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk); 1168 struct rxrpc_connection *conn; 1169 struct rxrpc_channel *chan; 1170 struct rxrpc_call *call = NULL; 1171 struct rxrpc_skb_priv *sp; 1172 struct rxrpc_peer *peer = NULL; 1173 struct rxrpc_sock *rx = NULL; 1174 unsigned int channel; 1175 1176 _enter("%p", udp_sk); 1177 1178 if (unlikely(!local)) { 1179 kfree_skb(skb); 1180 return 0; 1181 } 1182 if (skb->tstamp == 0) 1183 skb->tstamp = ktime_get_real(); 1184 1185 rxrpc_new_skb(skb, rxrpc_skb_received); 1186 1187 skb_pull(skb, sizeof(struct udphdr)); 1188 1189 /* The UDP protocol already released all skb resources; 1190 * we are free to add our own data there. 1191 */ 1192 sp = rxrpc_skb(skb); 1193 1194 /* dig out the RxRPC connection details */ 1195 if (rxrpc_extract_header(sp, skb) < 0) 1196 goto bad_message; 1197 1198 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { 1199 static int lose; 1200 if ((lose++ & 7) == 7) { 1201 trace_rxrpc_rx_lose(sp); 1202 rxrpc_free_skb(skb, rxrpc_skb_lost); 1203 return 0; 1204 } 1205 } 1206 1207 if (skb->tstamp == 0) 1208 skb->tstamp = ktime_get_real(); 1209 trace_rxrpc_rx_packet(sp); 1210 1211 switch (sp->hdr.type) { 1212 case RXRPC_PACKET_TYPE_VERSION: 1213 if (rxrpc_to_client(sp)) 1214 goto discard; 1215 rxrpc_post_packet_to_local(local, skb); 1216 goto out; 1217 1218 case RXRPC_PACKET_TYPE_BUSY: 1219 if (rxrpc_to_server(sp)) 1220 goto discard; 1221 /* Fall through */ 1222 case RXRPC_PACKET_TYPE_ACK: 1223 case RXRPC_PACKET_TYPE_ACKALL: 1224 if (sp->hdr.callNumber == 0) 1225 goto bad_message; 1226 /* Fall through */ 1227 case RXRPC_PACKET_TYPE_ABORT: 1228 break; 1229 1230 case RXRPC_PACKET_TYPE_DATA: 1231 if (sp->hdr.callNumber == 0 || 1232 sp->hdr.seq == 0) 1233 goto bad_message; 1234 if (!rxrpc_validate_data(skb)) 1235 goto bad_message; 1236 1237 /* Unshare the packet so that it can be modified for in-place 1238 * decryption. 1239 */ 1240 if (sp->hdr.securityIndex != 0) { 1241 struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC); 1242 if (!nskb) { 1243 rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem); 1244 goto out; 1245 } 1246 1247 if (nskb != skb) { 1248 rxrpc_eaten_skb(skb, rxrpc_skb_received); 1249 skb = nskb; 1250 rxrpc_new_skb(skb, rxrpc_skb_unshared); 1251 sp = rxrpc_skb(skb); 1252 } 1253 } 1254 break; 1255 1256 case RXRPC_PACKET_TYPE_CHALLENGE: 1257 if (rxrpc_to_server(sp)) 1258 goto discard; 1259 break; 1260 case RXRPC_PACKET_TYPE_RESPONSE: 1261 if (rxrpc_to_client(sp)) 1262 goto discard; 1263 break; 1264 1265 /* Packet types 9-11 should just be ignored. */ 1266 case RXRPC_PACKET_TYPE_PARAMS: 1267 case RXRPC_PACKET_TYPE_10: 1268 case RXRPC_PACKET_TYPE_11: 1269 goto discard; 1270 1271 default: 1272 _proto("Rx Bad Packet Type %u", sp->hdr.type); 1273 goto bad_message; 1274 } 1275 1276 if (sp->hdr.serviceId == 0) 1277 goto bad_message; 1278 1279 if (rxrpc_to_server(sp)) { 1280 /* Weed out packets to services we're not offering. Packets 1281 * that would begin a call are explicitly rejected and the rest 1282 * are just discarded. 1283 */ 1284 rx = rcu_dereference(local->service); 1285 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service && 1286 sp->hdr.serviceId != rx->second_service)) { 1287 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && 1288 sp->hdr.seq == 1) 1289 goto unsupported_service; 1290 goto discard; 1291 } 1292 } 1293 1294 conn = rxrpc_find_connection_rcu(local, skb, &peer); 1295 if (conn) { 1296 if (sp->hdr.securityIndex != conn->security_ix) 1297 goto wrong_security; 1298 1299 if (sp->hdr.serviceId != conn->service_id) { 1300 int old_id; 1301 1302 