137 lines
3.9 KiB
Go
137 lines
3.9 KiB
Go
package edgediscovery
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import (
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"fmt"
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"sync"
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"github.com/rs/zerolog"
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"github.com/cloudflare/cloudflared/edgediscovery/allregions"
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)
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const (
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LogFieldConnIndex = "connIndex"
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)
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var errNoAddressesLeft = fmt.Errorf("there are no free edge addresses left")
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// Edge finds addresses on the Cloudflare edge and hands them out to connections.
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type Edge struct {
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regions *allregions.Regions
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sync.Mutex
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log *zerolog.Logger
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}
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// ------------------------------------
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// Constructors
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// ------------------------------------
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// ResolveEdge runs the initial discovery of the Cloudflare edge, finding Addrs that can be allocated
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// to connections.
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func ResolveEdge(log *zerolog.Logger, region string) (*Edge, error) {
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regions, err := allregions.ResolveEdge(log, region)
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if err != nil {
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return new(Edge), err
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}
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return &Edge{
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log: log,
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regions: regions,
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}, nil
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}
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// StaticEdge creates a list of edge addresses from the list of hostnames. Mainly used for testing connectivity.
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func StaticEdge(log *zerolog.Logger, hostnames []string) (*Edge, error) {
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regions, err := allregions.StaticEdge(hostnames, log)
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if err != nil {
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return new(Edge), err
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}
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return &Edge{
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log: log,
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regions: regions,
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}, nil
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}
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// MockEdge creates a Cloudflare Edge from arbitrary TCP addresses. Used for testing.
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func MockEdge(log *zerolog.Logger, addrs []*allregions.EdgeAddr) *Edge {
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regions := allregions.NewNoResolve(addrs)
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return &Edge{
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log: log,
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regions: regions,
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}
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}
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// ------------------------------------
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// Methods
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// ------------------------------------
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// GetAddrForRPC gives this connection an edge Addr.
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func (ed *Edge) GetAddrForRPC() (*allregions.EdgeAddr, error) {
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ed.Lock()
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defer ed.Unlock()
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addr := ed.regions.GetAnyAddress()
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if addr == nil {
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return nil, errNoAddressesLeft
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}
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return addr, nil
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}
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// GetAddr gives this proxy connection an edge Addr. Prefer Addrs this connection has already used.
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func (ed *Edge) GetAddr(connIndex int) (*allregions.EdgeAddr, error) {
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log := ed.log.With().Int(LogFieldConnIndex, connIndex).Logger()
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ed.Lock()
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defer ed.Unlock()
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// If this connection has already used an edge addr, return it.
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if addr := ed.regions.AddrUsedBy(connIndex); addr != nil {
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log.Debug().Msg("edgediscovery - GetAddr: Returning same address back to proxy connection")
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return addr, nil
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}
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// Otherwise, give it an unused one
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addr := ed.regions.GetUnusedAddr(nil, connIndex)
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if addr == nil {
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log.Debug().Msg("edgediscovery - GetAddr: No addresses left to give proxy connection")
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return nil, errNoAddressesLeft
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}
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log.Debug().Msg("edgediscovery - GetAddr: Giving connection its new address")
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return addr, nil
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}
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// GetDifferentAddr gives back the proxy connection's edge Addr and uses a new one.
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func (ed *Edge) GetDifferentAddr(connIndex int) (*allregions.EdgeAddr, error) {
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log := ed.log.With().Int(LogFieldConnIndex, connIndex).Logger()
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ed.Lock()
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defer ed.Unlock()
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oldAddr := ed.regions.AddrUsedBy(connIndex)
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if oldAddr != nil {
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ed.regions.GiveBack(oldAddr)
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}
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addr := ed.regions.GetUnusedAddr(oldAddr, connIndex)
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if addr == nil {
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log.Debug().Msg("edgediscovery - GetDifferentAddr: No addresses left to give proxy connection")
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// note: if oldAddr were not nil, it will become available on the next iteration
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return nil, errNoAddressesLeft
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}
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log.Debug().Msgf("edgediscovery - GetDifferentAddr: Giving connection its new address: %v from the address list: %v",
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addr, ed.regions.AvailableAddrs())
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return addr, nil
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}
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// AvailableAddrs returns how many unused addresses there are left.
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func (ed *Edge) AvailableAddrs() int {
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ed.Lock()
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defer ed.Unlock()
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return ed.regions.AvailableAddrs()
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}
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// GiveBack the address so that other connections can use it.
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// Returns true if the address is in this edge.
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func (ed *Edge) GiveBack(addr *allregions.EdgeAddr) bool {
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ed.Lock()
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defer ed.Unlock()
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ed.log.Debug().Msg("edgediscovery - GiveBack: Address now unused")
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return ed.regions.GiveBack(addr)
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}
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