diff options
Diffstat (limited to 'dhcpv4/client.go')
| -rw-r--r-- | dhcpv4/client.go | 45 |
1 files changed, 22 insertions, 23 deletions
diff --git a/dhcpv4/client.go b/dhcpv4/client.go index c132eaa..2962fc5 100644 --- a/dhcpv4/client.go +++ b/dhcpv4/client.go @@ -81,23 +81,23 @@ func MakeRawBroadcastPacket(payload []byte) ([]byte, error) { func MakeBroadcastSocket(ifname string) (int, error) { fd, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, syscall.IPPROTO_RAW) if err != nil { - return -1, err + return fd, err } err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1) if err != nil { - return -1, err + return fd, err } err = syscall.SetsockoptInt(fd, syscall.IPPROTO_IP, syscall.IP_HDRINCL, 1) if err != nil { - return -1, err + return fd, err } err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1) if err != nil { - return -1, err + return fd, err } err = BindToInterface(fd, ifname) if err != nil { - return -1, err + return fd, err } return fd, nil } @@ -108,15 +108,9 @@ func MakeBroadcastSocket(ifname string) (int, error) { // ordered as Discovery, Offer, Request and Acknowledge. In case of errors, an // error is returned, and the list of DHCPv4 objects will be shorted than 4, // containing all the sent and received DHCPv4 messages. -func Exchange(client *Client, ifname string, discover *DHCPv4) ([]DHCPv4, error) { +func (c *Client) Exchange(ifname string, discover *DHCPv4) ([]DHCPv4, error) { conversation := make([]DHCPv4, 1) var err error - if discover == nil { - discover, err = NewDiscoveryForInterface(ifname) - if err != nil { - return conversation, err - } - } // Get our file descriptor for the broadcast socket. fd, err := MakeBroadcastSocket(ifname) @@ -125,10 +119,16 @@ func Exchange(client *Client, ifname string, discover *DHCPv4) ([]DHCPv4, error) } // Discover + if discover == nil { + discover, err = NewDiscoveryForInterface(ifname) + if err != nil { + return conversation, err + } + } conversation[0] = *discover // Offer - offer, err := SendReceive(client, fd, discover) + offer, err := BroadcastSendReceive(fd, discover, c.ReadTimeout, c.WriteTimeout) if err != nil { return conversation, err } @@ -142,7 +142,7 @@ func Exchange(client *Client, ifname string, discover *DHCPv4) ([]DHCPv4, error) conversation = append(conversation, *request) // Ack - ack, err := SendReceive(client, fd, discover) + ack, err := BroadcastSendReceive(fd, discover, c.ReadTimeout, c.WriteTimeout) if err != nil { return conversation, err } @@ -150,10 +150,9 @@ func Exchange(client *Client, ifname string, discover *DHCPv4) ([]DHCPv4, error) return conversation, nil } -// SendReceive broadcasts packet (with some write timeout) and waits for a +// BroadcastSendReceive broadcasts packet (with some write timeout) and waits for a // response up to some read timeout value. -func SendReceive(client *Client, fd int, packet *DHCPv4) (*DHCPv4, error) { - // Build up our packet bytes. +func BroadcastSendReceive(fd int, packet *DHCPv4, readTimeout, writeTimeout time.Duration) (*DHCPv4, error) { packetBytes, err := MakeRawBroadcastPacket(packet.ToBytes()) if err != nil { return nil, err @@ -170,23 +169,23 @@ func SendReceive(client *Client, fd int, packet *DHCPv4) (*DHCPv4, error) { if err != nil { return nil, err } - case <-time.After(client.WriteTimeout): - return nil, errors.New("timed out while communicating with server") + case <-time.After(writeTimeout): + return nil, errors.New("timed out while sending broadcast") } - // Open up a connection to listen. conn, err := net.ListenUDP("udp4", &net.UDPAddr{IP: net.IPv4zero, Port: ClientPort}) + if err != nil { + return nil, err + } defer conn.Close() - conn.SetReadDeadline(time.Now().Add(client.ReadTimeout)) + conn.SetReadDeadline(time.Now().Add(readTimeout)) - // Wait for a response from the server. buf := make([]byte, MaxUDPReceivedPacketSize) n, _, _, _, err := conn.ReadMsgUDP(buf, []byte{}) if err != nil { return nil, err } - // Serialize to a DHCPv4 packet. response, err := FromBytes(buf[:n]) if err != nil { return nil, err |