56 lines
1.2 KiB
Go
56 lines
1.2 KiB
Go
// Copyright 2012 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 "net"
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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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oob := NewControlMessage(c.rawOpt.cflags)
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c.rawOpt.RUnlock()
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n, nn, _, src, err := c.ReadMsgIP(b, oob)
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if err != nil {
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return nil, nil, nil, err
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}
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var hs []byte
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if hs, p, err = slicePacket(b[:n]); err != nil {
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return nil, nil, nil, err
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}
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if h, err = ParseHeader(hs); err != nil {
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return nil, nil, nil, err
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}
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if nn > 0 {
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cm = new(ControlMessage)
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if err := cm.Parse(oob[:nn]); err != nil {
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return nil, nil, nil, err
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}
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}
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if src != nil && 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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oob := cm.Marshal()
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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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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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wh = append(wh, p...)
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_, _, err = c.WriteMsgIP(wh, oob, dst)
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return err
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}
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