AdGuardHome/internal/aghnet/arpdb_openbsd.go
2022-11-02 16:18:02 +03:00

76 lines
1.4 KiB
Go

//go:build openbsd
package aghnet
import (
"bufio"
"net"
"net/netip"
"strings"
"sync"
"github.com/AdguardTeam/golibs/log"
)
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 OpenBSD. The
// expected input format:
//
// Host Ethernet Address Netif Expire Flags
// 192.168.1.1 ab:cd:ef:ab:cd:ef em0 19m59s
func parseArpA(sc *bufio.Scanner, lenHint int) (ns []Neighbor) {
// Skip the header.
if !sc.Scan() {
return nil
}
ns = make([]Neighbor, 0, lenHint)
for sc.Scan() {
ln := sc.Text()
fields := strings.Fields(ln)
if len(fields) < 2 {
continue
}
n := Neighbor{}
ip, err := netip.ParseAddr(fields[0])
if err != nil {
log.Debug("arpdb: parsing arp output: ip: %s", err)
continue
} else {
n.IP = ip
}
mac, err := net.ParseMAC(fields[1])
if err != nil {
log.Debug("arpdb: parsing arp output: mac: %s", err)
continue
} else {
n.MAC = mac
}
ns = append(ns, n)
}
return ns
}