Moves to official vendoring solution

vendor/github.com/d2g/dhcp4client/inetsock.go

@@ -0,0 +1,75 @@
+package dhcp4client
+
+import (
+	"net"
+	"time"
+)
+
+type inetSock struct {
+	*net.UDPConn
+
+	laddr net.UDPAddr
+	raddr net.UDPAddr
+}
+
+func NewInetSock(options ...func(*inetSock) error) (*inetSock, error) {
+	c := &inetSock{
+		laddr: net.UDPAddr{IP: net.IPv4(0, 0, 0, 0), Port: 68},
+		raddr: net.UDPAddr{IP: net.IPv4bcast, Port: 67},
+	}
+
+	err := c.setOption(options...)
+	if err != nil {
+		return nil, err
+	}
+
+	conn, err := net.ListenUDP("udp4", &c.laddr)
+	if err != nil {
+		return nil, err
+	}
+
+	c.UDPConn = conn
+	return c, err
+}
+
+func (c *inetSock) setOption(options ...func(*inetSock) error) error {
+	for _, opt := range options {
+		if err := opt(c); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func SetLocalAddr(l net.UDPAddr) func(*inetSock) error {
+	return func(c *inetSock) error {
+		c.laddr = l
+		return nil
+	}
+}
+
+func SetRemoteAddr(r net.UDPAddr) func(*inetSock) error {
+	return func(c *inetSock) error {
+		c.raddr = r
+		return nil
+	}
+}
+
+func (c *inetSock) Write(packet []byte) error {
+	_, err := c.WriteToUDP(packet, &c.raddr)
+	return err
+}
+
+func (c *inetSock) ReadFrom() ([]byte, net.IP, error) {
+	readBuffer := make([]byte, MaxDHCPLen)
+	n, source, err := c.ReadFromUDP(readBuffer)
+	if source != nil {
+		return readBuffer[:n], source.IP, err
+	} else {
+		return readBuffer[:n], net.IP{}, err
+	}
+}
+
+func (c *inetSock) SetReadTimeout(t time.Duration) error {
+	return c.SetReadDeadline(time.Now().Add(t))
+}