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 26static 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 */ 38static 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_count == 0) 95 goto out; 96 if (ktime_before(skb->tstamp, 97 ktime_add_us(call->cong_tstamp, 98 call->peer->srtt_us >> 3))) 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 155resume_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; 164out: 165 cumulative_acks = 0; 166out_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 176packet_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 182send_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 */ 198static 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 */ 257static 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 state = call->state; 279 break; 280 281 default: 282 goto bad_state; 283 } 284 285 write_unlock(&call->state_lock); 286 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY) 287 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); 288 else 289 trace_rxrpc_transmit(call, rxrpc_transmit_end); 290 _leave(" = ok"); 291 return true; 292 293bad_state: 294 write_unlock(&call->state_lock); 295 kdebug("end_tx %s", rxrpc_call_states[call->state]); 296 rxrpc_proto_abort(abort_why, call, call->tx_top); 297 return false; 298} 299 300/* 301 * Begin the reply reception phase of a call. 302 */ 303static bool rxrpc_receiving_reply(struct rxrpc_call *call) 304{ 305 struct rxrpc_ack_summary summary = { 0 }; 306 unsigned long now, timo; 307 rxrpc_seq_t top = READ_ONCE(call->tx_top); 308 309 if (call->ackr_reason) { 310 spin_lock_bh(&call->lock); 311 call->ackr_reason = 0; 312 spin_unlock_bh(&call->lock); 313 now = jiffies; 314 timo = now + MAX_JIFFY_OFFSET; 315 WRITE_ONCE(call->resend_at, timo); 316 WRITE_ONCE(call->ack_at, timo); 317 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now); 318 } 319 320 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { 321 if (!rxrpc_rotate_tx_window(call, top, &summary)) { 322 rxrpc_proto_abort("TXL", call, top); 323 return false; 324 } 325 } 326 if (!rxrpc_end_tx_phase(call, true, "ETD")) 327 return false; 328 call->tx_phase = false; 329 return true; 330} 331 332/* 333 * Scan a data packet to validate its structure and to work out how many 334 * subpackets it contains. 335 * 336 * A jumbo packet is a collection of consecutive packets glued together with 337 * little headers between that indicate how to change the initial header for 338 * each subpacket. 339 * 340 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but 341 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any 342 * size. 343 */ 344static bool rxrpc_validate_data(struct sk_buff *skb) 345{ 346 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 347 unsigned int offset = sizeof(struct rxrpc_wire_header); 348 unsigned int len = skb->len; 349 u8 flags = sp->hdr.flags; 350 351 for (;;) { 352 if (flags & RXRPC_REQUEST_ACK) 353 __set_bit(sp->nr_subpackets, sp->rx_req_ack); 354 sp->nr_subpackets++; 355 356 if (!(flags & RXRPC_JUMBO_PACKET)) 357 break; 358 359 if (len - offset < RXRPC_JUMBO_SUBPKTLEN) 360 goto protocol_error; 361 if (flags & RXRPC_LAST_PACKET) 362 goto protocol_error; 363 offset += RXRPC_JUMBO_DATALEN; 364 if (skb_copy_bits(skb, offset, &flags, 1) < 0) 365 goto protocol_error; 366 offset += sizeof(struct rxrpc_jumbo_header); 367 } 368 369 if (flags & RXRPC_LAST_PACKET) 370 sp->rx_flags |= RXRPC_SKB_INCL_LAST; 371 return true; 372 373protocol_error: 374 return false; 375} 376 377/* 378 * Handle reception of a duplicate packet. 379 * 380 * We have to take care to avoid an attack here whereby we're given a series of 381 * jumbograms, each with a sequence number one before the preceding one and 382 * filled up to maximum UDP size. If they never send us the first packet in 383 * the sequence, they can cause us to have to hold on to around 2MiB of kernel 384 * space until the call times out. 385 * 386 * We limit the space usage by only accepting three duplicate jumbo packets per 387 * call. After that, we tell the other side we're no longer accepting jumbos 388 * (that information is encoded in the ACK packet). 389 */ 390static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, 391 bool is_jumbo, bool *_jumbo_bad) 392{ 393 /* Discard normal packets that are duplicates. */ 394 if (is_jumbo) 395 return; 396 397 /* Skip jumbo subpackets that are duplicates. When we've had three or 398 * more partially duplicate jumbo packets, we refuse to take any more 399 * jumbos for this call. 400 */ 401 if (!