syscall: add AIX operating system

This commit adds AIX operating system to syscall package for ppc64
architecture.
It also adds the file syscall_aix.go in the runtime package for
syscalls needed during fork and exec.

Updates: #25893

Change-Id: I301b1051b178a3efb7bbc39cdbd8e00b594d65ef
Reviewed-on: https://go-review.googlesource.com/c/138720
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/runtime/syscall_aix.go

+// Copyright 2018 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.
+
+package runtime
+
+import "unsafe"
+
+// This file handles some syscalls from the syscall package
+// Especially, syscalls use during forkAndExecInChild which must not split the stack
+
+//go:cgo_import_dynamic libc_chdir chdir "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_chroot chroot "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_dup2 dup2 "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_execve execve "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_fcntl fcntl "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_fork fork "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_ioctl ioctl "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_setgid setgid "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_setgroups setgroups "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_setsid setsid "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_setuid setuid "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_setpgid setpgid "libc.a/shr_64.o"
+
+//go:linkname libc_chdir libc_chdir
+//go:linkname libc_chroot libc_chroot
+//go:linkname libc_dup2 libc_dup2
+//go:linkname libc_execve libc_execve
+//go:linkname libc_fcntl libc_fcntl
+//go:linkname libc_fork libc_fork
+//go:linkname libc_ioctl libc_ioctl
+//go:linkname libc_setgid libc_setgid
+//go:linkname libc_setgroups libc_setgroups
+//go:linkname libc_setsid libc_setsid
+//go:linkname libc_setuid libc_setuid
+//go:linkname libc_setpgid libc_setpgid
+
+var (
+	libc_chdir,
+	libc_chroot,
+	libc_dup2,
+	libc_execve,
+	libc_fcntl,
+	libc_fork,
+	libc_ioctl,
+	libc_setgid,
+	libc_setgroups,
+	libc_setsid,
+	libc_setuid,
+	libc_setpgid libFunc
+)
+
+// In syscall_syscall6 and syscall_rawsyscall6, r2 is always 0
+// as it's never used on AIX
+// TODO: remove r2 from zsyscall_aix_$GOARCH.go
+
+// Syscall is needed because some packages (like net) need it too.
+// The best way is to return EINVAL and let Golang handles its failure
+// If the syscall can't fail, this function can redirect it to a real syscall.
+//go:linkname syscall_Syscall syscall.Syscall
+//go:nosplit
+func syscall_Syscall(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
+	return 0, 0, _EINVAL
+}
+
+// This is syscall.RawSyscall, it exists to satisfy some build dependency,
+// but it doesn't work.
+//go:linkname syscall_RawSyscall syscall.RawSyscall
+func syscall_RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
+	panic("RawSyscall not available on AIX")
+}
+
+//go:linkname syscall_syscall6 syscall.syscall6
+//go:nosplit
+func syscall_syscall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
+	c := getg().m.libcall
+	c.fn = uintptr(unsafe.Pointer(fn))
+	c.n = nargs
+	c.args = uintptr(noescape(unsafe.Pointer(&a1)))
+
+	entersyscallblock()
+	asmcgocall(unsafe.Pointer(&asmsyscall6), unsafe.Pointer(&c))
+	exitsyscall()
+	return c.r1, 0, c.err
+}
+
