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_count == 0) 95 goto out; 96 if (ktime_before(skb->tstamp, 97 ktime_add_us(call->cong_tstamp, 98 call->peer->srtt_us >> 3))) 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 state = call->state; 279 break; 280 281 default: 282 goto bad_state; 283 } 284 285 write_unlock(&call->state_lock); 286 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY) 287 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); 288 else 289 trace_rxrpc_transmit(call, rxrpc_transmit_end); 290 _leave(" = ok"); 291 return true; 292 293 bad_state: 294 write_unlock(&call->state_lock); 295 kdebug("end_tx %s", rxrpc_call_states[call->state]); 296 rxrpc_proto_abort(abort_why, call, call->tx_top); 297 return false; 298 } 299 300 /* 301 * Begin the reply reception phase of a call. 302 */ 303 static bool rxrpc_receiving_reply(struct rxrpc_call *call) 304 { 305 struct rxrpc_ack_summary summary = { 0 }; 306 unsigned long now, timo; 307 rxrpc_seq_t top = READ_ONCE(call->tx_top); 308 309 if (call->ackr_reason) { 310 spin_lock_bh(&call->lock); 311 call->ackr_reason = 0; 312 spin_unlock_bh(&call->lock); 313 now = jiffies; 314 timo = now + MAX_JIFFY_OFFSET; 315 WRITE_ONCE(call->resend_at, timo); 316 WRITE_ONCE(call->ack_at, timo); 317 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now); 318 } 319 320 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { 321 if (!rxrpc_rotate_tx_window(call, top, &summary)) { 322 rxrpc_proto_abort("TXL", call, top); 323 return false; 324 } 325 } 326 if (!rxrpc_end_tx_phase(call, true, "ETD")) 327 return false; 328 call->tx_phase = false; 329 return true; 330 } 331 332 /* 333 * Scan a data packet to validate its structure and to work out how many 334 * subpackets it contains. 335 * 336 * A jumbo packet is a collection of consecutive packets glued together with 337 * little headers between that indicate how to change the initial header for 338 * each subpacket. 339 * 340 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but 341 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any 342 * size. 343 */ 344 static bool rxrpc_validate_data(struct sk_buff *skb) 345 { 346 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 347 unsigned int offset = sizeof(struct rxrpc_wire_header); 348 unsigned int len = skb->len; 349 u8 flags = sp->hdr.flags; 350 351 for (;;) { 352 if (flags & RXRPC_REQUEST_ACK) 353 __set_bit(sp->nr_subpackets, sp->rx_req_ack); 354 sp->nr_subpackets++; 355 356 if (!(flags & RXRPC_JUMBO_PACKET)) 357 break; 358 359 if (len - offset < RXRPC_JUMBO_SUBPKTLEN) 360 goto protocol_error; 361 if (flags & RXRPC_LAST_PACKET) 362 goto protocol_error; 363 offset += RXRPC_JUMBO_DATALEN; 364 if (skb_copy_bits(skb, offset, &flags, 1) < 0) 365 goto protocol_error; 366 offset += sizeof(struct rxrpc_jumbo_header); 367 } 368 369 if (flags & RXRPC_LAST_PACKET) 370 sp->rx_flags |= RXRPC_SKB_INCL_LAST; 371 return true; 372 373 protocol_error: 374 return false; 375 } 376 377 /* 378 * Handle reception of a duplicate packet. 379 * 380 * We have to take care to avoid an attack here whereby we're given a series of 381 * jumbograms, each with a sequence number one before the preceding one and 382 * filled up to maximum UDP size. If they never send us the first packet in 383 * the sequence, they can cause us to have to hold on to around 2MiB of kernel 384 * space until the call times out. 385 * 386 * We limit the space usage by only accepting three duplicate jumbo packets per 387 * call. After that, we tell the other side we're no longer accepting jumbos 388 * (that information is encoded in the ACK packet). 389 */ 390 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, 391 bool is_jumbo, bool *_jumbo_bad) 392 { 393 /* Discard normal packets that are duplicates. */ 394 if (is_jumbo) 395 return; 396 397 /* Skip jumbo subpackets that are duplicates. When we've had three or 398 * more partially duplicate jumbo packets, we refuse to take any more 399 * jumbos for this call. 400 */ 401 if (!*_jumbo_bad) { 402 call->nr_jumbo_bad++; 403 *_jumbo_bad = true; 404 } 405 } 406 407 /* 408 * Process a DATA packet, adding the packet to the Rx ring. The caller's 409 * packet ref must be passed on or discarded. 