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 * Ping the other end to fill our RTT cache and to retrieve the rwind 197 * and MTU parameters. 198 */ 199 static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb, 200 int skew) 201 { 202 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 203 ktime_t now = skb->tstamp; 204 205 if (call->peer->rtt_usage < 3 || 206 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now)) 207 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, 208 true, true, 209 rxrpc_propose_ack_ping_for_params); 210 } 211 212 /* 213 * Apply a hard ACK by advancing the Tx window. 214 */ 215 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to, 216 struct rxrpc_ack_summary *summary) 217 { 218 struct sk_buff *skb, *list = NULL; 219 bool rot_last = false; 220 int ix; 221 u8 annotation; 222 223 if (call->acks_lowest_nak == call->tx_hard_ack) { 224 call->acks_lowest_nak = to; 225 } else if (before_eq(call->acks_lowest_nak, to)) { 226 summary->new_low_nack = true; 227 call->acks_lowest_nak = to; 228 } 229 230 spin_lock(&call->lock); 231 232 while (before(call->tx_hard_ack, to)) { 233 call->tx_hard_ack++; 234 ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK; 235 skb = call->rxtx_buffer[ix]; 236 annotation = call->rxtx_annotations[ix]; 237 rxrpc_see_skb(skb, rxrpc_skb_tx_rotated); 238 call->rxtx_buffer[ix] = NULL; 239 call->rxtx_annotations[ix] = 0; 240 skb->next = list; 241 list = skb; 242 243 if (annotation & RXRPC_TX_ANNO_LAST) { 244 set_bit(RXRPC_CALL_TX_LAST, &call->flags); 245 rot_last = true; 246 } 247 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK) 248 summary->nr_rot_new_acks++; 249 } 250 251 spin_unlock(&call->lock); 252 253 trace_rxrpc_transmit(call, (rot_last ? 254 rxrpc_transmit_rotate_last : 255 rxrpc_transmit_rotate)); 256 wake_up(&call->waitq); 257 258 while (list) { 259 skb = list; 260 list = skb->next; 261 skb_mark_not_on_list(skb); 262 rxrpc_free_skb(skb, rxrpc_skb_tx_freed); 263 } 264 265 return rot_last; 266 } 267 268 /* 269 * End the transmission phase of a call. 270 * 271 * This occurs when we get an ACKALL packet, the first DATA packet of a reply, 272 * or a final ACK packet. 273 */ 274 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun, 275 const char *abort_why) 276 { 277 unsigned int state; 278 279 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags)); 280 281 write_lock(&call->state_lock); 282 283 state = call->state; 284 switch (state) { 285 case RXRPC_CALL_CLIENT_SEND_REQUEST: 286 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 287 if (reply_begun) 288 call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY; 289 else 290 call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY; 291 break; 292 293 case RXRPC_CALL_SERVER_AWAIT_ACK: 294 __rxrpc_call_completed(call); 295 rxrpc_notify_socket(call); 296 state = call->state; 297 break; 298 299 default: 300 goto bad_state; 301 } 302 303 write_unlock(&call->state_lock); 304 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY) 305 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); 306 else 307 trace_rxrpc_transmit(call, rxrpc_transmit_end); 308 _leave(" = ok"); 309 return true; 310 311 bad_state: 312 write_unlock(&call->state_lock); 313 kdebug("end_tx %s", rxrpc_call_states[call->state]); 314 rxrpc_proto_abort(abort_why, call, call->tx_top); 315 return false; 316 } 317 318 /* 319 * Begin the reply reception phase of a call. 320 */ 321 static bool rxrpc_receiving_reply(struct rxrpc_call *call) 322 { 323 struct rxrpc_ack_summary summary = { 0 }; 324 unsigned long now, timo; 325 rxrpc_seq_t top = READ_ONCE(call->tx_top); 326 327 if (call->ackr_reason) { 328 spin_lock_bh(&call->lock); 329 call->ackr_reason = 0; 330 spin_unlock_bh(&call->lock); 331 now = jiffies; 332 timo = now + MAX_JIFFY_OFFSET; 333 WRITE_ONCE(call->resend_at, timo); 334 WRITE_ONCE(call->ack_at, timo); 335 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now); 336 } 337 338 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { 339 if (!rxrpc_rotate_tx_window(call, top, &summary)) { 340 rxrpc_proto_abort("TXL", call, top); 341 return false; 342 } 343 } 344 if (!rxrpc_end_tx_phase(call, true, "ETD")) 345 return false; 346 call->tx_phase = false; 347 return true; 348 } 349 350 /* 351 * Scan a jumbo packet to validate its structure and to work out how many 352 * subpackets it contains. 