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 (call->tx_winsize != rwind) { 726 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) 727 rwind = RXRPC_RXTX_BUFF_SIZE - 1; 728 if (rwind > call->tx_winsize) 729 wake = true; 730 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, 731 ntohl(ackinfo->rwind), wake); 732 call->tx_winsize = rwind; 733 } 734 735 if (call->cong_ssthresh > rwind) 736 call->cong_ssthresh = rwind; 737 738 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); 739 740 peer = call->peer; 741 if (mtu < peer->maxdata) { 742 spin_lock_bh(&peer->lock); 743 peer->maxdata = mtu; 744 peer->mtu = mtu + peer->hdrsize; 745 spin_unlock_bh(&peer->lock); 746 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); 747 } 748 749 if (wake) 750 wake_up(&call->waitq); 751 } 752 753 /* 754 * Process individual soft ACKs. 755 * 756 * Each ACK in the array corresponds to one packet and can be either an ACK or 757 * a NAK. If we get find an explicitly NAK'd packet we resend immediately; 758 * packets that lie beyond the end of the ACK list are scheduled for resend by 759 * the timer on the basis that the peer might just not have processed them at 760 * the time the ACK was sent. 761 */ 762 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, 763 rxrpc_seq_t seq, int nr_acks, 764 struct rxrpc_ack_summary *summary) 765 { 766 int ix; 767 u8 annotation, anno_type; 768 769 for (; nr_acks > 0; nr_acks--, seq++) { 770 ix = seq & RXRPC_RXTX_BUFF_MASK; 771 annotation = call->rxtx_annotations[ix]; 772 anno_type = annotation & RXRPC_TX_ANNO_MASK; 773 annotation &= ~RXRPC_TX_ANNO_MASK; 774 switch (*acks++) { 775 case RXRPC_ACK_TYPE_ACK: 776 summary->nr_acks++; 777 if (anno_type == RXRPC_TX_ANNO_ACK) 778 continue; 779 summary->nr_new_acks++; 780 call->rxtx_annotations[ix] = 781 RXRPC_TX_ANNO_ACK | annotation; 782 break; 783 case RXRPC_ACK_TYPE_NACK: 784 if (!summary->nr_nacks && 785 call->acks_lowest_nak != seq) { 786 call->acks_lowest_nak = seq; 787 summary->new_low_nack = true; 788 } 789 summary->nr_nacks++; 790 if (anno_type == RXRPC_TX_ANNO_NAK) 791 continue; 792 summary->nr_new_nacks++; 793 if (anno_type == RXRPC_TX_ANNO_RETRANS) 794 continue; 795 call->rxtx_annotations[ix] = 796 RXRPC_TX_ANNO_NAK | annotation; 797 break; 798 default: 799 return rxrpc_proto_abort("SFT", call, 0); 800 } 801 } 802 } 803 804 /* 805 * Return true if the ACK is valid - ie. it doesn't appear to have regressed 806 * with respect to the ack state conveyed by preceding ACKs. 807 */ 808 static bool rxrpc_is_ack_valid(struct rxrpc_call *call, 809 rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt) 810 { 811 rxrpc_seq_t base = READ_ONCE(call->ackr_first_seq); 812 813 if (after(first_pkt, base)) 814 return true; /* The window advanced */ 815 816 if (before(first_pkt, base)) 817 return false; /* firstPacket regressed */ 818 819 if (after_eq(prev_pkt, call->ackr_prev_seq)) 820 return true; /* previousPacket hasn't regressed. */ 821 822 /* Some rx implementations put a serial number in previousPacket. */ 823 if (after_eq(prev_pkt, base + call->tx_winsize)) 824 return false; 825 return true; 826 } 827 828 /* 829 * Process an ACK packet. 830 * 831 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet 832 * in the ACK array. Anything before that is hard-ACK'd and may be discarded. 