From 0abbb3a6ca37df0a4b2cff39b9b9f39d1f5fa03e Mon Sep 17 00:00:00 2001
From: Stefan Catargiu <13122921+5kt@users.noreply.github.com>
Date: Wed, 5 Jun 2024 12:06:23 +0200
Subject: [PATCH] Add httpboot plugin

---
 main.go                    |   2 +
 plugins/httpboot/plugin.go | 103 +++++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+)
 create mode 100644 plugins/httpboot/plugin.go

diff --git a/main.go b/main.go
index bcfb6be..6ba2611 100644
--- a/main.go
+++ b/main.go
@@ -30,6 +30,7 @@ import (
 	pl_sleep "github.com/coredhcp/coredhcp/plugins/sleep"
 	pl_staticroute "github.com/coredhcp/coredhcp/plugins/staticroute"
 	pl_bluefield "github.com/ironcore-dev/fedhcp/plugins/bluefield"
+	pl_httpboot "github.com/ironcore-dev/fedhcp/plugins/httpboot"
 	pl_ipam "github.com/ironcore-dev/fedhcp/plugins/ipam"
 	pl_onmetal "github.com/ironcore-dev/fedhcp/plugins/onmetal"
 	pl_oob "github.com/ironcore-dev/fedhcp/plugins/oob"
@@ -86,6 +87,7 @@ var desiredPlugins = []*plugins.Plugin{
 	&pl_onmetal.Plugin,
 	&pl_oob.Plugin,
 	&pl_pxeboot.Plugin,
+	&pl_httpboot.Plugin,
 }
 
 func main() {
diff --git a/plugins/httpboot/plugin.go b/plugins/httpboot/plugin.go
new file mode 100644
index 0000000..526ddee
--- /dev/null
+++ b/plugins/httpboot/plugin.go
@@ -0,0 +1,103 @@
+// SPDX-FileCopyrightText: 2023 SAP SE or an SAP affiliate company and IronCore contributors
+// SPDX-License-Identifier: MIT
+
+package httpboot
+
+import (
+	"fmt"
+	"github.com/coredhcp/coredhcp/handler"
+	"github.com/coredhcp/coredhcp/logger"
+	"github.com/coredhcp/coredhcp/plugins"
+	"github.com/insomniacslk/dhcp/dhcpv4"
+	"github.com/insomniacslk/dhcp/dhcpv6"
+	"net/url"
+	"strings"
+)
+
+var bootFile4 string
+var bootFile6 string
+
+var log = logger.GetLogger("plugins/httpboot")
+
+var Plugin = plugins.Plugin{
+	Name:   "httpboot",
+	Setup6: setup6,
+	Setup4: setup4,
+}
+
+func parseArgs(args ...string) (*url.URL, error) {
+	if len(args) != 1 {
+		return nil, fmt.Errorf("Exactly one argument must be passed to the httpboot plugin, got %d", len(args))
+	}
+	return url.Parse(args[0])
+}
+
+func setup6(args ...string) (handler.Handler6, error) {
+	u, err := parseArgs(args...)
+	if err != nil {
+		return nil, err
+	}
+	bootFile6 = u.String()
+	log.Printf("loaded httpboot plugin for DHCPv6.")
+	return Handler6, nil
+}
+
+func setup4(args ...string) (handler.Handler4, error) {
+	u, err := parseArgs(args...)
+	if err != nil {
+		return nil, err
+	}
+	bootFile4 = u.String()
+	log.Printf("loaded httpboot plugin for DHCPv4.")
+	return Handler4, nil
+}
+
+func Handler6(req, resp dhcpv6.DHCPv6) (dhcpv6.DHCPv6, bool) {
+	log.Debugf("Received DHCPv6 request: %s", req.Summary())
+	decap, err := req.GetInnerMessage()
+	if err != nil {
+		log.Errorf("Could not decapsulate request: %v", err)
+		return nil, true
+	}
+
+	if decap.GetOneOption(dhcpv6.OptionVendorClass) != nil {
+		vc := decap.GetOneOption(dhcpv6.OptionVendorClass).String()
+		if strings.Contains(vc, "HTTPClient") {
+			bf := &dhcpv6.OptionGeneric{
+				OptionCode: dhcpv6.OptionBootfileURL,
+				OptionData: []byte(bootFile6),
+			}
+			resp.AddOption(bf)
+			vid := &dhcpv6.OptionGeneric{
+				OptionCode: dhcpv6.OptionVendorClass,
+				// 0000 (4 bytes) Enterprise Identifier
+				// 0a (2 bytes) length of "HTTPClient"
+				// - rest with HTTPClient
+				OptionData: []byte("00000aHTTPClient"),
+			}
+			resp.AddOption(vid)
+		}
+	}
+
+	return resp, false
+}
+
+func Handler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
+	log.Debugf("Received DHCPv4 request: %s", req.Summary())
+	if req.GetOneOption(dhcpv4.OptionClassIdentifier) != nil {
+		vc := req.GetOneOption(dhcpv4.OptionClassIdentifier)
+		if strings.Contains(string(vc), "HTTPClient") {
+			bf := &dhcpv4.Option{
+				Code:  dhcpv4.OptionBootfileName,
+				Value: dhcpv4.String(bootFile4),
+			}
+			resp.Options.Update(*bf)
+			vid := &dhcpv4.Option{
+				Code:  dhcpv4.OptionClassIdentifier,
+				Value: dhcpv4.String("HTTPClient"),
+			}
+			resp.Options.Update(*vid)
+		}
+	}
+	return resp, false
+}