undo CL 6395055 / 2518eee18c4f

Broke TCP selfConnect

««« original CL description
net: avoid nil pointer dereference when RemoteAddr.String method chain is called

Fixes #3721.

R=dave, rsc
CC=golang-dev
https://golang.org/cl/6395055
»»»

R=rsc
CC=golang-dev
https://golang.org/cl/6533043

src/pkg/net/fd_unix.go

@@ -615,7 +615,8 @@ func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (netfd *netFD, err e
 		closesocket(s)
 		return nil, err
 	}
-	netfd.setAddr(localSockname(fd, toAddr), toAddr(rsa))
+	lsa, _ := syscall.Getsockname(netfd.sysfd)
+	netfd.setAddr(toAddr(lsa), toAddr(rsa))
 	return netfd, nil
 }
 

src/pkg/net/file_unix.go

@@ -58,13 +58,15 @@ func newFileFD(f *os.File) (*netFD, error) {
 		}
 	}
 	laddr := toAddr(lsa)
+	rsa, _ := syscall.Getpeername(fd)
+	raddr := toAddr(rsa)
 
 	netfd, err := newFD(fd, family, sotype, laddr.Network())
 	if err != nil {
 		closesocket(fd)
 		return nil, err
 	}
-	netfd.setAddr(laddr, remoteSockname(netfd, toAddr))
+	netfd.setAddr(laddr, raddr)
 	return netfd, nil
 }
 

src/pkg/net/ipraw_test.go

@@ -14,55 +14,6 @@ import (
 	"time"
 )
 
-var ipConnAddrStringTests = []struct {
-	net   string
-	laddr string
-	raddr string
-	ipv6  bool
-}{
-	{"ip:icmp", "127.0.0.1", "", false},
-	{"ip:icmp", "::1", "", true},
-	{"ip:icmp", "", "127.0.0.1", false},
-	{"ip:icmp", "", "::1", true},
-}
-
-func TestIPConnAddrString(t *testing.T) {
-	if os.Getuid() != 0 {
-		t.Logf("skipping test; must be root")
-		return
-	}
-
-	for i, tt := range ipConnAddrStringTests {
-		if tt.ipv6 && !supportsIPv6 {
-			continue
-		}
-		var (
-			err  error
-			c    *IPConn
-			mode string
-		)
-		if tt.raddr == "" {
-			mode = "listen"
-			la, _ := ResolveIPAddr(tt.net, tt.laddr)
-			c, err = ListenIP(tt.net, la)
-			if err != nil {
-				t.Fatalf("ListenIP(%q, %q) failed: %v", tt.net, la.String(), err)
-			}
-		} else {
-			mode = "dial"
-			la, _ := ResolveIPAddr(tt.net, tt.laddr)
-			ra, _ := ResolveIPAddr(tt.net, tt.raddr)
-			c, err = DialIP(tt.net, la, ra)
-			if err != nil {
-				t.Fatalf("DialIP(%q, %q) failed: %v", tt.net, ra.String(), err)
-			}
-		}
-		t.Logf("%s-%v: LocalAddr: %q, %q", mode, i, c.LocalAddr(), c.LocalAddr().String())
-		t.Logf("%s-%v: RemoteAddr: %q, %q", mode, i, c.RemoteAddr(), c.RemoteAddr().String())
-		c.Close()
-	}
-}
-
 var icmpTests = []struct {
 	net   string
 	laddr string

src/pkg/net/sock_posix.go

@@ -58,13 +58,16 @@ func socket(net string, f, t, p int, ipv6only bool, ulsa, ursa syscall.Sockaddr,
 		fd.isConnected = true
 	}
 
+	lsa, _ := syscall.Getsockname(s)
 	var laddr Addr
 	if ulsa != nil && blsa != ulsa {
 		laddr = toAddr(ulsa)
 	} else {
-		laddr = localSockname(fd, toAddr)
+		laddr = toAddr(lsa)
 	}
-	fd.setAddr(laddr, remoteSockname(fd, toAddr))
+	rsa, _ := syscall.Getpeername(s)
+	raddr := toAddr(rsa)
+	fd.setAddr(laddr, raddr)
 	return fd, nil
 }
 
@@ -78,39 +81,3 @@ func genericReadFrom(w io.Writer, r io.Reader) (n int64, err error) {
 	// Use wrapper to hide existing r.ReadFrom from io.Copy.
 	return io.Copy(writerOnly{w}, r)
 }
-
-func localSockname(fd *netFD, toAddr func(syscall.Sockaddr) Addr) Addr {
-	sa, _ := syscall.Getsockname(fd.sysfd)
-	if sa == nil {
-		return nullProtocolAddr(fd.family, fd.sotype)
-	}
-	return toAddr(sa)
-}
-
-func remoteSockname(fd *netFD, toAddr func(syscall.Sockaddr) Addr) Addr {
-	sa, _ := syscall.Getpeername(fd.sysfd)
-	if sa == nil {
-		return nullProtocolAddr(fd.family, fd.sotype)
-	}
-	return toAddr(sa)
-}
-
-func nullProtocolAddr(f, t int) Addr {
-	switch f {
-	case syscall.AF_INET, syscall.AF_INET6:
-		switch t {
-		case syscall.SOCK_STREAM:
-			return (*TCPAddr)(nil)
-		case syscall.SOCK_DGRAM:
-			return (*UDPAddr)(nil)
-		case syscall.SOCK_RAW:
-			return (*IPAddr)(nil)
-		}
-	case syscall.AF_UNIX:
-		switch t {
-		case syscall.SOCK_STREAM, syscall.SOCK_DGRAM, syscall.SOCK_SEQPACKET:
-			return (*UnixAddr)(nil)
-		}
-	}
-	panic("unreachable")
-}

src/pkg/net/udp_test.go

@@ -9,33 +9,6 @@ import (
 	"testing"
 )
 
-var udpConnAddrStringTests = []struct {
-	net   string
-	laddr string
-	raddr string
-	ipv6  bool
-}{
-	{"udp", "127.0.0.1:0", "", false},
-	{"udp", "[::1]:0", "", true},
-}
-
-func TestUDPConnAddrString(t *testing.T) {
-	for i, tt := range udpConnAddrStringTests {
-		if tt.ipv6 && !supportsIPv6 {
-			continue
-		}
-		mode := "listen"
-		la, _ := ResolveUDPAddr(tt.net, tt.laddr)
-		c, err := ListenUDP(tt.net, la)
-		if err != nil {
-			t.Fatalf("ListenUDP(%q, %q) failed: %v", tt.net, la.String(), err)
-		}
-		t.Logf("%s-%v: LocalAddr: %q, %q", mode, i, c.LocalAddr(), c.LocalAddr().String())
-		t.Logf("%s-%v: RemoteAddr: %q, %q", mode, i, c.RemoteAddr(), c.RemoteAddr().String())
-		c.Close()
-	}
-}
-
 func TestWriteToUDP(t *testing.T) {
 	switch runtime.GOOS {
 	case "plan9":