p2p: return masked IP (not the actual IP) in addrbook#groupKey

Closes #4846 
Spec https://github.com/tendermint/spec/pull/96

CHANGELOG_PENDING.md

@@ -83,3 +83,4 @@ Friendly reminder, we have a [bug bounty program](https://hackerone.com/tendermi
 - [rpc] \#4805 Attempt to handle panics during panic recovery (@erikgrinaker)
 - [types] [\#4764](https://github.com/tendermint/tendermint/pull/4764) Return an error if voting power overflows in `VerifyCommitTrusting` (@melekes)
 - [privval] [\#4812](https://github.com/tendermint/tendermint/pull/4812) Retry `GetPubKey/SignVote/SignProposal` a few times before returning an error (@melekes)
+- [p2p] [\#4847](https://github.com/tendermint/tendermint/pull/4847) Return masked IP (not the actual IP) in addrbook#groupKey (@melekes)

p2p/netaddress.go

@@ -312,21 +312,43 @@ var rfc4862 = net.IPNet{IP: net.ParseIP("FE80::"), Mask: net.CIDRMask(64, 128)}
 var rfc6052 = net.IPNet{IP: net.ParseIP("64:FF9B::"), Mask: net.CIDRMask(96, 128)}
 var rfc6145 = net.IPNet{IP: net.ParseIP("::FFFF:0:0:0"), Mask: net.CIDRMask(96, 128)}
 var zero4 = net.IPNet{IP: net.ParseIP("0.0.0.0"), Mask: net.CIDRMask(8, 32)}
+var (
+	// 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)
+)
+
+// 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)}
+}
 
 func (na *NetAddress) RFC1918() bool {
 	return rfc1918_10.Contains(na.IP) ||
 		rfc1918_192.Contains(na.IP) ||
 		rfc1918_172.Contains(na.IP)
 }
-func (na *NetAddress) RFC3849() bool { return rfc3849.Contains(na.IP) }
-func (na *NetAddress) RFC3927() bool { return rfc3927.Contains(na.IP) }
-func (na *NetAddress) RFC3964() bool { return rfc3964.Contains(na.IP) }
-func (na *NetAddress) RFC4193() bool { return rfc4193.Contains(na.IP) }
-func (na *NetAddress) RFC4380() bool { return rfc4380.Contains(na.IP) }
-func (na *NetAddress) RFC4843() bool { return rfc4843.Contains(na.IP) }
-func (na *NetAddress) RFC4862() bool { return rfc4862.Contains(na.IP) }
-func (na *NetAddress) RFC6052() bool { return rfc6052.Contains(na.IP) }
-func (na *NetAddress) RFC6145() bool { return rfc6145.Contains(na.IP) }
+func (na *NetAddress) RFC3849() bool     { return rfc3849.Contains(na.IP) }
+func (na *NetAddress) RFC3927() bool     { return rfc3927.Contains(na.IP) }
+func (na *NetAddress) RFC3964() bool     { return rfc3964.Contains(na.IP) }
+func (na *NetAddress) RFC4193() bool     { return rfc4193.Contains(na.IP) }
+func (na *NetAddress) RFC4380() bool     { return rfc4380.Contains(na.IP) }
+func (na *NetAddress) RFC4843() bool     { return rfc4843.Contains(na.IP) }
+func (na *NetAddress) RFC4862() bool     { return rfc4862.Contains(na.IP) }
+func (na *NetAddress) RFC6052() bool     { return rfc6052.Contains(na.IP) }
+func (na *NetAddress) RFC6145() bool     { return rfc6145.Contains(na.IP) }
+func (na *NetAddress) OnionCatTor() bool { return onionCatNet.Contains(na.IP) }
 
 func removeProtocolIfDefined(addr string) string {
 	if strings.Contains(addr, "://") {

p2p/pex/addrbook.go

@@ -870,31 +870,36 @@ func (a *addrBook) calcOldBucket(addr *p2p.NetAddress) (int, error) {
 }
 
 // Return a string representing the network group of this address.
-// This is the /16 for IPv4, the /32 (/36 for he.net) for IPv6, the string
+// This is the /16 for IPv4 (e.g. 1.2.0.0), the /32 (/36 for he.net) for IPv6, the string
 // "local" for a local address and the string "unroutable" for an unroutable
 // address.
 func (a *addrBook) groupKey(na *p2p.NetAddress) string {
-	if a.routabilityStrict && na.Local() {
+	return groupKeyFor(na, a.routabilityStrict)
+}
+
+func groupKeyFor(na *p2p.NetAddress, routabilityStrict bool) string {
+	if routabilityStrict && na.Local() {
 		return "local"
 	}
-	if a.routabilityStrict && !na.Routable() {
+	if routabilityStrict && !na.Routable() {
 		return "unroutable"
 	}
 
 	if ipv4 := na.IP.To4(); ipv4 != nil {
-		return (&net.IPNet{IP: na.IP, Mask: net.CIDRMask(16, 32)}).String()
+		return na.IP.Mask(net.CIDRMask(16, 32)).String()
 	}
+
 	if na.RFC6145() || na.RFC6052() {
 		// last four bytes are the ip address
 		ip := na.IP[12:16]
-		return (&net.IPNet{IP: ip, Mask: net.CIDRMask(16, 32)}).String()
+		return ip.Mask(net.CIDRMask(16, 32)).String()
 	}
 
