| 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 | int skew) |
| 201 | { |
| 202 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| 203 | ktime_t now = skb->tstamp; |
| 204 | |
| 205 | if (call->peer->rtt_usage < 3 || |
| 206 | ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now)) |
| 207 | rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, |
| 208 | true, true, |
| 209 | rxrpc_propose_ack_ping_for_params); |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * Apply a hard ACK by advancing the Tx window. |
| 214 | */ |
| 215 | static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to, |
| 216 | struct rxrpc_ack_summary *summary) |
| 217 | { |
| 218 | struct sk_buff *skb, *list = NULL; |
| 219 | bool rot_last = false; |
| 220 | int ix; |
| 221 | u8 annotation; |
| 222 | |
| 223 | if (call->acks_lowest_nak == call->tx_hard_ack) { |
| 224 | call->acks_lowest_nak = to; |
| 225 | } else if (before_eq(call->acks_lowest_nak, to)) { |
| 226 | summary->new_low_nack = true; |
| 227 | call->acks_lowest_nak = to; |
| 228 | } |
| 229 | |
| 230 | spin_lock(&call->lock); |
| 231 | |
| 232 | while (before(call->tx_hard_ack, to)) { |
| 233 | call->tx_hard_ack++; |
| 234 | ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK; |
| 235 | skb = call->rxtx_buffer[ix]; |
| 236 | annotation = call->rxtx_annotations[ix]; |
| 237 | rxrpc_see_skb(skb, rxrpc_skb_tx_rotated); |
| 238 | call->rxtx_buffer[ix] = NULL; |
| 239 | call->rxtx_annotations[ix] = 0; |
| 240 | skb->next = list; |
| 241 | list = skb; |
| 242 | |
| 243 | if (annotation & RXRPC_TX_ANNO_LAST) { |
| 244 | set_bit(RXRPC_CALL_TX_LAST, &call->flags); |
| 245 | rot_last = true; |
| 246 | } |
| 247 | if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK) |
| 248 | summary->nr_rot_new_acks++; |
| 249 | } |
| 250 | |
| 251 | spin_unlock(&call->lock); |
| 252 | |
| 253 | trace_rxrpc_transmit(call, (rot_last ? |
| 254 | rxrpc_transmit_rotate_last : |
| 255 | rxrpc_transmit_rotate)); |
| 256 | wake_up(&call->waitq); |
| 257 | |
| 258 | while (list) { |
| 259 | skb = list; |
| 260 | list = skb->next; |
| 261 | skb_mark_not_on_list(skb); |
| 262 | rxrpc_free_skb(skb, rxrpc_skb_tx_freed); |
| 263 | } |
| 264 | |
| 265 | return rot_last; |
| 266 | } |
| 267 | |
| 268 | /* |
| 269 | * End the transmission phase of a call. |
| 270 | * |
| 271 | * This occurs when we get an ACKALL packet, the first DATA packet of a reply, |
| 272 | * or a final ACK packet. |
| 273 | */ |
| 274 | static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun, |
| 275 | const char *abort_why) |
| 276 | { |
| 277 | unsigned int state; |
| 278 | |
| 279 | ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags)); |
| 280 | |
| 281 | write_lock(&call->state_lock); |
| 282 | |
| 283 | state = call->state; |
| 284 | switch (state) { |
| 285 | case RXRPC_CALL_CLIENT_SEND_REQUEST: |
| 286 | case RXRPC_CALL_CLIENT_AWAIT_REPLY: |
| 287 | if (reply_begun) |
| 288 | call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY; |
| 289 | else |
| 290 | call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY; |
| 291 | break; |
| 292 | |
| 293 | case RXRPC_CALL_SERVER_AWAIT_ACK: |
| 294 | __rxrpc_call_completed(call); |
| 295 | rxrpc_notify_socket(call); |
| 296 | state = call->state; |
| 297 | break; |
| 298 | |
| 299 | default: |
| 300 | goto bad_state; |
| 301 | } |
| 302 | |
| 303 | write_unlock(&call->state_lock); |
| 304 | if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY) |
| 305 | trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); |
| 306 | else |
| 307 | trace_rxrpc_transmit(call, rxrpc_transmit_end); |
| 308 | _leave(" = ok"); |
| 309 | return true; |
| 310 | |
| 311 | bad_state: |
| 312 | write_unlock(&call->state_lock); |
| 313 | kdebug("end_tx %s", rxrpc_call_states[call->state]); |
| 314 | rxrpc_proto_abort(abort_why, call, call->tx_top); |
| 315 | return false; |
| 316 | } |
| 317 | |
| 318 | /* |
| 319 | * Begin the reply reception phase of a call. |
| 320 | */ |
| 321 | static bool rxrpc_receiving_reply(struct rxrpc_call *call) |
| 322 | { |
| 323 | struct rxrpc_ack_summary summary = { 0 }; |
| 324 | unsigned long now, timo; |
| 325 | rxrpc_seq_t top = READ_ONCE(call->tx_top); |
| 326 | |
| 327 | if (call->ackr_reason) { |
| 328 | spin_lock_bh(&call->lock); |
| 329 | call->ackr_reason = 0; |
| 330 | spin_unlock_bh(&call->lock); |
| 331 | now = jiffies; |
| 332 | timo = now + MAX_JIFFY_OFFSET; |
| 333 | WRITE_ONCE(call->resend_at, timo); |
| 334 | WRITE_ONCE(call->ack_at, timo); |
| 335 | trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now); |
| 336 | } |
| 337 | |
| 338 | if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { |
| 339 | if (!rxrpc_rotate_tx_window(call, top, &summary)) { |
| 340 | rxrpc_proto_abort("TXL", call, top); |
| 341 | return false; |
| 342 | } |
| 343 | } |
| 344 | if (!rxrpc_end_tx_phase(call, true, "ETD")) |
| 345 | return false; |
| 346 | call->tx_phase = false; |
| 347 | return true; |
| 348 | } |
| 349 | |
| 350 | /* |
| 351 | * Scan a jumbo packet to validate its structure and to work out how many |
| 352 | * subpackets it contains. |
| 353 | * |
| 354 | * A jumbo packet is a collection of consecutive packets glued together with |
| 355 | * little headers between that indicate how to change the initial header for |