833 * 834 * A hard-ACK means that a packet has been processed and may be discarded; a 835 * soft-ACK means that the packet may be discarded and retransmission 836 * requested. A phase is complete when all packets are hard-ACK'd. 837 */ 838 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb) 839 { 840 struct rxrpc_ack_summary summary = { 0 }; 841 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 842 union { 843 struct rxrpc_ackpacket ack; 844 struct rxrpc_ackinfo info; 845 u8 acks[RXRPC_MAXACKS]; 846 } buf; 847 rxrpc_serial_t acked_serial; 848 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; 849 int nr_acks, offset, ioffset; 850 851 _enter(""); 852 853 offset = sizeof(struct rxrpc_wire_header); 854 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { 855 _debug("extraction failure"); 856 return rxrpc_proto_abort("XAK", call, 0); 857 } 858 offset += sizeof(buf.ack); 859 860 acked_serial = ntohl(buf.ack.serial); 861 first_soft_ack = ntohl(buf.ack.firstPacket); 862 prev_pkt = ntohl(buf.ack.previousPacket); 863 hard_ack = first_soft_ack - 1; 864 nr_acks = buf.ack.nAcks; 865 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? 866 buf.ack.reason : RXRPC_ACK__INVALID); 867 868 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial, 869 first_soft_ack, prev_pkt, 870 summary.ack_reason, nr_acks); 871 872 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) 873 rxrpc_input_ping_response(call, skb->tstamp, acked_serial, 874 sp->hdr.serial); 875 if (buf.ack.reason == RXRPC_ACK_REQUESTED) 876 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial, 877 sp->hdr.serial); 878 879 if (buf.ack.reason == RXRPC_ACK_PING) { 880 _proto("Rx ACK %%%u PING Request", sp->hdr.serial); 881 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, 882 sp->hdr.serial, true, true, 883 rxrpc_propose_ack_respond_to_ping); 884 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { 885 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, 886 sp->hdr.serial, true, true, 887 rxrpc_propose_ack_respond_to_ack); 888 } 889 890 /* Discard any out-of-order or duplicate ACKs (outside lock). */ 891 if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) { 892 trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial, 893 first_soft_ack, call->ackr_first_seq, 894 prev_pkt, call->ackr_prev_seq); 895 return; 896 } 897 898 buf.info.rxMTU = 0; 899 ioffset = offset + nr_acks + 3; 900 if (skb->len >= ioffset + sizeof(buf.info) && 901 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) 902 return rxrpc_proto_abort("XAI", call, 0); 903 904 spin_lock(&call->input_lock); 905 906 /* Discard any out-of-order or duplicate ACKs (inside lock). */ 907 if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) { 908 trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial, 909 first_soft_ack, call->ackr_first_seq, 910 prev_pkt, call->ackr_prev_seq); 911 goto out; 912 } 913 call->acks_latest_ts = skb->tstamp; 914 915 call->ackr_first_seq = first_soft_ack; 916 call->ackr_prev_seq = prev_pkt; 917 918 /* Parse rwind and mtu sizes if provided. */ 919 if (buf.info.rxMTU) 920 rxrpc_input_ackinfo(call, skb, &buf.info); 921 922 if (first_soft_ack == 0) { 923 rxrpc_proto_abort("AK0", call, 0); 924 goto out; 925 } 926 927 /* Ignore ACKs unless we are or have just been transmitting. */ 928 switch (READ_ONCE(call->state)) { 929 case RXRPC_CALL_CLIENT_SEND_REQUEST: 930 case RXRPC_CALL_CLIENT_AWAIT_REPLY: 931 case RXRPC_CALL_SERVER_SEND_REPLY: 932 case RXRPC_CALL_SERVER_AWAIT_ACK: 933 break; 934 default: 935 goto out; 936 } 937 938 if (before(hard_ack, call->tx_hard_ack) || 939 after(hard_ack, call->tx_top)) { 940 rxrpc_proto_abort("AKW", call, 0); 941 goto out; 942 } 943 if (nr_acks > call->tx_top - hard_ack) { 944 rxrpc_proto_abort("AKN", call, 0); 945 goto