73 lines
2.4 KiB
Go
73 lines
2.4 KiB
Go
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// Copyright 2018 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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//
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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 packet
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import (
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"gvisor.dev/gvisor/pkg/tcpip/buffer"
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"gvisor.dev/gvisor/pkg/tcpip/stack"
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)
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// saveData saves packet.data field.
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func (p *packet) saveData() buffer.VectorisedView {
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// We cannot save p.data directly as p.data.views may alias to p.views,
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// which is not allowed by state framework (in-struct pointer).
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return p.data.Clone(nil)
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}
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// loadData loads packet.data field.
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func (p *packet) loadData(data buffer.VectorisedView) {
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// NOTE: We cannot do the p.data = data.Clone(p.views[:]) optimization
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// here because data.views is not guaranteed to be loaded by now. Plus,
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// data.views will be allocated anyway so there really is little point
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// of utilizing p.views for data.views.
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p.data = data
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}
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// beforeSave is invoked by stateify.
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func (ep *endpoint) beforeSave() {
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// Stop incoming packets from being handled (and mutate endpoint state).
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// The lock will be released after saveRcvBufSizeMax(), which would have
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// saved ep.rcvBufSizeMax and set it to 0 to continue blocking incoming
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// packets.
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ep.rcvMu.Lock()
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}
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// saveRcvBufSizeMax is invoked by stateify.
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func (ep *endpoint) saveRcvBufSizeMax() int {
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max := ep.rcvBufSizeMax
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// Make sure no new packets will be handled regardless of the lock.
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ep.rcvBufSizeMax = 0
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// Release the lock acquired in beforeSave() so regular endpoint closing
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// logic can proceed after save.
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ep.rcvMu.Unlock()
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return max
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}
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// loadRcvBufSizeMax is invoked by stateify.
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func (ep *endpoint) loadRcvBufSizeMax(max int) {
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ep.rcvBufSizeMax = max
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}
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// afterLoad is invoked by stateify.
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func (ep *endpoint) afterLoad() {
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// StackFromEnv is a stack used specifically for save/restore.
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ep.stack = stack.StackFromEnv
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// TODO(gvisor.dev/173): Once bind is supported, choose the right NIC.
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if err := ep.stack.RegisterPacketEndpoint(0, ep.netProto, ep); err != nil {
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panic(*err)
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}
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}
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