eae4b2abe5
The daemon transmit timestamps are precompensated for the time it takes to generate a MAC using a symmetric key (as measured on chronyd start) and also an average round-trip time of the Samba signing of MS-SNTP responses. This improves accuracy of the transmit timestamp, but it has some issues. The correction has a random error which is changing over time due to variable CPU frequency, system load, migration to a different machine, etc. If the measured delay is too large, the correction may cause the transmit timestamp to be later than the actual transmission. Also, the delay is measured for a packet of a minimal length with no extension fields, and there is no support for NTS. Drop the precompensation in favor of the interleaved mode, which now avoids the authentication delay even when no kernel/hardware timestamps are available.
42 lines
1.5 KiB
C
42 lines
1.5 KiB
C
/*
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chronyd/chronyc - Programs for keeping computer clocks accurate.
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**********************************************************************
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* Copyright (C) Miroslav Lichvar 2016
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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**********************************************************************
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=======================================================================
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Header for MS-SNTP authentication via Samba (ntp_signd) */
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#ifndef GOT_NTP_SIGND_H
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#define GOT_NTP_SIGND_H
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#include "addressing.h"
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#include "ntp.h"
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/* Initialisation function */
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extern void NSD_Initialise(void);
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/* Finalisation function */
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extern void NSD_Finalise(void);
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/* Function to sign an NTP packet and send it */
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extern int NSD_SignAndSendPacket(uint32_t key_id, NTP_Packet *packet, NTP_PacketInfo *info,
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NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr);
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#endif
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