Merge pull request loxilb-io#550 from TrekkieCoder/main

PR - Added an embedded ip resolver

loxinet/dpbroker.go

@@ -372,6 +372,12 @@ func (ct *DpCtInfo) Key() string {
 	return str
 }
 
+// KeyState - outputs a key string for given DpCtInfo pointer with state info
+func (ct *DpCtInfo) KeyState() string {
+	str := fmt.Sprintf("%s%s%d%d%s-%s", ct.DIP.String(), ct.SIP.String(), ct.Dport, ct.Sport, ct.Proto, ct.CState)
+	return str
+}
+
 // String - stringify the given DpCtInfo
 func (ct *DpCtInfo) String() string {
 	str := fmt.Sprintf("%s:%d->%s:%d (%s), ", ct.SIP.String(), ct.Sport, ct.DIP.String(), ct.Dport, ct.Proto)

loxinet/dpebpf_linux.go

@@ -37,6 +37,7 @@ package loxinet
 int bpf_map_get_next_key(int fd, const void *key, void *next_key);
 int bpf_map_lookup_elem(int fd, const void *key, void *value);
 extern void goMapNotiHandler(struct ll_dp_map_notif *);
+extern void goLinuxArpResolver(unsigned int);
 #cgo CFLAGS:  -I./../loxilb-ebpf/libbpf/src/ -I./../loxilb-ebpf/common
 #cgo LDFLAGS: -L. -L/lib64 -L./../loxilb-ebpf/kernel -L./../loxilb-ebpf/libbpf/src/build/usr/lib64/ -Wl,-rpath=/lib64/ -lloxilbdp -lbpf -lelf -lz
 */
@@ -1034,6 +1035,7 @@ func (e *DpEbpfH) DpStat(w *StatDpWorkQ) int {
 	switch {
 	case w.Name == MapNameNat4:
 		tbl = append(tbl, int(C.LL_DP_NAT_STATS_MAP))
+		sync = 1
 	case w.Name == MapNameBD:
 		tbl = append(tbl, int(C.LL_DP_BD_STATS_MAP), int(C.LL_DP_TX_BD_STATS_MAP))
 	case w.Name == MapNameRxBD:
@@ -2059,3 +2061,9 @@ func (e *DpEbpfH) DpRelLock() {
 func (e *DpEbpfH) DpTableGC() {
 	e.trigGC <- true
 }
+
+//export goLinuxArpResolver
+func goLinuxArpResolver(dIP C.uint) {
+	goDest := uint32(dIP)
+	ArpResolver(goDest)
+}

loxinet/rules.go

@@ -746,6 +746,8 @@ func (R *RuleH) GetNatLbRule() ([]cmn.LbRuleMod, error) {
 			ret.Serv.Proto = "icmp"
 		} else if data.tuples.l4Prot.val == 132 {
 			ret.Serv.Proto = "sctp"
+		} else if data.tuples.l4Prot.val == 0 {
+			ret.Serv.Proto = "none"
 		} else {
 			return []cmn.LbRuleMod{}, errors.New("malformed service proto")
 		}
@@ -907,6 +909,8 @@ func (R *RuleH) GetNatLbRuleByServArgs(serv cmn.LbServiceArg) *ruleEnt {
 		ipProto = 1
 	} else if serv.Proto == "sctp" {
 		ipProto = 132
+	} else if serv.Proto == "none" {
+		ipProto = 0
 	} else {
 		return nil
 	}
@@ -1252,6 +1256,8 @@ func (R *RuleH) AddNatLbRule(serv cmn.LbServiceArg, servSecIPs []cmn.LbSecIPArg,
 		ipProto = 1
 	} else if serv.Proto == "sctp" {
 		ipProto = 132
+	} else if serv.Proto == "none" {
+		ipProto = 0
 	} else {
 		return RuleUnknownServiceErr, errors.New("malformed-proto error")
 	}
@@ -1483,6 +1489,8 @@ func (R *RuleH) DeleteNatLbRule(serv cmn.LbServiceArg) (int, error) {
 		ipProto = 1
 	} else if serv.Proto == "sctp" {
 		ipProto = 132
+	} else if serv.Proto == "none" {
+		ipProto = 0
 	} else {
 		return RuleUnknownServiceErr, errors.New("malformed-proto error")
 	}
@@ -2213,6 +2221,8 @@ func (R *RuleH) RuleDestructAll() {
 			lbs.Proto = "udp"
 		} else if r.tuples.l4Prot.val == 132 {
 			lbs.Proto = "sctp"
+		} else if r.tuples.l4Prot.val == 0 {
+			lbs.Proto = "none"
 		} else {
 			continue
 		}

loxinet/utils.go

@@ -24,7 +24,6 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
-	tk "github.com/loxilb-io/loxilib"
 	"io/ioutil"
 	"net"
 	"net/http"
@@ -34,6 +33,10 @@ import (
 	"strings"
 	"syscall"
 	"time"
+	"unsafe"
+
+	tk "github.com/loxilb-io/loxilib"
+	nlp "github.com/vishvananda/netlink"
 )
 
