1 /* RxRPC packet reception 2 * 3 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/module.h> 15 #include <linux/net.h> 16 #include <linux/skbuff.h> 17 #include <linux/errqueue.h> 18 #include <linux/udp.h> 19 #include <linux/in.h> 20 #include <linux/in6.h> 21 #include <linux/icmp.h> 22 #include <linux/gfp.h> 23 #include <net/sock.h> 24 #include <net/af_rxrpc.h> 25 #include <net/ip.h> 26 #include <net/udp.h> 27 #include <net/net_namespace.h> 28 #include "ar-internal.h" 29 30 static void rxrpc_proto_abort(const char *why, 31 struct rxrpc_call *call, rxrpc_seq_t seq) 32 { 33 if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) { 34 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 35 rxrpc_queue_call(call); 36 } 37 } 38 39 /* 40 * Do TCP-style congestion management [RFC 5681]. 41 */ 42 static void rxrpc_congestion_management(struct rxrpc_call *call, 43 struct sk_buff *skb, 44 struct rxrpc_ack_summary *summary, 45 rxrpc_serial_t acked_serial) 46 { 47 enum rxrpc_congest_change change = rxrpc_cong_no_change; 48 unsigned int cumulative_acks = call->cong_cumul_acks; 49 unsigned int cwnd = call->cong_cwnd; 50 bool resend = false; 51 52 summary->flight_size = 53 (call->tx_top - call->tx_hard_ack) - summary->nr_acks; 54 55 if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) { 56 summary->retrans_timeo = true; 57 call->cong_ssthresh = max_t(unsigned int, 58 summary->flight_size / 2, 2); 59 cwnd = 1; 60 if (cwnd >= call->cong_ssthresh && 61 call->cong_mode == RXRPC_CALL_SLOW_START) { 62 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 63 call->cong_tstamp = skb->tstamp; 64 cumulative_acks = 0; 65 } 66 } 67 68 cumulative_acks += summary->nr_new_acks; 69 cumulative_acks += summary->nr_rot_new_acks; 70 if (cumulative_acks > 255) 71 cumulative_acks = 255; 72 73 summary->mode = call->cong_mode; 74 summary->cwnd = call->cong_cwnd; 75 summary->ssthresh = call->cong_ssthresh; 76 summary->cumulative_acks = cumulative_acks; 77 summary->dup_acks = call->cong_dup_acks; 78 79 switch (call->cong_mode) { 80 case RXRPC_CALL_SLOW_START: 81 if (summary->nr_nacks > 0) 82 goto packet_loss_detected; 83 if (summary->cumulative_acks > 0) 84 cwnd += 1; 85 if (cwnd >= call->cong_ssthresh) { 86 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 87 call->cong_tstamp = skb->tstamp; 88 } 89 goto out; 90 91 case RXRPC_CALL_CONGEST_AVOIDANCE: 92 if (summary->nr_nacks > 0) 93 goto packet_loss_detected; 94 95 /* We analyse the number of packets that get ACK'd per RTT 96 * period and increase the window if we managed to fill it. 97 */ 98 if (call->peer->rtt_usage == 0) 99 goto out; 100 if (ktime_before(skb->tstamp, 101 ktime_add_ns(call->cong_tstamp, 102 call->peer->rtt))) 103 goto out_no_clear_ca; 104 change = rxrpc_cong_rtt_window_end; 105 call->cong_tstamp = skb->tstamp; 106 if (cumulative_acks >= cwnd) 107 cwnd++; 108 goto out; 109 110 case RXRPC_CALL_PACKET_LOSS: 111 if (summary->nr_nacks == 0) 112 goto resume_normality; 113 114 if (summary->new_low_nack) { 115 change = rxrpc_cong_new_low_nack; 116 call->cong_dup_acks = 1; 117 if (call->cong_extra > 1) 118 call->cong_extra = 1; 119 goto send_extra_data; 120 } 121 122 call->cong_dup_acks++; 123 if (call->cong_dup_acks < 3) 124 goto send_extra_data; 125 126 change = rxrpc_cong_begin_retransmission; 127 call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT; 128 call->cong_ssthresh = max_t(unsigned int, 129 summary->flight_size / 2, 2); 130 cwnd = call->cong_ssthresh + 3; 131 call->cong_extra = 0; 132 call->cong_dup_acks = 0; 133 resend = true; 134 goto out; 135 136 case RXRPC_CALL_FAST_RETRANSMIT: 137 if (!summary->new_low_nack) { 138 if (summary->nr_new_acks == 0) 139 cwnd += 1; 140 call->cong_dup_acks++; 141 if (call->cong_dup_acks == 2) { 142 change = rxrpc_cong_retransmit_again; 143 call->cong_dup_acks = 0; 144 resend = true; 145 } 146 } else { 147 change = rxrpc_cong_progress; 148 cwnd = call->cong_ssthresh; 149 if (summary->nr_nacks == 0) 150 goto resume_normality; 151 } 152 goto out; 153 154 default: 155 BUG(); 156 goto out; 157 } 158 159 resume_normality: 160 change = rxrpc_cong_cleared_nacks; 161 call->cong_dup_acks = 0; 162 call->cong_extra = 0; 163 call->cong_tstamp = skb->tstamp; 164 if (cwnd < call->cong_ssthresh) 165 call->cong_mode = RXRPC_CALL_SLOW_START; 166 else 167 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 168 out: 169 cumulative_acks = 0; 170 out_no_clear_ca: 171 if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1) 172 cwnd = RXRPC_RXTX_BUFF_SIZE - 1; 173 call->cong_cwnd = cwnd; 174 call->cong_cumul_acks = cumulative_acks; 175 trace_rxrpc_congest(call, summary, acked_serial, change); 176 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 177 rxrpc_queue_call(call); 178 return; 179 180 packet_loss_detected: 181 change = rxrpc_cong_saw_nack; 182 call->cong_mode = RXRPC_CALL_PACKET_LOSS; 183 call->cong_dup_acks = 0; 184 goto send_extra_data; 185 186 send_extra_data: 187 /* Send some previously unsent DATA if we have some to advance the ACK 188 * state. 189 */ 190 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 191 RXRPC_TX_ANNO_LAST || 192 summary->nr_acks != call->tx_top - call->tx_hard_ack) { 193 call->cong_extra++; 194 wake_up(&call->waitq); 195 } 196 goto out_no_clear_ca; 197 } 198 199 /* 200 * Ping the other end to fill our RTT cache and to retrieve the rwind 201 * and MTU parameters. 202 */ 203 static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb, 204 int skew) 205 { 206 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 207 ktime_t now = skb->tstamp; 208 209 if (call->peer->rtt_usage < 3 || 210 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now)) 211 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, 212 true, true, 213 rxrpc_propose_ack_ping_for_params); 214 } 215 216 /* 217 * Apply a hard ACK by advancing the Tx window. 218 */ 219 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to, 220 struct rxrpc_ack_summary *summary) 221 { 222 struct sk_buff *skb, *list = NULL; 223 bool rot_last = false; 224 int ix; 225 u8 annotation; 226 227 if (call->acks_lowest_nak == call->tx_hard_ack) { 228 call->acks_lowest_nak = to; 229 } else if (before_eq(call->acks_lowest_nak, to)) { 230 summary->new_low_nack = true; 231 call->acks_lowest_nak = to; 232 } 233 234 spin_lock(&call->lock); 235 236 while (before(call->tx_hard_ack, to)) { 237 call->tx_hard_ack++; 238 ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK; 239 skb = call->rxtx_buffer[ix]; 240 annotation = call->rxtx_annotations[ix]; 241 rxrpc_see_skb(skb, rxrpc_skb_tx_rotated); 242 call->rxtx_buffer[ix] = NULL; 243 call->rxtx_annotations[ix] = 0; 244 skb->next = list; 245 list = skb; 246 247 if (annotation & RXRPC_TX_ANNO_LAST) { 248 set_bit(RXRPC_CALL_TX_LAST, &call->flags); 249 rot_last = true; 250 } 251 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK) 252 summary->nr_rot_new_acks++; 253 } 254 255 spin_unlock(&call->lock); 256 257 trace_rxrpc_transmit(call, (rot_last ? 258 rxrpc_transmit_rotate_last : 259 rxrpc_transmit_rotate)); 260 wake_up(&call->waitq); 261 262 while (list) { 263 skb = list; 264 list = skb->next; 265 skb_mark_not_on_list(skb); 266 rxrpc_free_skb(skb, rxrpc_skb_tx_freed); 267 } 268 269 return rot_last; 270 } 271 272 /* 273 * End the transmission phase of a call. 274 * 275 * This occurs when we get an ACKALL packet, the first DATA packet of a reply, 276 * or a final ACK packet. 277 */ 278 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun, 279 const char *abort_why) 280 { 281 unsigned int state; 282 283 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags)); 284 285 write_lock(&call->state_lock); 286 287 state = call->state; 288 switch (state) { 289 case RXRPC_CALL_CLIENT_SEND_REQUEST: 290 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 291 if (reply_begun) 292 call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY; 293 else 294 call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY; 295 break; 296 297 case RXRPC_CALL_SERVER_AWAIT_ACK: 298 __rxrpc_call_completed(call); 299 rxrpc_notify_socket(call); 300 state = call->state; 301 break; 302 303 default: 304 goto bad_state; 305 } 306 307 write_unlock(&call->state_lock); 308 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY) 309 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); 310 else 311 trace_rxrpc_transmit(call, rxrpc_transmit_end); 312 _leave(" = ok"); 313 return true; 314 315 bad_state: 316 