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