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Source file src/syscall/syscall_darwin.go

Documentation: syscall

     1  // Copyright 2009,2010 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  // Darwin 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 wrap
    10  // it in our own nicer implementation, either here or in
    11  // syscall_bsd.go or syscall_unix.go.
    12  
    13  package syscall
    14  
    15  import (
    16  	errorspkg "errors"
    17  	"unsafe"
    18  )
    19  
    20  const ImplementsGetwd = true
    21  
    22  func Getwd() (string, error) {
    23  	buf := make([]byte, 2048)
    24  	attrs, err := getAttrList(".", attrList{CommonAttr: attrCmnFullpath}, buf, 0)
    25  	if err == nil && len(attrs) == 1 && len(attrs[0]) >= 2 {
    26  		wd := string(attrs[0])
    27  		// Sanity check that it's an absolute path and ends
    28  		// in a null byte, which we then strip.
    29  		if wd[0] == '/' && wd[len(wd)-1] == 0 {
    30  			return wd[:len(wd)-1], nil
    31  		}
    32  	}
    33  	// If pkg/os/getwd.go gets ENOTSUP, it will fall back to the
    34  	// slow algorithm.
    35  	return "", ENOTSUP
    36  }
    37  
    38  type SockaddrDatalink struct {
    39  	Len    uint8
    40  	Family uint8
    41  	Index  uint16
    42  	Type   uint8
    43  	Nlen   uint8
    44  	Alen   uint8
    45  	Slen   uint8
    46  	Data   [12]int8
    47  	raw    RawSockaddrDatalink
    48  }
    49  
    50  // Translate "kern.hostname" to []_C_int{0,1,2,3}.
    51  func nametomib(name string) (mib []_C_int, err error) {
    52  	const siz = unsafe.Sizeof(mib[0])
    53  
    54  	// NOTE(rsc): It seems strange to set the buffer to have
    55  	// size CTL_MAXNAME+2 but use only CTL_MAXNAME
    56  	// as the size. I don't know why the +2 is here, but the
    57  	// kernel uses +2 for its own implementation of this function.
    58  	// I am scared that if we don't include the +2 here, the kernel
    59  	// will silently write 2 words farther than we specify
    60  	// and we'll get memory corruption.
    61  	var buf [CTL_MAXNAME + 2]_C_int
    62  	n := uintptr(CTL_MAXNAME) * siz
    63  
    64  	p := (*byte)(unsafe.Pointer(&buf[0]))
    65  	bytes, err := ByteSliceFromString(name)
    66  	if err != nil {
    67  		return nil, err
    68  	}
    69  
    70  	// Magic sysctl: "setting" 0.3 to a string name
    71  	// lets you read back the array of integers form.
    72  	if err = sysctl([]_C_int{0, 3}, p, &n, &bytes[0], uintptr(len(name))); err != nil {
    73  		return nil, err
    74  	}
    75  	return buf[0 : n/siz], nil
    76  }
    77  
    78  func direntIno(buf []byte) (uint64, bool) {
    79  	return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
    80  }
    81  
    82  func direntReclen(buf []byte) (uint64, bool) {
    83  	return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
    84  }
    85  
    86  func direntNamlen(buf []byte) (uint64, bool) {
    87  	return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))
    88  }
    89  
    90  //sys   ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
    91  func PtraceAttach(pid int) (err error) { return ptrace(PT_ATTACH, pid, 0, 0) }
    92  func PtraceDetach(pid int) (err error) { return ptrace(PT_DETACH, pid, 0, 0) }
    93  
    94  const (
    95  	attrBitMapCount = 5
    96  	attrCmnModtime  = 0x00000400
    97  	attrCmnAcctime  = 0x00001000
    98  	attrCmnFullpath = 0x08000000
    99  )
   100  
   101  type attrList struct {
   102  	bitmapCount uint16
   103  	_           uint16
   104  	CommonAttr  uint32
   105  	VolAttr     uint32
   106  	DirAttr     uint32
   107  	FileAttr    uint32
   108  	Forkattr    uint32
   109  }
   110  
   111  func getAttrList(path string, attrList attrList, attrBuf []byte, options uint) (attrs [][]byte, err error) {
   112  	if len(attrBuf) < 4 {
   113  		return nil, errorspkg.New("attrBuf too small")
   114  	}
   115  	attrList.bitmapCount = attrBitMapCount
   116  
   117  	var _p0 *byte
   118  	_p0, err = BytePtrFromString(path)
   119  	if err != nil {
   120  		return nil, err
   121  	}
   122  
   123  	_, _, e1 := Syscall6(
   124  		SYS_GETATTRLIST,
   125  		uintptr(unsafe.Pointer(_p0)),
   126  		uintptr(unsafe.Pointer(&attrList)),
   127  		uintptr(unsafe.Pointer(&attrBuf[0])),
   128  		uintptr(len(attrBuf)),
   129  		uintptr(options),
   130  		0,
   131  	)
   132  	if e1 != 0 {
   133  		return nil, e1
   134  	}
   135  	size := *(*uint32)(unsafe.Pointer(&attrBuf[0]))
   136  
   137  	// dat is the section of attrBuf that contains valid data,
   138  	// without the 4 byte length header. All attribute offsets
   139  	// are relative to dat.