write_unlock(&call->state_lock); 317 kdebug("end_tx %s", rxrpc_call_states[call->state]); 318 rxrpc_proto_abort(abort_why, call, call->tx_top); 319 return false; 320 } 321 322 /* 323 * Begin the reply reception phase of a call. 324 */ 325 static bool rxrpc_receiving_reply(struct rxrpc_call *call) 326 { 327 struct rxrpc_ack_summary summary = { 0 }; 328 unsigned long now, timo; 329 rxrpc_seq_t top = READ_ONCE(call->tx_top); 330 331 if (call->ackr_reason) { 332 spin_lock_bh(&call->lock); 333 call->ackr_reason = 0; 334 spin_unlock_bh(&call->lock); 335 now = jiffies; 336 timo = now + MAX_JIFFY_OFFSET; 337 WRITE_ONCE(call->resend_at, timo); 338 WRITE_ONCE(call->ack_at, timo); 339 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now); 340 } 341 342 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { 343 if (!rxrpc_rotate_tx_window(call, top, &summary)) { 344 rxrpc_proto_abort("TXL", call, top); 345 return false; 346 } 347 } 348 if (!rxrpc_end_tx_phase(call, true, "ETD")) 349 return false; 350 call->tx_phase = false; 351 return true; 352 } 353 354 /* 355 * Scan a jumbo packet to validate its structure and to work out how many 356 * subpackets it contains. 357 * 358 * A jumbo packet is a collection of consecutive packets glued together with 359 * little headers between that indicate how to change the initial header for 360 * each subpacket. 361 * 362 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but 363 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any 364 * size. 365 */ 366 static bool rxrpc_validate_jumbo(struct sk_buff *skb) 367 { 368 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 369 unsigned int offset = sizeof(struct rxrpc_wire_header); 370 unsigned int len = skb->len; 371 int nr_jumbo = 1; 372 u8 flags = sp->hdr.flags; 373 374 do { 375 nr_jumbo++; 376 if (len - offset < RXRPC_JUMBO_SUBPKTLEN) 377 goto protocol_error; 378 if (flags & RXRPC_LAST_PACKET) 379 goto protocol_error; 380 offset += RXRPC_JUMBO_DATALEN; 381 if (skb_copy_bits(skb, offset, &flags, 1) < 0) 382 goto protocol_error; 383 offset += sizeof(struct rxrpc_jumbo_header); 384 } while (flags & RXRPC_JUMBO_PACKET); 385 386 sp->nr_jumbo = nr_jumbo; 387 return true; 388 389 protocol_error: 390 return false; 391 } 392 393 /* 394 * Handle reception of a duplicate packet. 395 * 396 * We have to take care to avoid an attack here whereby we're given a series of 397 * jumbograms, each with a sequence number one before the preceding one and 398 * filled up to maximum UDP size. If they never send us the first packet in 399 * the sequence, they can cause us to have to hold on to around 2MiB of kernel 400 * space until the call times out. 401 * 402 * We limit the space usage by only accepting three duplicate jumbo packets per 403 * call. After that, we tell the other side we're no longer accepting jumbos 404 * (that information is encoded in the ACK packet). 405 */ 406 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, 407 u8 annotation, bool *_jumbo_bad) 408 { 409 /* Discard normal packets that are duplicates. */ 410 if (annotation == 0) 411 return; 412 413 /* Skip jumbo subpackets that are duplicates. When we've had three or 414 * more partially duplicate jumbo packets, we refuse to take any more 415 * jumbos for this call. 416 */ 417 if (!*_jumbo_bad) { 418 call->nr_jumbo_bad++; 419 *_jumbo_bad = true; 420 } 421 } 422 423 /* 424 * Process a DATA packet, adding the packet to the Rx ring. 425 */ 426 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb, 427 u16 skew) 428 { 429 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 430 enum rxrpc_call_state state; 431 unsigned int offset = sizeof(struct rxrpc_wire_header); 432 unsigned int ix; 433 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0; 434 rxrpc_seq_t seq = sp->hdr.seq, hard_ack; 435 bool immediate_ack = false, jumbo_bad = false, queued; 436 u16 len; 437 u8 ack = 0, flags, annotation = 0; 438 439 _enter("{%u,%u},{%u,%u}", 440 call->rx_hard_ack, call->rx_top, skb->len, seq); 441 442 _proto("Rx DATA %%%u { #%u f=%02x }", 443 sp->hdr.serial, seq, sp->hdr.flags); 444 445 state = READ_ONCE(call->state); 446 if (state >= RXRPC_CALL_COMPLETE) 447 return; 448 449 if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) { 450 unsigned long timo = READ_ONCE(call->next_req_timo); 451 unsigned long now, expect_req_by; 452 453 if (timo) { 454 now = jiffies; 455 expect_req_by = now + timo; 456 WRITE_ONCE(call->expect_req_by, expect_req_by); 457 rxrpc_reduce_call_timer(call, expect_req_by, now, 458 rxrpc_timer_set_for_idle); 459 } 460 } 461 462 spin_lock(&call->input_lock); 463 464 /* Received data implicitly ACKs all of the request packets we sent 465 * when we're acting as a client. 