Source file src/syscall/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 syscall
    14  
    15  import (
    16  	"runtime"
    17  	"unsafe"
    18  )
    19  
    20  const ImplementsGetwd = true
    21  
    22  func Getwd() (string, error) {
    23  	var buf [pathMax]byte
    24  	_, err := getcwd(buf[:])
    25  	if err != nil {
    26  		return "", err
    27  	}
    28  	n := clen(buf[:])
    29  	if n < 1 {
    30  		return "", EINVAL
    31  	}
    32  	return string(buf[:n]), nil
    33  }
    34  
    35  /*
    36   * Wrapped
    37   */
    38  
    39  //sysnb	getgroups(ngid int, gid *_Gid_t) (n int, err error)
    40  //sysnb	setgroups(ngid int, gid *_Gid_t) (err error)
    41  
    42  func Getgroups() (gids []int, err error) {
    43  	n, err := getgroups(0, nil)
    44  	if err != nil {
    45  		return nil, err
    46  	}
    47  	if n == 0 {
    48  		return nil, nil
    49  	}
    50  
    51  	// Sanity check group count. Max is 16 on BSD.
    52  	if n < 0 || n > 1000 {
    53  		return nil, EINVAL
    54  	}
    55  
    56  	a := make([]_Gid_t, n)
    57  	n, err = getgroups(n, &a[0])
    58  	if err != nil {
    59  		return nil, err
    60  	}
    61  	gids = make([]int, n)
    62  	for i, v := range a[0:n] {
    63  		gids[i] = int(v)
    64  	}
    65  	return
    66  }
    67  
    68  func Setgroups(gids []int) (err error) {
    69  	if len(gids) == 0 {
    70  		return setgroups(0, nil)
    71  	}
    72  
    73  	a := make([]_Gid_t, len(gids))
    74  	for i, v := range gids {
    75  		a[i] = _Gid_t(v)
    76  	}
    77  	return setgroups(len(a), &a[0])
    78  }
    79  
    80  func ReadDirent(fd int, buf []byte) (n int, err error) {
    81  	// Final argument is (basep *uintptr) and the syscall doesn't take nil.
    82  	// 64 bits should be enough. (32 bits isn't even on 386). Since the
    83  	// actual system call is getdirentries64, 64 is a good guess.
    84  	// TODO(rsc): Can we use a single global basep for all calls?
    85  	var base = (*uintptr)(unsafe.Pointer(new(uint64)))
    86  	return Getdirentries(fd, buf, base)
    87  }
    88  
    89  // Wait status is 7 bits at bottom, either 0 (exited),
    90  // 0x7F (stopped), or a signal number that caused an exit.
    91  // The 0x80 bit is whether there was a core dump.
    92  // An extra number (exit code, signal causing a stop)
    93  // is in the high bits.
    94  
    95  type WaitStatus uint32
    96  
    97  const (
    98  	mask  = 0x7F
    99  	core  = 0x80
   100  	shift = 8
   101  
   102  	exited  = 0
   103  	stopped = 0x7F
   104  )
   105  
   106  func (w WaitStatus) Exited() bool { return w&mask == exited }
   107  
   108  func (w WaitStatus) ExitStatus() int {
   109  	if w&mask != exited {
   110  		return -1
   111  	}
   112  	return int(w >> shift)
   113  }
   114  
   115  func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }
   116  
   117  func (w WaitStatus) Signal() Signal {
   118  	sig := Signal(w & mask)
   119  	if sig == stopped || sig == 0 {
   120  		return -1
   121  	}
   122  	return sig
   123  }
   124  
   125  func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
   126  
   127  func (w WaitStatus) Stopped() bool { return w&mask == stopped && Signal(w>>shift) != SIGSTOP }
   128  
   129  func (w WaitStatus) Continued() bool { return w&mask == stopped && Signal(w>>shift) == SIGSTOP }
   130  
   131  func (w WaitStatus) StopSignal() Signal {
   132  	if !w.Stopped() {
   133  		return -1
   134  	}
   135  	return Signal(w>>shift) & 0xFF
   136  }
   137  
   138  func (w WaitStatus) TrapCause() int { return -1 }
   139  
   140  //sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)
   141  
   142  func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
   143  	var status _C_int
   144  	wpid, err = wait4(pid, &status, options, rusage)
   145  	if wstatus != nil {
   146  		*wstatus = WaitStatus(status)
   147  	}
   148  	return
   149  }
   150  
   151  //sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error)
