libgo: Update Go library to master revision 15489/921e53d4863c.

From-SVN: r195560

7 files changed, 174 insertions, 168 deletions

diff --git a/libgo/go/syscall/exec_bsd.go b/libgo/go/syscall/exec_bsd.go
index f1f7a18..c8eed53 100644
--- a/libgo/go/syscall/exec_bsd.go
+++ b/libgo/go/syscall/exec_bsd.go
@@ -223,3 +223,17 @@ childerror:
 	// and this shuts up the compiler.
 	panic("unreached")
 }
+
+// Try to open a pipe with O_CLOEXEC set on both file descriptors.
+func forkExecPipe(p []int) error {
+	err := Pipe(p)
+	if err != nil {
+		return err
+	}
+	_, err = fcntl(p[0], F_SETFD, FD_CLOEXEC)
+	if err != nil {
+		return err
+	}
+	_, err = fcntl(p[1], F_SETFD, FD_CLOEXEC)
+	return err
+}
diff --git a/libgo/go/syscall/exec_linux.go b/libgo/go/syscall/exec_linux.go
index 75c61f0..e29878a 100644
--- a/libgo/go/syscall/exec_linux.go
+++ b/libgo/go/syscall/exec_linux.go
@@ -250,3 +250,20 @@ childerror:
 	// and this shuts up the compiler.
 	panic("unreached")
 }
+
+// Try to open a pipe with O_CLOEXEC set on both file descriptors.
+func forkExecPipe(p []int) (err error) {
+	err = Pipe2(p, O_CLOEXEC)
+	// pipe2 was added in 2.6.27 and our minimum requirement is 2.6.23, so it
+	// might not be implemented.
+	if err == ENOSYS {
+		if err = Pipe(p); err != nil {
+			return
+		}
+		if _, err = fcntl(p[0], F_SETFD, FD_CLOEXEC); err != nil {
+			return
+		}
+		_, err = fcntl(p[1], F_SETFD, FD_CLOEXEC)
+	}
+	return
+}
diff --git a/libgo/go/syscall/exec_unix.go b/libgo/go/syscall/exec_unix.go
index e51878e..d4aa959 100644
--- a/libgo/go/syscall/exec_unix.go
+++ b/libgo/go/syscall/exec_unix.go
@@ -219,13 +219,7 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 	ForkLock.Lock()
 
 	// Allocate child status pipe close on exec.
-	if err = Pipe(p[0:]); err != nil {
-		goto error
-	}
-	if _, err = fcntl(p[0], F_SETFD, FD_CLOEXEC); err != nil {
-		goto error
-	}
-	if _, err = fcntl(p[1], F_SETFD, FD_CLOEXEC); err != nil {
+	if err = forkExecPipe(p[:]); err != nil {
 		goto error
 	}
 
diff --git a/libgo/go/syscall/libcall_linux.go b/libgo/go/syscall/libcall_linux.go
index 482a23f..7d780e6 100644
--- a/libgo/go/syscall/libcall_linux.go
+++ b/libgo/go/syscall/libcall_linux.go
@@ -166,6 +166,24 @@ func Reboot(cmd int) (err error) {
 	return reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, "")
 }
 
+//sys	accept4(fd int, sa *RawSockaddrAny, len *Socklen_t, flags int) (nfd int, err error)
+//accept4(fd _C_int, sa *RawSockaddrAny, len *Socklen_t, flags _C_int) _C_int
+
+func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) {
+	var rsa RawSockaddrAny
+	var len Socklen_t = SizeofSockaddrAny
+	nfd, err = accept4(fd, &rsa, &len, flags)
+	if err != nil {
+		return -1, nil, err
+	}
+	sa, err = anyToSockaddr(&rsa)
+	if err != nil {
+		Close(nfd)
+		return -1, nil, err
+	}
+	return nfd, sa, nil
+}
+
 //sys	Acct(path string) (err error)
 //acct(path *byte) int
 
@@ -271,6 +289,19 @@ func ParseDirent(buf []byte, max int, names []string) (consumed int, count int,
 //sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
 //mknodat(dirfd int, path *byte, mode Mode_t, dev _dev_t) int
 
