1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build darwin dragonfly freebsd linux netbsd openbsd solaris nacl 6 7 // Read system port mappings from /etc/services 8 9 package net 10 11 import "sync" 12 13 var onceReadServices sync.Once 14 15 func readServices() { 16 file, err := open("/etc/services") 17 if err != nil { 18 return 19 } 20 defer file.close() 21 22 for line, ok := file.readLine(); ok; line, ok = file.readLine() { 23 // "http 80/tcp www www-http # World Wide Web HTTP" 24 if i := byteIndex(line, '#'); i >= 0 { 25 line = line[:i] 26 } 27 f := getFields(line) 28 if len(f) < 2 { 29 continue 30 } 31 portnet := f[1] // "80/tcp" 32 port, j, ok := dtoi(portnet) 33 if !ok || port <= 0 || j >= len(portnet) || portnet[j] != '/' { 34 continue 35 } 36 netw := portnet[j+1:] // "tcp" 37 m, ok1 := services[netw] 38 if !ok1 { 39 m = make(map[string]int) 40 services[netw] = m 41 } 42 for i := 0; i < len(f); i++ { 43 if i != 1 { // f[1] was port/net 44 m[f[i]] = port 45 } 46 } 47 } 48 } 49 50 // goLookupPort is the native Go implementation of LookupPort. 51 func goLookupPort(network, service string) (port int, err error) { 52 onceReadServices.Do(readServices) 53 return lookupPortMap(network, service) 54 } 55
