syscall: reduce duplication between *bsd and linux

Part 3 of several.

* Linux has grown a SetsockoptByte.
* SetsockoptIPMreqn is handled directly by syscall_linux.go and syscall_freebsd.go.

R=golang-dev, mikioh.mikioh, r, bradfitz
CC=golang-dev
https://golang.org/cl/10775043

src/pkg/syscall/syscall_bsd.go

@@ -352,44 +352,6 @@ func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
 	return &value, err
 }
 
-func SetsockoptByte(fd, level, opt int, value byte) (err error) {
-	var n = byte(value)
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 1)
-}
-
-func SetsockoptInt(fd, level, opt int, value int) (err error) {
-	var n = int32(value)
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 4)
-}
-
-func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value[0])), 4)
-}
-
-func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(tv)), unsafe.Sizeof(*tv))
-}
-
-func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(l)), unsafe.Sizeof(*l))
-}
-
-func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), unsafe.Sizeof(*mreq))
-}
-
-func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), unsafe.Sizeof(*mreq))
-}
-
-func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(filter)), SizeofICMPv6Filter)
-}
-
-func SetsockoptString(fd, level, opt int, s string) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), uintptr(len(s)))
-}
-
 //sys   recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
 //sys   sendto(s int, buf []byte, flags int, to uintptr, addrlen _Socklen) (err error)
 //sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)

src/pkg/syscall/syscall_linux.go

@@ -485,42 +485,10 @@ func GetsockoptUcred(fd, level, opt int) (*Ucred, error) {
 	return &value, err
 }
 
-func SetsockoptInt(fd, level, opt int, value int) (err error) {
-	var n = int32(value)
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 4)
-}
-
-func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value[0])), 4)
-}
-
-func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(tv)), unsafe.Sizeof(*tv))
-}
-
-func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(l)), unsafe.Sizeof(*l))
-}
-
-func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), unsafe.Sizeof(*mreq))
-}
-
 func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {
 	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), unsafe.Sizeof(*mreq))
 }
 
-func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), unsafe.Sizeof(*mreq))
-}
-
-func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(filter)), SizeofICMPv6Filter)
-}
-func SetsockoptString(fd, level, opt int, s string) (err error) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), uintptr(len(s)))
-}
-
 func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
 	var msg Msghdr
 	var rsa RawSockaddrAny

src/pkg/syscall/syscall_unix.go

@@ -230,6 +230,43 @@ func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
 	return sendto(fd, p, flags, ptr, n)
 }
 
+func SetsockoptByte(fd, level, opt int, value byte) (err error) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value)), 1)
+}
+
+func SetsockoptInt(fd, level, opt int, value int) (err error) {
+	var n = int32(value)
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 4)
+}
+
+func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value[0])), 4)
+}
+
+func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), SizeofIPMreq)
+}
+
+func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), SizeofIPv6Mreq)
+}
+
+func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(filter)), SizeofICMPv6Filter)
+}
+
+func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(l)), SizeofLinger)
+}
+
+func SetsockoptString(fd, level, opt int, s string) (err error) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), uintptr(len(s)))
+}
+
+func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(tv)), unsafe.Sizeof(*tv))
+}
+
 func Socket(domain, typ, proto int) (fd int, err error) {
 	if domain == AF_INET6 && SocketDisableIPv6 {
 		return -1, EAFNOSUPPORT