410 */ 411 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb) 412 { 413 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 414 enum rxrpc_call_state state; 415 unsigned int j, nr_subpackets; 416 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0; 417 rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack; 418 bool immediate_ack = false, jumbo_bad = false; 419 u8 ack = 0; 420 421 _enter("{%u,%u},{%u,%u}", 422 call->rx_hard_ack, call->rx_top, skb->len, seq0); 423 424 _proto("Rx DATA %%%u { #%u f=%02x n=%u }", 425 sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets); 426 427 state = READ_ONCE(call->state); 428 if (state >= RXRPC_CALL_COMPLETE) { 429 rxrpc_free_skb(skb, rxrpc_skb_freed); 430 return; 431 } 432 433 if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) { 434 unsigned long timo = READ_ONCE(call->next_req_timo); 435 unsigned long now, expect_req_by; 436 437 if (timo) { 438 now = jiffies; 439 expect_req_by = now + timo; 440 WRITE_ONCE(call->expect_req_by, expect_req_by); 441 rxrpc_reduce_call_timer(call, expect_req_by, now, 442 rxrpc_timer_set_for_idle); 443 } 444 } 445 446 spin_lock(&call->input_lock); 447 448 /* Received data implicitly ACKs all of the request packets we sent 449 * when we're acting as a client. 450 */ 451 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST || 452 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) && 453 !rxrpc_receiving_reply(call)) 454 goto unlock; 455 456 call->ackr_prev_seq = seq0; 457 hard_ack = READ_ONCE(call->rx_hard_ack); 458 459 nr_subpackets = sp->nr_subpackets; 460 if (nr_subpackets > 1) { 461 if (call->nr_jumbo_bad > 3) { 462 ack = RXRPC_ACK_NOSPACE; 463 ack_serial = serial; 464 goto ack; 465 } 466 } 467 468 for (j = 0; j < nr_subpackets; j++) { 469 rxrpc_serial_t serial = sp->hdr.serial + j; 470 rxrpc_seq_t seq = seq0 + j; 471 unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK; 472 bool terminal = (j == nr_subpackets - 1); 473 bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST); 474 u8 flags, annotation = j; 475 476 _proto("Rx DATA+%u %%%u { #%x t=%u l=%u }", 477 j, serial, seq, terminal, last); 478 479 if (last) { 480 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 481 seq != call->rx_top) { 482 rxrpc_proto_abort("LSN", call, seq); 483 goto unlock; 484 } 485 } else { 486 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && 487 after_eq(seq, call->rx_top)) { 488 rxrpc_proto_abort("LSA", call, seq); 489 goto unlock; 490 } 491 } 492 493 flags = 0; 494 if (last) 495 flags |= RXRPC_LAST_PACKET; 496 if (!terminal) 497 flags |= RXRPC_JUMBO_PACKET; 498 if (test_bit(j, sp->rx_req_ack)) 499 flags |= RXRPC_REQUEST_ACK; 500 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation); 501 502 if (before_eq(seq, hard_ack)) { 503 ack = RXRPC_ACK_DUPLICATE; 504 ack_serial = serial; 505 continue; 506 } 507 508 if (call->rxtx_buffer[ix]) { 509 rxrpc_input_dup_data(call, seq, nr_subpackets > 1, 510 &jumbo_bad); 511 if (ack != RXRPC_ACK_DUPLICATE) { 512 ack = RXRPC_ACK_DUPLICATE; 513 ack_serial = serial; 514 } 515 immediate_ack = true; 516 continue; 517 } 518 519 if (after(seq, hard_ack + call->rx_winsize)) { 520 ack = RXRPC_ACK_EXCEEDS_WINDOW; 521 ack_serial = serial; 522 if (flags & RXRPC_JUMBO_PACKET) { 523 if (!jumbo_bad) { 524 call->nr_jumbo_bad++; 525 jumbo_bad = true; 526 } 527 } 528 529 goto ack; 530 } 531 532 if (flags & RXRPC_REQUEST_ACK && !ack) { 533 ack = RXRPC_ACK_REQUESTED; 534 ack_serial = serial; 535 } 536 537 /* Queue the packet. We use a couple of memory barriers here as need 538 * to make sure that rx_top is perceived to be set after the buffer 539 * pointer and that the buffer pointer is set after the annotation and 540 * the skb data. 541 * 542 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() 543 * and also rxrpc_fill_out_ack(). 