out; 946 } 947 948 if (after(hard_ack, call->tx_hard_ack)) { 949 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { 950 rxrpc_end_tx_phase(call, false, "ETA"); 951 goto out; 952 } 953 } 954 955 if (nr_acks > 0) { 956 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) { 957 rxrpc_proto_abort("XSA", call, 0); 958 goto out; 959 } 960 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, 961 &summary); 962 } 963 964 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & 965 RXRPC_TX_ANNO_LAST && 966 summary.nr_acks == call->tx_top - hard_ack && 967 rxrpc_is_client_call(call)) 968 rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial, 969 false, true, 970 rxrpc_propose_ack_ping_for_lost_reply); 971 972 rxrpc_congestion_management(call, skb, &summary, acked_serial); 973 out: 974 spin_unlock(&call->input_lock); 975 } 976 977 /* 978 * Process an ACKALL packet. 979 */ 980 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) 981 { 982 struct rxrpc_ack_summary summary = { 0 }; 983 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 984 985 _proto("Rx ACKALL %%%u", sp->hdr.serial); 986 987 spin_lock(&call->input_lock); 988 989 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) 990 rxrpc_end_tx_phase(call, false, "ETL"); 991 992 spin_unlock(&call->input_lock); 993 } 994 995 /* 996 * Process an ABORT packet directed at a call. 997 */ 998 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) 999 { 1000 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1001 __be32 wtmp; 1002 u32 abort_code = RX_CALL_DEAD; 1003 1004 _enter(""); 1005 1006 if (skb->len >= 4 && 1007 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 1008 &wtmp, sizeof(wtmp)) >= 0) 1009 abort_code = ntohl(wtmp); 1010 1011 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code); 1012 1013 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); 1014 1015 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 1016 abort_code, -ECONNABORTED); 1017 } 1018 1019 /* 1020 * Process an incoming call packet. 1021 */ 1022 static void rxrpc_input_call_packet(struct rxrpc_call *call, 1023 struct sk_buff *skb) 1024 { 1025 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 1026 unsigned long timo; 1027 1028 _enter("%p,%p", call, skb); 1029 1030 timo = READ_ONCE(call->next_rx_timo); 1031 if (timo) { 1032 unsigned long now = jiffies, expect_rx_by; 1033 1034 expect_rx_by = now + timo; 1035 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 1036 rxrpc_reduce_call_timer(call, expect_rx_by, now, 1037 rxrpc_timer_set_for_normal); 1038 } 1039 1040 switch (sp->hdr.type) { 1041 case RXRPC_PACKET_TYPE_DATA: 1042 rxrpc_input_data(call, skb); 1043 goto no_free; 1044 1045 case RXRPC_PACKET_TYPE_ACK: 1046 rxrpc_input_ack(call, skb); 1047 break; 1048 1049 case RXRPC_PACKET_TYPE_BUSY: 1050 _proto("Rx BUSY %%%u", sp->hdr.serial); 1051 1052 /* Just ignore BUSY packets from the server; the retry and 1053 * lifespan timers will take care of business. BUSY packets 1054 * from the client don't make sense. 1055 */ 1056 break; 1057 1058 case RXRPC_PACKET_TYPE_ABORT: 1059 rxrpc_input_abort(call, skb); 1060 break; 1061 1062 case RXRPC_PACKET_TYPE_ACKALL: 1063 rxrpc_input_ackall(call, skb); 1064 break; 1065 1066 default: 1067 break; 1068 } 1069 1070 rxrpc_free_skb(skb, rxrpc_skb_freed); 1071 no_free: 1072 _leave(""); 1073 } 1074 1075 /* 1076 * Handle a new service call on a channel implicitly completing the preceding 1077 * call on that channel. This does not apply to client conns. 1078 * 1079 * TODO: If callNumber > call_id + 1, renegotiate security. 