github.com/code-reading/golang@v0.0.0-20220303082512-ba5bc0e589a3/go/src/net/file_unix.go (about)

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
     6  // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
     7  
     8  package net
     9  
    10  import (
    11  	"internal/poll"
    12  	"os"
    13  	"syscall"
    14  )
    15  
    16  func dupSocket(f *os.File) (int, error) {
    17  	s, call, err := poll.DupCloseOnExec(int(f.Fd()))
    18  	if err != nil {
    19  		if call != "" {
    20  			err = os.NewSyscallError(call, err)
    21  		}
    22  		return -1, err
    23  	}
    24  	if err := syscall.SetNonblock(s, true); err != nil {
    25  		poll.CloseFunc(s)
    26  		return -1, os.NewSyscallError("setnonblock", err)
    27  	}
    28  	return s, nil
    29  }
    30  
    31  func newFileFD(f *os.File) (*netFD, error) {
    32  	s, err := dupSocket(f)
    33  	if err != nil {
    34  		return nil, err
    35  	}
    36  	family := syscall.AF_UNSPEC
    37  	sotype, err := syscall.GetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_TYPE)
    38  	if err != nil {
    39  		poll.CloseFunc(s)
    40  		return nil, os.NewSyscallError("getsockopt", err)
    41  	}
    42  	lsa, _ := syscall.Getsockname(s)
    43  	rsa, _ := syscall.Getpeername(s)
    44  	switch lsa.(type) {
    45  	case *syscall.SockaddrInet4:
    46  		family = syscall.AF_INET
    47  	case *syscall.SockaddrInet6:
    48  		family = syscall.AF_INET6
    49  	case *syscall.SockaddrUnix:
    50  		family = syscall.AF_UNIX
    51  	default:
    52  		poll.CloseFunc(s)
    53  		return nil, syscall.EPROTONOSUPPORT
    54  	}
    55  	fd, err := newFD(s, family, sotype, "")
    56  	if err != nil {
    57  		poll.CloseFunc(s)
    58  		return nil, err
    59  	}
    60  	laddr := fd.addrFunc()(lsa)
    61  	raddr := fd.addrFunc()(rsa)
    62  	fd.net = laddr.Network()
    63  	if err := fd.init(); err != nil {
    64  		fd.Close()
    65  		return nil, err
    66  	}
    67  	fd.setAddr(laddr, raddr)
    68  	return fd, nil
    69  }
    70  
    71  func fileConn(f *os.File) (Conn, error) {
    72  	fd, err := newFileFD(f)
    73  	if err != nil {
    74  		return nil, err
    75  	}
    76  	switch fd.laddr.(type) {
    77  	case *TCPAddr:
    78  		return newTCPConn(fd), nil
    79  	case *UDPAddr:
    80  		return newUDPConn(fd), nil
    81  	case *IPAddr:
    82  		return newIPConn(fd), nil
    83  	case *UnixAddr:
    84  		return newUnixConn(fd), nil
    85  	}
    86  	fd.Close()
    87  	return nil, syscall.EINVAL
    88  }
    89  
    90  func fileListener(f *os.File) (Listener, error) {
    91  	fd, err := newFileFD(f)
    92  	if err != nil {
    93  		return nil, err
    94  	}
    95  	switch laddr := fd.laddr.(type) {
    96  	case *TCPAddr:
    97  		return &TCPListener{fd: fd}, nil
    98  	case *UnixAddr:
    99  		return &UnixListener{fd: fd, path: laddr.Name, unlink: false}, nil
   100  	}
   101  	fd.Close()
   102  	return nil, syscall.EINVAL
   103  }
   104  
   105  func filePacketConn(f *os.File) (PacketConn, error) {
   106  	fd, err := newFileFD(f)
   107  	if err != nil {
   108  		return nil, err
   109  	}
   110  	switch fd.laddr.(type) {
   111  	case *UDPAddr:
   112  		return newUDPConn(fd), nil
   113  	case *IPAddr:
   114  		return newIPConn(fd), nil
   115  	case *UnixAddr:
   116  		return newUnixConn(fd), nil
   117  	}
   118  	fd.Close()
   119  	return nil, syscall.EINVAL
   120  }