syscall: Create syscall_bsd.go for code used by Darwin and other *BSDs

In this change I'd like to combine the common code that is
present in syscall_darwin.go and syscall_freebsd.go.  I
have three reasons for wanting to do this now:

1. reducing code duplication is nearly always good :-)
2. the duplication will get worse if I duplicate this code
   a third time for the NetBSD port I'm working on, which
   I need to do almost immediately
3. by making this change all in one lump and ignoring any
   commonality with the syscall_linux*.go files the diff
   is long but, I think, readable

In future it may be possible to cherry pick functions that
also apply to Linux and put them in (say) syscall_unix.go,
and of course some functions may diverge in future and have
to move out to OS or architecture specific files, but today
I want just the low hanging fruit.

Tested and passed on:

  Darwin (Snow Leopard, 10.6): amd64 and 386
  FreeBSD (8.0-RELEASE):       386 only(*)

(*) All my virtualisation software has stopped playing nice
with FreeBSD for the moment, so I don't have facilities to
test the amd64 port.  As the OS X port is OK and the diff
looks all right to my eyes I shall keep my fingers crossed.
If someone with a FreeBSD/amd64 system cares to test and
report I would be appreciative.

2010-03-27 update: I have replaced my virtualisation software, and have working FreeBSD/i386 and FreeBSD/amd64 virtual machines again.

As I hoped (and expected -- programmers are optimists :-) the code built and passed all but the two currently known to fail tests on FreeBSD/amd64. I rechecked FreeBSD/i386 too: same results.

