isValid() method

Signed-off-by: KonnovKM <boneyandoom@gmail.com>

1 files changed, 4 insertions, 12 deletions

diff --git a/dhcpv4/nclient4/conn_unix.go b/dhcpv4/nclient4/conn_unix.go
index 239d007..1495dc2 100644
--- a/dhcpv4/nclient4/conn_unix.go
+++ b/dhcpv4/nclient4/conn_unix.go
@@ -99,24 +99,16 @@ func (upc *BroadcastRawUDPConn) ReadFrom(b []byte) (int, net.Addr, error) {
 		pkt = pkt[:n]
 		buf := uio.NewBigEndianBuffer(pkt)
 
-		// To read the header length, access data directly.
-		if !buf.Has(ipv4MinimumSize) {
-			continue
-		}
-
 		ipHdr := ipv4(buf.Data())
-		headerLength := ipHdr.headerLength()
 
-		if !buf.Has(int(headerLength)) {
+		if !ipHdr.isValid(n) {
 			continue
 		}
 
-		ipHdr = ipv4(buf.Consume(int(headerLength)))
+		ipHdr = ipv4(buf.Consume(int(ipHdr.headerLength())))
 
-		if headerLength > protocol {
-			if ipHdr.transportProtocol() != udpProtocolNumber {
-				continue
-			}
+		if ipHdr.transportProtocol() != udpProtocolNumber {
+			continue
 		}
 
 		if !buf.Has(udpHdrLen) {