mirror of
https://github.com/autc04/Retro68.git
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204 lines
5.4 KiB
Go
204 lines
5.4 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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//go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
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package net
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import (
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"context"
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"internal/poll"
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"os"
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"runtime"
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"syscall"
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)
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const (
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readSyscallName = "read"
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readFromSyscallName = "recvfrom"
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readMsgSyscallName = "recvmsg"
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writeSyscallName = "write"
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writeToSyscallName = "sendto"
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writeMsgSyscallName = "sendmsg"
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)
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func newFD(sysfd, family, sotype int, net string) (*netFD, error) {
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ret := &netFD{
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pfd: poll.FD{
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Sysfd: sysfd,
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IsStream: sotype == syscall.SOCK_STREAM,
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ZeroReadIsEOF: sotype != syscall.SOCK_DGRAM && sotype != syscall.SOCK_RAW,
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},
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family: family,
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sotype: sotype,
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net: net,
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}
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return ret, nil
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}
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func (fd *netFD) init() error {
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return fd.pfd.Init(fd.net, true)
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}
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func (fd *netFD) name() string {
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var ls, rs string
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if fd.laddr != nil {
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ls = fd.laddr.String()
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}
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if fd.raddr != nil {
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rs = fd.raddr.String()
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}
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return fd.net + ":" + ls + "->" + rs
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}
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func (fd *netFD) connect(ctx context.Context, la, ra syscall.Sockaddr) (rsa syscall.Sockaddr, ret error) {
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// Do not need to call fd.writeLock here,
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// because fd is not yet accessible to user,
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// so no concurrent operations are possible.
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switch err := connectFunc(fd.pfd.Sysfd, ra); err {
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case syscall.EINPROGRESS, syscall.EALREADY, syscall.EINTR:
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case nil, syscall.EISCONN:
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select {
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case <-ctx.Done():
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return nil, mapErr(ctx.Err())
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default:
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}
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if err := fd.pfd.Init(fd.net, true); err != nil {
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return nil, err
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}
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runtime.KeepAlive(fd)
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return nil, nil
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case syscall.EINVAL:
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// On Solaris and illumos we can see EINVAL if the socket has
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// already been accepted and closed by the server. Treat this
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// as a successful connection--writes to the socket will see
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// EOF. For details and a test case in C see
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// https://golang.org/issue/6828.
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if runtime.GOOS == "solaris" || runtime.GOOS == "illumos" {
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return nil, nil
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}
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fallthrough
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default:
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return nil, os.NewSyscallError("connect", err)
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}
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if err := fd.pfd.Init(fd.net, true); err != nil {
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return nil, err
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}
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if deadline, hasDeadline := ctx.Deadline(); hasDeadline {
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fd.pfd.SetWriteDeadline(deadline)
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defer fd.pfd.SetWriteDeadline(noDeadline)
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}
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// Start the "interrupter" goroutine, if this context might be canceled.
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//
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// The interrupter goroutine waits for the context to be done and
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// interrupts the dial (by altering the fd's write deadline, which
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// wakes up waitWrite).
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ctxDone := ctx.Done()
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if ctxDone != nil {
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// Wait for the interrupter goroutine to exit before returning
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// from connect.
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done := make(chan struct{})
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interruptRes := make(chan error)
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defer func() {
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close(done)
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if ctxErr := <-interruptRes; ctxErr != nil && ret == nil {
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// The interrupter goroutine called SetWriteDeadline,
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// but the connect code below had returned from
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// waitWrite already and did a successful connect (ret
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// == nil). Because we've now poisoned the connection
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// by making it unwritable, don't return a successful
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// dial. This was issue 16523.
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ret = mapErr(ctxErr)
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fd.Close() // prevent a leak
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}
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}()
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go func() {
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select {
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case <-ctxDone:
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// Force the runtime's poller to immediately give up
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// waiting for writability, unblocking waitWrite
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// below.
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fd.pfd.SetWriteDeadline(aLongTimeAgo)
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testHookCanceledDial()
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interruptRes <- ctx.Err()
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case <-done:
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interruptRes <- nil
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}
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}()
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}
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for {
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// Performing multiple connect system calls on a
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// non-blocking socket under Unix variants does not
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// necessarily result in earlier errors being
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// returned. Instead, once runtime-integrated network
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// poller tells us that the socket is ready, get the
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// SO_ERROR socket option to see if the connection
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// succeeded or failed. See issue 7474 for further
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// details.
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if err := fd.pfd.WaitWrite(); err != nil {
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select {
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case <-ctxDone:
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return nil, mapErr(ctx.Err())
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default:
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}
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return nil, err
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}
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nerr, err := getsockoptIntFunc(fd.pfd.Sysfd, syscall.SOL_SOCKET, syscall.SO_ERROR)
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if err != nil {
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return nil, os.NewSyscallError("getsockopt", err)
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}
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switch err := syscall.Errno(nerr); err {
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case syscall.EINPROGRESS, syscall.EALREADY, syscall.EINTR:
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case syscall.EISCONN:
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return nil, nil
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case syscall.Errno(0):
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// The runtime poller can wake us up spuriously;
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// see issues 14548 and 19289. Check that we are
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// really connected; if not, wait again.
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if rsa, err := syscall.Getpeername(fd.pfd.Sysfd); err == nil {
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return rsa, nil
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}
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default:
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return nil, os.NewSyscallError("connect", err)
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}
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runtime.KeepAlive(fd)
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}
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}
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func (fd *netFD) accept() (netfd *netFD, err error) {
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d, rsa, errcall, err := fd.pfd.Accept()
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if err != nil {
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if errcall != "" {
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err = wrapSyscallError(errcall, err)
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}
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return nil, err
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}
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if netfd, err = newFD(d, fd.family, fd.sotype, fd.net); err != nil {
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poll.CloseFunc(d)
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return nil, err
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}
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if err = netfd.init(); err != nil {
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netfd.Close()
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return nil, err
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}
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lsa, _ := syscall.Getsockname(netfd.pfd.Sysfd)
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netfd.setAddr(netfd.addrFunc()(lsa), netfd.addrFunc()(rsa))
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return netfd, nil
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}
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func (fd *netFD) dup() (f *os.File, err error) {
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ns, call, err := fd.pfd.Dup()
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if err != nil {
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if call != "" {
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err = os.NewSyscallError(call, err)
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}
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return nil, err
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}
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return os.NewFile(uintptr(ns), fd.name()), nil
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}
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