544 */ 545 if (!terminal) 546 rxrpc_get_skb(skb, rxrpc_skb_got); 547 call->rxtx_annotations[ix] = annotation; 548 smp_wmb(); 549 call->rxtx_buffer[ix] = skb; 550 if (after(seq, call->rx_top)) { 551 smp_store_release(&call->rx_top, seq); 552 } else if (before(seq, call->rx_top)) { 553 /* Send an immediate ACK if we fill in a hole */ 554 if (!ack) { 555 ack = RXRPC_ACK_DELAY; 556 ack_serial = serial; 557 } 558 immediate_ack = true; 559 } 560 561 if (terminal) { 562 /* From this point on, we're not allowed to touch the 563 * packet any longer as its ref now belongs to the Rx 564 * ring. 565 */ 566 skb = NULL; 567 sp = NULL; 568 } 569 570 if (last) { 571 set_bit(RXRPC_CALL_RX_LAST, &call->flags); 572 if (!ack) { 573 ack = RXRPC_ACK_DELAY; 574 ack_serial = serial; 575 } 576 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); 577 } else { 578 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); 579 } 580 581 if (after_eq(seq, call->rx_expect_next)) { 582 if (after(seq, call->rx_expect_next)) { 583 _net("OOS %u > %u", seq, call->rx_expect_next); 584 ack = RXRPC_ACK_OUT_OF_SEQUENCE; 585 ack_serial = serial; 586 } 587 call->rx_expect_next = seq + 1; 588 } 589 } 590 591 ack: 592 if (ack) 593 rxrpc_propose_ACK(call, ack, ack_serial, 594 immediate_ack, true, 595 rxrpc_propose_ack_input_data); 596 else 597 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial, 598 false, true, 599 rxrpc_propose_ack_input_data); 600 601 trace_rxrpc_notify_socket(call->debug_id, serial); 602 rxrpc_notify_socket(call); 603 604 unlock: 605 spin_unlock(&call->input_lock); 606 rxrpc_free_skb(skb, rxrpc_skb_freed); 607 _leave(" [queued]"); 608 } 609 610 /* 611 * Process a requested ACK. 612 */ 613 static void rxrpc_input_requested_ack(struct rxrpc_call *call, 614 ktime_t resp_time, 615 rxrpc_serial_t orig_serial, 616 rxrpc_serial_t ack_serial) 617 { 618 struct rxrpc_skb_priv *sp; 619 struct sk_buff *skb; 620 ktime_t sent_at; 621 int ix; 622 623 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) { 624 skb = call->rxtx_buffer[ix]; 625 if (!skb) 626 continue; 627 628 sent_at = skb->tstamp; 629 smp_rmb(); /* Read timestamp before serial. */ 630 sp = rxrpc_skb(skb); 631 if (sp->hdr.serial != orig_serial) 632 continue; 633 goto found; 634 } 635 636 return; 637 638 found: 639 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack, 640 orig_serial, ack_serial, sent_at, resp_time); 641 } 642 643 /* 644 * Process the response to a ping that we sent to find out if we lost an ACK. 645 * 646 * If we got back a ping response that indicates a lower tx_top than what we 647 * had at the time of the ping transmission, we adjudge all the DATA packets 648 * sent between the response tx_top and the ping-time tx_top to have been lost. 649 */ 650 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call) 651 { 652 rxrpc_seq_t top, bottom, seq; 653 bool resend = false; 654 655 spin_lock_bh(&call->lock); 656 657 bottom = call->tx_hard_ack + 1; 658 top = call->acks_lost_top; 659 if (before(bottom, top)) { 660 for (seq = bottom; before_eq(seq, top); seq++) { 661 int ix = seq & RXRPC_RXTX_BUFF_MASK; 662 u8 annotation = call->rxtx_annotations[ix]; 663 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK; 664 665 if (anno_type != RXRPC_TX_ANNO_UNACK) 666 continue; 667 annotation &= ~RXRPC_TX_ANNO_MASK; 668 annotation |= RXRPC_TX_ANNO_RETRANS; 669 call->rxtx_annotations[ix] = annotation; 670 resend = true; 671 } 672 } 673 674 spin_unlock_bh(&call->lock); 675 676 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) 677 rxrpc_queue_call(call); 678 } 679 680 /* 681 * Process a ping response. 682 */ 683 static void rxrpc_input_ping_response(struct rxrpc_call *call, 684 ktime_t resp_time, 685 rxrpc_serial_t orig_serial, 686 rxrpc_serial_t ack_serial) 687 { 688 rxrpc_serial_t ping_serial; 689 ktime_t ping_time; 690 691 ping_time = call->ping_time; 692 smp_rmb(); 693 ping_serial = READ_ONCE(call->ping_serial); 694 695 if (orig_serial == call->acks_lost_ping) 696 rxrpc_input_check_for_lost_ack(call); 697 698 if (before(orig_serial, ping_serial) || 699 !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags)) 700 return; 701 if (after(orig_serial, ping_serial)) 702 return; 703 704 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response, 705 orig_serial, ack_serial, ping_time, resp_time); 706 } 707 708 /* 709 * Process the extra information that may be appended to an ACK packet 710 */ 711 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, 712 struct rxrpc_ackinfo *ackinfo) 713 { 714 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 715 struct rxrpc_peer *peer; 716 unsigned int mtu; 717 bool wake = false; 718 u32 rwind = ntohl(ackinfo->rwind); 719 720 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", 