diff options
Diffstat (limited to 'dhcpv4/nclient4/conn_linux.go')
| -rw-r--r-- | dhcpv4/nclient4/conn_linux.go | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/dhcpv4/nclient4/conn_linux.go b/dhcpv4/nclient4/conn_linux.go index 2fe69ce..6cdb071 100644 --- a/dhcpv4/nclient4/conn_linux.go +++ b/dhcpv4/nclient4/conn_linux.go @@ -2,6 +2,7 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. +//go:build go1.12 // +build go1.12 package nclient4 @@ -98,12 +99,26 @@ func (upc *BroadcastRawUDPConn) ReadFrom(b []byte) (int, net.Addr, error) { buf := uio.NewBigEndianBuffer(pkt) // To read the header length, access data directly. + if !buf.Has(ipv4MinimumSize) { + continue + } + ipHdr := ipv4(buf.Data()) + + if !buf.Has(int(ipHdr.headerLength())) { + continue + } + ipHdr = ipv4(buf.Consume(int(ipHdr.headerLength()))) if ipHdr.transportProtocol() != udpProtocolNumber { continue } + + if !buf.Has(udpHdrLen) { + continue + } + udpHdr := udp(buf.Consume(udpHdrLen)) addr := &net.UDPAddr{ |