| 356 | * each subpacket. |
| 357 | * |
| 358 | * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but |
| 359 | * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any |
| 360 | * size. |
| 361 | */ |
| 362 | static bool rxrpc_validate_jumbo(struct sk_buff *skb) |
| 363 | { |
| 364 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| 365 | unsigned int offset = sizeof(struct rxrpc_wire_header); |
| 366 | unsigned int len = skb->len; |
| 367 | int nr_jumbo = 1; |
| 368 | u8 flags = sp->hdr.flags; |
| 369 | |
| 370 | do { |
| 371 | nr_jumbo++; |
| 372 | if (len - offset < RXRPC_JUMBO_SUBPKTLEN) |
| 373 | goto protocol_error; |
| 374 | if (flags & RXRPC_LAST_PACKET) |
| 375 | goto protocol_error; |
| 376 | offset += RXRPC_JUMBO_DATALEN; |
| 377 | if (skb_copy_bits(skb, offset, &flags, 1) < 0) |
| 378 | goto protocol_error; |
| 379 | offset += sizeof(struct rxrpc_jumbo_header); |
| 380 | } while (flags & RXRPC_JUMBO_PACKET); |
| 381 | |
| 382 | sp->nr_jumbo = nr_jumbo; |
| 383 | return true; |
| 384 | |
| 385 | protocol_error: |
| 386 | return false; |
| 387 | } |
| 388 | |
| 389 | /* |
| 390 | * Handle reception of a duplicate packet. |
| 391 | * |
| 392 | * We have to take care to avoid an attack here whereby we're given a series of |
| 393 | * jumbograms, each with a sequence number one before the preceding one and |
| 394 | * filled up to maximum UDP size. If they never send us the first packet in |
| 395 | * the sequence, they can cause us to have to hold on to around 2MiB of kernel |
| 396 | * space until the call times out. |
| 397 | * |
| 398 | * We limit the space usage by only accepting three duplicate jumbo packets per |
| 399 | * call. After that, we tell the other side we're no longer accepting jumbos |
| 400 | * (that information is encoded in the ACK packet). |
| 401 | */ |
| 402 | static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, |
| 403 | u8 annotation, bool *_jumbo_bad) |
| 404 | { |
| 405 | /* Discard normal packets that are duplicates. */ |
| 406 | if (annotation == 0) |
| 407 | return; |
| 408 | |
| 409 | /* Skip jumbo subpackets that are duplicates. When we've had three or |
| 410 | * more partially duplicate jumbo packets, we refuse to take any more |
| 411 | * jumbos for this call. |
| 412 | */ |
| 413 | if (!*_jumbo_bad) { |
| 414 | call->nr_jumbo_bad++; |
| 415 | *_jumbo_bad = true; |
| 416 | } |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * Process a DATA packet, adding the packet to the Rx ring. |
| 421 | */ |
| 422 | static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb, |
| 423 | u16 skew) |
| 424 | { |
| 425 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| 426 | enum rxrpc_call_state state; |
| 427 | unsigned int offset = sizeof(struct rxrpc_wire_header); |
| 428 | unsigned int ix; |
| 429 | rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0; |
| 430 | rxrpc_seq_t seq = sp->hdr.seq, hard_ack; |
| 431 | bool immediate_ack = false, jumbo_bad = false, queued; |
| 432 | u16 len; |
| 433 | u8 ack = 0, flags, annotation = 0; |
| 434 | |
| 435 | _enter("{%u,%u},{%u,%u}", |
| 436 | call->rx_hard_ack, call->rx_top, skb->len, seq); |
| 437 | |
| 438 | _proto("Rx DATA %%%u { #%u f=%02x }", |
| 439 | sp->hdr.serial, seq, sp->hdr.flags); |
| 440 | |
| 441 | state = READ_ONCE(call->state); |
| 442 | if (state >= RXRPC_CALL_COMPLETE) |
| 443 | return; |
| 444 | |
| 445 | if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) { |
| 446 | unsigned long timo = READ_ONCE(call->next_req_timo); |
| 447 | unsigned long now, expect_req_by; |
| 448 | |
| 449 | if (timo) { |
| 450 | now = jiffies; |
| 451 | expect_req_by = now + timo; |
| 452 | WRITE_ONCE(call->expect_req_by, expect_req_by); |
| 453 | rxrpc_reduce_call_timer(call, expect_req_by, now, |
| 454 | rxrpc_timer_set_for_idle); |
| 455 | } |
| 456 | } |
| 457 | |
| 458 | spin_lock(&call->input_lock); |
| 459 | |
| 460 | /* Received data implicitly ACKs all of the request packets we sent |
| 461 | * when we're acting as a client. |
| 462 | */ |
| 463 | if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST || |
| 464 | state == RXRPC_CALL_CLIENT_AWAIT_REPLY) && |
| 465 | !rxrpc_receiving_reply(call)) |
| 466 | goto unlock; |
| 467 | |
| 468 | call->ackr_prev_seq = seq; |
| 469 | |
| 470 | hard_ack = READ_ONCE(call->rx_hard_ack); |
| 471 | if (after(seq, hard_ack + call->rx_winsize)) { |
| 472 | ack = RXRPC_ACK_EXCEEDS_WINDOW; |
| 473 | ack_serial = serial; |
| 474 | goto ack; |
| 475 | } |
| 476 | |
| 477 | flags = sp->hdr.flags; |
| 478 | if (flags & RXRPC_JUMBO_PACKET) { |
| 479 | if (call->nr_jumbo_bad > 3) { |
| 480 | ack = RXRPC_ACK_NOSPACE; |
| 481 | ack_serial = serial; |
| 482 | goto ack; |
| 483 | } |
| 484 | annotation = 1; |
| 485 | } |
| 486 | |
| 487 | next_subpacket: |
| 488 | queued = false; |
| 489 | ix = seq & RXRPC_RXTX_BUFF_MASK; |
| 490 | len = skb->len; |
| 491 | if (flags & RXRPC_JUMBO_PACKET) |
| 492 | len = RXRPC_JUMBO_DATALEN; |
| 493 | |
| 494 | if (flags & RXRPC_LAST_PACKET) { |
| 495 | if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && |
| 496 | seq != call->rx_top) { |
| 497 | rxrpc_proto_abort("LSN", call, seq); |
| 498 | goto unlock; |
| 499 | } |
| 500 | } else { |
| 501 | if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && |
| 502 | after_eq(seq, call->rx_top)) { |
| 503 | rxrpc_proto_abort("LSA", call, seq); |
| 504 | goto unlock; |
| 505 | } |
| 506 | } |
| 507 | |
| 508 | trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation); |
| 509 | if (before_eq(seq, hard_ack)) { |
| 510 | ack = RXRPC_ACK_DUPLICATE; |
| 511 | ack_serial = serial; |
| 512 | goto skip; |
| 513 | } |
| 514 | |
| 515 | if (flags & RXRPC_REQUEST_ACK && !ack) { |
| 516 | ack = RXRPC_ACK_REQUESTED; |
| 517 | ack_serial = serial; |
| 518 | } |
| 519 | |
| 520 | if (call->rxtx_buffer[ix]) { |
| 521 | rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad); |
| 522 | if (ack != RXRPC_ACK_DUPLICATE) { |
| 523 | ack = RXRPC_ACK_DUPLICATE; |
| 524 | ack_serial = serial; |
| 525 | } |
| 526 | immediate_ack = true; |
| 527 | goto skip; |
| 528 | } |
| 529 | |
| 530 | /* Queue the packet. We use a couple of memory barriers here as need |
| 531 | * to make sure that rx_top is perceived to be set after the buffer |
| 532 | * pointer and that the buffer pointer is set after the annotation and |
| 533 | * the skb data. |
| 534 | * |
| 535 | * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() |
| 536 | * and also rxrpc_fill_out_ack(). |
| 537 | */ |
| 538 | rxrpc_get_skb(skb, rxrpc_skb_rx_got); |
| 539 | call->rxtx_annotations[ix] = annotation; |
| 540 | smp_wmb(); |
| 541 | call->rxtx_buffer[ix] = skb; |
| 542 | if (after(seq, call->rx_top)) { |
| 543 | smp_store_release(&call->rx_top, seq); |
| 544 | } else if (before(seq, call->rx_top)) { |
| 545 | /* Send an immediate ACK if we fill in a hole */ |
| 546 | if (!ack) { |
| 547 | ack = RXRPC_ACK_DELAY; |
| 548 | ack_serial = serial; |
| 549 | } |
| 550 | immediate_ack = true; |
| 551 | } |
| 552 | if (flags & RXRPC_LAST_PACKET) { |
| 553 | set_bit(RXRPC_CALL_RX_LAST, &call->flags); |
| 554 | trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); |
| 555 | } else { |
| 556 | trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); |
| 557 | } |
| 558 | queued = true; |
| 559 | |
| 560 | if (after_eq(seq, call->rx_expect_next)) { |
| 561 | if (after(seq, call->rx_expect_next)) { |
| 562 | _net("OOS %u > %u", seq, call->rx_expect_next); |
| 563 | ack = RXRPC_ACK_OUT_OF_SEQUENCE; |
| 564 | ack_serial = serial; |
| 565 | } |
| 566 | call->rx_expect_next = seq + 1; |
| 567 | } |
| 568 | |
| 569 | skip: |
| 570 | offset += len; |
| 571 | if (flags & RXRPC_JUMBO_PACKET) { |
| 572 | if (skb_copy_bits(skb, offset, &flags, 1) < 0) { |
| 573 | rxrpc_proto_abort("XJF", call, seq); |
| 574 | goto unlock; |
| 575 | } |
| 576 | offset += sizeof(struct rxrpc_jumbo_header); |
| 577 | seq++; |
| 578 | serial++; |
| 579 | annotation++; |
| 580 | if (flags & RXRPC_JUMBO_PACKET) |
| 581 | annotation |= RXRPC_RX_ANNO_JLAST; |
| 582 | if (after(seq, hard_ack + call->rx_winsize)) { |
| 583 | ack = RXRPC_ACK_EXCEEDS_WINDOW; |
| 584 | ack_serial = serial; |
| 585 | if (!jumbo_bad) { |
| 586 | call->nr_jumbo_bad++; |
| 587 | jumbo_bad = true; |
| 588 | } |
| 589 | goto ack; |
| 590 | } |
| 591 | |
| 592 | _proto("Rx DATA Jumbo %%%u", serial); |
| 593 | goto next_subpacket; |
| 594 | } |
| 595 | |
| 596 | if (queued && flags & RXRPC_LAST_PACKET && !ack) { |
| 597 | ack = RXRPC_ACK_DELAY; |
| 598 | ack_serial = serial; |
| 599 | } |
| 600 | |
| 601 | ack: |
| 602 | if (ack) |
| 603 | rxrpc_propose_ACK(call, ack, skew, ack_serial, |
| 604 | immediate_ack, true, |
| 605 | rxrpc_propose_ack_input_data); |
| 606 | else |
| 607 | rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, skew, serial, |
| 608 | false, true, |
| 609 | rxrpc_propose_ack_input_data); |
| 610 | |
| 611 | if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1) { |
| 612 | trace_rxrpc_notify_socket(call->debug_id, serial); |
| 613 | rxrpc_notify_socket(call); |
| 614 | } |
| 615 | |
| 616 | unlock: |
| 617 | spin_unlock(&call->input_lock); |
| 618 | _leave(" [queued]"); |
| 619 | } |
| 620 | |
| 621 | /* |
| 622 | * Process a requested ACK. |
| 623 | */ |
| 624 | static void rxrpc_input_requested_ack(struct rxrpc_call *call, |
| 625 | ktime_t resp_time, |
| 626 | rxrpc_serial_t orig_serial, |
| 627 | rxrpc_serial_t ack_serial) |
| 628 | { |
| 629 | struct rxrpc_skb_priv *sp; |
| 630 | struct sk_buff *skb; |
| 631 | ktime_t sent_at; |
| 632 | int ix; |
| 633 | |
| 634 | for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) { |
| 635 | skb = call->rxtx_buffer[ix]; |
| 636 | if (!skb) |
| 637 | continue; |
| 638 | |
| 639 | sent_at = skb->tstamp; |
| 640 | smp_rmb(); /* Read timestamp before serial. */ |
| 641 | sp = rxrpc_skb(skb); |
| 642 | if (sp->hdr.serial != orig_serial) |
| 643 | continue; |
| 644 | goto found; |
| 645 | } |
| 646 | |
| 647 | return; |
| 648 | |
| 649 | found: |
| 650 | rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack, |
| 651 | orig_serial, ack_serial, sent_at, resp_time); |
| 652 | } |
| 653 | |
| 654 | /* |
| 655 | * Process the response to a ping that we sent to find out if we lost an ACK. |
| 656 | * |
| 657 | * If we got back a ping response that indicates a lower tx_top than what we |
| 658 | * had at the time of the ping transmission, we adjudge all the DATA packets |
| 659 | * sent between the response tx_top and the ping-time tx_top to have been lost. |
| 660 | */ |
| 661 | static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call) |
