Safe Haskell	Safe-Inferred
Language	Haskell2010

Network.NTP.Client.Query

Contents

Logging

Synopsis

data NtpSettings = NtpSettings {
- ntpServers ∷ [String]
- ntpRequiredNumberOfResults ∷ Int
- ntpResponseTimeout ∷ Microsecond
- ntpPollDelay ∷ Microsecond
}
data NtpStatus
- = NtpDrift !NtpOffset
- | NtpSyncPending
- | NtpSyncUnavailable
data CompletedNtpStatus
- = CNtpDrift !NtpOffset
- | CNtpSyncUnavailable
ntpQuery ∷ IOManager → Tracer IO NtpTrace → NtpSettings → IO CompletedNtpStatus
data NtpTrace
data IPVersion
- = IPv4
- | IPv6
data ResultOrFailure a
- = BothSucceeded !a
- | SuccessAndFailure !a !IPVersion !IOException
- | BothFailed !IOException !IOException

Documentation

data NtpSettings Source #

Settings of the ntp client.

Constructors

NtpSettings

Fields

ntpServers ∷ [String]
List of server addresses. At least three servers are needed.
ntpRequiredNumberOfResults ∷ Int
Minimum number of results to compute the offset, this should be less or equal to the length of ntpServers (we send a single tnp packet / query to a each server, if the dns name resolves to many addresses we pick the first one).
ntpResponseTimeout ∷ Microsecond
Timeout for receiving a response from an ntp server.
ntpPollDelay ∷ Microsecond
How long to wait between two rounds of requests. This should be set to something of an order of one hour, ntp servers should not be abused.

data NtpStatus Source #

The Ntp client state: either cached results is availbale, or the ntp client is engaged in ntp-protocol or there was a failure: e.g. connection lost, or dns lookups did not return at least ntpRequiredNumberOfResults addresses.

Constructors

NtpDrift !NtpOffset	The difference between NTP time and local system time
NtpSyncPending	NTP client has send requests to the servers
NtpSyncUnavailable	NTP is not available: the client has not received any respond within `ntpResponseTimeout` from at least `ntpRequiredNumberOfResults` servers.

Instances

Instances details

Show NtpStatus Source #
Instance details Defined in Network.NTP.Client.Query Methods showsPrec ∷ Int → NtpStatus → ShowS # show ∷ NtpStatus → String # showList ∷ [NtpStatus] → ShowS #
Eq NtpStatus Source #
Instance details Defined in Network.NTP.Client.Query Methods (==) ∷ NtpStatus → NtpStatus → Bool # (/=) ∷ NtpStatus → NtpStatus → Bool #

data CompletedNtpStatus Source #

A version of NtpStatus specialized to the two "completed" states of that type: NtpDrift and NtpSyncUnavailable.

Constructors

CNtpDrift !NtpOffset	Corresponds to `NtpDrift`
CNtpSyncUnavailable	Corresponds to `NtpSyncUnavailable`

ntpQuery ∷ IOManager → Tracer IO NtpTrace → NtpSettings → IO CompletedNtpStatus Source #

Perform a series of NTP queries: one for each dns name. Resolve each dns name, get local addresses: both IPv4 and IPv6 and engage in ntp protocol towards one ip address per address family per dns name, but only for address families for which we have a local address. This is to avoid trying to send IPv4/6 requests if IPv4/6 gateway is not configured.

We produce a CompletedNtpStatus rather than an NtpStatus because we would never construct an NtpStatus using NtpSyncPending, so callers can avoid catching and killing that case.

It may throw an IOException:

if neither IPv4 nor IPv6 address is configured
if network I/O errors

Logging

data NtpTrace Source #

Instances

Instances details

Show NtpTrace Source #
Instance details Defined in Network.NTP.Client.Query Methods showsPrec ∷ Int → NtpTrace → ShowS # show ∷ NtpTrace → String # showList ∷ [NtpTrace] → ShowS #

data IPVersion Source #

A tag which describes which version of the ip protocol was used.

Constructors

IPv4
IPv6

Instances

Instances details

Show IPVersion Source #
Instance details Defined in Network.NTP.Client.Query Methods showsPrec ∷ Int → IPVersion → ShowS # show ∷ IPVersion → String # showList ∷ [IPVersion] → ShowS #
Eq IPVersion Source #
Instance details Defined in Network.NTP.Client.Query Methods (==) ∷ IPVersion → IPVersion → Bool # (/=) ∷ IPVersion → IPVersion → Bool #

data ResultOrFailure a Source #

Result of two threads running concurrently.

Constructors

BothSucceeded !a	both threads suceeded
SuccessAndFailure !a !IPVersion !IOException	one of the threads errors. `IPVersion` indicates which one.
BothFailed !IOException !IOException	both threads failed

Instances

Instances details

Foldable ResultOrFailure Source #
Instance details Defined in Network.NTP.Client.Query Methods fold ∷ Monoid m ⇒ ResultOrFailure m → m # foldMap ∷ Monoid m ⇒ (a → m) → ResultOrFailure a → m # foldMap' ∷ Monoid m ⇒ (a → m) → ResultOrFailure a → m # foldr ∷ (a → b → b) → b → ResultOrFailure a → b # foldr' ∷ (a → b → b) → b → ResultOrFailure a → b # foldl ∷ (b → a → b) → b → ResultOrFailure a → b # foldl' ∷ (b → a → b) → b → ResultOrFailure a → b # foldr1 ∷ (a → a → a) → ResultOrFailure a → a # foldl1 ∷ (a → a → a) → ResultOrFailure a → a # toList ∷ ResultOrFailure a → [a] # null ∷ ResultOrFailure a → Bool # length ∷ ResultOrFailure a → Int # elem ∷ Eq a ⇒ a → ResultOrFailure a → Bool # maximum ∷ Ord a ⇒ ResultOrFailure a → a # minimum ∷ Ord a ⇒ ResultOrFailure a → a # sum ∷ Num a ⇒ ResultOrFailure a → a # product ∷ Num a ⇒ ResultOrFailure a → a #
Show a ⇒ Show (ResultOrFailure a) Source #
Instance details Defined in Network.NTP.Client.Query Methods showsPrec ∷ Int → ResultOrFailure a → ShowS # show ∷ ResultOrFailure a → String # showList ∷ [ResultOrFailure a] → ShowS #
Eq a ⇒ Eq (ResultOrFailure a) Source #
Instance details Defined in Network.NTP.Client.Query Methods (==) ∷ ResultOrFailure a → ResultOrFailure a → Bool # (/=) ∷ ResultOrFailure a → ResultOrFailure a → Bool #

NtpTraceStartNtpClient
NtpTraceRestartDelay Int
NtpTraceRestartingClient
NtpTraceIOError IOError
NtpTraceLookupsFails
NtpTraceClientStartQuery
NtpTraceNoLocalAddr
NtpTraceResult NtpStatus
NtpTraceRunProtocolResults (ResultOrFailure [NtpOffset])
NtpTracePacketSent SockAddr NtpPacket
NtpTracePacketSendError SockAddr IOException
NtpTracePacketDecodeError SockAddr String
NtpTracePacketReceived SockAddr NtpPacket
NtpTraceWaitingForRepliesTimeout IPVersion