github.com/HACKERALERT/Picocrypt/src/external/sys@v0.0.0-20210609020157-e519952f829f/unix/syscall_bsd.go (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build darwin || dragonfly || freebsd || netbsd || openbsd
     6  // +build darwin dragonfly freebsd netbsd openbsd
     7  
     8  // BSD system call wrappers shared by *BSD based systems
     9  // including OS X (Darwin) and FreeBSD.  Like the other
    10  // syscall_*.go files it is compiled as Go code but also
    11  // used as input to mksyscall which parses the //sys
    12  // lines and generates system call stubs.
    13  
    14  package unix
    15  
    16  import (
    17  	"runtime"
    18  	"syscall"
    19  	"unsafe"
    20  )
    21  
    22  const ImplementsGetwd = true
    23  
    24  func Getwd() (string, error) {
    25  	var buf [PathMax]byte
    26  	_, err := Getcwd(buf[0:])
    27  	if err != nil {
    28  		return "", err
    29  	}
    30  	n := clen(buf[:])
    31  	if n < 1 {
    32  		return "", EINVAL
    33  	}
    34  	return string(buf[:n]), nil
    35  }
    36  
    37  /*
    38   * Wrapped
    39   */
    40  
    41  //sysnb	getgroups(ngid int, gid *_Gid_t) (n int, err error)
    42  //sysnb	setgroups(ngid int, gid *_Gid_t) (err error)
    43  
    44  func Getgroups() (gids []int, err error) {
    45  	n, err := getgroups(0, nil)
    46  	if err != nil {
    47  		return nil, err
    48  	}
    49  	if n == 0 {
    50  		return nil, nil
    51  	}
    52  
    53  	// Sanity check group count. Max is 16 on BSD.
    54  	if n < 0 || n > 1000 {
    55  		return nil, EINVAL
    56  	}
    57  
    58  	a := make([]_Gid_t, n)
    59  	n, err = getgroups(n, &a[0])
    60  	if err != nil {
    61  		return nil, err
    62  	}
    63  	gids = make([]int, n)
    64  	for i, v := range a[0:n] {
    65  		gids[i] = int(v)
    66  	}
    67  	return
    68  }
    69  
    70  func Setgroups(gids []int) (err error) {
    71  	if len(gids) == 0 {
    72  		return setgroups(0, nil)
    73  	}
    74  
    75  	a := make([]_Gid_t, len(gids))
    76  	for i, v := range gids {
    77  		a[i] = _Gid_t(v)
    78  	}
    79  	return setgroups(len(a), &a[0])
    80  }
    81  
    82  // Wait status is 7 bits at bottom, either 0 (exited),
    83  // 0x7F (stopped), or a signal number that caused an exit.
    84  // The 0x80 bit is whether there was a core dump.
    85  // An extra number (exit code, signal causing a stop)
    86  // is in the high bits.