R=rsc
CC=golang-dev
http://codereview.appspot.com/751041

Committer: Russ Cox <rsc@golang.org>

1 files changed, 467 insertions, 0 deletions

diff --git a/src/pkg/syscall/syscall_bsd.go b/src/pkg/syscall/syscall_bsd.go
new file mode 100644
index 000000000..cb7264863
--- /dev/null
+++ b/src/pkg/syscall/syscall_bsd.go
@@ -0,0 +1,467 @@
+// Copyright 2009,2010 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.
+
+// BSD system call wrappers shared by *BSD based systems
+// including OS X (Darwin) and FreeBSD.  Like the other
+// syscall_*.go files it is compiled as Go code but also
+// used as input to mksyscall which parses the //sys
+// lines and generates system call stubs.
+
+package syscall
+
+import "unsafe"
+
+/*
+ * Pseudo-system calls
+ */
+// The const provides a compile-time constant so clients
+// can adjust to whether there is a working Getwd and avoid
+// even linking this function into the binary.  See ../os/getwd.go.
+const ImplementsGetwd = false
+
+func Getwd() (string, int) { return "", ENOTSUP }
+
+
+/*
+ * Wrapped
+ */
+
+//sys	getgroups(ngid int, gid *_Gid_t) (n int, errno int)
+//sys	setgroups(ngid int, gid *_Gid_t) (errno int)
+
+func Getgroups() (gids []int, errno int) {
+	n, err := getgroups(0, nil)
+	if err != 0 {
+		return nil, errno
+	}
+	if n == 0 {
+		return nil, 0
+	}
+
+	// Sanity check group count.  Max is 16 on BSD.
+	if n < 0 || n > 1000 {
+		return nil, EINVAL
+	}
+
+	a := make([]_Gid_t, n)
+	n, err = getgroups(n, &a[0])
+	if err != 0 {
+		return nil, errno
+	}
+	gids = make([]int, n)
+	for i, v := range a[0:n] {
+		gids[i] = int(v)
+	}
+	return
+}
+
+func Setgroups(gids []int) (errno int) {
+	if len(gids) == 0 {
+		return setgroups(0, nil)
+	}
+
+	a := make([]_Gid_t, len(gids))
+	for i, v := range gids {
+		a[i] = _Gid_t(v)
+	}
+	return setgroups(len(a), &a[0])
+}
+
+// Wait status is 7 bits at bottom, either 0 (exited),
+// 0x7F (stopped), or a signal number that caused an exit.
+// The 0x80 bit is whether there was a core dump.
+// An extra number (exit code, signal causing a stop)
+// is in the high bits.
+
+type WaitStatus uint32
+
+const (
+	mask  = 0x7F
+	core  = 0x80
+	shift = 8
+
+	exited  = 0
+	stopped = 0x7F
+)
+
+func (w WaitStatus) Exited() bool { return w&mask == exited }
+
+func (w WaitStatus) ExitStatus() int {
+	if w&mask != exited {
+		return -1
+	}
+	return int(w >> shift)
+}
+
+func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }
+
+func (w WaitStatus) Signal() int {
+	sig := int(w & mask)
+	if sig == stopped || sig == 0 {
+		return -1
+	}
+	return sig
+}
+
+func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
+
+func (w WaitStatus) Stopped() bool { return w&mask == stopped && w>>shift != SIGSTOP }
+
+func (w WaitStatus) Continued() bool { return w&mask == stopped && w>>shift == SIGSTOP }
+
+func (w WaitStatus) StopSignal() int {
+	if !w.Stopped() {
+		return -1
+	}
+	return int(w>>shift) & 0xFF
+}
+
+func (w WaitStatus) TrapCause() int { return -1 }
+
+//sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, errno int)
+
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, errno int) {
+	var status _C_int
+	wpid, errno = wait4(pid, &status, options, rusage)
+	if wstatus != nil {
+		*wstatus = WaitStatus(status)
+	}
+	return
+}
+
+//sys	pipe() (r int, w int, errno int)
+
+func Pipe(p []int) (errno int) {
+	if len(p) != 2 {
+		return EINVAL
+	}
+	p[0], p[1], errno = pipe()
+	return
+}
+
+func Sleep(ns int64) (errno int) {
+	tv := NsecToTimeval(ns)
+	return Select(0, nil, nil, nil, &tv)
+}
+
+//sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, errno int)
+//sys	bind(s int, addr uintptr, addrlen _Socklen) (errno int)
+//sys	connect(s int, addr uintptr, addrlen _Socklen) (errno int)
+//sys	socket(domain int, typ int, proto int) (fd int, errno int)
+//sys	setsockopt(s int, level int, name int, val uintptr, vallen int) (errno int)
+//sys	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (errno int)
+//sys	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (errno int)
+//sys	Shutdown(s int, how int) (errno int)
+
+// For testing: clients can set this flag to force
+// creation of IPv6 sockets to return EAFNOSUPPORT.
+var SocketDisableIPv6 bool
+