721 sp->hdr.serial, 722 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU), 723 rwind, ntohl(ackinfo->jumbo_max)); 724 725 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) 726 rwind = RXRPC_RXTX_BUFF_SIZE - 1; 727 if (call->tx_winsize != rwind) { 728 if (rwind > call->tx_winsize) 729 wake = true; 730 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake); 731 call->tx_winsize = rwind; 732 } 733 734 if (call->cong_ssthresh > rwind) 735 call->cong_ssthresh = rwind; 736 737 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); 738 739 peer = call->peer; 740 if (mtu < peer->maxdata) { 741 spin_lock_bh(&peer->lock); 742 peer->maxdata = mtu; 743 peer->mtu = mtu + peer->hdrsize; 744 spin_unlock_bh(&peer->lock); 745 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 746 } 747 748 if (wake) 749 wake_up(&call->waitq); 750 } 751 752 /* 753 * Process individual soft ACKs. 754 * 755 * Each ACK in the array corresponds to one packet and can be either an ACK or 756 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 757 * packets that lie beyond the end of the ACK list are scheduled for resend by 758 * the timer on the basis that the peer might just not have processed them at 759 * the time the ACK was sent. 760 */ 761 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, 762 rxrpc_seq_t seq, int nr_acks, 763 struct rxrpc_ack_summary *summary) 764 { 765 int ix; 766 u8 annotation, anno_type; 767 768 for (; nr_acks > 0; nr_acks--, seq++) { 769 ix = seq & RXRPC_RXTX_BUFF_MASK; 770 annotation = call->rxtx_annotations[ix]; 771 anno_type = annotation & RXRPC_TX_ANNO_MASK; 772 annotation &= ~RXRPC_TX_ANNO_MASK; 773 switch (*acks++) { 774 case RXRPC_ACK_TYPE_ACK: 775 summary->nr_acks++; 776 if (anno_type == RXRPC_TX_ANNO_ACK) 777 continue; 778 summary->nr_new_acks++; 779 call->rxtx_annotations[ix] = 780 RXRPC_TX_ANNO_ACK | annotation; 781 break; 782 case RXRPC_ACK_TYPE_NACK: 783 if (!summary->nr_nacks && 784 call->acks_lowest_nak != seq) { 785 call->acks_lowest_nak = seq; 786 summary->new_low_nack = true; 787 } 788 summary->nr_nacks++; 789 if (anno_type == RXRPC_TX_ANNO_NAK) 790 continue; 791 summary->nr_new_nacks++; 792 if (anno_type == RXRPC_TX_ANNO_RETRANS) 793 continue; 794 call->rxtx_annotations[ix] = 795 RXRPC_TX_ANNO_NAK | annotation; 796 break; 797 default: 798 return rxrpc_proto_abort("SFT", call, 0); 799 } 800 } 801 } 802 803 /* 804 * Return true if the ACK is valid - ie. it doesn't appear to have regressed 805 * with respect to the ack state conveyed by preceding ACKs. 806 */ 807 static bool rxrpc_is_ack_valid(struct rxrpc_call *call, 808 rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt) 809 { 810 rxrpc_seq_t base = READ_ONCE(call->ackr_first_seq); 811 812 if (after(first_pkt, base)) 813 return true; /* The window advanced */ 814 815 if (before(first_pkt, base)) 816 return false; /* firstPacket regressed */ 817 818 if (after_eq(prev_pkt, call->ackr_prev_seq)) 819 return true; /* previousPacket hasn't regressed. */ 820 821 /* Some rx implementations put a serial number in previousPacket. */ 822 if (after_eq(prev_pkt, base + call->tx_winsize)) 823 return false; 824 return true; 825 } 826 827 /* 828 * Process an ACK packet. 829 * 830 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 831 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 832 * 833 * A hard-ACK means that a packet has been processed and may be discarded; a 834 * soft-ACK means that the packet may be discarded and retransmission 835 * requested. A phase is complete when all packets are hard-ACK'd. 836 */ 837 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb) 838 { 839 struct rxrpc_ack_summary summary = { 0 }; 840 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 841 union { 842 struct rxrpc_ackpacket ack; 843 struct rxrpc_ackinfo info; 844 u8 acks[RXRPC_MAXACKS]; 845 } buf; 846 rxrpc_serial_t acked_serial; 847 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; 848 int nr_acks, offset, ioffset; 849 850 _enter(""); 851 852 offset = sizeof(struct rxrpc_wire_header); 853 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { 854 _debug("extraction failure"); 855 return rxrpc_proto_abort("XAK", call, 0); 856 } 857 offset += sizeof(buf.ack); 858 859 acked_serial = ntohl(buf.ack.serial); 860 first_soft_ack = ntohl(buf.ack.firstPacket); 861 prev_pkt = ntohl(buf.ack.previousPacket); 862 hard_ack = first_soft_ack - 1; 863 nr_acks = buf.ack.nAcks; 864 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? 