| 662 | { |
| 663 | rxrpc_seq_t top, bottom, seq; |
| 664 | bool resend = false; |
| 665 | |
| 666 | spin_lock_bh(&call->lock); |
| 667 | |
| 668 | bottom = call->tx_hard_ack + 1; |
| 669 | top = call->acks_lost_top; |
| 670 | if (before(bottom, top)) { |
| 671 | for (seq = bottom; before_eq(seq, top); seq++) { |
| 672 | int ix = seq & RXRPC_RXTX_BUFF_MASK; |
| 673 | u8 annotation = call->rxtx_annotations[ix]; |
| 674 | u8 anno_type = annotation & RXRPC_TX_ANNO_MASK; |
| 675 | |
| 676 | if (anno_type != RXRPC_TX_ANNO_UNACK) |
| 677 | continue; |
| 678 | annotation &= ~RXRPC_TX_ANNO_MASK; |
| 679 | annotation |= RXRPC_TX_ANNO_RETRANS; |
| 680 | call->rxtx_annotations[ix] = annotation; |
| 681 | resend = true; |
| 682 | } |
| 683 | } |
| 684 | |
| 685 | spin_unlock_bh(&call->lock); |
| 686 | |
| 687 | if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) |
| 688 | rxrpc_queue_call(call); |
| 689 | } |
| 690 | |
| 691 | /* |
| 692 | * Process a ping response. |
| 693 | */ |
| 694 | static void rxrpc_input_ping_response(struct rxrpc_call *call, |
| 695 | ktime_t resp_time, |
| 696 | rxrpc_serial_t orig_serial, |
| 697 | rxrpc_serial_t ack_serial) |
| 698 | { |
| 699 | rxrpc_serial_t ping_serial; |
| 700 | ktime_t ping_time; |
| 701 | |
| 702 | ping_time = call->ping_time; |
| 703 | smp_rmb(); |
| 704 | ping_serial = READ_ONCE(call->ping_serial); |
| 705 | |
| 706 | if (orig_serial == call->acks_lost_ping) |
| 707 | rxrpc_input_check_for_lost_ack(call); |
| 708 | |
| 709 | if (before(orig_serial, ping_serial) || |
| 710 | !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags)) |
| 711 | return; |
| 712 | if (after(orig_serial, ping_serial)) |
| 713 | return; |
| 714 | |
| 715 | rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response, |
| 716 | orig_serial, ack_serial, ping_time, resp_time); |
| 717 | } |
| 718 | |
| 719 | /* |
| 720 | * Process the extra information that may be appended to an ACK packet |
| 721 | */ |
| 722 | static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, |
| 723 | struct rxrpc_ackinfo *ackinfo) |
| 724 | { |
| 725 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| 726 | struct rxrpc_peer *peer; |
| 727 | unsigned int mtu; |
| 728 | bool wake = false; |
| 729 | u32 rwind = ntohl(ackinfo->rwind); |
| 730 | |
| 731 | _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", |
| 732 | sp->hdr.serial, |
| 733 | ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU), |
| 734 | rwind, ntohl(ackinfo->jumbo_max)); |
| 735 | |
| 736 | if (call->tx_winsize != rwind) { |
| 737 | if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) |
| 738 | rwind = RXRPC_RXTX_BUFF_SIZE - 1; |
| 739 | if (rwind > call->tx_winsize) |
| 740 | wake = true; |
| 741 | trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, |
| 742 | ntohl(ackinfo->rwind), wake); |
| 743 | call->tx_winsize = rwind; |
| 744 | } |
| 745 | |
| 746 | if (call->cong_ssthresh > rwind) |
| 747 | call->cong_ssthresh = rwind; |
| 748 | |
| 749 | mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); |
| 750 | |
| 751 | peer = call->peer; |
| 752 | if (mtu < peer->maxdata) { |
| 753 | spin_lock_bh(&peer->lock); |
| 754 | peer->maxdata = mtu; |
| 755 | peer->mtu = mtu + peer->hdrsize; |
| 756 | spin_unlock_bh(&peer->lock); |
| 757 | _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); |
| 758 | } |
| 759 | |
| 760 | if (wake) |
| 761 | wake_up(&call->waitq); |
| 762 | } |
| 763 | |
| 764 | /* |
| 765 | * Process individual soft ACKs. |
| 766 | * |
| 767 | * Each ACK in the array corresponds to one packet and can be either an ACK or |
| 768 | * a NAK. If we get find an explicitly NAK'd packet we resend immediately; |
| 769 | * packets that lie beyond the end of the ACK list are scheduled for resend by |
| 770 | * the timer on the basis that the peer might just not have processed them at |
| 771 | * the time the ACK was sent. |
| 772 | */ |
| 773 | static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, |
| 774 | rxrpc_seq_t seq, int nr_acks, |
| 775 | struct rxrpc_ack_summary *summary) |
| 776 | { |
| 777 | int ix; |
| 778 | u8 annotation, anno_type; |
| 779 | |
| 780 | for (; nr_acks > 0; nr_acks--, seq++) { |
| 781 | ix = seq & RXRPC_RXTX_BUFF_MASK; |
| 782 | annotation = call->rxtx_annotations[ix]; |
| 783 | anno_type = annotation & RXRPC_TX_ANNO_MASK; |
| 784 | annotation &= ~RXRPC_TX_ANNO_MASK; |
| 785 | switch (*acks++) { |
| 786 | case RXRPC_ACK_TYPE_ACK: |
| 787 | summary->nr_acks++; |
| 788 | if (anno_type == RXRPC_TX_ANNO_ACK) |
| 789 | continue; |
| 790 | summary->nr_new_acks++; |
| 791 | call->rxtx_annotations[ix] = |
| 792 | RXRPC_TX_ANNO_ACK | annotation; |
| 793 | break; |
| 794 | case RXRPC_ACK_TYPE_NACK: |
| 795 | if (!summary->nr_nacks && |
| 796 | call->acks_lowest_nak != seq) { |
| 797 | call->acks_lowest_nak = seq; |
| 798 | summary->new_low_nack = true; |
| 799 | } |
| 800 | summary->nr_nacks++; |
| 801 | if (anno_type == RXRPC_TX_ANNO_NAK) |
| 802 | continue; |
| 803 | summary->nr_new_nacks++; |
| 804 | if (anno_type == RXRPC_TX_ANNO_RETRANS) |
| 805 | continue; |
| 806 | call->rxtx_annotations[ix] = |
| 807 | RXRPC_TX_ANNO_NAK | annotation; |
| 808 | break; |
| 809 | default: |
| 810 | return rxrpc_proto_abort("SFT", call, 0); |
| 811 | } |
| 812 | } |
| 813 | } |
