net: implement ip protocol name to number resolver for windows

Fixes #2215.
Fixes #2216.

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/5248055

src/pkg/net/ipraw_test.go

@@ -11,6 +11,7 @@ import (
 	"bytes"
 	"flag"
 	"os"
+	"runtime"
 	"testing"
 )
 
@@ -64,7 +65,7 @@ var dsthost = flag.String("dsthost", "127.0.0.1", "Destination for the ICMP ECHO
 
 // test (raw) IP socket using ICMP
 func TestICMP(t *testing.T) {
-	if os.Getuid() != 0 {
+	if runtime.GOOS != "windows" && os.Getuid() != 0 {
 		t.Logf("test disabled; must be root")
 		return
 	}

src/pkg/net/iprawsock_posix.go

@@ -10,12 +10,9 @@ package net
 
 import (
 	"os"
-	"sync"
 	"syscall"
 )
 
-var onceReadProtocols sync.Once
-
 func sockaddrToIP(sa syscall.Sockaddr) Addr {
 	switch sa := sa.(type) {
 	case *syscall.SockaddrInet4:
@@ -209,33 +206,7 @@ func (c *IPConn) WriteTo(b []byte, addr Addr) (n int, err os.Error) {
 	return c.WriteToIP(b, a)
 }
 
-var protocols map[string]int
-
-func readProtocols() {
-	protocols = make(map[string]int)
-	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 {
-				protocols[f[0]] = proto
-				for _, alias := range f[2:] {
-					protocols[alias] = proto
-				}
-			}
-		}
-		file.close()
-	}
-}
-
 func splitNetProto(netProto string) (net string, proto int, err os.Error) {
-	onceReadProtocols.Do(readProtocols)
 	i := last(netProto, ':')
 	if i < 0 { // no colon
 		return "", 0, os.NewError("no IP protocol specified")
@@ -244,13 +215,12 @@ func splitNetProto(netProto string) (net string, proto int, err os.Error) {
 	protostr := netProto[i+1:]
 	proto, i, ok := dtoi(protostr, 0)
 	if !ok || i != len(protostr) {
-		// lookup by name
-		proto, ok = protocols[protostr]
-		if ok {
-			return
+		proto, err = lookupProtocol(protostr)
+		if err != nil {
+			return "", 0, err
 		}
 	}
-	return
+	return net, proto, nil
 }
 
 // DialIP connects to the remote address raddr on the network net,

src/pkg/net/lookup_unix.go

@@ -8,8 +8,50 @@ package net
 
 import (
 	"os"
+	"sync"
 )
 
+var (
+	protocols         map[string]int
+	onceReadProtocols sync.Once
+)
+
+// readProtocols loads contents of /etc/protocols into protocols map
+// for quick access.
+func readProtocols() {
+	protocols = make(map[string]int)
+	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 {
+				protocols[f[0]] = proto
+				for _, alias := range f[2:] {
+					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 os.Error) {
+	onceReadProtocols.Do(readProtocols)
+	proto, found := protocols[name]
+	if !found {
+		return 0, os.NewError("unknown IP protocol specified: " + name)
+	}
+	return
+}
+
 // LookupHost looks up the given host using the local resolver.
 // It returns an array of that host's addresses.
 func LookupHost(host string) (addrs []string, err os.Error) {

src/pkg/net/lookup_windows.go

@@ -11,8 +11,22 @@ import (
 	"sync"
 )
 
-var hostentLock sync.Mutex
-var serventLock sync.Mutex
+var (
+	protoentLock sync.Mutex
+	hostentLock  sync.Mutex
+	serventLock  sync.Mutex
+)
+
+// lookupProtocol looks up IP protocol name and returns correspondent protocol number.
+func lookupProtocol(name string) (proto int, err os.Error) {
+	protoentLock.Lock()
+	defer protoentLock.Unlock()
+	p, e := syscall.GetProtoByName(name)
+	if e != 0 {
+		return 0, os.NewSyscallError("GetProtoByName", e)
+	}
+	return int(p.Proto), nil
+}
 
 func LookupHost(name string) (addrs []string, err os.Error) {
 	ips, err := LookupIP(name)