865 buf.ack.reason : RXRPC_ACK__INVALID); 866 867 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial, 868 first_soft_ack, prev_pkt, 869 summary.ack_reason, nr_acks); 870 871 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) 872 rxrpc_input_ping_response(call, skb->tstamp, acked_serial, 873 sp->hdr.serial); 874 if (buf.ack.reason == RXRPC_ACK_REQUESTED) 875 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial, 876 sp->hdr.serial); 877 878 if (buf.ack.reason == RXRPC_ACK_PING) { 879 _proto("Rx ACK %%%u PING Request", sp->hdr.serial); 880 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 881 sp->hdr.serial, true, true, 882 rxrpc_propose_ack_respond_to_ping); 883 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { 884 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, 885 sp->hdr.serial, true, true, 886 rxrpc_propose_ack_respond_to_ack); 887 } 888 889 /* Discard any out-of-order or duplicate ACKs (outside lock). */ 890 if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) { 891 trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial, 892 first_soft_ack, call->ackr_first_seq, 893 prev_pkt, call->ackr_prev_seq); 894 return; 895 } 896 897 buf.info.rxMTU = 0; 898 ioffset = offset + nr_acks + 3; 899 if (skb->len >= ioffset + sizeof(buf.info) && 900 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) 901 return rxrpc_proto_abort("XAI", call, 0); 902 903 spin_lock(&call->input_lock); 904 905 /* Discard any out-of-order or duplicate ACKs (inside lock). */ 906 if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) { 907 trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial, 908 first_soft_ack, call->ackr_first_seq, 909 prev_pkt, call->ackr_prev_seq); 910 goto out; 911 } 912 call->acks_latest_ts = skb->tstamp; 913 914 call->ackr_first_seq = first_soft_ack; 915 call->ackr_prev_seq = prev_pkt; 916 917 /* Parse rwind and mtu sizes if provided. */ 918 if (buf.info.rxMTU) 919 rxrpc_input_ackinfo(call, skb, &buf.info); 920 921 if (first_soft_ack == 0) { 922 rxrpc_proto_abort("AK0", call, 0); 923 goto out; 924 } 925 926 /* Ignore ACKs unless we are or have just been transmitting. */ 927 switch (READ_ONCE(call->state)) { 928 case RXRPC_CALL_CLIENT_SEND_REQUEST: 929 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 930 case RXRPC_CALL_SERVER_SEND_REPLY: 931 case RXRPC_CALL_SERVER_AWAIT_ACK: 932 break; 933 default: 934 goto out; 935 } 936 937 if (before(hard_ack, call->tx_hard_ack) || 938 after(hard_ack, call->tx_top)) { 939 rxrpc_proto_abort("AKW", call, 0); 940 goto out; 941 } 942 if (nr_acks > call->tx_top - hard_ack) { 943 rxrpc_proto_abort("AKN", call, 0); 944 goto out; 945 } 946 947 if (after(hard_ack, call->tx_hard_ack)) { 948 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { 949 rxrpc_end_tx_phase(call, false, "ETA"); 950 goto out; 951 } 952 } 953 954 if (nr_acks > 0) { 955 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) { 956 rxrpc_proto_abort("XSA", call, 0); 957 goto out; 958 } 959 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, 960 &summary); 961 } 962 963 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 964 RXRPC_TX_ANNO_LAST && 965 summary.nr_acks == call->tx_top - hard_ack && 966 rxrpc_is_client_call(call)) 967 rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial, 968 false, true, 969 rxrpc_propose_ack_ping_for_lost_reply); 970 971 rxrpc_congestion_management(call, skb, &summary, acked_serial); 972 out: 973 spin_unlock(&call->input_lock); 974 } 975 976 /* 977 * Process an ACKALL packet. 