55 lines
2.0 KiB
Go
55 lines
2.0 KiB
Go
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// Copyright 2019 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at //
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package tcpip
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import "gvisor.dev/gvisor/pkg/tcpip/buffer"
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// A PacketBuffer contains all the data of a network packet.
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//
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// As a PacketBuffer traverses up the stack, it may be necessary to pass it to
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// multiple endpoints. Clone() should be called in such cases so that
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// modifications to the Data field do not affect other copies.
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//
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// +stateify savable
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type PacketBuffer struct {
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// Data holds the payload of the packet. For inbound packets, it also
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// holds the headers, which are consumed as the packet moves up the
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// stack. Headers are guaranteed not to be split across views.
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//
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// The bytes backing Data are immutable, but Data itself may be trimmed
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// or otherwise modified.
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Data buffer.VectorisedView
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// The bytes backing these views are immutable. Each field may be nil
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// if either it has not been set yet or no such header exists (e.g.
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// packets sent via loopback may not have a link header).
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//
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// These fields may be Views into other Views. SR dosen't support this,
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// so deep copies are necessary in some cases.
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LinkHeader buffer.View
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NetworkHeader buffer.View
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TransportHeader buffer.View
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}
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// Clone makes a copy of pk. It clones the Data field, which creates a new
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// VectorisedView but does not deep copy the underlying bytes.
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func (pk PacketBuffer) Clone() PacketBuffer {
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return PacketBuffer{
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Data: pk.Data.Clone(nil),
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LinkHeader: pk.LinkHeader,
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NetworkHeader: pk.NetworkHeader,
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TransportHeader: pk.TransportHeader,
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}
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}
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