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Diffstat (limited to 'ntp.h')
| -rw-r--r-- | ntp.h | 200 |
1 files changed, 200 insertions, 0 deletions
@@ -0,0 +1,200 @@ +/* + chronyd/chronyc - Programs for keeping computer clocks accurate. + + ********************************************************************** + * Copyright (C) Richard P. Curnow 1997-2003 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + ********************************************************************** + + ======================================================================= + + Header file containing common NTP bits and pieces + */ + +#ifndef GOT_NTP_H +#define GOT_NTP_H + +#include "sysincl.h" + +#include "hash.h" + +typedef struct { + uint32_t hi; + uint32_t lo; +} NTP_int64; + +typedef uint32_t NTP_int32; + +/* The UDP port number used by NTP */ +#define NTP_PORT 123 + +/* The NTP protocol version that we support */ +#define NTP_VERSION 4 + +/* Maximum stratum number (infinity) */ +#define NTP_MAX_STRATUM 16 + +/* Invalid stratum number */ +#define NTP_INVALID_STRATUM 0 + +/* The minimum and maximum supported length of MAC */ +#define NTP_MIN_MAC_LENGTH (4 + 16) +#define NTP_MAX_MAC_LENGTH (4 + MAX_HASH_LENGTH) + +/* The minimum valid length of an extension field */ +#define NTP_MIN_EF_LENGTH 16 + +/* The maximum assumed length of all extension fields in an NTP packet, + including a MAC (RFC 5905 doesn't specify a limit on length or number of + extension fields in one packet) */ +#define NTP_MAX_EXTENSIONS_LENGTH (1024 + NTP_MAX_MAC_LENGTH) + +/* The maximum length of MAC in NTPv4 packets which allows deterministic + parsing of extension fields (RFC 7822) */ +#define NTP_MAX_V4_MAC_LENGTH (4 + 20) + +/* Type definition for leap bits */ +typedef enum { + LEAP_Normal = 0, + LEAP_InsertSecond = 1, + LEAP_DeleteSecond = 2, + LEAP_Unsynchronised = 3 +} NTP_Leap; + +typedef enum { + MODE_UNDEFINED = 0, + MODE_ACTIVE = 1, + MODE_PASSIVE = 2, + MODE_CLIENT = 3, + MODE_SERVER = 4, + MODE_BROADCAST = 5 +} NTP_Mode; + +typedef struct { + uint8_t lvm; + uint8_t stratum; + int8_t poll; + int8_t precision; + NTP_int32 root_delay; + NTP_int32 root_dispersion; + NTP_int32 reference_id; + NTP_int64 reference_ts; + NTP_int64 originate_ts; + NTP_int64 receive_ts; + NTP_int64 transmit_ts; + + uint8_t extensions[NTP_MAX_EXTENSIONS_LENGTH]; +} NTP_Packet; + +#define NTP_HEADER_LENGTH (int)offsetof(NTP_Packet, extensions) + +/* Macros to work with the lvm field */ +#define NTP_LVM_TO_LEAP(lvm) (((lvm) >> 6) & 0x3) +#define NTP_LVM_TO_VERSION(lvm) (((lvm) >> 3) & 0x7) +#define NTP_LVM_TO_MODE(lvm) ((lvm) & 0x7) +#define NTP_LVM(leap, version, mode) \ + ((((leap) << 6) & 0xc0) | (((version) << 3) & 0x38) | ((mode) & 0x07)) + +/* Special NTP reference IDs */ +#define NTP_REFID_UNSYNC 0x0UL +#define NTP_REFID_LOCAL 0x7F7F0101UL /* 127.127.1.1 */ +#define NTP_REFID_SMOOTH 0x7F7F01FFUL /* 127.127.1.255 */ + +/* Non-authentication extension fields and corresponding internal flags */ + +#define NTP_EF_EXP_MONO_ROOT 0xF323 +#define NTP_EF_EXP_NET_CORRECTION 0xF324 + +#define NTP_EF_FLAG_EXP_MONO_ROOT 0x1 +#define NTP_EF_FLAG_EXP_NET_CORRECTION 0x2 + +/* Pre-NTPv5 experimental extension field */ +typedef struct { + uint32_t magic; + NTP_int32 root_delay; + NTP_int32 root_dispersion; + NTP_int64 mono_receive_ts; + uint32_t mono_epoch; +} NTP_EFExpMonoRoot; + +#define NTP_EF_EXP_MONO_ROOT_MAGIC 0xF5BEDD9AU + +/* Experimental extension field to provide PTP corrections */ +typedef struct { + uint32_t magic; + NTP_int64 correction; + uint32_t reserved[3]; +} NTP_EFExpNetCorrection; + +#define NTP_EF_EXP_NET_CORRECTION_MAGIC 0x07AC2CEBU + +/* Authentication extension fields */ + +#define NTP_EF_NTS_UNIQUE_IDENTIFIER 0x0104 +#define NTP_EF_NTS_COOKIE 0x0204 +#define NTP_EF_NTS_COOKIE_PLACEHOLDER 0x0304 +#define NTP_EF_NTS_AUTH_AND_EEF 0x0404 + +/* Enumeration for authentication modes of NTP packets */ +typedef enum { + NTP_AUTH_NONE = 0, /* No authentication */ + NTP_AUTH_SYMMETRIC, /* NTP MAC or CMAC using a symmetric key + (RFC 1305, RFC 5905, RFC 8573) */ + NTP_AUTH_MSSNTP, /* MS-SNTP authenticator field */ + NTP_AUTH_MSSNTP_EXT, /* MS-SNTP extended authenticator field */ + NTP_AUTH_NTS, /* Network Time Security (RFC 8915) */ +} NTP_AuthMode; + +/* Structure describing an NTP packet */ +typedef struct { + int length; + int version; + NTP_Mode mode; + + int ext_fields; + int ext_field_flags; + + struct { + NTP_AuthMode mode; + struct { + int start; + int length; + uint32_t key_id; + } mac; + } auth; +} NTP_PacketInfo; + +/* Structure used to save NTP measurements. time is the local time at which + the sample is to be considered to have been made and offset is the offset at + the time (positive indicates that the local clock is slow relative to the + source). root_delay/root_dispersion include peer_delay/peer_dispersion. */ +typedef struct { + struct timespec time; + double offset; + double peer_delay; + double peer_dispersion; + double root_delay; + double root_dispersion; +} NTP_Sample; + +/* Possible sources of timestamps */ +typedef enum { + NTP_TS_DAEMON = 0, + NTP_TS_KERNEL, + NTP_TS_HARDWARE +} NTP_Timestamp_Source; + +#endif /* GOT_NTP_H */ |