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6fdd34d43b
This removes the use of the sysctl and the minisock variable for the Send Ack
Vector feature, as it now is handled fully dynamically via feature negotiation
(i.e. when CCID-2 is enabled, Ack Vectors are automatically enabled as per
RFC 4341, 4.).
Using a sysctl in parallel to this implementation would open the door to
crashes, since much of the code relies on tests of the boolean minisock /
sysctl variable. Thus, this patch replaces all tests of type
if (dccp_msk(sk)->dccpms_send_ack_vector)
/* ... */
with
if (dp->dccps_hc_rx_ackvec != NULL)
/* ... */
The dccps_hc_rx_ackvec is allocated by the dccp_hdlr_ackvec() when feature
negotiation concluded that Ack Vectors are to be used on the half-connection.
Otherwise, it is NULL (due to dccp_init_sock/dccp_create_openreq_child),
so that the test is a valid one.
The activation handler for Ack Vectors is called as soon as the feature
negotiation has concluded at the
* server when the Ack marking the transition RESPOND => OPEN arrives;
* client after it has sent its ACK, marking the transition REQUEST => PARTOPEN.
Adding the sequence number of the Response packet to the Ack Vector has been
removed, since
(a) connection establishment implies that the Response has been received;
(b) the CCIDs only look at packets received in the (PART)OPEN state, i.e.
this entry will always be ignored;
(c) it can not be used for anything useful - to detect loss for instance, only
packets received after the loss can serve as pseudo-dupacks.
There was a FIXME to change the error code when dccp_ackvec_add() fails.
I removed this after finding out that:
* the check whether ackno < ISN is already made earlier,
* this Response is likely the 1st packet with an Ackno that the client gets,
* so when dccp_ackvec_add() fails, the reason is likely not a packet error.
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>
106 lines
2.4 KiB
C
106 lines
2.4 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 = "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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