73 lines
2.1 KiB
Go
73 lines
2.1 KiB
Go
// 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 stack
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import (
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"golang.org/x/time/rate"
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"gvisor.dev/gvisor/pkg/tcpip"
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)
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const (
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// icmpLimit is the default maximum number of ICMP messages permitted by this
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// rate limiter.
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icmpLimit = 1000
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// icmpBurst is the default number of ICMP messages that can be sent in a single
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// burst.
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icmpBurst = 50
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)
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// ICMPRateLimiter is a global rate limiter that controls the generation of
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// ICMP messages generated by the stack.
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type ICMPRateLimiter struct {
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limiter *rate.Limiter
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clock tcpip.Clock
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}
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// NewICMPRateLimiter returns a global rate limiter for controlling the rate
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// at which ICMP messages are generated by the stack. The returned limiter
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// does not apply limits to any ICMP types by default.
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func NewICMPRateLimiter(clock tcpip.Clock) *ICMPRateLimiter {
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return &ICMPRateLimiter{
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clock: clock,
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limiter: rate.NewLimiter(icmpLimit, icmpBurst),
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}
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}
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// SetLimit sets a new Limit for the limiter.
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func (l *ICMPRateLimiter) SetLimit(limit rate.Limit) {
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l.limiter.SetLimitAt(l.clock.Now(), limit)
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}
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// Limit returns the maximum overall event rate.
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func (l *ICMPRateLimiter) Limit() rate.Limit {
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return l.limiter.Limit()
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}
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// SetBurst sets a new burst size for the limiter.
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func (l *ICMPRateLimiter) SetBurst(burst int) {
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l.limiter.SetBurstAt(l.clock.Now(), burst)
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}
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// Burst returns the maximum burst size.
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func (l *ICMPRateLimiter) Burst() int {
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return l.limiter.Burst()
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}
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// Allow reports whether one ICMP message may be sent now.
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func (l *ICMPRateLimiter) Allow() bool {
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return l.limiter.AllowN(l.clock.Now(), 1)
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}
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