cloudflare/cloudflared
Publicmirrored from https://github.com/cloudflare/cloudflaredAvailable
edgediscovery/allregions/regions.go
125lines · modecode
| 1 | package allregions |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "net" |
| 6 | |
| 7 | "github.com/cloudflare/cloudflared/logger" |
| 8 | ) |
| 9 | |
| 10 | // Regions stores Cloudflare edge network IPs, partitioned into two regions. |
| 11 | // This is NOT thread-safe. Users of this package should use it with a lock. |
| 12 | type Regions struct { |
| 13 | region1 Region |
| 14 | region2 Region |
| 15 | } |
| 16 | |
| 17 | // ------------------------------------ |
| 18 | // Constructors |
| 19 | // ------------------------------------ |
| 20 | |
| 21 | // ResolveEdge resolves the Cloudflare edge, returning all regions discovered. |
| 22 | func ResolveEdge(logger logger.Service) (*Regions, error) { |
| 23 | addrLists, err := edgeDiscovery(logger) |
| 24 | if err != nil { |
| 25 | return nil, err |
| 26 | } |
| 27 | if len(addrLists) < 2 { |
| 28 | return nil, fmt.Errorf("expected at least 2 Cloudflare Regions regions, but SRV only returned %v", len(addrLists)) |
| 29 | } |
| 30 | return &Regions{ |
| 31 | region1: NewRegion(addrLists[0]), |
| 32 | region2: NewRegion(addrLists[1]), |
| 33 | }, nil |
| 34 | } |
| 35 | |
| 36 | // StaticEdge creates a list of edge addresses from the list of hostnames. |
| 37 | // Mainly used for testing connectivity. |
| 38 | func StaticEdge(hostnames []string) (*Regions, error) { |
| 39 | addrs, err := ResolveAddrs(hostnames) |
| 40 | if err != nil { |
| 41 | return nil, err |
| 42 | } |
| 43 | return NewNoResolve(addrs), nil |
| 44 | } |
| 45 | |
| 46 | // NewNoResolve doesn't resolve the edge. Instead it just uses the given addresses. |
| 47 | // You probably only need this for testing. |
| 48 | func NewNoResolve(addrs []*net.TCPAddr) *Regions { |
| 49 | region1 := make([]*net.TCPAddr, 0) |
| 50 | region2 := make([]*net.TCPAddr, 0) |
| 51 | for i, v := range addrs { |
| 52 | if i%2 == 0 { |
| 53 | region1 = append(region1, v) |
| 54 | } else { |
| 55 | region2 = append(region2, v) |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | return &Regions{ |
| 60 | region1: NewRegion(region1), |
| 61 | region2: NewRegion(region2), |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | // ------------------------------------ |
| 66 | // Methods |
| 67 | // ------------------------------------ |
| 68 | |
| 69 | // GetAnyAddress returns an arbitrary address from the larger region. |
| 70 | func (rs *Regions) GetAnyAddress() *net.TCPAddr { |
| 71 | if addr := rs.region1.GetAnyAddress(); addr != nil { |
| 72 | return addr |
| 73 | } |
| 74 | return rs.region2.GetAnyAddress() |
| 75 | } |
| 76 | |
| 77 | // AddrUsedBy finds the address used by the given connection. |
| 78 | // Returns nil if the connection isn't using an address. |
| 79 | func (rs *Regions) AddrUsedBy(connID int) *net.TCPAddr { |
| 80 | if addr := rs.region1.AddrUsedBy(connID); addr != nil { |
| 81 | return addr |
| 82 | } |
| 83 | return rs.region2.AddrUsedBy(connID) |
| 84 | } |
| 85 | |
| 86 | // GetUnusedAddr gets an unused addr from the edge, excluding the given addr. Prefer to use addresses |
| 87 | // evenly across both regions. |
| 88 | func (rs *Regions) GetUnusedAddr(excluding *net.TCPAddr, connID int) *net.TCPAddr { |
| 89 | if rs.region1.AvailableAddrs() > rs.region2.AvailableAddrs() { |
| 90 | return getAddrs(excluding, connID, &rs.region1, &rs.region2) |
| 91 | } |
| 92 | |
| 93 | return getAddrs(excluding, connID, &rs.region2, &rs.region1) |
| 94 | } |
| 95 | |
| 96 | // getAddrs tries to grab address form `first` region, then `second` region |
| 97 | // this is an unrolled loop over 2 element array |
| 98 | func getAddrs(excluding *net.TCPAddr, connID int, first *Region, second *Region) *net.TCPAddr { |
| 99 | addr := first.GetUnusedIP(excluding) |
| 100 | if addr != nil { |
| 101 | first.Use(addr, connID) |
| 102 | return addr |
| 103 | } |
| 104 | addr = second.GetUnusedIP(excluding) |
| 105 | if addr != nil { |
| 106 | second.Use(addr, connID) |
| 107 | return addr |
| 108 | } |
| 109 | |
| 110 | return nil |
| 111 | } |
| 112 | |
| 113 | // AvailableAddrs returns how many edge addresses aren't used. |
| 114 | func (rs *Regions) AvailableAddrs() int { |
| 115 | return rs.region1.AvailableAddrs() + rs.region2.AvailableAddrs() |
| 116 | } |
| 117 | |
| 118 | // GiveBack the address so that other connections can use it. |
| 119 | // Returns true if the address is in this edge. |
| 120 | func (rs *Regions) GiveBack(addr *net.TCPAddr) bool { |
| 121 | if found := rs.region1.GiveBack(addr); found { |
| 122 | return found |
| 123 | } |
| 124 | return rs.region2.GiveBack(addr) |
| 125 | } |
| 126 | |