cloudflare/cloudflared
Publicmirrored from https://github.com/cloudflare/cloudflaredAvailable
edgediscovery/edgediscovery.go
135lines · modecode
| 1 | package edgediscovery |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "sync" |
| 6 | |
| 7 | "github.com/rs/zerolog" |
| 8 | |
| 9 | "github.com/cloudflare/cloudflared/edgediscovery/allregions" |
| 10 | ) |
| 11 | |
| 12 | const ( |
| 13 | LogFieldConnIndex = "connIndex" |
| 14 | ) |
| 15 | |
| 16 | var errNoAddressesLeft = fmt.Errorf("there are no free edge addresses left") |
| 17 | |
| 18 | // Edge finds addresses on the Cloudflare edge and hands them out to connections. |
| 19 | type Edge struct { |
| 20 | regions *allregions.Regions |
| 21 | sync.Mutex |
| 22 | log *zerolog.Logger |
| 23 | } |
| 24 | |
| 25 | // ------------------------------------ |
| 26 | // Constructors |
| 27 | // ------------------------------------ |
| 28 | |
| 29 | // ResolveEdge runs the initial discovery of the Cloudflare edge, finding Addrs that can be allocated |
| 30 | // to connections. |
| 31 | func ResolveEdge(log *zerolog.Logger, region string) (*Edge, error) { |
| 32 | regions, err := allregions.ResolveEdge(log, region) |
| 33 | if err != nil { |
| 34 | return new(Edge), err |
| 35 | } |
| 36 | return &Edge{ |
| 37 | log: log, |
| 38 | regions: regions, |
| 39 | }, nil |
| 40 | } |
| 41 | |
| 42 | // StaticEdge creates a list of edge addresses from the list of hostnames. Mainly used for testing connectivity. |
| 43 | func StaticEdge(log *zerolog.Logger, hostnames []string) (*Edge, error) { |
| 44 | regions, err := allregions.StaticEdge(hostnames, log) |
| 45 | if err != nil { |
| 46 | return new(Edge), err |
| 47 | } |
| 48 | return &Edge{ |
| 49 | log: log, |
| 50 | regions: regions, |
| 51 | }, nil |
| 52 | } |
| 53 | |
| 54 | // MockEdge creates a Cloudflare Edge from arbitrary TCP addresses. Used for testing. |
| 55 | func MockEdge(log *zerolog.Logger, addrs []*allregions.EdgeAddr) *Edge { |
| 56 | regions := allregions.NewNoResolve(addrs) |
| 57 | return &Edge{ |
| 58 | log: log, |
| 59 | regions: regions, |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | // ------------------------------------ |
| 64 | // Methods |
| 65 | // ------------------------------------ |
| 66 | |
| 67 | // GetAddrForRPC gives this connection an edge Addr. |
| 68 | func (ed *Edge) GetAddrForRPC() (*allregions.EdgeAddr, error) { |
| 69 | ed.Lock() |
| 70 | defer ed.Unlock() |
| 71 | addr := ed.regions.GetAnyAddress() |
| 72 | if addr == nil { |
| 73 | return nil, errNoAddressesLeft |
| 74 | } |
| 75 | return addr, nil |
| 76 | } |
| 77 | |
| 78 | // GetAddr gives this proxy connection an edge Addr. Prefer Addrs this connection has already used. |
| 79 | func (ed *Edge) GetAddr(connIndex int) (*allregions.EdgeAddr, error) { |
| 80 | log := ed.log.With().Int(LogFieldConnIndex, connIndex).Logger() |
| 81 | ed.Lock() |
| 82 | defer ed.Unlock() |
| 83 | |
| 84 | // If this connection has already used an edge addr, return it. |
| 85 | if addr := ed.regions.AddrUsedBy(connIndex); addr != nil { |
| 86 | log.Debug().Msg("edgediscovery - GetAddr: Returning same address back to proxy connection") |
| 87 | return addr, nil |
| 88 | } |
| 89 | |
| 90 | // Otherwise, give it an unused one |
| 91 | addr := ed.regions.GetUnusedAddr(nil, connIndex) |
| 92 | if addr == nil { |
| 93 | log.Debug().Msg("edgediscovery - GetAddr: No addresses left to give proxy connection") |
| 94 | return nil, errNoAddressesLeft |
| 95 | } |
| 96 | log.Debug().Msg("edgediscovery - GetAddr: Giving connection its new address") |
| 97 | return addr, nil |
| 98 | } |
| 99 | |
| 100 | // GetDifferentAddr gives back the proxy connection's edge Addr and uses a new one. |
| 101 | func (ed *Edge) GetDifferentAddr(connIndex int) (*allregions.EdgeAddr, error) { |
| 102 | log := ed.log.With().Int(LogFieldConnIndex, connIndex).Logger() |
| 103 | |
| 104 | ed.Lock() |
| 105 | defer ed.Unlock() |
| 106 | |
| 107 | oldAddr := ed.regions.AddrUsedBy(connIndex) |
| 108 | if oldAddr != nil { |
| 109 | ed.regions.GiveBack(oldAddr) |
| 110 | } |
| 111 | addr := ed.regions.GetUnusedAddr(oldAddr, connIndex) |
| 112 | if addr == nil { |
| 113 | log.Debug().Msg("edgediscovery - GetDifferentAddr: No addresses left to give proxy connection") |
| 114 | // note: if oldAddr were not nil, it will become available on the next iteration |
| 115 | return nil, errNoAddressesLeft |
| 116 | } |
| 117 | log.Debug().Msg("edgediscovery - GetDifferentAddr: Giving connection its new address") |
| 118 | return addr, nil |
| 119 | } |
| 120 | |
| 121 | // AvailableAddrs returns how many unused addresses there are left. |
| 122 | func (ed *Edge) AvailableAddrs() int { |
| 123 | ed.Lock() |
| 124 | defer ed.Unlock() |
| 125 | return ed.regions.AvailableAddrs() |
| 126 | } |
| 127 | |
| 128 | // GiveBack the address so that other connections can use it. |
| 129 | // Returns true if the address is in this edge. |
| 130 | func (ed *Edge) GiveBack(addr *allregions.EdgeAddr) bool { |
| 131 | ed.Lock() |
| 132 | defer ed.Unlock() |
| 133 | ed.log.Debug().Msg("edgediscovery - GiveBack: Address now unused") |
| 134 | return ed.regions.GiveBack(addr) |
| 135 | } |
| 136 | |