cb8660e79a
Add a structure for length and other information about received and transmitted NTP packets to minimize the number of parameters and avoid repeated parsing of the packet.
135 lines
3.8 KiB
C
135 lines
3.8 KiB
C
/*
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chronyd/chronyc - Programs for keeping computer clocks accurate.
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**********************************************************************
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* Copyright (C) Richard P. Curnow 1997-2003
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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 file containing common NTP bits and pieces
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*/
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#ifndef GOT_NTP_H
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#define GOT_NTP_H
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#include "sysincl.h"
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#include "hash.h"
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typedef struct {
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uint32_t hi;
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uint32_t lo;
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} NTP_int64;
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typedef uint32_t NTP_int32;
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/* The UDP port number used by NTP */
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#define NTP_PORT 123
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/* The NTP protocol version that we support */
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#define NTP_VERSION 4
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/* Maximum stratum number (infinity) */
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#define NTP_MAX_STRATUM 16
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/* The minimum and maximum supported length of MAC */
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#define NTP_MIN_MAC_LENGTH (4 + 16)
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#define NTP_MAX_MAC_LENGTH (4 + MAX_HASH_LENGTH)
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/* The minimum valid length of an extension field */
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#define NTP_MIN_EF_LENGTH 16
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/* The maximum assumed length of all extension fields in an NTP packet,
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including a MAC (RFC 5905 doesn't specify a limit on length or number of
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extension fields in one packet) */
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#define NTP_MAX_EXTENSIONS_LENGTH (1024 + NTP_MAX_MAC_LENGTH)
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/* The maximum length of MAC in NTPv4 packets which allows deterministic
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parsing of extension fields (RFC 7822) */
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#define NTP_MAX_V4_MAC_LENGTH (4 + 20)
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/* Type definition for leap bits */
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typedef enum {
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LEAP_Normal = 0,
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LEAP_InsertSecond = 1,
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LEAP_DeleteSecond = 2,
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LEAP_Unsynchronised = 3
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} NTP_Leap;
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typedef enum {
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MODE_UNDEFINED = 0,
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MODE_ACTIVE = 1,
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MODE_PASSIVE = 2,
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MODE_CLIENT = 3,
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MODE_SERVER = 4,
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MODE_BROADCAST = 5
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} NTP_Mode;
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typedef struct {
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uint8_t lvm;
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uint8_t stratum;
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int8_t poll;
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int8_t precision;
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NTP_int32 root_delay;
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NTP_int32 root_dispersion;
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NTP_int32 reference_id;
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NTP_int64 reference_ts;
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NTP_int64 originate_ts;
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NTP_int64 receive_ts;
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NTP_int64 transmit_ts;
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uint8_t extensions[NTP_MAX_EXTENSIONS_LENGTH];
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} NTP_Packet;
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#define NTP_HEADER_LENGTH (int)offsetof(NTP_Packet, extensions)
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/* Macros to work with the lvm field */
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#define NTP_LVM_TO_LEAP(lvm) (((lvm) >> 6) & 0x3)
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#define NTP_LVM_TO_VERSION(lvm) (((lvm) >> 3) & 0x7)
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#define NTP_LVM_TO_MODE(lvm) ((lvm) & 0x7)
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#define NTP_LVM(leap, version, mode) \
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((((leap) << 6) & 0xc0) | (((version) << 3) & 0x38) | ((mode) & 0x07))
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/* Special NTP reference IDs */
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#define NTP_REFID_UNSYNC 0x0UL
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#define NTP_REFID_LOCAL 0x7F7F0101UL /* 127.127.1.1 */
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#define NTP_REFID_SMOOTH 0x7F7F01FFUL /* 127.127.1.255 */
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/* Structure describing an NTP packet */
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typedef struct {
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int length;
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int version;
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NTP_Mode mode;
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} NTP_PacketInfo;
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/* Structure used to save NTP measurements. time is the local time at which
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the sample is to be considered to have been made and offset is the offset at
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the time (positive indicates that the local clock is slow relative to the
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source). root_delay/root_dispersion include peer_delay/peer_dispersion. */
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typedef struct {
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struct timespec time;
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double offset;
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double peer_delay;
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double peer_dispersion;
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double root_delay;
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double root_dispersion;
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int stratum;
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NTP_Leap leap;
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} NTP_Sample;
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#endif /* GOT_NTP_H */
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