+//go:linkname syscall_rawSyscall6 syscall.rawSyscall6
+//go:nosplit
+func syscall_rawSyscall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
+	c := getg().m.libcall
+	c.fn = uintptr(unsafe.Pointer(fn))
+	c.n = nargs
+	c.args = uintptr(noescape(unsafe.Pointer(&a1)))
+
+	asmcgocall(unsafe.Pointer(&asmsyscall6), unsafe.Pointer(&c))
+
+	return c.r1, 0, c.err
+}
+
+//go:linkname syscall_chdir syscall.chdir
+//go:nosplit
+func syscall_chdir(path uintptr) (err uintptr) {
+	_, err = syscall1(&libc_chdir, path)
+	return
+}
+
+//go:linkname syscall_chroot1 syscall.chroot1
+//go:nosplit
+func syscall_chroot1(path uintptr) (err uintptr) {
+	_, err = syscall1(&libc_chroot, path)
+	return
+}
+
+// like close, but must not split stack, for fork.
+//go:linkname syscall_close syscall.close
+//go:nosplit
+func syscall_close(fd int32) int32 {
+	_, err := syscall1(&libc_close, uintptr(fd))
+	return int32(err)
+}
+
+//go:linkname syscall_dup2child syscall.dup2child
+//go:nosplit
+func syscall_dup2child(old, new uintptr) (val, err uintptr) {
+	val, err = syscall2(&libc_dup2, old, new)
+	return
+}
+
+//go:linkname syscall_execve syscall.execve
+//go:nosplit
+func syscall_execve(path, argv, envp uintptr) (err uintptr) {
+	_, err = syscall3(&libc_execve, path, argv, envp)
+	return
+}
+
+// like exit, but must not split stack, for fork.
+//go:linkname syscall_exit syscall.exit
+//go:nosplit
+func syscall_exit(code uintptr) {
+	syscall1(&libc_exit, code)
+}
+
+//go:linkname syscall_fcntl1 syscall.fcntl1
+//go:nosplit
+func syscall_fcntl1(fd, cmd, arg uintptr) (val, err uintptr) {
+	val, err = syscall3(&libc_fcntl, fd, cmd, arg)
+	return
+
+}
+
+//go:linkname syscall_forkx syscall.forkx
+//go:nosplit
+func syscall_forkx(flags uintptr) (pid uintptr, err uintptr) {
+	pid, err = syscall1(&libc_fork, flags)
+	return
+}
+
+//go:linkname syscall_getpid syscall.getpid
+//go:nosplit
+func syscall_getpid() (pid, err uintptr) {
+	pid, err = syscall0(&libc_getpid)
+	return
+}
+
+//go:linkname syscall_ioctl syscall.ioctl
+//go:nosplit
+func syscall_ioctl(fd, req, arg uintptr) (err uintptr) {
+	_, err = syscall3(&libc_ioctl, fd, req, arg)
+	return
+}
+
+//go:linkname syscall_setgid syscall.setgid
+//go:nosplit
+func syscall_setgid(gid uintptr) (err uintptr) {
+	_, err = syscall1(&libc_setgid, gid)
+	return
+}
+
+//go:linkname syscall_setgroups1 syscall.setgroups1
+//go:nosplit
+func syscall_setgroups1(ngid, gid uintptr) (err uintptr) {
+	_, err = syscall2(&libc_setgroups, ngid, gid)
+	return
+}
+
+//go:linkname syscall_setsid syscall.setsid
+//go:nosplit
+func syscall_setsid() (pid, err uintptr) {
+	pid, err = syscall0(&libc_setsid)
+	return
+}
+
+//go:linkname syscall_setuid syscall.setuid
+//go:nosplit
+func syscall_setuid(uid uintptr) (err uintptr) {
+	_, err = syscall1(&libc_setuid, uid)
+	return
+}
+
+//go:linkname syscall_setpgid syscall.setpgid
+//go:nosplit
+func syscall_setpgid(pid, pgid uintptr) (err uintptr) {
+	_, err = syscall2(&libc_setpgid, pid, pgid)
+	return
+}
+
+//go:linkname syscall_write1 syscall.write1
+//go:nosplit
+func syscall_write1(fd, buf, nbyte uintptr) (n, err uintptr) {
+	n, err = syscall3(&libc_write, fd, buf, nbyte)
+	return
+}

src/syscall/dirent.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
 
 package syscall
 

src/syscall/env_unix.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
 
 // Unix environment variables.
 