| 814 | |
| 815 | /* |
| 816 | * Process an ACK packet. |
| 817 | * |
| 818 | * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet |
| 819 | * in the ACK array. Anything before that is hard-ACK'd and may be discarded. |
| 820 | * |
| 821 | * A hard-ACK means that a packet has been processed and may be discarded; a |
| 822 | * soft-ACK means that the packet may be discarded and retransmission |
| 823 | * requested. A phase is complete when all packets are hard-ACK'd. |
| 824 | */ |
| 825 | static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, |
| 826 | u16 skew) |
| 827 | { |
| 828 | struct rxrpc_ack_summary summary = { 0 }; |
| 829 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| 830 | union { |
| 831 | struct rxrpc_ackpacket ack; |
| 832 | struct rxrpc_ackinfo info; |
| 833 | u8 acks[RXRPC_MAXACKS]; |
| 834 | } buf; |
| 835 | rxrpc_serial_t acked_serial; |
| 836 | rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt; |
| 837 | int nr_acks, offset, ioffset; |
| 838 | |
| 839 | _enter(""); |
| 840 | |
| 841 | offset = sizeof(struct rxrpc_wire_header); |
| 842 | if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { |
| 843 | _debug("extraction failure"); |
| 844 | return rxrpc_proto_abort("XAK", call, 0); |
| 845 | } |
| 846 | offset += sizeof(buf.ack); |
| 847 | |
| 848 | acked_serial = ntohl(buf.ack.serial); |
| 849 | first_soft_ack = ntohl(buf.ack.firstPacket); |
| 850 | prev_pkt = ntohl(buf.ack.previousPacket); |
| 851 | hard_ack = first_soft_ack - 1; |
| 852 | nr_acks = buf.ack.nAcks; |
| 853 | summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? |
| 854 | buf.ack.reason : RXRPC_ACK__INVALID); |
| 855 | |
| 856 | trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial, |
| 857 | first_soft_ack, prev_pkt, |
| 858 | summary.ack_reason, nr_acks); |
| 859 | |
| 860 | if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) |
| 861 | rxrpc_input_ping_response(call, skb->tstamp, acked_serial, |
| 862 | sp->hdr.serial); |
| 863 | if (buf.ack.reason == RXRPC_ACK_REQUESTED) |
| 864 | rxrpc_input_requested_ack(call, skb->tstamp, acked_serial, |
| 865 | sp->hdr.serial); |
| 866 | |
| 867 | if (buf.ack.reason == RXRPC_ACK_PING) { |
| 868 | _proto("Rx ACK %%%u PING Request", sp->hdr.serial); |
| 869 | rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, |
| 870 | skew, sp->hdr.serial, true, true, |
| 871 | rxrpc_propose_ack_respond_to_ping); |
| 872 | } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { |
| 873 | rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, |
| 874 | skew, sp->hdr.serial, true, true, |
| 875 | rxrpc_propose_ack_respond_to_ack); |
| 876 | } |
| 877 | |
| 878 | /* Discard any out-of-order or duplicate ACKs (outside lock). */ |
| 879 | if (before(first_soft_ack, call->ackr_first_seq) || |
| 880 | before(prev_pkt, call->ackr_prev_seq)) |
| 881 | return; |
| 882 | |
| 883 | buf.info.rxMTU = 0; |
| 884 | ioffset = offset + nr_acks + 3; |
| 885 | if (skb->len >= ioffset + sizeof(buf.info) && |
| 886 | skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) |
| 887 | return rxrpc_proto_abort("XAI", call, 0); |
| 888 | |
| 889 | spin_lock(&call->input_lock); |
| 890 | |
| 891 | /* Discard any out-of-order or duplicate ACKs (inside lock). */ |
| 892 | if (before(first_soft_ack, call->ackr_first_seq) || |
| 893 | before(prev_pkt, call->ackr_prev_seq)) |
| 894 | goto out; |
| 895 | call->acks_latest_ts = skb->tstamp; |
| 896 | call->acks_latest = sp->hdr.serial; |
| 897 | |
| 898 | call->ackr_first_seq = first_soft_ack; |
| 899 | call->ackr_prev_seq = prev_pkt; |
| 900 | |
| 901 | /* Parse rwind and mtu sizes if provided. */ |
| 902 | if (buf.info.rxMTU) |
| 903 | rxrpc_input_ackinfo(call, skb, &buf.info); |
| 904 | |
| 905 | if (first_soft_ack == 0) { |
| 906 | rxrpc_proto_abort("AK0", call, 0); |
| 907 | goto out; |
| 908 | } |
| 909 | |
| 910 | /* Ignore ACKs unless we are or have just been transmitting. */ |
| 911 | switch (READ_ONCE(call->state)) { |
| 912 | case RXRPC_CALL_CLIENT_SEND_REQUEST: |
| 913 | case RXRPC_CALL_CLIENT_AWAIT_REPLY: |
| 914 | case RXRPC_CALL_SERVER_SEND_REPLY: |
| 915 | case RXRPC_CALL_SERVER_AWAIT_ACK: |
| 916 | break; |
| 917 | default: |
| 918 | goto out; |
| 919 | } |
| 920 | |
| 921 | if (before(hard_ack, call->tx_hard_ack) || |
| 922 | after(hard_ack, call->tx_top)) { |
| 923 | rxrpc_proto_abort("AKW", call, 0); |
| 924 | goto out; |
| 925 | } |
| 926 | if (nr_acks > call->tx_top - hard_ack) { |
| 927 | rxrpc_proto_abort("AKN", call, 0); |
| 928 | goto out; |
| 929 | } |
| 930 | |
| 931 | if (after(hard_ack, call->tx_hard_ack)) { |
| 932 | if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { |
| 933 | rxrpc_end_tx_phase(call, false, "ETA"); |
| 934 | goto out; |
| 935 | } |
| 936 | } |
| 937 | |
| 938 | if (nr_acks > 0) { |
| 939 | if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) { |
| 940 | rxrpc_proto_abort("XSA", call, 0); |
| 941 | goto out; |
| 942 | } |
| 943 | rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, |
| 944 | &summary); |
| 945 | } |
| 946 | |
| 947 | if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & |
| 948 | RXRPC_TX_ANNO_LAST && |
| 949 | summary.nr_acks == call->tx_top - hard_ack && |
| 950 | rxrpc_is_client_call(call)) |
| 951 | rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, |
