From 23d4e52ac97fc7e4e7c47d4e277693c516c3b420 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Fri, 5 Nov 2021 01:52:54 +0100
Subject: global: use netip where possible now

There are more places where we'll need to add it later, when Go 1.18
comes out with support for it in the "net" package. Also, allowedips
still uses slices internally, which might be suboptimal.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 device/allowedips.go | 41 ++++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 19 deletions(-)

(limited to 'device/allowedips.go')

diff --git a/device/allowedips.go b/device/allowedips.go
index c08399b..a6534b1 100644
--- a/device/allowedips.go
+++ b/device/allowedips.go
@@ -12,6 +12,8 @@ import (
 	"net"
 	"sync"
 	"unsafe"
+
+	"golang.zx2c4.com/go118/netip"
 )
 
 type parentIndirection struct {
@@ -26,7 +28,7 @@ type trieEntry struct {
 	cidr        uint8
 	bitAtByte   uint8
 	bitAtShift  uint8
-	bits        net.IP
+	bits        []byte
 	perPeerElem *list.Element
 }
 
@@ -51,7 +53,7 @@ func swapU64(i uint64) uint64 {
 	return bits.ReverseBytes64(i)
 }
 
-func commonBits(ip1 net.IP, ip2 net.IP) uint8 {
+func commonBits(ip1, ip2 []byte) uint8 {
 	size := len(ip1)
 	if size == net.IPv4len {
 		a := (*uint32)(unsafe.Pointer(&ip1[0]))
@@ -85,7 +87,7 @@ func (node *trieEntry) removeFromPeerEntries() {
 	}
 }
 
-func (node *trieEntry) choose(ip net.IP) byte {
+func (node *trieEntry) choose(ip []byte) byte {
 	return (ip[node.bitAtByte] >> node.bitAtShift) & 1
 }
 
@@ -104,7 +106,7 @@ func (node *trieEntry) zeroizePointers() {
 	node.parent.parentBit = nil
 }
 
-func (node *trieEntry) nodePlacement(ip net.IP, cidr uint8) (parent *trieEntry, exact bool) {
+func (node *trieEntry) nodePlacement(ip []byte, cidr uint8) (parent *trieEntry, exact bool) {
 	for node != nil && node.cidr <= cidr && commonBits(node.bits, ip) >= node.cidr {
 		parent = node
 		if parent.cidr == cidr {
@@ -117,7 +119,7 @@ func (node *trieEntry) nodePlacement(ip net.IP, cidr uint8) (parent *trieEntry,
 	return
 }
 
-func (trie parentIndirection) insert(ip net.IP, cidr uint8, peer *Peer) {
+func (trie parentIndirection) insert(ip []byte, cidr uint8, peer *Peer) {
 	if *trie.parentBit == nil {
 		node := &trieEntry{
 			peer:       peer,
@@ -207,7 +209,7 @@ func (trie parentIndirection) insert(ip net.IP, cidr uint8, peer *Peer) {
 	}
 }
 
-func (node *trieEntry) lookup(ip net.IP) *Peer {
+func (node *trieEntry) lookup(ip []byte) *Peer {
 	var found *Peer
 	size := uint8(len(ip))
 	for node != nil && commonBits(node.bits, ip) >= node.cidr {
@@ -229,13 +231,13 @@ type AllowedIPs struct {
 	mutex sync.RWMutex
 }
 
-func (table *AllowedIPs) EntriesForPeer(peer *Peer, cb func(ip net.IP, cidr uint8) bool) {
+func (table *AllowedIPs) EntriesForPeer(peer *Peer, cb func(prefix netip.Prefix) bool) {
 	table.mutex.RLock()
 	defer table.mutex.RUnlock()
 
 	for elem := peer.trieEntries.Front(); elem != nil; elem = elem.Next() {
 		node := elem.Value.(*trieEntry)
-		if !cb(node.bits, node.cidr) {
+		if !cb(netip.PrefixFrom(netip.AddrFromSlice(node.bits), int(node.cidr))) {
 			return
 		}
 	}
@@ -283,28 +285,29 @@ func (table *AllowedIPs) RemoveByPeer(peer *Peer) {
 	}
 }
 
-func (table *AllowedIPs) Insert(ip net.IP, cidr uint8, peer *Peer) {
+func (table *AllowedIPs) Insert(prefix netip.Prefix, peer *Peer) {
 	table.mutex.Lock()
 	defer table.mutex.Unlock()
 
-	switch len(ip) {
-	case net.IPv6len:
-		parentIndirection{&table.IPv6, 2}.insert(ip, cidr, peer)
-	case net.IPv4len:
-		parentIndirection{&table.IPv4, 2}.insert(ip, cidr, peer)
-	default:
+	if prefix.Addr().Is6() {
+		ip := prefix.Addr().As16()
+		parentIndirection{&table.IPv6, 2}.insert(ip[:], uint8(prefix.Bits()), peer)
+	} else if prefix.Addr().Is4() {
+		ip := prefix.Addr().As4()
+		parentIndirection{&table.IPv4, 2}.insert(ip[:], uint8(prefix.Bits()), peer)
+	} else {
 		panic(errors.New("inserting unknown address type"))
 	}
 }
 
-func (table *AllowedIPs) Lookup(address []byte) *Peer {
+func (table *AllowedIPs) Lookup(ip []byte) *Peer {
 	table.mutex.RLock()
 	defer table.mutex.RUnlock()
-	switch len(address) {
+	switch len(ip) {
 	case net.IPv6len:
-		return table.IPv6.lookup(address)
+		return table.IPv6.lookup(ip)
 	case net.IPv4len:
-		return table.IPv4.lookup(address)
+		return table.IPv4.lookup(ip)
 	default:
 		panic(errors.New("looking up unknown address type"))
 	}
-- 
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