353 * 354 * A jumbo packet is a collection of consecutive packets glued together with 355 * little headers between that indicate how to change the initial header for 356 * each subpacket. 357 * 358 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but 359 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any 360 * size. 361 */ 362 static bool rxrpc_validate_jumbo(struct sk_buff *skb) 363 { 364 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 365 unsigned int offset = sizeof(struct rxrpc_wire_header); 366 unsigned int len = skb->len; 367 int nr_jumbo = 1; 368 u8 flags = sp->hdr.flags; 369 370 do { 371 nr_jumbo++; 372 if (len - offset < RXRPC_JUMBO_SUBPKTLEN) 373 goto protocol_error; 374 if (flags & RXRPC_LAST_PACKET) 375 goto protocol_error; 376 offset += RXRPC_JUMBO_DATALEN; 377 if (skb_copy_bits(skb, offset, &flags, 1) < 0) 378 goto protocol_error; 379 offset += sizeof(struct rxrpc_jumbo_header); 380 } while (flags & RXRPC_JUMBO_PACKET); 381 382 sp->nr_jumbo = nr_jumbo; 383 return true; 384 385 protocol_error: 386 return false; 387 } 388 389 /* 390 * Handle reception of a duplicate packet. 391 * 392 * We have to take care to avoid an attack here whereby we're given a series of 393 * jumbograms, each with a sequence number one before the preceding one and 394 * filled up to maximum UDP size. If they never send us the first packet in 395 * the sequence, they can cause us to have to hold on to around 2MiB of kernel 396 * space until the call times out. 397 * 398 * We limit the space usage by only accepting three duplicate jumbo packets per 399 * call. After that, we tell the other side we're no longer accepting jumbos 400 * (that information is encoded in the ACK packet). 401 */ 402 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, 403 u8 annotation, bool *_jumbo_bad) 404 { 405 /* Discard normal packets that are duplicates. */ 406 if (annotation == 0) 407 return; 408 409 /* Skip jumbo subpackets that are duplicates. When we've had three or 410 * more partially duplicate jumbo packets, we refuse to take any more 411 * jumbos for this call. 412 */ 413 if (!*_jumbo_bad) { 414 call->nr_jumbo_bad++; 415 *_jumbo_bad = true; 416 } 417 } 418 419 /* 420 * Process a DATA packet, adding the packet to the Rx ring. 421 */ 422 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb, 423 u16 skew) 424 { 425 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 426 enum rxrpc_call_state state; 427 unsigned int offset = sizeof(struct rxrpc_wire_header); 428 unsigned int ix; 429 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0; 430 rxrpc_seq_t seq = sp->hdr.seq, hard_ack; 431 bool immediate_ack = false, jumbo_bad = false, queued; 432 u16 len; 433 u8 ack = 0, flags, annotation = 0; 434 435 _enter("{%u,%u},{%u,%u}", 436 call->rx_hard_ack, call->rx_top, skb->len, seq); 437 438 _proto("Rx DATA %%%u { #%u f=%02x }", 439 sp->hdr.serial, seq, sp->hdr.flags); 440 441 state = READ_ONCE(call->state); 442 if (state >= RXRPC_CALL_COMPLETE) 443 return; 444 445 if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) { 446 unsigned long timo = READ_ONCE(call->next_req_timo); 447 unsigned long now, expect_req_by; 448 449 if (timo) { 450 now = jiffies; 451 expect_req_by = now + timo; 452 WRITE_ONCE(call->expect_req_by, expect_req_by); 453 rxrpc_reduce_call_timer(call, expect_req_by, now, 454 rxrpc_timer_set_for_idle); 455 } 456 } 457 458 spin_lock(&call->input_lock); 459 460 /* Received data implicitly ACKs all of the request packets we sent 461 * when we're acting as a client. 462 */ 463 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST || 464 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) && 465 !rxrpc_receiving_reply(call)) 466 goto unlock; 467 468 call->ackr_prev_seq = seq; 469 470 hard_ack = READ_ONCE(call->rx_hard_ack); 471 if (after(seq, hard_ack + call->rx_winsize)) { 472 ack = RXRPC_ACK_EXCEEDS_WINDOW; 473 ack_serial = serial; 474 goto ack; 475 } 476 477 flags = sp->hdr.flags; 478 if (flags & RXRPC_JUMBO_PACKET) { 479 if (call->nr_jumbo_bad > 3) { 480 ack = RXRPC_ACK_NOSPACE; 481 ack_serial = serial; 482 goto ack; 483 } 484 annotation = 1; 485 } 486 487 next_subpacket: 488 queued = false; 489 ix = seq & RXRPC_RXTX_BUFF_MASK; 490 len = skb->len; 491 if (flags & RXRPC_JUMBO_PACKET) 492 len = RXRPC_JUMBO_DATALEN; 493 494 if (flags & RXRPC_LAST_PACKET) { 495 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 496 seq != call->rx_top) { 497 rxrpc_proto_abort("LSN", call, seq); 498 goto unlock; 499 } 500 } else { 501 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 502 after_eq(seq, call->rx_top)) { 503 rxrpc_proto_abort("LSA", call, seq); 504 goto unlock; 505 } 506 } 507 508 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation); 509 if (before_eq(seq, hard_ack)) { 510 ack = RXRPC_ACK_DUPLICATE; 511 ack_serial = serial; 512 goto skip; 513 } 514 515 if (flags & RXRPC_REQUEST_ACK && !ack) { 516 ack = RXRPC_ACK_REQUESTED; 517 ack_serial = serial; 518 } 519 520 if (call->rxtx_buffer[ix]) { 521 rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad); 522 if (ack != RXRPC_ACK_DUPLICATE) { 523 ack = RXRPC_ACK_DUPLICATE; 524 ack_serial = serial; 525 } 526 immediate_ack = true; 527 goto skip; 528 } 529 530 /* Queue the packet. We use a couple of memory barriers here as need 531 * to make sure that rx_top is perceived to be set after the buffer 532 * pointer and that the buffer pointer is set after the annotation and 533 * the skb data. 534 * 535 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() 536 * and also rxrpc_fill_out_ack(). 537 */ 538 rxrpc_get_skb(skb, rxrpc_skb_rx_got); 539 call->rxtx_annotations[ix] = annotation; 540 smp_wmb(); 541 call->rxtx_buffer[ix] = skb; 542 if (after(seq, call->rx_top)) { 543 smp_store_release(&call->rx_top, seq); 544 } else if (before(seq, call->rx_top)) { 545 /* Send an immediate ACK if we fill in a hole */ 546 if (!ack) { 547 ack = RXRPC_ACK_DELAY; 548 ack_serial = serial; 549 } 550 immediate_ack = true; 551 } 552 if (flags & RXRPC_LAST_PACKET) { 553 set_bit(RXRPC_CALL_RX_LAST, &call->flags); 554 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); 555 } else { 556 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); 557 } 558 queued = true; 559 560 if (after_eq(seq, call->rx_expect_next)) { 561 if (after(seq, call->rx_expect_next)) { 562 _net("OOS %u > %u", seq, call->rx_expect_next); 563 ack = RXRPC_ACK_OUT_OF_SEQUENCE; 564 ack_serial = serial; 565 } 566 call->rx_expect_next = seq + 1; 567 } 568 569 skip: 570 offset += len; 571 if (flags & RXRPC_JUMBO_PACKET) { 572 if (skb_copy_bits(skb, offset, &flags, 1) < 0) { 573 rxrpc_proto_abort("XJF", call, seq); 574 goto unlock; 575 } 576 offset += sizeof(struct rxrpc_jumbo_header); 577 seq++; 578 serial++; 579 annotation++; 580 if (flags & RXRPC_JUMBO_PACKET) 581 annotation |= RXRPC_RX_ANNO_JLAST; 582 if (after(seq, hard_ack + call->rx_winsize)) { 583 ack = RXRPC_ACK_EXCEEDS_WINDOW; 584 ack_serial = serial; 585 if (!jumbo_bad) { 586 call->nr_jumbo_bad++; 587 jumbo_bad = true; 588 } 589 goto ack; 590 } 591 592 _proto("Rx DATA Jumbo %%%u", serial); 593 goto next_subpacket; 594 } 595 596 if (queued && flags & RXRPC_LAST_PACKET && !ack) { 597 ack = RXRPC_ACK_DELAY; 598 ack_serial = serial; 599 } 600 601 ack: 602 if (ack) 603 rxrpc_propose_ACK(call, ack, skew, ack_serial, 604 immediate_ack, true, 605 rxrpc_propose_ack_input_data); 606 else 607 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, skew, serial, 608 false, true, 609 rxrpc_propose_ack_input_data); 610 611 if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1) { 612 trace_rxrpc_notify_socket(call->debug_id, serial); 613 rxrpc_notify_socket(call); 614 } 615 616 unlock: 617 spin_unlock(&call->input_lock); 618 _leave(" [queued]"); 619 } 620 621 /* 622 * Process a requested ACK. 623 */ 624 static void rxrpc_input_requested_ack(struct rxrpc_call *call, 625 ktime_t resp_time, 626 rxrpc_serial_t orig_serial, 627 rxrpc_serial_t ack_serial) 628 { 629 struct rxrpc_skb_priv *sp; 630 struct sk_buff *skb; 631 ktime_t sent_at; 632 int ix; 633 634 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) { 635 skb = call->rxtx_buffer[ix]; 636 if (!skb) 637 continue; 638 639 sent_at = skb->tstamp; 640 smp_rmb(); /* Read timestamp before serial. */ 641 sp = rxrpc_skb(skb); 642 if (sp->hdr.serial != orig_serial) 643 continue; 644 goto found; 645 } 646 647 return; 648 649 found: 650 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack, 651 orig_serial, ack_serial, sent_at, resp_time); 652 } 653 654 /* 655 * Process the response to a ping that we sent to find out if we lost an ACK. 656 * 657 * If we got back a ping response that indicates a lower tx_top than what we 658 * had at the time of the ping transmission, we adjudge all the DATA packets 659 * sent between the response tx_top and the