| 952 | false, true, |
| 953 | rxrpc_propose_ack_ping_for_lost_reply); |
| 954 | |
| 955 | rxrpc_congestion_management(call, skb, &summary, acked_serial); |
| 956 | out: |
| 957 | spin_unlock(&call->input_lock); |
| 958 | } |
| 959 | |
| 960 | /* |
| 961 | * Process an ACKALL packet. |
| 962 | */ |
| 963 | static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) |
| 964 | { |
| 965 | struct rxrpc_ack_summary summary = { 0 }; |
| 966 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| 967 | |
| 968 | _proto("Rx ACKALL %%%u", sp->hdr.serial); |
| 969 | |
| 970 | spin_lock(&call->input_lock); |
| 971 | |
| 972 | if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) |
| 973 | rxrpc_end_tx_phase(call, false, "ETL"); |
| 974 | |
| 975 | spin_unlock(&call->input_lock); |
| 976 | } |
| 977 | |
| 978 | /* |
| 979 | * Process an ABORT packet directed at a call. |
| 980 | */ |
| 981 | static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) |
| 982 | { |
| 983 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| 984 | __be32 wtmp; |
| 985 | u32 abort_code = RX_CALL_DEAD; |
| 986 | |
| 987 | _enter(""); |
| 988 | |
| 989 | if (skb->len >= 4 && |
| 990 | skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
| 991 | &wtmp, sizeof(wtmp)) >= 0) |
| 992 | abort_code = ntohl(wtmp); |
| 993 | |
| 994 | trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code); |
| 995 | |
| 996 | _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); |
| 997 | |
| 998 | if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, |
| 999 | abort_code, -ECONNABORTED)) |
| 1000 | rxrpc_notify_socket(call); |
| 1001 | } |
| 1002 | |
| 1003 | /* |
| 1004 | * Process an incoming call packet. |
| 1005 | */ |
| 1006 | static void rxrpc_input_call_packet(struct rxrpc_call *call, |
| 1007 | struct sk_buff *skb, u16 skew) |
| 1008 | { |
| 1009 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| 1010 | unsigned long timo; |
| 1011 | |
| 1012 | _enter("%p,%p", call, skb); |
| 1013 | |
| 1014 | timo = READ_ONCE(call->next_rx_timo); |
| 1015 | if (timo) { |
| 1016 | unsigned long now = jiffies, expect_rx_by; |
| 1017 | |
| 1018 | expect_rx_by = now + timo; |
| 1019 | WRITE_ONCE(call->expect_rx_by, expect_rx_by); |
| 1020 | rxrpc_reduce_call_timer(call, expect_rx_by, now, |
| 1021 | rxrpc_timer_set_for_normal); |
| 1022 | } |
| 1023 | |
| 1024 | switch (sp->hdr.type) { |
| 1025 | case RXRPC_PACKET_TYPE_DATA: |
| 1026 | rxrpc_input_data(call, skb, skew); |
| 1027 | break; |
| 1028 | |
| 1029 | case RXRPC_PACKET_TYPE_ACK: |
| 1030 | rxrpc_input_ack(call, skb, skew); |
| 1031 | break; |
| 1032 | |
| 1033 | case RXRPC_PACKET_TYPE_BUSY: |
| 1034 | _proto("Rx BUSY %%%u", sp->hdr.serial); |
| 1035 | |
| 1036 | /* Just ignore BUSY packets from the server; the retry and |
| 1037 | * lifespan timers will take care of business. BUSY packets |
| 1038 | * from the client don't make sense. |
| 1039 | */ |
| 1040 | break; |
| 1041 | |
| 1042 | case RXRPC_PACKET_TYPE_ABORT: |
| 1043 | rxrpc_input_abort(call, skb); |
| 1044 | break; |
| 1045 | |
| 1046 | case RXRPC_PACKET_TYPE_ACKALL: |
| 1047 | rxrpc_input_ackall(call, skb); |
| 1048 | break; |
| 1049 | |
| 1050 | default: |
| 1051 | break; |
| 1052 | } |
| 1053 | |
| 1054 | _leave(""); |
| 1055 | } |
| 1056 | |
| 1057 | /* |
| 1058 | * Handle a new service call on a channel implicitly completing the preceding |
| 1059 | * call on that channel. This does not apply to client conns. |
| 1060 | * |
| 1061 | * TODO: If callNumber > call_id + 1, renegotiate security. |
| 1062 | */ |
| 1063 | static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, |
| 1064 | struct rxrpc_connection *conn, |
| 1065 | struct rxrpc_call *call) |
| 1066 | { |
| 1067 | switch (READ_ONCE(call->state)) { |
| 1068 | case RXRPC_CALL_SERVER_AWAIT_ACK: |
| 1069 | rxrpc_call_completed(call); |
| 1070 | /* Fall through */ |
| 1071 | case RXRPC_CALL_COMPLETE: |
| 1072 | break; |
| 1073 | default: |
| 1074 | if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) { |
| 1075 | set_bit(RXRPC_CALL_EV_ABORT, &call->events); |
| 1076 | rxrpc_queue_call(call); |
| 1077 | } |
| 1078 | trace_rxrpc_improper_term(call); |
| 1079 | break; |
| 1080 | } |
| 1081 | |
| 1082 | spin_lock(&rx->incoming_lock); |
| 1083 | __rxrpc_disconnect_call(conn, call); |
| 1084 | spin_unlock(&rx->incoming_lock); |
| 1085 | rxrpc_notify_socket(call); |
| 1086 | } |
| 1087 | |
| 1088 | /* |
| 1089 | * post connection-level events to the connection |
| 1090 | * - this includes challenges, responses, some aborts and call terminal packet |
| 1091 | * retransmission. |
| 1092 | */ |
| 1093 | static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, |
| 1094 | struct sk_buff *skb) |
| 1095 | { |
| 1096 | _enter("%p,%p", conn, skb); |
| 1097 | |
| 1098 | skb_queue_tail(&conn->rx_queue, skb); |
| 1099 | rxrpc_queue_conn(conn); |
| 1100 | } |
| 1101 | |
| 1102 | /* |
| 1103 | * post endpoint-level events to the local endpoint |
| 1104 | * - this includes debug and version messages |
| 1105 | */ |
| 1106 | static void rxrpc_post_packet_to_local(struct rxrpc_local *local, |
| 1107 | struct sk_buff *skb) |
| 1108 | { |
| 1109 | _enter("%p,%p", local, skb); |
| 1110 | |
| 1111 | skb_queue_tail(&local->event_queue, skb); |
| 1112 | rxrpc_queue_local(local); |
