Source file src/pkg/cmd/vendor/golang.org/x/sys/unix/syscall_unix.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	// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
     6	
     7	package unix
     8	
     9	import (
    10		"bytes"
    11		"sort"
    12		"sync"
    13		"syscall"
    14		"unsafe"
    15	)
    16	
    17	var (
    18		Stdin  = 0
    19		Stdout = 1
    20		Stderr = 2
    21	)
    22	
    23	// Do the interface allocations only once for common
    24	// Errno values.
    25	var (
    26		errEAGAIN error = syscall.EAGAIN
    27		errEINVAL error = syscall.EINVAL
    28		errENOENT error = syscall.ENOENT
    29	)
    30	
    31	var (
    32		signalNameMapOnce sync.Once
    33		signalNameMap     map[string]syscall.Signal
    34	)
    35	
    36	// errnoErr returns common boxed Errno values, to prevent
    37	// allocations at runtime.
    38	func errnoErr(e syscall.Errno) error {
    39		switch e {
    40		case 0:
    41			return nil
    42		case EAGAIN:
    43			return errEAGAIN
    44		case EINVAL:
    45			return errEINVAL
    46		case ENOENT:
    47			return errENOENT
    48		}
    49		return e
    50	}
    51	
    52	// ErrnoName returns the error name for error number e.
    53	func ErrnoName(e syscall.Errno) string {
    54		i := sort.Search(len(errorList), func(i int) bool {
    55			return errorList[i].num >= e
    56		})
    57		if i < len(errorList) && errorList[i].num == e {
    58			return errorList[i].name
    59		}
    60		return ""
    61	}
    62	
    63	// SignalName returns the signal name for signal number s.
    64	func SignalName(s syscall.Signal) string {
    65		i := sort.Search(len(signalList), func(i int) bool {
    66			return signalList[i].num >= s
    67		})
    68		if i < len(signalList) && signalList[i].num == s {
    69			return signalList[i].name
    70		}
    71		return ""
    72	}
    73	
    74	// SignalNum returns the syscall.Signal for signal named s,
    75	// or 0 if a signal with such name is not found.
    76	// The signal name should start with "SIG".
    77	func SignalNum(s string) syscall.Signal {
    78		signalNameMapOnce.Do(func() {
    79			signalNameMap = make(map[string]syscall.Signal)
    80			for _, signal := range signalList {
    81				signalNameMap[signal.name] = signal.num
    82			}
    83		})
    84		return signalNameMap[s]
    85	}
    86	
    87	// clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
    88	func clen(n []byte) int {
    89		i := bytes.IndexByte(n, 0)
    90		if i == -1 {
    91			i = len(n)
    92		}
    93		return i
    94	}
    95	
    96	// Mmap manager, for use by operating system-specific implementations.
    97	
    98	type mmapper struct {
    99		sync.Mutex
   100		active map[*byte][]byte // active mappings; key is last byte in mapping
   101		mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
   102		munmap func(addr uintptr, length uintptr) error
   103	}
   104	
   105	func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
   106		if length <= 0 {
   107			return nil, EINVAL
   108		}
   109	
   110		// Map the requested memory.
   111		addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
   112		if errno != nil {
   113			return nil, errno
   114		}
   115	
   116		// Slice memory layout
   117		var sl = struct {
   118			addr uintptr
   119			len  int
   120			cap  int
   121		}{addr, length, length}
   122	
   123		// Use unsafe to turn sl into a []byte.
   124		b := *(*[]byte)(unsafe.Pointer(&sl))
   125	
   126		// Register mapping in m and return it.
   127		p := &b[cap(b)-1]
   128		m.Lock()
   129		defer m.Unlock()
   130		m.active[p] = b
   131		return b, nil
   132	}
   133	
   134	func (m *mmapper) Munmap(data []byte) (err error) {
   135		if len(data) == 0 || len(data) != cap(data) {
   136			return EINVAL
   137		}
   138	
   139		// Find the base of the mapping.
   140		p := &data[cap(data)-1]
   141		m.Lock()
   142		defer m.Unlock()
   143		b := m.active[p]
   144		if b == nil || &b[0] != &data[0] {
   145			return EINVAL
   146		}
   147	
   148		// Unmap the memory and update m.
