//go:build darwin || freebsd package aghnet import ( "bufio" "net" "net/netip" "strings" "sync" "github.com/AdguardTeam/golibs/log" "github.com/AdguardTeam/golibs/netutil" ) func newARPDB() (arp *cmdARPDB) { return &cmdARPDB{ parse: parseArpA, ns: &neighs{ mu: &sync.RWMutex{}, ns: make([]Neighbor, 0), }, cmd: "arp", // Use -n flag to avoid resolving the hostnames of the neighbors. By // default ARP attempts to resolve the hostnames via DNS. See man 8 // arp. // // See also https://github.com/AdguardTeam/AdGuardHome/issues/3157. args: []string{"-a", "-n"}, } } // parseArpA parses the output of the "arp -a -n" command on macOS and FreeBSD. // The expected input format: // // host.name (192.168.0.1) at ff:ff:ff:ff:ff:ff on en0 ifscope [ethernet] func parseArpA(sc *bufio.Scanner, lenHint int) (ns []Neighbor) { ns = make([]Neighbor, 0, lenHint) for sc.Scan() { ln := sc.Text() fields := strings.Fields(ln) if len(fields) < 4 { continue } n := Neighbor{} if ipStr := fields[1]; len(ipStr) < 2 { continue } else if ip, err := netip.ParseAddr(ipStr[1 : len(ipStr)-1]); err != nil { log.Debug("arpdb: parsing arp output: ip: %s", err) continue } else { n.IP = ip } hwStr := fields[3] mac, err := net.ParseMAC(hwStr) if err != nil { log.Debug("arpdb: parsing arp output: mac: %s", err) continue } else { n.MAC = mac } host := fields[0] err = netutil.ValidateDomainName(host) if err != nil { log.Debug("arpdb: parsing arp output: host: %s", err) } else { n.Name = host } ns = append(ns, n) } return ns }