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 DefaultPathWatcherFactory
  • func (f *DefaultPathWatcherFactory) New(ctx context.Context, remote addr.IA, path snet.Path) (PathWatcher, error)
• 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(ctx context.Context, rev *path_mgmt.RevInfo)
  • func (s *MemoryRevocationStore) Cleanup(ctx context.Context)
  • func (s *MemoryRevocationStore) IsRevoked(path snet.Path) bool
• type Monitor
  • func (m *Monitor) Register(remote addr.IA, selector PathSelector) *Registration
• type PathInfo
• type PathInfoEntry
• 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 DefaultPathWatcherFactory

type DefaultPathWatcherFactory struct {
	// LocalIA is the ID of the local AS.
	LocalIA addr.IA
	// Topology is the helper class to get control-plane information for the
	// local AS.
	Topology snet.Topology
	// LocalIP is the IP address of the local host.
	LocalIP netip.Addr
	// RevocationHandler is the revocation handler.
	RevocationHandler snet.RevocationHandler
	// Probeinterval defines the interval at which probes are sent. If it is not
	// set a default is used.
	ProbeInterval time.Duration
	// ProbesSent keeps track of how many path probes have been sent per remote
	// AS.
	ProbesSent func(remote addr.IA) metrics.Counter
	// ProbesReceived keeps track of how many path probes have been received per
	// remote AS.
	ProbesReceived func(remote addr.IA) metrics.Counter
	// ProbesSendErrors keeps track of how many time sending probes failed per
	// remote.
	ProbesSendErrors func(remote addr.IA) metrics.Counter

	SCMPErrors             metrics2.Counter
	SCIONPacketConnMetrics snet.SCIONPacketConnMetrics
}

DefaultPathWatcherFactory creates PathWatchers.

func (*DefaultPathWatcherFactory) New

func (f *DefaultPathWatcherFactory) New(
	ctx context.Context,
	remote addr.IA,
	path snet.Path,
) (PathWatcher, error)

New creates a PathWatcher that monitors a specific path.

type DefaultRemoteWatcherFactory

type DefaultRemoteWatcherFactory struct {
	// Router is used to find paths to remote ASes.
	Router interface {
		AllRoutes(ctx context.Context, dst addr.IA) ([]snet.Path, error)
	}
	// PathWatcherFactory is used to construct PathWatchers.
	PathWatcherFactory PathWatcherFactory
	// PathUpdateInterval specified how often the paths are retrieved from the
	// daemon. If not specified a default is used.
	PathUpdateInterval time.Duration
	// PathFetchTimeout is the timeout for the path fetch operation. If not set
	// a default value is used.
	PathFetchTimeout time.Duration
	// PathsMonitored is a gauge counting the number of paths currently
	// monitored to a remote AS.
	PathsMonitored func(remote addr.IA) 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 {
	// 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(ctx context.Context, rev *path_mgmt.RevInfo)

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

func (*MemoryRevocationStore) Cleanup

func (s *MemoryRevocationStore) Cleanup(ctx context.Context)

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 {
	// RemoteWatcherFactory creates a RemoteWatcher for the specified remote.
	RemoteWatcherFactory RemoteWatcherFactory
	// contains filtered or unexported fields
}

func (*Monitor) Register

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

Register starts monitoring given AS under the specified selector.

type PathInfo

type PathInfo []PathInfoEntry

PathInfo contains debug info about onging path monitoring.

type PathInfoEntry

type PathInfoEntry struct {
	Path         string
	Rejected     bool
	RejectReason string
	Current      bool
	Revoked      bool
}

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 {
	// Run runs the path watcher until the context is cancelled.
	Run(context.Context)
	// 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)
	// Path returns a fresh copy of the monitored path.
	Path() snet.Path
	// State returns the state of the monitored path.
	State() State
}

PathWatcher monitors a specific path.

type PathWatcherFactory

type PathWatcherFactory interface {
	New(ctx context.Context, remote addr.IA, path snet.Path) (PathWatcher, error)
}

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 {
	Run(context.Context)
	PathWatchers() []PathWatcher
}

type RemoteWatcherFactory

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

RemoteWatcherFactory creates RemoteWatchers.

type RevocationStore

type RevocationStore interface {
	// AddRevocation adds a revocation.
	AddRevocation(ctx context.Context, 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(ctx context.Context)
}

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
	// PathInfo provides more info about why the path was selected.
	PathInfo PathInfo
	// 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
	// IsExpired indicates that the path is expired. IsExpired == true implies IsAlive == false but
	// not vice versa.
	IsExpired bool
}

State is the path state used during selection.