src/syscall/exec_aix_test.go

+// Copyright 2015 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.
+
+// +build aix
+
+package syscall
+
+import "unsafe"
+
+//go:cgo_import_dynamic libc_Getpgid getpgid "libc.a/shr_64.o"
+//go:cgo_import_dynamic libc_Getpgrp getpgrp "libc.a/shr_64.o"
+
+//go:linkname libc_Getpgid libc_Getpgid
+//go:linkname libc_Getpgrp libc_Getpgrp
+
+var (
+	libc_Getpgid,
+	libc_Getpgrp libcFunc
+)
+
+func Getpgid(pid int) (pgid int, err error) {
+	r0, _, e1 := syscall6(uintptr(unsafe.Pointer(&libc_Getpgid)), 1, uintptr(pid), 0, 0, 0, 0, 0)
+	pgid = int(r0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+func Getpgrp() (pgrp int) {
+	r0, _, _ := syscall6(uintptr(unsafe.Pointer(&libc_Getpgrp)), 0, 0, 0, 0, 0, 0, 0)
+	pgrp = int(r0)
+	return
+}
+
+var Ioctl = ioctl

src/syscall/exec_unix_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
 
 package syscall_test
 

src/syscall/flock_aix.go

+// Copyright 2018 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.
+
+package syscall
+
+import "unsafe"
+
+// On AIX, there is no flock() system call, we emulate it.
+// Moreover, we can't call the default fcntl syscall because the arguments
+// must be integer and it's not possible to transform a pointer (lk)
+// to a int value.
+// It's easier to call syscall6 than to transform fcntl for every GOOS.
+func fcntlFlock(fd, cmd int, lk *Flock_t) (err error) {
+	_, _, e1 := syscall6(uintptr(unsafe.Pointer(&libc_fcntl)), 3, uintptr(fd), uintptr(cmd), uintptr(unsafe.Pointer(lk)), 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func Flock(fd int, op int) (err error) {
+	lk := &Flock_t{}
+	if (op & LOCK_UN) != 0 {
+		lk.Type = F_UNLCK
+	} else if (op & LOCK_EX) != 0 {
+		lk.Type = F_WRLCK
+	} else if (op & LOCK_SH) != 0 {
+		lk.Type = F_RDLCK
+	} else {
+		return nil
+	}
+	if (op & LOCK_NB) != 0 {
+		err = fcntlFlock(fd, F_SETLK, lk)
+		if err != nil && (err == EAGAIN || err == EACCES) {
+			return EWOULDBLOCK
+		}
+		return err
+	}
+	return fcntlFlock(fd, F_SETLKW, lk)
+}

src/syscall/forkpipe.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly solaris
+// +build aix darwin dragonfly solaris
 
 package syscall
 

src/syscall/mkerrors.sh

@@ -20,6 +20,16 @@ fi
 
 uname=$(uname)
 
+includes_AIX='
+#include <net/if.h>
+#include <net/netopt.h>
+#include <netinet/ip_mroute.h>
+#include <sys/mman.h>
+#include <sys/protosw.h>
+#include <sys/ptrace.h>
+#include <sys/stropts.h>
+'
+
 includes_Darwin='
 #define _DARWIN_C_SOURCE
 #define KERNEL

src/syscall/mmap_unix_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux netbsd openbsd
+// +build aix darwin dragonfly freebsd linux netbsd openbsd
 
 package syscall_test
 

src/syscall/sockcmsg_unix.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
 
 // Socket control messages
 

src/syscall/syscall_aix_ppc64.go

+// Copyright 2018 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.
+
+package syscall
+
+func (iov *Iovec) SetLen(length int) {
+	iov.Len = uint64(length)
+}
+
+func (msghdr *Msghdr) SetControllen(length int) {
+	msghdr.Controllen = uint32(length)
+}
+
+func (cmsg *Cmsghdr) SetLen(length int) {
+	cmsg.Len = uint32(length)
+}