*_jumbo_bad) { 402 call->nr_jumbo_bad++; 403 *_jumbo_bad = true; 404 } 405} 406 407/* 408 * Process a DATA packet, adding the packet to the Rx ring. The caller's 409 * packet ref must be passed on or discarded. 410 */ 411static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb) 412{ 413 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 414 enum rxrpc_call_state state; 415 unsigned int j, nr_subpackets, nr_unacked = 0; 416 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = serial; 417 rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack; 418 bool immediate_ack = false, jumbo_bad = false; 419 u8 ack = 0; 420 421 _enter("{%u,%u},{%u,%u}", 422 call->rx_hard_ack, call->rx_top, skb->len, seq0); 423 424 _proto("Rx DATA %%%u { #%u f=%02x n=%u }", 425 sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets); 426 427 state = READ_ONCE(call->state); 428 if (state >= RXRPC_CALL_COMPLETE) { 429 rxrpc_free_skb(skb, rxrpc_skb_freed); 430 return; 431 } 432 433 if (state == RXRPC_CALL_SERVER_RECV_REQUEST) { 434 unsigned long timo = READ_ONCE(call->next_req_timo); 435 unsigned long now, expect_req_by; 436 437 if (timo) { 438 now = jiffies; 439 expect_req_by = now + timo; 440 WRITE_ONCE(call->expect_req_by, expect_req_by); 441 rxrpc_reduce_call_timer(call, expect_req_by, now, 442 rxrpc_timer_set_for_idle); 443 } 444 } 445 446 spin_lock(&call->input_lock); 447 448 /* Received data implicitly ACKs all of the request packets we sent 449 * when we're acting as a client. 450 */ 451 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST || 452 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) && 453 !rxrpc_receiving_reply(call)) 454 goto unlock; 455 456 hard_ack = READ_ONCE(call->rx_hard_ack); 457 458 nr_subpackets = sp->nr_subpackets; 459 if (nr_subpackets > 1) { 460 if (call->nr_jumbo_bad > 3) { 461 ack = RXRPC_ACK_NOSPACE; 462 ack_serial = serial; 463 goto ack; 464 } 465 } 466 467 for (j = 0; j < nr_subpackets; j++) { 468 rxrpc_serial_t serial = sp->hdr.serial + j; 469 rxrpc_seq_t seq = seq0 + j; 470 unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK; 471 bool terminal = (j == nr_subpackets - 1); 472 bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST); 473 u8 flags, annotation = j; 474 475 _proto("Rx DATA+%u %%%u { #%x t=%u l=%u }", 476 j, serial, seq, terminal, last); 477 478 if (last) { 479 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 480 seq != call->rx_top) { 481 rxrpc_proto_abort("LSN", call, seq); 482 goto unlock; 483 } 484 } else { 485 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 486 after_eq(seq, call->rx_top)) { 487 rxrpc_proto_abort("LSA", call, seq); 488 goto unlock; 489 } 490 } 491 492 flags = 0; 493 if (last) 494 flags |= RXRPC_LAST_PACKET; 495 if (!terminal) 496 flags |= RXRPC_JUMBO_PACKET; 497 if (test_bit(j, sp->rx_req_ack)) 498 flags |= RXRPC_REQUEST_ACK; 499 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation); 500 501 if (before_eq(seq, hard_ack)) { 502 ack = RXRPC_ACK_DUPLICATE; 503 ack_serial = serial; 504 continue; 505 } 506 507 if (call->rxtx_buffer[ix]) { 508 rxrpc_input_dup_data(call, seq, nr_subpackets > 1, 509 &jumbo_bad); 510 if (ack != RXRPC_ACK_DUPLICATE) { 511 ack = RXRPC_ACK_DUPLICATE; 512 ack_serial = serial; 513 } 514 immediate_ack = true; 515 continue; 516 } 517 518 if (after(seq, hard_ack + call->rx_winsize)) { 519 ack = RXRPC_ACK_EXCEEDS_WINDOW; 520 ack_serial = serial; 521 if (flags & RXRPC_JUMBO_PACKET) { 522 if (!jumbo_bad) { 523 call->nr_jumbo_bad++; 524 jumbo_bad = true; 525 } 526 } 527 528 goto ack; 529 } 530 531 if (flags & RXRPC_REQUEST_ACK && !ack) { 532 ack = RXRPC_ACK_REQUESTED; 533 ack_serial = serial; 534 } 535 536 if (after(seq0, call->ackr_highest_seq)) 537 call->ackr_highest_seq = seq0; 538 539 /* Queue the packet. We use a couple of memory barriers here as need 540 * to make sure that rx_top is perceived to be set after the buffer 541 * pointer and that the buffer pointer is set after the annotation and 542 * the skb data. 543 * 544 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() 545 * and also rxrpc_fill_out_ack(). 