506b459842
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
119 lines
2.7 KiB
Go
119 lines
2.7 KiB
Go
package aghnet
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"time"
|
|
|
|
"github.com/AdguardTeam/golibs/log"
|
|
)
|
|
|
|
// IPVersion is a documentational alias for int. Use it when the integer means
|
|
// IP version.
|
|
type IPVersion = int
|
|
|
|
// IP version constants.
|
|
const (
|
|
IPVersion4 IPVersion = 4
|
|
IPVersion6 IPVersion = 6
|
|
)
|
|
|
|
// NetIface is the interface for network interface methods.
|
|
type NetIface interface {
|
|
Addrs() ([]net.Addr, error)
|
|
}
|
|
|
|
// IfaceIPAddrs returns the interface's IP addresses.
|
|
func IfaceIPAddrs(iface NetIface, ipv IPVersion) (ips []net.IP, err error) {
|
|
addrs, err := iface.Addrs()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
for _, a := range addrs {
|
|
var ip net.IP
|
|
switch a := a.(type) {
|
|
case *net.IPAddr:
|
|
ip = a.IP
|
|
case *net.IPNet:
|
|
ip = a.IP
|
|
default:
|
|
continue
|
|
}
|
|
|
|
// Assume that net.(*Interface).Addrs can only return valid IPv4
|
|
// and IPv6 addresses. Thus, if it isn't an IPv4 address, it
|
|
// must be an IPv6 one.
|
|
switch ipv {
|
|
case IPVersion4:
|
|
if ip4 := ip.To4(); ip4 != nil {
|
|
ips = append(ips, ip4)
|
|
}
|
|
case IPVersion6:
|
|
if ip6 := ip.To4(); ip6 == nil {
|
|
ips = append(ips, ip)
|
|
}
|
|
default:
|
|
return nil, fmt.Errorf("invalid ip version %d", ipv)
|
|
}
|
|
}
|
|
|
|
return ips, nil
|
|
}
|
|
|
|
// IfaceDNSIPAddrs returns IP addresses of the interface suitable to send to
|
|
// clients as DNS addresses. If err is nil, addrs contains either no addresses
|
|
// or at least two.
|
|
//
|
|
// It makes up to maxAttempts attempts to get the addresses if there are none,
|
|
// each time using the provided backoff. Sometimes an interface needs a few
|
|
// seconds to really ititialize.
|
|
//
|
|
// See https://github.com/AdguardTeam/AdGuardHome/issues/2304.
|
|
func IfaceDNSIPAddrs(
|
|
iface NetIface,
|
|
ipv IPVersion,
|
|
maxAttempts int,
|
|
backoff time.Duration,
|
|
) (addrs []net.IP, err error) {
|
|
var n int
|
|
for n = 1; n <= maxAttempts; n++ {
|
|
addrs, err = IfaceIPAddrs(iface, ipv)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("getting ip addrs: %w", err)
|
|
}
|
|
|
|
if len(addrs) > 0 {
|
|
break
|
|
}
|
|
|
|
log.Debug("dhcpv%d: attempt %d: no ip addresses", ipv, n)
|
|
|
|
time.Sleep(backoff)
|
|
}
|
|
|
|
switch len(addrs) {
|
|
case 0:
|
|
// Don't return errors in case the users want to try and enable
|
|
// the DHCP server later.
|
|
t := time.Duration(n) * backoff
|
|
log.Error("dhcpv%d: no ip for iface after %d attempts and %s", ipv, n, t)
|
|
|
|
return nil, nil
|
|
case 1:
|
|
// Some Android devices use 8.8.8.8 if there is not a secondary
|
|
// DNS server. Fix that by setting the secondary DNS address to
|
|
// the same address.
|
|
//
|
|
// See https://github.com/AdguardTeam/AdGuardHome/issues/1708.
|
|
log.Debug("dhcpv%d: setting secondary dns ip to itself", ipv)
|
|
addrs = append(addrs, addrs[0])
|
|
default:
|
|
// Go on.
|
|
}
|
|
|
|
log.Debug("dhcpv%d: got addresses %s after %d attempts", ipv, addrs, n)
|
|
|
|
return addrs, nil
|
|
}
|