1080 */ 1081 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, 1082 struct rxrpc_connection *conn, 1083 struct rxrpc_call *call) 1084 { 1085 switch (READ_ONCE(call->state)) { 1086 case RXRPC_CALL_SERVER_AWAIT_ACK: 1087 rxrpc_call_completed(call); 1088 /* Fall through */ 1089 case RXRPC_CALL_COMPLETE: 1090 break; 1091 default: 1092 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) { 1093 set_bit(RXRPC_CALL_EV_ABORT, &call->events); 1094 rxrpc_queue_call(call); 1095 } 1096 trace_rxrpc_improper_term(call); 1097 break; 1098 } 1099 1100 spin_lock(&rx->incoming_lock); 1101 __rxrpc_disconnect_call(conn, call); 1102 spin_unlock(&rx->incoming_lock); 1103 } 1104 1105 /* 1106 * post connection-level events to the connection 1107 * - this includes challenges, responses, some aborts and call terminal packet 1108 * retransmission. 1109 */ 1110 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 1111 struct sk_buff *skb) 1112 { 1113 _enter("%p,%p", conn, skb); 1114 1115 skb_queue_tail(&conn->rx_queue, skb); 1116 rxrpc_queue_conn(conn); 1117 } 1118 1119 /* 1120 * post endpoint-level events to the local endpoint 1121 * - this includes debug and version messages 1122 */ 1123 static void rxrpc_post_packet_to_local(struct rxrpc_local *local, 1124 struct sk_buff *skb) 1125 { 1126 _enter("%p,%p", local, skb); 1127 1128 if (rxrpc_get_local_maybe(local)) { 1129 skb_queue_tail(&local->event_queue, skb); 1130 rxrpc_queue_local(local); 1131 } else { 1132 rxrpc_free_skb(skb, rxrpc_skb_freed); 1133 } 1134 } 1135 1136 /* 1137 * put a packet up for transport-level abort 1138 */ 1139 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 1140 { 1141 CHECK_SLAB_OKAY(&local->usage); 1142 1143 if (rxrpc_get_local_maybe(local)) { 1144 skb_queue_tail(&local->reject_queue, skb); 1145 rxrpc_queue_local(local); 1146 } else { 1147 rxrpc_free_skb(skb, rxrpc_skb_freed); 1148 } 1149 } 1150 1151 /* 1152 * Extract the wire header from a packet and translate the byte order. 1153 */ 1154 static noinline 1155 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) 1156 { 1157 struct rxrpc_wire_header whdr; 1158 1159 /* dig out the RxRPC connection details */ 1160 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) { 1161 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 1162 tracepoint_string("bad_hdr")); 1163 return -EBADMSG; 1164 } 1165 1166 memset(sp, 0, sizeof(*sp)); 1167 sp->hdr.epoch = ntohl(whdr.epoch); 1168 sp->hdr.cid = ntohl(whdr.cid); 1169 sp->hdr.callNumber = ntohl(whdr.callNumber); 1170 sp->hdr.seq = ntohl(whdr.seq); 1171 sp->hdr.serial = ntohl(whdr.serial); 1172 sp->hdr.flags = whdr.flags; 1173 sp->hdr.type = whdr.type; 1174 sp->hdr.userStatus = whdr.userStatus; 1175 sp->hdr.securityIndex = whdr.securityIndex; 1176 sp->hdr._rsvd = ntohs(whdr._rsvd); 1177 sp->hdr.serviceId = ntohs(whdr.serviceId); 1178 return 0; 1179 } 1180 1181 /* 1182 * handle data received on the local endpoint 1183 * - may be called in interrupt context 1184 * 1185 * [!] Note that as this is called from the encap_rcv hook, the socket is not 1186 * held locked by the caller and nothing prevents sk_user_data on the UDP from 1187 * being cleared in the middle of processing this function. 