546 */ 547 if (!terminal) 548 rxrpc_get_skb(skb, rxrpc_skb_got); 549 call->rxtx_annotations[ix] = annotation; 550 smp_wmb(); 551 call->rxtx_buffer[ix] = skb; 552 if (after(seq, call->rx_top)) { 553 smp_store_release(&call->rx_top, seq); 554 } else if (before(seq, call->rx_top)) { 555 /* Send an immediate ACK if we fill in a hole */ 556 if (!ack) { 557 ack = RXRPC_ACK_DELAY; 558 ack_serial = serial; 559 } 560 immediate_ack = true; 561 } 562 563 if (terminal) { 564 /* From this point on, we're not allowed to touch the 565 * packet any longer as its ref now belongs to the Rx 566 * ring. 567 */ 568 skb = NULL; 569 sp = NULL; 570 } 571 572 nr_unacked++; 573 574 if (last) { 575 set_bit(RXRPC_CALL_RX_LAST, &call->flags); 576 if (!ack) { 577 ack = RXRPC_ACK_DELAY; 578 ack_serial = serial; 579 } 580 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); 581 } else { 582 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); 583 } 584 585 if (after_eq(seq, call->rx_expect_next)) { 586 if (after(seq, call->rx_expect_next)) { 587 _net("OOS %u > %u", seq, call->rx_expect_next); 588 ack = RXRPC_ACK_OUT_OF_SEQUENCE; 589 ack_serial = serial; 590 } 591 call->rx_expect_next = seq + 1; 592 } 593 if (!ack) 594 ack_serial = serial; 595 } 596 597ack: 598 if (atomic_add_return(nr_unacked, &call->ackr_nr_unacked) > 2 && !ack) 599 ack = RXRPC_ACK_IDLE; 600 601 if (ack) 602 rxrpc_propose_ACK(call, ack, ack_serial, 603 immediate_ack, true, 604 rxrpc_propose_ack_input_data); 605 else 606 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial, 607 false, true, 608 rxrpc_propose_ack_input_data); 609 610 trace_rxrpc_notify_socket(call->debug_id, serial); 611 rxrpc_notify_socket(call); 612 613unlock: 614 spin_unlock(&call->input_lock); 615 rxrpc_free_skb(skb, rxrpc_skb_freed); 616 _leave(" [queued]"); 617} 618 619/* 620 * See if there's a cached RTT probe to complete. 621 */ 622static void rxrpc_complete_rtt_probe(struct rxrpc_call *call, 623 ktime_t resp_time, 624 rxrpc_serial_t acked_serial, 625 rxrpc_serial_t ack_serial, 626 enum rxrpc_rtt_rx_trace type) 627{ 628 rxrpc_serial_t orig_serial; 629 unsigned long avail; 630 ktime_t sent_at; 631 bool matched = false; 632 int i; 633 634 avail = READ_ONCE(call->rtt_avail); 635 smp_rmb(); /* Read avail bits before accessing data. */ 636 637 for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) { 638 if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail)) 639 continue; 640 641 sent_at = call->rtt_sent_at[i]; 642 orig_serial = call->rtt_serial[i]; 643 644 if (orig_serial == acked_serial) { 645 clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail); 646 smp_mb(); /* Read data before setting avail bit */ 647 set_bit(i, &call->rtt_avail); 648 if (type != rxrpc_rtt_rx_cancel) 649 rxrpc_peer_add_rtt(call, type, i, acked_serial, ack_serial, 650 sent_at, resp_time); 651 else 652 trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_cancel, i, 653 orig_serial, acked_serial, 0, 0); 654 matched = true; 655 } 656 657 /* If a later serial is being acked, then mark this slot as 658 * being available. 659 */ 660 if (after(acked_serial, orig_serial)) { 661 trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i, 662 orig_serial, acked_serial, 0, 0); 663 clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail); 664 smp_wmb(); 665 set_bit(i, &call->rtt_avail); 666 } 667 } 668 669 if (!matched) 670 trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0); 671} 672 673/* 674 * Process the response to a ping that we sent to find out if we lost an ACK. 675 * 676 * If we got back a ping response that indicates a lower tx_top than what we 677 * had at the time of the ping transmission, we adjudge all the DATA packets 678 * sent between the response tx_top and the ping-time tx_top to have been lost. 679 */ 680static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call) 681{ 682 rxrpc_seq_t top, bottom, seq; 683 bool resend = false; 684 685 spin_lock_bh(&call->lock); 686 687 bottom = call->tx_hard_ack + 1; 688 top = call->acks_lost_top; 689 if (before(bottom, top)) { 690 for (seq = bottom; before_eq(seq, top); seq++) { 691 int ix = seq & RXRPC_RXTX_BUFF_MASK; 692 u8 annotation = call->rxtx_annotations[ix]; 693 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK; 694 695 if (anno_type != RXRPC_TX_ANNO_UNACK) 696 continue; 697 annotation &= ~RXRPC_TX_ANNO_MASK; 698 annotation |= RXRPC_TX_ANNO_RETRANS; 699 call->rxtx_annotations[ix] = annotation; 700 resend = true; 701 } 702 } 703 704 spin_unlock_bh(&call->lock); 705 706 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 707 rxrpc_queue_call(call); 708} 709 710/* 711 * Process a ping response. 