pathhealth

Documentation

Overview

Package pathhealth monitors paths to different ASes. Call Monitor.Register() to start monitoring paths to a remote AS using a chosen path policy. The call returns a registration object which can be used to obtain the best path.

Index

• type DefaultPathWatcher
  • func (pw *DefaultPathWatcher) Close()
  • func (pw *DefaultPathWatcher) HandleProbeReply(seq uint16)
  • func (pw *DefaultPathWatcher) Path() snet.Path
  • func (pw *DefaultPathWatcher) SendProbe(conn snet.PacketConn, localAddr snet.SCIONAddress)
  • func (pw *DefaultPathWatcher) State() State
  • func (pw *DefaultPathWatcher) UpdatePath(path snet.Path)
• type DefaultPathWatcherFactory
  • func (f *DefaultPathWatcherFactory) New(remote addr.IA, path snet.Path, id uint16) PathWatcher
• type DefaultRemoteWatcher
  • func (w *DefaultRemoteWatcher) Cleanup()
  • func (w *DefaultRemoteWatcher) HandleProbeReply(id, seq uint16)
  • func (w *DefaultRemoteWatcher) SendProbes(conn snet.PacketConn, localAddr snet.SCIONAddress)
  • func (w *DefaultRemoteWatcher) UpdatePaths(router snet.Router)
  • func (w *DefaultRemoteWatcher) Watchers() []PathWatcher
• type DefaultRemoteWatcherFactory
  • func (f *DefaultRemoteWatcherFactory) New(remote addr.IA) RemoteWatcher
• type FilteringPathSelector
  • func (f *FilteringPathSelector) Select(selectables []Selectable, current FingerprintSet) Selection
• type FingerprintSet
• type MemoryRevocationStore
  • func (s *MemoryRevocationStore) AddRevocation(rev *path_mgmt.RevInfo)
  • func (s *MemoryRevocationStore) Cleanup()
  • func (s *MemoryRevocationStore) IsRevoked(path snet.Path) bool
• type Monitor
  • func (m *Monitor) Close()
  • func (m *Monitor) Register(remote addr.IA, selector PathSelector) *Registration
  • func (m *Monitor) Run()
• type PathPolicy
• type PathSelector
• type PathWatcher
• type PathWatcherFactory
• type Registration
  • func (r *Registration) Close()
  • func (r *Registration) Get() Selection
• type RemoteWatcher
• type RemoteWatcherFactory
• type RevocationStore
• type Selectable
• type Selection
• type State

Types

type DefaultPathWatcher

type DefaultPathWatcher struct {
	// contains filtered or unexported fields
}

DefaultPathWatcher monitors a single SCION path.

func (*DefaultPathWatcher) Close

func (pw *DefaultPathWatcher) Close()

Close stops the PathWatcher.

func (*DefaultPathWatcher) HandleProbeReply

func (pw *DefaultPathWatcher) HandleProbeReply(seq uint16)

HandleProbeReply dispatches a single probe reply packet.

func (*DefaultPathWatcher) Path

func (pw *DefaultPathWatcher) Path() snet.Path

Path returns a fresh copy of the monitored path.

func (*DefaultPathWatcher) SendProbe

func (pw *DefaultPathWatcher) SendProbe(conn snet.PacketConn, localAddr snet.SCIONAddress)

SendProbe sends a probe along the monitored path.

func (*DefaultPathWatcher) State

func (pw *DefaultPathWatcher) State() State

State returns the state of the monitored path.

func (*DefaultPathWatcher) UpdatePath

func (pw *DefaultPathWatcher) UpdatePath(path snet.Path)

UpdatePath changes a path to be monitored. While actual path, as in "sequence of SCION interfaces", must never change for a single PathWatcher object, some elements of the path structure (e.g. expiration) do change and should be updated accordingly.

type DefaultPathWatcherFactory

type DefaultPathWatcherFactory struct {
	// Logger is the parent logger. If nil, the PathWatcher is constructed
	// without any logger.
	Logger log.Logger
}

DefaultPathWatcherFactory creates PathWatchers.

func (*DefaultPathWatcherFactory) New

func (f *DefaultPathWatcherFactory) New(remote addr.IA, path snet.Path, id uint16) PathWatcher

New creates a PathWatcher that monitors a specific path.

