github.com/fanux/shipyard@v0.0.0-20161009071005-6515ce223235/Godeps/_workspace/src/golang.org/x/sys/unix/syscall_linux.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  // Linux system calls.
     6  // This file is compiled as ordinary Go code,
     7  // but it is also input to mksyscall,
     8  // which parses the //sys lines and generates system call stubs.
     9  // Note that sometimes we use a lowercase //sys name and
    10  // wrap it in our own nicer implementation.
    11  
    12  package unix
    13  
    14  import (
    15  	"syscall"
    16  	"unsafe"
    17  )
    18  
    19  /*
    20   * Wrapped
    21   */
    22  
    23  func Access(path string, mode uint32) (err error) {
    24  	return Faccessat(AT_FDCWD, path, mode, 0)
    25  }
    26  
    27  func Chmod(path string, mode uint32) (err error) {
    28  	return Fchmodat(AT_FDCWD, path, mode, 0)
    29  }
    30  
    31  func Chown(path string, uid int, gid int) (err error) {
    32  	return Fchownat(AT_FDCWD, path, uid, gid, 0)
    33  }
    34  
    35  func Creat(path string, mode uint32) (fd int, err error) {
    36  	return Open(path, O_CREAT|O_WRONLY|O_TRUNC, mode)
    37  }
    38  
    39  //sys	Linkat(olddirfd int, oldpath string, newdirfd int, newpath string, flags int) (err error)
    40  
    41  func Link(oldpath string, newpath string) (err error) {
    42  	return Linkat(AT_FDCWD, oldpath, AT_FDCWD, newpath, 0)
    43  }
    44  
    45  func Mkdir(path string, mode uint32) (err error) {
    46  	return Mkdirat(AT_FDCWD, path, mode)
    47  }
    48  
    49  func Mknod(path string, mode uint32, dev int) (err error) {
    50  	return Mknodat(AT_FDCWD, path, mode, dev)
    51  }
    52  
    53  func Open(path string, mode int, perm uint32) (fd int, err error) {
    54  	return openat(AT_FDCWD, path, mode|O_LARGEFILE, perm)
    55  }
    56  
    57  //sys	openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
    58  
    59  func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) {
    60  	return openat(dirfd, path, flags|O_LARGEFILE, mode)
    61  }
    62  
    63  //sys	readlinkat(dirfd int, path string, buf []byte) (n int, err error)
    64  
    65  func Readlink(path string, buf []byte) (n int, err error) {
    66  	return readlinkat(AT_FDCWD, path, buf)
    67  }
    68  
    69  func Rename(oldpath string, newpath string) (err error) {
    70  	return Renameat(AT_FDCWD, oldpath, AT_FDCWD, newpath)
    71  }
    72  
    73  func Rmdir(path string) error {
    74  	return unlinkat(AT_FDCWD, path, AT_REMOVEDIR)
    75  }
    76  
    77  //sys	symlinkat(oldpath string, newdirfd int, newpath string) (err error)
    78  
    79  func Symlink(oldpath string, newpath string) (err error) {
    80  	return symlinkat(oldpath, AT_FDCWD, newpath)
    81  }
    82  
    83  func Unlink(path string) error {
    84  	return unlinkat(AT_FDCWD, path, 0)
    85  }
    86  
    87  //sys	unlinkat(dirfd int, path string, flags int) (err error)
    88  
    89  func Unlinkat(dirfd int, path string, flags int) error {
    90  	return unlinkat(dirfd, path, flags)
    91  }
    92  
    93  //sys	utimes(path string, times *[2]Timeval) (err error)
    94  
    95  func Utimes(path string, tv []Timeval) error {
    96  	if tv == nil {
    97  		err := utimensat(AT_FDCWD, path, nil, 0)
    98  		if err != ENOSYS {
    99  			return err
   100  		}
   101  		return utimes(path, nil)
   102  	}
   103  	if len(tv) != 2 {
   104  		return EINVAL
   105  	}
   106  	var ts [2]Timespec
   107  	ts[0] = NsecToTimespec(TimevalToNsec(tv[0]))
   108  	ts[1] = NsecToTimespec(TimevalToNsec(tv[1]))
   109  	err := utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
   110  	if err != ENOSYS {
   111  		return err
   112  	}
   113  	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   114  }
   115  
   116  //sys	utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error)
   117  
   118  func UtimesNano(path string, ts []Timespec) error {
   119  	if ts == nil {
   120  		err := utimensat(AT_FDCWD, path, nil, 0)
   121  		if err != ENOSYS {
   122  			return err
   123  		}
   124  		return utimes(path, nil)
   125  	}
   126  	if len(ts) != 2 {
   127  		return EINVAL
   128  	}
   129  	err := utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
   130  	if err != ENOSYS {
   131  		return err
   132  	}
   133  	// If the utimensat syscall isn't available (utimensat was added to Linux
   134  	// in 2.6.22, Released, 8 July 2007) then fall back to utimes
   135  	var tv [2]Timeval
   136  	for i := 0; i < 2; i++ {
   137  		tv[i].Sec = ts[i].Sec
   138  		tv[i].Usec = ts[i].Nsec / 1000
   139  	}
   140  	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   141  }
   142  
   143  func UtimesNanoAt(dirfd int, path string, ts []Timespec, flags int) error {
   144  	if ts == nil {
   145  		return utimensat(dirfd, path, nil, flags)
   146  	}
   147  	if len(ts) != 2 {
   148  		return EINVAL
   149  	}
   150  	return utimensat(dirfd, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), flags)
   151  }
   152  
   153  //sys	futimesat(dirfd int, path *byte, times *[2]Timeval) (err error)
   154  
   155  func Futimesat(dirfd int, path string, tv []Timeval) error {
   156  	pathp, err := BytePtrFromString(path)
   157  	if err != nil {
   158  		return err
   159  	}
   160  	if tv == nil {
   161  		return futimesat(dirfd, pathp, nil)
   162  	}
   163  	if len(tv) != 2 {
   164  		return EINVAL
   165  	}
   166  	return futimesat(dirfd, pathp, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   167  }
   168  
   169  func Futimes(fd int, tv []Timeval) (err error) {
   170  	// Believe it or not, this is the best we can do on Linux
   171  	// (and is what glibc does).