src/pkg/syscall/syscall_windows.go

@@ -502,6 +502,7 @@ func Chmod(path string, mode uint32) (errno int) {
 //sys	GetHostByName(name string) (h *Hostent, errno int) [failretval==nil] = ws2_32.gethostbyname
 //sys	GetServByName(name string, proto string) (s *Servent, errno int) [failretval==nil] = ws2_32.getservbyname
 //sys	Ntohs(netshort uint16) (u uint16) = ws2_32.ntohs
+//sys	GetProtoByName(name string) (p *Protoent, errno int) [failretval==nil] = ws2_32.getprotobyname
 //sys	DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status uint32) = dnsapi.DnsQuery_W
 //sys	DnsRecordListFree(rl *DNSRecord, freetype uint32) = dnsapi.DnsRecordListFree
 //sys	GetIfEntry(pIfRow *MibIfRow) (errcode int) = iphlpapi.GetIfEntry

src/pkg/syscall/zsyscall_windows_386.go

@@ -101,6 +101,7 @@ var (
 	procgethostbyname              = modws2_32.NewProc("gethostbyname")
 	procgetservbyname              = modws2_32.NewProc("getservbyname")
 	procntohs                      = modws2_32.NewProc("ntohs")
+	procgetprotobyname             = modws2_32.NewProc("getprotobyname")
 	procDnsQuery_W                 = moddnsapi.NewProc("DnsQuery_W")
 	procDnsRecordListFree          = moddnsapi.NewProc("DnsRecordListFree")
 	procGetIfEntry                 = modiphlpapi.NewProc("GetIfEntry")
@@ -1314,6 +1315,21 @@ func Ntohs(netshort uint16) (u uint16) {
 	return
 }
 
+func GetProtoByName(name string) (p *Protoent, errno int) {
+	r0, _, e1 := Syscall(procgetprotobyname.Addr(), 1, uintptr(unsafe.Pointer(StringBytePtr(name))), 0, 0)
+	p = (*Protoent)(unsafe.Pointer(r0))
+	if p == nil {
+		if e1 != 0 {
+			errno = int(e1)
+		} else {
+			errno = EINVAL
+		}
+	} else {
+		errno = 0
+	}
+	return
+}
+
 func DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status uint32) {
 	r0, _, _ := Syscall6(procDnsQuery_W.Addr(), 6, uintptr(unsafe.Pointer(StringToUTF16Ptr(name))), uintptr(qtype), uintptr(options), uintptr(unsafe.Pointer(extra)), uintptr(unsafe.Pointer(qrs)), uintptr(unsafe.Pointer(pr)))
 	status = uint32(r0)

src/pkg/syscall/zsyscall_windows_amd64.go

@@ -101,6 +101,7 @@ var (
 	procgethostbyname              = modws2_32.NewProc("gethostbyname")
 	procgetservbyname              = modws2_32.NewProc("getservbyname")
 	procntohs                      = modws2_32.NewProc("ntohs")
+	procgetprotobyname             = modws2_32.NewProc("getprotobyname")
 	procDnsQuery_W                 = moddnsapi.NewProc("DnsQuery_W")
 	procDnsRecordListFree          = moddnsapi.NewProc("DnsRecordListFree")
 	procGetIfEntry                 = modiphlpapi.NewProc("GetIfEntry")
@@ -1314,6 +1315,21 @@ func Ntohs(netshort uint16) (u uint16) {
 	return
 }
 
+func GetProtoByName(name string) (p *Protoent, errno int) {
+	r0, _, e1 := Syscall(procgetprotobyname.Addr(), 1, uintptr(unsafe.Pointer(StringBytePtr(name))), 0, 0)
+	p = (*Protoent)(unsafe.Pointer(r0))
+	if p == nil {
+		if e1 != 0 {
+			errno = int(e1)
+		} else {
+			errno = EINVAL
+		}
+	} else {
+		errno = 0
+	}
+	return
+}
+
 func DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status uint32) {
 	r0, _, _ := Syscall6(procDnsQuery_W.Addr(), 6, uintptr(unsafe.Pointer(StringToUTF16Ptr(name))), uintptr(qtype), uintptr(options), uintptr(unsafe.Pointer(extra)), uintptr(unsafe.Pointer(qrs)), uintptr(unsafe.Pointer(pr)))
 	status = uint32(r0)

src/pkg/syscall/ztypes_windows.go

@@ -411,6 +411,12 @@ type Hostent struct {
 	AddrList **byte
 }
 
+type Protoent struct {
+	Name    *byte
+	Aliases **byte
+	Proto   uint16
+}
+
 const (
 	DNS_TYPE_A       = 0x0001
 	DNS_TYPE_NS      = 0x0002