   152  //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
   153  //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
   154  //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
   155  //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
   156  //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
   157  //sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
   158  //sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
   159  //sys	Shutdown(s int, how int) (err error)
   160  
   161  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
   162  	if sa.Port < 0 || sa.Port > 0xFFFF {
   163  		return nil, 0, EINVAL
   164  	}
   165  	sa.raw.Len = SizeofSockaddrInet4
   166  	sa.raw.Family = AF_INET
   167  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   168  	p[0] = byte(sa.Port >> 8)
   169  	p[1] = byte(sa.Port)
   170  	sa.raw.Addr = sa.Addr
   171  	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
   172  }
   173  
   174  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
   175  	if sa.Port < 0 || sa.Port > 0xFFFF {
   176  		return nil, 0, EINVAL
   177  	}
   178  	sa.raw.Len = SizeofSockaddrInet6
   179  	sa.raw.Family = AF_INET6
   180  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   181  	p[0] = byte(sa.Port >> 8)
   182  	p[1] = byte(sa.Port)
   183  	sa.raw.Scope_id = sa.ZoneId
   184  	sa.raw.Addr = sa.Addr
   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  	sa.raw.Data = sa.Data
   214  	return unsafe.Pointer(&sa.raw), SizeofSockaddrDatalink, nil
   215  }
   216  
   217  func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
   218  	switch rsa.Addr.Family {
   219  	case AF_LINK:
   220  		pp := (*RawSockaddrDatalink)(unsafe.Pointer(rsa))
   221  		sa := new(SockaddrDatalink)
   222  		sa.Len = pp.Len
   223  		sa.Family = pp.Family
   224  		sa.Index = pp.Index
   225  		sa.Type = pp.Type
   226  		sa.Nlen = pp.Nlen
   227  		sa.Alen = pp.Alen
   228  		sa.Slen = pp.Slen
   229  		sa.Data = pp.Data
   230  		return sa, nil
   231  
   232  	case AF_UNIX:
   233  		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
   234  		if pp.Len < 2 || pp.Len > SizeofSockaddrUnix {
   235  			return nil, EINVAL
   236  		}
   237  		sa := new(SockaddrUnix)
   238  
   239  		// Some BSDs include the trailing NUL in the length, whereas
   240  		// others do not. Work around this by subtracting the leading
   241  		// family and len. The path is then scanned to see if a NUL
   242  		// terminator still exists within the length.
   243  		n := int(pp.Len) - 2 // subtract leading Family, Len
   244  		for i := 0; i < n; i++ {
   245  			if pp.Path[i] == 0 {
   246  				// found early NUL; assume Len included the NUL
   247  				// or was overestimating.
   248  				n = i
   249  				break
   250  			}
   251  		}
   252  		sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n))
   253  		return sa, nil
   254  
   255  	case AF_INET:
   256  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
   257  		sa := new(SockaddrInet4)
   258  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   259  		sa.Port = int(p[0])<<8 + int(p[1])
   260  		sa.Addr = pp.Addr
   261  		return sa, nil
   262  
   263  	case AF_INET6:
   264  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
   265  		sa := new(SockaddrInet6)
   266  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   267  		sa.Port = int(p[0])<<8 + int(p[1])
   268  		sa.ZoneId = pp.Scope_id
   269  		sa.Addr = pp.Addr
   270  		return sa, nil
   271  	}
   272  	return nil, EAFNOSUPPORT
   273  }
   274  
   275  func Accept(fd int) (nfd int, sa Sockaddr, err error) {
   276  	var rsa RawSockaddrAny
   277  	var len _Socklen = SizeofSockaddrAny
   278  	nfd, err = accept(fd, &rsa, &len)
   279  	if err != nil {
   280  		return
   281  	}
   282  	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && len == 0 {
   283  		// Accepted socket has no address.
   284  		// This is likely due to a bug in xnu kernels,
   285  		// where instead of ECONNABORTED error socket
   286  		// is accepted, but has no address.