+type Sockaddr interface {
+	sockaddr() (ptr uintptr, len _Socklen, errno int) // lowercase; only we can define Sockaddrs
+}
+
+type SockaddrInet4 struct {
+	Port int
+	Addr [4]byte
+	raw  RawSockaddrInet4
+}
+
+func (sa *SockaddrInet4) sockaddr() (uintptr, _Socklen, int) {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return 0, 0, EINVAL
+	}
+	sa.raw.Len = SizeofSockaddrInet4
+	sa.raw.Family = AF_INET
+	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	for i := 0; i < len(sa.Addr); i++ {
+		sa.raw.Addr[i] = sa.Addr[i]
+	}
+	return uintptr(unsafe.Pointer(&sa.raw)), _Socklen(sa.raw.Len), 0
+}
+
+type SockaddrInet6 struct {
+	Port int
+	Addr [16]byte
+	raw  RawSockaddrInet6
+}
+
+func (sa *SockaddrInet6) sockaddr() (uintptr, _Socklen, int) {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return 0, 0, EINVAL
+	}
+	sa.raw.Len = SizeofSockaddrInet6
+	sa.raw.Family = AF_INET6
+	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	for i := 0; i < len(sa.Addr); i++ {
+		sa.raw.Addr[i] = sa.Addr[i]
+	}
+	return uintptr(unsafe.Pointer(&sa.raw)), _Socklen(sa.raw.Len), 0
+}
+
+type SockaddrUnix struct {
+	Name string
+	raw  RawSockaddrUnix
+}
+
+func (sa *SockaddrUnix) sockaddr() (uintptr, _Socklen, int) {
+	name := sa.Name
+	n := len(name)
+	if n >= len(sa.raw.Path) || n == 0 {
+		return 0, 0, EINVAL
+	}
+	sa.raw.Len = byte(3 + n) // 2 for Family, Len; 1 for NUL
+	sa.raw.Family = AF_UNIX
+	for i := 0; i < n; i++ {
+		sa.raw.Path[i] = int8(name[i])
+	}
+	return uintptr(unsafe.Pointer(&sa.raw)), _Socklen(sa.raw.Len), 0
+}
+
+func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, int) {
+	switch rsa.Addr.Family {
+	case AF_UNIX:
+		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
+		if pp.Len < 3 || pp.Len > SizeofSockaddrUnix {
+			return nil, EINVAL
+		}
+		sa := new(SockaddrUnix)
+		n := int(pp.Len) - 3 // subtract leading Family, Len, terminating NUL
+		for i := 0; i < n; i++ {
+			if pp.Path[i] == 0 {
+				// found early NUL; assume Len is overestimating
+				n = i
+				break
+			}
+		}
+		bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]))
+		sa.Name = string(bytes[0:n])
+		return sa, 0
+
+	case AF_INET:
+		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
+		sa := new(SockaddrInet4)
+		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+		sa.Port = int(p[0])<<8 + int(p[1])
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, 0
+
+	case AF_INET6:
+		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
+		sa := new(SockaddrInet6)
+		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+		sa.Port = int(p[0])<<8 + int(p[1])
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, 0
+	}
+	return nil, EAFNOSUPPORT
+}
+
+func Accept(fd int) (nfd int, sa Sockaddr, errno int) {
+	var rsa RawSockaddrAny
+	var len _Socklen = SizeofSockaddrAny
+	nfd, errno = accept(fd, &rsa, &len)
+	if errno != 0 {
+		return
+	}
+	sa, errno = anyToSockaddr(&rsa)
+	if errno != 0 {
+		Close(nfd)
+		nfd = 0
+	}
+	return
+}
+
+func Getsockname(fd int) (sa Sockaddr, errno int) {
+	var rsa RawSockaddrAny
+	var len _Socklen = SizeofSockaddrAny
+	if errno = getsockname(fd, &rsa, &len); errno != 0 {
+		return
+	}
+	return anyToSockaddr(&rsa)
+}
+
+func Getpeername(fd int) (sa Sockaddr, errno int) {
+	var rsa RawSockaddrAny
+	var len _Socklen = SizeofSockaddrAny
+	if errno = getpeername(fd, &rsa, &len); errno != 0 {
+		return
+	}
+	return anyToSockaddr(&rsa)
+}
+
+func Bind(fd int, sa Sockaddr) (errno int) {
+	ptr, n, err := sa.sockaddr()
+	if err != 0 {
+		return err
+	}
+	return bind(fd, ptr, n)
+}
+
+func Connect(fd int, sa Sockaddr) (errno int) {
+	ptr, n, err := sa.sockaddr()
+	if err != 0 {
+		return err
+	}
+	return connect(fd, ptr, n)
+}
+
+func Socket(domain, typ, proto int) (fd, errno int) {
+	if domain == AF_INET6 && SocketDisableIPv6 {
+		return -1, EAFNOSUPPORT
+	}
+	fd, errno = socket(domain, typ, proto)
+	return
+}
+
+func SetsockoptInt(fd, level, opt int, value int) (errno int) {
+	var n = int32(value)
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 4)
+}
+
+func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (errno int) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(tv)), unsafe.Sizeof(*tv))
+}
+
