1 files changed, 203 insertions, 0 deletions
diff --git a/src/net/fd_unix.go b/src/net/fd_unix.go
new file mode 100644
index 0000000..a400c60
--- /dev/null
+++ b/src/net/fd_unix.go
@@ -0,0 +1,203 @@
+// 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 net
+
+import (
+	"context"
+	"internal/poll"
+	"os"
+	"runtime"
+	"syscall"
+)
+
+const (
+	readSyscallName     = "read"
+	readFromSyscallName = "recvfrom"
+	readMsgSyscallName  = "recvmsg"
+	writeSyscallName    = "write"
+	writeToSyscallName  = "sendto"
+	writeMsgSyscallName = "sendmsg"
+)
+
+func newFD(sysfd, family, sotype int, net string) (*netFD, error) {
+	ret := &netFD{
+		pfd: poll.FD{
+			Sysfd:         sysfd,
+			IsStream:      sotype == syscall.SOCK_STREAM,
+			ZeroReadIsEOF: sotype != syscall.SOCK_DGRAM && sotype != syscall.SOCK_RAW,
+		},
+		family: family,
+		sotype: sotype,
+		net:    net,
+	}
+	return ret, nil
+}
+
+func (fd *netFD) init() error {
+	return fd.pfd.Init(fd.net, true)
+}
+
+func (fd *netFD) name() string {
+	var ls, rs string
+	if fd.laddr != nil {
+		ls = fd.laddr.String()
+	}
+	if fd.raddr != nil {
+		rs = fd.raddr.String()
+	}
+	return fd.net + ":" + ls + "->" + rs
+}
+
+func (fd *netFD) connect(ctx context.Context, la, ra syscall.Sockaddr) (rsa syscall.Sockaddr, ret error) {
+	// Do not need to call fd.writeLock here,
+	// because fd is not yet accessible to user,
+	// so no concurrent operations are possible.
+	switch err := connectFunc(fd.pfd.Sysfd, ra); err {
+	case syscall.EINPROGRESS, syscall.EALREADY, syscall.EINTR:
+	case nil, syscall.EISCONN:
+		select {
+		case <-ctx.Done():
+			return nil, mapErr(ctx.Err())
+		default:
+		}
+		if err := fd.pfd.Init(fd.net, true); err != nil {
+			return nil, err
+		}
+		runtime.KeepAlive(fd)
+		return nil, nil
+	case syscall.EINVAL:
+		// On Solaris and illumos we can see EINVAL if the socket has
+		// already been accepted and closed by the server.  Treat this
+		// as a successful connection--writes to the socket will see
+		// EOF.  For details and a test case in C see
+		// https://golang.org/issue/6828.
+		if runtime.GOOS == "solaris" || runtime.GOOS == "illumos" {
+			return nil, nil
+		}
+		fallthrough
+	default:
+		return nil, os.NewSyscallError("connect", err)
+	}
+	if err := fd.pfd.Init(fd.net, true); err != nil {
+		return nil, err
+	}
+	if deadline, hasDeadline := ctx.Deadline(); hasDeadline {
+		fd.pfd.SetWriteDeadline(deadline)
+		defer fd.pfd.SetWriteDeadline(noDeadline)
+	}
+
+	// Start the "interrupter" goroutine, if this context might be canceled.
+	//
+	// The interrupter goroutine waits for the context to be done and
+	// interrupts the dial (by altering the fd's write deadline, which
+	// wakes up waitWrite).
+	ctxDone := ctx.Done()
+	if ctxDone != nil {
+		// Wait for the interrupter goroutine to exit before returning
+		// from connect.
+		done := make(chan struct{})
+		interruptRes := make(chan error)
+		defer func() {
+			close(done)
+			if ctxErr := <-interruptRes; ctxErr != nil && ret == nil {
+				// The interrupter goroutine called SetWriteDeadline,
+				// but the connect code below had returned from
+				// waitWrite already and did a successful connect (ret
+				// == nil). Because we've now poisoned the connection
+				// by making it unwritable, don't return a successful
+				// dial. This was issue 16523.
+				ret = mapErr(ctxErr)
+				fd.Close() // prevent a leak
+			}
+		}()
+		go func() {
+			select {
+			case <-ctxDone:
+				// Force the runtime's poller to immediately give up
+				// waiting for writability, unblocking waitWrite
+				// below.
+				fd.pfd.SetWriteDeadline(aLongTimeAgo)
+				testHookCanceledDial()
+				interruptRes <- ctx.Err()
+			case <-done:
+				interruptRes <- nil
+			}
+		}()
+	}
+
+	for {
+		// Performing multiple connect system calls on a
+		// non-blocking socket under Unix variants does not
+		// necessarily result in earlier errors being
+		// returned. Instead, once runtime-integrated network
+		// poller tells us that the socket is ready, get the
+		// SO_ERROR socket option to see if the connection
+		// succeeded or failed. See issue 7474 for further
+		// details.
+		if err := fd.pfd.WaitWrite(); err != nil {
+			select {
+			case <-ctxDone:
+				return nil, mapErr(ctx.Err())
+			default:
+			}
+			return nil, err
+		}
+		nerr, err := getsockoptIntFunc(fd.pfd.Sysfd, syscall.SOL_SOCKET, syscall.SO_ERROR)
+		if err != nil {
+			return nil, os.NewSyscallError("getsockopt", err)
+		}
+		switch err := syscall.Errno(nerr); err {
+		case syscall.EINPROGRESS, syscall.EALREADY, syscall.EINTR:
+		case syscall.EISCONN:
+			return nil, nil
+		case syscall.Errno(0):
+			// The runtime poller can wake us up spuriously;
+			// see issues 14548 and 19289. Check that we are
+			// really connected; if not, wait again.
+			if rsa, err := syscall.Getpeername(fd.pfd.Sysfd); err == nil {
+				return rsa, nil
+			}
+		default:
+			return nil, os.NewSyscallError("connect", err)
+		}
+		runtime.KeepAlive(fd)
+	}
+}
+
+func (fd *netFD) accept() (netfd *netFD, err error) {
+	d, rsa, errcall, err := fd.pfd.Accept()
+	if err != nil {
+		if errcall != "" {
+			err = wrapSyscallError(errcall, err)
+		}
+		return nil, err
+	}
+
+	if netfd, err = newFD(d, fd.family, fd.sotype, fd.net); err != nil {
+		poll.CloseFunc(d)
+		return nil, err
+	}
+	if err = netfd.init(); err != nil {
+		netfd.Close()
+		return nil, err
+	}
+	lsa, _ := syscall.Getsockname(netfd.pfd.Sysfd)
+	netfd.setAddr(netfd.addrFunc()(lsa), netfd.addrFunc()(rsa))
+	return netfd, nil
+}
+
+func (fd *netFD) dup() (f *os.File, err error) {
+	ns, call, err := fd.pfd.Dup()
+	if err != nil {
+		if call != "" {
+			err = os.NewSyscallError(call, err)
+		}
+		return nil, err
+	}
+
+	return os.NewFile(uintptr(ns), fd.name()), nil
+}