+//sysnb	pipe2(p *[2]_C_int, flags int) (err error)
+//pipe2(p *[2]_C_int, flags _C_int) _C_int
+func Pipe2(p []int, flags int) (err error) {
+	if len(p) != 2 {
+		return EINVAL
+	}
+	var pp [2]_C_int
+	err = pipe2(&pp, flags)
+	p[0] = int(pp[0])
+	p[1] = int(pp[1])
+	return
+}
+
 //sys	PivotRoot(newroot string, putold string) (err error)
 //pivot_root(newroot *byte, putold *byte) int
 
diff --git a/libgo/go/syscall/netlink_linux.go b/libgo/go/syscall/netlink_linux.go
index d535713..49550ea 100644
--- a/libgo/go/syscall/netlink_linux.go
+++ b/libgo/go/syscall/netlink_linux.go
@@ -6,9 +6,7 @@
 
 package syscall
 
-import (
-	"unsafe"
-)
+import "unsafe"
 
 // Round the length of a netlink message up to align it properly.
 func nlmAlignOf(msglen int) int {
@@ -21,8 +19,8 @@ func rtaAlignOf(attrlen int) int {
 	return (attrlen + RTA_ALIGNTO - 1) & ^(RTA_ALIGNTO - 1)
 }
 
-// NetlinkRouteRequest represents the request message to receive
-// routing and link states from the kernel.
+// NetlinkRouteRequest represents a request message to receive routing
+// and link states from the kernel.
 type NetlinkRouteRequest struct {
 	Header NlMsghdr
 	Data   RtGenmsg
@@ -49,167 +47,131 @@ func newNetlinkRouteRequest(proto, seq, family int) []byte {
 	return rr.toWireFormat()
 }
 
-// NetlinkRIB returns routing information base, as known as RIB,
-// which consists of network facility information, states and
-// parameters.
+// NetlinkRIB returns routing information base, as known as RIB, which
+// consists of network facility information, states and parameters.
 func NetlinkRIB(proto, family int) ([]byte, error) {
-	var (
-		lsanl SockaddrNetlink
-		tab   []byte
-	)
-
-	s, e := Socket(AF_NETLINK, SOCK_RAW, 0)
-	if e != nil {
-		return nil, e
+	s, err := Socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)
+	if err != nil {
+		return nil, err
 	}
 	defer Close(s)
-
-	lsanl.Family = AF_NETLINK
-	e = Bind(s, &lsanl)
-	if e != nil {
-		return nil, e
+	lsa := &SockaddrNetlink{Family: AF_NETLINK}
+	if err := Bind(s, lsa); err != nil {
+		return nil, err
 	}
-
-	seq := 1
-	wb := newNetlinkRouteRequest(proto, seq, family)
-	e = Sendto(s, wb, 0, &lsanl)
-	if e != nil {
-		return nil, e
+	wb := newNetlinkRouteRequest(proto, 1, family)
+	if err := Sendto(s, wb, 0, lsa); err != nil {
+		return nil, err
 	}
-
+	var tab []byte
+done:
 	for {
-		var (
-			rb  []byte
-			nr  int
-			lsa Sockaddr
-		)
-
-		rb = make([]byte, Getpagesize())
-		nr, _, e = Recvfrom(s, rb, 0)
-		if e != nil {
-			return nil, e
+		rb := make([]byte, Getpagesize())
+		nr, _, err := Recvfrom(s, rb, 0)
+		if err != nil {
+			return nil, err
 		}
 		if nr < NLMSG_HDRLEN {
 			return nil, EINVAL
 		}
 		rb = rb[:nr]
 		tab = append(tab, rb...)
-
-		msgs, _ := ParseNetlinkMessage(rb)
+		msgs, err := ParseNetlinkMessage(rb)
+		if err != nil {
+			return nil, err
+		}
 		for _, m := range msgs {
-			if lsa, e = Getsockname(s); e != nil {
-				return nil, e
+			lsa, err := Getsockname(s)
+			if err != nil {
+				return nil, err
 			}
 			switch v := lsa.(type) {
 			case *SockaddrNetlink:
-				if m.Header.Seq != uint32(seq) || m.Header.Pid != v.Pid {
+				if m.Header.Seq != 1 || m.Header.Pid != v.Pid {
 					return nil, EINVAL
 				}
 			default:
 				return nil, EINVAL
 			}
 			if m.Header.Type == NLMSG_DONE {
-				goto done
+				break done
 			}
 			if m.Header.Type == NLMSG_ERROR {
 				return nil, EINVAL
 			}
 		}
 	}
-
-done:
 	return tab, nil
 }
 
