linux/net/rxrpc/misc.c

242 lines
7.7 KiB
C
Raw Normal View History

/* Miscellaneous bits
*
* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
rxrpc: Limit the listening backlog Limit the socket incoming call backlog queue size so that a remote client can't pump in sufficient new calls that the server runs out of memory. Note that this is partially theoretical at the moment since whilst the number of calls is limited, the number of packets trying to set up new calls is not. This will be addressed in a later patch. If the caller of listen() specifies a backlog INT_MAX, then they get the current maximum; anything else greater than max_backlog or anything negative incurs EINVAL. The limit on the maximum queue size can be set by: echo N >/proc/sys/net/rxrpc/max_backlog where 4<=N<=32. Further, set the default backlog to 0, requiring listen() to be called before we start actually queueing new calls. Whilst this kind of is a change in the UAPI, the caller can't actually *accept* new calls anyway unless they've first called listen() to put the socket into the LISTENING state - thus the aforementioned new calls would otherwise just sit there, eating up kernel memory. (Note that sockets that don't have a non-zero service ID bound don't get incoming calls anyway.) Given that the default backlog is now 0, make the AFS filesystem call kernel_listen() to set the maximum backlog for itself. Possible improvements include: (1) Trimming a too-large backlog to max_backlog when listen is called. (2) Trimming the backlog value whenever the value is used so that changes to max_backlog are applied to an open socket automatically. Note that the AFS filesystem opens one socket and keeps it open for extended periods, so would miss out on changes to max_backlog. (3) Having a separate setting for the AFS filesystem. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-11 05:30:37 +08:00
/*
* The maximum listening backlog queue size that may be set on a socket by
* listen().
*/
unsigned int rxrpc_max_backlog __read_mostly = 10;
/*
* Maximum lifetime of a call (in mx).
*/
unsigned int rxrpc_max_call_lifetime = 60 * 1000;
/*
* How long to wait before scheduling ACK generation after seeing a
* packet with RXRPC_REQUEST_ACK set (in ms).
*/
unsigned int rxrpc_requested_ack_delay = 1;
/*
* How long to wait before scheduling an ACK with subtype DELAY (in ms).
*
* We use this when we've received new data packets. If those packets aren't
* all consumed within this time we will send a DELAY ACK if an ACK was not
* requested to let the sender know it doesn't need to resend.
*/
unsigned int rxrpc_soft_ack_delay = 1 * 1000;
/*
* How long to wait before scheduling an ACK with subtype IDLE (in ms).
*
* We use this when we've consumed some previously soft-ACK'd packets when
* further packets aren't immediately received to decide when to send an IDLE
* ACK let the other end know that it can free up its Tx buffer space.
*/
unsigned int rxrpc_idle_ack_delay = 0.5 * 1000;
/*
* Receive window size in packets. This indicates the maximum number of
* unconsumed received packets we're willing to retain in memory. Once this
* limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
* packets.
*/
unsigned int rxrpc_rx_window_size = RXRPC_INIT_RX_WINDOW_SIZE;
#if (RXRPC_RXTX_BUFF_SIZE - 1) < RXRPC_INIT_RX_WINDOW_SIZE
#error Need to reduce RXRPC_INIT_RX_WINDOW_SIZE
#endif
/*
* Maximum Rx MTU size. This indicates to the sender the size of jumbo packet
* made by gluing normal packets together that we're willing to handle.
*/
unsigned int rxrpc_rx_mtu = 5692;
/*
* The maximum number of fragments in a received jumbo packet that we tell the
* sender that we're willing to handle.
*/
unsigned int rxrpc_rx_jumbo_max = 4;
/*
* Time till packet resend (in milliseconds).