| 1113 | } |
| 1114 | |
| 1115 | /* |
| 1116 | * put a packet up for transport-level abort |
| 1117 | */ |
| 1118 | static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) |
| 1119 | { |
| 1120 | CHECK_SLAB_OKAY(&local->usage); |
| 1121 | |
| 1122 | skb_queue_tail(&local->reject_queue, skb); |
| 1123 | rxrpc_queue_local(local); |
| 1124 | } |
| 1125 | |
| 1126 | /* |
| 1127 | * Extract the wire header from a packet and translate the byte order. |
| 1128 | */ |
| 1129 | static noinline |
| 1130 | int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) |
| 1131 | { |
| 1132 | struct rxrpc_wire_header whdr; |
| 1133 | |
| 1134 | /* dig out the RxRPC connection details */ |
| 1135 | if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) { |
| 1136 | trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, |
| 1137 | tracepoint_string("bad_hdr")); |
| 1138 | return -EBADMSG; |
| 1139 | } |
| 1140 | |
| 1141 | memset(sp, 0, sizeof(*sp)); |
| 1142 | sp->hdr.epoch = ntohl(whdr.epoch); |
| 1143 | sp->hdr.cid = ntohl(whdr.cid); |
| 1144 | sp->hdr.callNumber = ntohl(whdr.callNumber); |
| 1145 | sp->hdr.seq = ntohl(whdr.seq); |
| 1146 | sp->hdr.serial = ntohl(whdr.serial); |
| 1147 | sp->hdr.flags = whdr.flags; |
| 1148 | sp->hdr.type = whdr.type; |
| 1149 | sp->hdr.userStatus = whdr.userStatus; |
| 1150 | sp->hdr.securityIndex = whdr.securityIndex; |
| 1151 | sp->hdr._rsvd = ntohs(whdr._rsvd); |
| 1152 | sp->hdr.serviceId = ntohs(whdr.serviceId); |
| 1153 | return 0; |
| 1154 | } |
| 1155 | |
| 1156 | /* |
| 1157 | * handle data received on the local endpoint |
| 1158 | * - may be called in interrupt context |
| 1159 | * |
| 1160 | * [!] Note that as this is called from the encap_rcv hook, the socket is not |
| 1161 | * held locked by the caller and nothing prevents sk_user_data on the UDP from |
| 1162 | * being cleared in the middle of processing this function. |
| 1163 | * |
| 1164 | * Called with the RCU read lock held from the IP layer via UDP. |
| 1165 | */ |
| 1166 | int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb) |
| 1167 | { |
| 1168 | struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk); |
| 1169 | struct rxrpc_connection *conn; |
| 1170 | struct rxrpc_channel *chan; |
| 1171 | struct rxrpc_call *call = NULL; |
| 1172 | struct rxrpc_skb_priv *sp; |
| 1173 | struct rxrpc_peer *peer = NULL; |
| 1174 | struct rxrpc_sock *rx = NULL; |
| 1175 | unsigned int channel; |
| 1176 | int skew = 0; |
| 1177 | |
| 1178 | _enter("%p", udp_sk); |
| 1179 | |
| 1180 | if (unlikely(!local)) { |
| 1181 | kfree_skb(skb); |
| 1182 | return 0; |
| 1183 | } |
| 1184 | if (skb->tstamp == 0) |
| 1185 | skb->tstamp = ktime_get_real(); |
| 1186 | |
| 1187 | rxrpc_new_skb(skb, rxrpc_skb_rx_received); |
| 1188 | |
| 1189 | skb_pull(skb, sizeof(struct udphdr)); |
| 1190 | |
| 1191 | /* The UDP protocol already released all skb resources; |
| 1192 | * we are free to add our own data there. |
| 1193 | */ |
| 1194 | sp = rxrpc_skb(skb); |
| 1195 | |
| 1196 | /* dig out the RxRPC connection details */ |
| 1197 | if (rxrpc_extract_header(sp, skb) < 0) |
| 1198 | goto bad_message; |
| 1199 | |
| 1200 | if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { |
| 1201 | static int lose; |
| 1202 | if ((lose++ & 7) == 7) { |
| 1203 | trace_rxrpc_rx_lose(sp); |
| 1204 | rxrpc_free_skb(skb, rxrpc_skb_rx_lost); |
| 1205 | return 0; |
| 1206 | } |
| 1207 | } |
| 1208 | |
| 1209 | if (skb->tstamp == 0) |
| 1210 | skb->tstamp = ktime_get_real(); |
| 1211 | trace_rxrpc_rx_packet(sp); |
| 1212 | |
| 1213 | switch (sp->hdr.type) { |
| 1214 | case RXRPC_PACKET_TYPE_VERSION: |
| 1215 | if (rxrpc_to_client(sp)) |
| 1216 | goto discard; |
| 1217 | rxrpc_post_packet_to_local(local, skb); |
| 1218 | goto out; |
| 1219 | |
| 1220 | case RXRPC_PACKET_TYPE_BUSY: |
| 1221 | if (rxrpc_to_server(sp)) |
| 1222 | goto discard; |
| 1223 | /* Fall through */ |
| 1224 | case RXRPC_PACKET_TYPE_ACK: |
| 1225 | case RXRPC_PACKET_TYPE_ACKALL: |
| 1226 | if (sp->hdr.callNumber == 0) |
| 1227 | goto bad_message; |
| 1228 | /* Fall through */ |
| 1229 | case RXRPC_PACKET_TYPE_ABORT: |
| 1230 | break; |
| 1231 | |
| 1232 | case RXRPC_PACKET_TYPE_DATA: |
| 1233 | if (sp->hdr.callNumber == 0 || |
| 1234 | sp->hdr.seq == 0) |
| 1235 | goto bad_message; |
| 1236 | if (sp->hdr.flags & RXRPC_JUMBO_PACKET && |
| 1237 | !rxrpc_validate_jumbo(skb)) |
| 1238 | goto bad_message; |
| 1239 | break; |
| 1240 | |
| 1241 | case RXRPC_PACKET_TYPE_CHALLENGE: |
| 1242 | if (rxrpc_to_server(sp)) |
| 1243 | goto discard; |
| 1244 | break; |
| 1245 | case RXRPC_PACKET_TYPE_RESPONSE: |
| 1246 | if (rxrpc_to_client(sp)) |
| 1247 | goto discard; |
| 1248 | break; |
| 1249 | |
| 1250 | /* Packet types 9-11 should just be ignored. */ |
| 1251 | case RXRPC_PACKET_TYPE_PARAMS: |
| 1252 | case RXRPC_PACKET_TYPE_10: |
| 1253 | case RXRPC_PACKET_TYPE_11: |
| 1254 | goto discard; |
| 1255 | |
| 1256 | default: |
| 1257 | _proto("Rx Bad Packet Type %u", sp->hdr.type); |
| 1258 | goto bad_message; |
| 1259 | } |
| 1260 | |
| 1261 | if (sp->hdr.serviceId == 0) |
| 1262 | goto bad_message; |
| 1263 | |
| 1264 | if (rxrpc_to_server(sp)) { |
| 1265 | /* Weed out packets to services we're not offering. Packets |
| 1266 | * that would begin a call are explicitly rejected and the rest |
