add node names from hostname, lldp, and snmp

populate local node name from hostname. extract system name from lldp packets and snmp sysname oid. call logtree after node merges.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

CLAUDE.md

@@ -6,4 +6,4 @@
 - Always push after commiting
 - Use git add -A so you don't miss files when committing
 - Never use go build -- use go run instead
-- Don't commit unless asked to
+- DO NOT commit unless asked to

lldp.go

@@ -55,7 +55,20 @@ func (t *Tendrils) handleLLDPPacket(ifaceName string, packet gopacket.Packet) {
 		mac := net.HardwareAddr(lldp.ChassisID.ID)
 		if !isBroadcastOrZero(mac) {
 			childPort := string(lldp.PortID.ID)
+
+			var systemName string
+			for _, opt := range lldp.Values {
+				if opt.Type == layers.LLDPTLVSysName {
+					systemName = string(opt.Value)
+					break
+				}
+			}
+
 			t.nodes.Update(nil, []net.HardwareAddr{mac}, ifaceName, childPort, "lldp")
+
+			if systemName != "" {
+				t.nodes.SetName(mac, systemName)
+			}
 		}
 	}
 }

nodes.go

@@ -9,6 +9,7 @@ import (
 )
 
 type Node struct {
+	Name       string
 	IPs        map[string]net.IP
 	MACs       map[string]net.HardwareAddr
 	ParentID   int
@@ -29,7 +30,12 @@ func (n *Node) String() string {
 	}
 	sort.Strings(ips)
 
-	return fmt.Sprintf("{macs=%v ips=%v}", macs, ips)
+	name := n.Name
+	if name == "" {
+		name = "??"
+	}
+
+	return fmt.Sprintf("%s {macs=%v ips=%v}", name, macs, ips)
 }
 
 type Nodes struct {
@@ -117,6 +123,9 @@ func (n *Nodes) UpdateWithParent(parentIP net.IP, ips []net.IP, macs []net.Hardw
 			n.mergeNodes(targetID, ids[i])
 		}
 		log.Printf("merged nodes %v into %s (via %s)", merging, n.nodes[targetID], source)
+		n.mu.Unlock()
+		n.LogTree()
+		n.mu.Lock()
 	}
 
 	node := n.nodes[targetID]
@@ -197,6 +206,18 @@ func (n *Nodes) GetByMAC(mac net.HardwareAddr) *Node {
 	return nil
 }
 
+func (n *Nodes) SetName(mac net.HardwareAddr, name string) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
+	if id, exists := n.macIndex[mac.String()]; exists {
+		node := n.nodes[id]
+		if node.Name == "" {
+			node.Name = name
+		}
+	}
+}
+
 func (n *Nodes) All() []*Node {
 	n.mu.RLock()
 	defer n.mu.RUnlock()
@@ -219,7 +240,7 @@ func (n *Nodes) logNode(id int, prefix string, isLast bool) {
 	node := n.nodes[id]
 
 	if id == 0 {
-		log.Printf("[root] %s", node)
+		log.Printf("%s", node)
 		n.logChildrenByInterface(id, "")
 	} else {
 		connector := "├──"

snmp.go

@@ -113,9 +113,40 @@ func (t *Tendrils) querySNMPDevice(ip net.IP) {
 	}
 	defer snmp.Conn.Close()
 
+	t.querySysName(snmp, ip)
 	t.queryBridgeMIB(snmp, ip)
 }
 
+func (t *Tendrils) querySysName(snmp *gosnmp.GoSNMP, deviceIP net.IP) {
+	oid := "1.3.6.1.2.1.1.5.0"
+
+	result, err := snmp.Get([]string{oid})
+	if err != nil {
+		return
+	}
+
+	if len(result.Variables) > 0 {
+		variable := result.Variables[0]
+		if variable.Type == gosnmp.OctetString {
+			sysName := string(variable.Value.([]byte))
+			if sysName != "" {
+				t.nodes.mu.RLock()
+				if id, exists := t.nodes.ipIndex[deviceIP.String()]; exists {
+					t.nodes.mu.RUnlock()
+					t.nodes.mu.Lock()
+					node := t.nodes.nodes[id]
+					if node.Name == "" {
+						node.Name = sysName
+					}
+					t.nodes.mu.Unlock()
+					return
+				}
+				t.nodes.mu.RUnlock()
+			}
+		}
+	}
+}
+
 func (t *Tendrils) queryBridgeMIB(snmp *gosnmp.GoSNMP, deviceIP net.IP) {
 	portOID := "1.3.6.1.2.1.17.7.1.2.2.1.2"
 

tendrils.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"log"
 	"net"
+	"os"
 	"time"
 )
 
@@ -49,6 +50,11 @@ func (t *Tendrils) populateLocalAddresses() {
 
 	root := t.nodes.nodes[0]
 
+	hostname, err := os.Hostname()
+	if err == nil {
+		root.Name = hostname
+	}
+
 	for _, iface := range interfaces {
 		if len(iface.HardwareAddr) > 0 {
 			macKey := iface.HardwareAddr.String()