+func SetsockoptLinger(fd, level, opt int, l *Linger) (errno int) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(l)), unsafe.Sizeof(*l))
+}
+
+func SetsockoptString(fd, level, opt int, s string) (errno int) {
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), len(s))
+}
+
+//sys recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, errno int)
+
+func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, errno int) {
+	var rsa RawSockaddrAny
+	var len _Socklen = SizeofSockaddrAny
+	if n, errno = recvfrom(fd, p, flags, &rsa, &len); errno != 0 {
+		return
+	}
+	from, errno = anyToSockaddr(&rsa)
+	return
+}
+
+//sys sendto(s int, buf []byte, flags int, to uintptr, addrlen _Socklen) (errno int)
+
+func Sendto(fd int, p []byte, flags int, to Sockaddr) (errno int) {
+	ptr, n, err := to.sockaddr()
+	if err != 0 {
+		return err
+	}
+	return sendto(fd, p, flags, ptr, n)
+}
+
+//sys	kevent(kq int, change uintptr, nchange int, event uintptr, nevent int, timeout *Timespec) (n int, errno int)
+
+func Kevent(kq int, changes, events []Kevent_t, timeout *Timespec) (n int, errno int) {
+	var change, event uintptr
+	if len(changes) > 0 {
+		change = uintptr(unsafe.Pointer(&changes[0]))
+	}
+	if len(events) > 0 {
+		event = uintptr(unsafe.Pointer(&events[0]))
+	}
+	return kevent(kq, change, len(changes), event, len(events), timeout)
+}
+
+//sys	sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (errno int) = SYS___SYSCTL
+
+// Translate "kern.hostname" to []_C_int{0,1,2,3}.
+func nametomib(name string) (mib []_C_int, errno int) {
+	const CTL_MAXNAME = 12
+	const siz = uintptr(unsafe.Sizeof(mib[0]))
+
+	// NOTE(rsc): It seems strange to set the buffer to have
+	// size CTL_MAXNAME+2 but use only CTL_MAXNAME
+	// as the size.  I don't know why the +2 is here, but the
+	// kernel uses +2 for its own implementation of this function.
+	// I am scared that if we don't include the +2 here, the kernel
+	// will silently write 2 words farther than we specify
+	// and we'll get memory corruption.
+	var buf [CTL_MAXNAME + 2]_C_int
+	n := uintptr(CTL_MAXNAME) * siz
+
+	p := (*byte)(unsafe.Pointer(&buf[0]))
+	bytes := StringByteSlice(name)
+
+	// Magic sysctl: "setting" 0.3 to a string name
+	// lets you read back the array of integers form.
+	if errno = sysctl([]_C_int{0, 3}, p, &n, &bytes[0], uintptr(len(name))); errno != 0 {
+		return nil, errno
+	}
+	return buf[0 : n/siz], 0
+}
+
+func Sysctl(name string) (value string, errno int) {
+	// Translate name to mib number.
+	mib, errno := nametomib(name)
+	if errno != 0 {
+		return "", errno
+	}
+
+	// Find size.
+	n := uintptr(0)
+	if errno = sysctl(mib, nil, &n, nil, 0); errno != 0 {
+		return "", errno
+	}
+	if n == 0 {
+		return "", 0
+	}
+
+	// Read into buffer of that size.
+	buf := make([]byte, n)
+	if errno = sysctl(mib, &buf[0], &n, nil, 0); errno != 0 {
+		return "", errno
+	}
+
+	// Throw away terminating NUL.
+	if n > 0 && buf[n-1] == '\x00' {
+		n--
+	}
+	return string(buf[0:n]), 0
+}
+
+func SysctlUint32(name string) (value uint32, errno int) {
+	// Translate name to mib number.
+	mib, errno := nametomib(name)
+	if errno != 0 {
+		return 0, errno
+	}
+
+	// Read into buffer of that size.
+	n := uintptr(4)
+	buf := make([]byte, 4)
+	if errno = sysctl(mib, &buf[0], &n, nil, 0); errno != 0 {
+		return 0, errno
+	}
+	if n != 4 {
+		return 0, EIO
+	}
+	return *(*uint32)(unsafe.Pointer(&buf[0])), 0
+}
+
+// TODO: wrap
+//	Acct(name nil-string) (errno int)
+//	Futimes(fd int, timeval *Timeval) (errno int)	// Pointer to 2 timevals!
+//	Gethostuuid(uuid *byte, timeout *Timespec) (errno int)
+//	Getsockopt(s int, level int, name int, val *byte, vallen *int) (errno int)
+//	Madvise(addr *byte, len int, behav int) (errno int)
+//	Mprotect(addr *byte, len int, prot int) (errno int)
+//	Msync(addr *byte, len int, flags int) (errno int)
+//	Munmap(addr *byte, len int) (errno int)
+//	Ptrace(req int, pid int, addr uintptr, data int) (ret uintptr, errno int)
+//	Recvmsg(s int, msg *Msghdr, flags int) (n int, errno int)
+//	Sendmsg(s int, msg *Msghdr, flags int) (n int, errno int)
+//	Utimes(path string, timeval *Timeval) (errno int)	// Pointer to 2 timevals!
+//sys	fcntl(fd int, cmd int, arg int) (val int, errno int)