   172  	return Utimes("/proc/self/fd/"+itoa(fd), tv)
   173  }
   174  
   175  const ImplementsGetwd = true
   176  
   177  //sys	Getcwd(buf []byte) (n int, err error)
   178  
   179  func Getwd() (wd string, err error) {
   180  	var buf [PathMax]byte
   181  	n, err := Getcwd(buf[0:])
   182  	if err != nil {
   183  		return "", err
   184  	}
   185  	// Getcwd returns the number of bytes written to buf, including the NUL.
   186  	if n < 1 || n > len(buf) || buf[n-1] != 0 {
   187  		return "", EINVAL
   188  	}
   189  	return string(buf[0 : n-1]), nil
   190  }
   191  
   192  func Getgroups() (gids []int, err error) {
   193  	n, err := getgroups(0, nil)
   194  	if err != nil {
   195  		return nil, err
   196  	}
   197  	if n == 0 {
   198  		return nil, nil
   199  	}
   200  
   201  	// Sanity check group count.  Max is 1<<16 on Linux.
   202  	if n < 0 || n > 1<<20 {
   203  		return nil, EINVAL
   204  	}
   205  
   206  	a := make([]_Gid_t, n)
   207  	n, err = getgroups(n, &a[0])
   208  	if err != nil {
   209  		return nil, err
   210  	}
   211  	gids = make([]int, n)
   212  	for i, v := range a[0:n] {
   213  		gids[i] = int(v)
   214  	}
   215  	return
   216  }
   217  
   218  func Setgroups(gids []int) (err error) {
   219  	if len(gids) == 0 {
   220  		return setgroups(0, nil)
   221  	}
   222  
   223  	a := make([]_Gid_t, len(gids))
   224  	for i, v := range gids {
   225  		a[i] = _Gid_t(v)
   226  	}
   227  	return setgroups(len(a), &a[0])
   228  }
   229  
   230  type WaitStatus uint32
   231  
   232  // Wait status is 7 bits at bottom, either 0 (exited),
   233  // 0x7F (stopped), or a signal number that caused an exit.
   234  // The 0x80 bit is whether there was a core dump.
   235  // An extra number (exit code, signal causing a stop)
   236  // is in the high bits.  At least that's the idea.
   237  // There are various irregularities.  For example, the
   238  // "continued" status is 0xFFFF, distinguishing itself
   239  // from stopped via the core dump bit.
   240  
   241  const (
   242  	mask    = 0x7F
   243  	core    = 0x80
   244  	exited  = 0x00
   245  	stopped = 0x7F
   246  	shift   = 8
   247  )
   248  
   249  func (w WaitStatus) Exited() bool { return w&mask == exited }
   250  
   251  func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != exited }
   252  
   253  func (w WaitStatus) Stopped() bool { return w&0xFF == stopped }
   254  
   255  func (w WaitStatus) Continued() bool { return w == 0xFFFF }
   256  
   257  func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
   258  
   259  func (w WaitStatus) ExitStatus() int {
   260  	if !w.Exited() {
   261  		return -1
   262  	}
   263  	return int(w>>shift) & 0xFF
   264  }
   265  
   266  func (w WaitStatus) Signal() syscall.Signal {
   267  	if !w.Signaled() {
   268  		return -1
   269  	}
   270  	return syscall.Signal(w & mask)
   271  }
   272  
   273  func (w WaitStatus) StopSignal() syscall.Signal {
   274  	if !w.Stopped() {
   275  		return -1
   276  	}
   277  	return syscall.Signal(w>>shift) & 0xFF
   278  }
   279  
   280  func (w WaitStatus) TrapCause() int {
   281  	if w.StopSignal() != SIGTRAP {
   282  		return -1
   283  	}
   284  	return int(w>>shift) >> 8
   285  }
   286  
   287  //sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)
   288  
   289  func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
   290  	var status _C_int
   291  	wpid, err = wait4(pid, &status, options, rusage)
   292  	if wstatus != nil {
   293  		*wstatus = WaitStatus(status)
   294  	}
   295  	return
   296  }
   297  
   298  func Mkfifo(path string, mode uint32) (err error) {
   299  	return Mknod(path, mode|S_IFIFO, 0)
   300  }
   301  
   302  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
   303  	if sa.Port < 0 || sa.Port > 0xFFFF {
   304  		return nil, 0, EINVAL
   305  	}
   306  	sa.raw.Family = AF_INET
   307  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   308  	p[0] = byte(sa.Port >> 8)
   309  	p[1] = byte(sa.Port)