-// NetlinkMessage represents the netlink message.
+// NetlinkMessage represents a netlink message.
 type NetlinkMessage struct {
 	Header NlMsghdr
 	Data   []byte
 }
 
-// ParseNetlinkMessage parses buf as netlink messages and returns
-// the slice containing the NetlinkMessage structs.
-func ParseNetlinkMessage(buf []byte) ([]NetlinkMessage, error) {
-	var (
-		h    *NlMsghdr
-		dbuf []byte
-		dlen int
-		e    error
-		msgs []NetlinkMessage
-	)
-
-	for len(buf) >= NLMSG_HDRLEN {
-		h, dbuf, dlen, e = netlinkMessageHeaderAndData(buf)
-		if e != nil {
-			break
+// ParseNetlinkMessage parses b as an array of netlink messages and
+// returns the slice containing the NetlinkMessage structures.
+func ParseNetlinkMessage(b []byte) ([]NetlinkMessage, error) {
+	var msgs []NetlinkMessage
+	for len(b) >= NLMSG_HDRLEN {
+		h, dbuf, dlen, err := netlinkMessageHeaderAndData(b)
+		if err != nil {
+			return nil, err
 		}
-		m := NetlinkMessage{}
-		m.Header = *h
-		m.Data = dbuf[:int(h.Len)-NLMSG_HDRLEN]
+		m := NetlinkMessage{Header: *h, Data: dbuf[:int(h.Len)-NLMSG_HDRLEN]}
 		msgs = append(msgs, m)
-		buf = buf[dlen:]
+		b = b[dlen:]
 	}
-
-	return msgs, e
+	return msgs, nil
 }
 
-func netlinkMessageHeaderAndData(buf []byte) (*NlMsghdr, []byte, int, error) {
-	h := (*NlMsghdr)(unsafe.Pointer(&buf[0]))
-	if int(h.Len) < NLMSG_HDRLEN || int(h.Len) > len(buf) {
+func netlinkMessageHeaderAndData(b []byte) (*NlMsghdr, []byte, int, error) {
+	h := (*NlMsghdr)(unsafe.Pointer(&b[0]))
+	if int(h.Len) < NLMSG_HDRLEN || int(h.Len) > len(b) {
 		return nil, nil, 0, EINVAL
 	}
-	return h, buf[NLMSG_HDRLEN:], nlmAlignOf(int(h.Len)), nil
+	return h, b[NLMSG_HDRLEN:], nlmAlignOf(int(h.Len)), nil
 }
 
-// NetlinkRouteAttr represents the netlink route attribute.
+// NetlinkRouteAttr represents a netlink route attribute.
 type NetlinkRouteAttr struct {
 	Attr  RtAttr
 	Value []byte
 }
 
-// ParseNetlinkRouteAttr parses msg's payload as netlink route
-// attributes and returns the slice containing the NetlinkRouteAttr
-// structs.
-func ParseNetlinkRouteAttr(msg *NetlinkMessage) ([]NetlinkRouteAttr, error) {
-	var (
-		buf   []byte
-		a     *RtAttr
-		alen  int
-		vbuf  []byte
-		e     error
-		attrs []NetlinkRouteAttr
-	)
-
-	switch msg.Header.Type {
+// ParseNetlinkRouteAttr parses m's payload as an array of netlink
+// route attributes and returns the slice containing the
+// NetlinkRouteAttr structures.
+func ParseNetlinkRouteAttr(m *NetlinkMessage) ([]NetlinkRouteAttr, error) {
+	var b []byte
+	switch m.Header.Type {
 	case RTM_NEWLINK, RTM_DELLINK:
-		buf = msg.Data[SizeofIfInfomsg:]
+		b = m.Data[SizeofIfInfomsg:]
 	case RTM_NEWADDR, RTM_DELADDR:
-		buf = msg.Data[SizeofIfAddrmsg:]
+		b = m.Data[SizeofIfAddrmsg:]
 	case RTM_NEWROUTE, RTM_DELROUTE:
-		buf = msg.Data[SizeofRtMsg:]
+		b = m.Data[SizeofRtMsg:]
 	default:
 		return nil, EINVAL
 	}
-
-	for len(buf) >= SizeofRtAttr {
-		a, vbuf, alen, e = netlinkRouteAttrAndValue(buf)
-		if e != nil {
-			break
+	var attrs []NetlinkRouteAttr
+	for len(b) >= SizeofRtAttr {
+		a, vbuf, alen, err := netlinkRouteAttrAndValue(b)
+		if err != nil {
+			return nil, err
 		}
-		ra := NetlinkRouteAttr{}
-		ra.Attr = *a
-		ra.Value = vbuf[:int(a.Len)-SizeofRtAttr]
+		ra := NetlinkRouteAttr{Attr: *a, Value: vbuf[:int(a.Len)-SizeofRtAttr]}
 		attrs = append(attrs, ra)
-		buf = buf[alen:]
+		b = b[alen:]
 	}
-
 	return attrs, nil
 }
 