ping-time tx_top to have been lost. 660 */ 661 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call) 662 { 663 rxrpc_seq_t top, bottom, seq; 664 bool resend = false; 665 666 spin_lock_bh(&call->lock); 667 668 bottom = call->tx_hard_ack + 1; 669 top = call->acks_lost_top; 670 if (before(bottom, top)) { 671 for (seq = bottom; before_eq(seq, top); seq++) { 672 int ix = seq & RXRPC_RXTX_BUFF_MASK; 673 u8 annotation = call->rxtx_annotations[ix]; 674 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK; 675 676 if (anno_type != RXRPC_TX_ANNO_UNACK) 677 continue; 678 annotation &= ~RXRPC_TX_ANNO_MASK; 679 annotation |= RXRPC_TX_ANNO_RETRANS; 680 call->rxtx_annotations[ix] = annotation; 681 resend = true; 682 } 683 } 684 685 spin_unlock_bh(&call->lock); 686 687 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 688 rxrpc_queue_call(call); 689 } 690 691 /* 692 * Process a ping response. 693 */ 694 static void rxrpc_input_ping_response(struct rxrpc_call *call, 695 ktime_t resp_time, 696 rxrpc_serial_t orig_serial, 697 rxrpc_serial_t ack_serial) 698 { 699 rxrpc_serial_t ping_serial; 700 ktime_t ping_time; 701 702 ping_time = call->ping_time; 703 smp_rmb(); 704 ping_serial = READ_ONCE(call->ping_serial); 705 706 if (orig_serial == call->acks_lost_ping) 707 rxrpc_input_check_for_lost_ack(call); 708 709 if (before(orig_serial, ping_serial) || 710 !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags)) 711 return; 712 if (after(orig_serial, ping_serial)) 713 return; 714 715 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response, 716 orig_serial, ack_serial, ping_time, resp_time); 717 } 718 719 /* 720 * Process the extra information that may be appended to an ACK packet 721 */ 722 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 723 struct rxrpc_ackinfo *ackinfo) 724 { 725 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 726 struct rxrpc_peer *peer; 727 unsigned int mtu; 728 bool wake = false; 729 u32 rwind = ntohl(ackinfo->rwind); 730 731 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 732 sp->hdr.serial, 733 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU), 734 rwind, ntohl(ackinfo->jumbo_max)); 735 736 if (call->tx_winsize != rwind) { 737 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) 738 rwind = RXRPC_RXTX_BUFF_SIZE - 1; 739 if (rwind > call->tx_winsize) 740 wake = true; 741 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, 742 ntohl(ackinfo->rwind), wake); 743 call->tx_winsize = rwind; 744 } 745 746 if (call->cong_ssthresh > rwind) 747 call->cong_ssthresh = rwind; 748 749 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); 750 751 peer = call->peer; 752 if (mtu < peer->maxdata) { 753 spin_lock_bh(&peer->lock); 754 peer->maxdata = mtu; 755 peer->mtu = mtu + peer->hdrsize; 756 spin_unlock_bh(&peer->lock); 757 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 758 } 759 760 if (wake) 761 wake_up(&call->waitq); 762 } 763 764 /* 765 * Process individual soft ACKs. 766 * 767 * Each ACK in the array corresponds to one packet and can be either an ACK or 768 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 769 * packets that lie beyond the end of the ACK list are scheduled for resend by 770 * the timer on the basis that the peer might just not have processed them at 771 * the time the ACK was sent. 772 */ 773 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, 774 rxrpc_seq_t seq, int nr_acks, 775 struct rxrpc_ack_summary *summary) 776 { 777 int ix; 778 u8 annotation, anno_type; 779 780 for (; nr_acks > 0; nr_acks--, seq++) { 781 ix = seq & RXRPC_RXTX_BUFF_MASK; 782 annotation = call->rxtx_annotations[ix]; 783 anno_type = annotation & RXRPC_TX_ANNO_MASK; 784 annotation &= ~RXRPC_TX_ANNO_MASK; 785 switch (*acks++) { 786 case RXRPC_ACK_TYPE_ACK: 787 summary->nr_acks++; 788 if (anno_type == RXRPC_TX_ANNO_ACK) 789 continue; 790 summary->nr_new_acks++; 791 call->rxtx_annotations[ix] = 792 RXRPC_TX_ANNO_ACK | annotation; 793 break; 794 case RXRPC_ACK_TYPE_NACK: 795 if (!summary->nr_nacks && 796 call->acks_lowest_nak != seq) { 797 call->acks_lowest_nak = seq; 798 summary->new_low_nack = true; 799 } 800 summary->nr_nacks++; 801 if (anno_type == RXRPC_TX_ANNO_NAK) 802 continue; 803 summary->nr_new_nacks++; 804 if (anno_type == RXRPC_TX_ANNO_RETRANS) 805 continue; 806 call->rxtx_annotations[ix] = 807 RXRPC_TX_ANNO_NAK | annotation; 808 break; 809 default: 810 return rxrpc_proto_abort("SFT", call, 0); 811 } 812 } 813 } 814 815 /* 816 * Process an ACK packet. 