Initial commit: IT Nexus Web-App

nexus-scanner/internal/modules/macvendor/macvendor.go

@@ -0,0 +1,129 @@
+// Package macvendor implements the mac_vendor module.
+// It maps the OUI (first 3 bytes) of every known host's MAC address to a
+// human-readable vendor name and persists the result in the database.
+// The mapping is based on a built-in table; no external files are required.
+package macvendor
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"strings"
+	"time"
+
+	"github.com/cereda-systems/nexus-scanner/internal/db"
+)
+
+// ouiTable maps lowercase OUI prefixes (aa:bb:cc) to vendor names.
+// Broadcast / multicast entries are intentionally kept with an empty string
+// so they are recognised but not written to the database.
+var ouiTable = map[string]string{
+	"00:0c:29": "VMware",
+	"00:50:56": "VMware",
+	"bc:24:11": "Proxmox/Ceph",
+	"90:1b:0e": "Supermicro",
+	"90:09:d0": "Synology",
+	"00:17:c8": "Hewlett-Packard",
+	"00:be:43": "Ubiquiti",
+	"e4:43:4b": "Ubiquiti",
+	"24:6a:0e": "Ubiquiti",
+	"40:86:cb": "Intel",
+	"68:c6:ac": "Intel",
+	"1c:af:4a": "Dell",
+	"50:81:40": "Dell",
+	"4c:5f:70": "Lenovo",
+	"dc:58:bc": "Apple",
+	"c8:4b:d6": "Kyocera",
+	"38:d5:7a": "Samsung",
+	"00:04:a5": "Barco",
+	"7c:5a:1c": "LANCOM",
+	"00:0a:b3": "Cisco",
+	"00:e0:67": "Aten",
+	"ff:ff:ff": "", // broadcast — leave vendor empty
+}
+
+// LookupVendor returns the vendor name for a MAC address.
+// The MAC must be in the format aa:bb:cc:dd:ee:ff (colon-separated).
+// An empty string is returned when no match is found.
+func LookupVendor(mac string) string {
+	if len(mac) < 8 {
+		return ""
+	}
+	oui := strings.ToLower(mac[:8])
+	return ouiTable[oui]
+}
+
+// Module enriches hosts in the database with OUI-based vendor names.
+type Module struct {
+	site  string
+	store *db.Store
+	log   *slog.Logger
+}
+
+// New returns a new mac_vendor module.
+func New(site string, store *db.Store) *Module {
+	return &Module{
+		site:  site,
+		store: store,
+		log:   slog.With("module", "mac_vendor"),
+	}
+}
+
+func (m *Module) Name() string { return "mac_vendor" }
+
+// Interval returns 0, which causes the scheduler to run this module once at
+// startup and never repeat it automatically.
+func (m *Module) Interval() time.Duration { return 0 }
+
+// Run assigns vendor names to all hosts that have none recorded yet.
+func (m *Module) Run(ctx context.Context) error {
+	scanID, err := m.store.BeginScan(m.Name())
+	if err != nil {
+		return fmt.Errorf("begin scan: %w", err)
+	}
+
+	scanErr := m.scan(ctx)
+	if endErr := m.store.EndScan(scanID, scanErr); endErr != nil {
+		m.log.Error("record scan end", "err", endErr)
+	}
+	return scanErr
+}
+
+func (m *Module) scan(ctx context.Context) error {
+	hosts, err := m.store.ListHosts("")
+	if err != nil {
+		return fmt.Errorf("list hosts: %w", err)
+	}
+
+	enriched := 0
+	for _, h := range hosts {
+		// Skip hosts that already have a vendor assigned.
+		if h.Vendor != "" {
+			continue
+		}
+
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
+		}
+
+		vendor := LookupVendor(h.MAC)
+		if vendor == "" {
+			// No entry in our table — leave vendor empty.
+			continue
+		}
+
+		h.Vendor = vendor
+		if err := m.store.UpsertHost(h); err != nil {
+			m.log.Error("upsert host", "ip", h.IP, "err", err)
+			continue
+		}
+
+		m.log.Info("vendor resolved", "ip", h.IP, "mac", h.MAC, "vendor", vendor)
+		enriched++
+	}
+
+	m.log.Info("scan complete", "checked", len(hosts), "enriched", enriched)
+	return nil
+}