type DefaultRemoteWatcher

type DefaultRemoteWatcher struct {
	// contains filtered or unexported fields
}

DefaultRemoteWatcher monitors a remote IA.

func (*DefaultRemoteWatcher) Cleanup

func (w *DefaultRemoteWatcher) Cleanup()

Cleanup stops monitoring paths that are not being used any more.

func (*DefaultRemoteWatcher) HandleProbeReply

func (w *DefaultRemoteWatcher) HandleProbeReply(id, seq uint16)

HandleProbeReply dispatches a single probe reply packet.

func (*DefaultRemoteWatcher) SendProbes

func (w *DefaultRemoteWatcher) SendProbes(conn snet.PacketConn, localAddr snet.SCIONAddress)

SendProbes sends probes via all the available paths to the monitored IA.

func (*DefaultRemoteWatcher) UpdatePaths

func (w *DefaultRemoteWatcher) UpdatePaths(router snet.Router)

UpdatePaths gets new paths from the SCION daemon. This function may block for up to routerTimeout.

func (*DefaultRemoteWatcher) Watchers

func (w *DefaultRemoteWatcher) Watchers() []PathWatcher

Watchers returns a list of all active PathWatchers.

type DefaultRemoteWatcherFactory

type DefaultRemoteWatcherFactory struct {
	// PathWatcherFactory is used to construct PathWatchers.
	PathWatcherFactory PathWatcherFactory
	// Logger is the parent logger. If nil, the RemoteWatcher is constructed without
	// any logger.
	Logger log.Logger
	// PathsMonitored is a gauge counting the number of paths currently
	// monitored to a remote AS.
	PathsMonitored metrics.Gauge
}

DefaultRemoteWatcherFactory is a default factory for creating RemoteWatchers.

func (*DefaultRemoteWatcherFactory) New

func (f *DefaultRemoteWatcherFactory) New(remote addr.IA) RemoteWatcher

New creates an RemoteWatcher that keeps track of all the paths for a given remote, and spawns/kills PathWatchers appropriately.

type FilteringPathSelector

type FilteringPathSelector struct {
	// PathPolicy is used to determine which paths are eligible and which are not.
	PathPolicy PathPolicy
	// RevocationStore keeps track of the revocations.
	RevocationStore
	// PathCount is the max number of paths to return to the user. Defaults to 1.
	PathCount int
}

FilteringPathSelector selects the best paths from a filtered set of paths.

func (*FilteringPathSelector) Select

func (f *FilteringPathSelector) Select(selectables []Selectable, current FingerprintSet) Selection

Select selects the best paths.

type FingerprintSet

type FingerprintSet map[snet.PathFingerprint]struct{}

FingerprintSet is a set of path fingerprints.

type MemoryRevocationStore

type MemoryRevocationStore struct {
	Logger log.Logger
	// contains filtered or unexported fields
}

MemoryRevocationStore holds a list of current revocations. It can be used to determine whether a path goes through interfaces which are revoked.

func (*MemoryRevocationStore) AddRevocation

func (s *MemoryRevocationStore) AddRevocation(rev *path_mgmt.RevInfo)

AddRevocation adds the revocation to the list of currently active revocations.

func (*MemoryRevocationStore) Cleanup

func (s *MemoryRevocationStore) Cleanup()

Cleanup removes all expired revocations.

func (*MemoryRevocationStore) IsRevoked

func (s *MemoryRevocationStore) IsRevoked(path snet.Path) bool

IsRevoked returns true if there is at least one revoked interface on the path.

type Monitor

type Monitor struct {
	// LocalIA is the ID of the local AS.
	LocalIA addr.IA
	// LocalIP is the IP address of the local host.
	LocalIP net.IP
	// Conn is the underlying conn for sending probes
	Conn net.PacketConn
	// RevocationHandler is the revocation handler.
	RevocationHandler snet.RevocationHandler
	// Router is the path manager connected to the SCION daemon.
	Router snet.Router
	// PathUpdateInterval specified how often the paths are retrieved from the daemon.
	PathUpdateInterval time.Duration
	// Probeinterval defines the interval at which probes are sent. If it is not
	// set a default is used.
	ProbeInterval time.Duration
	// RevocationStore keeps track of the revocations.
	RevocationStore RevocationStore
	// RemoteWatcherFactory creates a RemoteWatcher for the specified remote.
	RemoteWatcherFactory RemoteWatcherFactory
	// Logger is the logger. If nil, nothing is logged.
	Logger log.Logger
	// contains filtered or unexported fields
}