   310  	for i := 0; i < len(sa.Addr); i++ {
   311  		sa.raw.Addr[i] = sa.Addr[i]
   312  	}
   313  	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil
   314  }
   315  
   316  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
   317  	if sa.Port < 0 || sa.Port > 0xFFFF {
   318  		return nil, 0, EINVAL
   319  	}
   320  	sa.raw.Family = AF_INET6
   321  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   322  	p[0] = byte(sa.Port >> 8)
   323  	p[1] = byte(sa.Port)
   324  	sa.raw.Scope_id = sa.ZoneId
   325  	for i := 0; i < len(sa.Addr); i++ {
   326  		sa.raw.Addr[i] = sa.Addr[i]
   327  	}
   328  	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet6, nil
   329  }
   330  
   331  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
   332  	name := sa.Name
   333  	n := len(name)
   334  	if n >= len(sa.raw.Path) {
   335  		return nil, 0, EINVAL
   336  	}
   337  	sa.raw.Family = AF_UNIX
   338  	for i := 0; i < n; i++ {
   339  		sa.raw.Path[i] = int8(name[i])
   340  	}
   341  	// length is family (uint16), name, NUL.
   342  	sl := _Socklen(2)
   343  	if n > 0 {
   344  		sl += _Socklen(n) + 1
   345  	}
   346  	if sa.raw.Path[0] == '@' {
   347  		sa.raw.Path[0] = 0
   348  		// Don't count trailing NUL for abstract address.
   349  		sl--
   350  	}
   351  
   352  	return unsafe.Pointer(&sa.raw), sl, nil
   353  }
   354  
   355  type SockaddrLinklayer struct {
   356  	Protocol uint16
   357  	Ifindex  int
   358  	Hatype   uint16
   359  	Pkttype  uint8
   360  	Halen    uint8
   361  	Addr     [8]byte
   362  	raw      RawSockaddrLinklayer
   363  }
   364  
   365  func (sa *SockaddrLinklayer) sockaddr() (unsafe.Pointer, _Socklen, error) {
   366  	if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {
   367  		return nil, 0, EINVAL
   368  	}
   369  	sa.raw.Family = AF_PACKET
   370  	sa.raw.Protocol = sa.Protocol
   371  	sa.raw.Ifindex = int32(sa.Ifindex)
   372  	sa.raw.Hatype = sa.Hatype
   373  	sa.raw.Pkttype = sa.Pkttype
   374  	sa.raw.Halen = sa.Halen
   375  	for i := 0; i < len(sa.Addr); i++ {
   376  		sa.raw.Addr[i] = sa.Addr[i]
   377  	}
   378  	return unsafe.Pointer(&sa.raw), SizeofSockaddrLinklayer, nil
   379  }
   380  
   381  type SockaddrNetlink struct {
   382  	Family uint16
   383  	Pad    uint16
   384  	Pid    uint32
   385  	Groups uint32
   386  	raw    RawSockaddrNetlink
   387  }
   388  
   389  func (sa *SockaddrNetlink) sockaddr() (unsafe.Pointer, _Socklen, error) {
   390  	sa.raw.Family = AF_NETLINK
   391  	sa.raw.Pad = sa.Pad
   392  	sa.raw.Pid = sa.Pid
   393  	sa.raw.Groups = sa.Groups
   394  	return unsafe.Pointer(&sa.raw), SizeofSockaddrNetlink, nil
   395  }
   396  
   397  type SockaddrHCI struct {
   398  	Dev     uint16
   399  	Channel uint16
   400  	raw     RawSockaddrHCI
   401  }
   402  
   403  func (sa *SockaddrHCI) sockaddr() (unsafe.Pointer, _Socklen, error) {
   404  	sa.raw.Family = AF_BLUETOOTH
   405  	sa.raw.Dev = sa.Dev
   406  	sa.raw.Channel = sa.Channel
   407  	return unsafe.Pointer(&sa.raw), SizeofSockaddrHCI, nil
   408  }
   409  
   410  func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
   411  	switch rsa.Addr.Family {
   412  	case AF_NETLINK:
   413  		pp := (*RawSockaddrNetlink)(unsafe.Pointer(rsa))
   414  		sa := new(SockaddrNetlink)
   415  		sa.Family = pp.Family
   416  		sa.Pad = pp.Pad
   417  		sa.Pid = pp.Pid
   418  		sa.Groups = pp.Groups
   419  		return sa, nil
   420  
   421  	case AF_PACKET:
   422  		pp := (*RawSockaddrLinklayer)(unsafe.Pointer(rsa))
   423  		sa := new(SockaddrLinklayer)
   424  		sa.Protocol = pp.Protocol
   425  		sa.Ifindex = int(pp.Ifindex)
   426  		sa.Hatype = pp.Hatype
   427  		sa.Pkttype = pp.Pkttype
   428  		sa.Halen = pp.Halen
   429  		for i := 0; i < len(sa.Addr); i++ {
   430  			sa.Addr[i] = pp.Addr[i]
   431  		}
   432  		return sa, nil
   433  
   434  	case AF_UNIX:
   435  		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
   436  		sa := new(SockaddrUnix)
   437  		if pp.Path[0] == 0 {
   438  			// "Abstract" Unix domain socket.
