engine: resources: Add dhcp:server and dhcp:host resources

This adds a new dhcp server resource, as well as a dhcp host resource used to specify the static mapping between mac address and ip address. It also adds a simple, pure-golang example dhcp client which might make testing easier. The dhcp resource is not meant to be a full-featured dhcp server replacement, and it might still be useful to use the venerable dhcpd, however for integrated, pure-golang bootstrapping environments, this might prove to be very useful. It can be combined with the tftp resource to build PXE setups with mgmt. This resource can be extended further to support a dhcp:range directive, automatic edges, and more!
2020-03-29 03:02:56 -04:00
parent 016d021d5a
commit 583344138a
5 changed files with 1340 additions and 0 deletions
--- a/examples/dhcp_client/dhcp_client.go
+++ b/examples/dhcp_client/dhcp_client.go
@@ -0,0 +1,107 @@
+// Mgmt
+// Copyright (C) 2013-2020+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"os"
+
+	"github.com/insomniacslk/dhcp/dhcpv4"
+	"github.com/insomniacslk/dhcp/dhcpv4/nclient4"
+)
+
+const (
+	iface   = "lo" // loopback for local testing
+	address = "127.0.0.1"
+)
+
+func main() {
+	if len(os.Args) < 2 || len(os.Args) > 3 {
+		log.Printf("Usage: %s [port] <mac address>", os.Args[0])
+		return
+	}
+
+	port := string(nclient4.ServerPort) // the default is 67
+	if len(os.Args) >= 3 {
+		port = os.Args[1]
+	}
+	hwAddr := os.Args[len(os.Args)-1] // argv[1]
+
+	hw, err := net.ParseMAC(hwAddr)
+	if err != nil {
+		log.Printf("Invalid mac address: %v", err)
+		return
+	}
+
+	addr := fmt.Sprintf("%s:%s", address, port)
+	log.Printf("Connecting to: %s", addr)
+
+	opts := []nclient4.ClientOpt{}
+	{
+		opt := nclient4.WithHWAddr(hw)
+		opts = append(opts, opt)
+	}
+	{
+		opt := nclient4.WithSummaryLogger()
+		opts = append(opts, opt)
+	}
+	//{
+	//	opt := nclient4.WithDebugLogger()
+	//	opts = append(opts, opt)
+	//}
+
+	//c, err := nclient4.NewWithConn(conn net.PacketConn, ifaceHWAddr net.HardwareAddr, opts...)
+	c, err := nclient4.New(iface, opts...)
+	if err != nil {
+		log.Printf("Error connecting to server: %v", err)
+		return
+	}
+	defer func() {
+		if err := c.Close(); err != nil {
+			log.Printf("Error closing client: %v", err)
+		}
+	}()
+
+	modifiers := []dhcpv4.Modifier{}
+	//{
+	//	mod := dhcpv4.WithYourIP(net.ParseIP(?))
+	//	modifiers = append(modifiers, mod)
+	//}
+	//{
+	//	mod := dhcpv4.WithClientIP(net.ParseIP(?))
+	//	modifiers = append(modifiers, mod)
+	//}
+	// TODO: add modifiers
+
+	log.Printf("Requesting...")
+	ctx := context.Background()                     // TODO: add to ^C handler
+	offer, ack, err := c.Request(ctx, modifiers...) // (offer, ack *dhcpv4.DHCPv4, err error)
+	if err != nil {
+		log.Printf("Error requesting from server: %v", err)
+		return
+	}
+
+	// Show the results of the D-O-R-A exchange.
+	log.Printf("Offer: %+v", offer)
+	log.Printf("Ack: %+v", ack)
+
+	log.Printf("Done!")
+}