978 */ 979 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 980 { 981 struct rxrpc_ack_summary summary = { 0 }; 982 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 983 984 _proto("Rx ACKALL %%%u", sp->hdr.serial); 985 986 spin_lock(&call->input_lock); 987 988 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) 989 rxrpc_end_tx_phase(call, false, "ETL"); 990 991 spin_unlock(&call->input_lock); 992 } 993 994 /* 995 * Process an ABORT packet directed at a call. 996 */ 997 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 998 { 999 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1000 __be32 wtmp; 1001 u32 abort_code = RX_CALL_DEAD; 1002 1003 _enter(""); 1004 1005 if (skb->len >= 4 && 1006 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 1007 &wtmp, sizeof(wtmp)) >= 0) 1008 abort_code = ntohl(wtmp); 1009 1010 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code); 1011 1012 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); 1013 1014 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1015 abort_code, -ECONNABORTED); 1016 } 1017 1018 /* 1019 * Process an incoming call packet. 1020 */ 1021 static void rxrpc_input_call_packet(struct rxrpc_call *call, 1022 struct sk_buff *skb) 1023 { 1024 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1025 unsigned long timo; 1026 1027 _enter("%p,%p", call, skb); 1028 1029 timo = READ_ONCE(call->next_rx_timo); 1030 if (timo) { 1031 unsigned long now = jiffies, expect_rx_by; 1032 1033 expect_rx_by = now + timo; 1034 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 1035 rxrpc_reduce_call_timer(call, expect_rx_by, now, 1036 rxrpc_timer_set_for_normal); 1037 } 1038 1039 switch (sp->hdr.type) { 1040 case RXRPC_PACKET_TYPE_DATA: 1041 rxrpc_input_data(call, skb); 1042 goto no_free; 1043 1044 case RXRPC_PACKET_TYPE_ACK: 1045 rxrpc_input_ack(call, skb); 1046 break; 1047 1048 case RXRPC_PACKET_TYPE_BUSY: 1049 _proto("Rx BUSY %%%u", sp->hdr.serial); 1050 1051 /* Just ignore BUSY packets from the server; the retry and 1052 * lifespan timers will take care of business. BUSY packets 1053 * from the client don't make sense. 1054 */ 1055 break; 1056 1057 case RXRPC_PACKET_TYPE_ABORT: 1058 rxrpc_input_abort(call, skb); 1059 break; 1060 1061 case RXRPC_PACKET_TYPE_ACKALL: 1062 rxrpc_input_ackall(call, skb); 1063 break; 1064 1065 default: 1066 break; 1067 } 1068 1069 rxrpc_free_skb(skb, rxrpc_skb_freed); 1070 no_free: 1071 _leave(""); 1072 } 1073 1074 /* 1075 * Handle a new service call on a channel implicitly completing the preceding 1076 * call on that channel. This does not apply to client conns. 1077 * 1078 * TODO: If callNumber > call_id + 1, renegotiate security. 1079 */ 1080 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, 1081 struct rxrpc_connection *conn, 1082 struct rxrpc_call *call) 1083 { 1084 switch (READ_ONCE(call->state)) { 1085 case RXRPC_CALL_SERVER_AWAIT_ACK: 1086 rxrpc_call_completed(call); 1087 /* Fall through */ 1088 case RXRPC_CALL_COMPLETE: 1089 break; 1090 default: 1091 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) { 1092 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 1093 rxrpc_queue_call(call); 1094 } 1095 trace_rxrpc_improper_term(call); 1096 break; 1097 } 1098 1099 spin_lock(&rx->incoming_lock); 1100 __rxrpc_disconnect_call(conn, call); 1101 spin_unlock(&rx->incoming_lock); 1102 } 1103 1104 /* 1105 * post connection-level events to the connection 1106 * - this includes challenges, responses, some aborts and call terminal packet 1107 * retransmission. 1108 */ 1109 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 1110 struct sk_buff *skb) 1111 { 1112 _enter("%p,%p", conn, skb); 1113 1114 skb_queue_tail(&conn->rx_queue, skb); 1115 rxrpc_queue_conn(conn); 1116 } 1117 1118 /* 1119 * post endpoint-level events to the local endpoint 1120 * - this includes debug and version messages 1121 */ 1122 static void rxrpc_post_packet_to_local(struct rxrpc_local *local, 1123 struct sk_buff *skb) 1124 { 1125 _enter("%p,%p", local, skb); 1126 1127 if (rxrpc_get_local_maybe(local)) { 1128 skb_queue_tail(&local->event_queue, skb); 1129 rxrpc_queue_local(local); 1130 } else { 1131 rxrpc_free_skb(skb, rxrpc_skb_freed); 1132 } 1133 } 1134 1135 /* 1136 * put a packet up for transport-level abort 1137 */ 1138 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 1139 { 1140 CHECK_SLAB_OKAY(&local->usage); 1141 1142 if (rxrpc_get_local_maybe(local)) { 1143 skb_queue_tail(&local->reject_queue, skb); 1144 rxrpc_queue_local(local); 1145 } else { 1146 rxrpc_free_skb(skb, rxrpc_skb_freed); 1147 } 1148 } 1149 1150 /* 1151 * Extract the wire header from a packet and translate the byte order. 