712 */ 713static void rxrpc_input_ping_response(struct rxrpc_call *call, 714 ktime_t resp_time, 715 rxrpc_serial_t acked_serial, 716 rxrpc_serial_t ack_serial) 717{ 718 if (acked_serial == call->acks_lost_ping) 719 rxrpc_input_check_for_lost_ack(call); 720} 721 722/* 723 * Process the extra information that may be appended to an ACK packet 724 */ 725static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 726 struct rxrpc_ackinfo *ackinfo) 727{ 728 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 729 struct rxrpc_peer *peer; 730 unsigned int mtu; 731 bool wake = false; 732 u32 rwind = ntohl(ackinfo->rwind); 733 734 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 735 sp->hdr.serial, 736 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU), 737 rwind, ntohl(ackinfo->jumbo_max)); 738 739 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) 740 rwind = RXRPC_RXTX_BUFF_SIZE - 1; 741 if (call->tx_winsize != rwind) { 742 if (rwind > call->tx_winsize) 743 wake = true; 744 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake); 745 call->tx_winsize = rwind; 746 } 747 748 if (call->cong_ssthresh > rwind) 749 call->cong_ssthresh = rwind; 750 751 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); 752 753 peer = call->peer; 754 if (mtu < peer->maxdata) { 755 spin_lock_bh(&peer->lock); 756 peer->maxdata = mtu; 757 peer->mtu = mtu + peer->hdrsize; 758 spin_unlock_bh(&peer->lock); 759 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 760 } 761 762 if (wake) 763 wake_up(&call->waitq); 764} 765 766/* 767 * Process individual soft ACKs. 768 * 769 * Each ACK in the array corresponds to one packet and can be either an ACK or 770 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 771 * packets that lie beyond the end of the ACK list are scheduled for resend by 772 * the timer on the basis that the peer might just not have processed them at 773 * the time the ACK was sent. 774 */ 775static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, 776 rxrpc_seq_t seq, int nr_acks, 777 struct rxrpc_ack_summary *summary) 778{ 779 int ix; 780 u8 annotation, anno_type; 781 782 for (; nr_acks > 0; nr_acks--, seq++) { 783 ix = seq & RXRPC_RXTX_BUFF_MASK; 784 annotation = call->rxtx_annotations[ix]; 785 anno_type = annotation & RXRPC_TX_ANNO_MASK; 786 annotation &= ~RXRPC_TX_ANNO_MASK; 787 switch (*acks++) { 788 case RXRPC_ACK_TYPE_ACK: 789 summary->nr_acks++; 790 if (anno_type == RXRPC_TX_ANNO_ACK) 791 continue; 792 summary->nr_new_acks++; 793 call->rxtx_annotations[ix] = 794 RXRPC_TX_ANNO_ACK | annotation; 795 break; 796 case RXRPC_ACK_TYPE_NACK: 797 if (!summary->nr_nacks && 798 call->acks_lowest_nak != seq) { 799 call->acks_lowest_nak = seq; 800 summary->new_low_nack = true; 801 } 802 summary->nr_nacks++; 803 if (anno_type == RXRPC_TX_ANNO_NAK) 804 continue; 805 summary->nr_new_nacks++; 806 if (anno_type == RXRPC_TX_ANNO_RETRANS) 807 continue; 808 call->rxtx_annotations[ix] = 809 RXRPC_TX_ANNO_NAK | annotation; 810 break; 811 default: 812 return rxrpc_proto_abort("SFT", call, 0); 813 } 814 } 815} 816 817/* 818 * Return true if the ACK is valid - ie. it doesn't appear to have regressed 819 * with respect to the ack state conveyed by preceding ACKs. 820 */ 821static bool rxrpc_is_ack_valid(struct rxrpc_call *call, 822 rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt) 823{ 824 rxrpc_seq_t base = READ_ONCE(call->acks_first_seq); 825 826 if (after(first_pkt, base)) 827 return true; /* The window advanced */ 828 829 if (before(first_pkt, base)) 830 return false; /* firstPacket regressed */ 831 832 if (after_eq(prev_pkt, call->acks_prev_seq)) 833 return true; /* previousPacket hasn't regressed. */ 834 835 /* Some rx implementations put a serial number in previousPacket. */ 836 if (after_eq(prev_pkt, base + call->tx_winsize)) 837 return false; 838 return true; 839} 840 841/* 842 * Process an ACK packet. 