    87  
    88  type WaitStatus uint32
    89  
    90  const (
    91  	mask  = 0x7F
    92  	core  = 0x80
    93  	shift = 8
    94  
    95  	exited  = 0
    96  	killed  = 9
    97  	stopped = 0x7F
    98  )
    99  
   100  func (w WaitStatus) Exited() bool { return w&mask == exited }
   101  
   102  func (w WaitStatus) ExitStatus() int {
   103  	if w&mask != exited {
   104  		return -1
   105  	}
   106  	return int(w >> shift)
   107  }
   108  
   109  func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }
   110  
   111  func (w WaitStatus) Signal() syscall.Signal {
   112  	sig := syscall.Signal(w & mask)
   113  	if sig == stopped || sig == 0 {
   114  		return -1
   115  	}
   116  	return sig
   117  }
   118  
   119  func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
   120  
   121  func (w WaitStatus) Stopped() bool { return w&mask == stopped && syscall.Signal(w>>shift) != SIGSTOP }
   122  
   123  func (w WaitStatus) Killed() bool { return w&mask == killed && syscall.Signal(w>>shift) != SIGKILL }
   124  
   125  func (w WaitStatus) Continued() bool { return w&mask == stopped && syscall.Signal(w>>shift) == SIGSTOP }
   126  
   127  func (w WaitStatus) StopSignal() syscall.Signal {
   128  	if !w.Stopped() {
   129  		return -1
   130  	}
   131  	return syscall.Signal(w>>shift) & 0xFF
   132  }
   133  
   134  func (w WaitStatus) TrapCause() int { return -1 }
   135  
   136  //sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)
   137  
   138  func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
   139  	var status _C_int
   140  	wpid, err = wait4(pid, &status, options, rusage)
   141  	if wstatus != nil {
   142  		*wstatus = WaitStatus(status)
   143  	}
   144  	return
   145  }
   146  
   147  //sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error)
   148  //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
   149  //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
   150  //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
   151  //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
   152  //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
   153  //sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
   154  //sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
   155  //sys	Shutdown(s int, how int) (err error)
   156  
   157  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
   158  	if sa.Port < 0 || sa.Port > 0xFFFF {
   159  		return nil, 0, EINVAL
   160  	}
   161  	sa.raw.Len = SizeofSockaddrInet4
   162  	sa.raw.Family = AF_INET
   163  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   164  	p[0] = byte(sa.Port >> 8)
   165  	p[1] = byte(sa.Port)
   166  	for i := 0; i < len(sa.Addr); i++ {
   167  		sa.raw.Addr[i] = sa.Addr[i]
   168  	}
   169  	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
   170  }
   171  
   172  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
   173  	if sa.Port < 0 || sa.Port > 0xFFFF {
   174  		return nil, 0, EINVAL
   175  	}
   176  	sa.raw.Len = SizeofSockaddrInet6
   177  	sa.raw.Family = AF_INET6
   178  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   179  	p[0] = byte(sa.Port >> 8)
   180  	p[1] = byte(sa.Port)
   181  	sa.raw.Scope_id = sa.ZoneId
   182  	for i := 0; i < len(sa.Addr); i++ {
   183  		sa.raw.Addr[i] = sa.Addr[i]
   184  	}
   185  	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
   186  }
   187  
   188  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
   189  	name := sa.Name
   190  	n := len(name)
   191  	if n >= len(sa.raw.Path) || n == 0 {
   192  		return nil, 0, EINVAL
   193  	}
   194  	sa.raw.Len = byte(3 + n) // 2 for Family, Len; 1 for NUL
   195  	sa.raw.Family = AF_UNIX
   196  	for i := 0; i < n; i++ {
   197  		sa.raw.Path[i] = int8(name[i])
   198  	}
   199  	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
   200  }
   201  
   202  func (sa *SockaddrDatalink) sockaddr() (unsafe.Pointer, _Socklen, error) {
   203  	if sa.Index == 0 {
   204  		return nil, 0, EINVAL
   205  	}
   206  	sa.raw.Len = sa.Len
   207  	sa.raw.Family = AF_LINK
   208  	sa.raw.Index = sa.Index
   209  	sa.raw.Type = sa.Type
   210  	sa.raw.Nlen = sa.Nlen
   211  	sa.raw.Alen = sa.Alen
   212  	sa.raw.Slen = sa.Slen
   213  	for i := 0; i < len(sa.raw.Data); i++ {
   214  		sa.raw.Data[i] = sa.Data[i]
   215  	}
   216  	return unsafe.Pointer(&sa.raw), SizeofSockaddrDatalink, nil
   217  }
   218  
   219  func anyToSockaddr(fd int, rsa *RawSockaddrAny) (Sockaddr, error) {
   220  	switch rsa.Addr.Family {
   221  	case AF_LINK:
   222  		pp := (*RawSockaddrDatalink)(unsafe.Pointer(rsa))
   223  		sa := new(SockaddrDatalink)
   224  		sa.Len = pp.Len
   225  		sa.Family = pp.Family
   226  		sa.Index = pp.Index
   227  		sa.Type = pp.Type
   228  		sa.Nlen = pp.Nlen
   229  		sa.Alen = pp.Alen
   230  		sa.Slen = pp.Slen
   231  		for i := 0; i < len(sa.Data); i++ {
   232  			sa.Data[i] = pp.Data[i]
   233  		}
   234  		return sa, nil
   235  
   236  	case AF_UNIX:
   237  		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
   238  		if pp.Len < 2 || pp.Len > SizeofSockaddrUnix {
   239  			return nil, EINVAL
   240  		}
   241  		sa := new(SockaddrUnix)
   242  
   243  		// Some BSDs include the trailing NUL in the length, whereas
   244  		// others do not. Work around this by subtracting the leading
   245  		// family and len. The path is then scanned to see if a NUL
   246  		// terminator still exists within the length.