   149		if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
   150			return errno
   151		}
   152		delete(m.active, p)
   153		return nil
   154	}
   155	
   156	func Read(fd int, p []byte) (n int, err error) {
   157		n, err = read(fd, p)
   158		if raceenabled {
   159			if n > 0 {
   160				raceWriteRange(unsafe.Pointer(&p[0]), n)
   161			}
   162			if err == nil {
   163				raceAcquire(unsafe.Pointer(&ioSync))
   164			}
   165		}
   166		return
   167	}
   168	
   169	func Write(fd int, p []byte) (n int, err error) {
   170		if raceenabled {
   171			raceReleaseMerge(unsafe.Pointer(&ioSync))
   172		}
   173		n, err = write(fd, p)
   174		if raceenabled && n > 0 {
   175			raceReadRange(unsafe.Pointer(&p[0]), n)
   176		}
   177		return
   178	}
   179	
   180	// For testing: clients can set this flag to force
   181	// creation of IPv6 sockets to return EAFNOSUPPORT.
   182	var SocketDisableIPv6 bool
   183	
   184	// Sockaddr represents a socket address.
   185	type Sockaddr interface {
   186		sockaddr() (ptr unsafe.Pointer, len _Socklen, err error) // lowercase; only we can define Sockaddrs
   187	}
   188	
   189	// SockaddrInet4 implements the Sockaddr interface for AF_INET type sockets.
   190	type SockaddrInet4 struct {
   191		Port int
   192		Addr [4]byte
   193		raw  RawSockaddrInet4
   194	}
   195	
   196	// SockaddrInet6 implements the Sockaddr interface for AF_INET6 type sockets.
   197	type SockaddrInet6 struct {
   198		Port   int
   199		ZoneId uint32
   200		Addr   [16]byte
   201		raw    RawSockaddrInet6
   202	}
   203	
   204	// SockaddrUnix implements the Sockaddr interface for AF_UNIX type sockets.
   205	type SockaddrUnix struct {
   206		Name string
   207		raw  RawSockaddrUnix
   208	}
   209	
   210	func Bind(fd int, sa Sockaddr) (err error) {
   211		ptr, n, err := sa.sockaddr()
   212		if err != nil {
   213			return err
   214		}
   215		return bind(fd, ptr, n)
   216	}
   217	
   218	func Connect(fd int, sa Sockaddr) (err error) {
   219		ptr, n, err := sa.sockaddr()
   220		if err != nil {
   221			return err
   222		}
   223		return connect(fd, ptr, n)
   224	}
   225	
   226	func Getpeername(fd int) (sa Sockaddr, err error) {
   227		var rsa RawSockaddrAny
   228		var len _Socklen = SizeofSockaddrAny
   229		if err = getpeername(fd, &rsa, &len); err != nil {
   230			return
   231		}
   232		return anyToSockaddr(fd, &rsa)
   233	}
   234	
   235	func GetsockoptByte(fd, level, opt int) (value byte, err error) {
   236		var n byte
   237		vallen := _Socklen(1)
   238		err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
   239		return n, err
   240	}
   241	
   242	func GetsockoptInt(fd, level, opt int) (value int, err error) {
   243		var n int32
   244		vallen := _Socklen(4)
   245		err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
   246		return int(n), err
   247	}
   248	
   249	func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
   250		vallen := _Socklen(4)
   251		err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
   252		return value, err
   253	}
   254	
   255	func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
   256		var value IPMreq
   257		vallen := _Socklen(SizeofIPMreq)
   258		err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   259		return &value, err
   260	}
   261	
   262	func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
   263		var value IPv6Mreq
   264		vallen := _Socklen(SizeofIPv6Mreq)
   265		err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   266		return &value, err
   267	}
   268	
   269	func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
   270		var value IPv6MTUInfo
   271		vallen := _Socklen(SizeofIPv6MTUInfo)
   272		err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   273		return &value, err
   274	}
   275	
   276	func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
   277		var value ICMPv6Filter
   278		vallen := _Socklen(SizeofICMPv6Filter)
   279		err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
   280		return &value, err
   281	}
   282	
   283	func GetsockoptLinger(fd, level, opt int) (*Linger, error) {
   284		var linger Linger
   285		vallen := _Socklen(SizeofLinger)
   286		err := getsockopt(fd, level, opt, unsafe.Pointer(&linger), &vallen)
   287		return &linger, err
   288	}
   289	
   290	func GetsockoptTimeval(fd, level, opt int) (*Timeval, error) {
   291		var tv Timeval
   292		vallen := _Socklen(unsafe.Sizeof(tv))
   293		err := getsockopt(fd, level, opt, unsafe.Pointer(&tv), &vallen)
   294		return &tv, err
   295	}
   296	
   297	func GetsockoptUint64(fd, level, opt int) (value uint64, err error) {
   298		var n uint64
   299		vallen := _Socklen(8)