1188 * 1189 * Called with the RCU read lock held from the IP layer via UDP. 1190 */ 1191 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb) 1192 { 1193 struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk); 1194 struct rxrpc_connection *conn; 1195 struct rxrpc_channel *chan; 1196 struct rxrpc_call *call = NULL; 1197 struct rxrpc_skb_priv *sp; 1198 struct rxrpc_peer *peer = NULL; 1199 struct rxrpc_sock *rx = NULL; 1200 unsigned int channel; 1201 1202 _enter("%p", udp_sk); 1203 1204 if (unlikely(!local)) { 1205 kfree_skb(skb); 1206 return 0; 1207 } 1208 if (skb->tstamp == 0) 1209 skb->tstamp = ktime_get_real(); 1210 1211 rxrpc_new_skb(skb, rxrpc_skb_received); 1212 1213 skb_pull(skb, sizeof(struct udphdr)); 1214 1215 /* The UDP protocol already released all skb resources; 1216 * we are free to add our own data there. 1217 */ 1218 sp = rxrpc_skb(skb); 1219 1220 /* dig out the RxRPC connection details */ 1221 if (rxrpc_extract_header(sp, skb) < 0) 1222 goto bad_message; 1223 1224 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { 1225 static int lose; 1226 if ((lose++ & 7) == 7) { 1227 trace_rxrpc_rx_lose(sp); 1228 rxrpc_free_skb(skb, rxrpc_skb_lost); 1229 return 0; 1230 } 1231 } 1232 1233 if (skb->tstamp == 0) 1234 skb->tstamp = ktime_get_real(); 1235 trace_rxrpc_rx_packet(sp); 1236 1237 switch (sp->hdr.type) { 1238 case RXRPC_PACKET_TYPE_VERSION: 1239 if (rxrpc_to_client(sp)) 1240 goto discard; 1241 rxrpc_post_packet_to_local(local, skb); 1242 goto out; 1243 1244 case RXRPC_PACKET_TYPE_BUSY: 1245 if (rxrpc_to_server(sp)) 1246 goto discard; 1247 /* Fall through */ 1248 case RXRPC_PACKET_TYPE_ACK: 1249 case RXRPC_PACKET_TYPE_ACKALL: 1250 if (sp->hdr.callNumber == 0) 1251 goto bad_message; 1252 /* Fall through */ 1253 case RXRPC_PACKET_TYPE_ABORT: 1254 break; 1255 1256 case RXRPC_PACKET_TYPE_DATA: 1257 if (sp->hdr.callNumber == 0 || 1258 sp->hdr.seq == 0) 1259 goto bad_message; 1260 if (!rxrpc_validate_data(skb)) 1261 goto bad_message; 1262 1263 /* Unshare the packet so that it can be modified for in-place 1264 * decryption. 1265 */ 1266 if (sp->hdr.securityIndex != 0) { 1267 struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC); 1268 if (!nskb) { 1269 rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem); 1270 goto out; 1271 } 1272 1273 if (nskb != skb) { 1274 rxrpc_eaten_skb(skb, rxrpc_skb_received); 1275 skb = nskb; 1276 rxrpc_new_skb(skb, rxrpc_skb_unshared); 1277 sp = rxrpc_skb(skb); 1278 } 1279 } 1280 break; 1281 1282 case RXRPC_PACKET_TYPE_CHALLENGE: 1283 if (rxrpc_to_server(sp)) 1284 goto discard; 1285 break; 1286 case RXRPC_PACKET_TYPE_RESPONSE: 1287 if (rxrpc_to_client(sp)) 1288 goto discard; 1289 break; 1290 1291 /* Packet types 9-11 should just be ignored. */ 1292 case RXRPC_PACKET_TYPE_PARAMS: 1293 case RXRPC_PACKET_TYPE_10: 1294 case RXRPC_PACKET_TYPE_11: 1295 goto discard; 1296 1297 default: 1298 _proto("Rx Bad Packet Type %u", sp->hdr.type); 1299 goto bad_message; 1300 } 1301 1302 if (sp->hdr.serviceId == 0) 1303 goto bad_message; 1304 1305 if (rxrpc_to_server(sp)) { 1306 /* Weed out packets to services we're not offering. Packets 1307 * that would begin a call are explicitly rejected and the rest 1308 * are just discarded. 1309 */ 1310 rx = rcu_dereference(local->service); 1311 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service && 1312 sp->hdr.serviceId != rx->second_service)) { 1313 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && 1314 sp->hdr.seq == 1) 1315 goto unsupported_service; 1316 goto discard; 1317 } 1318 } 1319 1320 conn = rxrpc_find_connection_rcu(local, skb, &peer); 1321 if (conn) { 1322 if (sp->hdr.securityIndex != conn->security_ix) 1323 goto wrong_security; 1324 1325 if (sp->hdr.serviceId != conn->service_id) { 1326 int old_id; 1327 1328 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) 1329 goto reupgrade; 1330 old_id = cmpxchg(&conn->service_id, conn->params.service_id, 