   439  			// Rewrite leading NUL as @ for textual display.
   440  			// (This is the standard convention.)
   441  			// Not friendly to overwrite in place,
   442  			// but the callers below don't care.
   443  			pp.Path[0] = '@'
   444  		}
   445  
   446  		// Assume path ends at NUL.
   447  		// This is not technically the Linux semantics for
   448  		// abstract Unix domain sockets--they are supposed
   449  		// to be uninterpreted fixed-size binary blobs--but
   450  		// everyone uses this convention.
   451  		n := 0
   452  		for n < len(pp.Path) && pp.Path[n] != 0 {
   453  			n++
   454  		}
   455  		bytes := (*[10000]byte)(unsafe.Pointer(&pp.Path[0]))[0:n]
   456  		sa.Name = string(bytes)
   457  		return sa, nil
   458  
   459  	case AF_INET:
   460  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
   461  		sa := new(SockaddrInet4)
   462  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   463  		sa.Port = int(p[0])<<8 + int(p[1])
   464  		for i := 0; i < len(sa.Addr); i++ {
   465  			sa.Addr[i] = pp.Addr[i]
   466  		}
   467  		return sa, nil
   468  
   469  	case AF_INET6:
   470  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
   471  		sa := new(SockaddrInet6)
   472  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   473  		sa.Port = int(p[0])<<8 + int(p[1])
   474  		sa.ZoneId = pp.Scope_id
   475  		for i := 0; i < len(sa.Addr); i++ {
   476  			sa.Addr[i] = pp.Addr[i]
   477  		}
   478  		return sa, nil
   479  	}
   480  	return nil, EAFNOSUPPORT
   481  }
   482  
   483  func Accept(fd int) (nfd int, sa Sockaddr, err error) {
   484  	var rsa RawSockaddrAny
   485  	var len _Socklen = SizeofSockaddrAny
   486  	nfd, err = accept(fd, &rsa, &len)
   487  	if err != nil {
   488  		return
   489  	}
   490  	sa, err = anyToSockaddr(&rsa)
   491  	if err != nil {
   492  		Close(nfd)
   493  		nfd = 0
   494  	}
   495  	return
   496  }
   497  
   498  func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) {
   499  	var rsa RawSockaddrAny
   500  	var len _Socklen = SizeofSockaddrAny
   501  	nfd, err = accept4(fd, &rsa, &len, flags)
   502  	if err != nil {
   503  		return
   504  	}
   505  	if len > SizeofSockaddrAny {
   506  		panic("RawSockaddrAny too small")
   507  	}
   508  	sa, err = anyToSockaddr(&rsa)
   509  	if err != nil {
   510  		Close(nfd)
   511  		nfd = 0
   512  	}
   513  	return
   514  }
   515  
   516  func Getsockname(fd int) (sa Sockaddr, err error) {
   517  	var rsa RawSockaddrAny
   518  	var len _Socklen = SizeofSockaddrAny
   519  	if err = getsockname(fd, &rsa, &len); err != nil {
   520  		return
   521  	}
   522  	return anyToSockaddr(&rsa)
   523  }
   524  
   525  func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
   526  	vallen := _Socklen(4)
   527  	err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
   528  	return value, err
   529  }
   530  
   531  func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
   532  	var value IPMreq
   533  	vallen := _Socklen(SizeofIPMreq)
   534  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   535  	return &value, err
   536  }
   537  
   538  func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {
   539  	var value IPMreqn
   540  	vallen := _Socklen(SizeofIPMreqn)
   541  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   542  	return &value, err
   543  }
   544  
   545  func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
   546  	var value IPv6Mreq
   547  	vallen := _Socklen(SizeofIPv6Mreq)
   548  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   549  	return &value, err
   550  }
   551  
   552  func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
   553  	var value IPv6MTUInfo
   554  	vallen := _Socklen(SizeofIPv6MTUInfo)
   555  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   556  	return &value, err
   557  }
   558  
   559  func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
   560  	var value ICMPv6Filter
   561  	vallen := _Socklen(SizeofICMPv6Filter)
   562  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   563  	return &value, err
   564  }
   565  
   566  func GetsockoptUcred(fd, level, opt int) (*Ucred, error) {
   567  	var value Ucred
   568  	vallen := _Socklen(SizeofUcred)
   569  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   570  	return &value, err
   571  }
   572  
   573  func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {
   574  	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq))
   575  }
   576  
   577  func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
   578  	var msg Msghdr
   579  	var rsa RawSockaddrAny
   580  	msg.Name = (*byte)(unsafe.Pointer(&rsa))
   581  	msg.Namelen = uint32(SizeofSockaddrAny)
   582  	var iov Iovec
   583  	if len(p) > 0 {
   584  		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
   585  		iov.SetLen(len(p))