843 * 844 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 845 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 846 * 847 * A hard-ACK means that a packet has been processed and may be discarded; a 848 * soft-ACK means that the packet may be discarded and retransmission 849 * requested. A phase is complete when all packets are hard-ACK'd. 850 */ 851static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb) 852{ 853 struct rxrpc_ack_summary summary = { 0 }; 854 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 855 union { 856 struct rxrpc_ackpacket ack; 857 struct rxrpc_ackinfo info; 858 u8 acks[RXRPC_MAXACKS]; 859 } buf; 860 rxrpc_serial_t ack_serial, acked_serial; 861 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; 862 int nr_acks, offset, ioffset; 863 864 _enter(""); 865 866 offset = sizeof(struct rxrpc_wire_header); 867 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { 868 _debug("extraction failure"); 869 return rxrpc_proto_abort("XAK", call, 0); 870 } 871 offset += sizeof(buf.ack); 872 873 ack_serial = sp->hdr.serial; 874 acked_serial = ntohl(buf.ack.serial); 875 first_soft_ack = ntohl(buf.ack.firstPacket); 876 prev_pkt = ntohl(buf.ack.previousPacket); 877 hard_ack = first_soft_ack - 1; 878 nr_acks = buf.ack.nAcks; 879 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? 880 buf.ack.reason : RXRPC_ACK__INVALID); 881 882 trace_rxrpc_rx_ack(call, ack_serial, acked_serial, 883 first_soft_ack, prev_pkt, 884 summary.ack_reason, nr_acks); 885 886 switch (buf.ack.reason) { 887 case RXRPC_ACK_PING_RESPONSE: 888 rxrpc_input_ping_response(call, skb->tstamp, acked_serial, 889 ack_serial); 890 rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial, 891 rxrpc_rtt_rx_ping_response); 892 break; 893 case RXRPC_ACK_REQUESTED: 894 rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial, 895 rxrpc_rtt_rx_requested_ack); 896 break; 897 default: 898 if (acked_serial != 0) 899 rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial, 900 rxrpc_rtt_rx_cancel); 901 break; 902 } 903 904 if (buf.ack.reason == RXRPC_ACK_PING) { 905 _proto("Rx ACK %%%u PING Request", ack_serial); 906 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 907 ack_serial, true, true, 908 rxrpc_propose_ack_respond_to_ping); 909 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { 910 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, 911 ack_serial, true, true, 912 rxrpc_propose_ack_respond_to_ack); 913 } 914 915 /* Discard any out-of-order or duplicate ACKs (outside lock). */ 916 if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) { 917 trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial, 918 first_soft_ack, call->acks_first_seq, 919 prev_pkt, call->acks_prev_seq); 920 return; 921 } 922 923 buf.info.rxMTU = 0; 924 ioffset = offset + nr_acks + 3; 925 if (skb->len >= ioffset + sizeof(buf.info) && 926 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) 927 return rxrpc_proto_abort("XAI", call, 0); 928 929 spin_lock(&call->input_lock); 930 931 /* Discard any out-of-order or duplicate ACKs (inside lock). */ 932 if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) { 933 trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial, 934 first_soft_ack, call->acks_first_seq, 935 prev_pkt, call->acks_prev_seq); 936 goto out; 937 } 938 call->acks_latest_ts = skb->tstamp; 939 940 call->acks_first_seq = first_soft_ack; 941 call->acks_prev_seq = prev_pkt; 942 943 /* Parse rwind and mtu sizes if provided. */ 944 if (buf.info.rxMTU) 945 rxrpc_input_ackinfo(call, skb, &buf.info); 946 947 if (first_soft_ack == 0) { 948 rxrpc_proto_abort("AK0", call, 0); 949 goto out; 950 } 951 952 /* Ignore ACKs unless we are or have just been transmitting. */ 953 switch (READ_ONCE(call->state)) { 954 case RXRPC_CALL_CLIENT_SEND_REQUEST: 955 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 956 case RXRPC_CALL_SERVER_SEND_REPLY: 957 case RXRPC_CALL_SERVER_AWAIT_ACK: 958 break; 959 default: 960 goto out; 961 } 962 963 if (before(hard_ack, call->tx_hard_ack) || 964 after(hard_ack, call->tx_top)) { 965 rxrpc_proto_abort("AKW", call, 0); 966 goto out; 967 } 968 if (nr_acks > call->tx_top - hard_ack) { 969 rxrpc_proto_abort("AKN", call, 0); 970 goto out; 971 } 972 973 if (after(hard_ack, call->tx_hard_ack)) { 974 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { 975 rxrpc_end_tx_phase(call, false, "ETA"); 976 goto out; 977 } 978 } 979 980 if (nr_acks > 0) { 981 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) { 982 rxrpc_proto_abort("XSA", call, 0); 983 goto out; 984 } 985 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, 986 &summary); 987 } 988 989 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 990 RXRPC_TX_ANNO_LAST && 991 summary.nr_acks == call->tx_top - hard_ack && 992 rxrpc_is_client_call(call)) 993 rxrpc_propose_ACK(call, RXRPC_ACK_PING, ack_serial, 994 false, true, 995 rxrpc_propose_ack_ping_for_lost_reply); 996 997 rxrpc_congestion_management(call, skb, &summary, acked_serial); 998out: 999 spin_unlock(&call->input_lock); 1000} 1001 1002/* 1003 * Process an ACKALL packet. 