// Accept4 wraps syscall.Accept4.
func (sw *Switch) Accept4(s, flags int) (ns int, sa syscall.Sockaddr, err error) {
so := sw.sockso(s)
if so == nil {
return syscall.Accept4(s, flags)
}
sw.fmu.RLock()
f, _ := sw.fltab[FilterAccept]
sw.fmu.RUnlock()
af, err := f.apply(so)
if err != nil {
return -1, nil, err
}
ns, sa, so.Err = syscall.Accept4(s, flags)
if err = af.apply(so); err != nil {
if so.Err == nil {
syscall.Close(ns)
}
return -1, nil, err
}
sw.smu.Lock()
defer sw.smu.Unlock()
if so.Err != nil {
sw.stats.getLocked(so.Cookie).AcceptFailed++
return -1, nil, so.Err
}
nso := sw.addLocked(ns, so.Cookie.Family(), so.Cookie.Type(), so.Cookie.Protocol())
sw.stats.getLocked(nso.Cookie).Accepted++
return ns, sa, nil
}
// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(fd int) (int, syscall.Sockaddr, error) {
nfd, sa, err := syscall.Accept4(fd, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
// The accept4 system call was introduced in Linux 2.6.28. If
// we get an ENOSYS error, fall back to using accept.
if err == nil || err != syscall.ENOSYS {
return nfd, sa, err
}
// See ../syscall/exec_unix.go for description of ForkLock.
// It is probably okay to hold the lock across syscall.Accept
// because we have put fd.sysfd into non-blocking mode.
// However, a call to the File method will put it back into
// blocking mode. We can't take that risk, so no use of ForkLock here.
nfd, sa, err = syscall.Accept(fd)
if err == nil {
syscall.CloseOnExec(nfd)
}
if err != nil {
return -1, nil, err
}
if err = syscall.SetNonblock(nfd, true); err != nil {
syscall.Close(nfd)
return -1, nil, err
}
return nfd, sa, nil
}
// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(s int) (int, syscall.Sockaddr, error) {
ns, sa, err := syscall.Accept4(s, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
// On Linux the accept4 system call was introduced in 2.6.28
// kernel and on FreeBSD it was introduced in 10 kernel. If we
// get an ENOSYS error on both Linux and FreeBSD, or EINVAL
// error on Linux, fall back to using accept.
if err == nil || (err != syscall.ENOSYS && err != syscall.EINVAL) {
return ns, sa, err
}
// See ../syscall/exec_unix.go for description of ForkLock.
// It is probably okay to hold the lock across syscall.Accept
// because we have put fd.sysfd into non-blocking mode.
// However, a call to the File method will put it back into
// blocking mode. We can't take that risk, so no use of ForkLock here.
ns, sa, err = syscall.Accept(s)
if err == nil {
syscall.CloseOnExec(ns)
}
if err != nil {
return -1, nil, err
}
if err = syscall.SetNonblock(ns, true); err != nil {
syscall.Close(ns)
return -1, nil, err
}
return ns, sa, nil
}
// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(fd int) (int, syscall.Sockaddr, error) {
nfd, sa, err := syscall.Accept4(fd, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
// The accept4 system call was introduced in Linux 2.6.28. If
// we get an ENOSYS error, fall back to using accept.
if err == nil || err != syscall.ENOSYS {
return nfd, sa, err
}
// See ../syscall/exec_unix.go for description of ForkLock.
// It is okay to hold the lock across syscall.Accept
// because we have put fd.sysfd into non-blocking mode.
syscall.ForkLock.RLock()
nfd, sa, err = syscall.Accept(fd)
if err == nil {
syscall.CloseOnExec(nfd)
}
syscall.ForkLock.RUnlock()
if err != nil {
return -1, nil, err
}
if err = syscall.SetNonblock(nfd, true); err != nil {
syscall.Close(nfd)
return -1, nil, err
}
return nfd, sa, nil
}