466 */ 467 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST || 468 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) && 469 !rxrpc_receiving_reply(call)) 470 goto unlock; 471 472 call->ackr_prev_seq = seq; 473 474 hard_ack = READ_ONCE(call->rx_hard_ack); 475 if (after(seq, hard_ack + call->rx_winsize)) { 476 ack = RXRPC_ACK_EXCEEDS_WINDOW; 477 ack_serial = serial; 478 goto ack; 479 } 480 481 flags = sp->hdr.flags; 482 if (flags & RXRPC_JUMBO_PACKET) { 483 if (call->nr_jumbo_bad > 3) { 484 ack = RXRPC_ACK_NOSPACE; 485 ack_serial = serial; 486 goto ack; 487 } 488 annotation = 1; 489 } 490 491 next_subpacket: 492 queued = false; 493 ix = seq & RXRPC_RXTX_BUFF_MASK; 494 len = skb->len; 495 if (flags & RXRPC_JUMBO_PACKET) 496 len = RXRPC_JUMBO_DATALEN; 497 498 if (flags & RXRPC_LAST_PACKET) { 499 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 500 seq != call->rx_top) { 501 rxrpc_proto_abort("LSN", call, seq); 502 goto unlock; 503 } 504 } else { 505 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 506 after_eq(seq, call->rx_top)) { 507 rxrpc_proto_abort("LSA", call, seq); 508 goto unlock; 509 } 510 } 511 512 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation); 513 if (before_eq(seq, hard_ack)) { 514 ack = RXRPC_ACK_DUPLICATE; 515 ack_serial = serial; 516 goto skip; 517 } 518 519 if (flags & RXRPC_REQUEST_ACK && !ack) { 520 ack = RXRPC_ACK_REQUESTED; 521 ack_serial = serial; 522 } 523 524 if (call->rxtx_buffer[ix]) { 525 rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad); 526 if (ack != RXRPC_ACK_DUPLICATE) { 527 ack = RXRPC_ACK_DUPLICATE; 528 ack_serial = serial; 529 } 530 immediate_ack = true; 531 goto skip; 532 } 533 534 /* Queue the packet. We use a couple of memory barriers here as need 535 * to make sure that rx_top is perceived to be set after the buffer 536 * pointer and that the buffer pointer is set after the annotation and 537 * the skb data. 538 * 539 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() 540 * and also rxrpc_fill_out_ack(). 541 */ 542 rxrpc_get_skb(skb, rxrpc_skb_rx_got); 543 call->rxtx_annotations[ix] = annotation; 544 smp_wmb(); 545 call->rxtx_buffer[ix] = skb; 546 if (after(seq, call->rx_top)) { 547 smp_store_release(&call->rx_top, seq); 548 } else if (before(seq, call->rx_top)) { 549 /* Send an immediate ACK if we fill in a hole */ 550 if (!ack) { 551 ack = RXRPC_ACK_DELAY; 552 ack_serial = serial; 553 } 554 immediate_ack = true; 555 } 556 if (flags & RXRPC_LAST_PACKET) { 557 set_bit(RXRPC_CALL_RX_LAST, &call->flags); 558 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); 559 } else { 560 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); 561 } 562 queued = true; 563 564 if (after_eq(seq, call->rx_expect_next)) { 565 if (after(seq, call->rx_expect_next)) { 566 _net("OOS %u > %u", seq, call->rx_expect_next); 567 ack = RXRPC_ACK_OUT_OF_SEQUENCE; 568 ack_serial = serial; 569 } 570 call->rx_expect_next = seq + 1; 571 } 572 573 skip: 574 offset += len; 575 if (flags & RXRPC_JUMBO_PACKET) { 576 if (skb_copy_bits(skb, offset, &flags, 1) < 0) { 577 rxrpc_proto_abort("XJF", call, seq); 578 goto unlock; 579 } 580 offset += sizeof(struct rxrpc_jumbo_header); 581 seq++; 582 serial++; 583 annotation++; 584 if (flags & RXRPC_JUMBO_PACKET) 585 annotation |= RXRPC_RX_ANNO_JLAST; 586 if (after(seq, hard_ack + call->rx_winsize)) { 587 ack = RXRPC_ACK_EXCEEDS_WINDOW; 588 ack_serial = serial; 589 if (!jumbo_bad) { 590 call->nr_jumbo_bad++; 591 jumbo_bad = true; 592 } 593 goto ack; 594 } 595 596 _proto("Rx DATA Jumbo %%%u", serial); 597 goto next_subpacket; 598 } 599 600 if (queued && flags & RXRPC_LAST_PACKET && !ack) { 601 ack = RXRPC_ACK_DELAY; 602 ack_serial = serial; 603 } 604 605 ack: 606 if (ack) 607 