   586  	}
   587  	var dummy byte
   588  	if len(oob) > 0 {
   589  		// receive at least one normal byte
   590  		if len(p) == 0 {
   591  			iov.Base = &dummy
   592  			iov.SetLen(1)
   593  		}
   594  		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
   595  		msg.SetControllen(len(oob))
   596  	}
   597  	msg.Iov = &iov
   598  	msg.Iovlen = 1
   599  	if n, err = recvmsg(fd, &msg, flags); err != nil {
   600  		return
   601  	}
   602  	oobn = int(msg.Controllen)
   603  	recvflags = int(msg.Flags)
   604  	// source address is only specified if the socket is unconnected
   605  	if rsa.Addr.Family != AF_UNSPEC {
   606  		from, err = anyToSockaddr(&rsa)
   607  	}
   608  	return
   609  }
   610  
   611  func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
   612  	_, err = SendmsgN(fd, p, oob, to, flags)
   613  	return
   614  }
   615  
   616  func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
   617  	var ptr unsafe.Pointer
   618  	var salen _Socklen
   619  	if to != nil {
   620  		var err error
   621  		ptr, salen, err = to.sockaddr()
   622  		if err != nil {
   623  			return 0, err
   624  		}
   625  	}
   626  	var msg Msghdr
   627  	msg.Name = (*byte)(unsafe.Pointer(ptr))
   628  	msg.Namelen = uint32(salen)
   629  	var iov Iovec
   630  	if len(p) > 0 {
   631  		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
   632  		iov.SetLen(len(p))
   633  	}
   634  	var dummy byte
   635  	if len(oob) > 0 {
   636  		// send at least one normal byte
   637  		if len(p) == 0 {
   638  			iov.Base = &dummy
   639  			iov.SetLen(1)
   640  		}
   641  		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
   642  		msg.SetControllen(len(oob))
   643  	}
   644  	msg.Iov = &iov
   645  	msg.Iovlen = 1
   646  	if n, err = sendmsg(fd, &msg, flags); err != nil {
   647  		return 0, err
   648  	}
   649  	if len(oob) > 0 && len(p) == 0 {
   650  		n = 0
   651  	}
   652  	return n, nil
   653  }
   654  
   655  // BindToDevice binds the socket associated with fd to device.
   656  func BindToDevice(fd int, device string) (err error) {
   657  	return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device)
   658  }
   659  
   660  //sys	ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
   661  
   662  func ptracePeek(req int, pid int, addr uintptr, out []byte) (count int, err error) {
   663  	// The peek requests are machine-size oriented, so we wrap it
   664  	// to retrieve arbitrary-length data.
   665  
   666  	// The ptrace syscall differs from glibc's ptrace.
   667  	// Peeks returns the word in *data, not as the return value.
   668  
   669  	var buf [sizeofPtr]byte
   670  
   671  	// Leading edge.  PEEKTEXT/PEEKDATA don't require aligned
   672  	// access (PEEKUSER warns that it might), but if we don't
   673  	// align our reads, we might straddle an unmapped page
   674  	// boundary and not get the bytes leading up to the page
   675  	// boundary.
   676  	n := 0
   677  	if addr%sizeofPtr != 0 {
   678  		err = ptrace(req, pid, addr-addr%sizeofPtr, uintptr(unsafe.Pointer(&buf[0])))
   679  		if err != nil {
   680  			return 0, err
   681  		}
   682  		n += copy(out, buf[addr%sizeofPtr:])
   683  		out = out[n:]
   684  	}
   685  
   686  	// Remainder.
   687  	for len(out) > 0 {
   688  		// We use an internal buffer to guarantee alignment.
   689  		// It's not documented if this is necessary, but we're paranoid.
   690  		err = ptrace(req, pid, addr+uintptr(n), uintptr(unsafe.Pointer(&buf[0])))
   691  		if err != nil {
   692  			return n, err
   693  		}
   694  		copied := copy(out, buf[0:])
   695  		n += copied
   696  		out = out[copied:]
   697  	}
   698  
   699  	return n, nil
   700  }
   701  
   702  func PtracePeekText(pid int, addr uintptr, out []byte) (count int, err error) {
   703  	return ptracePeek(PTRACE_PEEKTEXT, pid, addr, out)
   704  }
   705  
   706  func PtracePeekData(pid int, addr uintptr, out []byte) (count int, err error) {
   707  	return ptracePeek(PTRACE_PEEKDATA, pid, addr, out)
   708  }
   709  
   710  func ptracePoke(pokeReq int, peekReq int, pid int, addr uintptr, data []byte) (count int, err error) {
   711  	// As for ptracePeek, we need to align our accesses to deal
   712  	// with the possibility of straddling an invalid page.
   713  
   714  	// Leading edge.
   715  	n := 0
   716  	if addr%sizeofPtr != 0 {
   717  		var buf [sizeofPtr]byte
   718  		err = ptrace(peekReq, pid, addr-addr%sizeofPtr, uintptr(unsafe.Pointer(&buf[0])))
   719  		if err != nil {
   720  			return 0, err
   721  		}
   722  		n += copy(buf[addr%sizeofPtr:], data)
   723  		word := *((*uintptr)(unsafe.Pointer(&buf[0])))
   724  		err = ptrace(pokeReq, pid, addr-addr%sizeofPtr, word)
   725  		if err != nil {
   726  			return 0, err
   727  		}
   728  		data = data[n:]
   729  	}
   730  
   731  	// Interior.