   247  		n := int(pp.Len) - 2 // subtract leading Family, Len
   248  		for i := 0; i < n; i++ {
   249  			if pp.Path[i] == 0 {
   250  				// found early NUL; assume Len included the NUL
   251  				// or was overestimating.
   252  				n = i
   253  				break
   254  			}
   255  		}
   256  		bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]))[0:n]
   257  		sa.Name = string(bytes)
   258  		return sa, nil
   259  
   260  	case AF_INET:
   261  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
   262  		sa := new(SockaddrInet4)
   263  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   264  		sa.Port = int(p[0])<<8 + int(p[1])
   265  		for i := 0; i < len(sa.Addr); i++ {
   266  			sa.Addr[i] = pp.Addr[i]
   267  		}
   268  		return sa, nil
   269  
   270  	case AF_INET6:
   271  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
   272  		sa := new(SockaddrInet6)
   273  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   274  		sa.Port = int(p[0])<<8 + int(p[1])
   275  		sa.ZoneId = pp.Scope_id
   276  		for i := 0; i < len(sa.Addr); i++ {
   277  			sa.Addr[i] = pp.Addr[i]
   278  		}
   279  		return sa, nil
   280  	}
   281  	return anyToSockaddrGOOS(fd, rsa)
   282  }
   283  
   284  func Accept(fd int) (nfd int, sa Sockaddr, err error) {
   285  	var rsa RawSockaddrAny
   286  	var len _Socklen = SizeofSockaddrAny
   287  	nfd, err = accept(fd, &rsa, &len)
   288  	if err != nil {
   289  		return
   290  	}
   291  	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && len == 0 {
   292  		// Accepted socket has no address.
   293  		// This is likely due to a bug in xnu kernels,
   294  		// where instead of ECONNABORTED error socket
   295  		// is accepted, but has no address.
   296  		Close(nfd)
   297  		return 0, nil, ECONNABORTED
   298  	}
   299  	sa, err = anyToSockaddr(fd, &rsa)
   300  	if err != nil {
   301  		Close(nfd)
   302  		nfd = 0
   303  	}
   304  	return
   305  }
   306  
   307  func Getsockname(fd int) (sa Sockaddr, err error) {
   308  	var rsa RawSockaddrAny
   309  	var len _Socklen = SizeofSockaddrAny
   310  	if err = getsockname(fd, &rsa, &len); err != nil {
   311  		return
   312  	}
   313  	// TODO(jsing): DragonFly has a "bug" (see issue 3349), which should be
   314  	// reported upstream.
   315  	if runtime.GOOS == "dragonfly" && rsa.Addr.Family == AF_UNSPEC && rsa.Addr.Len == 0 {
   316  		rsa.Addr.Family = AF_UNIX
   317  		rsa.Addr.Len = SizeofSockaddrUnix
   318  	}
   319  	return anyToSockaddr(fd, &rsa)
   320  }
   321  
   322  //sysnb	socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)
   323  
   324  // GetsockoptString returns the string value of the socket option opt for the
   325  // socket associated with fd at the given socket level.