src/syscall/syscall_unix.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
 
 package syscall
 

src/syscall/timestruct.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
 
 package syscall
 

src/syscall/types_aix.go

+// Copyright 2018 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.
+
+// +build ignore
+
+/*
+Input to cgo -godefs.  See also mkerrors.sh and mkall.sh
+*/
+
+// +godefs map struct_in_addr [4]byte /* in_addr */
+// +godefs map struct_in6_addr [16]byte /* in6_addr */
+
+package syscall
+
+/*
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/limits.h>
+#include <sys/un.h>
+#include <sys/utsname.h>
+#include <sys/ptrace.h>
+#include <sys/statfs.h>
+
+#include <net/if.h>
+#include <netinet/in.h>
+#include <netinet/icmp6.h>
+
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <gcrypt.h>
+
+enum {
+	sizeofPtr = sizeof(void*),
+};
+
+union sockaddr_all {
+	struct sockaddr s1;	// this one gets used for fields
+	struct sockaddr_in s2;	// these pad it out
+	struct sockaddr_in6 s3;
+	struct sockaddr_un s4;
+};
+
+struct sockaddr_any {
+	struct sockaddr addr;
+	char pad[sizeof(union sockaddr_all) - sizeof(struct sockaddr)];
+};
+
+*/
+import "C"
+
+// Machine characteristics; for internal use.
+
+const (
+	sizeofPtr      = C.sizeofPtr
+	sizeofShort    = C.sizeof_short
+	sizeofInt      = C.sizeof_int
+	sizeofLong     = C.sizeof_long
+	sizeofLongLong = C.sizeof_longlong
+	PathMax        = C.PATH_MAX
+)
+
+// Basic types
+
+type (
+	_C_short     C.short
+	_C_int       C.int
+	_C_long      C.long
+	_C_long_long C.longlong
+)
+
+// Time
+
+type Timespec C.struct_timespec
+
+type Timeval C.struct_timeval
+
+type Timeval32 C.struct_timeval32
+
+type Timezone C.struct_timezone
+
+// Processes
+
+type Rusage C.struct_rusage
+
+type Rlimit C.struct_rlimit
+
+type Pid_t C.pid_t
+
+type _Gid_t C.gid_t
+
+// Files
+
+type Flock_t C.struct_flock
+
+type Stat_t C.struct_stat
+
+type Statfs_t C.struct_statfs
+
+type Fsid64_t C.fsid64_t
+
+type StTimespec_t C.st_timespec_t
+
+type Dirent C.struct_dirent
+
+// Sockets
+
+type RawSockaddrInet4 C.struct_sockaddr_in
+
+type RawSockaddrInet6 C.struct_sockaddr_in6
+
+type RawSockaddrUnix C.struct_sockaddr_un
+
+type RawSockaddr C.struct_sockaddr
+
+type RawSockaddrAny C.struct_sockaddr_any
+
+type _Socklen C.socklen_t
+
+type Cmsghdr C.struct_cmsghdr
+
+type ICMPv6Filter C.struct_icmp6_filter
+
+type Iovec C.struct_iovec
+
+type IPMreq C.struct_ip_mreq
+
+type IPv6Mreq C.struct_ipv6_mreq
+
+type Linger C.struct_linger
+
+type Msghdr C.struct_msghdr
+
+const (
+	SizeofSockaddrInet4 = C.sizeof_struct_sockaddr_in
+	SizeofSockaddrInet6 = C.sizeof_struct_sockaddr_in6
+	SizeofSockaddrAny   = C.sizeof_struct_sockaddr_any
+	SizeofSockaddrUnix  = C.sizeof_struct_sockaddr_un
+	SizeofLinger        = C.sizeof_struct_linger
+	SizeofIPMreq        = C.sizeof_struct_ip_mreq
+	SizeofIPv6Mreq      = C.sizeof_struct_ipv6_mreq
+	SizeofMsghdr        = C.sizeof_struct_msghdr
+	SizeofCmsghdr       = C.sizeof_struct_cmsghdr
+	SizeofICMPv6Filter  = C.sizeof_struct_icmp6_filter
+)
+
+// Ptrace requests
+
+const (
+	PTRACE_TRACEME = C.PT_TRACE_ME
+	PTRACE_CONT    = C.PT_CONTINUE
+	PTRACE_KILL    = C.PT_KILL
+)
+
+// Routing and interface messages
+
+const (
+	SizeofIfMsghdr = C.sizeof_struct_if_msghdr
+)
+
+type IfMsgHdr C.struct_if_msghdr
+
+// Misc
+
+type Utsname C.struct_utsname
+
+const (
+	_AT_FDCWD            = C.AT_FDCWD
+	_AT_REMOVEDIR        = C.AT_REMOVEDIR
+	_AT_SYMLINK_NOFOLLOW = C.AT_SYMLINK_NOFOLLOW
+)