1152 */ 1153 static noinline 1154 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) 1155 { 1156 struct rxrpc_wire_header whdr; 1157 1158 /* dig out the RxRPC connection details */ 1159 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) { 1160 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 1161 tracepoint_string("bad_hdr")); 1162 return -EBADMSG; 1163 } 1164 1165 memset(sp, 0, sizeof(*sp)); 1166 sp->hdr.epoch = ntohl(whdr.epoch); 1167 sp->hdr.cid = ntohl(whdr.cid); 1168 sp->hdr.callNumber = ntohl(whdr.callNumber); 1169 sp->hdr.seq = ntohl(whdr.seq); 1170 sp->hdr.serial = ntohl(whdr.serial); 1171 sp->hdr.flags = whdr.flags; 1172 sp->hdr.type = whdr.type; 1173 sp->hdr.userStatus = whdr.userStatus; 1174 sp->hdr.securityIndex = whdr.securityIndex; 1175 sp->hdr._rsvd = ntohs(whdr._rsvd); 1176 sp->hdr.serviceId = ntohs(whdr.serviceId); 1177 return 0; 1178 } 1179 1180 /* 1181 * handle data received on the local endpoint 1182 * - may be called in interrupt context 1183 * 1184 * [!] Note that as this is called from the encap_rcv hook, the socket is not 1185 * held locked by the caller and nothing prevents sk_user_data on the UDP from 1186 * being cleared in the middle of processing this function. 1187 * 1188 * Called with the RCU read lock held from the IP layer via UDP. 1189 */ 1190 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb) 1191 { 1192 struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk); 1193 struct rxrpc_connection *conn; 1194 struct rxrpc_channel *chan; 1195 struct rxrpc_call *call = NULL; 1196 struct rxrpc_skb_priv *sp; 1197 struct rxrpc_peer *peer = NULL; 1198 struct rxrpc_sock *rx = NULL; 1199 unsigned int channel; 1200 1201 _enter("%p", udp_sk); 1202 1203 if (unlikely(!local)) { 1204 kfree_skb(skb); 1205 return 0; 1206 } 1207 if (skb->tstamp == 0) 1208 skb->tstamp = ktime_get_real(); 1209 1210 rxrpc_new_skb(skb, rxrpc_skb_received); 1211 1212 skb_pull(skb, sizeof(struct udphdr)); 1213 1214 /* The UDP protocol already released all skb resources; 1215 * we are free to add our own data there. 1216 */ 1217 sp = rxrpc_skb(skb); 1218 1219 /* dig out the RxRPC connection details */ 1220 if (rxrpc_extract_header(sp, skb) < 0) 1221 goto bad_message; 1222 1223 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { 1224 static int lose; 1225 if ((lose++ & 7) == 7) { 1226 trace_rxrpc_rx_lose(sp); 1227 rxrpc_free_skb(skb, rxrpc_skb_lost); 1228 return 0; 1229 } 1230 } 1231 1232 if (skb->tstamp == 0) 1233 skb->tstamp = ktime_get_real(); 1234 trace_rxrpc_rx_packet(sp); 1235 1236 switch (sp->hdr.type) { 1237 case RXRPC_PACKET_TYPE_VERSION: 1238 if (rxrpc_to_client(sp)) 1239 goto discard; 1240 rxrpc_post_packet_to_local(local, skb); 1241 goto out; 1242 1243 case RXRPC_PACKET_TYPE_BUSY: 1244 if (rxrpc_to_server(sp)) 1245 goto discard; 1246 /* Fall through */ 1247 case RXRPC_PACKET_TYPE_ACK: 1248 case RXRPC_PACKET_TYPE_ACKALL: 1249 if (sp->hdr.callNumber == 0) 1250 goto bad_message; 1251 /* Fall through */ 1252 case RXRPC_PACKET_TYPE_ABORT: 1253 break; 1254 1255 case RXRPC_PACKET_TYPE_DATA: 1256 if (sp->hdr.callNumber == 0 || 1257 sp->hdr.seq == 0) 1258 goto bad_message; 1259 if (!rxrpc_validate_data(skb)) 1260 goto bad_message; 1261 1262 /* Unshare the packet so that it can be modified for in-place 1263 * decryption. 1264 */ 1265 if (sp->hdr.securityIndex != 0) { 1266 struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC); 1267 if (!nskb) { 1268 rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem); 1269 goto out; 1270 } 1271 1272 if (nskb != skb) { 1273 rxrpc_eaten_skb(skb, rxrpc_skb_received); 1274 skb = nskb; 1275 rxrpc_new_skb(skb, rxrpc_skb_unshared); 1276 sp = rxrpc_skb(skb); 1277 } 1278 } 1279 break; 1280 1281 case RXRPC_PACKET_TYPE_CHALLENGE: 1282 if (rxrpc_to_server(sp)) 1283 goto discard; 1284 break; 1285 case RXRPC_PACKET_TYPE_RESPONSE: 1286 if (rxrpc_to_client(sp)) 1287 goto discard; 1288 break; 1289 1290 /* Packet types 9-11 should just be ignored. */ 1291 case RXRPC_PACKET_TYPE_PARAMS: 1292 case RXRPC_PACKET_TYPE_10: 1293 case RXRPC_PACKET_TYPE_11: 1294 goto discard; 1295 1296 default: 1297 _proto("Rx Bad Packet Type %u", sp->hdr.type); 1298 goto bad_message; 1299 } 1300 1301 if (sp->hdr.serviceId == 0) 1302 goto bad_message; 1303 1304 if (rxrpc_to_server(sp)) { 1305 /* Weed out packets to services we're not offering. Packets 1306 * that would begin a call are explicitly rejected and the rest 1307 * are just discarded. 