817 * 818 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 819 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 820 * 821 * A hard-ACK means that a packet has been processed and may be discarded; a 822 * soft-ACK means that the packet may be discarded and retransmission 823 * requested. A phase is complete when all packets are hard-ACK'd. 824 */ 825 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, 826 u16 skew) 827 { 828 struct rxrpc_ack_summary summary = { 0 }; 829 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 830 union { 831 struct rxrpc_ackpacket ack; 832 struct rxrpc_ackinfo info; 833 u8 acks[RXRPC_MAXACKS]; 834 } buf; 835 rxrpc_serial_t acked_serial; 836 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; 837 int nr_acks, offset, ioffset; 838 839 _enter(""); 840 841 offset = sizeof(struct rxrpc_wire_header); 842 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { 843 _debug("extraction failure"); 844 return rxrpc_proto_abort("XAK", call, 0); 845 } 846 offset += sizeof(buf.ack); 847 848 acked_serial = ntohl(buf.ack.serial); 849 first_soft_ack = ntohl(buf.ack.firstPacket); 850 prev_pkt = ntohl(buf.ack.previousPacket); 851 hard_ack = first_soft_ack - 1; 852 nr_acks = buf.ack.nAcks; 853 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? 854 buf.ack.reason : RXRPC_ACK__INVALID); 855 856 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial, 857 first_soft_ack, prev_pkt, 858 summary.ack_reason, nr_acks); 859 860 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) 861 rxrpc_input_ping_response(call, skb->tstamp, acked_serial, 862 sp->hdr.serial); 863 if (buf.ack.reason == RXRPC_ACK_REQUESTED) 864 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial, 865 sp->hdr.serial); 866 867 if (buf.ack.reason == RXRPC_ACK_PING) { 868 _proto("Rx ACK %%%u PING Request", sp->hdr.serial); 869 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 870 skew, sp->hdr.serial, true, true, 871 rxrpc_propose_ack_respond_to_ping); 872 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { 873 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, 874 skew, sp->hdr.serial, true, true, 875 rxrpc_propose_ack_respond_to_ack); 876 } 877 878 /* Discard any out-of-order or duplicate ACKs (outside lock). */ 879 if (before(first_soft_ack, call->ackr_first_seq) || 880 before(prev_pkt, call->ackr_prev_seq)) 881 return; 882 883 buf.info.rxMTU = 0; 884 ioffset = offset + nr_acks + 3; 885 if (skb->len >= ioffset + sizeof(buf.info) && 886 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) 887 return rxrpc_proto_abort("XAI", call, 0); 888 889 spin_lock(&call->input_lock); 890 891 /* Discard any out-of-order or duplicate ACKs (inside lock). */ 892 if (before(first_soft_ack, call->ackr_first_seq) || 893 before(prev_pkt, call->ackr_prev_seq)) 894 goto out; 895 call->acks_latest_ts = skb->tstamp; 896 call->acks_latest = sp->hdr.serial; 897 898 call->ackr_first_seq = first_soft_ack; 899 call->ackr_prev_seq = prev_pkt; 900 901 /* Parse rwind and mtu sizes if provided. */ 902 if (buf.info.rxMTU) 903 rxrpc_input_ackinfo(call, skb, &buf.info); 904 905 if (first_soft_ack == 0) { 906 rxrpc_proto_abort("AK0", call, 0); 907 goto out; 908 } 909 910 /* Ignore ACKs unless we are or have just been transmitting. */ 911 switch (READ_ONCE(call->state)) { 912 case RXRPC_CALL_CLIENT_SEND_REQUEST: 913 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 914 case RXRPC_CALL_SERVER_SEND_REPLY: 915 case RXRPC_CALL_SERVER_AWAIT_ACK: 916 break; 917 default: 918 goto out; 919 } 920 921 if (before(hard_ack, call->tx_hard_ack) || 922 after(hard_ack, call->tx_top)) { 923 rxrpc_proto_abort("AKW", call, 0); 924 goto out; 925 } 926 if (nr_acks > call->tx_top - hard_ack) { 927 rxrpc_proto_abort("AKN", call, 0); 928 goto out; 929 } 930 931 if (after(hard_ack, call->tx_hard_ack)) { 932 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { 933 rxrpc_end_tx_phase(call, false, "ETA"); 934 goto out; 935 } 936 } 937 938 if (nr_acks > 0) { 939 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) { 940 rxrpc_proto_abort("XSA", call, 0); 941 goto out; 942 } 943 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, 944 &summary); 945 } 946 947 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 948 RXRPC_TX_ANNO_LAST && 949 summary.nr_acks == call->tx_top - hard_ack && 950 rxrpc_is_client_call(call)) 951 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, 952 false, true, 953 rxrpc_propose_ack_ping_for_lost_reply); 954 955 rxrpc_congestion_management(call, skb, &summary, acked_serial); 956 out: 957 spin_unlock(&call->input_lock); 958 } 959 960 /* 961 * Process an ACKALL packet. 