// 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 (
errorspkg "errors"
"internal/asan"
"internal/bytealg"
"internal/itoa"
"internal/msan"
"internal/oserror"
"internal/race"
"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.
b := unsafe.Slice((*byte)(unsafe.Pointer(addr)), 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 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
case errorspkg.ErrUnsupported:
return e == ENOSYS || e == ENOTSUP || e == EOPNOTSUPP
}
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 msan.Enabled && n > 0 {
msan.Write(unsafe.Pointer(&p[0]), uintptr(n))
}
if asan.Enabled && n > 0 {
asan.Write(unsafe.Pointer(&p[0]), uintptr(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 msan.Enabled && n > 0 {
msan.Read(unsafe.Pointer(&p[0]), uintptr(n))
}
if asan.Enabled && n > 0 {
asan.Read(unsafe.Pointer(&p[0]), uintptr(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 msan.Enabled && n > 0 {
msan.Write(unsafe.Pointer(&p[0]), uintptr(n))
}
if asan.Enabled && n > 0 {
asan.Write(unsafe.Pointer(&p[0]), uintptr(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 msan.Enabled && n > 0 {
msan.Read(unsafe.Pointer(&p[0]), uintptr(n))
}
if asan.Enabled && n > 0 {
asan.Read(unsafe.Pointer(&p[0]), uintptr(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) {
var (
ptr unsafe.Pointer
salen _Socklen
)
if to != nil {
ptr, salen, err = to.sockaddr()
if err != nil {
return err
}
}
return sendto(fd, p, flags, ptr, salen)
}
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