1331 sp->hdr.serviceId); 1332 1333 if (old_id != conn->params.service_id && 1334 old_id != sp->hdr.serviceId) 1335 goto reupgrade; 1336 } 1337 1338 if (sp->hdr.callNumber == 0) { 1339 /* Connection-level packet */ 1340 _debug("CONN %p {%d}", conn, conn->debug_id); 1341 rxrpc_post_packet_to_conn(conn, skb); 1342 goto out; 1343 } 1344 1345 if ((int)sp->hdr.serial - (int)conn->hi_serial > 0) 1346 conn->hi_serial = sp->hdr.serial; 1347 1348 /* Call-bound packets are routed by connection channel. */ 1349 channel = sp->hdr.cid & RXRPC_CHANNELMASK; 1350 chan = &conn->channels[channel]; 1351 1352 /* Ignore really old calls */ 1353 if (sp->hdr.callNumber < chan->last_call) 1354 goto discard; 1355 1356 if (sp->hdr.callNumber == chan->last_call) { 1357 if (chan->call || 1358 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) 1359 goto discard; 1360 1361 /* For the previous service call, if completed 1362 * successfully, we discard all further packets. 1363 */ 1364 if (rxrpc_conn_is_service(conn) && 1365 chan->last_type == RXRPC_PACKET_TYPE_ACK) 1366 goto discard; 1367 1368 /* But otherwise we need to retransmit the final packet 1369 * from data cached in the connection record. 1370 */ 1371 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) 1372 trace_rxrpc_rx_data(chan->call_debug_id, 1373 sp->hdr.seq, 1374 sp->hdr.serial, 1375 sp->hdr.flags, 0); 1376 rxrpc_post_packet_to_conn(conn, skb); 1377 goto out; 1378 } 1379 1380 call = rcu_dereference(chan->call); 1381 1382 if (sp->hdr.callNumber > chan->call_id) { 1383 if (rxrpc_to_client(sp)) 1384 goto reject_packet; 1385 if (call) 1386 rxrpc_input_implicit_end_call(rx, conn, call); 1387 call = NULL; 1388 } 1389 1390 if (call) { 1391 if (sp->hdr.serviceId != call->service_id) 1392 call->service_id = sp->hdr.serviceId; 1393 if ((int)sp->hdr.serial - (int)call->rx_serial > 0) 1394 call->rx_serial = sp->hdr.serial; 1395 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) 1396 set_bit(RXRPC_CALL_RX_HEARD, &call->flags); 1397 } 1398 } 1399 1400 if (!call || atomic_read(&call->usage) == 0) { 1401 if (rxrpc_to_client(sp) || 1402 sp->hdr.type != RXRPC_PACKET_TYPE_DATA) 1403 goto bad_message; 1404 if (sp->hdr.seq != 1) 1405 goto discard; 1406 call = rxrpc_new_incoming_call(local, rx, skb); 1407 if (!call) 1408 goto reject_packet; 1409 } 1410 1411 /* Process a call packet; this either discards or passes on the ref 1412 * elsewhere. 1413 */ 1414 rxrpc_input_call_packet(call, skb); 1415 goto out; 1416 1417 discard: 1418 rxrpc_free_skb(skb, rxrpc_skb_freed); 1419 out: 1420 trace_rxrpc_rx_done(0, 0); 1421 return 0; 1422 1423 wrong_security: 1424 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1425 RXKADINCONSISTENCY, EBADMSG); 1426 skb->priority = RXKADINCONSISTENCY; 1427 goto post_abort; 1428 1429 unsupported_service: 1430 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1431 RX_INVALID_OPERATION, EOPNOTSUPP); 1432 skb->priority = RX_INVALID_OPERATION; 1433 goto post_abort; 1434 1435 reupgrade: 1436 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1437 RX_PROTOCOL_ERROR, EBADMSG); 1438 goto protocol_error; 1439 1440 bad_message: 1441 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 1442 RX_PROTOCOL_ERROR, EBADMSG); 1443 protocol_error: 1444 skb->priority = RX_PROTOCOL_ERROR; 1445 post_abort: 1446 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT; 1447 reject_packet: 1448 trace_rxrpc_rx_done(skb->mark, skb->priority); 1449 rxrpc_reject_packet(local, skb); 1450 _leave(" [badmsg]"); 1451 return 0; 1452 } 1453