 	if na.RFC3964() {
-		ip := na.IP[2:7]
-		return (&net.IPNet{IP: ip, Mask: net.CIDRMask(16, 32)}).String()
-
+		ip := na.IP[2:6]
+		return ip.Mask(net.CIDRMask(16, 32)).String()
 	}
+
 	if na.RFC4380() {
 		// teredo tunnels have the last 4 bytes as the v4 address XOR
 		// 0xff.
@@ -902,20 +907,24 @@ func (a *addrBook) groupKey(na *p2p.NetAddress) string {
 		for i, byte := range na.IP[12:16] {
 			ip[i] = byte ^ 0xff
 		}
-		return (&net.IPNet{IP: ip, Mask: net.CIDRMask(16, 32)}).String()
+		return ip.Mask(net.CIDRMask(16, 32)).String()
+	}
+
+	if na.OnionCatTor() {
+		// 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
-	heNet := &net.IPNet{IP: net.ParseIP("2001:470::"),
-		Mask: net.CIDRMask(32, 128)}
+	heNet := &net.IPNet{IP: net.ParseIP("2001:470::"), Mask: net.CIDRMask(32, 128)}
 	if heNet.Contains(na.IP) {
 		bits = 36
 	}
-
-	return (&net.IPNet{IP: na.IP, Mask: net.CIDRMask(bits, 128)}).String()
+	ipv6Mask := net.CIDRMask(bits, 128)
+	return na.IP.Mask(ipv6Mask).String()
 }
 
 func (a *addrBook) hash(b []byte) ([]byte, error) {

p2p/pex/addrbook_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"math"
+	"net"
 	"os"
 	"testing"
 	"time"
@@ -572,6 +573,73 @@ func TestMultipleAddrBookAddressSelection(t *testing.T) {
 	}
 }
 
+func TestAddrBookGroupKey(t *testing.T) {
+	// non-strict routability
+	testCases := []struct {
+		name   string
+		ip     string
+		expKey string
+	}{
+		// IPv4 normal.
+		{"ipv4 normal class a", "12.1.2.3", "12.1.0.0"},
+		{"ipv4 normal class b", "173.1.2.3", "173.1.0.0"},
+		{"ipv4 normal class c", "196.1.2.3", "196.1.0.0"},
+
+		// IPv6/IPv4 translations.
+		{"ipv6 rfc3964 with ipv4 encap", "2002:0c01:0203::", "12.1.0.0"},
+		{"ipv6 rfc4380 toredo ipv4", "2001:0:1234::f3fe:fdfc", "12.1.0.0"},
+		{"ipv6 rfc6052 well-known prefix with ipv4", "64:ff9b::0c01:0203", "12.1.0.0"},
+		{"ipv6 rfc6145 translated ipv4", "::ffff:0:0c01:0203", "12.1.0.0"},
+
+		// Tor.
+		{"ipv6 tor onioncat", "fd87:d87e:eb43:1234::5678", "tor:2"},
+		{"ipv6 tor onioncat 2", "fd87:d87e:eb43:1245::6789", "tor:2"},
+		{"ipv6 tor onioncat 3", "fd87:d87e:eb43:1345::6789", "tor:3"},
+
+		// IPv6 normal.
+		{"ipv6 normal", "2602:100::1", "2602:100::"},
+		{"ipv6 normal 2", "2602:0100::1234", "2602:100::"},
+		{"ipv6 hurricane electric", "2001:470:1f10:a1::2", "2001:470:1000::"},
+		{"ipv6 hurricane electric 2", "2001:0470:1f10:a1::2", "2001:470:1000::"},
+	}
+
+	for i, tc := range testCases {
+		nip := net.ParseIP(tc.ip)
+		key := groupKeyFor(p2p.NewNetAddressIPPort(nip, 26656), false)
+		assert.Equal(t, tc.expKey, key, "#%d", i)
+	}
+
+	// strict routability
+	testCases = []struct {
+		name   string
+		ip     string
+		expKey string
+	}{
+		// Local addresses.
+		{"ipv4 localhost", "127.0.0.1", "local"},
+		{"ipv6 localhost", "::1", "local"},
+		{"ipv4 zero", "0.0.0.0", "local"},
+		{"ipv4 first octet zero", "0.1.2.3", "local"},
+
+		// Unroutable addresses.
+		{"ipv4 invalid bcast", "255.255.255.255", "unroutable"},
+		{"ipv4 rfc1918 10/8", "10.1.2.3", "unroutable"},
+		{"ipv4 rfc1918 172.16/12", "172.16.1.2", "unroutable"},
+		{"ipv4 rfc1918 192.168/16", "192.168.1.2", "unroutable"},
+		{"ipv6 rfc3849 2001:db8::/32", "2001:db8::1234", "unroutable"},
+		{"ipv4 rfc3927 169.254/16", "169.254.1.2", "unroutable"},
+		{"ipv6 rfc4193 fc00::/7", "fc00::1234", "unroutable"},
+		{"ipv6 rfc4843 2001:10::/28", "2001:10::1234", "unroutable"},
+		{"ipv6 rfc4862 fe80::/64", "fe80::1234", "unroutable"},
+	}
+
+	for i, tc := range testCases {
+		nip := net.ParseIP(tc.ip)
+		key := groupKeyFor(p2p.NewNetAddressIPPort(nip, 26656), true)
+		assert.Equal(t, tc.expKey, key, "#%d", i)
+	}
+}
+
 func assertMOldAndNNewAddrsInSelection(t *testing.T, m, n int, addrs []*p2p.NetAddress, book *addrBook) {
 	nOld, nNew := countOldAndNewAddrsInSelection(addrs, book)
 	assert.Equal(t, m, nOld, "old addresses")