Monitor monitors paths to a set of remote ASes.

func (*Monitor) Close

func (m *Monitor) Close()

Close stops the path monitor.

func (*Monitor) Register

func (m *Monitor) Register(remote addr.IA, selector PathSelector) *Registration

Register starts monitoring given AS under the specified selector.

func (*Monitor) Run

func (m *Monitor) Run()

Run starts the monitor and blocks until Close is called.

type PathPolicy

type PathPolicy interface {
	Filter(paths []snet.Path) []snet.Path
}

PathPolicy filters the set of paths.

type PathSelector

type PathSelector interface {
	Select(selectable []Selectable, current FingerprintSet) Selection
}

PathSelector selects the best paths from all the available path watchers.

type PathWatcher

type PathWatcher interface {
	// UpdatePath changes a path to be monitored. While actual path, as in
	// "sequence of SCION interfaces", must never change for a single
	// PathWatcher object, some elements of the path structure (e.g. expiration)
	// do change and should be updated accordingly.
	UpdatePath(path snet.Path)
	// SendProbe sends a probe along the monitored path.
	SendProbe(conn snet.PacketConn, localAddr snet.SCIONAddress)
	// HandleProbeReply dispatches a single probe reply packet.
	HandleProbeReply(seq uint16)
	// Path returns a fresh copy of the monitored path.
	Path() snet.Path
	// State returns the state of the monitored path.
	State() State
	// Close stops the PathWatcher.
	Close()
}

PathWatcher monitors a specific path.

type PathWatcherFactory

type PathWatcherFactory interface {
	New(remote addr.IA, path snet.Path, id uint16) PathWatcher
}

PathWatcherFactory constructs a PathWatcher.

type Registration

type Registration struct {
	// contains filtered or unexported fields
}

Registration represents a single remote IA monitoring registration

func (*Registration) Close

func (r *Registration) Close()

Close cancels the registration.

func (*Registration) Get

func (r *Registration) Get() Selection

Get returns your own copy of the best available path.

type RemoteWatcher

type RemoteWatcher interface {
	// UpdatePaths gets new paths from the SCION daemon. This method may block.
	UpdatePaths(snet.Router)
	// SendProbes sends probes on all the monitored paths.
	SendProbes(conn snet.PacketConn, localAddr snet.SCIONAddress)
	// HandleProbeReply handles a single probe reply packet.
	HandleProbeReply(id, seq uint16)
	// Cleanup stops monitoring paths that are not being used anymore.
	Cleanup()
	// Watchers returns a list of all active PathWatchers
	Watchers() []PathWatcher
}

RemoteWatcher watches multiple paths to a given remote.

type RemoteWatcherFactory

type RemoteWatcherFactory interface {
	New(remote addr.IA) RemoteWatcher
}

RemoteWatcherFactory creates RemoteWatchers.

type RevocationStore

type RevocationStore interface {
	// AddRevocation adds a revocation.
	AddRevocation(rev *path_mgmt.RevInfo)
	// IsRevoked returns true if there is at least one revoked interface on the path.
	IsRevoked(path snet.Path) bool
	// Cleanup removes all expired revocations.
	Cleanup()
}

RevocationStore keeps track of revocations.

type Selectable

type Selectable interface {
	Path() snet.Path
	State() State
}

Selectable is a subset of the PathWatcher that is used for path selection.

type Selection

type Selection struct {
	// Path is the list of selected paths. The list is sorted from best to worst
	// according to the scoring function used by the selector.
	Paths []snet.Path
	// Info is an info string providing more info about why the path was selected.
	Info string
	// PathsAlive is the number of active paths available.
	PathsAlive int
	// PathsDead is the number of dead paths.
	PathsDead int
	// PathsRejected is the number of paths that are rejected by the policy.
	PathsRejected int
}

Selection contains the set of selected paths with metadata.

type State

type State struct {
	// IsAlive indicates that the path is currently alive.
	IsAlive bool
}

State is the path state used during selection.