Reworked logic on the dhcp reply (#8297)

inverse-inc · Sep 12, 2024 · 43cca14 · 43cca14
1 parent 0009032
commit 43cca14
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Showing 3 changed files with 27 additions and 10 deletions.
diff --git a/go/cmd/pfdhcp/config.go b/go/cmd/pfdhcp/config.go
@@ -318,6 +318,7 @@ func (d *Interfaces) readConfig() {
 							backend = ConfNet.PoolBackend
 						}
 						var dstReplyIp string
+
 						if ConfNet.DhcpReplyIp == "" {
 							dstReplyIp = "giaddr"
 						} else {

diff --git a/go/cmd/pfdhcp/main.go b/go/cmd/pfdhcp/main.go
@@ -355,7 +355,7 @@ func (I *Interface) ServeDHCP(ctx context.Context, p dhcp.Packet, msgType dhcp.M
 	if VIP[I.Name] || handler.available.Listen() {
 
 		defer recoverName(options)
-
+		answer.DstIP = handler.dstIp
 		var Options map[string]string
 		Options = make(map[string]string)
 		for option, value := range options {
@@ -556,7 +556,7 @@ func (I *Interface) ServeDHCP(ctx context.Context, p dhcp.Packet, msgType dhcp.M
 			}
 			GlobalOptions = options
 			leaseDuration := handler.leaseDuration
-			answer.DstIP = handler.dstIp
+
 			// Add network options on the fly
 			x, err := decodeOptions(NetScope.IP.String())
 			if err == nil {

diff --git a/go/cmd/pfdhcp/workers_pool.go b/go/cmd/pfdhcp/workers_pool.go
@@ -7,6 +7,7 @@ import (
 	"strconv"
 
 	dhcp "github.com/inverse-inc/dhcp4"
+	"github.com/inverse-inc/go-utils/log"
 )
 
 type job struct {
@@ -23,22 +24,37 @@ func doWork(id int, element job) {
 	var ans Answer
 	if ans = element.handler.ServeDHCP(element.localCtx, element.DHCPpacket, element.msgType, element.clientAddr, element.srvAddr); ans.D != nil {
 		ipStr, portStr, _ := net.SplitHostPort(element.clientAddr.String())
-		if !(element.DHCPpacket.GIAddr().Equal(net.IPv4zero) && net.ParseIP(ipStr).Equal(net.IPv4zero)) {
+		ctx = log.AddToLogContext(ctx, "mac", ans.MAC.String())
+		log.LoggerWContext(ctx).Debug("Giaddr " + element.DHCPpacket.GIAddr().String())
+
+		// If giaddr is 0.0.0.0 and source ip is 0.0.0.0 (broadcast)
+		if element.DHCPpacket.GIAddr().Equal(net.IPv4zero) && net.ParseIP(ipStr).Equal(net.IPv4zero) {
+			log.LoggerWContext(ctx).Debug("Broadcast")
+			client, _ := NewRawClient(element.Int.intNet)
+			client.sendDHCP(ans.MAC, ans.D, ans.IP, element.Int.Ipv4)
+			client.Close()
+		} else {
+			// Non broadcast
 			dstPort, _ := strconv.Atoi(portStr)
-			if !(net.ParseIP(ipStr).Equal(element.DHCPpacket.GIAddr())) {
-				if !(element.DHCPpacket.GIAddr().Equal(net.IPv4zero)) {
+			// If the source ip is equal to the giaddr then send it to the source ip
+			if net.ParseIP(ipStr).Equal(element.DHCPpacket.GIAddr()) {
+				log.LoggerWContext(ctx).Debug("L3 coming from the dhcp relay " + element.DHCPpacket.GIAddr().String())
+				sendUnicastDHCP(ans.D, ans.SrcIP, net.ParseIP(ipStr), bootpServer, dstPort)
+			} else {
+				// Probably L2
+				if element.DHCPpacket.GIAddr().Equal(net.IPv4zero) {
+					log.LoggerWContext(ctx).Debug("L2 - no giaddr, send it to " + ipStr)
+					sendUnicastDHCP(ans.D, ans.SrcIP, net.ParseIP(ipStr), bootpServer, dstPort)
+				} else {
 					if ans.DstIP == "giaddr" {
+						log.LoggerWContext(ctx).Debug("L3 - reply to giaddr " + element.DHCPpacket.GIAddr().String())
 						sendUnicastDHCP(ans.D, ans.SrcIP, element.DHCPpacket.GIAddr(), bootpServer, dstPort)
 					} else {
+						log.LoggerWContext(ctx).Debug("L3 - sent to source IP" + ipStr)
 						sendUnicastDHCP(ans.D, ans.SrcIP, net.ParseIP(ipStr), bootpServer, dstPort)
 					}
 				}
 			}
-			sendUnicastDHCP(ans.D, ans.SrcIP, net.ParseIP(ipStr), bootpServer, dstPort)
-		} else {
-			client, _ := NewRawClient(element.Int.intNet)
-			client.sendDHCP(ans.MAC, ans.D, ans.IP, element.Int.Ipv4)
-			client.Close()
 		}
 	}
 }