1004 */ 1005static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 1006{ 1007 struct rxrpc_ack_summary summary = { 0 }; 1008 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1009 1010 _proto("Rx ACKALL %%%u", sp->hdr.serial); 1011 1012 spin_lock(&call->input_lock); 1013 1014 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) 1015 rxrpc_end_tx_phase(call, false, "ETL"); 1016 1017 spin_unlock(&call->input_lock); 1018} 1019 1020/* 1021 * Process an ABORT packet directed at a call. 1022 */ 1023static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 1024{ 1025 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1026 __be32 wtmp; 1027 u32 abort_code = RX_CALL_DEAD; 1028 1029 _enter(""); 1030 1031 if (skb->len >= 4 && 1032 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 1033 &wtmp, sizeof(wtmp)) >= 0) 1034 abort_code = ntohl(wtmp); 1035 1036 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code); 1037 1038 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); 1039 1040 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1041 abort_code, -ECONNABORTED); 1042} 1043 1044/* 1045 * Process an incoming call packet. 1046 */ 1047static void rxrpc_input_call_packet(struct rxrpc_call *call, 1048 struct sk_buff *skb) 1049{ 1050 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1051 unsigned long timo; 1052 1053 _enter("%p,%p", call, skb); 1054 1055 timo = READ_ONCE(call->next_rx_timo); 1056 if (timo) { 1057 unsigned long now = jiffies, expect_rx_by; 1058 1059 expect_rx_by = now + timo; 1060 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 1061 rxrpc_reduce_call_timer(call, expect_rx_by, now, 1062 rxrpc_timer_set_for_normal); 1063 } 1064 1065 switch (sp->hdr.type) { 1066 case RXRPC_PACKET_TYPE_DATA: 1067 rxrpc_input_data(call, skb); 1068 goto no_free; 1069 1070 case RXRPC_PACKET_TYPE_ACK: 1071 rxrpc_input_ack(call, skb); 1072 break; 1073 1074 case RXRPC_PACKET_TYPE_BUSY: 1075 _proto("Rx BUSY %%%u", sp->hdr.serial); 1076 1077 /* Just ignore BUSY packets from the server; the retry and 1078 * lifespan timers will take care of business. BUSY packets 1079 * from the client don't make sense. 1080 */ 1081 break; 1082 1083 case RXRPC_PACKET_TYPE_ABORT: 1084 rxrpc_input_abort(call, skb); 1085 break; 1086 1087 case RXRPC_PACKET_TYPE_ACKALL: 1088 rxrpc_input_ackall(call, skb); 1089 break; 1090 1091 default: 1092 break; 1093 } 1094 1095 rxrpc_free_skb(skb, rxrpc_skb_freed); 1096no_free: 1097 _leave(""); 1098} 1099 1100/* 1101 * Handle a new service call on a channel implicitly completing the preceding 1102 * call on that channel. This does not apply to client conns. 1103 * 1104 * TODO: If callNumber > call_id + 1, renegotiate security. 1105 */ 1106static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, 1107 struct rxrpc_connection *conn, 1108 struct rxrpc_call *call) 1109{ 1110 switch (READ_ONCE(call->state)) { 1111 case RXRPC_CALL_SERVER_AWAIT_ACK: 1112 rxrpc_call_completed(call); 1113 fallthrough; 1114 case RXRPC_CALL_COMPLETE: 1115 break; 1116 default: 1117 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) { 1118 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 1119 rxrpc_queue_call(call); 1120 } 1121 trace_rxrpc_improper_term(call); 1122 break; 1123 } 1124 1125 spin_lock(&rx->incoming_lock); 1126 __rxrpc_disconnect_call(conn, call); 1127 spin_unlock(&rx->incoming_lock); 1128} 1129 1130/* 1131 * post connection-level events to the connection 1132 * - this includes challenges, responses, some aborts and call terminal packet 1133 * retransmission. 1134 */ 1135static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 1136 struct sk_buff *skb) 1137{ 1138 _enter("%p,%p", conn, skb); 1139 1140 skb_queue_tail(&conn->rx_queue, skb); 1141 rxrpc_queue_conn(conn); 1142} 1143 1144/* 1145 * post endpoint-level events to the local endpoint 1146 * - this includes debug and version messages 1147 */ 1148static void rxrpc_post_packet_to_local(struct rxrpc_local *local, 1149 struct sk_buff *skb) 1150{ 1151 _enter("%p,%p", local, skb); 1152 1153 if (rxrpc_get_local_maybe(local)) { 1154 skb_queue_tail(&local->event_queue, skb); 1155 rxrpc_queue_local(local); 1156 } else { 1157 rxrpc_free_skb(skb, rxrpc_skb_freed); 1158 } 1159} 1160 1161/* 1162 * put a packet up for transport-level abort 1163 */ 1164static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 1165{ 1166 if (rxrpc_get_local_maybe(local)) { 1167 skb_queue_tail(&local->reject_queue, skb); 1168 rxrpc_queue_local(local); 1169 } else { 1170 rxrpc_free_skb(skb, rxrpc_skb_freed); 1171 } 1172} 1173 1174/* 1175 * Extract the wire header from a packet and translate the byte order. 