   326  func GetsockoptString(fd, level, opt int) (string, error) {
   327  	buf := make([]byte, 256)
   328  	vallen := _Socklen(len(buf))
   329  	err := getsockopt(fd, level, opt, unsafe.Pointer(&buf[0]), &vallen)
   330  	if err != nil {
   331  		return "", err
   332  	}
   333  	return string(buf[:vallen-1]), nil
   334  }
   335  
   336  //sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
   337  //sys	sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
   338  //sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
   339  
   340  func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
   341  	var msg Msghdr
   342  	var rsa RawSockaddrAny
   343  	msg.Name = (*byte)(unsafe.Pointer(&rsa))
   344  	msg.Namelen = uint32(SizeofSockaddrAny)
   345  	var iov Iovec
   346  	if len(p) > 0 {
   347  		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
   348  		iov.SetLen(len(p))
   349  	}
   350  	var dummy byte
   351  	if len(oob) > 0 {
   352  		// receive at least one normal byte
   353  		if len(p) == 0 {
   354  			iov.Base = &dummy
   355  			iov.SetLen(1)
   356  		}
   357  		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
   358  		msg.SetControllen(len(oob))
   359  	}
   360  	msg.Iov = &iov
   361  	msg.Iovlen = 1
   362  	if n, err = recvmsg(fd, &msg, flags); err != nil {
   363  		return
   364  	}
   365  	oobn = int(msg.Controllen)
   366  	recvflags = int(msg.Flags)
   367  	// source address is only specified if the socket is unconnected
   368  	if rsa.Addr.Family != AF_UNSPEC {
   369  		from, err = anyToSockaddr(fd, &rsa)
   370  	}
   371  	return
   372  }
   373  
   374  //sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
   375  
   376  func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
   377  	_, err = SendmsgN(fd, p, oob, to, flags)
   378  	return
   379  }
   380  
   381  func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
   382  	var ptr unsafe.Pointer
   383  	var salen _Socklen
   384  	if to != nil {
   385  		ptr, salen, err = to.sockaddr()
   386  		if err != nil {
   387  			return 0, err
   388  		}
   389  	}
   390  	var msg Msghdr
   391  	msg.Name = (*byte)(unsafe.Pointer(ptr))
   392  	msg.Namelen = uint32(salen)
   393  	var iov Iovec
   394  	if len(p) > 0 {
   395  		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
   396  		iov.SetLen(len(p))
   397  	}
   398  	var dummy byte
   399  	if len(oob) > 0 {
   400  		// send at least one normal byte
   401  		if len(p) == 0 {
   402  			iov.Base = &dummy
   403  			iov.SetLen(1)
   404  		}
   405  		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
   406  		msg.SetControllen(len(oob))
   407  	}
   408  	msg.Iov = &iov
   409  	msg.Iovlen = 1
   410  	if n, err = sendmsg(fd, &msg, flags); err != nil {
   411  		return 0, err
   412  	}
   413  	if len(oob) > 0 && len(p) == 0 {
   414  		n = 0
   415  	}
   416  	return n, nil
   417  }
   418  
   419  //sys	kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error)
   420  
   421  func Kevent(kq int, changes, events []Kevent_t, timeout *Timespec) (n int, err error) {
   422  	var change, event unsafe.Pointer
   423  	if len(changes) > 0 {
   424  		change = unsafe.Pointer(&changes[0])
   425  	}
   426  	if len(events) > 0 {
   427  		event = unsafe.Pointer(&events[0])
   428  	}
   429  	return kevent(kq, change, len(changes), event, len(events), timeout)
   430  }
   431  
   432  // sysctlmib translates name to mib number and appends any additional args.