-func netlinkRouteAttrAndValue(buf []byte) (*RtAttr, []byte, int, error) {
-	h := (*RtAttr)(unsafe.Pointer(&buf[0]))
-	if int(h.Len) < SizeofRtAttr || int(h.Len) > len(buf) {
+func netlinkRouteAttrAndValue(b []byte) (*RtAttr, []byte, int, error) {
+	a := (*RtAttr)(unsafe.Pointer(&b[0]))
+	if int(a.Len) < SizeofRtAttr || int(a.Len) > len(b) {
 		return nil, nil, 0, EINVAL
 	}
-	return h, buf[SizeofRtAttr:], rtaAlignOf(int(h.Len)), nil
+	return a, b[SizeofRtAttr:], rtaAlignOf(int(a.Len)), nil
 }
diff --git a/libgo/go/syscall/sockcmsg_linux.go b/libgo/go/syscall/sockcmsg_linux.go
index 0b4caa1..a2e26a1 100644
--- a/libgo/go/syscall/sockcmsg_linux.go
+++ b/libgo/go/syscall/sockcmsg_linux.go
@@ -6,33 +6,31 @@
 
 package syscall
 
-import (
-	"unsafe"
-)
+import "unsafe"
 
 // UnixCredentials encodes credentials into a socket control message
 // for sending to another process. This can be used for
 // authentication.
 func UnixCredentials(ucred *Ucred) []byte {
-	buf := make([]byte, CmsgSpace(SizeofUcred))
-	cmsg := (*Cmsghdr)(unsafe.Pointer(&buf[0]))
-	cmsg.Level = SOL_SOCKET
-	cmsg.Type = SCM_CREDENTIALS
-	cmsg.SetLen(CmsgLen(SizeofUcred))
-	*((*Ucred)(cmsgData(cmsg))) = *ucred
-	return buf
+	b := make([]byte, CmsgSpace(SizeofUcred))
+	h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
+	h.Level = SOL_SOCKET
+	h.Type = SCM_CREDENTIALS
+	h.SetLen(CmsgLen(SizeofUcred))
+	*((*Ucred)(cmsgData(h))) = *ucred
+	return b
 }
 
 // ParseUnixCredentials decodes a socket control message that contains
 // credentials in a Ucred structure. To receive such a message, the
 // SO_PASSCRED option must be enabled on the socket.
-func ParseUnixCredentials(msg *SocketControlMessage) (*Ucred, error) {
-	if msg.Header.Level != SOL_SOCKET {
+func ParseUnixCredentials(m *SocketControlMessage) (*Ucred, error) {
+	if m.Header.Level != SOL_SOCKET {
 		return nil, EINVAL
 	}
-	if msg.Header.Type != SCM_CREDENTIALS {
+	if m.Header.Type != SCM_CREDENTIALS {
 		return nil, EINVAL
 	}
-	ucred := *(*Ucred)(unsafe.Pointer(&msg.Data[0]))
+	ucred := *(*Ucred)(unsafe.Pointer(&m.Data[0]))
 	return &ucred, nil
 }
diff --git a/libgo/go/syscall/sockcmsg_unix.go b/libgo/go/syscall/sockcmsg_unix.go
index 943ebdd..fc83df1 100644
--- a/libgo/go/syscall/sockcmsg_unix.go
+++ b/libgo/go/syscall/sockcmsg_unix.go
@@ -8,9 +8,7 @@
 
 package syscall
 
-import (
-	"unsafe"
-)
+import "unsafe"
 
 // Round the length of a raw sockaddr up to align it propery.
 func cmsgAlignOf(salen int) int {
@@ -38,77 +36,69 @@ func CmsgSpace(datalen int) int {
 	return cmsgAlignOf(SizeofCmsghdr) + cmsgAlignOf(datalen)
 }
 
-func cmsgData(cmsg *Cmsghdr) unsafe.Pointer {
-	return unsafe.Pointer(uintptr(unsafe.Pointer(cmsg)) + SizeofCmsghdr)
+func cmsgData(h *Cmsghdr) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + SizeofCmsghdr)
 }
 
