// Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. //go:build unix package syscall import ( "internal/bytealg" "internal/itoa" "internal/oserror" "internal/race" "internal/unsafeheader" "runtime" "sync" "unsafe" ) var ( Stdin = 0 Stdout = 1 Stderr = 2 ) const ( darwin64Bit = (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && sizeofPtr == 8 netbsd32Bit = runtime.GOOS == "netbsd" && sizeofPtr == 4 ) // clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte. func clen(n []byte) int { if i := bytealg.IndexByte(n, 0); i != -1 { return i } return len(n) } // Mmap manager, for use by operating system-specific implementations. type mmapper struct { sync.Mutex active map[*byte][]byte // active mappings; key is last byte in mapping mmap func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error) munmap func(addr uintptr, length uintptr) error } func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) { if length <= 0 { return nil, EINVAL } // Map the requested memory. addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset) if errno != nil { return nil, errno } // Use unsafe to turn addr into a []byte. var b []byte hdr := (*unsafeheader.Slice)(unsafe.Pointer(&b)) hdr.Data = unsafe.Pointer(addr) hdr.Cap = length hdr.Len = length // Register mapping in m and return it. p := &b[cap(b)-1] m.Lock() defer m.Unlock() m.active[p] = b return b, nil } func (m *mmapper) Munmap(data []byte) (err error) { if len(data) == 0 || len(data) != cap(data) { return EINVAL } // Find the base of the mapping. p := &data[cap(data)-1] m.Lock() defer m.Unlock() b := m.active[p] if b == nil || &b[0] != &data[0] { return EINVAL } // Unmap the memory and update m. if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil { return errno } delete(m.active, p) return nil } // An Errno is an unsigned number describing an error condition. // It implements the error interface. The zero Errno is by convention // a non-error, so code to convert from Errno to error should use: // // err = nil // if errno != 0 { // err = errno // } // // Errno values can be tested against error values from the os package // using errors.Is. For example: // // _, _, err := syscall.Syscall(...) // if errors.Is(err, fs.ErrNotExist) ... type Errno uintptr func (e Errno) Error() string { if 0 <= int(e) && int(e) < len(errors) { s := errors[e] if s != "" { return s } } return "errno " + itoa.Itoa(int(e)) } func (e Errno) Is(target error) bool { switch target { case oserror.ErrPermission: return e == EACCES || e == EPERM case oserror.ErrExist: return e == EEXIST || e == ENOTEMPTY case oserror.ErrNotExist: return e == ENOENT } return false } func (e Errno) Temporary() bool { return e == EINTR || e == EMFILE || e == ENFILE || e.Timeout() } func (e Errno) Timeout() bool { return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT } // Do the interface allocations only once for common // Errno values. var ( errEAGAIN error = EAGAIN errEINVAL error = EINVAL errENOENT error = ENOENT ) // errnoErr returns common boxed Errno values, to prevent // allocations at runtime. func errnoErr(e Errno) error { switch e { case 0: return nil case EAGAIN: return errEAGAIN case EINVAL: return errEINVAL case ENOENT: return errENOENT } return e } // A Signal is a number describing a process signal. // It implements the os.Signal interface. type Signal int func (s Signal) Signal() {} func (s Signal) String() string { if 0 <= s && int(s) < len(signals) { str := signals[s] if str != "" { return str } } return "signal " + itoa.Itoa(int(s)) } func Read(fd int, p []byte) (n int, err error) { n, err = read(fd, p) if race.Enabled { if n > 0 { race.WriteRange(unsafe.Pointer(&p[0]), n) } if err == nil { race.Acquire(unsafe.Pointer(&ioSync)) } } if msanenabled && n > 0 { msanWrite(unsafe.Pointer(&p[0]), n) } if asanenabled && n > 0 { asanWrite(unsafe.Pointer(&p[0]), n) } return } func Write(fd int, p []byte) (n int, err error) { if race.Enabled { race.ReleaseMerge(unsafe.Pointer(&ioSync)) } if faketime && (fd == 1 || fd == 2) { n = faketimeWrite(fd, p) if n < 0 { n, err = 0, errnoErr(Errno(-n)) } } else { n, err = write(fd, p) } if race.Enabled && n > 0 { race.ReadRange(unsafe.Pointer(&p[0]), n) } if msanenabled && n > 0 { msanRead(unsafe.Pointer(&p[0]), n) } if asanenabled && n > 0 { asanRead(unsafe.Pointer(&p[0]), n) } return } func Pread(fd int, p []byte, offset int64) (n int, err error) { n, err = pread(fd, p, offset) if race.Enabled { if n > 0 { race.WriteRange(unsafe.Pointer(&p[0]), n) } if err == nil { race.Acquire(unsafe.Pointer(&ioSync)) } } if msanenabled && n > 0 { msanWrite(unsafe.Pointer(&p[0]), n) } if asanenabled && n > 0 { asanWrite(unsafe.Pointer(&p[0]), n) } return } func Pwrite(fd int, p []byte, offset int64) (n int, err error) { if race.Enabled { race.ReleaseMerge(unsafe.Pointer(&ioSync)) } n, err = pwrite(fd, p, offset) if race.Enabled && n > 0 { race.ReadRange(unsafe.Pointer(&p[0]), n) } if msanenabled && n > 0 { msanRead(unsafe.Pointer(&p[0]), n) } if asanenabled && n > 0 { asanRead(unsafe.Pointer(&p[0]), n) } return } // For testing: clients can set this flag to force // creation of IPv6 sockets to return EAFNOSUPPORT. var SocketDisableIPv6 bool type Sockaddr interface { sockaddr() (ptr unsafe.Pointer, len _Socklen, err error) // lowercase; only we can define Sockaddrs } type SockaddrInet4 struct { Port int Addr [4]byte raw RawSockaddrInet4 } type SockaddrInet6 struct { Port int ZoneId uint32 Addr [16]byte raw RawSockaddrInet6 } type SockaddrUnix struct { Name string raw RawSockaddrUnix } func Bind(fd int, sa Sockaddr) (err error) { ptr, n, err := sa.sockaddr() if err != nil { return err } return bind(fd, ptr, n) } func Connect(fd int, sa Sockaddr) (err error) { ptr, n, err := sa.sockaddr() if err != nil { return err } return connect(fd, ptr, n) } func Getpeername(fd int) (sa Sockaddr, err error) { var rsa RawSockaddrAny var len _Socklen = SizeofSockaddrAny if err = getpeername(fd, &rsa, &len); err != nil { return } return anyToSockaddr(&rsa) } func GetsockoptInt(fd, level, opt int) (value int, err error) { var n int32 vallen := _Socklen(4) err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen) return int(n), err } func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) { var rsa RawSockaddrAny var len _Socklen = SizeofSockaddrAny if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil { return } if rsa.Addr.Family != AF_UNSPEC { from, err = anyToSockaddr(&rsa) } return } func recvfromInet4(fd int, p []byte, flags int, from *SockaddrInet4) (n int, err error) { var rsa RawSockaddrAny var socklen _Socklen = SizeofSockaddrAny if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil { return } pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa)) port := (*[2]byte)(unsafe.Pointer(&pp.Port)) from.Port = int(port[0])<<8 + int(port[1]) from.Addr = pp.Addr return } func recvfromInet6(fd int, p []byte, flags int, from *SockaddrInet6) (n int, err error) { var rsa RawSockaddrAny var socklen _Socklen = SizeofSockaddrAny if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil { return } pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa)) port := (*[2]byte)(unsafe.Pointer(&pp.Port)) from.Port = int(port[0])<<8 + int(port[1]) from.ZoneId = pp.Scope_id from.Addr = pp.Addr return } func recvmsgInet4(fd int, p, oob []byte, flags int, from *SockaddrInet4) (n, oobn int, recvflags int, err error) { var rsa RawSockaddrAny n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa) if err != nil { return } pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa)) port := (*[2]byte)(unsafe.Pointer(&pp.Port)) from.Port = int(port[0])<<8 + int(port[1]) from.Addr = pp.Addr return } func recvmsgInet6(fd int, p, oob []byte, flags int, from *SockaddrInet6) (n, oobn int, recvflags int, err error) { var rsa RawSockaddrAny n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa) if err != nil { return } pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa)) port := (*[2]byte)(unsafe.Pointer(&pp.Port)) from.Port = int(port[0])<<8 + int(port[1]) from.ZoneId = pp.Scope_id from.Addr = pp.Addr return } func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) { var rsa RawSockaddrAny n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa) // source address is only specified if the socket is unconnected if rsa.Addr.Family != AF_UNSPEC { from, err = anyToSockaddr(&rsa) } return } func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) { _, err = SendmsgN(fd, p, oob, to, flags) return } func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) { var ptr unsafe.Pointer var salen _Socklen if to != nil { ptr, salen, err = to.sockaddr() if err != nil { return 0, err } } return sendmsgN(fd, p, oob, ptr, salen, flags) } func sendmsgNInet4(fd int, p, oob []byte, to *SockaddrInet4, flags int) (n int, err error) { ptr, salen, err := to.sockaddr() if err != nil { return 0, err } return sendmsgN(fd, p, oob, ptr, salen, flags) } func sendmsgNInet6(fd int, p, oob []byte, to *SockaddrInet6, flags int) (n int, err error) { ptr, salen, err := to.sockaddr() if err != nil { return 0, err } return sendmsgN(fd, p, oob, ptr, salen, flags) } func sendtoInet4(fd int, p []byte, flags int, to *SockaddrInet4) (err error) { ptr, n, err := to.sockaddr() if err != nil { return err } return sendto(fd, p, flags, ptr, n) } func sendtoInet6(fd int, p []byte, flags int, to *SockaddrInet6) (err error) { ptr, n, err := to.sockaddr() if err != nil { return err } return sendto(fd, p, flags, ptr, n) } func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) { ptr, n, err := to.sockaddr() if err != nil { return err } return sendto(fd, p, flags, ptr, n) } func SetsockoptByte(fd, level, opt int, value byte) (err error) { return setsockopt(fd, level, opt, unsafe.Pointer(&value), 1) } func SetsockoptInt(fd, level, opt int, value int) (err error) { var n = int32(value) return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4) } func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) { return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4) } func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) { return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPMreq) } func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) { return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPv6Mreq) } func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error { return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter) } func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) { return setsockopt(fd, level, opt, unsafe.Pointer(l), SizeofLinger) } func SetsockoptString(fd, level, opt int, s string) (err error) { var p unsafe.Pointer if len(s) > 0 { p = unsafe.Pointer(&[]byte(s)[0]) } return setsockopt(fd, level, opt, p, uintptr(len(s))) } func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) { return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv)) } func Socket(domain, typ, proto int) (fd int, err error) { if domain == AF_INET6 && SocketDisableIPv6 { return -1, EAFNOSUPPORT } fd, err = socket(domain, typ, proto) return } func Socketpair(domain, typ, proto int) (fd [2]int, err error) { var fdx [2]int32 err = socketpair(domain, typ, proto, &fdx) if err == nil { fd[0] = int(fdx[0]) fd[1] = int(fdx[1]) } return } func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) { if race.Enabled { race.ReleaseMerge(unsafe.Pointer(&ioSync)) } return sendfile(outfd, infd, offset, count) } var ioSync int64