962 */ 963 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 964 { 965 struct rxrpc_ack_summary summary = { 0 }; 966 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 967 968 _proto("Rx ACKALL %%%u", sp->hdr.serial); 969 970 spin_lock(&call->input_lock); 971 972 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) 973 rxrpc_end_tx_phase(call, false, "ETL"); 974 975 spin_unlock(&call->input_lock); 976 } 977 978 /* 979 * Process an ABORT packet directed at a call. 980 */ 981 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 982 { 983 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 984 __be32 wtmp; 985 u32 abort_code = RX_CALL_DEAD; 986 987 _enter(""); 988 989 if (skb->len >= 4 && 990 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 991 &wtmp, sizeof(wtmp)) >= 0) 992 abort_code = ntohl(wtmp); 993 994 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code); 995 996 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); 997 998 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 999 abort_code, -ECONNABORTED)) 1000 rxrpc_notify_socket(call); 1001 } 1002 1003 /* 1004 * Process an incoming call packet. 1005 */ 1006 static void rxrpc_input_call_packet(struct rxrpc_call *call, 1007 struct sk_buff *skb, u16 skew) 1008 { 1009 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1010 unsigned long timo; 1011 1012 _enter("%p,%p", call, skb); 1013 1014 timo = READ_ONCE(call->next_rx_timo); 1015 if (timo) { 1016 unsigned long now = jiffies, expect_rx_by; 1017 1018 expect_rx_by = now + timo; 1019 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 1020 rxrpc_reduce_call_timer(call, expect_rx_by, now, 1021 rxrpc_timer_set_for_normal); 1022 } 1023 1024 switch (sp->hdr.type) { 1025 case RXRPC_PACKET_TYPE_DATA: 1026 rxrpc_input_data(call, skb, skew); 1027 break; 1028 1029 case RXRPC_PACKET_TYPE_ACK: 1030 rxrpc_input_ack(call, skb, skew); 1031 break; 1032 1033 case RXRPC_PACKET_TYPE_BUSY: 1034 _proto("Rx BUSY %%%u", sp->hdr.serial); 1035 1036 /* Just ignore BUSY packets from the server; the retry and 1037 * lifespan timers will take care of business. BUSY packets 1038 * from the client don't make sense. 1039 */ 1040 break; 1041 1042 case RXRPC_PACKET_TYPE_ABORT: 1043 rxrpc_input_abort(call, skb); 1044 break; 1045 1046 case RXRPC_PACKET_TYPE_ACKALL: 1047 rxrpc_input_ackall(call, skb); 1048 break; 1049 1050 default: 1051 break; 1052 } 1053 1054 _leave(""); 1055 } 1056 1057 /* 1058 * Handle a new service call on a channel implicitly completing the preceding 1059 * call on that channel. This does not apply to client conns. 1060 * 1061 * TODO: If callNumber > call_id + 1, renegotiate security. 1062 */ 1063 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, 1064 struct rxrpc_connection *conn, 1065 struct rxrpc_call *call) 1066 { 1067 switch (READ_ONCE(call->state)) { 1068 case RXRPC_CALL_SERVER_AWAIT_ACK: 1069 rxrpc_call_completed(call); 1070 /* Fall through */ 1071 case RXRPC_CALL_COMPLETE: 1072 break; 1073 default: 1074 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) { 1075 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 1076 rxrpc_queue_call(call); 1077 } 1078 trace_rxrpc_improper_term(call); 1079 break; 1080 } 1081 1082 spin_lock(&rx->incoming_lock); 1083 __rxrpc_disconnect_call(conn, call); 1084 spin_unlock(&rx->incoming_lock); 1085 rxrpc_notify_socket(call); 1086 } 1087 1088 /* 1089 * post connection-level events to the connection 1090 * - this includes challenges, responses, some aborts and call terminal packet 1091 * retransmission. 1092 */ 1093 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 1094 struct sk_buff *skb) 1095 { 1096 _enter("%p,%p", conn, skb); 1097 1098 skb_queue_tail(&conn->rx_queue, skb); 1099 rxrpc_queue_conn(conn); 1100 } 1101 1102 /* 1103 * post endpoint-level events to the local endpoint 1104 * - this includes debug and version messages 1105 */ 1106 static void rxrpc_post_packet_to_local(struct rxrpc_local *local, 1107 struct sk_buff *skb) 1108 { 1109 _enter("%p,%p", local, skb); 1110 1111 skb_queue_tail(&local->event_queue, skb); 1112 rxrpc_queue_local(local); 1113 } 1114 1115 /* 1116 * put a packet up for transport-level abort 1117 */ 1118 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 1119 { 1120 CHECK_SLAB_OKAY(&local->usage); 1121 1122 skb_queue_tail(&local->reject_queue, skb); 1123 rxrpc_queue_local(local); 1124 } 1125 1126 /* 1127 * Extract the wire header from a packet and translate the byte order. 