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