17c30b40ed
This patch deprecates the Ack Ratio sysctl, since
* Ack Ratio is entirely ignored by CCID-3 and CCID-4,
* Ack Ratio currently doesn't work in CCID-2 (i.e. is always set to 1);
* even if it would work in CCID-2, there is no point for a user to change it:
- Ack Ratio is constrained by cwnd (RFC 4341, 6.1.2),
- if Ack Ratio > cwnd, the system resorts to spurious RTO timeouts
(since waiting for Acks which will never arrive in this window),
- cwnd is not a user-configurable value.
The only reasonable place for Ack Ratio is to print it for debugging. It is
planned to do this later on, as part of e.g. dccp_probe.
With this patch Ack Ratio is now under full control of feature negotiation:
* Ack Ratio is resolved as a dependency of the selected CCID;
* if the chosen CCID supports it (i.e. CCID == CCID-2), Ack Ratio is set to
the default of 2, following RFC 4340, 11.3 - "New connections start with Ack
Ratio 2 for both endpoints";
* what happens then is part of another patch set, since it concerns the
dynamic update of Ack Ratio while the connection is in full flight.
Thanks to Tomasz Grobelny for discussion leading up to this patch.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
119 lines
2.8 KiB
C
119 lines
2.8 KiB
C
/*
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* net/dccp/sysctl.c
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*
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* An implementation of the DCCP protocol
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* Arnaldo Carvalho de Melo <acme@mandriva.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License v2
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* as published by the Free Software Foundation.
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*/
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#include <linux/mm.h>
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#include <linux/sysctl.h>
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#include "dccp.h"
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#include "feat.h"
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#ifndef CONFIG_SYSCTL
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#error This file should not be compiled without CONFIG_SYSCTL defined
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#endif
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static struct ctl_table dccp_default_table[] = {
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{
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.procname = "seq_window",
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.data = &sysctl_dccp_feat_sequence_window,
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.maxlen = sizeof(sysctl_dccp_feat_sequence_window),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "rx_ccid",
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.data = &sysctl_dccp_feat_rx_ccid,
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.maxlen = sizeof(sysctl_dccp_feat_rx_ccid),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "tx_ccid",
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.data = &sysctl_dccp_feat_tx_ccid,
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.maxlen = sizeof(sysctl_dccp_feat_tx_ccid),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "send_ackvec",
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.data = &sysctl_dccp_feat_send_ack_vector,
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.maxlen = sizeof(sysctl_dccp_feat_send_ack_vector),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "send_ndp",
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.data = &sysctl_dccp_feat_send_ndp_count,
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.maxlen = sizeof(sysctl_dccp_feat_send_ndp_count),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "request_retries",
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.data = &sysctl_dccp_request_retries,
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.maxlen = sizeof(sysctl_dccp_request_retries),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "retries1",
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.data = &sysctl_dccp_retries1,
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.maxlen = sizeof(sysctl_dccp_retries1),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "retries2",
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.data = &sysctl_dccp_retries2,
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.maxlen = sizeof(sysctl_dccp_retries2),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "tx_qlen",
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.data = &sysctl_dccp_tx_qlen,
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.maxlen = sizeof(sysctl_dccp_tx_qlen),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{
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.procname = "sync_ratelimit",
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.data = &sysctl_dccp_sync_ratelimit,
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.maxlen = sizeof(sysctl_dccp_sync_ratelimit),
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.mode = 0644,
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.proc_handler = proc_dointvec_ms_jiffies,
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},
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{ .ctl_name = 0, }
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};
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static struct ctl_path dccp_path[] = {
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{ .procname = "net", .ctl_name = CTL_NET, },
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{ .procname = "dccp", .ctl_name = NET_DCCP, },
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{ .procname = "default", .ctl_name = NET_DCCP_DEFAULT, },
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{ }
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};
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static struct ctl_table_header *dccp_table_header;
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int __init dccp_sysctl_init(void)
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{
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dccp_table_header = register_sysctl_paths(dccp_path,
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dccp_default_table);
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return dccp_table_header != NULL ? 0 : -ENOMEM;
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}
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void dccp_sysctl_exit(void)
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{
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if (dccp_table_header != NULL) {
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unregister_sysctl_table(dccp_table_header);
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dccp_table_header = NULL;
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}
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}
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