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