1128 */ 1129 static noinline 1130 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) 1131 { 1132 struct rxrpc_wire_header whdr; 1133 1134 /* dig out the RxRPC connection details */ 1135 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) { 1136 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 1137 tracepoint_string("bad_hdr")); 1138 return -EBADMSG; 1139 } 1140 1141 memset(sp, 0, sizeof(*sp)); 1142 sp->hdr.epoch = ntohl(whdr.epoch); 1143 sp->hdr.cid = ntohl(whdr.cid); 1144 sp->hdr.callNumber = ntohl(whdr.callNumber); 1145 sp->hdr.seq = ntohl(whdr.seq); 1146 sp->hdr.serial = ntohl(whdr.serial); 1147 sp->hdr.flags = whdr.flags; 1148 sp->hdr.type = whdr.type; 1149 sp->hdr.userStatus = whdr.userStatus; 1150 sp->hdr.securityIndex = whdr.securityIndex; 1151 sp->hdr._rsvd = ntohs(whdr._rsvd); 1152 sp->hdr.serviceId = ntohs(whdr.serviceId); 1153 return 0; 1154 } 1155 1156 /* 1157 * handle data received on the local endpoint 1158 * - may be called in interrupt context 1159 * 1160 * [!] Note that as this is called from the encap_rcv hook, the socket is not 1161 * held locked by the caller and nothing prevents sk_user_data on the UDP from 1162 * being cleared in the middle of processing this function. 1163 * 1164 * Called with the RCU read lock held from the IP layer via UDP. 1165 */ 1166 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb) 1167 { 1168 struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk); 1169 struct rxrpc_connection *conn; 1170 struct rxrpc_channel *chan; 1171 struct rxrpc_call *call = NULL; 1172 struct rxrpc_skb_priv *sp; 1173 struct rxrpc_peer *peer = NULL; 1174 struct rxrpc_sock *rx = NULL; 1175 unsigned int channel; 1176 int skew = 0; 1177 1178 _enter("%p", udp_sk); 1179 1180 if (unlikely(!local)) { 1181 kfree_skb(skb); 1182 return 0; 1183 } 1184 if (skb->tstamp == 0) 1185 skb->tstamp = ktime_get_real(); 1186 1187 rxrpc_new_skb(skb, rxrpc_skb_rx_received); 1188 1189 skb_pull(skb, sizeof(struct udphdr)); 1190 1191 /* The UDP protocol already released all skb resources; 1192 * we are free to add our own data there. 1193 */ 1194 sp = rxrpc_skb(skb); 1195 1196 /* dig out the RxRPC connection details */ 1197 if (rxrpc_extract_header(sp, skb) < 0) 1198 goto bad_message; 1199 1200 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { 1201 static int lose; 1202 if ((lose++ & 7) == 7) { 1203 trace_rxrpc_rx_lose(sp); 1204 rxrpc_free_skb(skb, rxrpc_skb_rx_lost); 1205 return 0; 1206 } 1207 } 1208 1209 if (skb->tstamp == 0) 1210 skb->tstamp = ktime_get_real(); 1211 trace_rxrpc_rx_packet(sp); 1212 1213 switch (sp->hdr.type) { 1214 case RXRPC_PACKET_TYPE_VERSION: 1215 if (rxrpc_to_client(sp)) 1216 goto discard; 1217 rxrpc_post_packet_to_local(local, skb); 1218 goto out; 1219 1220 case RXRPC_PACKET_TYPE_BUSY: 1221 if (rxrpc_to_server(sp)) 1222 goto discard; 1223 /* Fall through */ 1224 case RXRPC_PACKET_TYPE_ACK: 1225 case RXRPC_PACKET_TYPE_ACKALL: 1226 if (sp->hdr.callNumber == 0) 1227 goto bad_message; 1228 /* Fall through */ 1229 case RXRPC_PACKET_TYPE_ABORT: 1230 break; 1231 1232 case RXRPC_PACKET_TYPE_DATA: 1233 if (sp->hdr.callNumber == 0 || 1234 sp->hdr.seq == 0) 1235 goto bad_message; 1236 if (sp->hdr.flags & RXRPC_JUMBO_PACKET && 1237 !rxrpc_validate_jumbo(skb)) 1238 goto bad_message; 1239 break; 1240 1241 case RXRPC_PACKET_TYPE_CHALLENGE: 1242 if (rxrpc_to_server(sp)) 1243 goto discard; 1244 break; 1245 case RXRPC_PACKET_TYPE_RESPONSE: 1246 if (rxrpc_to_client(sp)) 1247 goto discard; 1248 break; 1249 1250 /* Packet types 9-11 should just be ignored. */ 1251 case RXRPC_PACKET_TYPE_PARAMS: 1252 case RXRPC_PACKET_TYPE_10: 1253 case RXRPC_PACKET_TYPE_11: 1254 goto discard; 1255 1256 default: 1257 _proto("Rx Bad Packet Type %u", sp->hdr.type); 1258 goto bad_message; 1259 } 1260 1261 if (sp->hdr.serviceId == 0) 1262 goto bad_message; 1263 1264 if (rxrpc_to_server(sp)) { 1265 /* Weed out packets to services we're not offering. Packets 1266 * that would begin a call are explicitly rejected and the rest 1267 * are just discarded. 