   732  	for len(data) > sizeofPtr {
   733  		word := *((*uintptr)(unsafe.Pointer(&data[0])))
   734  		err = ptrace(pokeReq, pid, addr+uintptr(n), word)
   735  		if err != nil {
   736  			return n, err
   737  		}
   738  		n += sizeofPtr
   739  		data = data[sizeofPtr:]
   740  	}
   741  
   742  	// Trailing edge.
   743  	if len(data) > 0 {
   744  		var buf [sizeofPtr]byte
   745  		err = ptrace(peekReq, pid, addr+uintptr(n), uintptr(unsafe.Pointer(&buf[0])))
   746  		if err != nil {
   747  			return n, err
   748  		}
   749  		copy(buf[0:], data)
   750  		word := *((*uintptr)(unsafe.Pointer(&buf[0])))
   751  		err = ptrace(pokeReq, pid, addr+uintptr(n), word)
   752  		if err != nil {
   753  			return n, err
   754  		}
   755  		n += len(data)
   756  	}
   757  
   758  	return n, nil
   759  }
   760  
   761  func PtracePokeText(pid int, addr uintptr, data []byte) (count int, err error) {
   762  	return ptracePoke(PTRACE_POKETEXT, PTRACE_PEEKTEXT, pid, addr, data)
   763  }
   764  
   765  func PtracePokeData(pid int, addr uintptr, data []byte) (count int, err error) {
   766  	return ptracePoke(PTRACE_POKEDATA, PTRACE_PEEKDATA, pid, addr, data)
   767  }
   768  
   769  func PtraceGetRegs(pid int, regsout *PtraceRegs) (err error) {
   770  	return ptrace(PTRACE_GETREGS, pid, 0, uintptr(unsafe.Pointer(regsout)))
   771  }
   772  
   773  func PtraceSetRegs(pid int, regs *PtraceRegs) (err error) {
   774  	return ptrace(PTRACE_SETREGS, pid, 0, uintptr(unsafe.Pointer(regs)))
   775  }
   776  
   777  func PtraceSetOptions(pid int, options int) (err error) {
   778  	return ptrace(PTRACE_SETOPTIONS, pid, 0, uintptr(options))
   779  }
   780  
   781  func PtraceGetEventMsg(pid int) (msg uint, err error) {
   782  	var data _C_long
   783  	err = ptrace(PTRACE_GETEVENTMSG, pid, 0, uintptr(unsafe.Pointer(&data)))
   784  	msg = uint(data)
   785  	return
   786  }
   787  
   788  func PtraceCont(pid int, signal int) (err error) {
   789  	return ptrace(PTRACE_CONT, pid, 0, uintptr(signal))
   790  }
   791  
   792  func PtraceSyscall(pid int, signal int) (err error) {
   793  	return ptrace(PTRACE_SYSCALL, pid, 0, uintptr(signal))
   794  }
   795  
   796  func PtraceSingleStep(pid int) (err error) { return ptrace(PTRACE_SINGLESTEP, pid, 0, 0) }
   797  
   798  func PtraceAttach(pid int) (err error) { return ptrace(PTRACE_ATTACH, pid, 0, 0) }
   799  
   800  func PtraceDetach(pid int) (err error) { return ptrace(PTRACE_DETACH, pid, 0, 0) }
   801  
   802  //sys	reboot(magic1 uint, magic2 uint, cmd int, arg string) (err error)
   803  
   804  func Reboot(cmd int) (err error) {
   805  	return reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, "")
   806  }
   807  
   808  func clen(n []byte) int {
   809  	for i := 0; i < len(n); i++ {
   810  		if n[i] == 0 {
   811  			return i
   812  		}
   813  	}
   814  	return len(n)
   815  }
   816  
   817  func ReadDirent(fd int, buf []byte) (n int, err error) {
   818  	return Getdents(fd, buf)
   819  }
   820  
   821  func ParseDirent(buf []byte, max int, names []string) (consumed int, count int, newnames []string) {
   822  	origlen := len(buf)
   823  	count = 0
   824  	for max != 0 && len(buf) > 0 {
   825  		dirent := (*Dirent)(unsafe.Pointer(&buf[0]))
   826  		buf = buf[dirent.Reclen:]
   827  		if dirent.Ino == 0 { // File absent in directory.
   828  			continue
   829  		}
   830  		bytes := (*[10000]byte)(unsafe.Pointer(&dirent.Name[0]))
   831  		var name = string(bytes[0:clen(bytes[:])])
   832  		if name == "." || name == ".." { // Useless names
   833  			continue
   834  		}
   835  		max--
   836  		count++
   837  		names = append(names, name)
   838  	}
   839  	return origlen - len(buf), count, names
   840  }
   841  
   842  //sys	mount(source string, target string, fstype string, flags uintptr, data *byte) (err error)
   843  
   844  func Mount(source string, target string, fstype string, flags uintptr, data string) (err error) {
   845  	// Certain file systems get rather angry and EINVAL if you give
   846  	// them an empty string of data, rather than NULL.
