syscall_bsd.go

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