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) 1303 goto reupgrade; 1304 old_id = cmpxchg(&conn->service_id, conn->params.service_id, 1305 sp->hdr.serviceId); 1306 1307 if (old_id != conn->params.service_id && 1308 old_id != sp->hdr.serviceId) 1309 goto reupgrade; 1310 } 1311 1312 if (sp->hdr.callNumber == 0) { 1313 /* Connection-level packet */ 1314 _debug("CONN %p {%d}", conn, conn->debug_id); 1315 rxrpc_post_packet_to_conn(conn, skb); 1316 goto out; 1317 } 1318 1319 if ((int)sp->hdr.serial - (int)conn->hi_serial > 0) 1320 conn->hi_serial = sp->hdr.serial; 1321 1322 /* Call-bound packets are routed by connection channel. */ 1323 channel = sp->hdr.cid & RXRPC_CHANNELMASK; 1324 chan = &conn->channels[channel]; 1325 1326 /* Ignore really old calls */ 1327 if (sp->hdr.callNumber < chan->last_call) 1328 goto discard; 1329 1330 if (sp->hdr.callNumber == chan->last_call) { 1331 if (chan->call || 1332 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) 1333 goto discard; 1334 1335 /* For the previous service call, if completed 1336 * successfully, we discard all further packets. 1337 */ 1338 if (rxrpc_conn_is_service(conn) && 1339 chan->last_type == RXRPC_PACKET_TYPE_ACK) 1340 goto discard; 1341 1342 /* But otherwise we need to retransmit the final packet 1343 * from data cached in the connection record. 1344 */ 1345 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) 1346 trace_rxrpc_rx_data(chan->call_debug_id, 1347 sp->hdr.seq, 1348 sp->hdr.serial, 1349 sp->hdr.flags, 0); 1350 rxrpc_post_packet_to_conn(conn, skb); 1351 goto out; 1352 } 1353 1354 call = rcu_dereference(chan->call); 1355 1356 if (sp->hdr.callNumber > chan->call_id) { 1357 if (rxrpc_to_client(sp)) 1358 goto reject_packet; 1359 if (call) 1360 rxrpc_input_implicit_end_call(rx, conn, call); 1361 call = NULL; 1362 } 1363 1364 if (call) { 1365 if (sp->hdr.serviceId != call->service_id) 1366 call->service_id = sp->hdr.serviceId; 1367 if ((int)sp->hdr.serial - (int)call->rx_serial > 0) 1368 call->rx_serial = sp->hdr.serial; 1369 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) 1370 set_bit(RXRPC_CALL_RX_HEARD, &call->flags); 1371 } 1372 } 1373 1374 if (!call || atomic_read(&call->usage) == 0) { 1375 if (rxrpc_to_client(sp) || 1376 sp->hdr.type != RXRPC_PACKET_TYPE_DATA) 1377 goto bad_message; 1378 if (sp->hdr.seq != 1) 1379 goto discard; 1380 call = rxrpc_new_incoming_call(local, rx, skb); 1381 if (!call) 1382 goto reject_packet; 1383 } 1384 1385 /* Process a call packet; this either discards or passes on the ref 1386 * elsewhere. 1387 */ 1388 rxrpc_input_call_packet(call, skb); 1389 goto out; 1390 1391 discard: 1392 rxrpc_free_skb(skb, rxrpc_skb_freed); 1393 out: 1394 trace_rxrpc_rx_done(0, 0); 1395 return 0; 1396 1397 wrong_security: 1398 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1399 RXKADINCONSISTENCY, EBADMSG); 1400 skb->priority = RXKADINCONSISTENCY; 1401 goto post_abort; 1402 1403 unsupported_service: 1404 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1405 RX_INVALID_OPERATION, EOPNOTSUPP); 1406 skb->priority = RX_INVALID_OPERATION; 1407 goto post_abort; 1408 1409 reupgrade: 1410 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1411 RX_PROTOCOL_ERROR, EBADMSG); 1412 goto protocol_error; 1413 1414 bad_message: 1415 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1416 RX_PROTOCOL_ERROR, EBADMSG); 1417 protocol_error: 1418 skb->priority = RX_PROTOCOL_ERROR; 1419 post_abort: 1420 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT; 1421 reject_packet: 1422 trace_rxrpc_rx_done(skb->mark, skb->priority); 1423 rxrpc_reject_packet(local, skb); 1424 _leave(" [badmsg]"); 1425 return 0; 1426 } 1427