fix: iSCSI login and discovery bugs found in WSL2 smoke test

- Skip InitiatorAlias in negotiation (was returning NotUnderstood)
- Capture TargetName in StageLoginOp direct-jump path (iscsiadm skips
  security stage, sends CSG=LoginOp directly -- nil SCSIHandler crash)
- Add portalAddr to TargetServer for discovery responses (listener on
  [::] is not routable from WSL2 clients)
- Add -portal flag to iscsi-target binary

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

weed/storage/blockvol/iscsi/cmd/iscsi-target/main.go

@@ -22,9 +22,10 @@ import (
 func main() {
 	volPath := flag.String("vol", "", "path to BlockVol file")
 	addr := flag.String("addr", ":3260", "listen address")
+	portal := flag.String("portal", "", "advertised address for discovery (e.g. 10.0.0.1:3260,1)")
 	iqn := flag.String("iqn", "iqn.2024.com.seaweedfs:vol1", "target IQN")
 	create := flag.Bool("create", false, "create a new volume file")
-	size := flag.String("size", "1G", "volume size (e.g., 1G, 100M) — used with -create")
+	size := flag.String("size", "1G", "volume size (e.g., 1G, 100M) -- used with -create")
 	flag.Parse()
 
 	if *volPath == "" {
@@ -73,6 +74,9 @@ func main() {
 	config.TargetName = *iqn
 	config.TargetAlias = "SeaweedFS BlockVol"
 	ts := iscsi.NewTargetServer(*addr, config, logger)
+	if *portal != "" {
+		ts.SetPortalAddr(*portal)
+	}
 	ts.AddVolume(*iqn, adapter)
 
 	// Graceful shutdown on signal

weed/storage/blockvol/iscsi/login.go

@@ -216,6 +216,27 @@ func (ln *LoginNegotiator) HandleLoginPDU(req *PDU, resolver TargetResolver) *PD
 					setLoginReject(resp, LoginStatusInitiatorErr, LoginDetailMissingParam)
 					return resp
 				}
+				// Session type
+				if st, ok := params.Get("SessionType"); ok {
+					ln.SessionType = st
+				}
+				if ln.SessionType == "" {
+					ln.SessionType = "Normal"
+				}
+				// Target name (required for Normal sessions)
+				if tn, ok := params.Get("TargetName"); ok {
+					if ln.SessionType == "Normal" {
+						if resolver == nil || !resolver.HasTarget(tn) {
+							setLoginReject(resp, LoginStatusInitiatorErr, LoginDetailNotFound)
+							return resp
+						}
+					}
+					ln.TargetName = tn
+					ln.targetOK = true
+				} else if ln.SessionType == "Normal" && !ln.targetOK {
+					setLoginReject(resp, LoginStatusInitiatorErr, LoginDetailMissingParam)
+					return resp
+				}
 			} else {
 				setLoginReject(resp, LoginStatusInitiatorErr, LoginDetailInitiatorError)
 				return resp
@@ -319,9 +340,9 @@ func (ln *LoginNegotiator) negotiateParams(req *Params, resp *Params) {
 		case "DataDigest":
 			resp.Set(key, "None")
 		case "TargetName", "InitiatorName", "SessionType", "AuthMethod":
-			// Already handled or declarative — skip
-		case "TargetAlias":
-			// Informational from initiator — skip
+			// Already handled or declarative -- skip
+		case "TargetAlias", "InitiatorAlias":
+			// Informational -- skip
 		default:
 			// Unknown keys: respond with NotUnderstood
 			resp.Set(key, "NotUnderstood")

weed/storage/blockvol/iscsi/target.go

@@ -17,11 +17,12 @@ var (
 // TargetServer manages the iSCSI target: TCP listener, volume registry,
 // and active sessions.
 type TargetServer struct {
-	mu       sync.RWMutex
-	listener net.Listener
-	config   TargetConfig
-	volumes  map[string]BlockDevice // target IQN -> device
-	addr     string
+	mu           sync.RWMutex
+	listener     net.Listener
+	config       TargetConfig
+	volumes      map[string]BlockDevice // target IQN -> device
+	addr         string
+	portalAddr   string // advertised address for discovery (if empty, uses listener addr)
 
 	// Active session tracking for graceful shutdown
 	activeMu sync.Mutex
@@ -72,15 +73,28 @@ func (ts *TargetServer) HasTarget(name string) bool {
 	return ok
 }
 
+// SetPortalAddr sets the address advertised in discovery responses.
+// Use this when the listen address is 0.0.0.0 or [::] and clients
+// need a routable IP. Format: "ip:port,portal-group" (e.g. "10.0.0.1:3260,1").
+func (ts *TargetServer) SetPortalAddr(addr string) {
+	ts.mu.Lock()
+	defer ts.mu.Unlock()
+	ts.portalAddr = addr
+}
+
 // ListTargets implements TargetLister.
 func (ts *TargetServer) ListTargets() []DiscoveryTarget {
 	ts.mu.RLock()
 	defer ts.mu.RUnlock()
+	addr := ts.portalAddr
+	if addr == "" {
+		addr = ts.ListenAddr()
+	}
 	targets := make([]DiscoveryTarget, 0, len(ts.volumes))
 	for iqn := range ts.volumes {
 		targets = append(targets, DiscoveryTarget{
 			Name:    iqn,
-			Address: ts.ListenAddr(),
+			Address: addr,
 		})
 	}
 	return targets