orion/openwrt/dhcp_client.go

package openwrt

import (
	"bufio"
	"regexp"
	"strings"
)

// DhcpClient represents a dhcp client ... :)
type DhcpClient struct {
	exec  Executor
	iface string
}

// DhcpResult contains sorted result form AskFroIP
type DhcpResult struct {
	CmdRes  *CommandResult
	IP      string
	Netmask string
}

// NewDhcpClient return an UCI instance to interact with UCI
func NewDhcpClient(netIface string) *DhcpClient {
	exec := &localExecutor{}
	iface := netIface
	return &DhcpClient{exec, iface}
}

// NewDhcpClientWithExecutor return an UCI instance to interact with UCI
func NewDhcpClientWithExecutor(netIface string, exe Executor) *DhcpClient {
	exec := exe
	iface := netIface
	return &DhcpClient{exec, iface}
}

// NewDhcpClient return an UCI instance to interact with UCI
//func NewDhcpClient(netIface string, exe Executor) *DhcpClient {
//	var exec Executor
//	if exe == nil {
//		exec = &localExecutor{}
//	} else {
//		exec = exe
//	}
//	iface := netIface
//	return &DhcpClient{exec, iface}
//}

func parseDhcpClientOut(out *CommandResult) *DhcpResult {
	if out.ReturnCode != 0 {
		return &DhcpResult{
			out,
			"",
			"",
		}
	}

	scanner := bufio.NewScanner(strings.NewReader(out.Stdout))
	for scanner.Scan() {
		line := scanner.Text()
		re := regexp.MustCompile(`^udhcpc: ifconfig`)
		if re.MatchString(line) {
			spl := strings.Split(line, " ")
			ip := spl[3]
			mask := spl[5]
			return &DhcpResult{
				out,
				ip,
				mask,
			}
		}

	}
	return nil
}

// AskForIP runs a dhclient ip request with udhcpc
func (dc *DhcpClient) AskForIP() *DhcpResult {
	out := dc.exec.Run("udhcpc", "-i", dc.iface)
	return parseDhcpClientOut(out)
}