 // IterIntf - interface implementation to iterate various loxinet
@@ -341,3 +344,150 @@ func FormatTimedelta(t time.Time) string {
 	}
 	return fmt.Sprintf("%dd ", days) + fmt.Sprintf("%02d:%02d:%02d", hours, mins, secs)
 }
+
+// Ntohll - Network to host byte-order long long
+func Ntohll(i uint64) uint64 {
+	return binary.BigEndian.Uint64((*(*[8]byte)(unsafe.Pointer(&i)))[:])
+}
+
+// GetIfaceIpAddr - Get interface IP address
+func GetIfaceIpAddr(ifName string) (addr net.IP, err error) {
+	var (
+		ief    *net.Interface
+		addrs  []net.Addr
+		ipAddr net.IP
+	)
+	if ief, err = net.InterfaceByName(ifName); err != nil {
+		return
+	}
+	if addrs, err = ief.Addrs(); err != nil {
+		return
+	}
+	for _, addr := range addrs {
+		if ipAddr = addr.(*net.IPNet).IP.To4(); ipAddr != nil {
+			break
+		}
+	}
+	if ipAddr == nil {
+		return nil, errors.New(fmt.Sprintf("%s - no ipv4 address\n", ifName))
+	}
+	return ipAddr, nil
+}
+
+// SendArpReq - sends a  arp request given the DIP, SIP and interface name
+func SendArpReq(AdvIP net.IP, ifName string) (int, error) {
+	zeroAddr := []byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
+
+	srcIP, err := GetIfaceIpAddr(ifName)
+	if err != nil {
+		return -1, errors.New(fmt.Sprintf("%s", err))
+	}
+	fd, err := syscall.Socket(syscall.AF_PACKET, syscall.SOCK_DGRAM, int(tk.Htons(syscall.ETH_P_ARP)))
+	if err != nil {
+		return -1, errors.New("af-packet-err")
+	}
+	defer syscall.Close(fd)
+
+	if err := syscall.BindToDevice(fd, ifName); err != nil {
+		return -1, errors.New("bind-err")
+	}
+
+	ifi, err := net.InterfaceByName(ifName)
+	if err != nil {
+		return -1, errors.New("intf-err")
+	}
+
+	ll := syscall.SockaddrLinklayer{
+		Protocol: tk.Htons(syscall.ETH_P_ARP),
+		Ifindex:  ifi.Index,
+		Pkttype:  0, // syscall.PACKET_HOST
+		Hatype:   1,
+		Halen:    6,
+	}
+
+	for i := 0; i < 8; i++ {
+		ll.Addr[i] = 0xff
+	}
+
+	buf := new(bytes.Buffer)
+
+	var sb = make([]byte, 2)
+	binary.BigEndian.PutUint16(sb, 1) // HwType = 1
+	buf.Write(sb)
+
+	binary.BigEndian.PutUint16(sb, 0x0800) // protoType
+	buf.Write(sb)
+
+	buf.Write([]byte{6}) // hwAddrLen
+	buf.Write([]byte{4}) // protoAddrLen
+
+	binary.BigEndian.PutUint16(sb, 0x1) // OpCode
+	buf.Write(sb)
+
+	buf.Write(ifi.HardwareAddr) // senderHwAddr
+	buf.Write(srcIP.To4())      // senderProtoAddr
+
+	buf.Write(zeroAddr)    // targetHwAddr
+	buf.Write(AdvIP.To4()) // targetProtoAddr
+
+	if err := syscall.Bind(fd, &ll); err != nil {
+		return -1, errors.New("bind-err")
+	}
+	if err := syscall.Sendto(fd, buf.Bytes(), 0, &ll); err != nil {
+		return -1, errors.New("send-err")
+	}
+
+	return 0, nil
+}
+
+// ArpReqWithCtx - sends a arp req given the DIP, SIP and interface name
+func ArpReqWithCtx(ctx context.Context, rCh chan<- int, AdvIP net.IP, ifName string) (int, error) {
+	for {
+		select {
+		case <-ctx.Done():
+			return -1, ctx.Err()
+		default:
+			ret, _ := SendArpReq(AdvIP, ifName)
+			rCh <- ret
+			return 0, nil
+		}
+	}
+}
+
+func ArpResolver(dIP uint32) {
+	var gw net.IP
+	var ifName string
+	dest := tk.NltoIP(dIP)
+
+	routes, err := nlp.RouteGet(dest)
+	if err != nil {
+		return
+	}
+
+	for _, r := range routes {
+		if r.Gw == nil {
+			gw = r.Dst.IP
+		} else {
+			gw = r.Gw
+		}
+		if gw == nil {
+			continue
+		}
+		link, err := nlp.LinkByIndex(r.LinkIndex)
+		if err != nil {
+			return
+		}
+		ifName = link.Attrs().Name
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer cancel()
+		rCh := make(chan int)
+		go ArpReqWithCtx(ctx, rCh, gw, ifName)
+		select {
+		case <-rCh:
+			break
+		case <-ctx.Done():
+			tk.LogIt(tk.LogInfo, "%s - iface %s : ARP timeout\n", gw.String(), ifName)
+		}
+		return
+	}
+}