   287  		Close(nfd)
   288  		return 0, nil, ECONNABORTED
   289  	}
   290  	sa, err = anyToSockaddr(&rsa)
   291  	if err != nil {
   292  		Close(nfd)
   293  		nfd = 0
   294  	}
   295  	return
   296  }
   297  
   298  func Getsockname(fd int) (sa Sockaddr, err error) {
   299  	var rsa RawSockaddrAny
   300  	var len _Socklen = SizeofSockaddrAny
   301  	if err = getsockname(fd, &rsa, &len); err != nil {
   302  		return
   303  	}
   304  	// TODO(jsing): DragonFly has a "bug" (see issue 3349), which should be
   305  	// reported upstream.
   306  	if runtime.GOOS == "dragonfly" && rsa.Addr.Family == AF_UNSPEC && rsa.Addr.Len == 0 {
   307  		rsa.Addr.Family = AF_UNIX
   308  		rsa.Addr.Len = SizeofSockaddrUnix
   309  	}
   310  	return anyToSockaddr(&rsa)
   311  }
   312  
   313  //sysnb socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)
   314  
   315  func GetsockoptByte(fd, level, opt int) (value byte, err error) {
   316  	var n byte
   317  	vallen := _Socklen(1)
   318  	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
   319  	return n, err
   320  }
   321  
   322  func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
   323  	vallen := _Socklen(4)
   324  	err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
   325  	return value, err
   326  }
   327  
   328  func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
   329  	var value IPMreq
   330  	vallen := _Socklen(SizeofIPMreq)
   331  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   332  	return &value, err
   333  }
   334  
   335  func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
   336  	var value IPv6Mreq
   337  	vallen := _Socklen(SizeofIPv6Mreq)
   338  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   339  	return &value, err
   340  }
   341  
   342  func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
   343  	var value IPv6MTUInfo
   344  	vallen := _Socklen(SizeofIPv6MTUInfo)
   345  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   346  	return &value, err
   347  }
   348  
   349  func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
   350  	var value ICMPv6Filter
   351  	vallen := _Socklen(SizeofICMPv6Filter)
   352  	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   353  	return &value, err
   354  }
   355  
   356  //sys   recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
   357  //sys   sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
   358  //sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
   359  
   360  func recvmsgRaw(fd int, p, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {
   361  	var msg Msghdr
   362  	msg.Name = (*byte)(unsafe.Pointer(rsa))
   363  	msg.Namelen = uint32(SizeofSockaddrAny)
   364  	var iov Iovec
   365  	if len(p) > 0 {
   366  		iov.Base = &p[0]
   367  		iov.SetLen(len(p))
   368  	}
   369  	var dummy byte
   370  	if len(oob) > 0 {
   371  		// receive at least one normal byte
   372  		if len(p) == 0 {
   373  			iov.Base = &dummy
   374  			iov.SetLen(1)
   375  		}
   376  		msg.Control = &oob[0]
   377  		msg.SetControllen(len(oob))
   378  	}
   379  	msg.Iov = &iov
   380  	msg.Iovlen = 1
   381  	if n, err = recvmsg(fd, &msg, flags); err != nil {
   382  		return
   383  	}
   384  	oobn = int(msg.Controllen)
   385  	recvflags = int(msg.Flags)
   386  	return
   387  }
   388  
   389  //sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
   390  
   391  func sendmsgN(fd int, p, oob []byte, ptr unsafe.Pointer, salen _Socklen, flags int) (n int, err error) {
   392  	var msg Msghdr
   393  	msg.Name = (*byte)(ptr)
   394  	msg.Namelen = uint32(salen)
   395  	var iov Iovec
   396  	if len(p) > 0 {
   397  		iov.Base = &p[0]
   398  		iov.SetLen(len(p))
   399  	}
   400  	var dummy byte
   401  	if len(oob) > 0 {
   402  		// send at least one normal byte
   403  		if len(p) == 0 {
   404  			iov.Base = &dummy
   405  			iov.SetLen(1)
   406  		}
   407  		msg.Control = &oob[0]
   408  		msg.SetControllen(len(oob))
   409  	}
   410  	msg.Iov = &iov
   411  	msg.Iovlen = 1
   412  	if n, err = sendmsg(fd, &msg, flags); err != nil {
   413  		return 0, err
   414  	}
   415  	if len(oob) > 0 && len(p) == 0 {
   416  		n = 0
   417  	}
   418  	return n, nil
   419  }
   420  
   421  //sys	kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error)
   422  
   423  func Kevent(kq int, changes, events []Kevent_t, timeout *Timespec) (n int, err error) {
   424  	var change, event unsafe.Pointer
   425  	if len(changes) > 0 {
   426  		change = unsafe.Pointer(&changes[0])
   427  	}
   428  	if len(events) > 0 {
   429  		event = unsafe.Pointer(&events[0])
   430  	}
   431  	return kevent(kq, change, len(changes), event, len(events), timeout)
   432  }
   433  
   434  func Sysctl(name string) (value string, err error) {
   435  	// Translate name to mib number.
