sys_unix.go

Documentation: golang.org/x/net/internal/socket

     1  // Copyright 2017 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  
     7  package socket
     8  
     9  import (
    10  	"net"
    11  	"unsafe"
    12  
    13  	"golang.org/x/sys/unix"
    14  )
    15  
    16  //go:linkname syscall_getsockopt syscall.getsockopt
    17  func syscall_getsockopt(s, level, name int, val unsafe.Pointer, vallen *uint32) error
    18  
    19  //go:linkname syscall_setsockopt syscall.setsockopt
    20  func syscall_setsockopt(s, level, name int, val unsafe.Pointer, vallen uintptr) error
    21  
    22  func getsockopt(s uintptr, level, name int, b []byte) (int, error) {
    23  	l := uint32(len(b))
    24  	err := syscall_getsockopt(int(s), level, name, unsafe.Pointer(&b[0]), &l)
    25  	return int(l), err
    26  }
    27  
    28  func setsockopt(s uintptr, level, name int, b []byte) error {
    29  	return syscall_setsockopt(int(s), level, name, unsafe.Pointer(&b[0]), uintptr(len(b)))
    30  }
    31  
    32  func recvmsg(s uintptr, buffers [][]byte, oob []byte, flags int, network string) (n, oobn int, recvflags int, from net.Addr, err error) {
    33  	var unixFrom unix.Sockaddr
    34  	n, oobn, recvflags, unixFrom, err = unix.RecvmsgBuffers(int(s), buffers, oob, flags)
    35  	if unixFrom != nil {
    36  		from = sockaddrToAddr(unixFrom, network)
    37  	}
    38  	return
    39  }
    40  
    41  func sendmsg(s uintptr, buffers [][]byte, oob []byte, to net.Addr, flags int) (int, error) {
    42  	var unixTo unix.Sockaddr
    43  	if to != nil {
    44  		unixTo = addrToSockaddr(to)
    45  	}
    46  	return unix.SendmsgBuffers(int(s), buffers, oob, unixTo, flags)
    47  }
    48  
    49  // addrToSockaddr converts a net.Addr to a unix.Sockaddr.
    50  func addrToSockaddr(a net.Addr) unix.Sockaddr {
    51  	var (
    52  		ip   net.IP
    53  		port int
    54  		zone string
    55  	)
    56  	switch a := a.(type) {
    57  	case *net.TCPAddr:
    58  		ip = a.IP
    59  		port = a.Port
    60  		zone = a.Zone
    61  	case *net.UDPAddr:
    62  		ip = a.IP
    63  		port = a.Port
    64  		zone = a.Zone
    65  	case *net.IPAddr:
    66  		ip = a.IP
    67  		zone = a.Zone
    68  	default:
    69  		return nil
    70  	}
    71  
    72  	if ip4 := ip.To4(); ip4 != nil {
    73  		sa := unix.SockaddrInet4{Port: port}
    74  		copy(sa.Addr[:], ip4)
    75  		return &sa
    76  	}
    77  
    78  	if ip6 := ip.To16(); ip6 != nil && ip.To4() == nil {
    79  		sa := unix.SockaddrInet6{Port: port}
    80  		copy(sa.Addr[:], ip6)
    81  		if zone != "" {
    82  			sa.ZoneId = uint32(zoneCache.index(zone))
    83  		}
    84  		return &sa
    85  	}
    86  
    87  	return nil
    88  }
    89  
    90  // sockaddrToAddr converts a unix.Sockaddr to a net.Addr.
    91  func sockaddrToAddr(sa unix.Sockaddr, network string) net.Addr {
    92  	var (
    93  		ip   net.IP
    94  		port int
    95  		zone string
    96  	)
    97  	switch sa := sa.(type) {
    98  	case *unix.SockaddrInet4:
    99  		ip = make(net.IP, net.IPv4len)
   100  		copy(ip, sa.Addr[:])
   101  		port = sa.Port
   102  	case *unix.SockaddrInet6:
   103  		ip = make(net.IP, net.IPv6len)
   104  		copy(ip, sa.Addr[:])
   105  		port = sa.Port
   106  		if sa.ZoneId > 0 {
   107  			zone = zoneCache.name(int(sa.ZoneId))
   108  		}
   109  	default:
   110  		return nil
   111  	}
   112  
   113  	switch network {
   114  	case "tcp", "tcp4", "tcp6":
   115  		return &net.TCPAddr{IP: ip, Port: port, Zone: zone}
   116  	case "udp", "udp4", "udp6":
   117  		return &net.UDPAddr{IP: ip, Port: port, Zone: zone}
   118  	default:
   119  		return &net.IPAddr{IP: ip, Zone: zone}
   120  	}
   121  }
   122
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