1176 */ 1177static noinline 1178int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) 1179{ 1180 struct rxrpc_wire_header whdr; 1181 1182 /* dig out the RxRPC connection details */ 1183 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) { 1184 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 1185 tracepoint_string("bad_hdr")); 1186 return -EBADMSG; 1187 } 1188 1189 memset(sp, 0, sizeof(*sp)); 1190 sp->hdr.epoch = ntohl(whdr.epoch); 1191 sp->hdr.cid = ntohl(whdr.cid); 1192 sp->hdr.callNumber = ntohl(whdr.callNumber); 1193 sp->hdr.seq = ntohl(whdr.seq); 1194 sp->hdr.serial = ntohl(whdr.serial); 1195 sp->hdr.flags = whdr.flags; 1196 sp->hdr.type = whdr.type; 1197 sp->hdr.userStatus = whdr.userStatus; 1198 sp->hdr.securityIndex = whdr.securityIndex; 1199 sp->hdr._rsvd = ntohs(whdr._rsvd); 1200 sp->hdr.serviceId = ntohs(whdr.serviceId); 1201 return 0; 1202} 1203 1204/* 1205 * handle data received on the local endpoint 1206 * - may be called in interrupt context 1207 * 1208 * [!] Note that as this is called from the encap_rcv hook, the socket is not 1209 * held locked by the caller and nothing prevents sk_user_data on the UDP from 1210 * being cleared in the middle of processing this function. 1211 * 1212 * Called with the RCU read lock held from the IP layer via UDP. 1213 */ 1214int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb) 1215{ 1216 struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk); 1217 struct rxrpc_connection *conn; 1218 struct rxrpc_channel *chan; 1219 struct rxrpc_call *call = NULL; 1220 struct rxrpc_skb_priv *sp; 1221 struct rxrpc_peer *peer = NULL; 1222 struct rxrpc_sock *rx = NULL; 1223 unsigned int channel; 1224 1225 _enter("%p", udp_sk); 1226 1227 if (unlikely(!local)) { 1228 kfree_skb(skb); 1229 return 0; 1230 } 1231 if (skb->tstamp == 0) 1232 skb->tstamp = ktime_get_real(); 1233 1234 rxrpc_new_skb(skb, rxrpc_skb_received); 1235 1236 skb_pull(skb, sizeof(struct udphdr)); 1237 1238 /* The UDP protocol already released all skb resources; 1239 * we are free to add our own data there. 1240 */ 1241 sp = rxrpc_skb(skb); 1242 1243 /* dig out the RxRPC connection details */ 1244 if (rxrpc_extract_header(sp, skb) < 0) 1245 goto bad_message; 1246 1247 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { 1248 static int lose; 1249 if ((lose++ & 7) == 7) { 1250 trace_rxrpc_rx_lose(sp); 1251 rxrpc_free_skb(skb, rxrpc_skb_lost); 1252 return 0; 1253 } 1254 } 1255 1256 if (skb->tstamp == 0) 1257 skb->tstamp = ktime_get_real(); 1258 trace_rxrpc_rx_packet(sp); 1259 1260 switch (sp->hdr.type) { 1261 case RXRPC_PACKET_TYPE_VERSION: 1262 if (rxrpc_to_client(sp)) 1263 goto discard; 1264 rxrpc_post_packet_to_local(local, skb); 1265 goto out; 1266 1267 case RXRPC_PACKET_TYPE_BUSY: 1268 if (rxrpc_to_server(sp)) 1269 goto discard; 1270 fallthrough; 1271 case RXRPC_PACKET_TYPE_ACK: 1272 case RXRPC_PACKET_TYPE_ACKALL: 1273 if (sp->hdr.callNumber == 0) 1274 goto bad_message; 1275 fallthrough; 1276 case RXRPC_PACKET_TYPE_ABORT: 1277 break; 1278 1279 case RXRPC_PACKET_TYPE_DATA: 1280 if (sp->hdr.callNumber == 0 || 1281 sp->hdr.seq == 0) 1282 goto bad_message; 1283 if (!rxrpc_validate_data(skb)) 1284 goto bad_message; 1285 1286 /* Unshare the packet so that it can be modified for in-place 1287 * decryption. 1288 */ 1289 if (sp->hdr.securityIndex != 0) { 1290 struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC); 1291 if (!nskb) { 1292 rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem); 1293 goto out; 1294 } 1295 1296 if (nskb != skb) { 1297 rxrpc_eaten_skb(skb, rxrpc_skb_received); 1298 skb = nskb; 1299 rxrpc_new_skb(skb, rxrpc_skb_unshared); 1300 sp = rxrpc_skb(skb); 1301 } 1302 } 1303 break; 1304 1305 case RXRPC_PACKET_TYPE_CHALLENGE: 1306 if (rxrpc_to_server(sp)) 1307 goto discard; 1308 break; 1309 case RXRPC_PACKET_TYPE_RESPONSE: 1310 if (rxrpc_to_client(sp)) 1311 goto discard; 1312 break; 1313 1314 /* Packet types 9-11 should just be ignored. */ 1315 case RXRPC_PACKET_TYPE_PARAMS: 1316 case RXRPC_PACKET_TYPE_10: 1317 case RXRPC_PACKET_TYPE_11: 1318 goto discard; 1319 1320 default: 1321 _proto("Rx Bad Packet Type %u", sp->hdr.type); 1322 goto bad_message; 1323 } 1324 1325 if (sp->hdr.serviceId == 0) 1326 goto bad_message; 1327 1328 if (rxrpc_to_server(sp)) { 1329 /* Weed out packets to services we're not offering. Packets 1330 * that would begin a call are explicitly rejected and the rest 1331 * are just discarded. 