141 lines
3.5 KiB
Go
141 lines
3.5 KiB
Go
// socket_linux.go -- Socket handling specific to Linux.
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// Copyright 2010 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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// Low-level socket interface.
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// Only for implementing net package.
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// DO NOT USE DIRECTLY.
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package syscall
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import "unsafe"
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type RawSockaddrInet4 struct {
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Family uint16;
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Port uint16;
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Addr [4]byte /* in_addr */;
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Zero [8]uint8;
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}
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type RawSockaddrInet6 struct {
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Family uint16;
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Port uint16;
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Flowinfo uint32;
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Addr [16]byte /* in6_addr */;
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Scope_id uint32;
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}
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type RawSockaddrUnix struct {
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Family uint16;
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Path [108]int8;
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}
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type RawSockaddr struct {
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Family uint16;
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Data [14]int8;
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}
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func (sa *SockaddrInet4) sockaddr() (*RawSockaddrAny, Socklen_t, int) {
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if sa.Port < 0 || sa.Port > 0xFFFF {
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return nil, 0, EINVAL;
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}
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sa.raw.Family = AF_INET;
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p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port));
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p[0] = byte(sa.Port>>8);
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p[1] = byte(sa.Port);
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for i := 0; i < len(sa.Addr); i++ {
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sa.raw.Addr[i] = sa.Addr[i];
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}
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return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), SizeofSockaddrInet4, 0;
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}
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func (sa *SockaddrInet6) sockaddr() (*RawSockaddrAny, Socklen_t, int) {
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if sa.Port < 0 || sa.Port > 0xFFFF {
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return nil, 0, EINVAL;
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}
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sa.raw.Family = AF_INET6;
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p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port));
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p[0] = byte(sa.Port>>8);
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p[1] = byte(sa.Port);
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for i := 0; i < len(sa.Addr); i++ {
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sa.raw.Addr[i] = sa.Addr[i];
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}
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return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), SizeofSockaddrInet6, 0;
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}
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func (sa *SockaddrUnix) sockaddr() (*RawSockaddrAny, Socklen_t, int) {
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name := sa.Name;
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n := len(name);
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if n >= len(sa.raw.Path) || n == 0 {
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return nil, 0, EINVAL;
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}
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sa.raw.Family = AF_UNIX;
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for i := 0; i < n; i++ {
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sa.raw.Path[i] = int8(name[i]);
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}
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if sa.raw.Path[0] == '@' {
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sa.raw.Path[0] = 0;
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}
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// length is family, name, NUL.
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return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), 1 + Socklen_t(n) + 1, 0;
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}
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func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, int) {
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switch rsa.Addr.Family {
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case AF_UNIX:
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pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa));
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sa := new(SockaddrUnix);
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if pp.Path[0] == 0 {
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// "Abstract" Unix domain socket.
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// Rewrite leading NUL as @ for textual display.
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// (This is the standard convention.)
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// Not friendly to overwrite in place,
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// but the callers below don't care.
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pp.Path[0] = '@';
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}
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// Assume path ends at NUL.
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// This is not technically the Linux semantics for
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// abstract Unix domain sockets--they are supposed
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// to be uninterpreted fixed-size binary blobs--but
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// everyone uses this convention.
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n := 0;
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for n < len(pp.Path) - 3 && pp.Path[n] != 0 {
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n++;
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}
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bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]));
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sa.Name = string(bytes[0:n]);
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return sa, 0;
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case AF_INET:
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pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa));
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sa := new(SockaddrInet4);
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p := (*[2]byte)(unsafe.Pointer(&pp.Port));
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sa.Port = int(p[0])<<8 + int(p[1]);
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for i := 0; i < len(sa.Addr); i++ {
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sa.Addr[i] = pp.Addr[i];
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}
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return sa, 0;
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case AF_INET6:
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pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa));
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sa := new(SockaddrInet6);
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p := (*[2]byte)(unsafe.Pointer(&pp.Port));
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sa.Port = int(p[0])<<8 + int(p[1]);
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for i := 0; i < len(sa.Addr); i++ {
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sa.Addr[i] = pp.Addr[i];
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}
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return sa, 0;
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}
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return nil, EAFNOSUPPORT;
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}
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// BindToDevice binds the socket associated with fd to device.
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func BindToDevice(fd int, device string) (errno int) {
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return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device)
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}
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