src/syscall/ztypes_aix_ppc64.go

+// Code generated by cmd/cgo -godefs; DO NOT EDIT.
+// cgo -godefs types_aix.go | go run mkpost.go
+
+package syscall
+
+const (
+	sizeofPtr      = 0x8
+	sizeofShort    = 0x2
+	sizeofInt      = 0x4
+	sizeofLong     = 0x8
+	sizeofLongLong = 0x8
+	PathMax        = 0x3ff
+)
+
+type (
+	_C_short     int16
+	_C_int       int32
+	_C_long      int64
+	_C_long_long int64
+)
+
+type Timespec struct {
+	Sec  int64
+	Nsec int64
+}
+
+type Timeval struct {
+	Sec       int64
+	Usec      int32
+	Pad_cgo_0 [4]byte
+}
+
+type Timeval32 struct {
+	Sec  int32
+	Usec int32
+}
+
+type Timezone struct {
+	Minuteswest int32
+	Dsttime     int32
+}
+
+type Rusage struct {
+	Utime    Timeval
+	Stime    Timeval
+	Maxrss   int64
+	Ixrss    int64
+	Idrss    int64
+	Isrss    int64
+	Minflt   int64
+	Majflt   int64
+	Nswap    int64
+	Inblock  int64
+	Oublock  int64
+	Msgsnd   int64
+	Msgrcv   int64
+	Nsignals int64
+	Nvcsw    int64
+	Nivcsw   int64
+}
+
+type Rlimit struct {
+	Cur uint64
+	Max uint64
+}
+
+type Pid_t int32
+
+type _Gid_t uint32
+
+type Flock_t struct {
+	Type   int16
+	Whence int16
+	Sysid  uint32
+	Pid    int32
+	Vfs    int32
+	Start  int64
+	Len    int64
+}
+
+type Stat_t struct {
+	Dev       uint64
+	Ino       uint64
+	Mode      uint32
+	Nlink     int16
+	Flag      uint16
+	Uid       uint32
+	Gid       uint32
+	Rdev      uint64
+	Ssize     int32
+	Pad_cgo_0 [4]byte
+	Atim      StTimespec_t
+	Mtim      StTimespec_t
+	Ctim      StTimespec_t
+	Blksize   int64
+	Blocks    int64
+	Vfstype   int32
+	Vfs       uint32
+	Type      uint32
+	Gen       uint32
+	Reserved  [9]uint32
+	Padto_ll  uint32
+	Size      int64
+}
+
+type Statfs_t struct {
+	Version   int32
+	Type      int32
+	Bsize     uint64
+	Blocks    uint64
+	Bfree     uint64
+	Bavail    uint64
+	Files     uint64
+	Ffree     uint64
+	Fsid      Fsid64_t
+	Vfstype   int32
+	Pad_cgo_0 [4]byte
+	Fsize     uint64
+	Vfsnumber int32
+	Vfsoff    int32
+	Vfslen    int32
+	Vfsvers   int32
+	Fname     [32]uint8
+	Fpack     [32]uint8
+	Name_max  int32
+	Pad_cgo_1 [4]byte
+}
+
+type Fsid64_t struct {
+	Val [2]uint64
+}
+
+type StTimespec_t struct {
+	Sec       int64
+	Nsec      int32