1308 */ 1309 rx = rcu_dereference(local->service); 1310 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service && 1311 sp->hdr.serviceId != rx->second_service)) { 1312 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && 1313 sp->hdr.seq == 1) 1314 goto unsupported_service; 1315 goto discard; 1316 } 1317 } 1318 1319 conn = rxrpc_find_connection_rcu(local, skb, &peer); 1320 if (conn) { 1321 if (sp->hdr.securityIndex != conn->security_ix) 1322 goto wrong_security; 1323 1324 if (sp->hdr.serviceId != conn->service_id) { 1325 int old_id; 1326 1327 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) 1328 goto reupgrade; 1329 old_id = cmpxchg(&conn->service_id, conn->params.service_id, 1330 sp->hdr.serviceId); 1331 1332 if (old_id != conn->params.service_id && 1333 old_id != sp->hdr.serviceId) 1334 goto reupgrade; 1335 } 1336 1337 if (sp->hdr.callNumber == 0) { 1338 /* Connection-level packet */ 1339 _debug("CONN %p {%d}", conn, conn->debug_id); 1340 rxrpc_post_packet_to_conn(conn, skb); 1341 goto out; 1342 } 1343 1344 if ((int)sp->hdr.serial - (int)conn->hi_serial > 0) 1345 conn->hi_serial = sp->hdr.serial; 1346 1347 /* Call-bound packets are routed by connection channel. */ 1348 channel = sp->hdr.cid & RXRPC_CHANNELMASK; 1349 chan = &conn->channels[channel]; 1350 1351 /* Ignore really old calls */ 1352 if (sp->hdr.callNumber < chan->last_call) 1353 goto discard; 1354 1355 if (sp->hdr.callNumber == chan->last_call) { 1356 if (chan->call || 1357 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) 1358 goto discard; 1359 1360 /* For the previous service call, if completed 1361 * successfully, we discard all further packets. 1362 */ 1363 if (rxrpc_conn_is_service(conn) && 1364 chan->last_type == RXRPC_PACKET_TYPE_ACK) 1365 goto discard; 1366 1367 /* But otherwise we need to retransmit the final packet 1368 * from data cached in the connection record. 1369 */ 1370 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) 1371 trace_rxrpc_rx_data(chan->call_debug_id, 1372 sp->hdr.seq, 1373 sp->hdr.serial, 1374 sp->hdr.flags, 0); 1375 rxrpc_post_packet_to_conn(conn, skb); 1376 goto out; 1377 } 1378 1379 call = rcu_dereference(chan->call); 1380 1381 if (sp->hdr.callNumber > chan->call_id) { 1382 if (rxrpc_to_client(sp)) 1383 goto reject_packet; 1384 if (call) 1385 rxrpc_input_implicit_end_call(rx, conn, call); 1386 call = NULL; 1387 } 1388 1389 if (call) { 1390 if (sp->hdr.serviceId != call->service_id) 1391 call->service_id = sp->hdr.serviceId; 1392 if ((int)sp->hdr.serial - (int)call->rx_serial > 0) 1393 call->rx_serial = sp->hdr.serial; 1394 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) 1395 set_bit(RXRPC_CALL_RX_HEARD, &call->flags); 1396 } 1397 } 1398 1399 if (!call || atomic_read(&call->usage) == 0) { 1400 if (rxrpc_to_client(sp) || 1401 sp->hdr.type != RXRPC_PACKET_TYPE_DATA) 1402 goto bad_message; 1403 if (sp->hdr.seq != 1) 1404 goto discard; 1405 call = rxrpc_new_incoming_call(local, rx, skb); 1406 if (!call) 1407 goto reject_packet; 1408 } 1409 1410 /* Process a call packet; this either discards or passes on the ref 1411 * elsewhere. 1412 */ 1413 rxrpc_input_call_packet(call, skb); 1414 goto out; 1415 1416 discard: 1417 rxrpc_free_skb(skb, rxrpc_skb_freed); 1418 out: 1419 trace_rxrpc_rx_done(0, 0); 1420 return 0; 1421 1422 wrong_security: 1423 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1424 RXKADINCONSISTENCY, EBADMSG); 1425 skb->priority = RXKADINCONSISTENCY; 1426 goto post_abort; 1427 1428 unsupported_service: 1429 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1430 RX_INVALID_OPERATION, EOPNOTSUPP); 1431 skb->priority = RX_INVALID_OPERATION; 1432 goto post_abort; 1433 1434 reupgrade: 1435 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1436 RX_PROTOCOL_ERROR, EBADMSG); 1437 goto protocol_error; 1438 1439 bad_message: 1440 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1441 RX_PROTOCOL_ERROR, EBADMSG); 1442 protocol_error: 1443 skb->priority = RX_PROTOCOL_ERROR; 1444 post_abort: 1445 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT; 1446 reject_packet: 1447 trace_rxrpc_rx_done(skb->mark, skb->priority); 1448 rxrpc_reject_packet(local, skb); 1449 _leave(" [badmsg]"); 1450 return 0; 1451 } 1452