+// SocketControlMessage represents a socket control message.
 type SocketControlMessage struct {
 	Header Cmsghdr
 	Data   []byte
 }
 
-func ParseSocketControlMessage(buf []byte) ([]SocketControlMessage, error) {
-	var (
-		h     *Cmsghdr
-		dbuf  []byte
-		e     error
-		cmsgs []SocketControlMessage
-	)
-
-	for len(buf) >= CmsgLen(0) {
-		h, dbuf, e = socketControlMessageHeaderAndData(buf)
-		if e != nil {
-			break
+// ParseSocketControlMessage parses b as an array of socket control
+// messages.
+func ParseSocketControlMessage(b []byte) ([]SocketControlMessage, error) {
+	var msgs []SocketControlMessage
+	for len(b) >= CmsgLen(0) {
+		h, dbuf, err := socketControlMessageHeaderAndData(b)
+		if err != nil {
+			return nil, err
 		}
-		m := SocketControlMessage{}
-		m.Header = *h
-		m.Data = dbuf[:int(h.Len)-cmsgAlignOf(SizeofCmsghdr)]
-		cmsgs = append(cmsgs, m)
-		buf = buf[cmsgAlignOf(int(h.Len)):]
+		m := SocketControlMessage{Header: *h, Data: dbuf[:int(h.Len)-cmsgAlignOf(SizeofCmsghdr)]}
+		msgs = append(msgs, m)
+		b = b[cmsgAlignOf(int(h.Len)):]
 	}
-
-	return cmsgs, e
+	return msgs, nil
 }
 
-func socketControlMessageHeaderAndData(buf []byte) (*Cmsghdr, []byte, error) {
-	h := (*Cmsghdr)(unsafe.Pointer(&buf[0]))
-	if h.Len < SizeofCmsghdr || int(h.Len) > len(buf) {
+func socketControlMessageHeaderAndData(b []byte) (*Cmsghdr, []byte, error) {
+	h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
+	if h.Len < SizeofCmsghdr || int(h.Len) > len(b) {
 		return nil, nil, EINVAL
 	}
-	return h, buf[cmsgAlignOf(SizeofCmsghdr):], nil
+	return h, b[cmsgAlignOf(SizeofCmsghdr):], nil
 }
 
 // UnixRights encodes a set of open file descriptors into a socket
 // control message for sending to another process.
 func UnixRights(fds ...int) []byte {
 	datalen := len(fds) * 4
-	buf := make([]byte, CmsgSpace(datalen))
-	cmsg := (*Cmsghdr)(unsafe.Pointer(&buf[0]))
-	cmsg.Level = SOL_SOCKET
-	cmsg.Type = SCM_RIGHTS
-	cmsg.SetLen(CmsgLen(datalen))
-
-	data := uintptr(cmsgData(cmsg))
+	b := make([]byte, CmsgSpace(datalen))
+	h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
+	h.Level = SOL_SOCKET
+	h.Type = SCM_RIGHTS
+	h.SetLen(CmsgLen(datalen))
+	data := uintptr(cmsgData(h))
 	for _, fd := range fds {
 		*(*int32)(unsafe.Pointer(data)) = int32(fd)
 		data += 4
 	}
-
-	return buf
+	return b
 }
 
 // ParseUnixRights decodes a socket control message that contains an
 // integer array of open file descriptors from another process.
-func ParseUnixRights(msg *SocketControlMessage) ([]int, error) {
-	if msg.Header.Level != SOL_SOCKET {
+func ParseUnixRights(m *SocketControlMessage) ([]int, error) {
+	if m.Header.Level != SOL_SOCKET {
 		return nil, EINVAL
 	}
-	if msg.Header.Type != SCM_RIGHTS {
+	if m.Header.Type != SCM_RIGHTS {
 		return nil, EINVAL
 	}
-	fds := make([]int, len(msg.Data)>>2)
-	for i, j := 0, 0; i < len(msg.Data); i += 4 {
-		fds[j] = int(*(*int32)(unsafe.Pointer(&msg.Data[i])))
+	fds := make([]int, len(m.Data)>>2)
+	for i, j := 0, 0; i < len(m.Data); i += 4 {
+		fds[j] = int(*(*int32)(unsafe.Pointer(&m.Data[i])))
 		j++
 	}
 	return fds, nil