67 lines
1.2 KiB
Go
67 lines
1.2 KiB
Go
package iputil
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import (
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"encoding/binary"
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"fmt"
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"net"
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)
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type VpnIp uint32
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const maxIPv4StringLen = len("255.255.255.255")
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func (ip VpnIp) String() string {
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b := make([]byte, maxIPv4StringLen)
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n := ubtoa(b, 0, byte(ip>>24))
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b[n] = '.'
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n++
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n += ubtoa(b, n, byte(ip>>16&255))
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b[n] = '.'
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n++
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n += ubtoa(b, n, byte(ip>>8&255))
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b[n] = '.'
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n++
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n += ubtoa(b, n, byte(ip&255))
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return string(b[:n])
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}
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func (ip VpnIp) MarshalJSON() ([]byte, error) {
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return []byte(fmt.Sprintf("\"%s\"", ip.String())), nil
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}
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func (ip VpnIp) ToIP() net.IP {
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nip := make(net.IP, 4)
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binary.BigEndian.PutUint32(nip, uint32(ip))
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return nip
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}
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func Ip2VpnIp(ip []byte) VpnIp {
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if len(ip) == 16 {
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return VpnIp(binary.BigEndian.Uint32(ip[12:16]))
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}
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return VpnIp(binary.BigEndian.Uint32(ip))
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}
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// ubtoa encodes the string form of the integer v to dst[start:] and
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// returns the number of bytes written to dst. The caller must ensure
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// that dst has sufficient length.
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func ubtoa(dst []byte, start int, v byte) int {
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if v < 10 {
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dst[start] = v + '0'
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return 1
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} else if v < 100 {
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dst[start+1] = v%10 + '0'
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dst[start] = v/10 + '0'
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return 2
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}
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dst[start+2] = v%10 + '0'
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dst[start+1] = (v/10)%10 + '0'
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dst[start] = v/100 + '0'
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return 3
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}
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