   436  	mib, err := nametomib(name)
   437  	if err != nil {
   438  		return "", err
   439  	}
   440  
   441  	// Find size.
   442  	n := uintptr(0)
   443  	if err = sysctl(mib, nil, &n, nil, 0); err != nil {
   444  		return "", err
   445  	}
   446  	if n == 0 {
   447  		return "", nil
   448  	}
   449  
   450  	// Read into buffer of that size.
   451  	buf := make([]byte, n)
   452  	if err = sysctl(mib, &buf[0], &n, nil, 0); err != nil {
   453  		return "", err
   454  	}
   455  
   456  	// Throw away terminating NUL.
   457  	if n > 0 && buf[n-1] == '\x00' {
   458  		n--
   459  	}
   460  	return string(buf[0:n]), nil
   461  }
   462  
   463  func SysctlUint32(name string) (value uint32, err error) {
   464  	// Translate name to mib number.
   465  	mib, err := nametomib(name)
   466  	if err != nil {
   467  		return 0, err
   468  	}
   469  
   470  	// Read into buffer of that size.
   471  	n := uintptr(4)
   472  	buf := make([]byte, 4)
   473  	if err = sysctl(mib, &buf[0], &n, nil, 0); err != nil {
   474  		return 0, err
   475  	}
   476  	if n != 4 {
   477  		return 0, EIO
   478  	}
   479  	return *(*uint32)(unsafe.Pointer(&buf[0])), nil
   480  }
   481  
   482  //sys	utimes(path string, timeval *[2]Timeval) (err error)
   483  
   484  func Utimes(path string, tv []Timeval) (err error) {
   485  	if len(tv) != 2 {
   486  		return EINVAL
   487  	}
   488  	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   489  }
   490  
   491  func UtimesNano(path string, ts []Timespec) error {
   492  	if len(ts) != 2 {
   493  		return EINVAL
   494  	}
   495  	err := utimensat(_AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
   496  	if err != ENOSYS {
   497  		return err
   498  	}
   499  	// Not as efficient as it could be because Timespec and
   500  	// Timeval have different types in the different OSes
   501  	tv := [2]Timeval{
   502  		NsecToTimeval(TimespecToNsec(ts[0])),
   503  		NsecToTimeval(TimespecToNsec(ts[1])),
   504  	}
   505  	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   506  }
   507  
   508  //sys	futimes(fd int, timeval *[2]Timeval) (err error)
   509  
   510  func Futimes(fd int, tv []Timeval) (err error) {
   511  	if len(tv) != 2 {
   512  		return EINVAL
   513  	}
   514  	return futimes(fd, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
   515  }
   516  
   517  //sys	fcntl(fd int, cmd int, arg int) (val int, err error)
   518  //sys	fcntlPtr(fd int, cmd int, arg unsafe.Pointer) (val int, err error) = SYS_FCNTL
   519  //sysnb ioctl(fd int, req int, arg int) (err error)
   520  //sysnb ioctlPtr(fd int, req uint, arg unsafe.Pointer) (err error) = SYS_IOCTL
   521  
   522  var mapper = &mmapper{
   523  	active: make(map[*byte][]byte),
   524  	mmap:   mmap,
   525  	munmap: munmap,
   526  }
   527  
   528  func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
   529  	return mapper.Mmap(fd, offset, length, prot, flags)
   530  }
   531  
   532  func Munmap(b []byte) (err error) {
   533  	return mapper.Munmap(b)
   534  }
   535  

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