883ca833e5
This patch takes care of initialising and type-checking sysctls
related to feature negotiation. Type checking is important since some
of the sysctls now directly impact the feature-negotiation process.
The sysctls are initialised with the known default values for each
feature. For the type-checking the value constraints from RFC 4340
are used:
* Sequence Window uses the specified Wmin=32, the maximum is ulong (4 bytes),
tested and confirmed that it works up to 4294967295 - for Gbps speed;
* Ack Ratio is between 0 .. 0xffff (2-byte unsigned integer);
* CCIDs are between 0 .. 255;
* request_retries, retries1, retries2 also between 0..255 for good measure;
* tx_qlen is checked to be non-negative;
* sync_ratelimit remains as before.
Notes:
------
1. Die s@sysctl_dccp_feat@sysctl_dccp@g since the sysctls are now in feat.c.
2. As pointed out by Arnaldo, the pattern of type-checking repeats itself in
other places, sometimes with exactly the same kind of definitions (e.g.
"static int zero;"). It may be a good idea (kernel janitors?) to consolidate
type checking. For the sake of keeping the changeset small and in order not
to affect other subsystems, I have not strived to generalise here.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
123 lines
2.9 KiB
C
123 lines
2.9 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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/* Boundary values */
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static int zero = 0,
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u8_max = 0xFF;
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static unsigned long seqw_min = 32;
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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_sequence_window,
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.maxlen = sizeof(sysctl_dccp_sequence_window),
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.mode = 0644,
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.proc_handler = proc_doulongvec_minmax,
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.extra1 = &seqw_min, /* RFC 4340, 7.5.2 */
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},
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{
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.procname = "rx_ccid",
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.data = &sysctl_dccp_rx_ccid,
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.maxlen = sizeof(sysctl_dccp_rx_ccid),
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.mode = 0644,
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.proc_handler = proc_dointvec_minmax,
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.extra1 = &zero,
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.extra2 = &u8_max, /* RFC 4340, 10. */
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},
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{
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.procname = "tx_ccid",
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.data = &sysctl_dccp_tx_ccid,
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.maxlen = sizeof(sysctl_dccp_tx_ccid),
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.mode = 0644,
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.proc_handler = proc_dointvec_minmax,
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.extra1 = &zero,
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.extra2 = &u8_max, /* RFC 4340, 10. */
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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_minmax,
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.extra1 = &zero,
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.extra2 = &u8_max,
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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_minmax,
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.extra1 = &zero,
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.extra2 = &u8_max,
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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_minmax,
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.extra1 = &zero,
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.extra2 = &u8_max,
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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_minmax,
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.extra1 = &zero,
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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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