   847  	if data == "" {
   848  		return mount(source, target, fstype, flags, nil)
   849  	}
   850  	datap, err := BytePtrFromString(data)
   851  	if err != nil {
   852  		return err
   853  	}
   854  	return mount(source, target, fstype, flags, datap)
   855  }
   856  
   857  // Sendto
   858  // Recvfrom
   859  // Socketpair
   860  
   861  /*
   862   * Direct access
   863   */
   864  //sys	Acct(path string) (err error)
   865  //sys	Adjtimex(buf *Timex) (state int, err error)
   866  //sys	Chdir(path string) (err error)
   867  //sys	Chroot(path string) (err error)
   868  //sys	ClockGettime(clockid int32, time *Timespec) (err error)
   869  //sys	Close(fd int) (err error)
   870  //sys	Dup(oldfd int) (fd int, err error)
   871  //sys	Dup3(oldfd int, newfd int, flags int) (err error)
   872  //sysnb	EpollCreate(size int) (fd int, err error)
   873  //sysnb	EpollCreate1(flag int) (fd int, err error)
   874  //sysnb	EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
   875  //sys	Exit(code int) = SYS_EXIT_GROUP
   876  //sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
   877  //sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
   878  //sys	Fchdir(fd int) (err error)
   879  //sys	Fchmod(fd int, mode uint32) (err error)
   880  //sys	Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)
   881  //sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
   882  //sys	fcntl(fd int, cmd int, arg int) (val int, err error)
   883  //sys	Fdatasync(fd int) (err error)
   884  //sys	Flock(fd int, how int) (err error)
   885  //sys	Fsync(fd int) (err error)
   886  //sys	Getdents(fd int, buf []byte) (n int, err error) = SYS_GETDENTS64
   887  //sysnb	Getpgid(pid int) (pgid int, err error)
   888  
   889  func Getpgrp() (pid int) {
   890  	pid, _ = Getpgid(0)
   891  	return
   892  }
   893  
   894  //sysnb	Getpid() (pid int)
   895  //sysnb	Getppid() (ppid int)
   896  //sys	Getpriority(which int, who int) (prio int, err error)
   897  //sysnb	Getrusage(who int, rusage *Rusage) (err error)
   898  //sysnb	Gettid() (tid int)
   899  //sys	Getxattr(path string, attr string, dest []byte) (sz int, err error)
   900  //sys	InotifyAddWatch(fd int, pathname string, mask uint32) (watchdesc int, err error)
   901  //sysnb	InotifyInit1(flags int) (fd int, err error)
   902  //sysnb	InotifyRmWatch(fd int, watchdesc uint32) (success int, err error)
   903  //sysnb	Kill(pid int, sig syscall.Signal) (err error)
   904  //sys	Klogctl(typ int, buf []byte) (n int, err error) = SYS_SYSLOG
   905  //sys	Listxattr(path string, dest []byte) (sz int, err error)
   906  //sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
   907  //sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
   908  //sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
   909  //sys	PivotRoot(newroot string, putold string) (err error) = SYS_PIVOT_ROOT
   910  //sysnb prlimit(pid int, resource int, old *Rlimit, newlimit *Rlimit) (err error) = SYS_PRLIMIT64
   911  //sys   Prctl(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (err error)
   912  //sys	read(fd int, p []byte) (n int, err error)
   913  //sys	Removexattr(path string, attr string) (err error)
   914  //sys	Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error)
   915  //sys	Setdomainname(p []byte) (err error)
   916  //sys	Sethostname(p []byte) (err error)
   917  //sysnb	Setpgid(pid int, pgid int) (err error)
   918  //sysnb	Setsid() (pid int, err error)
   919  //sysnb	Settimeofday(tv *Timeval) (err error)
   920  //sys	Setns(fd int, nstype int) (err error)
   921  
   922  // issue 1435.
   923  // On linux Setuid and Setgid only affects the current thread, not the process.
   924  // This does not match what most callers expect so we must return an error
   925  // here rather than letting the caller think that the call succeeded.
   926  
   927  func Setuid(uid int) (err error) {
   928  	return EOPNOTSUPP
   929  }
   930  
   931  func Setgid(uid int) (err error) {
   932  	return EOPNOTSUPP
   933  }
   934  
   935  //sys	Setpriority(which int, who int, prio int) (err error)
   936  //sys	Setxattr(path string, attr string, data []byte, flags int) (err error)
   937  //sys	Sync()
   938  //sysnb	Sysinfo(info *Sysinfo_t) (err error)
   939  //sys	Tee(rfd int, wfd int, len int, flags int) (n int64, err error)
   940  //sysnb	Tgkill(tgid int, tid int, sig syscall.Signal) (err error)
   941  //sysnb	Times(tms *Tms) (ticks uintptr, err error)
   942  //sysnb	Umask(mask int) (oldmask int)
   943  //sysnb	Uname(buf *Utsname) (err error)
   944  //sys	Unmount(target string, flags int) (err error) = SYS_UMOUNT2
   945  //sys	Unshare(flags int) (err error)
   946  //sys	Ustat(dev int, ubuf *Ustat_t) (err error)
   947  //sys	write(fd int, p []byte) (n int, err error)
   948  //sys	exitThread(code int) (err error) = SYS_EXIT
   949  //sys	readlen(fd int, p *byte, np int) (n int, err error) = SYS_READ
   950  //sys	writelen(fd int, p *byte, np int) (n int, err error) = SYS_WRITE
   951  
   952  // mmap varies by architecture; see syscall_linux_*.go.
