68 lines
1.8 KiB
Go
68 lines
1.8 KiB
Go
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// Copyright 2017 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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// +build go1.9
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package ipv4
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import (
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"net"
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"golang.org/x/net/internal/socket"
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)
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func (c *packetHandler) readFrom(b []byte) (h *Header, p []byte, cm *ControlMessage, err error) {
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c.rawOpt.RLock()
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m := socket.Message{
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Buffers: [][]byte{b},
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OOB: NewControlMessage(c.rawOpt.cflags),
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}
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c.rawOpt.RUnlock()
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if err := c.RecvMsg(&m, 0); err != nil {
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return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err}
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}
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var hs []byte
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if hs, p, err = slicePacket(b[:m.N]); err != nil {
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return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err}
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}
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if h, err = ParseHeader(hs); err != nil {
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return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err}
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}
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if m.NN > 0 {
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cm = new(ControlMessage)
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if err := cm.Parse(m.OOB[:m.NN]); err != nil {
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return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err}
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}
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}
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if src, ok := m.Addr.(*net.IPAddr); ok && cm != nil {
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cm.Src = src.IP
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}
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return
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}
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func (c *packetHandler) writeTo(h *Header, p []byte, cm *ControlMessage) error {
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m := socket.Message{
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OOB: cm.Marshal(),
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}
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wh, err := h.Marshal()
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if err != nil {
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return err
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}
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m.Buffers = [][]byte{wh, p}
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dst := new(net.IPAddr)
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if cm != nil {
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if ip := cm.Dst.To4(); ip != nil {
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dst.IP = ip
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}
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}
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if dst.IP == nil {
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dst.IP = h.Dst
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}
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m.Addr = dst
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if err := c.SendMsg(&m, 0); err != nil {
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return &net.OpError{Op: "write", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Addr: opAddr(dst), Err: err}
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}
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return nil
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}
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