   300		err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
   301		return n, err
   302	}
   303	
   304	func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
   305		var rsa RawSockaddrAny
   306		var len _Socklen = SizeofSockaddrAny
   307		if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
   308			return
   309		}
   310		if rsa.Addr.Family != AF_UNSPEC {
   311			from, err = anyToSockaddr(fd, &rsa)
   312		}
   313		return
   314	}
   315	
   316	func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
   317		ptr, n, err := to.sockaddr()
   318		if err != nil {
   319			return err
   320		}
   321		return sendto(fd, p, flags, ptr, n)
   322	}
   323	
   324	func SetsockoptByte(fd, level, opt int, value byte) (err error) {
   325		return setsockopt(fd, level, opt, unsafe.Pointer(&value), 1)
   326	}
   327	
   328	func SetsockoptInt(fd, level, opt int, value int) (err error) {
   329		var n = int32(value)
   330		return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
   331	}
   332	
   333	func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
   334		return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
   335	}
   336	
   337	func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
   338		return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPMreq)
   339	}
   340	
   341	func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
   342		return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPv6Mreq)
   343	}
   344	
   345	func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
   346		return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
   347	}
   348	
   349	func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
   350		return setsockopt(fd, level, opt, unsafe.Pointer(l), SizeofLinger)
   351	}
   352	
   353	func SetsockoptString(fd, level, opt int, s string) (err error) {
   354		var p unsafe.Pointer
   355		if len(s) > 0 {
   356			p = unsafe.Pointer(&[]byte(s)[0])
   357		}
   358		return setsockopt(fd, level, opt, p, uintptr(len(s)))
   359	}
   360	
   361	func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
   362		return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv))
   363	}
   364	
   365	func SetsockoptUint64(fd, level, opt int, value uint64) (err error) {
   366		return setsockopt(fd, level, opt, unsafe.Pointer(&value), 8)
   367	}
   368	
   369	func Socket(domain, typ, proto int) (fd int, err error) {
   370		if domain == AF_INET6 && SocketDisableIPv6 {
   371			return -1, EAFNOSUPPORT
   372		}
   373		fd, err = socket(domain, typ, proto)
   374		return
   375	}
   376	
   377	func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
   378		var fdx [2]int32
   379		err = socketpair(domain, typ, proto, &fdx)
   380		if err == nil {
   381			fd[0] = int(fdx[0])
   382			fd[1] = int(fdx[1])
   383		}
   384		return
   385	}
   386	
   387	var ioSync int64
   388	
   389	func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }
   390	
   391	func SetNonblock(fd int, nonblocking bool) (err error) {
   392		flag, err := fcntl(fd, F_GETFL, 0)
   393		if err != nil {
   394			return err
   395		}
   396		if nonblocking {
   397			flag |= O_NONBLOCK
   398		} else {
   399			flag &= ^O_NONBLOCK
   400		}
   401		_, err = fcntl(fd, F_SETFL, flag)
   402		return err
   403	}
   404	
   405	// Exec calls execve(2), which replaces the calling executable in the process
   406	// tree. argv0 should be the full path to an executable ("/bin/ls") and the
   407	// executable name should also be the first argument in argv (["ls", "-l"]).
   408	// envv are the environment variables that should be passed to the new
   409	// process (["USER=go", "PWD=/tmp"]).
   410	func Exec(argv0 string, argv []string, envv []string) error {
   411		return syscall.Exec(argv0, argv, envv)
   412	}
   413	
   414	// Lutimes sets the access and modification times tv on path. If path refers to
   415	// a symlink, it is not dereferenced and the timestamps are set on the symlink.
   416	// If tv is nil, the access and modification times are set to the current time.
   417	// Otherwise tv must contain exactly 2 elements, with access time as the first
   418	// element and modification time as the second element.
   419	func Lutimes(path string, tv []Timeval) error {
   420		if tv == nil {
   421			return UtimesNanoAt(AT_FDCWD, path, nil, AT_SYMLINK_NOFOLLOW)
   422		}
   423		if len(tv) != 2 {
   424			return EINVAL
   425		}
   426		ts := []Timespec{
   427			NsecToTimespec(TimevalToNsec(tv[0])),
   428			NsecToTimespec(TimevalToNsec(tv[1])),
   429		}
   430		return UtimesNanoAt(AT_FDCWD, path, ts, AT_SYMLINK_NOFOLLOW)
   431	}
   432	

View as plain text