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package bsdp
import (
"errors"
"github.com/insomniacslk/dhcp/dhcpv4"
"github.com/insomniacslk/dhcp/dhcpv4/client4"
)
// Client represents a BSDP client that can perform BSDP exchanges via the
// broadcast address.
type Client struct {
client4.Client
}
// NewClient constructs a new client with default read and write timeouts from
// dhcpv4.Client.
func NewClient() *Client {
return &Client{Client: client4.Client{}}
}
// Exchange runs a full BSDP exchange (Inform[list], Ack, Inform[select],
// Ack). Returns a list of DHCPv4 structures representing the exchange.
func (c *Client) Exchange(ifname string) ([]*Packet, error) {
conversation := make([]*Packet, 0)
// Get our file descriptor for the broadcast socket.
sendFd, err := client4.MakeBroadcastSocket(ifname)
if err != nil {
return conversation, err
}
recvFd, err := client4.MakeListeningSocket(ifname)
if err != nil {
return conversation, err
}
// INFORM[LIST]
informList, err := NewInformListForInterface(ifname, dhcpv4.ClientPort)
if err != nil {
return conversation, err
}
conversation = append(conversation, informList)
// ACK[LIST]
ackForList, err := c.Client.SendReceive(sendFd, recvFd, informList.v4(), dhcpv4.MessageTypeAck)
if err != nil {
return conversation, err
}
// Rewrite vendor-specific option for pretty printing.
conversation = append(conversation, PacketFor(ackForList))
// Parse boot images sent back by server
bootImages, err := ParseBootImageListFromAck(ackForList)
if err != nil {
return conversation, err
}
if len(bootImages) == 0 {
return conversation, errors.New("got no BootImages from server")
}
// INFORM[SELECT]
informSelect, err := InformSelectForAck(PacketFor(ackForList), dhcpv4.ClientPort, bootImages[0])
if err != nil {
return conversation, err
}
conversation = append(conversation, informSelect)
// ACK[SELECT]
ackForSelect, err := c.Client.SendReceive(sendFd, recvFd, informSelect.v4(), dhcpv4.MessageTypeAck)
if err != nil {
return conversation, err
}
return append(conversation, PacketFor(ackForSelect)), nil
}
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