badguardhome/internal/dhcpd/broadcast_others.go
Eugene Burkov da86620288 Pull request: 3443 dhcp broadcast vol.2
Merge in DNS/adguard-home from 3443-dhcp-broadcast-vol.2 to master

Closes #3443.

Squashed commit of the following:

commit a85af89cb43f2489126fe3c12366fc034e89f59d
Merge: 72eb3a88 a4e07827
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Sep 30 18:08:19 2021 +0300

    Merge branch 'master' into 3443-dhcp-broadcast-vol.2

commit 72eb3a8853540b06ee1096decf50e836b539fe45
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Sep 30 18:03:19 2021 +0300

    dhcpd: imp code readability

commit 2d1fbc40d04a4125855d6be9f02e09d15430150d
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Sep 30 14:16:59 2021 +0300

    dhcpd: imp tests

commit 889fad3084ad2b81edfc12100e2ce29d323227ba
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Wed Sep 29 20:09:25 2021 +0300

    dhcpd: imp code, docs

commit 1fd6b2346ff66e033bceaa169aed751be5822ca8
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Sep 23 16:08:18 2021 +0300

    dhcpd: unicast to mac address
2021-09-30 18:28:19 +03:00

32 lines
1.1 KiB
Go

//go:build aix || darwin || dragonfly || linux || netbsd || solaris
// +build aix darwin dragonfly linux netbsd solaris
package dhcpd
import (
"net"
)
// broadcast sends resp to the broadcast address specific for network interface.
func (c *dhcpConn) broadcast(respData []byte, peer *net.UDPAddr) (n int, err error) {
// This write to 0xffffffff reverts some behavior changes made in
// https://github.com/AdguardTeam/AdGuardHome/issues/3289. The DHCP
// server should broadcast the message to 0xffffffff but it's
// inconsistent with the actual mental model of DHCP implementation
// which requires the network interface selection to bind to.
//
// See https://github.com/AdguardTeam/AdGuardHome/issues/3480 and
// https://github.com/AdguardTeam/AdGuardHome/issues/3366.
//
// See also https://github.com/AdguardTeam/AdGuardHome/issues/3539.
if n, err = c.udpConn.WriteTo(respData, peer); err != nil {
return n, err
}
// Broadcast the message one more time using the interface-specific
// broadcast address.
peer.IP = c.bcastIP
return c.udpConn.WriteTo(respData, peer)
}