badguardhome/internal/dhcpd/helpers.go
Eugene Burkov 506b459842 Pull request: 3225 bsd dhcp
Merge in DNS/adguard-home from 3225-bsd-dhcp to master

Closes #3225.
Closes #3417.

Squashed commit of the following:

commit e7ea691824c7ebc8cafd8c9e206679346cbc8592
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Thu Aug 12 17:02:02 2021 +0300

    all: imp code, docs

commit 5b598fc18a9b69a0256569f4c691bb6a2193dfbd
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Thu Aug 12 16:28:12 2021 +0300

    all: mv logic, imp code, docs, log changes

commit e3e1577a668fe3e5c61d075c390e4bd7268181ba
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Thu Aug 12 14:15:10 2021 +0300

    dhcpd: imp checkother

commit 3cc8b058195c30a7ef0b7741ee8463270d9e47ff
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Wed Aug 11 13:20:18 2021 +0300

    all: imp bsd support
2021-08-12 17:33:53 +03:00

37 lines
586 B
Go

package dhcpd
import (
"encoding/binary"
"fmt"
"net"
)
func tryTo4(ip net.IP) (ip4 net.IP, err error) {
if ip == nil {
return nil, fmt.Errorf("%v is not an IP address", ip)
}
ip4 = ip.To4()
if ip4 == nil {
return nil, fmt.Errorf("%v is not an IPv4 address", ip)
}
return ip4, nil
}
// Return TRUE if subnet mask is correct (e.g. 255.255.255.0)
func isValidSubnetMask(mask net.IP) bool {
var n uint32
n = binary.BigEndian.Uint32(mask)
for i := 0; i != 32; i++ {
if n == 0 {
break
}
if (n & 0x80000000) == 0 {
return false
}
n <<= 1
}
return true
}