diff --git a/device/allowedips.go b/device/allowedips.go index 7a0b275..06c5465 100644 --- a/device/allowedips.go +++ b/device/allowedips.go @@ -7,6 +7,7 @@ package device import ( "container/list" + "encoding/binary" "errors" "math/bits" "net" @@ -32,45 +33,24 @@ type trieEntry struct { perPeerElem *list.Element } -func isLittleEndian() bool { - one := uint32(1) - return *(*byte)(unsafe.Pointer(&one)) != 0 -} - -func swapU32(i uint32) uint32 { - if !isLittleEndian() { - return i - } - - return bits.ReverseBytes32(i) -} - -func swapU64(i uint64) uint64 { - if !isLittleEndian() { - return i - } - - return bits.ReverseBytes64(i) -} - func commonBits(ip1, ip2 []byte) uint8 { size := len(ip1) if size == net.IPv4len { - a := (*uint32)(unsafe.Pointer(&ip1[0])) - b := (*uint32)(unsafe.Pointer(&ip2[0])) - x := *a ^ *b - return uint8(bits.LeadingZeros32(swapU32(x))) + a := binary.BigEndian.Uint32(ip1) + b := binary.BigEndian.Uint32(ip2) + x := a ^ b + return uint8(bits.LeadingZeros32(x)) } else if size == net.IPv6len { - a := (*uint64)(unsafe.Pointer(&ip1[0])) - b := (*uint64)(unsafe.Pointer(&ip2[0])) - x := *a ^ *b + a := binary.BigEndian.Uint64(ip1) + b := binary.BigEndian.Uint64(ip2) + x := a ^ b if x != 0 { - return uint8(bits.LeadingZeros64(swapU64(x))) + return uint8(bits.LeadingZeros64(x)) } - a = (*uint64)(unsafe.Pointer(&ip1[8])) - b = (*uint64)(unsafe.Pointer(&ip2[8])) - x = *a ^ *b - return 64 + uint8(bits.LeadingZeros64(swapU64(x))) + a = binary.BigEndian.Uint64(ip1[8:]) + b = binary.BigEndian.Uint64(ip2[8:]) + x = a ^ b + return 64 + uint8(bits.LeadingZeros64(x)) } else { panic("Wrong size bit string") }