1 files changed, 168 insertions, 0 deletions
diff --git a/src/net/lookup_unix.go b/src/net/lookup_unix.go
new file mode 100644
index 000000000..a54578456
--- /dev/null
+++ b/src/net/lookup_unix.go
@@ -0,0 +1,168 @@
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package net
+
+import (
+	"errors"
+	"sync"
+)
+
+var onceReadProtocols sync.Once
+
+// readProtocols loads contents of /etc/protocols into protocols map
+// for quick access.
+func readProtocols() {
+	if file, err := open("/etc/protocols"); err == nil {
+		for line, ok := file.readLine(); ok; line, ok = file.readLine() {
+			// tcp    6   TCP    # transmission control protocol
+			if i := byteIndex(line, '#'); i >= 0 {
+				line = line[0:i]
+			}
+			f := getFields(line)
+			if len(f) < 2 {
+				continue
+			}
+			if proto, _, ok := dtoi(f[1], 0); ok {
+				if _, ok := protocols[f[0]]; !ok {
+					protocols[f[0]] = proto
+				}
+				for _, alias := range f[2:] {
+					if _, ok := protocols[alias]; !ok {
+						protocols[alias] = proto
+					}
+				}
+			}
+		}
+		file.close()
+	}
+}
+
+// lookupProtocol looks up IP protocol name in /etc/protocols and
+// returns correspondent protocol number.
+func lookupProtocol(name string) (proto int, err error) {
+	onceReadProtocols.Do(readProtocols)
+	proto, found := protocols[name]
+	if !found {
+		return 0, errors.New("unknown IP protocol specified: " + name)
+	}
+	return
+}
+
+func lookupHost(host string) (addrs []string, err error) {
+	addrs, err, ok := cgoLookupHost(host)
+	if !ok {
+		addrs, err = goLookupHost(host)
+	}
+	return
+}
+
+func lookupIP(host string) (addrs []IP, err error) {
+	addrs, err, ok := cgoLookupIP(host)
+	if !ok {
+		addrs, err = goLookupIP(host)
+	}
+	return
+}
+
+func lookupPort(network, service string) (port int, err error) {
+	port, err, ok := cgoLookupPort(network, service)
+	if !ok {
+		port, err = goLookupPort(network, service)
+	}
+	return
+}
+
+func lookupCNAME(name string) (cname string, err error) {
+	cname, err, ok := cgoLookupCNAME(name)
+	if !ok {
+		cname, err = goLookupCNAME(name)
+	}
+	return
+}
+
+func lookupSRV(service, proto, name string) (cname string, addrs []*SRV, err error) {
+	var target string
+	if service == "" && proto == "" {
+		target = name
+	} else {
+		target = "_" + service + "._" + proto + "." + name
+	}
+	var records []dnsRR
+	cname, records, err = lookup(target, dnsTypeSRV)
+	if err != nil {
+		return
+	}
+	addrs = make([]*SRV, len(records))
+	for i, rr := range records {
+		r := rr.(*dnsRR_SRV)
+		addrs[i] = &SRV{r.Target, r.Port, r.Priority, r.Weight}
+	}
+	byPriorityWeight(addrs).sort()
+	return
+}
+
+func lookupMX(name string) (mx []*MX, err error) {
+	_, records, err := lookup(name, dnsTypeMX)
+	if err != nil {
+		return
+	}
+	mx = make([]*MX, len(records))
+	for i, rr := range records {
+		r := rr.(*dnsRR_MX)
+		mx[i] = &MX{r.Mx, r.Pref}
+	}
+	byPref(mx).sort()
+	return
+}
+
+func lookupNS(name string) (ns []*NS, err error) {
+	_, records, err := lookup(name, dnsTypeNS)
+	if err != nil {
+		return
+	}
+	ns = make([]*NS, len(records))
+	for i, r := range records {
+		r := r.(*dnsRR_NS)
+		ns[i] = &NS{r.Ns}
+	}
+	return
+}
+
+func lookupTXT(name string) (txt []string, err error) {
+	_, records, err := lookup(name, dnsTypeTXT)
+	if err != nil {
+		return
+	}
+	txt = make([]string, len(records))
+	for i, r := range records {
+		txt[i] = r.(*dnsRR_TXT).Txt
+	}
+	return
+}
+
+func lookupAddr(addr string) (name []string, err error) {
+	name = lookupStaticAddr(addr)
+	if len(name) > 0 {
+		return
+	}
+	var arpa string
+	arpa, err = reverseaddr(addr)
+	if err != nil {
+		return
+	}
+	var records []dnsRR
+	_, records, err = lookup(arpa, dnsTypePTR)
+	if err != nil {
+		return
+	}
+	name = make([]string, len(records))
+	for i := range records {
+		r := records[i].(*dnsRR_PTR)
+		name[i] = r.Ptr
+	}
+	return
+}