+	Pad_cgo_0 [4]byte
+}
+
+type Dirent struct {
+	Offset    uint64
+	Ino       uint64
+	Reclen    uint16
+	Namlen    uint16
+	Name      [256]uint8
+	Pad_cgo_0 [4]byte
+}
+
+type RawSockaddrInet4 struct {
+	Len    uint8
+	Family uint8
+	Port   uint16
+	Addr   [4]byte /* in_addr */
+	Zero   [8]uint8
+}
+
+type RawSockaddrInet6 struct {
+	Len      uint8
+	Family   uint8
+	Port     uint16
+	Flowinfo uint32
+	Addr     [16]byte /* in6_addr */
+	Scope_id uint32
+}
+
+type RawSockaddrUnix struct {
+	Len    uint8
+	Family uint8
+	Path   [1023]uint8
+}
+
+type RawSockaddr struct {
+	Len    uint8
+	Family uint8
+	Data   [14]uint8
+}
+
+type RawSockaddrAny struct {
+	Addr RawSockaddr
+	Pad  [1012]uint8
+}
+
+type _Socklen uint32
+
+type Cmsghdr struct {
+	Len   uint32
+	Level int32
+	Type  int32
+}
+
+type ICMPv6Filter struct {
+	Filt [8]uint32
+}
+
+type Iovec struct {
+	Base *byte
+	Len  uint64
+}
+
+type IPMreq struct {
+	Multiaddr [4]byte /* in_addr */
+	Interface [4]byte /* in_addr */
+}
+
+type IPv6Mreq struct {
+	Multiaddr [16]byte /* in6_addr */
+	Interface uint32
+}
+
+type Linger struct {
+	Onoff  int32
+	Linger int32
+}
+
+type Msghdr struct {
+	Name       *byte
+	Namelen    uint32
+	Pad_cgo_0  [4]byte
+	Iov        *Iovec
+	Iovlen     int32
+	Pad_cgo_1  [4]byte
+	Control    *byte
+	Controllen uint32
+	Flags      int32
+}
+
+const (
+	SizeofSockaddrInet4 = 0x10
+	SizeofSockaddrInet6 = 0x1c
+	SizeofSockaddrAny   = 0x404
+	SizeofSockaddrUnix  = 0x401
+	SizeofLinger        = 0x8
+	SizeofIPMreq        = 0x8
+	SizeofIPv6Mreq      = 0x14
+	SizeofMsghdr        = 0x30
+	SizeofCmsghdr       = 0xc
+	SizeofICMPv6Filter  = 0x20
+)
+
+const (
+	PTRACE_TRACEME = 0x0
+	PTRACE_CONT    = 0x7
+	PTRACE_KILL    = 0x8
+)
+
+const (
+	SizeofIfMsghdr = 0x10
+)
+
+type IfMsgHdr struct {
+	Msglen    uint16
+	Version   uint8
+	Type      uint8
+	Addrs     int32
+	Flags     int32
+	Index     uint16
+	Addrlen   uint8
+	Pad_cgo_0 [1]byte
+}
+
+type Utsname struct {
+	Sysname  [32]uint8
+	Nodename [32]uint8
+	Release  [32]uint8
+	Version  [32]uint8
+	Machine  [32]uint8
+}
+
+const (
+	_AT_FDCWD            = -0x2
+	_AT_REMOVEDIR        = 0x1
+	_AT_SYMLINK_NOFOLLOW = 0x1
+)