   140  	dat := attrBuf
   141  	if int(size) < len(attrBuf) {
   142  		dat = dat[:size]
   143  	}
   144  	dat = dat[4:] // remove length prefix
   145  
   146  	for i := uint32(0); int(i) < len(dat); {
   147  		header := dat[i:]
   148  		if len(header) < 8 {
   149  			return attrs, errorspkg.New("truncated attribute header")
   150  		}
   151  		datOff := *(*int32)(unsafe.Pointer(&header[0]))
   152  		attrLen := *(*uint32)(unsafe.Pointer(&header[4]))
   153  		if datOff < 0 || uint32(datOff)+attrLen > uint32(len(dat)) {
   154  			return attrs, errorspkg.New("truncated results; attrBuf too small")
   155  		}
   156  		end := uint32(datOff) + attrLen
   157  		attrs = append(attrs, dat[datOff:end])
   158  		i = end
   159  		if r := i % 4; r != 0 {
   160  			i += (4 - r)
   161  		}
   162  	}
   163  	return
   164  }
   165  
   166  //sysnb pipe() (r int, w int, err error)
   167  
   168  func Pipe(p []int) (err error) {
   169  	if len(p) != 2 {
   170  		return EINVAL
   171  	}
   172  	p[0], p[1], err = pipe()
   173  	return
   174  }
   175  
   176  func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
   177  	var _p0 unsafe.Pointer
   178  	var bufsize uintptr
   179  	if len(buf) > 0 {
   180  		_p0 = unsafe.Pointer(&buf[0])
   181  		bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
   182  	}
   183  	r0, _, e1 := Syscall(SYS_GETFSSTAT64, uintptr(_p0), bufsize, uintptr(flags))
   184  	n = int(r0)
   185  	if e1 != 0 {
   186  		err = e1
   187  	}
   188  	return
   189  }
   190  
   191  func setattrlistTimes(path string, times []Timespec) error {
   192  	_p0, err := BytePtrFromString(path)
   193  	if err != nil {
   194  		return err
   195  	}
   196  
   197  	var attrList attrList
   198  	attrList.bitmapCount = attrBitMapCount
   199  	attrList.CommonAttr = attrCmnModtime | attrCmnAcctime
   200  
   201  	// order is mtime, atime: the opposite of Chtimes
   202  	attributes := [2]Timespec{times[1], times[0]}
   203  	const options = 0
   204  	_, _, e1 := Syscall6(
   205  		SYS_SETATTRLIST,
   206  		uintptr(unsafe.Pointer(_p0)),
   207  		uintptr(unsafe.Pointer(&attrList)),
   208  		uintptr(unsafe.Pointer(&attributes)),
   209  		uintptr(unsafe.Sizeof(attributes)),
   210  		uintptr(options),
   211  		0,
   212  	)
   213  	if e1 != 0 {
   214  		return e1
   215  	}
   216  	return nil
   217  }
   218  
   219  func utimensat(dirfd int, path string, times *[2]Timespec, flag int) error {
   220  	// Darwin doesn't support SYS_UTIMENSAT
   221  	return ENOSYS
   222  }
   223  
   224  /*
   225   * Wrapped
   226   */
   227  
   228  //sys	kill(pid int, signum int, posix int) (err error)
   229  
   230  func Kill(pid int, signum Signal) (err error) { return kill(pid, int(signum), 1) }
   231  
   232  /*
   233   * Exposed directly
   234   */
   235  //sys	Access(path string, mode uint32) (err error)
   236  //sys	Adjtime(delta *Timeval, olddelta *Timeval) (err error)
   237  //sys	Chdir(path string) (err error)
   238  //sys	Chflags(path string, flags int) (err error)
   239  //sys	Chmod(path string, mode uint32) (err error)
   240  //sys	Chown(path string, uid int, gid int) (err error)
   241  //sys	Chroot(path string) (err error)
   242  //sys	Close(fd int) (err error)
   243  //sys	Dup(fd int) (nfd int, err error)
   244  //sys	Dup2(from int, to int) (err error)
   245  //sys	Exchangedata(path1 string, path2 string, options int) (err error)
   246  //sys	Fchdir(fd int) (err error)
   247  //sys	Fchflags(fd int, flags int) (err error)
   248  //sys	Fchmod(fd int, mode uint32) (err error)
   249  //sys	Fchown(fd int, uid int, gid int) (err error)
   250  //sys	Flock(fd int, how int) (err error)
   251  //sys	Fpathconf(fd int, name int) (val int, err error)
   252  //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64