*/
unsigned int rxrpc_resend_timeout = 4 * 1000;
const char *const rxrpc_pkts[] = {
"?00",
"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
"?09", "?10", "?11", "?12", "VERSION", "?14", "?15"
};
const s8 rxrpc_ack_priority[] = {
[0] = 0,
[RXRPC_ACK_DELAY] = 1,
[RXRPC_ACK_REQUESTED] = 2,
[RXRPC_ACK_IDLE] = 3,
[RXRPC_ACK_DUPLICATE] = 4,
[RXRPC_ACK_OUT_OF_SEQUENCE] = 5,
[RXRPC_ACK_EXCEEDS_WINDOW] = 6,
[RXRPC_ACK_NOSPACE] = 7,
[RXRPC_ACK_PING_RESPONSE] = 8,
};
const char rxrpc_ack_names[RXRPC_ACK__INVALID + 1][4] = {
"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
"IDL", "-?-"
};
const char rxrpc_skb_traces[rxrpc_skb__nr_trace][7] = {
[rxrpc_skb_rx_cleaned] = "Rx CLN",
[rxrpc_skb_rx_freed] = "Rx FRE",
[rxrpc_skb_rx_got] = "Rx GOT",
[rxrpc_skb_rx_lost] = "Rx *L*",
[rxrpc_skb_rx_received] = "Rx RCV",
[rxrpc_skb_rx_purged] = "Rx PUR",
[rxrpc_skb_rx_rotated] = "Rx ROT",
[rxrpc_skb_rx_seen] = "Rx SEE",
[rxrpc_skb_tx_cleaned] = "Tx CLN",
[rxrpc_skb_tx_freed] = "Tx FRE",
[rxrpc_skb_tx_got] = "Tx GOT",
[rxrpc_skb_tx_new] = "Tx NEW",
[rxrpc_skb_tx_rotated] = "Tx ROT",
[rxrpc_skb_tx_seen] = "Tx SEE",
};
const char rxrpc_conn_traces[rxrpc_conn__nr_trace][4] = {
[rxrpc_conn_new_client] = "NWc",
[rxrpc_conn_new_service] = "NWs",
[rxrpc_conn_queued] = "QUE",
[rxrpc_conn_seen] = "SEE",
[rxrpc_conn_got] = "GOT",
[rxrpc_conn_put_client] = "PTc",
[rxrpc_conn_put_service] = "PTs",
};
const char rxrpc_client_traces[rxrpc_client__nr_trace][7] = {
[rxrpc_client_activate_chans] = "Activa",
[rxrpc_client_alloc] = "Alloc ",
[rxrpc_client_chan_activate] = "ChActv",
[rxrpc_client_chan_disconnect] = "ChDisc",
[rxrpc_client_chan_pass] = "ChPass",
[rxrpc_client_chan_unstarted] = "ChUnst",
[rxrpc_client_cleanup] = "Clean ",
[rxrpc_client_count] = "Count ",
[rxrpc_client_discard] = "Discar",
[rxrpc_client_duplicate] = "Duplic",
[rxrpc_client_exposed] = "Expose",
[rxrpc_client_replace] = "Replac",
[rxrpc_client_to_active] = "->Actv",
[rxrpc_client_to_culled] = "->Cull",
[rxrpc_client_to_idle] = "->Idle",
[rxrpc_client_to_inactive] = "->Inac",
[rxrpc_client_to_waiting] = "->Wait",
[rxrpc_client_uncount] = "Uncoun",
};
const char rxrpc_transmit_traces[rxrpc_transmit__nr_trace][4] = {
[rxrpc_transmit_wait] = "WAI",
[rxrpc_transmit_queue] = "QUE",
[rxrpc_transmit_queue_last] = "QLS",
[rxrpc_transmit_rotate] = "ROT",
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 19:39:22 +08:00
[rxrpc_transmit_rotate_last] = "RLS",
[rxrpc_transmit_await_reply] = "AWR",
[rxrpc_transmit_end] = "END",
};
const char rxrpc_receive_traces[rxrpc_receive__nr_trace][4] = {
[rxrpc_receive_incoming] = "INC",
[rxrpc_receive_queue] = "QUE",