rxrpc_propose_ACK(call, ack, skew, ack_serial, 608 immediate_ack, true, 609 rxrpc_propose_ack_input_data); 610 else 611 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, skew, serial, 612 false, true, 613 rxrpc_propose_ack_input_data); 614 615 if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1) { 616 trace_rxrpc_notify_socket(call->debug_id, serial); 617 rxrpc_notify_socket(call); 618 } 619 620 unlock: 621 spin_unlock(&call->input_lock); 622 _leave(" [queued]"); 623 } 624 625 /* 626 * Process a requested ACK. 627 */ 628 static void rxrpc_input_requested_ack(struct rxrpc_call *call, 629 ktime_t resp_time, 630 rxrpc_serial_t orig_serial, 631 rxrpc_serial_t ack_serial) 632 { 633 struct rxrpc_skb_priv *sp; 634 struct sk_buff *skb; 635 ktime_t sent_at; 636 int ix; 637 638 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) { 639 skb = call->rxtx_buffer[ix]; 640 if (!skb) 641 continue; 642 643 sent_at = skb->tstamp; 644 smp_rmb(); /* Read timestamp before serial. */ 645 sp = rxrpc_skb(skb); 646 if (sp->hdr.serial != orig_serial) 647 continue; 648 goto found; 649 } 650 651 return; 652 653 found: 654 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack, 655 orig_serial, ack_serial, sent_at, resp_time); 656 } 657 658 /* 659 * Process the response to a ping that we sent to find out if we lost an ACK. 660 * 661 * If we got back a ping response that indicates a lower tx_top than what we 662 * had at the time of the ping transmission, we adjudge all the DATA packets 663 * sent between the response tx_top and the ping-time tx_top to have been lost. 664 */ 665 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call) 666 { 667 rxrpc_seq_t top, bottom, seq; 668 bool resend = false; 669 670 spin_lock_bh(&call->lock); 671 672 bottom = call->tx_hard_ack + 1; 673 top = call->acks_lost_top; 674 if (before(bottom, top)) { 675 for (seq = bottom; before_eq(seq, top); seq++) { 676 int ix = seq & RXRPC_RXTX_BUFF_MASK; 677 u8 annotation = call->rxtx_annotations[ix]; 678 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK; 679 680 if (anno_type != RXRPC_TX_ANNO_UNACK) 681 continue; 682 annotation &= ~RXRPC_TX_ANNO_MASK; 683 annotation |= RXRPC_TX_ANNO_RETRANS; 684 call->rxtx_annotations[ix] = annotation; 685 resend = true; 686 } 687 } 688 689 spin_unlock_bh(&call->lock); 690 691 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 692 rxrpc_queue_call(call); 693 } 694 695 /* 696 * Process a ping response. 697 */ 698 static void rxrpc_input_ping_response(struct rxrpc_call *call, 699 ktime_t resp_time, 700 rxrpc_serial_t orig_serial, 701 rxrpc_serial_t ack_serial) 702 { 703 rxrpc_serial_t ping_serial; 704 ktime_t ping_time; 705 706 ping_time = call->ping_time; 707 smp_rmb(); 708 ping_serial = READ_ONCE(call->ping_serial); 709 710 if (orig_serial == call->acks_lost_ping) 711 rxrpc_input_check_for_lost_ack(call); 712 713 if (before(orig_serial, ping_serial) || 714 !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags)) 715 return; 716 if (after(orig_serial, ping_serial)) 717 return; 718 719 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response, 720 orig_serial, ack_serial, ping_time, resp_time); 721 } 722 723 /* 724 * Process the extra information that may be appended to an ACK packet 725 */ 726 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 727 struct rxrpc_ackinfo *ackinfo) 728 { 729 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 730 struct rxrpc_peer *peer; 731 unsigned int mtu; 732 bool wake = false; 733 u32 rwind = ntohl(ackinfo->rwind); 734 735 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 736 sp->hdr.serial, 737 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU), 738 rwind, ntohl(ackinfo->jumbo_max)); 739 740 if (call->tx_winsize != rwind) { 741 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) 742 rwind = RXRPC_RXTX_BUFF_SIZE - 1; 743 if (rwind > call->tx_winsize) 744 wake = true; 745 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, 746 ntohl(ackinfo->rwind), wake); 747 call->tx_winsize = rwind; 748 } 749 750 if (call->cong_ssthresh > rwind) 751 call->cong_ssthresh = rwind; 752 753 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); 754 755 peer = call->peer; 756 if (mtu < peer->maxdata) { 757 