   253  //sys	Fstatfs(fd int, stat *Statfs_t) (err error) = SYS_FSTATFS64
   254  //sys	Fsync(fd int) (err error)
   255  //sys	Ftruncate(fd int, length int64) (err error)
   256  //sys	Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error) = SYS_GETDIRENTRIES64
   257  //sys	Getdtablesize() (size int)
   258  //sysnb	Getegid() (egid int)
   259  //sysnb	Geteuid() (uid int)
   260  //sysnb	Getgid() (gid int)
   261  //sysnb	Getpgid(pid int) (pgid int, err error)
   262  //sysnb	Getpgrp() (pgrp int)
   263  //sysnb	Getpid() (pid int)
   264  //sysnb	Getppid() (ppid int)
   265  //sys	Getpriority(which int, who int) (prio int, err error)
   266  //sysnb	Getrlimit(which int, lim *Rlimit) (err error)
   267  //sysnb	Getrusage(who int, rusage *Rusage) (err error)
   268  //sysnb	Getsid(pid int) (sid int, err error)
   269  //sysnb	Getuid() (uid int)
   270  //sysnb	Issetugid() (tainted bool)
   271  //sys	Kqueue() (fd int, err error)
   272  //sys	Lchown(path string, uid int, gid int) (err error)
   273  //sys	Link(path string, link string) (err error)
   274  //sys	Listen(s int, backlog int) (err error)
   275  //sys	Lstat(path string, stat *Stat_t) (err error) = SYS_LSTAT64
   276  //sys	Mkdir(path string, mode uint32) (err error)
   277  //sys	Mkfifo(path string, mode uint32) (err error)
   278  //sys	Mknod(path string, mode uint32, dev int) (err error)
   279  //sys	Mlock(b []byte) (err error)
   280  //sys	Mlockall(flags int) (err error)
   281  //sys	Mprotect(b []byte, prot int) (err error)
   282  //sys	Munlock(b []byte) (err error)
   283  //sys	Munlockall() (err error)
   284  //sys	Open(path string, mode int, perm uint32) (fd int, err error)
   285  //sys	Pathconf(path string, name int) (val int, err error)
   286  //sys	Pread(fd int, p []byte, offset int64) (n int, err error)
   287  //sys	Pwrite(fd int, p []byte, offset int64) (n int, err error)
   288  //sys	read(fd int, p []byte) (n int, err error)
   289  //sys	Readlink(path string, buf []byte) (n int, err error)
   290  //sys	Rename(from string, to string) (err error)
   291  //sys	Revoke(path string) (err error)
   292  //sys	Rmdir(path string) (err error)
   293  //sys	Seek(fd int, offset int64, whence int) (newoffset int64, err error) = SYS_LSEEK
   294  //sys	Select(n int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (err error)
   295  //sys	Setegid(egid int) (err error)
   296  //sysnb	Seteuid(euid int) (err error)
   297  //sysnb	Setgid(gid int) (err error)
   298  //sys	Setlogin(name string) (err error)
   299  //sysnb	Setpgid(pid int, pgid int) (err error)
   300  //sys	Setpriority(which int, who int, prio int) (err error)
   301  //sys	Setprivexec(flag int) (err error)
   302  //sysnb	Setregid(rgid int, egid int) (err error)
   303  //sysnb	Setreuid(ruid int, euid int) (err error)
   304  //sysnb	Setrlimit(which int, lim *Rlimit) (err error)
   305  //sysnb	Setsid() (pid int, err error)
   306  //sysnb	Settimeofday(tp *Timeval) (err error)
   307  //sysnb	Setuid(uid int) (err error)
   308  //sys	Stat(path string, stat *Stat_t) (err error) = SYS_STAT64
   309  //sys	Statfs(path string, stat *Statfs_t) (err error) = SYS_STATFS64
   310  //sys	Symlink(path string, link string) (err error)
   311  //sys	Sync() (err error)
   312  //sys	Truncate(path string, length int64) (err error)
   313  //sys	Umask(newmask int) (oldmask int)
   314  //sys	Undelete(path string) (err error)
   315  //sys	Unlink(path string) (err error)
   316  //sys	Unmount(path string, flags int) (err error)
   317  //sys	write(fd int, p []byte) (n int, err error)
   318  //sys   mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
   319  //sys   munmap(addr uintptr, length uintptr) (err error)
   320  //sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
   321  //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
   322  

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