85 lines
1.7 KiB
Go
85 lines
1.7 KiB
Go
package dhcpd
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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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"github.com/AdguardTeam/golibs/log"
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"github.com/joomcode/errorx"
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)
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func isTimeout(err error) bool {
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operr, ok := err.(*net.OpError)
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if !ok {
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return false
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}
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return operr.Timeout()
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}
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// return first IPv4 address of an interface, if there is any
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func getIfaceIPv4(iface *net.Interface) *net.IPNet {
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ifaceAddrs, err := iface.Addrs()
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if err != nil {
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panic(err)
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}
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for _, addr := range ifaceAddrs {
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ipnet, ok := addr.(*net.IPNet)
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if !ok {
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// not an IPNet, should not happen
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log.Fatalf("SHOULD NOT HAPPEN: got iface.Addrs() element %s that is not net.IPNet", addr)
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}
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if ipnet.IP.To4() == nil {
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log.Tracef("Got IP that is not IPv4: %v", ipnet.IP)
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continue
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}
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log.Tracef("Got IP that is IPv4: %v", ipnet.IP)
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return &net.IPNet{
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IP: ipnet.IP.To4(),
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Mask: ipnet.Mask,
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}
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}
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return nil
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}
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func wrapErrPrint(err error, message string, args ...interface{}) error {
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var errx error
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if err == nil {
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errx = fmt.Errorf(message, args...)
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} else {
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errx = errorx.Decorate(err, message, args...)
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}
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log.Println(errx.Error())
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return errx
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}
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func parseIPv4(text string) (net.IP, error) {
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result := net.ParseIP(text)
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if result == nil {
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return nil, fmt.Errorf("%s is not an IP address", text)
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}
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if result.To4() == nil {
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return nil, fmt.Errorf("%s is not an IPv4 address", text)
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}
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return result.To4(), nil
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}
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// Return TRUE if subnet mask is correct (e.g. 255.255.255.0)
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func isValidSubnetMask(mask net.IP) bool {
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var n uint32
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n = binary.BigEndian.Uint32(mask)
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for i := 0; i != 32; i++ {
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if n == 0 {
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break
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}
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if (n & 0x80000000) == 0 {
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return false
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}
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n <<= 1
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}
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return true
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}
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