   953  //sys	munmap(addr uintptr, length uintptr) (err error)
   954  
   955  var mapper = &mmapper{
   956  	active: make(map[*byte][]byte),
   957  	mmap:   mmap,
   958  	munmap: munmap,
   959  }
   960  
   961  func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
   962  	return mapper.Mmap(fd, offset, length, prot, flags)
   963  }
   964  
   965  func Munmap(b []byte) (err error) {
   966  	return mapper.Munmap(b)
   967  }
   968  
   969  //sys	Madvise(b []byte, advice int) (err error)
   970  //sys	Mprotect(b []byte, prot int) (err error)
   971  //sys	Mlock(b []byte) (err error)
   972  //sys	Munlock(b []byte) (err error)
   973  //sys	Mlockall(flags int) (err error)
   974  //sys	Munlockall() (err error)
   975  
   976  /*
   977   * Unimplemented
   978   */
   979  // AddKey
   980  // AfsSyscall
   981  // Alarm
   982  // ArchPrctl
   983  // Brk
   984  // Capget
   985  // Capset
   986  // ClockGetres
   987  // ClockNanosleep
   988  // ClockSettime
   989  // Clone
   990  // CreateModule
   991  // DeleteModule
   992  // EpollCtlOld
   993  // EpollPwait
   994  // EpollWaitOld
   995  // Eventfd
   996  // Execve
   997  // Fgetxattr
   998  // Flistxattr
   999  // Fork
  1000  // Fremovexattr
  1001  // Fsetxattr
  1002  // Futex
  1003  // GetKernelSyms
  1004  // GetMempolicy
  1005  // GetRobustList
  1006  // GetThreadArea
  1007  // Getitimer
  1008  // Getpmsg
  1009  // IoCancel
  1010  // IoDestroy
  1011  // IoGetevents
  1012  // IoSetup
  1013  // IoSubmit
  1014  // Ioctl
  1015  // IoprioGet
  1016  // IoprioSet
  1017  // KexecLoad
  1018  // Keyctl
  1019  // Lgetxattr
  1020  // Llistxattr
  1021  // LookupDcookie
  1022  // Lremovexattr
  1023  // Lsetxattr
  1024  // Mbind
  1025  // MigratePages
  1026  // Mincore
  1027  // ModifyLdt
  1028  // Mount
  1029  // MovePages
  1030  // Mprotect
  1031  // MqGetsetattr
  1032  // MqNotify
  1033  // MqOpen
  1034  // MqTimedreceive
  1035  // MqTimedsend
  1036  // MqUnlink
  1037  // Mremap
  1038  // Msgctl
  1039  // Msgget
  1040  // Msgrcv
  1041  // Msgsnd
  1042  // Msync
  1043  // Newfstatat
  1044  // Nfsservctl
  1045  // Personality
  1046  // Poll
  1047  // Ppoll
  1048  // Pselect6
  1049  // Ptrace
  1050  // Putpmsg
  1051  // QueryModule
  1052  // Quotactl
  1053  // Readahead
  1054  // Readv
  1055  // RemapFilePages
  1056  // RequestKey
  1057  // RestartSyscall
  1058  // RtSigaction
  1059  // RtSigpending
  1060  // RtSigprocmask
  1061  // RtSigqueueinfo
  1062  // RtSigreturn
  1063  // RtSigsuspend
  1064  // RtSigtimedwait
  1065  // SchedGetPriorityMax
  1066  // SchedGetPriorityMin
  1067  // SchedGetaffinity
  1068  // SchedGetparam
  1069  // SchedGetscheduler
  1070  // SchedRrGetInterval
  1071  // SchedSetaffinity
  1072  // SchedSetparam
  1073  // SchedYield
  1074  // Security
  1075  // Semctl
  1076  // Semget
  1077  // Semop
  1078  // Semtimedop
  1079  // SetMempolicy
  1080  // SetRobustList
  1081  // SetThreadArea
  1082  // SetTidAddress
  1083  // Shmat
  1084  // Shmctl
  1085  // Shmdt
  1086  // Shmget
  1087  // Sigaltstack
  1088  // Signalfd
  1089  // Swapoff
  1090  // Swapon
  1091  // Sysfs
  1092  // TimerCreate
  1093  // TimerDelete
  1094  // TimerGetoverrun
  1095  // TimerGettime
  1096  // TimerSettime
  1097  // Timerfd
  1098  // Tkill (obsolete)
  1099  // Tuxcall
  1100  // Umount2
  1101  // Uselib
  1102  // Utimensat
  1103  // Vfork
  1104  // Vhangup
  1105  // Vmsplice
  1106  // Vserver
  1107  // Waitid
  1108  // _Sysctl