spin_lock_bh(&peer->lock); 758 peer->maxdata = mtu; 759 peer->mtu = mtu + peer->hdrsize; 760 spin_unlock_bh(&peer->lock); 761 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 762 } 763 764 if (wake) 765 wake_up(&call->waitq); 766 } 767 768 /* 769 * Process individual soft ACKs. 770 * 771 * Each ACK in the array corresponds to one packet and can be either an ACK or 772 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 773 * packets that lie beyond the end of the ACK list are scheduled for resend by 774 * the timer on the basis that the peer might just not have processed them at 775 * the time the ACK was sent. 776 */ 777 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, 778 rxrpc_seq_t seq, int nr_acks, 779 struct rxrpc_ack_summary *summary) 780 { 781 int ix; 782 u8 annotation, anno_type; 783 784 for (; nr_acks > 0; nr_acks--, seq++) { 785 ix = seq & RXRPC_RXTX_BUFF_MASK; 786 annotation = call->rxtx_annotations[ix]; 787 anno_type = annotation & RXRPC_TX_ANNO_MASK; 788 annotation &= ~RXRPC_TX_ANNO_MASK; 789 switch (*acks++) { 790 case RXRPC_ACK_TYPE_ACK: 791 summary->nr_acks++; 792 if (anno_type == RXRPC_TX_ANNO_ACK) 793 continue; 794 summary->nr_new_acks++; 795 call->rxtx_annotations[ix] = 796 RXRPC_TX_ANNO_ACK | annotation; 797 break; 798 case RXRPC_ACK_TYPE_NACK: 799 if (!summary->nr_nacks && 800 call->acks_lowest_nak != seq) { 801 call->acks_lowest_nak = seq; 802 summary->new_low_nack = true; 803 } 804 summary->nr_nacks++; 805 if (anno_type == RXRPC_TX_ANNO_NAK) 806 continue; 807 summary->nr_new_nacks++; 808 if (anno_type == RXRPC_TX_ANNO_RETRANS) 809 continue; 810 call->rxtx_annotations[ix] = 811 RXRPC_TX_ANNO_NAK | annotation; 812 break; 813 default: 814 return rxrpc_proto_abort("SFT", call, 0); 815 } 816 } 817 } 818 819 /* 820 * Process an ACK packet. 821 * 822 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 823 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 824 * 825 * A hard-ACK means that a packet has been processed and may be discarded; a 826 * soft-ACK means that the packet may be discarded and retransmission 827 * requested. A phase is complete when all packets are hard-ACK'd. 828 */ 829 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, 830 u16 skew) 831 { 832 struct rxrpc_ack_summary summary = { 0 }; 833 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 834 union { 835 struct rxrpc_ackpacket ack; 836 struct rxrpc_ackinfo info; 837 u8 acks[RXRPC_MAXACKS]; 838 } buf; 839 rxrpc_serial_t acked_serial; 840 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; 841 int nr_acks, offset, ioffset; 842 843 _enter(""); 844 845 offset = sizeof(struct rxrpc_wire_header); 846 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { 847 _debug("extraction failure"); 848 return rxrpc_proto_abort("XAK", call, 0); 849 } 850 offset += sizeof(buf.ack); 851 852 acked_serial = ntohl(buf.ack.serial); 853 first_soft_ack = ntohl(buf.ack.firstPacket); 854 prev_pkt = ntohl(buf.ack.previousPacket); 855 hard_ack = first_soft_ack - 1; 856 nr_acks = buf.ack.nAcks; 857 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? 858 buf.ack.reason : RXRPC_ACK__INVALID); 859 860 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial, 861 first_soft_ack, prev_pkt, 862 summary.ack_reason, nr_acks); 863 864 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) 865 rxrpc_input_ping_response(call, skb->tstamp, acked_serial, 866 sp->hdr.serial); 867 if (buf.ack.reason == RXRPC_ACK_REQUESTED) 868 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial, 869 sp->hdr.serial); 870 871 if (buf.ack.reason == RXRPC_ACK_PING) { 872 _proto("Rx ACK %%%u PING Request", sp->hdr.serial); 873 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 874 skew, sp->hdr.serial, true, true, 875 rxrpc_propose_ack_respond_to_ping); 876 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { 877 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, 878 skew, sp->hdr.serial, true, true, 879 rxrpc_propose_ack_respond_to_ack); 880 } 881 882 /* Discard any out-of-order or duplicate ACKs (outside lock). */ 883 if (before(first_soft_ack, call->ackr_first_seq) || 884 before(prev_pkt, call->ackr_prev_seq)) 885 return; 886 887 buf.info.rxMTU = 0; 888 ioffset = offset + nr_acks + 3; 889 if (skb->len >= ioffset + sizeof(buf.info) && 890 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) 891 return rxrpc_proto_abort("XAI", call, 0); 892 893 spin_lock(&call->input_lock); 894 895 /* Discard any out-of-order or duplicate ACKs (inside lock). */ 896 if (before(first_soft_ack, call->ackr_first_seq) || 897 before(prev_pkt, call->ackr_prev_seq)) 898 goto out; 899 call->acks_latest_ts = skb->tstamp; 900 call->acks_latest = sp->hdr.serial; 901 902 call->ackr_first_seq = first_soft_ack; 903 call->ackr_prev_seq = prev_pkt; 904 905 /* Parse rwind and mtu sizes if provided. */ 906 if (buf.info.rxMTU) 907 rxrpc_input_ackinfo(call, skb, &buf.info); 908 909 if (first_soft_ack == 0) { 910 rxrpc_proto_abort("AK0", call, 0); 911 goto out; 912 } 913 914 /* Ignore ACKs unless we are or have just been transmitting. */ 915 switch (READ_ONCE(call->state)) { 916 case RXRPC_CALL_CLIENT_SEND_REQUEST: 917 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 918 case RXRPC_CALL_SERVER_SEND_REPLY: 919 case RXRPC_CALL_SERVER_AWAIT_ACK: 920 break; 921 default: 922 goto out; 923 } 924 925 if (before(hard_ack, call->tx_hard_ack) || 926 after(hard_ack, call->tx_top)) { 927 rxrpc_proto_abort("AKW", call, 0); 928 goto out; 929 } 930 if (nr_acks > call->tx_top - hard_ack) { 931 rxrpc_proto_abort("AKN", call, 0); 932 goto out; 933 } 934 935 if (after(hard_ack, call->tx_hard_ack)) { 936 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { 937 rxrpc_end_tx_phase(call, false, "ETA"); 938 goto out; 939 } 940 } 941 942 if (nr_acks > 0) { 943 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) { 944 rxrpc_proto_abort("XSA", call, 0); 945 goto out; 946 } 947 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, 948 &summary); 949 } 950 951 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 952 RXRPC_TX_ANNO_LAST && 953 summary.nr_acks == call->tx_top - hard_ack && 954 rxrpc_is_client_call(call)) 955 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, 956 false, true, 957 rxrpc_propose_ack_ping_for_lost_reply); 958 959 rxrpc_congestion_management(call, skb, &summary, acked_serial); 960 out: 961 spin_unlock(&call->input_lock); 962 } 963 964 /* 965 * Process an ACKALL packet. 966 */ 967 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 968 { 969 struct rxrpc_ack_summary summary = { 0 }; 970 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 971 972 _proto("Rx ACKALL %%%u", sp->hdr.serial); 973 974 spin_lock(&call->input_lock); 975 976 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) 977 rxrpc_end_tx_phase(call, false, "ETL"); 978 979 spin_unlock(&call->input_lock); 980 } 981 982 /* 983 * Process an ABORT packet directed at a call. 984 */ 985 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 986 { 987 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 988 __be32 wtmp; 989 u32 abort_code = RX_CALL_DEAD; 990 991 _enter(""); 992 993 if (skb->len >= 4 && 994 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 995 &wtmp, sizeof(wtmp)) >= 0) 996 abort_code = ntohl(wtmp); 997 998 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code); 999 1000 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); 1001 1002 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1003 abort_code, -ECONNABORTED)) 1004 rxrpc_notify_socket(call); 1005 } 1006 1007 /* 1008 * Process an incoming call packet. 1009 */ 1010 static void rxrpc_input_call_packet(struct rxrpc_call *call, 1011 struct sk_buff *skb, u16 skew) 1012 { 1013 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1014 unsigned long timo; 1015 1016 _enter("%p,%p", call, skb); 1017 1018 timo = READ_ONCE(call->next_rx_timo); 1019 if (timo) { 1020 unsigned long now = jiffies, expect_rx_by; 1021 1022 expect_rx_by = now + timo; 1023 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 1024 rxrpc_reduce_call_timer(call, expect_rx_by, now, 1025 rxrpc_timer_set_for_normal); 1026 } 1027 1028 switch (sp->hdr.type) { 1029 case RXRPC_PACKET_TYPE_DATA: 1030 rxrpc_input_data(call, skb, skew); 1031 break; 1032 1033 case RXRPC_PACKET_TYPE_ACK: 1034 rxrpc_input_ack(call, skb, skew); 1035 break; 1036 1037 case RXRPC_PACKET_TYPE_BUSY: 1038 _proto("Rx BUSY %%%u", sp->hdr.serial); 1039 1040 /* Just ignore BUSY packets from the server; the retry and 1041 * lifespan timers will take care of business. BUSY packets 1042 * from the client don't make sense. 