1332 */ 1333 rx = rcu_dereference(local->service); 1334 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service && 1335 sp->hdr.serviceId != rx->second_service)) { 1336 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && 1337 sp->hdr.seq == 1) 1338 goto unsupported_service; 1339 goto discard; 1340 } 1341 } 1342 1343 conn = rxrpc_find_connection_rcu(local, skb, &peer); 1344 if (conn) { 1345 if (sp->hdr.securityIndex != conn->security_ix) 1346 goto wrong_security; 1347 1348 if (sp->hdr.serviceId != conn->service_id) { 1349 int old_id; 1350 1351 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) 1352 goto reupgrade; 1353 old_id = cmpxchg(&conn->service_id, conn->params.service_id, 1354 sp->hdr.serviceId); 1355 1356 if (old_id != conn->params.service_id && 1357 old_id != sp->hdr.serviceId) 1358 goto reupgrade; 1359 } 1360 1361 if (sp->hdr.callNumber == 0) { 1362 /* Connection-level packet */ 1363 _debug("CONN %p {%d}", conn, conn->debug_id); 1364 rxrpc_post_packet_to_conn(conn, skb); 1365 goto out; 1366 } 1367 1368 if ((int)sp->hdr.serial - (int)conn->hi_serial > 0) 1369 conn->hi_serial = sp->hdr.serial; 1370 1371 /* Call-bound packets are routed by connection channel. */ 1372 channel = sp->hdr.cid & RXRPC_CHANNELMASK; 1373 chan = &conn->channels[channel]; 1374 1375 /* Ignore really old calls */ 1376 if (sp->hdr.callNumber < chan->last_call) 1377 goto discard; 1378 1379 if (sp->hdr.callNumber == chan->last_call) { 1380 if (chan->call || 1381 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) 1382 goto discard; 1383 1384 /* For the previous service call, if completed 1385 * successfully, we discard all further packets. 1386 */ 1387 if (rxrpc_conn_is_service(conn) && 1388 chan->last_type == RXRPC_PACKET_TYPE_ACK) 1389 goto discard; 1390 1391 /* But otherwise we need to retransmit the final packet 1392 * from data cached in the connection record. 1393 */ 1394 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) 1395 trace_rxrpc_rx_data(chan->call_debug_id, 1396 sp->hdr.seq, 1397 sp->hdr.serial, 1398 sp->hdr.flags, 0); 1399 rxrpc_post_packet_to_conn(conn, skb); 1400 goto out; 1401 } 1402 1403 call = rcu_dereference(chan->call); 1404 1405 if (sp->hdr.callNumber > chan->call_id) { 1406 if (rxrpc_to_client(sp)) 1407 goto reject_packet; 1408 if (call) 1409 rxrpc_input_implicit_end_call(rx, conn, call); 1410 call = NULL; 1411 } 1412 1413 if (call) { 1414 if (sp->hdr.serviceId != call->service_id) 1415 call->service_id = sp->hdr.serviceId; 1416 if ((int)sp->hdr.serial - (int)call->rx_serial > 0) 1417 call->rx_serial = sp->hdr.serial; 1418 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) 1419 set_bit(RXRPC_CALL_RX_HEARD, &call->flags); 1420 } 1421 } 1422 1423 if (!call || refcount_read(&call->ref) == 0) { 1424 if (rxrpc_to_client(sp) || 1425 sp->hdr.type != RXRPC_PACKET_TYPE_DATA) 1426 goto bad_message; 1427 if (sp->hdr.seq != 1) 1428 goto discard; 1429 call = rxrpc_new_incoming_call(local, rx, skb); 1430 if (!call) 1431 goto reject_packet; 1432 } 1433 1434 /* Process a call packet; this either discards or passes on the ref 1435 * elsewhere. 1436 */ 1437 rxrpc_input_call_packet(call, skb); 1438 goto out; 1439 1440discard: 1441 rxrpc_free_skb(skb, rxrpc_skb_freed); 1442out: 1443 trace_rxrpc_rx_done(0, 0); 1444 return 0; 1445 1446wrong_security: 1447 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1448 RXKADINCONSISTENCY, EBADMSG); 1449 skb->priority = RXKADINCONSISTENCY; 1450 goto post_abort; 1451 1452unsupported_service: 1453 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1454 RX_INVALID_OPERATION, EOPNOTSUPP); 1455 skb->priority = RX_INVALID_OPERATION; 1456 goto post_abort; 1457 1458reupgrade: 1459 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1460 RX_PROTOCOL_ERROR, EBADMSG); 1461 goto protocol_error; 1462 1463bad_message: 1464 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1465 RX_PROTOCOL_ERROR, EBADMSG); 1466protocol_error: 1467 skb->priority = RX_PROTOCOL_ERROR; 1468post_abort: 1469 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT; 1470reject_packet: 1471 trace_rxrpc_rx_done(skb->mark, skb->priority); 1472 rxrpc_reject_packet(local, skb); 1473 _leave(" [badmsg]"); 1474 return 0; 1475} 1476