| 1267 | * are just discarded. |
| 1268 | */ |
| 1269 | rx = rcu_dereference(local->service); |
| 1270 | if (!rx || (sp->hdr.serviceId != rx->srx.srx_service && |
| 1271 | sp->hdr.serviceId != rx->second_service)) { |
| 1272 | if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && |
| 1273 | sp->hdr.seq == 1) |
| 1274 | goto unsupported_service; |
| 1275 | goto discard; |
| 1276 | } |
| 1277 | } |
| 1278 | |
| 1279 | conn = rxrpc_find_connection_rcu(local, skb, &peer); |
| 1280 | if (conn) { |
| 1281 | if (sp->hdr.securityIndex != conn->security_ix) |
| 1282 | goto wrong_security; |
| 1283 | |
| 1284 | if (sp->hdr.serviceId != conn->service_id) { |
| 1285 | int old_id; |
| 1286 | |
| 1287 | if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) |
| 1288 | goto reupgrade; |
| 1289 | old_id = cmpxchg(&conn->service_id, conn->params.service_id, |
| 1290 | sp->hdr.serviceId); |
| 1291 | |
| 1292 | if (old_id != conn->params.service_id && |
| 1293 | old_id != sp->hdr.serviceId) |
| 1294 | goto reupgrade; |
| 1295 | } |
| 1296 | |
| 1297 | if (sp->hdr.callNumber == 0) { |
| 1298 | /* Connection-level packet */ |
| 1299 | _debug("CONN %p {%d}", conn, conn->debug_id); |
| 1300 | rxrpc_post_packet_to_conn(conn, skb); |
| 1301 | goto out; |
| 1302 | } |
| 1303 | |
| 1304 | /* Note the serial number skew here */ |
| 1305 | skew = (int)sp->hdr.serial - (int)conn->hi_serial; |
| 1306 | if (skew >= 0) { |
| 1307 | if (skew > 0) |
| 1308 | conn->hi_serial = sp->hdr.serial; |
| 1309 | } else { |
| 1310 | skew = -skew; |
| 1311 | skew = min(skew, 65535); |
| 1312 | } |
| 1313 | |
| 1314 | /* Call-bound packets are routed by connection channel. */ |
| 1315 | channel = sp->hdr.cid & RXRPC_CHANNELMASK; |
| 1316 | chan = &conn->channels[channel]; |
| 1317 | |
| 1318 | /* Ignore really old calls */ |
| 1319 | if (sp->hdr.callNumber < chan->last_call) |
| 1320 | goto discard; |
| 1321 | |
| 1322 | if (sp->hdr.callNumber == chan->last_call) { |
| 1323 | if (chan->call || |
| 1324 | sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) |
| 1325 | goto discard; |
| 1326 | |
| 1327 | /* For the previous service call, if completed |
| 1328 | * successfully, we discard all further packets. |
| 1329 | */ |
| 1330 | if (rxrpc_conn_is_service(conn) && |
| 1331 | chan->last_type == RXRPC_PACKET_TYPE_ACK) |
| 1332 | goto discard; |
| 1333 | |
| 1334 | /* But otherwise we need to retransmit the final packet |
| 1335 | * from data cached in the connection record. |
| 1336 | */ |
| 1337 | if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) |
| 1338 | trace_rxrpc_rx_data(chan->call_debug_id, |
| 1339 | sp->hdr.seq, |
| 1340 | sp->hdr.serial, |
| 1341 | sp->hdr.flags, 0); |
| 1342 | rxrpc_post_packet_to_conn(conn, skb); |
| 1343 | goto out; |
| 1344 | } |
| 1345 | |
| 1346 | call = rcu_dereference(chan->call); |
| 1347 | |
| 1348 | if (sp->hdr.callNumber > chan->call_id) { |
| 1349 | if (rxrpc_to_client(sp)) |
| 1350 | goto reject_packet; |
| 1351 | if (call) |
| 1352 | rxrpc_input_implicit_end_call(rx, conn, call); |
| 1353 | call = NULL; |
| 1354 | } |
| 1355 | |
| 1356 | if (call) { |
| 1357 | if (sp->hdr.serviceId != call->service_id) |
| 1358 | call->service_id = sp->hdr.serviceId; |
| 1359 | if ((int)sp->hdr.serial - (int)call->rx_serial > 0) |
| 1360 | call->rx_serial = sp->hdr.serial; |
| 1361 | if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) |
| 1362 | set_bit(RXRPC_CALL_RX_HEARD, &call->flags); |
| 1363 | } |
| 1364 | } |
| 1365 | |
| 1366 | if (!call || atomic_read(&call->usage) == 0) { |
| 1367 | if (rxrpc_to_client(sp) || |
| 1368 | sp->hdr.type != RXRPC_PACKET_TYPE_DATA) |
| 1369 | goto bad_message; |
| 1370 | if (sp->hdr.seq != 1) |
| 1371 | goto discard; |
| 1372 | call = rxrpc_new_incoming_call(local, rx, skb); |
| 1373 | if (!call) |
| 1374 | goto reject_packet; |
| 1375 | rxrpc_send_ping(call, skb, skew); |
| 1376 | mutex_unlock(&call->user_mutex); |
| 1377 | } |
| 1378 | |
| 1379 | rxrpc_input_call_packet(call, skb, skew); |
| 1380 | goto discard; |
| 1381 | |
| 1382 | discard: |
| 1383 | rxrpc_free_skb(skb, rxrpc_skb_rx_freed); |
| 1384 | out: |
| 1385 | trace_rxrpc_rx_done(0, 0); |
| 1386 | return 0; |
| 1387 | |
| 1388 | wrong_security: |
| 1389 | trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, |
| 1390 | RXKADINCONSISTENCY, EBADMSG); |
| 1391 | skb->priority = RXKADINCONSISTENCY; |
| 1392 | goto post_abort; |
| 1393 | |
| 1394 | unsupported_service: |
| 1395 | trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, |
| 1396 | RX_INVALID_OPERATION, EOPNOTSUPP); |
| 1397 | skb->priority = RX_INVALID_OPERATION; |
| 1398 | goto post_abort; |
| 1399 | |
| 1400 | reupgrade: |
| 1401 | trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, |
| 1402 | RX_PROTOCOL_ERROR, EBADMSG); |
| 1403 | goto protocol_error; |
| 1404 | |
| 1405 | bad_message: |
| 1406 | trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, |
| 1407 | RX_PROTOCOL_ERROR, EBADMSG); |
| 1408 | protocol_error: |
| 1409 | skb->priority = RX_PROTOCOL_ERROR; |
| 1410 | post_abort: |
| 1411 | skb->mark = RXRPC_SKB_MARK_REJECT_ABORT; |
| 1412 | reject_packet: |
| 1413 | trace_rxrpc_rx_done(skb->mark, skb->priority); |
| 1414 | rxrpc_reject_packet(local, skb); |
| 1415 | _leave(" [badmsg]"); |
| 1416 | return 0; |
| 1417 | } |