1043 */ 1044 break; 1045 1046 case RXRPC_PACKET_TYPE_ABORT: 1047 rxrpc_input_abort(call, skb); 1048 break; 1049 1050 case RXRPC_PACKET_TYPE_ACKALL: 1051 rxrpc_input_ackall(call, skb); 1052 break; 1053 1054 default: 1055 break; 1056 } 1057 1058 _leave(""); 1059 } 1060 1061 /* 1062 * Handle a new service call on a channel implicitly completing the preceding 1063 * call on that channel. This does not apply to client conns. 1064 * 1065 * TODO: If callNumber > call_id + 1, renegotiate security. 1066 */ 1067 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, 1068 struct rxrpc_connection *conn, 1069 struct rxrpc_call *call) 1070 { 1071 switch (READ_ONCE(call->state)) { 1072 case RXRPC_CALL_SERVER_AWAIT_ACK: 1073 rxrpc_call_completed(call); 1074 /* Fall through */ 1075 case RXRPC_CALL_COMPLETE: 1076 break; 1077 default: 1078 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) { 1079 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 1080 rxrpc_queue_call(call); 1081 } 1082 trace_rxrpc_improper_term(call); 1083 break; 1084 } 1085 1086 spin_lock(&rx->incoming_lock); 1087 __rxrpc_disconnect_call(conn, call); 1088 spin_unlock(&rx->incoming_lock); 1089 rxrpc_notify_socket(call); 1090 } 1091 1092 /* 1093 * post connection-level events to the connection 1094 * - this includes challenges, responses, some aborts and call terminal packet 1095 * retransmission. 1096 */ 1097 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 1098 struct sk_buff *skb) 1099 { 1100 _enter("%p,%p", conn, skb); 1101 1102 skb_queue_tail(&conn->rx_queue, skb); 1103 rxrpc_queue_conn(conn); 1104 } 1105 1106 /* 1107 * post endpoint-level events to the local endpoint 1108 * - this includes debug and version messages 1109 */ 1110 static void rxrpc_post_packet_to_local(struct rxrpc_local *local, 1111 struct sk_buff *skb) 1112 { 1113 _enter("%p,%p", local, skb); 1114 1115 skb_queue_tail(&local->event_queue, skb); 1116 rxrpc_queue_local(local); 1117 } 1118 1119 /* 1120 * put a packet up for transport-level abort 1121 */ 1122 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 1123 { 1124 CHECK_SLAB_OKAY(&local->usage); 1125 1126 skb_queue_tail(&local->reject_queue, skb); 1127 rxrpc_queue_local(local); 1128 } 1129 1130 /* 1131 * Extract the wire header from a packet and translate the byte order. 1132 */ 1133 static noinline 1134 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) 1135 { 1136 struct rxrpc_wire_header whdr; 1137 1138 /* dig out the RxRPC connection details */ 1139 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) { 1140 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 1141 tracepoint_string("bad_hdr")); 1142 return -EBADMSG; 1143 } 1144 1145 memset(sp, 0, sizeof(*sp)); 1146 sp->hdr.epoch = ntohl(whdr.epoch); 1147 sp->hdr.cid = ntohl(whdr.cid); 1148 sp->hdr.callNumber = ntohl(whdr.callNumber); 1149 sp->hdr.seq = ntohl(whdr.seq); 1150 sp->hdr.serial = ntohl(whdr.serial); 1151 sp->hdr.flags = whdr.flags; 1152 sp->hdr.type = whdr.type; 1153 sp->hdr.userStatus = whdr.userStatus; 1154 sp->hdr.securityIndex = whdr.securityIndex; 1155 sp->hdr._rsvd = ntohs(whdr._rsvd); 1156 sp->hdr.serviceId = ntohs(whdr.serviceId); 1157 return 0; 1158 } 1159 1160 /* 1161 * handle data received on the local endpoint 1162 * - may be called in interrupt context 1163 * 1164 * The socket is locked by the caller and this prevents the socket from being 1165 * shut down and the local endpoint from going away, thus sk_user_data will not 1166 * be cleared until this function returns. 1167 * 1168 * Called with the RCU read lock held from the IP layer via UDP. 1169 */ 1170 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb) 1171 { 1172 struct rxrpc_connection *conn; 1173 struct rxrpc_channel *chan; 1174 struct rxrpc_call *call = NULL; 1175 struct rxrpc_skb_priv *sp; 1176 struct rxrpc_local *local = udp_sk->sk_user_data; 1177 struct rxrpc_peer *peer = NULL; 1178 struct rxrpc_sock *rx = NULL; 1179 unsigned int channel; 1180 int skew = 0; 1181 1182 _enter("%p", udp_sk); 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