   433  func sysctlmib(name string, args ...int) ([]_C_int, error) {
   434  	// Translate name to mib number.
   435  	mib, err := nametomib(name)
   436  	if err != nil {
   437  		return nil, err
   438  	}
   439  
   440  	for _, a := range args {
   441  		mib = append(mib, _C_int(a))
   442  	}
   443  
   444  	return mib, nil
   445  }
   446  
   447  func Sysctl(name string) (string, error) {
   448  	return SysctlArgs(name)
   449  }
   450  
   451  func SysctlArgs(name string, args ...int) (string, error) {
   452  	buf, err := SysctlRaw(name, args...)
   453  	if err != nil {
   454  		return "", err
   455  	}
   456  	n := len(buf)
   457  
   458  	// Throw away terminating NUL.
   459  	if n > 0 && buf[n-1] == '\x00' {
   460  		n--
   461  	}
   462  	return string(buf[0:n]), nil
   463  }
   464  
   465  func SysctlUint32(name string) (uint32, error) {
   466  	return SysctlUint32Args(name)
   467  }
   468  
   469  func SysctlUint32Args(name string, args ...int) (uint32, error) {
   470  	mib, err := sysctlmib(name, args...)
   471  	if err != nil {
   472  		return 0, err
   473  	}
   474  
   475  	n := uintptr(4)
   476  	buf := make([]byte, 4)
   477  	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
   478  		return 0, err
   479  	}
   480  	if n != 4 {
   481  		return 0, EIO
   482  	}
   483  	return *(*uint32)(unsafe.Pointer(&buf[0])), nil
   484  }
   485  
   486  func SysctlUint64(name string, args ...int) (uint64, error) {
   487  	mib, err := sysctlmib(name, args...)
   488  	if err != nil {
   489  		return 0, err
   490  	}
   491  
   492  	n := uintptr(8)
   493  	buf := make([]byte, 8)
   494  	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
   495  		return 0, err
   496  	}
   497  	if n != 8 {
   498  		return 0, EIO
   499  	}
   500  	return *(*uint64)(unsafe.Pointer(&buf[0])), nil
   501  }
   502  
   503  func SysctlRaw(name string, args ...int) ([]byte, error) {
   504  	mib, err := sysctlmib(name, args...)
   505  	if err != nil {
   506  		return nil, err
   507  	}
   508  
   509  	// Find size.
   510  	n := uintptr(0)
   511  	if err := sysctl(mib, nil, &n, nil, 0); err != nil {
   512  		return nil, err
   513  	}
   514  	if n == 0 {
   515  		return nil, nil
   516  	}
   517  
   518  	// Read into buffer of that size.
   519  	buf := make([]byte, n)
   520  	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
   521  		return nil, err
   522  	}
   523  
   524  	// The actual call may return less than the original reported required
   525  	// size so ensure we deal with that.