[rxrpc_receive_queue_last] = "QLS",
[rxrpc_receive_front] = "FRN",
[rxrpc_receive_rotate] = "ROT",
[rxrpc_receive_end] = "END",
};
const char rxrpc_recvmsg_traces[rxrpc_recvmsg__nr_trace][5] = {
[rxrpc_recvmsg_enter] = "ENTR",
[rxrpc_recvmsg_wait] = "WAIT",
[rxrpc_recvmsg_dequeue] = "DEQU",
[rxrpc_recvmsg_hole] = "HOLE",
[rxrpc_recvmsg_next] = "NEXT",
[rxrpc_recvmsg_cont] = "CONT",
[rxrpc_recvmsg_full] = "FULL",
[rxrpc_recvmsg_data_return] = "DATA",
[rxrpc_recvmsg_terminal] = "TERM",
[rxrpc_recvmsg_to_be_accepted] = "TBAC",
[rxrpc_recvmsg_return] = "RETN",
};
const char rxrpc_rtt_tx_traces[rxrpc_rtt_tx__nr_trace][5] = {
[rxrpc_rtt_tx_ping] = "PING",
[rxrpc_rtt_tx_data] = "DATA",
};
const char rxrpc_rtt_rx_traces[rxrpc_rtt_rx__nr_trace][5] = {
[rxrpc_rtt_rx_ping_response] = "PONG",
[rxrpc_rtt_rx_requested_ack] = "RACK",
};
const char rxrpc_timer_traces[rxrpc_timer__nr_trace][8] = {
[rxrpc_timer_begin] = "Begin ",
[rxrpc_timer_expired] = "*EXPR*",
[rxrpc_timer_init_for_reply] = "IniRpl",
[rxrpc_timer_init_for_send_reply] = "SndRpl",
[rxrpc_timer_set_for_ack] = "SetAck",
[rxrpc_timer_set_for_ping] = "SetPng",
[rxrpc_timer_set_for_send] = "SetTx ",
[rxrpc_timer_set_for_resend] = "SetRTx",
};
const char rxrpc_propose_ack_traces[rxrpc_propose_ack__nr_trace][8] = {
[rxrpc_propose_ack_client_tx_end] = "ClTxEnd",
[rxrpc_propose_ack_input_data] = "DataIn ",
[rxrpc_propose_ack_ping_for_lost_ack] = "LostAck",
[rxrpc_propose_ack_ping_for_lost_reply] = "LostRpl",
[rxrpc_propose_ack_ping_for_params] = "Params ",
[rxrpc_propose_ack_processing_op] = "ProcOp ",
[rxrpc_propose_ack_respond_to_ack] = "Rsp2Ack",
[rxrpc_propose_ack_respond_to_ping] = "Rsp2Png",
[rxrpc_propose_ack_retry_tx] = "RetryTx",
[rxrpc_propose_ack_rotate_rx] = "RxAck ",
[rxrpc_propose_ack_terminal_ack] = "ClTerm ",
};
const char *const rxrpc_propose_ack_outcomes[rxrpc_propose_ack__nr_outcomes] = {
[rxrpc_propose_ack_use] = "",
[rxrpc_propose_ack_update] = " Update",
[rxrpc_propose_ack_subsume] = " Subsume",
};
const char rxrpc_congest_modes[NR__RXRPC_CONGEST_MODES][10] = {
[RXRPC_CALL_SLOW_START] = "SlowStart",
[RXRPC_CALL_CONGEST_AVOIDANCE] = "CongAvoid",
[RXRPC_CALL_PACKET_LOSS] = "PktLoss ",
[RXRPC_CALL_FAST_RETRANSMIT] = "FastReTx ",
};
const char rxrpc_congest_changes[rxrpc_congest__nr_change][9] = {
[rxrpc_cong_begin_retransmission] = " Retrans",
[rxrpc_cong_cleared_nacks] = " Cleared",
[rxrpc_cong_new_low_nack] = " NewLowN",
[rxrpc_cong_no_change] = "",
[rxrpc_cong_progress] = " Progres",
[rxrpc_cong_retransmit_again] = " ReTxAgn",
[rxrpc_cong_rtt_window_end] = " RttWinE",
[rxrpc_cong_saw_nack] = " SawNack",
};