// Copyright (c) 2013-2014 The btcsuite developers // Use of this source code is governed by an ISC // license that can be found in the LICENSE file. package addrmgr import ( "fmt" "net" "github.com/btcsuite/btcd/wire" ) var ( // rfc1918Nets specifies the IPv4 private address blocks as defined by // by RFC1918 (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16). rfc1918Nets = []net.IPNet{ ipNet("10.0.0.0", 8, 32), ipNet("172.16.0.0", 12, 32), ipNet("192.168.0.0", 16, 32), } // rfc2544Net specifies the the IPv4 block as defined by RFC2544 // (198.18.0.0/15) rfc2544Net = ipNet("198.18.0.0", 15, 32) // rfc3849Net specifies the IPv6 documentation address block as defined // by RFC3849 (2001:DB8::/32). rfc3849Net = ipNet("2001:DB8::", 32, 128) // rfc3927Net specifies the IPv4 auto configuration address block as // defined by RFC3927 (169.254.0.0/16). rfc3927Net = ipNet("169.254.0.0", 16, 32) // rfc3964Net specifies the IPv6 to IPv4 encapsulation address block as // defined by RFC3964 (2002::/16). rfc3964Net = ipNet("2002::", 16, 128) // rfc4193Net specifies the IPv6 unique local address block as defined // by RFC4193 (FC00::/7). rfc4193Net = ipNet("FC00::", 7, 128) // rfc4380Net specifies the IPv6 teredo tunneling over UDP address block // as defined by RFC4380 (2001::/32). rfc4380Net = ipNet("2001::", 32, 128) // rfc4843Net specifies the IPv6 ORCHID address block as defined by // RFC4843 (2001:10::/28). rfc4843Net = ipNet("2001:10::", 28, 128) // rfc4862Net specifies the IPv6 stateless address autoconfiguration // address block as defined by RFC4862 (FE80::/64). rfc4862Net = ipNet("FE80::", 64, 128) // rfc5737Net specifies the IPv4 documentation address blocks as defined // by RFC5737 (192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24) rfc5737Net = []net.IPNet{ ipNet("192.0.2.0", 24, 32), ipNet("198.51.100.0", 24, 32), ipNet("203.0.113.0", 24, 32), } // rfc6052Net specifies the IPv6 well-known prefix address block as // defined by RFC6052 (64:FF9B::/96). rfc6052Net = ipNet("64:FF9B::", 96, 128) // rfc6145Net specifies the IPv6 to IPv4 translated address range as // defined by RFC6145 (::FFFF:0:0:0/96). rfc6145Net = ipNet("::FFFF:0:0:0", 96, 128) // rfc6598Net specifies the IPv4 block as defined by RFC6598 (100.64.0.0/10) rfc6598Net = ipNet("100.64.0.0", 10, 32) // onionCatNet defines the IPv6 address block used to support Tor. // bitcoind encodes a .onion address as a 16 byte number by decoding the // address prior to the .onion (i.e. the key hash) base32 into a ten // byte number. It then stores the first 6 bytes of the address as // 0xfd, 0x87, 0xd8, 0x7e, 0xeb, 0x43. // // This is the same range used by OnionCat, which is part part of the // RFC4193 unique local IPv6 range. // // In summary the format is: // { magic 6 bytes, 10 bytes base32 decode of key hash } onionCatNet = ipNet("fd87:d87e:eb43::", 48, 128) // zero4Net defines the IPv4 address block for address staring with 0 // (0.0.0.0/8). zero4Net = ipNet("0.0.0.0", 8, 32) // heNet defines the Hurricane Electric IPv6 address block. heNet = ipNet("2001:470::", 32, 128) ) // ipNet returns a net.IPNet struct given the passed IP address string, number // of one bits to include at the start of the mask, and the total number of bits // for the mask. func ipNet(ip string, ones, bits int) net.IPNet { return net.IPNet{IP: net.ParseIP(ip), Mask: net.CIDRMask(ones, bits)} } // IsIPv4 returns whether or not the given address is an IPv4 address. func IsIPv4(na *wire.NetAddress) bool { return na.IP.To4() != nil } // IsLocal returns whether or not the given address is a local address. func IsLocal(na *wire.NetAddress) bool { return na.IP.IsLoopback() || zero4Net.Contains(na.IP) } // IsOnionCatTor returns whether or not the passed address is in the IPv6 range // used by bitcoin to support Tor (fd87:d87e:eb43::/48). Note that this range // is the same range used by OnionCat, which is part of the RFC4193 unique local // IPv6 range. func IsOnionCatTor(na *wire.NetAddress) bool { return onionCatNet.Contains(na.IP) } // IsRFC1918 returns whether or not the passed address is part of the IPv4 // private network address space as defined by RFC1918 (10.0.0.0/8, // 172.16.0.0/12, or 192.168.0.0/16). func IsRFC1918(na *wire.NetAddress) bool { for _, rfc := range rfc1918Nets { if rfc.Contains(na.IP) { return true } } return false } // IsRFC2544 returns whether or not the passed address is part of the IPv4 // address space as defined by RFC2544 (198.18.0.0/15) func IsRFC2544(na *wire.NetAddress) bool { return rfc2544Net.Contains(na.IP) } // IsRFC3849 returns whether or not the passed address is part of the IPv6 // documentation range as defined by RFC3849 (2001:DB8::/32). func IsRFC3849(na *wire.NetAddress) bool { return rfc3849Net.Contains(na.IP) } // IsRFC3927 returns whether or not the passed address is part of the IPv4 // autoconfiguration range as defined by RFC3927 (169.254.0.0/16). func IsRFC3927(na *wire.NetAddress) bool { return rfc3927Net.Contains(na.IP) } // IsRFC3964 returns whether or not the passed address is part of the IPv6 to // IPv4 encapsulation range as defined by RFC3964 (2002::/16). func IsRFC3964(na *wire.NetAddress) bool { return rfc3964Net.Contains(na.IP) } // IsRFC4193 returns whether or not the passed address is part of the IPv6 // unique local range as defined by RFC4193 (FC00::/7). func IsRFC4193(na *wire.NetAddress) bool { return rfc4193Net.Contains(na.IP) } // IsRFC4380 returns whether or not the passed address is part of the IPv6 // teredo tunneling over UDP range as defined by RFC4380 (2001::/32). func IsRFC4380(na *wire.NetAddress) bool { return rfc4380Net.Contains(na.IP) } // IsRFC4843 returns whether or not the passed address is part of the IPv6 // ORCHID range as defined by RFC4843 (2001:10::/28). func IsRFC4843(na *wire.NetAddress) bool { return rfc4843Net.Contains(na.IP) } // IsRFC4862 returns whether or not the passed address is part of the IPv6 // stateless address autoconfiguration range as defined by RFC4862 (FE80::/64). func IsRFC4862(na *wire.NetAddress) bool { return rfc4862Net.Contains(na.IP) } // IsRFC5737 returns whether or not the passed address is part of the IPv4 // documentation address space as defined by RFC5737 (192.0.2.0/24, // 198.51.100.0/24, 203.0.113.0/24) func IsRFC5737(na *wire.NetAddress) bool { for _, rfc := range rfc5737Net { if rfc.Contains(na.IP) { return true } } return false } // IsRFC6052 returns whether or not the passed address is part of the IPv6 // well-known prefix range as defined by RFC6052 (64:FF9B::/96). func IsRFC6052(na *wire.NetAddress) bool { return rfc6052Net.Contains(na.IP) } // IsRFC6145 returns whether or not the passed address is part of the IPv6 to // IPv4 translated address range as defined by RFC6145 (::FFFF:0:0:0/96). func IsRFC6145(na *wire.NetAddress) bool { return rfc6145Net.Contains(na.IP) } // IsRFC6598 returns whether or not the passed address is part of the IPv4 // shared address space specified by RFC6598 (100.64.0.0/10) func IsRFC6598(na *wire.NetAddress) bool { return rfc6598Net.Contains(na.IP) } // IsValid returns whether or not the passed address is valid. The address is // considered invalid under the following circumstances: // IPv4: It is either a zero or all bits set address. // IPv6: It is either a zero or RFC3849 documentation address. func IsValid(na *wire.NetAddress) bool { // IsUnspecified returns if address is 0, so only all bits set, and // RFC3849 need to be explicitly checked. return na.IP != nil && !(na.IP.IsUnspecified() || na.IP.Equal(net.IPv4bcast)) } // IsRoutable returns whether or not the passed address is routable over // the public internet. This is true as long as the address is valid and is not // in any reserved ranges. func IsRoutable(na *wire.NetAddress) bool { return IsValid(na) && !(IsRFC1918(na) || IsRFC2544(na) || IsRFC3927(na) || IsRFC4862(na) || IsRFC3849(na) || IsRFC4843(na) || IsRFC5737(na) || IsRFC6598(na) || IsLocal(na) || (IsRFC4193(na) && !IsOnionCatTor(na))) } // GroupKey returns a string representing the network group an address is part // of. This is the /16 for IPv4, the /32 (/36 for he.net) for IPv6, the string // "local" for a local address, the string "tor:key" where key is the /4 of the // onion address for Tor address, and the string "unroutable" for an unroutable // address. func GroupKey(na *wire.NetAddress) string { if IsLocal(na) { return "local" } if !IsRoutable(na) { return "unroutable" } if IsIPv4(na) { return na.IP.Mask(net.CIDRMask(16, 32)).String() } if IsRFC6145(na) || IsRFC6052(na) { // last four bytes are the ip address ip := na.IP[12:16] return ip.Mask(net.CIDRMask(16, 32)).String() } if IsRFC3964(na) { ip := na.IP[2:6] return ip.Mask(net.CIDRMask(16, 32)).String() } if IsRFC4380(na) { // teredo tunnels have the last 4 bytes as the v4 address XOR // 0xff. ip := net.IP(make([]byte, 4)) for i, byte := range na.IP[12:16] { ip[i] = byte ^ 0xff } return ip.Mask(net.CIDRMask(16, 32)).String() } if IsOnionCatTor(na) { // group is keyed off the first 4 bits of the actual onion key. return fmt.Sprintf("tor:%d", na.IP[6]&((1<<4)-1)) } // OK, so now we know ourselves to be a IPv6 address. // bitcoind uses /32 for everything, except for Hurricane Electric's // (he.net) IP range, which it uses /36 for. bits := 32 if heNet.Contains(na.IP) { bits = 36 } return na.IP.Mask(net.CIDRMask(bits, 128)).String() }