Refactor stations discovery and add hostapd discovery

internal/station/hostapd/correlation.go

@@ -0,0 +1,130 @@
+package hostapd
+
+import (
+	"bufio"
+	"log"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/nemunaire/repeater/internal/models"
+)
+
+// DHCPCorrelator helps correlate hostapd stations with DHCP leases to discover IP addresses
+type DHCPCorrelator struct {
+	backend        *Backend
+	dhcpLeasesPath string
+	stopChan       chan struct{}
+	running        bool
+}
+
+// NewDHCPCorrelator creates a new DHCP correlator
+func NewDHCPCorrelator(backend *Backend, dhcpLeasesPath string) *DHCPCorrelator {
+	if dhcpLeasesPath == "" {
+		dhcpLeasesPath = "/var/lib/dhcp/dhcpd.leases"
+	}
+
+	return &DHCPCorrelator{
+		backend:        backend,
+		dhcpLeasesPath: dhcpLeasesPath,
+		stopChan:       make(chan struct{}),
+	}
+}
+
+// Start begins periodic correlation of DHCP leases with hostapd stations
+func (dc *DHCPCorrelator) Start() {
+	if dc.running {
+		return
+	}
+
+	dc.running = true
+	go dc.correlationLoop()
+	log.Printf("DHCP correlation started for hostapd backend")
+}
+
+// Stop stops the correlation loop
+func (dc *DHCPCorrelator) Stop() {
+	if !dc.running {
+		return
+	}
+
+	dc.running = false
+	close(dc.stopChan)
+	log.Printf("DHCP correlation stopped")
+}
+
+// correlationLoop periodically correlates DHCP leases with stations
+func (dc *DHCPCorrelator) correlationLoop() {
+	// Do an initial correlation immediately
+	dc.correlate()
+
+	// Then correlate every 10 seconds
+	ticker := time.NewTicker(10 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			dc.correlate()
+		case <-dc.stopChan:
+			return
+		}
+	}
+}
+
+// correlate performs one correlation cycle
+func (dc *DHCPCorrelator) correlate() {
+	// Parse DHCP leases
+	leases, err := parseDHCPLeases(dc.dhcpLeasesPath)
+	if err != nil {
+		log.Printf("Warning: Failed to parse DHCP leases: %v", err)
+		return
+	}
+
+	// Build MAC -> IP mapping
+	macToIP := make(map[string]string)
+	for _, lease := range leases {
+		macToIP[lease.MAC] = lease.IP
+	}
+
+	// Update backend with IP mappings
+	dc.backend.UpdateIPMapping(macToIP)
+}
+
+// parseDHCPLeases reads and parses DHCP lease file
+func parseDHCPLeases(path string) ([]models.DHCPLease, error) {
+	var leases []models.DHCPLease
+
+	file, err := os.Open(path)
+	if err != nil {
+		return leases, err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	var currentLease models.DHCPLease
+
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+
+		if strings.HasPrefix(line, "lease ") {
+			ip := strings.Fields(line)[1]
+			currentLease = models.DHCPLease{IP: ip}
+		} else if strings.Contains(line, "hardware ethernet") {
+			mac := strings.Fields(line)[2]
+			mac = strings.TrimSuffix(mac, ";")
+			currentLease.MAC = mac
+		} else if strings.Contains(line, "client-hostname") {
+			hostname := strings.Fields(line)[1]
+			hostname = strings.Trim(hostname, `";`)
+			currentLease.Hostname = hostname
+		} else if line == "}" {
+			if currentLease.IP != "" && currentLease.MAC != "" {
+				leases = append(leases, currentLease)
+			}
+			currentLease = models.DHCPLease{}
+		}
+	}
+
+	return leases, scanner.Err()
+}