1268 */ 1269 rx = rcu_dereference(local->service); 1270 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service && 1271 sp->hdr.serviceId != rx->second_service)) { 1272 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && 1273 sp->hdr.seq == 1) 1274 goto unsupported_service; 1275 goto discard; 1276 } 1277 } 1278 1279 conn = rxrpc_find_connection_rcu(local, skb, &peer); 1280 if (conn) { 1281 if (sp->hdr.securityIndex != conn->security_ix) 1282 goto wrong_security; 1283 1284 if (sp->hdr.serviceId != conn->service_id) { 1285 int old_id; 1286 1287 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) 1288 goto reupgrade; 1289 old_id = cmpxchg(&conn->service_id, conn->params.service_id, 1290 sp->hdr.serviceId); 1291 1292 if (old_id != conn->params.service_id && 1293 old_id != sp->hdr.serviceId) 1294 goto reupgrade; 1295 } 1296 1297 if (sp->hdr.callNumber == 0) { 1298 /* Connection-level packet */ 1299 _debug("CONN %p {%d}", conn, conn->debug_id); 1300 rxrpc_post_packet_to_conn(conn, skb); 1301 goto out; 1302 } 1303 1304 /* Note the serial number skew here */ 1305 skew = (int)sp->hdr.serial - (int)conn->hi_serial; 1306 if (skew >= 0) { 1307 if (skew > 0) 1308 conn->hi_serial = sp->hdr.serial; 1309 } else { 1310 skew = -skew; 1311 skew = min(skew, 65535); 1312 } 1313 1314 /* Call-bound packets are routed by connection channel. */ 1315 channel = sp->hdr.cid & RXRPC_CHANNELMASK; 1316 chan = &conn->channels[channel]; 1317 1318 /* Ignore really old calls */ 1319 if (sp->hdr.callNumber < chan->last_call) 1320 goto discard; 1321 1322 if (sp->hdr.callNumber == chan->last_call) { 1323 if (chan->call || 1324 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) 1325 goto discard; 1326 1327 /* For the previous service call, if completed 1328 * successfully, we discard all further packets. 1329 */ 1330 if (rxrpc_conn_is_service(conn) && 1331 chan->last_type == RXRPC_PACKET_TYPE_ACK) 1332 goto discard; 1333 1334 /* But otherwise we need to retransmit the final packet 1335 * from data cached in the connection record. 1336 */ 1337 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) 1338 trace_rxrpc_rx_data(chan->call_debug_id, 1339 sp->hdr.seq, 1340 sp->hdr.serial, 1341 sp->hdr.flags, 0); 1342 rxrpc_post_packet_to_conn(conn, skb); 1343 goto out; 1344 } 1345 1346 call = rcu_dereference(chan->call); 1347 1348 if (sp->hdr.callNumber > chan->call_id) { 1349 if (rxrpc_to_client(sp)) 1350 goto reject_packet; 1351 if (call) 1352 rxrpc_input_implicit_end_call(rx, conn, call); 1353 call = NULL; 1354 } 1355 1356 if (call) { 1357 if (sp->hdr.serviceId != call->service_id) 1358 call->service_id = sp->hdr.serviceId; 1359 if ((int)sp->hdr.serial - (int)call->rx_serial > 0) 1360 call->rx_serial = sp->hdr.serial; 1361 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) 1362 set_bit(RXRPC_CALL_RX_HEARD, &call->flags); 1363 } 1364 } 1365 1366 if (!call || atomic_read(&call->usage) == 0) { 1367 if (rxrpc_to_client(sp) || 1368 sp->hdr.type != RXRPC_PACKET_TYPE_DATA) 1369 goto bad_message; 1370 if (sp->hdr.seq != 1) 1371 goto discard; 1372 call = rxrpc_new_incoming_call(local, rx, skb); 1373 if (!call) 1374 goto reject_packet; 1375 rxrpc_send_ping(call, skb, skew); 1376 mutex_unlock(&call->user_mutex); 1377 } 1378 1379 rxrpc_input_call_packet(call, skb, skew); 1380 goto discard; 1381 1382 discard: 1383 rxrpc_free_skb(skb, rxrpc_skb_rx_freed); 1384 out: 1385 trace_rxrpc_rx_done(0, 0); 1386 return 0; 1387 1388 wrong_security: 1389 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1390 RXKADINCONSISTENCY, EBADMSG); 1391 skb->priority = RXKADINCONSISTENCY; 1392 goto post_abort; 1393 1394 unsupported_service: 1395 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1396 RX_INVALID_OPERATION, EOPNOTSUPP); 1397 skb->priority = RX_INVALID_OPERATION; 1398 goto post_abort; 1399 1400 reupgrade: 1401 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1402 RX_PROTOCOL_ERROR, EBADMSG); 1403 goto protocol_error; 1404 1405 bad_message: 1406 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1407 RX_PROTOCOL_ERROR, EBADMSG); 1408 protocol_error: 1409 skb->priority = RX_PROTOCOL_ERROR; 1410 post_abort: 1411 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT; 1412 reject_packet: 1413 trace_rxrpc_rx_done(skb->mark, skb->priority); 1414 rxrpc_reject_packet(local, skb); 1415 _leave(" [badmsg]"); 1416 return 0; 1417 } 1418