   526  	return buf[:n], nil
   527  }
   528  
   529  func SysctlClockinfo(name string) (*Clockinfo, error) {
   530  	mib, err := sysctlmib(name)
   531  	if err != nil {
   532  		return nil, err
   533  	}
   534  
   535  	n := uintptr(SizeofClockinfo)
   536  	var ci Clockinfo
   537  	if err := sysctl(mib, (*byte)(unsafe.Pointer(&ci)), &n, nil, 0); err != nil {
   538  		return nil, err
   539  	}
   540  	if n != SizeofClockinfo {
   541  		return nil, EIO
   542  	}
   543  	return &ci, nil
   544  }
   545  
   546  func SysctlTimeval(name string) (*Timeval, error) {
   547  	mib, err := sysctlmib(name)
   548  	if err != nil {
   549  		return nil, err
   550  	}
   551  
   552  	var tv Timeval
   553  	n := uintptr(unsafe.Sizeof(tv))
   554  	if err := sysctl(mib, (*byte)(unsafe.Pointer(&tv)), &n, nil, 0); err != nil {
   555  		return nil, err
   556  	}
   557  	if n != unsafe.Sizeof(tv) {
   558  		return nil, EIO
   559  	}
   560  	return &tv, nil
   561  }
   562  
   563  //sys	utimes(path string, timeval *[2]Timeval) (err error)
   564  
   565  func Utimes(path string, tv []Timeval) error {
   566  	if tv == nil {
   567  		return utimes(path, nil)
   568  	}
   569  	if len(tv) != 2 {
   570  		return EINVAL
   571  	}
   572  	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   573  }
   574  
   575  func UtimesNano(path string, ts []Timespec) error {
   576  	if ts == nil {
   577  		err := utimensat(AT_FDCWD, path, nil, 0)
   578  		if err != ENOSYS {
   579  			return err
   580  		}
   581  		return utimes(path, nil)
   582  	}
   583  	if len(ts) != 2 {
   584  		return EINVAL
   585  	}
   586  	// Darwin setattrlist can set nanosecond timestamps
   587  	err := setattrlistTimes(path, ts, 0)
   588  	if err != ENOSYS {
   589  		return err
   590  	}
   591  	err = utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
   592  	if err != ENOSYS {
   593  		return err
   594  	}
   595  	// Not as efficient as it could be because Timespec and
   596  	// Timeval have different types in the different OSes
   597  	tv := [2]Timeval{
   598  		NsecToTimeval(TimespecToNsec(ts[0])),
   599  		NsecToTimeval(TimespecToNsec(ts[1])),
   600  	}
   601  	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   602  }
   603  
   604  func UtimesNanoAt(dirfd int, path string, ts []Timespec, flags int) error {
   605  	if ts == nil {
   606  		return utimensat(dirfd, path, nil, flags)
   607  	}
   608  	if len(ts) != 2 {
   609  		return EINVAL
   610  	}
   611  	err := setattrlistTimes(path, ts, flags)
   612  	if err != ENOSYS {
   613  		return err
   614  	}
   615  	return utimensat(dirfd, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), flags)
   616  }
   617  
   618  //sys	futimes(fd int, timeval *[2]Timeval) (err error)
   619  
   620  func Futimes(fd int, tv []Timeval) error {
   621  	if tv == nil {
   622  		return futimes(fd, nil)
   623  	}
   624  	if len(tv) != 2 {
   625  		return EINVAL
   626  	}
   627  	return futimes(fd, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   628  }
   629  
   630  //sys	poll(fds *PollFd, nfds int, timeout int) (n int, err error)
   631  
   632  func Poll(fds []PollFd, timeout int) (n int, err error) {
   633  	if len(fds) == 0 {
   634  		return poll(nil, 0, timeout)
   635  	}
   636  	return poll(&fds[0], len(fds), timeout)
   637  }
   638  
   639  // TODO: wrap
   640  //	Acct(name nil-string) (err error)
   641  //	Gethostuuid(uuid *byte, timeout *Timespec) (err error)
   642  //	Ptrace(req int, pid int, addr uintptr, data int) (ret uintptr, err error)
   643  
   644  var mapper = &mmapper{
   645  	active: make(map[*byte][]byte),
   646  	mmap:   mmap,
   647  	munmap: munmap,
   648  }
   649  
   650  func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
   651  	return mapper.Mmap(fd, offset, length, prot, flags)
   652  }
   653  
   654  func Munmap(b []byte) (err error) {
   655  	return mapper.Munmap(b)
   656  }
   657  
   658  //sys	Madvise(b []byte, behav int) (err error)
   659  //sys	Mlock(b []byte) (err error)
   660  //sys	Mlockall(flags int) (err error)
   661  //sys	Mprotect(b []byte, prot int) (err error)
   662  //sys	Msync(b []byte, flags int) (err error)
   663  //sys	Munlock(b []byte) (err error)
   664  //sys	Munlockall() (err error)